Al-Doped HZO: A BEoL compatible Ferroelectric Material for Automotive-Grade Memory

Hafnium-zirconium oxide (HZO) is a promising ferroelectric (FE) material for non-volatile memories (NVMs) and compute-in-memory (CiM) applications. However, its reliability under bias and temperature stress (BTS) presents a significant challenge, especially for automotive environments. This study presents aluminum-doped HZO (HZAO), which crystallizes within a back-end-of-line (BEoL)-compatible thermal budget while significantly improving BTS stability without compromising key performance parameters. The novel material demonstrates exceptional reliability, operating stably up to 175 °C with minimal leakage of 0.02 A/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> during positive-up-negative-down (PUND) testing (±3 MV/cm, 1 kHz). Additionally, HZAO exhibits a record-low imprint of 0.5 V after 12 h of thermal treatment at 200 °C, the best performance reported to date for fluorite-structured FE films. These advancements position HZAO as a strong candidate for meeting AEC-Q100 grade 0 requirements in automotive applications.