Effect of vacuum heat treatment on the surface properties of epitaxial GaAs

We have examined the effect of heating under vacuum on the electronic and structural state of the real surface of epitaxial GaAs films. Vacuum heat treatment reduces the height of the surface potential barrier, increases the surface electron affinity, and raises the density of surface recombination centers and traps. The changes in the electrical and physical properties are due to disorder in the subsurface region, which is apparent in the formation of a block GaAs structure and a polycrystalline Ga2O3 layer.