昇華再結晶法SiC単結晶成長機構に関する熱力学的考察(<特集>機能性単結晶の最近の進展)

抄録

Growth processes occurring in Physical Vapor Transport (PVT) method for SiC single crystals are described in view of quasi-equilibrium phase transitions. Si-C binary phase diagrams are found to be successful in giving a consistent explanation for sublimationrecrystallization phenomena under appropriate assumptions. In particular, technical directions obtainable from thermodynamic descriptions of the PVT will be quite useful when growth conditions have to be optimized for realizing SiC crystals with higher crystallinity upon suppressing unwanted perturbations such as foreign phase precipitations. In order to establish more semi-quantitative views of the PVT mechanism, the thermodynamic description proposed so far has to include the effects of reactions between vapors and other graphite constituents existing inside crucibles such as graphite crucible walls or particles formed after thermal decomposition of SiC source powders.