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arXiv · 2403.12361

Multi-State, Ultra-thin, BEOL-Compatible AlScN Ferroelectric Diodes

Kwan-Ho Kim·Zirun Han·Yinuo Zhang·Pariasadat Musavigharavi·Jeffrey Zheng·Dhiren K. Pradhan·Eric A. Stach·Roy H. Olsson III·Deep Jariwala
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Abstract

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.

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Kwan-Ho Kim, Zirun Han, Yinuo Zhang, Pariasadat Musavigharavi, Jeffrey Zheng, Dhiren K. Pradhan, Eric A. Stach, Roy H. Olsson III, Deep Jariwala. 2024-03-19. Multi-State, Ultra-thin, BEOL-Compatible AlScN Ferroelectric Diodes. https://arxiv.org/abs/2403.12361

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