Simulation study of perfect lenses for near-field optical nanolithography
Simulation results exploring the use of near field perfect lenses (NFPLs) in optical nanolithography are presented. A 40 nm thick silver NFPL 20 nm beneath a chrome amplitude mask is studied using vector electromagnetic field modelling. For a 140 nm period grating mask illuminated at 341 nm, a sub-diffraction-limited image is obtained 23 nm below the NFPL. This opens up the possibility of proximity near field optical nanolithography. Resolution below 50 nm is predicted, which requires NFPL materials with very low loss. It is also found that the position of the image is a function of both mask period and the loss in the NFPL.
nanolithography optical lithography electromagnetic field simulation perfect lens plasmon