Asymmetric fluid-structure dynamics in nanoscale imprint lithography

Chapter 6: Experimental Results6.1 INTRODUCTIONIn order to verify the validity of the numerical simulations andscientifically quantify the effects of the etch barrier layer on the dynamics of themechanical system, experiments were performed using the active stage prototype.The data collected during the experiments included: 1) the motor shaft encoderoutputs from each of three high-resolution DC micrometer actuators, 2) thedynamic force reading from each of three quartz force sensors mounted in serieswith the actuators, and 3) gap sensing/film thickness measurements at twolocations across the template. The following sections discuss the process ofcollecting this data and present the experimental results.6.2 EXPERIMENTAL SETUP6.2.1 Experimental Adaptations of the Active Stage Test BedSince a few of the subsystems of the active stage test bed have not beenfully implemented, a couple of adaptations were required to complete theexperiments and gather the necessary data. First, a wafer chuck system was notreadily available. In the active stage, the wafer chuck holds the spin-coated waferduring the imprinting process and air solenoids pneumatically lift the wafertowards the template stage. Thus, a temporary holding device to approximate thesemblance of an actual wafer chuck was designed and used. This component hadto be stiff in the lateral directions and hold the substrate close to the templatesurface. It was designed to hold a 2.54 × 2.54 × 0.635 cm (1 × 1 × 1/4 inch)77