PHOTOSENSITIVITY OF SURFACE-BARRIER INP STRUCTURES WITH MICRORELIEF INTERFACE

The photosensitivity of surface-barrier structures based on InP with a thin intermediate layer of an intrinsic oxide (d almost-equal-to 50-6 0 angstrom) has been studied. The utilization of incident light was im proved by using a textured (microrelief) interface. Optimization of th e recombination and transport properties (an increase in the barrier h eight and a reduction in the reverse dark current and in the density o f the surface electron states) was achieved by passivation of the inte rface through the introduction of thin intermediate layers of hydrothe rmally grown intrinsic oxides between the metal and the semiconductor and also by sulfiding in an aqueous 2N solution of Na2S . 9H2O. The ph otosensitivity of the structures was increased by a factor of 3-5 in t he working range of wavelengths (lambda = 0.3 - 1.0 mum) and the photo current was enhanced greatly in the short-wavelength part of the spect rum (lambda < 0.5 mum). The latter was due to a reduction in the recom bination losses in the space charge region and at the interface becaus e of an improvement in the interface structure and electronic properti es as a result of anisotropic etching and passivation of the surface e lectron states.