Effects of different nitrogen-to-titanium atomic ratios on the evolution of Ti-Si-N islands on TiN(0Â 0Â 1) surfaces: First-principle studies

To investigate the interface formation during Ti-Si-N film growth, a series of calculations were outperformed using the first-principles method to determine the total energies and adsorption energies of 4N-1Ti-1Si, 4N-2Ti-1Si, 4N-3Ti-1Si, and 4N-4Ti-1Si island configurations on a TiN(0 0 1) surface. The study also investigated the activation energies of these island evolutions. The calculations present interesting results. First, configurations in which the titanium atom is inside the island are generally stable and have relatively low energy. This finding implies that silicon atoms outside the TiN island stabilize the structure. Second, of the four types of island evolutions, 4N4Ti1Si has relatively low activation energy. Third, the phase separation of SiN and TiN readily occurs in the evolution of 4N4Ti1Si islands compared with those in the 2Ti2N1Si and 3N1Ti-1Si island evolutions. Finally, when the nitrogen-to-titanium ratio reaches 4:3 or 1:1, interface formation is relatively easy.