Design of metal slits for higher harmonic fringe patterns generated with surface plasmon interference lithography

In this paper, based on numerical study using the finite difference time domain method, we designed metal slits for higher harmonic fringe patterns generated with surface plasmon interference lithography. The slits were designed to generate higher fringe patterns having high intensity output, high contrast and good uniformity in sub-100nm scale. After fabricating several types of slits on aluminum film mask according to the calculated designs with a focused ion beam facility, lithography experiments using the aluminum slits were performed to record the near-filed fringe patterns using i-line Hg lamp and SU-8 negative photoresist.