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:
Dec. 08, 1998
Filed:
Dec. 17, 1996
Takayuki Gomi, Tokyo, JP;
Hiroaki Ammo, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A method of producing a bipolar transistor includes the step of forming an emitter contact layer containing a high concentration of impurity by means of plasma doping or solid-state diffusion without causing diffusion of impurity in a base layer. This makes it possible to realize a thin base layer having a high impurity concentration. The invention also provides a method of producing a semiconductor device including a bipolar transistor and another device element such as a resistor element including a polysilicon layer containing an activated impurity in such a manner that both the bipolar transistor and the device element are disposed on the same single substrate, the method including the steps of: forming a polysilicon layer containing an activated impurity on the surface of a substrate; and then forming a base layer of the bipolar transistor. This method prevents the base layer from being affected by heat treatment on the polysilicon layer.