Preparation and effect of annealing ambient on thermal stability of Cu/ZrSiN/Si structure

Zr-Si-N diffusion barrier and Cu/Zr-Si-N/Si contact systems were deposited by magnetron sputtering technique. The Cu/Zr-Si-N/Si structures were annealed in vacuum and H₂/N₂ ambient at 800°C for 1 h, respectively. The Cu/Zr-Si-N/Si structures were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), four-point probe sheet resistance measurements (R_s), and Auger electron spectroscopy (AES) respectively. The analysis of Zr-Si-N diffusion barrier indicates that the existing states of Si and Zr in the films are Si₃N₄-like phase and ZrN phase. It is evident that the residual oxygen in vacuum annealing ambient can increase the sheet resistances of Cu/Zr-Si-N/Si contact structures. The thermal stabilities of Cu/Zr-Si-N/Si structures are maintained when annealed in both ambient at 800°C. Compared with vacuum annealing, the H₂/N₂ ambient annealing can improve the properties of the structures such as the sheet resistances of Cu films and the interface conditions.