Atomic Layer Deposition Films for Resistive Random-Access Memories

Resistive random-access memory (RRAM) stands out as a promising memory technology due to its ease of operation, high speed, affordability, exceptional stability, and potential to enable smaller memory devices with sizes under 10 nm. This has drawn significant attention, with atomic layer deposition (ALD) emerging as an ideal technology to tackle the challenges of nanoscale fabrication in the micro- and nanomanufacturing industry. ALD offers technological advantages such as functional multiple-layer stacking, doping capabilities, and incorporating oxygen reservoirs or reactive layers. These factors contribute to achieving more intriguing, stable, and reliable nonvolatile resistance switching behaviors in RRAM. Specifically, ALD greatly benefits RRAM, that relies on the valence change mechanism, where high-k transition metal oxides are commonly used as switching materials, and precise control over oxygen vacancies is achievable. This review provides a comprehensive overview of ALD films used in RRAM, delves into resistive switching properties and microscopic mechanisms in binary and ternary oxides and nitrides, and explores the impact of ALD-prepared electrodes. Furthermore, the current status and future prospects of ALD-based RRAM are highlighted, which is poised to catalyze further advancements in the fields of information storage and neural networks. RRAM, utilizing ALD, assures efficient and stable resistance switching in sub-10 nm devices. This review highlights the technological advantages of ALD and delves into the impact of ALD on the microscopic resistive mechanisms, the switching films, and the electrodes. ALD-driven RRAM is poised to revolutionize information storage and neural networks, offering smaller, faster, and more reliable memory solutions. image