Collaborative Research: Controlling Process Variability in Bottom-up Nanoelectronic Devices

Realizing the new products, systems, and applications promised by the nanotechnology revolution requires the stringency of high-quality manufacturing applied to nanoscale structures. Importantly, no mass-manufactured component, whether a car part, transistor, or commodity chemical, is perfect. Variations in structure (e.g., geometry, composition, etc.), and thus function, are unavoidable. However, by quantitatively understanding these variations and their distribution, a process or product designer can compensate for them. The objective of this project is to secure such knowledge for the case of bottom-up (i.e., additive) nanoelectronic device fabrication. Success of this project promises to enable new electronic technologies that benefit the consumer, industrial, and defense sectors, ranging from desktop-printable integrated circuits to retinal implants for sight restoration. The investigators will carry out multiple educational and outreach activities, ranging from demonstrations at a summer camp for girls to the launch of a new conversational podcast that addresses big challenges in manufacturing. This project will provide fundamental statistical insight into the connection between bottom-up nanoelectronic device processing and device electronic properties using two newly developed high-throughput, non-contact methods. Si nanowire p-n diodes will serve as model electronic components; they are widely used in rectification, sensing, and power-harvesting applications. The vapor-liquid-solid nanowire growth method will allow for systematic control of diode doping profile, nanowire diameter, and surface characteristics and passivation. Solution-based electro-translation and electro-orientation measurements will provide access to the junction and surface properties of individual diodes in an ensemble as a function of key process parameters. The high-throughput, non-contact nature of the electro-translation and electro-orientation techniques will permit the most statistically meaningful characterization to date, and aid in the design of processes that yield nanoelectronic devices with performance superior to, and far better controlled than, the state-of-the-art. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.