Abstract: SiC powder was synthesized by using Si and C powder at favorable temperature and pressure. Then silicon carbide crystal was grown by the sublimation method under a low pressure and high temperature region. The decomposition reaction of SiC was simulated according to the thermodynamic theory. The result shows that the dominating species under thermodynamic equilibrium are Si ,SiC2 and Si2C at about 2 300 ℃. The equilibrium partial pressures of these three species are three magnitude degrees higher than those of the other species. Therefore, they are the main species during the sublimation process, and their mass flow determines the growth process. Furthermore, crystal defects were observed by optical microscopy. Carbon inclusions are the important origin of micropipes. It was found that the propagation of micropipes along the growth direction could be interrupted by modulation nitrogen doping. 6H-SiC of good quality is obtained after optimizing growth parameters.
Growth of large diameter SiC crystal by sublimation method
Abstract：
SiC powder was synthesized by using Si and C powder at favorable temperature and pressure. Then silicon carbide crystal was grown by the sublimation method under a low pressure and high temperature region. The decomposition reaction of SiC was simulated according to the thermodynamic theory. The result shows that the dominating species under thermodynamic equilibrium are Si , SiC2 and Si2C at about 2 300 ℃. The equilibrium partial pressures of these three species are three magnitude degrees higher than those of the other species. Therefore, they are the main species during the sublimation process, and their mass flow determines the growth process. Furthermore, crystal defects were observed by optical microscopy. Carbon inclusions are the important origin of micropipes. It was found that the propagation of micropipes along the growth direction could be interrupted by modulation nitrogen doping. 6H-SiC of good quality is obtained after optimizing growth parameters.
