Method and apparatus for controlling the oxygen concentration of a silicon single crystal, and method and apparatus for providing guidance for controlling the oxygen concentration

摘要

In a method/apparatus for controlling the oxygen concentration of a silicon single crystal during a process of growing it using the CZ method, and in a method/apparatus for providing guidance for controlling the oxygen concentration, influence coefficients indicating the degrees of influence of control factors on the oxygen concentration are determined on the basis of data of silicon single crystals actually grown in the past, and an optimum profile of a control factor is determined through learning by modifying the profile employed in the reference batch so as to minimize the deviation of the oxygen concentration, thereby automatically setting the control factors in the growth process in accordance with the optimized profile. To control the oxygen concentration of the silicon single crystal, guidance information is provided which indicates the manner of adjusting the growth process parameters such as a crucible rotation speed and a pressure in the furnace during the process of growing the silicon single crystal. The confidence level for the profiles of the growth process parameters is evaluated, and the confidence level or the evaluation value is presented together with the guidance information on the profiles of the growth process parameters.