Analysis of Graphitization during Physical Vapor Transport Growth of Silicon Carbide

We have analyzed the graphitization process of the source material during physical vapor transport growth of SiC by comparison of experimental monitoring (digital x-ray imaging, and 13 C-labeling) and 2D numerical modeling of the sublimation and recrystallization process. Growth runs under different conditions (temperature and inert gas pressure) were used for verification of the calculated source evolution. Effects like formation of a condensed disk on top of the source material, consumption of SiC powder close to the hot graphite walls, mass transport through the core part and along the side walls could be confirmed. The rate of the sublimation and recrystallization effect, however, was overestimated by the model in the range of the experimental parameters in this study. Regardless of the latter, the crystal growth rate was described very well (modeling: 280µm/h, experiment: 310µm/h and 300µm/h).