This work dedicates to the investigation of the formation, friction, and friction effects on metallic direct nanoimprint by utilizing molecular dynamics (MD) simulation. The MD model consists of a silicon mold and an aluminum thin film as the transfer material. The silicon mold is employed in the simulation to study the formation mechanisms from the atomic perspectives including force behavior and plastic deformation in the film. A simple mathematical model is suggested to predict the processing force. From the simulation results, dead-zone-like, substrate effect, and phenomenon of springback are observed. Friction mechanisms and its effects on metallic direct nanoimprint is then investigated during the entire process. The asperities on the sidewalls of the mold are considered because the existence of asperities is unavoidable in a practical situation. Since the nickel mold is adopted in many industrial applications, it is also simulated to compare with the silicon mold for the purpose of illustrating the material effect on friction mechanisms. From plastic deformation perspective, effects of rough sidewalls on pattern formation are also discussed. This study explores not only friction mechanisms at different stages of the process but the friction force affected by various geometric configurations of the mold, for example, linewidth-to-pitch ratio and average roughness on the sidewalls. This work also provides the general concept on which force dominates and what percentage of the friction force takes in the imprinting force.
In addition, the process of metallic direct nanoimprint is performed to fabricate subwavelength structures on an aluminum thin film. The subwavelength aluminum structures are finally accomplished by using the silicon mold with nanoscale feature structures. Comparing with simulation results, it shows good agreement with simulation results.

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