Si/SiO2 interface structures in laser-recrystallized Si on SiO2

Abstract

Si/SiO₂ interface structures in laser‐recrystallized Si on SiO₂ were studied with a high‐resolution transmission electron microscope. The (001) Si/SiO₂ interface with (001) Si substrate as a seed was excellent in flatness, flatter than that of the initial interface before recrystallization. However, the (11̄5) Si/SiO₂ interface with (11̄5) Si substrate was saw‐toothed with {100}_T and {111}_T microfacets. After twin boundary generation, the interface was changed to {110}_T or {111}_T and was flattened considerably. A Si/SiO₂ interface reaction occurred during laser recrystallization. Since low‐index Si planes are thought to have low interface energies with SiO₂ at their interface, atomically flat or saw‐toothed interfaces appeared as a result of this interface reaction. Moreover, twin boundaries, rather than saw‐toothed interfaces, might have been generated for the reduction of the interface energy.