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:
Jun. 23, 1992
Filed:
Sep. 10, 1990
Makoto Hideshima, Tokyo, JP;
Tetsujiro Tsunoda, Fujisawa, JP;
Masashi Kuwahara, Yokohama, JP;
Shingo Yanagida, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a power semiconductor device such as an IGBT, a fifth region of n conductivity type is provided. The fifth region is formed in a portion of a second region (drain region) contacting an insulating layer below the gate layer. The fifth region contacts a third region (base region) and has an impurity concentration higher than that of the second region. Therefore, even when a carrier life time is sufficiently short, an electron distribution density can be kept high in the entire fifth region and the second region under the third region (base region) near the fifth region, and the localization of a hole current is moderated (in a case of a p-type base and an n-type drain). As a result, a maximum controllable current is increased, and a wide safe operation area can be obtained.