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:
Nov. 03, 1981
Filed:
Feb. 04, 1980
Hemraj K Hingarh, San Jose, CA (US);
Fairchild Camera & Instrument Corp., Mountain View, CA (US);
Abstract
A surface oriented lateral bipolar transistor having a base of narrow width is fabricated by using a doped polycrystalline silicon layer as an ion implantation mask when implanting ions for the emitter and base regions. In forming the doped polysilicon mask, a first layer of dopant masking material is formed on the surface of a semiconductor substrate, a second layer of undoped polysilicon is formed over the first layer, and a third layer of dopant masking material is formed over the second layer. Portions of the second and third layers are removed and a dopant is diffused into the exposed edge portion of the second layer. The third layer and the undoped portion of the second layer are then removed thereby leaving only the doped portion of the second layer on the first layer.