| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a bulk crystal, by which a bulk crystal having a uniform composition can be grown with an arbitrary compositional ratio. SOLUTION: A concentration stripe of an impurity is formed in a crystal by applying a thermal pulse at a prescribed cycle during crystal growth, and then the temperature holding time, the crystal growth speed, and the temperature gradient, required to grow a bulk crystal having a uniform composition with an arbitrary compositional ratio, are searched from the position and the interval of the concentration stripe. Further, when the bulk crystal having a uniform composition is grown, after holding the temperature for a prescribed time until the compositional ratio of the crystal to be grown becomes a target value, the temperature in a heating furnace is lowered according to the temperature lowering speed obtained from the product of the crystal growth speed and the temperature gradient corresponding to the target compositional ratio. Alternatively, the temperature of the crystal growth interface is kept constant by relatively moving a vessel to a lower temperature side with moving speed in response to the crystal growth speed corresponding to the target compositional ratio. COPYRIGHT: (C)2008,JPO&INPIT
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