Simultaneous calculation of reflection, physical sputtering and secondary electron emission from a metal surface due to impact of low-energy ions

A computer simulation code which treats elastic and inelastic collision pro cesses of low-energy ions in solids is presented. Tn the code, the direct e xcitation of electrons by a penetrating ion and recoiling atoms is simulate d using the Monte Carlo technique, in addition to the simulation of elastic collisions of the moving particles with solid atoms. Electron cascades of the excited electrons and collision cascades of the recoil atoms are also t aken into account, and as a result. the code allows us to simulate ion-soli d interactions such as ion reflection, physical sputtering and secondary el ectron emission from the solids. This code is applied to calculations of th e energy and angular distributions of emitted particles and the total parti cle yields of aluminum by impact of ions with the atomic numbers Z(1) of 1 to 17 and energies E-i of 10 eV to 10 keV at normal incidence. The calculat ed sputtering yield and ion reflection coefficient are in reasonable agreem ent with empirical formulae which have been recently presented. The calcula ted electron yield shows the clear dependence on Z(1) and E-i, but the E-i- dependence is different from that of the electronic stopping power at such low impact energies. The energy and angular distributions of emitted partic les indicate the similarities of the secondary electron emission and the ph ysical sputtering, as observed in recent experiments.