Patent ID: 8414701
Filing Date: 2013-04-09
Classification: C30B,Y10T

Abstract:
1. A method for manufacturing a silicon single crystal comprising: a melting step in which a polycrystalline silicon accommodated in a crucible is melted to form a silicon melt in the crucible; and a pulling step in which a silicon single crystal is pulled upward from the silicon melt by a Czochralski method, wherein the pulling step further includes: an imaging step which an image of a high intensity band appearing in the vicinity of the solid-liquid interface that is present between the silicon melt and the silicon single crystal is taken using an image taking device; a central position of the silicon single crystal identifying step in which image data of the high intensity band undergo a circular approximation or an elliptical approximation to identify a central position, using one region within the high intensity band, where a meniscus angle satisfies a range which is equal to or greater than 30° and equal to or less than 60°; a level position calculating step in which a level position of the silicon melt surface is calculated based on the central position; a level position adjusting step in which a level position of the silicon melt surface is adjusted by raising the crucible in accordance with the distance between the calculated level position of the silicon melt surface and the heat shielding member; and a controlling step in which a crystallization temperature gradient (Gc) in a vicinity of a solid-liquid interface within a crystal center of the silicon single crystal and a crystallization temperature gradient (Ge) in a vicinity of a solid-liquid interface within a crystal periphery of the silicon single crystal are controlled, respectively.