Electrical properties of ideal metal contacts to GaAs: Schottky‐barrier height

The electrical properties, with emphasis on Schottky‐barrier height φ_B, of ideal (no interfacial oxide) contacts to GaAs have been measured for a diverse group of 14 metals by using current‐voltage and capacitance–voltage methods. The contact interfaces were formed under controlled ultrahigh vacuum conditions by metal evaporation onto clean (100) surfaces of both n‐type and p‐type GaAs. The range of φ_B for n‐type contacts is 0.96 to 0.62 eV in the decreasing order: Cu, Pd, Ag, Au, Al, Ti, Mn, Pb, Bi, Ni, Cr, Co, Fe, and Mg. For p‐type contacts, the φ_B range is 0.45 to 0.62 eV. No simple correlation is apparent between φ_B and contact metal work function nor between φ_B and the metal–GaAs interface chemistry.