First-principles study of the electronic structure and mechanical properties of TiN||SrTiO3 interfaces

Titanium nitride (TiN) as a buffer layer can effectively solve the problems of lattice mismatch and incompatible growth conditions faced by strontium titanate (SrTiO3) when integrating into semiconductors. However, there are fewer studies on the electronic structure and mechanical properties of TiN||SrTiO3 heterointerfaces. Therefore, in this study, we investigate the electronic structure and mechanical properties of two preferred TiN (110)||SrTiO3(1 1 0) interfaces based on first-principles calculations. The results show that the potentially candidated interfaces constructed by both N (Ti) termination of TiN and corresponding counterpart of SrTiO3 are electrically conductive and that the band gap of SrTiO3 broadens with increasing thickness. Using various analytical methods, we find that the presence of O2-termination improves the bond strength of the interfaces, and the shear strength and interfacial toughness of the SrTiO-terminated preferred interface are superior to those of the O2-terminated preferred interface. These findings have important implications for the application of TiN|| SrTiO3 heterointerfacesin microelectronic devices.