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. 11, 1990
Filed:
Nov. 03, 1988
Robert T Fuller, Durham, NC (US);
Joseph C Tsang, Raleigh, NC (US);
William R Richards, Jr, Cary, NC (US);
Harris Corporation, Melbourne, FL (US);
Abstract
A semiconductor material is overlayed with sequentially stacked layers including a protective layer, an affinity layer having an affinity for a second implant blocking material comprising tungsten, a first implant blocking layer and a masking layer having a first pattern. A portion of the first blocking layer not being masked is removed to expose a first portion of the affinity layer and a first dopant is implanted into the underlying semiconductor through the exposed first portion of the affinity layer. The mask is removed to expose the first blocking layer and a second blocking layer is formed from the second blocking material over the exposed first portion of the affinity layer but not over the exposed first blocking layer. The first blocking layer is removed to expose a second portion of the affinity layer which constitutes a second pattern. A second dopant is implanted into the underlying semiconductor through the exposed second portion of the affinity layer. The first blocking layer may include silicon oxide, the second blocking layer may include tungsten and the affinity layer may include polysilicon.