| 摘要 |
PURPOSE:To decrease the laminar surface exfoliation which is observed with the conventional thermal decomposition type boron nitride crucible and to extend the life of the crucible by forming the thermal decomposition type boron nitride in such a manner that the X-ray diffraction intensity of the hexagonal boron nitride is made smaller than the X-ray diffraction intensity of the boron nitride having the irregular laminar structure in the crystal structure of the thermal decomposition type boron nitride. CONSTITUTION:This thermal decomposition type boron nitride has the crystal structure consisting of the hexagonal boron nitride and the boron nitride of the irregular laminar structure having the larger inter-plane spacing of the C plane than the hexagonal boron nitride and has the diffraction strength of the hexagonal boron nitride smaller than the diffraction intensity of the boron nitride of the irregular laminar structure in the X-ray diffraction. The laminar surface exfoliation is prevented simply by controlling the lamination state of the C plane in the stage of forming the film of the boron nitride by a thermal decomposition method, for example, CVD method. The lamination state of the C plane is controllable by, for example, CVD conditions and the examination of the lamination state is possible by X-ray diffraction. |
