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:
Jun. 12, 1990
Filed:
Mar. 10, 1989
George W Conner, Ben Lomond, CA (US);
Raymond G Donald, San Jose, CA (US);
Ronald L Cline, Los Gatos, CA (US);
North American Philips Corporation, Signetics Division, Sunnyvale, CA (US);
Abstract
A semiconductor PROM contains a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22) fully adjoining a recessed oxide insulating region (16). A composite buried layer consisting of buried regions (32) which adjoin the insulating region below the lower cell regions (20) and an opposite-conductivity buried web (44) which laterally surrounds each buried region is employed to improve programming efficiency. Connective regions (46) extend from the buried web to the upper semiconductor surface to contact electrical leads (54) typically arranged in a parallel pattern. The maximum dopant concentration in the intermediate cell regions occurs vertically within 20% of their mid-points.