Measuring method, stage apparatus, and exposure apparatus

Abstract

An exposure apparatus can mitigate the impact of fluctuations in the refractive index of ambient gas, and improve, for example, stage positioning accuracy. An exposure apparatus radiates an exposure illumination light to a wafer on a wafer stage through a projection optical system, and forms a prescribed pattern on the wafer, and comprises: a scale, which is provided to the wafer stage; a plurality of X heads, which detect information related to the position of the scale; a measurement frame that integrally supports the plurality of X heads and has a coefficient of linear thermal expansion that is smaller than that of the main body of the wafer stage (portions excepting a plate wherein the scale is formed); and a control apparatus that derives information related to the displacement of the wafer stage based on the detection results of the plurality of X heads.

What is claimed is: 
     
         1 . An exposure apparatus for exposing a substrate with illumination light via a projection optical system, the apparatus comprising:
 a frame member for supporting the projection optical system;   a detection system provided at the frame member apart from the projection optical system and configured to detect a mark of the substrate;   a plurality of grating members, each of which having a reflecting-type grating, and each of which being provided at the frame member such that the reflecting-type grating is arranged substantially parallel with a predetermined plane perpendicular to an optical axis of the projection optical system;   a base arranged below the projection optical system and the detection system;   a stage arranged on the base, the stage having a holder configured to hold the substrate and being movable below the grating members;   a drive system configured to move the stage so as to arrange the substrate opposite to the projection optical system and the detection system, respectively;   an encoder system having a plurality of heads provided at the stage, each of which being configured to irradiate a beam onto the grating member from below the grating member, so as to obtain position information of the stage; and   a controller configured to control the drive system based on the position information obtained by the encoder system,   wherein the grating members are supported via a flexural member by the frame member.   
     
     
         2 . The exposure apparatus according to  claim 1 ,
 wherein the holder is arranged in a recess of an upper surface of the stage, and   wherein each of the heads is provided at a more outward position than the upper surface.   
     
     
         3 . The exposure apparatus according to  claim 1 , further comprising:
 a nozzle member provided to surround a lens, the lens being one of a plurality of optical elements of the projection optical system and being arranged closest to an image surface, the nozzle member being configured to form an immersion area with liquid so as to include an optical path of the illumination light between the lens and the substrate,   wherein the grating members are arranged at a more outward position than the nozzle member, and   wherein the apparatus is configured for exposing the substrate with the illumination light via the projection optical system and the liquid of the immersion area.   
     
     
         4 . The exposure apparatus according to  claim 3 ,
 wherein the nozzle member includes a supply port of the liquid, a recovery port of the liquid, and an opening through which the illumination light passes, the recovery port being arranged around the opening and on the lower surface side of the nozzle member, and   wherein the apparatus is configured for supplying liquid via the supply port to the immersion area and for recovering the liquid of the immersion area via the recovery port.   
     
     
         5 . The exposure apparatus according to  claim 4 ,
 wherein the grating members are provided such that the nozzle member is positioned in the opening around which the reflecting-type grating is arranged.   
     
     
         6 . The exposure apparatus according to  claim 4 , further comprising:
 another frame member that is different from the frame member,   wherein the nozzle member is provided at the another frame member.   
     
     
         7 . The exposure apparatus according to  claim 4 ,
 wherein the nozzle member is provided at the frame member.   
     
     
         8 . The exposure apparatus according to  claim 4 ,
 wherein the holder is arranged in a recess of an upper surface of the stage, and   wherein the stage supports the substrate in the recess such that a surface of the substrate is substantially flush with the upper surface.   
     
     
         9 . The exposure apparatus according to  claim 8 ,
 wherein the stage includes a metrology member arranged in an opening of the upper surface, the opening being different from the recess, and having a fiducial mark that is detectable by the detection system.   
     
     
         10 . A device manufacturing method comprising:
 exposing a substrate by using the exposure apparatus according to  claim 1 ; and   developing the exposed substrate.   
     
     
         11 . An exposure method for exposing a substrate with illumination light via a projection optical system, the method comprising:
 moving a stage having a holder configured to hold the substrate, such that a mark of the substrate is detected by a detection system provided at a frame member configured to support the projection optical system apart from the projection optical system, above a base arranged below the projection optical system and the detection system;   moving the stage such that the substrate is exposed with the illumination light via the projection optical system;   obtaining position information of the stage by an encoder system having a plurality of heads, each of which being provided at the stage, and each of which being configured to irradiate a beam onto one of a plurality of grating members from below, each of which having a reflecting-type grating, and each of which being provided at the frame member such that the reflecting-type grating is arranged substantially parallel with a predetermined plane perpendicular to an optical axis of the projection optical system; and   controlling the movement of the stage based on the position information obtained by the encoder system,   wherein the grating members are supported via a flexural member by the frame member.   
     
     
         12 . The exposure method according to  claim 11 ,
 wherein the holder is arranged in a recess of an upper surface of the stage, and   wherein each of the heads is provided at a more outward position than the upper surface.   
     
     
         13 . The exposure method according to  claim 11 ,
 wherein an immersion area is formed with liquid so as to include an optical path of the illumination light between the lens and the substrate by a nozzle member provided to surround a lens, the lens being one of a plurality of optical elements of the projection optical system and being arranged closest to an image surface,   wherein the substrate is exposed with the illumination light via the projection optical system and the liquid of the immersion area, and   wherein the grating members are arranged at a more outward position than the nozzle member.   
     
     
         14 . The exposure method according to  claim 13 ,
 wherein liquid is supplied to the immersion area via a supply port of the nozzle member, and   wherein the liquid of the immersion area is recovered via a recovery port arranged on the lower surface side of the nozzle member and around an opening through which the illumination light passes.   
     
     
         15 . The exposure method according to  claim 14 ,
 wherein the holder is arranged in a recess of an upper surface of the stage, and   wherein the substrate is held in the recess such that a surface of the substrate is substantially flush with the upper surface of the stage.   
     
     
         16 . The exposure method according to  claim 15 ,
 wherein a fiducial mark of a metrology member arranged in an opening of the upper surface of the stage, the opening being different from the recess, is detected by the detection system.   
     
     
         17 . A device manufacturing method comprising:
 exposing a substrate by using the exposure method according to  claim 11 ; and   developing the exposed substrate.   
     
     
         18 . A manufacturing method of an exposure apparatus for exposing a substrate with illumination light via a projection optical system, the method comprising:
 providing a frame member for supporting the projection optical system;   providing a detection system provided at the frame member apart from the projection optical system and configured to detect a mark of the substrate;   providing a plurality of grating members, each of which having a reflecting-type grating, and each of which being provided at the frame member such that the reflecting-type grating is arranged substantially parallel with a predetermined plane perpendicular to an optical axis of the projection optical system;   providing a base arranged below the projection optical system and the detection system;   providing a stage arranged on the base, the stage having a holder configured to hold the substrate and being movable below the grating members;   providing a drive system configured to move the stage so as to arrange the substrate opposite to the projection optical system and the detection system, respectively;   providing an encoder system having a plurality of heads provided at the stage, each of which being configured to irradiate a beam onto the grating member from below the grating member, so as to obtain position information of the stage; and   providing a controller configured to control the drive system based on the position information obtained by the encoder system,   wherein the grating members are supported via a flexural member by the frame member.