Effect of imprinting pressure on residual layer thickness in ultraviolet nanoimprint lithography

Since ultraviolet (UV) imprint lithography can be used to fabricate nanosized patterns with extremely high throughput, it is regarded as one of the most promising technologies for nanosized patterning. However, for it to become a mass production technology for the fabrication of nanosized patterns, UV imprint lithography must demonstrate the capability to perform imprinting with a uniform and minimized residual layer. In UV imprint lithography, the thickness of the imprint residual layer is determined by various process parameters, including the initial thickness of the applied resin layer dependent on the spin speed, the viscosity of the resin, the imprint pressure, and the structure of the imprint template and pattern area. Among these process parameters, the thickness of the applied resin layer and the imprint pressure are focused on in this study. In order to transfer patterns with a uniform and minimized residual layer, the imprint resin must be rearranged during imprinting. Thus, the ability to achieve uniform pressing with a high pressure (>15 atm) is very important. In this study, a commercially available imprinting system was used. The imprint system is of the pressurized chamber type and uses isotropic pressure to deliver the pressing force uniformly. A commercially available UV curable imprint resin was used.