8 April 2011 Acid proliferation to improve the sensitivity of EUV resists: a pulse radiolysis study
Author Affiliations +
The yields of acid have been measured in the electron-beam irradiation of triphenylsulfonium triflate (TPS-Tf) and pinanediol monosulfonates, which consist of tosylate (PiTs), 4-fluorobenzenesulfonate (Pi1F), or 4-trifluoromethylbenzenesulfonate (Pi3F), as an acid amplifier blended in 4-hydroxystyrene matrixes. The acid yields efficiency decreases when PiTs is present, while its efficiency increases in the presence of Pi3F. Reactions of the electrons with TPS-Tf and pinanediol monosulfonates have been studied using pulse radiolysis in liquid tetrahydrofuran (THF) to evaluate the kinetic contributions to acid production. The THF-solvated electrons react with PiTs, Pi1F, and Pi3F to produce the corresponding radical anions; the rate constants are estimated to be 4.1, 5.1, and 9.2 × 1010 M-1 s-1, respectively. Electron transfer from PiTs•-, Pi1F•-, and Pi3F•- radical anions to TPS-Tf occurs with the rate constants of 5.7×1010, 1.2×1011, and 6.3 × 1010 M-1 s-1, respectively. The long-lived Pi3F•- efficiently undergoes the electron transfer to TPS-Tf to form the TPS-Tf•-, which subsequently decompose to generate TfOH. On the other hand, the decay channels of PiTs•- and Pi1F•-, which possess a relatively short lifetime, are presumably dependent on its reactions with solvated protons (charge recombination) rather than the electron transfer to TPS-Tf. The novel acid production pathway via the electron transfer from pinanediol monosulfonate radical anions to TPS-Tf is presented.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kazuyuki Enomoto, Kazuyuki Enomoto, Koji Arimitsu, Koji Arimitsu, Atsutaro Yoshizawa, Atsutaro Yoshizawa, Hiroki Yamamoto, Hiroki Yamamoto, Akihiro Oshima, Akihiro Oshima, Takahiro Kozawa, Takahiro Kozawa, Seiichi Tagawa, Seiichi Tagawa, "Acid proliferation to improve the sensitivity of EUV resists: a pulse radiolysis study", Proc. SPIE 7969, Extreme Ultraviolet (EUV) Lithography II, 79692M (8 April 2011); doi: 10.1117/12.881672; https://doi.org/10.1117/12.881672


Mechanisms of EUV exposure: electrons and holes
Proceedings of SPIE (March 26 2017)
Polymer effects on PAG acid yield in EUV resists
Proceedings of SPIE (March 20 2018)
Outlook for 157-nm resist design
Proceedings of SPIE (June 10 1999)
Polymer matrix effects on acid generation
Proceedings of SPIE (March 25 2008)

Back to Top