| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a C/C material provided with properties of material of denseness, high density and high strength, having high purity, for example, useful for various members for producing a semiconductor by efficiently packing holes of the C/C material with thermally decomposed carbon in by a vapor phase method. SOLUTION: A carbon fiber is impregnated with a thermosetting resin, which is cured and molded. The molding product is baked and carbonized in a nonoxidizing atmosphere to give a C/C composite material, which is subjected to high-purity treatment. CVD reaction conditions are set at 1,200-1,300 deg.C reaction temperature 10-100 Torr total pressure in a reactor, 10-20 Vol.% raw material gas concentration in the first period of the reaction <10 Vol.% raw material gas concentration in the second period of the reaction and thermally decomposed carbon is deposited in holes of the C/C composite material to densify the composite material. The CVD reaction time of the first period of the reaction is preferably 20-70% whole CVD reaction time, more preferably 20-40%. |
