Beneficial Photoacid Generator for CA Resist in EUVL

We succeeded in developing beneficial photoacid generator (PAG) based on onium salts for extreme ultraviolet lithography resist. The CA resist employing this beneficial PAG has E0 sensitivity of 1.1 mJ/cm2. We confirmed that the distinctive acid production reaction is occurred under EUV exposure in comparing under EB exposure. As results of the time dependent mass spectroscopy and the Fourier Transform Infrared Spectroscopy (FT-IR), it is confirmed that multiple acids are generated from cyclo(1,3-perfluoropropanedisulfone) imidate employed as an anion of PAG under EUV exposure.