Method for producing semiconductor wafers composed of silicon having a diameter of at least 450 mm, and semiconductor wafer composed of silicon having a diameter of 450 mm

摘要

Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ≧450 mm and a length of ≧800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ≧70 mm is present between a heat shield surrounding the single crystal and the melt surface.