Ion beam-induced nanostructuring of AIIIBV semiconductor surfaces studied with dynamic force microscopy and Kelvin probe force spectroscopy

Evolution and structuring of InSb(0 0 1) surface due to ion bombardment has been studied with dynamic force microscopy (DFM) and Kelvin probe force spectroscopy (KPFS) in UHV. Clean surface of InSb(0 0 1) composed of large, atomically flat terraces was obtained by repetitive cycles of low energy ion bombardment and annealing. DFM images revealed that the surface was composed of dimer rows arranged along the 〈1 1 0〉 crystallographic direction. The InSb surface prepared as above was subsequently irradiated, at room temperature with 4 keV Ar+ ions at oblique incidence. As a result, wire-like structures were produced which are parallel to the projection of the ion beam on the irradiated surface. The wires with the width of 50–60 nm and the length up to few microns were incorporated into a flat amorphous substrate. KPFS was used to determine the local surface potential on the substrate and along the wires. The surface potential was determined with respect to the work function of the polycrystalline Au film grown on mica.