Air Bearing Guided High Speed XY Stage

In order to realize higher throughput in submicron X-ray lithography, higher velocity X-Y stage studies are conducted on a completely non-contact movement using an externally pressurized air bearing guide and a moving coil linear actuator. Results are as follows: (1) Sraightness of 0.05 μm and orthogonality of 0.5 arc sec over 100×190 mm area are achieved by constructing a stage capable of X-Y movements on a base plate. (2) An X-Y stage using an air bearing guide requires long settling time due to the lack of friction. To realize high velocity positioning, a new servo feedback circuit using the horizontal acceleration signal of the base plate is developed, and maximum velocity of 150 mm/s, 0.5 s for 15 mm stroke, and positional accuracy of 0.1 μm are achieved. (3) A fine positioning mechanism using a vacuum clamp and a moving coil linear actuator demonstrates step movements of 0.01 μm.