Epitaxial Transformation of Ion-Implanted Polycrystalline Si Films on (100) Si Substrates by Rapid Thermal Annealing

The epitaxial realignment of CVD deposited and As+ ion-implanted poly-Si layers on (100) Si substrates has been investigated by both plan-view and cross-section TEM observations. High density annealing twins, running parallel to <110 > orientations on {111} planes, remain in epitaxially regrown films, although epitaxial realignment is realized for 1.5×1016 As+/cm2 implanted samples annealed at 1150°C for 30 s. The perfectness of a regrown film is shown by crystal lattice imaging in high-resolution electron microscopy from a cross-section sample. High-resolution TEM also reveals the existence of precipitates at the interface between the regrown film and the substrate.