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. 30, 1993
Filed:
Apr. 03, 1991
Douglas P Verret, Sugarland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
Disclosed is a process for forming a bipolar transistor at the face (22) of a semiconductor layer. A refractory metal layer (34) is deposited on the face (22) to cover a base area (38) thereof. A dopant (40) is implanted through the metal layer (34) within the base area (38) to penetrate the face (22). The metal layer (34) is then removed from the face within an emitter area (48) contained within the base area (38). A dopant is then diffused into the face within the emitter area (48). Finally, the dopants are annealed to form a shallow base region (66) that spaces an emitter region (64) from a collector region (12, 14). The process of the invention can form a high-concentration emitter/base junction only 400 Angstroms from the surface of the semiconductor layer.