Unraveling Fatigue Mechanisms in Ferroelectric AlScN Films: The Role of Oxygen Infiltration

Confronting the endurance challenge in wurtzite ferroelectrics, this study provides a pioneering microscopic investigation into the fatigue mechanisms of AlScN films, identifying oxygen infiltration as the key factor. Utilizing transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS), we dynamically tracked the redistribution of oxygen elements within Al
_0.65
Sc
_0.35
N films during electrical stress cycling. Results reveal that prolonged stress cycling drives oxygen penetration along the grain boundaries into the bulk, leading to fatigue [Fig. 1]. Importantly, removing the oxygen source effectively suppresses oxygen infiltration, achieving an impressive endurance of 4.6×10
⁷
cycles under a
P
_r
of 114.6 μC/cm
²
. These insights are pivotal for developing next-generation ferroelectric memory devices with superior endurance properties