Method for determining life of laser light source

Abstract

In a method for determining the life of a laser light source for use with an exposure apparatus using KrF or ArF excimer laser as a light source for exposure, the method for determining the life of the laser light source is implemented by subjecting an excimer laser light source to single oscillation by blocking a pulse light, acquiring data relating to plural parameters for learning a periodical variation of the excimer laser light source and its structuring parts through an interface, and determining the life of the excimer laser light source on the basis of the data acquired. Those data is acquired on a regular basis in accompany with the work for exchanging gases at the time of exchanging gases for the excimer laser light source.

What is claimed is:  
     
         1 . A method for determining the life of a laser light source for emitting laser light for use in an exposure apparatus; comprising the steps of: 
 acquiring information for learning a periodical variation in said laser light source; and    estimating the life of said laser light source on the basis of said information.    
     
     
         2 . The method as claimed in    claim 1   , wherein said information is acquired on a regular basis.  
     
     
         3 . The method as claimed in    claim 1   , wherein said information is acquired in accompany with work for exchanging gases at the time of exchanging gases of said laser light source.  
     
     
         4 . The method as claimed in    claim 1   , wherein said laser light is pulse light; and said information comprises information corresponding to at least one of high voltage to be applied to a discharging voltage of said laser light source, a spectrum line width of said pulse light, stability of pulse energy of said pulse light, and a number of emission of said pulse light.  
     
     
         5 . The method as claimed in    claim 1   , wherein the life of said laser light source is determined by comparing a value corresponding to said information with a preset limit value.  
     
     
         6 . A method for maintaining a laser light source for emitting laser light for use in an exposure apparatus, comprising the steps of: 
 acquiring information relating to maintenance of said laser light source; and    estimating a timing for maintenance of said laser light source on the basis of the information acquired.    
     
     
         7 . The method as claimed in    claim 6   , wherein said information relating to maintenance is acquired on a regular basis.  
     
     
         8 . The method as claimed in    claim 6   , further comprising the step of storing said information relating to maintenance in a time series; 
 wherein estimate of the timing for maintenance is implemented on the basis of said information stored in a time series.    
     
     
         9 . The method as claimed in    claim 8   , wherein a value of voltage to be applied to said laser light source is stored in a time series as said information relating to maintenance; and estimate of said timing of maintenance is implemented on the basis of said value of voltage stored in a time series.  
     
     
         10 . The method as claimed in    claim 6   , wherein said laser light is excimer pulse light.  
     
     
         11 . The method as claimed in    claim 6   , wherein said maintenance includes exchange of a part of said laser light source or inspection of said laser light source.  
     
     
         12 . The method as claimed in    claim 6   , wherein said information is information corresponding to at least one of a value of voltage to be applied to said laser light source, a spectrum width of said pulse light, and an energy of said pulse light.  
     
     
         13 . The method as claimed in    claim 6   , further comprising the step of exchanging gases of said laser light source for activating said laser light.  
     
     
         14 . A method for maintaining a laser light source for emitting laser light for use in an exposure apparatus, comprising the steps of: 
 acquiring information relating to maintenance of said laser light source; and    identifying an object of maintenance on the basis of the information acquired.    
     
     
         15 . The method as claimed in    claim 14   , wherein said maintenance includes exchange of a part of said laser light source or inspection of said laser light source.  
     
     
         16 . The method as claimed in    claim 14   , wherein said laser light source includes a plurality of parts; and at least one of said plurality of parts is identified as the object of maintenance.  
     
     
         17 . The method as claimed in    claim 16   , wherein said plurality of parts includes at least one of a laser chamber, a band-narrowing module, a mirror member and a beam splitter.  
     
     
         18 . The method as claimed in    claim 14   , wherein said information is information corresponding to at least one of a value of voltage to be applied to said laser light source, a spectrum width of said pulse light, and an energy of said pulse light.  
     
     
         19 . A method for making an exposure apparatus, the method comprising the steps of: 
 providing a laser light source which emits laser light;    providing an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    providing a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, which acquires information relating to maintenance of said laser light source, and which estimates a timing for maintenance of said laser light source.    
     
     
         20 . The method as claimed in    claim 19   , wherein said information relating to maintenance is acquired on a regular basis.  
     
     
         21 . The method as claimed in    claim 19   , further comprising the step of storing said information relating to maintenance in a time series; 
 wherein estimate of said timing of maintenance is implemented on the basis of said information stored in a time series.    
     
     
         22 . The method as claimed in    claim 21   , wherein a value of voltage to be applied to said laser light source is stored in a time series as said information relating to maintenance; and estimate of said timing for maintenance is implemented on the basis of said value of voltage stored in a time series.  
     
     
         23 . The method as claimed in    claim 19   , wherein said information relating to maintenance is acquired from said laser light source.  
     
     
         24 . The method as claimed in    claim 19   , wherein said maintenance includes exchange of a part of said laser light source or inspection of said laser light source.  
     
     
         25 . The method as claimed in    claim 19   , wherein said information is information corresponding to at least one of a value of voltage to be applied to said laser light source, a spectrum width of said pulse light, and an energy of said pulse light.  
     
     
         26 . The method as claimed in    claim 19   , wherein said control system generates a demand for maintenance of said laser light source on the basis of a result of said estimate.  
     
     
         27 . A method for making an exposure apparatus, the method comprising the steps of: 
 providing a laser light source which emits laser light;    providing an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    providing a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, which acquires information relating to maintenance of said laser light source, and which identifies an object of maintenance.    
     
     
         28 . The method as claimed in    claim 27   , wherein said maintenance includes exchange of a part of said laser light source or inspection of said laser light source.  
     
     
         29 . The method as claimed in    claim 27   , wherein: 
 said laser light source includes a plurality of parts; and    said control system identifies at least one of said plurality of parts as the object of maintenance.    
     
     
         30 . The method as claimed in    claim 27   , wherein said information relating to maintenance is acquired from said laser light source.  
     
     
         31 . The method as claimed in    claim 27   , wherein said information is information corresponding to at least one of a value of voltage to be applied to said laser light source, a spectrum width of said pulse light, and an energy of said pulse light.  
     
     
         32 . The method as claimed in    claim 27   , wherein said control system generates a demand for maintenance of the object identified.  
     
     
         33 . A method for making an exposure apparatus, the method comprising the steps of: 
 providing a laser light source which emits laser light;    providing an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    providing a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, and which requires a demand to said laser light source for sending information relating to maintenance of said laser light source.    
     
     
         34 . The method as claimed in    claim 33   , wherein said maintenance includes exchange of a part of said laser light source or inspection of said laser light source.  
     
     
         35 . The method as claimed in    claim 33   , further comprising the step of estimating a timing for maintenance of said laser light source on the basis of said information relating to maintenance sent from said laser light source.  
     
     
         36 . The method as claimed in    claim 33   , wherein said control system generates a demand for maintenance of said laser light source on the basis of said information relating to maintenance sent from said laser light source.  
     
     
         37 . The method as claimed in    claim 33   , wherein said information is information corresponding to at least one of a value of voltage to be applied to said laser light source, a spectrum width of said pulse light, and an energy of said pulse light.  
     
     
         38 . An exposure apparatus comprising: 
 a laser light source which emits laser light;    an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, which acquires information relating to maintenance of said laser light source, and which estimates a timing for maintenance of said laser light source.    
     
     
         39 . An exposure apparatus comprising: 
 a laser light source which emits laser light;    an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, which acquires information relating to maintenance of said laser light source, and which identifies an object of maintenance.    
     
     
         40 . An exposure apparatus comprising: 
 a laser light source which emits laser light;    an exposure system which is optically connected to said laser light source and exposes a substrate to laser light from said laser light source; and    a control system which is connected to said laser light source and said exposure system, which controls an operation of said exposure system, and which requires a demand to said laser light source for sending said information relating to maintenance of said laser light source.