A physical model for innovative laser direct write lithography

Laser Direct Write Lithography (LDWL) is a serial maskless lithography technique where a focused laser beam is scanned through a photoresist. We present a simulation flow for LDWL that includes focusing of Gaussian beams, free radical polymerization chemistry of the resist, and photoresist development. The developed simulation flow was applied to analyze the results of an experiment where laser direct write lithography is combined with Nanoimprint lithography. Specifically, we investigate the root causes of experimental observations on the improvement of the process performance by sub-division of the total exposure dose into several discrete writing cycles, which are separated in time. In addition, the developed modeling approach is used to investigate innovative laser write methods: two photon absorption (TPA), stimulated emission depletion (STED) lithography, and quencher diffusion assisted lithography.