Deposition and characterization of TaN-Cu nanocomposite thin films

TaN-Cu nanocomposite thin films with Cu nanoparticles dispersed in TaN matrix were prepared by reactive co-sputtering of Ta and Cu in the plasma of N₂ and Ar. After deposition, the films were annealed using RTA (Rapid Thermal Annealing) at 400 °C for 2, 4, 8 min respectively to induce the nucleation and growth of Cu particles. XRD and TEM were both applied to characterize the phases and microstructures of TaN-Cu thin films in this study. The results reveal that Cu incorporation will result in fine or near-amorphous TaN phase. During annealing, Cu nano-particles will emerge in the matrix of TaN and grow. Consequently, hardness and Young's modulus values will increase or decrease with the increase of annealing time, depending on Cu content and TaN morphology (particularly, preferred orientation). The increase of nitrogen will result in higher hardness and Young's modulus due to the formation of stoichiometric TaN phase.