Memristive stateful logic enables energy‐ and cost‐efficient in‐memory computing, which is desirable for edge computing in the coming Internet of Things  (IoT) era. Researchers have recently developed various stateful logic gates and have shown viable computing applications based on ideal memristive characteristics. However, few studies have demonstrated a system‐level in‐memory computing operation that can address the practical issues affecting device realization. Herein, a practically viable stateful logic device based on a 1‐transistor−1‐memristor (1T1M) array structure is proposed, considering the inherently stochastic memristor characteristics. Details on how to select the viable stateful logic gates in a given memristor are shown, and as an example of logic cascading, they are implemented in a device to operate a multibit carry look‐ahead adder. Then, an in‐memory computing layout that can perform all of the computing functions—data storing, transferring, and executing—inside the memory, addressing data traffic issues, is suggested. Finally, a software/hardware mixed stateful logic emulator that can virtually mimic array‐level in‐memory computing hardware based on cell‐level memristive characteristics is demonstrated.

Memristive stateful logic enables complete in-memory computing, allowing low-power and low-cost Boolean computing. Its characteristics are consistent with the requirements of edge computing devices, which will occupy a considerable segment in the coming Internet of things (IoT) era. In this review, recent developments in stateful logic technology are intensively explored. The topics include a summary of the evolution of stateful logic gates and their cascading strategies for Boolean computing. Also, array-level data manipulation is discussed, and its role in realizing massive computation inside the memory. Finally, the logic operation error issue is discussed, with feasible solutions.

A memristive stateful neural network allowing complete Boolean in-memory computing attracts high interest in future electronics. Various Boolean logic gates and functions demonstrated so far confirm their practical potential as an emerging computing device. However, spatio-temporal efficiency of the stateful logic is still too limited to replace conventional computing technologies. This study proposes a ternary-state memristor device (simply a ternary memristor) for application to ternary stateful logic. The ternary-state implementable memristor device is developed with bilayered tantalum oxide by precisely controlling the oxygen content in each oxide layer. The device can operate 157 ternary logic gates in one operational clock, which allows an experimental demonstration of a functionally complete three-valued Łukasiewicz logic system. An optimized logic cascading strategy with possible ternary gates is ≈20% more efficient than conventional binary stateful logic, suggesting it can be beneficial for higher performance in-memory computing.

Cu interconnects suffer from increased resistance and poor reliability at a sub-10 nm width. Ru and Mo have been highlighted recently as the next interconnection material candidate due to their various advantages over Cu; they have lower resistance than Cu at sub-10 nm, do not diffuse into SiO2, and are etchable. Here, we evaluated the electromigration (EM) reliability of Ru and Mo to confirm their feasibility for the next-generation interconnection. The activation energy for EM failure is calculated by measuring the mean time to failure (MTTF) of film and wire structures while factoring in temperature increases with thermal coefficient of resistance (TCR) measurements. In addition, we investigate the EM properties in terms of resistivity-increasing parameters that originate from geometry and additional fabrication processes. Furthermore, we evaluate the EM performance in terms of electrochemical potential. Our findings confirm the feasibility of Ru as a promising candidate for next-generation interconnection applications, providing enhanced reliability compared to conventional Cu interconnects.