Thickness‐Driven Transition of Switching Kinetics in Wurtzite Ferroelectrics

Abstract Wurtzite ferroelectrics, such as aluminum scandium nitride (AlScN), provide promising candidates to develop complementary‐metal‐oxide‐semiconductor (CMOS)‐integrated non‐volatile memory devices. A comprehensive understanding of ferroelectric switching kinetics in AlScN film is critical to fully exploit its potential, which, however, remains to be explored. In this work, a thickness‐driven transition of switching kinetics from the Kolmogorov‐Avrami‐Ishibashi model to nucleation‐limited switching behavior is reported in AlScN films through pulsed transient electrical measurements. In addition, an asymmetry of switching between N‐polar and M‐polar states is observed, which decreases as the film thickness reduces. Integrated differential phase contrast scanning transmission electron microscopy reveals an inhomogeneous distribution of defects between interfacial and bulk regions, as well as the pinning of ferroelectric domains near the interface during switching, which could account for the change of switching behaviors with thickness scaling. The thickness‐dependent switching kinetics and their correlation to defects present an alternative route to engineer the wurtzite ferroelectrics, potentially enabling novel applications in multi‐state ferroelectric memory and neuromorphic computing architecture.