PHOTOSENSITIVE ELEMENT WITH BUILT-IN CIRCUIT

摘要

PROBLEM TO BE SOLVED: To realize high photosensitivity, rapid processing and low consumption current, and prevent lowering of S/N. SOLUTION: A photodiode 27 where a photosensitive layer 17a is constituted of an SiGe layer and a bipolar transistor 28 as a signal processing circuit of the photodiode 27 are provided on an SOI substrate 29. A base layer 17b of the bipolar transistor 28 is also constituted of an SiGe layer.