Chemical vapor deposition condition dependence of reconstructed surfaces on 4H-SiC (0001), (000(1)over-bar), and (1(1)over-bar00) surfaces

Chemical vapor deposition has been developed to enable defect-free 4H-SiC crystals to be grown at lower cost and with higher growth rates. However, the structure and stability of 4H-SiC surfaces during crystal growth has not been clarified. In this study, we performed first-principles calculations and obtained the surface energies of ideal surfaces and Si-terminated surfaces on (0001), (000 (1) over bar) and (1 (1) over bar 00) surfaces. For the (0001) and (000 (1) over bar) surfaces, the Si-terminated surfaces are more stable than the ideal surfaces and Si atoms are adsorbed onto the surfaces up to high temperatures. The ideal surface on the (1 (1) over bar 00) surface is stable, and the Si-terminated surface changes to an ideal surface at lower temperatures than on the (0001) and (000 (1) over bar) surfaces. These results indicate the possible temperature ranges in which to perform crystal growth. Thus, we clarified the conditions required to grow 4H-SiC crystals and the dependency of these structures on surface orientation. (C) 2019 The Japan Society of Applied Physics