Incorporating Organosilanes into EUV Photoresists: Diphenyltrimethylsilylmethylsulfonium Triflate as a New PAG

摘要

The synthesis and characterization data for a new sulfonium photoacid generator (PAG), diphenyltrimethylsilylmethylsulfonium triflate (I), is reported. It is shown that the molecule undergoes rapid silyl group transfer to water or phenol in the presence of a strong, nucleophilic base such as trioctylamine (TOA). The resulting PAG, diphenyl-methylsulfonium triflate (II), is subsequently degraded by TOA via methyl group transfer from S to N leading to the formation of Ph_2S and methyltriocylammonium triflate. Both I and II are stable when non-nucleophilic base quenchers are used. Dose-to-clear and patterning results obtained from EUV exposures at Intel-MET are presented, illustrating that increased sensitivity can be obtained with PAGs I and II relative to triphenylsulfonium triflate (TPS-OTf), but that LWR is compromised.