Ultraviolet Nanoimprint Lithography Based On Soft Mold Fabricated By Silicon Oil Diluted PDMS

Ultra-violet Nanoimprint Lithography(UV-NIL) is a low cost, high resolution and high throughput technique which can be used at room temperature. The mold making is one of the most critical issues for the realization of UV-NIL. The ultimate resolution of the patterns fabricated by UV-NIL is primarily determined by the resolution of the soft mold. Traditionally, the pattern on the soft mold is fabricated by Electron Beam direct-write Lithography or Extreme Ultra-Violet Lithography which has very high resolution but high cost and slow speed. Furthermore, traditional cast molding method could not produce soft mold with nanometer dots arrays.In this paper, an improved mold fabrication process was developed, using silicon oil diluted polydimethylsiloxane(PDMS) as flexible mold material, using Anodic Aluminum Oxide(AAO) template which has highly ordered 100nm holes arrays as master mold. The transferred feature's scale remained about 100nm, and the aspect ratio was about 1:2. Most of the area got dots arrays replicated, while some area had defects. Possible reasons were analyzed and discussed. Several suggestions had been made. Compared to other methods, the cost of this method is lower and the procedure is simpler which means it is more promising in future mass production.The following UV-NIL process had been done in this paper, using fabricated PDMS soft mold and glass substrate. The transferred feature's scale remained about 100nm, however, there were much more defects area. Even two holes linking together happened. Possible reasons for those phenomenon were analyzed and discussed. Several improving suggestions had been made.The fabricated 100nm dots arrays could be recognized as photon crystal, which is antireflective and superhydrophobic. It is expected that they would find applications in light emitting diodes device, solar cell and biosensor.