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:
Aug. 24, 2021
Filed:
Jun. 21, 2019
Mitsubishi Electric Corporation, Tokyo, JP;
Katsumi Nakamura, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An object of the present invention is to provide stable withstand voltage characteristics, reduce turn-off losses along with a reduction in leakage current when the device is off, improve controllability of turn-off operations, and improve blocking capability at turn-off. An N buffer layer includes a first buffer layer joined to an active layer and having one peak in impurity concentration, and a second buffer layer joined to the first buffer layer and an Ndrift layer, having at least one peak point in impurity concentration, and having a lower maximum impurity concentration than the first buffer layer. The impurity concentration at the peak point of the first buffer layer is higher than the impurity concentration of the Ndrift layer, and the impurity concentration of the second buffer layer is higher than the impurity concentration of the Ndrift layer in the entire area of the second buffer layer.