A method, apparatus, and system for controlling a reticle-masking blade in a
photolithography
system. A reticle-masking blade is supported with a reticle-masking blade carriage
assembly. The reticle-masking blade carriage assembly is levitated at a position
with respect to a reference frame and at an orientation with respect to the reference
frame. Preferably, the reticle-masking blade carriage assembly is electromagnetically
levitated. At least one of the position and the orientation of the reticle-masking
blade carriage assembly is measured. At least one of the position and the orientation
of the reticle-masking blade carriage assembly is controlled. Optionally, the reticle-masking
blade carriage assembly is moved within a dimension within a range defined by the
reference frame. The dimension can be two dimensions. The movement of the reticle-masking
blade carriage assembly can be controlled.