High-fluence ion irradiation, an overview

The more fundamental concepts involved in high-fluence and flux-density effects in ion bombardment substrates are addressed. This is first accomplished by an examination of processes involved in individual ion impacts and the conditions necessary to be able to cumulatively and linearly sum the effects of many successive impacts. Ion bombardment introduces both extraneous atoms to and generates atomic recoils within substrates and the spatial and temporal evolution and integration of these processes is examined in various situations of stationary and moving boundaries; the latter mode itself arising from the sputtering effects of bombardment. It is shown how this boundary condition alone can totally modify impurity incorporation and atomic redistribution effects with resulting impact on the magnitude and extent of possible substrate property changes. Finally, a further examination of prompt and delayed processes within and between successive ion impact events outlines the necessity to consider the influence of thermodynamic influences with full incorporation of transient atomic, defect and local energy concentrations and gradients in these constraints. 75 refs.; 2 figs