Robust low-temperature (350 °C) ferroelectric Hf0.5Zr0.5O2 fabricated using anhydrous H2O2 as the ALD oxidant
Yong Chan Jung, Jin-Hyun Kim, Jin-Hyun Kim, Heber Hernandez‐Arriaga, Jaidah Mohan, Su Min Hwang, Dan N. Le, Akshay Sahota, Harrison Sejoon Kim, Kihyun Kim, Rino Choi, Chang‐Yong Nam, Daniel Alvarez, Jeffrey Spiegelman, Si Joon Kim, Jiyoung Kim, Jiyoung Kim
Abstract
In this Letter, the robust ferroelectric properties of low-temperature (350 °C) Hf0.5Zr0.5O2 (HZO) films are investigated. We demonstrate that the lower crystallization temperature of HZO films originates from a densified film deposition with an anhydrous H2O2 oxidant in the atomic layer deposition process. As a consequence of this densification, H2O2-based HZO films showed completely crystallinity with fewer defects at a lower annealing temperature of 350 °C. This reduction in the crystallization temperature additionally suppresses the oxidation of TiN electrodes, thereby improving device reliability. The low-temperature crystallization process produces an H2O2-based HZO capacitor with a high remanent polarization (Pr), reduced leakage current, high breakdown voltage, and better endurance. Furthermore, while an O3-based HZO capacitor requires wake-up cycling to achieve stable Pr, the H2O2-based HZO capacitor demonstrates a significantly reduced wake-up nature. Anhydrous H2O2 oxidant enables the fabrication of a more reliable ferroelectric HZO device using a low process thermal budget (350 °C).