HfO₂-ZrO₂ Superlattice Ferroelectric Capacitor With Improved Endurance Performance and Higher Fatigue Recovery Capability

HfO ₂ -ZrO ₂ superlattice (SL) ferroelectric (FE) capacitor is demonstrated to have improved endurance performance and higher fatigue recovery capability compared to the HfZrO _x (HZO) device. During the cycling of polarization ( ${P}$ ) vs. voltage ( ${V}$ ) loops, the SL metal-FE-metal (MFM) capacitor exhibits the higher ${P}$ and the lower leakage current over the HZO device indicating the lower defect density in SL. The SL capacitor achieves an endurance of ${5}\times {10} ^{{12}}$ cycles, which is three orders of magnitude higher than the HZO device. The ${P}$ fatigue of the SL capacitor can be fully recovered through a ~30 s break, and that of HZO is only partially recovered utilizing the higher field cycling. This is because the trapping/detrapping process significantly decreases in HfO ₂ -ZrO ₂ SL over HZO capacitor by the reduced defect density. These results prove that the HfO ₂ -ZrO ₂ SL is a promising technology for endurance unlimited FE random access memory.