Flexible Quasi‐van der Waals Ferroelectric Hafnium‐Based Oxide for Integrated High‐Performance Nonvolatile Memory

Ferroelectric memories with ultralow‐power‐consumption are attracting a great deal of interest with the ever‐increasing demand for information storage in wearable electronics. However, sufficient scalability, semiconducting compatibility, and robust flexibility of the ferroelectric memories remain great challenges, e.g., owing to Pb‐containing materials, oxide electrode, and limited thermal stability. Here, high‐performance flexible nonvolatile memories based on ferroelectric Hf0.5Zr0.5O2 (HZO) via quasi‐van der Waals heteroepitaxy are reported. The flexible ferroelectric HZO exhibits not only high remanent polarization up to 32.6 µC cm−2 without a wake‐up effect during cycling, but also remarkably robust mechanical properties, degradation‐free retention, and endurance performance under a series of bent deformations and cycling tests. Intriguingly, using HZO as a gate, flexible ferroelectric thin‐film transistors with a low operating voltage of ±3 V, high on/off ratio of 6.5 × 105, and a small subthreshold slope of about 100 mV dec−1, which outperform reported flexible ferroelectric transistors, are demonstrated. The results make ferroelectric HZO a promising candidate for the next‐generation of wearable, low‐power, and nonvolatile memories with manufacturability and scalability. Flexible quasi‐van der Waals hafnium‐based oxides are fabricated and investigated systematically. Due to high remanent polarization, robust mechanical properties, and degradation‐free retention and endurance, the nonvolatile memories based on ferroelectric capacitors and thin‐film transistors show excellent performance and mechanical durability, which outperform reported flexible ferroelectric devices. The findings provide a pathway for wearable nonvolatile memories with manufacturability and scalability.