Control of the Supersaturation in the CF-PVT Process for the Growth of Silicon Carbide Crystals: Research and Applications
Résumé
In the classical sublimation growth of silicon carbide (SiC) single crystals, the supersatn. in the surrounding of the seed is mainly controlled by pressure and temp. distributions within the growth cavity. Precise control of the supersatn. is difficult, esp. if it needs to be adjusted during the process. In the first part of the paper, an exptl. study performed in a continuous feed-phys. 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 dild. in argon) and/or the temp. allow precise control of the supersatn. close to the seed, much more easily than in the classical sublimation process. In the second part of the paper, the application of the supersatn. control to SiC polytype engineering is demonstrated.