Surface damage induced by reactive ion etching (RIE) was investigated in terms of its depth, distribution, and correlation with dislocation generation due to subsequent oxidation. Damage structure was evaluated using transmission electron microscopy, reflection high energy electron diffraction (RHEED), Auger electron spectroscopy, and thermal wave measurement technique. A chemical dry etching and surface analyze technique of RHEED and TW were utilized to profile the damage distribution. It is identified that the surface damaged layer consists of two parts; the upper part from the surface to about 4 nm is a heavily damaged amorphous structure containing carbon and the lower part, between 5 and 30 nm, is a single crystal Si with a lot of lattice defects, It is found that RIE damage may form film edge dislocations by the interaction of subsequent selective oxidation even though damage was minimized to suppress oxidation induced stacking faults generation. High leakage current occurs when n(+)-p junctions are fabricated on this RIE and selective oxidation because of these him edge dislocations. It seems that generation of film edge dislocations has correlated with this carbon contained amorphous layer.