Light-receiving element

摘要

A light-receiving element includes a semiconductor substrate of a first conductivity type; a first semiconductor layer of a second conductivity type which is formed in a predetermined region on a surface of the semiconductor substrate of the first conductivity type; and at least one semiconductor region of the first conductivity type which is formed so as to extend from an upper surface of the first semiconductor layer of the second conductivity type to the surface of the semiconductor substrate of the first conductivity type, thereby dividing the first semiconductor layer of the second conductivity type into a plurality of semiconductor regions of the second conductivity type. In the light-receiving element, a specific resistance of the semiconductor substrate of the first conductivity type is set in a predetermined range such that a condition Xd>/=Xj is satisfied between a depth Xd of a depletion layer to be formed in the semiconductor substrate of the first conductivity type upon an application of an inverse bias and a diffusion depth Xj of the semiconductor region of the first conductivity type into the semiconductor substrate of the first conductivity type.