Lithographic apparatus, drying device, metrology apparatus and device manufacturing method

Abstract

An immersion lithographic apparatus is described in which a two-phase flow is separated into liquid-rich and gas-rich flows by causing the liquid-rich flow to preferentially flow along a surface.

1 . A lithographic apparatus comprising:
 a substrate table constructed to hold a substrate; and   a fluid handling structure arranged to remove liquid and gas in a two-phase flow from a surface, the fluid handling structure comprising a phase separator having a surface and arranged to separate the two-phase flow into a first flow and a second flow, the first flow having a higher ratio of liquid to gas than the two-phase flow and flowing along the phase separator surface, the second flow having a higher ratio of gas to liquid than the two-phase flow.   
     
     
         2 . The apparatus of  claim 1 , wherein the phase separator comprises a channel having first and second walls and arranged so that liquid preferentially flows along the first wall, the first wall defining the surface. 
     
     
         3 . The apparatus of  claim 2 , wherein the phase separator further comprises a dry chamber connected to the channel via an opening in the second wall. 
     
     
         4 . The apparatus of  claim 2 , wherein the first wall has a lower contact angle than the second wall. 
     
     
         5 . The apparatus of  claim 2 , wherein the phase separator further comprises a wet chamber arranged so that liquid flowing along the first wall enters the wet chamber. 
     
     
         6 . The apparatus of  claim 5 , wherein the wet chamber is connected to the channel by a slit defined by the first wall and a divider, wherein the first wall is substantially straight between an inlet of the channel and the wet chamber and the slit has a width arranged so that capillary forces encourage substantially only liquid to enter the slit. 
     
     
         7 . The apparatus of  claim 5 , wherein the first wall is curved so that at a point where the channel enters the wet chamber the first wall is lower than the second wall. 
     
     
         8 . The apparatus of  claim 3 , wherein the phase separator further comprises a gas extraction channel separated from the wet chamber by a gas-permeable liquidphobic membrane. 
     
     
         9 . The apparatus of  claim 8 , wherein the phase separator further comprises a liquid extraction opening defined in a wall of the wet chamber, the liquid extraction opening being below the gas-permeable liquidphobic membrane. 
     
     
         10 . The apparatus of  claim 8 , wherein the phase separator further comprises a drain path to allow liquid to drain from the wet chamber to a space between the substrate and a projection system arranged to project a patterned radiation beam onto the substrate. 
     
     
         11 . The apparatus of  claim 1 , wherein the phase separator comprises a chamber, defined by first and second walls, and a plurality of channels entering into the chamber through the second wall, the channels being arranged at an angle to the second wall such that a two-phase flow entering the chamber from a channel at least partially separates into a liquid flow along the first wall and a gas flow along the second wall. 
     
     
         12 . The apparatus of  claim 11 , wherein the phase separator further comprises a plurality of flow directing structures in the chamber adjacent the openings of the channels. 
     
     
         13 . The apparatus of  claim 12 , wherein the flow directing structures have curved surfaces that define flow paths leading away from the openings, the flow paths increasing in width away from the openings over at least part of their length and the curved surfaces are arranged so that the flow paths turn through at least 90°. 
     
     
         14 . The apparatus of  claim 1 , wherein the phase separator comprises a conduit defined by a wall and having a substantially circular cross-section over at least a part of the length thereof and a substantially helical structure provided on the wall. 
     
     
         15 . The apparatus of  claim 1 , wherein the phase separator further comprises a gas extraction conduit arranged within a part of a conduit so as to define an annular gap between an outer surface of the gas extraction conduit and an inner surface of the conduit. 
     
     
         16 . The apparatus of  claim 1 , wherein the surface is in part defined by a porous member through which liquid can be extracted. 
     
     
         17 . The apparatus of  claim 1 , wherein the phase separator further comprises a gas supply arranged to add additional gas to the two-phase flow. 
     
     
         18 . The apparatus of  claim 1 , wherein the fluid handling structure comprises a barrier member arranged to at least partly confine a liquid to a space between the substrate and a projection system arranged to project a patterned radiation beam onto the substrate, the phase separator being contained in the barrier member. 
     
     
         19 . A liquid-gas separator comprising:
 a conduit or chamber divided into two parts by a porous plate, the first part being substantially filled with liquid; and   a current generator configured to supply liquid to the first part and constructed and arranged to generate a current in the liquid so as to substantially prevent bubbles of gas remaining on a surface of the porous plate which defines in part the first part.