Reflection Anisotropy Spectroscopy Study Of The Near Surface Electric Field In Low-Temperature Grown Gaas (001)

We have evaluated an ''effective depletion width'' of less than or equal to 45 Angstrom and the sign (n-type/upward band bending) of the near surface electric field in low-temperature grown GaAs (001) using the optical method of reflection anisotropy spectroscopy in the vicinity of the spin-orbit split E(1), E(1) + Delta(1) optical features. Our results provide evidence that surface Fermi level pinning occurs for air exposed (001) surfaces of undoped low temperature grown GaAs. (C) 1997 American Institute of Physics.