Fundamental aspects of plasma‐assisted etching processes can be investigated in a well‐defined and controllable manner by ion‐beam techniques. We review here our experiments aimed at simulating a plasma environment using beams to investigate the effects of a number of fundamental parameters of plasma processes, such as the chemical identity of bombarding ions, flux of ions and neutrals to a surface, and ejection of products from a surface. Enhanced ion etching due to reactions of neutral gases with surfaces is demonstrated, and product ejection mechanisms are shown to be possible rate limiting factors in reactive etching processes. A simple chemically enhanced sputtering model suffices to account for the main features of ion‐induced etching. Applications of this model to bulk plasma processes, dependence of etch yield on ion angle of incidence, and surface composition modification are suggested.