EXHIBIT 32.2

                            LAM RESEARCH CORPORATION

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

         In connection with the Annual Report of Lam Research Corporation (the
"Company") on Form 10-K for the fiscal period ending June 29, 2003 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Mercedes Johnson, Senior Vice President, Finance, Chief Financial Officer and
Chief Accounting Officer of the Company, certify, pursuant to 18 U.S.C. Section
1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002,
that:

         (1) The Report fully complies with the requirements of section 13(a) or
15(d) of the Securities Exchange Act of 1934; and

         (2) The information contained in the Report fairly presents, in all
material respects, the financial condition and results of operations of the
Company.

September 24, 2003

                                 /s/ Mercedes Johnson
                                 --------------------------------------------
                                 Mercedes Johnson
                                 Senior Vice President, Finance, Chief Financial
                                 Officer and Chief Accounting Officer