PRODUCTION OF SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To produce a single crystal with which the nonuniformity of crystal quality in a crystal axis direction is suppressed. SOLUTION: The rule of the time series fluctuation of existing data is learned and predicted with respect to the pulling up speed estimated to participate in the nonuniformity of the crystal quality. The presence or absence of the corresponding relation between this predicted value and the predicted value of the nonuniformity data of the crystal quality is judged in a decision section 42. The correct value of the pulling up speed is predicted in the case of the presence. The production of the single crystal is executed while the pulling up speed is controlled in an adjustment section 44.