Linear Motor and Lithography Arrangement Including Linear Motor

Abstract

A lithographic apparatus including a uniformity correction system is disclosed. The lithographic apparatus comprises an illumination system configured to condition a beam of radiation. The illumination system comprises a uniformity correction system located at a plane configured to receive a substantially constant pupil when illuminated with the beam of radiation. The uniformity correction system includes fingers configured to be movable into and out of intersection with a radiation beam so as to correct an intensity of respective portions of the radiation beam. A linear motor actuator arrangement drives the fingers to their respective appropriate positions to compensate for non-uniform illumination. Control is provided by a control system that precisely manipulates carriers of the fingers.

What is claimed is: 
     
         1 . A linear switched reluctance motor comprising:
 a stator having a fixed coil arrangement, the stator including at least three poles disposed on a plane in a spatial sequence; and   a rotor including at least two poles disposed in the plane, the rotor constructed and arranged to be linearly movable in two dimensions by the fixed coil arrangement while the stator is constructed and arranged to remain stationary relative to the rotor, wherein the at least two poles are disposed opposite the at least three poles.   
     
     
         2 . The linear switched reluctance motor according to  claim 1 , wherein the fixed coil arrangement further comprising a coil wound on each of at least two poles of the at least three poles. 
     
     
         3 . A linear switched reluctance motor comprising:
 a fixed stator including first, second and third poles disposed on a plane in a spatial sequence, wherein the first and third poles having a coil wound thereon; and   a rotor including fourth and fifth poles disposed in the plane, the rotor constructed and arranged to be linearly movable in two dimensions when the first, second and third poles of the fixed stator become energized in response to the coils wound on the first and third poles being energized in a temporal sequence, wherein the fourth and fifth poles are disposed opposite the first, second and third poles and the fixed stator is constructed and arranged to be fixed relative to the rotor.   
     
     
         4 . The linear switched reluctance motor according to  claim 3 , wherein the rotor is coupled to a finger, the rotor is constructed and arranged to position the finger in response to adjusting of a current in each of the coils in micro steps. 
     
     
         5 . The linear switched reluctance motor according to  claim 4 , wherein the current in the each of the coils is adjusted with sine cosine microstepping. 
     
     
         6 . A linear switched reluctance motor comprising:
 a stator having a fixed coil arrangement, the stator including at least two poles disposed on a plane in a spatial sequence; and   a rotor including at least one pole disposed in the plane, the rotor constructed and arranged to be linearly movable in two dimensions by the fixed coil arrangement while the stator is constructed and arranged to remain stationary relative to the rotor, wherein the at least one pole is disposed opposite the at least two poles.   
     
     
         7 . The linear switched reluctance motor according to  claim 6 , wherein the fixed coil arrangement further comprising a coil wound on each of the at least two poles.