Experimental identification of unique oxide defect regions by characteristic response of charge pumping

Although multi-frequency charge pumping (MFCP) is a widely used characterization technique to study oxide defects, the range and type of defects probed by the technique awaits conclusive identification. In this paper, we use characteristic response of variable channel length, as well as variable Tcharge-Tdischarge CP experiments to self-consistently isolate and assign specific defect energy regions to CP signals. The results confirm the existence of shallow traps in Al2O3 samples and deep traps in HfO2 bulk oxide, as has been speculated by various research groups in the past. We also provide specific experimental guidelines to identify the most prominent defect region for a given transistor technology. Such identification is essential to correctly interpret CP experiments and decide on optimization schemes for gate stacks.