Gold-Assisted Nanowire Growth on Silicon Surfaces with Different Orientations (Monte Carlo Simulation)

The Monte Carlo simulation of nanowire formation on silicon surfaces with different orientations using gold was carried out. The gold deposition on $\mathrm{Si}(011)$ and vicinal $\mathrm{Si}(111)$ surfaces at temperatures below the Au-Si system eutectic temperature results in a gold planar nanowire formation. The gold deposition on a silicon surface in the definite temperature range above the eutectic temperature leads to the $\mathrm{Au}-\mathrm{Si}$ melt droplet formation. The silicon nanowire growth by the vapor-liquid-solid mechanism was demonstrated during the silicon deposition on the surface with gold droplets. The vertical or tilted silicon nanowire growth was observed on (111) and (011) surfaces; the tilted or planar nanowire growth was observed on the $\mathbf{S i}(\mathbf{1 0 0})$ surface. A necessary condition for the planar nanowire growth is surface passivation, which leads to an increase in the silicon surface wettability by the droplet. The influence of temperature and silicon flux intensity on the planar nanowire morphology is analyzed. It is shown that the silicon planar nanowire growth is possible either in <011> or <001> directions. Varying the silicon flux intensity and temperature allows changing the growth directions and morphology of planar nanowires.