Kelvin probe force microscopy on InAs thin films on (110) GaAs substrates

Surface potential distributions on InAs thin films grown on (110) GaAs substrates were studied by Kelvin probe force microscopy. The topography showed that their surfaces were covered by many terraces. The surface Fermi levels (E-FS) were evaluated from the potential images, and EFS near the terrace edge was higher than that on the terrace top, while both of them were above the conduction band edge of bulk InAs. These results indicate that the electrons are more concentrated near the terrace edge. The film thickness dependence of EFS was also studied, but the quantum confinement effects in the InAs thin films were not confirmed experimentally.