As filed with the Securities and Exchange Commission on June 6, 2018

Registration No. 333-224982

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1

to

FORM S-4

REGISTRATION STATEMENT

UNDER THE SECURITIES ACT OF 1933

KLA-Tencor Corporation

(Exact name of Registrant as specified in its charter)

One Technology Drive

Milpitas, California 95305

(408) 875-3000

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Teri A. Little

Executive Vice President and Chief Legal Officer

KLA-Tencor Corporation

One Technology Drive

Milpitas, California 95305

(408) 875-3000

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this Registration Statement becomes effective and upon completion of the merger described in the enclosed proxy statement/prospectus.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

☐  Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer)

☐  Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)

The registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act, or until the Registration Statement shall become effective on such dates as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This proxy statement/prospectus shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of such securities, in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to appropriate registration or qualification under the securities laws of such jurisdiction.

PRELIMINARY—SUBJECT TO COMPLETION—DATED JUNE 6, 2018

MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT

Dear Orbotech Ltd. shareholder:

You are cordially invited to attend the extraordinary general meeting of shareholders of Orbotech Ltd. (“Orbotech” or “we”) to be held at 10:00 a.m., Israel time, on Thursday, July 12, 2018, at Orbotech’s offices at 7 Sanhedrin Boulevard, North Industrial Zone, Yavne, Israel.

As previously announced, on March 18, 2018, Orbotech entered into an agreement and plan of merger, as amended (the “Merger Agreement”), with KLA-Tencor Corporation (“KLA-Tencor”) and Tiburon Merger Sub Technologies Ltd. (“Merger Sub”) under which Orbotech would be acquired by KLA-Tencor (the “Merger”). Pursuant to the terms of the Merger Agreement, each ordinary share of Orbotech that is issued and outstanding (other than certain Excluded Shares) will be canceled and converted into the right to receive $38.86 in cash and 0.25 of a share of KLA-Tencor common stock. You will be asked at the meeting to consider and vote on the approval and adoption of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement (the “Merger Proposal”). We encourage you to read the Merger Agreement, a copy of which is attached to this proxy statement/prospectus as Annex A, in its entirety.

The Orbotech Board of Directors has (i) determined that the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, and assuming, among other things, the accuracy of the representations and warranties of the other parties in the Merger Agreement, no reasonable concern exists that the surviving company, as a result of the Merger, will be unable to fulfill the obligations of Orbotech to its creditors; (ii) approved the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger; and (iii) resolved to direct that the Merger Agreement and the transactions contemplated by the Merger Agreement be submitted to the shareholders of Orbotech for approval and adoption and recommended that the shareholders of Orbotech vote in favor of the approval and adoption of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement, all upon the terms and subject to the conditions set forth in the Merger Agreement. Accordingly, the Orbotech Board of Directors unanimously recommends that you vote “FOR” the Merger Proposal.

We urge you to read the accompanying proxy statement/prospectus, including the Annexes and the documents incorporated by reference, carefully and in its entirety. In particular, we urge you to read carefully the section entitled “Risk Factors”.

We look forward to greeting personally those Orbotech shareholders who are able to be present at the meeting. If you do plan to attend, to gain access to the meeting we ask that you bring with you some form of personal identification and verification of your status as a shareholder as of the close of trading on June 6, 2018, the record date for the meeting. However, whether or not you will be with us at the meeting, it is important that your shares be represented. Accordingly, you are requested to complete, date, sign and mail the enclosed proxy in the envelope provided at your earliest convenience and in any event so as to be received in a timely manner as discussed in the enclosed proxy statement/prospectus. Your shares can be voted at the meeting only if you are present or represented by a valid proxy.

Thank you for your cooperation.

Very truly yours,

ASHER LEVY

Chief Executive Officer, Orbotech Ltd.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under this proxy statement/prospectus or determined if this proxy statement/prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This proxy statement/prospectus is dated June 7, 2018 and is first being made available to Orbotech shareholders on or about June 7, 2018.

ORBOTECH LTD.

7 Sanhedrin Boulevard

North Industrial Zone

P.O. Box 215

Yavne 8110101, Israel

PROXY STATEMENT

EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS

This proxy statement/prospectus is being furnished to the holders of ordinary shares, New Israeli Shekels (“NIS”) 0.14 nominal (par) value per share (“Orbotech shares”), of Orbotech Ltd. (“Orbotech”) in connection with the solicitation by the Board of Directors of Orbotech (the “Orbotech Board”) of proxies for use at Orbotech’s extraordinary general meeting of shareholders (the “meeting”) or at any adjournment thereof.

The meeting will be held on Thursday, July 12, 2018 at 10:00 a.m., Israel time, at Orbotech’s principal executive offices at 7 Sanhedrin Boulevard, North Industrial Zone, Yavne, Israel, to consider and vote on the following matter in connection with the acquisition of Orbotech by KLA-Tencor Corporation, a Delaware corporation (“KLA-Tencor”):

Voting procedures. A form of proxy for use at the meeting and a return envelope for the proxy are enclosed. No postage is required if mailed in the United States. Shareholders may revoke the authority granted by their execution of a proxy at any time before the effective exercise thereof by filing with Orbotech a written notice of revocation or a duly executed proxy bearing a later date, or by voting in person at the meeting. In order for a proxy to be counted, it must be duly executed and received prior to the meeting. This will be deemed to have occurred only if such proxy is received either by Orbotech at its principal executive offices at 7 Sanhedrin Boulevard, North Industrial Zone, Yavne, Israel, at any time prior to the commencement of the meeting, or by American Stock Transfer & Trust Company, LLC, Orbotech’s transfer agent, in New York City, New York, by no later than 11:59 p.m., New York City time, on July 11, 2018, the last business day immediately preceding the date of the meeting (and, in each case, not revoked prior to such time). Orbotech shares represented by any proxy received after the time specified above will not be counted as present at the meeting and will not be voted.

If a shareholder properly executes and returns the form of proxy to Orbotech prior to the meeting (as specified above) without indicating how the shareholder intends to vote with respect to the Merger Proposal, the Orbotech shares represented by the proxy will be counted as being present for quorum purposes, but will not be treated as having been voted in respect of the Merger Proposal and will have no effect on the voting with respect to the Merger Proposal.

Joint holders of Orbotech shares should take note that, pursuant to Article 62 of the Articles of Association of Orbotech, the vote of the senior holder of joint holders of any Orbotech share who tenders a vote, whether in person or by proxy, will be accepted to the exclusion of the vote(s) of the other joint holder(s) of such Orbotech

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share, and for this purpose seniority will be determined by the order in which the names stand in Orbotech’s share register.

Record date. Proxies for use at the meeting are being solicited by the Orbotech Board. Only shareholders with Orbotech shares registered in his, her, its or their name or names, at the close of trading on June 6, 2018, the record date (“Orbotech shareholders of record”), will be entitled to vote at the meeting or at any adjournment thereof. Proxies are expected to be mailed to Orbotech shareholders of record on or about June 15, 2018, and their return will be solicited chiefly by mail; however, certain officers, directors, employees and agents of Orbotech, none of whom will receive additional compensation therefor, as well as Okapi Partners LLC, the proxy solicitor for Orbotech, may solicit proxies by telephone, facsimile transmission, electronic mail or other personal contact. Orbotech will bear the costs of the solicitation of proxies, including postage, printing and handling, and will reimburse the reasonable expenses of brokerage firms and others for forwarding material to beneficial owners of Orbotech shares.

Quorum. At the close of trading on June 6, 2018, the record date, 48,569,735 Orbotech shares were outstanding¹, each of which is entitled to one vote upon each of the matters to be presented at the meeting. No less than two Orbotech shareholders of record present in person or by proxy, and holding or representing between them Orbotech shares conferring in the aggregate more than 50% of the voting rights of Orbotech, shall constitute a quorum at the meeting. If within one-half hour from the time appointed for the holding of the meeting a quorum is not present, the meeting shall be adjourned to July 23, 2018, at the same time and place. At any such adjourned meeting, if a quorum is not present within one-half hour from the specified time, any shareholders present in person or by proxy shall constitute a quorum even if they hold or represent Orbotech shares conferring 50% or less of the voting rights of Orbotech.

In determining whether there is a quorum for the meeting and whether the required number of votes for the Merger Proposal has been cast, Orbotech shares subject to abstentions or to broker non-votes are counted for purposes of determining whether there is a quorum for the meeting but, with regard to the Merger Proposal, are not counted as having been voted in respect thereof. Broker non-votes are votes that brokers holding Orbotech shares of record for their clients are, pursuant to applicable stock exchange or other rules, precluded from casting in respect of certain non-routine proposals because such brokers have not received specific instructions from their clients as to the manner in which such Orbotech shares should be voted on those proposals and as to which the brokers have advised Orbotech that, accordingly, they lack voting authority.

Required vote. The affirmative vote of a simple majority of the voting rights of Orbotech shares represented and voting thereon at the meeting is necessary for the approval of the Merger Proposal, provided that such majority includes at least a majority of the votes cast by Orbotech shareholders that are not KLA-Tencor, Merger Sub or a KLA Related Person (as defined below), who are present and voting (abstentions are disregarded) (the “Merger Majority”).

Pursuant to the ICL, each Orbotech shareholder voting on the Merger Proposal is required to inform Orbotech as detailed below prior to voting at the meeting if the shareholder is any of KLA-Tencor, Merger Sub, or a KLA Related Person and to indicate such matter in the appropriate place in the enclosed proxy, as further detailed below. A “KLA Related Person” is (a) a person holding, directly or indirectly, either (i) 25% or more of the voting rights of KLA-Tencor or Merger Sub, or (ii) the right to appoint 25% or more of the directors of KLA-Tencor or Merger Sub, or (b) one of such person’s spouse, siblings, parents, grandparents, descendants, spouse’s descendants, siblings or parents or the spouse of any such person, or a corporation controlled by any one or more of such persons or by KLA-Tencor or Merger Sub.

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Special voting instructions under the ICL. In order to provide for proper counting of your shareholder vote, in the enclosed proxy you are required to indicate whether or not you are KLA-Tencor, Merger Sub, or a KLA Related Person with respect to the Merger Proposal. If you have not marked “NO” on the proxy (or in your electronic submission), thereby confirming that you are not any of KLA-Tencor, Merger Sub, or a KLA Related Person with respect to the Merger Proposal, your vote will not be counted for purposes of the Merger Majority with respect to the Merger Proposal, and your signature on the enclosed proxy (or the submission of an electronic vote) will constitute a certification that you are either KLA-Tencor, Merger Sub or a KLA Related Person.

Based on information provided by KLA-Tencor and Merger Sub to Orbotech, as of the date of this proxy statement/prospectus, Orbotech is not aware of any holdings of Orbotech shares by KLA-Tencor, Merger Sub or any KLA Related Persons, and therefore believes that all of its shareholders should mark “NO” in the appropriate place on the enclosed proxy (or in their electronic submission).

Abstentions and broker non-votes will be counted for purposes of determining whether there is a quorum for the meeting but will not be treated as having been voted in respect of the Merger Proposal. Consequently, assuming a quorum is present at the meeting, broker non-votes and abstentions will have no effect on the voting with respect to the Merger Proposal.

Orbotech is unaware at this time of any other matters that will come before the meeting. If any other matters properly come before the meeting, it is the intention of the persons designated as proxies to vote in accordance with their judgment on such matters. Orbotech shares represented by executed and unrevoked proxies will be voted in accordance with such judgment.

ADDITIONAL INFORMATION

This proxy statement/prospectus incorporates important business and financial information about KLA-Tencor and Orbotech from other documents that are not included in or delivered with this proxy statement/prospectus. This information is available to you without charge upon your request. You can obtain the documents incorporated by reference into the proxy statement/prospectus free of charge by requesting them in writing or by telephone from the appropriate company at the following addresses and telephone numbers:

Investors may also consult KLA-Tencor’s or Orbotech’s website for more information concerning the Merger described in this proxy statement/prospectus. KLA-Tencor’s website is www.kla-tencor.com. Orbotech’s website is www.orbotech.com. Information included on these websites is not incorporated by reference into this proxy statement/prospectus.

In addition, if you have questions about the Merger, the merger consideration or related matters or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus or need to obtain proxy cards or other information related to the proxy solicitation, please contact Okapi Partners LLC, the proxy solicitor for Orbotech, toll-free at +1 (855) 305-0857 or collect at +1 (212) 297-0720. You will not be charged for any of these documents that you request. If you have any questions about the merger consideration or related matters, you may also contact D.F. King & Co., Inc., the information agent for the Merger, by phone at +1 (800) 628-8538 (toll-free for stockholders) or +1 (212) 269-5550 (banks and brokers) or by email at orbotech@dfking.com.

If you would like to request any documents, please do so by July 5, 2018 in order to receive them before the extraordinary general meeting of Orbotech shareholders.

For a more detailed description of the information incorporated by reference into this proxy statement/prospectus and how you may obtain it, see the section entitled “Where You Can Find More Information”.

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ABOUT THIS PROXY STATEMENT/PROSPECTUS

This proxy statement/prospectus, which forms part of a registration statement on Form S-4 filed with the U.S. Securities and Exchange Commission (the “SEC”) by KLA-Tencor, constitutes a prospectus of KLA-Tencor under Section 5 of the Securities Act of 1933, as amended (the “Securities Act”) with respect to the shares of KLA-Tencor common stock to be issued to Orbotech shareholders pursuant to the Merger Agreement. This proxy statement/prospectus also constitutes a notification with respect to the extraordinary general meeting of Orbotech shareholders.

You should rely only on the information contained in or incorporated by reference into this proxy statement/prospectus. No one has been authorized to provide you with information that is different from that contained in, or incorporated by reference into, this proxy statement/prospectus. This proxy statement/prospectus is dated June 7, 2018. You should not assume that the information contained in this proxy statement/prospectus is accurate as of any other date. You should not assume that the information incorporated by reference into this proxy statement/prospectus is accurate as of any date other than the date of the incorporated document. Neither our making available this proxy statement/prospectus to Orbotech shareholders nor the issuance by KLA-Tencor of shares of common stock pursuant to the Merger Agreement will create any implication to the contrary.

This proxy statement/prospectus does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation. Information contained in this proxy statement/prospectus regarding KLA-Tencor has been provided by KLA-Tencor and information contained in this proxy statement/prospectus regarding Orbotech has been provided by Orbotech.

All references in this proxy statement/prospectus to “KLA-Tencor” refer to KLA-Tencor Corporation, a Delaware corporation; all references in this proxy statement/prospectus to “Orbotech” refer to Orbotech Ltd., a company organized under the laws of the State of Israel; all references to “Merger Sub” refer to Tiburon Merger Sub Technologies Ltd., a company organized under the laws of the State of Israel and a wholly owned subsidiary of KLA-Tencor formed for the sole purpose of effecting the Merger, or its permitted assignees; unless otherwise indicated or as the context requires, all references in this proxy statement/prospectus to “we,” “our” and “us” refer to KLA-Tencor and Orbotech collectively; unless otherwise indicated or as the context requires, all references to the “combined company” refer to KLA-Tencor, Orbotech and their subsidiaries, collectively, following the consummation of the Merger; unless otherwise indicated or as the context requires, all references to the “Merger Agreement” refer to the agreement and plan of merger, dated as of March 18, 2018, as amended, among KLA-Tencor, Merger Sub and Orbotech, a copy of which is attached to this proxy statement/prospectus as Annex A; all references to the “Merger” refer to the merger of Merger Sub with and into Orbotech, with Orbotech as the surviving company.

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TABLE OF CONTENTS

QUESTIONS AND ANSWERS

The following are some questions that you, as a shareholder of Orbotech, may have regarding the Merger Proposal being considered at the extraordinary general meeting of Orbotech shareholders (the “meeting”) and the answers to those questions. KLA-Tencor and Orbotech urge you to carefully read the remainder of this proxy statement/prospectus because the information in this section does not provide all the information that might be important to you with respect to the Merger Proposal being considered at the meeting. Additional important information is also contained in the Annexes to, and the documents incorporated by reference into, this proxy statement/prospectus. For more information, see the section entitled “Where You Can Find More Information”.

In order to consummate the Merger, Orbotech shareholders must vote to approve and adopt the Merger Proposal described in this proxy statement/prospectus, and all other conditions to the Merger must be satisfied or waived.

Orbotech will hold the meeting to obtain this approval for the Merger Proposal. This proxy statement/prospectus contains important information about the Merger, the Merger Proposal and the meeting, and you should read it carefully. The enclosed proxy materials allow you to vote your shares without attending the meeting.

Your vote is important. We encourage you to vote as soon as possible. For more information on how to vote your shares, see the section entitled “The Orbotech Extraordinary General Meeting—Voting Procedures”.

This proxy statement/prospectus is for the extraordinary general meeting of the shareholders of Orbotech to consider the Merger Proposal and does not relate to the 2018 annual general meeting of Orbotech shareholders (the “2018 Orbotech Annual Meeting”) scheduled to be held on June 21, 2018 . To vote on the Merger Proposal, you must follow the procedures in this proxy statement/prospectus. Completing the proxy for or voting at the 2018 Orbotech Annual Meeting is not a vote on the Merger Proposal. This proxy statement/prospectus is not soliciting votes for the 2018 Orbotech Annual Meeting and a separate proxy statement relating to the 2018 Orbotech Annual Meeting was made available to Orbotech shareholders on or about May 17, 2018. See the section entitled “Where You Can Find More Information”.

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Questions and Answers about the Merger Proposal and Extraordinary General Meeting

In determining whether there is a quorum for the meeting and whether the required number of votes for the Merger Proposal has been cast, Orbotech shares subject to abstentions or to broker non-votes are counted for purposes of determining whether there is a quorum for the meeting but, with regard to the Merger Proposal, are not counted as having been voted in respect thereof. Broker non-votes are votes that brokers holding Orbotech shares of record for their clients are, pursuant to applicable stock exchange or other rules, precluded from casting in respect of certain non-routine proposals because such brokers have not received specific instructions from their clients as to the manner in which such Orbotech shares should be voted on

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those proposals and as to which the brokers have advised Orbotech that, accordingly, they lack voting authority.

For a discussion of the factors that the Orbotech Board considered in determining to recommend the approval and adoption of the Merger Agreement, the Merger and all other transactions contemplated by thereby, see the section entitled “The Merger—Orbotech’s Reasons for the Merger; Recommendation of the Orbotech Board”.

Your shares can be voted at the meeting only if you are present or represented by a valid proxy. In order to provide for proper counting of your shareholder vote, in the enclosed proxy you are required to indicate whether or not you are KLA-Tencor, Merger Sub, or a KLA Related Person with respect to the Merger Proposal. If you have not marked “NO” on the proxy (or in your electronic submission), thereby confirming that you are not any of KLA-Tencor, Merger Sub, or a KLA Related Person with respect to the Merger Proposal, your vote will not be counted for purposes of the Merger Majority with respect to the Merger Proposal, and your signature on the enclosed proxy (or the submission of an electronic vote) will constitute a certification that you are either KLA-Tencor, Merger Sub or a KLA Related Person.

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Joint holders of Orbotech shares should take note that, pursuant to Article 62 of the Articles of Association of Orbotech, the vote of the senior holder of joint holders of any Orbotech share who tenders a vote, whether in person or by proxy, will be accepted to the exclusion of the vote(s) of the other joint holder(s) of the Orbotech share, and for this purpose seniority will be determined by the order in which the names stand in Orbotech’s share register.

If you are an Orbotech shareholder of record who properly executes and returns the form of proxy to Orbotech prior to the meeting (as specified above) without indicating how you intend to vote with respect to the Merger Proposal, the Orbotech shares represented by the proxy will be counted as being present for quorum purposes, but will not be treated as having been voted in respect of the Merger Proposal and will have no effect on the voting with respect to the Merger Proposal.

Merely attending the meeting will not, by itself, revoke a proxy. Please note that if you want to revoke your proxy by sending a new proxy or an instrument revoking such proxy to Orbotech, you should ensure that you send your new proxy or instrument revoking such proxy in sufficient time for it to be received by Orbotech prior to the meeting. Only your last-dated proxy will count. If you are an Orbotech shareholder of record, you may obtain a new legal proxy by contacting Okapi Partners LLC, Orbotech’s proxy solicitor, at 1212 Avenue of the Americas, 24th Floor, New York, NY 10036 or by telephone at +1 (212) 297-0720.

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If you are an Orbotech shareholder with Orbotech shares held in “street name,” you should follow the instructions of your broker regarding the revocation of proxies. If your broker allows you to submit a proxy via the internet or by telephone, you may be able to change your vote by submitting a new proxy via the internet or by telephone or by mail. Please note that if your Orbotech shares are held in the name of a broker, you must obtain and bring to the meeting a proxy issued in your name from the broker to be able to vote at the meeting.

Promptly after the Effective Time (as defined below in the answer to the question “When do you expect the Merger to be completed?”), each holder of record of a certificate representing any Orbotech share (each a “certificate”) or uncertificated Orbotech shares, in each case that have been converted into the right to receive the Merger Consideration (as defined in the section entitled “The Merger—Effects of the Merger”), will be sent a letter of transmittal describing the procedure for surrendering such certificate or acknowledging the conversion of such uncertificated shares into the right to receive the Merger Consideration. Upon delivery to the exchange agent of the letter of transmittal and a declaration for tax withholding purposes or a valid tax certificate and, if applicable, surrender of the certificates for cancellation to the exchange agent, the holders of such certificates or uncertificated shares, as applicable, will be entitled to receive in exchange therefor the Merger Consideration. Payments and deliveries will be made to such addresses or bank accounts as set forth in the letter of transmittal. For more information, see the sections entitled “The Merger—Procedures for Surrendering Orbotech Shares in the Merger” and “The Merger Agreement—Exchange Agent; Letter of Transmittal”.

Questions and Answers about the Merger

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The consummation of the Merger is not subject to a financing condition. For more information, see the section entitled “The Merger Agreement—Conditions to Completion of the Merger” as well as the copy of the Merger Agreement attached to this proxy statement/prospectus as Annex A and incorporated herein by reference.

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Holders of Orbotech Equity Awards granted under Section 102 of the Israeli Income Tax Ordinance [New Version], 1961 (the “ITO” and, such Orbotech Equity Awards, the “102 Compensatory Awards”), that are not being assumed by KLA-Tencor will receive the Merger Consideration to which such holders are entitled through the 102 Trustee (as described in the section entitled “The Merger Agreement—Merger Consideration”), in accordance with the terms and conditions of Section 102 of the ITO and the Tax Rulings (as defined below in the answer to the question “What are the Israeli tax consequences of the exchange of Orbotech shares for the Merger Consideration?”).

Holders of Orbotech Equity Awards (other than 102 Compensatory Awards) that are not being assumed by KLA-Tencor will receive the Merger Consideration to which such holders are entitled from Orbotech or, if applicable, a relevant engaging subsidiary, through its payroll system, subject to applicable withholdings.

More information on the documentation required to be delivered to the exchange agent may be found under the section entitled “Material Israeli Tax Consequences”.

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Because particular circumstances may differ, we recommend that you consult your own tax advisor to determine the U.S. federal income tax consequences to you relating to the Merger in light of your own particular circumstances and the consequences to you arising under U.S. federal non-income tax laws or the laws of any state, local or non-U.S. taxing jurisdiction. A more complete description of material U.S. federal income tax consequences of the Merger is provided in the section entitled “Material U.S. Federal Income Tax Consequences of the Merger”.

As a consequence of the Merger, holders of Orbotech shares will be treated as having sold their Orbotech shares in the Merger. When an Israeli company is sold, regardless of whether the consideration in the sale is cash or stock, its shareholders are generally subject to Israeli taxation.

The ITO distinguishes between ‘Real Capital Gain’ and ‘Inflationary Surplus’. The Inflationary Surplus is the portion of the total capital gain which is equivalent to the increase of the relevant asset’s purchase price which is attributable to the increase in the Israeli CPI or, in certain circumstances, a foreign currency exchange rate, between the date of purchase and the date of sale. The Real Capital Gain is the excess of the total capital gain over the Inflationary Surplus.

The capital gains tax rate applicable to the Real Capital Gain is 25% for individuals (and if such individual is holding or is entitled to purchase, directly or indirectly, alone or together with such person’s relative or

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another person who collaborates with such person on a permanent basis, one of the following: (i) at least 10% of the issued and outstanding Orbotech shares, (ii) at least 10% of the voting rights of Orbotech, (iii) the right to receive at least 10% of Orbotech’s profits or its assets upon liquidation, (iv) the right to appoint a manager/director, or (v) the right to instruct any other person to do any of the foregoing (a “Major Stockholder”) on the date of sale or on any date falling within the 12-month period preceding that date of sale, such Major Stockholder would be subject to Israeli taxation at the rate of 30%) and 23% for corporations. An additional tax at a rate of three percent on the Real Capital Gain may be imposed upon individual shareholders whose annual income from all sources that is taxable in Israel exceeds a certain amount. The Inflationary Surplus is generally exempt from tax, provided that the shares being sold were acquired after December 31, 1993.

Shareholders of a company, such as Orbotech, whose shares are traded on an authorized stock exchange outside Israel, or on a regulated market outside of Israel, who are non-Israeli residents, would generally be exempt from Israeli capital gains tax, provided that certain conditions are met (e.g., including that the capital gain is not made through a permanent establishment that the non-Israeli resident shareholder maintains in Israel). In addition, such sale may be exempt from Israeli capital gain tax (or be subject to a reduced tax rate) under the provisions of an applicable tax treaty between Israel and the seller’s country of residence (subject to the receipt of a valid certificate from the Israel Tax Authority allowing for an exemption or a reduced tax rate).

Orbotech has filed requests for tax rulings from the Israel Tax Authority with respect to (i) exemption from withholding of Israeli tax on payments of Merger Consideration paid to Orbotech shareholders who are non-Israeli residents and meet certain conditions, (ii) deferral of the obligation of Israeli tax resident holders of Orbotech shares, to pay Israeli tax on the exchange of the Orbotech shares for KLA-Tencor common stock in accordance with the provisions of Section 104H of the ITO and (iii) the application of Israeli tax withholding and other Israeli tax treatment applicable to holders of Orbotech options, RSUs and shares issued to certain directors and employees under Section 102 of the ITO and to certain directors and others under Section 3(i) of the ITO (collectively, the “Tax Rulings”). If and when the tax rulings are finalized, Orbotech will issue a press release and furnish a Form 6-K or other document with the SEC describing the scope of the exemptions provided by the rulings. There can be no assurance that such rulings will be granted before the Closing or at all or that, if obtained, such rulings will be granted under the conditions requested by Orbotech.

Whether or not a particular Orbotech shareholder is actually subject to Israeli capital gains tax in connection with the Merger, absent receipt by Orbotech of a tax ruling from the Israel Tax Authority prior to Closing, all Orbotech shareholders will be subject to Israeli tax withholding at the rate of 25% (for individuals) and 23% (for corporations) on the gross Merger Consideration (unless the shareholder requests and obtains an individual certificate of exemption or a reduced tax rate from the Israel Tax Authority, as described below), and KLA-Tencor or the exchange agent will withhold and deduct from the Cash Consideration an amount equal to 25%, 23% or such other reduced tax rate as stipulated in the certificate obtained, as applicable, of the gross Merger Consideration received by such shareholder and, if the Cash Consideration is lower than the required amount to be withheld, no KLA-Tencor common stock will be issued to such shareholder of Orbotech, until such shareholder remits sufficient cash to cover the required amount to be withheld.

Regardless of whether Orbotech obtains the requested tax rulings from the Israel Tax Authority, any holder of Orbotech shares who believes that it is entitled to such an exemption (or reduced tax rate) may separately apply to the Israel Tax Authority to obtain a certificate of exemption from withholding or an individual tax ruling providing for no withholding or withholding at a reduced rate, and submit such certificate of exemption or ruling to the exchange agent at least five business days prior to the date that is 180 days following the Closing Date. If KLA-Tencor or the exchange agent receive a valid exemption certificate or tax ruling (as determined in KLA-Tencor’s or the exchange agent’s discretion) at least five business days prior to the date that is 180 days following the Closing Date, then the withholding (if any) of any amounts under the ITO, from the Merger Consideration payable shall be made only in accordance with the provisions of such Israeli tax certificate or tax ruling.

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You are urged to consult with your own tax advisor for a full understanding of the tax consequences of the Merger to you, including the consequences under any applicable, state, local, foreign or other tax laws.

For a more detailed description of the material Israeli tax consequences of the Merger, see the section entitled “Material Israeli Tax Consequences”.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus and the documents incorporated by reference into this proxy statement/prospectus contain forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 that are not limited to historical facts, but reflect KLA-Tencor’s and Orbotech’s current beliefs, expectations or intentions regarding future events. Words such as “may,” “will,” “could,” “should,” “expect,” “plan,” “project,” “intend,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “pursue,” “target,” “continue,” and similar expressions are intended to identify such forward-looking statements. These forward-looking statements include, without limitation, the manner in which the parties plan to effect the proposed Merger, including the share repurchase program; the ability to raise additional capital necessary to complete the repurchase program within the time frame expected; the expected benefits, synergies and costs of the proposed Merger; management plans relating to the proposed Merger; the expected timing of the completion of the proposed Merger; the parties’ ability to complete the proposed Merger considering the various closing conditions, including conditions related to regulatory and Orbotech shareholder approvals; the plans, strategies and objectives of management for future operations; product development, product extensions, product integration, complementary product offerings and growth opportunities in certain business areas; the potential future financial impact of the proposed Merger; and any assumptions underlying any of the foregoing. Without limiting the generality of the preceding sentence, certain statements contained in the sections entitled “The Merger—Background of the Merger,” “The Merger—Orbotech’s Reasons for the Merger; Recommendation of the Orbotech Board,” “The Merger—Certain Projections of Orbotech” contain forward-looking statements.

All forward-looking statements involve significant risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements, many of which are generally outside the control of KLA-Tencor and Orbotech and are difficult to predict. In addition to the risks and uncertainties described in the section entitled “Risk Factors” and those described in any documents that are incorporated by reference into this proxy statement/prospectus, such risks and uncertainties include, among others: (1) the risk that the conditions to the Closing are not satisfied, including the risk that required approvals for the Merger from governmental authorities or the shareholders of Orbotech are not obtained; (2) the risk that the value of the Stock Consideration will fluctuate over time; (3) litigation relating to the Merger, if any; (4) uncertainties as to the timing of the consummation of the Merger and the ability of each party to consummate the Merger; (5) risks that the proposed Merger disrupts the current plans and operations of Orbotech or KLA-Tencor; (6) the ability of Orbotech and KLA-Tencor to retain and hire key personnel; (7) competitive responses to the proposed Merger and the impact of competitive products; (8) unexpected costs, charges or expenses resulting from the Merger; (9) potential adverse reactions or changes to business relationships resulting from the announcement or completion of the Merger, including related to Frontline (as defined below); (10) the combined company’s ability to achieve the financial and operating results, growth prospects and synergies expected from the Merger, as well as delays, challenges and expenses associated with integrating the existing businesses of KLA-Tencor and Orbotech; (11) the combined company’s ability to maintain and improve relationships with customers, suppliers and other third parties following the Merger; (12) the terms and availability of the indebtedness that may be incurred in connection with the Merger; and (13) legislative, regulatory and economic developments, including changing business conditions in the industries in which KLA-Tencor and Orbotech operate, including the semiconductor industry, and overall economy as well as the financial performance and expectations of KLA-Tencor’s and Orbotech’s existing and prospective customers.

KLA-Tencor and Orbotech caution that the foregoing list of factors is not exclusive and that you should not place undue reliance on any forward-looking statement. All subsequent written and oral forward-looking statements concerning KLA-Tencor, Orbotech, the proposed Merger or other matters and attributable to KLA-Tencor or Orbotech or any person acting on their behalf are expressly qualified in their entirety by the cautionary statements above. All forward-looking statements contained in this proxy statement/prospectus and the documents incorporated by reference herein are made only as of the date of the document in which they are contained and, except as required by law, neither KLA-Tencor nor Orbotech undertakes any obligation to update publicly any of these forward-looking statements to reflect events or circumstances that may arise after the date hereof.

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RISK FACTORS

In addition to the other information included and incorporated by reference into this proxy statement/prospectus, including the matters addressed in the section entitled “Special Note Regarding Forward-Looking Statements”, you should carefully consider the following risks before deciding whether to vote for the Merger Proposal. In addition, you should read and consider the risks associated with each of the businesses of KLA-Tencor and Orbotech because these risks will also affect the combined company. The risks associated with KLA-Tencor’s business can be found in KLA-Tencor’s Annual Report on Form 10-K for the fiscal year ended June 30, 2017, and any amendments thereto, as such risks may be updated or supplemented in KLA-Tencor’s subsequently filed Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. The risks associated with Orbotech’s business can be found in Orbotech’s Annual Report on Form 20-F for the fiscal year ended December 31, 2017 and any amendments thereto, as such risks may be updated or supplemented in Orbotech’s Annual Reports on Form 20-F or subsequently filed or furnished Reports on Form 6-K. Such filings by KLA-Tencor and Orbotech will be incorporated by reference into this proxy statement/prospectus to the extent described in the section entitled “Where You Can Find More Information”. You should also read and consider the other information in this proxy statement/prospectus and the other documents incorporated by reference into this proxy statement/prospectus. For more information, see the section entitled “Where You Can Find More Information”.

Risk Factors Relating to the Merger

The value of the stock portion of the Merger Consideration that Orbotech shareholders will receive in the Merger will fluctuate over time.

At the time that the Merger is consummated, each issued and outstanding ordinary share of Orbotech (except for Excluded Shares) will be converted into the right to receive, without interest and less any applicable withholding taxes, (a) $38.86 in cash and (b) 0.25 of a share of KLA-Tencor common stock, in each case, subject to the terms and conditions set forth in the Merger Agreement. Orbotech shareholders will not receive any fractional shares of KLA-Tencor common stock and will instead receive cash in lieu of any such fractional shares.

Time will elapse between each of the date of this proxy statement/prospectus, the date on which Orbotech shareholders vote to approve and adopt the Merger Proposal at the meeting and the date on which Orbotech shareholders are entitled to receive the Stock Consideration in the form of KLA-Tencor common stock and the Cash Consideration in the form of cash from KLA-Tencor. The respective market value of KLA-Tencor’s common stock and Orbotech’s ordinary shares may fluctuate during any or all of these periods as a result of a variety of factors, including general market and economic conditions, changes in KLA-Tencor’s or Orbotech’s businesses, operations and prospects, catastrophic events, both natural and man-made, and regulatory considerations. Many of these factors are outside the control of Orbotech and KLA-Tencor. There will be no adjustment to the exchange ratio of the Stock Consideration (except for adjustments to reflect the effect of any stock dividend, subdivision, reclassification, recapitalization, split, combination or exchange of shares or other like changes with respect to the KLA-Tencor common stock) and the parties do not have a right to terminate the Merger Agreement based upon changes in the market price of the KLA-Tencor common stock. Consequently, at the time that Orbotech shareholders must decide whether to approve and adopt the Merger Proposal, they will not know the market price of the KLA-Tencor common stock they will receive and the market price of the Orbotech shares that they will surrender when the Merger is actually consummated. The value of the KLA-Tencor common stock received by Orbotech shareholders upon consummation of the Merger will depend on the market price of the KLA-Tencor common stock at that time, and the value of the Orbotech shares surrendered by Orbotech shareholders will depend on the market price of the Orbotech shares at that time.

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The Merger is subject to a number of conditions, some of which are outside of the parties’ control, and, if these conditions are not satisfied, the Merger Agreement may be terminated and the Merger may not be completed.

The Merger Agreement contains a number of conditions that must be fulfilled to complete the Merger. These conditions include:

The required satisfaction of the foregoing conditions could delay the completion of the Merger for a significant period of time or prevent it from occurring. Any delay in completing the Merger could cause KLA-Tencor not to realize some or all of the benefits that the parties expect KLA-Tencor to achieve following the Merger. Further, there can be no assurance that the conditions to the Closing will be satisfied or waived or that the Merger will be completed.

In addition, if the Merger is not completed by March 18, 2019 (subject to a potential extension to June 18, 2019), either KLA-Tencor or Orbotech may choose to terminate the Merger Agreement. KLA-Tencor or Orbotech may also elect to terminate the Merger Agreement in certain other circumstances, and the parties may mutually decide to terminate the Merger Agreement at any time prior to the Closing Date, before or after Orbotech shareholder approval is received, as applicable. For more information, see the section entitled “The Merger Agreement—Termination of the Merger Agreement”.

Failure to complete the Merger could negatively affect the share prices and the future business and financial results of either or both of KLA-Tencor and Orbotech.

If the Merger is not completed, the ongoing businesses of either or both of KLA-Tencor and Orbotech may be adversely affected. Additionally, if the Merger is not completed and the Merger Agreement is terminated, in certain circumstances Orbotech may be required to pay KLA-Tencor a termination fee of $125.0 million. For more information, see the sections entitled “The Merger Agreement—Termination of the Merger Agreement” and “The Merger Agreement—Termination Fees”. In addition, KLA-Tencor and Orbotech have incurred and will continue to incur significant transaction expenses in connection with the Merger regardless of whether the

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Merger is completed. Furthermore, either or both of KLA-Tencor or Orbotech may experience negative reactions from the financial markets, including negative impacts on their stock prices, or negative reactions from their customers, suppliers or other business partners, should the Merger not be completed.

The foregoing risks, or other risks arising in connection with the failure to consummate the Merger, including the diversion of management attention from conducting the businesses of the respective companies and pursuing other opportunities during the pendency of the Merger, may have a material adverse effect on the businesses, operations, financial results and stock prices of either or both of KLA-Tencor and Orbotech. Either or both of KLA-Tencor or Orbotech could also be subject to litigation related to any failure to consummate the Merger or any related action that could be brought to enforce a party’s obligations under the Merger Agreement.

Litigation against KLA-Tencor and Orbotech, or the members of the Orbotech Board, could prevent or delay the completion of the Merger or result in the payment of damages following completion of the Merger.

Claims may be asserted by purported shareholder plaintiffs related to the Merger. The results of any such potential legal proceedings are difficult to predict and could delay or prevent the Merger from becoming effective in a timely manner. The existence of litigation related to the Merger could affect the likelihood of obtaining the required approval from Orbotech shareholders. Moreover, any litigation could be time consuming and expensive, could divert KLA-Tencor’s and Orbotech’s management’s attention away from their respective regular businesses and, if any lawsuit is adversely resolved against any of KLA-Tencor, Orbotech or the members of the Orbotech Board, could have a material adverse effect on KLA-Tencor’s or Orbotech’s financial condition. For more information, see the section entitled “The Merger—Litigation Related to the Merger”.

One of the conditions to the Closing is the absence of any law, order, judgment, injunction or other ruling, instituted by a governmental entity with competent jurisdiction, that is in effect and has the effect of making the Merger illegal, or prohibiting or otherwise preventing the consummation of the Merger in any jurisdiction. Consequently, if a settlement or other resolution is not reached in any lawsuit that is filed and a claimant secures injunctive or other relief prohibiting, delaying or otherwise adversely affecting KLA-Tencor’s and/or Orbotech’s ability to complete the Merger on the terms contemplated by the Merger Agreement, then such injunctive or other relief may prevent the Merger from becoming effective in a timely manner or at all.

The Merger Agreement contains provisions that limit Orbotech’s ability to pursue alternatives to the Merger, could discourage a potential competing acquiror of Orbotech from making an alternative transaction proposal and, in specified circumstances, could require Orbotech to pay a termination fee to KLA-Tencor.

The Merger Agreement prohibits Orbotech and its representatives from soliciting, participating in negotiations with respect to or approving or recommending any third-party proposal for an alternative transaction, subject to exceptions set forth in the Merger Agreement relating to the receipt of certain unsolicited offers. If the Merger Agreement is terminated by either party after the Orbotech Board has changed its recommendation regarding the Merger or due to Orbotech’s material breach of its non-solicitation obligations, then Orbotech may be required to pay a termination fee of $125.0 million to KLA-Tencor. For more information, see the sections entitled “The Merger Agreement—Termination of the Merger Agreement” and “The Merger Agreement—Termination Fees”.

These provisions could discourage a potential third-party acquiror or merger partner that might have an interest in acquiring all or a significant portion of Orbotech or pursuing an alternative transaction from considering or proposing such a transaction, even if it were prepared to pay consideration with a higher per share cash or market value than the consideration to be paid in the Merger, or might result in a potential third-party acquiror or merger partner proposing to pay a lower price to Orbotech shareholders than it might otherwise have proposed to pay because of the added expense of the termination fee that may become payable in certain circumstances.

If the Merger Agreement is terminated and Orbotech determines to seek another business combination, Orbotech may not be able to negotiate a transaction with another party on terms comparable to, or better than, the terms of the Merger.

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The Merger is subject to the expiration of applicable waiting periods under and the receipt of approvals, consents or clearances from foreign antitrust regulatory authorities that may impose conditions that could have an adverse effect on KLA-Tencor or Orbotech or, if not obtained, could prevent completion of the Merger.

The Closing remains subject to the exemption or approval of applicable government entities under the antitrust laws of China, Korea and Japan. In deciding whether to grant the required regulatory approvals, consents or clearances, the relevant governmental entities will consider the effect of the Merger on competition within their relevant jurisdiction. The terms and conditions of the approvals, consents and clearances that are granted may impose requirements, limitations or costs or place restrictions on the conduct of KLA-Tencor’s business and which may adversely affect the financial position and prospects of KLA-Tencor and its ability to achieve the cost savings and other synergies projected to result from the Merger.

Under the Merger Agreement, KLA-Tencor and Orbotech have agreed to use their reasonable best efforts to obtain any consents, clearances or approvals (provided that such actions do not reduce the reasonably anticipated benefits to KLA-Tencor of the Merger in an amount that is financially material relative to the value of Orbotech and its subsidiaries, as a whole) and therefore may be required to comply with conditions or limitations imposed by governmental antitrust authorities. However, there can be no assurance that antitrust regulators will not impose unanticipated conditions, terms, obligations or restrictions and that such conditions, terms, obligations or restrictions will not have the effect of delaying completion of the Merger or imposing additional costs on or limiting the revenues of KLA-Tencor following the completion of the Merger and which may adversely affect the financial position and prospects of KLA-Tencor and its ability to achieve the cost savings and other synergies projected to result from the Merger. In addition, one of the conditions to the obligation of KLA-Tencor to close the Merger consists of the absence of any legal proceeding seeking to enjoin, restrain or prohibit the Merger pursuant to any applicable antitrust laws or seeking to impose certain burdensome conditions on the Merger. As a result, neither KLA-Tencor nor Orbotech can provide assurance that any such conditions, terms, obligations or restrictions will not result in the delay or abandonment of the Merger. For a more detailed description of the regulatory review process, see the section entitled “The Merger—Competition Clearances Required for the Merger”.

Until the completion of the Merger or the termination of the Merger Agreement in accordance with its terms, in consideration of the agreements made by the parties in the Merger Agreement, Orbotech is prohibited from entering into certain transactions and taking certain actions that might otherwise be beneficial to Orbotech and its shareholders.

Until the Merger is completed, the Merger Agreement restricts Orbotech from taking specified actions without the consent of KLA-Tencor, and requires Orbotech to operate in the ordinary course of business consistent with past practices. These restrictions may prevent Orbotech from making appropriate changes to its businesses, retaining its workforce, paying dividends or pursuing attractive business opportunities that may arise prior to the completion of the Merger. For more information, see the section entitled “The Merger Agreement—Restrictions on Orbotech’s Business Pending the Closing”.

The opinion of Orbotech’s financial advisor does not reflect changes in circumstances that may occur between the original signing of the Merger Agreement and the completion of the Merger.

Consistent with market practices, the Orbotech Board has not obtained an updated opinion from its financial advisor as of the date of this proxy statement/prospectus and does not expect to receive an updated, revised or reaffirmed opinion prior to the completion of the Merger. Changes in the operations and prospects of Orbotech, general market and economic conditions and other factors that may be beyond the control of Orbotech, and on which Orbotech’s financial advisor’s opinion was based, may significantly alter the value of Orbotech or the price of Orbotech shares by the time the Merger is completed. The opinion does not speak as of the time the Merger will be completed or as of any date other than the date of such opinion. Because Orbotech’s financial

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advisor will not be updating its opinion, the opinion will not address the fairness of the Merger Consideration from a financial point of view at the time the Merger is completed. For a description of the opinion that the Orbotech Board received from its financial advisor, see the section entitled “The Merger—Opinion of Orbotech’s Financial Advisor”.

After the Merger, Orbotech shareholders will have a significantly lower ownership and voting interest in KLA-Tencor than they currently have in Orbotech, and will exercise less influence over management.

Based on the number of Orbotech shares issued and outstanding as of June 4, 2018, the number of shares of KLA-Tencor common stock issued and outstanding as of June 4, 2018, the number of vested Orbotech Equity Awards outstanding as of June 4, 2018, and assuming a KLA-Tencor Average Closing Price (as defined in the section entitled “The Merger Agreement—Merger Consideration”) of $113.77 (calculated based on the ten trading days ended June 4, 2018, the most recent practicable range of trading days prior to the date of this proxy statement/prospectus), it is expected that, immediately after completion of the Merger, former Orbotech shareholders will receive shares of KLA-Tencor common stock in the Merger representing approximately 7.3% of the outstanding shares of KLA-Tencor common stock, immediately following the Effective Time, assuming the Effective Time is on June 5, 2018. Consequently, Orbotech shareholders will have substantially less influence over the management and policies of KLA-Tencor than they currently have over Orbotech.

The executive officers and directors of Orbotech have interests in the Merger that are different from, or in addition to, those of the other Orbotech shareholders. Therefore, the executive officers and directors of Orbotech may have a conflict of interest in recommending the Merger Proposal being voted on at the meeting.

The directors and executive officers of Orbotech have interests in the Merger that may be different from, or in addition to, those of the Orbotech shareholders generally. These interests include the treatment of Orbotech Equity Awards in connection with the Merger (including potential accelerated vesting and payout or settlement of Orbotech Equity Awards held by directors and executive officers in connection with the Closing of the Merger or upon certain qualifying terminations of employment, as applicable), potential cash severance payments and other benefits payable to certain executive officers and the Active Chairman of the Orbotech Board pursuant to their employment agreements and as otherwise agreed by KLA-Tencor in the event of a resignation or termination of employment following the approval of the Merger by Orbotech’s shareholders, extension of eligibility of executive officers to continue to receive severance benefits triggered by the approval of the Merger by Orbotech’s shareholders for so long as such executive officer is employed by Orbotech, cash-based and equity-based retention awards that may be granted in some instances to employees and executive officers of Orbotech in connection with the Merger, proposed new post-Closing compensation arrangements for the Active Chairman of the Orbotech Board, the Chief Executive Officer of Orbotech and the President and Chief Operating Officer of Orbotech, certain other retention arrangements for the Chief Executive Officer of Orbotech and the President and Chief Operating Officer of Orbotech, KLA-Tencor’s undertakings with respect to continuing director and officer indemnity arrangements and the purchase of a seven year ‘tail’ policy on directors’ and officers’ insurance. These interests may influence the directors and executive officers of Orbotech to support or approve the Merger Proposal to be presented at the meeting.

For more information, see the section entitled “The Merger—Interests of Orbotech’s Directors and Executive Officers in the Merger”.

The shares of KLA-Tencor common stock to be received by Orbotech shareholders as a result of the Merger will have different rights from the Orbotech shares.

Upon completion of the Merger, Orbotech shareholders will become stockholders of KLA-Tencor and their rights as stockholders will be governed by the KLA-Tencor Charter and the KLA-Tencor amended and restated bylaws. The rights associated with Orbotech shares are different from the rights associated with shares of KLA-Tencor common stock. For more information, see the section entitled “Comparison of Rights of Orbotech Shareholders and KLA-Tencor Stockholders”.

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Orbotech shareholders may be subject to Israeli capital gains tax in connection with the Merger and absent receipt of a ruling or exemption, will generally be subject to Israeli tax withholding on the gross Merger Consideration.

As a consequence of the Merger, holders of Orbotech shares will be treated as having sold their Orbotech shares in the Merger.

When an Israeli company is sold, regardless of whether the consideration in the sale is cash or stock, its shareholders are generally subject to Israeli taxation. The Israeli Income Tax Ordinance [New Version], 1961 (the “ITO”) distinguishes between ‘Real Capital Gain’ and ‘Inflationary Surplus’. The Inflationary Surplus is the portion of the total capital gain which is equivalent to the increase of the relevant asset’s purchase price which is attributable to the increase in the Israeli CPI or, in certain circumstances, a foreign currency exchange rate, between the date of purchase and the date of sale. The Real Capital Gain is the excess of the total capital gain over the Inflationary Surplus.

The capital gains tax rate applicable to the Real Capital Gain is 25% for individuals, 30% for individuals who are Major Stockholders on the date of sale or on any date falling within the 12-month period preceding that date of sale and 23% for corporations. An additional tax at a rate of three percent on the Real Capital Gain may be imposed upon individual shareholders whose annual income from all sources that is taxable in Israel exceeds a certain amount. The Inflationary Surplus is generally exempt from tax, provided that the shares being sold were acquired after December 31, 1993.

Shareholders of a company, such as Orbotech, whose shares are traded on an authorized stock exchange outside Israel, or on a regulated market outside of Israel, who are non-Israeli residents, would generally be exempt from Israeli capital gains tax, provided that certain conditions are met (e.g., including that the capital gain is not made through a permanent establishment that the non-Israeli resident shareholder maintains in Israel). In addition, such sale may be exempt from Israeli capital gain tax (or be subject to a reduced tax rate) under the provisions of an applicable tax treaty between Israel and the seller’s country of residence (subject to the receipt of a valid certificate from the Israel Tax Authority allowing for an exemption or a reduced tax rate).

Orbotech has filed requests for tax rulings from the Israel Tax Authority with respect to (i) exemption from withholding of Israeli tax on payments of Merger Consideration paid to Orbotech shareholders who are non-Israeli residents and meet certain conditions, (ii) deferral of the obligation of Israeli tax resident holders of Orbotech shares to pay Israeli tax on the exchange of the Orbotech shares for KLA-Tencor common stock in accordance with the provisions of Section 104H of the ITO and (iii) the application of Israeli tax withholding and other Israeli tax treatment applicable to holders of Orbotech options, RSUs and shares issued to certain directors and employees under Section 102 of the ITO and to certain directors and others under Section 3(i) of the ITO. If and when the tax rulings are finalized, Orbotech will issue a press release and furnish a Form 6-K or other document with the SEC describing the scope of the exemptions provided by the rulings. There can be no assurance that such rulings will be granted before the Closing or at all or that, if obtained, such rulings will be granted under the conditions requested by Orbotech.

Whether or not a particular shareholder is actually subject to Israeli capital gains tax in connection with the Merger, absent receipt by Orbotech of a tax ruling from the Israel Tax Authority prior to Closing, all Orbotech shareholders will be subject to Israeli tax withholding at the rate of 25% (for individuals) and 23% (for corporations) on the gross Merger Consideration (unless the shareholder requests and obtains an individual certificate of exemption or a reduced tax rate from the Israel Tax Authority, as described below), and KLA-Tencor or the exchange agent will withhold and deduct from the Cash Consideration an amount equal to 25%, 23% or such other reduced tax rate as stipulated in the certificate obtained, as applicable, of the gross Merger Consideration received by such shareholder and, if the Cash Consideration is lower than the required amount to be withheld, no KLA-Tencor common stock will be issued to such shareholder of Orbotech, until such recipient remits sufficient cash to cover the required amount to be withheld.

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The Israeli tax withholding consequences of the Merger to Orbotech shareholders and holders of certain Orbotech Options, RSUs and shares issued subject to Section 102 of the ITO may vary depending upon the particular circumstances of each shareholder or holder of Orbotech options, RSUs or ordinary shares issued subject to Section 102 of the ITO, as applicable, and the final tax rulings issued by the Israel Tax Authority. To the extent that tax is withheld on payments to U.S. taxpayers, it is possible that such withheld taxes may not be able to be credited against such taxpayers’ U.S. income tax liability.

You are urged to consult with your own tax advisor for a full understanding of the tax consequences of the Merger to you, including the consequences under any applicable, state, local, foreign or other tax laws or tax treaties.

For a more detailed description of the material Israeli tax consequences of the Merger, see the section entitled “Material Israeli Tax Consequences”.

Orbotech may be required to perform certain obligations with respect to Orbotech’s ownership interest in Frontline even if the Merger does not close.

In 1998, Orbotech entered into an agreement (the “JV Agreement”) with Mentor Graphics Development Services (Israel) Ltd. (the “JV Partner”) (then called Valor Computerized Systems Ltd.), an Israeli corporation, for the formation of Frontline P.C.B. Solutions Limited Partnership (“Frontline”), a joint venture with respect to computer-aided manufacturing (“CAM”) software for printed circuit board fabrication applications owned equally by Orbotech and the JV Partner and which combines their respective former CAM operations. Under the JV Agreement, the approval of the Merger by the Orbotech shareholders constitutes a change in control of Orbotech, which gives the JV Partner, based on procedures set forth in the JV Agreement, the right to exercise certain sell-buy rights that may require Orbotech to either purchase all outstanding shares in Frontline held by the JV Partner or to sell to the JV Partner all of its interest in Frontline, as the case may be, based on procedures set forth in the JV Agreement. Failure to consummate the Merger after receiving shareholder approval will not negate Orbotech’s obligations to perform its commitments under the JV Agreement. Accordingly, Orbotech may not continue to own any of its interest in, or may be required to acquire all of the JV Partner’s interest in, Frontline. For the year ended December 31, 2017, equity in earnings of Frontline were $4.5 million. Orbotech cannot presently predict the effects, if any, in the event Orbotech is obligated to consummate the sell-buy process with the JV Partner notwithstanding the failure of the Merger to close, but expects any effects would be material.

For more information about Frontline’s contribution to Orbotech’s financial results, see Note 2 of Orbotech’s audited financial statements for the year ended December 31, 2017 in its Annual Report on Form 20-F, incorporated by reference herein.

Risk Factors Relating to the Combined Company Following the Merger

There is the possibility that KLA-Tencor, following the Merger, may be unable to successfully integrate the business of Orbotech to realize the anticipated benefits of the Merger or to do so within the intended timeframe. KLA-Tencor may overestimate the synergies that will result from the Merger or underestimate the cost of implementing such synergies.

KLA-Tencor will be required to devote significant management attention and resources to integrating the businesses and operations of Orbotech with KLA-Tencor. Due to legal restrictions, KLA-Tencor and Orbotech have only been able to conduct limited planning regarding the integration of Orbotech into KLA-Tencor after completion of the Merger and KLA-Tencor has not yet determined the exact nature of how the businesses and operations of Orbotech will be run following the Merger. Potential difficulties KLA-Tencor may encounter as part of the integration process include the following:

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Any of these factors could adversely affect the ability of KLA-Tencor following the Merger to maintain relationships with customers, suppliers, employees and other constituencies or its ability to achieve the anticipated benefits of the Merger or could reduce the earnings or otherwise adversely affect the business and financial results of KLA-Tencor after the Merger. In addition, many of these factors will be outside of KLA-Tencor’s control and any one of them could result in increased costs, decreases in the amount of expected revenues and diversion of management’s time and energy, which could materially impact the business, financial condition and results of operations of the combined company. As such, KLA-Tencor may not realize the full benefits of the Merger (within the anticipated timeframe, or at all), including the expected combined annual cost run rate synergies of approximately $50 million within 24 months following the Closing. Even if the operations of KLA-Tencor’s and Orbotech’s businesses are integrated successfully, KLA-Tencor may not realize some or all of the anticipated benefits of the Merger.

The Merger may not be accretive and may cause dilution to KLA-Tencor’s earnings per share, which may harm the market price of KLA-Tencor common stock following the Merger.

There can be no assurance with respect to the timing and scope of the accretive effect of the Merger on KLA-Tencor’s future earnings per share or whether it will be accretive at all. KLA-Tencor following the Merger could encounter additional transaction and integration-related costs or other factors such as the failure to realize all of the benefits anticipated in the Merger or a downturn in its business. All of these factors could cause dilution to KLA-Tencor’s earnings per share following the Merger or decrease the expected accretive effect of the Merger and cause a decrease in the price of shares of KLA-Tencor common stock following the Merger.

After paying the Cash Consideration to the former Orbotech shareholders upon the Closing, KLA-Tencor will have a substantially lower balance of cash, cash equivalents and short-term investments and may have increased borrowings under its credit agreement.

At March 31, 2018, KLA-Tencor’s balance of cash, cash equivalents and marketable securities was $2.89 billion. KLA-Tencor currently expects to finance the cash portion of the purchase price of the Merger using its cash, cash equivalents, and short-term investments. However, if it deems it prudent at the time of the Closing, KLA-Tencor may finance a portion of the cash purchase price with proceeds available to it under its revolving line of credit.

KLA-Tencor following the Merger will incur significant transaction and integration related costs in connection with the Merger.

KLA-Tencor expects to incur costs associated with integrating the operations of Orbotech following the Closing. The amount of these costs could be material to the financial position and results of operations of KLA-Tencor following the Merger. A substantial amount of such expenses will be comprised of transaction costs related to the Merger, facilities and systems consolidation costs, and employee-related costs. KLA-Tencor will also incur fees and costs related to formulating integration plans and performing integration activities. Additional unanticipated costs may be incurred in the integration of the two companies’ businesses. The elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses, may not offset incremental transaction and other integration related costs in the near term.

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Orbotech’s counterparties may acquire certain rights upon the Merger, which could negatively affect KLA-Tencor following the Merger.

Orbotech is party to numerous contracts, agreements, licenses, permits, authorizations and other arrangements that contain provisions giving counterparties certain rights (including, in some cases, termination rights) in the event of an “assignment” of the agreement or a “change in control” of Orbotech or its subsidiaries. The definitions of “assignment” and “change in control” vary from contract to contract and, in some cases, the “assignment” or “change in control” provisions may be implicated by the Merger. If an “assignment” or “change in control” occurs, a counterparty may be permitted to terminate its contract with Orbotech.

Whether a counterparty would have cancellation rights in connection with the Merger depends upon the language and governing law of its agreement with Orbotech. Whether a counterparty exercises any cancellation rights it has would depend on, among other factors, such counterparty’s views with respect to the financial strength and business reputation of KLA-Tencor following the Merger and prevailing market conditions. Orbotech cannot presently predict the effects, if any, if the Merger is deemed to constitute a change in control under certain of its contracts and other arrangements, including the extent to which cancellation rights would be exercised, if at all, or the effect on KLA-Tencor’s financial condition, results of operations or cash flows following the Merger, but such effect could be material.

Uncertainties associated with the Merger may cause a loss of employees, including senior management and key employees and may otherwise materially adversely affect the future business and operations of KLA-Tencor following the Merger.

KLA-Tencor’s success following the Merger will depend upon the ability of KLA-Tencor to retain senior management and key employees of KLA-Tencor and Orbotech following the Merger. In some of the fields in which KLA-Tencor and Orbotech operate, there are only a limited number of people in the job market who possess the requisite skills, and it may be difficult for KLA-Tencor following the Merger to hire qualified personnel over time. KLA-Tencor following the Merger will operate in many geographic locations, where the labor markets, especially for engineers, are particularly competitive. Furthermore, certain unvested stock awards and benefits held by Orbotech employees may vest in connection with the Merger, and KLA-Tencor following the Merger may need to offer new awards and benefits to increase retention.

Current and prospective employees of KLA-Tencor and Orbotech may experience uncertainty about their roles with KLA-Tencor following the Merger. In addition, key employees may depart because of issues relating to the uncertainty and difficulty of integration or a desire not to remain with KLA-Tencor following the Merger. The loss of services of certain senior management or key employees of Orbotech or the inability to hire new personnel with the requisite skills could restrict the ability of KLA-Tencor following the Merger to develop new products or enhance existing products in a timely manner, to sell products to customers or to manage the business of KLA-Tencor effectively. Also, the business, financial condition and results of operations of KLA-Tencor following the Merger could be materially adversely affected by the loss of any of its key employees, by the failure of any key employee to perform in his or her current position, or by KLA-Tencor’s inability to attract and retain skilled employees, particularly engineers.

KLA-Tencor following the Merger will have a more complex organizational structure, which could result in unfavorable tax or other consequences and could have an adverse effect on its net income and financial condition.

KLA-Tencor following the Merger will operate legal entities in many countries around the world where it will conduct manufacturing, design and sales operations. In some countries, it will maintain multiple entities for tax or other purposes. Changes in tax laws, regulations, and related interpretations in the countries in which it operates may adversely affect its results of operations. KLA-Tencor following the Merger will have many entities globally and may have unsettled intercompany balances between some of these entities that could result, if changes in law, regulations or related interpretations occur, in adverse tax or other consequences affecting its capital structure, intercompany interest rates and legal structure.

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Future results of KLA-Tencor following the Merger may differ materially from the unaudited pro forma financial information and from the Orbotech Management Projections included in this proxy statement/prospectus.

The future results of KLA-Tencor following the Merger may be materially different from those shown in the unaudited pro forma financial information presented in this proxy statement/prospectus that shows only a combination of KLA-Tencor’s and Orbotech’s historical results. Furthermore, no assurances can be made regarding future events or that the assumptions made in preparing the Orbotech Management Projections (as defined in the section entitled “The Merger—Certain Projections of Orbotech”) will accurately reflect future conditions or that the projected results set forth in the Orbotech Management Projections will be realized, and actual results will likely differ, and may differ materially, from such projections, which could result in a material adverse effect on the business, financial condition, results of operations and prospects of KLA-Tencor following the Merger. In addition, KLA-Tencor expects to incur significant costs associated with completing the Merger and integrating the operations of Orbotech, and the exact magnitude of these costs is not yet known. Furthermore, these costs may decrease the amount of capital that could be used by KLA-Tencor for other purposes.

The business and operating results of KLA-Tencor following the Merger could be harmed by the highly cyclical nature of the semiconductor industry.

Orbotech and KLA-Tencor operate in the semiconductor industry. Historically, the semiconductor industry has been highly cyclical with recurring periods of diminished product demand. Significant downturns in the semiconductor industry are often experienced in connection with, or in anticipation of, excess manufacturing capacity worldwide, maturing product cycles and declines in general economic conditions. Even if demand for the products and solutions of KLA-Tencor following the Merger remains constant after the completion of the Merger, a slowdown in the semiconductor industry may create competitive pressures that can degrade pricing levels and reduce revenues of KLA-Tencor following the Merger. Any failure to expand in cycle upturns to meet customer demand and delivery requirements or contract in cycle downturns at a pace consistent with cycles in the industry could have an adverse effect on the business of KLA-Tencor following the Merger.

Other Risk Factors of KLA-Tencor and Orbotech

KLA-Tencor’s and Orbotech’s businesses are, and will continue to be, subject to the risks described above. In addition, KLA-Tencor is, and will continue to be, subject to the risks described in KLA-Tencor’s Annual Report on Form 10-K for the fiscal year ended June 30, 2017, as may be amended and updated by subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, all of which are filed or furnished with the SEC and incorporated by reference into this proxy statement/prospectus to the extent described in the section entitled “Where You Can Find More Information”. Orbotech is, and will continue to be, subject to the risks described in Orbotech’s Annual Report on Form 20-F for the fiscal year ended December 31, 2017, as may be amended and updated by subsequent Reports on Form 6-K, all of which are filed or furnished with the SEC and incorporated by reference into this proxy statement/prospectus to the extent described in the section entitled “Where You Can Find More Information”. For more information, see the section entitled “Where You Can Find More Information”.

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THE COMPANIES

KLA-Tencor Corporation

KLA-Tencor is a leading supplier of process control and yield management solutions for the semiconductor and related nanoelectronics industries. KLA-Tencor’s broad portfolio of defect inspection and metrology products, and related service, software and other offerings primarily supports chip manufacturers throughout the entire semiconductor fabrication process, from research and development to final volume production. KLA-Tencor provides leading-edge equipment, software and support that enable IC manufacturers to identify, resolve and manage significant advanced technology manufacturing process challenges and obtain higher finished product yields at lower overall cost. In addition to serving the semiconductor industry, KLA-Tencor also provides a range of technology solutions to a number of other high technology industries, including the LED and data storage industries, as well as general materials research.

KLA-Tencor’s common stock is traded on NASDAQ under the symbol “KLAC.”

The principal executive offices of KLA-Tencor are located at One Technology Drive, Milpitas, California, 95035, and its telephone number is (408) 875-3000.

Orbotech Ltd.

Orbotech is a global innovator and supplier of enabling solutions used to manufacture the world’s most sophisticated consumer and industrial electronic products and is part of a select group of companies whose technology is literally driving the future of electronics. Orbotech’s core business lies in enabling electronic device manufacturers to inspect, test and measure printed circuit boards (“PCB”s) and flat panel displays (“FPD”s) to verify their quality (‘reading’); pattern the desired electronic circuitry on the relevant substrate and perform three-dimensional shaping of metalized circuits on multiple surfaces (‘writing’); and utilize advanced vacuum deposition and etching processes in semiconductor devices (“SD”) and semiconductor manufacturing and to perform laser drilling of electronic substrates (‘connecting’). Orbotech refers to this ‘reading’, ‘writing’ and ‘connecting’ as enabling the ‘Language of Electronics’.

Orbotech shares are traded on NASDAQ under the symbol “ORBK”.

The principal executive offices of Orbotech are located at 7 Sanhedrin Boulevard, North Industrial Zone, Yavne 8110101 Israel, and its telephone number is +972-8-9423533.

Tiburon Merger Sub Technologies Ltd.

Merger Sub, a wholly-owned subsidiary of KLA-Tencor, is a company organized under the laws of the State of Israel that was formed on March 15, 2018 for the sole purpose of effecting the Merger. In the Merger, Merger Sub will be merged with and into Orbotech, with Orbotech surviving as a wholly owned subsidiary of KLA-Tencor.

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THE ORBOTECH EXTRAORDINARY GENERAL MEETING

This proxy statement/prospectus is being made available to the Orbotech shareholders as part of a solicitation of proxies by the Orbotech Board for use at the meeting to be held at the time and place specified below, and at any properly convened meeting following any adjournment or postponement thereof. This proxy statement/prospectus provides Orbotech shareholders with the information they need to know to be able to vote or instruct their vote to be cast at the meeting.

Date, Time and Place

The meeting will be held on Thursday, July 12, 2018 at 10:00 a.m., Israel time, at Orbotech’s principal executive offices at 7 Sanhedrin Boulevard, North Industrial Zone, Yavne, Israel.

Attendance at the meeting is limited to holders of record of Orbotech shares and holders of valid proxies. If you plan to attend the meeting, to gain access to the meeting we ask that you bring with you some form of personal identification and verification of your status as a shareholder as of the close of trading on June 6, 2018, the record date for the meeting. If you are a representative of an institutional investor, please bring evidence demonstrating your representative capacity for such entity to be verified against our list of shareholders as of the close of trading on the record date for the meeting. In addition, if your Orbotech shares are held in the name of a broker, bank or other nominee, you will need a valid legal proxy from such entity evidencing your authority to vote Orbotech shares that the institution or other nominee held for your account as of the close of trading on the record date for the meeting. You must contact your broker, bank or other nominee directly in advance of the meeting to obtain a “legal” proxy.

Purpose of the Meeting

The meeting is being held to consider and vote the following item:

A copy of the Merger Agreement is attached as Annex A to this proxy statement/prospectus and incorporated herein by reference. The text of the proposed resolution to approve the Merger Proposal is set out below (see the section entitled “The Orbotech Proposal—Approval and Adoption of the Merger Proposal”).

Recommendation of the Orbotech Board

After careful consideration, the Orbotech Board has (i) determined that the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, and assuming, among other things, the accuracy of the representations and warranties of KLA-Tencor and Merger Sub in the Merger Agreement, no reasonable concern exists that the surviving company, as a result of the Merger, will be unable to fulfill the obligations of Orbotech to its creditors; (ii) approved the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger; and (iii) resolved to direct that the Merger Agreement be submitted to the shareholders of Orbotech for approval and adoption and recommend that the shareholders of Orbotech vote in favor of the approval and adoption of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement, all upon the terms and

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subject to the conditions set forth in the Merger Agreement. Accordingly, the Orbotech Board unanimously recommends that Orbotech shareholders vote “FOR” the Merger Proposal. For a discussion of the factors that the Orbotech Board considered in determining to recommend the approval and adoption of the Merger Proposal, see the section entitled “The Merger—Orbotech’s Reasons for the Merger; Recommendation of the Orbotech Board”.

Record Date and Orbotech Shareholders Entitled to Vote

Only Orbotech shareholders with Orbotech shares registered in his, her, its or their name or names as of the close of trading on June 6, 2018, the record date for the meeting (“Orbotech shareholders of record”), are entitled to vote the Orbotech shares they held on the record date at the meeting. As of the close of trading on the record date, 48,569,735 Orbotech shares were outstanding, each of which is entitled to one vote upon each of the matters presented at the meeting.

Quorum

No less than two Orbotech shareholders of record present in person or by proxy, and holding or representing between them Orbotech shares conferring in the aggregate more than 50% of the voting rights of Orbotech, shall constitute a quorum at the meeting. If within one-half hour from the time appointed for the holding of the meeting a quorum is not present, the meeting shall be adjourned to July 23, 2018 at the same time and place. At any such adjourned meeting, if a quorum is not present within one-half hour from the specified time, any Orbotech shareholders of record present in person or by proxy shall constitute a quorum even if they hold or represent Orbotech shares conferring 50% or less of the voting rights of Orbotech.

In determining whether there is a quorum for the meeting and whether the required number of votes for the approval of the Merger Proposal has been cast, Orbotech shares subject to broker non-votes and abstentions are counted for purposes of determining whether there is a quorum for the meeting but, with regard to the Merger Proposal, are not counted as having been voted in respect thereof. Broker non-votes are votes that brokers holding Orbotech shares of record for their clients are, pursuant to applicable stock exchange or other rules, precluded from casting in respect of certain non-routine proposals because such brokers have not received specific instructions from their clients as to the manner in which such Orbotech shares should be voted on those proposals and as to which the brokers have advised Orbotech that, accordingly, they lack voting authority.

Vote Required at the Meeting

The affirmative vote of a simple majority of the voting rights of Orbotech represented and voting thereon at the meeting is necessary for the approval of the Merger Proposal, provided that such majority includes at least a majority of the votes cast by Orbotech shareholders that are not KLA-Tencor, Merger Sub or a KLA Related Person (as defined below), who are present and voting (abstentions are disregarded) (the “Merger Majority”).

Pursuant to the ICL, each Orbotech shareholder voting on the Merger Proposal is required to inform Orbotech as detailed below prior to voting at the meeting if the shareholder is any of KLA-Tencor, Merger Sub, or a KLA Related Person and to indicate such matter in the appropriate place in the enclosed proxy, as further detailed below. A “KLA Related Person” is (a) a person holding, directly or indirectly, either (i) 25% or more of the voting rights of KLA-Tencor or Merger Sub, or (ii) the right to appoint 25% or more of the directors of KLA-Tencor or Merger Sub, or (b) one of such person’s spouse, siblings, parents, grandparents, descendants, spouse’s descendants, siblings or parents or the spouse of any such person, or a corporation controlled by any one or more of such persons or by KLA-Tencor or Merger Sub.

Special voting instructions under the ICL. In order to provide for proper counting of your shareholder vote, in the enclosed proxy you are required to indicate whether or not you are:

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Based on information provided by KLA-Tencor and Merger Sub to Orbotech, as of the date of this proxy statement/prospectus, Orbotech is not aware of any holdings of Orbotech shares by KLA-Tencor, Merger Sub or any KLA Related Persons, and therefore believes that all of its shareholders should mark “NO” in the appropriate place on the enclosed proxy (or in their electronic submission).

Abstentions and broker non-votes will not be treated as having been voted in respect of the Merger Proposal. Consequently, assuming a quorum is present at the meeting, broker non-votes and abstentions will have no effect on the voting with respect to the Merger Proposal.

Orbotech is unaware at this time of any other matters that will come before the meeting. If any other matters properly come before the meeting, it is the intention of the persons designated as proxies to vote in accordance with their judgment on such matters. Orbotech shares represented by executed and unrevoked proxies will be voted in accordance with such judgment.

Voting Procedures

Whether or not you plan to attend the meeting and regardless of the number of Orbotech shares you own, your careful consideration of, and vote on, the Merger Proposal is important and we encourage you to vote promptly.

To ensure that your Orbotech shares are voted at the meeting, we recommend that you provide voting instructions promptly by proxy, even if you plan to attend the meeting in person, by marking, dating and signing the proxy and returning it by mail in the enclosed postage-paid envelope. If you are mailing your proxy to an address outside your country of residence, you should add any necessary postage to the enclosed envelope to ensure delivery. In order to ensure that your vote is received on or prior to the date of the meeting, we recommend that your proxy be returned to us by overnight mail.

If you are an Orbotech shareholder with Orbotech shares held in “street name”, which means your Orbotech shares are held in an account at a broker, bank or other nominee, you must follow the instructions from your broker, bank or other nominee in order to vote. Without following those instructions, your Orbotech shares will not be voted.

YOU SHOULD NOT SEND IN YOUR SHARE CERTIFICATE(S) WITH YOUR PROXY. A letter of transmittal with instructions for the surrender of your certificates representing any Orbotech shares will be mailed to Orbotech shareholders if the Merger is completed.

For additional questions about the Merger, assistance in submitting proxies or voting Orbotech shares, or to request additional copies of this proxy statement/prospectus or the enclosed proxy, please contact Okapi Partners LLC, which is acting as Orbotech’s proxy solicitor in connection with the Merger, toll free at +1 (855) 305-0857. Brokers, banks and other nominees may call collect at +1 (212) 297-0720.

How Proxies Are Voted

If you properly execute, date and return the form of proxy to Orbotech prior to the meeting, each person named as proxy will follow your instructions. If you properly execute and return the form of proxy to Orbotech prior to the meeting without indicating how you intend to vote with respect to the Merger Proposal, the Orbotech shares represented by the proxy will be counted as being present for quorum purposes, but not be treated as having been voted in respect of the Merger Proposal and will have no effect on the voting with respect to the Merger Proposal.

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Revocation of Proxies

If you are an Orbotech shareholder of record, once you have given your proxy votes for the matters before our Orbotech shareholders as described in this proxy statement/prospectus, you may revoke such vote with respect to the meeting at any time prior to the time it is voted, (1) by filing with Orbotech an instrument revoking such proxy; (2) by completing, signing, dating and returning a new proxy bearing a later date by mail to Orbotech; or (3) by attending the meeting and voting in person.

Merely attending the meeting will not, by itself, revoke a proxy. Please note that if you want to revoke your proxies by sending a new proxy or an instrument revoking such proxy to Orbotech, you should ensure that you send your new proxy or instrument revoking such proxy in sufficient time for it to be received by Orbotech prior to the meeting. Please note, however, that only your last-dated proxy will count. If you are an Orbotech shareholder of record, you may obtain a new proxy by contacting Okapi Partners LLC at 1212 Avenue of the Americas, 24th Floor, New York, NY, 10036, or by telephone at +1 (212) 297-0720.

If you are an Orbotech shareholder with Orbotech shares held in “street name”, you should follow the instructions of your broker regarding the revocation of proxies. If your broker allows you to submit a proxy via the internet or by telephone, you may be able to change your vote by submitting a new proxy via the internet or by telephone or by mail. Please note that if your Orbotech shares are held in the name of a broker, you must obtain and bring to the meeting a proxy issued in your name from the broker to be able to vote at the meeting.

Voting in Person

Attendance at the meeting is limited to Orbotech shareholders of record and holders of valid proxies. If you plan to attend the meeting, to gain access to the meeting we ask that you bring with you some form of personal identification and verification of your status as a shareholder as of the close of trading on June 6, 2018, the record date for the meeting. If you are a representative of an institutional investor, please bring evidence demonstrating your representative capacity for such entity to be verified against our list of shareholders as of the close of trading on the record date for the meeting. In addition, if your Orbotech shares are held in the name of a broker, bank or other nominee, you will need a valid “legal” proxy from such entity evidencing your authority to vote Orbotech shares that the institution or other nominee held for your account as of the close of trading on the record date for the meeting. You must contact your broker, bank or other nominee directly in advance of the meeting to obtain a valid “legal” proxy.

Even if you plan to attend the meeting in person, we encourage you to vote your Orbotech shares by proxy so that your vote will be counted if you later decide not to attend the meeting.

Appraisal Rights

Under Israeli law, holders of Orbotech shares are not entitled to statutory appraisal rights in connection with the Merger.

Solicitation of Proxies

Proxies for use at the meeting are being solicited by the Orbotech Board. Only Orbotech shareholders of record at the close of trading on June 6, 2018, the record date, will be entitled to vote at the meeting or at any adjournment thereof. Proxies are expected to be mailed to shareholders on or about June 15, 2018, and their return will be solicited chiefly by mail; however, certain officers, directors, employees and agents of Orbotech, none of whom will receive additional compensation therefor, may solicit proxies by telephone, facsimile transmission, electronic mail or other personal contact. In addition, Orbotech has retained Okapi Partners LLC to solicit Orbotech shareholder proxies at a total cost to Orbotech of approximately $25,000, plus reimbursement of reasonable out-of-pocket expenses and indemnification of losses in certain circumstances.

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Adjournments and Postponements

If within one-half hour from the time appointed for the holding of the meeting a quorum is not present, the meeting shall be adjourned to July 23, 2018, at the same time and place. At any such adjourned meeting, if a quorum is not present within one-half hour from the specified time, any shareholders present in person or by proxy shall constitute a quorum even if they hold or represent Orbotech shares conferring 50% or less of the voting rights of Orbotech.

Orbotech Shares Held by Orbotech Directors and Executive Officers

As of the close of business on June 6, 2018, the record date for the meeting, Orbotech’s directors and executive officers beneficially owned, in the aggregate, 4,252,546 Orbotech shares, or collectively approximately 8.74% of the outstanding Orbotech shares. For more information, see the section entitled “Security Ownership of Certain Beneficial Owners and Management of Orbotech”. Orbotech’s directors and executive officers have interests in the Merger that may be different from, or in addition to, the interests of the Orbotech shareholders generally. For more information, please see the section entitled “The Merger—Interests of the Orbotech Directors and Executive Officers in the Merger”.

Assistance

If you need assistance in completing your proxy or have questions regarding the meeting, please contact Okapi Partners LLC, which is acting as Orbotech’s proxy solicitor in connection with the Merger, toll free at +1 (855) 305-0857 or via email at info@okapipartners.com. Brokers, banks and other nominees may call collect at +1 (212) 297-0720.

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THE ORBOTECH PROPOSAL

APPROVAL AND ADOPTION OF THE MERGER PROPOSAL

As discussed elsewhere in this proxy statement/prospectus, Orbotech shareholders will consider and vote on the Merger Proposal, which consists of a proposal for Orbotech shareholders to approve and adopt (i) the Merger Agreement; (ii) the Merger on the terms and subject to the conditions set forth in the Merger Agreement and in accordance with the provisions of Sections 314-327 of the ICL, following which Merger Sub will cease to exist, and Orbotech will become a wholly owned subsidiary of KLA-Tencor; and (iii) all other transactions contemplated by the Merger Agreement, all upon the terms and subject to the conditions set forth in the Merger Agreement.

You are urged to carefully read this proxy statement/prospectus in its entirety for more detailed information concerning the Merger and the Merger Agreement, including the information set forth under the sections entitled “The Merger” and “The Merger Agreement”. A copy of the Merger Agreement is attached as Annex A to this proxy statement/prospectus and incorporated by reference herein. You are urged to read the Merger Agreement carefully and in its entirety.

It is proposed that at the meeting the following resolution is adopted to approve the Merger Proposal:

“RESOLVED, that (i) the agreement and plan of merger dated March 18, 2018, as amended, among KLA-Tencor, Merger Sub and Orbotech; (ii) the merger of Merger Sub with and into Orbotech on the terms and subject to the conditions set forth in the Merger Agreement and in accordance with the provisions of Sections 314-327 of the ICL, following which Merger Sub will cease to exist, and Orbotech will become a wholly owned subsidiary of KLA-Tencor; and (iii) all other transactions contemplated by the Merger Agreement, all upon the terms and subject to the conditions set forth in the Merger Agreement be, and each hereby is, approved and adopted in all respects.”

The Orbotech Board unanimously recommends a vote “FOR” the Merger Proposal and the above resolution by the Orbotech shareholders.

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THE MERGER

The following is a discussion of the Merger and the material terms of the Merger Agreement between KLA-Tencor and Orbotech. You are urged to read the Merger Agreement carefully and in its entirety, a copy of which is attached as Annex A to this proxy statement/prospectus and incorporated by reference herein.

Effects of the Merger

Subject to the terms and conditions of the Merger Agreement and the applicable provisions of Sections 314-327 of the ICL, at the Effective Time (as defined in the section entitled “The Merger Agreement—Closing and Effective Time”), Merger Sub will be merged with and into Orbotech, with (a) Orbotech surviving the Merger as a wholly owned subsidiary of KLA-Tencor; (b) all the properties, rights, privileges, powers and franchises of Orbotech and Merger Sub shall vest in Orbotech (as the surviving company); (c) all debts, liabilities and duties of Orbotech and Merger Sub shall become the debts, liabilities and duties of the Orbotech (as the surviving company); and (d) all the rights, privileges, immunities, powers and franchises of Orbotech (as the surviving company) shall continue unaffected by the Merger in accordance with the ICL.

At the Effective Time, by virtue of the Merger, each Orbotech share issued and outstanding immediately prior to the Effective Time, other than the Excluded Shares, will be cancelled and converted into the right to receive (1) cash, without interest, in an amount equal to $38.86, and (2) 0.25 of a share of KLA-Tencor common stock, subject to the conditions and restrictions set forth in the Merger Agreement.

Background of the Merger

Orbotech’s management and the Orbotech Board have consistently reviewed growth options available to Orbotech and challenges related thereto, including organic growth of Orbotech’s core businesses through product and customer initiatives, and growth through acquisitions and joint ventures in particular geographies. In addition, from time to time, Orbotech has received oral indications of interest from third parties that never progressed past an initial discussion. One of those parties was KLA-Tencor. In the Spring of 2017, KLA-Tencor approached Orbotech about a potential acquisition, but Orbotech’s management believed that it was premature to engage in any such discussions in view of Orbotech’s share price, which Orbotech’s Active Chairman and senior management believed undervalued Orbotech in light of the positive business outlook at that time. A potential purchase price was not discussed at that time. In August of 2017, Orbotech and KLA-Tencor agreed to discuss some matters related to their respective customer service businesses and entered into a mutual non-disclosure agreement on September 11, 2017 to cover such discussions, which then occurred later in the same month. An acquisition transaction was not discussed during these conversations.

On November 6, 2017, Amichai Steimberg, the President and Chief Operating Officer of Orbotech, was approached by Bren Higgins, the Chief Financial Officer of KLA-Tencor, regarding KLA-Tencor’s potential interest in pursuing a strategic transaction. In the absence of a formal proposal from KLA-Tencor, Orbotech’s management sought to better assess the legitimacy of KLA-Tencor’s interest before informing the Board of such inquiry. In November and early December of 2017, representatives of Orbotech and KLA-Tencor negotiated a new mutual confidentiality agreement in order to facilitate the exchange of certain non-public and confidential information between the parties and, on December 14, 2017, Orbotech and KLA-Tencor executed a new mutual confidentiality agreement.

On December 14, 2017, at a previously scheduled meeting of the audit committee of the Orbotech Board, the committee discussed the exchange of non-public information with KLA-Tencor for purposes of evaluating a potential strategic transaction and the process by which Orbotech would continue discussions with KLA-Tencor. Orbotech’s management stated that a proposed purchase price had not been discussed and that KLA-Tencor had requested an initial in-person due diligence meeting to cover fundamental business topics to determine whether there was a mutual basis to continue discussions, including on terms such as price, structure and timing.

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The initial in-person due diligence session was held on January 17 and 18, 2018 in New York City. Mr. Steimberg, Alon Rozner, Chief Financial Officer of Orbotech, and Lior Maayan, Corporate Vice President, Business Development and Chief Marketing Officer of Orbotech, attended from Orbotech. Mr. Higgins, David Fisher, Senior Vice President of Corporate Business Development, and Michael Kirk, Executive Vice President, attended from KLA-Tencor. These representatives presented reciprocal information regarding their respective businesses for preliminary due diligence purposes and discussed certain high level terms of a potential merger other than price.

On February 8, 2018, KLA-Tencor delivered a letter to Orbotech containing a non-binding proposal for a transaction in which each Orbotech share would be exchanged for $36.00 in cash and 0.244 shares of KLA-Tencor common stock, representing, based on market closing prices as of February 8, 2018, a nominal purchase price of approximately $60 per Orbotech share, a 1-day implied premium of 29% and an implied premium of 15% to the 30-day average closing price. The proposal also indicated that, in connection with the announcement of any transaction, KLA-Tencor would announce $50 million of run-rate synergies, as well as a $2 billion buyback of KLA-Tencor common stock following the closing of the transaction. The proposal was subject to the completion of confirmatory due diligence and negotiation of definitive agreements. In addition, considering the significant resources KLA-Tencor was prepared to invest in expediently conducting due diligence, KLA-Tencor requested that Orbotech sign an exclusivity agreement as a condition to proceeding with discussions. The proposal was scheduled to expire at 5 p.m., Pacific time, on Friday, February 16, 2018.

On February 14, 2018, at a regularly scheduled meeting, the Orbotech Board considered the legal and financial aspects of KLA-Tencor’s proposal and evaluated proposed responses. At this meeting, Cravath, Swaine & Moore LLP (“Cravath”), Orbotech’s U.S. legal advisors, and Tulchinsky, Stern, Marciano, Cohen, Levitski & Co. (“Tulchinsky”), Orbotech’s Israeli legal advisors, advised the members of the Orbotech Board as to their legal duties in connection with KLA-Tencor’s proposal. Representatives of Barclays Capital Inc. (“Barclays”) then reviewed its preliminary financial analysis of KLA-Tencor’s proposal and discussed certain considerations relating to potential responses. Orbotech and its advisors also discussed the possible benefits and strategic fit of a combination with KLA-Tencor, as well as KLA-Tencor’s stated intention to maintain Orbotech’s operations in the State of Israel and KLA-Tencor’s own long-standing presence and infrastructure in Israel. At the meeting, Orbotech’s senior management, including Yochai Richter, Active Chairman of the Orbotech Board, presented certain long-term risks to Orbotech, particularly with regard to China, and discussed the importance of scale to compete effectively.

With the assistance of representatives of Barclays and input from management on overlap and strategic fit, the Orbotech Board also discussed a list of other potential strategic partners for Orbotech. Based on a variety of factors, including size, potential strategic fit and capacity to complete a transaction, the Orbotech Board identified three primary companies other than KLA-Tencor, as well as several additional entities based in China, that it believed would potentially have some interest in a strategic transaction with Orbotech. However, due to a number of factors, including strategic fit and regulatory uncertainty with respect to such parties’ ability to consummate a potential transaction, the Orbotech Board determined that those companies were either unlikely to have any serious interest in an acquisition of Orbotech at that time or otherwise would pose a greater risk of completion than a potential transaction with KLA-Tencor. Following this discussion, the Orbotech Board determined that it would be willing to proceed with exclusive negotiations with KLA-Tencor if KLA-Tencor were to first agree to an increased purchase price per share, either based on an all cash or a mixed cash and stock offer. At the meeting, the Orbotech Board also authorized management to negotiate and enter into an engagement letter with Barclays, and Orbotech and Barclays subsequently executed such engagement letter on February 22, 2018.

Also at the February 14, 2018 meeting, in view of the Orbotech Board’s desire to announce the transaction by the end of March, the Orbotech Board formed a transaction committee consisting of Mr. Richter, Michael Anghel, Dan Falk, Joseph Tenne and Arie Weisberg to provide real-time guidance to management in negotiating the proposed transaction. On February 15, 2018, the transaction committee met to review Orbotech’s response to KLA-Tencor.

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On February 16, 2018, based on the authorization of the Orbotech Board, Mr. Richter and Mr. Steimberg called Rick Wallace, Chief Executive Officer of KLA-Tencor, and Mr. Higgins to indicate that, while Orbotech would be prepared to proceed with negotiation of a strategic transaction, it would only be prepared to do so at a price of $68.75 per Orbotech share, which could be delivered as either an all cash or a mixed cash and stock offer, at KLA-Tencor’s discretion. Messrs. Richter and Steimberg indicated that Orbotech would be able to move quickly to announce the transaction prior to the Passover holiday, which began on March 30, 2018, if the parties could reach an agreed price.

On February 18, 2018, KLA-Tencor delivered an updated offer letter containing a revised non-binding proposal to acquire Orbotech for an implied purchase price of $63.50 per Orbotech share, with $38.10 (60% of the proposed consideration) in cash and the remainder in shares of KLA-Tencor common stock, representing, based on market closing prices as of February 18, 2018, a 1-day implied premium of 19% and an implied premium of 23% to the 30-day average closing price. At the time, KLA-Tencor indicated that this was their best offer and that, if it was not acceptable, the parties could cease their discussions until a later date.

On February 20, 2018, Orbotech’s transaction committee convened to discuss the revised offer from KLA-Tencor and possible responses. Representatives of Barclays reviewed its preliminary financial analysis of KLA-Tencor’s revised proposal and discussed certain considerations relating to potential responses. Following discussion, the transaction committee instructed management to continue negotiations with KLA-Tencor to determine whether additional value for Orbotech’s shareholders was available from KLA-Tencor.

Later on February 20, 2018, Mr. Steimberg called Mr. Higgins to discuss KLA-Tencor’s latest proposal. In the course of that discussion, Messrs. Steimberg and Higgins reached a preliminary, non-binding understanding that, subject to confirmatory due diligence, each of them would be willing to recommend to their respective senior management and board that the parties move forward in negotiating a transaction in which each Orbotech share would be exchanged for $38.86 in cash and 0.25 of a share of KLA-Tencor common stock, which at the time, based on market closing prices as of February 20, 2018, provided an implied value of approximately $66.50 per Orbotech share and represented a 1-day implied premium of 23% and an implied premium of 29% to the 30-day average closing price. Later on February 20, 2018, KLA-Tencor reaffirmed this understanding in an updated non-binding proposal letter delivered to the Orbotech Board reflecting this consideration and indicating that KLA-Tencor would be prepared to move forward quickly to announce a transaction by March 26, 2018, subject to prompt agreement on terms of an exclusivity agreement with Orbotech.

On February 21, 2018, the Orbotech Board met to consider KLA-Tencor’s latest proposal with the assistance of Barclays, Cravath and Tulchinsky. At this meeting, representatives of Barclays reviewed its preliminary financial analysis of KLA-Tencor’s latest revised proposal and each of Cravath and Tulchinsky reminded the Orbotech Board of their legal duties in evaluating the proposed transaction with KLA-Tencor. Following this discussion, the Orbotech Board authorized management to proceed with due diligence and to enter into exclusive negotiations with KLA-Tencor until March 26, 2018, on the basis of the consideration proposed in KLA-Tencor’s February 20, 2018 offer.

On February 22, 2018, Messrs. Levy, Steimberg, Rozner and Maayan from Orbotech’s management team and Messrs. Higgins and Fisher and Ms. Teri Little, Chief Legal Officer of KLA-Tencor, from KLA-Tencor’s management team met via video conference to discuss the timeline for a potential transaction and process to announcing a deal, which included promptly commencing in-person due diligence, together with concurrent meetings between the legal advisors to discuss draft definitive transaction agreements.

On February 24, 2018, Orbotech and KLA-Tencor signed an exclusivity agreement effective until March 26, 2018.

Shortly thereafter, Orbotech and KLA-Tencor exchanged initial due diligence request lists for various information and documents with respect to each party, and the parties opened their respective due diligence data

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rooms on February 26, 2018 and March 1, 2018, respectively. From such time until the execution of the Merger Agreement, Orbotech, KLA-Tencor and certain of their respective advisors and other representatives conducted due diligence with respect to each other.

On March 2, 2018, KLA-Tencor’s legal advisors delivered an initial draft of the Merger Agreement to Orbotech and its legal advisors. Beginning on March 4, 2018 and continuing through March 7, 2018, representatives of each of Orbotech’s senior management and certain of its advisors commenced reciprocal in-person due diligence meetings with representatives of each of KLA-Tencor’s senior management and certain of its advisors, including Wilson Sonsini Goodrich & Rosati, Professional Corporation (“WSGR”), its legal advisor, in Palo Alto, California. The due diligence meetings with respect to Orbotech focused on Orbotech’s operating plans and strategy, product development efforts, employee compensation and benefits, financial position and liabilities and certain legal diligence matters. The due diligence meetings with respect to KLA-Tencor focused on KLA-Tencor’s operating plans and strategy, technology, financial recordkeeping and accounting practices and certain legal diligence matters.

On March 6, 2018, Mr. Richter met Mr. Wallace separately in Palo Alto, California to further discuss the transaction. Also on March 6, 2018, Orbotech’s management team met with Orbotech’s transaction committee via telephone conference to discuss the current status of negotiations and due diligence.

On March 7, 2018, representatives from Orbotech, KLA-Tencor, Cravath and WSGR met to discuss Orbotech’s initial feedback in its mark-up of the draft of the Merger Agreement provided to KLA-Tencor and WSGR on March 6, 2018. In these discussions, representatives of each of Orbotech and KLA-Tencor indicated certain key issues for each party. For Orbotech, these related to KLA-Tencor’s commitment to maintain Orbotech’s operations in the State of Israel and to the exclusion of certain publicly disclosed matters from consideration of a “material adverse effect.” For KLA-Tencor, these related to the treatment of outstanding Orbotech equity awards and certain retention, interim period and post-closing employee compensation and benefits matters and to the obligations that may be imposed on KLA-Tencor to seek and obtain regulatory approval for the transaction. Representatives of each party’s management then left and the parties’ legal advisors and members of KLA-Tencor’s internal legal team continued to discuss various additional issues on the draft Merger Agreement, including certain deal protection provisions, issues related to closing conditions and termination rights and the general scope of the Merger Agreement’s representations and covenants.

From March 7 to 9, 2018, the parties met to discuss the various open issues in the draft of the Merger Agreement.

On March 7 and 8, 2018, representatives of Orbotech and KLA-Tencor also discussed a substantially inaccurate speculative news article that was published in Israel on March 8, 2018 relating to a potential change of control of Orbotech. Following such article, on March 8, 2018, Orbotech shares closed at a price of $58.83 per share, which represented a five percent increase from the prior’s day close of $56.25 per share. Although Orbotech did not comment on the article, the parties agreed to proceed expediently to finalizing their negotiations if the remaining open issues could be addressed. Considering the limited amount of remaining open issues, representatives of Orbotech and KLA-Tencor also agreed to target March 18, 2018 for the execution of the Merger Agreement with the goal of announcing the transaction before market open in New York on March 19, 2018. In addition, representatives of Orbotech agreed to expediently prepare Orbotech’s confidential disclosure letter with respect to the Merger Agreement.

On March 9, 2018, representatives of Cravath held a conference call with representatives of WSGR to discuss various open issues related to the Merger Agreement based on a revised mark-up of the Merger Agreement delivered by WSGR on March 8, 2018. Also on March 9, 2018, Mr. Steimberg and representatives of Cravath met with Mr. Higgins, Ms. Little, Mr. Fisher, Jeffrey Cannon, Associate General Counsel, and representatives of WSGR to address the remaining open issues. The parties also reiterated a mutual desire to announce the transaction on March 19, 2018. On March 11, 2018, Cravath delivered a revised mark-up of the Merger Agreement to KLA-Tencor and WSGR.

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On March 13, 2018, Orbotech’s transaction committee met and reviewed the status of the negotiations with KLA-Tencor with representatives of each of Orbotech’s management, Cravath, Tulchinsky and Barclays. Representatives of each of Cravath and Tulchinsky reviewed the principal terms of and open issues in the draft Merger Agreement, with a particular focus on KLA-Tencor’s proposals for its efforts obligations and closing conditions relating to antitrust approval, the proposed approach on the definition of “material adverse effect” and related closing conditions and certain deal protection matters, as well as the then-current proposals relating to employee retention and interim period equity awards and compensation. Following such discussion, the transaction committee authorized management to proceed with its final proposals to KLA-Tencor on the key remaining open issues. At such time, the transaction committee also authorized the engagement of Goldman Sachs Israel LLC (“Goldman Sachs”) to provide its views to the transaction committee with respect to the proposed transaction.

Following such transaction committee meeting, on March 14, 2018, representatives of WSGR delivered a revised draft of the Merger Agreement to the legal representatives of Orbotech, reflecting KLA-Tencor’s final proposals on certain outstanding open issues, including a further limitation to the exclusion of certain publicly disclosed matters from the “material adverse effect” definition under discussion between the parties. From March 14 to 18, 2018, representatives of each of the parties’ legal and financial advisors extensively discussed this proposed limitation, together with other open issues on the draft Merger Agreement, with revised drafts of the Merger Agreement exchanged on March 16 and 18, 2018.

On March 17, 2018, representatives of Goldman Sachs delivered to Orbotech’s transaction committee, at an in-person meeting in Tel Aviv also attended by representatives of Cravath and Tulchinsky, its assessment of the proposed transaction, including a further assessment of other potential strategic partners. Following such discussion, the transaction committee again concluded that the proposed transaction with KLA-Tencor represented the best strategic option for Orbotech and directed Orbotech’s management to proceed with a meeting of the full Orbotech Board scheduled for March 18, 2018.

On March 18, 2018, the Orbotech Board met to review the potential transaction, which, based on market closing prices as of March 16, 2018, provided an implied value of approximately $69.02 per Orbotech share and represented a 1-day implied premium of 15% and an implied premium of 23% to the 30-day average closing price. At such meeting, the Orbotech Board reviewed the potential personal interests of Orbotech’s directors and executive officers in the Merger and the transactions contemplated thereby and representatives of Cravath and Tulchinsky reviewed the terms of the Merger Agreement and updated the Orbotech Board regarding the changes from the terms discussed at the prior meetings of the Orbotech Board and the transaction committee. Further, the representatives of each of Cravath and Tulchinsky reviewed the Orbotech Board’s legal duties in evaluating the proposed transaction with the Orbotech Board, including with respect to potential personal interests of directors and executive officers in the Merger and the transactions contemplated thereby as a result of proposed retention arrangements and other post-closing compensation and benefits matters. In particular, the Orbotech Board considered that there were no retention arrangements then in place for Orbotech’s senior management and in light of, among other things, the severance and additional benefits that would become available to such officers pursuant to their existing arrangements following a successful shareholder meeting to approve the Merger, considered that retention arrangements for such individuals would need to be determined by KLA-Tencor and Orbotech and entered into in advance of such shareholder meeting. At the request of the Orbotech Board, representatives of Barclays then reviewed its financial analyses of the proposed transaction. Following such review, representatives of Barclays delivered its oral opinion (which was subsequently confirmed in writing as of March 18, 2018) that, as of such date and based upon and subject to the qualifications, limitations and assumptions stated in its opinion, the consideration to be offered to the holders of Orbotech shares (other than holders of the Excluded Shares (as defined in “The Merger— Merger Consideration”)) in the proposed transaction was fair, from a financial point of view, to such holders. The full text of Barclay’s written opinion dated March 18, 2018, which sets forth, among other things, the assumptions made, procedures followed, factors considered and the limitations on the review undertaken by Barclays in rendering its opinion, is attached to this proxy statement/prospectus as Annex B. Representatives of Orbotech’s management then discussed the due

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diligence conducted with respect to KLA-Tencor. Finally, representatives of Kesselman & Kesselman, Certified Public Accountants (Israel), an independent registered public accounting firm and a member firm of PricewaterhouseCoopers International Limited (“Kesselman”), Orbotech’s auditor, presented certain accounting analyses related to the transaction.

Following the presentations by Cravath, Tulchinsky, Barclays, Orbotech’s management and Kesselman, the Orbotech Board discussed the proposed transaction in more detail. In considering the Merger Agreement and the advisability of the Merger and the other transactions, the Orbotech Board considered a number of factors as described under “The Merger—Orbotech’s Reasons for the Merger.”

Taking into account these considerations, including the advice received from its management and financial and legal advisors and after further concerted deliberation, the Orbotech Board unanimously (1) determined that the Merger Agreement and the proposed transactions, including the Merger, are advisable, that the Merger Agreement and the proposed transactions, including the Merger, are fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, no reasonable concern exists that the merged company will be unable to fulfill the obligations of Orbotech to its creditors, (2) approved the Merger Agreement and the proposed transactions, including the Merger, and (3) resolved to recommend that Orbotech’s shareholders approve the Merger Agreement, the Merger and the other proposed transactions, all upon the terms and subject to the conditions set forth in the Merger Agreement. At sessions immediately preceding the final deliberations of the Orbotech Board, the audit committee and remuneration committee of the Orbotech Board each similarly reviewed all relevant information about the proposed transactions, including the anticipated personal interests of Orbotech’s directors and executive officers therein, and each unanimously approved the Merger Agreement and the proposed transactions, including the Merger, on the terms described above and recommended to the Orbotech Board to do the same.

On March 18, 2018, following receipt of the approval of the Orbotech Board, representatives of KLA-Tencor and Orbotech and their respective legal advisors finalized the Merger Agreement and related confidential disclosure letters. Orbotech and KLA-Tencor thereafter executed the Merger Agreement and, prior to market open on the morning of March 19, 2018, KLA-Tencor and Orbotech issued a joint press release announcing the transaction and the execution of the Merger Agreement.

Orbotech’s Reasons for the Merger; Recommendation of the Orbotech Board

At its meeting on March 18, 2018, the Orbotech Board (i) determined that the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, and assuming, among other things, the accuracy of the representations and warranties of KLA-Tencor and Merger Sub in the Merger Agreement, no reasonable concern exists that the surviving company, as a result of the Merger, will be unable to fulfill the obligations of Orbotech to its creditors; (ii) approved the Merger Agreement and transactions contemplated by the Merger Agreement, including the Merger; and (iii) resolved to direct that the Merger Agreement be submitted to the shareholders of Orbotech for approval and adoption and recommend that the shareholders of Orbotech vote in favor of the approval and adoption of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement, all upon the terms and subject to the conditions set forth in the Merger Agreement. The Orbotech Board unanimously recommends that you vote “FOR” the Merger Proposal.

The Orbotech Board considered many factors in making its determination that the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement are advisable, fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, and assuming, among other things, the accuracy of the representations and warranties of KLA-Tencor and Merger Sub in the Merger Agreement, no reasonable concern exists that the surviving company, as a result of the Merger, will be unable to fulfill the obligations of Orbotech to its creditors. In arriving at its determination, the

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Orbotech Board consulted with and received the advice of its outside financial and legal advisors, discussed certain issues with Orbotech’s management and considered a variety of factors weighing positively in favor of the Merger, including the following:

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The Orbotech Board also identified and considered a number of other matters, some of which are countervailing factors and risks to Orbotech and its shareholders, relating to the Merger and the Merger Agreement, including the following:

The foregoing discussion of the factors considered by the Orbotech Board is not intended to be exhaustive, but rather includes the material factors considered by the Orbotech Board. The Orbotech Board collectively (i) determined that the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger, are advisable, fair to and in the best interests of Orbotech and its shareholders and that, considering the financial position of the merging companies, and assuming, among other things, the accuracy of the representations and warranties of KLA-Tencor and Merger Sub in the Merger Agreement, no reasonable concern exists that the surviving company, as a result of the Merger, will be unable to fulfill the obligations of Orbotech to its creditors; (ii) approved the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Merger; and (iii) resolved to direct that the Merger Agreement be submitted to the shareholders of Orbotech for approval and adoption and recommend that the shareholders of Orbotech vote in favor of the approval and adoption of the Merger Agreement, the Merger and the other transactions contemplated by the Merger Agreement, all upon the terms and subject to the conditions set forth in the Merger Agreement. In view of the wide variety of factors considered by the Orbotech Board in connection with its evaluation of the Merger and the complexity of these matters, the Orbotech Board did not consider it practical, and did not attempt, to quantify, rank or otherwise assign relative or specific weights or values to any of the factors it considered in reaching its decision and did not undertake to make any specific determination as to whether any particular factor, or any aspect of any particular factor, was favorable or unfavorable to the ultimate

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determination of the Orbotech Board. Rather, the Orbotech Board considered all of these factors as a whole and made its recommendation based on the totality of the information available to the Orbotech Board, including discussions with, and questioning of, Orbotech’s management and its legal and financial advisors. In considering the factors discussed above, individual members of the Orbotech Board may have given different weights to different factors and the factors are not presented in any order of priority.

This explanation of the Orbotech Board’s reasons to recommend that Orbotech’s shareholders vote in favor of the Merger Proposal presented in this section is forward-looking in nature and, therefore, should be read in light of the factors described in the section entitled “Special Note Regarding Forward-Looking Statements”.

Opinion of Orbotech’s Financial Advisor

Orbotech engaged Barclays to act as its financial advisor in connection with a possible sale of Orbotech. On March 18, 2018, Barclays rendered its oral opinion (which was subsequently confirmed in writing) to the Orbotech Board that, as of such date and based upon and subject to the qualifications, limitations and assumptions stated in its opinion, the consideration to be offered to the holders of Orbotech shares (other than the holders of the Excluded Shares) in the proposed transaction was fair, from a financial point of view, to such holders.

The full text of Barclays’ written opinion, dated as of March 18, 2018, is attached as Annex B to this proxy statement/prospectus. Barclays’ written opinion sets forth, among other things, the assumptions made, procedures followed, factors considered and limitations upon the review undertaken by Barclays in rendering its opinion. You are encouraged to read the opinion carefully in its entirety. The following is a summary of Barclays’ opinion and the methodology that Barclays used to render its opinion. This summary is qualified in its entirety by reference to the full text of the opinion.

Barclays’ opinion, the issuance of which was approved by Barclays’ Fairness Opinion Committee, is addressed to the Orbotech Board, addresses only the fairness, from a financial point of view, of the consideration to be offered to the holders of Orbotech shares (other than the holders of the Excluded Shares) in the proposed transaction and does not constitute a recommendation to any holder of Orbotech shares as to how such holder should vote with respect to the proposed transaction or any other matter. The terms of the proposed transaction were determined through arm’s-length negotiations between Orbotech and KLA-Tencor and were unanimously approved by the Orbotech Board. Barclays did not recommend any specific form of consideration to Orbotech or that any specific form of consideration constituted the only appropriate consideration for the proposed transaction. Barclays was not requested to address, and its opinion does not in any manner address, Orbotech’s underlying business decision to proceed with or effect the proposed transaction, the likelihood of the consummation of the proposed transaction, or the relative merits of the proposed transaction as compared to any other transaction or business strategy in which Orbotech may engage. In addition, Barclays expressed no opinion on, and its opinion does not in any manner address, the fairness of the amount or the nature of any compensation to any officers, directors or employees of any parties to the proposed transaction, or any class of such persons, relative to the consideration to be offered to the holders of Orbotech shares in the proposed transaction. No limitations were imposed by the Orbotech Board upon Barclays with respect to the investigations made or procedures followed by it in rendering its opinion.

In arriving at its opinion, Barclays, among other things:

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In arriving at its opinion, Barclays assumed and relied upon the accuracy and completeness of the financial and other information used by Barclays without any independent verification of such information (and did not assume responsibility or liability for any independent verification of such information). Barclays also relied upon the assurances of management of Orbotech that they were not aware of any facts or circumstances that would make such information inaccurate or misleading. With respect to the Orbotech Management Projections, upon the advice of Orbotech, Barclays assumed that the Orbotech Management Projections were reasonably prepared on a basis reflecting the best currently available estimates and judgments of the management of Orbotech as to Orbotech’s future financial performance. Furthermore, upon the advice of Orbotech, Barclays assumed that the amounts and timing of the expected synergies were reasonable and that the expected synergies would be realized in accordance with such estimates. Barclays was not provided with, and did not have any access to, financial projections of KLA-Tencor prepared by management of Orbotech or management of KLA-Tencor. Accordingly, upon the advice of Orbotech, Barclays assumed that the KLA-Tencor Published Estimates were a reasonable basis upon which to evaluate the future financial performance of KLA-Tencor and that KLA-Tencor would perform substantially in accordance with such KLA-Tencor Published Estimates. In arriving at its opinion, Barclays assumed no responsibility for and expressed no view as to any such projections or estimates or the assumptions on which they were based. In arriving at its opinion, Barclays did not conduct a physical inspection of the properties and facilities of Orbotech or KLA-Tencor and did not make or obtain any evaluations or

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appraisals of the assets or liabilities of Orbotech or KLA-Tencor. In addition, Barclays was not authorized by Orbotech to solicit, and did not solicit, any indications of interest from any third party with respect to the purchase of all or a part of Orbotech’s business. Barclays’ opinion was necessarily based upon market, economic and other conditions as they existed on, and could be evaluated as of, March 18, 2018. Barclays assumed no responsibility for updating or revising its opinion based on events or circumstances that may have occurred after March 18, 2018.

Barclays assumed the accuracy of the representations and warranties contained in the Merger Agreement and all the agreements related thereto. Barclays also assumed, upon the advice of Orbotech, that all material governmental, regulatory and third party approvals, consents and releases for the proposed transaction would be obtained within the constraints contemplated by the Merger Agreement and that the proposed transaction will be consummated in accordance with the terms of the Merger Agreement, without waiver, modification or amendment of any material term, condition or agreement thereof. Barclays did not express any opinion as to any tax or other consequences that might result from the proposed transaction, nor did Barclays’ opinion address any legal, tax, regulatory or accounting matters, as to which Barclays understood Orbotech had obtained such advice as it deemed necessary from qualified professionals.

In connection with rendering its opinion, Barclays performed certain financial, comparative and other analyses as summarized below. In arriving at its opinion, Barclays did not ascribe a specific range of values to the Orbotech shares but rather made its determination as to fairness, from a financial point of view, to holders of Orbotech shares of the consideration to be offered to such holders in the proposed transaction on the basis of various financial and comparative analyses. The preparation of a fairness opinion is a complex process and involves various determinations as to the most appropriate and relevant methods of financial and comparative analyses and the application of those methods to the particular circumstances. Therefore, a fairness opinion is not readily susceptible to summary description.

In arriving at its opinion, Barclays did not attribute any particular weight to any single analysis or factor considered by it but rather made qualitative judgments as to the significance and relevance of each analysis and factor relative to all other analyses and factors performed and considered by it and in the context of the circumstances of the proposed transaction. Accordingly, Barclays believes that its analyses must be considered as a whole, as considering any portion of such analyses and factors, without considering all analyses and factors as a whole, could create a misleading or incomplete view of the process underlying its opinion.

Summary of Material Financial Analyses

The following is a summary of the material financial analyses used by Barclays in preparing its opinion to the Orbotech Board. The summary of Barclays’ analyses and reviews provided below is not a complete description of the analyses and reviews underlying Barclays’ opinion. The preparation of a fairness opinion is a complex process involving various determinations as to the most appropriate and relevant methods of analysis and review and the application of those methods to particular circumstances, and, therefore, is not readily susceptible to summary description.

For the purposes of its analyses and reviews, Barclays made numerous assumptions with respect to industry performance, general business, economic, market and financial conditions and other matters, many of which are beyond the control of Orbotech or any other parties to the proposed transaction. No company, business or transaction considered in Barclays’ analyses and reviews is identical to Orbotech, KLA-Tencor, Merger Sub or the proposed transaction, and an evaluation of the results of those analyses and reviews is not entirely mathematical. Rather, the analyses and reviews involve complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the acquisition, public trading or other values of the companies, businesses or transactions considered in Barclays’ analyses and reviews. None of Orbotech, KLA-Tencor, Merger Sub, Barclays or any other person assumes responsibility if future results are materially different from those discussed. Any estimates contained in these analyses and reviews and the ranges

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of valuations resulting from any particular analysis or review are not necessarily indicative of actual values or predictive of future results or values, which may be significantly more or less favorable than as set forth below. In addition, analyses relating to the value of companies, businesses or securities do not purport to be appraisals or reflect the prices at which the companies, businesses or securities may actually be sold. Accordingly, the estimates used in, and the results derived from, Barclays’ analyses and reviews are inherently subject to substantial uncertainty.

The summaries of the financial analyses and reviews identified below include information presented in tabular format. In order to fully understand the financial analyses and reviews used by Barclays, the tables must be read together with the text of each summary, as the tables alone do not constitute a complete description of the financial analyses and reviews. Considering the data in the tables below without considering the full description of the analyses and reviews, including the methodologies and assumptions underlying the analyses and reviews, could create a misleading or incomplete view of Barclays’ analyses and reviews.

Selected Comparable Company Analysis for Orbotech

In order to assess how the public market values shares of publicly traded companies similar to Orbotech and to provide a range of relative implied equity values per Orbotech share by reference to those companies, Barclays reviewed and compared specific financial and operating data relating to Orbotech with that of selected companies that Barclays deemed comparable to Orbotech.

The selected comparable companies were:

Applied Materials, Inc.

ASM International N.V. ADR

BE Semiconductor Industries N.V. ADR

Camtek Ltd.

KLA-Tencor Corporation

Lam Research Corporation

Nanometrics Incorporated

Rudolph Technologies, Inc.

Tokyo Electron Ltd.

Veeco Instruments Inc.

Barclays calculated and compared various financial multiples and ratios of Orbotech and the selected comparable companies. As part of its selected comparable company analysis, Barclays calculated and analyzed each company’s enterprise value, or EV, as a multiple of (i) its calendar year 2018 and 2019 estimated revenue and (ii) its calendar year 2018 and 2019 estimated earnings before interest, taxes, depreciation, amortization and stock-based compensation, or adjusted EBITDA. Barclays also calculated and analyzed each company’s ratio of its current stock price to its projected non-GAAP earnings per share, or EPS, as adjusted for non-recurring items, amortization of intangibles and stock-based compensation, or non-GAAP EPS, for each company’s calendar year 2018 and 2019. The EV of each company was obtained by adding its short and long-term debt to the sum of the market value of its fully diluted equity value, using the treasury stock method, based on closing stock prices on March 16, 2018, the value of any preferred stock (at liquidation value), the value of any pension liabilities and the book value of any minority interest, and subtracting its cash equivalents and short and long-term liquid investments. All of these calculations for the comparable companies were performed, and based, on generally available financial data and closing prices, as of March 16, 2018, the last trading date prior to the delivery of Barclays’ opinion. All of these calculations for KLA-Tencor were performed, and based, on the KLA-Tencor Published Estimates. All of these calculations for Orbotech were performed, and based, on the Orbotech Management Projections and the Orbotech Published Estimates.

Barclays selected the comparable companies listed above because of similarities in one or more business or operating characteristics with Orbotech. However, because no selected comparable company is exactly the same

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as Orbotech, Barclays believed that it was inappropriate to, and therefore did not, rely solely on the quantitative results of the selected comparable company analysis. Accordingly, Barclays also made qualitative judgments concerning differences between the business, financial and operating characteristics and prospects of Orbotech and the selected comparable companies that could affect the public trading values of each in order to provide a context in which to consider the results of the quantitative analysis. These qualitative judgments related primarily to the differing sizes, growth prospects, profitability levels and degree of operational risk between Orbotech and the companies included in the selected company analysis. Based upon these judgments, Barclays selected a range of multiples for Orbotech and applied such range to the Orbotech Management Projections to calculate a range of implied values per Orbotech share. The following summarizes the result of these calculations:

For purposes of its opinion, Barclays calculated the implied value, as of March 16, 2018, of the Merger Consideration per Orbotech share to be $69.02, which was determined by adding the cash portion of the Merger Consideration of $38.86 per Orbotech share to $30.16, the implied value of the stock portion of the Merger Consideration per Orbotech share that was derived by multiplying the closing price of $120.62 per share of KLA-Tencor common stock on March 16, 2018, the last trading day prior to the announcement of the proposed transaction, by the exchange ratio of 0.25 of a share of KLA-Tencor common stock per Orbotech share.

Barclays noted that on the basis of the selected comparable company analysis with respect to Orbotech, the implied value of the Merger Consideration of $69.02 per share was (i) above the range of implied values per Orbotech share calculated using estimated calendar year 2018 adjusted EBITDA and estimated calendar year 2018 non-GAAP EPS, and (ii) within the range of implied values per Orbotech share calculated using estimated calendar year 2018 and 2019 revenue, estimated calendar year 2019 adjusted EBITDA and estimated calendar year 2019 non-GAAP EPS.

Selected Comparable Company Analysis for KLA-Tencor

In order to assess how the public market values shares of similar publicly traded companies and to provide a range of relative implied equity values per share of KLA-Tencor by reference to those companies, Barclays reviewed and compared specific financial and operating data relating to KLA-Tencor with selected companies that Barclays deemed comparable to KLA-Tencor.

The selected comparable companies were:

Applied Materials, Inc.

ASM International N.V. ADR

ASML Holding NV

Lam Research Corporation

Orbotech Ltd.

Tokyo Electron Ltd.

Barclays calculated and compared various financial multiples and ratios of KLA-Tencor and the selected comparable companies. As part of its selected comparable company analysis, Barclays calculated and analyzed

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each company’s EV (calculated as described above), as a multiple of (i) its calendar year 2018 and 2019 estimated revenue and (ii) its calendar year 2018 and 2019 estimated adjusted EBITDA. Barclays also calculated and analyzed each company’s ratio of its current stock price to its projected non-GAAP EPS. All of these calculations for the comparable companies were performed, and based, on generally available financial data and closing prices, as of March 16, 2018. All of these calculations for Orbotech were performed, and based, on the Orbotech Management Projections. All of these calculations for KLA-Tencor were performed, and based, on the KLA-Tencor Published Estimates.

Barclays selected the comparable companies listed above because of similarities in one or more business or operating characteristics with KLA-Tencor. However, because no selected comparable company is exactly the same as KLA-Tencor, Barclays believed that it was inappropriate to, and therefore did not, rely solely on the quantitative results of the selected comparable company analysis. Accordingly, Barclays also made qualitative judgments concerning differences between the business, financial and operating characteristics and prospects of KLA-Tencor and the selected comparable companies that could affect the public trading values of each in order to provide a context in which to consider the results of the quantitative analysis. These qualitative judgments related primarily to the differing sizes, growth prospects, profitability levels and degree of operational risk between KLA-Tencor and the companies included in the selected company analysis. Based upon these judgments, Barclays selected a range of multiples for KLA-Tencor and applied such range to the KLA-Tencor Published Estimates to calculate a range of implied values per share of KLA-Tencor common stock. The following summarizes the result of these calculations:

Barclays noted that on the basis of the selected comparable company analysis with respect to KLA-Tencor, the closing price of $120.62 per share of KLA-Tencor common stock on March 16, 2018, the last trading day prior to the announcement of the proposed transaction, was (i) above the range of implied values per share of KLA-Tencor common stock calculated using estimated calendar year 2018 and 2019 revenue and (ii) within the range of implied values per share of KLA-Tencor common stock calculated using estimated calendar year 2018 and 2019 adjusted EBITDA and estimated calendar year 2018 and 2019 non-GAAP EPS.

Selected Precedent Transaction Analysis

Barclays reviewed and compared the purchase prices and financial multiples paid in selected other transactions that Barclays, based on its experience with merger and acquisition transactions, deemed relevant. Barclays chose such transactions based on, among other things, the similarity of the applicable target companies in the transactions to Orbotech with respect to the size, mix, margins and other characteristics of their businesses.

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As part of its precedent transactions analysis, for each of the selected transactions, based on information Barclays obtained from publicly available information, Barclays analyzed the EV to last-12-months’, or LTM, and forward-12-months’, or FTM, revenue and to LTM and FTM adjusted EBITDA. The results of this precedent transaction analysis are summarized below:

The reasons for and the circumstances surrounding each of the selected precedent transactions analyzed were diverse and there are inherent differences in the business, operations, financial conditions and prospects of each of Orbotech and KLA-Tencor and the companies included in the selected precedent transaction analysis. Accordingly, Barclays believed that a purely quantitative selected precedent transaction analysis would not be particularly meaningful in the context of considering the proposed transaction. Barclays therefore made qualitative judgments concerning differences between the characteristics of the selected precedent transactions and the proposed transaction that would affect the acquisition values of the selected target companies and Orbotech. Based upon these judgments, Barclays selected ranges of multiples for Orbotech and applied such

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ranges to the Orbotech Management Projections to calculate ranges of implied value per Orbotech share. The following table sets forth the results of such analysis:

Barclays noted that on the basis of the selected precedent transaction analysis, the implied value of the Merger Consideration of $69.02 per Orbotech share was (i) above the range of implied values per Orbotech share calculated using LTM revenue and LTM adjusted EBITDA, and (ii) within the range of implied values per Orbotech share calculated using FTM revenue and FTM adjusted EBITDA.

Discounted Cash Flow Analysis

In order to estimate the present value of Orbotech shares, Barclays performed a discounted cash flow analysis of Orbotech. A discounted cash flow analysis is a traditional valuation methodology used to derive a valuation of an asset by calculating the “present value” of estimated future cash flows of the asset. “Present value” refers to the current value of future cash flows or amounts and is obtained by discounting those future cash flows or amounts by a discount rate that takes into account macroeconomic assumptions and estimates of risk, the opportunity cost of capital, expected returns and other appropriate factors.

To calculate the estimated EV of Orbotech using the discounted cash flow method, Barclays added (i) Orbotech’s projected after-tax unlevered free cash flows (calculated as described below) for calendar years 2018 through 2021 based on the Orbotech Management Projections to (ii) the “terminal value” of Orbotech as of the end of calendar year 2021 and discounted such amount to its present value (as of March 16, 2018) using a range of selected discount rates. Barclays used the mid-year convention in its discounted cash flow analysis to more accurately reflect the present value of future cash flows because cash flows are actually earned throughout the year rather than at the end of the year. The after-tax unlevered free cash flows were calculated by taking the after tax non-GAAP operating income of Orbotech, adding depreciation and amortization, subtracting capital expenditures and adjusting for changes in net working capital. The residual value of Orbotech at the end of calendar year 2021, or “terminal value,” was estimated by selecting a range of estimated FTM adjusted EBITDA exit multiples. Barclays assumed a range of FTM adjusted EBITDA exit multiples of 8.0x to 10.0x, which was derived by Barclays utilizing its professional judgment and experience, taking into account the financial forecasts and market expectations and applying such ranges to the Orbotech Management Projections. The range of after-tax discount rates of 10% to 12% was selected based on an analysis of the weighted average cost of capital of Orbotech and the selected comparable companies used in the “Selected Comparable Company Analysis for Orbotech” described above. Barclays then calculated a range of implied values per Orbotech share by subtracting net debt as of December 31, 2017 from the estimated EV using the discounted cash flow method and dividing such amount by the fully diluted number of Orbotech shares, calculated using the treasury stock method, and using the number of Orbotech shares, options to purchase Orbotech shares and Orbotech restricted share units outstanding as of March 5, 2018. This analysis implied a range of values per Orbotech share of $61.81 to $77.37 based on the range of FTM adjusted EBITDA exit multiples.

Barclays also performed a similar analysis using the same methodology described above, other than that the terminal value was estimated by selecting a range of perpetuity growth rates. Barclays assumed a range of perpetuity growth rates of 3.0% to 4.5%, which was derived by Barclays utilizing its professional judgment and experience, taking into account the financial forecasts and market expectations and applying such ranges to the Orbotech Management Projections. This analysis implied a range of values per Orbotech share of $52.82 to $81.04 based on the range of perpetuity growth rates.

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Barclays noted that on the basis of the discounted cash flow analyses performed, the implied value of the Merger Consideration of $69.02 per Orbotech share was within the range of implied values per Orbotech share calculated using the Orbotech Management Projections, FTM adjusted EBITDA exit multiples and perpetuity growth rates.

Other Factors

Barclays also noted the following additional factors that were not considered part of its financial analyses with respect to its fairness determination, but were referenced for informational purposes:

Research Analysts Price Targets Analysis for Orbotech and KLA-Tencor

Barclays reviewed publicly available research on per share price targets for Orbotech shares and the KLA-Tencor common stock obtained from brokers. The equity research analysts’ per share price targets ranged from $58.00 to $65.00 for Orbotech and ranged from $110.00 to $153.00 for KLA-Tencor. The publicly available per share price targets published by equity research firms do not necessarily reflect the current market trading price of the Orbotech shares or the KLA-Tencor common stock, respectively, and these estimates are subject to uncertainties, including the future financial performance of Orbotech and KLA-Tencor as well as future market conditions.

Historical Share Price Analysis of Orbotech and KLA-Tencor

To illustrate the trend in the historical trading prices of the Orbotech shares, Barclays considered historical data with regard to the trading prices of the Orbotech shares over the 52-week period prior to the announcement of the proposed transaction. During such period, the closing price of Orbotech shares ranged from $30.59 to $59.90 per share.

To illustrate the trend in the historical trading prices of the KLA-Tencor common stock, Barclays considered historical data with regard to the trading prices of the KLA-Tencor common stock over the 52-week period prior to the announcement of the proposed transaction. During such period, the closing price of KLA-Tencor common stock ranged from $88.14 to $122.39 per share.

Premiums Paid Analysis

In order to assess the premium offered to the holders of Orbotech shares in the proposed transaction relative to the premiums offered to stockholders in other transactions, Barclays reviewed the premiums paid in all electronics mergers and acquisitions transactions valued between $1.0 billion and $5.0 billion from January 1, 2010 to March 16, 2018, of which there were 42. For each transaction, Barclays calculated the implied value per share paid by the acquiror by comparing the announced transaction value per share to the target company’s: (i) closing price on the last trading day prior to announcement of the transaction or first reference in the public news media about the transaction, and (ii) average closing price for the 30 calendar days prior to announcement of the transaction or first reference in the public news media about the transaction.

The reasons for and the circumstances surrounding each of the transactions analyzed in the transaction premium analysis were diverse and there are inherent differences in the business, operations, financial conditions and prospects of Orbotech, KLA-Tencor and the companies included in the transaction premium analysis. Accordingly, Barclays believed that a purely quantitative transaction premium analysis would not be particularly meaningful in the context of considering the proposed transaction. Barclays therefore made qualitative judgments concerning the differences between the characteristics of the selected transactions and the proposed transaction that would affect the acquisition values of the target companies and Orbotech. Based upon these judgments, Barclays selected a range of premiums to (i) the closing price of the Orbotech shares on March 7, 2018 (the last unaffected trading day prior to the first reference to a potential sale of Orbotech in the public news media) and

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(ii) the 30-day average of the closing prices of the Orbotech shares ended on March 7, 2018, to calculate a range of implied values per Orbotech share. The following summarizes the result of these calculations: