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. 12, 2020
Filed:
Feb. 04, 2019
Fuji Electric Co., Ltd., Kawasaki-shi, JP;
Hiroshi Takishita, Matsumoto, JP;
Takashi Yoshimura, Matsumoto, JP;
Masayuki Miyazaki, Matsumoto, JP;
Hidenao Kuribayashi, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., Kawasaki-Shi, JP;
Abstract
Proton irradiation is performed a plurality of times from rear surface of an n-type semiconductor substrate, which is an ndrift layer, forming an n-type FS layer having lower resistance than the n-type semiconductor substrate in the rear surface of the ndrift layer. When the proton irradiation is performed a plurality of times, the next proton irradiation is performed to as to compensate for a reduction in mobility due to disorder which remains after the previous proton irradiation. In this case, the second or subsequent proton irradiation is performed at the position of the disorder which is formed by the previous proton irradiation. In this way, even after proton irradiation and a heat treatment, the disorder is reduced and it is possible to prevent deterioration of characteristics, such as increase in leakage current. It is possible to form an n-type FS layer including a high-concentration hydrogen-related donor layer.