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                                                                    EXHIBIT 3.2

                     RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                           HMT TECHNOLOGY CORPORATION


         HMT Technology Corporation, a corporation organized and existing under
the laws of the State of Delaware, hereby certifies as follows:

         1. The name of the Corporation is HMT Technology Corporation. The HMT
Technology Corporation was originally incorporated under the same name, and the
original Certificate of Incorporation of the Corporation was filed with the
Secretary of State of the State of Delaware on December 28, 1988.

         2. Pursuant to Section 245 of the General Corporation Law of the State
of Delaware, this Restated Certificate of Incorporation restates and integrates
the provisions of the Certificate of Incorporation of this Corporation.

         3. The text of the Restated Certificate of Incorporation of this 
Corporation is hereby restated as follows:

                                       I.

         The name of this Corporation is HMT Technology Corporation.

                                       II.

         The address of the registered office of the Corporation in the State of
Delaware is 1013 Centre Road, City of Wilmington, County of New Castle, and the
name of the registered agent of the Corporation in the State of Delaware at such
address is The Prentice-Hall Corporation System, Inc.

                                      III.

         The purpose of this Corporation is to engage in any lawful act or
activity for which a corporation may be organized under the General Corporation
Law of the State of Delaware.

                                       IV.

         A. This Corporation is authorized to issue two classes of stock to be
designated, respectively, "Common Stock" and "Preferred Stock." The total number
of shares which the Corporation is authorized to issue is one hundred nine
million one hundred thousand (109,100,000) shares. One hundred million
(100,000,000) shares shall be Common Stock, each


                                       1.

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having a par value of one-tenth of one cent ($.001). Nine million one hundred
thousand (9,100,000) shall be Preferred Stock, each having a par value of
one-tenth of one cent ($.001).

         B. Shares of Preferred Stock may be issued from time to time in one or
more series. The Board of Directors is hereby authorized, by filing a
certificate (a "Preferred Stock Designation") pursuant to the Delaware General
Corporation Law, to fix or alter from time to time the designation, powers,
preferences and rights of the shares of each such series and the qualifications,
limitations or restrictions of any wholly unissued series of Preferred Stock,
and to establish from time to time the number of shares constituting any such
series or any of them; and to increase or decrease the number of shares of any
series subsequent to the issuance of shares of that series, but not below the
number of shares of such series then outstanding. In case the number of shares
of any series shall be decreased in accordance with the foregoing sentence, the
shares constituting such decrease shall resume the status that they had prior to
the adoption of the resolution originally fixing the number of shares of such
series.

                                       V.

         For the management of the business and for the conduct of the affairs
of the Corporation, and in further definition, limitation and regulation of the
powers of the Corporation, of its directors and of its stockholders or any class
thereof, as the case may be, it is further provided that:

         A.

                  (1) The management of the business and the conduct of the
affairs of the Corporation shall be vested in its Board of Directors. The number
of directors which shall constitute the whole Board of Directors shall be fixed
exclusively by one or more resolutions adopted by the Board of Directors.

                  (2) Subject to the rights of the holders of any series of
Preferred Stock to elect additional directors under specified circumstances,
directors shall be elected at each annual meeting of stockholders for a term of
one year. Each director shall serve until his successor is duly elected and
qualified or until his death, resignation or removal. No decrease in the number
of directors constituting the Board of Directors shall shorten the term of any
incumbent director.

                  (3) Subject to the rights of the holders of any series of
Preferred Stock, the Board of Directors or any individual director may be
removed from office at any time (i) with cause by the affirmative vote of the
holders of a majority of the voting power of all the then outstanding shares of
voting stock of the Corporation, entitled to vote at an election of directors
(the "Voting Stock") or (ii) without cause by the affirmative vote of the
holders of at least sixty-six and two-thirds percent (66 2/3%) of the voting
power of all the then outstanding shares of the Voting Stock.

                 
                                       2.

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                 (4) Subject to the rights of the holders of any series of
Preferred Stock, any vacancies on the Board of Directors resulting from death,
resignation, disqualification, removal or other causes and any newly created
directorships resulting from any increase in the number of directors, shall,
unless the Board of Directors determines by resolution that any such vacancies
or newly created directorships shall be filled by the stockholders, except as
otherwise provided by law, be filled only by the affirmative vote of a majority
of the directors then in office, even though less than a quorum of the Board of
Directors, and not by the stockholders. Any director elected in accordance with
the preceding sentence shall hold office for the remainder of the full term of
the director for which the vacancy was created or occurred and until such
director's successor shall have been elected and qualified.

        B.

                  (1) Subject to paragraph (h) of Section 42 of the Bylaws, the
Bylaws may be altered or amended or new Bylaws adopted by the affirmative vote
of at least sixty-six and two-thirds percent (66 2/3%) of the voting power of
all of the then outstanding shares of the Voting Stock. The Board of Directors
shall also have the power to adopt, amend or repeal Bylaws.

                  (2) The directors of the Corporation need not be elected by 
written ballot unless the Bylaws so provide.

                  (3) No action shall be taken by the stockholders of the
Corporation except at an annual or special meeting of stockholders called in
accordance with the Bylaws, and following the closing of the Initial Public
Offering no action shall be taken by the stockholders by written consent.

                  (4) Special meetings of the stockholders of the Corporation
may be called, for any purpose or purposes, by (i) the Chairman of the Board of
Directors, (ii) the Chief Executive Officer, (iii) the Board of Directors
pursuant to a resolution adopted by a majority of the total number of authorized
directors (whether or not there exist any vacancies in previously authorized
directorships at the time any such resolution is presented to the Board of
Directors for adoption) or (iv) by the holders of the shares entitled to cast
not less than twenty percent (20%) of the votes at the meeting, and shall be
held at such place, on such date, and at such time as the Board of Directors
shall fix.

                  (5) Advance notice of stockholder nominations for the election
of directors and of business to be brought by stockholders before any meeting of
the stockholders of the Corporation shall be given in the manner provided in the
Bylaws of the Corporation.

                                       VI.

         A.       A director of the Corporation shall not be personally liable 
to the Corporation or its stockholders for monetary damages for any 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,

                                       3.

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(ii) for act or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law (iii) under Section 174 of the Delaware
General Corporation Law, or (iv) for any transaction from which the director
derived an improper personal benefit. If the Delaware General Corporation Law is
amended after approval by the stockholders of this Article to authorize
corporate action further eliminating or limiting the personal liability of
directors, then the liability of a director shall be eliminated or limited to
the fullest extent permitted by the Delaware General Corporation Law, as so
amended.

         B. Any repeal or modification of this Article VI shall be prospective
and shall not affect the rights under this Article VI in effect at the time of
the alleged occurrence of any act or omission to act giving rise to liability or
indemnification.

                                      VII.

         A. The Corporation reserves the right to amended, alter, change or
repeal any provision contained in this Certificate of Incorporation, in the
manner now or hereafter prescribed by statute, except as provided in paragraph
B. of this Article VII, and all rights conferred upon the stockholders herein
are granted subject to this reservation.

         B. Notwithstanding any other provisions of this 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 the Voting Stock required by law, this Certificate
of Incorporation or any Preferred Stock Designation, the affirmative vote of the
holders of at least sixty-six and two-thirds percent (66-2/3%) of the voting
power of all of the then-outstanding shares of the Voting Stock, voting together
as a single class, shall be required to alter, amend or repeal Articles V, VI,
and VII.

         The foregoing Restated Certificate of Incorporation has been duly
approved by the Board of Directors.

         I further declare under penalty of perjury under the laws of the state
of Delaware that the matters set forth in this Restated Certificate of
Incorporation are true and correct.

         IN WITNESS WHEREOF, this Restated Certificate of Incorporation has been
signed by Ronald L. Schauer, its authorized officer this 27th day of March,
1997.


                                           HMT TECHNOLOGY CORPORATION



                                           /s/ Ronald L. Schauer
                                           --------------------------
                                           Ronald L. Schauer
                                           President, Chief Executive
                                           Officer and Chairman of
                                           the Board