Trap parameters and conduction mechanism in HfO2–Ta2O5 mixed stacks in response to microwave irradiation

The effect of microwave treatment at room temperature on the leakage current and mechanisms of conductivity in mixed HfO2–Ta2O5 (10 nm) stacks has been studied by temperature dependent (20–100 °C) current–voltage characteristics. It was established that the short term irradiation (∼6 s) affects the electrically active centers in the mixed oxide, provokes modification of the dominant conduction mechanism at about and above 1 MV/cm and improves the temperature stability of capacitors manifesting as low level of current at high temperatures (current decrease up to two orders of magnitude at 100 °C after the treatment is detected). The traps involved in the conduction processes in pre- and post-irradiation capacitors are identified. The longer exposure (10–15 s) is effective in a significant reduction of leakage current (up to 3–4 orders of magnitude in wide range of applied voltages). The potential of microwave treatment at room temperature as technological step for improving the temperature stability of leakage current in high-k stacked capacitors is discussed.