An investigation of molecular beam epitaxy “in-situ” grown Ag/GaAs schottky diodes

Electrical properties of molecular beam epitaxy “in-situ” grown Ag on (001) GaAs Schottky diodes were investigated. X-ray rocking curves show a (111) main peak for “in-situ” Ag grown at low temperature. During annealing, the main peak of Ag rotates from (111) to (200) to closely match that of the underlying GaAs lattice. The barrier height, 0.991 eV (determined by C-V measurement), decreases whereas doping concentration increases with increasing annealing temperature. Interdiffusion and the formation of some compound phases were also observed during annealing. A simple model, in which Ga dissociates from GaAs resulting in an increase in uncompensated ions at the metal-semiconductor interface, is proposed to explain the observation that carrier concentrations increase after annealing.