Demonstration of Highly Scaled AlScN Ferroelectric Diode Memory with a Storage Density of >100 Mbit/mm²

Wurtzite nitride ferroelectric materials have emerged as promising candidates for next-generation memory applications, due to their exceptional polarization properties and compatibility with conventional semiconductor processing techniques. Here, we demonstrate the first successful areal scaling of aluminum scandium nitride (AlScN) ferroelectric diode (FeDiode) memory down to device diameter of 40 nm while maintaining an ON/OFF ratio of >60. Using a 20-nm-thick Al_0.64Sc_0.36N ferroelectric layer, we evaluate both metal-insulator-ferroelectric-metal (MIFM) and metal-ferroelectric-metal (MFM) architectures for scaled resistive memory devices. Our scaled devices exhibit an enhanced breakdown-to-coercive field ratio exceeding 2.6 due to increased breakdown field. The MIFM devices demonstrate stable 3-bit nonvolatile multistate behavior with clearly distinguishable resistance states and retention exceeding 4 × 10⁴ s at 85 °C. By achieving more than a million-fold areal scaling with enhanced performance metrics, this work establishes AlScN-based FeDiode memory as a highly promising platform for nonvolatile storage with potential for direct integration into CMOS technology.