Biocompatible Porphyrin Derivatives Electron Beam and Extreme Ultraviolet Photoresists: High Resolution and High Etch Resistance

Abstract Electron beam lithography (EBL) and extreme ultraviolet lithography (EUVL) have been continuously improved and applied in semiconductor and biomedical device manufacturing. With the development of biomedical nanodevices, the demand for biodegradable, and environmentally friendly materials is growing. Some biocompatible photoresists have been reported, and their sensitivity, resolution, and line edge roughness need to be further improved. In this work, porphyrin derivatives (H₂TP‐4Epoxy and CuTP‐4Epoxy) are introduced for EBL and EUVL. Owing to their smaller sizes and higher EUV absorptivity compared to traditional polymer photoresists, CuTP‐4Epoxy shows good resolution and etch resistance. As a result of EBL studies, 18 nm line/space patterns have been achieved at a dose of 1014 µC cm⁻². Meanwhile, 20 nm dense patterns are also achieved using EUVL at a dose of 88.8 mJ cm⁻², revealing the great potential of this approach for high resolution patterning. Etching experiments show an etch selectivity for silicon of 11.7, significantly higher than some of commercial photoresists. Biocompatibility experiments show that metalloporphyrin photoresist have potential applications in the fabrication of chips that are biocompatible with living organisms. This work demonstrates the structural advantages of porphyrin derivatives as high‐resolution biocompatible photoresist materials, inspiring future exploration of metalloporphyrin materials for advanced lithography and biocompatible nanodevices.