Mechanisms for plasma and reactive ion etch-front roughening

Through extensive (2+1)-dimensional numerical integration and Monte Carlo simulations, we compute the scaling exponents of a flux redistribution model that is proposed to describe plasma etching and reactive ion etching of surfaces. It is found that, while the surface morphology depends on the etching conditions, the roughness exponent alpha, the growth exponent beta, and the dynamic exponent z are universal with regard to the details of the re-emission mechanism and are given by alpha approximate to beta approximate to z approximate to 1. These exponents are in agreement with recent experiments on plasma etch-front roughening.