Patent ID: 6396117
Filing Date: 2002-05-28
Classification: G02B,H01L

Abstract:
A semiconductor photodetector comprising:a first light-absorbing layer, a buffer layer of a second conductivity type, a second light-absorbing layer of a second conductivity type and a window layer of a second conductivity type laminated in said order onto a first principal surface of a substrate of a first conductivity type; said first light-absorbing layer comprising a region of a first conductivity type and a region of a second conductivity type provided in a laminated fashion in said order from the substrate; a diffused region of a first conductivity type having a depth extending from the upper face of said window layer to the interface between said window layer and said second light-absorbing layer, being provided in a portion of said window layer; a main electrode of a first conductivity type, electrically connected to said diffused region, being provided on said diffused region; a main electrode of a second conductivity type, electrically connected to said window region, being provided on said window region; an auxiliary electrode of a first conductivity type provided on a second principal surface of said substrate; and an interconnection for providing a shorting connection between said auxiliary electrode of a first conductivity type and said main electrode of a second conductivity type, said interconnection making a potential of said main electrode of a second conductivity type equal to a potential of said auxiliary electrode of a first conductivity type; wherein the energy gap wavelength of said second light-absorbing layer is longer than the energy gap wavelength of said first light-absorbing layer, and the energy gap wavelength of said first light-absorbing layer is longer than the respective energy gap wavelengths of said substrate, buffer layer and window layer.