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. 16, 1999
Filed:
Sep. 27, 1996
Katsumi Ishikawa, Hitachi, JP;
Katsuaki Saito, Hitachi, JP;
Yutaka Sato, Hitachi, JP;
Atsuo Watanabe, Hitachiota, JP;
Shuji Katoh, Hitachi, JP;
Naohiro Momma, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a semiconductor device, such as a diode and thyristor, having at least one pn junction between a pair of main surfaces, a first main electrode formed on the surface of one of the main surfaces and a second main electrode formed on the surface of the other one of the main surfaces, a semiconductor lattice defect is formed such that its lattice defect density increases gradually in the direction from the first main electrode to the second main electrode. Since the distribution of the carrier density in the conduction state can be flattened, the reverse recovery charge can be reduced substantially without causing the ON-state voltage to increase.