Hybrid Recovery Strategy for the Imprint Effect in HZO-Based FeRAM Under Incomplete Polarization State

HZO-based FeRAM will often operate under an incomplete polarization state in the high-speed and low-power applications. Under such circumstance, incomplete polarization will exacerbate device degradation caused by the imprint effect. In this work, a hybrid recovery pulse sequence consisting of high-voltage unipolar pulses and low-voltage bipolar cycles is proposed to restore the retention performance of HZO devices. Under the drive of pulses, a uniform redistribution of oxygen vacancies was achieved without increasing the risk of breakdown. Experiments on 3D-trench FeCAPs demonstrate 92.4% recovery of remnant polarization through hybrid recovery strategy, outperforming conventional bipolar cycles. Validation in 128 Kb 2T2C FeRAM arrays achieves 92% memory window recovery efficiency after 2.5×10⁴ cycles, with wafer-level testing confirming the stable performance. The hybrid strategy achieves effective recovery of the imprint effect under incomplete polarization state, providing a scalable solution for high-speed FeRAM in artificial intelligence and big data applications.