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:
Apr. 18, 2006
Filed:
Mar. 26, 2004
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
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 mesa is formed, followed by successive formation of gold germanium, nickel and Au in this order over the entire surface of a substrate, so that the resulting stacked film will not become an isolated pattern. Thus, the stacked film over the base mesa is connected to a stacked film at the outer periphery of the region OA, facilitating peeling of the stacked film over the base mesa. 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 which hardly reacts with an n-type GaAs layer or n-type InGaAs layer.