Rapid, High-Resolution, Large-Area Patterning of Semiconducting Polymers using Projection Photothermal Lithography

Semiconducting Polymers (SPs) have received widespread attention due to their promising qualities like superior absorbance/emission, easy chemical tunablity, low-temperature solution processing, lightweight and flexible substrates, and low environmental toxicity. A significant obstacle for the industrial development of SPs is the lack of a patterning technology that is inexpensive, rapid and viable and capable of producing sub-micron features. Photomask lithography is impossible because the SPs cannot withstand the processing steps. The Moule group recently developed a new photopatterning concept that enables micropatterning of SPs. We present a novel solution based optical patterning method that is compatible with any non-cross linked SP, termed Projection Photothermal Lithography (PPL). We have built a lab scale PPL microscope and demonstrated rapid (∼ 4cm²hr⁻¹), large single exposure area (0.21 mm²), sub-μm patterns can be obtained optically. Selective polymer domains are removed as a photo-induced temperature gradient enables selective dissolution. We estimate the commercial patterning throughput of (∼ 5 m²hr⁻¹) can be obtained through optimization of optical components.