Lithographic apparatus and device manufacturing method

Abstract

A method for generating radiation includes supplying a fuel to a discharge space, creating a discharge in the fuel to form a plasma, and reducing a volume defined by the plasma by controlling radiation emission by the plasma. The reducing includes supplying a substance including at least one of Ga, In, Bi, Pb or Al to the plasma to control the radiation emission.

What is claimed is: 
     
         1 . A method for generating radiation, the method comprising:
 supplying a fuel to a discharge space;   creating a discharge in the fuel to form a plasma; and   reducing a volume defined by the plasma by controlling radiation emission by the plasma, said reducing including supplying a substance including at least one of Ga, In, Bi, Pb or Al to the plasma to control the radiation emission.   
     
     
         2 . The method of  claim 1 , wherein the fuel includes at least one of Sn, Xe or Li, 
     
     
         3 . The method of  claim 1 , wherein the substance and the fuel are separately supplied to the discharge space. 
     
     
         4 . The method of  claim 1 , wherein the substance is part of a mixture including the fuel. 
     
     
         5 . The method of  claim 4 , wherein the mixture is solid or liquid. 
     
     
         6 . The method of  claim 1 , wherein the substance is selected to increase radiation emission in a pre-determined wavelength range. 
     
     
         7 . The method of  claim 1 , wherein said reducing the volume defined by the plasma includes reducing a radial size of the plasma. 
     
     
         8 . A device manufacturing method comprising:
 generating a beam of radiation, said generating including
 supplying a fuel to a discharge space; 
 creating a discharge in the fuel to form a plasma; and 
 reducing a volume defined by the plasma by controlling radiation emission by the plasma, said reducing including supplying a substance including at least one of Ga, In, Bi, Pb or Al to the plasma to control the radiation emission; 
   patterning the beam of radiation to form a patterned beam of radiation; and   projecting the patterned beam of radiation onto a substrate.   
     
     
         9 . The method of  claim 8 , wherein the fuel includes at least one of Sn, Xe or Li. 
     
     
         10 . The method of  claim 8 , wherein the substance and the fuel are separately supplied to the discharge space. 
     
     
         11 . The method of  claim 8 , wherein the substance is selected to increase radiation emission in a pre-determined wavelength range. 
     
     
         12 . A source configured to generate radiation, the source comprising:
 a fuel supply configured to supply a fuel to a discharge space for generation of a plasma, the discharge space including, in use, a substance including at least one of Ga, In, Bi or Al configured to adjust radiation emission by the plasma so as to reduce a volume defined by the plasma.   
     
     
         13 . The source of  claim 12 , wherein the fuel includes at least one of Sn, Xe or Li. 
     
     
         14 . The source of  claim 12 , further comprising a supply configured to supply the substance in the discharge space. 
     
     
         15 . The source of  claim 12 , wherein the substance and the fuel are separately supplied to the discharge space. 
     
     
         16 . The source of  claim 12 , wherein the substance is part of a mixture including the fuel. 
     
     
         17 . The source of  claim 16 , wherein the mixture is solid or liquid. 
     
     
         18 . The source of  claim 12 , wherein the substance is selected to increase the radiation emission in a pre-determined wavelength range. 
     
     
         19 . The source of  claim 12 , wherein the substance is configured to reduce a radial size of the plasma. 
     
     
         20 . A lithographic system comprising the source of  claim 12 . 
     
     
         21 . An inspection system comprising the source of  claim 12 . 
     
     
         22 . A metrology system comprising the source of  claim 12 .