Design of protective topcoats for immersion lithography

Interactions of water and 193nm resists are described and detailed. Leaching of PAGs is experimentally verified, and the influence of PAG structure on leaching rate is determined. The mode of action of immersion topcoats is described. The influence of the topcoat/resist interaction in assessed. Finally, the design evolution of immersion topcoats with desirable properties is discussed. © 2005 TAPJ.