JP2004140291A - Stage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve accuracy in stage control since, in a conventional stage device, there is a problem that heightening of accuracy of stage control is prevented. <P>SOLUTION: This stage device comprises a stage 5 moving on a reference structure 4, an actuator containing stators 1, 1' and a moving member 2 coupled with the stage 5, a support 18 which supports a measuring mirror above the moving member 2 so as to allow movement of the measuring mirror and the moving member 2 while its end is coupled to the reference structure 4, and a vibration control member which supports a center or its neighborhood of the support 18 so as to suppress the vibration of the measuring mirror. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to a stage apparatus, and more particularly, to exposing a workpiece using the same.
[0002]
[Prior art]
2. Description of the Related Art In an exposure apparatus used for manufacturing a semiconductor device or the like, an original (eg, a reticle, a mask) is projected through a projection optical system onto a plurality of exposure regions on a substrate while a substrate (eg, a wafer, a glass substrate, etc.) is moved stepwise. , Etc.), there is a step-and-repeat type exposure apparatus (hereinafter, referred to as “stepper”) for sequentially exposing the pattern. Further, there is a step-and-scan type exposure apparatus (hereinafter, referred to as “scanner”) that repeats exposure and transfer to a plurality of regions on a substrate by repeating step movement and scanning exposure. In particular, since the scanner uses a portion of the projection optical system relatively close to the optical axis, which is limited by the slit, it is possible to expose a fine pattern with higher precision and a wider angle of view.
[0003]
These exposure apparatuses have a stage device (for example, a wafer stage, a reticle stage, etc.) for moving and positioning a wafer or a reticle at a high speed. The weight and vibration characteristics of the movable part of the stage device greatly affect the performance of the stage such as speeding up and positioning accuracy.
[0004]
In a conventional stage device, a bar mirror having a length corresponding to a stage stroke is mounted on a movable portion of the stage in order to perform position measurement by a laser interferometer. However, the conventional stage device has a problem that the weight of the stage movable unit increases and the natural frequency decreases by disposing the long mirror on the stage movable unit. Such a problem has caused deterioration of control performance during exposure.
[0005]
On the other hand, the stage device disclosed in Japanese Patent Application Laid-Open No. 2001-345254 does not arrange a long mirror on the stage movable portion, but arranges a mirror on a member other than the stage, thereby reducing the weight of the stage. The vibration characteristics are improved.
[0006]
[Patent Document 1]
JP 2001-345254 A [Problems to be Solved by the Invention]
However, in the conventional stage device, since the mirror and its support are long, there is a limitation in increasing the natural frequency, and there is a problem that further high precision of stage control is hindered.
[0007]
The present invention has been made in view of the above problems, and has as its object to improve the accuracy of stage control.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to a stage device, a stage that moves on a reference structure, an actuator having a stator and a mover connected to the stage, a measurement mirror, A support for supporting the measurement mirror above the mover so as to allow the mover to move, the support having an end connected to the reference structure, and the measurement mirror And a vibration damping member that supports the central portion of the support or its vicinity so as to suppress the vibration of the support.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0010]
(1st Embodiment)
As an example of the stage device according to the first preferred embodiment of the present invention, a stage device that positions a movable stage on a reference structure by a laser interferometer will be described.
[0011]
FIG. 1 is a view showing a stage device according to a preferred first embodiment of the present invention. Here, a reticle scan stage having three degrees of freedom in XYθ axes will be described as an example of the stage device. As shown in FIG. 1, a plane guide surface 6 serving as a reference is provided on the reference structure 4. The stage guide 3 is mounted on the plane guide surface 6. The top plate 5 is supported by the hydrostatic bearing in a non-contact manner with respect to the stage guide 3, and is movable in the XYθ direction (plane direction). The left and right movers 2 are rigidly connected to the top plate 5. Electromagnetic actuators for driving the mover 2 in a long stroke in the Y direction and a short stroke in the X direction are provided on both sides of the top plate 5, respectively. The electromagnetic actuator has a mover 2 and left and right stators 1 and 1 'which are separated and independent from each other. The left and right stators 1 and 1 'are supported by a static pressure bearing in a non-contact manner with respect to the plane guide surface 6, and are movable in the XYθ direction (plane direction). Further, the stators 1 and 1 'have a predetermined weight and have a function of a "reaction counter" described later. The mover 2 is provided with two left and right movable part Y magnets 10 and two left and right movable part X magnets 11. Inside the left and right stators 1 and 1 ′, an X-axis linear motor single-phase coil 12 and a Y-axis linear motor multi-phase coil 13 in which a plurality of coils are arranged in the Y direction are arranged. 13 is switched to move the X axis-Yθ axis.
[0012]
The position information of the top plate 5 includes a laser head 16, a Y-axis measurement mirror 17, an X-axis measurement bar mirror 32 (see FIG. 2), two left and right Y-axis measurement interferometers 19, and two front and rear X-axes. The measurement is performed by a laser interferometer including the measurement interferometers 22 and 22 ′. As shown in FIG. 1, the Y-axis positions of the stators 1 and 1 ′ are measured by two left and right stator Y-axis measurement interferometers 21. The X-axis position of the top 5 is such that the X-axis measurement interferometers 22 and 22 ′ mounted on the top 5 are irradiated with laser light from the Y direction, and the measurement light is reflected or polarized in the X-axis direction. Thereafter, the light is irradiated onto the X-axis measurement bar mirror 32 (see FIG. 2), and is measured by being received by the receiver 20.
[0013]
As shown in FIG. 2, the stage device according to the present embodiment includes a support body 51 that supports the X-axis measurement bar mirror 32, and a vibration damping member 50 that suppresses vibration of the X-axis measurement bar mirror 32. The support body 51 includes, for example, the bar mirror support body 18 and the fixing member 34 that fixes both ends or the vicinity of both ends to the reference structure 4. The vibration damping member 50 includes a reinforcing member support column 31 disposed on the reference structure 4, and a reinforcing member 30 provided at the tip of the reinforcing member support column 31 and connected to the bar mirror support 18. The vibration damping member 50 supports the center portion or the vicinity of the bar mirror support 18 so as to suppress the vibration of the X-axis measurement bar mirror 32 in the measurement direction. Further, it is preferable that the reinforcing member support column 31 and the fixing member 34 are arranged on the same member (for example, on the reference structure 4).
[0014]
As shown in FIG. 2, the bar mirror support 18 supports the X-axis measurement bar mirror 32 above the mover 2 so as to allow the mover 2 to move. In this case, for example, the X-axis measurement interferometers 22 and 22 ′ (see FIG. 1) and the X-axis measurement bar mirror 32 can be configured so that the interval is a predetermined interval. Therefore, the interval between the X-axis measurement interferometers 22 and 22 'and the X-axis measurement bar mirror 32 can be reduced to a distance where they do not contact each other. As shown in FIG. 1, the reinforcing member 30 is provided above the stators 1 and 1 'provided on the left and right of the top plate 5 constituting the stage. In FIG. 1, the reinforcing member 30 is provided on the stator 1 side, but the present invention is not limited to this. For example, the reinforcing member 30 may be provided on the stator 1 'side in the same manner. As shown in FIG. 3, an elastic material (for example, a damping rubber) 33 may be disposed between the bar mirror support 18 and the reinforcing member 30 constituting the damping member 50.
[0015]
In FIG. 2, the reinforcing member 30 is illustrated as a plate, but the present invention is not limited to this. For example, the reinforcing plate 30 may be formed of a member other than the plate, such as a bar. Further, in FIG. 2, the damping member 50 is configured by the reinforcing member support column 31 and the reinforcing plate 30, but the present invention is not limited to this. May be integrally formed. Further, the damping member 50 may be configured by attaching a mass damper to the mirror support 18.
[0016]
According to the present embodiment, since the reinforcing member support column 31 and the fixing member 34 are mounted on the same member (for example, the reference structure 4), other components (for example, the reference structure There is an advantage that vibration does not leak to the components other than (4). This also has the advantage that external vibrations are less likely to enter. As described above, according to the present embodiment, the vibration that affects the measurement accuracy and the stage performance is suppressed, and the overlay accuracy, the line width accuracy, the throughput, and the like can be improved.
[0017]
Next, a case will be described in which the XY stage included in the stage device according to the preferred embodiment of the present embodiment is used as a reticle stage and / or a wafer stage of an exposure apparatus.
[0018]
An original (for example, a reticle, a mask, etc.) and a substrate (for example, a wafer, a glass substrate, etc.) are placed on a top plate 5 (XY stage) of the movable unit. Similar to the top plate 5, the sub-top plate 8 is supported by the hydrostatic bearing in a non-contact manner with respect to the stage guide 3, and is movable in the XYθ directions. The mover 7 is rigidly connected to both sides of the sub top plate 8. Electromagnetic actuators for driving the mover 7 in a long stroke in the Y direction and a short stroke in the X direction are provided on both sides of the sub top plate 8. The left and right movers 7 are attached with two left and right movable part Y magnets and two left and right movable part X magnets. Note that the left and right stators 1 and 1 ′ are used in common with the stator that drives the top plate 5.
[0019]
The position information of the sub-top 8 is measured by a laser interferometer including two left and right Y-axis measurement interferometers 23 and the like. An electromagnetic actuator capable of generating a driving force without contact is provided between the top plate 5 and the sub-top plate 8. The two left and right coils 25 are attached to the sub top plate 8. The top plate 5 is provided with a magnet. Between the top plate 5 and the sub-top plate 8, a mounting 28 such as wiring and piping is connected. A flat cable, a flat tube type, and the like are connected between the mover 7 and the reference platen 4. These move on the plane 6 with the movement of the mover 7.
[0020]
The mover 7 is moved left and right with the mover 2 in a state where an original plate 24 (for example, a reticle, a mask, etc.) and a substrate (for example, a wafer, a glass substrate, etc.) are placed on a top plate 5 (XY stage). Move in the XYθ direction by the driving force from the electromagnetic actuator having the stators 1 and 1 ′. The left and right stators 1 and 1 'receive a driving reaction force of a force acting when moving the entire movable part including the movable element 7. The left and right stators 1 and 1 'move on the planar guide surface 6 by the driving reaction force. As the left and right stators 1 and 1 'move on the planar guide surface 6, the left and right stators 1 and 1' serve as a "reaction counter". That is, in the present embodiment, for example, when the entire movable portion including the mover 7 moves in the + Y direction, the left and right stators 1 and 1 ′ receive a driving reaction force in the −Y direction and move in the −Y direction. Can be.
[0021]
In the present embodiment, two left and right Y-axis position control linear motors 14 are disposed on the reference structure 4 so as to push back the left and right stators 1 and 1 ′ that have moved a predetermined distance or more in the Y-axis direction. ing. Similarly, four X-axis position control linear motors 15 are arranged on the reference structure 4 so as to push back the stators 1 and 1 'that have moved a predetermined distance or more in the X-axis direction. As a result, when the movable portion moves over a predetermined distance, the stators 1 and 1 'also move over a predetermined distance. However, the stators 1 and 1' are moved by the Y-axis position control linear motor 14 and the X-axis position control linear motor 15, 1, 1 'can be controlled to be at a predetermined position. Further, when the positions of the stators 1 and 1 'are displaced due to the influence of resistance, friction and the like, the linear motor 14 for controlling the Y-axis position and the X-axis By using the linear motor 15, the positions of the stators 1, 1 'can be corrected.
[0022]
Next, a case where the stage device according to the present embodiment is used for a scanner will be described.
[0023]
When performing a scanning operation, the top plate 5 is accelerated to a predetermined speed by an electromagnetic force acting between the left and right movers 2 and the stators 1 and 1 'during acceleration. The stage device according to the present embodiment controls the current of the polyphase coil 13 so that when the movement of the top 5 enters the constant velocity region, the electromagnetic force acting on the mover 2 of the top 5 in the Y direction is not generated. I do. In this case, the control of the top plate 5 in the yθ direction is performed by controlling the electromagnetic force between the two single-phase coils and the magnet. The control of the top plate 5 in the X direction is performed by a long single-phase coil 12. The sub-top 8 is controlled by an electromagnetic force acting between the left and right movers 7 and the stators 1 and 1 'both at constant speed and during acceleration / deceleration. Since the top 5 and the sub-top 8 are measured by an interferometer, they can be positioned independently. Therefore, the top plate 5 may be precisely positioned so as to satisfy the exposure accuracy, and the sub-top plate 8 may be positioned so as not to cause mechanical interference.
[0024]
The stage device according to the present embodiment exposes a reticle and a wafer while performing synchronous scanning together, performs exposure transfer of a reticle pattern to one shot area of the wafer, and moves the wafer stepwise to a plurality of shot areas. It can be suitably used for a “scanner” for arranging and transferring patterns. Note that the present invention is not limited to application to a “scanner”, but can also be applied to a “stepper” in which a wafer stage moves at high speed.
[0025]
As described above, according to the present embodiment, the natural frequency of the stage movable section can be increased by arranging the bar mirror elongated in the stroke direction of the stage outside the stage. Further, by attaching the vibration damping member to the mirror support member, it is possible to suppress the vibration of the mirror itself, which is a reference for measurement. This enables faster and more accurate positioning. In addition, by supporting the measurement mirror above the mover to allow the mover to move, the distance between the interferometer and the mirror can be reduced, reducing measurement errors due to air fluctuations in the measurement path. can do.
[0026]
As described above, control accuracy during exposure of the stage is improved, and image performance, overlay accuracy, and the like can be improved. In addition, the vibration characteristics of the stage during exposure can be improved, and measurement errors of the interferometer due to air fluctuations can be reduced, so that overlay accuracy, line width accuracy, and the like can be improved. Furthermore, since the stage device is configured as described above, the deterioration of the positioning accuracy is reduced, so that the moving speed of the stage is increased and the throughput is improved.
[0027]
(Exposure equipment)
FIG. 4 is a schematic diagram showing the configuration of an exposure apparatus provided with the stage device of the present invention. In FIG. 4, light emitted from an illumination optical system 3001 is irradiated onto a reticle 3002 as an original. The reticle 3002 is held on a reticle stage 3003, and the pattern of the reticle 3002 is reduced and projected at the magnification of the reduction projection lens 3004 to form a reticle pattern image on its image plane. The image plane of the reduction projection lens 3004 is perpendicular to the Z direction. A resist is applied to the surface of the substrate 3005 which is a sample to be exposed, and shots formed in the exposure step are arranged. The substrate 3005 to be controlled is placed on the top plate 5 (XY stage). On the top plate 5 (XY stage), a chuck for fixing the substrate 3005, an XY stage as a driver that can move horizontally in the X-axis direction and the Y-axis direction, and the like are provided.
[0028]
(Embodiment)
Examples of embodiments according to the present invention are listed below.
[0029]
[Embodiment 1] A stage moving on a reference structure,
An actuator having a stator and a mover coupled to the stage,
A measuring mirror,
A support that supports the measurement mirror above the mover so as to allow the mover to move, and a support whose end is connected to the reference structure,
A vibration damping member that supports the central portion or the vicinity thereof so as to suppress the vibration of the measurement mirror,
A stage device comprising:
[0030]
[Embodiment 2] The vibration damping member includes: a vibration damping member supporting portion disposed on the reference structure; and a reinforcing member provided at a tip of the vibration damping member supporting portion and connected to the support. The stage device according to the first embodiment, comprising:
[0031]
[Embodiment 3] The stage device according to Embodiment 2, wherein an elastic member is provided between the reinforcing member and the mirror holding member.
[0032]
[Embodiment 4] The stage device according to Embodiment 3, wherein the elastic member is rubber.
[0033]
[Embodiment 5] The stage apparatus according to Embodiment 1, wherein the support includes a fixing member for fixing both ends or near both ends to the reference structure.
[0034]
[Sixth Embodiment] The stage apparatus according to the first embodiment, wherein the fixing member and the vibration-damping member supporting portion are arranged on the same member.
[0035]
Embodiment 7 The stage apparatus according to Embodiment 6, wherein the same member is the reference structure.
[0036]
[Embodiment 8] An optical system for projecting exposure light applied to a pattern-formed original onto a substrate,
Holding the substrate or the original, a stage device having a stage movable on a reference structure,
With
The stage device,
A stage moving on the reference structure,
An actuator having a stator and a mover coupled to the stage,
A measuring mirror,
A support that supports the measurement mirror above the mover so as to allow the mover to move, and a support whose end is connected to the reference structure,
A vibration damping member that supports the central portion or the vicinity thereof so as to suppress the vibration of the measurement mirror,
An exposure apparatus comprising:
[0037]
【The invention's effect】
According to the present invention, for example, the accuracy of stage control can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a stage device according to a preferred embodiment of the present invention.
FIG. 2 is a perspective view of a vibration damping member.
FIG. 3 is a side view of the vibration damping member.
FIG. 4 is a schematic diagram illustrating a configuration of an exposure apparatus including a stage device of the present invention.
[Explanation of symbols]
1, 1 ': stator, 2: movable element, 3: stage guide, 4: reference structure, 5: top plate, 6: flat guide surface, 7: sub-top movable element, 8: sub-top plate, 9 : Mirror for sub-top measurement, 10: Y magnet for movable part, 11: X magnet for movable part, 12: Single-phase coil for X-axis linear motor, 13: Multi-phase coil for Y-axis linear motor, 14: Linear for Y-axis position control Motor: 15: Linear motor for X-axis position control, 16: Laser head, 17: Mirror for Y-axis measurement, 18: Bar mirror support for X-axis measurement, 19: Interferometer for Y-axis measurement, 20: Receiver, 21: Stator Y-axis measurement interferometer, 22, 22 ': X-axis measurement interferometer, 23: sub-top Y-axis measurement interferometer, 24: board, 25: single-phase linear motor coil, 26: single-phase linear Motor magnet, 27: flat cable, flat tube , 28: wiring, piping, 29: sub-top plate X-axis measurement interferometer, 30: reinforcing plate, 31: reinforcing member support column, 32: X-axis measurement bar mirror, 33: damping rubber, 34: fixing member , 50: damping member, support body 51

Claims (1)

A stage moving on the reference structure,
An actuator having a stator and a mover coupled to the stage,
A measuring mirror,
A support that supports the measurement mirror above the mover so as to allow the mover to move, and a support whose end is connected to the reference structure,
A vibration damping member that supports a central portion or the vicinity thereof so as to suppress vibration of the measurement mirror,
A stage device comprising:

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