EXHIBIT 8.1


                      [MORRISON & FOERSTER LLP LETTERHEAD]




                                October 22, 2002




Novellus Systems, Inc.
4000 N. First Street
San Jose, CA  95134

Ladies and Gentlemen:

            We have acted as counsel to Novellus Systems, Inc., a California
corporation ("Parent"), in connection with the preparation and execution of the
Agreement and Plan of Merger (the "Agreement") dated as of August 11, 2002, by
and among Parent, NHL Acquisition-Sub, Inc., a Delaware corporation and a
wholly-owned subsidiary of Parent ("Merger Sub"), and SpeedFam-IPEC, Inc., an
Illinois corporation ("Company"). Pursuant to the Agreement, Merger Sub will
merge with and into Company, with Company surviving (the "Merger"). The Merger
is described in the Registration Statement of Parent on Form S-4, as amended
(the "Registration Statement") filed on August 29, 2002 with the Securities and
Exchange Commission (the "Commission") under the Securities Act of 1933, as
amended (the "Securities Act"). The Registration Statement includes the joint
proxy statement and prospectus of Parent and Company (the "Proxy
Statement/Prospectus"). Unless otherwise indicated, any capitalized terms used
herein and not otherwise defined have the meaning ascribed to them in the
Registration Statement.


            In that connection, we have reviewed the Agreement, the Registration
Statement and such other materials as we have deemed necessary or appropriate
for purposes of this opinion. In addition, we have assumed (i) that the Merger
will be consummated in the manner contemplated by the Registration Statement and
in accordance with the Agreement, without waiver or modification of the material
terms and conditions thereof; (ii) the truth and accuracy, on the date of the
Agreement and on the date hereof, of the representations and warranties made by
Parent, Merger Sub and Company in the Agreement; (iii) the truth and accuracy of
the officer's certificates dated October 22, 2002 (the "Officer's Certificates")
provided to us by Parent and Company for use in preparing our opinion; (iv) that
any representation in an Officer's Certificate made "to the knowledge" or
similarly qualified is correct without such qualification.


Novellus Systems, Inc.
October 22, 2002
Page 2



            Based upon and subject to the foregoing, in our opinion, the Merger
will constitute a "reorganization" within the meaning of Section 368(a) of the
Internal Revenue Code of 1986, as amended. In addition, the discussion contained
in the section of the Proxy Statement/Prospectus entitled "The Merger - Material
United States Federal Income Tax Consequences of the Merger," subject to the
limitations and qualifications set forth herein and in that discussion,
constitutes our opinion as to the material United States federal income tax
consequences to holders of Company stock who receive Parent common stock
pursuant to the Merger. Because this opinion is being delivered prior to the
Effective Time of the Merger, it must be considered prospective and dependent on
future events. There can be no assurance that changes in the law will not take
place that could affect the U.S. federal income tax consequences of the Merger
or that contrary positions may not be taken by the Internal Revenue Service.

            This opinion is being furnished in connection with the Registration
Statement. We hereby consent to the use of our name under the caption "Legal
Matters" in the Proxy Statement/Prospectus and to the filing of this opinion as
an Exhibit to the Registration Statement. In giving this consent, we do not
admit that we come within the category of persons whose consent is required
under Section 7 of the Securities Act or the rules and regulations of the
Commission thereunder.


                                      Very truly yours,

                                      /s/ MORRISON & FOERSTER LLP