Patent ID: 6702892
Filing Date: 2004-03-09
Classification: C30B,Y10T

Abstract:
An apparatus for producing silicon single crystals by pulling up the same from the melt which comprises:a cooling member surrounding the single crystal and having an internal surface coaxial with the pulling axis and thermal insulating members disposed outside the outer surface and below the bottom surface of the cooling member, the cooling member having an internal surface diameter of 1.20D to 2.50D (D being the diameter of the single crystal to be pulled up) and a length of not less than 0.25D, the distance from the melt surface to the bottom surface of the cooling member being 0.30D to 0.85D and the bottom side of the thermal insulating member below the cooling member having an inside diameter smaller than the inside diameter of the bottom of the cooling member, wherein the single crystal, just after pulling up, will show a higher temperature in the peripheral region of the crystal than in the central portion.