A novel approach of fabricating laminated TiO 2 /HfO 2 bilayer multimetal oxide dielectric has been developed for high-performance CMOS applications. Ultrathin equivalent oxide thickness (∼ 8 Å) has been achieved with increased effective permittivity (κ ∼ 36). Hysteresis was significantly reduced using the bilayer dielectric. Top TiO 2 layer was found to induce effective negative charge from the flatband voltage shift. Leakage current characteristic was slightly higher than control HfO 2 , and this is believed to be due to the lower band offset of TiO 2 . However, the interface state density of this bilayer structure was found to be similar to that of HfO 2 MOSCAP because the bottom layer is HfO 2 . These results demonstrate the feasibility of new multimetal dielectric application for future CMOS technology.
- Equivalent oxide thickness (EOT)
- Fixed charge
- Flatband voltage
- Leakage current density