Patent ID: 7808065

Claim:
A semiconductor photosensitive element comprising: a semiconductor substrate of a first conductivity type; a stack of semiconductor layers on said semiconductor substrate and including a first light absorption layer, a first semiconductor layer of a second conductivity type, a first semiconductor layer of the first conductivity type, and a second light absorption layer, arranged in this order on said semiconductor substrate, said second light absorption layer including a region of the second conductivity type and on which light for detection is incident, wherein part of said stack of semiconductor layers includes a mesa having first and second side surfaces spaced from and on opposite sides of said region of the second conductivity type, and first and second bottom surfaces respectively transverse to and extending from said first and second side surfaces, said first side surface extending through said second light absorption layer and said first semiconductor layer of the first conductivity type to said first bottom surface, said first bottom surface exposing said first semiconductor layer of the second conductivity type; a first electrode electrically connected to said region of the second conductivity type; a second electrode connected to said semiconductor substrate; and a third electrode disposed on said first side surface of said mesa and electrically connecting said first semiconductor layer of the first conductivity type to said first semiconductor layer of the second conductivity type.