PREFERENTIAL SPUTTERING OF BINARY-ALLOYS WITH DIFFUSION - EQUILIBRIUM DISTRIBUTION

The preferential sputtering of a binary alloy is considered using diffusion theory. It is shown that this leads to nonlinear terms in both the bulk diffusion equation and the boundary conditions. The steady-state solution is investigated in detail, and the results indicate that some of the nonlinearities are negligible, while others cannot be omitted without appreciable errors. The surface depletion of the more volatile component is much smaller than earlier diffusion studies had suggested.