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/cm(2). From the synthesis and lithographic characterization results, it can be assumed that fluorinated metallophthalocyanine materials can be considered EUV resist candidates. However, for high-resolution patterning, it is necessary to maintain an appropriate film thickness and adjust the processing parameters, including the adhesion to the substrate.