Consequences of plasmonic effects in photomasks

For 45nm lithography and beyond, polarization and other electromagnetic effects such as surface plasmons may begin to affect the transmission through a photomask. Such phenomena are highly polarization sensitive, and may amplify the effects of line-edge roughness (LER) and variations in mask composition. A reduction in the mask material conductivity can mitigate the impact of these effects, but more accurate simulation is required to predict these effects well.