  The growth in data generation necessitates efficient data processing
technologies to address the von Neumann bottleneck in conventional computer
architecture. Memory-driven computing, which integrates non-volatile memory
(NVM) devices in a 3D stack, is gaining attention, with CMOS back-end-of-line
(BEOL) compatible ferroelectric (FE) diodes being ideal due to their
two-terminal design and inherently selector-free nature, facilitating
high-density crossbar arrays. Here, we demonstrate BEOL-compatible,
high-performance FE-diodes scaled to 5, 10, and 20 nm FE
Al0.72Sc0.28N/Al0.64Sc0.36N films. Through interlayer (IL) engineering, we show
substantial improvements in the ON/OFF ratios (>166 times) and rectification
ratios (>176 times) in these scaled devices. The superlative characteristics
also enables 5-bit multi-state operation with a stable retention. We also
experimentally and theoretically demonstrate the counterintuitive result that
the inclusion of an IL can lead to a decrease in the ferroelectric switching
voltage of the device. An in-depth analysis into the device transport
mechanisms is performed, and our compact model aligns seamlessly with the
experimental results. Our results suggest the possibility of using scaled
AlxSc1-xN FE-diodes for high performance, low-power, embedded NVM.
