HIGH-PRECISION MAGNETIC-LEVITATION STAGE FOR PHOTOLITHOGRAPHY

In this paper, we present a high-precision magnetic levitation (maglev ) stage for photolithography in semiconductor manufacturing. This stag e is the world's first maglev stage that provides fine six-degree-of-f reedom motion controls and realizes large (50 mm x 50 mm) planar motio ns with only a single magnetically levitated moving part. The key elem ent of this stage is a linear motor capable of providing forces in bot h suspension and translation without contact. The advantage of such a stage is that the mechanical design is far simpler than competing conv entional approaches and, thus, promises faster dynamic response and hi gher mechanical reliability. The stage operates with a positioning noi se as low as 5 nm rms in x and y, and acceleration capabilities in exc ess of 1 g (10 m/s(2)). We demonstrate the utility of this stage for n ext-generation photolithography or in other high-precision motion cont rol applications. (C) 1998 Elsevier Science Inc.