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                                                FILED PURSUANT TO RULE 424(b)(3)
                                            REGISTRATION STATEMENT NO. 333-39167


PROSPECTUS SUPPLEMENT NO. 11
(TO PROSPECTUS DATED NOVEMBER 10, 1997)



                                  $310,000,000
                            LAM RESEARCH CORPORATION
                   5% CONVERTIBLE SUBORDINATED NOTES DUE 2002


     This Prospectus Supplement supplements information contained in that
certain Prospectus dated November 10, 1997 and supersedes Prospectus Supplement
No. 10 dated July 14, 1999 (the "Prospectus"), relating to the potential sale
from time to time of up to $310,000,000 aggregate amount of Notes and the Common
Stock issuable upon conversion thereof by the Selling Securityholders. This
Prospectus Supplement is not complete without, and may not be delivered or
utilized except in connection with, the Prospectus. Capitalized terms used
herein but not defined have the meanings assigned to such terms in the
Prospectus.

     The line items "Forum Capital Markets LLC, 247,000, *, 2,814, *"
"Nesbitt Burns Inc., 1,187,000, *, 13,524" and "North Star Hedge Fund, LP,
1,900,000, *, 21,647, *" contained in the table set forth in the Prospectus
under the caption "Selling Securityholders" are deleted in their entirety and
replaced with the following:

                                                                                      
    Forum Capital Markets LLC                         477,000          *             5,484         *
    Nesbitt Burns Inc.                                961,000          *            10,949         *
    North Star Hedge Fund, LP                       1,650,000          *            18,799         *



     The following line items contained in the table set forth in the Prospectus
under the caption "Selling Security holders" are deleted in their entirety:

                                                                                      
    Arnhold and S. Bleichoeder Inc.                    68,000          *               774         *
    Goldman Sachs & Co.                               900,000          *            10,254         *
    People's Bank                                   1,000,000          *            11,393         *



The last three line items contained in the table set forth in the Prospectus
under the caption "Selling Securityholders": "Any other holder . . . " , "Notes
Sold Under Registration Statement", and "Total . . . " (other than the footnotes
to the table which remain unchanged), are deleted in their entirety and replaced
with the following:

                                                                        
    Any other holder of Notes or future
    transferee from any such holder (3)
    Notes Sold Under Registration Statement      $226,530,000                    2,580,950
                  Total                          $310,000,000        100%        3,531,958


     All information provided in this Prospectus Supplement is as of August 11,
1999.


           THE DATE OF THIS PROSPECTUS SUPPLEMENT IS AUGUST 11, 1999.