Temperature-dependent surface diffusion parameters on amorphous materials

Diffusion on amorphous surfaces represents a little-studied physical phenomenon that controls several important kinds of material processing. To elucidate some general features of this phenomenon, we obtain Arrhenius parameters for the surface self-diffusion of amorphous silicon by measuring the formation kinetics of hemispherical grained silicon. Comparison with literature results suggests the existence of a significant temperature dependence in the activation energy and pre-exponential factor for total mass transport. We develop a physical model to show that this behavior should characterize diffusion on amorphous surfaces in general.