Electrochemical formation of GaAs/Bi Schottky barriers

Bismuth layers have been deposited electrochemically on (100) n- and p-type GaAs. The electrical properties of junctions on n-GaAs were dependent on the bismuth deposition potential. Bismuth films deposited at -0.2 V (Ag/AgCl) were compact, continuous, and exhibited good adhesion; the n-GaAs/Bi junctions exhibited an average barrier height of 0.83 eV. Films deposited at less than or equal to-0.3 V were porous and the barrier heights exhibited an aging effect decreasing to 0.73 eV after several days under ambient conditions. Bismuth films deposited on p-GaAs exhibited barrier heights of 0.57 eV. The sum of the barrier heights for n- and p-type junctions correspond to 1.40 eV, close to the band gap of GaAs consistent with Fermi-level pinning. (C) 1999 American Institute of Physics. [S0003-6951(99)00646-4].