content: <HTML><HEAD>
  <TITLE>Prepared by R.R. Donnelley Financial -- Form 8-K</TITLE>
  </HEAD>
    <BODY BGCOLOR="WHITE">
   <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="5" COLOR="#000000"><B>UNITED STATES </B></FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman"
  SIZE="5" COLOR="#000000"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="3" COLOR="#000000"><B>Washington, D.C. 20549 </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <HR
  NOSHADE WIDTH="21%" COLOR="#000000"><DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="5" COLOR="#000000"><B>FORM 8-K </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT
  FACE="Times New Roman" SIZE="5" COLOR="#000000"><B>CURRENT REPORT </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="3" COLOR="#000000"><B>Pursuant to Section 13 or 15(d) of the
  Securities Exchange Act of 1934 </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>Date of Report (Date of earliest event reported) May 21, 2002 </B></FONT></DIV>
  <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="5" COLOR="#000000"><B>MATTSON TECHNOLOGY, INC. </B></FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><B>(Exact name
  of registrant as specified in its charter) </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <HR NOSHADE WIDTH="21%" COLOR="#000000"><DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <HR NOSHADE COLOR="#000000" ALIGN="left"><DIV ALIGN="center">
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0">
  
  <TR>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>Delaware</B></FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>0-21970</B></FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>77-0208119</B></FONT></DIV> </TD> </TR>
  <TR>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><B>(State or other jurisdiction of incorporation)</B></FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><B>(Commission File Number)</B></FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="31%" ALIGN="center"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="1" COLOR="#000000"><B>(IRS Employer Identification No.)</B></FONT></DIV> </TD> </TR>
   </TABLE> </DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <HR NOSHADE COLOR="#000000" ALIGN="left"><DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"
  COLOR="#000000"><B>2800 Bayview Drive </B></FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>Fremont, California 94538 </B></FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"
  COLOR="#000000"><B>(Address of principal executive offices) (Zip Code) </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <HR NOSHADE COLOR="#000000" ALIGN="left"><DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT
  FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>Registrant&#146;s telephone number, including area code (510) 657-5900 </B></FONT></DIV>
  
  <p Style='page-break-before:always'>
  <HR  SIZE="3" COLOR="#CCEEFF" WIDTH="100%" ALIGN="CENTER">
   <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B></B><B><I>Item 4.&nbsp;&nbsp;&nbsp;&nbsp;Changes in Registrant&#146;s Certifying Accountant
  </I></B><B></B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="text-indent:4%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(a)(1)&nbsp;&nbsp;&nbsp;&nbsp;Previous independent accountants </FONT></DIV> <DIV><FONT
  SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:8%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(i)&nbsp;&nbsp;&nbsp;&nbsp;On May 21, 2002 the Company dismissed Arthur Andersen LLP (&#147;Andersen&#148;) as its independent
  accountants. Andersen had served as the independent auditors of the Company since November 1, 1999. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:8%"><FONT FACE="Times New Roman" SIZE="2"
  COLOR="#000000">(ii)&nbsp;&nbsp;&nbsp;&nbsp;The reports of Andersen on the financial statements of the Company for each of the past two fiscal years contained no adverse opinion or disclaimer of opinion and were not qualified or modified as to
  uncertainty, audit scope or accounting principle. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:8%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(iii)&nbsp;&nbsp;&nbsp;&nbsp;The decision to change independent
  accountants was approved by the Company&#146;s Audit Committee. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:8%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(iv)&nbsp;&nbsp;&nbsp;&nbsp;During the
  Company&#146;s two most recent fiscal years and through the date of this Report, the Company has had no disagreements with Andersen on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure,
  which disagreements, if not resolved to the satisfaction of Andersen, would have caused it to make reference thereto in its report on the financial statements of the Company for such periods. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV>
  <DIV STYLE="margin-left:8%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(v)&nbsp;&nbsp;&nbsp;&nbsp;During the Company&#146;s two most recent fiscal years and through the date of this Report, the Company has had no reportable events under
  Item 304(a)(1)(v)(B), (C) or (D) of Regulation S-K. With reference to Item 304(a)(1)(v)(A), in its Memorandum on Internal Control in connection with the audit for 2001, Andersen noted four conditions that it considered to be reportable events. In
  particular, Andersen suggested that the Company needed to (i) better document the job descriptions, procedure manuals, and reporting lines within the finance organization, (ii) improve and formalize monitoring procedures regarding controller or
  management level review of entries posted by the staff, (iii) improve and automate procedures for month-end closings, and (iv) improve policies and procedures for tracking inventory balances. Company management did not disagree with the suggestions
  made by Andersen. The Company is currently addressing each of these conditions and believes it has made substantial progress toward implementing corrective measures. The Audit Committee of the Board of Directors discussed these matters with
  Andersen, and the Company has authorized Andersen to respond fully to any inquiries by PricewaterhouseCoopers LLP concerning these matters. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:8%"><FONT
  FACE="Times New Roman" SIZE="2" COLOR="#000000">The Company has requested that Andersen furnish it with a letter addressed to the Commission stating whether or not it agrees with the above statements. A copy of such letter, dated May 28, 2002 is
  filed as Exhibit 16 to this Form 8-K. </FONT></DIV>
  
  <p Style='page-break-before:always'>
  <HR  SIZE="3" COLOR="#CCEEFF" WIDTH="100%" ALIGN="CENTER">
   <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="text-indent:4%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">(2)&nbsp;&nbsp;&nbsp;&nbsp;New independent accountants </FONT></DIV> <DIV><FONT
  SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="margin-left:4%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">The Company engaged PricewaterhouseCoopers LLP (&#147;PWC&#148;) as its new independent accountants as of May 23, 2002. During the two
  most recent fiscal years and through the date of their engagement by the Company, the Company did not consult with PWC regarding issues of the type described in Item 304(a)(2) of Regulation S-K. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV>
  <DIV><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B></B><B><I>Item 7.&nbsp;&nbsp;&nbsp;&nbsp;Financial Statements and Exhibits </I></B><B></B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV STYLE="text-indent:4%"><FONT
  FACE="Times New Roman" SIZE="2" COLOR="#000000">Exhibit 16:&nbsp;&nbsp;&nbsp;&nbsp;Letter from Arthur Andersen LLP to the Securities and Exchange Commission </FONT></DIV>
  
  <p Style='page-break-before:always'>
  <HR  SIZE="3" COLOR="#CCEEFF" WIDTH="100%" ALIGN="CENTER">
   <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000"><B>SIGNATURES </B></FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV
  STYLE="text-indent:4%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned hereunto duly
  authorized. </FONT></DIV> <DIV><FONT SIZE="1">&nbsp;</FONT></DIV> <DIV>
  <TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0">
  
  <TR>
  <TD> <FONT SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="top" COLSPAN="3" WIDTH="43%"> <DIV><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">MATTSON TECHNOLOGY, INC.</FONT></DIV> </TD> </TR>
  <TR>
  <TD HEIGHT="16"> </TD> </TR>
  <TR>
  <TD VALIGN="top" WIDTH="52%"> <DIV STYLE="margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">Date: May 28, 2002</FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="top" WIDTH="3%"> <DIV STYLE="margin-left:2%; text-indent:-2%"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">By:</FONT></DIV> </TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="top" ALIGN="center" WIDTH="43%"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">/s/&nbsp;&nbsp;&nbsp;&nbsp;Ludger Viefhues&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT></DIV> <HR NOSHADE
  COLOR="#000000" ALIGN="left"></TD> </TR>
  <TR>
  <TD> <FONT SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;</FONT></TD>
  <TD> <FONT SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="bottom" WIDTH="3%"><FONT FACE="Times New Roman" SIZE="1">&nbsp;</FONT></TD>
  <TD VALIGN="bottom" ALIGN="center" WIDTH="43%"> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">Ludger Viefhues,</FONT></DIV> <DIV ALIGN="center"><FONT FACE="Times New Roman" SIZE="2" COLOR="#000000">Executive Vice
  President and Chief Financial Officer</FONT></DIV> </TD> </TR>
   </TABLE> </DIV>
   </BODY></HTML>
metadata_documents: [{"type": "8-K", "sequence": "1", "filename": "d8k.htm", "description": "FORM 8-K", "secsgml_size_bytes": 11658}]
metadata_filer: {"company-data": {"conformed-name": "MATTSON TECHNOLOGY INC", "cik": "0000928421", "assigned-sic": "3559", "irs-number": "770208119", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-24838", "film-number": "02663932"}, "business-address": {"street1": "2800 BAYVIEW DR", "city": "FREMONT", "state": "CA", "zip": "94538", "phone": "5106575900"}}
text: Prepared by R.R. Donnelley Financial -- Form 8-K
  UNITED STATES
  SECURITIES AND EXCHANGE COMMISSION
  Washington, D.C. 20549
  FORM 8-K
  CURRENT REPORT
  Pursuant to Section 13 or 15(d) of the
  Securities Exchange Act of 1934
  Date of Report (Date of earliest event reported) May 21, 2002
  MATTSON TECHNOLOGY, INC.
  (Exact name
  of registrant as specified in its charter)
  Delaware
  0-21970
  77-0208119
  (State or other jurisdiction of incorporation)
  (Commission File Number)
  (IRS Employer Identification No.)
  2800 Bayview Drive
  Fremont, California 94538
  (Address of principal executive offices) (Zip Code)
  Registrant's telephone number, including area code (510) 657-5900
  Item 4.    Changes in Registrant's Certifying Accountant
  (a)(1)    Previous independent accountants
  (i)    On May 21, 2002 the Company dismissed Arthur Andersen LLP ("Andersen") as its independent
  accountants. Andersen had served as the independent auditors of the Company since November 1, 1999.
  (ii)    The reports of Andersen on the financial statements of the Company for each of the past two fiscal years contained no adverse opinion or disclaimer of opinion and were not qualified or modified as to
  uncertainty, audit scope or accounting principle.
  (iii)    The decision to change independent
  accountants was approved by the Company's Audit Committee.
  (iv)    During the
  Company's two most recent fiscal years and through the date of this Report, the Company has had no disagreements with Andersen on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure,
  which disagreements, if not resolved to the satisfaction of Andersen, would have caused it to make reference thereto in its report on the financial statements of the Company for such periods.
  (v)    During the Company's two most recent fiscal years and through the date of this Report, the Company has had no reportable events under
  Item 304(a)(1)(v)(B), (C) or (D) of Regulation S-K. With reference to Item 304(a)(1)(v)(A), in its Memorandum on Internal Control in connection with the audit for 2001, Andersen noted four conditions that it considered to be reportable events. In
  particular, Andersen suggested that the Company needed to (i) better document the job descriptions, procedure manuals, and reporting lines within the finance organization, (ii) improve and formalize monitoring procedures regarding controller or
  management level review of entries posted by the staff, (iii) improve and automate procedures for month-end closings, and (iv) improve policies and procedures for tracking inventory balances. Company management did not disagree with the suggestions
  made by Andersen. The Company is currently addressing each of these conditions and believes it has made substantial progress toward implementing corrective measures. The Audit Committee of the Board of Directors discussed these matters with
  Andersen, and the Company has authorized Andersen to respond fully to any inquiries by PricewaterhouseCoopers LLP concerning these matters.
  The Company has requested that Andersen furnish it with a letter addressed to the Commission stating whether or not it agrees with the above statements. A copy of such letter, dated May 28, 2002 is
  filed as Exhibit 16 to this Form 8-K.
  (2)    New independent accountants
  The Company engaged PricewaterhouseCoopers LLP ("PWC") as its new independent accountants as of May 23, 2002. During the two
  most recent fiscal years and through the date of their engagement by the Company, the Company did not consult with PWC regarding issues of the type described in Item 304(a)(2) of Regulation S-K.
  Item 7.    Financial Statements and Exhibits
  Exhibit 16:    Letter from Arthur Andersen LLP to the Securities and Exchange Commission
  SIGNATURES
  Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned hereunto duly
  authorized.
  MATTSON TECHNOLOGY, INC.
  Date: May 28, 2002
  By:
  /s/    Ludger Viefhues
  Ludger Viefhues,
  Executive Vice
  President and Chief Financial Officer