METHOD FOR MEASURING DISTANCE BETWEEN MELT LEVEL AND LOWER EDGE PART OF STRUCTURE IN FURNACE, METHOD FOR CONTROLLING MELT LEVEL POSITION USING THE SAME, METHOD FOR PRODUCING SINGLE CRYSTAL AND SINGLE CRYSTAL PRODUCTION DEVICE

摘要

PROBLEM TO BE SOLVED: To correctly measure the distance between the lower edge of a heat insulation tube arranged around a single crystal and a melt level.;SOLUTION: In the method where, when a single crystal 3 is pulled up from a silicon melt 2 stored in a crucible 5a by a CZ (Czochralski) process, the relative distance between a melt level and the lower edge part of a structure 10 in a furnace is measured, at least, the growth point of the single crystal 3 as a contact point between the single crystal 3 and the melt level and the lower edge part of the structure 10 in the furnace is photographed from the outside of the furnace by a CCD (Charge Coupled Device) camera 11, the position at which the diameter of the single crystal 3 is made the maximum and the position at which the inside diameter of the structure 10 in the furnace is made the maximum are detected from the obtained image, a difference between the position of the growth point at which the diameter of the single crystal 3 is made the maximum and a position obtained by projecting the position at which the inside diameter of the structure 10 in the furnace is made the maximum on the melt level is obtained, the obtained difference of the positions is defined as a difference in the vertical direction on the image, and, using the difference of the positions in the vertical direction and a set angle to the vertical direction of the CCD camera 11, the relative distance between the melt level and the lower edge part of the structure 10 in the furnace is calculated.;COPYRIGHT: (C)2010,JPO&INPIT