Asymmetric fluid-structure dynamics in nanoscale imprint lithography

film thickness, nm400038003600340032003000280026002400220020000 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1time, sFigure 6.4 Average film thicknesses from simulation results (solid line) andexperimental results (circles). Calibration set.The trends in the motion for both the experimental results and thesimulation results are very similar. The influence of the s-curve actuation profileis evident in Figure 6.4. At the beginning of the actuation where the velocity issmall, there is no change in the base layer thickness. As the actuators acceleratedownward, the base layer thickness decreases and the rate of sinkage of thetemplate is fairly constant. Then as the actuators slow down the rate of sinkagealso decreases and the base layer thickness levels off. It is observed in theexperiments that after the actuators stop moving, the base layer thickness continueto decrease at a slow rate until the strain energy is minimized.An encouraging result seen in both the experiments and the simulation isthat there is a corrective torque in the fluid damping that corrects the initialangular misalignment of the template relative to the substrate. The angle ofinclination from simulation and experiments are in good agreement. This86