Ion reflection analysis of the surface topography induced by ion bombardment of a hot metal target

Abstract

A platinum polycrystalline target and the (100) surface of a silver crystal target were bombarded with 11 keV Kr + ions to a dose of 10 18 ions cm −2 at a temperature of 1000 K and an incidence of angle Ψ 0 = 30° (essential bombardment). After such treatment, for the targets at room temperature, the energy spectra of backscattered krypton and argon ions were examined. The second maximum on the energy distribution curve, the so-called double scattering maximum, shows some structure which depends on the incidence angle. Comparison of the experimental points which correspond to the energy position of structure peaks with the theoretical curves calculated for correlated (Molière potential) and uncorrelated collisions may suggest that the microfurrows (with a width of a few Å) perpendicular to the incidence plane are created on the hot target surface during the krypton ion bombardment. The furrows are triangular in shape. The entry plane of a furrow coincides with the direction of essential ion bombardment and for polycrystalline platinum it is a low-index (100) crystal plane. For the crystalline silver target it is a high-index plane, probably a (210) crystal plane. In both cases the output plane of the furrow is a (110) crystal plane and its azimuthal orientation is such that the closest-packed 〈110〉 atomic rows are parallel to the incidence plane.