Direct observation of anomalous positive charge and electron-trapping dynamics in high-k films using pulsed-MOS-capacitor measurements

Due to the rapid transient charging and discharging effects in high-k dielectrics, conventional "stress and sense" techniques cannot be reliably applied to study the oxide traps in these dielectrics. We introduce a new transient methodology based on the pulsed-MOS-capacitor measurement, which allows us to observe aspects of the dynamics of transient charging and discharging behavior in the high-k dielectric. The method is relatively simple and easy to employ. It has the advantage that the surface is depleted during the initial transient allowing the effect of anomalous positive charge and electron trapping to be isolated. We apply this technique to explain oxide charging in HfO2 samples deposited by atomic layer deposition and metal-organic chemical vapor deposition.