Patent ID: 6755911
Filing Date: 2004-06-29
Classification: C30B,Y10S,Y10T

Abstract:
A crucible for a single crystal pulling process, comprising:a carbon fiber reinforced carbon composite material having a lateral cylindrical portion and a bottom portion integrally formed as multiple layers wound by a filament winding method, the multiple layers including a first layer, a second layer, a third layer and at least one succeeding layer, the first layer forming the innermost crucible layer which is wound such that carbon fibers form tracks passing the polar point at the bottom, the second layer being wound on the outer surface of the first layer along a track to form a first outer circular bottom that extends outwardly from about a middle part of a raised portion where the carbon fibers of the first layer are localized to the polar point, and the third and the at least one succeeding layers being wound on the outer surface of the second layer respectively along tracks to form outer circular bottoms that extend stepwise outwardly from about the middle parts of the outer surfaces of layers situated inside the respective layers, the top for the raised portion of the first layer and the top for each of the outer circular bottoms at the bottom of the carbon fibers wound around as the multiple layers being at an substantially identical height.