Role of critical size of nuclei for liquid-phase epitaxy on polycrystalline Si films

Liquid-phase epitaxy of Si on fine-grained polycrystalline Si seeding films reveals the effect of a critical size of nuclei. As a consequence, during deposition appreciable parts of fine-grained polycrystalline Si films dissolve in the initially supersaturated growth solution. The observed dependences of the nucleation density on supersaturation and saturation temperature are in agreement with the concept of the critical size of nuclei as predicted by thermodynamic considerations. A comparison of nucleation densities obtained in liquid-phase epitaxy experiments and grain size distributions in seeding films allows to confirm the theoretically predicted critical grain size of about 500 nm.