Low Power Logic Functions in Non-Planar Oxide Metal–Insulator–Semiconductor Tunnel Diodes via Tunneling–Coupling Current Competition

A compact logic-configurable device based on a concentric structure with a non-planar oxide structure is demonstrated. The implementation of a non-planar oxide structure minimizes leakage current paths, leading to a reduction in total current. The device maintains stable and different current levels over 100 repeated switching cycles for center biased at + 1 V and rings between flat-band voltage ( <tex-math notation="LaTeX">≈ </tex-math> –0.9 V) and 0 V, demonstrating excellent reliability and suitability for multi-state computing in AI applications. When the center was biased at a selected negative bias, the output current polarity at the center electrode is determined by the interplay between tunneling and coupling effects. By adjusting the center bias, multiple logic functions of OR, MAJ, and AND can be realized within a single device by detecting current polarity. The proposed structure exhibits stable operation over 1000 cycles. Notably, the use of a non-planar oxide leads to a dramatic reduction in power consumption, reaching nearly two orders of magnitude improvement with respect to planar oxide structure. TCAD simulations confirm its scalability down to the nanoscale, underscoring its potential for energy-efficient compute-in-memory applications.