Asymmetric fluid-structure dynamics in nanoscale imprint lithography

500045004000film thickness, nm350030002500200015000 0.5 1 1.5time, sFigure 6.11 Film thickness during squeezing with five micron of downwardactuation. Spectrometer probe 1 (circles) and probe 2 (squares)6.4.3 Experiments with Filtered WaterIt was determined that particle contamination in the fluid may be a factorin the minimum possible gap height that could be achieved. The water used in thecurrent set of results was filtered through a 0.02-micron filter. The filter removesparticles that are larger than 20 nm from the water. For thin base layers, the datashown in Figure 6.12 represents the best set of data obtained over the course ofthe experiments. It was shown that the gap heights achieved after filtering thewater (Figure 6.12) was appreciably smaller than for unfiltered water (Figure6.10). Unfortunately, performing the experiments with filtered water poses thesame problem as unfiltered water when the particles are introduced by thehandling of the substrate and template.92