Scalable Nanomanufacturing of Organic Electronics Using Laser Patterning in a Continuous Solvent Flow Liquid Cell

University Of California-Davis, Davis CA

Investigators

Abstract

This grant supports research that contributes to new knowledge in scalable nanomanufacturing processes, thereby promoting progress in science, technology, economic development, and human wellbeing. Photolithography is a manufacturing process that enables the patterning of electronic elements into small, controlled volumes to produce all modern integrated circuits, displays and computers. The aspect of photolithography that makes it so useful is that the size and shape of electronic components are controlled by focused light or laser patterning, which makes the technique fast, inexpensive, and reconfigurable for many applications. This award supports fundamental research to modify existing photolithography tools and methods and enables optical micropatterning of organic semiconducting polymers into electronic circuits. The new processing tool enables micro and nanopatterning, controlled doping and layering of a broad class of organic electronic materials that currently cannot be micro or nanopatterned into functional devices, such as, flexible electronics and wearables. Results from this research enables advancements in many applications such as chemical sensing, neuromorphic computing, and medical diagnostics. The ensuing technological impacts result in economic opportunities in healthcare, energy, and environment. This research lowers the cost for production of prototype organic electronic devices by orders of magnitude, which spurs economic growth and national prosperity. The project partners with instrument manufacturers, trains students at all levels and broadens participation of women and under-represented minorities. Photothermal patterning is a method that enables the optical writing of organic electronic materials (OEMs) into sub-micrometer domains, which is a critical processing step for fabrication of a wide variety of OEM devices. Photothermal patterning uses a focused laser to heat and dissolve portions of an OEM film that is in contact with a flowing solvent layer. The laser creates a negative resist pattern and the solvent flow removes dissolved material. Practical and technical barriers currently prevent the widespread use of photothermal patterning for OEMs. This project solves the practical problem by developing a unique design for an OEM micro and nanopatterning insert that is compatible with existing photolithography instruments. This allows researchers everywhere to use their existing cleanroom equipment to pattern this new class of materials. The main technical challenges are to understand and predict how processing conditions must be controlled to achieve high resolution patterning for different OEM materials. The research team develops a time-dependent continuum model that uses easily measurable experimental parameters to predict the shape, resolution, doping level and write-speed of real films under real conditions. 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.