RUI: A Molecular-Ruler Process to Create Nanostructures through Self- and Directed-Assembly

One of the great engineering challenges of the modern era is to create nanometer-scale structures and devices with high throughput and reproducibility. In nanoelectronics, the speed and density of devices have been the driving forces behind the increased resolution and capabilities of traditional top-down methods. The ability to maintain this trajectory is predicated upon the development of novel fabrication methods. This Research in Undergraduate Institutions (RUI) award supports the development of a hybrid approach that couples a key aspect of conventional lithography, the ability to create complex architectures over large areas, to the resolution afforded by molecular self-assembly. The goal of this work is to create new economical nanomanufacturing techniques for the electronics and communications industries. Given the interdisciplinary nature of this project, undergraduate students will learn to communicate across disciplines and will receive broad scientific and technical training in preparation for their careers beyond the University of North Florida.

In the molecular-ruler process, conventional lithography is combined with the selective deposition of multilayers that are comprised of bifunctional thiol molecules and metal ions. The chemical multilayer defines the nanometer-scale spacings of the lithographically patterned surface structures. This hybrid approach is inherently parallel and, hence, scalable and can be integrated into existing lithographic methods. The molecular-ruler process has great potential as a fabrication technique, however its general effectiveness and reproducibility is limited by the quality of the multilayer. This award will support an investigation of extending the capabilities of the molecular-ruler process by utilizing self- and directed-assembly strategies. Bifunctional thiol molecules will be designed and synthesized for use in metal-ligated multilayers. Monolayers and metal-ligated multilayers will be assembled, and their structure and quality will be characterized using a range of surface analytical techniques. Combining the molecular-ruler process with atomic force lithography, devices with single-nanometer interconnects within tailored nanogaps will be fabricated and their electronic behavior will be characterized. This hybrid strategy for the fabrication of nanogaps should provide a general and widely applicable methodology to produce well defined, registered nanometer scale features. Additionally, this award will support the interdisciplinary training of undergraduate students in the areas of organic synthesis, analytical surface science, and electronic device fabrication and characterization.