The highly lyophobic perfluoropolymer Cytop is widely recognized as an excellent interfacial layer material for organic thin-film transistors (OTFTs), owing to its ability to eliminate interfacial traps and to enable steep subthreshold swing (SS), high carrier mobility, and stable operation. However, its strong lyophobicity poses a major challenge for subsequent solution-based processing, particularly in achieving high-resolution electrode patterning. In this study, we demonstrate that an extended meniscus technique enables direct photolithographic processing of photoresists on pristine Cytop. Uniform photoresist layers were deposited by blade coating under substrate heating, allowing fabrication of short-channel electrodes with lengths below 10 µm. Bottom-gate, bottom-contact OTFTs incorporating single-crystal organic semiconductor (OSC) thin films of phenyl/alkyl-substituted benzothieno[3,2-b]naphtho[2,3-b]thiophene exhibited steep SS values as low as 70–85 mV ${\mathrm{dec}}^{-1}$ and field-effect mobilities exceeding 1 ${\mathrm{cm}}^2$ ${\mathrm{V}}^{-1}$ ${\mathrm{s}}^{-1}$. The contact resistance, estimated from the channel-length dependence of the transfer characteristics, was approximately 1.5 kΩ cm. The gate-voltage dependence indicates that carrier accumulation at the OSC/electrode/dielectric ternary interface contributes to reducing contact resistance. This study represents a significant step toward realizing short-channel OTFTs with high mobility, low operating voltage, and stable performance.

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• Carrier dynamics
• Coatings
• Organic transistors
• Patterning
• Field-effect transistors
• Organic semiconductors
• Polymer thin films
• Single crystal materials