| 摘要 |
PROBLEM TO BE SOLVED: To accurately monitor a distance between a liquid surface of a silicon melt and a lower end of a heat-shielding plate when pulling up a single crystal by the Czochralski method wherein a silicon single crystal is pulled by relatively bringing the liquid surface of the silicon melt close to the heat-shielding plate. SOLUTION: At the lower end of the heat-shielding plate 15, a tapered member 16 having a shape wherein size of a cross-section decreases at a constant rate toward the vertically downward direction is established. When pulling up the silicon single crystal, at least a tip of the tapered member 16 is kept immersed in a silicon melt 21, and an image of a meniscus formed at a contact surface of the tapered member 16 and the silicon melt 21 is taken. The obtained image is processed so as to determine the diameter of the tapered member 16 at the contact surface, and the length of the tapered member 16 is calculated from the determined diameter of the tapered member 16. Based on the determined diameter of the tapered member 16, a gap which represents the distance between the liquid surface of the silicon melt 21 and the lower end of the heat-shielding plate 15 is monitored. COPYRIGHT: (C)2011,JPO&INPIT
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