Advancing Semiconducting Polymer Patterning: Analysis and Predictive Modeling of Micropatterns Achieved via Photothermal Lithography

The industrial development of semiconducting polymers (SPs) faces a significant hurdle in the absence of an inexpensive, rapid, and viable patterning technology capable of producing submicron features. In this study, we explore photothermal patterning as a promising technique that leverages the solubility characteristics of SPs to address this challenge. We demonstrate the rapid adaptability of this technique using one of the commercially available direct-write photolithography apparatuses, the Alvéole PRIMO that is commonly found in university clean rooms. Additionally, we developed a predictive model to quantify photothermal dissolution of SPs in solvent mixtures. We successfully determined the depth and width of the resulting patterns and identified the influence of solubility kinetics on heat transfer within the film, tying feature size to laser intensity, dwell time, and solvent quality for two different semiconducting polymers. We then demonstrate the technology by etching complex artwork into SP films with μm lateral resolution and ∼10 nm depth control. Put together, this method and the associated theoretical model set the stage for the development of a cost-effective and rapid photopatterning technology for SPs, opening up possibilities for industrial applications in microfabricating organic electronic devices.