Patent ID: 7918934
Filing Date: 2011-04-05
Classification: C30B,Y10T

Abstract:
1. A single crystal semiconductor manufacturing method in which a quartz crucible is accommodated inside a single crystal pulling vessel, a polycrystalline raw material is melted inside the quartz crucible, a single crystal semiconductor is pulled up from the melt inside the quartz crucible, and an oxygen concentration in the single crystal semiconductor is controlled during the pulling, comprising the steps of: adjusting the diameter of the single crystal semiconductor to a desired diameter by controlling an output from an upper-side heating means based on a length of the single crystal semiconductor being pulled up; adjusting a ratio of an amount of heating by a lower-side heating means to an amount of heating by the upper-side heating means by controlling the output from the lower-side heating means, so that the amount of heating by the lower side heating means is larger than the amount of heating by the upper-side heating means and thereby promoting natural convection in the melt while suppressing fluctuation in the oxygen concentration in an axial direction of the single crystal semiconductor; and increasing a rotation speed of the quartz crucible or raising a heating temperature for the quartz crucible in a later stage of the pulling of the single crystal semiconductor, and shifting the oxygen concentration in the later stage of the pulling of the single crystal semiconductor to a high oxygen side, so that a control range of the oxygen concentration in the later stage of the pulling of the single crystal semiconductor has an equal range to a control range of the oxygen concentration in an earlier stage of the pulling, to thereby control the distribution of the oxygen concentration in the axial direction of the single crystal semiconductor as desired.