| 摘要 |
PROBLEM TO BE SOLVED: To monitor the revolving speed of a molten semiconductor revolved by an electromagnetic force with high precision by impressing a magnetic field in the molten semiconductor and providing a float rotating along with the melt on the surface of the molten semiconductor of a device for applying a current orthogonal to the magnetic field. SOLUTION: A current is applied orthogonally to a magnetic field by an electrode 4 of the same material as a quartz crucible 1 between a molten semiconductor 2 of silicon or the like, held in the crucible 1 and impressed with the magnetic field and a growing semiconductor single crystal 3 to rotate the molten semiconductor 2, and the semiconductor single crystal 3 is grown and pulled up at the same time. While the semiconductor single crystal 3 is grown, a ring 5 for measuring the revolving speed of the molten semiconductor 2 with the inner diameter larger than the diameter of the crystal 3 and provided with a deformed part is floated on the surface of the molten semiconductor 2 to monitor the revolving speed, and an impurity concn. corresponding to the revolving speed is obtained. In this case, 1.3×rs<ri<1.5×rs and 1×ri<ro<1.25×ri, for which ri is the inner diameter of the ring 5, ro is the outer diameter and rs is the diameter of the singel crystal 3, and 0.025×ri<t<0.125×ri, for which (t) is the thickness of the ring 5.
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