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. 17, 1987
Filed:
Mar. 19, 1985
Applicant:
Inventors:
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 30 ; 357 13 ; 357 16 ; 357 20 ; 357 52 ;
Abstract
An avalanche photodiode having a semiconducting light absorbing layer and an overlying avalanche gain layer of wide band-gap. The usual heavily doped region is formed in the avalanche gain region to form an abrupt p-n junction. Two semiconducting guard rings are formed around the heavily doped region. The doping of both rings provide graded p-n junctions with the avalanche gain layer. The inner guard ring extends more deeply into the avalanche gain layer than either the outer ring or the heavily doped region.