High detectivity GaInAs-InP quantum-well infrared photodetectors grown on Si substrates

We report an improvement in the growth and the device performance of GaInAs-InP quantum well infrared photodetectors grown on Si substrates. Material growth techniques, like low-temperature nucleation layers and thick buffer layers were used to grow InP on Si. An in situ thermal cycle annealing technique was used to reduce the threading dislocation density in the InP-on-Si. Detector dark current was reduced 2 orders of magnitude by this method. Record high detectivity of 2.3 × 10/sup 9/ cmHz¹2//W was obtained for QWIP-on-Si detectors in the 7-9 μm range at 77 K.