Hydrodynamic and Solid Mechanics Analysis of Capillary Force-Induced Mold Deformation in Sub-10 nm UV Nanoimprint Lithography

A model has been developed to study the dynamic filling process and to investigate the capillary force-induced deformation of nanostructures on the imprint mold during ultraviolet nanoimprint lithography (UV-NIL) down to sub-10 nm resolution. The dynamic behavior of resist filling with varied physical parameters was investigated by a hydrodynamic model. The capillary force-induced deformation of mold structures was modeled using beam bending mechanics for both wetting and non-wetting mold structures. Theoretically calculated results were cross-validated with finite-element simulations using two-phase flow and solid mechanics methods. Based on the theoretical analysis, a general parameter of critical aspect ratio for design of imprint mold for UV-NIL is developed. The investigation of capillary force-induced deformation in UV-NIL helps to deepen the understanding of dynamic mechanism of resist filling and structural deformation at sub-10 nm scale and enable optimization for high-fidelity UV-NIL.