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:
Feb. 23, 1993
Filed:
Aug. 29, 1988
William L Ahlgren, Goleta, CA (US);
Santa Barbara Research Center, Goleta, CA (US);
Abstract
A double layer heterojunction array 10 of IR photodiodes has formed within an upper planar surface region of a collector layer 16 a plurality of isolation junctions 20 which are disposed between individual photodiodes. The isolation junctions are formed by a thermally driven process of type-converting the p-type or n-type collector layer to the opposite type of material. This type conversion forms p-n homojunctions at the edges of the isolation junctions which isolate the individual photodiodes one from another. The type-conversion process of the invention provides two isotype junctions which together reflect excess minority charge carriers away from the surface of the device as well as from neighboring photodiodes. One method of the invention discloses the selective annealing of the surface of an n-type collector layer to extract mercury atoms thereby creating mercury vacancies which act as acceptors. Other methods disclose the type conversion as being accomplished by the selective diffusion of a dopant layer into the collector layer.