ANGULAR-DISTRIBUTION OF IN AND P PARTICLES SPUTTERED FROM INP BY INERT-GAS ION-BOMBARDMENT

An InP(100) surface was bombarded with 1 and 3 keV Ar+ and Xe+ ions at normal incidence in ultra-high vacuum at 153 and 293 K. We determined the angular distributions of sputtered In and P particles using a col lection method. The surfaces sputtered at 153 K were free of cones, ir respective of ion species and energy. The angular distribution of In w as almost identical with that of P at 153 K. This strongly suggests th at no radiation-enhanced Gibbsian segregation occurred at this tempera ture in the surface region, where the in-depth composition is almost h omogeneous. In contrast, a preferential ejection of In in the oblique direction was observed for samples bombarded with 3 keV ions at 293 K, where the surface was flatly eroded. We thus conclude that the outerm ost layer of the sample sputtered at 293 K is enriched with In. (C) 19 97 Elsevier Science B.V.