Lithographic support structure

Abstract

The invention relates to a transfer apparatus for transferring an object (W). the transfer apparatus comprises a gripper ( 15 ) for at least one of gripping the object (W) at a first position and then releasing the object (W) at a second position proximate to a receiver ( 20 ) and releasing the object (W) at a first position after gripping the object at a second position proximate to the receiver ( 20 ). The transfer apparatus is further provided with a measurement device ( 22 ) arranged to measure the relative position of the gripper ( 15 ) with respect to the receiver ( 20 ) in at least one dimension. Further, a relative position error is defined with respect to a desired relative position based on the relative position measured. The relative position of the gripper ( 15 ) and the receiver ( 20 ) are adjusted for minimizing the relative position error in the second position.

1 .- 10 . (canceled) 
   
   
       11 . A lithographic clamping structure, comprising:
 a Johnson-Raybeck effect type clamp having an upper surface to clamp an object; and   an oxidized layer, provided on the upper surface of the Johnson-Raybeck effect type clamp, to minimize heating effects transferred to the object.   
   
   
       12 . The lithographic clamping structure of  claim 13 , wherein the decaying AC-profile is an RF AC profile. 
   
   
       13 . A lithographic support structure to hold and move an object, comprising:
 a Johnson-Raybeck effect type clamp; and   a controller coupled to the Johnson-Raybeck effect type clamp and configured to provide a clamping and de-clamping voltage to the Johnson-Raybeck effect type clamp, wherein the controller is arranged to generate the de-clamping voltage with a decaying AC-profile.   
   
   
       14 . Method of cleaning a substrate holder in a lithographic apparatus including a clamp for clamping a substrate, the method comprising:
 introducing a substrate in the lithographic apparatus;   clamping the substrate to the substrate holder such that the substrate contacts the substrate holder at a first location;   de-clamping the substrate from the substrate holder;   repeating the clamping and de-clamping a number of times such that the substrate contacts the substrate table repeatedly at the first location, or at a location other than the first location, or both at the first location and the location other than the first location.   
   
   
       15 .- 18 . (canceled) 
   
   
       19 . A lithographic apparatus, comprising:
 a support structure configured to support a patterning device, the patterning device configured to impart a desired pattern onto a beam of radiation;   a substrate holder configured to hold a substrate;   a projection system configured to project the patterned beam onto a target portion of the substrate; and   a Johnson Raybeck effect type clamp configured to clamp the substrate, or the patterning device, or both the substrate and the patterning device, the clamp having an upper surface and an oxidized layer, provided on the upper surface, to minimize heating effects transferred to the substrate and/or the patterning device.   
   
   
       20 . A lithographic apparatus, comprising:
 a support structure configured to support a patterning device, the patterning device configured to impart a desired pattern onto a beam of radiation;   a substrate holder configured to hold a substrate;   a projection system configured to project the patterned beam onto a target portion of the substrate;   a clamp configured to clamp the substrate to the substrate holder such that the substrate contacts the substrate holder at a first location; and   a processor configured to instruct repeated clamping and de-clamping of the substrate by the clamp, such that the substrate contacts the substrate holder repeatedly at the first location, or at a location other than the first location, or both at the first location and the location other than the first location.   
   
   
       21 . (canceled) 
   
   
       22 . A device manufacturing method, comprising:
 providing a substrate via a clamping structure, the clamping structure comprising a Johnson-Raybeck effect type clamp having an upper surface and an oxidized layer on the upper surface;   providing a beam of radiation;   imparting a desired pattern onto the beam of radiation using a patterning device; and   projecting the patterned beam of radiation onto a target portion of the substrate.   
   
   
       23 . The lithographic clamping structure of  claim 11 , further comprising a controller coupled to the Johnson-Raybeck effect type clamp and configured to provide a clamping and de-clamping voltage to the Johnson-Raybeck effect type clamp, wherein the controller is arranged to generate the de-clamping voltage with a decaying AC-profile. 
   
   
       24 . The lithographic clamping structure of  claim 23 , wherein the decaying AC-profile is a RF AC profile. 
   
   
       25 . The lithographic clamping structure of  claim 11 , wherein the Johnson-Raybeck effect type clamp is part of a moveable robot arm configured to support and move the object, and wherein the object comprises a substrate onto which a beam of radiation is to be projected. 
   
   
       26 . The lithographic support structure of  claim 13 , wherein the Johnson-Raybeck effect type clamp is part of a moveable robot arm configured to support and move the object, and wherein the object comprises a substrate onto which a beam of radiation is to be projected. 
   
   
       27 . The method of  claim 14 , further comprising, after a de-clamping of the substrate, rotating or shifting the substrate before a further clamping of the rotated or shifted substrate. 
   
   
       28 . The lithographic apparatus of  claim 19 , further comprising a controller coupled to the Johnson-Raybeck effect type clamp and configured to provide a clamping and de-clamping voltage to the Johnson-Raybeck effect type clamp, wherein the controller is arranged to generate the de-clamping voltage with a decaying AC-profile. 
   
   
       29 . The lithographic apparatus of  claim 28 , wherein the decaying AC-profile is a RF AC profile. 
   
   
       30 . The lithographic apparatus of  claim 19 , further comprising a moveable robot arm configured to support and move the substrate, or the patterning device, or both the substrate and the patterning device, the moveable robot arm comprising the Johnson-Raybeck effect type clamp. 
   
   
       31 . The lithographic apparatus of  claim 20 , further comprising a robot configured to, after a de-clamping of the substrate, rotate or shift the substrate before a further clamping of the rotated or shifted substrate. 
   
   
       32 . The method of  claim 22 , further comprising providing a clamping and de-clamping voltage to the Johnson-Raybeck effect type clamp, wherein the de-clamping voltage has a decaying AC-profile. 
   
   
       33 . The method of  claim 32 , wherein the decaying AC-profile is a RF AC profile. 
   
   
       34 . The method of  claim 22 , wherein the Johnson-Raybeck effect type clamp is part of a moveable robot arm supporting and moving the substrate.