Arithmetic Logic Unit Circuit Based on Zinc Oxide Nanogap Schottky Diodes

Abstract

The intrinsic high non‐linearity of Schottky diodes with the latest improvements in performance, material, and design novelties have made them invaluable in the emerging devices ecosystem. However, the reported studies on diodes based on 2D and metal‐oxide semiconductors for digital circuits are limited to basic logic gates. The Schottky diodes‐based integrated circuit feasibility and scalability discussions are lacking. In this work, the large throughput and cost‐effective adhesion lithography in tandem with the solution‐based method is used to fabricate integrated functional circuits for Arithmetic Logic Unit (ALU). The self‐aligned nanogap separation between interdigitated coplanar aluminum (Al) and gold (Au) electrodes is uniform throughout the fabricated diode width, resulting in a high rectification ratio of 5 × 106. The fundamental logic AND, OR, and XOR gates based on nanogap Schottky diodes are fabricated, from which arbitrary logic and arithmetic functional circuits can be constructed. To demonstrate the large‐area integration, a 3‐bit Binary Shifter circuit is implemented. The measurement‐based Keysight ADS diode model is used to design a complete 4‐bit ALU circuit. The excellent circuit‐level performance, large‐area scalability, design flexibility, and cost‐efficiency of logic circuits based on nanogap Schottky diodes make them promising candidates for future Internet of Things applications.