Impurity amount control system for manufacturing single crystal and impurity amount control method for manufacturing single crystal

An impurity amount control method for manufacturing a single crystal which is for running an impurity amount control system for manufacturing a single crystal which carries out, in single crystal growth by a crystal pulling process, impurity amount control when using a portion of a single crystal that is not sliced into wafers as reusable material for growing another single crystal, the impurity amount control method comprising:

• storing a resistivity profile for a portion of the single crystal that is rendered into wafers in a resistivity profile memory;
• simulating to determine, by a simulator, a resistivity profile formula for indicating a resistivity profile within a reusable ingot that is the reusable material in the single crystal from an impurity concentration estimating formula including one or more variables selected from among the resistivities at both ends of the reusable ingot in the crystal growth axis direction, the impurity concentration when crystal pulling begins, a segregation coefficient, a solidification ratio and a correction factor, and from the resistivity profile;
• and
• calculating using an impurity amount calculator, based on the resistivity profile formula, the amount of impurity within the reusable ingot.