The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 04, 2001
Filed:
Jul. 30, 1999
Robert Innes, Richmond, CA (US);
Lee H. Veneklasen, Castro Valley, CA (US);
Allan L. Sagle, Berkeley, CA (US);
Sergey Babin, Castro Valley, CA (US);
Chen Hwa, Fremont, CA (US);
Etec Systems, Inc., Hayward, CA (US);
Abstract
A shield assembly for reducing electron fogging effects in electron beam lithography. This shield, located between an electron beam column final aperture and the beam target, is of multiple vanes with sharp edges pointing towards the electron beam incident point on the target; the vanes are conically shaped and concentric around the electron beam path, which travels through the center of the assembly. Additionally, the sharp edges are such that they present oblique surfaces at the ends of the vanes angled between 10° and 20° relative to the outer vane surface and these oblique surfaces face towards the electron beam path. Furthermore, the shield assembly may also have the vanes angled towards the beam incident point such that the vertex of the conical vane assembly is coincident with the beam incident point.