Patent ID: 7767020

Claim:
A method for manufacturing a single crystal semiconductor, in which a seed crystal is dipped into melt in a crucible and is pulled up at a pulling-up speed corresponding to a pulling-up instruction to manufacture the single crystal semiconductor having an impurity added thereto, including the steps of: determining a deviation between a target value of a crystal diameter and a current value of the crystal diameter, controlling the amount of increase/decrease in speed from a current pulling-up speed to make the amount of the pulling-up instruction for making the deviation of the crystal diameter zero and setting a limit to a range of the pulling-up speed such that a pulling-up speed fluctuation in 10 seconds is less than 0.025 mm/min, and, outputting the pulling-up instruction to a pulling up mechanism to increase/decrease the pulling-up speed by the controlled amount of increase/decrease in speed from the current pulling-up speed, and pulling up the single crystal semiconductor.