Chucks and clamps for holding objects of a lithographic apparatus and methods for controlling a temperature of an object held by a clamp of a lithographic apparatus

Abstract

A lithographic apparatus includes a clamp (406) configured to receive an object (402). The clamp defines at least one channel (408) configured to pass a fluid at a first fluid temperature. The lithographic apparatus also includes a chuck (404) coupled to the clamp. The chuck (404) defines at least one void (464) configured to thermally insulate the chuck from the clamp.

What is claimed is: 
     
       1. A lithographic apparatus comprising:
 a clamp, configured to receive an object and, comprising:
 a first layer including at least one first channel arranged to be a first plurality of burls defining a first plurality of voids adjacent to the object and configured to pass a first fluid at a first fluid temperature, 
 a third layer including at least one second channel configured to pass a third fluid at a third fluid temperature a second plurality of burls defining a second plurality of voids, wherein the second plurality of voids is configured to be held at a vacuum during operation, and 
 a second layer sandwiched between the first layer and the third layer, the second layer including at least one void channel configured to thermally insulate the at least one first channel and the at least one second channel circulate a first fluid at a first fluid temperature; 
 
 a fluid conditioning device coupled to the at least one channel; and 
 a chuck coupled to the third layer of the clamp. 
 
     
     
       2. The lithographic apparatus of  claim 1 , wherein the at least one void is first plurality of voids is configured to be held at a vacuum during operation. 
     
     
       3. The lithographic apparatus of  claim 1 , wherein the at least one void is filled with a second fluid. 
     
     
       4. The lithographic apparatus of  claim 1 , wherein the at least one void comprises a plurality of voids. 
     
     
       5. The lithographic apparatus of  claim 1 , further comprising a wherein the fluid conditioning device is configured to change a temperature of the first fluid. 
     
     
       6. The lithographic apparatus of  claim 5 , wherein the fluid conditioning device is configured to change a temperature of the first fluid from a second fluid temperature to the first fluid temperature. 
     
     
       7. The lithographic apparatus of  claim 6 , wherein:
 the fluid conditioning device is configured to change the temperature of the first fluid from the second fluid temperature to the first fluid temperature when the object is being exposed with radiation, and 
 the second fluid temperature is greater than the first fluid temperature. 
 
     
     
       8. The lithographic apparatus of  claim 6 , wherein the first fluid temperature is in a range from about −15° C. to about 15° C., and wherein the second fluid temperature is in a range from about 17° C. to about 27° C. 
     
     
       9. The lithographic apparatus of  claim 1 , wherein the first fluid temperature is less than a target average temperature of the object when the object is being exposed with radiation. 
     
     
       10. The lithographic apparatus of  claim 1 , wherein:
 the object comprises a material having a coefficient of thermal expansion that varies as a function of temperature; 
 the coefficient of thermal expansion of the material of the object is about zero at a zero-crossing temperature of the object; and 
 the first fluid temperature is such that an average temperature of the object when the object is being exposed with radiation is equal to about the zero-crossing temperature of the object. 
 
     
     
       11. The lithographic apparatus of  claim 1 , wherein the first fluid temperature is such that internal forces of the object when the object is being exposed with radiation are substantially symmetric in a direction perpendicular to a surface of the clamp holding the object. 
     
     
       12. The lithographic apparatus of  claim 1 , wherein the first fluid temperature is such that a sum of the internal forces of the object when the object is being exposed with radiation is about equal to zero. 
     
     
       13. The lithographic apparatus of  claim 1 , wherein the at least one first channel comprises a plurality of first channels, and wherein the object is a patterning device. 
     
     
       14. A method for controlling a temperature of an object held by a clamp of a lithographic apparatus, the method comprising:
 exposing an object with radiation; passing and  
 circulating a first fluid at a first fluid temperature through at least one first channel defined by a firstsecond layer of the clamp to condition a temperature of the firstsecond layer of the clamp; passing a third fluid at a third fluid temperature through at least one second channel defined by a third layer of the clamp to condition a temperature of the third layer of the clamp; 
 wherein the clamp includes a the at least one channel is coupled to a fluid conditioning device and the second layer is sandwiched between the a first layer and the a third layer, the second first layer including at least one void configured to thermally insulate the at least one first channel and the at least one second channel a first plurality of burls defining a first plurality of voids adjacent to the object, the third layer including a second plurality of burls defining at a second plurality of voids, the second plurality of voids being configured to be at a vacuum during operation, 
 wherein the third layer of the clamp is coupled to a chuck. 
 
     
     
       15. The method of  claim 14 , further comprising:
 before passing the first fluid at the first fluid temperature through the at least one first channel, passing the first fluid at a second fluid temperature through the at least one first channel to condition the temperature of the first layer of the clamp; and 
 after passing the first fluid at the second fluid temperature through the at least one first channel, changing the second fluid temperature of the first fluid to the first fluid temperature of the first fluid, wherein the second fluid temperature is greater than the first fluid temperature. 
 
     
     
       16. The method of claim  14  15, wherein:
 the first fluid temperature is conditioned to be in a range from about −15° C. to about 15° C.; and 
 the second fluid temperature is conditioned to be in a range from about 17° C. to about 27° C. 
 
     
     
       17. The method of  claim 16 , wherein:
 the first fluid temperature is conditioned to be about −8° C.; and 
 the second fluid temperature is conditioned to be about 22° C. 
 
     
     
       18. The method of  claim 14 , wherein the first fluid temperature is conditioned to be less than an average temperature of the object when exposing the object with radiation. 
     
     
       19. The method of  claim 14 , wherein:
 the object comprises a material having a coefficient of thermal expansion that varies as a function of temperature; 
 the coefficient of thermal expansion of the material of the object is about zero at a zero-crossing temperature; and 
 passing the fluid at the first fluid temperature through the at least one channel generates an average temperature of the object when exposing the object with radiation that is equal to about the zero-crossing temperature of the material of the object. 
 
     
     
       20. A clamp configured to be arranged in a lithography system to receive an object, comprising:
 a first layer including at least one first channel a first plurality of burls defining a first plurality of voids arranged to be adjacent to the object and configured to pass a first fluid at a first fluid temperature, a third layer including at least one second channel arranged to be adjacent to a chunk and configured to pass a third fluid at a third fluid temperature a second plurality of burls defining a second plurality of voids, arranged to be adjacent to a chuck, wherein the second plurality of voids is configured to be held at a vacuum during operation; and 
 a second layer sandwiched between the first layer and the third layer, the second layer including at least one void channel configured to thermally insulate the at least one first channel and the at least one second channel circulate a first fluid at a first fluid temperature; and 
 a fluid conditioning device coupled to the at least one channel. 
 
     
     
       21. The clamp of  claim 20 , wherein the at least one void is at a vacuum first plurality of voids is configured to be held at a vacuum during operation. 
     
     
       22. The clamp of  claim 20 , wherein the at least one void is filled with a second fluid. 
     
     
       23. The clamp of  claim 20 , wherein the at least one void comprises a plurality of voids. 
     
     
       24. The clamp of  claim 20 , wherein the at least one first channel is connected to a fluid conditioning device is configured to change a temperature of the first fluid. 
     
     
       25. A support comprising:
 a clamp configured to receive an object and comprising:
 a first layer including a first plurality of burls defining a first plurality of voids adjacent to the object, 
 a third layer including a second plurality of burls defining a second plurality of voids, wherein the second plurality of voids is configured to be held at a vacuum during operation, and 
 a second layer sandwiched between the first layer and the third layer, the second layer including at least one first channel configured to circulate a first fluid at a first fluid temperature; 
   a fluid conditioning device coupled to the at least one first channel; and   a chuck coupled to the third layer of the clamp.    
     
     
       26. The support of claim 25, wherein the first plurality of voids is configured to be at a vacuum during operation.  
     
     
       27. The support of claim 25, wherein the fluid conditioning device is configured to change a temperature of the first fluid.  
     
     
       28. The support of claim 27, wherein the fluid conditioning device is configured to change a temperature of the first fluid from a second fluid temperature to the first fluid temperature.  
     
     
       29. The support of claim 28, wherein:
 the fluid conditioning device is configured to change the temperature of the first fluid from the second fluid temperature to the first fluid temperature when the object is being exposed with radiation, and   the second fluid temperature is greater than the first fluid temperature.    
     
     
       30. The support of claim 29, wherein the first fluid temperature is in a range from about −15° C. to about 15° C., and wherein the second fluid temperature is in a range from about 17° C. to about 27° C.  
     
     
       31. The support of claim 25, wherein the first fluid temperature is less than a target average temperature of the object when the object is being exposed with radiation.  
     
     
       32. The support of claim 25, wherein:
 the object comprises a material having a coefficient of thermal expansion that varies as a function of temperature;   the coefficient of thermal expansion of the material of the object is about zero at a zero-crossing temperature of the object; and   the first fluid temperature is such that an average temperature of the object when the object is being exposed with radiation is equal to about the zero-crossing temperature of the object.    
     
     
       33. The support of claim 25, wherein the first fluid temperature is such that internal forces of the object when the object is being exposed with radiation are substantially symmetric in a direction perpendicular to a surface of the clamp holding the object.  
     
     
       34. The support of claim 25, wherein the first fluid temperature is such that a sum of the internal forces of the object when the object is being exposed with radiation is about equal to zero.  
     
     
       35. The support of claim 25, wherein the at least one first channel comprises a plurality of first channels, and wherein the object is a patterning device.  
     
     
       36. The support of claim 25, wherein the third layer further includes at least one second channel configured to circulate a second fluid at a temperature higher than the temperature of the first fluid.  
     
     
       37. The support of claim 36, wherein the at least one second channel comprises a plurality of second channels.  
     
     
       38. The support of claim 25, wherein the first layer and the second layer are optically coupled to each other at a first interface, and the second layer and the third layer are optically coupled to each other at a second interface.  
     
     
       39. A method for controlling a temperature of an object held by a clamp, the method comprising:
 exposing the object with radiation; and   circulating a first fluid at a first fluid temperature through at least one first channel defined by a second layer of the clamp to condition a temperature of the second layer of the clamp, wherein the at least one first channel is coupled to a fluid conditioning device,   wherein the second layer is sandwiched between a first layer and a third layer, the first layer including a first plurality of burls defining a first plurality of voids, the third layer including a second plurality of burls defining a second plurality of voids,   wherein the second plurality of voids is configured to be held at a vacuum during operation, and   wherein the third layer of the clamp is coupled to a chuck.    
     
     
       40. The method of claim 39, further comprising:
 before passing the first fluid at the first fluid temperature through the at least one first channel, passing the first fluid at a second fluid temperature through the at least one first channel to condition the temperature of the first layer of the clamp; and   after passing the first fluid at the second fluid temperature through the at least one first channel, changing the second fluid temperature of the first fluid to the first fluid temperature of the first fluid, wherein the second fluid temperature is greater than the first fluid temperature.    
     
     
       41. The method of claim 40, wherein:
 the first fluid temperature is conditioned to be in a range from about −15° C. to about 15° C.; and   the second fluid temperature is conditioned to be in a range from about 17° C. to about 27° C.    
     
     
       42. The method of claim 41, wherein:
 the first fluid temperature is conditioned to be about −8° C.; and   the second fluid temperature is conditioned to be about 22° C.    
     
     
       43. The method of claim 39, wherein the first fluid temperature is conditioned to be less than an average temperature of the object when exposing the object with radiation.  
     
     
       44. The method of claim 39, wherein:
 the object comprises a material having a coefficient of thermal expansion that varies as a function of temperature;   the coefficient of thermal expansion of the material of the object is about zero at a zero-crossing temperature; and   passing the fluid at the first fluid temperature through the at least one channel generates an average temperature of the object when exposing the object with radiation that is equal to about the zero-crossing temperature of the material of the object.    
     
     
       45. A clamp configured to receive an object, comprising:
 a first layer including a first plurality of burls defining a first plurality of voids adjacent to the object;   a third layer including a second plurality of burls defining a second plurality of voids arranged to be adjacent to a chuck and configured to be held at a vacuum during operation; and   a second layer sandwiched between the first layer and the third layer, the second layer including at least one first channel configured to circulate a first fluid at a first fluid temperature, wherein the at least one first channel is coupled to a fluid conditioning device.    
     
     
       46. The clamp of claim 45, wherein the first plurality of voids is configured to be held at a vacuum during operation.  
     
     
       47. The clamp of claim 45, wherein the fluid conditioning device is configured to change a temperature of the first fluid.  
     
     
       48. The clamp of claim 45, wherein the third layer further includes at least one second channel configured to circulate a second fluid at a temperature higher than the temperature of the first fluid.  
     
     
       49. The clamp of claim 48, wherein the at least one second channel comprises a plurality of second channels.  
     
     
       50. The clamp of claim 45, wherein the first layer and the second layer are optically coupled to each other at a first interface, and the second layer and the third layer are optically coupled to each other at a second interface.