Deep-etched pixels for dualband SLS FPAs

Deep etching is necessary for pixel definition in multi-band infrared focal plane arrays (FPAs) consisting of stacked photodiodes.To eliminate optical crosstalk between pixels and improve modulation transfer function (MTF), the trenches between pixels have to be etched sufficiently deep, resulting in high aspect ratios greater than ~ 5-to-1 in short-pitch FPAs.The resulting loss in optical fill-factor can be restored by carefully controlling the etch profile to achieve total internal reflection of incident light. A good dry etch process will produce smooth pixel sidewalls, remove the need for a subsequent clean-up wet-etch, and be uniform and reproducible.QmagiQ will apply its experience and skills to develop such a process for antimony-based strained layer superlattice (SLS) material.In Phase II, we will apply the process to realize high-performance dualband SLS FPAs with short pixel pitch.This will complement the larger-pitch dualband FPAs we have already commercialized.