SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

STEAG ELECTRONIC SYSTEMS AG

(Last)

(First)

(Middle)

RUETTENSCHEIDER STRASSE 1-3

(Street)

ESSEN

45128

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
MATTSON TECHNOLOGY INC [ MTSN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

Director	X	10% Owner
Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
07/25/2005

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	07/25/2005		S		12,500	D	$8.87	123,074	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		7,500	D	$8.89	115,574	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		9,076	D	$8.9	106,498	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		200	D	$8.91	106,298	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		1,005	D	$8.92	105,293	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		6,081	D	$8.93	99,212	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		1,000	D	$8.94	98,212	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		920	D	$8.95	97,292	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		200	D	$8.96	97,092	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		3,400	D	$9	93,692	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		2,600	D	$9.1	91,092	I	By Limited Liability Company⁽¹⁾
Common Stock	07/25/2005		S		1,300	D	$9.12	89,792	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		120	D	$8.6	89,672	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		100	D	$8.61	89,572	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		1,450	D	$8.72	88,122	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		400	D	$8.9	87,722	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		50	D	$8.91	87,672	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		710	D	$8.92	86,962	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		2,290	D	$8.95	84,672	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		2,418	D	$9	82,254	I	By Limited Liability Company⁽¹⁾
Common Stock	07/26/2005		S		2,000,000	D	$8.25	5,061,144	D⁽²⁾

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

1. Name and Address of Reporting Person^*

STEAG ELECTRONIC SYSTEMS AG

(Last)

(First)

(Middle)

RUETTENSCHEIDER STRASSE 1-3

(Street)

ESSEN

45128

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director	X	10% Owner
Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

RAG AKTIENGESELLSCHAFT

(Last)

(First)

(Middle)

RELLINGHAUSER STRASSE 1-11

(Street)

ESSEN

D-45128

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director	X	10% Owner
Officer (give title below)		Other (specify below)

Explanation of Responses:

1. These shares represent the 50% proportionate interest of STEAG Electronic Systems AG ("SES") and RAG Aktiengesellschaft ("RAG") in shares of Mattson stock owned by West STEAG Partners GmbH, a German limited liability corporation ("WSP"). WSP is a venture capital firm, 50% of the capital of which is owned by SES. WSP does not act, and has no agreement with SES or RAG to act, together with SES and/or RAG for the purpose of acquiring, holding, voting or disposing of Mattson Stock. Accordingly, WSP does not beneficially own any of the shares of Mattson Stock beneficially owned by SES and RAG other than the 164,508 shares of Mattson Stock owned by WSP (after taking into account the sales by WSP of Mattson Stock disclosed on this Form 4).

2. These shares are owned directly by SES, an indirect wholly owned subsidiary of RAG, and indirectly by RAG.

Remarks:

	STEAG Electronic Systems AG, By: /s/ Wilhelm Pueschel, Member of the Board; By: /s/ Werner Beder, Member of the Board	07/27/2005
	RAG Aktiengesellschaft, By: /s/ Dr. Ignace van Meenen, Senior Vice President; By: /s/ Dr. Norbert Schellen, Legal Counsel	07/27/2005
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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