Abstract
This thesis presents a study on the forces generated between the mold and thin film and their impacts on the formation of nano-scale structures on aluminum thin film by using direct nanoimprint. Molecular dynamics (MD) simulation is first employed to investigate how the forces acting on the mold in different geometrical and fabricating conditions. The former includes the thin-film thickness and the ratio of line width and pitch of the patterns, while the latter is the imprinting speed. Since we assume that the shear force between two contacting surfaces only causes the friction force, we select two layers of atoms above the bottom two layers from the side of the mold to calculate the friction force in order to differentiate from the plowing force. In addition, the aforementioned geometrical and fabricating factors that influence the friction force, which, in turn, affects the quality of formation are studied systematically. For the verification of MD simulation results, we conduct the nanoindentation and nanoimprint experiments correspondingly. The mold and aluminum thin film are first fabricated. Then, we characterize the material properties of the thin film by using nanoindentation and measure the geometrical profiles of both mold and thin film by using SEM and AFM. We then perform nanoindentation and nanoimprint experiments on the thin films with various thicknesses by different molds. Then, observe the patterns being imprinted on the thin film. Consequently, the results of MD simulation and experiment correspond well, that may provide valuable guidelines for the design of direct nanoimprint.