JP2005268700A - Staging device and aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate disturbance to gap formation between moving surfaces of a bed even if a liquid is left on the bed. <P>SOLUTION: A moving body PS moving on the moving surface 41A of the bed 41 is provided. A recovery unit 61 for sucking to recover liquids 1a to 1d on the moving surface 41A is provided to the moving body PS. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stage apparatus and an exposure apparatus, and more particularly to a stage apparatus and an exposure apparatus suitable for use when exposing a substrate on a stage via a projection optical system and a liquid.

Semiconductor devices and liquid crystal display devices are manufactured by a so-called photolithography technique in which a pattern formed on a mask is transferred onto a photosensitive substrate. An exposure apparatus used in this photolithography process has a mask stage for supporting a mask and a substrate stage for supporting a substrate, and a mask pattern is transferred via a projection optical system while sequentially moving the mask stage and the substrate stage. It is transferred to the substrate. In recent years, in order to cope with higher integration of device patterns, higher resolution of the projection optical system is desired. The resolution of the projection optical system becomes higher as the exposure wavelength used is shorter and the numerical aperture of the projection optical system is larger. Therefore, the exposure wavelength used in the exposure apparatus is shortened year by year, and the numerical aperture of the projection optical system is also increasing. The mainstream exposure wavelength is 248 nm of the KrF excimer laser, but the 193 nm of the shorter wavelength ArF excimer laser is also being put into practical use. Also, when performing exposure, the depth of focus (DOF) is important as well as the resolution. The resolution R and the depth of focus δ are each expressed by the following equations.
R = k1 · λ / NA (1)
δ = ± k2 · λ / NA ² (2)
Here, λ is the exposure wavelength, NA is the numerical aperture of the projection optical system, and k1 and k2 are process coefficients. From equations (1) and (2), it can be seen that if the exposure wavelength λ is shortened and the numerical aperture NA is increased to increase the resolution R, the depth of focus δ becomes narrower.

If the depth of focus δ becomes too narrow, it becomes difficult to match the substrate surface with the image plane of the projection optical system, and the focus margin during the exposure operation may be insufficient. Therefore, as a method for substantially shortening the exposure wavelength and increasing the depth of focus, for example, a liquid immersion method disclosed in Patent Document 1 below has been proposed. In this immersion method, a space between the lower surface of the projection optical system and the substrate surface is filled with a liquid such as water or an organic solvent to form an immersion region, and the wavelength of exposure light in the liquid is 1 / n of that in air. (Where n is the refractive index of the liquid, which is usually about 1.2 to 1.6), the resolution is improved, and the depth of focus is expanded about n times.
International Publication No. 99/49504 Pamphlet

In the above exposure apparatus, since exposure is performed in a state where the liquid is filled between the projection optical system and the wafer, some error occurs when the stage as the moving body moves, and it is out of control (unexpected). When the operation is performed, there is a possibility that the liquid is scattered around.
For example, in a conventional exposure apparatus, a liquid is supplied between a projection optical system and a wafer by a liquid supply mechanism, and the supplied liquid is recovered by a liquid recovery mechanism using vacuum suction or the like. When the operation of the liquid recovery mechanism is stopped in a state where the liquid crystal is operating, it is conceivable that the liquid on the wafer increases and scatters around.

Usually, the stage in the exposure apparatus has an air outlet for blowing gas (air) to the surface (moving surface) of the surface plate, and an air inlet for sucking gas between the lower surface of the stage (bearing surface) and the moving surface. An air bearing is provided, and a constant gap (gap) is maintained between the lower surface of the stage and the moving surface by balancing the repulsive force caused by the gas blown from the air outlet and the suction force caused by the air inlet. Yes. The stage can move in a non-contact manner on the surface of the surface plate with high gas spring rigidity due to the minute gap.
However, when the above-described error occurs and the liquid remains on the surface plate, there is a possibility that the liquid is sucked by the air bearing when the stage is moved.
In this case, the sucked liquid may cause a malfunction in the pressure gauge and the regulator constituting the suction device. In addition, the amount of gap varies due to fluctuations in the amount of air sucked, and the position of the wafer in the optical axis direction may deviate from a predetermined position, and in some cases, the stage may come into contact with the surface plate during movement.

  The present invention has been made in consideration of the above points, and does not hinder the formation of a gap with the moving surface of the surface plate even when liquid remains on the surface plate. An object is to provide a stage apparatus and an exposure apparatus.

In order to achieve the above object, the present invention adopts the following configuration corresponding to FIGS. 1 to 8 showing the embodiment.
The stage apparatus of the present invention is a stage apparatus (ST) including a moving body (PST, 70) that moves on a moving surface (41A) of a surface plate (41), and moves to the moving body (PST, 70). A collection device (61, 81) for sucking and collecting the liquid (1a to 1d) on the surface (41A) is provided.

  Therefore, in the stage apparatus of the present invention, when the liquid (1a to 1d) remains on the moving surface (41A) of the surface plate (41), the moving body (PST, 70) is collected by the recovery device (61, 81). Since the liquids (1a to 1d) on the movement path are collected, the moving body (PST, 70) moves on the moving surface (41A) where no liquid exists, and the fluid bearings (42, 72), the liquid can be prevented from being sucked, and the gap with the moving surface (41A) can be stably formed.

  The exposure apparatus of the present invention is an exposure apparatus (EX) that exposes a pattern of a mask (M) onto a photosensitive substrate (P) held on a substrate stage (PST) via a projection optical system (PL). The stage apparatus (ST) according to any one of claims 1 to 8 is used as a substrate stage, and an image of the pattern is formed between a tip portion of a projection optical system (PL) and a photosensitive substrate (P). It is projected onto the photosensitive substrate (P) through the liquid (1) filled therebetween.

Therefore, in the exposure apparatus of the present invention, the liquid (1) filled between the front end of the projection optical system (PL) and the photosensitive substrate (P) is scattered and the moving surface (41A) of the surface plate (41). Even if it remains above, the moving body (PST, 70) moves on the moving surface (41A) from which the liquid has been collected, and can move in a stable state while maintaining a certain amount of gap. This makes it possible to form a pattern on the photosensitive substrate (P) with a predetermined transfer accuracy.
In order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings showing one embodiment, but it goes without saying that the present invention is not limited to the embodiment.

  In the present invention, it is possible to stably form a gap between the moving surface of the surface plate by collecting the liquid on the moving surface. Further, according to the present invention, it is possible to prevent inconveniences such as damage to apparatuses and members, and to perform stable exposure processing.

Hereinafter, the stage apparatus and exposure apparatus of the present embodiment will be described with reference to FIGS.
(First embodiment)
In the first embodiment, a stage apparatus according to the present embodiment will be described.
FIG. 1 is a schematic configuration diagram showing an embodiment of the stage apparatus of the present embodiment.

  A stage apparatus ST shown in FIG. 1 supports a substrate surface plate (surface plate) 41 supported on a base plate 4 via a vibration isolation unit 9 at three or four points, and a substrate P such as a photosensitive substrate. A substrate stage PST as a moving body that moves the upper surface (moving surface) 41A of the surface plate 41, an X linear motor 47 that drives the substrate stage PST in the X-axis direction (left-right direction in FIG. 1), and a substrate stage PST A Y linear motor 48 that drives in the Y-axis direction (a direction orthogonal to the paper surface in FIG. 1) is mainly configured. The upper surface 41A of the substrate surface plate 41 is provided with a liquid repellent coating by fluorine or a fluorine compound. The vibration isolation unit 9 includes an actuator such as an air mount and a voice coil motor capable of controlling the internal pressure, and is configured to drive the substrate surface plate 41 in a direction orthogonal to the upper surface 41A (Z-axis direction) by driving the actuator. Yes.

  The substrate stage PST includes a table portion PH that holds the substrate P by suction, and a stage portion PS that is movably provided along with the table portion PH. A substrate surface plate 41 is provided on the lower surface of the stage portion PS. A plurality of gas bearings (air bearings) 42, which are a plurality of non-contact bearings, are provided along the periphery of the stage portion PS (for example, four corner portions of the stage portion PS). The air bearing 42 includes an air outlet 42B that blows gas (air) to the upper surface 41A of the substrate surface plate 41, and an air inlet 42A that sucks gas between the lower surface (bearing surface) of the substrate stage PST and the guide surface 41A. And a constant gap (gap) between the lower surface of the substrate stage PST (stage part PS) and the moving surface 41A due to the balance between the repulsive force due to the blowing of gas from the air outlet 42B and the suction force by the air inlet 42A. ) Is a preloaded fluid bearing. That is, the substrate stage PST is supported by the gas bearing 42 in a non-contact manner with respect to the upper surface 41A of the substrate surface plate 41, and in a plane parallel to the upper surface 41A, that is, in the XY plane, by a substrate stage driving mechanism such as a linear motor. Can be moved two-dimensionally and can be slightly rotated in the θZ direction around the axis parallel to the Z axis orthogonal to the upper surface 41A. Further, the table PH is provided so as to be movable in the Z-axis direction, the θX direction (direction around the axis parallel to the X axis), and the θY direction (direction around the axis parallel to the X axis). The substrate stage driving mechanism is controlled by the control device CONT. In other words, the table portion PH controls the Z position and the tilt angle of the substrate P to adjust the surface of the substrate P to a predetermined surface position, and positions the substrate P in the X axis direction and the Y axis direction.

A movable mirror 45 is provided on the substrate stage PST (table portion PH). A laser interferometer 46 is provided at a position facing the moving mirror 45. The two-dimensional position and rotation angle of the substrate P on the substrate stage PST are measured in real time by the laser interferometer 46, and the measurement result is output to the control device CONT. The controller CONT positions the substrate P supported by the substrate stage PST by driving a substrate stage driving mechanism including a linear motor based on the measurement result of the laser interferometer 46.
Further, on the substrate stage PST (table portion PH), a supply nozzle (supply device) 14 for supplying the liquid 1 onto the substrate P and the liquid 1 on the substrate P are collected. A collection nozzle 21 arranged in the vicinity is provided.

  Further, the substrate stage PST is provided with a recovery device 61 for recovering the liquid remaining on the upper surface 41A of the substrate surface plate 41. As shown in FIG. 2, the recovery device 61 includes a suction part 62 provided in the vicinity of the lower end of the side surface of the stage part PS and surrounding the stage part PS, and a partial sectional view of FIG. 3. In addition, a negative pressure suction source (suction device) 64 connected to the suction part 62 via a suction pipe 63 is mainly configured. The suction part 62 is substantially the same as the cross section shown in FIG. 3 in any cross section in the length direction, and includes a frame 65 having a substantially U-shaped cross section having a recess 68 facing the upper surface 41A of the substrate surface plate 41, and a frame. It comprises a plate body 66 provided in a plurality of stacked states in the recess 68 of the body 65. The frame body 65 and the plate body 66 are made of a material having lyophilicity and rust resistance, for example, stainless steel (SUS) with respect to the liquid 1 (see FIG. 1) supplied on the substrate P described later. The plurality of plate bodies 66 and the frame body 65 are arranged with a minute gap of about 0.5 mm, for example, in the horizontal direction, and a plurality of openings 67 facing the upper surface 41A are formed by these minute gaps. . The negative pressure suction source 64 sucks the liquid 68 remaining on the upper surface 41 </ b> A of the substrate surface plate 41 from the opening 67 by sucking the concave portion 68 of the frame body 65 through the suction pipe 63. The plurality of plate bodies 66 are supported by the frame body 65 via spacers (not shown), for example.

  The lower surface 65a of the frame body 65 that surrounds the plate body 66 and the lower surface 66a of the plate body 66 are arranged with steps that increase in distance from the upper surface 41A of the substrate surface plate 41 as the distance from the stage portion PS increases. Along with this, the distance (height) from the upper surface 41A of the substrate surface plate 41 is sequentially increased as the position of the opening 67 to the upper surface 41A formed by the frame body 65 and the plate body 66 is also separated from the stage portion PS. It is getting bigger. The positions of the lower surfaces 65a and 66a (that is, the position of the opening 67) are such that the air suction between the suction portion 62 and the upper surface 41A by driving the negative pressure suction source 64 does not affect the pre-pressure of the gas bearing 42. The size (height) of the liquid (droplet) remaining on the upper surface 41A having liquid repellency varies from about 1 mm to about 4 to 5 mm, so that any size liquid can be sucked without any trouble. The position nearest to the PS is about 1 mm, and the position farthest from the stage part PS is set to about 5 mm.

  The suction pipe 63 connected between the frame body 65 and the negative pressure suction source 64 is provided with a sensor (detection device) 69 for liquid detection. As the sensor 69, for example, when the detection beam is irradiated toward the suction tube 63 and the reflected light is received, the liquid is changed by utilizing the change in the light amount because the refractive index varies depending on the presence or absence of the liquid in the tube. What is detected is used. In this case, the suction tube 63 is formed of a material that transmits the detection beam. The detection result of the sensor 69 is output to the control device CONT. The control device CONT is configured to control the liquid supply onto the substrate P based on the output information.

  In FIG. 2, the substrate stage PST (stage part PS) is supported by an X guide stage 44 so as to be movable in the X-axis direction. The substrate stage PST is movable with a predetermined stroke in the X-axis direction by the X linear motor 47 while being guided by the X guide stage 44. The X linear motor 47 includes a stator 47A provided on the X guide stage 44 so as to extend in the X-axis direction, and a mover 47B provided corresponding to the stator 47A and fixed to the substrate stage PST. Yes. Then, when the mover 47B is driven with respect to the stator 47A, the substrate stage PST moves in the X-axis direction. Here, the substrate stage PST is supported in a non-contact manner by a magnetic guide (not shown) including a magnet and an actuator that maintain a predetermined amount of gap in the Z-axis direction with respect to the X guide stage 44. The substrate stage PST is moved in the X-axis direction by the X linear motor 47 while being supported in a non-contact manner on the X guide stage 44.

  On the other hand, at both ends in the longitudinal direction of the X guide stage 44, a pair of Y linear motors 48, 48 capable of moving the X guide stage 44 together with the substrate stage PST in the Y axis direction are provided. Each of the Y linear motors 48 includes a mover 48B provided at both ends in the longitudinal direction of the X guide stage 44, and a stator 48A provided so as to extend in the Y-axis direction corresponding to the mover 48B. I have. Then, when the mover 48B is driven relative to the stator 48A, the X guide stage 44 moves in the Y axis direction together with the substrate stage PST. Further, the X guide stage 44 can be rotated in the θZ direction by adjusting the driving of the Y linear motors 48 and 48. Therefore, the substrate stage PST can move in the Y axis direction and the θZ direction almost integrally with the X guide stage 44 by the Y linear motors 48, 48.

  Further, support members (moving bodies) 70 extending in the Y direction that move integrally with the X guide stage 44 are respectively provided on the back surfaces of both ends of the X guide stage 44 in the longitudinal direction. A gas bearing (air bearing) 72 is provided opposite to the upper surface 41A of the surface plate 41 (see FIG. 1). The gas bearing 72 is a preload fluid bearing similar to the gas bearing 42 described above, and includes a blowout port 72B that blows gas (air) to the upper surface 41A of the substrate surface plate 41, and a lower surface (bearing surface) of the support member 70. And an air inlet 72A for sucking the gas between the guide surface 41A and the lower surface of the support member 70 by the balance between the repulsive force caused by the blowing of gas from the air outlet 72B and the suction force caused by the air inlet 72A. A fixed gap (gap) is formed and maintained between the moving surface 41A. That is, the X guide stage 44 is supported in a non-contact manner with respect to the upper surface 41A of the substrate surface plate 41 by the gas bearing 72 via the support member 70, and is in a plane parallel to the upper surface 41A by the Y linear motor 48. That is, it can move in the Y direction and the θZ direction within the XY plane.

  Further, the support member 70 is provided with a recovery device 81 for recovering the liquid remaining on the upper surface 41A of the substrate surface plate 41. As shown in FIG. 2, the collection device 81 has suction portions 82 provided on three surfaces surrounding the periphery of the support member 70 so as to face the upper surface 41 </ b> A of the substrate surface plate 41 in the vicinity of the lower end portion of the side surface of the support member 70. As shown in the partial cross-sectional view of FIG. 3, a negative pressure suction source (suction device) 84 connected to the suction portion 82 via a suction tube 83 is mainly configured.

In addition, since the structure of the collection | recovery apparatuses 61 and 81 is the same, description of the collection | recovery apparatus 81 is performed by adding a code | symbol to the component of the collection | recovery apparatus 61 shown in FIG.
The suction part 82 is substantially the same as the cross section shown in FIG. 3 in any cross section in the length direction, and includes a frame 85 having a substantially U-shaped cross section having a recess 88 facing the upper surface 41A of the substrate surface plate 41, and a frame. It is comprised from the board | substrate 86 provided in the recessed part 88 of the body 85 in multiple lamination | stacking state. The frame body 85 and the plate body 86 are formed of a material having lyophilicity and rust resistance, for example, stainless steel (SUS) with respect to the liquid 1 (see FIG. 1) supplied on the substrate P described later. The plurality of plates 86 and the frame 85 are arranged with a small gap of, for example, about 0.5 mm in the horizontal direction, and a plurality of openings 87 facing the upper surface 41A are formed by these minute gaps. . The negative pressure suction source 84 sucks the liquid remaining on the upper surface 41 </ b> A of the substrate surface plate 41 from the opening 87 by sucking the concave portion 88 of the frame body 85 through the suction pipe 83. The negative pressure suction sources 64 and 84 may share the same device.

  The lower surface 85a of the frame body 85 surrounding the plate body 86 and the lower surface 86a of the plate body 86 are arranged with steps that gradually increase in distance from the upper surface 41A of the substrate surface plate 41 as the distance from the support member 70 increases. Accordingly, as the position of the opening 87 to the upper surface 41A formed by the frame body 85 and the plate body 86 is also separated from the support member 70, the distance (height) from the upper surface 41A of the substrate surface plate 41 is sequentially increased. It is getting bigger. The positions of the lower surfaces 85a and 86a (that is, the position of the opening 87) are such that the air suction between the suction portion 82 and the upper surface 41A due to the driving of the negative pressure suction source 84 does not affect the pre-pressure of the gas bearing 42. In order to be able to suck the liquid (droplets) that vary in size and remain on the upper surface 41A having liquid repellency, the position closest to the support member 70 is about 1 mm, and the position farthest from the support member 70 is about 5 mm. Is set.

In the stage apparatus ST having the above-described configuration, a certain amount of liquid 1 is held on the surface of the substrate P by controlling the supply amount of the liquid 1 from the supply nozzle 14 and the recovery amount of the liquid 1 by the recovery nozzle 21. Thus, the substrate stage PST can be moved along the upper surface 41A of the surface plate 41 by the substrate stage drive mechanism (X linear motor 47, Y linear motor 48).
Here, trouble occurs in the liquid recovery by the recovery nozzle 21, and the liquid drips or scatters from the substrate (substrate stage PST) to the upper surface 41 </ b> A of the substrate surface plate 41, or the substrate stage PST supplies the nozzle for replacing the substrate. The liquid may remain on the upper surface 41A of the surface plate because the liquid supply is not stopped even when it is moved from just below the surface 14.

  For example, when the liquid 1 remains ahead in the traveling direction on the moving path of the substrate stage PST (stage part PS), the substrate stage PST moves and the stage part PS moves to the stage part PS before the gas bearing 42 reaches the residual liquid. The provided suction part 62 comes into contact with the residual liquid. Here, as shown by a two-dot chain line in FIG. 3, the size of the residual liquid varies, but for example, when the liquid 1a having a height of about 5 mm remains, it is farthest from the stage part PS. The liquid 1 a comes into contact with the plate body 66 at the position, and is sucked from the opening 67 between the plate body 66 and the side wall of the frame body 65.

  In addition, when the liquid 1b that is lower than the lower surface 66a of the plate body 66 at the far position and is in contact with the lower surface 66a of the adjacent plate body 66 remains, the space between the adjacent plate bodies 66 is left. The liquid 1b is sucked from the opening 67. As described above, even when the liquids 1a to 1d having different heights remain on the upper surface 41A, the liquids 1a to 1d are formed in at least one of the plurality of openings 67 at positions corresponding to the heights of the liquids 1a to 1d. Can be sucked. Here, each opening 67 is formed with a minute gap, and since the frame body 65 and the plate body 66 are lyophilic, the liquids 1a to 1d in contact with the frame body 65 and the plate body 66 are In addition to the suction force generated by driving the negative pressure suction source 64, the suction force is quickly drawn by a suction force caused by a capillary phenomenon. Thus, the liquid remaining on the movement path of the substrate stage PST is sucked and collected by the collecting device 61.

  The liquid 1 (1a to 1d) sucked from the opening 67 is drained through the suction pipe 63 from the recess 68 of the frame 65, but the sensor 69 removes the liquid passing through the inside from the suction pipe 63. It is constantly monitored. When the liquid 1 (1a to 1d) on the upper surface 41A is sucked and passes through the monitoring region of the sensor 69 in the suction pipe 63, the refractive index of the detection beam is changed by the liquids 1a to 1d. The amount of reflected light varies depending on the presence or absence of liquid. Therefore, when the sensor 69 detects a change in the amount of reflected light of the detection beam, the sensor 69 outputs the result to the control device CONT. Upon receiving the detection result from the sensor 69, the control device CONT determines that the liquid 1 has leaked to the upper surface 41A of the surface plate 41 for some reason, stops the liquid supply from the supply nozzle 14, and issues an alarm. Thereby, it is possible to prevent the leakage or scattering of the liquid to the substrate surface plate 41 from expanding.

  Even when liquid remains on the movement path of the support member 70 on the upper surface 41A of the substrate surface plate 41, the liquid is sucked by the suction unit 82 on the front side in the movement direction by the recovery device 81 as in the case of the substrate stage PST. Collected. Note that the support member 70 does not move in the X direction (even if it moves), the liquid remaining on the + X side or the −X side of the movement path of the support member 70 is sucked by air suction of the gas bearing 72. In this case as well, the liquid can be sucked and collected by the suction portion 82 provided on the + X side or the −X side of the support member 70.

  As described above, in the present embodiment, even when the liquid remains on the upper surface 41A of the substrate surface plate 41, the recovery devices 61 and 81 cause the substrate stage PST and the supporting member 70 to move along the liquid and the liquid in the vicinity thereof. Therefore, the substrate stage PST and the support member 70 are moved on the moving surface 41A where there is no liquid, and it is possible to prevent the gas bearings 42 and 72 from sucking the liquid and causing problems of the apparatus and members. Therefore, in the present embodiment, it is possible to maintain a gap formed between the movable body such as the substrate stage PST and the support member 70 and the upper surface 41A at a predetermined amount, and the position of the substrate P in the Z direction. It is possible to prevent fluctuations and contact between the moving body and the substrate surface plate 41.

  Further, when the openings 67 and 87 for sucking the liquid are uniformly formed at a high position, there is a possibility that a small liquid droplet cannot be sucked, and conversely, the openings 67 and 87 are uniform. However, in this embodiment, the openings 67 and 87 are formed on the substrate stage PST. However, in the present embodiment, a part of the liquid having a large droplet diameter may be scattered on the side walls of the frames 65 and 85. Since the distance from the upper surface 41A is gradually increased as the distance from the support member 70 increases, the liquid can be reliably sucked and collected even when the liquid remains in a plurality of non-uniform sizes.

  Furthermore, in this embodiment, in addition to the suction force by the negative pressure suction sources 64 and 84, the openings 67 and 87 are formed with minute gaps, and the frame bodies 65 and 85 and the plate bodies 66 and 86 are lyophilic. Since the liquid is sucked in a state where the suction force due to the capillary phenomenon is also added, it becomes possible to reduce the suction force by the negative pressure suction sources 64 and 84, resulting from the driving of the negative pressure suction sources 64 and 84. The vibration which occurs can be suppressed, and the positioning accuracy fall of the board | substrate P by vibration can be prevented. In addition, in the present embodiment, the capillary phenomenon can be expressed with a simple configuration in which the plates 66 and 88 are stacked with a gap therebetween, which can contribute to simplification and cost reduction of the apparatus.

Further, in the present embodiment, the arrangement of the frame bodies 65 and 85 and the plate bodies 66 and 86 is also set to a height that does not affect the preload of the gas bearings 42 and 72, so that the substrate stage PST and The support member 70 can move on the moving surface 41A while maintaining a predetermined amount of gap, and the movement and positioning accuracy of the substrate P can be maintained.
Furthermore, in the present embodiment, the sensors 69 and 89 detect that the liquid has been recovered by the recovery devices 61 and 81, and the liquid supply onto the substrate P is stopped accordingly. It is possible to prevent the liquid from leaking and spreading.

(Second Embodiment)
Next, an exposure apparatus provided with the stage apparatus ST shown in the first embodiment will be described with reference to FIGS. In the present embodiment, description will be given using an example in which the stage apparatus of the above embodiment is applied to a substrate stage that holds and moves a photosensitive substrate in an exposure apparatus that projects and exposes a mask pattern image onto the photosensitive substrate. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

FIG. 4 is a schematic block diagram showing the exposure apparatus of the present invention.
4, the exposure apparatus EX includes a mask stage MST that supports a mask M, a substrate stage PST that supports a substrate (photosensitive substrate) P, and the stage apparatus ST shown in FIGS. 1 to 3 and the mask stage MST. An illumination optical system IL that illuminates the mask M supported by the exposure light EL, and a projection optical system that projects and exposes the pattern image of the mask M illuminated by the exposure light EL onto the substrate P supported by the substrate stage PST. PL and a control device CONT that controls the overall operation of the exposure apparatus EX are provided. The control device CONT is connected to an alarm device K that issues an alarm when an abnormality occurs in the exposure process. The exposure apparatus EX further includes a main column 3 that supports the mask stage MST and the projection optical system PL. The main column 3 is installed on a base plate 4 placed horizontally on the floor surface. The main column 3 is formed with an upper step 3A and a lower step 3B that protrude inward.

  The exposure apparatus EX of the present embodiment is an immersion exposure apparatus to which an immersion method is applied in order to improve the resolution by substantially shortening the exposure wavelength and substantially increase the depth of focus. A liquid supply mechanism 10 for supplying the liquid 1 to the substrate P, and a liquid recovery mechanism 20 for recovering the liquid 1 on the substrate P. In the exposure apparatus EX, at least while the pattern image of the mask M is transferred onto the substrate P, the liquid 1 supplied from the liquid supply mechanism 10 applies liquid to a part of the substrate P including the projection area AR1 of the projection optical system PL. An immersion area AR2 is formed. Specifically, the exposure apparatus EX fills the liquid 1 between the optical element 2 at the front end (end portion) of the projection optical system PL and the surface of the substrate P, and between the projection optical system PL and the substrate P. The substrate P is exposed by projecting the pattern image of the mask M onto the substrate P through the liquid 1 and the projection optical system PL.

In the present embodiment, the exposure apparatus EX is a scanning exposure apparatus (so-called so-called exposure apparatus EX) that exposes the pattern formed on the mask M onto the substrate P while synchronously moving the mask M and the substrate P in different directions (reverse directions) in the scanning direction. A case where a scanning stepper) is used will be described as an example. In the following description, the direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, the synchronous movement direction (scanning direction) between the mask M and the substrate P in the plane perpendicular to the Z-axis direction is the X-axis direction, A direction (non-scanning direction) perpendicular to the Z-axis direction and the X-axis direction is defined as a Y-axis direction.
Here, the “substrate” includes a semiconductor wafer coated with a photoresist, which is a photosensitive material, and the “mask” includes a reticle on which a device pattern to be reduced and projected on the substrate is formed.

The illumination optical system IL is supported by a support column 5 fixed to the upper part of the main column 3. The illumination optical system IL illuminates the mask M supported by the mask stage MST with the exposure light EL. The exposure light source, the optical integrator for uniformizing the illuminance of the light beam emitted from the exposure light source, and the optical integrator A condenser lens that collects the exposure light EL from the light source, a relay lens system, and a variable field stop that sets the illumination area on the mask M by the exposure light EL in a slit shape. 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 emitted from the illumination optical system IL, for example, far ultraviolet light (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp, DUV light), vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F ₂ laser light (wavelength 157 nm), or the like is used. In this embodiment, ArF excimer laser light is used.

  In the present embodiment, pure water is used for the liquid 1. Pure water is not only ArF excimer laser light, but also far ultraviolet light (DUV light) such as ultraviolet emission lines (g-line, h-line, i-line) emitted from mercury lamps and KrF excimer laser light (wavelength 248 nm). Can also be transmitted.

  The mask stage MST supports the mask M, and has an opening 34A through which the pattern image of the mask M passes at the center. A mask surface plate 31 is supported on the upper step portion 3 </ b> A of the main column 3 via the vibration isolation unit 6. An opening 34 </ b> B that allows the pattern image of the mask M to pass through is also formed at the center of the mask base plate 31. A plurality of gas bearings (air bearings) 32 that are non-contact bearings are provided on the lower surface of the mask stage MST. The mask stage MST is supported in a non-contact manner on the upper surface (moving surface) 31A of the mask surface plate 31 by an air bearing 32, and is perpendicular to the optical axis AX of the projection optical system PL by a mask stage driving mechanism such as a linear motor. It can move two-dimensionally in the plane, that is, in the XY plane, and can rotate in the θZ direction. A movable mirror 35 is provided on the mask stage MST. A laser interferometer 36 is provided at a position facing the movable mirror 35. The position of the mask M on the mask stage MST in the two-dimensional direction and the rotation angle in the θZ direction (including rotation angles in the θX and θY directions in some cases) are measured in real time by the laser interferometer 36, and the measurement result is a control device. Output to CONT. The control device CONT controls the position of the mask M supported by the mask stage MST by driving the mask stage driving mechanism based on the measurement result of the laser interferometer 36.

  The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a predetermined projection magnification β, and includes a plurality of optical elements including an optical element (lens) 2 provided at the front end portion on the substrate P side. These optical elements are supported by a lens barrel PK. In the present embodiment, the projection optical system PL is a reduction system having a projection magnification β of, for example, 1/4 or 1/5. Note that the projection optical system PL may be either an equal magnification system or an enlargement system. A flange portion FLG is provided on the outer peripheral portion of the lens barrel PK. A lens barrel surface plate 8 is supported on the lower step portion 3 </ b> B of the main column 3 via a vibration isolation unit 7. The projection optical system PL is supported on the lens barrel base plate 8 by engaging the flange portion FLG of the projection optical system PL with the lens barrel base plate 8.

  The optical element 2 at the tip of the projection optical system PL of the present embodiment is provided so as to be detachable (replaceable) with respect to the barrel PK. The liquid 1 in the liquid immersion area AR2 comes into contact with the optical element 2. The optical element 2 is made of meteorite. Since meteorite has high affinity with water, the liquid 1 can be brought into close contact with almost the entire liquid contact surface 2a of the optical element 2. That is, in this embodiment, since the liquid (water) 1 having high affinity with the liquid contact surface 2a of the optical element 2 is supplied, the adhesion between the liquid contact surface 2a of the optical element 2 and the liquid 1 is set. The optical path between the optical element 2 and the substrate P can be reliably filled with the liquid 1. The optical element 2 may be quartz having a high affinity for water. Further, the liquid contact surface 2 a of the optical element 2 may be subjected to a hydrophilic treatment (lyophilic treatment) to further increase the affinity with the liquid 1.

  A plate member 2P is provided so as to surround the optical element 2. The surface (namely, the lower surface) facing the substrate P of the plate member 2P is a flat surface. The lower surface (liquid contact surface) 2a of the optical element 2 is also a flat surface, and the lower surface of the plate member 2P and the lower surface of the optical element 2 are substantially flush. Thereby, the liquid immersion area AR2 can be satisfactorily formed in a wide range. Further, similarly to the optical element 2, a surface treatment (lyophilic treatment) can be performed on the lower surface of the plate member 2P.

  FIG. 5 is an enlarged view showing the liquid supply mechanism 10, the liquid recovery mechanism 20, and the vicinity of the projection optical system PL tip. The liquid supply mechanism 10 supplies the liquid 1 between the projection optical system PL and the substrate P. The liquid supply unit 11 can deliver the liquid 1 and the liquid supply unit 11 via the supply pipe 15. A supply nozzle 14 connected to supply the liquid 1 delivered from the liquid supply unit 11 onto the substrate P is provided. The supply nozzle 14 is disposed close to the surface of the substrate P. The liquid supply unit 11 includes a tank that stores the liquid 1, a pressure pump, and the like, and supplies the liquid 1 onto the substrate P through the supply pipe 15 and the supply nozzle 14. The liquid supply operation of the liquid supply unit 11 is controlled by the control device CONT, and the control device CONT can control the liquid supply amount per unit time on the substrate P by the liquid supply unit 11.

  In the middle of the supply pipe 15, a flow meter 12 that measures the amount of liquid 1 (liquid supply amount per unit time) supplied onto the substrate P from the liquid supply unit 11 is provided. The flow meter 12 constantly monitors the amount of the liquid 1 supplied onto the substrate P, and outputs the measurement result to the control device CONT. A valve 13 that opens and closes the flow path of the supply pipe 15 is provided between the flow meter 12 and the supply nozzle 14 in the supply pipe 15. The opening / closing operation of the valve 13 is controlled by the control device CONT. Note that the valve 13 in the present embodiment is a so-called normal-off system that mechanically closes the flow path of the supply pipe 15 when the drive source (power supply) of the exposure apparatus EX (control apparatus CONT) stops due to, for example, a power failure. It has become.

  The liquid recovery mechanism 20 recovers the liquid 1 on the substrate P supplied by the liquid supply mechanism 10, and includes a recovery nozzle (suction port) 21 disposed near the surface of the substrate P, and a recovery nozzle 21 and a vacuum system 25 connected via a recovery tube 24. The vacuum system 25 includes a vacuum pump, and its operation is controlled by the control device CONT. When the vacuum system 25 is driven, the liquid 1 on the substrate P is recovered through the recovery nozzle 21 together with the surrounding gas (air). As the vacuum system 25, a vacuum system in a factory where the exposure apparatus EX is disposed may be used without providing a vacuum pump in the exposure apparatus.

  A gas-liquid separator 22 that separates the liquid 1 sucked from the recovery nozzle 21 and the gas is provided in the middle of the recovery pipe 24. Here, as described above, the recovery nozzle 21 recovers the surrounding gas as well as the liquid 1 on the substrate P. The gas-liquid separator 22 separates the liquid 1 and gas recovered from the recovery nozzle 21. As the gas-liquid separator 22, for example, the collected liquid and gas are circulated through a tube member having a plurality of holes, and the liquid and the gas are separated by dropping the liquid through the holes by gravity. A gravity separation system, a centrifugal separation system that separates recovered liquid and gas using centrifugal force, or the like can be employed. The vacuum system 25 sucks the gas separated by the gas-liquid separator 22.

  In the recovery tube 24, a dryer 23 that dries the gas separated by the gas-liquid separator 22 is provided between the vacuum system 25 and the gas-liquid separator 22. Even if a liquid component is mixed in the gas separated by the gas-liquid separator 22, the liquid component flows in by drying the gas with the dryer 23 and flowing the dried gas into the vacuum system 25. It is possible to prevent the occurrence of inconvenience such as failure of the vacuum system 25 due to the above. As the dryer 23, for example, a method of removing the liquid component by cooling the gas supplied from the gas-liquid separator 22 (a gas in which the liquid component is mixed) below the dew point of the liquid, or the boiling point of the liquid. A method of removing the liquid component by heating to the above can be adopted.

  On the other hand, the liquid 1 separated by the gas-liquid separator 22 is recovered by the liquid recovery unit 28 via the second recovery pipe 26. The liquid recovery unit 28 includes a tank or the like that stores the recovered liquid 1. The liquid 1 recovered by the liquid recovery unit 28 is discarded or cleaned, for example, and returned to the liquid supply unit 11 or the like for reuse. Further, in the middle of the second recovery pipe 26 and between the gas-liquid separator 22 and the liquid recovery unit 28, a flow meter 27 that measures the amount of recovered liquid 1 (liquid recovery amount per unit time). Is provided. The flow meter 27 constantly monitors the amount of the liquid 1 collected from the substrate P, and outputs the measurement result to the control device CONT. As described above, the liquid 1 on the substrate P and the surrounding gas are also recovered from the recovery nozzle 21, but the liquid 1 and the gas are separated by the gas-liquid separator 22, and only the liquid component is supplied to the flow meter 27. By sending, the flow meter 27 can accurately measure the amount of the liquid 1 collected from the substrate P.

  Further, the exposure apparatus EX includes a focus detection system 56 that detects the position of the surface of the substrate P supported by the substrate stage PST. The focus detection system 56 includes a light projecting unit 56A that projects a detection light beam on the substrate P from an oblique direction via the liquid 1, and a light receiving unit 56B that receives the reflected light of the detection light beam reflected by the substrate P. I have. The light reception result of the focus detection system 56 (light receiving unit 56B) is output to the control device CONT. The control device CONT can detect the position information in the Z-axis direction of the surface of the substrate P based on the detection result of the focus detection system 56. In addition, by projecting a plurality of detection light beams from the light projecting unit 56A, it is possible to detect inclination information of the substrate P in the θX and θY directions.

  As shown in the partial cross-sectional view of FIG. 1, the liquid supply mechanism 10 and the liquid recovery mechanism 20 are separately supported with respect to the lens barrel surface plate 8. Thereby, the vibration generated in the liquid supply mechanism 10 and the liquid recovery mechanism 20 is not transmitted to the projection optical system PL via the lens barrel surface plate 8.

  FIG. 6 is a plan view showing the positional relationship between the liquid supply mechanism 10 and the liquid recovery mechanism 20 and the projection area AR1 of the projection optical system PL. The projection area AR1 of the projection optical system PL has a rectangular shape (slit shape) elongated in the Y-axis direction, and three supply nozzles 14A to 14C are arranged on the + X side so as to sandwich the projection area AR1 in the X-axis direction. The two recovery nozzles 21A and 21B are arranged on the −X side. The supply nozzles 14 </ b> A to 14 </ b> C are connected to the liquid supply unit 11 via the supply pipe 15, and the recovery nozzles 21 </ b> A and 21 </ b> B are connected to the vacuum system 25 via the recovery pipe 24. Further, the supply nozzles 14A 'to 14C' and the recovery nozzles 21A 'and 21B' are arranged so that the supply nozzles 14A to 14C and the recovery nozzles 21A and 21B are rotated by approximately 180 °. The supply nozzles 14A to 14C and the recovery nozzles 21A ′ and 21B ′ are alternately arranged in the Y-axis direction, and the supply nozzles 14A ′ to 14C ′ and the recovery nozzles 21A and 21B are alternately arranged in the Y-axis direction. 14A ′ to 14C ′ are connected to the liquid supply unit 11 via the supply pipe 15 ′, and the recovery nozzles 21A ′ and 21B ′ are connected to the vacuum system 25 via the recovery pipe 24 ′. In the middle of the supply pipe 15 ′, a flow meter 12 ′ and a valve 13 ′ are provided like the supply pipe 15. Further, in the middle of the recovery pipe 24 ′, a gas-liquid separator 22 ′ and a dryer 23 ′ are provided in the same manner as the recovery pipe 24.

Next, a procedure for exposing the pattern of the mask M onto the substrate P using the above-described exposure apparatus EX will be described.
After the mask M is loaded on the mask stage MST and the substrate P is loaded on the substrate stage PST, the control device CONT drives the liquid supply unit 11 of the liquid supply mechanism 10 to connect the supply pipe 15 and the supply nozzle 14. A predetermined amount of liquid 1 per unit time is supplied onto the substrate P. Further, the control device CONT drives the vacuum system 25 of the liquid recovery mechanism 20 in accordance with the supply of the liquid 1 by the liquid supply mechanism 10, and supplies a predetermined amount of the liquid 1 per unit time via the recovery nozzle 21 and the recovery pipe 24. to recover. Thereby, an immersion area AR2 of the liquid 1 is formed between the optical element 2 at the tip of the projection optical system PL and the substrate P (step of filling the liquid). Here, in order to form the liquid immersion area AR2, the control device CONT uses the liquid supply mechanism 10 and the liquid so that the liquid supply amount on the substrate P and the liquid recovery amount from the substrate P are substantially the same. Each of the collection mechanisms 20 is controlled. Then, the control device CONT illuminates the mask M with the exposure light EL by the illumination optical system IL, and projects an image of the pattern of the mask M onto the substrate P through the projection optical system PL and the liquid 1.

  At the time of scanning exposure, a part of the pattern image of the mask M is projected onto the projection area AR1, and the mask M moves in the −X direction (or + X direction) at the velocity V with respect to the projection optical system PL. Then, the substrate P moves in the + X direction (or -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 is completed, the next shot area is moved to the scanning start position by stepping the substrate P, and thereafter, the exposure process for each shot area is sequentially performed by the step-and-scan method. In the present embodiment, the liquid 1 is set to flow in the same direction as the movement direction of the substrate P in parallel with the movement direction of the substrate P. That is, when scanning exposure is performed by moving the substrate P in the scanning direction (−X direction) indicated by the arrow Xa (see FIG. 6), the supply pipe 15, the supply nozzles 14A to 14C, the recovery pipe 24, and the recovery nozzle Supply and recovery of the liquid 1 by the liquid supply mechanism 10 and the liquid recovery mechanism 20 are performed using 21A and 21B. That is, when the substrate P moves in the −X direction, the liquid 1 is supplied from the supply nozzle 14 (14A to 14C) between the projection optical system PL and the substrate P, and the recovery nozzle 21 (21A, 21B). ), The liquid 1 on the substrate P is collected together with the surrounding gas, and the liquid 1 flows in the −X direction so as to fill the space between the optical element 2 at the tip of the projection optical system PL and the substrate P.

  On the other hand, when scanning exposure is performed by moving the substrate P in the scanning direction (+ X direction) indicated by the arrow Xb (see FIG. 6), the supply pipe 15 ′, the supply nozzles 14A ′ to 14C ′, the recovery pipe 24 ′, and The liquid supply mechanism 10 and the liquid recovery mechanism 20 supply and recover the liquid 1 using the recovery nozzles 21A ′ and 21B ′. That is, when the substrate P moves in the + X direction, the liquid 1 is supplied between the projection optical system PL and the substrate P from the supply nozzle 14 ′ (14A ′ to 14C ′), and the recovery nozzle 21 ′ ( 21A ′, 21B ′) collects the liquid 1 on the substrate P together with the surrounding gas, and the liquid 1 flows in the + X direction so as to satisfy the space between the optical element 2 at the tip of the projection optical system PL and the substrate P. . In this case, for example, the liquid 1 supplied via the supply nozzle 14 flows so as to be drawn between the optical element 2 and the substrate P as the substrate P moves in the −X direction. Even if the supply energy of the (liquid supply unit 11) is small, the liquid 1 can be easily supplied between the optical element 2 and the substrate P. Then, by switching the direction in which the liquid 1 flows according to the scanning direction, the liquid 1 is moved between the optical element 2 and the substrate P when the substrate P is scanned in either the + X direction or the −X direction. And a high resolution and a wide depth of focus can be obtained.

  During the exposure process, the measurement result of the flow meter 12 provided in the liquid supply mechanism 10 and the measurement result of the flow meter 27 provided in the liquid recovery mechanism 20 are always output to the control device CONT. The control device CONT recovered from the measurement result of the flow meter 12, that is, the amount of liquid supplied onto the substrate P by the liquid supply mechanism 10, and the measurement result of the flow meter 27, that is, recovered from the substrate P by the liquid recovery mechanism 20. The amount of liquid is compared, and the valve 13 of the liquid supply mechanism 10 is controlled based on the comparison result. Specifically, the control device CONT obtains the difference between the liquid supply amount on the substrate P (measurement result of the flow meter 12) and the liquid recovery amount from the substrate P (measurement result of the flow meter 27). The valve 13 is controlled based on whether or not the obtained difference exceeds a preset allowable value (threshold value). Here, as described above, the control device CONT sets each of the liquid supply mechanism 10 and the liquid recovery mechanism 20 so that the liquid supply amount on the substrate P and the liquid recovery amount from the substrate P are substantially the same. Therefore, if the liquid supply operation by the liquid supply mechanism 10 and the liquid recovery operation by the liquid recovery mechanism 20 are normally performed, the difference obtained is almost zero.

  When the calculated difference is equal to or larger than the allowable value, that is, when the liquid recovery amount is extremely small compared to the liquid supply amount, the control unit CONT recovers the liquid 1 sufficiently due to an abnormality in the recovery operation of the liquid recovery mechanism 20. Judge that it is not done. At this time, the control device CONT determines that an abnormality such as a failure has occurred in the vacuum system 25 of the liquid recovery mechanism 20, for example, and prevents the liquid 1 from leaking due to the liquid 1 being unable to recover the liquid 1 normally. In order to do this, the valve 13 of the liquid supply mechanism 10 is operated to shut off the flow path of the supply pipe 15 and the supply of the liquid 1 onto the substrate P by the liquid supply mechanism 10 is stopped. As described above, the control device CONT compares the amount of liquid supplied onto the substrate P from the liquid supply mechanism 10 with the amount of liquid recovered by the liquid recovery mechanism 20, and based on the comparison result, the liquid recovery mechanism 20. When the abnormality of the recovery operation is detected and the liquid 1 is excessively supplied, and the abnormality is detected, the supply of the liquid 1 onto the substrate P is stopped.

  At this time, the liquid 1 already supplied onto the substrate P and not recovered by the liquid recovery mechanism 20 flows out from the substrate stage PST to the upper surface 41A of the substrate surface plate 41 as described in the first embodiment. When the substrate stage PST and the support member 70 are moved, the liquid remaining on the surface plate upper surface 41A can be sucked and collected by the collection devices 61 and 81 (liquid collection step).

  As described above, in the present embodiment, by filling the space between the optical element 2 and the substrate P with the liquid 1, high resolution and a wide depth of focus can be obtained, and the liquid is scattered from the substrate P for some reason. Even if it flows out and remains on the surface plate upper surface 41A, the substrate P is moved in a state where the liquid is recovered by the above-described recovery devices 61 and 81 and the gap amount with the surface plate upper surface 41A is maintained. Thus, the exposure process can be carried out smoothly without causing the position change of the substrate P in the Z direction and the contact between the moving body and the substrate surface plate 41.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above-described embodiment, the recovery devices 61 and 81 are configured to use both the negative pressure suction force by the negative pressure suction sources 64 and 84 and the suction force due to the capillary phenomenon at the openings 67 and 87. It is not limited to the above, and a configuration in which the liquid is sucked and collected only by the negative pressure suction force by the negative pressure suction sources 64 and 84, and particularly when the moving speed of the moving body is low, the capillary phenomenon in the openings 67 and 87 is used. It is also possible to employ a configuration in which liquid is sucked and collected only by the suction force generated by.

  Further, in the above embodiment, the plate bodies 66 and 86 are arranged with a step so that the heights of the openings 67 and 87 from the upper surface 41A of the surface plate are sequentially increased as the distance from the substrate stage PST and the support member 70 increases. However, the present invention is not limited to this. For example, the liquid repellency of the surface plate upper surface 41A is managed with high accuracy, and the size of the liquid (droplet) remaining on the surface plate upper surface 41A is almost the same. When it is known that it is constant, the lower surfaces 65a and 85a of the frame members 65 and 85 and the lower surfaces 66a and 86a of the plate members 66 and 86 are connected to the upper surface 41A of the platen and the liquid as shown in FIG. It is good also as a structure arrange | positioned in parallel by the substantially fixed distance which can be attracted | sucked and collect | recovered.

  Furthermore, in the said embodiment, although it was set as the structure which forms the opening parts 66 and 86 by the several plate body 66 and 86 arrange | positioned in a lamination | stacking state, without using a plate body other than this structure, FIG. As shown in the figure, the frame bodies 65 and 85 are formed in a substantially rectangular shape in cross section, and the openings 67 and 87 having a size that develops capillary action are formed in the wall portions 65A and 85A facing the upper surface 41A of the surface plate. Also good. Also in this case, by forming the wall portions 65A and 85A so as to gradually move upward as the distance from the stage portion PS and the support member 70 increases, the distances from the top surface 41A of the openings 67 and 87 also increase sequentially. Thus, it becomes possible to smoothly suck and collect various sizes of liquid remaining on the upper surface 41A of the surface plate.

  As described above, since ArF excimer laser light is used as exposure light in this embodiment, pure water is supplied as a liquid for immersion exposure. Pure water has the advantage that it can be easily obtained in large quantities at a semiconductor manufacturing factory or the like and has no adverse effect on the photoresist, optical element (lens), etc. on the substrate (wafer). In addition, pure water has no adverse effects on the environment, and since the impurity content is extremely low, it can be expected to clean the surface of the substrate and the surface of the optical element provided on the front end surface of the projection optical system.

It is said that the refractive index n of pure water (water) for exposure light having a wavelength of about 193 nm is approximately 1.44. When ArF excimer laser light (wavelength 193 nm) is used as a light source for exposure light, the wavelength is shortened to 1 / n, that is, about 134 nm on the substrate, and high resolution is obtained. Further, the depth of focus is expanded by about n times, that is, about 1.44 times compared to the air.
In addition, as the liquid, it is possible to use a liquid that is transparent to the exposure light, has a refractive index as high as possible, and is stable with respect to the projection optical system and the photoresist applied to the substrate surface. .
When F ₂ laser light is used as the exposure light, a fluorine-based liquid such as fluorine-based oil or perfluorinated polyether (PFPE) that can transmit the F ₂ laser light may be used as the liquid.

  In the above-described embodiment, the exposure apparatus that locally fills the liquid between the projection optical system PL and the substrate P is adopted. However, the stage that holds the substrate to be exposed is moved in the liquid tank. Even in an immersion exposure apparatus or an immersion exposure apparatus in which a liquid tank having a predetermined depth is formed on a stage and a substrate is held therein, the surface plate and the moving body are arranged outside the liquid tank. The present invention is applicable. For the structure and exposure operation of an immersion exposure apparatus that moves a stage holding a substrate to be exposed in a liquid tank, a liquid tank having a predetermined depth is formed on the stage, for example, in JP-A-6-124873. A liquid immersion exposure apparatus that holds a substrate in it is disclosed in, for example, Japanese Patent Laid-Open No. 10-303114 and US Pat. No. 5,825,043.

  The present invention can also be applied to a twin stage type exposure apparatus. The structure and exposure operation of a twin stage type exposure apparatus are described in, for example, Japanese Patent Laid-Open Nos. 10-163099 and 10-214783 (corresponding US Pat. Nos. 6,341,007, 6,400,441, 6,549). , 269 and 6,590,634), JP 2000-505958 (corresponding US Pat. No. 5,969,441) or US Pat. No. 6,208,407.

  When the immersion method as described above is used, the numerical aperture NA of the projection optical system may be 0.9 to 1.3. As described above, when the numerical aperture NA of the projection optical system is increased, the imaging characteristics may be deteriorated due to the polarization effect in the case of the random polarized light conventionally used as the exposure light. Is desirable. In that case, linearly polarized illumination is performed in accordance with the longitudinal direction of the line pattern of the mask (reticle) line-and-space pattern. From the mask (reticle) pattern, the S-polarized light component (TE-polarized light component), that is, the line pattern It is preferable that a large amount of diffracted light having a polarization direction component is emitted along the longitudinal direction. When the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with a liquid, the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with air (gas). In comparison with the case where the numerical aperture NA of the projection optical system exceeds 1.0, the transmittance of the diffracted light of the S-polarized component (TE-polarized component), which contributes to the improvement of contrast, on the resist surface is increased. High imaging performance can be obtained. Further, it is more effective to appropriately combine a phase shift mask or an oblique incidence illumination method (particularly a dipole illumination method) adapted to the longitudinal direction of the line pattern as disclosed in JP-A-6-188169.

  Further, for example, ArF excimer laser light is used as exposure light, and a fine line and space pattern (for example, L / S of about 25 to 50 nm) is formed on the substrate P by using the projection optical system PL with a reduction magnification of about 1/4. When exposing upward, depending on the structure of the mask M (for example, the fineness of the pattern and the thickness of chrome), the mask M acts as a polarizing plate due to the wave guide effect, and the P-polarized component (TM-polarized component) reduces the contrast. More diffracted light of the S-polarized component (TE polarized component) than the diffracted light of) is emitted from the mask. In this case as well, it is desirable to use linearly polarized illumination as described above, but even if the mask M is illuminated with random polarized light, high resolution is achieved using a projection optical system having a large numerical aperture NA such as 0.9 to 1.3. It becomes possible to obtain performance.

  When an extremely fine line and space pattern on the mask M is exposed on the substrate P, the P-polarized component (TM-polarized component) is replaced with the S-polarized component (TE-polarized component) by the Wave guide effect. Although, for example, ArF excimer laser light is used as exposure light, and a line and space pattern larger than 25 nm is exposed on the substrate P using a projection optical system with a reduction ratio of about 1/4. Under such conditions, the diffracted light of the S-polarized component (TE-polarized component) is emitted from the mask more than the diffracted light of the P-polarized component (TM-polarized component), so the numerical aperture NA of the projection optical system is 0.9. High resolution performance can be obtained even when it is as large as ˜1.3.

  Furthermore, not only linearly polarized illumination (S-polarized illumination) matched to the longitudinal direction of the mask (reticle) line pattern, but also polarized illumination and oblique incidence that linearly polarizes in the tangential (circumferential) direction of the circle around the optical axis. Combination with the lighting method is also effective. In particular, when the mask (reticle) pattern includes not only a line pattern extending in a predetermined direction but also a plurality of line patterns extending in different directions, linear polarization is performed in a tangential direction of a circle centering on the optical axis. By using the polarized illumination method and the annular illumination method in combination, high imaging performance can be obtained even when the numerical aperture NA of the projection optical system is large.

  The substrate P in each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus EX, in addition to the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by moving the mask M and the substrate P synchronously, the mask M and the substrate P Can be applied to a step-and-repeat type projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while the substrate P is stationary and the substrate P is sequentially moved stepwise. The present invention can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on the substrate P.

  The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). ) Or an exposure apparatus for manufacturing reticles or masks.

  When using a linear motor (see USP5,623,853 or USP5,528,118) for the substrate stage PST and mask stage MST, use either an air levitation type using air bearings or a magnetic levitation type using Lorentz force or reactance force. Also good. Each stage PST, MST may be a type that moves along a guide, or may be a guideless type that does not have a guide.

  As a driving mechanism for each stage PST, MST, a planar motor that drives each stage PST, MST by electromagnetic force with a magnet unit having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil facing each other is provided. It may be used. In this case, either one of the magnet unit and the armature unit may be connected to the stages PST and MST, and the other of the magnet unit and the armature unit may be provided on the moving surface side of the stages PST and MST.

As described in JP-A-8-166475 (USP 5,528,118), the reaction force generated by the movement of the substrate stage PST is not transmitted to the projection optical system PL, but mechanically using a frame member. You may escape to the floor (ground).
As described in JP-A-8-330224 (US S / N 08 / 416,558), a frame member is used so that the reaction force generated by the movement of the mask stage MST is not transmitted to the projection optical system PL. May be mechanically released to the floor (ground).

  As described above, the exposure apparatus EX according to the present embodiment maintains various mechanical subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 9, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate as a base material of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic block diagram which shows the surface plate and stage apparatus of this invention. It is a top view of the same stage apparatus. It is the elements on larger scale which show a collection | recovery apparatus. It is a schematic block diagram which shows the exposure apparatus of this invention. It is a schematic block diagram which shows the vicinity of the front-end | tip part of a projection optical system, a liquid supply mechanism, and a liquid collection | recovery mechanism. It is a top view which shows the positional relationship of the projection area | region of a projection optical system, a liquid supply mechanism, and a liquid collection | recovery mechanism. It is the elements on larger scale which show another form of a collection | recovery apparatus. It is the elements on larger scale which show another form of a collection | recovery apparatus. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

EX Exposure device CONT control device M Mask (reticle)
P substrate (photosensitive substrate)
PL Projection optical system PS Stage unit (moving body)
PST substrate stage (moving body)
ST stage device 1, 1a to 1d Liquid 2 Optical element (tip portion)
14 Supply nozzle (supply device)
41 Substrate surface plate (surface plate)
41A Upper surface (moving surface)
42, 72 Gas bearing (preload fluid bearing)
61, 81 Recovery device 64, 84 Negative pressure suction source (suction device)
66, 86 Plate body 67, 87 Opening 69, 89 Sensor (detection device)
70 Support member (moving body)

Claims (9)

A stage device including a moving body that moves on a moving surface of a surface plate,
A stage device, wherein the moving body is provided with a collecting device for sucking and collecting the liquid on the moving surface. The stage apparatus according to claim 1, wherein
The recovery device includes an opening that opens toward the moving surface, and a suction device that sucks the opening at a negative pressure. The stage apparatus according to claim 2, wherein
The moving body is provided with a preload type fluid bearing facing the moving surface,
The position of the opening with respect to the moving surface is set based on a preload of the preload type fluid bearing. The stage apparatus according to claim 2 or 3,
The stage device characterized in that the opening sucks the liquid by a capillary phenomenon. The stage apparatus according to claim 4, wherein
The opening is formed by a plurality of plates stacked with a gap therebetween. The stage apparatus according to claim 5, wherein
The stage apparatus is characterized in that the plurality of plate bodies are arranged with a level difference in which the distance from the moving surface sequentially increases as they are separated from the moving body. In the stage apparatus as described in any one of Claim 4 to 6,
At least a part of the plate has lyophilicity with respect to the liquid. The stage apparatus according to any one of claims 1 to 7,
A detection device for detecting the sucked liquid;
A supply device for supplying a liquid to the surface of the substrate held by the movable body;
A control device for controlling the liquid supply of the supply device based on the detection result of the detection device;
A stage apparatus characterized by comprising: An exposure apparatus that exposes a pattern of a mask to a photosensitive substrate held on a substrate stage via a projection optical system,
The stage apparatus according to any one of claims 1 to 8 is used as the substrate stage,
An exposure apparatus characterized in that the image of the pattern is projected onto the photosensitive substrate through the liquid filled between the tip of the projection optical system and the photosensitive substrate.

Images