BIAS AND THICKNESS DEPENDENCE OF THE INFRARED PTSI P-SI SCHOTTKY DIODE STUDIED BY INTERNAL PHOTOEMISSION/

A series of p-type PtSi/Si infra-red Schottky diodes with different me tal thicknesses was studied at about 80 K by internal photoemission as a function of reverse bias. The zero-bias barrier height of PtSi/p-Si is found to increase only marginally with metal thickness. The Schott ky emission coefficient is interpreted by a simple model and it is fou nd that the mean free path of the carrier in Si decreases with the inc rease in the acceptor density of the semiconductor. We attribute this mainly to scattering of the carriers by the ionized impurities, as the se are the dominant scatterers at low temperatures for lightly and mod erately doped Si.