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.

Date of Patent:
May. 18, 2010

Filed:

Dec. 08, 2006
Applicants:

Mitsuru Soma, Saitama, JP;

Hirotsugu Hata, Gunma, JP;

Minoru Akaishi, Gunma, JP;

Inventors:

Mitsuru Soma, Saitama, JP;

Hirotsugu Hata, Gunma, JP;

Minoru Akaishi, Gunma, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 21/8228 (2006.01);
U.S. Cl.
CPC ...
Abstract

In a semiconductor device of the present invention, an epitaxial layer is formed on a P type single crystal silicon substrate. Isolation regions are formed in the epitaxial layer, and are divided into a plurality of element formation regions. An NPN transistor is formed in one of the element formation regions. An N type diffusion layer is formed between a P type isolation region and a P type diffusion layer which is used as a base region of the NPN transistor. This structure makes the base region and the isolation region tend not to be short-circuited. Hence, the breakdown voltage characteristics of the NPN transistor can be improved.


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