Method and apparatus for manufacturing a silicon single crystal having few crystal defects, and a silicon single crystal and silicon wafers manufactured by the same

摘要

In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface +/- 5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, characterized in that during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference DELTA G (= Ge - Gc) is not greater than 5 DEG C/cm, where Ge is a temperature gradient ( DEG C/cm) at a peripheral portion of the crystal, and Gc is a temperature gradient ( DEG C/cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420 DEG C and 1350 DEG C or between a melting point of silicon and 1400 DEG C in the vicinity of the solid-liquid interface of the crystal. The method maintains high productivity and enables a silicon single crystal and silicon wafers to be manufactured such that a defect density is very low over the entire crystal cross section, and the oxygen concentration distribution over the surface of each silicon wafer is improved.