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:
Jan. 08, 1991
Filed:
Dec. 20, 1988
Katsuhiko Mitani, Kokubunji, JP;
Tomonori Tanoue, Ebina, JP;
Chushirou Kusano, Tokorozawa, JP;
Susumu Takahashi, Tokyo, JP;
Masayoshi Saito, Kokubunji, JP;
Hiroshi Miyazaki, Fuchu, JP;
Fumio Murai, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Microfabrication and large scale integration of a device can be realized by using a planar heterojunction bipolar transistor formed by a process comprising successively growing semiconductor layers serving as a subcollector, a collector, a base, and an emitter, respectively, through epitaxial growth on a compound semiconductor substrate in such a manner that at least one of the emitter junction and collector junction is a heterojunction, wherein a collector drawing-out metal layer is formed by the selective CVD method.