A new XY stage employing ultrasonic linear motors that is simple, compact,
and completely nonmagnetic was developed for an e-beam x-ray mask writer em
ploying step-and-repeat writing. The main performance results are: (1) posi
tion fluctuations during writing are less than +/-4 nm; (2) the time for a
650 mu m step movement is less than 270 ms; (3) the magnetic interference i
s less than +/-1 nT at the e-beam deflection center; and (4) the vibration
of the stage when moving at a constant speed is less than +/-0.25 m/s(2). T
he new stage is also very easy to maintain. It has been installed in the EB
-X3 e-beam x-ray mask writer. (C) 1999 American Vacuum Society. [S0734-211X
(99)16606-X].