Advancing Semiconducting\nPolymer Patterning: Analysis\nand Predictive Modeling of Micropatterns Achieved via Photothermal\nLithography

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