Testing the Compatibility of Photothermal Lithography with Commercial Lithography Equipment

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 Photothermal Lithography. Selective polymer domains are removed as a photo-induced temperature gradient enables selective dissolution in a combination of solvents. In this study we test the compatibility of this technique with the Alvéole PRIMO. Alvéole PRIMO is a commercially available cleanroom equipment that enables Micropatterning, hydrogel polymerization and microfabrication, all in a single device. We were able to use this equipment to enable and test out Photothermal patterning technique on P3HT at various solvent concentrations and laser fluences. In this study we analyze the effect of depth of field, solvent concentrations, and laser fluences that effect the pattern size and resolution. This proves that Photothermal Patterning is compatible with available commercial Lithography equipment and this can be the way forward to fabricate patterned electronic devices with SPs.