METHOD AND APPARATUS OF CONTROLLING OXYGEN CONCENTRATION IN SILICON SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for controlling oxygen concentration in a silicon single crystal when pulling up the crystal from silicon molten liquid by CZ method. SOLUTION: An operational control factor is automatically set by performing learning control so as to reduce deviation between a measured value of oxygen concentration in a reference batch and that of objective value to zero, while excessively identifying affecting coefficient of the control factor which affects to the oxygen concentration in the crystal, based on the actual pulling up data achieved in the past.