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, 2010
Filed:
Dec. 01, 2006
Monir El-diwany, Saratoga, CA (US);
Alexei Sadovnikov, Sunnyvale, CA (US);
Jamal Ramdani, Scarborough, ME (US);
Monir El-Diwany, Saratoga, CA (US);
Alexei Sadovnikov, Sunnyvale, CA (US);
Jamal Ramdani, Scarborough, ME (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A method for forming a self-aligned bipolar transistor structure uses the selective growth of a doped silicon emitter in a sloped oxide emitter window to form the self-aligned structure. In an alternate process flow, the top emitter layer is SiGe with a high Ge content that is etched off selectively after deposition of the extrinsic base layer. In another alternate flow, a nitride plug formed on top of the emitter blocks the extrinsic base implant from the emitter region.