Ion-implanted, improved ohmic contacts for GaAs semiconductor devices

摘要

A method of attaining n+ regions with fine planar geometry in the source and drain of GaAs devices utilizing ion implantation which improves Ohmic contact with a refractory film. A layer of TiW refractory film is deposited on GaAs. 29Si ions are implanted in the GaAs through the refractory film so that the peak concentration is no more than approximately 100 A below the TiW-GaAs interface. The entire structure is then annealed. A gold overlay is then deposited on the TiW layer to which electrical contacts may be attached and by which the contact resistivity is measured. Typical specific contact resistivity values are in the low 10-6 ohm/cm2 range.