METHOD FOR PRODUCING SILICON SINGLE CRYSTAL WAFER AND SILICON SINGLE CRYSTAL WAFER

摘要

Silicon single crystal wafers for semiconductor devices of high quality are obtained with high productivity by effectively reducing or eliminating grown-in defects in surface layers of silicon single crystal wafers produced by the CZ method. The present invention provides a method for producing a silicon single crystal wafer, which comprises growing a silicon single crystal ingot by the Czochralski method, slicing the single crystal ingot into a wafer, subjecting the wafer to a heat treatment at a temperature of 1100-1300 DEG C for 1 minute or more under a non-oxidative atmosphere, and successively subjecting the wafer to a heat treatment at a temperature of 700-1300 DEG C for 1 minute or more under an oxidative atmosphere without cooling the wafer to a temperature lower than 700 DEG C. The present invention also provides a CZ silicon single crystal wafer, wherein density of COPs having a size of 0.09 mu m or more in a surface layer having a thickness of up to 5 mu m from a surface is 1.3 COPs/cm<2> or less, and density of COPs having a size of 0.09 mu m or more in a bulk portion other than the surface layer is larger than the density of COPs of the surface layer.