Abstract
In order to fabricate silicon grating at nano-scale for nano-imprint lithography, we develop a novel laser interference lithography system to achieve the goal. Our robust Lloyd’s mirror interferometer is designed for fabricating periodic structures with a flexibility of variable line-width and pitch. Even thought, these kinds of system is the most stable design compared to multi-beam interferometer, the stability of Lloyd’s mirror is still an issue due to laser pointing ability. Fringe-locking mechanism is demonstrated to improve stability, but it’s extremely expensive and complex. The main focus of this study is to eliminate the effects of pointing stability of laser by Single Mode Fiber (SMF) which also serves as the spatial filter, beam transport system, and beam expander for a laser interference lithography (LIL) system. This study will discuss the principle of interference lithography and SMF, and then exam the possibility of the theory by experiment.Now, the fiber could stably preserve the linear polarization of the light with ITE:ITM >100. Exposure times over 10 minutes with expanded beams result in high contrast patterns without any need for fringe-locking. This study will improve the yield rate and the identity of each process in the future.