Evanescent-wave interferometric nanoscale photolithography using guided-mode resonant gratings

Generation of interference patterns of the evanescent electromagnetic waves with significantly subwavelength period using guided-mode resonant gratings is studied. The potential application field is the near-field interference lithography aimed at fabrication of periodic structures with nanoscale features. Calculations, based on the rigorous coupled-wave analysis of Maxwell’s equations, demonstrate the possibility of obtaining high-quality interference patterns by means of evanescent diffraction orders enhancement at the resonance conditions. The interference pattern feature size is up to 8 times smaller than the incident wavelength and the intensity at the interference maxima exceeds the incident wave intensity by an order-of-magnitude. The possibility of generating high-frequency interference patterns using low-frequency diffraction gratings is demonstrated. The 1D and 2D interference patterns with the periods 6 times smaller than those of the used diffraction gratings are generated.