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:
May. 23, 2006
Filed:
Oct. 26, 2004
Teruhito Ohnishi, Osaka, JP;
Akira Asai, Osaka, JP;
Teruhito Ohnishi, Osaka, JP;
Akira Asai, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A SiGelayerfunctioning as the base composed of an i-SiGelayer and a pSiGelayer is formed on a collector layerand a Si cap layeras the emitter is formed on the pSiGelayer. An emitter lead electrodewhich is composed of an npolysilicon layercontaining phosphorus in a concentration equal to or lower than the solid-solubility limit for single-crystal silicon and a npolysilicon layercontaining phosphorus in a high concentration, is formed on the Si cap layerin a base openingThe impurity concentration distribution in the base layer is properly maintained by suppressing the Si cap layerfrom being doped with phosphorus (P) in an excessively high concentration. The upper portion of the Si cap layermay contain a p-type impurity. The p-type impurity concentration distribution in the base layer of an NPN bipolar transistor is thus properly maintained.