Asymmetric fluid-structure dynamics in nanoscale imprint lithography

when measuring thin layers in the range of about 300 to 400 nm. Figure 6.15illustrates the case when a false peak masks the true peak. The differencebetween 6.14a and 6.14b is that the number of zeros used to pad the FFT has beenincreased by a power of two. This stretches the FFT out and the spectral leakageis increased, however, note that the index at the maximum of the FFT has nowbeen approximately doubled. Spectral leakage is the smearing of energy acrossthe FFT domain, which results in wider peaks. This doubles the resolution since apeak at an FFT index of 200.5, which cannot be resolved in 6.14a, is now equal toa peak at an FFT index of 401 in 6.14b, for example.y g18magnitude of the FFT1614121086False peakTrue peak4200 1000 2000 3000 4000 5000 6000 7000 8000 9000FFT indexFigure 6.15 False signal masking the true signal in FFT6.5.3 Template/Substrate DeformationThe template and substrate can be deformed when using setscrews toconstrain their positions. The setscrews cause local stress concentrations that areundesirable. This leads to possible bowing of the template and substrate. Tominimize the effect of stress concentrations on the bowing of the template andsubstrate, flat aluminum plates were placed between the setscrews and the quartzpieces.98