Structural and mechanical properties of well-relaxed amorphous–crystal interface in silicon: molecular dynamics study

Abstract

Amorphous–crystal interface properties in silicon are key parameters for the control of the mechanical and electrical properties of polycrystalline thin film. We propose a method to calculate the interface properties of the well-relaxed amorphous–crystal interface by using structural parameters to evaluate the interface structures. The amorphous–crystal interface energies, γ I=0.29 and 0.33 J/m 2, are obtained for (0 0 1) and (1 1 1) plane, respectively. Structural relaxation greatly influences those values. It is found that the interface energies are smaller than the surface energies and depend weakly on the crystal orientation. These findings agree very well with the experiments. The interface stress is small as compared with that of metal/metal interface and involves the scattering across a broad range. A critical nucleus size estimated by the calculated interface energy is slightly smaller than that estimated by the direct MD simulation for homogeneous nucleation. That small mismatch is thought to be caused by the limit of the classical nucleation theory.