A physical model for the hysteresis phenomenon of the ultrathin ZrO2 film

Abstract

This work studies and presents an inner-interface trapping physical model for the ultra-thin (effective oxide thickness=15 Å) zirconium oxide (ZrO2) film to explain its hysteresis phenomenon. The shift of the capacitance–voltage characteristics swept from accumulation to inversion and then swept back with light illumination is about 110 mV, which is larger than the shift without light illumination (∼45 mV). The mobile ion effect is obviated using bias-temperature stress measurement. The proposed model successfully explains not only the phenomenon but also the thickness effect for the capacitance–voltage characteristics and the different turn-around voltages of the current density–voltage characteristics of the zirconium dielectrics.