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:
Sep. 20, 1983
Filed:
Mar. 26, 1982
Peter L Young, North Wales, PA (US);
Sperry Corporation, New York, NY (US);
Abstract
During the process of vacuum deposition, metals and materials are evaporated at a point source so as to create a vapor which is dispersed isotropically. Layers of the evaporating material are deposited as built-up layers which have sharp vertical edges or steps at the areas defined by the photoresist stencil. When the line of sight of the depositing material is from an oblique angle, the layer being deposited can have a negative slope which appears as an undercut edge. The present invention employs a lift-off overhang photoresist stencil in conjunction with a relatively high pressure of inert gas in the vacuum chamber so as to promote collision of the evaporated atoms and molecules with the inert gas. The colliding atoms and molecules of the evaporating material no longer appear to be originating from a point source but appear to originate from an extended area in the end of the vacuum chamber and deposit under the overhang photoresist stencil so as to provide symmetrical positive slope step changes at the edges of the material being deposited.