Review of the wafer stage for nanoimprint lithography

Nanoimprint lithography (NIL) has been flagged as one of the most promising processes for next generation lithography due to its simplicity, low cost, high replication fidelity and relatively high throughput. As a key subsystem, the ultra-precision positioning substrate stage plays a particularly critical role for NIL machines. This paper summarizes firstly various schemes of substrate stages. Subsequently, the issue of actively controlled stages versus passive compliant stages is to be discussed. Furthermore, based on the investigation for numerous ultra-precision positioning stages and considering the practically functional requirements for the step and flash imprint lithography (SFIL) machine, two preliminary schemes to implement the six-degree-of-freedom active control for SFIL stage with multi-step and multi-level functions were proposed. Finally, some useful conclusions are presented. As a result, the objective of the investigation is to offer some proposals and schemes to develop a practical SFIL stepper and further improving the performance of current SFIL machines. (c) 2007 Elsevier B.V. All rights reserved.