Impact of surface processing on Al/GaAs(100) interface states

Discrete deep levels form at Al/GaAs(100) interfaces whose energies and state densities change with surface preparation conditions. Modifications in surface chemical composition and reconstruction with annealing temperature produce systematic changes in a set of interface states spanning the energy range ≈0.8 eV to 1.2 eV, as well as alter the interface barrier height. These results demonstrate close correlation between the interface states observed directly via low-energy cathodoluminescence spectroscopy and the Fermi level movement at Al/GaAs(100) interfaces and emphasize the central role of surface preparation in achieving controlled Schottky barrier behavior. © 1992.