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:
Jun. 16, 2009
Filed:
Jun. 28, 2007
Ryo Kanda, Gunma, JP;
Iwao Takahashi, Gunma, JP;
Yoshinori Sato, Gunma, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A conventional semiconductor device has a problem that it is difficult to obtain a desired breakdown voltage characteristic due to a reduction in a punch-through breakdown voltage between drain and source regions. In a semiconductor device according to the present invention, a P type diffusion layer is formed in an N type epitaxial layer. An N type diffusion layer as a back gate region is formed in the P type diffusion layer. The N type diffusion layer is formed by self-alignment using a drain electrode. This structure makes it possible to increase an impurity concentration of the N type diffusion layer in a vicinity of a P type diffusion layer as a source region. As a result, it is possible to improve a punch-through breakdown voltage between the drain and the source regions, and to achieve a desired breakdown voltage characteristic of the MOS transistor.