Improved Ec control in Hf1−xZrxO2 FeNAND applications using SiO2 nanolaminate structure

Abstract

The coercive field (Ec) is a key parameter governing the switching behavior of ferroelectric devices, yet its effective modulation remains challenging due to intrinsic material constraints. In this study, we demonstrate a domain-wall-engineering approach to control Ec in Hf1−xZrxO2 (HZO) thin films by inserting 0.5 nm-thick interlayers without altering the overall film thickness. Incorporation of ZrO2 interlayers reduced Ec by 34.7%, enabling low-voltage and energy-efficient operation for ferroelectric random-access memory. Conversely, integrating SiO2 interlayers increased Ec by 62.8%, which is particularly advantageous for ferroelectric NAND (FeNAND) applications requiring a wide memory window. The effectiveness of this strategy was validated using InGaZnO-based ferroelectric field-effect transistors, where the HZO/SiO2 stack achieved enhanced multi-level cell functionality, a substantial threshold-voltage shift, and a gradual switching slope. These results highlight a scalable and CMOS-compatible method to overcome the conventional tradeoffs between operating voltage and memory density, offering a promising route toward high-performance FeNAND and future three-dimensional nonvolatile memory architectures.