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. 10, 1987
Filed:
Mar. 18, 1985
Satoshi Kudo, Takasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A process for producing semiconductor devices with a high-performance vertical pnp transistor having a high h.sub.fe and a high f.sub.T, comprising a step for forming an impurity region of a high concentration in a portion of a p-type buried layer and for increasing the concentration in a diffusion layer for isolation, a step for forming an n-type well region that reaches the p-type buried layer and that serves as a base of the vertical pnp transistor, and a step for forming an emitter of the vertical pnp transistor in a portion of said n-type well region, and for forming a collector electrode contact portion of the vertical pnp transistor, said contact portion reaching said impurity region of high concentration, by introducing p-type impurities into a portion of the p-type buried layer that serves as a portion of the collector of the vertical pnp transistor and into the p-type diffusion layer that works as an isolation layer or channel stop layer.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile