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                                                                     EXHIBIT 3.1


                     RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                           AXCELIS TECHNOLOGIES, INC.


         FIRST. The name of the corporation is Axcelis Technologies, Inc. The
name under which the corporation was originally incorporated is Eaton
Semiconductor Equipment Inc. The Corporation's original Certificate of
Incorporation was filed with the Secretary of State of the State of Delaware on
December 21, 1995.

         SECOND. This Restated Certificate of Incorporation was duly adopted in
accordance with the applicable provisions of Sections 242 and 245 of the General
Corporation Law of the State of Delaware.

         THIRD. The original Certificate of Incorporation of the Corporation is
amended and restated to read in full as follows:


         1. Name. The name of the Corporation is Axcelis Technologies, Inc.

         2. Registered Office and Agent. The address of its registered office in
the State of Delaware is 1209 Orange Street, Wilmington, New Castle County,
Delaware 19801. The name of its registered agent at such address is The
Corporation Trust Company.

         3. Purpose. The nature of the business or purposes to be conducted or
promoted is to engage in any lawful act or activity for which corporations may
be organized under the General Corporation Law of the State of Delaware (the
"DGCL").

         4. a. Authorized Capitalization. The total number of all shares of
capital stock which the Corporation shall have the authority to issue is
330,000,000 shares consisting of: (i) 300,000,000 shares of Common Stock, par
value of $0.001 per share; and (ii) 30,000,000 shares of Preferred Stock, par
value of $0.001 per share.

            b. Preferred Stock. The Corporation's Board of Directors is hereby
expressly authorized to provide by resolution or resolutions from time to time
for the issue of the Preferred Stock in one or more series, the shares of each
of which series may have such voting powers, full or limited, or no voting
powers, and such designations, preferences and relative, participating, optional
or other special rights, and qualifications, limitations or restrictions
thereon, as shall be permitted under the DGCL and as shall be stated in the
resolution or resolutions providing for the issue of such stock adopted by the
Board of Directors pursuant to the authority expressly vested in the Board of
Directors hereby.

            c. Reclassification. Upon the effective date of this Restated
Certificate of Incorporation (the "Effective Time"), each issued share of the
capital stock of the Corporation theretofore designated as "Common Stock," par
value $1.00 per share ("Old Common Stock"),



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shall, without any action on the part of the holder thereof, be reclassified so
that each existing share of Old Common Stock shall become one share of Common
Stock, par value $0.001 per share. Each holder of a certificate or certificates
which immediately prior to the Effective Time represented outstanding shares of
Old Common Stock ("Old Certificates"), shall be entitled to receive upon
surrender of such Old Certificates to the Corporation or its stock transfer
agent for cancellation, a certificate or certificates ("New Certificates")
representing the number of shares of Common Stock, par value $0.001 per share,
into which and for which shares of Old Common Stock formerly represented by such
Old Certificates so surrendered are reclassified. From and after the Effective
Time, Old Certificates shall represent only the right to receive New
Certificates pursuant to the provisions hereof.

         5. Period of Existence. The period of existence of the Corporation
shall be perpetual.

         6. Number of Directors.

            a. The number of members of the Board of Directors will be fixed
from time to time by resolution adopted by the affirmative vote of a majority of
the entire Board of Directors but (subject to vacancies) in no event may there
be less than three directors nor more than 15 directors.

            b. The Directors shall be divided into three classes, each
consisting of one-third of such directors, as nearly as possible. Promptly
following the Effective Time, in 2000, the sole stockholder shall designate that
one class of directors shall be elected for a one-year term, one class for a
two-year term and one class for a three-year term. Commencing with the
stockholders meeting in 2001, and at each succeeding annual stockholders
meeting, successors to the class of directors whose term expires at such annual
stockholders meeting shall be elected for a three-year term. If the number of
such directors is changed, an increase or decrease in such directors shall be
apportioned among the classes so as to maintain the number of directors
comprising each class as nearly equal as possible, and any additional directors
of any class shall hold office for a term which shall coincide with the
remaining term of such class. A director shall hold office until the annual
stockholders meeting for the year in which such director's term expires and
until a successor shall be elected and shall qualify, subject, however, to prior
death, resignation, retirement, disqualification, or removal from office.

            c. Except as otherwise required by law, any vacancy on the board of
directors that results from an increase in the number of directors shall be
filled only by a majority of the board of directors then in office, provided
that a quorum is present, and any other vacancy occurring in the board of
directors shall be filled by a majority of the directors then in office, even if
less than a quorum, or by a sole remaining director. Any director elected to
fill a vacancy not resulting from an increase in the number of directors shall
have the same remaining term as that of his or her predecessor. A director may
be removed only for cause by the stockholders.

            d. Notwithstanding the foregoing, whenever the holders of any one or
more classes or series of stock issued by the Corporation shall have the right,
voting separately by class or series, to elect directors at an annual or special
meeting of stockholders, the election, term of office,




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filling of vacancies and other features of such directorships shall be governed
by the terms of this Restated Certificate of Incorporation applicable thereto
and such directors so elected shall not be divided into classes pursuant to this
Article 6, in each case unless expressly provided by such terms.

         7. Amendments to Certificate of Incorporation. The Corporation reserves
the right to amend, alter, change or repeal any provision contained in this
Restated Certificate of Incorporation, in the manner now or hereafter prescribed
by statute, and all rights conferred upon stockholders herein are granted
subject to this reservation.

         8. Amendments to By-laws. In furtherance and not in limitation of the
powers conferred by statute, the Board of Directors is expressly authorized to
adopt, amend or repeal the By-laws of the Corporation.

         9. Meetings of Stockholders. Meetings of stockholders may be held
within or without the State of Delaware as the By-laws may provide. The books of
the Corporation may be kept (subject to any provision contained in the statutes)
outside the State of Delaware at such place or places as may be designated from
time to time by the Board of Directors or in the By-laws of the Corporation.
Elections of directors need not be by written ballot unless the By-laws of the
Corporation shall so provide.

        10. Liability of Directors; Indemnification.

            a. The personal liability of the directors of the Corporation is
hereby eliminated to the fullest extent permitted by Section 102(b)(7) of the
DGCL, as the same may be amended and supplemented. Without limiting the
generality of the foregoing, no director shall be personally liable to the
Corporation or any of its stockholders for monetary damages for breach of
fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to the Corporation or its stockholders, (ii) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) pursuant to Section 174 of the DGCL, or (iv) for
any transaction from which the director derived an improper personal benefit.

            b. The Corporation shall indemnify and hold harmless, to the fullest
extent permitted by applicable law as it presently exists or may hereafter be
amended, any person who was or is made or is threatened to be made a party or is
otherwise involved in any action, suit or proceeding, whether civil, criminal,
administrative or investigative (a "proceeding") by reason of the fact that such
person, or a person for whom he or she is the legal representative, is or was a
director, officer, employee or agent of the Corporation or is or was serving at
the request of the Corporation as a director, officer, employee or agent of
another corporation or of a partnership, joint venture, trust, enterprise or
non-profit entity, including service with respect to employee benefit plans,
against all liability and loss suffered and expenses reasonably incurred by such
person. The Corporation shall be required to indemnify a person in connection
with a proceeding initiated by such person only if the proceeding was authorized
by the Board of Directors of the Corporation. The rights to indemnification and
advancement of expenses conferred by this Article shall be presumed to have been
relied upon by directors and officers of the Corporation in serving or
continuing to serve the Corporation and shall be enforceable as




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contract rights. Said rights shall not be exclusive of any other rights to which
those seeking indemnification may otherwise be entitled. The Corporation may
enter into contracts to provide such persons with specific rights to
indemnification, which contracts may confer rights and protections to the
maximum extent permitted by the DGCL. The Corporation may create trust funds,
grant security interests, obtain letters of credit, or use other means to ensure
payment of such amounts as may be necessary to perform the obligations provided
for in this Article or in any such contract.

            c. Any repeal or modification of this Article 10 by the stockholders
of the Corporation shall not adversely affect any right or protection of a
director of the Corporation existing at the time of such repeal or modification
with respect to acts or omissions occurring prior to such repeal or
modification.

       11. Other Considerations. In addition to any other considerations which
the Board of Directors, any committee thereof or any individual director
lawfully may take into account in determining whether to take or refrain from
taking corporate action on any matter, including making or declining to make any
recommendations to the stockholders of the Corporation, the Board of Directors,
any committee thereof or any individual director may in its, his or her
discretion consider the long term as well as the short term best interests of
the Corporation (including the possibility that these interests may best be
served by the continued independence of the Corporation), taking into account
and weighing as deemed appropriate the effects of such action on employees,
suppliers, distributors and customers of the Corporation and its subsidiaries
and the effect upon communities in which the offices or facilities of the
Corporation and its subsidiaries are located and any other factors considered
pertinent. This Article 11 shall be deemed to grant discretionary authority to
the Board of Directors, any committee thereof and each individual director, and
shall not be deemed to provide to any specific constituency any right to be
considered.

       12. Special Meetings of Stockholders. Effective as of the time at which
Eaton Corporation, an Ohio corporation, and its affiliates shall cease to be the
beneficial owners of an aggregate of at least a majority of the then outstanding
shares of Common Stock of the Corporation (the "Change of Majority Ownership
Date"), the stockholders of the Corporation shall have no authority to call a
special meeting of the stockholders, subject to the rights of the holders of any
class or series of capital stock having a preference over the Common Stock as to
dividends or upon liquidation.

       13. Action Without a Meeting. Effective as of the Change of Majority
Ownership Date, no action required to be taken or which may be taken at any
annual or special meeting of stockholders of the Corporation may be taken
without a meeting; and the power of the stockholders to consent in writing,
without a meeting, to the taking of any action is specifically denied.

       14. Additional Vote Required. Notwithstanding any other provisions of
this Restated Certificate of Incorporation or any provision of law which might
otherwise permit a lesser vote or no vote, but in addition to any affirmative
vote of the holders of any particular class or series of stock required by law
or this Restated Certificate of Incorporation, the affirmative vote of the




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holders of at least 75% of the then outstanding shares of Common Stock shall be
required to alter, amend, supplement or repeal, or to adopt any provision
inconsistent with the purpose or intent of, Articles 4, 6, 12, 13 or 14 of this
Restated Certificate of Incorporation.


         FOURTH: The foregoing amendment and restatement of the Certificate of
Incorporation has been approved by the Board of Directors of the Corporation.

                  IN WITNESS WHEREOF Axcelis Technologies, Inc. has caused this
Restated Certificate of Incorporation to be signed and attested this 14th day
of June, 2000.

Attest:                                AXCELIS TECHNOLOGIES, INC.



By: /s/ Earl R. Franklin               By: /s/ Brian R. Bachman
    ---------------------------            -------------------------------

Title: Assistant Secretary             Title: Vice Chairman and
                                              Chief Executive Officer





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