Ion-irradiation-induced solid-phase epitaxial growth

A model is proposed to explain ion-induced solid phase epitaxial growth (SPEG). The crystallization is by the adjustment of atomic positions in the vicinity of the crystalline/amorphous interface due to self-diffusion in the amorphous solid. The driving energy of SPEG is the difference in free energies between the amorphous and crystalline solids. Irradiation increases the self diffusivity of the amorphous solid by generating point defects in the amorphous solid and thus enhances the crystallization. An expression for the velocity of epitaxial growth is derived. The model explains numerous experimental facts and, at the limit of no irradiation, also gives a correct model of thermal solid-phase epitaxial growth.