Perfluoroalkylated metallophthalocyanines as EUV resist candidates

In this study, a molecular resist capable of high-resolution patterning with excellent sensitivity was pursued by introducing a metal atom into a small molecular fluorinated core. After selecting the phthalocyanine (Pc) unit as a molecular framework, exhibiting excellent chemical stability and etch resistance, fluorinated alkyl and aryl moieties and zinc atoms were incorporated into the framework to complete the synthesis of Pc-based EUV resists. Analyses of the recovered compounds were performed by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT IR), and ultraviolet–visible (UV-vis) spectroscopy to confirm that the structures of the desired materials were secured properly. Through the electron-beam lithographic experiments, it was verified that all the thin films composed of the three Pc materials lost their solubility by interacting with high-energy electrons to form negative-tone images. When EUV lithography was carried out on ZnPc-A, which has linear perfluoroalkyl moieties, 40 nm-sized patterns were formed at the relatively small energy of 34 mJ/cm². From the synthesis and lithographic characterization results, it can be assumed that fluorinated metallophthalocyanine materials can be considered EUV resist candidates. However, for highresolution patterning, it is necessary to maintain an appropriate film thickness and adjust the processing parameters, including the adhesion to the substrate.