Development of a force-decoupled parallel alignment device for nanoimprint applications

High-precision parallel alignment between the substrate and the template is of great importance for nanoimprint lithography. Recently, flexure-based mechanism is commonly employed to realize high-precision parallel alignment; however, stiffness in imprint axis is hard to guarantee. In this article, a new parallel alignment device is proposed, which enables the imprinting force bypass the delicate alignment mechanism, thus eliminating the side effects of imprint forces and ensuring parallel alignment able to be carried out properly. A spherical air bearing is adopted in the device for the above-mentioned purpose through decoupling the nonuniform imprinting forces distributing on the template, allowing only the torque to reach the delicate alignment mechanism. The structural parameters of the air bearing are optimized through modeling and analysis of the bearing performances in terms of load-carrying capacity and stiffness. For the bearing preload, a set of permanent magnets are employed. The preliminary experimental results show that high load capacity and stiffness are achieved, which are consistent with the derived model.