Reverse Nonequilibrium Molecular Dynamics Calculation of the Resist Shear Viscosity in UV-Nanoimprint Lithography

In UV nanoimprint lithography process, the shear viscosity of a photo-curable resist is one of the key physical parameters to determine the resist flow behavior in recesses of a mold. To obtain the viscosity properties of resist, the molecular model of shear viscosity of thin resist film confined between mold and substrate was constructed by simplifying the flow pattern as the relative motion of two plates, the reverse nonequilibrium molecular dynamics method was applied to investigate the shear viscosity of resist mixture solution. In the model, an all-atom model was adopted and some influencing factors such as ensemble, resist composition, shear velocity and resist thickness were considered. The results indicated that when the layer number of substrate atomic is up to 10, the influence of layer number to viscosity can be neglected; the resist viscosity decreases as the shear velocity increases. Parametric regression model of the shear viscosity is established base on the above-mentioned factors.