Control of the Supersaturation in the CF-PVT Process for the Growth of Silicon Carbide Crystals: Research and Applications

In the classical sublimation growth of silicon carbide (SiC) single crystals, the supersaturation in the surrounding of the seed is mainly controlled by pressure and temperature distributions within the growth cavity. Precise control of the supersaturation is difficult, especially if it needs to be adjusted during the process. In the first part of the paper, an experimental study performed in a continuous feed−physical vapor transport reactor (CF−PVT) is shown. This process combines CVD for the feeding of the SiC source and PVT for the growth of the single crystal. It is shown that the feeding gas flow rate (TMS diluted in argon) and/or the temperature allow precise control of the supersaturation close to the seed, much more easily than in the classical sublimation process. In the second part of the paper, the application of the supersaturation control to SiC polytype engineering is demonstrated.