SEMICONDUCTOR LIGHT DETECTING ELEMENT

摘要

A semiconductor light detecting element 1A is provided with a silicon substrate 2 having a semiconductor layer 20, and an epitaxial semiconductor layer 21 grown on the semiconductor layer 20 and having a lower impurity concentration than the semiconductor layer 20; and conductors provided on a surface of the epitaxial semiconductor layer 21. A photosensitive region is formed in the epitaxial semiconductor layer 21. Irregular asperity 22 is formed at least in a surface 2BK opposed to the photosensitive region in the semiconductor layer 20. The irregular asperity 22 is optically exposed.