Improvement of memory storage capacity and prolongation of endurance/retention through H2 plasma treatment of IGZO/HZO structure

Abstract

In this study, we integrated an Indium Gallium Zinc Oxide (IGZO) channel with a superlattice of HfO2/ZrO2 (HZO) under low-thermal-budget microwave annealing to produce nearly wake-up-free ferroelectric capacitors. To eliminate the impact of trap-charges during the atomic layer deposition process, we conducted H2 plasma treatment to eliminate leak defects induced by carbon contamination and maintain neutrality to achieve high-quality IGZO/HZO interfaces, confirmed by x-ray photoelectron spectroscopy. The H2 plasma treatment improved polarization (Pr) and coercive field (Ec), reaching 2Pr: 40 μC/cm2 and Ec: 2.33 MV/cm, enabling a low-power writing speed of 30 ns with eight states (three bits per cell). The defect engineering method ensures endurance of up to 108 cycles and retains ten-year data storage at 90 °C. This research provides a new avenue for improving emerging oxide interfaces controlled by ferroelectric polarization.