The structure and morphology of epitaxial layer defects in epitaxial Si wafers produced by the Czochralski methodwere studied using focused ion beam (FIB) milling, scanning electron microscopy (SEM), and transmission electron microscopy(TEM). Epitaxial growth was carried out in a horizontal reactor at atmospheric pressure. The p-type Si wafers were loaded intothe reactor at about 800oC and heated to about 1150oC in H2. An epitaxial layer with a thickness of 4µm was grown at atemperature of 1080-1100oC. Octahedral void defects, the inner walls of which were covered with a 2-4nm-thick oxide, weresurrounded mainly by 111 planes. The formation of octahedral void defects was closely related to the agglomeration ofvacancies during the growth process. Cross-sectional TEM observation suggests that the carbon impurities might possibly berelated to the formation of oxide defects, considering that some kinds of carbon impurities remain on the Si surface duringoxidation. In addition, carbon and oxygen impurities might play a crucial role in the formation of void defects during growthof the epitaxial layer.

• Lim, Sung-Hwan