Lithographic apparatus and scanning method

Abstract

A lithographic apparatus includes a first support to support a first patterning device; a second support to support a second patterning device, each of the first and the second patterning device capable of imparting a radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table constructed to hold a substrate; a projection system to project the patterned radiation beam onto a target portion of the substrate; a controller to drive the first support and the second support and arranged to: drive the first support to perform a scanning movement; drive the second support to accelerate during at least part of the scanning movement of the first support; and drive the second support to perform a scanning movement upon completion of the scanning movement of the first support, so as to scan a die adjacent a die previously scanned during the scanning movement of the first support.

1 . A lithographic apparatus comprising:
 a first support constructed to support a first patterning device;   a second support constructed to support a second patterning device;   wherein the first patterning device is capable of imparting a radiation beam with a pattern in its cross section to form a first patterned radiation beam;   wherein the second patterning device is capable of imparting a radiation beam with a pattern in its cross section to form a second patterned radiation beam;   a substrate table constructed to hold a substrate;   a projection system configured to project the first and second patterned radiation beams next to each other onto a target portion of the substrate; and   a controller configured to drive the first support and the second support, the controller being arranged to:
 drive the first support to perform a scanning movement; 
 drive the second support to accelerate during at least part of the scanning movement of the first support. 
   
     
     
         2 . The lithographic apparatus of  claim 1 , wherein the projection system is configured to project the first and second patterned radiation beams adjacent to each other. 
     
     
         3 . The lithographic apparatus of  claim 1 , wherein the controller is further arranged to drive the second support to perform a scanning movement upon completion of the scanning movement of the first support, so as to scan a die adjacent a die previously scanned during the scanning movement of the first support. 
     
     
         4 . The lithographic apparatus of  claim 3 , wherein the controller is further arranged to drive the substrate table at a substantially constant substrate table scanning velocity during the scanning movement of the first support and the scanning movement of the second support. 
     
     
         5 . The lithographic apparatus of  claim 1 , wherein the projection system is arranged to alternately project the pattern of the patterning device and the second patterning device onto a row or column of adjacent dies. 
     
     
         6 . The lithographic apparatus of  claims 1 , wherein the second support is moved, during the scanning movement of the support, to a scanning start position and velocity by:
 decelerating the second support from a previous scanning movement;   stopping the second support;   accelerating the second support to move back in a direction reverse to the scanning movement;   decelerating and stopping the second support; and   accelerating the second support to the scanning speed.   
     
     
         7 . The lithographic apparatus of  claim 1 , wherein the second support is moved during the scanning movement of the first support, to a scanning start position and velocity by:
 decelerating the second support from a previous scanning movement;   stopping the second support; and   accelerating the second support to the scanning speed in reverse direction as compared to the previous scanning movement of the second support.   
     
     
         8 . The lithographic apparatus of  claim 1 , wherein the projection system comprises:
 a first projection system part configured to project a beam patterned by the first patterning device held by the first support;   a second projection system part configured to project a beam patterned by the second patterning device held by the second support; and   a third projection system part configured to project the patterned beam projected by the first and/or second projection system parts onto the substrate.   
     
     
         9 . The lithographic apparatus of  claim 7 , wherein the controller is arranged to activate a first optical path via the first projection system part during the scanning movement of the first support and to activate a second optical path via the second projection system part during the scanning movement of the second support. 
     
     
         10 . The lithographic apparatus of  claim 1 , comprising an illumination system comprising a first illuminator configured to illuminate the patterning device held by the first support and a second illuminator configured to illuminate the second patterning device held by the second support. 
     
     
         11 . The lithographic apparatus of  claim 10 , wherein the illumination system comprises two sources of radiation 
     
     
         12 . The lithographic apparatus of  claim 1 , comprising an optical switch arranged to couple the patterned beam into a first projection system part and/or a second projection system part of the projection system. 
     
     
         13 . The lithographic apparatus of  claim 1 , wherein the lithographic apparatus is a dual stage lithographic apparatus comprising a measurement part configured to perform a substrate levelling measurement, and an exposure part, the lithographic apparatus comprising dual levelling sensors at the measurement part. 
     
     
         14 . The lithographic apparatus of  claim 13 , wherein the dual levelling sensors comprise a coarse levelling sensor and a fine levelling sensor. 
     
     
         15 . The lithographic apparatus of  claim 14 , wherein the dual levelling sensors are configured to each measure in parallel a part of a surface of the substrate. 
     
     
         16 . The lithographic apparatus of  claim 1 , wherein the lithographic apparatus is a dual stage lithographic apparatus comprising a measurement part configured to perform a substrate levelling measurement, and an exposure part, the lithographic apparatus comprising a levelling sensor at the measure part and a levelling sensor at the exposure part. 
     
     
         17 . The lithographic apparatus of  claim 1 , wherein, in use, the second support accelerates during the at least part of the scanning movement of the first support to a scanning start position and velocity. 
     
     
         18 . A combination of a lithographic apparatus of  claim 1  and a handler, the hander comprising a leveling sensor configured to perform a substrate leveling measurement. 
     
     
         19 . A lithographic scanning method for projecting patterns from a first patterning device and a second patterning device onto a substrate, the method comprising:
 performing a scanning movement by a first support configured to hold the first patterning device;   accelerating a second support configured to hold the second patterning device, during at least part of the scanning movement of the first support, to a scanning start position and velocity; and   performing a scanning movement by the second support upon completion of the scanning movement of the first support, so as to scan a die adjacent a die previously scanned during the scanning movement by the first support.   
     
     
         20 . The method of  claim 19 , wherein, in use, the second support accelerates during the at least part of the scanning movement of the first support to a scanning start position and velocity.