Abstract
When the dimension of the microelectronic structure decreases, high manufacturing cost is inevitable. A low-cost manufacturing technique for nanostructures is desired. Nano-imprint lithography (NIL) has the potential to meet the expectations. Nano-imprint lithography patterns the resist with physical deformation using a mold at nano-scale. However, the variation of environmental conditions and process parameters seriously affect the reproduction quality. To ensure the quality of the imprinted pattern is essential for industry. In this study, the author applies the surface plasmon resonance (SPR) to develop a functional imprinting mold, which has non-destructive measurement capability for the quality of the imprinted pattern. During measuring process, the excited surface plasmon can penetrate into the interface between mold surface and imprinted material. If there is filling defects in the interface, the SPR behavior will be affected, including the reflectivity spectrum change and resonance angle shift. If the penetration of surface plasmon can reach the substrate, the thickness of residual layer also affects the SPR behavior. Based on the reflectivity spectrum curve and resonance angle, the quality of the imprinted pattern can be told. According to the simulation and experimental results, the developed system can detect the filling defects as low as 1.7 % of the volume of the mold cavity and 8 nm residual layer thickness. This new application of SPR promises to improve NIL performance in the nanofabrication industry.