Overshoot Stress on Ultra-Thin HfO2 High-κ Layer and Its Impact on Lifetime Extraction

Overshoot stress (stimulating the actual IC operating condition) on an ultra-thin HfO2 (EOT similar to 0.8 nm) high-kappa layer is investigated, which reveals that overshoot is of great importance to high-kappa layer leakage degradation. The dynamic stress-induced leakage current is correlated with traps generation and recovery, which is dependent on stress input and release. A degradation model based on the oxygen vacancies is proposed to interpret the experimental observation.