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:
May. 06, 2003
Filed:
Oct. 18, 2000
Applicant:
Inventor:
Naohiro Shimizu, Nagoya, JP;
Assignee:
NGK Insulators, Inc., Nagoya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 2/1337 ;
U.S. Cl.
CPC ...
H01L 2/1337 ;
Abstract
Plural p -type regions are formed on a silicon substrate, and thereafter, an n-type epitaxial growth layer is formed. Narrow concave portions are formed to extend between the surface of the epitaxial growth layer and the silicon substrate and to have the almost the same lateral sectional shape. As a result, remaining parts, which are defined by the concave portions, of the epitaxial growth layer on p -type field limiting rings are separated from the silicon substrate. Thus, a depletion layer is spread beyond the field limiting rings and a large forward voltage-resistance can be realized.