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:
Sep. 06, 2005
Filed:
Jul. 02, 2004
Akira Asai, Osaka, JP;
Teruhito Ohnishi, Osaka, JP;
Takeshi Takagi, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A SiGe spacer layera graded SiGe base layerincluding boron, and an Si-cap layerare sequentially grown through epitaxial growth over a collector layeron an Si substrate. A second deposited oxide filmhaving a base opening portionand a P+ polysilicon layerthat will be made into an emitter connecting electrode filling the base opening portion are formed on the Si-cap layerand an emitter diffusion layeris formed by diffusing phosphorus into the Si-cap layerWhen the Si-cap layeris grown, by allowing the Si-cap layerto include boron only at the upper part thereof by in-situ doping, the width of a depletion layeris narrowed and a recombination current is reduced, thereby making it possible to improve the linearity of the current characteristics.