Molecular Dynamics Study to Identify Mold Geometry Effect on the Pattern Transfer in Thermal Nanoimprint Lithography

Abstract

Molecular dynamics simulations are performed to investigate the mold geometry effect on the pattern transfer in thermal nano imprint lithography (NIL). Layered structures composed of single crystalline diamond molds with different taper angles of 0, 15, 30, and 45°, an amorphous poly(methyl methacrylate) (PMMA) thin film, and a rigid silicon substrate were investigated, and the sequential movement of the mold followed by NVT (isothermal ensemble) simulation was implemented in accordance with a real NIL process. Both van der Waals interaction and electrostatic potentials were considered in all non-bond interactions between each layer. From the relative atomic concentration profile of the PMMA resist, the springback effects of the different mold geometries were compared. As a result, mold-PMMA interaction energy, the potential energy variation of the PMMA resist and lateral springback length were determined to be affected by the mold geometry.