Optimal Process Design for Wake-Up Free Hf0.5Zr0.5O2 Ferroelectric Capacitors: Toward Low-Power Devices with Enhanced Ferroelectric Performance

Abstract

Ferroelectric hafnium and zirconium oxides have recently garnered significant attention due to their potential applications in in-memory computing. In this study, we present an optimized process design for a wake-up free 15 nm thick Hf0.5Zr0.5O2 (HZO) ferroelectric capacitor by fine-tuning the dual-oxygen process and incorporating oxygen annealing after post-metallization annealing (PMA). The optimized approach resulted in a competitive polarization of 28.6 μC/cm2, consistently exceeding 25 μC/cm2 at 3 V after 2 × 107 cycles, showcasing a current density of 3.2 mA/cm2 at 2 V after 105 cycles. The synergistic effect of oxygen vacancies and grain properties (grain size, phase proportion) enables competitive ferroelectric polarization at lower voltages, while the generation of WOx near the top electrode and increased grain size further ensure the reliability of the HZO ferroelectric capacitor. This work presents innovative perspectives for the development of non-volatile devices characterized by low leakage current and low power consumption.