Strained-layer superlattice focal plane array having a planar structure

摘要

An infrared focal plane array (FPA) is disclosed which utilizes a strained-layer superlattice (SLS) formed of alternating layers of InAs and In_xGa_1−xSb with 0≦x≦0.5 epitaxially grown on a GaSb substrate. The FPA avoids the use of a mesa structure to isolate each photodetector element and instead uses impurity-doped regions formed in or about each photodetector for electrical isolation. This results in a substantially-planar structure in which the SLS is unbroken across the entire width of a 2-D array of the photodetector elements which are capped with an epitaxially-grown passivation layer to reduce or eliminate surface recombination. The FPA has applications for use in the wavelength range of 3-25 μm.