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:
Jul. 15, 2003
Filed:
Jan. 31, 2001
Heterojunction bipolar transistor, manufacturing method therefor, and communication device therewith
Yoshiteru Ishimaru, Tenri, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An emitter of a heterojunction bipolar transistor has a double-layer protrusion formed of a first emitter layer and a second emitter layer and protruded outside an external base region. The protrusion of 50 nm in total thickness is enough to prevent damage during formation of the protrusion by etching or during later fabricating processes. Penetration of moisture through damaged places is eliminated. A base ohmic electrode is continuously formed on the first and second emitter layers on the external base region up to the protrusion. Thus, the protrusion is reinforced so as to be further hard to damage. By ensuring a large area for the base ohmic electrode, an alignment margin can be taken during formation of a base lead electrode.