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. 06, 1996
Filed:
Apr. 14, 1995
Sheng-Hsing Yang, Hsinchu, TW;
Ying-Tzung Wang, Hsinchu, TW;
United Microelectronics Corporation, Hsinchu, TW;
Abstract
A process of fabricating a bipolar junction transistor forms, on the substrate, a masking layer including an opening, an intermediate masking portion surrounded by the opening and an outer masking portion. The masking layer consists of a pad oxide and a silicon nitride. A photoresist is then formed on the outer masking portion. A first ion implantation process at a relatively low dose and a relatively high energy is performed to form a base region underlying the intermediate masking portion, and a second ion implantation process at a relatively high dose and a relatively low energy is performed to form a base contact region underlying the opening. Then, the photoresist is removed. A field oxide is grown in the opening of the masking layer, followed by removing the masking layer. A highly-doped polysilicon layer is deposited over the structure, and a rapid thermal annealing process is performed to diffuse the impurities within the polysilicon layer into the substrate to form an emitter region in the base region and to form a collector contact region, by using the field oxide as a mask.