Liquid immersion optical tool, method for cleaning liquid immersion optical tool, and method for manufacturing semiconductor device

Abstract

There is disclosed is a liquid immersion optical tool, which comprises a light source, an optical lens system, a stage which moves an object base on which an object is to be placed, a head comprising a liquid immersion medium fluid supply device and a liquid immersion medium fluid discharge device to provide a layer of liquid immersion medium fluid between the optical lens system and the object, a fence which limits a region of the layer of liquid immersion medium fluid, and a cleaning device which cleans a portion having been contacted with the liquid immersion medium fluid by means of a cleaning solution.

1 . A liquid immersion optical tool comprising: 
 a light source;    an optical lens system;    a stage which moves an object base on which an object is to be placed;    a head comprising a liquid immersion medium fluid supply device and a liquid immersion medium fluid discharge device to provide a layer of liquid immersion medium fluid between the optical lens system and the object;    a fence which limits a region of the layer of liquid immersion medium fluid; and    a cleaning device which cleans a portion having been contacted with the liquid immersion medium fluid by means of a cleaning solution.    
   
   
       2 . The liquid immersion optical tool according to  claim 1 , wherein the portion having been contacted with the liquid immersion medium fluid is one or more selected from the group including the optical lens system, the fence, the object base, the stage, the head, the liquid immersion medium fluid supply device, and the liquid immersion medium fluid discharge device.  
   
   
       3 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning device generates cavities in the cleaning solution.  
   
   
       4 . The liquid immersion optical tool according to  claim 3 , wherein an average diameter of the cavities is equal to or smaller than 1 μm.  
   
   
       5 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning device has any of a cavitation jet, a venturi tube, a Pitot tube, and a ultrasound generator, and the cavities are generated by any of the cavitation jet, the venturi tube, the Pitot tube, and the ultrasound generator.  
   
   
       6 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning device is connected to the liquid immersion medium fluid supply device.  
   
   
       7 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning device is loaded on the stage.  
   
   
       8 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning device is detachable.  
   
   
       9 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning solution is one selected from the group of function waters including ozone water, ionized water, carbonated water, and peroxide water.  
   
   
       10 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning solution is acid.  
   
   
       11 . The liquid immersion optical tool according to  claim 1 , wherein the cleaning solution is water vapor.  
   
   
       12 . The liquid immersion optical tool according to  claim 1 , further comprising a measuring mechanism which measures intensity of light transmitting the optical lens system.  
   
   
       13 . The liquid immersion optical tool according to  claim 12 , further comprising: 
 a computing mechanism which computes a lowered quantity of light intensity from information on the light intensity measured by the measuring mechanism; and    a calculating mechanism which calculates a period of cleaning by the cleaning device from the computed lowered quantity of light intensity.    
   
   
       14 . The liquid immersion optical tool according to  claim 1 , wherein a predetermined pattern is transferred to the object by using the optical lens system.  
   
   
       15 . The liquid immersion optical tool according to  claim 14 , wherein the predetermined pattern is a pattern of a semiconductor element.  
   
   
       16 . The liquid immersion optical tool according to  claim 1 , wherein a surface of the object is observed or measured by using the optical lens.  
   
   
       17 . A cleaning method in the liquid immersion optical tool comprising a light source; an optical lens system; a stage which moves an object base on which an object is to be placed; a head comprising a liquid immersion medium fluid supply device and a liquid immersion medium fluid discharge device to provide a layer of liquid immersion medium fluid between the optical lens system and the object; a fence which limits a region of the layer of liquid immersion medium fluid; and a cleaning device which cleans a portion having been contacted with the liquid immersion medium fluid by means of a cleaning solution, 
 wherein the portion having been contacted with the liquid immersion medium fluid is cleaned for a predetermined time by means of the cleaning device.    
   
   
       18 . The cleaning method according to  claim 17 , wherein a rinse process is carried out by means of a rinse solution in which no cavities exist, after cleaning by the cleaning solution is carried out for the predetermined time.  
   
   
       19 . The cleaning method according to  claim 18 , wherein the rinse solution is water.  
   
   
       20 . A semiconductor device manufacturing method in which a semiconductor device is manufactured by using a liquid immersion exposure tool, the liquid immersion exposure tool comprising: 
 a light source;    an optical lens system;    a stage which moves an object base on which an object is to be placed;    a head comprising a liquid immersion medium fluid supply device and a liquid immersion medium fluid discharge device to provide a layer of liquid immersion medium fluid between the optical lens system and the object;    a fence which limits a region of the layer of liquid immersion medium fluid; and    a cleaning device which cleans a portion having been contacted with the liquid immersion medium fluid by means of a cleaning solution.