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                                                                    EXHIBIT 99.5
 
                             ONTRAK SYSTEMS, INC.
 
                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                         TO BE HELD ON AUGUST 5, 1997
 
TO THE STOCKHOLDERS OF ONTRAK SYSTEMS, INC.:
 
  NOTICE IS HEREBY GIVEN that a special meeting of stockholders of OnTrak
Systems, Inc. ("OnTrak") will be held at the offices of OnTrak at 1010 Rincon
Circle, San Jose, California, on August 5, 1997, at 2:00 p.m., local time (the
"OnTrak Special Meeting"), for the following purpose, which is more fully
described in the accompanying Joint Proxy Statement/Prospectus:
 
    1. To consider and vote upon a proposal to approve and adopt the
  Agreement and Plan of Merger dated as of March 24, 1997 (the "Merger
  Agreement"), by and among OnTrak, Lam Research Corporation ("Lam"), and
  Omega Acquisition Corporation, a Delaware corporation and wholly-owned
  subsidiary of Lam ("Merger Sub"), and the transactions contemplated
  thereby. Pursuant to the Merger Agreement, (i) Merger Sub will be merged
  with and into OnTrak (the "Merger"), (ii) OnTrak will become a wholly-owned
  subsidiary of Lam, and (iii) each share of common stock of OnTrak, par
  value $0.0001 per share ("OnTrak Common Stock") will be converted into the
  right to receive, and become exchangeable for, 0.83 of a share of common
  stock of Lam, par value $0.001 per share ("Lam Common Stock"), subject to
  the following adjustment (the "Exchange Ratio"). If the average of the
  daily closing sales prices per share of the Lam Common Stock as reported on
  the Nasdaq National Market on the ten trading days ending the eighth
  trading day preceding the OnTrak Special Meeting (the "Lam Closing Value")
  falls below certain thresholds specified in the Merger Agreement, then, Lam
  may elect to adjust the Exchange Ratio to that number of shares of Lam
  Common Stock equal to $24.90 divided by the Lam Closing Value. If Lam
  determines not to adjust the Exchange Ratio in those circumstances, OnTrak
  has the option to terminate the Merger Agreement. If adjusted, the Exchange
  Ratio will be fixed prior to the OnTrak Special Meeting and the special
  meeting of stockholders of Lam. Stockholders may ascertain whether Lam has
  adjusted the Exchange Ratio or whether OnTrak has terminated the Merger
  Agreement by phoning 1-888-LAM-TRAK or logging onto the World Wide Web at
  http://www.lamrc.com at any time after July 25, 1997. If, subsequent to the
  mailing of the Proxy Card, a stockholder wishes to revoke or change such
  stockholder's vote, the stockholder may do so by phoning 1-888-LAM-TRAK or
  logging onto the World Wide Web at http://www.lamrc.com at any time after
  July 25, 1997, and following the instructions provided by the messages
  thereon. In addition, each outstanding option or right to purchase shares
  of OnTrak Common Stock under OnTrak's stock option and stock purchase plans
  will be assumed by Lam and will be converted into an option or right to
  purchase Lam Common Stock, with appropriate adjustments, based upon the
  Exchange Ratio, made to the number of shares issuable under the option and
  the exercise or purchase price of each option or right.
 
  Pursuant to the Merger Agreement, an Office of the Chairman will be created
at Lam and will include Roger D. Emerick, the current Chairman of the Board
and Chief Executive Officer and James W. Bagley. Mr. Emerick will be the
Chairman of the Board, and as contemplated by the Merger Agreement, Lam will
enter into an employment agreement with Mr. Bagley pursuant to which Mr.
Bagley will serve as Chief Executive Officer of Lam. In addition, the Lam
Board of Directors will be expanded, and Mr. Bagley and Richard J. Elkus, Jr.,
currently directors of OnTrak, will be appointed to the Board of Directors of
Lam.
 
  The Merger and the Merger Agreement are described more fully in the
accompanying Joint Proxy Statement/Prospectus and a copy of the Merger
Agreement is attached as Annex A thereto.
 
  The OnTrak Board of Directors has fixed the close of business on July 3,
1997 as the record date for the determination of stockholders entitled to
notice of and to vote at the OnTrak Special Meeting and any adjournments or
postponements thereof. Only stockholders of record at the close of business on
such date are
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entitled to notice of and to vote at the OnTrak Special Meeting. A list of
OnTrak stockholders entitled to vote at the OnTrak Special Meeting will be
available for examination, during ordinary business hours, at the corporate
offices of OnTrak at 1010 Rincon Circle, San Jose, California during the ten
days prior to the OnTrak Special Meeting.
 
  Your vote is important regardless of the number of shares you own. Each
stockholder, even though he or she now plans to attend the OnTrak Special
Meeting, is requested to sign, date and return the enclosed proxy without
delay in the enclosed postage-paid envelope. You may revoke your proxy at any
time prior to its exercise. Any stockholder present at the OnTrak Special
Meeting or at any adjournments or postponements thereof may revoke his or her
proxy and vote personally on each matter brought before the OnTrak Special
Meeting.
 
                                          By Order of the Board of Directors
 
 
                                          /s/Jerauld J. Cutini
                                          Jerauld J. Cutini
                                          Secretary
 
San Jose, California
July 7, 1997
 
 PLEASE DATE AND SIGN THE ENCLOSED PROXY AND MAIL IT PROMPTLY IN THE ENCLOSED
                         POSTAGE-PAID RETURN ENVELOPE.
