| AVS 54th International Symposium | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM-ThP |
| Session: | Electronic Materials and Processing Poster Session |
| Presenter: | C.M. Lin, National Cheng Kung University, Taiwan |
| Authors: | C.M. Lin, National Cheng Kung University, Taiwan J.-S. Chen, National Cheng Kung University, Taiwan |
| Correspondent: | Click to Email |
Metallic gate electrodes (including metals, metal nitrides and metal silicides) are potential candidates desirable to replace the poly-Si gate electrode for reducing the gate depletion, gate resistance, and dopant penetration problems. In additional, threshold voltage modification is necessary to achieve high-performance NMOS and PMOS devices. Refractory metal silicides have received attention for decades in MOS technology. Among the various metal silicides, tungsten silicide is of particular interest due to its low resistivity, good adhesion and high-temperature stability. The variation of nitrogen content in WNx will lead to the change of work function of W was confirmed in our previous work. In this study, we try to tune the work function of tungsten by adding Si. The W:Si ratio of WSix is experimentally controlled. The microstructure and the C-V curves of the (WSix/SiO2/Si) MOS structure are measured. The work function of WSix films is extracted from the plot of flatband voltage versus SiO2 thickness. For W and WSi0.56 films, the work functions are 4.67 and 4.78 V, respectively. The correlation between work function and the materials characteristics of WSix films will be discussed.