Monolithic heteroepitaxial PbTe-on-Si infrared focal plane array with 96 x128 pixels

A two-dimensional (2-D) infrared focal plane array in a heteroepitaxial nar row gap semiconductor layer has been realized for the first time on a Si su bstrate containing the read-out electronics. The infrared-sensitive layer ( PbTe for the 3-5 mum wavelength range) is grown by molecular beam epitaxy a t temperatures below 450 degreesC, allowing fully processed and tested Si c hips to be employed. Individual pixels are obtained by mesa-etching, and ph otovoltaic sensors are fabricated with standard photolithographic technique s. Within the >97% Operational pixels, high quantum efficiencies and differ ential resistances at zero bias up to several 100 k Omega at 95K are observ ed.