Patent ID: 7211829
Filing Date: 2007-05-01
Classification: H01L,Y02E

Abstract:
1. A semiconductor photodetector device comprising: a first semiconductor layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type; and a second semiconductor layer of a second conductivity type formed on the first semiconductor layer and having a light-receiving region, wherein the first semiconductor layer includes a first region of the first conductivity type and a second region of the first conductivity type formed on the first region and containing an impurity at a concentration lower than that of the first region, and the second semiconductor layer includes in the light-receiving region, a third region containing an impurity of the second conductivity type at a concentration equal to or higher than that of the second region and a fourth region of the second conductivity type selectively formed in an internal space and below an upper surface of the third region and containing an impurity at a concentration higher than that of the third region.