Versum Materials’ Board of Directors to Review Unsolicited Tender Offer from Merck KGaA

Shareholders Advised to Not Take Action Pending Review

TEMPE, Ariz.–(BUSINESS WIRE)–Versum Materials, Inc. (NYSE: VSM) today confirmed that Merck KGaA
(“Merck”) has commenced an unsolicited tender offer to acquire all
outstanding shares of Versum for $48 per share in cash. The Merck tender
offer is at the same price per share as the proposal made by Merck on
February 27, 2019, which the Versum Board of Directors unanimously
rejected on March 1, 2019.

Consistent with its fiduciary duties and applicable law, and in
consultation with its financial and legal advisors, the Versum Board of
Directors will carefully review Merck’s offer to determine the course of
action that it believes is in the best interest of Versum and its
stockholders. Versum stockholders are urged to take no action with
respect to the Merck tender offer at this time pending the Board’s
review of the offer.

Versum intends to advise its stockholders of the formal position of the
Versum Board of Directors regarding the Merck tender offer within ten
business days (no later than April 9, 2019) by making available to
Versum stockholders and filing with the Securities and Exchange
Commission a solicitation/recommendation statement on Schedule 14D-9.
Applicable securities laws prevent Versum from making any further
comments with respect to Merck’s tender offer or the terms thereof until
after the Schedule 14D-9 is filed.

The Versum Board of Directors has not changed its recommendation in
support of the pending all-stock merger of equals with Entegris, Inc.

Lazard and Citi are serving as financial advisors to Versum and Simpson
Thacher & Bartlett LLP is serving as legal counsel.

About Versum Materials

Versum Materials, Inc. (NYSE: VSM) is a leading global specialty
materials company providing high-purity chemicals and gases, delivery
systems, services and materials expertise to meet the evolving needs of
the global semiconductor and display industries. Derived from the Latin
word for “toward,” the name “Versum” communicates the company’s deep
commitment to helping customers move toward the future by collaborating,
innovating and creating cutting-edge solutions.

A global leader in technology, quality, safety and reliability, Versum
Materials is one of the world’s leading suppliers of next-generation CMP
slurries, ultra-thin dielectric and metal film precursors, formulated
cleans and etching products, and delivery equipment that has
revolutionized the semiconductor industry. Versum Materials reported
fiscal year 2018 annual sales of about U.S. $1.4 billion, has
approximately 2,300 employees and operates 14 major facilities in Asia
and the North America. It is headquartered in Tempe, Arizona. Versum
Materials had operated for more than three decades as a division of Air
Products and Chemicals, Inc. (NYSE:APD).

For additional information, please visit http://www.versummaterials.com.

Additional Information About the Merck Tender Offer

Versum Materials, Inc. (“Versum Materials”) intends to file a
solicitation/recommendation statement with respect to the tender offer
with the SEC within 10 business days of the commencement of the tender
offer. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE
SOLICITATION/RECOMMENDATION STATEMENT WITH RESPECT TO THE TENDER OFFER
AND OTHER RELEVANT DOCUMENTS THAT ARE FILED WITH THE SEC WHEN THEY
BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT
THE TENDER OFFER.
You will be able to obtain free copies of the
solicitation/recommendation statement with respect to the tender offer
and other documents filed with the Securities and Exchange Commission
(“SEC”) by Versum Materials through the website maintained by the SEC at http://www.sec.gov.
Copies of the documents filed with the SEC by Versum Materials will be
available free of charge on Versum Materials’ website at http://investors.versummaterials.com
or by phone at 484-275-5907.

Forward-Looking Statements

This communication contains forward-looking statements within the
meaning of the Private Securities Litigation Reform Act of 1995 that are
subject to risks and uncertainties and are made pursuant to the safe
harbor provisions of Section 27A of the Securities Act of 1993, as
amended and Section 21E of the Securities Exchange Act of 1934, as
amended. Where a forward-looking statement expresses or implies an
expectation or belief as to future events or results, such expectation
or belief is expressed in good faith and believed to have a reasonable
basis. The words “believe” “continue,” “could,” “expect,” “anticipate,”
“intends,” “estimate,” “forecast,” “project,” “should,” “may,” “will,”
“would” or the negative thereof and similar expressions are intended to
identify such forward-looking statements. These forward-looking
statements are only predictions and involve known and unknown risks and
uncertainties, many of which are beyond Versum Materials’ and Entegris,
Inc.’s (“Entegris”) control. Statements in this communication regarding
Versum Materials, Entegris and the combined company that are
forward-looking, including projections as to the anticipated benefits of
the proposed transaction, the impact of the proposed transaction on
Versum Materials’ and Entegris’ business and future financial and
operating results, the amount and timing of synergies from the proposed
transaction, and the closing date for the proposed transaction, are
based on management’s estimates, assumptions and projections, and are
subject to significant uncertainties and other factors, many of which
are beyond Versum Materials’ and Entegris’ control. These factors and
risks include, but are not limited to, (i) weakening of global and/or
regional economic conditions, generally or specifically in the
semiconductor industry, which could decrease the demand for Versum
Materials’ and Entegris’ products and solutions; (ii) the ability to
meet rapid demand shifts; (iii) the ability to continue technological
innovation and introduce new products to meet customers’ rapidly
changing requirements; (iv) the concentrated customer base; (v) the
ability to identify, effect and integrate acquisitions, joint ventures
or other transactions; (vi) the ability to protect and enforce
intellectual property rights; (vii) operational, political and legal
risks of Versum Materials’ and Entegris’ international operations;
(viii) Versum Materials’ and Entegris’ dependence on sole source and
limited source suppliers; (ix) the increasing complexity of certain
manufacturing processes; (x) raw material shortages and price increases;
(xi) changes in government regulations of the countries in which Versum
Materials and Entegris operate; (xii) the fluctuation of currency
exchange rates; (xiii) fluctuations in the market price of Entegris’
stock; (xiv) the level of, and obligations associated with, Versum
Materials’ and Entegris’ indebtedness; and (xv) other risk factors and
additional information. In addition, material risks that could cause
actual results to differ from forward-looking statements include: the
inherent uncertainty associated with financial or other projections; the
prompt and effective integration of Entegris’ businesses and the ability
to achieve the anticipated synergies and value-creation contemplated by
the proposed transaction; the risk associated with Versum Materials’ and
Entegris’ ability to obtain the approval of the proposed transaction by
their shareholders required to consummate the proposed transaction and
the timing of the closing of the proposed transaction, including the
risk that the conditions to the transaction are not satisfied on a
timely basis or at all and the failure of the transaction to close for
any other reason; the risk that a consent or authorization that may be
required for the proposed transaction is not obtained or is obtained
subject to conditions that are not anticipated; unanticipated
difficulties or expenditures relating to the transaction, the response
of business partners and retention as a result of the announcement and
pendency of the transaction; and the diversion of management time on
transaction-related issues. For a more detailed discussion of such risks
and other factors, see Versum Materials’ and Entegris’ filings with the
SEC, including under the headings “Cautionary Statement Regarding
Forward-Looking Statements” and “Risk Factors” in Entegris’ and Versum
Materials’ preliminary joint proxy statement/prospectus that forms part
of the registration statement on Form S-4 filed by Entegris, “Risks
Factors” in Item 1A of Entegris’ Annual Report on Form 10-K for the
fiscal year ended December 31, 2018, filed on February 11, 2019, and
Versum Materials’ Annual Report on Form 10-K for the fiscal year ended
September 30, 2018, filed on November 21, 2018 and in other periodic
filings, available on the SEC website or www.entegris.com
or www.versummaterials.com.
Versum Materials and Entegris assume no obligation to update any
forward-looking statements or information, which speak as of their
respective dates, to reflect events or circumstances after the date of
this communication, or to reflect the occurrence of unanticipated
events, except as may be required under applicable securities laws.
Investors should not assume that any lack of update to a previously
issued “forward-looking statement” constitutes a reaffirmation of that
statement.

Additional Information and Where to Find It

This communication does not constitute an offer to buy or sell or the
solicitation of an offer to buy or sell any securities or a solicitation
of any vote or approval. This communication relates to a proposed
business combination between Versum Materials and Entegris. In
connection with the proposed transaction, Entegris filed with the
Securities and Exchange Commission (the “SEC”) a registration statement
on Form S-4 on February 28, 2019, as amended on March 18, 2019, that
includes a joint proxy statement of Versum Materials and Entegris and
that also constitutes a prospectus of Entegris. The registration
statement was declared effective by the SEC on March 20, 2019, and
Versum Materials and Entegris commenced mailing of the definitive joint
proxy statement/prospectus to the stockholders of Versum Materials and
Entegris on or about March 22, 2019. Each of Versum Materials and
Entegris also plan to file other relevant documents with the SEC
regarding the proposed transaction. No offering of securities shall be
made, except by means of a prospectus meeting the requirements of
Section 10 of the U.S. Securities Act of 1933, as amended. INVESTORS
AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, JOINT
PROXY STATEMENT/PROSPECTUS AND OTHER DOCUMENTS FILED OR THAT MAY BE
FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY IF AND WHEN THEY
BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT
THE PROPOSED TRANSACTION.
Investors and security holders will be
able to obtain free copies of these documents (if and when available)
and other documents containing important information about Versum
Materials and Entegris, once such documents are filed with the SEC
through the website maintained by the SEC at http://www.sec.gov.
Copies of the documents filed with the SEC by Entegris will be available
free of charge on Entegris’ website at http://www.entegris.com
or by contacting Entegris’ Investor Relations Department by email at irelations@entegris.com
or by phone at 978-436-6500. Copies of the documents filed with the SEC
by Versum Materials will be available free of charge on Versum
Materials’ website at http://investors.versummaterials.com
or by phone at 484-275-5907.

Participants in the Solicitation for the Proposed Versum
Materials/Entegris Merger

Versum Materials, Entegris and certain of their respective directors and
executive officers may be deemed to be participants in the solicitation
of proxies in respect of the proposed transaction. Information about the
directors and executive officers of Versum Materials are set forth in
its proxy statement for its 2019 annual meeting of shareholders, which
was filed with the SEC on December 20, 2018, and Versum Materials’
Annual Report on Form 10-K for the fiscal year ended September 30, 2018,
which was filed with the SEC on November 21, 2018. Information about the
directors and executive officers of Entegris are set forth in Entegris’
proxy statement for its 2019 annual meeting of shareholders, which was
filed with the SEC on March 20, 2019, and Entegris’ Annual Report on
Form 10-K for the fiscal year ended December 31, 2018, which was filed
with the SEC on February 11, 2019. Other information regarding the
participants in the proxy solicitations and a description of their
direct and indirect interests, by security holdings or otherwise, will
be contained in the joint proxy statement/prospectus and other relevant
materials to be filed with the SEC regarding the proposed transaction
when such materials become available. Investors should read the joint
proxy statement/prospectus carefully when it becomes available before
making any voting or investment decisions. You may obtain free copies of
these documents from Versum Materials or Entegris using the sources
indicated above.

Contacts

Versum Materials
Soohwan Kim, CFA
Head of Investor
Relations
602-282-0957
Soohwan.Kim@versummaterials.com

Tiffany
Elle
Global Communications
480-282-6475
Tiffany.Elle@versummaterials.com

Or

Meghan
Gavigan / Emily Claffey / Julie Rudnick
Sard Verbinnen & Co
212-687-8080