Stable solid-phase contact to n-GaAs

An ohmic contact to n-type GaAs of the configuration GaAs/Ni/Ge/W/sub 60/N/sub 40//Au has been investigated. The contacting layer in this metallization is formed by a solid-state reaction between Ni/Ge and GaAs. Backscattering spectrometry and electrical measurements show that the interposed W-N layer acts as an excellent diffusion barrier both in preventing the intermixing of the top Au layer with Ni/Ge and in confining the reaction between Ni/Ge and GaAs. The contact resistivity is in the range of 10/sup -6/ Omega cm/sup 2/ and remains stable after annealing at 500 degrees C for 60 min.<
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