Hydrostatic pressure-enhanced solid-phase epitaxy

Abstract

A large enhancement of solid-phase epitaxial growth (SPEG) due to hydrostatic pressure is explained by stress-enhanced self-diffusivity in the amorphous solid. The crystallization is by the adjustment of atomic positions in the vicinity of the crystalline/amorphous (c-a) interface due to self-diffusion in the amorphous phase, assisted by a free-energy decrease equal to the difference in free energies between the amorphous and crystalline phases. Owing to a mismatch in the bulk moduli between the amorphous and crystalline phases, non-hydrostatic stresses are developed near the c-a interface under hydrostatic pressure. Non-hydrostatic stresses in the amorphous layer enhance the mobility of point defects in the amorphous layer. This leads to an increased self-diffusivity in the amorphous layer and, therefore, an enhancement of the SPEG rate.