摘要 |
<p>In a photolithography apparatus, a cable slab 16 carries compressed air, coolant and/or power supply channels from a stationary frame 19 to a wafer table 12. Forces exerted on the moveable table 12 by the cable slab 16 are measured by a force sensor 17 mounted between the moveable table 12 and a mounting bracket 16a for the cable slab. Control signals are generated from the force signals outputted by the force sensor 17, and applied to linear electric motors which drive the wafer table to counteract the effects of forces exerted on the wafer table by the cable slab 16. <IMAGE></p> |