Characterization of 'metal resist' for EUV lithography

We characterized EIDEC metal resist for EUV lithography by various measurement methods. The low-voltage aberration-corrected scanning transmission electron microscopy combined with electron energy-loss spectroscopy showed the morphology of metal resists in nanometer regions and enabled studying the distribution of resist component in the resist film. The zirconium oxide metal resist kept the core-shell structure in the resist films and the titanium oxide metal resist showed the aggregation in the film. X-ray diffractometry and ab initio molecular dynamics simulation showed the amorphous structure with short-range order of the zirconium oxide metal resist. X-ray Photoelectron spectroscopy of the zirconium oxide-methacrylic acid metal resist showed the decomposition of the shell molecules and the increase of electron density at zirconium atoms after the EUV exposure. Infrared (IR) spectra indicated that the shell molecules made the various bindings to the metal core and the specific vibrational mode of shell molecules showed the divergent responsivity to the irradiation wavenumber of the IR Free electron laser.