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:
Oct. 05, 2004
Filed:
Jan. 08, 2002
Roger E. Welser, Providence, RI (US);
Paul M. Deluca, Providence, RI (US);
Barbara E. Landini, North Attleboro, MA (US);
Kopin Corporation, Taunton, MA (US);
Abstract
InP heterojunction bipolar transistors having a base layer of InGaAs which are compositionally graded to engineer the bandgap of the base layer to be larger at the emitter/base junction than at the collector/base junction. The graded bandgap can increase DC current gain and speed of the device. A metalorganic chemical vapor deposition method of preparing InP heterojunction bipolar transistors having a base layer with a relatively high concentration of carbon dopant. The high carbon dopant concentration lowers the base sheet resistivity and turn-on voltage of the device.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile