Multi-layered resist process in nanoimprint lithography for high aspect ratio pattern

Multi-layered resist process for nanoimprint lithography is newly proposed to fabricate high aspect ratio pattern under low pressured condition. A low molecular weight polymer is coated on a high molecular weight polymer and a mold is pressed to the bi-layered resist structure over the glass transition temperature of the polymers. The upper layered resist easily flows into the mold groove under low pressured condition and the lower layered resist stays near the base area of the pattern, which makes the base area strong. As the result, the defect at the mold releasing process is eliminated for the high aspect pattern fabrication. The deformation process is confirmed by numerical simulation and the thickness of each layer is optimized. Using the multi-layered resist process, high aspect ratio pattern is successfully fabricated under low pressured condition and the fracture defect at the mold releasing step is eliminated.