Growth and morphology of 6H-SiC epitaxial layers by CVD

Single crystals of 6H-SiC were epitaxially grown on 6H-SiC substrates in the temperature range of 1500 to 1750°C with gas composition: H₂ ≈ 1 l/min, SiCl₄ ≈ 1 ml/min, C₃H₈ ≈ 0.05 ml/min. The grown layers were transparent and mirror-like. The morphology of the grown layer was strongly influenced by the polarity of the substrate surface. Aggregates of trapezoidal crystals were observed on the (000$\text{1}$)C surface and a mosaic pattern was observed on the (0001)Si surface. By observing the initial stage of the crystal growth, the growth mechanism of 6H-SiC is discussed. On (000$\text{1}$)C surfaces the vertical growth dominates, while on (0001)Si surfaces the lateral growth dominates.