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:
Jul. 12, 2005
Filed:
Mar. 26, 2003
Masahiro Sakuragi, Kyoto, JP;
Masahiro Sakuragi, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A bipolar transistor is provided, which is low in collector-to-emitter saturation voltage, small in size and to be manufactured by a reduced number of processes, and a semiconductor device formed with such a bipolar transistor and a MOS transistor on a same substrate. A high concentration region for reducing the collector-to-emitter saturation voltage VCE(sat) is formed in a manner surrounding a base region of an NPN transistor. This high concentration region is not necessarily formed in such a depth as reaching a buried layer, and can be reduced in the spread in a lateral direction. Because a high concentration region can be formed in a same process as upon forming source and drain regions for an NMOS transistor to be formed together with an NPN transistor on a same silicon substrate, it is possible to omit a diffusion process exclusive for forming a high concentration region and hence to manufacture a semiconductor device through a reduced number of processes.