Sn/Pd/GaAs ohmic contacts with reactive metals

The contribution deals with the problems of the Sn/Pd/GaAs contacts with a thin layer of a reactive metal - chromium, titanium and nickel. These metals react with the native oxides on the GaAs surface and affect the parameters of the contact structure. The influence of the reactive metals to the contact resistivity and to the thermal stability of prepared contact structures was followed. The best of all seems to be the chromium structure deposited at the temperature of 130/spl deg/C. This metallization reached the contact resistivity of 5.73/spl times/10/sup -6/ /spl Omega/cm/sup 2/, during the stability test at 400/spl deg/C temperature the partial deterioration of resistivity occurred only after 10 hours.