SILICON WAFER HAVING SMALL VARIABILITY IN OXYGEN CONCENTRATION

摘要

PURPOSE:To produce wafers having small variability of oxygen concentration between lattices resulting from oxygen growth stripes by restricting variation of oxygen concentration between lattices in silicon wafers made from single crystal produced by Czochralski method (CZ method). CONSTITUTION:A rod of single crystal of silicon grown by CZ method is cut round and cut in parallel with the longer axial direction to form silicon slubs. Both sides of the slubs are chemically abraded and oxygen concentration between lattices is measured by using a given measuring device. Then, concentration difference part of a peak and trough of the peak in the measured values is calculated to evaluate growth stripes of oxygen concentration between lattices. Silicon wafers having variation of oxygen concentration between lattices contained in the silicon wafers of <=0.4 ppma (calculated as AST in 1979) are obtained.