Periodic feature patterning by lens based solid immersion multiple beam laser interference lithography

Abstract

In this paper, we report a novel concept and methodology to fabricate high resolution periodic features using i-line laser source and multiple converging lenses. This configuration reduces the number of optical elements by employing a converging two-lens system to direct the beams on to the sample instead of conventional multiple mirror assembly that is normally associated with multiple beam interference configurations. A simple optical configuration using a 60° prism, 364 nm laser source and two converging lenses are employed to implement immersion lithography concept to achieve four beam interference. Square lattice patterns with pitch size of 210±8 and 240±6 nm are recorded on a positive photo resist using this technique.