Patent ID: 6870207

Claim:
A semiconductor imaging device, comprising: a) a semiinsulating gallium arsenide (GaAs) substrate; b) a distributed Bragg reflector mirror epitaxially grown on said semiinsulating GaAs substrate; c) a first layer of P+ type GaAs deposited on said distributed Bragg reflector mirror for contacting a collector electrode; d) at least one layer of aluminum gallium arsenide (AlGaAs) disposed on said first layer of P+ type GaAs; e) an epitaxial layer structure of at least one quantum well of InGaAs having GaAs layers on each either side; f) a first spacer layer of AlGaAs disposed on said epitaxial layer structure; g) an N type modulation doped layer of AlGaAs disposed on said first spacer layer; h) a second spacer layer of AlGaAs disposed on said modulation doped layer; i) a planar doped layer of P+ type AlGaAs disposed on said second spacer layer; j) a cladding layer of AlGaAs of modest P type doping disposed on said planar doped layer; and k) a layer of GaAs of P++ type doping disposed on said cladding layer for contacting a gate electrode, wherein a forward bias is applied to said gate electrode with respect to said collector electrode such that light incident on said semiconductor imaging device causes charge to leave said at least one quantum well.