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:
Sep. 03, 1996
Filed:
May. 10, 1995
Albert Bergemont, Palo Alto, CA (US);
Carver A Mead, Pasadena, CA (US);
Min-hwa Chi, Palo Alto, CA (US);
Hosam Haggag, Santa Clara, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A capacitor coupled contactless imager structure and a method of manufacturing the structure results is a phototransistor that structure includes an N-type collector region formed in P-type semiconductor material. A P-type base region is formed in the collector region. An n-doped polysilicon emitter contact is formed in contact with the surface to the P-type base region such that an n+ epitaxial region is formed in the base region as the emitter of the phototransistor. Silicon dioxide separates the poly1 emitter contact and exposed surfaces at the base region from a layer of poly2 about 3000-4000 .ANG. thick that partially covers the base region; the gates of the CMOS peripheral devices are also poly2. The poly2 over the base region serves as a base coupling capacitor and a row conductor for the imager structure. The thickness of the poly2 capacitor plate allows it to be doped utilizing conventional techniques and silicided to improve the RC constant.