Ion beam induced transient amorphous nucleation in silicon

Abstract

Ion-beam amorphization of crystalline silicon is reviewed. All the peculiar features of the process (temperature effect, incubation fluence, superlinear behavior of the amorphous fraction as a function of the ion fluence, dose–rate effects, ion mass/energy dependence, doping influence, etc.) can be explained within the classical theory of nucleation and growth based on capillarity. Nucleation and growth rates depend on the free energy of the amorphous clusters and on the kinetics balance between damage creation at the prompt stage of each ion collision cascade and competitive re–crystallization induced by atomic jumps of long living defects at the cluster surface. The model explains the damage accumulation kinetics either in dilute or dense collision cascade. It is an extension of the theoretical approach describing the reverse process, i.e. the ion–beam assisted nucleation and growth of crystalline clusters in the amorphous material. The description is independent on the atomistic nature of the involved defects.