JP2010098142A - Supporting device for optical element and exposing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting device capable of minimizing the deformation of an optical element in contact with liquid when exposure is performed, for example, by an immersion method. <P>SOLUTION: The supporting device for an optical element 2 in contact with liquid Lq includes: a nozzle member 30 supporting the optical element 2 via a plurality of supporting points 33A; an O-ring 35 making an airtight space 36 surrounded by the optical element 2, the liquid Lq and the nozzle member 30 into an airtight state; an O-ring 37A making an airtight space 38A surrounded by the optical element 2 and the nozzle member 30 in a region of the opposite side to the liquid Lq with respect to the supporting points 33A into an airtight state; and a vent hole 30d making the airtight space 36 communicate with the airtight space 38A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a support device for supporting an optical element in contact with a liquid, an exposure apparatus that includes the support device and performs exposure using, for example, a liquid immersion method, and a device manufacturing method that uses the exposure apparatus.

In an exposure apparatus used to transfer a mask pattern onto a substrate such as a wafer coated with a resist (photosensitive agent) in a lithography process for manufacturing a device (electronic device) such as a semiconductor element, projection optics is used. An exposure apparatus has been developed that performs exposure using an immersion method that supplies a liquid that transmits exposure light between an optical element at the tip of the system and a substrate (see, for example, Patent Document 1 and Patent Document 2). According to this liquid immersion method, the exposure wavelength can be substantially shortened and the depth of focus can be increased compared to the air.
International Publication No. 2004/053955 Pamphlet International Publication No. 2005/122218 Pamphlet

  When exposure is performed using the liquid immersion method as described above, for example, when the substrate moves relative to the projection optical system, the optical element slightly changes due to the liquid between the optical element at the tip of the projection optical system and the substrate. It has been found to be deformed. In the future, for example, when the refractive power of the optical element at the tip of the projection optical system increases, there is a possibility that the imaging characteristics such as predetermined aberrations of the projection optical system are affected by such deformation of the optical element.

  In view of such circumstances, the present invention provides, for example, a support device that can suppress deformation of an optical element that is in contact with a liquid when exposure is performed by a liquid immersion method, an exposure device that uses the support device, and a device manufacturing method that uses the exposure device. The purpose is to provide.

An optical element support device according to the present invention is a support device for an optical element in contact with a liquid, and includes a base member that supports the optical element via a plurality of support points, and a deformation of the optical element as the liquid moves. And a deformation mechanism for deforming the optical element so as to suppress the above.
An exposure apparatus according to the present invention illuminates a pattern with exposure light, and exposes the substrate with the exposure light through the pattern and the projection optical system. A liquid supply device for supplying a liquid between the optical element at the tip of the system and the substrate, and a support device for the optical element of the present invention, and the optical element at the tip of the projection optical system is supported by the support device To do.

  The device manufacturing method according to the present invention includes exposing a substrate using the exposure apparatus of the present invention and processing the exposed substrate.

  According to the present invention, since the optical element is provided with a deformation mechanism that deforms the optical element so as to suppress the deformation of the optical element accompanying the movement of the liquid, the optical element that comes into contact with the liquid, for example, when performing exposure by a liquid immersion method. Deformation can be suppressed.

Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic block diagram that shows an exposure apparatus EX of the present embodiment. In FIG. 1, an exposure apparatus EX includes an illumination optical system IL that illuminates a mask M on which a transfer pattern is formed with exposure light EL, a mask stage MST that supports the mask M, and a mask that is illuminated with exposure light EL. A projection optical system PL that projects an image of an M pattern onto a projection area AR1 on the substrate P, a substrate stage PST that supports the substrate P, and a control device CONT that includes a computer that controls the overall operation of the exposure apparatus EX; A liquid supply mechanism 10 that supplies the liquid Lq onto the substrate P and a liquid recovery mechanism 20 that recovers the liquid Lq supplied onto the substrate P for application of the liquid immersion method are provided.

  In the exposure apparatus EX, at least during transfer of the pattern image of the mask M onto the substrate P, the optical element (this embodiment) at the image plane side end portion of the projection optical system PL is supplied by the liquid Lq supplied from the liquid supply mechanism 10. Then, a local space between the plano-convex lens 2 having a substantially flat bottom surface and the surface of the substrate P disposed on the image plane side is filled. The liquid Lq is supplied to the liquid immersion area AR2 including the projection area AR1 on the substrate P and collected.

  In the present embodiment, as the exposure apparatus EX, a scanning exposure apparatus (so-called scanning stepper) that exposes a pattern formed on the mask M onto the substrate P while moving the mask M and the substrate P synchronously in a predetermined scanning direction. The case of using is described as an example. Hereinafter, the Z-axis is taken in parallel to the optical axis AX of the projection optical system PL, and the X-axis is taken in the scanning direction along the synchronous movement direction (scanning direction) of the mask M and the substrate P in a plane perpendicular to the Z-axis. A description will be given by taking the Y axis along a direction perpendicular to (non-scanning direction). In the present embodiment, the XY plane is substantially parallel to the horizontal plane. Further, the rotation (inclination) directions around the X axis, the Y axis, and the Z axis are the θX, θY, and θZ directions, respectively. Further, the substrate P of the present embodiment includes, for example, a mask in which a resist, which is a photosensitive agent, is applied with a predetermined thickness (for example, about 200 nm) on a disk-shaped semiconductor wafer having a diameter of about 200 mm to 450 mm. Includes a reticle on which a device pattern to be reduced and projected on the substrate P is formed.

  First, the illumination optical system IL includes an exposure light source, an optical integrator for equalizing the illuminance of the exposure light EL emitted from the exposure light source, a condenser lens for condensing the exposure light EL from the optical integrator, and a relay. A lens system and a variable field stop for setting the illumination area on the mask M by the exposure light EL in a slit shape are provided. A predetermined illumination area on the mask M is illuminated with the exposure light EL having a uniform illuminance distribution by the illumination optical system IL. As the exposure light EL, ArF excimer laser light (wavelength 193 nm) is used. In addition, as the exposure light EL, vacuum ultraviolet light such as an ultraviolet line from a mercury lamp, far ultraviolet light (DUV light) such as KrF excimer laser light (wavelength 248 nm), or harmonics of a solid laser (semiconductor laser, etc.) (VUV light) or the like is used.

  Further, the mask stage MST can hold the mask M by suction, can move two-dimensionally in an XY plane on a mask base (not shown), and can be slightly rotated in the θZ direction. Mask stage MST is driven by a mask stage driving device MSTD such as a linear motor. The laser interferometer 56A disposed opposite to the movable mirror 55A on the mask stage MST actually has a measurement beam having three or more axes, and is at least in the X direction of the mask stage MST (mask M) by the laser interferometer 56A. The position in the Y direction and the rotation angle in the θZ direction are measured, and the measurement result is output to the control device CONT. The control device CONT moves or positions the mask stage MST (mask M) by driving the mask stage driving device MSTD based on the measurement result.

  The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a predetermined projection magnification β (β is a reduction magnification of, for example, 1/4, 1/5, etc.). It comprises a plurality of optical elements including the optical element 2 provided at the terminal portion on the surface side, and these optical elements are supported by the lens barrel PK. Note that the projection optical system PL is not limited to a reduction system, and may be any of an equal magnification system and an enlargement system. Further, the liquid Lq in the liquid immersion area AR2 is in contact with the optical element 2 at the tip of the projection optical system PL.

In this example, pure water is used as the liquid Lq. Pure water can transmit not only ArF excimer laser light but also far ultraviolet light (DUV light) such as KrF excimer laser light. The optical element 2 is made of, for example, fluorite (CaF ₂ ). Since fluorite has a high affinity with water, the liquid Lq can be brought into close contact with almost the entire liquid contact surface including the lower surface 2 a of the optical element 2. The optical element 2 may be formed of quartz having a high affinity with water. The resist applied to the substrate P is, for example, a liquid repellent resist that repels the liquid Lq, and a protective top coat is applied thereon as necessary.

  Note that as the liquid Lq, Decalin (Decalin: Decahydronaphthalene) (trans-decalin or cis-decalin), which is a liquid that has a higher refractive index than water and transmits ArF excimer laser light, may be used. Since the refractive index of water with respect to ArF excimer laser light is about 1.44, and the refractive index of decalin with respect to ArF excimer laser light is about 1.60, the use of decalin as the liquid Lq reduces the resolving power and the depth of focus. Each can be improved by about 10%.

  Further, a substrate holder PH for holding the substrate P by, for example, vacuum suction is fixed to the upper part of the substrate stage PST. The substrate stage PST includes a Z stage unit that controls the position (focus position) in the Z direction of the substrate holder PH (substrate P) and the inclination angle in the θX and θY directions, and an XY that moves while supporting the Z stage unit. The XY stage portion is mounted on an air plane (gas bearing) so that the XY stage portion can move in the X direction and the Y direction on a plane parallel to the XY plane on the base 54. The substrate stage PST (Z stage portion and XY stage portion) is driven by a substrate stage driving device PSTD such as a linear motor.

  A laser interferometer 56B is provided at a position facing the reflecting surface (or moving mirror) on the side surface of the substrate stage PST. The laser interferometer 56B also has a plurality of measurement beams, and the laser interferometer 56B measures at least the position in the X direction, the Y direction, and the rotation angle in the θZ direction of the substrate holder PH (substrate P) on the substrate stage PST. The measurement result is output to the control device CONT. The control device CONT is supported by the substrate stage PST by driving the substrate stage driving device PSTD based on the measurement result and the measurement result of an autofocus sensor (not shown) that measures the position of the surface of the substrate P in the Z direction. The substrate P is moved or positioned.

  A mask alignment system 90 for measuring the position of the alignment mark of the mask M is disposed above the mask stage MST, and an alignment system 91 for measuring the position of the alignment mark of the substrate P is disposed on the side surface of the projection optical system PL. The alignment of the mask M and the substrate P is performed by these alignment systems 90 and 91. On the substrate stage PST, a reference mark member (not shown) for measuring a baseline (positional relationship between the pattern image of the mask M and the detection center of the alignment system 91) is provided. In addition to the substrate stage PST, a measurement stage equipped with a measuring device or the like for measuring the imaging characteristics of the projection optical system PL may be arranged.

  Further, on the substrate holder PH of the substrate stage PST in FIG. 1, an annular and flat liquid-repellent plate portion 97 is provided so as to surround the substrate P. The upper surface of the plate portion 97 is a flat surface having substantially the same height as the surface of the substrate P held by the substrate holder PH. Although there is a gap of about 0.1 to 1 mm between the edge of the substrate P and the plate portion 97, the resist applied to the substrate P is usually liquid repellent and the liquid Lq has surface tension. Therefore, the liquid Lq hardly flows into the gap, and the liquid Lq can be held between the plate portion 97 and the projection optical system PL even when the vicinity of the periphery of the substrate P is exposed.

  Next, the configuration of the local liquid immersion mechanism including the liquid supply mechanism 10 and the liquid recovery mechanism 20 in FIG. 1 will be described. The liquid supply mechanism 10 includes a liquid supply unit 11 that can deliver the liquid Lq, and a supply pipe 12 that connects one end of the liquid supply unit 11 to the liquid supply unit 11. The liquid recovery mechanism 20 includes a liquid recovery unit 21 that can recover the liquid Lq, and a recovery pipe 22 that is connected to the liquid recovery unit 21 at one end thereof. A nozzle member (flow path forming member) 30 is disposed in the vicinity of the optical element 2 at the end of the projection optical system PL. The nozzle member 30 is an annular member provided so as to surround the front end portion of the optical element 2 above the substrate P (substrate stage PST), and is provided at the lower end portion of the cylindrical barrel PK of the projection optical system PL. It is fixed by a plurality of bolts 39 (see FIG. 3). The nozzle member 30 constitutes a part of the liquid supply mechanism 10 and the liquid recovery mechanism 20.

  In a state where the projection area AR1 of the projection optical system PL is on the substrate P, the nozzle member 30 includes, as an example, a first supply port 13 and a second supply port 14 that are arranged to face the side surface of the optical element 2. I have. The supply ports 13 and 14 are arranged so as to sandwich the tip portion of the optical element 2 and the projection area AR1 in the X direction (scanning direction of the substrate P). The nozzle member 30 has supply flow paths 82A and 82B therein. One end of the supply channel 82A is connected to the first supply port 13, the second supply port 14 is connected to the supply channel 82A through the supply channel 82B, and the other end of the supply channel 82A is The liquid supply unit 11 is connected via a supply pipe 12. Furthermore, the nozzle member 30 includes a rectangular or circular frame-shaped recovery port 24 disposed so as to face the surface of the substrate P, and a large number of small holes are formed in a mesh shape so as to cover the recovery port 24. A mesh filter 25 that is a porous member is fitted. The recovery port 24 is connected to the liquid recovery unit 21 via the recovery flow path 84 and the recovery pipe 22 in the nozzle member 30. A region surrounded by the recovery port 24 is a liquid immersion region AR2 to which almost the liquid Lq is supplied. In addition, since the recovery of the liquid Lq from the recovery port 24 is performed, for example, intermittently, the liquid immersion area AR2 may be wider than the outline of the recovery port 24.

  2 is a schematic perspective view showing the optical element 2 and the nozzle member 30 in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. As shown in FIG. 2, the nozzle member 30 is configured by connecting a lower first member 31 and an upper second member 32 by a bolt (not shown) or the like via a seal member (not shown), as an example. The distal end portion of the optical element 2 is arranged in the circular opening 30b in the center of the nozzle member 30 with a predetermined interval. As shown in FIG. 3, the recovery port 24 and the recovery flow path 84 are formed on the first member 31 side, and the supply ports 13 and 14 and the supply flow paths 82A and 82B are formed on the second member 32 side. The optical element 2 has, for example, a flat surface facing the substrate P and a convex surface on the opposite side.

  The first member 31, the second member 32, and the mesh filter 25 of the nozzle member 30 are each formed of a lyophilic material that is easily compatible with the liquid Lq, such as stainless steel (SUS) or titanium. Therefore, the liquid Lq flows smoothly inside the nozzle member 30. The configuration of the nozzle member 30 is arbitrary. For example, the supply ports 13 and 14 may be provided on the bottom surface of the nozzle member 30, and the number of the supply ports 13 and 14 may be increased or decreased. Further, the shape, number, and arrangement of the recovery ports 24 are arbitrary. For example, as disclosed in International Publication No. 2005/122218 pamphlet, the recovery ports may be formed in duplicate. In addition, the mesh filter 25 is not necessarily provided when there is a low possibility of foreign matter adhering. Further, the supply ports 13 and 14 and the recovery port 24 may be provided in different members (nozzles). Furthermore, the nozzle member 30 may be configured by integrally forming the first member 31 and the second member 32 with a single member.

  In FIG. 1, the operations of the liquid supply unit 11 and the liquid recovery unit 21 are controlled by the control device CONT. The control device CONT can control the liquid supply amount per unit time on the substrate P by the liquid supply unit 11, and can control the liquid recovery amount per unit time by the liquid recovery unit 21. The liquid Lq delivered from the liquid supply unit 11 is supplied to the liquid immersion area AR2 on the substrate P through the supply pipe 12 and the supply channels 82A and 82B of the nozzle member 30 and the supply ports 13 and 14. Then, the liquid Lq in the liquid immersion area AR2 is recovered from the recovery port 24 of the nozzle member 30 via the mesh filter 25 and then to the liquid recovery unit 21 via the recovery flow path 84 and the recovery pipe 22 of the nozzle member 30. Collected.

  In FIG. 2, cylindrical support portions 33A, 33B, and 33C that are small at equal angular intervals around the optical axis AX are formed on the upper surface 30c of the nozzle member 30, and the periphery of the optical element 2 is formed on the support portions 33A to 33C. The bottom surface 2c (see FIG. 3) of the part is placed. The upper surface of the peripheral portion of the optical element 2 facing the support portions 33A to 33C is held by, for example, a pressing member 34A (see FIG. 3) attached to the lens barrel PK. Further, an annular O-ring 35 is placed inside the support portions 33A to 33C of the upper surface 30c of the nozzle member 30, and small ellipses are provided on the opposite side of the O-ring 35 with respect to the support portions 33A, 33B, and 33C of the upper surface 30c. Ring-shaped O-rings 37A, 37B, and 37C are placed. The O-ring 35 and the O-rings 37 </ b> A to 37 </ b> C are placed so that the bottom surface 2 c of the peripheral portion of the optical element 2 is in close contact. Further, the center of the O-rings 37A, 37B, 37C on the upper surface 30c of the nozzle member 30 and the inner surface 30b of the nozzle member 30 are each a communication hole 30d formed in the second member 32 of the nozzle member 30 (see FIG. 3). , 30e, 30f.

  In this case, in FIG. 3, the liquid Lq, the side surface 2 b and the bottom surface 2 c of the peripheral portion of the optical element 2, the inner surface 30 b of the nozzle member 30, and the O-ring 35 surround the side surface of the optical element 2. An airtight first airtight space 36 is formed. In addition, second airtight spaces 38A, 38B, and 38C that are airtight are formed by the upper surface 30c of the nozzle member 30, the bottom surface 2c of the peripheral portion of the optical element 2, and the O-rings 37A, 37B, and 37C, respectively. Yes. In the first hermetic space 36 and the second hermetic spaces 38A, 38B, and 38C, the volume of the first hermetic space 36 is larger than the respective volumes of the second hermetic spaces 38A, 38B, and 38C. The first hermetic space 36 and the three second hermetic spaces 38A to 3C communicate with each other through the communication holes 30d to 30f. A mechanism that includes the O-rings 35, 37A to 37C, and the nozzle member 30 (communication holes 30d to 30f) and that deforms the optical element 2 to suppress the deformation of the optical element 2 accompanying the movement of the liquid Lq is configured. Yes.

  In FIG. 1, at the time of exposure of the substrate P by the exposure apparatus EX, an image of a part of the pattern of the mask M is projected through the projection optical system PL onto the projection area AR1 by the projection optical system PL. In synchronism with the movement of the mask M in the X direction at the speed V, the substrate P moves in the X direction at a speed β · V (β is the projection magnification) via the substrate stage PST. Then, after the exposure of one shot area on the substrate P is completed, the next shot area on the substrate P is moved to the scanning start position by the step movement of the substrate stage PST. In this way, the pattern image of the mask M is exposed to all shot regions on the substrate P by the step-and-scan method.

  When performing this exposure process, the control device CONT drives the liquid supply mechanism 10 and starts the liquid supply operation on the substrate P. The liquid Lq delivered from the liquid supply unit 11 of the liquid supply mechanism 10 flows through the supply pipe 12 and then is supplied onto the substrate P via the supply flow paths 82A and 82B and the supply ports 13 and 14 in the nozzle member 30. Is done. The liquid Lq supplied onto the substrate P flows under the projection optical system PL in accordance with the movement of the substrate P. For example, when the substrate P is moving in the + X direction during exposure of a certain shot region, the liquid Lq moves under the projection optical system PL in the + X direction, which is the same direction as the substrate P, at almost the same speed as the substrate P. Flowing. In this state, the exposure light EL emitted from the illumination optical system IL and passing through the mask M is irradiated to the image plane side of the projection optical system PL, and the pattern image of the mask M is liquid in the projection optical system PL and the liquid immersion area AR2. The substrate P is exposed via Lq.

  The control device CONT supplies the liquid Lq onto the substrate P by the liquid supply mechanism 10 when the exposure light EL is irradiated on the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. . On the other hand, as an example, the control device CONT uses the liquid recovery mechanism 20 to apply the liquid Lq on the substrate P when the exposure light EL is irradiated on the image plane side of the projection optical system PL, that is, during the exposure operation of the substrate P. Is not collected. By not collecting the liquid Lq by the liquid collection mechanism 20 during the exposure light EL irradiation, the exposure process can be performed while suppressing the sound and vibration caused by the liquid Lq collection operation.

  During the exposure operation, the recovery operation of the liquid Lq by the liquid recovery mechanism 20 is not performed, and the controller CONT recovers the liquid Lq on the substrate P by the liquid recovery unit 21 after the exposure is completed. For example, the control device CONT is a part of the period after the completion of exposure of one shot area on the substrate P until the start of exposure of the next shot area (at least part of the step movement period of the substrate P). The liquid recovery unit 21 recovers the liquid Lq on the substrate P.

  The control device CONT includes a liquid supply mechanism in a period after the completion of exposure of one shot area until the start of exposure of the next shot area, including during the recovery operation of the liquid Lq on the substrate P by the liquid recovery unit 21. 10 continues the supply of the liquid Lq. By continuing the supply of the liquid Lq in this way, if the supply and stop of the supply of the liquid Lq are repeated, the vibration of the liquid Lq that occurs between the projection optical system PL and the substrate P (so-called water hammer phenomenon). Occurrence can be prevented. In this way, the entire shot area of the substrate P can be exposed by the liquid immersion method.

  At the time of exposure by this immersion method, as shown in FIG. 4A, for example, when the substrate P moves in the −X direction indicated by the arrow 40A with respect to the optical element 2 of the projection optical system PL, the inner surface 30b of the nozzle member 30 is obtained. And the liquid Lq existing between the optical element 2 and the side surface 2b of the optical element 2 flows in the −Z direction as indicated by the arrow 40B, so that the tip of the optical element 2 is supported at the supporting points 33A and 33B as the liquid Lq moves. , 33C as a fulcrum, as shown by a two-dot chain line CA. 4A and 4B, the illustration of the local liquid immersion mechanism is omitted. In this case, in this embodiment, when the liquid Lq flows in the −Z direction and the air pressure in the first airtight space 36 decreases, the air pressure in the second airtight space 38A outside the support portion 33A via the communication hole 30d. As a result, a force for sucking the optical element 2 toward the nozzle member 30 also acts on the second airtight space 38A side. Therefore, as indicated by a two-dot chain line CB in FIG. 4B, the deformation amount of the optical element 2 is reduced, and deterioration of the wavefront aberration and the like of the projection optical system PL is suppressed. Such suppression of deformation of the optical element 2 is similarly performed in the other second airtight spaces 38B and 38C of the bottom surface of the peripheral edge of the optical element 2 in FIG.

  That is, the wavefront aberration (or the deformation amount of the optical element) of the exposure light due to the deformation of the optical element 2 at the time of exposure by the immersion method without providing the O-rings 35 and 37A to 37C in FIG. A) is represented by the equiphase curve group 41A. As described above, the wavefront aberration is deteriorated particularly in the vicinity of the support portions 33A to 33C. On the other hand, the wavefront aberration of the exposure light due to the deformation of the optical element 2 at the time of exposure by the liquid immersion method with the O-rings 35 and 37A to 37C provided as in the present embodiment is, for example, FIG. As shown by the equiphase curve group 41B, it becomes smaller. Therefore, the deformation amount of the optical element 2, and hence the wavefront aberration of the projection optical system PL is reduced, and the pattern image of the mask M can be exposed on the substrate P with high accuracy.

Effects and the like of this embodiment are as follows.
(1) The support device for the optical element 2 that is in contact with the liquid Lq at the tip of the projection optical system PL of the present embodiment includes the nozzle member 30 that supports the optical element 2 via the three support portions 33A to 33C, and the liquid And a mechanism for deforming the optical element 2 so as to suppress deformation of the optical element 2 accompanying the movement of Lq. This mechanism relates to the support portions 33A to 33C, the O-ring 35 for airtightening the first airtight space 36 on the optical axis AX side of the optical element 2, and the support portions 33A to 33C. O-rings 37A to 37C for airtightening the second airtight spaces 38A to 38C on the opposite side to the first airtight space 36, and air holes 30d to 30f for communicating the first airtight space 36 and the second airtight spaces 38A to 38C are formed. Nozzle member 30 formed.

Accordingly, when exposure is performed by the immersion method using the exposure apparatus EX, the force acting on the optical element 2 by the liquid Lq on the first airtight space 36 side and the optical element on the second airtight space 38A to 38C side. Since the force (negative pressure or positive pressure) acting on 2 substantially cancels out, deformation of the optical element 2 in contact with the liquid Lq can be suppressed. Therefore, the imaging characteristics of the projection optical system PL can be maintained high.
Further, even when a high refractive index liquid is used as the liquid Lq and the amount of deformation of the optical element 2 may increase, the deformation of the optical element 2 can be suppressed.

Further, it is only necessary to provide the O-rings 35, 37A to 37C and the communication holes 30d to 30f, and it is not necessary to provide an electrically driven mechanism or the like, so that no load is applied to the control system.
(2) In FIG. 2, the size and number of the plurality of small spaces 38A to 38C arranged outside the support portions 33A to 33C are the aberrations to be corrected (wavefront aberration) of the projection optical system PL including the optical element 2. , Distortion (including magnification), coma, astigmatism, curvature of field, spherical aberration, and the like. The 2nd airtight space 38A-38C can also be arrange | positioned in the area | region between support part 33A-33C, for example. It is also possible to provide the second airtight spaces 38A to 38C at only two places, or at four or more places. Furthermore, one ring-shaped airtight space may be provided so as to surround the support portions 33A to 33C, and this space and the inner space 36 may be communicated with each other.

(3) The optical element 2 is optically stably supported on the nozzle member 30 via the three support portions 33A to 33C. Therefore, even if a stress that deforms the optical element 2 acts, the optical element 2 is stably supported. In addition, it is also possible to provide support part 33A-33C in four or more places.
(4) Liquid supply channels 82A and 82B and a liquid recovery channel 84 are formed in the nozzle member 30 that supports the optical element 2. Therefore, since the nozzle member 30 also serves as a part of the local liquid immersion mechanism, the configuration is simple.

(5) The liquid Lq is supplied between the optical element 2 and the substrate P, and the exposure light EL is irradiated onto the substrate P through the optical element 2 and the liquid Lq. Therefore, even if the liquid Lq moves with the relative movement of the substrate P, the deformation of the optical element 2 is suppressed.
(6) Moreover, since the exposure apparatus EX of this embodiment is provided with the support apparatus of the optical element 2, it can expose the image of the pattern of the mask M on the board | substrate P with high precision using the immersion method.

Next, modifications as shown in FIGS. 6 and 7 can be made to the above embodiment. 6 and 7, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted. In the following description, illustration and description of a local liquid immersion mechanism that supplies and recovers the liquid Lq to the liquid immersion area AR2 on the substrate P in FIG. 1 are omitted.
In the modification of FIG. 6, the optical element 2 is supported on the lower end portion PKa of the lens barrel PK of the projection optical system PL. That is, in FIG. 6, the peripheral portion of the optical element 2 is supported by three support portions 33A on the lower end portion PKa (the other two support portions are not shown, the same applies hereinafter), and the lower end portion PKa and the optical element 2 are supported. An O-ring 35A (corresponding to the O-ring 35 in FIG. 2), three O-rings 37A, and the like are arranged between the two. In this case, the nozzle member 30 is supported by, for example, a frame (not shown) different from the lens barrel PK, and the O-ring 35B is sealed so as to seal between the lower end portion PKa of the lens barrel PK and the upper surface of the nozzle member 30. Is arranged. Further, a large airtight space 36 surrounded by the liquid Lq, the optical element 2, the nozzle member 30, and the O-rings 35A and 35B, a small airtight space 38A surrounded by the optical element 2, the lower end portion PKa, the O-ring 37A, and the like. A communication hole 30d and the like are formed in the lower end portion PKa so as to communicate with each other.

Further, the upper surface corresponding to the support portion 33A and the like of the optical element 2 is held by a pressing member 34A fixed to an annular support member 42 fixed in the lens barrel PK. Other configurations are the same as those of the embodiment of FIGS.
According to the modification of FIG. 6, for example, when the liquid Lq is moved by the movement of the substrate P during exposure by the liquid immersion method and the air pressure in the airtight space 36 is reduced, the air pressure in the airtight space 38A via the communication hole 30d. Therefore, the deformation of the optical element 2 is suppressed. Furthermore, since the optical element 2 is directly supported by the lens barrel PK, vibration caused by the liquid Lq flowing in the nozzle member 30 is not transmitted to the optical element 2. Therefore, the stability of the imaging characteristics is improved.

  Next, in the modification of FIG. 7, the three support portions 33A on the upper surface of the nozzle member 30 (the other two support portions are not shown, the same applies hereinafter) inside (close to the optical axis AX of the projection optical system PL). The drive element 43A such as a piezoelectric element (piezo element) that displaces the optical element 2 in the + Z direction is installed on the side). In this case, the pressure of a load cell or the like is used to hold the optical element 2 and to detect the force from the optical element 2 so as to be positioned on the upper surface of the optical element 2 corresponding to a position slightly outside the support portion 33A. The sensor 44A is provided on the lens barrel PK. The detection result of the pressure sensor 44A is supplied to the control unit 45, and the control unit 45 controlled by the control device CONT in FIG. 1 controls the drive amount of the drive element 43A based on the detection result.

  As an example, when the optical element 2 is deformed in the −Z direction inside the support portion 33A with the movement of the liquid Lq during exposure by the liquid immersion method, the pressure detected by the pressure sensor 44A increases. Therefore, the control unit 45 displaces the optical element 2 in the + Z direction by the drive element 43A so that the pressure decreases. Thereby, the deformation of the optical element 2 is suppressed, and the imaging characteristics of the projection optical system PL are maintained high.

In the modification of FIG. 7, the drive element 43A is preferably provided in the vicinity of all of the three support portions 33A and the like on the nozzle member 30, but at least one of the three support portions 33A and the like is provided. You may provide only in the vicinity of a location.
It is also possible to predict the movement state of the liquid Lq in FIG. 7 based on the movement speeds of the substrate stage PST in FIG. 1 in the X direction and the Y direction, and obtain the deformation amount of the optical element 2 from this prediction. In this case, a simple pressing member can be provided instead of the pressure sensor 44A.

  Further, the drive element 43A is provided on the upper surface of the nozzle member 30 on the optical axis AX (liquid immersion area) side with respect to the support portion 33A, as shown by a two-dot chain line position DA, with respect to the support portion 33A. A driving element 43A may be provided at a position on the opposite side to AX to bias the upper surface of the optical element 2 toward the substrate P side. Further, the drive element 43A may be provided on both the bottom surface of the optical element 2 on the optical axis AX side and the top surface of the optical element 2 on the opposite side to the optical axis AX with respect to the support portion 33A.

Also in the embodiment of FIG. 3, a drive element that urges the optical element 2 toward the substrate P is provided at a position corresponding to the position DA of FIG. 7, and the drive element is also driven to deform the optical element 2. It may be suppressed.
Further, in the above-described embodiment, the control device CONT has described the case where the liquid Lq is supplied onto the substrate P and the liquid Lq is not collected during the exposure operation of the substrate P. However, the liquid Lq may be recovered during the exposure operation of the substrate P.
When a device (electronic device, microdevice) such as a semiconductor device is manufactured using the exposure apparatus of the above-described embodiment, this device performs function / performance design of the device as shown in FIG. Step 222 for manufacturing a mask based on this design step, Step 223 for manufacturing a substrate (wafer or the like) as a base material of the device, and a mask pattern on the substrate by the exposure apparatus (projection exposure apparatus) of the above-described embodiment. Exposure step, development step of the exposed substrate, substrate processing step 224 including heating (curing) and etching step of the developed substrate, device assembly step (including processing processes such as dicing step, bonding step, packaging step) 225 and the inspection step 226 and the like.

  In other words, the device manufacturing method includes a step of exposing the substrate using the exposure apparatus of the above embodiment, and a step of processing the exposed substrate (step 224). According to this device manufacturing method, it is possible to suppress the deformation of the optical element at the tip of the projection optical system at the time of exposure by the immersion method, and to maintain good imaging characteristics. Can be manufactured.

In addition to a scanning exposure apparatus (scanning stepper), the present invention is a step-and-repeat projection exposure in which a mask pattern is collectively exposed while the mask and the substrate are stationary, and the substrate is sequentially moved stepwise. The present invention can also be applied to an apparatus (stepper).
Further, the present invention is not limited to the application to the manufacturing process of a semiconductor device. For example, a manufacturing process such as a liquid crystal display element and a plasma display, an imaging element (CMOS type, CCD, etc.), a micromachine, a MEMS ( (Microelectromechanical Systems), thin film magnetic heads, and manufacturing processes of various devices (electronic devices) such as DNA chips, and a process of manufacturing a mask itself.

  As described above, the present invention is not limited to the above-described embodiment, and various configurations can be taken without departing from the gist of the present invention.

1 is a partially cutaway view showing a schematic configuration of an exposure apparatus as an example of an embodiment. It is a perspective view which shows the optical element 2 and the nozzle member 30 in FIG. It is sectional drawing which follows the III-III line of FIG. (A) is sectional drawing which shows the state which the optical element 2 of FIG. 3 deform | transformed, (B) is sectional drawing which shows the state by which the deformation | transformation of the optical element 2 is suppressed. (A) is a figure showing the deformation | transformation of the optical element 2 corresponding to FIG. 4 (A), (B) is a figure showing the deformation | transformation of the optical element 2 corresponding to FIG. 4 (B). It is sectional drawing which shows the principal part of the 1st modification of embodiment. It is sectional drawing which shows the principal part of the 2nd modification of embodiment. It is a flowchart which shows an example of the manufacturing process of a device.

Explanation of symbols

  M ... Mask, PL ... Projection optical system, P ... Substrate, PST ... Substrate stage, Lq ... Liquid, AR1 ... Projection area, AR2 ... Immersion area, 2 ... Optical element, 10 ... Liquid supply mechanism, 13, 14 ... Supply 24, recovery port, 30 ... nozzle member, 30d-30f ... communication hole, 35 ... O-ring, 37A-37C ... O-ring, 82A, 82B ... supply channel, 84 ... recovery channel

Claims (12)

A device for supporting an optical element in contact with a liquid,
A base member that supports the optical element via a plurality of support points;
A deformation mechanism for deforming the optical element so as to suppress deformation of the optical element accompanying the movement of the liquid;
A support device for an optical element, comprising: The deformation mechanism is:
A first seal member that hermetically seals the first space on the optical axis side of the optical element with respect to the support point;
With respect to the support point, a second seal member that hermetically seals the second space opposite to the first space, and a passage provided in the base member for communicating the first space and the second space. The support device for an optical element according to claim 1, further comprising a pore. The first space is a space surrounded by a part of the surface of the optical element, a part of the liquid, and a part of the base member,
The optical element support device according to claim 2, wherein the second space is a space formed between the optical element and the base member. The first space is formed so as to surround a tip portion of the optical element,
The second space is disposed outside the plurality of support points with respect to the first space, and the size and number of the second spaces depend on the aberration to be corrected by the optical system including the optical element. 4. The optical element supporting device according to claim 2, wherein the optical element supporting device is set. The deformation mechanism is:
A drive element that urges the optical element from the base member side between a portion of the surface of the optical element that is in contact with the liquid and at least one of the plurality of support points; The apparatus for supporting an optical element according to claim 1. The deformation mechanism is:
A drive element that urges the optical element toward the base member at a portion outside the at least one of the plurality of support points with respect to a portion of the surface of the optical element that contacts the liquid; The optical element supporting device according to claim 1, wherein the optical element supporting device is an optical element supporting device. The deformation mechanism is:
A sensor for detecting deformation information of the optical element;
The optical element support device according to claim 5, further comprising: a drive system that drives the drive element based on a detection result of the sensor.   8. The optical element according to claim 1, wherein the plurality of support points of the base member are arranged at three positions so as to surround a tip portion of the optical element. Support device.   9. The optical element supporting device according to claim 1, wherein the base member is provided with a supply path for supplying the liquid and a recovery path for recovering the liquid. 10. The optical element is disposed facing an object that is irradiated with a light beam passing through the optical element and is relatively movable with respect to the optical element,
10. The optical element supporting device according to claim 1, wherein the liquid is supplied between the optical element and the object. 11. In an exposure apparatus that illuminates a pattern with exposure light and exposes the substrate through the pattern and the projection optical system with the exposure light,
A stage system for moving the substrate;
A liquid supply device for supplying a liquid between the optical element at the tip of the projection optical system and the substrate;
A support device for an optical element according to any one of claims 1 to 10,
An exposure apparatus, wherein an optical element at a tip of the projection optical system is supported by a support device for the optical element. Exposing the substrate using the exposure apparatus of claim 11;
Processing the exposed substrate. A device manufacturing method comprising:

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