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:
Mar. 13, 1984
Filed:
Mar. 21, 1983
Stephen E Bernacki, Northboro, MA (US);
Bernard B Kosicki, Acton, MA (US);
Sperry Corporation, New York, NY (US);
Abstract
A method for dry anisotropic etching of semiconductor material by a reactive gas infused in the presence of a low-pressure plasma discharge uses a photoresist mask superposed on a semiconductive film with the slope of the photoresist edges defined within a critical angular range to allow selective formation of a protective polymer film which prevents lateral etching of the edges of the photoresist and sidewalls of the film, while not inhibiting vertical etching, thereby allowing precision definition of the etched pattern. A novel technique to determine the conditions of the photoresist sidewall geometry necessary for polymer film formation and predictable etching behavior encapsulates the film in a thick layer of photoresist, which after cleaving the structure permits selectively etching the photoresist to expose and retain the polymer film without deformation.