Patent ID: 8655471

Claim:
A non-transitory computer-readable storage medium containing therein a set of computer-readable instructions executable by a processor for performing a process for 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 process for impurity amount control comprising: storing a resistivity profile for a portion of a 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 from an impurity concentration estimating formula including one or more variables selected from among resistivities at both ends of the reusable ingot in a crystal growth axis direction, an 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, an amount of impurity within the reusable ingot.