Circuit-integrated light-receiving device

Abstract

A circuit-integrated light-receiving device of the present invention includes: a semiconductor substrate of a first conductivity type; a first semiconductor crystal growth layer of the first conductivity type provided on a surface of the semiconductor substrate, wherein the first semiconductor crystal growth layer includes a first portion whose impurity concentration gradually decreases in a direction away from the surface of the semiconductor substrate and a second portion located in a first region above the first portion whose impurity concentration distribution is uniform in a depth direction; a buried diffusion layer of the first conductivity type located in a second region which is above the first portion of the first semiconductor crystal growth layer and does not overlap the first region; a second semiconductor crystal growth layer of a second conductivity type which is provided across a surface of the first semiconductor crystal growth layer and a surface of the buried diffusion layer; and a separation diffusion region having the first conductivity type for dividing the second semiconductor crystal growth layer into a light-receiving device section and a signal processing circuit section. The first region is located in the light-receiving device section. In the signal processing circuit section, the buried diffusion layer is in contact with the first portion of the first semiconductor crystal growth layer.