SURFACE ROUGHENING DURING ION-ASSISTED FILM DEPOSITION

The surface roughening of films deposited atomically and eroded by ion irradiation sputtering, resulting from the stochastic or noisy nature s of these processes, is investigated analytically. Serial modes of su ccessive deposition and irradiation and parallel modes of congruent de position and irradiation are compared and the superiority of one or th e other mode shown to depend upon growth and erosion-rate ratios. Diff erent surface relaxation processes including viscous flow and surface diffusion are examined and shown to affect both the average surface ro ughness and the spatial frequency spectrum of the roughness. (C) 1998 Elsevier Science S.A. All rights reserved.