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. 28, 1989
Filed:
Oct. 06, 1986
Hirobumi Ouchi, Hino, JP;
Ichiro Fujiwara, Kawasaki, JP;
Hiroshi Matsuda, Hachioji, JP;
Kazuhiro Ito, Nishitama, JP;
Kazuyuki Nagatsuma, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An avalanche photodiode including a substrate, a first semiconductor region of a first conductivity type having a relatively large band gap, a second semiconductor region of a second conductivity type having a relatively large band gap, and a third semiconductor region of the first conductivity type having a band gap smaller than the band gap of the first and second semiconductor regions, is disclosed in which, in order to suppress an increase in dark current and to cause the avalanche photodiode to operate on a low voltage, a fourth semiconductor region equal in conductivity type to and larger in impurity concentration than the first semiconductor region is formed in the first semiconductor region at a position below a central portion of a pn junction formed between the first semiconductor region and the second semiconductor region. The avalanche photodiode formed with this structure has low-noise and low operation voltage characteristics.