JP2017151171A - Stage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stage device having a structure added with a mechanism of moving in a θ-direction without causing high center of gravity to adjust a posture in a θ-direction and conduct the position control of the stage with high accuracy.SOLUTION: A stage 1 is mounted on a X-direction slider 23 guided by a X-direction guide 21 disposed astride a pair of Y-direction sliders 33, 34 guided by a pair of Y-direction guides 31, 32 extending in a Y-direction in parallel, and can move in XY directions. One Y-direction slider 31 is connected to the X-direction guide 21 through a hinge 81. The X-direction guide 21, the X-direction slider 23 and the stage 1 are moved together in one body in a θ-direction by moving a pair of the Y-direction sliders 31, 32 to respectively reverse directions in a Y-direction. The other Y-direction guide 32 is a flat guide and the other Y-direction slider 34 is displaceable in a X-direction.SELECTED DRAWING: Figure 3

Description

  The invention of this application relates to a stage apparatus including a stage on which articles are arranged, and relates to a stage apparatus including a stage moving mechanism.

The placement of the article on the stage is often performed when various processes are performed on the article or when the article is inspected. At this time, in order to perform processing or inspect while appropriately changing the position of the article, an apparatus (stage apparatus) having a mechanism for moving the stage is often used.
For example, when manufacturing various electronic components, an exposure apparatus is used in a photolithography process in order to form a fine circuit on a wafer. The exposure apparatus includes a stage device having a stage on which a wafer is arranged, and exposes the wafer by irradiating the wafer on the stage with light of a circuit pattern. The moving mechanism in this type of stage apparatus is a mechanism that moves the stage in at least the XY directions (two directions orthogonal to each other).

FIG. 13 is a perspective view schematically showing a conventional stage apparatus. Stage devices having the above-described XY-direction moving mechanisms are roughly classified into a stack type and an H type.
As shown in FIG. 13A, the stack type has a structure in which the X-direction moving mechanism 2 is mounted (stacked) on the Y-direction moving mechanism 3, and the stage 1 is mounted on the X-direction moving mechanism 2. It has become. The X-direction moving mechanism 2 has an X-direction base board 201, on which a mechanism portion for movement in the X direction is fixed.
The Y direction moving mechanism 3 is a mechanism that moves the entire X direction moving mechanism 2 in the Y direction by moving the X direction base board 201 in the Y direction. When the X-direction moving mechanism 2 is operated, the stage 1 on the X-direction moving mechanism 2 is moved in the X direction, and when the Y-direction moving mechanism 3 is operated, the X-direction moving mechanism 2 and the stage 3 are integrally moved in the Y direction. ing. In this specification, it is needless to say that the “X direction” and the “Y direction” are for convenience and may be reversed.

  As shown in FIG. 13B, the stack type is provided with a single X-direction guide 21 so as to straddle the two Y-direction guides 31 and 32 extending in the Y direction in parallel. ing. Y direction sliders (not shown) are attached to both ends of the X direction guide 21 in the X direction, and the Y direction sliders 31 and 32 can be guided by the Y direction guides 31 and 32, respectively. 32. The stage 1 is placed on the X direction guide 21 in a state where it can be guided by the X direction guide 21. In FIG. 13B, when a Y-direction drive source (not shown) operates, the X-direction guide 21 moves on the Y-direction guides 31 and 32 in the Y direction. Then, when an X direction drive source (not shown) operates, the stage 1 moves in the X direction on the X direction guide 21.

  Comparing the above two types of stage apparatuses, the H type is superior to the stack type in terms of controlling the amount of movement and controlling the position after movement. Since the stack type has a structure in which the mechanisms in the X direction and the Y direction are simply stacked, the center of gravity inevitably increases. The center of gravity in this case is the center of gravity of the stage 1 that is the object to be moved. In the case of the stack type, it is difficult to sufficiently increase the positioning accuracy of the stage 1 because the rigidity of the fastening portion between the X direction moving mechanism 2 and the Y direction moving mechanism 3 cannot be sufficiently secured. Further, the high center of gravity means that the center of gravity of the object is located at a distance from the drive source of the Y-direction moving mechanism 3, and a relatively large moment is generated. For this reason, the operation tends to become unstable during acceleration and deceleration during movement, and the problem that vibration remains after the movement stops is likely to occur.

Further, in the case of the stack type, the problem of so-called Abbe error is easily manifested due to the high center of gravity. The Abbe error is an error that occurs due to the swinging of the stage such as pitching, rolling, and yawing during the movement because the driving source and the center of gravity of the stage 1 are separated from each other.
In the case of the H type, each of the above problems is small because the number of fastening points is small and the center of gravity is low as compared with the stack type.

Japanese Patent No. 5387760 JP 2014-6162 A Japanese Patent No. 4740605

  In the stage apparatus described above, it may be necessary to move the stage in the θ direction in addition to the XY direction. The movement in the θ direction is an operation of rotating the stage around an axis perpendicular to the plane to which the XY direction belongs. For example, in the example of the exposure apparatus described above, it may be necessary to move the stage in the θ direction in order to place the wafer placed on the stage in a predetermined posture with respect to the exposure optical system.

  When the θ-direction moving mechanism is mounted on the conventional stage apparatus, the θ-direction base board is provided between the X-direction moving mechanism 2 and the stage 1 for the stack type of FIG. A rotating mechanism including a motor is provided as a θ direction moving mechanism, and the stage 1 is mounted on the θ direction moving mechanism. 13 (2), a θ-direction base board is attached to the X-direction guide 21 in a state where it can be guided by the X-direction guide 21, and a θ-direction moving mechanism is provided on the θ-direction base board. , Stage 1 is mounted on it.

However, if the θ-direction moving mechanism is added as described above, the center of gravity increases by that amount, so the above problem becomes more serious. In the case of the H type, although the degree of seriousness is small compared to the stack type, problems of moment generation and Abbe error due to the high center of gravity cannot be avoided.
The invention of the present application has been made to solve such a problem, and provides a stage apparatus having a structure in which a θ-direction moving mechanism is added without causing an increase in the center of gravity. It is possible to control the position of the stage with high accuracy.

In order to solve the above problems, the invention according to claim 1 of this application is
Stage,
An X-direction moving mechanism for moving the stage in the X direction;
A stage device including a Y-direction moving mechanism for moving the stage in the Y direction perpendicular to the X direction,
The Y-direction moving mechanism includes a pair of Y-direction guides extending in the Y direction in parallel.
The X direction moving mechanism includes an X direction guide extending in the X direction and straddling a pair of Y direction guides.
Y direction sliders are provided at both ends of the X direction guide, and each Y direction slider is placed on each Y direction guide in a state where it can be guided by each Y direction guide,
The stage is placed on the X direction guide in a state where it can be guided by the X direction guide,
In the Y-direction moving mechanism, at least one Y-direction slider is connected to the X-direction guide via a hinge.
The at least one Y-direction slider is placed on the Y-direction guide in a state where displacement in the X-direction is allowed, or an X-direction displacement absorbing member is provided between the at least one Y-direction slider and the X-direction guide. It has a configuration that is.
In order to solve the above-mentioned problem, the invention according to claim 2 is the configuration according to claim 1, wherein the hinge rotates in a direction around an axis perpendicular to a plane to which the X direction and the Y direction belong. The elastic hinge is configured to act elastically in a state resisting the movement of the X-direction slider in the θ direction.
In order to solve the above-mentioned problem, the invention according to claim 3 is the configuration according to claim 1 or 2, wherein the Y-direction guide on which the one Y-direction slider is mounted is a flat surface. It has the structure that it is a flat guide to guide.
In order to solve the above-mentioned problem, the invention according to claim 4 has a configuration in which, in the configuration of claim 1 or 2, the directional displacement absorbing member is a bellows.
In order to solve the above problem, the invention according to claim 5 is the drive source according to any one of claims 1 to 4, wherein the Y-direction moving mechanism moves the one Y-direction slider in the Y-direction. The shaft motor has a shaft-shaped magnet and a motor slider through which the shaft-shaped magnet is inserted, and there is a clearance between the shaft-shaped magnet and the motor slider. It has the composition of being.
In order to solve the above-mentioned problem, according to a sixth aspect of the present invention, in the configuration according to any one of the first to fifth aspects, the X-direction moving mechanism includes an X-direction slider guided by the X-direction guide. And the stage is mounted on an X-direction slider,
The X direction moving mechanism and the Y direction moving mechanism are mounted on a surface plate,
The X-direction slider has a configuration that includes a floating body that floats on the surface plate by air injection or magnetic action.
In order to solve the above-mentioned problem, the invention according to claim 7 is the configuration according to any one of claims 1 to 6, wherein an X-direction position sensor that detects a position of the stage in the X direction and a stage in the Y direction. A Y-direction position sensor that detects the position of the X-direction, and a controller that feedback-controls the X-direction movement mechanism according to the output from the X-direction position sensor and feedback-controls the Y-direction movement mechanism according to the output from the Y-direction position sensor. And
At least one of the X-direction position sensor and the Y-direction position sensor is a laser interferometer that detects the position of the stage by irradiating a reflecting mirror attached to the stage and capturing the reflected light. Yes,
The controller has a storage unit that stores the curved shape of the reflecting mirror, and has a configuration in which feedback control is performed by a control signal corrected according to the curved shape of the reflecting mirror.

As described below, according to the first aspect of the present invention, the X-direction guide can be moved in the θ direction by moving one of the pair of Y-direction sliders relative to the other. . For this reason, it is not necessary to interpose a special mechanism for moving in the θ direction between the X direction slider and the stage, and the center of gravity of the stage can be kept low while allowing the movement in the θ direction. Accordingly, there is provided a stage apparatus that is free from the problems of moment generation and Abbe error due to the high center of gravity, can adjust the orientation in the θ direction, and can control the position of the stage with high accuracy.
According to the invention described in claim 2, in addition to the above effect, since an elastic hinge is used as the hinge, it is difficult for rattling to occur and the accuracy of position control can be further increased.
According to the invention of claim 6, in addition to the above effect, it is possible to prevent a large load from being applied to the X-direction guide by the X-direction slider and the members on the X-direction slider. Does not occur.
According to the seventh aspect of the invention, in addition to the above effect, the feedback control of the stage position is performed in a state where the curvature of the reflecting mirror is corrected, so that the positioning can be performed with higher accuracy.

It is a perspective schematic diagram of the stage device of a first embodiment. It is a front section schematic diagram of the stage device of a first embodiment. It is a plane schematic diagram of the stage device of a first embodiment. It is the cross-sectional schematic in the Y direction of the stage apparatus of 1st embodiment. It is a perspective schematic diagram of hinge 81 in the stage device of a first embodiment. It is the schematic shown about the control of the angle in (theta) direction movement. It is the schematic which showed the problem of the surface accuracy of a reflective mirror. It is the schematic shown about the suitable method which investigates the curve of a reflecting mirror beforehand. It is the schematic which showed a mode that the position control data of a Y direction were correct | amended according to the curved shape of the reflective mirror investigated beforehand. It is the conceptual diagram shown about the automatic correction | amendment of the position shift of XY direction accompanying a (theta) direction movement. It is the cross-sectional schematic in the X direction of the stage apparatus of 2nd embodiment. It is a plane schematic diagram of the stage device of a second embodiment. It is the perspective view which showed schematically about the conventional stage apparatus.

Next, modes for carrying out the invention of the present application (hereinafter referred to as embodiments) will be described.
1 to 3 are schematic views of a stage apparatus according to the first embodiment. FIG. 1 is a schematic perspective view, FIG. 2 is a schematic front sectional view, and FIG. 3 is a schematic plan view. 1 to 3 includes a stage 1, an X-direction moving mechanism 2 that moves the stage 1 in the X direction, and a Y that moves the stage 1 in the Y direction perpendicular to the X direction. And a direction moving mechanism 3.
As shown in FIGS. 1 and 3, the stage apparatus of this embodiment is basically H-shaped, and the Y-direction moving mechanism 3 includes a pair of Y-direction guides 31 and 32 extending in the Y-direction in parallel. The X-direction moving mechanism 2 includes an X-direction guide 21 extending in the X direction and straddling a pair of Y-direction guides 31 and 32. In the stage apparatus, the moving mechanisms 2 and 3 are mounted on the surface plate 4.

  First, the Y direction moving mechanism 3 will be described. As shown in FIG. 2, one of the pair of Y direction guides 31 is a V guide, and the other Y direction guide 32 is a flat guide. More specifically, the Y-direction guide (hereinafter referred to as the first Y-direction guide) 31 on the right side in FIG. 2 is a long rod-like member extending in the Y direction. As shown in FIG. 2, the first Y-direction guide 31 has an inverted V-shaped cross section on the top surface. The cross-sectional shape is the same at any position in the length direction, and the apex of the inverted V shape is continuous in a straight line along the Y direction.

  A first Y-direction slider 33 is placed on the first Y-direction guide 31. The first Y-direction slider 33 is a rod-like member that is long in the Y direction. The lower surface of the first Y-direction slider 33 is a groove having a V-shaped cross section as shown in FIG. The cross-sectional shape of the reverse V-groove conforms to the reverse V-shaped cross-sectional shape of the first Y-direction guide 31, and the upper surface of the first Y-direction guide 31 is fitted into the lower surface of the first Y-direction slider 33. It has become.

On the other hand, unlike the first Y-direction guide 31, the Y-direction guide 32 (hereinafter referred to as the second Y-direction guide) 32 on the left side in FIG. 2 is a rectangular bar-like member having a flat upper surface. The second Y-direction guide 32 is arranged with high accuracy so as to extend in the Y direction and have a flat upper surface in a horizontal posture.
A second Y-direction slider 34 is placed on the second Y-direction guide 32. The second Y-direction slider 34 is a rectangular bar-like member whose bottom surface is a flat surface, and is similarly arranged in a posture extending in the Y direction. The flat lower surface of the second Y-direction slider 34 is in a horizontal posture and is in contact with the upper surface of the second Y-direction guide 32.

A first Y-direction drive source 35 is arranged inside the first Y-direction slider 33. The first Y-direction slider 33 and the first Y-direction drive source 35 are connected by a first Y-direction connecting plate 37. Similarly, a second Y-direction drive source 36 is disposed inside the second Y-direction slider 34. The second Y-direction slider 34 and the second Y-direction drive source 36 are connected by a second Y-direction connecting plate 38.
In each of the Y-direction drive sources 35 and 36, a shaft motor that performs linear drive with a cylindrical shaft-shaped magnet is used in this embodiment. Each Y-direction drive source 35, 36, which is a shaft motor, is composed of shaft-shaped magnets 351, 361 and motor sliders 352, 362 incorporating a coil.

  The Y-direction moving mechanism 3 operates the Y-direction drive sources 35 and 36 in synchronization (that is, operates in the same direction for the same distance). As a result, the Y-direction sliders 33 and 34 held by the connecting plates 37 and 38 move in the Y direction. At this time, the first Y-direction slider 33 is guided to the first Y-direction guide 31 while being V-fitted. The second Y-direction slider 34 is guided by the second Y-direction guide 32 while contacting the flat surfaces.

Next, the X direction moving mechanism 2 will be described. FIG. 4 is a schematic cross-sectional view in the Y direction of the stage apparatus of the first embodiment. The X direction guide 21 is a long member extending in the X direction. As can be seen from FIGS. 1 and 4, in this embodiment, the X-direction guide 21 is a member having a U-shaped cross section with the opening portion facing upward, and includes a bottom plate portion 211 and side plate portions 212 on both sides. ing.
One end of the X direction guide 21 is connected to the first Y direction connecting plate 37 and the other end is fixed to the second Y direction connecting plate 38. Accordingly, when the Y-direction drive sources 35 and 36 are operated as described above, the X-direction guide 21 is also moved integrally in the Y direction.

As shown in FIG. 4, an X-direction drive source 22 is provided in the X-direction guide 21. A shaft motor is also used for the X-direction drive source 22, and includes a shaft-shaped magnet 221 and a motor slider 222. As shown in FIG. 1, the shaft-shaped magnet 221 of the X-direction drive source 22 extends in the X direction and is held at both ends by a retainer 223 fixed to the bottom plate portion 211.
The X-direction moving mechanism 2 includes an X-direction slider 23, and the X-direction slider 23 is fixed to a motor slider 222 of the X-direction drive source 22 as shown in FIG. The stage 1 is fixed to the upper surface of the X-direction slider 23. Therefore, when the X-direction drive source 22 operates, the X-direction slider 23 and the stage 1 move together with the motor slider 222 in the X direction.

The X-direction slider 23 is a plate-like member having a horizontal posture and a rectangular shape in plan view. As shown in FIG. 4, a pair of engagement plates 231 are fixed to the lower surface of the X-direction slider 23. The engagement plate 231 is a strip-like member that is long in the X direction, and is fixed to the X direction slider 23 with the width direction being vertical.
If the side where the pair of engagement plates 231 face is the inside, and the opposite side is the outside, the distance between the outer surfaces of the pair of engagement plates 231 is slightly smaller than the distance between the inner surfaces of the side plates 212 of the X direction guide 21. It has become a thing. Therefore, the engagement plate 231 on one side is approaching or in contact with the side plate portion 212 on one side with a slight clearance, and the engagement plate 231 on the other side is the side plate portion 212 on the other side. Is approaching or touching with a slight clearance. The X-direction slider 23 is guided by the X-direction guide 21 via the engagement plates 231 when the X-direction drive source 22 operates as described above.

Such an X-direction slider 23 includes a levitation mechanism 5 in order to reduce the load on the X-direction guide 21. The X-direction slider 23 includes a leg portion 232 on the lower side. The levitation mechanism 5 includes an air levitation body 51 provided at the lower end of each leg 232 and a compressed air supply system (not shown) that supplies compressed air to each air levitation body 51. Each air levitation body 51 has a hollow inside, and a large number of air holes are formed on the lower surface. The compressed air supply system supplies the compressed air to the air floating body 51 and releases the air floating bodies 51 from the surface plate 4 by releasing the air from the air holes. For this reason, it is possible to prevent the X direction guide 21 from being subjected to a large load of the X direction slider 23 and a member mounted on the X direction slider 23. When a large load is applied to the X direction guide 21, there is a problem that the X direction guide 21 bends. However, in this embodiment, there is no such problem.
In addition, in the state where each air floating body 51 floated, the X-direction slider 23 is in contact via a bearing (rolling bearing or linear bearing) (not shown). Further, instead of the air levitation mechanism, a magnetic levitation mechanism may be employed. In the case of magnetic levitation, a configuration is adopted in which magnets are provided in the levitation body, magnets are embedded in the surface plate, and the magnetic poles are different from each other.

  As shown in FIG. 3, the stage apparatus of the embodiment includes a controller 6. The controller 6 sends a control signal to each of the drive sources 22, 35, and 36 to instruct an operation amount. More specifically, a signal is sent to the motor sliders 222, 352, and 362 in each of the drive sources 22, 35, and 36 to instruct the direction and amount of movement when moving along the motor shafts 221, 351, and 361. It has become.

  Moreover, in order to monitor the position of the stage 1 after movement, the stage apparatus of the embodiment includes a position sensor. Laser interferometers 71, 72, and 73 are used as position sensors. As shown in FIG. 1, the stage 1 is provided with two reflecting plates 74 and 75. One is along the X direction and the other is along the Y direction. The reflector 74 along the Y direction is for measuring the position in the X direction (hereinafter referred to as the X direction reflector), and the reflector 75 along the X direction is for measuring the distance in the Y direction. (Hereinafter referred to as the Y-direction reflector). Two laser interferometers 72 and 73 are provided side by side with respect to the Y-direction reflecting plate 75, and one laser interferometer 71 is provided with respect to the X-direction reflecting plate 74. The output lines of the laser interferometers 71 to 73 are connected to the controller 6.

The controller 6 and the laser interferometers 71 to 73 constitute a feedback control system for the position of the stage 1. That is, when the controller 6 sends the control signal to each of the drive sources 22, 35, and 36 to move the stage 1 as described above, the stage 1 is positioned at the correct position according to the output signals of the laser interferometers 71 to 73. If it is not located in the correct position, the difference is calculated and a control signal for making the difference zero is sent to each drive source 22, 35, 36.
For the Y direction, the position in the Y direction is specified based on the average value of the outputs of the two laser interferometers 72 and 73. The outputs from the two laser interferometers 72 and 73 are used to detect the position of the stage 1 in the θ direction (the posture of the stage 1). This point will be described later.

The stage apparatus of the first embodiment has a structure that enables the stage 1 to move in the θ direction. Hereinafter, this point will be described.
As shown in FIGS. 1 to 3, the X direction guide 21 is connected to the first Y direction guide 31 via a hinge 81 at one end. The hinge 81 allows the X direction guide 21 to rotate about an axis perpendicular to the XY plane. FIG. 5 is a schematic perspective view of the hinge 81 in the stage apparatus of the first embodiment.

The hinge 81 includes first and second two plates 811 and 812. (1) in FIG. 5 shows a state in which the hinge 81 is configured by combining two plates 811 and 812, and (2) shows a state in which the hinge 81 is disassembled to easily understand the structure.
As shown in FIG. 5 (2), each of the plates 811 and 812 has an oblong rectangular shape with chamfered corners. When the hinge 81 is attached, each of the plates 811 and 812 takes a posture along the Y direction. The first plate 811 is located on the first Y-direction slider 33 side, and the second plate 812 is located on the X-direction guide 21 side.

The first plate 811 has two rectangular openings 813 and 814. One opening 813 is formed on the upper side of a position closer to one side in the Y direction with respect to the center of the first plate 811, and the other opening 814 is formed on the lower side on the other side in the Y direction.
Leaf springs 815 and 816 are attached to the second plate 812 at positions where they fit into the two openings 813 and 814 of the first plate 811, respectively. One leaf spring 815 is located on the upper side (hereinafter referred to as the upper leaf spring), and the other leaf spring 816 is located on the lower side (hereinafter referred to as the lower leaf spring).

  The upper leaf spring 815 has an end fixed on the other side in the Y direction and extends toward one side, and extends obliquely in a direction approaching the first plate 811. The lower leaf spring 816 has an end fixed on one side in the Y direction and extends to the other side, and also extends obliquely toward the first plate 811. That is, as shown in FIG. 5 (2), the upper and lower leaf springs 815 and 816 extend so as to cross obliquely in plan view. The tips of the leaf springs 815 and 816 are fitted into the openings 813 and 814 of the first plate 811, respectively. With such a connection structure, the two plates 811 and 812 are connected.

  As can be understood from the above description, the posture of the second plate 812 can be changed with respect to the first plate 811 having a fixed posture. In other words, the leaf springs 815 and 816 maintain the state of being fitted into the openings 813 of the first plate 811 while applying elasticity to move the second plate 812 away from the first plate 811 or push it against the elasticity. As a result, the second plate 812 can be brought close to the first plate 811. Therefore, as shown by the arrow R1 in FIG. 5A, the second plate 812 can be rotated so that the edge on one side approaches the first plate 811, and conversely, the arrow R2 It is possible to rotate in the direction in which the edge on the other side approaches the second plate 812 as shown by. The axis of rotation A is perpendicular to the XY plane.

As shown in FIG. 2, the first plate 811 is fixed to the first Y-direction connecting plate 37 by a first back plate 817, and the second plate 812 is fixed to the X-direction guide 21 by a second back plate 818. The X direction guide 21 is connected to the second Y direction slider 34 at the other end. Therefore, when the second Y-direction drive source 36 operates in a state where the first Y-direction drive source 35 does not operate, the X-direction guide 21 rotates with the hinge 81 as a fulcrum as shown by an arrow R in FIG. Since this rotation is within the range in which the elasticity of the leaf springs 815 and 816 constituting the hinge 81 acts, the rotation is not so large. This angle (indicated by θ in FIG. 3) is, for example, about ± 100 μ radians.
The hinge 81 is a kind of the elastic hinge 81, but the leaf springs 815 and 816 constituting the hinge 81 have a certain degree of rigidity due to the necessity of eliminating rattling or increasing the accuracy of the rotational position. Is used. The second Y-direction drive source 36 deforms the leaf springs 815 and 816 against this rigidity.

  The second Y-direction drive source 36 is a shaft motor in this embodiment, and the motor slider 362 is connected to the second Y-direction slider 34 by a second Y-direction connecting plate 38. It is a non-contact linear drive source, and there is a clearance between the shaft-shaped magnet and the motor slider. In this embodiment, since both ends of the shaft-like magnet 361 are fixed, the motor slider 362 moves in the θ direction integrally with the second Y-direction connecting plate 38 and the second Y-direction slider 34 within this clearance.

The movement angle in the θ direction movement as described above is controlled by the operation amount of each Y direction drive source 35, 36. This point will be described with reference to FIG. FIG. 6 is a schematic diagram showing the angle control in the movement in the θ direction.
In the above description, the first Y-direction slider 33 is stationary and the second Y-direction slider 34 is moved to move by θ. However, the center of the X-direction slider 21 is not moved substantially regardless of the rotation. The first Y-direction slider 33 and the second Y-direction slider 34 are moved in opposite directions so that the θ movement is performed in order to achieve the position of Is called. FIG. 6 conceptually shows this state.

In FIG. 6, the first Y direction guide 31 is indicated by a straight line Y1, and the second Y direction guide 32 is indicated by a straight line Y2. The center of rotation (the center of the hinge 81) is located on the X axis, and P is a point where the X axis (a straight line passing through C and extending in the X direction) intersects Y1. In this case, the distance L between the point P and the rotation center C substantially corresponds to the length of the rotating X-direction guide 21.
When moving in the θ direction, as described above, the first Y-direction drive source 35 and the second Y-direction drive source 36 are driven so that movements in opposite directions in the Y direction are performed. If the upper side on the paper surface of FIG. 6 is + and the lower side is-, for example, the first Y-direction drive source 35 is driven in the-direction, and the second Y-direction drive source 36 is driven in the + direction.

従って、コントローラ６は、所望のθｄとなるようにδを計算し、−δの移動距離の信号を第一Ｙ方向駆動源３５に送り、＋δの移動距離の信号を第二Ｙ方向駆動源３６に送る。これにより、θｄの回転が達成される。逆方向のθ移動の場合、正負の符号を逆にした信号が送られることはいうまでもない。 For the sake of simplicity, assuming that the movement distances of the two Y-direction drive sources 35 and 36 are the same δ (+ δ, −δ), and the rotation angles are θd, the relationship between δ and θd is given by the following formula 1. expressed.

Therefore, the controller 6 calculates δ so as to obtain a desired θd, sends a signal of −δ movement distance to the first Y-direction drive source 35, and sends a signal of + δ movement distance to the second Y-direction drive source 36. Send to. Thereby, the rotation of θd is achieved. In the case of θ movement in the reverse direction, it goes without saying that a signal having the opposite sign is sent.

  As described above, the amount of movement in the θ direction in the embodiment is as small as several hundred μradians. Even if it is such a small angle of movement, it is significant to be able to move in the θ direction. For example, when the workpiece W is placed on the stage 1 by a robot, it is assumed that although the robot is a high-performance robot, an arrangement error in the θ direction of about several hundred μradians occurs. In this case, it is possible to detect the mark provided on the workpiece W, measure the error in the θ direction, and move the θ direction so as to compensate for the error.

  Further, when the movement in the X direction or the Y direction causes a movement in the θ direction that should not occur originally due to a problem in mechanism accuracy, the movement in the θ direction can be performed for the purpose of correcting this. The θ-direction movement accompanying such linear movement is called yawing, but the occurrence of yawing can be detected by monitoring the output difference (optical path difference) between the two laser interferometers shown in FIG. . Accordingly, when yawing is detected, the yawing is corrected by moving the same direction in the opposite direction to the yawing, so that the stage 1 can always be kept in the correct orientation in the θ direction.

  As described above, the stage apparatus according to the embodiment moves the X-direction guide 21 in the θ direction by moving the pair of Y-direction sliders 33 and 34 in the Y direction opposite to each other, whereby the X-direction slider 23 and the stage are moved. 1 is moved together in the θ direction. For this reason, it is not necessary to interpose a special mechanism for moving in the θ direction between the X-direction slider 23 and the stage 1, and the center of gravity of the stage 1 can be kept low while allowing movement in the θ direction. Therefore, the merit of the H type having a low center of gravity is not hindered, and it is unrelated to the problems of moment generation and Abbe error due to the high center of gravity. Therefore, a stage apparatus is provided that can adjust the orientation in the θ direction and can control the position of the stage 1 with high accuracy. In some cases, it is desirable that the X-direction slider is engaged with the X-direction guide during the movement in the θ direction. In this case, the operation of the levitation mechanism 5 is stopped during the movement in the θ direction. The

Moreover, the above-mentioned movement in the θ direction can be suitably performed for the purpose of compensating the surface accuracy of the reflector used together with the laser interferometer. Hereinafter, this point will be described.
As described above, each of the reflecting mirrors 74 and 75 enables distance measurement by reflecting and returning the laser light from the laser interferometers 71 to 73. Since the stage 1 moves in the X direction and the Y direction, the reflecting mirrors 74 and 75 are long and are disposed along the X direction and the Y direction, respectively. In this case, for example, the reflecting surface of the Y-direction reflecting mirror 75 needs to form a flat surface along the X direction. However, it is difficult to ensure flatness due to a problem in processing accuracy, and the submicron level is difficult. This can be a problem when performing fine positioning. FIG. 7 is a schematic view showing the problem of surface accuracy of the reflecting mirror.

  As shown in FIG. 7, it is assumed that the reflecting mirror 75 is curved, for example, in a concave shape with respect to the laser interferometer 72 (FIG. 7 is exaggerated for the sake of understanding). In this case, when the stage 1 is moved and stopped in the X direction or the Y direction, the reflecting mirror 75 is curved although the stage 1 is positioned in the correct position in the Y direction. 72 measures a distance L ′ shorter than the original distance L. For this reason, the controller 6 determines that it is located at an incorrect position in the Y direction, and issues a control signal for moving the stage 1 in the Y direction by −ΔL so as to eliminate the difference ΔL. As a result, the stage 1 located at the correct position is displaced by −ΔL.

In order to prevent this problem, the curvature of the reflecting mirror 75 is examined in advance, and correction is performed using the data. FIG. 8 is a schematic diagram showing a preferred method for examining the curvature of the reflecting mirror in advance.
As described above, the stage apparatus of the embodiment has the two laser interferometers 72 and 73 arranged in parallel in the X direction. This structure is suitable for examining the curvature of the reflecting surface of the reflecting mirror (Y-direction reflecting mirror) 75 arranged along the X direction.

After the Y-direction reflecting mirror 75 is attached to the stage 1 as shown in FIG. 1, the stage 1 is sequentially moved in the X direction as shown in FIG. At this time, the difference between the outputs of the two laser interferometers 72 and 73 is calculated. If the reflecting mirror 75 is not curved, the difference is zero. On the other hand, if it is curved, the difference is not zero and Δd is generated. As shown in FIG. 8 (2), Δd indicates the tilt angle θt of the reflecting surface between the optical axes of the two laser interferometers 72 and 73. If the distance between the optical axes is G, θt = tan ⁻ (Δd / G). Therefore, for example, if the value of θt is acquired for the midpoint M between the optical axes and the value of θt is plotted for each midpoint M, a curved shape (profile) of the reflecting surface as shown in FIG. 7 is obtained. It will be.

As described above, the tilt angle θt at each measurement point is acquired while sequentially moving the stage 1 with the stroke of the distance G between the optical axes. The acquired θt is stored in a storage unit such as a memory in the controller 6 together with the data of the position in the Y direction. For example, the inclination angle θt at which the number of sequential movements is measured n-th is stored as the inclination angle between the n-th position (Y _n ) and the n + 1-th position (Y _{n + 1} ). That is, it is stored as data of the inclination angle θt for each optical axis distance G.
The data of θt of each point stored in this way is used for correcting the position control data in the Y direction. This point is illustrated in FIG. FIG. 9 is a schematic diagram illustrating how the position control data in the Y direction is corrected in accordance with the curved shape of the reflecting mirror examined in advance.

In order to position the workpiece at a certain position, it is assumed that the stage 1 is stopped at a position that is moved in the X direction. As shown in FIG. 9 (1), this stop position is a position where a certain point Q is located on the optical axis of the Y-direction interferometer 72. The point Q is located between Y _n and Y _{n + 1 in} the correction data, and the inclination angle is θt.
In this case, the X direction moving distance signal is sent from the controller 6 to the X direction driving source 22 so that the stage 1 stops at the point Q. At the same time, the first Y direction driving source is moved by θt in the θ direction. A control signal is sent to 35 and the second Y-direction drive source 36. That is, when the X-direction movement is performed, the Y-direction movement signal for correcting the surface accuracy of the Y-direction reflecting mirror 75 is sent to the Y-direction drive sources 35 and 36 together. As a result, as shown in FIG. 9 (2), θ movement is performed at an angle of θt, and position detection in the Y direction is performed and feedback control is performed in a state in which the decrease in surface accuracy (curvature) is corrected. The controller 6 reads the value of θt from the storage unit according to the position of the stage 1 after moving in the X direction, and sends control signals of + δ and −δ so as to be θt. Therefore, even if the position is stopped at any position in the X direction, the decrease in surface accuracy is corrected, and the stage 1 is positioned in the Y direction with high accuracy without erroneously detecting the position in the Y direction.

  Note that, when such a movement in the θ direction is performed, the measurement point by the laser interferometer 72 is deviated from the center of rotation, so that the shift from the original position is caused by the movement in the θ direction. However, this shift is automatically corrected by feedback control by the laser interferometers 72 and 73. This point will be described with reference to FIG. FIG. 10 is a conceptual diagram showing automatic correction of the positional deviation in the XY directions accompanying the movement in the θ direction.

FIG. 10 is a view similar to FIG. 6, but considers the measurement points by the laser interferometers 71 to 73. For example, if one of the two laser interferometers 72 and 73 for the Y direction is used for position detection in the Y direction, the optical axis of the laser interferometer 72 and the optical axis of the X direction laser interferometer 71 Let α be the point where. α is a point at which the position is measured by the laser interferometers 71 and 72 in the stage 1 (hereinafter referred to as a measurement point). In order to simplify the explanation, it is assumed that the point α is on a line extending through the rotation center C in the X direction, and the distance to the rotation center C is Xa.
As described above, the first Y-direction slider 33 and the second Y-direction slider 34 move by | δ | in opposite directions. Therefore, although the rotation center C is the hinge 81, the point where the X direction guide 21 is located is hardly displaced regardless of the rotation. This point is substantially the center of the X direction guide 21. As shown in FIG. 10 (1), when the measurement point α on the stage 1 is not at this point, the position shifts with the movement in the θ direction. Assuming that the amount of displacement is ΔX and ΔY, and the fixed point is at the center of the X direction guide 21, ΔX and ΔY are expressed by the following Expression 2.

  Such a shift of the measurement point α accompanying the movement in the θ direction is detected by the laser interferometers 71 and 72. Therefore, in the configuration of the embodiment in which feedback control is performed by the controller 6 as described above, the shift is automatically corrected. That is, as shown in FIG. 10 (2), when the stage 1 moves in the θ direction as described above after moving in the X direction or Y direction and stopping at a predetermined position, the laser interferometer 71 for X direction Therefore, the controller 6 outputs a control signal to the X-direction drive source 22 so as to move by + ΔX. Further, since the laser interferometer 72 for Y direction determines that the position is shifted by −ΔY, the controller 6 outputs a control signal to each of the Y direction drive sources 35 and 36 so as to move by + ΔY. As a result, the X-direction guide 21 is shifted obliquely while maintaining the rotation angle as indicated by an arrow in FIG. 10B, and the point α is returned to the original correct position.

  That is, when moving in the X direction, the rotation of θt is performed in accordance with the X direction position after moving in the X direction, and the shift in the measurement point α is corrected while compensating for the decrease in surface accuracy of the reflecting mirror 75. And movement in the Y direction will be performed. That is, regarding the amount of movement in the Y direction, the movement of + ΔY is weighted in order to feedback-correct the measured shift of −ΔY while instructing each of the Y-direction drive sources 35 and 36 to move + δ and −δ. Instructed. That is, in the above example, −δ + ΔY is instructed to the first Y-direction drive source 35, and + δ + ΔY is instructed to the second Y-direction drive source 36. As a result, the measurement point α is positioned at the correct position in the Y direction regardless of the surface accuracy of the reflecting mirror 75.

Although the above example is based on the assumption that feedback control is performed, even a system that performs open loop control can correct a shift accompanying rotation. That is, the position of the rotation center C is fixed, and therefore the distance L from the point P is a constant. Further, since Xα is the distance between the measurement point α after movement in the X direction and the rotation center, this is also determined by the control signal for the movement distance in the X direction. Since how much ΔX and ΔY are generated when ± δ is moved due to the rotation of θd is obtained by the above equations 1 and 2, when the stage 1 is positioned at a certain measurement point α, ± δ The movement may be instructed to each of the Y-direction drive sources 35 and 36 and ΔX and ΔY may be instructed together as the open loop control amount.
In any case, the stage apparatus according to the embodiment moves in the θ direction by moving the pair of Y direction sliders 33 and 34 in opposite directions to each other in the Y direction. Therefore, the reflecting mirror 75 does not increase the center of gravity. This eliminates the problem of reduced surface accuracy.

  FIG. 2 also shows a usage example of the stage apparatus of the embodiment. In this example, the stage apparatus is used by being mounted on an exposure apparatus. The exposure apparatus includes the exposure optical system 9 and the stage apparatus according to the embodiment. The stage device has a function of positioning the workpiece W at a position where a predetermined pattern of light is irradiated by the exposure optical system 9.

  Although details of the exposure optical system 9 are omitted, in the case of an apparatus of a type that performs projection exposure through a mask, a mask and an image of the mask arranged at a position where light from the light source is irradiated are placed on the stage 1. It includes an imaging lens that forms an image on a work (not shown). The stage apparatus of the embodiment can also be suitably used for a two-beam laser interference exposure apparatus that performs exposure by causing two laser beams to interfere on the workpiece W. The configuration of the exposure optical system in the two-beam laser interference exposure apparatus is disclosed in Japanese Patent No. 4514317 and Japanese Patent Application Laid-Open No. 2015-170780.

Next, the stage apparatus of 2nd embodiment is demonstrated. 11 and 12 are schematic views of the stage apparatus according to the second embodiment. FIG. 11 is a schematic cross-sectional view in the X direction, and FIG. 12 is a schematic plan view.
The stage device of the second embodiment is different from the first embodiment in the structure of the pair of Y-direction guides 31 and 32. That is, as shown in FIG. 11, the pair of Y-direction guides 31 and 32 both have a V-guide structure. Each Y-direction guide 31, 32 has a surface shape with an inverted V-shaped cross section that is convex upward, like the first Y-direction guide 31 of the first embodiment. The lower surfaces of the Y-direction sliders 33 and 34 are grooves having a V-shaped cross section, and the upper surfaces of the Y-direction guides 31 and 32 are fitted into the lower surfaces of the respective direction sliders 33 and 34. Yes.

In the stage apparatus of the second embodiment as well, the X direction guide 21 is connected to the first Y direction guide 31 via a hinge 81 at one end, as in the first embodiment. In order to enable movement in the θ direction, the other end of the X direction guide 21 is connected to the second Y direction guide 32 via an X direction displacement absorbing member 82.
As the X-direction displacement absorbing member 82, a bellows is used in this embodiment. The bellows is preferably formed of a rubber material that is somewhat rigid.

  Also in the second embodiment, the first Y-direction drive source 35 and the second Y-direction drive source 36 are driven in directions opposite to each other to perform the θ-direction movement of a predetermined angle. At this time, since both Y-direction guides 31 and 32 are V-guides, they cannot be displaced essentially in the X-direction, but the X-direction absorption displacement member 82 that is a bellows expands and contracts in the X-direction. Absorbs displacement. The expansion and contraction here means that, for example, the + side portion of the bellows extends in the Y direction and the-side portion contracts.

  Also in this embodiment, the stage apparatus moves the stage 1 in the θ direction by moving the pair of Y-direction sliders 33 and 34 in opposite directions in the Y direction. Is kept low. Therefore, the merit of the H type having a low center of gravity is not hindered, and it is unrelated to the problems of moment generation and Abbe error due to the high center of gravity. For this reason, a stage apparatus capable of adjusting the attitude of the stage 1 in the θ direction and capable of highly accurate position control is provided.

  In this embodiment, since the V guides are adopted for the Y direction guides 31 and 32 on both sides, there is an effect that the reliability of the position control in the X direction is higher than that in the first embodiment. That is, in the first embodiment, since the second Y-direction guide 32 is a flat guide, the restriction on the displacement in the X direction when moving in the Y direction is only on one side. In the second embodiment, since the displacement in the X direction is regulated on both sides, the reliability of the guide with respect to the linear movement is increased accordingly.

  In addition to the bellows, the X-direction displacement absorbing member 82 may be a cylindrical elastic body having appropriate elasticity, or may have a structure in which a fluid is filled inside the cylindrical elastic body. . Alternatively, a pair of coil springs may be employed as the X-direction displacement absorbing member 82. In this case, the axis of each coil spring is oriented in the X direction, and the X axis (passes through the center of the X direction guide 21 in the X direction). Are arranged at equidistant positions from each other.

In each of the above embodiments, the use of the hinge 81 shown in FIG. 5 is not an essential condition, and a hinge having another structure may be used. For example, a pivot structure, that is, a structure in which a conical protrusion is fitted into a mortar-shaped recess may be employed. However, if the elastic hinge 81 as described above is used, one end of the X-direction guide 21 is pressed against the first Y-direction slider 33 by the action of elasticity, so that the play is unlikely to occur and the accuracy of position control is further improved. This is preferable because it can be increased.
Also in the structure of the hinge 81 shown in FIG. 4, the leaf springs 815 and 816 are examples of elastic bodies, and a structure using another pair of elastic bodies such as coil springs may be employed.

  In addition, it has been described that the θ-direction movement can be performed for the purpose of compensating the surface accuracy of the reflecting mirror. However, the surface accuracy of the reflecting mirror may be poor for the X-direction reflecting mirror 74, so the surface of the X-direction reflecting mirror 74 may be deteriorated. A θ movement may be performed to compensate for accuracy. In this case, two laser interferometers are arranged in parallel along the Y direction, and similarly, the curved shape of the reflecting surface of the X direction reflecting mirror 74 is examined in advance and stored in the storage unit. When moving in the Y direction, a correction amount is selected according to the position in the Y direction, and surface accuracy compensation is performed by the θ movement. In this case, since it is necessary to rotate the X-direction reflecting mirror 74, the side opposite to the side where the X-direction reflecting mirror 74 is provided (in the example of FIG. 1, the second Y-direction guide 32 and the X-direction guide 21). Between) and a hinge.

In addition, as each drive source 22,35,36, drive sources other than the shaft motor mentioned above may be used. For example, a flat type linear motor actuator can be adopted because it is non-contact driving. However, the linear guide is not an accessory, and a flat guide as described above is appropriately employed.
In addition, when the V guide is adopted, the guide is not a convex guide as shown in FIG. 2 or the like, but the guide has a V-shaped cross section and the slider has a convex V-shaped cross section. It may be a thing. Further, a guide-slider combination having a V-shaped cross section that is convex and concave in the horizontal direction may be employed.
The stage apparatus can be used in addition to the exposure apparatus described above. For example, a bonding apparatus for bonding wafers to obtain a laminated structure can be preferably used because high-precision positioning is required.

  Further, in each of the above embodiments, the movement in the θ direction has moved the pair of Y direction sliders 33 and 34 at equal distances in the opposite directions. However, in this configuration, the position on the X direction guide 21 is almost the same. This is because the point that does not change is in the center of the X direction guide 21 to simplify the calculation. The movement in the θ direction is not necessarily performed in this manner. The pair of Y direction sliders are moved in the opposite direction but not at the same distance, or one Y direction slider is kept stationary and the other Y direction is moved. It is also possible to move in the θ direction by moving the slider.

DESCRIPTION OF SYMBOLS 1 Stage 2 X direction moving mechanism 21 X direction guide 22 X direction drive source 3 Y direction moving mechanism 31 First Y direction guide 32 Second Y direction guide 33 First Y direction slider 34 Second Y direction slider 35 First Y direction Drive source 36 Second Y-direction drive source 37 First Y-direction connecting plate 38 Second Y-direction connecting plate 4 Surface plate 5 Lifting mechanism 6 Controllers 71 to 73 Laser interferometers 74 and 75 Reflecting mirror 81 Hinge 82 X-direction displacement absorbing member 9 Exposure optical system

Claims (7)

Stage,
An X-direction moving mechanism for moving the stage in the X direction;
A stage device including a Y-direction moving mechanism for moving the stage in the Y direction perpendicular to the X direction,
The Y-direction moving mechanism includes a pair of Y-direction guides extending in the Y direction in parallel.
The X direction moving mechanism includes an X direction guide extending in the X direction and straddling a pair of Y direction guides.
Y direction sliders are provided at both ends of the X direction guide, and each Y direction slider is placed on each Y direction guide in a state where it can be guided by each Y direction guide,
The stage is placed on the X direction guide in a state where it can be guided by the X direction guide,
In the Y-direction moving mechanism, at least one Y-direction slider is connected to the X-direction guide via a hinge.
The at least one Y-direction slider is placed on the Y-direction guide in a state where displacement in the X-direction is allowed, or an X-direction displacement absorbing member is provided between the at least one Y-direction slider and the X-direction guide. A stage apparatus characterized by being provided.   The hinge is an elastic hinge that exerts elasticity while resisting movement of the X-direction slider in the θ direction, which is a rotation direction about an axis perpendicular to a plane to which the X direction and the Y direction belong. The stage apparatus according to claim 1, wherein:   3. The stage apparatus according to claim 1, wherein the Y direction guide on which the one Y direction slider is mounted is a flat guide for guiding the Y direction slider on a flat surface.   3. The stage apparatus according to claim 1, wherein the directional displacement absorbing member is a bellows.   The Y-direction moving mechanism includes a shaft motor as a drive source for moving the one Y-direction slider in the Y direction. The shaft motor includes a shaft-shaped magnet and a motor slider through which the shaft-shaped magnet is inserted. 5. The stage apparatus according to claim 1, wherein a clearance exists between the shaft-shaped magnet and the motor slider. The X-direction moving mechanism includes an X-direction slider guided by the X-direction guide, and the stage is mounted on the X-direction slider.
The X direction moving mechanism and the Y direction moving mechanism are mounted on a surface plate,
6. The stage apparatus according to claim 1, wherein the X-direction slider includes a floating body that floats on the surface plate by air injection or magnetic action. The X-direction position sensor that detects the position of the stage in the X direction, the Y-direction position sensor that detects the position of the stage in the Y direction, and feedback control of the X-direction moving mechanism according to the output from the X-direction position sensor and Y A controller that feedback-controls the Y-direction moving mechanism in accordance with the output from the direction position sensor,
At least one of the X-direction position sensor and the Y-direction position sensor is a laser interferometer that detects the position of the stage by irradiating a reflecting mirror attached to the stage and capturing the reflected light. Yes,
7. The controller according to claim 1, wherein the controller includes a storage unit that stores a curved shape of the reflecting mirror, and performs feedback control using a control signal corrected according to the curved shape of the reflecting mirror. The stage apparatus as described.

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