Semiconductor device having a high current gain and a higher Ge amount at the base region than at the emitter and collector regions, and photoelectric conversion apparatus using the device

摘要

A semiconductor device comprises at least an emitter region of a first conductivity type, a base region of a second conductivity type, and a collector region of a first conductivity type. The base region essentially consists of Si.sub.1-X Ge.sub.X (0 X 1), further comprises regions formed in a depletion layer close to an interface between the base region and the collector region or in the collector region and in a depletion layer close to an interface between the base region and the emitter region or in the emitter region, and has a larger Ge amount at the base region-side and a smaller Ge amount at the emitter and collector sides.