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:
Dec. 15, 2020
Filed:
May. 31, 2019
Fuji Electric Co., Ltd., Kawasaki, JP;
Takeshi Tawara, Tsukuba, JP;
Koji Nakayama, Tsukuba, JP;
Yoshiyuki Yonezawa, Tsukuba, JP;
Hidekazu Tsuchida, Yokosuka, JP;
Koichi Murata, Yokosuka, JP;
FUJI ELECTRIC CO., LTD., Kawasaki, JP;
Abstract
During epitaxial growth of an n-type drift layer having a uniform nitrogen concentration, vanadium is doped in addition to the nitrogen, whereby an n-type lifetime reduced layer is selectively formed in the n-type drift layer. The n-type lifetime reduced layer is disposed at a depth that is more than 5 μm from a pn junction surface between a p-type anode layer and the n-type drift layer in a direction toward a cathode side, and the n-type lifetime reduced layer is disposed separated from the pn junction surface. Further, the n-type lifetime reduced layer is disposed in a range from the pn junction surface to a depth that is ⅓ times a thickness of the n-type drift layer. A vanadium concentration of the n-type lifetime reduced layer is 1/100 to ⅕ of a nitrogen concentration of the n-type lifetime reduced layer.