Insight into the structure stability and bonding nature of HfB2 (0001)/SiC (111) interface: A first-principles study

The properties of HfB2(0001)/SiC(111) interface, including adhesion energy, interfacial energy and electronic structure, were performed based on density functional theory. Ten interface configurations with different terminations (Hf- and B- for HfB2(0001); Si- and C- for SiC(111)) and stacking positions (top, center and hollow) were investigated, and the results confirmed that Hf/C terminated hollow-site (Hf-HS-C) and B/Si terminated top-site (B-TS-Si) structures are the most stable configurations with the largest adhesion energy W-ad and the smallest interfacial energy gamma(int). Electronic structure analysis revealed that covalent and metallic bonds formed in Hf-HS-C, which is ascribed to the hybridization of interfacial C-p of SiC side and Hf-d, B-p of HfB2 side. The covalent and ionic characteristics presented in B-TS-Si interface are mainly attributed to the interaction between interfacial B-sp and Si-sp, Hf-d.