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:
Apr. 10, 2007
Filed:
Mar. 22, 2005
Manabu Imahashi, Osaka, JP;
Hiroyoshi Ogura, Kyoto, JP;
Masakatsu Nawate, Hyogo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor device includes an output pad and a surge absorption unit formed above a semiconductor region of a first conductivity type. The surge absorption unit includes: a semiconductor island region of a second conductivity type; a buried layer of the second conductivity type formed between a bottom of the semiconductor island region of the second conductivity type and the semiconductor region of the first conductivity type; a dopant layer of the first conductivity type formed in an upper portion of the semiconductor island region of the second conductivity type and connected to have the same potential as the semiconductor region of the first conductivity type; a dopant layer of the second conductivity type formed in an upper portion of the dopant layer of the first conductivity type and electrically connected to the output pad; and a ring layer of the second conductivity type surrounding the dopant layer of the first conductivity type and reaching the buried layer of the second conductivity type. In this device, the ring layer of the second conductivity type is electrically connected to a terminal with a fixed potential and contains a dopant of the second conductivity type having a higher concentration than the semiconductor island region of the second conductivity type.