JP2000243693A - Stage device and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stage device which is high in stability of stage, and can perform highly accurate positioning and shifting. SOLUTION: This is a stage device which is equipped with a stage shifting in noncontact on the shifting face made on a surface plate 11. A bearing assembly 18 is interposed between the bottom of the stage and the shifting face of the surface plate 11. The air bearing assembly 18 is equipped with an parallel board spring mechanism 21 and an actuator 22 which expands and shrinks in the direction of Z axis, and a controller 23 adjusts the attitude of the stage 15 itself so that the surface of a board 26 retained on the stage 15 may accord with the specified reference by controlling the operation of the actuator 22, based on the focus signal from a focus sensor 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage device for moving a moving object and an exposure apparatus having the stage device.

[0002]

2. Description of the Related Art For example, a photomask (or a reticle or the like) or a glass substrate (a reticle) is used in an exposure apparatus used for manufacturing a micro device such as a liquid crystal display, a semiconductor device, an imaging device (CCD or the like), or a thin film magnetic head. Alternatively, a mask stage or a substrate stage is used as a stage device for positioning a wafer or the like.

Recently, a scanning type exposure apparatus which sequentially transfers a mask pattern onto a substrate by synchronously scanning a mask and a substrate with respect to a projection optical system has been used. The stage device used in the above is also required to have a function of scanning the mask and the substrate at a constant speed with high accuracy.

FIG. 4 shows a schematic configuration of an exposure apparatus provided with a conventional stage apparatus. The exposure apparatus shown in FIG. 4 is a scanning projection exposure apparatus for manufacturing a liquid crystal display.

A guide beam 62 extending in the X-axis direction is provided on a surface plate 61 installed on the floor via a vibration isolator or the like, and a substrate stage 63 is provided so as to straddle the guide beam 62. ing. The substrate stage 63 is placed on the surface plate 61 in a non-contact manner by a plurality of air bearings 64A, and the guide beam 6 is moved by an air bearing 64B.
2 can be reciprocated in a non-contact manner.
The substrate stage 63 is driven by a driving device (such as a linear motor) not shown.

The number of air bearings 64A for supporting the substrate stage 63 on the surface plate 61 is generally four or three. However, in the case of four, it is difficult to adjust and one of them is floated. In the case of three, there is no such a disadvantage, but there is a disadvantage that the attitude stability during acceleration is slightly lowered.

On the substrate stage 63, a substrate holder 65 is placed via a plurality of actuators 65A which are displaced in the Z-axis direction (vertical direction). The substrate 66 to be exposed is fixed to the upper surface of the substrate holder 65 by vacuum suction.

A first column 72 is fixed on the surface plate 61, and a second column 73 is further fixed on the first column 72. A projection optical system 67 is fixed to the center of the first column 72. In the first column 72,
A mask holder 68 is provided above the projection optical system 67 via an air bearing or the like so as to be movable in the X-axis direction. The mask holder 68 is moved in the X direction by a stage device having a driving device such as a linear motor. Be moved. A mask 69 on which a fine pattern to be transferred is formed is detachably attached to the mask holder 68.

Illumination light from a light source 71 having a lamp or the like is guided by an illumination optical system 70 partially supported by a second column 73 to illuminate a mask 69 and to form a pattern formed on the mask 69. Is formed on the substrate 66 via the projection optical system 67. The illumination light is slit light elongated in the Y-axis direction, and the pattern on the mask 69 is transferred onto the substrate 66 by synchronously moving the mask 69 and the substrate 66 with respect to the slit light.

Incidentally, in order to form a fine pattern on the substrate 66 with high resolution, it is necessary to increase the numerical aperture (NA).
O. F) becomes shallow. For this reason, high precision and high rigidity are required for the stage device that moves the substrate 66 and the like and the surface plate 11 and the like that serve as a reference for the movement, which causes an increase in cost and weight.

From the viewpoints of improving such points and improving the exposure accuracy, during scanning exposure, the inclination of the surface (exposed surface) of the substrate 66 and the position in the Z-axis direction are detected, and the plurality of actuators 65A described above are operated. The whole or selective operation ensures that the surface of the substrate 66 is accurately aligned with the image plane of the projection optical system 67.

[0012]

However, according to the prior art, the actuator for adjusting the posture of the substrate is provided between the stage and the holder, and therefore, the dimension of the stage device in the Z-axis direction is large. Becomes, that is,
The dimensions from the surface of the surface plate to the surface of the holder are large, and the center of gravity is high, so that the stability is deteriorated and the motion performance of the stage is adversely affected.

In an exposure apparatus provided with a stage device for moving a mask or a substrate, if the stability of the stage is low, the exposure accuracy is reduced, and a high-quality micro device may not be manufactured. is there.

The present invention has been made in view of such problems of the prior art, and has as its object to provide a stage device having a high stage stability. Another object of the present invention is to provide an exposure apparatus capable of manufacturing a high-quality micro device.

[0015]

Means for Solving the Problems In the following description, in order to facilitate understanding, each constituent element of the present invention will be described with reference numerals shown in the drawings of the embodiments. The constituent elements of the invention are not limited by these reference numerals.

The stage device according to the present invention comprises a platen (1
In a stage apparatus provided with a stage (15) for moving a moving surface formed in 1) in a non-contact manner through a non-contact bearing (19), a displacement device (22) for displacing in a direction substantially orthogonal to the moving surface. Is connected to at least one of the stage (15) and the non-contact bearing (19).

In this case, the stage (15)
Measuring device (3) for measuring at least one of the inclination and the position of the moving object (26) held by
5) and independently controlling the displacement amount of the displacement device (22) based on the measurement result of the measurement device (35) such that the moving object (26) matches the predetermined reference. A control device (23) can be provided.

[0018] The displacement device may include a stage (15) and a non-contact bearing (19) so that a relative distance between the stage (15) and the non-contact bearing (19) can be changed while maintaining a relative posture. A support device (21) for connecting the contact bearings (19) to each other;
A combination of 5) and an actuator (22) for changing the relative distance between the non-contact bearing (19) can be adopted. In this case, as the supporting device, a parallel leaf spring mechanism (21) having a pair of leaf springs arranged substantially parallel to each other can be adopted.

According to the present invention, since the displacement device connected to at least one of the stage and the non-contact bearing is provided, the attitude of the stage itself can be controlled,
It is possible to provide a holder or the like for directly holding a moving object (substrate, mask, etc.) on the stage, or to use the stage itself as the holder, and to displace the holder as in the related art. Since the above device is not required, the height of the stage device can be reduced correspondingly. Therefore, the center of gravity of the stage device can be made lower than before, and the stability of the stage is high and the accuracy of positioning and movement can be improved.

The exposure apparatus according to the present invention is an exposure apparatus for exposing a substrate (26) through a mask (30) on which a pattern is formed, wherein at least the mask (30) and the substrate (26) are exposed. One is held on the stage (15) of the stage device according to the present invention. According to the exposure apparatus of the present invention including such a stage device, the stability of the stage device is high and the accuracy of positioning and movement is high, so that a high-precision, high-quality micro device can be manufactured. .

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing the overall schematic configuration of an exposure apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a stage apparatus employed in the exposure apparatus, and FIG. FIG.

The exposure apparatus according to the present embodiment is a scan type projection exposure apparatus that performs a plurality of scanning exposures while connecting screens in order to manufacture a liquid crystal display.

In FIG. 1, reference numeral 11 denotes a surface plate made of a highly rigid member such as stone, ceramics or iron.
1 is a vibration isolator 1 such as a piezo damper or a pneumatic damper
It is installed on the floor surface 13 through 2. A guide beam 14 extending in the X-axis direction (a direction orthogonal to the paper surface of FIG. 1) is provided on the surface plate 11, and a substrate stage 15 is provided above the guide beam 14.

As shown in FIG. 2, the guide beam 14 is supported on the surface plate 11 through a plurality of (three in this embodiment) air bearings 16A in a non-contact manner. It is configured to be movable along a guide rail 17 integrally mounted on the surface plate 11 so as to extend in the axial direction (the left-right direction along the plane of FIG. 1). A plurality of (four in this embodiment) air bearings 16B are also provided on the sliding portion of the guide beam 14 with respect to the guide rail 17.
By being interposed, it is possible to move in a non-contact manner. The guide beam 14 is driven by a driving device including a linear motor (not shown).

The substrate stage 15 is mounted on the surface plate 11 by a plurality (four in this embodiment) of air bearing assemblies 18 in a non-contact manner in the Z-axis direction (vertical direction along the plane of FIG. 1). And guide beam 14
Can be reciprocated in the X-axis direction in a non-contact manner along. The substrate stage 15 is driven by a driving device including a linear motor (not shown). In this embodiment, the number of the air bearing assemblies 18 for supporting the substrate stage 15 on the surface plate 11 is four in this embodiment so as to be symmetrical in consideration of stability. 2 on one side with respect to the guide beam 14 taking into account the advantages
And one on the other side, for a total of three.

The air bearing assembly 18 is shown in FIG.
As best shown in FIG.
A base bearing 19 which is a non-contact bearing such as an air bearing for floating on the surface plate 11 by floating in the axial direction, and an air bearing for allowing non-contact movement along the guide beam 14. , A parallel leaf spring mechanism 21, and a linear motion actuator 22.

The yaw bearing 20 includes an air pad portion 20 A facing the side surface of the guide beam 14 and the substrate stage 15.
The base bearing 19 includes an air pad 19A facing the surface (moving surface) of the surface plate 11 and an air pad 19A standing up against the surface. It is also a member formed in a substantially L-shape so as to have the provided standing portion 19B.

The base bearing 19 is connected via a parallel leaf spring mechanism 21 having a pair of parallelly disposed leaf springs.
It is attached to a yaw bearing 20. The parallel leaf spring mechanism 21 includes a surface facing the surface plate 11 of the air pad portion 19 </ b> A of the base bearing 19 and a yaw bearing 2.
0 predetermined reference plane (in this embodiment, the mounting portion 20B
Can be elastically deformed in the Z-axis direction while always maintaining the parallel state of the substrate stage 15).
It has a structure having high rigidity in other X-axis and Y-axis directions.

Between the base bearing 19 and the yaw bearing 20, there is interposed an actuator 22 made of, for example, a piezo element which expands and contracts in the Z-axis direction and displaces their relative positions. This actuator 22
In this embodiment, both ends in the expansion / contraction direction (Z-axis direction) are fixed to the air pad portion 19A of the base bearing 19 and the mounting portion 20B of the yaw bearing 20, respectively, but only one of them is fixed. Is also good. The operation of the actuator 22 is controlled based on a control signal from the control device 23.

Parallel leaf spring mechanism 21 and actuator 22
Thereby, the relative position between the surface of the base pad 19 facing the air pad 19A with respect to the surface plate 11 and the mounting surface of the mounting portion 20B of the yaw bearing 20 with respect to the lower surface of the substrate stage 15 can be freely adjusted while maintaining the parallel state. It can be varied and can be done independently for each air bearing assembly 18. Thereby, the posture of the substrate stage 15 (the position of the substrate stage 15 in the Z-axis direction and the inclination with respect to a plane orthogonal to the Z-axis) can be arbitrarily changed and adjusted. The actuator 22 is not limited to a piezo element (piezoelectric element), but may be a voice coil motor (VCM), a mechanical means such as a ball screw and a motor, or an actuator utilizing pneumatic or hydraulic pressure. .

A substrate holder 24 having a groove 25 for vacuum suction is directly mounted and fixed on the substrate stage 15, and a substrate 26 (for example, a glass plate) as an exposure target (moving target) is mounted on the substrate holder 24. By being vacuum-sucked through the groove 25, it is corrected and fixed to the upper surface of the substrate holder 24.

As shown in FIG. 1, a first column 27 is fixed on the surface plate 11, and a second column 28 is further fixed on the first column 27. A projection optical system 29 is fixed to the center of the first column 27.
Further, a stage device 31 for moving the mask 30 is attached to the first column 27 above the projection optical system 29. The stage device 31 includes a driving device such as a linear motor, an air bearing, and the like, and is a stage device that moves the mask holder 32 holding the mask 30 by suction in the X-axis direction. In the mask holder 32,
The mask 30 on which the fine pattern to be transferred is formed is exchangeably sucked and held.

Illumination light from a light source 33 having a lamp or the like is guided by an illumination optical system 34 partially supported by the second column 28 to illuminate the mask 30. Thereby, an image of the pattern formed on the mask 30 is formed on the substrate 26 via the projection optical system 29. The illumination light is shaped into a slit shape elongated in the Y-axis direction by the illumination optical system 34. By moving the mask 30 and the substrate 26 in synchronization with the slit light, the pattern on the mask 30 Is transferred to

The above-described air bearings 16A, 16A,
16B, 19 (19A) and 20 (20A) appropriately combine a repulsion force caused by the ejection of air and a suction force caused by suction of air. It is a non-contact bearing that realizes a state of facing with a small gap.

That is, a plurality of positive pressure grooves (or holes) and a plurality of negative pressure grooves (or holes) are formed in the air bearing (air pad portion), and the positive pressure groove is a positive pressure supply source (not shown). (Compressed air supply device), and when the positive pressure supply source is operated, compressed air is supplied to the positive pressure groove, and the air pad is separated (floating) from the moving surface (sliding surface). Energize in the direction to cause. On the other hand, the negative pressure groove is connected to a negative pressure supply source (vacuum suction device) (not shown). When the negative pressure supply source is operated, the air in the negative pressure groove is suctioned by vacuum, and the air pad portion is removed. It is urged in the direction to approach the moving surface.

The positive pressure supply source and the negative pressure supply source are appropriately adjusted and controlled to maintain the repulsive force of the positive pressure groove and the suction force of the negative pressure groove at a predetermined value, so that the moving surface corresponding to the air pad portion can be adjusted. Will face each other while maintaining a certain gap. In this embodiment, this gap was set to about 10 μm.

The first column 27 is separated in the Y-axis direction with the projection optical system 29 interposed therebetween, and detects the position in the Z-axis direction of the surface of the substrate 26 suction-held by the substrate holder 24 on the substrate stage 15. A pair of focus sensors 35 are mounted. The focus sensor 35 is a sensor that detects the position of the surface of the substrate 26 in the Z-axis direction by receiving the detection light emitted from one of the light transmitting units by the other light receiving unit. 23. By analyzing the focus signals from the pair of focus sensors 35, the inclination of the surface of the substrate 26 on the substrate stage 15 with respect to the horizontal plane (XY plane) and the position in the Z-axis direction can be detected.

A plurality of the focus sensors 35 may be further arranged in the Y-axis direction, or a similar focus sensor may be provided separately from the focus sensors 35 in the X-axis direction. it can.

At the time of scanning exposure, the substrate stage 15 is moved in the X-axis direction in synchronization with the movement of the mask 30 by the mask stage device 31, and based on a focus signal detected by each focus sensor 35 detected at this time. ,
The controller 23 operates the actuators 22 for each of the air bearing assemblies 18 independently so that the surface of the substrate 26 can be adjusted in real time so as to match a predetermined reference (for example, an image plane formed by the projection optical system 29). To control.

In the above-described embodiment, the actuator 22 of the air bearing assembly 18 is controlled to operate in real time based on the focus signal from the focus sensor 35 during scanning exposure. Preliminary scanning is performed while detecting signals, surface information relating to the attitude of the surface of the substrate 26 is collected and stored in a storage device, and based on this surface information during the subsequent main scanning, the air bearing assembly is used. The operation of the 18 actuators 22 may be controlled.

Also, the focus sensor 35 is provided only in the Y-axis direction as in this embodiment, and when performing posture control in real time, the two Air bearing assembly 1
The actuators 22 for 8 are operated with the same control amount as each other, and similarly, the actuators 22 for the two air bearing assemblies 18 on the other side are also operated with the same control amount. That is, only the attitude in the Y-axis direction of the surface of the substrate 26 is controlled, and the attitude in the X-axis direction is not controlled.
On the other hand, when a similar focus sensor is provided at a distance in the X-axis direction or when the main scanning is performed after the preliminary scanning is performed, the inclination of the surface of the substrate 26 in the X-axis direction can be determined. It is also possible to control the attitude in the direction along the axial direction.

Here, a fine pattern is formed on the substrate 2 at a high resolution.
In order to form an image on the C.6, it is necessary to increase the numerical aperture (NA), and accordingly, the depth of focus (DO.
F) becomes shallower, so that the stage device for moving the substrate 26 and the surface plate 11 as a reference for the movement thereof have high precision,
High rigidity is required, which causes an increase in cost and weight.

According to the present embodiment, however, the actuator 22 of each air bearing assembly 18 is selectively expanded and contracted based on the focus signal detected by the focus sensor 35, so that the actuator 22 is held on the substrate stage 15. Since the posture of the surface of the substrate 26 is adjusted to match a predetermined reference, for example, as shown in FIG. 3, when the surface (moving surface) of the surface plate 11 is not exactly flat. Even if there is, the surface of the substrate 26 can be in a state in which it matches a predetermined reference plane. Therefore, accurate exposure processing can be performed while achieving cost reduction and weight reduction of the surface plate and the like.

Further, since the posture of the substrate stage 15 is adjusted by operating the actuator 22 of the air bearing assembly 18, the substrate holder 24 for holding the substrate 26 on the substrate stage 15 can be directly adjusted. Since the position of the substrate stage 15 can be adjusted to adjust the surface of the substrate 26 to a predetermined standard, the position of the substrate holder can be adjusted by adjusting the position of the substrate holder as in the related art. Since it is not necessary to interpose an actuator or the like between the substrate stage and the substrate holder as compared with the one that adjusts the posture,
The height of the stage device can be reduced. Therefore,
The center of gravity of the stage device can be lower than before,
The stability of the stage is high, and the accuracy of positioning and movement can be improved.

According to the exposure apparatus of the present embodiment provided with such a stage device, the stage device for moving the substrate 26 has high stability and high positioning and moving accuracy. Liquid crystal displays can be manufactured. Such a liquid crystal display has a step of designing the function and performance of a device, a step of manufacturing a mask based on the design step, a step of manufacturing a glass substrate, and a step of forming a mask pattern by the exposure apparatus of the above-described embodiment. It is manufactured through a step of exposing and transferring to a device, a step of assembling a device (including a bonding process), an inspection step, and the like.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, in the above-described embodiment, the position of the surface of the substrate 26 in the Z-axis direction is detected by the focus sensor 35, but in addition to this, the lower surface of the mask 30 (pattern forming surface) ) Is provided, and the controller 23 controls the air bearing assembly 1 by taking into account the focus signals from these focus sensors.
The operation of the actuator 22 may be controlled.

In the above-described embodiment, the air bearing is a combination of the suction force by the negative pressure and the repulsion force by the positive pressure. However, the present invention is not limited to this. And a combination of a suction force by a negative pressure and a repulsion force by a magnetic force. Also, a combination of a magnetic attraction force and a magnetic repulsion force may be used. In addition, a gravity, a biasing force of a spring, and the above-described positive or negative pressure, magnetic force, or the like may be appropriately combined.

Further, in the above embodiment, the substrate 2
The case where the stage device of the present invention is applied only to the stage device that moves the mask 6 has been described.
Can be similarly applied to a stage device that moves the. As the linear motor that drives the substrate stage 15 in the X-axis direction and the Y-axis direction, either a moving coil type or a moving magnet type may be used. Further, a planar motor may be used as a driving device of the substrate stage.

The present invention can be applied not only to a projection exposure apparatus for manufacturing a liquid crystal display, but also to any type of exposure apparatus. For example, when the reticle and the wafer are stationary, the entire surface of the reticle pattern is exposed. Up-repeat type reduction projection type exposure apparatus (stepper) for irradiating exposure light for exposure onto a single area (shot area) on a wafer on which a reticle pattern is to be transferred, and a reticle And the wafer are moved synchronously to scan and illuminate with rectangular or other slit light to sequentially expose the shot areas on the wafer, and sequentially move the wafer to repeat the scanning and exposure for other shot areas The present invention can be similarly applied to a step-and-scan type reduction projection scanning exposure apparatus (scanning stepper).

[0051] As the exposure illumination light, emission lines (e.g., g-line, i-line), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), _{F 2} laser (wavelength 157 nm), Ar
Either _two lasers (having a wavelength of 126 nm) or harmonics such as a YAG laser may be used. In addition, a single-wavelength laser in the infrared or visible region oscillated from a DFB semiconductor laser or a fiber laser is amplified by, for example, a fiber amplifier doped with erbium (or both erbium and ytterbium) as exposure illumination light. Alternatively, a harmonic converted to ultraviolet light using a nonlinear optical crystal may be used.

Further, for example, EUV (Extreme) having an oscillation spectrum at 5 to 15 nm (soft X-ray region)
Ultra Violet) light as exposure illumination light,
The illumination area on the reflection mask is defined in the shape of a circular arc slit, and a reduction projection optical system including only a plurality of reflection optical elements (mirrors) is provided. The present invention can also be applied to an EUV exposure apparatus or the like that transfers a pattern of a reflection mask onto a wafer by synchronously moving the wafer and the wafer.

In addition, a liquid crystal display, a semiconductor device,
Not only projection exposure equipment used to manufacture thin-film magnetic heads and imaging devices (such as CCDs), but also projection exposure equipment that transfers circuit patterns to glass substrates or silicon wafers to manufacture reticles and masks. The invention can be applied.

[0054]

According to the present invention, there is an effect that a stage device having high stability of the stage and capable of performing high-precision positioning and movement can be provided. Further, there is an effect that an exposure apparatus capable of manufacturing a high-quality micro device can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an overall schematic configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a stage device according to the embodiment of the present invention.

FIG. 3 is a front view showing the configuration of the stage device according to the embodiment of the present invention.

FIG. 4 is a front view showing a configuration of a conventional exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Surface plate 14 ... Guide beam 15 ... Substrate stage 18 ... Air bearing assembly 19 ... Base bearing 20 ... Yaw bearing 21 ... Parallel leaf spring mechanism 22 ... Actuator 23 ... Control device 24 ... Substrate holder 26 ... Substrate 29 ... Projection optics System 30 Mask 33 Light source 34 Illumination optical system 35 Focus sensor

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) H01L 21/30 515G F-term (Reference) 2F078 CA08 CB02 CB13 CC01 5F031 CA05 CA07 HA53 HA57 JA22 JA30 LA02 LA08 LA10 MA27 5F046 AA23 BA04 BA05 CA04 CC01 CC02 CC03 CC05 CC08 CC09 CC10 CC13 CC18 DA05 DB05 DC10

Claims (5)

[Claims] 1. A stage device comprising a stage that moves a moving surface formed on a surface plate in a non-contact manner through a non-contact bearing, wherein a displacement device that displaces in a direction substantially orthogonal to the moving surface is provided with the stage. A stage device connected to at least one of the non-contact bearings. 2. A measuring device for measuring at least one of an inclination and a position of a moving object held on the stage with respect to a predetermined reference, and the moving object is determined based on a measurement result of the measuring device. 2. The stage device according to claim 1, further comprising: a control device that independently controls a displacement amount of the displacement device so as to match the displacement. 3. A supporting device for coupling the stage and the non-contact bearing to each other so that a relative distance can be changed while maintaining a relative posture between the stage and the non-contact bearing. The stage apparatus according to claim 2, further comprising an actuator for changing a relative distance between the stage and the non-contact bearing. 4. The stage device according to claim 3, wherein said support device is a parallel leaf spring mechanism having a pair of leaf springs arranged substantially parallel to each other. 5. An exposure apparatus for exposing a substrate through a mask on which a pattern is formed, wherein at least one of the mask and the substrate is exposed.
An exposure apparatus characterized in that the exposure apparatus is held on the stage of the stage apparatus according to any one of (1) to (4).