Method for manufacturing silicon single crystal

A method for manufacturing a silicon single crystal rod which pulls a silicon single crystal rod (24) from a silicon melt (13) molten by a heater (17), detects a change in diameter of the silicon single crystal rod (24) in the pulling process every predetermined time, and feeds back an output of the detection to a pulling speed of the silicon single crystal rod (24) and a temperature of the heater (17), thereby controlling a diameter of the silicon single crystal rod (24),

• wherein a method which directly feeds back a diameter deviation between a target diameter and a measured diameter of the silicon single crystal rod (24) to a method which subjects the pulling speed of the silicon single crystal rod (24) to a PID control so that the silicon single crystal rod (24) has the target diameter is combined with a method which feeds back a change quantity of the diameter deviation as a deviation to a current pulling speed.

A method for manufacturing a silicon single crystal rod which pulls a silicon single crystal rod (24) from a silicon melt (13) molten by a heater (17), detects a change in diameter of the silicon single crystal rod (24) in the pulling process every predetermined time, and feeds back an output of the detection to a pulling speed of the silicon single crystal rod (24) and a temperature of the heater (17), thereby controlling a diameter of the silicon single crystal rod (24),

• wherein, when feeding back a change quantity of a diameter deviation between a target diameter and a measured diameter of the silicon single crystal rod (24) as a deviation to the pulling speed of the silicon single crystal rod (24), the pulling speed is subjected to a PID control so as not to exceed a maximum fluctuation breadth of correction with respect to a current pulling speed.