SILICON EPITAXIAL WAFER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To uniformize the in-plane distribution of the surface roughness of a silicon epitaxial wafer layer by optimizing the in-plane distribution of susceptor temperature of a vapor-phase thin film growing apparatus. SOLUTION: A susceptor 5 is supported only at the circumferential part of the back face by using vertical pins 7b at the tip ends of spokes 7 radially branched from a rotary shaft 6 in place of supporting the susceptor at the center of the back face. The susceptor 5 is constructed in such a manner as to keep the difference between the maximum temperature and the minimum temperature on the surface of the silicon wafer within 7 deg.C. The in-plane distribution of the surface roughness of the silicon epitaxial wafer can be suppressed to <=0.02 ppm by this method.