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. 15, 2011
Filed:
Jul. 21, 2008
Kazuhiro Mochizuki, Tokyo, JP;
Hidekatsu Onose, Hitachi, JP;
Natsuki Yokoyama, Mitaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a bipolar device, such as transistor or a thyristor, the emitter layer or the anode layer is formed of two high-doped and low-doped layers, a semiconductor region for suppressing recombination comprising an identical semiconductor having an impurity density identical with that of the low-doped layer is present being in contact with a base layer or a gate layer and a surface passivation layer, and the width of the semiconductor region for suppressing recombination is defined equal with or longer than the diffusion length of the carrier. This provides, among other things, an effect of attaining reduction in the size of the bipolar transistor or improvement of the switching frequency of the thyristor without deteriorating the performance.