Patent ID: 7825442
Filing Date: 2010-11-02
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor layer; a diffusion layer of one conductivity type, which is formed in the semiconductor layer, and which serves as a base region, wherein the diffusion layer of the one conductivity type comprises first and second diffusion layers of the one conductivity type, wherein the entirety of the second diffusion layer of the one conductivity type overlaps a formation region of the first diffusion layer of the one conductivity type; a first diffusion layer of opposite conductivity type, which is formed in the diffusion layer of the one conductivity type, and which serves as an emitter region; a second diffusion layer of the opposite conductivity type, which is formed in the semiconductor layer, and which serves as a collector region; a third diffusion layer of the opposite conductivity type, which is formed in the semiconductor layer, and which serves as the collector region, wherein, in a formation region of the third diffusion layer of the opposite conductivity type, the second diffusion layer of the opposite conductivity type and the diffusion layer of the one conductivity type are formed.