Controllable 6H-SiC to 4H-SiC polytype transformation during PVT growth

Controllable polytype transformation from 6H-SiC seeding substrates to pure 4H-SiC by means of PVT bulk growth has been demonstrated. The furnace design and growth procedures are discussed. The thermodynamic parameters such as supersaturation and vapor stoichiometry for preferential 4H-SiC growth were analyzed using numerical simulation. The calculated parameters are discussed and compared with the experimental data. Furthermore, observed nucleation and propagation of different polytypes during 6H- to 4H-SiC transformation are discussed. Structural quality of the grown monocrystals were assessed using X-ray diffraction, polarized light microscopy, Raman spectroscopy, and KOH etching techniques, which revealed high quality of the grown samples.