Effects of enhanced diffusion on preferred sputtering of homogeneous alloy surfaces

Abstract

The effects of enhanced diffusion caused by sputter damage on the kinetics of preferred sputtering of alloy surfaces have been analyzed. The diffusion flux is specifically included in considering the mass balance within the altered layer and on the sputtered surface. An analytical solution has been derived by solving the two mass-balance equations simultaneously under certain conditions. The solution is used as the basis of an interative method to obtain exact numerical solutions as a function of sputtering time. The analysis enables one to define an altered layer with respect to the steady state and to express its thickness in terms of the sputter yields and the diffusivity. Illustrative results showing the evolution of the altered layer during sputtering are given for a typical binary alloy surface. Implications of this analysis and possible future experiments are discussed. © 1978.