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:
Aug. 26, 1997
Filed:
Oct. 05, 1994
Chen-Chiu Hsue, Hsin-Chu, TW;
Ming-Tzong Yang, Hsin-Chu, TW;
United Microelectronics Corporation, Hsin-Chu, TW;
Abstract
A method of forming bipolar ROM device on a semiconductor substrate comprises forming a collector region by doping with a dopant of a first polarity, forming an array of common base regions by doping with a dopant of an opposite polarity, forming a plurality of emitter regions selectively in the base regions by doping with a dopant of first polarity and diffusing the dopant into the emitter regions from doped conductors, which conductors are formed as an array of conductors disposed orthogonally relative to the array of common base elements. The conductors are connected to emitter regions traversed thereby and are isolated from other regions by dielectric layers selectively formed over the other regions to prevent diffusion of dopant therethrough to prevent formation of such emitter regions.