Improving the resolution in mask-aligner lithography

For the back-end microfabrication in integrated circuits and for the manufacturing of light emitting diodes, proximity mask-aligner lithography is still the tool of choice, due to its simplicity and low costs. However, the downscaling of functional elements requires also to enhance the resolution of mask-aligners. We report on sub-2 mu m structures using a continuous wave laser exposure source emitting at 193 nm. By using the self-imaging Talbot effect of periodic structures, we demonstrate periods below 700 nm, as required for optical metastructures. Furthermore, we present an optimization technique for optical proximity correction in mask-aligner lithography.