| 摘要 |
<p>A hydrostatic pad (32) and a hydrostatic pad (34) hold a wafer (W) and a table (TB) on which the wafer is mounted. The hydrostatic pad (32) maintains the distance between the bearing surface and the wafer (W) in the direction of the optical axis of a projection optical system (PL) at a predetermined value. Further, since the hydrostatic pads, unlike static gas bearings, utilize the static pressure of incompressible fluid (liquid) between the bearing surface and a support object (substrate), the rigidity of the bearing is high and the distance between the bearing surface and the substrate is maintained stable and constant. In addition, liquid (e. g. , pure water) is higher in viscosity than gas (e. g. , air), and is superior in vibration damping compared to gas. Accordingly, pattern transfer on a wafer (substrate) substantially free from defocus can be achieved, without necessarily having to arrange a focal position detection system.</p> |
