Crucible made of carbon fiber-reinforced carbon composite material for single crystal pulling apparatus

Abstract

A crucible made of a C/C composite material for use in single crystal pulling, the crucible having a lateral cylindrical portion and a bottom portion integrally formed as multiple layers wound by a filament winding method, in which the first layer as the innermost crucible layer, among the multiple layers, is wound such that carbon fibers form tracks passing the polar point O at the bottom , the second layer wound on the outer surface of the first layer is wound along tracks 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 O, and the third layer and the succeeding layers wound on the outer surface of the second layer are wound 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, and 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 are at an substantially identical height, detachment and deformation of carbon fibers during use being suppressed by reducing the machining for the bottom of the crucible after molding.