Improved Endurance of HfO2-Based Metal- Ferroelectric-Insulator-Silicon Structure by High-Pressure Hydrogen Annealing

We investigate the effects of high-pressure hydrogen annealing (HPHA) on W/ferroelectric Al:HfO₂/interface layer (IL)/Si stacks. With HPHA, degradation in remnant polarization is observed in the pristine state due to ferroelectric domain pinning. However, after wake-up, a comparable remnant polarization is observed by domain de-pinning. In addition, HPHA improves the quality current and low interface trap density are maintained up to 10⁷ cycles. As a result, the endurance improves up to 10⁹ cycles and a stable retention is achieved up to 10⁴ s at 85 °C. These results show that the HPHA can be a crucial process for ferroelectric HfO₂-based transistor applications.