Nanoscale gaps reveal new design rule for atom-thin chips and memory

A breakthrough in understanding how to build ultra-thin electronic components has emerged from research conducted at the National University of Singapore. Scientists have discovered that the reliability of atom-thin devices depends not just on the materials used but also on the minute physical gaps formed between electrodes. This insight provides engineers with a critical tool to manage electrical leakage in future microelectronic systems. The study, published in Nature Materials on July 1, 2026, highlights the importance of structural design in managing electron flow at the atomic level. The research team, led by Associate Professor Mario Lanza from the Department of Materials Science and Engineering and the NUS Institute for Functional Intelligent Materials, focused on two-dimensional (2D) materials. These materials, which are only one atom thick, offer the potential to create electronic devices that are significantly thinner than traditional silicon-based components. However, their extreme thinness introduces unique challenges, particularly regarding how electrons move through them. At such minuscule scales, electrons exhibit behaviors governed by quantum mechanics rather than classical physics. One such phenomenon is quantum tunneling, where electrons can pass through barriers that would normally prevent them from doing so. This effect leads to unintended leakage currents, which can degrade the performance of electronic devices. The NUS team found that the arrangement of these materials within a device plays a crucial role in determining how much leakage occurs. Dr. Yue Yuan, the lead author of the study, explained that the physical distance between the material and the electrode influences the likelihood of quantum tunneling. When an atom-thin material is placed on a slightly uneven metal surface, microscopic gaps can form. These gaps reduce the effective thickness of the barrier that electrons must traverse, thereby increasing the probability of leakage. This explains why similar-looking devices made from the same materials can display vastly different electrical characteristics depending on their construction. The researchers tested several 2D materials, including hexagonal boron nitride, molybdenum disulfide, and tungsten disulfide. Their findings revealed that while hexagonal boron nitride is typically considered a strong insulator, its monolayer form allows more current to pass through than some materials with weaker insulating properties. This counterintuitive result arises because the monolayer of hexagonal boron nitride is physically thinner, offering electrons a shorter path to tunnel through. To validate their conclusions, the team employed a combination of nanoscale electrical measurements, device-level testing, and computational modeling. They compared devices using atomically flat graphite electrodes with those using rougher metal electrodes such as gold and ruthenium. The results consistently showed that the roughness of the electrode surfaces created variations in the gap sizes, directly affecting the amount of leakage current observed. These findings challenge long-held assumptions about the relationship between material properties and device performance. Traditionally, the focus has been on selecting the best insulating materials to minimize leakage. However, this study emphasizes that the overall device architecture, including the interface between the material and the electrode, is equally vital. Engineers designing next-generation electronic components will need to consider both the intrinsic properties of the materials they use and the structural aspects of their designs. The implications of this research extend beyond theoretical interest. It could influence the development of advanced computer chips, ultra-thin memory devices, and other emerging technologies that require precise control over electrical behavior at the atomic scale. By providing a framework to predict and mitigate leakage currents based on structural factors, the study offers practical guidance for improving the efficiency and reliability of future electronic systems.