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:
Sep. 05, 2000
Filed:
Feb. 10, 1999
Applicant:
Inventors:
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438270 ; 438272 ; 257328 ; 257329 ; 257330 ; 257335 ;
Abstract
In a semiconductor device having a substrate, a p-type semiconductor layer, an n-type channel well region, a p-type lightly doped source region, and a source electrode formed on the substrate in this order, a p-type heavily-doped source region, an impurity concentration of which is higher than that of the lightly-doped source region, is formed in a surface region of the lightly-doped source region. The source electrode is formed to contact the heavily-doped source region. As a result, a punch through phenomenon between the p-type source region and the p-type semiconductor layer through the n-type channel well region can be prevented without increasing in the On resistance of the semiconductor device.