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:
Feb. 25, 1997
Filed:
Oct. 07, 1994
Hung-Sheng Chen, San Jose, CA (US);
Chih S Teng, San Jose, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
In fabricating a bipolar transistor, semiconductor dopant is introduced into a semiconductor body during a base doping operation to define a doped region, part of which constitutes a base region for the transistor. The base doping operation entails ion implanting the dopant into the body at a tilt angle of at least 15.degree. relative to the vertical. The minimum lateral base thickness and, when the base region abuts a slanted sidewall of a field insulating region, the minimum sidewall base thickness increase relative to the minimum vertical base thickness. As a result, the magnitude of the collector-to-emitter breakdown voltage typically increases. The minimum lateral, sidewall, and vertical base thicknesses vary with the tilt angle and base-implant energy in such a manner that the minimum lateral base thickness and the minimum sidewall base thickness are separately controllable from the minimum vertical base thickness.