An investigation of gold-zinc contacts on n-type indium phosphide

Experiments are described in which Schottky-type diodes were made by evaporating metal dots onto indium phosphide prepared by liquid phase epitaxy. Three types of metal dot were studied, one consisting of 2000 Å of gold, one of 2000 Å of a gold-zinc alloy and one composed of a layer of gold 2000 Å thick on a layer of zinc 1000 Å thick. The currents passed by the diodes under reverse bias and the capacitance-voltage characteristics were measured. Annealing treatments were applied to all specimens. It was found that the first two types of specimen deteriorated on annealing while the electrical properties of the third improved. Secondary ion mass spectroscopy was applied to specimens of all three types and the electrical results were interpreted in terms of the distribution of elements within a specimen.