Reliable Accessibility of Intermediate Polarization States in Textured Ferroelectric Al0.66Sc0.34N Thin Film

Ferroelectric materials are promising candidates for neuromorphic computing synaptic devices due to the nonvolatile multiplicity of spontaneous polarization. To ensure a sufficient memory window, ferroelectric materials with a large coercivity are urgently required for practical applications in highly scaled multi‐bit memory devices. Herein, a remarkable reliability of intermediate ferroelectric polarization states is demonstrated in a textured Al 0.66 Sc 0.34 N thin film with a coercive field of 2.4 MV cm −1 . Al 0.66 Sc 0.34 N thin films are prepared at 300 °C on Pt (111)/Ti/SiO 2 /Si substrates using a radio frequency reactive sputtering method. Al 0.66 Sc 0.34 N thin films exhibit viable ferroelectricity with a large remanent polarization value of >100 µC cm −2 . Through the conventional current–voltage characteristics, polarization switching kinetics, and temperature dependence of coercivity, the reproducibility of multiple polarization states with apparent accuracy is attributed to a small critical volume (3.7 × 10 −28 m 3 ) and a large activation energy (3.3 × 10 27 eV m −3 ) for nucleation of the ferroelectric domain. This study demonstrates the potential of ferroelectric Al 1‐x Sc x N for synaptic weight elements in neural network hardware.