Kinetics, chemical modeling and lithography of novel acid amplifiers for use in EUV photoresists

This paper describes the lithographic properties of eleven acid amplifiers (AAs) and the chemical modeling approach used to predict their thermal stability in an ESCAP polymer resist system at 70 and 110 °C. Specifically, we show how added AAs affect the sensitivity (Eo and Esize), resolution, line edge roughness (LER), exposure latitude, and Z-parameter of ESCAP resists. We found that acid amplifiers that generate fluorinated sulfonic acids give the best combination of sensitivity, LER, and exposure latitude. Additionally, we show that these compounds are not photochemically active. Five compounds were evaluated using ¹⁹F NMR kinetics. Combining thermodynamic and kinetic modeling has allowed us to predict the relative enthalpies of activation for catalyzed and uncatalyzed decomposition pathways and compare the results to experimental thermal stability tests.