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:
Mar. 24, 1992
Filed:
Jun. 15, 1990
Frank F Fang, Yorktown Heights, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A modulation doped base heterojunction bipolar transistor wherein the base is a modulation doped heterojunction formed of a layer of p wide gap semiconductor material and a layer of I narrow gap semiconductor material. The collector/base is formed with n+ narrow gap semiconductor material adjacent to the I region of the base. The emitter is n+ wide gap semiconductor material adjacent to the p wide gap layer of the base. The doping concentration and width of the p region of the base is such that all holes are depleted in that region, and a p type inversion layer is formed in the I narrow gap material at its interface with the p wide gap material. This structure provides a modulation doped base heterojunction bipolar transistor which exhibits low base resistance, enhanced performance at low temperatures, a built-in drift field, a reduced emitter injection barrier, no minority carrier storage effects in the base region, and a built-in hot electron effect.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile