| 摘要 |
PURPOSE:To suppress auto-doping of impurity from the periphery of wafer and eliminate concentration difference of impurity generated between the periphery and the center region by forming an epitaxial layer on a semiconductor wafer where impurity concentration of periphery is lower than that at the center region. CONSTITUTION:Concentration of periphery 15 with the width of 10mum of a silicon wafer 14 is 1X10<16>/mm<3> and that of the center region 16 is 5X10<17>/mm<3>. After polishing the main surface of such wafer 14 like a mirror surface, it is then set to the susceptor and the silicon epitaxial layer 17 with phosphorus concentration of 5X10<15>/mm<3> is caused to grow in view of manufacturing an epitaxial wafer 18. Measurement of distribution in impurity concentration in the longitudinal direction of the epitaxial layer 17 of the main surface of the wafer 18 proved that impurity concentration is uniform at the periphery and the center area.
|
