Projection optical system, exposure apparatus, and exposure method

Abstract

An immersion projection optical system having, for example, a catadioptric and off-axis structure, reduces the portion of an image space filled with liquid (immersion liquid). The projection optical system, which projects a reduced image of a first plane onto a second plane through the liquid, includes a refractive optical element (Lp) arranged nearest to the second plane. The refractive optical element includes a light emitting surface (Lpb) shaped to be substantially symmetric with respect to two axial directions (XY-axes) perpendicular to each other on the second plane. The light emitting surface has a central axis (Lpba) that substantially coincides with a central axis ( 40 a ) of a circle ( 40 ) corresponding to a circumference of a light entering surface (Lpa) of the refractive optical element. The central axis of the light emitting surface is decentered in one of the two axial directions (Y-axis) from an optical axis (AX).

1 . A projection optical system for projecting an image of a first plane onto a second plane through a liquid, the projection optical system comprising:
 a refractive optical element arranged nearest to the second plane;   wherein the refractive optical element includes a light emitting surface shaped to be rotationally asymmetric with respect to an optical axis of the projection optical system in accordance with the shape of an effective projection region formed on the second plane.   
   
   
       2 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element is one-fold rotationally symmetric with respect to the optical axis of the projection optical system. 
   
   
       3 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, the light emitting surface has a central axis that substantially coincides with a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element, and the central axis of the light emitting surface is decentered in one of the two axial directions from the optical axis. 
   
   
       4 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to one of two axial directions perpendicular to each other on the second plane and asymmetric with respect to the other one of the axial directions, a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element substantially coincide with the optical axis, and the light emitting surface has a central axis decentered in the one of the axial directions. 
   
   
       5 . The projection optical system according  claim 1 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element substantially coincide with the optical axis, and the light emitting surface has a central axis decentered in one of the two axial directions from the optical axis. 
   
   
       6 . The projection optical system according to  claim 3 , wherein a central axis of the effective projection region substantially coincides with the central axis of the light emitting surface. 
   
   
       7 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element is two-fold rotationally symmetric with respect to the optical axis of the projection optical system. 
   
   
       8 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, and the light emitting surface has a central axis that substantially coincides with the optical axis and a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element. 
   
   
       9 . The projection optical system according to  claim 8 , wherein the effective projection region has a central axis decentered in one of the two axial directions from the central axis of the light emitting surface. 
   
   
       10 . The projection optical system according to  claim 1 , wherein the refractive optical element is an interface lens of which first plane side comes in contact with gas and second plane side comes in contact with the liquid. 
   
   
       11 . The projection optical system according to  claim 1 , wherein the refractive optical element is an optical member that has substantially no refractive power and arranged in an optical path formed between the second plane and an interface lens of which first plane side comes in contact with the gas and second plane side comes in contact with the liquid. 
   
   
       12 . The projection optical system according to  claim 1 , wherein a reduced image of the first plane is projected onto the second plane through the liquid. 
   
   
       13 . The projection optical system according to  claim 1 , wherein a center of an effective projection region on the second plane is decentered from the optical axis of the projection optical system. 
   
   
       14 . The projection optical system according to  claim 1 , further comprising:
 at least one concave reflective mirror and a plurality of refractive optical elements, wherein an effective field of view region on the first plane and the effective projection region on the second plane excludes the optical axis.   
   
   
       15 . The projection optical system according to  claim 14 , further comprising:
 a refractive first imaging optical system for forming a first intermediate image based on light from the first plane;   a second imaging optical system including the at least one concave reflective mirror, for forming a second intermediate image based on light from the first intermediate image; and   a refractive third imaging optical system for forming the image on the second plane based on light from the second intermediate image.   
   
   
       16 . The projection optical system according to  claim 15 , further comprising:
 a first deflection mirror arranged in an optical path between the first imaging optical system and the second imaging optical system; and   a second deflection mirror arranged in an optical path between the second imaging optical system and the third imaging optical system.   
   
   
       17 .- 25 . (canceled) 
   
   
       26 . A projection optical system for projecting an image of a first plane onto a second plane through a liquid, the projection optical system comprising:
 a refractive optical element arranged nearest to the second plane, wherein when two axial directions perpendicular to each other are set on the second plane, a light emitting surface of the refractive optical element has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other.   
   
   
       27 . The projection optical system according to  claim 26 , wherein the refractive optical element includes a light entering surface having lengths in the two axial directions that are substantially equal to each other. 
   
   
       28 . The projection optical system according to  claim 26 , wherein:
 the projection optical system is used in an exposure apparatus that projects a pattern while changing a positional relationship of the image and a substrate arranged on the second plane in a scanning direction;   the length of the light emitting surface in the one of the axial directions is set to be shorter than the length of the light emitting surface in the other one of the axial directions; and   the one of the axial directions coincides with the scanning direction.   
   
   
       29 . The projection optical system according to  claim 26  wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, the light emitting surface has a central axis that substantially coincides with a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element, and the central axis of the light emitting surface is decentered in one of the two axial directions from the optical axis. 
   
   
       30 . The projection optical system according to  claim 26 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, and the light emitting surface has a central axis that substantially coincides with the optical axis and a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element. 
   
   
       31 . The projection optical system according to  claim 30 , wherein the effective projection region has a central axis decentered in one of the two axial directions from the central axis of the light emitting surface. 
   
   
       32 . The projection optical system according to  claim 26 , wherein the light emitting surface of the refractive optical element is shaped to be substantially symmetric with respect to one of two axial directions perpendicular to each other and asymmetric with respect to the other one of the axial directions on the second plane, a central axis of a circle corresponding to a circumference of a light entering surface of the refractive optical element substantially coincides with the optical axis, and the light emitting surface has a central axis decentered in the one of the axial directions from the optical axis. 
   
   
       33 . The projection optical system according to  claim 26  wherein the refractive optical element includes a light emitting surface shaped to be substantially symmetric with respect to two axial directions perpendicular to each other, a central axis of a circle corresponding to a circumference of the light emitting surface of the refractive optical element substantially coincides with the optical axis, and the light emitting surface has a central axis decentered in one of the two axial directions from the optical axis. 
   
   
       34 . The projection optical system according to  claim 29 , wherein the effective projection region has a central axis that coincides with the central axis of the light emitting surface. 
   
   
       35 . The projection optical system according to  claim 26 , wherein a reduced image of the first plane is projected onto the second plane through the liquid. 
   
   
       36 . The projection optical system according to  claim 26 , wherein when two axial directions perpendicular to each other are set on the second plane, a region on which the image is formed has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other. 
   
   
       37 . The projection optical system according to  claim 1 , wherein the light emitting surface of the refractive optical element includes a planar surface. 
   
   
       38 . The projection optical system according to  claim 1 , wherein the refractive optical element includes a light entering surface having a planar surface. 
   
   
       39 . An exposure apparatus comprising:
 the projection optical system according to  claim 1  for projecting an image of a predetermined pattern onto a photosensitive substrate that is set on the second plane based on illumination light from the pattern set on the first plane.   
   
   
       40 . The exposure apparatus according to  claim 39 , wherein the pattern is projected while changing a positional relationship of the image of the pattern and the photosensitive substrate in a scanning direction. 
   
   
       41 . The exposure apparatus according to  claim 39 , further comprising:
 a supply and discharge mechanism for supplying and discharging the liquid.   
   
   
       42 .- 43 . (canceled) 
   
   
       44 . A device manufacturing method comprising:
 an exposure step of projecting and exposing an image of a pattern set on the first plane onto a photosensitive substrate set on the second plane with the projection optical system according to  claim 1 ; and   a development step of developing the photosensitive substrate that has undergone the exposure step.   
   
   
       45 . The device manufacturing method according to  claim 44 , wherein in the exposure step include projecting the pattern while changing a positional relationship of the image of the pattern and the photosensitive substrate in a scanning direction. 
   
   
       46 . A refractive optical element for use in an immersion objective optical system that forms an image of a first plane onto an effective projection region on a second plane, wherein one optical surface comes in contact with a liquid, the refractive optical element wherein:
 the one optical surface of the refractive optical element is shaped to be rotationally asymmetric with respect to an optical axis of the immersion objective optical system in accordance with a shape of the effective projection region on the second plane.   
   
   
       47 . The refractive optical element according to  claim 46 , wherein the one optical surface of the refractive optical element is shaped to be one-fold rotationally symmetric with respect to the optical axis of the immersion objective optical system. 
   
   
       48 . The refractive optical element according to  claim 46 , wherein the one optical surface of the refractive optical element is shaped to be substantially symmetric with respect to one of two axial directions perpendicular to each other and asymmetric with respect to the other one of the axial directions on the second plane, a central axis of a circle corresponding to a circumference of another optical surface of the refractive optical element substantially coincides with the optical axis, and the one optical surface has a central axis that is decentered in the one of the axial directions from the optical axis. 
   
   
       49 . The refractive optical element according to  claim 46 , wherein the one optical surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, a central axis of a circle corresponding to a circumference of another optical surface of the refractive optical element substantially coincides with the optical axis, and the one optical surface has a central axis decentered in one of the two axial directions from the optical axis. 
   
   
       50 . The refractive optical element according to  claim 47 , wherein the effective projection region has a central axis that substantially coincides with a central axis of the one optical surface. 
   
   
       51 . The refractive optical element according to  claim 46 , wherein the one optical surface of the refractive optical element is shaped to be two-fold rotationally symmetric with respect to the optical axis of the immersion objective optical system. 
   
   
       52 . The refractive optical element according to  claim 46 , wherein the one optical surface of the refractive optical element is shaped to be substantially symmetric with respect to two axial directions perpendicular to each other on the second plane, and the one optical surface has a central axis that substantially coincides with a central axis of a circle corresponding to a circumference of another optical surface of the refractive optical element. 
   
   
       53 . The refractive optical element according to  claim 52 , wherein the effective projection region has a central axis decentered in one of the two axial directions from the central axis of the one optical surface. 
   
   
       54 . A refractive optical element for use in an immersion objective optical system that forms an image of a first plane on a second plane, wherein one optical surface comes in contact with a liquid, wherein:
 when two axial directions perpendicular to each other are set on the second plane, the one optical surface of the refractive optical element has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other.   
   
   
       55 . The refractive optical element according to  claim 54 , wherein another optical surface of the refractive optical element has substantially equal lengths in the first axial direction and the second axial direction. 
   
   
       56 . The refractive optical element according to  claim 54 , wherein the refractive optical element is an optical member that has substantially no refractive power and is arranged in an optical path between the second plane and an interface lens of which first plane side comes in contact with gas and second plane side comes in contact with the liquid. 
   
   
       57 . The refractive optical element according to  claim 54 , comprising:
 another optical surface having a flat plane.   
   
   
       58 . The refractive optical element according to  claim 54 , wherein the refractive optical element is an interface lens of which first plane side comes in contact with gas and second plane side comes in contact with the liquid. 
   
   
       59 . The refractive optical element according to  claim 54 , wherein the one optical surface of the refractive optical element has a planar surface. 
   
   
       60 . The refractive optical element according to  claim 54 , wherein when two axial directions perpendicular to each other are set on the second plane, an effective projection region on the second plane has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other. 
   
   
       61 .- 100 . (canceled) 
   
   
       101 . An immersion objective optical system for forming an image of a first plane on a second plane, the immersion objective optical system comprising:
 a reflective surface forming a two-way optical path;   a two-way optical element arranged in the two-way optical path;   a one-way optical element arranged in a one-way optical path that differs from the two-way optical path; and   an aspherical surface formed on an optical surface of the two-way optical element;   wherein an aspherical surface is not formed on every optical surface of the two-way optical element.   
   
   
       102 . The immersion objective optical system according to  claim 101 , wherein the reflective surface is a concave reflective surface. 
   
   
       103 . The immersion objective optical system according to  claim 101 , wherein the two-way optical element is formed by an amorphous material. 
   
   
       104 . An exposure apparatus comprising:
 the immersion objective optical system according to  claim 101  for projecting an image of a predetermined pattern onto a photosensitive substrate that is set on the second plane based on illumination light from the pattern set on the first plane.   
   
   
       105 . The exposure apparatus according to  claim 104 , wherein the pattern is projected while changing a positional relationship of the image of the pattern and the photosensitive substrate in a scanning direction. 
   
   
       106 . The exposure apparatus according to  claim 104 , further comprising:
 a supply and discharge mechanism for supplying and discharging the liquid.   
   
   
       107 .- 108 . (canceled) 
   
   
       109 . A device manufacturing method comprising:
 an exposure step of projecting and exposing an image of a pattern set on the first plane onto a photosensitive substrate set on the second plane with the immersion objective optical system according to  claim 101 ; and   a development step of developing the photosensitive substrate that has undergone the exposure step.   
   
   
       110 . The device manufacturing method according to  claim 109 , wherein the exposure step includes projecting the pattern while changing a positional relationship of the image of the pattern and the photosensitive substrate in a scanning direction. 
   
   
       111 .- 118 . (canceled) 
   
   
       119 . An exposure optical system for use in an exposure apparatus for forming a pattern on an immersion region defined on part of a substrate by exposing the substrate, the exposure optical system comprising:
 an optical member including one optical surface that is contactable with the liquid;   wherein when two axial directions perpendicular to each other are set on the substrate, the one optical surface of the optical member has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other.   
   
   
       120 . The exposure optical system according to  claim 119 , wherein the one optical surface of the optical member has lengths in the two axial directions that are substantially equal to each other. 
   
   
       121 . The exposure optical system according to  claim 119 , wherein the optical member has substantially no refractive power and is arranged in an optical path between the substrate and an interface lens with which another optical surface side comes in contact with gas and the one optical surface side comes in contact with the liquid. 
   
   
       122 . The exposure optical system according to  claim 119 , being characterized by comprising:
 the optical member including another optical surface having a flat plane.   
   
   
       123 . The exposure optical system according to  claim 119 , wherein the optical member is an interface lens with which another optical surface side comes in contact with gas and the one optical surface side comes in contact with the liquid. 
   
   
       124 . The exposure optical system according to  claim 123 , wherein the one optical surface of the optical member has a planar surface. 
   
   
       125 . The exposure optical system according to  claim 119 , wherein when two axial directions perpendicular to each other are set on the substrate, a pattern formation region in which a pattern is formed on the substrate has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other. 
   
   
       126 . The exposure optical system according to  claim 119 , wherein the substrate is exposed while changing a positional relationship of the pattern and the substrate in a scanning direction. 
   
   
       127 .- 128 . (canceled) 
   
   
       129 . A device manufacturing method comprising:
 an exposure step of forming a pattern set on a substrate through a liquid that forms an immersion region on part of the substrate with the exposure optical system according to  claim 119 ; and   a development step of developing the photosensitive substrate.   
   
   
       130 . The device manufacturing method according to  claim 129 , wherein the exposure step includes exposing the substrate while changing a positional relationship of the pattern and the substrate in a scanning direction. 
   
   
       131 . An exposure apparatus for exposing substrate based on exposure light through a liquid that forms an immersion region on part of the substrate, the exposure apparatus comprising:
 a supply and discharge mechanism for supplying and discharging the liquid; and   an optical member for transmitting the exposure light;   wherein the optical member includes a means for narrowing the immersion region.   
   
   
       132 . The exposure apparatus according to  claim 131 , wherein the substrate is exposed while changing a positional relationship of the exposure light and the substrate in a scanning direction. 
   
   
       133 . The exposure apparatus according to  claim 132 , wherein the means narrows the immersion region in the scanning direction. 
   
   
       134 . The exposure apparatus according to  claim 131 , wherein:
 the means is provided on a light emitting surface of the optical member, wherein the light emitting surface is contactable with the liquid.   
   
   
       135 . A device manufacturing method comprising:
 projecting and exposing a pattern on the substrate using the exposure apparatus according to  claim 131 .   
   
   
       136 . The projection optical system according to  claim 32 , wherein the effective projection region has a central axis that coincides with the central axis of the light emitting surface. 
   
   
       137 . The projection optical system according to  claim 33 , wherein the effective projection region has a central axis that coincides with the central axis of the light emitting surface. 
   
   
       138 . The refractive optical element according to  claim 46 , wherein the refractive optical element is an interface lens of which first plane side comes in contact with gas and second plane side comes in contact with the liquid. 
   
   
       139 . The refractive optical element according to  claim 46 , wherein the refractive optical element is an optical member that has substantially no refractive power and is arranged in an optical path between the second plane and an interface lens of which first plane side comes in contact with gas and second plane side comes in contact with the liquid. 
   
   
       140 . The refractive optical element according to  claim 46 , wherein when two axial directions perpendicular to each other are set on the second plane, an effective projection region on the second plane has a length in one of the axial directions and a length in the other one of the axial directions that differ from each other.