Degradation of Nonhysteretic Switching in HZO-Al₂O₃ Stacks Due to Positive Unipolar Stress

The presented measurement procedure in (Engl et al., 2023) is used to characterize the degradation of the hysteresis-free charge amplification in unipolar operation of stabilized negative capacitance capacitors. Two degradation processes, namely, remanent switching of domains and a change in the internal electric bias field, can be shown with this procedure and are here extended with PUND measurements to get further insides into the degradation mechanism. All characterizations were performed on double-layer stacks of Hf0.5Zr0.5O2 (HZO) and Al2O3 films featuring respective thicknesses of 11 and 4 nm.