Silicon single crystal production method
View Patent ↗Silicon single crystals having suppressed deformation and dislocations and the successful omission of the tail section are produced by growing the straight-body section of the silicon single crystal under the influence of a horizontal magnetic field with a magnetic flux density at its magnetic center being ≧1000 Gauss, and ≦2000 Gauss, reducing the lifting speed of the silicon single crystal relative to the surface of the melt to 0 mm/minute, maintaining a static state until there is a decrease in the apparent weight of the silicon single crystal, then further maintaining the static state so that the entire growth front of the silicon single crystal forms a convex shape protruding in a direction opposite to the lifting direction of the silicon single crystal, and separating the silicon single crystal from the melt.
1. A method for producing a silicon single crystal by the Czochralski method, comprising the steps of:
(1) growing a straight body section of the silicon single crystal by pulling up the silicon single crystal under the influence of a horizontal magnetic field applied to a raw material melt contained in a crucible, the horizontal magnetic field having a magnetic flux density at its magnetic center of greater than or equal to 1000 Gauss, and less than or equal to 2000 Gauss;
(2) reducing the pulling speed of the silicon single crystal relative to the surface of said melt to 0 mm/minute after step (1);
(3) measuring the apparent weight of the silicon single crystal and maintaining a static state where the relative lifting speed of the silicon single crystal is kept at 0 mm/minute until there is a decrease in the apparent weight of the silicon single crystal, after the step (2);
(4) further maintaining the static state so that the entire growth front of the silicon single crystal in contact with the melt forms a convex shape protruding in a direction opposite to the pulling direction of the silicon single crystal, after step (3); and
(5) separating the silicon single crystal from said melt, after step (4).