Theoretical investigation on the interfacial properties of carbon deposited on β-SiC(111) substrate

• Diamond-like stacking is identified for the interfacial carbon deposited on SiC(111).
• Regardless of deposition rate and substrate area, the stacking style always exists.
• After some layers deposited, the stacking will disappear caused by the perturbations.
• Stronger interfacial bonding exists on C-terminated SiC(111) than Si-terminated one.

The deposition process of carbon atoms on SiC(111) substrates is simulated step by step using density functional theory calculations. Three stacking sites [center-, hollow- and top-sites on clean SiC(111)], two deposition rates (one or two carbon layers per step), two substrate areas [SiC(111) (1 × 1) and (2 × 2)], and two SiC(111) terminations (C- and Si-terminations) are considered respectively. The interfacial atomic structure, binding energy and electronic structures are calculated. The results show that interfacial carbon layers tend to epitaxially deposit on SiC(111) with ordered diamond-like stacking style. Regardless of the different deposition rates and different substrate areas, the diamond-like stacking style always exists in the equilibrium structures. However, due to the perturbations caused by uncontrolled factors, this stacking style disappears after some carbon layers deposited, and the amorphous carbon layer will form. Besides that, the deposited carbon atoms have stronger interfacial bonding on C-terminated SiC(111) than Si-terminated substrate.

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