Electrical properties and thermally stability of Au/W/Ti ohmic contacts to (NH{sub}4){sub}2S treated n-GaAs

摘要

The electrical properties and thermally stability of Au/W/Ti ohmic contact to n-GaAs were investigated by means of X-ray diffraction (XRD), Auger Energy Spectrum (AES) and HP4145B analyzer. Structural analysis revealed a Ti-As and Ga-Ti phase in the interface between metal multilayer and GaAs at higher annealing temperature. AES results show that W is a good barrier for reducing the out-diffusion of GaAs. Electrical measurement shows a minimum ohmic contact resistance of 2×10{sup}(-6) Ωcm{sup}2 in (NH{sub}4){sub}2S treated sample. Thermal annealing experiment gives the result that Au/W/Ti contact to (NH{sub}4){sub}2S treated GaAs can stand 400℃ for 20 hours. All these indicate that Au/W/Ti contact to (NH{sub}4){sub}2S treated GaAs may be suitable for practical using.