SCHOTTKY BARRIERS ON ANISOTROPIC SEMICONDUCTOR GATE

Schottky barriers were studied on p-GaTe single crystals both normal a nd parallel to the layer planes. From the C-V characteristics the barr ier heights q phi(B) normal to the layer planes were found to be 0.75, 0.63 and 0.485 eV for Al, Ag and Au respectively dependent on the met al work functions. From the temperature dependence of the I-V characte ristics of Al Schottky barriers, the effective Richardson constants A were determined to be 120 and 56.4 A cm(-2) K-2 for current flow norm al and parallel respectively to the layer planes, in excellent agreeme nt with values obtained from the anisotropic hole effective masses. Th e corresponding ideality factors were 1.44 and 2.5 respectively at 300 K. The carrier concentration n increased while phi(B) decreased with decrease in temperature owing to increased tunnelling and recombinatio n currents. From the variation in phi(Bp) with phi(M) the interface in dex S was found to be 0.30 as predicted by Kurtin, McGill and Mead in 1971 from electronegativity considerations.