JP4993552B2 - Stage apparatus and exposure apparatus - Google Patents

Description

  The present invention relates to a stage apparatus including a stage base on a base and an exposure apparatus including the stage apparatus.

In general, in an exposure apparatus, a stage apparatus is arranged to move a substrate such as a wafer with high accuracy. Conventionally, such a stage apparatus has a stage base on a base. Then, the slider is guided along a guide member arranged on the stage base, and the stage is moved by the movement of the slider.
JP 2003-229350 A

However, in the conventional stage apparatus, the stage base may be deformed by the movement of the stage, the weight of the stage base, or the deformation of the base on which the stage base is placed. If the stage base is deformed, there is a possibility that the traveling performance of the slider is deteriorated or the apparatus is damaged.
The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a stage apparatus and an exposure apparatus that can significantly reduce the deformation of the stage base as compared with the prior art.

The stage apparatus of the present invention is arranged at each vertex of a polygon in plan view among the base and the stage base, and between the base and the stage base, a support member that horizontally supports the stage base. Are provided in a plurality of positions on both sides of the stage base where the support member is not disposed at a position that does not overlap the apex in plan view, and the pressing force can be controlled while pressing the stage base from the vertical direction. and the pressing means is a tilt detection means for detecting an inclination for each disposed in and stages based horizontal in the vicinity of a position in which a pressing means of the stage base, pressing on the basis of a signal from the inclination detecting unit Control means for controlling the pressing force of the means.

Specifically, it is preferable that the support member is disposed at each vertex of the triangle, and the pressing means is disposed at each vertex of the inverted triangle obtained by rotating the triangle by 180 degrees. As the support member, a jack screw that is screwed into a screw hole provided in the base and supports the stage base from below at the tip is suitable. It is desirable to place a plurality of inclination detecting means in the vicinity of the position of the stage base where the pressing means is provided.

As the pressing means , a structure capable of controlling the pressing force by fluid pressure may be used. Moreover, as a pressing means, you may utilize the thing of the structure which can control the said pressing force with magnetic force . Furthermore, the stage base may be disposed in a vacuum atmosphere.

The stage apparatus of the present invention may be used for an exposure apparatus. In this case, the reticle or substrate is held on the stage device, and the pattern formed on the reticle is transferred to the substrate via exposure light.

In the stage apparatus of the present invention, the deformation of the stage base can be greatly reduced as compared with the conventional art.
Since the exposure apparatus of the present invention uses the stage apparatus of the present invention, the exposure accuracy can be improved by improving the positioning accuracy of the substrate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
1 and 2 show a first embodiment of the stage apparatus of the present invention. In this embodiment, the present invention is applied to a coarse movement stage of a wafer stage.
The coarse movement stage of this embodiment has a stage base 11. A pair of guide members 13 are arranged in parallel on both sides of the stage base 11. The pair of guide members 13 are fixed on the stage base 11 via support members 15 at both ends. A pair of guide members 13 is provided with a Y slider 17 that is guided along the guide members 13.

A guide member 19 is disposed between the pair of Y sliders 17. Both ends of the guide member 19 are fixed to the Y slider 17. The guide member 19 is provided with an X slider 21 that is guided along the guide member 19.
In this coarse movement stage, the Y slider 17 is moved along the guide member 13 by an actuator (not shown) such as a linear motor, whereby the X slider 21 is positioned in the Y direction. Further, the X slider 21 is moved along the guide member 19 by an actuator (not shown) such as a linear motor, whereby the X slider 21 is positioned in the X direction.

A fine movement table (not shown) that can move in the X, Y, and Z directions with higher accuracy than the coarse movement stage is disposed on the upper surface of the X slider 21 of the coarse movement stage, and a wafer placed on the upper surface of the fine movement table. Positioning is performed.
As shown in FIG. 2, the stage base 11 is disposed on the base 23. The base 23 is composed of, for example, a chamber of an exposure apparatus, and a side wall portion 23a is formed along the outer periphery. The stage base 11 is supported on the base 23 by a support member 25 made of a jack screw.

  As shown in FIG. 1, the support members 25 are arranged in three triangles on the base 23. As shown in FIG. 2, a screw hole 23 b into which the support member 25 is screwed is formed in the base 23. Then, the height of the stage base 11 is adjusted by rotating the head 25a of the support member 25 with a wrench or the like. Thereby, the stage base 11 is horizontally supported by the three support members 25.

As shown in FIG. 2, an air mount 27 made of an elastic material such as rubber is disposed between the base 23 and the stage base 11. As shown in FIG. 1, the air mount 27 is arranged at three locations on the base 23 so as to have an inverted triangular shape with respect to the support members 25 at three locations.
As shown in FIG. 2, a pressure regulator 31 is connected to each air mount 27 via a pipe line 29. The pressure adjuster 31 adjusts the pressure of air in the air mount 27. The air mount 27 changes the pressing force for pressing the stage base 11. The structures of the air mount 27 and the pressure regulator 31 are well known and will not be described in detail.

As shown in FIG. 1, an inclination sensor 33 that detects the inclination of the stage base 11 is disposed on the upper surface of the stage base 11. The tilt sensor 33 is a biaxial tilt sensor and can detect tilts in the X direction and the Y direction. And it arrange | positions in the vicinity of the position corresponding to the three air mounts 27, respectively.
In FIG. 2, the code | symbol 35 has shown the controller. The controller 35 inputs a signal from the tilt sensor 33 and separately feedback-controls each pressure regulator 31 so that the stage base 11 has a predetermined tilt. That is, when a control signal from the controller 35 is output to the pressure regulator 31, the pressure regulator 31 adjusts the pressure of air in the air mount 27 based on the control signal. Thereby, the pressing force with which the air mount 27 presses the stage base 11 changes, and the inclination of the stage base 11 is adjusted.

  For example, when both sides of the stage base 11 are deformed as indicated by the broken line 37 as shown in FIG. 3, this deformation is detected by the inclination sensor 33 as an inclination with respect to the horizontal plane. The detected inclination is input to the controller 35. Based on this signal, the controller 35 feedback-controls the pressure regulator 31 so that the inclination of the signal input from the inclination sensor 33 becomes zero.

  In FIG. 3, since both sides of the stage base 11 are deformed downward, the pressure of air in the air mounts 27 on both sides of the stage base 11 is increased. Thereby, the pressing forces F1 and F2 with which the air mount 27 presses the stage base 11 are increased, and deformations on both sides of the stage base 11 are reduced. In this embodiment, strictly speaking, feedback control is performed so that the upper surface of the stage base 11 is parallel to the XY plane set on the wafer stage.

In the stage apparatus of this embodiment, an air mount 27 is disposed between the stage base 11 and the base 23, and the push of the air mount 27 is performed based on a signal from an inclination sensor 33 disposed on the upper surface of the stage base 11. Since the pressure is controlled so that the stage base 11 has a predetermined inclination, the deformation of the stage base 11 can be significantly reduced as compared with the conventional case.
Therefore, the deformation of the stage base 11 due to the movement of the sliders 17 and 21, the dead weight of the stage base 11, the deformation of the base 23, etc. can be eliminated. As a result, it is possible to reduce the possibility that the traveling performance of the sliders 17 and 21 deteriorates or the apparatus is damaged.

  Further, in this embodiment, since the three portions of the stage base 11 are supported in a triangular shape by the support member 25, the level adjustment of the stage base 11 becomes easy. Since the three air mounts 27 are arranged in an inverted triangle shape with respect to the three support members 25, even when the stage base 11 is supported in a triangular shape by the support member 25, the support member 25 is arranged. It is possible to effectively prevent the both sides of the stage base 11 that is not present from being bent and deformed.

Further, since the inclination sensors 33 are arranged in the vicinity of the positions corresponding to the three air mounts 27, the control by the controller 35 can be facilitated.
(Second Embodiment)
FIG. 4 shows a second embodiment of the stage apparatus of the present invention.
In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In this embodiment, a voice coil motor (VCM) 41 is disposed between the stage base 11 and the base 23 in place of the air mount 27.
The voice coil motor 41 has a pressing member 43 that is fixed to the lower surface of the stage base 11. The pressing member 43 has a recess 43a that opens downward, and a permanent magnet 45 is fixed to the inner surface of the recess 43a. An electromagnet 47 is disposed inside the permanent magnet 45. The lower end of the electromagnet 47 is fixed to the upper surface of the base 23. The electromagnet 47 is connected to a magnetic force regulator 49 that adjusts the current flowing through the electromagnet 47.

  In the voice coil motor 41, when the current flowing through the electromagnet 47 is increased by the magnetic force adjuster 49, the pressing force for pressing the pressing member 43 upward increases. Further, when the current flowing through the electromagnet 47 is decreased by the magnetic force adjuster 49, the pressing force that presses the pressing member 43 upward decreases. In addition, since the voice coil motor 41 and the magnetic force regulator 49 of this embodiment are well-known, detailed description is abbreviate | omitted.

  In this embodiment, the controller 35 inputs a signal from the tilt sensor 33 and separately controls the magnetic force adjusters 49 so that the stage base 11 has a predetermined tilt. That is, when the control signal from the controller 35 is output to the magnetic force adjuster 49, the magnetic force adjuster 49 adjusts the current flowing through the electromagnet 47 based on the control signal. Thereby, the pressing force with which the pressing member 43 of the voice coil motor 41 presses the stage base 11 changes, and the inclination of the stage base 11 is adjusted.

  For example, when both sides of the stage base 11 are deformed as indicated by a broken line 37 as shown in FIG. 3, this deformation is detected by the inclination sensor 33 as an inclination with respect to the horizontal plane. The detected inclination is input to the controller 35. Based on this signal, the controller 35 feedback-controls the magnetic force regulator 49 so that the inclination of the signal input from the inclination sensor 33 becomes zero.

In FIG. 3, since both sides of the stage base 11 are deformed downward, the current of the electromagnet 47 of the voice coil motor 41 on both sides of the stage base 11 is increased. As a result, the pressing force with which the pressing member 43 of the voice coil motor 41 presses the stage base 11 increases, and deformation on both sides of the stage base 11 is reduced.
Also in this embodiment, substantially the same effect as that of the first embodiment can be obtained.
(Embodiment of exposure apparatus)
FIG. 5 schematically shows an EUV exposure apparatus in which the stage apparatus of the above-described embodiment is arranged.

In this embodiment, EUV light is used as illumination light for exposure. The EUV light has a wavelength of 0.1 to 400 nm, and in this embodiment, a wavelength of about 1 to 50 nm is particularly preferable. The projection system uses the image optical system 101, and forms a reduced image of the pattern by the reticle 103 on the wafer 121.
The pattern irradiated on the wafer 121 is determined by the reflective reticle 103 disposed below the reticle stage 102 via the electrostatic chuck 104. The reflective reticle 103 is carried in and out by a vacuum robot (the vacuum robot is not shown). Further, the wafer 121 is disposed on the fine movement table 125 of the wafer stage 123 via an electrostatic chuck 127. Typically, exposure is done by step scanning.

  Since EUV light used as illumination light at the time of exposure has low permeability to the atmosphere, the light path through which the EUV light passes is surrounded by a vacuum chamber 106 that is kept in a vacuum using a suitable vacuum pump 107. EUV light is generated by a laser plasma X-ray source. The laser plasma X-ray source includes a laser source 108 (acting as an excitation light source) and a xenon gas supply device 109. The laser plasma X-ray source is surrounded by a vacuum chamber 110. EUV light generated by the laser plasma X-ray source passes through the window 111 of the vacuum chamber 110.

  The parabolic mirror 113 is disposed in the vicinity of the xenon gas discharge portion. The parabolic mirror 113 collects EUV light generated by the plasma. The parabolic mirror 113 constitutes a condensing optical system, and is arranged so that the focal position comes near the position where the xenon gas from the nozzle 112 is emitted. The EUV light is reflected by the multilayer film of the parabolic mirror 113 and reaches the condensing mirror 114 through the window 111 of the vacuum chamber 110. The condensing mirror 114 condenses and reflects EUV light to the reflective reticle 103. The EUV light is reflected by the condensing mirror 114 and illuminates a predetermined portion of the reticle 103. That is, the parabolic mirror 113 and the condensing mirror 114 constitute an illumination system of this apparatus.

The reticle 103 has a multilayer film that reflects EUV light and an absorber pattern layer for forming a pattern. The EUV light is “patterned” by being reflected by the reticle 103. The patterned EUV light reaches the wafer 121 through the image optical system 101.
The image optical system 101 of this embodiment includes four reflecting mirrors: a concave first mirror 115a, a convex second mirror 115b, a convex third mirror 115c, and a concave fourth mirror 115d. Each of the mirrors 115a to 115d is provided with a multilayer film that reflects EUV light.

The EUV light reflected by the reticle 103 is sequentially reflected from the first mirror 115a to the fourth mirror 115d to form a reduced image (for example, 1/4, 1/5, 1/6) of the reticle 103 pattern. . The image optical system 101 is telecentric on the image side (wafer 121 side).
The reticle 103 is supported at least in the XY plane by a movable reticle stage 102. The wafer 121 is preferably supported by a wafer stage 123 that is movable in the X, Y, and Z directions. In this embodiment, the wafer stage 123 has a fine movement table 125 arranged on a coarse movement stage 129, and the stage apparatus of the above-described embodiment is used for the coarse movement stage 129.

When exposing the die on the wafer 121, EUV light is irradiated onto a predetermined region of the reticle 103 by the illumination system, and the reticle 103 and the wafer 121 follow the reduction ratio of the image optical system 101 with respect to the image optical system 101. It moves at a predetermined speed. In this way, the reticle pattern is exposed to a predetermined exposure range (with respect to the die) on the wafer 121.
During exposure, the wafer 121 is desirably disposed behind the partition 116 so that the gas generated from the resist on the wafer 121 does not affect the mirrors 115a to 115d of the image optical system 101. The partition 116 has an opening 116 a through which EUV light is irradiated from the mirror 115 d onto the wafer 121. The space in the partition 116 is evacuated by a vacuum pump 117. In this manner, gaseous dust generated by irradiating the resist is prevented from adhering to the mirrors 115a to 115d or the reticle 103. Therefore, deterioration of these optical performances is prevented.

In the exposure apparatus of this embodiment, since the stage apparatus of the above-described embodiment is used for the coarse movement stage 129 of the wafer stage 123, the coarse movement is performed even when the vacuum chamber 106 (base 23) is deformed by evacuation. It is possible to prevent the stage base (11) of the stage 129 from being deformed. Therefore, the exposure accuracy can be improved by improving the positioning accuracy of the wafer 121.
(Supplementary items of the embodiment)
As mentioned above, although this invention was demonstrated by embodiment mentioned above, the technical scope of this invention is not limited to embodiment mentioned above, For example, the following forms may be sufficient.

(1) In the embodiment described above, an example in which the stage base 11 is pressed upward by the air mount 27 or the voice coil motor 41 has been described. However, the stage base 11 is directed upward and downward from both sides of the stage base 11. You may make it press.
(2) In the above embodiment, an example has been described in which supporting the stage base 11 in three positions by the support member 25, may be supported at four or more locations. Moreover, although the example which pressed the stage base 11 in three places by the air mount 27 or the voice coil motor 41 was demonstrated, you may make it press in four or more places.

(3) In the above-described embodiment, the example in which the three tilt sensors 33 are provided on the upper surface of the stage base 11 has been described. However, the tilt sensor 33 may be provided at four or more locations. Increasing the number of inclination sensors 33 can improve detection accuracy.
(4) In the above-described embodiment, an example in which the stage apparatus of the present invention is applied to an exposure apparatus has been described. However, it can be widely applied to a stage apparatus such as a machine tool.

(5) In the above-described embodiment, the example in which the air mount 27 or the voice coil motor 41 is used as the pressing means has been described. However, a pressing force such as air pressure and magnetic force can be widely used.
(6) In the above-described embodiment, the example in which the present invention is applied to the wafer stage of the exposure apparatus has been described. However, the present invention can be widely applied to a reticle stage and the like.
(7) In the above-described embodiment, an example in which the stage apparatus of the present invention is applied to an EUV exposure apparatus has been described. However, the present invention can be widely applied to an exposure apparatus such as a charged particle beam exposure apparatus.

It is explanatory drawing which shows 1st Embodiment of the stage apparatus of this invention. It is explanatory drawing which shows the cross section which follows the II-II line | wire of FIG. It is explanatory drawing which shows the state which the stage base of FIG. 2 deform | transformed. It is explanatory drawing which shows 2nd Embodiment of the stage apparatus of this invention. It is explanatory drawing which shows one Embodiment of the exposure apparatus of this invention.

Explanation of symbols

11: stage base, 13, 19: guide member, 17, 21: slider, 23: base, 25: support member, 27: air mount, 33: tilt sensor, 35: controller, 41: voice coil motor.

Claims (7)

In a stage apparatus that moves a stage by guiding a slider along a guide member provided on a stage base arranged on a base,
A support member for horizontally supporting the stage base, which is disposed at each vertex of the polygon in a plan view between the base and the stage base;
The stage base is provided in a plurality of positions on both sides of the stage base where the support member is not disposed at a position that does not overlap the apex in a plan view between the base and the stage base. Pressing means that can control the pressing force from the vertical direction,
Inclination detection means that is disposed in the vicinity of the position where the pressing means of the stage base is provided, and detects the inclination of the stage base with respect to the horizontal,
Control means for controlling the pressing force of the pressing means based on a signal from the inclination detecting means;
A stage apparatus characterized by comprising: The stage apparatus according to claim 1, wherein
The support member is arranged at each vertex of the triangle,
The stage device, wherein the pressing means is arranged at each vertex of an inverted triangle obtained by rotating the triangle by 180 degrees. The stage apparatus according to claim 1 or 2,
The stage device is characterized in that the support member is a jack screw that is screwed into a screw hole provided in the base and supports the stage base from below at the tip. The stage apparatus according to any one of claims 1 to 3 ,
The stage device characterized in that the pressing means can control the pressing force by a fluid pressure. The stage apparatus according to any one of claims 1 to 3 ,
The stage device characterized in that the pressing means can control the pressing force by magnetic force. The stage apparatus according to any one of claims 1 to 5 ,
The stage apparatus is characterized in that the stage base is disposed in a vacuum atmosphere. The stage according to any one of claims 1 to 6 , wherein said stage is an exposure apparatus that transfers a pattern formed on a reticle to a substrate via exposure light, and the stage or the stage apparatus that holds the substrate. An exposure apparatus comprising the apparatus.

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