Patent ID: 7755079

Claim:
An infrared focal plane array photodetector, comprising: a III-V compound semiconductor substrate; a plurality of III-V compound semiconductor layers epitaxially grown on the III-V compound semiconductor substrate, with the III-V compound semiconductor layers further comprising: a buffer layer above the substrate; a strained-layer superlattice above the buffer layer, with the strained-layer superlattice including a plurality of alternating layers of indium arsenide (InAs) and indium gallium antimonide (In x Ga 1−x Sb) with an indium content x in the range 0≦x≦0.5, and with the strained-layer superlattice having a semiconductor p-n or p-i-n junction formed therein; and a contact layer above the strained-layer superlattice; a substantially-planar passivation layer formed above the plurality of III-V compound semiconductor layers, with the substantially-planar passivation layer being etched to provide a two-dimensional (2-D) array of spaced-apart openings extending therethrough, with each opening defining the location of a photodetector element in the infrared focal plane array photodetector; an impurity-doped region extending down through the contact layer and at least partway into the strained-layer superlattice to electrically isolate each photodetector element from adjacent photodetector elements in the infrared focal plane array photodetector, with the strained-layer superlattice being contiguous across each photodetector element in the infrared focal plane array photodetector; and an electrode deposited in each opening through the substantially-planar passivation layer to provide an electrical connection to the photodetector element located therebeneath.