GaInAs/InP quantum well infrared photodetectors grown on Si substrates

GaInAs/InP quantum well IR photodetectors (QWIP) were grown on Si substrate by metalorganic chemical vapor deposition. The growth condition of InP buffer layer on Si was optimized and its crystal quality was evaluated by high-resolution x- ray diffraction and atomic force microscopy experiments. Two different in-situ thermal cyclic annealing techniques were used to reduce the threading dislocation density in the InP- on-Si. The new thermal annealing with larger temperature range was found to improve the quality of InP-on-Si dramatically. QWIP-on-Si samples with these two different thermal annealing were prepared. Important detector properties, like dark current, spectral response, peak responsivity, and specific detectivity were studied and compared with a QWIP-on-InP sample with identical structure. Small blue shift was observed in both QWIP-on-Si detector's spectral responses. Record high detectivity of 2.3 X 109 cmHz/W was obtained for one QWIP-on-Si detector at 77K.