Patent ID: 7368011

Claim:
A method for manufacturing a silicon single crystal comprising: detecting a position in a vertical direction of a crucible when pulling up a silicon single crystal from a molten silicon in the crucible to grow; and controlling a pulling rate of the silicon single crystal, based on the detected position of the crucible, wherein the controlling of the pulling rate further comprises: calculating an average crucible position by taking an average of positions of the crucible in the vertical direction during manufacturing silicon single crystals over a plurality of times in the past; and controlling the pulling rate for the silicon single crystal, based on an amount of positional deviation which is a value obtained by subtracting the average crucible position from the detected position of the crucible, in the controlling of the pulling rate, the pulling rate for the silicon single crystal is set to be higher than an initial speed which is set in advance when the amount of positional deviation is positive, the pulling rate for the silicon single crystal is set to be lower than the initial speed when the amount of positional deviation is negative, and the pulling rate for the silicon single crystal is set higher or lower within a range from 0% to 5% of the initial speed per 1 mm of the amount of positional deviation.