Abstract
Atomic force microscopy (AFM) revealed that 2-dimensional nuclei were generated at a stacking fault (SF) in microchannel epitaxy (MCE) by LPE. Their bow-like shapes with large radius of curvature allow the nucleation to occur at a very low critical supersaturation. As a result, 2-dimensional nucleation becomes a major step source when SF exists even under a very low supersaturation usually employed in MCE.