Nanoindentation-induced interface behavior between DLC film and monocrystalline silicon substrate at high temperature: A molecular dynamics simulation study

Diamond-like carbon (DLC) film is an excellent protective coating material, which has a wide range of applications. The interface behavior between around 1 nm DLC film and the monocrystalline silicon substrate is difficult to characterize through experiments. In this work, the nanoindentation molecular dynamics simulations are performed to investigate the interface behavior between DLC film and the silicon substrate at high temperature. A method for determining the depth of indentation has been proposed. As the temperature increases, the maximum repulsive force between indenter and DLC film decreases, the maximum adhesive force increases. High atomic shear strains locate at the interface between DLC and monocrystalline silicon during indentation process. High temperature enlarges the atomic strain distribution region. The number of holes in the monocrystalline silicon substrate increases with increase of temperature after indentation process. The evolution processes of silicon atomic structures have been revealed. Both the repulsive force and adhesive force in the indentation process contribute the silicon phase transformation. But the final silicon atom bonding structure and pop-out phenomena are determined by the adhesive force during the unloading process.