On the transformation of the potential barrier at a GaAs/Au interface during heat treatment

The effect of vacuum heat treatment on the electronic state of a GaAs(100) surface coated with island layer of gold is investigated. It is found that the effective band bending in the depletion layer decreases monotonically with increasing anneal temperature in the range 100–500 °C. The Fermi level at the surface remains approximately 0.8 eV below the conduction-band bottom. The transformation of the potential barrier is due to the formation of a strongly doped region near the surface with high tunneling transmittance. It is shown that the photoelectric properties of thin GaAs films can be controlled by adsorption of gold and heat treatment. Fiz. Tekh. Poluprovodn. 33, 1350–1354 (November 1999)