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:
Feb. 21, 2006
Filed:
Jan. 05, 2004
Kazuhiro Mochizuki, Tokyo, JP;
Tohru Oka, Osaka, JP;
Isao Ohbu, Sagamihara, JP;
Kiichi Yamashita, Shiroyama, JP;
Kazuhiro Mochizuki, Tokyo, JP;
Tohru Oka, Osaka, JP;
Isao Ohbu, Sagamihara, JP;
Kiichi Yamashita, Shiroyama, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
A semiconductor device comprising a plurality of heterojunction bipolar transistors with their base layer made of GaAsSb or InGaAs, a GaAs substrate, and a buffer layer placed between the base layer and the substrate is fabricated. The substrate and the buffer layer that lie directly under the intrinsic regions of a part or all of the plurality of heterojunction bipolar transistors are removed. Thereby, a semiconductor device using HBTs that can operate with a power supply voltage of 2V or below can be provided at reduced cost as a well-reliable product, and a power amplifier with high power conversion efficiency can be provided.