| AVS 54th International Symposium | |
| Thin Film | Thursday Sessions |
| Session TF-ThM |
| Session: | Thin Films for Electronic Applications |
| Presenter: | C.-W. Chen, National Cheng Kung University, Taiwan |
| Authors: | C.-W. Chen, National Cheng Kung University, Taiwan J.-S. Chen, National Cheng Kung University, Taiwan |
| Correspondent: | Click to Email |
In this study, the diffusion barrier properties of ruthenium-based thin films which contain different atomic percentage of tantalum and nitrogen are investigated in Cu/barrier/SiO2/Si system. The Ru-Ta-N films were deposited by co-sputtering from Ru and Ta targets in Ar+N2 atmosphere. Pure Ru and Ru-N films sputtered in Ar and Ar+N2 ambient, respectively, were studied as the comparison. The thickness of Ru, Ru-N and Ru-Ta-N samples is all set at 10 nm. The thermal stability of the Cu/barrier/SiO2/Si multilayers is assessed by annealing the samples in vacuum at 400~700 °C for 30 min. No significant change of sheet resistance is detected for the Cu/Ru-Ta-N/SiO2/Si system after annealing up to 700°C. However, the sheet resistance of the sample with pure Ru barrier increases abruptly after annealing at 400°C, and the sheet resistance of the sample with Ru-N barrier increases abruptly after annealing at 500°C. The performance of Ru-Ta-N barriers are also confirmed by Auger electron spectroscopy and Rutherford backscattering spectrometry in which Cu shows no obvious diffusion into underlayers after annealing at 500°C. As compared to pure Ru and Ru-N, the Ru-Ta-N films exhibit better electrical properties and capability for preventing Cu diffusion regardless of the different Ta contents. Correlation between the film resistivity and the microstructral characteristics of sputtered Ru, Ru-N and Ru-Ta-N films in the Cu/barrier/SiO2/Si multilayer systems upon annealing are discussed.