Polarity dependence of defect generation in ultrathin SiO2/ZrO2 gate dielectric stacks

The generation of defects during the injection of charge carriers in metal–oxide–semiconductor capacitors with ultrathin SiON/ZrO2 gate stacks is investigated. A polarity dependence for the defect generation is revealed. It is shown that this polarity effect is inconsistent with the predictions of the anode–hole injection model, but can be explained by assuming the release of hydrogen close to the SiON/ZrO2 interface, followed by its transport and trapping in the gate dielectric, resulting in the generation of hydrogen-induced positive charge and bulk neutral traps.