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:
Nov. 30, 2004
Filed:
Jan. 30, 2003
Yasuhiko Onishi, Nagano, JP;
Tatsuji Nagaoka, Nagano, JP;
Susumu Iwamoto, Nagano, JP;
Takahiro Sato, Nagano, JP;
Fuji Electric Co., Ltd., Tokyo, JP;
Abstract
A semiconductor device includes a drift region, which includes a first alternating conductivity type layer, and a peripheral region, which includes a second alternating conductivity type layer and a third alternating conductivity type layer in the surface portion of the peripheral region. The first layer includes first n-type regions and first p-type regions arranged alternately at a first pitch. The second layer is continuous with the first layer and includes second n-type regions and second p-type regions arranged alternately at the first pitch. The impurity concentration in the second layer is almost the same as the impurity concentration in the first layer. The third layer includes third n-type regions and third p-type regions arranged alternately at a second pitch. The third layer can be doped more lightly than the first and second alternating conductivity type layers. The second pitch can be the same as the first pitch or smaller.