Fabrication of High-Quality Nanogap Electrodes via Structurally Optimized Atomic Layer Lithography

Nanogap electrodes (NGEs) are composed of two adjacent metal electrodes separated by a nanoscale gap, and are commonly employed as essential components in various applications such as terahertz wave enhancement structures, molecular electronic devices, biosensing sensors, and beyond. In recent years, various fabrication techniques for NGEs based on tape adhesion and stripping methods have been widely studied due to their advantages of low cost and high throughput. Among these, atomic layer lithography (ALL), centered on atomic layer deposition (ALD) technique, enables precise control of the gap width, making it particularly suitable for applications with strict requirements on gap dimensions. However, this class of techniques also faces challenges such as low reproducibility and difficulties in tape stripping. This study introduces structural improvements to NGEs, which significantly enhance the yield of ALL and ensure good electrical isolation among the fabricated NGE devices. Moreover, the critical impact of the M1 electrode fabrication process on the nanogap formation process is also analyzed. Relying on these improvements and analyses, this technique is expected to accelerate the development of electronic devices dependent on NGEs.