Crystal-pulling apparatus for pulling and growing a monocrystalline silicon ingot, and method therefor

Abstract

A crystal-pulling apparatus for pulling and growing a monocrystalline silicon ingot comprises a quartz crucible placed in a chamber and containing a silicon melt from which a monocrystalline silicon ingot will be pulled, a graphite crucible container to support the quartz crucible by surrounding the outer circumferential surface and external base surface of crucible, and a heater provided around the outer circumferential surface of the crucible container to heat the silicon melt. This apparatus further comprises a spacer having a top surface whose area is smaller than the base area of the quartz crucible and having a melting point higher than that of silicon, is inserted between the base of the quartz crucible and the base of the crucible container while the monocrystalline silicon ingot is pulled. According to this invention, it is possible to obtain an N-type monocrystalline silicon ingot heavily doped with impurities and having a low resistivity in which the oxygen concentration is desirably controlled, or it is possible to obtain a monocrystalline silicon ingot of which the seed end retains an oxygen concentration determined by natural equilibrium conditions, while the cylindrical portion and tail end contain a relatively constant oxygen concentration, being relieved of a sharp fall in oxygen supply which is observed in a conventional apparatus.

Dependencies are inferred from the claim text.