| 摘要 |
PURPOSE:To suppress the convection in a raw material melt and to produce a uniform single crystal of high purity having a uniform cylindrical section by placing opposed magnets of the same poles in the upper and lower part on the outside wall of a pulling furnace, and generating radial and epiaxially symmetrical Gauss magnetic fields in the melt. CONSTITUTION:Opposed magnets 8, 8' of the same poles, for example, superconductive magnets, are placed in the upper and lower parts on the outside wall of a pulling furnace 7 for a single crystal and electric currents in directions 9, 9' are flowed. Then, the melt flows 10 shown by solid line arrows are generated in a melt 3 and the magnetic fields 11 shown by dotted line arrows are generated therein. More specifically, equiaxial-symmetrical and radial Gauss magnetic fields are generated in the melt 3 by the magnets 8, 8'. Since the magnetic fields 11 intersecting approximately orthogonally with each other in each part of the respective melt flows 10 (axial and radial directions) can be generated in this case, the flows 10 are suppressed uniformly by the magnetic field and the axial- symmetrical temp. distribution is obtd. The single crystal having a uniform circular section and uniform crystallinity is thus obtained. |
