A molecular dynamics simulation of nanoimprint lithography (NIL) is proposed in order to study its mechanical characteristics, pattern transfer mechanism, and the interaction between the mold, self-assembled layer (SAM) molecules, and polymethylmethacrylate (PMMA) film. The physical model consists of a nickel mold imprinted into PMMA film. The effects of the orientation of PMMA chains and the antistiction SAM were investigated to understand the mechanisms of deformation, stress, slip vector distribution, friction and adhesion forces between the interfaces. The chain molecules deform by folding upwards, resulting in a serious packing area under the mold when the PMMA chains are in the horizontal direction. In PMMA vertical chain imprinting, the forming mechanism is also folding; however, the mechanism is like a spring being compressed by an axial loading. SAM acted as elastic soft surfactant molecules, which can effectively avoided the generation of defects and molecular packing. The suffered stress was also greatly and directly decreased by SAM. However, the friction force between the mold walls and PMMA molecules was increased by SAM during the imprint process; however, it helped the mold to smoother separate during the unloading process. The pattern size was slightly extended by SAM, especially for small pattern imprints.
All Science Journal Classification (ASJC) codes
- Computer Science(all)
- Health(social science)
- Environmental Science(all)