<Original Paper>Evaluation of Crystallinity in the Si Epitaxial Layer by Nano-Area Characterization System

In order to evaluate the crystallinity of the Si epitaxial layer on a recently developed 400mm diameter wafer, detailed transmisson electron microscopic observations were carried out, using specimens with the following growth conditions; growth temperature at 900℃, the H_2 gas flow rate of 80slm and the SiH_4 gas flow rate of 300sccm. V-shaped micro defects, which basically consisted of stacking faults and micro twins, were observed in the epitaxial layer. The morphology and distribution of the defects depended on the positions on the wafer, i. e. the distance from the wafer edge. Mechanisms of defect formation are briefly discussed