Projection exposure apparatus, projection exposure method, and method for producing device

Abstract

A projection exposure apparatus transfers a pattern formed on a mask onto a substrate via a projection optical system. The projection exposure apparatus includes electricity removal units which removes electricity from a liquid supplied to a space between the projection optical system and the surface of a substrate. This makes it possible to prevent destruction of the circuit pattern or malfunction of the device which would otherwise caused by charging of the liquid.

1 . A projection exposure apparatus which transfers a pattern formed on a mask onto a substrate through a liquid, the projection exposure apparatus comprising: 
 a projection optical system which projects an image of the pattern onto the substrate; and    an electricity removal unit which removes electricity from the liquid to be supplied to a space between the projection optical system and a surface of the substrate.    
   
   
       2 . The projection exposure apparatus according to  claim 1 , wherein the electricity removal unit has an electricity-removing filter which is provided in a flow passage of a liquid supply piping for supplying the liquid to the space between the projection optical system and the surface of the substrate, and which is grounded.  
   
   
       3 . The projection exposure apparatus according to  claim 2 , wherein the electricity-removing filter is formed of a conductive metal foam.  
   
   
       4 . The projection exposure apparatus according to  claim 2 , wherein the electricity-removing filter is formed of a conductive mesh member.  
   
   
       5 . The projection exposure apparatus according to  claim 1 , further comprising a liquid supply unit which supplies the liquid to the space between the projection optical system and the surface of the substrate, wherein the liquid supply unit is provided with the electricity removal unit.  
   
   
       6 . The projection exposure apparatus according to  claim 5 , wherein the projection exposure apparatus is a step-and-repeat type projection exposure apparatus, and the liquid supply unit supplies the liquid in a direction in which the substrate is subjected to stepping.  
   
   
       7 . The projection exposure apparatus according to  claim 5 , wherein the projection exposure apparatus is a step-and-scan type projection exposure apparatus, and the liquid supply unit supplies the liquid in a scanning direction.  
   
   
       8 . A projection exposure apparatus which transfers a pattern formed on a mask onto a substrate through a liquid, the projection exposure apparatus comprising: 
 a projection optical system which projects an image of the pattern onto the substrate; and    an electricity removal unit which removes electricity from the liquid intervened between the projection optical system and a surface of the substrate.    
   
   
       9 . The projection exposure apparatus according to  claim 8 , wherein the electricity removal unit has an electrode member which is provided in an optical element of the projection optical system opposed to the substrate.  
   
   
       10 . The projection exposure apparatus according to  claim 9 , wherein the electrode member is an annular conductor which is provided on the optical element in coaxial with an optical axis of the optical element.  
   
   
       11 . The projection exposure apparatus according to  claim 8 , further comprising a liquid supply piping for supplying the liquid and a liquid recovery piping for recovering the liquid, wherein the electricity removal unit has an electricity-removing filter which is provided in at least one of a supply port of the liquid supply piping and a recovery port of the liquid recovery piping.  
   
   
       12 . The projection exposure apparatus according to  claim 8 , further comprising a liquid supply port for supplying the liquid and a liquid recovery port for recovering the liquid, wherein the electricity removal unit has at least one of a supply port which is made of a conductive material and a recovery port which is made of a conductive material.  
   
   
       13 . A projection exposure method for irradiating a mask with an exposure light beam and projecting a pattern formed on the mask onto a substrate through a liquid with a projection optical system, the projection exposure method comprising: 
 a step of removing electricity from the liquid; and    a step of supplying the liquid to a space between the projection optical system and a surface of the substrate.    
   
   
       14 . The projection exposure method according to  claim 13 , wherein the step of removing the electricity is performed prior to the step of supplying the liquid.  
   
   
       15 . The projection exposure method according to  claim 14 , further comprising making the liquid to pass through an electricity-removing filter in the step of supplying the liquid to the space between the projection optical system and the surface of the substrate.  
   
   
       16 . The projection exposure method according to  claim 15 , wherein the electricity-removing filter is provided at an end portion of a liquid supply tube for supplying the liquid to the space between the projection optical system and the surface of the substrate.  
   
   
       17 . The projection exposure method according to  claim 13 , further comprising causing the liquid, supplied to the space between the projection optical system and the surface of the substrate, make contact with a conductive member in the step of removing the electricity from the liquid.  
   
   
       18 . A method for producing a device, comprising a lithography step, wherein the projection exposure apparatus as defined in  claim 1  is used to perform exposure in the lithography step.  
   
   
       19 . A method for producing a device, comprising a lithography step, wherein the projection exposure apparatus as defined in  claim 8  is used to perform exposure in the lithography step.