Affordable Large-Format Mid-Infrared (IR) Imagers Using Large Metamorphic InSb-on-GaAs Wafers

We propose epitaxial InSb grown on large metamorphic GaAs substrates as a platform to enable large affordable midwave infrared focal plane arrays (FPAs). In Phase 1, we developed buffers to accommodate the InSb/GaAs lattice mismatch and quantified their effectiveness by fabricating hybrid chips of 320x256 arrays of detector pixels flip-chip bump-bonded to matching fanouts and readout multiplexers. A phenomenal quantum efficiency in excess of 80% was achieved in Phase 1, testifying to the promise of our approach. In Phase 2, we will focus on buffer optimization and pixel passivation with the goal of achieving superb FPAs with state-of-the-art performance in terms of high pixel operability and uniformity, and low noise equivalent temperature difference (NETD). A number of FPAs will be delivered at the conclusion of the program.