Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D originally filed on January 17, 2012 (including amendments thereto) with respect to the shares of Common Stock, par value $0.001 per share, of Mattson Technology, Inc.  This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated: July 10, 2013	POTOMAC CAPITAL PARTNERS II, L.P.
	By:	Potomac Capital Management II, L.L.C.
		General Partner
	By:	/s/ Paul J. Solit
	Name:	Paul J. Solit
	Title:	Co-Managing Member

POTOMAC CAPITAL MANAGEMENT II, L.L.C.
By:	/s/ Paul J. Solit
Name:	Paul J. Solit
Title:	Co-Managing Member

POTOMAC CAPITAL PARTNERS L.P.
By:	Potomac Capital Management, L.L.C.
	General Partner
By:	/s/ Paul J. Solit
Name:	Paul J. Solit
Title:	Managing Member

POTOMAC CAPITAL MANAGEMENT, L.L.C.
By:	/s/ Paul J. Solit
Name:	Paul J. Solit
Title:	Managing Member

/s/ Paul J. Solit

PAUL J. SOLIT

/s/ Eric Singer

ERIC SINGER