Method for producing semiconductor wafers composed of silicon with reduced pinholes

A method for producing silicon semiconductor wafers, comprising

• pulling a single crystal at a seed crystal from a melt having a free surface heated in a crucible by means of a side heater embodied as a resistance heater;
• during the pulling of a cylindrical section of the single crystal, supplying heat to the center of the crucible bottom by means of a heating device adjacent to the crucible bottom which can be lifted and lowered with the crucible, wherein the heat is supplied with a heating power which is increased at least once to not less than 2 kW and in a manner following a ramp within a time period which is ≧90 min and <900 min such that the highest temperature in the crucible bottom migrates from a position at the edge of the crucible bottom as far as the center of the crucible bottom, and the heating power is then decreased again;
• and
• slicing silicon semiconductor wafers from the pulled single crystal.