Excellent HZO ferroelectric thin films on flexible PET substrate

The development of flexible memory devices has been attracting more and more interests to advance next-generation lightweight and wearable electronics. Though HfO2-based ferroelectric thin film has shown promising future for the mass-production of low-cost ferroelectric memory, the fabrication of HfO2-based ferroelectric devices on thermosensitive flexible substrates has been a practical challenge due to the necessity of a high temperature thermal process to reach its potential of ferroelectric high-performance. In this work, a flexible Pt/W/Hf0.5Zr0.5O2/W/Pt multilayer stack with excellent ferroelectric properties is fabricated on PET by a controlled spalling technology, which is simple, reliable and cost-efficient. AFM characterizations proved that multilayer film exhibited a smooth surface after spalling process, and the e-testing results showed that Hf0.5Zr0.5O2 film did not show obvious deterioration in ferroelectric properties during spalling and transfer. Furthermore, the flexible Hf0.5Zr0.5O2 ferroelectric films maintained superior polarization, retention, and endurance performance under a series of bending deformations and cycling tests, indicating its outstanding mechanical resilience. This work is of great significance for the practical application of new HfO2-based thin film flexible ferroelectric memory in wearable electronics. [Display omitted] •A spalling process was successfully developed for transferring ferroelectric HZO onto PET.•The transfer process did not cause detectable damage to multilayer ferroelectric stack.•HZO remained its excellent ferroelectric properties when transferred on PET.•Flexible HZO exhibited robust stability under mechanical bending.•HZO capacitors demonstrated superior retention and endurance during deformation cycling.