Semiconductor device, a method of making a low-resistance contact between a metal and a layer of polycrystalline P-type CdTe in said semiconductor device and a cadmium-selective etchant which is useful for said method.

摘要

A semiconductor device comprises a layer 12 of polycrystalline p-type cadmium telluride and a layer 16 of metal in low reststance contact with the cadmium telluride layer. A layer 14 of tellurium is disposed between the-cadmium telluride layer 12 and the metal layer 16 which permits the use of non auric metals for the layer 16 provided that the surface portion 18 of the cadmium telluride layer is cadmium deficient and has intact grain boundaries. The tellurium layer 14 may be formed by selectively dissolving cadmium from the cadmium telluride layer 12. The cadmium may be dissolved by etching the layer 12 with a mixture of nitric acid and a leveling agent e.g. phosphoric acid.