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:
Mar. 08, 2011
Filed:
Aug. 27, 2008
Hiroyasu Ishida, Gunma, JP;
Yasuyuki Sayama, Ota, JP;
Hiroyasu Ishida, Gunma, JP;
Yasuyuki Sayama, Ota, JP;
Sanyo Electric Co., Ltd, Osaka, JP;
Sanyo Semiconductor Co., Ltd, Gunma, JP;
Abstract
Formation and etching of an n type epitaxial layer and formation and etching of a p type epitaxial layer are alternately performed on the semiconductor substrate for at least three times to form all semiconductor layers, of the epitaxial layers. Thereby, impurity concentration profiles of the semiconductor layers can be uniform, and pn junctions can be formed vertically to a wafer surface. Furthermore, the semiconductor layers can each be formed with a narrow width, so that impurity concentrations thereof are increased. With this configuration, high breakdown voltage and low resistance can be achieved.