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:
Apr. 21, 2009
Filed:
Jun. 21, 2007
Takashi Kobayashi, Nagano, JP;
Koji Sasaki, Nagano, JP;
Yasuharu Mikoshiba, Nagano, JP;
Masahiro Kato, Nagano, JP;
Takashi Kobayashi, Nagano, JP;
Koji Sasaki, Nagano, JP;
Yasuharu Mikoshiba, Nagano, JP;
Masahiro Kato, Nagano, JP;
Fuji Electric Device Technology Co., Ltd., Tokyo, JP;
Abstract
A semiconductor device includes a semiconductor substrate which has first and second principal surface regions; an insulated gate structure which is formed in the first principal surface region; a back surface region semiconductor layer which is formed in the second principal surface region and has a thickness of at most 5 μm; an outermost metal film; and a back surface electrode which is formed in the second principal surface region between the back surface region semiconductor layer and the outermost metal film and which is composed of a plurality of films which are laminated and include a stress relaxation film so that false judgment of chip quality based on leakage current measurements during manufacturing is reduced particularly when dust is present and skews leakage current measurements due to strain on the wafer and the piezoelectric effect produced.