Fatigue and retention in the growth window of ferroelectric Hf0.5Zr0.5O2 thin films
Jike Lyu, Ignasi Fina, Florencio Sánchez
Abstract
The growth window of epitaxial Hf0.5Zr0.5O2 is established taking into account the main ferroelectric properties that films have to present simultaneously: high remanent polarization, low fatigue, and long retention. Defects in the film and imprint field depend on deposition temperature and oxygen pressure, with an impact on fatigue and retention, respectively. Fatigue increases with substrate temperature and pressure, and retention is short if low temperature is used. The growth window of epitaxial stabilization of ferroelectric Hf0.5Zr0.5O2 is narrower when all major ferroelectric properties (remanence, endurance, and retention) are considered, but deposition temperature and pressure ranges are still sufficiently wide.