Document:

<PAGE>

                                                                     Exhibit 4.2

                           CERTIFICATE OF AMENDMENT OF
                              AMENDED AND RESTATED
                          CERTIFICATE OF INCORPORATION
                                       OF
                             VEECO INSTRUMENTS INC.

      It is hereby certified that:

      1.    The name of the corporation is Veeco Instruments Inc. (the
"Corporation").

      2.    Article 4 of the amended and restated certificate of incorporation
of the Corporation, as amended to date (the "Certificate of Incorporation"), is
hereby amended to read in its entirety as follows:

                  "4. The Corporation shall have authority to issue a total of
            40,500,000 shares, to be divided into 40,000,000 shares of common
            stock with a par value of $0.01 per share and 500,000 shares of
            preferred stock with a par value of $0.01 per share.

      3.    The amendment of the Certificate of Incorporation herein certified
has been duly adopted in accordance with the provisions of Section 242 of the
General Corporation Law of the State of Delaware.

Dated:  May 5, 2000

                                          VEECO INSTRUMENTS INC.

                                          By:  /s/ Gregory A. Robbins
                                             -----------------------------------
                                          Name:   Gregory A. Robbins
                                          Title:  Vice President and General
                                                  Counsel<PAGE>

                                                                     Exhibit 4.3

                       SECOND AMENDED AND RESTATED BYLAWS
                                       of
                             VEECO INSTRUMENTS INC.
                               (the "Corporation")

1.    MEETINGS OF STOCKHOLDERS.

      1.1 ANNUAL MEETING. The annual meeting of stockholders shall be held at a
place and time determined by the board of directors (the "Board").

      1.2 SPECIAL MEETINGS. Special meetings of the stockholders may be called
by resolution of the Board or by the chief executive officer of the Corporation
and shall be called by the chief executive officer of the Corporation or
secretary of the Corporation upon the written request (stating the purpose or
purposes of the meeting) of a majority of the directors then in office or of the
holders of 50% of the outstanding shares entitled to vote. Only business related
to the purposes set forth in the notice of the meeting may be transacted at a
special meeting.

      1.3 PLACE AND TIME OF MEETINGS. Meetings of the stockholders may be held
in or outside Delaware at the place and time specified by the Board, the chief
executive officer of the Corporation or the directors or stockholders requesting
the meeting (as applicable).

      1.4 NOTICE OF MEETINGS; WAIVER OF NOTICE. Written notice of each meeting
of stockholders shall be given to each stockholder entitled to vote at the
meeting, except that (a) it shall not be necessary to give notice to any
stockholder who submits a signed waiver of notice before or after the meeting,
and (b) no notice of an adjourned meeting need be given except when required
under Section 1.5 of these bylaws or by law. Each notice of a meeting shall be
given, personally or by mail, not less than 10 nor more than 60 days before the
meeting and shall state the time and place of the meeting, and unless it is the
annual meeting, shall state at whose direction or request the meeting is called
and the purposes for which it is called. If mailed, notice shall be considered
given when mailed to a stockholder at his address on the Corporation's records.
The attendance of any stockholder at a meeting, without protesting at the
beginning of the meeting that the meeting is not lawfully called or convened,
shall constitute a waiver of notice by him.

      1.5 QUORUM. At any meeting of stockholders, the presence in person or by
proxy of the holders of 50% of the shares entitled to vote shall constitute a
quorum for the transaction of any business. In the absence of a quorum, a
majority in voting interest of those present or, if no stockholders are present,
any officer entitled to preside at or to act as secretary of the meeting, may
adjourn the meeting until a quorum is present. At any adjourned meeting at which
a quorum is present any action may be taken which might have been taken at the
meeting as originally called. No notice of an adjourned meeting need be given if
the time and place are announced at the meeting at which the adjournment is
taken except that, if adjournment is for more than thirty days or if, after the
adjournment, a new record date is fixed for the meeting, notice of the adjourned
meeting shall be given pursuant to Section 1.4.

<PAGE>

      1.6 VOTING; PROXIES. Each stockholder of record shall be entitled to one
vote for every share registered in his name. Corporate action to be taken by
stockholder vote, other than the election of directors, shall be authorized by a
majority of the votes cast at a meeting of stockholders, except as otherwise
provided by law or by Section 1.8 of these bylaws. Directors shall be elected in
the manner provided in Section 2.1 of these bylaws. Voting need not be by ballot
unless ordered by the chairman of the meeting; however, all elections of
directors shall be by written ballot, unless otherwise provided in the
certificate of incorporation. Each stockholder entitled to vote at any meeting
of stockholders or to express consent to or dissent from corporate action in
writing without a meeting may authorize another person to act for him by proxy.
Every proxy must be signed by the stockholder or his attorney-in-fact. No proxy
shall be valid after three years from its date unless it provides otherwise.

      1.7 LIST OF STOCKHOLDERS. Not less than 10 days prior to the date of any
meeting of stockholders, the secretary of the Corporation shall prepare a
complete list of stockholders entitled to vote at the meeting, arranged in
alphabetical order and showing the address of each stockholder and the number of
shares registered in his name. For a period of not less than 10 days prior to
the meeting, the list shall be available during ordinary business hours for
inspection by any stockholder for any purpose germane to the meeting. During
this period, the list shall be kept either (a) at a place within the city where
the meeting is to be held, if that place shall have been specified in the notice
of the meeting, or (b) if not so specified, at the place where the meeting is to
be held. The list shall also be available for inspection by stockholders at the
time and place of the meeting.

      1.8 ACTION BY CONSENT WITHOUT A MEETING. No action required or permitted
to be taken at any meeting of stockholders may be taken by written consent
without a meeting.

2.    BOARD OF DIRECTORS.

      2.1 NUMBER, QUALIFICATION, ELECTION AND TERM OF DIRECTORS. The business of
the Corporation shall be managed by the Board, which shall consist of such
number of directors as may be set from time to time by resolution of a majority
of the Board or by the stockholders, but no decrease in the number of directors
that constitutes the Board may shorten the term of any incumbent director.
Unless otherwise provided in the certificate of incorporation, directors shall
be elected at each annual meeting of stockholders and shall hold office until
the next annual meeting of stockholders and until the election and qualification
of their respective successors, subject to the provisions of Section 2.9. As
used in these bylaws, the term "entire Board" means the total number of
directors which the Corporation would have if there were no vacancies on the
Board.

      2.2 QUORUM AND MANNER OF ACTING. A majority of the entire Board shall
constitute a quorum for the transaction of business at any meeting. Action of
the Board shall be authorized by the vote of a majority of the directors present
at the time of the vote if there is a quorum, unless otherwise provided by law
or these bylaws. In the absence of a quorum, a majority of the directors present
may adjourn any meeting from time to time until a quorum is present.

                                       2
<PAGE>

      2.3 PLACE OF MEETINGS. Meetings of the Board may be held in or outside
Delaware.

      2.4 ANNUAL AND REGULAR MEETINGS. Annual meetings of the Board, for the
election of officers and consideration of other matters, shall be held either
(a) without notice immediately after the annual meeting of stockholders and at
the same place, or (b) at such time and place as the chairman of the board shall
determine, on notice as provided in Section 2.6 of these Bylaws. Regular
meetings of the Board may be held without notice at such times and places as the
Board determines. If the day fixed for a regular meeting is a legal holiday, the
meeting shall be held on the next business day.

      2.5 SPECIAL MEETINGS. Special meetings of the Board may be called by the
chief executive officer of the Corporation or by a majority of the entire Board.

      2.6 NOTICE OF MEETINGS; WAIVER OF NOTICE. Notice of the time and place of
each special meeting of the Board, and of each annual meeting not held
immediately after the annual meeting of stockholders and at the same place,
shall be given to each director by mailing it to him at his residence or usual
place of business at least three days before the meeting, or by delivering or
telephoning or telecopying it to him at least two days before the meeting.
Notice of a special meeting shall also state the purpose or purposes for which
the meeting is called. Notice need not be given to any director who submits a
signed waiver of notice before or after the meeting or who attends the meeting
without protesting at the beginning of the meeting the transaction of any
business because the meeting was not lawfully called or convened. Notice of any
adjourned meeting need not be given, other than by announcement at the meeting
at which the adjournment is taken.

      2.7 BOARD OR COMMITTEE ACTION WITHOUT A MEETING. Any action required or
permitted to be taken by the Board or by any committee of the Board may be taken
without a meeting if all of the members of the Board or of the committee consent
in writing to the adoption of a resolution authorizing the action. The
resolution and the written consents by the members of the Board or the committee
shall be filed with the minutes of the proceeding of the Board or of the
committee.

      2.8 PARTICIPATION IN BOARD OR COMMITTEE MEETINGS BY CONFERENCE TELEPHONE.
Any or all members of the Board or of any committee of the Board may participate
in a meeting of the Board or of the committee by means of a conference telephone
or similar communications equipment allowing all persons participating in the
meeting to hear each other at the same time. Participation by such means shall
constitute presence in person at the meeting.

      2.9 RESIGNATION AND REMOVAL OF DIRECTORS. Any director may resign at any
time by delivering his resignation in writing to the chief executive officer of
the Corporation or secretary of the Corporation, to take effect at the time
specified in the resignation; the acceptance of a resignation, unless required
by its terms, shall not be necessary to make it effective. Any or all of the
directors may be removed at any time, either with or without cause, by vote of
the stockholders.

      2.10 VACANCIES. Any vacancy in the Board, including one created by an
increase in the number of directors, may be filled for the unexpired term by a
majority vote of the remaining

                                       3
<PAGE>

directors, though less than a quorum.

      2.11 COMPENSATION. Directors who are not executive officers of the
Corporation shall receive such compensation as the Board determines, together
with reimbursement of their reasonable expenses in connection with the
performance of their duties. Directors who are also executive officers of the
Corporation shall receive no additional compensation for service as directors. A
director may also be paid for serving the Corporation, its affiliates or
subsidiaries in other capacities.

3.    COMMITTEES.

      3.1 EXECUTIVE COMMITTEE. The Board, by resolution adopted by a majority of
the entire Board, may designate an Executive Committee of one or more directors
which shall have such powers and duties as the Board shall determine, except as
limited by section 141(c) of the Delaware General Corporation Law or any other
applicable law. The members of the Executive Committee shall serve at the
pleasure of the Board. All action of the Executive Committee shall be reported
to the Board at its next meeting.

      3.2 OTHER COMMITTEES. The Board, by resolution adopted by a majority of
the entire Board, may designate other committees of one or more directors, which
shall serve at the Board's pleasure and have such powers and duties as the Board
determines, except as limited by section 141(c) of the Delaware General
Corporation Law or any other applicable law.

      3.3 COMMITTEES. The following committees are hereby created, with the
powers and duties hereinafter set forth.

            (A) COMPENSATION COMMITTEE. The Compensation Committee shall be
comprised of three (3) or more directors (as set from time to time by resolution
of a majority of the entire Board). The Compensation Committee shall fix the
compensation of the chief executive officer and such other executive officers as
it shall determine and administer any stock option, stock appreciation or other
incentive compensation programs of the Corporation.

            (B) AUDIT COMMITTEE. The Audit Committee shall be comprised of three
(3) or more directors (as set from time to time by resolution of the majority of
the entire Board) who are not employees of the Corporation. The Audit Committee
shall have full corporate power and authority to act in respect of any matter
which may develop or arise in connection with any audit or the maintenance of
internal accounting controls or any other matter relating to the Corporation's
financial affairs. The Audit Committee shall review, at least once each fiscal
year, the services performed and to be performed by the Corporation's
independent public accountants and the fees charged therefor, and, in connection
therewith, consider the effect of any nonaudit services on the independence of
such accountants. The Audit Committee shall also review with the Corporation's
independent public accountants and its internal audit department the general
scope of their respective audit coverages, the procedure and internal accounting
controls adopted by the Corporation and any significant matters encountered by
any of them.

                                       4
<PAGE>

            (C) NOMINATING COMMITTEE. The Nominating Committee shall be
comprised of three (3) or more directors (as set from time to time by resolution
of a majority of the entire Board). The Nominating Committee shall provide to
the Board its recommendations regarding individuals to be considered for
election as directors of the Corporation at meetings of the stockholders of the
Corporation and shall have such other powers and duties as may be determined by
the Board from time to time.

      3.4 RULES APPLICABLE TO COMMITTEES. The Board may designate one or more
directors as alternate members of any committee, who may replace any absent or
disqualified member at any meeting of the committee. In the absence or
disqualification of any member of a committee, the member or members present at
a meeting of the committee and not disqualified, whether or not a quorum, may
unanimously appoint another director to act at the meeting in place of the
absent or disqualified member. All action of a committee shall be reported to
the Board at its next meeting.

4.    OFFICERS.

      4.1 NUMBER. The executive officers of the Corporation shall be the
chairman of the board and chief executive officer, the president, one or more
vice presidents, a secretary and a treasurer. Any two or more offices may be
held by the same person.

      4.2 ELECTION; TERM OF OFFICE. The executive officers of the Corporation
shall be elected annually by the Board, and each such officer shall hold office
until the next annual meeting of the Board, and until the election of his
successor, subject to the provisions of Section 4.4.

      4.3 SUBORDINATE OFFICERS. The Board and the chief executive officer may
appoint subordinate officers (including assistant secretaries and assistant
treasurers), agents or employees, each of whom shall hold office for such period
and have such powers and duties as the Board or the chief executive officer
determines. The chief executive officer may delegate to any executive officer
the power to appoint and define the powers and duties of any subordinate
officers, agents or employees.

      4.4 RESIGNATION AND REMOVAL OF OFFICERS. Any officer may resign at any
time by delivering his resignation in writing to the chief executive officer or
secretary of the Corporation, to take effect at the time specified in the
resignation; the acceptance of a resignation, unless required by its terms,
shall not be necessary to make it effective. Any officer appointed by the Board
or appointed by an executive officer or by a committee may be removed by the
Board either with or without cause, and in the case of an officer appointed by
an executive officer or by a committee, by the officer or committee who
appointed him or by the chief executive officer of the Corporation.

      4.5 VACANCIES. A vacancy in any office may be filled for the unexpired
term in the manner prescribed in Sections 4.2 and 4.3 of these bylaws for
election or appointment to the office.

      4.6 THE CHAIRMAN OF THE BOARD AND CHIEF EXECUTIVE OFFICER. The chairman of
the board and chief executive officer of the Corporation shall be the chief
executive officer of the Corporation, and shall preside at all meetings of the
Board and of the stockholders. The chief

                                       5
<PAGE>

executive officer of the Corporation shall be in charge of the business and
affairs of the Corporation and be its chief policy making officer, subject to
the powers of the Board. During the absence or disability of the president of
the Corporation, the chief executive officer of the Corporation shall exercise
all of the powers and discharge all of the duties of the president of the
Corporation. The chief executive officer of the Corporation shall also perform
such other duties and may exercise such other powers as may from time to time be
assigned to him by the Board.

      4.7 THE PRESIDENT. The president shall be the chief operating officer of
the Corporation. The president of the Corporation shall, subject to the control
of the Board and the chief executive officer of the Corporation, have general
supervision over the business of the Corporation and shall see that all orders
and resolutions of the Board are carried into effect. The president of the
Corporation shall also perform such other duties and may exercise such other
powers as may from time to time be assigned to him by the chief executive
officer of the Corporation.

      4.8 VICE PRESIDENT. Each vice president of the Corporation shall have such
powers and duties as the chief executive officer of the Corporation assigns to
him.

      4.9 THE TREASURER. The treasurer of the Corporation shall be the chief
financial officer of the Corporation and shall be in charge of the Corporation's
books and accounts. The treasurer shall also perform such other duties and may
exercise such other powers as may from time to time be assigned to him by the
chief executive officer of the Corporation.

      4.10 THE SECRETARY. The secretary of the Corporation shall be the
secretary of, and keep the minutes of, all meetings of the Board and of the
stockholders, shall be responsible for giving notice of all meetings of
stockholders and of the Board, and shall keep the seal and, when authorized by
the Board, apply it to any instrument requiring it. Subject to the control of
the Board, he shall have such powers and duties as the Board or the chief
executive officer of the Corporation assigns to him. In the absence of the
secretary of the Corporation from any meeting, the minutes shall be kept by the
person appointed for that purpose by the presiding officer.

      4.11 SALARIES. Subject to the provisions of Section 3.3(A) hereof, the
chief executive officer may fix the officers' salaries.

5.    SHARES.

      5.1 CERTIFICATES. The Corporation's shares shall be represented by
certificates in the form approved by the Board. Each certificate shall be signed
by the chief executive officer, the president or a vice president and by the
secretary or an assistant secretary, or the treasurer or an assistant treasurer,
and shall be sealed with the Corporation's seal or a facsimile of the seal. Any
or all of the signatures on the certificate may be a facsimile.

      5.2 TRANSFERS. Shares shall be transferable only on the Corporation's
books, upon surrender of the certificate for the shares, properly endorsed. The
Board may require satisfactory surety before issuing a new certificate to
replace a certificate claimed to have been lost or destroyed.

                                       6
<PAGE>

      5.3 DETERMINATION OF STOCKHOLDERS OF RECORD. The Board may fix, in
advance, a date as the record date for the determination of stockholders
entitled to notice of or to vote at any meeting of the stockholders, or to
express consent to or dissent from any proposal without a meeting, or to receive
payment of any dividend or the allotment of any rights, or for the purpose of
any other action. The record date may not be more than 60 or less than 10 days
before the date of the meeting or more than 60 days before any other action.

6.    MISCELLANEOUS.

      6.1 SEAL. The Board shall adopt a corporate seal, which shall be in the
form of a circle and shall bear the Corporation's name and the year and state in
which it was incorporated.

      6.2 FISCAL YEAR. The Board may determine the Corporation's fiscal year.
Until changed by the Board, the Corporation's fiscal year shall be the calendar
year.

      6.3 VOTING OF SHARES IN OTHER CORPORATIONS. Shares in other corporations
which are held by the Corporation may be represented and voted by the chief
executive officer, the president or a vice president of this Corporation or by
proxy or proxies appointed by one of them. The Board may, however, appoint some
other person to vote the shares.

      6.4 AMENDMENTS. Bylaws may be amended, repealed or adopted by the
stockholders or by a majority of the entire Board, but any bylaw adopted by the
Board may be amended or repealed by the stockholders.

      These Second Amended and Restated Bylaws became effective on May 5, 2000.

                                       7

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00010-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00010-of-00352.parquet"}]]