Patent ID: 7384477

Claim:
A method for producing a single crystal with pulling the single crystal from a raw material melt in a chamber by Czochralski method, wherein during growing the single crystal, where a pulling rate is defined as V (mm/min) and a temperature gradient of the crystal in the direction of pulling axis at the vicinity of a solid-liquid interface is defined as G (° C./mm) during growing a straight body of the single crystal, the temperature gradient G of the crystal is controlled by changing at least two or more of pulling conditions including a diameter of the straight body of the single crystal, a rotation rate of the single crystal during pulling the single crystal, a flow rate of an inert-gas introduced into the chamber, a position of a heater heating the raw material melt and a distance between a melt surface of the raw material melt and a heat insulating member provided in the chamber so as to oppose to the surface of the raw material melt, thereby V/G (mm 2 /° C.·min) which is a ratio of the pulling rate V and the temperature gradient G of the crystal is controlled so that a single crystal including a first defect region is grown.