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:
Jul. 14, 1992
Filed:
Apr. 17, 1990
George E Possin, Schenectady, NY (US);
Siegfried Aftergut, Schenectady, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A method for photolithographically forming a mask includes the steps of: forming an island structure of opaque material on a principal surface of a transparent substrate; depositing at least one layer of transparent material on the principal substrate surface and over the island structure; depositing a layer of photoresist material over the at least one transparent layer; exposing a back-side substrate surface, opposite to the principal substrate surface, to UV light to cause exposure of at least a portion of the photoresist, corresponding substantially to an area outside of a shadow of the island structure; reflecting at least a portion of UV light back into the photoresist layer, by depositing a non-specular layer over the photoresist layer before UV exposure, to expose another portion of the photoresist layer a selected overlap distance within the island structure shadow; and removing the exposed photoresist portion to form a mask which is aligned with the island structure and narrower than the island structure by the selected overlap distance on each side thereof.