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:
May. 08, 2007
Filed:
Oct. 25, 2005
Atsushi Kurokawa, Takasaki, JP;
Hiroshi Inagawa, Maebashi, JP;
Toshiaki Kitahara, Misato, JP;
Yoshinori Imamura, Sagamiko, JP;
Atsushi Kurokawa, Takasaki, JP;
Hiroshi Inagawa, Maebashi, JP;
Toshiaki Kitahara, Misato, JP;
Yoshinori Imamura, Sagamiko, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
Provided is a technique of improving the properties of a bipolar transistor. Described specifically, upon formation of a collector electrode around a base mesa by the lift-off method, a resist film is formed over connection portions between the outer periphery of a region OAand a region in which the base mesais formed, followed by successive formation of gold germanium (AuGe), nickel (Ni) and Au in the order of mention over the entire surface of a substrate so that the stacked film of them will not become an isolated pattern. As a result, the stacked film over the base mesais connected to a stacked film at the outer periphery of the region OA, facilitating peeling of the stacked film over the base mesa. In addition, generation of side etching upon formation of a via hole extending from the back side of the substrate to a backside via electrode is reduced by forming the backside via electrode using a material such as WSi which hardly reacts with an n type GaAs layer or n type InGaAs layer.