WO1999016080A1

WO1999016080A1 - Stage driving method, stage device and exposure device

Info

Publication number: WO1999016080A1
Application number: PCT/JP1998/004264
Authority: WO
Inventors: Hideaki Hara; Naohiko Iwata
Original assignee: Nikon Corporation
Priority date: 1997-09-22
Filing date: 1998-09-22
Publication date: 1999-04-01

Abstract

A stage device, which is hard to generate moments and deformation when suppressing vibration accompanying the driving of a movable section. A surface plate is supported through a vibrationproof plate on a base, and an X stage composed of a Y guide bar conveying body, a Y guide bar or the like is arranged on the surface plate so as to be movable along an X guide bar and driven through an X-axis linear motor in an X direction. A stator of the X-axis linear motor is supported on the surface plate to be movable through a translation guide in the X direction so that an X braking member mounted to a braking frame fixed to the base imparts to the stator a braking force which cancels a reaction force when the X stage is driven.

Description

Specification

Stage driving method, stage apparatus, and exposure apparatus

The present invention relates to a stage device with a vibration isolation function for precisely positioning a workpiece and a method of driving the same, and for example, a lithographic apparatus for manufacturing a semiconductor device, a liquid crystal display device, a thin film magnetic head, or the like. It is suitable for use in an exposure apparatus used for transferring a mask pattern onto a substrate such as a wafer, or a precision machine tool or a precision measuring instrument. Background technology

For example, in the manufacture of semiconductor devices and the like, a reticle pattern as a mask is transferred onto a wafer (or a glass plate or the like) coated with a resist as a photosensitive substrate. A reduced projection type exposure apparatus was used. In such a batch exposure type exposure apparatus, a wafer stage capable of stepping in two directions orthogonal to each other is used as an apparatus for moving each shot area of a plane 8 to a predetermined exposure position.

Recently, attention has been focused on a step-and-scan type reduction projection type exposure apparatus that performs exposure by synchronously scanning a reticle and a wafer with respect to a projection optical system. In such a scanning exposure type exposure apparatus, a wafer stage that performs stepping in two directions orthogonal to each other and continuously moves at a constant speed in the scanning direction is capable of continuously moving at a constant speed in the scanning direction and is capable of moving in the non-scanning direction. A reticle stage is used, which can move a very small amount and can rotate a small angle around an axis perpendicular to the moving surface.

The exposure apparatus main body including these stages is provided with a highly elastic air spring or coil spring and an attenuator as an attenuator in order to block vibration from the floor. It is generally supported via a vibration isolator that is made up of a steel plate.

FIG. 12 shows a schematic configuration of a conventional wafer stage for an exposure apparatus. In FIG. 12, a base plate 72 is provided on a base 70 via a plurality of anti-vibration tables 71 A and 7 IB. An X stage 73 is mounted on a surface plate 72 so as to be movable in a direction parallel to the plane of FIG. 12 (this direction is defined as an X direction). The X stage 73 is driven in the X direction via a feed screw 75 by a driving motor 74 fixed on the surface plate 72, and is fed on the X stage 73 in the Y direction orthogonal to the X direction. A Y stage 76 driven by a screw system is mounted.

In this case, when the X stage 73 starts to be driven in the X direction, a thrust F indicated by, for example, a solid arrow acts on the X stage 73, and the platen 72 is driven via the drive motor 74. On the side, a reaction force F shown by a dotted arrow acts as a reaction. Therefore, the surface plate 72 is displaced in the direction of the reaction as it is, causing vibration. In order to apply a braking force D in the X direction to the surface plate 72 on the base 70, as disclosed in, for example, Japanese Patent Laid-Open Publication No. 58-68118, Is installed, and a force of the same magnitude and opposite direction to the reaction acting on the surface plate 72 during acceleration and deceleration of the X stage 73 is applied to the surface plate 72 from the actuator 77 (ie, A method of preventing the vibration of the surface plate 72 by making the braking force D equal to the thrust F) has been proposed.

In addition, when a linear motor is used as the drive motor, when the linear motor is driven, a reaction is prevented from acting on the surface plate via the stator to prevent the linear motor from being operated. A method of securing the stator at the base (floor) side is disclosed in US Pat. No. 5,528,118. In the conventional technique as described above, as shown in FIG. 12, in the method of applying a braking force to the surface plate 72 via the actuator 77, the surface plate 72 (the drive motor 74 )), Because the position of F and the position of the braking force D applied to the platen 72 from Actuyue 77 are very different, such that the platen 72 is rotated or deformed. Moment and deformation force are generated. A large amplitude component of these moments and deformation forces causes a vibration mode in which the air springs (or coil springs) of the anti-vibration tables 71A and 71B are deformed. It is reduced to a considerable extent by 1A, 71B itself. However, the remaining small-amplitude vibration is becoming a non-negligible amount in applications requiring stability of several nm, such as semiconductor exposure equipment.

Also, in such a structure where the position of the reaction force-F and the position of the braking force D are greatly different, in order to minimize the remaining small-amplitude vibration, the drive mode 74 of the X-stage 73 and the external It is desirable that the drive characteristics of the actuator for applying a braking force from the vehicle almost completely match the drive characteristics. The driving characteristics are mainly the linearity of the magnitude of the generated thrust with respect to the thrust command value, and the time delay from when the thrust command is issued until the thrust is generated. However, in the method shown in Fig. 12, since the mechanism of the drive mode 74 is greatly different from that of the actuator mode 77, it is difficult to match the drive characteristics almost completely. It was difficult to reduce.

In the conventional technique, the method of fixing the linear actuator stator on the base side does not excite the vibration mode of deforming the surface plate and the exposure apparatus main body as in the former method, but requires a large braking mechanism. As a result, the size of the stage device becomes large as a whole, and the arrangement of the length measuring system and sensors provided in the stage device is greatly restricted. In the conventional stage apparatus shown in FIG. 12, the position of the X stage 73 (drive module 74) is constant in the direction perpendicular to the plane of FIG. 12 (Y direction). Even if the position (X coordinate) of 73 changes, the vibration during acceleration / deceleration can be suppressed to some extent by the actuator. On the other hand, as for the Y stage 76, the position in the X direction changes following the change in the position of the X stage 73, so that the Y stage does not depend on the position of the X stage 73. In order to suppress the vibration during acceleration / deceleration of 76, it is necessary to provide a vibration damping mechanism on X stage 73. However, providing the vibration damping mechanism on the X stage 73 in this way has disadvantages such as the large size of the X stage 73 and the deterioration of the drive characteristics of the X stage 73. Disclosure of the invention

In view of the above, the present invention provides a stage driving method that does not easily generate a momentary deformation force or the like when suppressing vibration accompanying driving of a movable unit, and a stage apparatus and an exposure apparatus that use this driving method. This is the primary purpose.

Further, the present invention provides a stage driving method capable of greatly reducing the vibration accompanying the driving of the movable portion without using a large vibration damping mechanism, and a stage apparatus and an exposure apparatus using this driving method. The purpose of 2. Further, the present invention provides a stage apparatus and an exposure apparatus which can suppress vibration generated in one of the moving directions without significantly affecting the other moving direction when driving the movable portion in two intersecting directions. Is the third purpose.

The stage driving method according to the present invention is a stage driving method for driving a movable table, which is movably mounted on a surface plate in a predetermined direction, with respect to the surface plate in a predetermined direction using a non-contact type driving means. And the non-contact type driving means When a thrust is applied to the movable table in a predetermined direction in a state where the stator is movably supported with respect to the surface plate, a braking force is applied to the stator.

In the present invention, as the non-contact type driving means, there are various types of non-contact braking force by electromagnetic force, such as a linear motor including a mover and a stator, or a driving device generating a thrust including Lorentz force. The device can be used. An object to be processed such as a wafer is placed on the movable table. When the movable table is driven by the non-contact type driving means, a braking force is applied from the control member to the stator so as to cancel a reaction (reaction force) generated in the stator. At this time, the reaction and the damping force act on almost the same straight line, so that moment and deformation force are not easily generated, and even if the timing of the reaction and the braking force is slightly deviated, the stator is fixed. Since it is movable with respect to the board, there is no force acting on the surface plate or the like to cause rotation or the like. Note that the above-described braking force can be applied in a non-contact manner by electromagnetic force by using, for example, a linear motor, a driving device using a mouth-to-lent force, or the like.

In this case, a feed force system may apply a braking force to the stator based on the command values of the position of the movable table and the moving speed. This increases the response speed.

In this case, the relative displacement of the stator with respect to the surface plate can be corrected when the non-contact driving means is not operating.

In addition, the above-described stage driving method includes the steps of: moving a second movable table movably installed in a second direction intersecting the movable table in a predetermined direction with respect to the movable table; When driving using the second non-contact type driving means, the movable member moves in the predetermined direction together with the movable table over the moving range of the movable member in the predetermined direction. A braking force in the second direction can be applied.

According to such a stage driving method, by changing the position of a movable table (hereinafter, “first movable table”) in a predetermined direction (hereinafter, “first direction”), the second movable table can be moved in the second direction. The position in direction 1 also changes. According to the present invention, a movable member is attached to the first movable table, and by applying a braking force to the movable member from the outside in the second direction, the movement of the first movable table is hardly affected. The vibration of the second movable table in the second direction can be suppressed without providing the second movable table.

Next, the stage device according to the present invention comprises: a surface plate; a movable table installed movably in a predetermined direction with respect to the surface plate; and the movable table driven in the predetermined direction with respect to the surface plate. Non-contact type driving means; supporting means for movably supporting the stator of the non-contact type driving means in the predetermined direction with respect to the surface plate; provided on a predetermined base; And a braking member for applying power.

According to the present invention, when the movable table is driven, a braking force is applied from the braking member to the stator so as to cancel the reaction (reaction force) generated in the stator. The stage driving method of the present invention can be used. At this time, since the reaction and the braking force act on substantially the same straight line, a moment and a deformation force are hardly generated, and the timing of the reaction and the braking force is not affected even if the magnitude is slightly shifted. Since it is movable with respect to the surface plate, no force that causes rotation or the like acts on the surface plate or the like. Therefore, the driving characteristics of the braking member may be different from the driving characteristics of the non-contact type driving means. In this sense, as the braking member, besides the electromagnetic active braking member, a passive braking member such as a pole joint or a viscoelastic joint may be used.

In other words, when the active braking member is used as in the former case, The stator of the non-contact type driving means is supported so as not to move in a direction perpendicular to the predetermined direction with respect to the surface plate, and the braking member provided on the base is provided on the base. And a thrust generator attached to the frame and applying a force of electromagnetic force to the stator of the non-contact type driving means, the thrust generator comprising: When the movable table is driven via the means, a thrust that substantially cancels a reaction force acting on the stator is generated as the braking force. In this case, there is an advantage that the vibration accompanying the driving of the movable portion can be significantly reduced without using a large-scale vibration damping mechanism.

On the other hand, when a passive braking member is used as in the latter case, as an example, the stator of the non-contact type driving means should not move in a direction perpendicular to the predetermined direction with respect to the surface plate. The braking member provided on the base is provided with a mechanical braking force on a frame provided on the base and on a stator of the non-contact type driving means mounted on the frame. And a passive brake. In this case, there is an advantage that the vibration accompanying the driving of the movable part can be greatly reduced by a passive and inexpensive braking mechanism without using a large-sized vibration damping mechanism.

Further, the stage device includes a second movable table movably installed in a second direction intersecting the predetermined direction with respect to the movable table, and a second movable table with respect to the movable table. Second non-contact type driving means for driving the table in the second direction, a movable member attached to the movable table and moving in the predetermined direction together with the movable table, and a movable member fixed on a predetermined base and And a braking member that applies a thrust to the movable member in the second direction over the movable range of the movable member in the first direction.

According to such a stage device, a wafer or the like is placed on the second movable table. The workpiece to be processed is placed, and the position of the second movable table changes two-dimensionally. That is, as the position of the movable table (hereinafter, “first movable table”) in a predetermined direction (hereinafter, “first direction”) changes, the second movable table moves in the first direction. The position also changes. In the present invention, a movable member is attached to the first movable table, and a braking force is applied to the movable member from the outside in the second direction, so that the movement of the first movable table can be substantially prevented. Vibration of the second movable table in the second direction can be suppressed without affecting the second movable table.

In this case, one example of the braking member has a fixed member arranged to face the first movable member over the entire movement range of the first movable member in the first direction. A thrust that substantially cancels a reaction force acting on the first movable member when the second movable table is driven through the non-contact type driving means between the first movable member and the fixed member. What happens. Thereby, the vibration in the second direction is actively suppressed. That is, when the movable portion is driven in two intersecting directions, there is an advantage that vibration generated in one moving direction can be suppressed without much affecting the other moving direction. In addition, there is an advantage that a moment, a deforming force, and the like are hardly generated when suppressing vibration caused by driving the second movable table (movable part).

In this case, the braking member has a fixed member disposed so as to face the movable member over the entire movement range of the movable member in the first direction, and a braking member is provided between the movable member and the fixed member. When driving the second movable table via the non-contact type driving means, a thrust which substantially cancels a reaction force acting on the movable member is generated. There is an advantage that even when the position in the direction changes, the vibration when the movable member is driven in the second direction in the same state is always reduced.

The stage driving method and the stage apparatus described above are Can be applied to For example, in the case of an exposure apparatus using the above stage device as a reticle stage, a pattern formed on an illuminated mask is projected through a projection lens onto a substrate mounted on the stage device. In the case of an exposure apparatus using the above stage device as a mask stage, a mask mounted on the stage device is illuminated, and a pattern formed on the mask is projected on a substrate stage through a projection lens. Project onto the board. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram showing a projection exposure apparatus used in an example of an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing a wafer stage of the projection exposure apparatus of FIG.

FIG. 3A is a partially cutaway plan view showing the Y braking mode of FIG. 1.

FIG. 3B is a side view of the Y braking mode in FIG. 3A.

FIG. 4A is a plan view showing a modification of the Y braking mode.

FIG. 4B is a side view of the Y braking mode in FIG. 4A.

FIG. 5 is a block diagram showing a stage system and a control system of a braking mechanism in an example of the embodiment.

FIG. 6 is a simplified side view of the wafer stage of FIG. 2 as viewed in the −Y direction.

Figure 7 is a _c Fig. 8 is a side view showing a main part of a second embodiment of the brake mechanism of the X-axis is a side view showing a main part of a third embodiment of the brake mechanism of the X-axis ( FIG. 9 is a side view showing a main part of a fourth embodiment of the X-axis braking mechanism, and FIG. 10 is a side view showing a main part of a fifth embodiment of the X-axis braking mechanism. You.

FIG. 11 is a view for explaining the structure of an exposure apparatus incorporating a stage device of another embodiment.

FIG. 12 is a simplified configuration diagram showing a conventional stage device. Embodiment

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the present invention is applied to a wafer stage of a projection exposure apparatus for manufacturing a semiconductor device.

FIG. 1 shows a schematic configuration of a projection exposure apparatus of the present example, and FIG. 2 shows a configuration of a wafer stage of the projection exposure apparatus. First, in FIG. 1, a rectangular flat platen 3 is placed on a flat base 1 via four vibration isolating tables 2A to 2D (2C and 2D are not shown in the drawing). Is supported. Each of the anti-vibration tables 2 A and 2 B is composed of a highly elastic air spring (or coil spring) and an oil damper as a vibration damper. Is not transmitted to the platen 3 side. The resonance frequency of the platen 3 and the mechanical part of the projection exposure apparatus thereon is about several Hz. The surface of the platen 3 is a plane with extremely good flatness, and the surface is kept almost parallel to the horizontal plane in a stationary state.Hereafter, the surface of the platen 3 is perpendicular to the plane of FIG. The X axis is taken in the direction, the Y axis is taken in a direction parallel to the plane of FIG. 1, and the Z axis is taken in a direction perpendicular to the surface of the surface plate 3.

In this case, an X guide bar 4 provided with a guide surface for the X stage is fixed on the surface of the surface plate 3 along the X direction. Also, a first Y guide bar carrier 5 is arranged movably in the X direction along the surface of the X guide bar 4 and the surface plate 3, and the Y guide bar carrier 5 is arranged along the surface of the surface plate 3 with the Y guide bar carrier 5. parallel A second Y guide bar carrier 8 is arranged so as to be movable in the X direction, and a guide surface for the stage is provided along the direction to connect the guide bars 5 and 8. In addition, (1) a guide bar (6) is installed, and (4) an X stage, which is a movable table, is composed of the guide bar carriers (5, 8) and (6) the guide bar.

In this case, an air ejection portion constituting an air bearing is provided on the bottom surface and the outer surface of the first guide bar transporter 5, respectively. Furthermore, a preload mechanism such as a magnet or a vacuum pocket is built in the vicinity of these air ejection parts, and the first 搬送 guide bar carrier 5 is provided on the surface of the surface plate 3 and the side of the X guide bar 4. It can be moved in the X direction while being restrained in the Ζ and Υ directions while keeping a certain interval between the two. Similarly, a prestressing mechanism such as an air ejection portion constituting an air bearing and a magnet or a vacuum pocket is incorporated into the bottom surface of the second guide bar carrier 8. The table is also restrained on the upper surface of the platen 5 while keeping a constant interval, and can move in the X direction.

Also, an X-axis linear motor 10, which is a non-contact drive means, is arranged on the surface plate 3 along the X direction so as to sandwich the X guide bar 4 together with the guide bar carrier 5. The evening 10 A and the Y guide bar-transport body 5 are connected via a connecting member 9 erected so as to straddle the X guide bar 4. Furthermore, the X-axis linear motor 10A is a stator composed of a mover 11A with a coil on the connecting member 9 side and a plurality of permanent magnets with alternately reversed polarities on the surface plate 3 side. The linear motion guide 13 A is interposed between the stator 12 A and the surface of the surface plate 3. As shown in Fig. 2 with a part of the stator 12A cut away, the linear motion guide 13A is composed of a rail 13Ab fixed on the surface plate 3 and a large number of small It consists of a plurality of sliding members 13 A a that can slide in the X direction via a pole bearing, The member 13Aa is fixed to the bottom surface of the stator 12A by bonding or the like. As the linear motion guide 13A, a guide of a static pressure gas bearing system or the like may be used.

Returning to FIG. 1, 10 B, which is an X-axis linear motor non-contact driving means arranged in the X direction, is connected to the left end of the Y guide bar 6 via a connecting member 18, and the X-axis linear motor 10 B Is composed of a stator 11 B having a coil on the connecting member 18 side and a stator 12 B on the surface plate 3 on which a plurality of permanent magnets are arranged.The stator 12 B and the surface plate A linear motion guide 13B, which can slide the stator 12B back and forth in the X direction, is interposed between the linear motion guide 13B and the surface 3B. That is, the stators 12A and 12B of the two-axis X-axis linear motors 10A and 10B of this example are restrained by the linear motion guides 13A and 13B as support means so that they cannot be displaced in the Y direction. It is supported so that it can slide in the X direction. In this case, a braking force is applied to the stators 12A and 128 by a braking member in a direction described later so as to cancel a reaction force (reaction) at the time of driving. The X-axis linear motors 10A and 1OB drive the X-stage in the X-direction using a moving coil system in parallel.

In FIG. 2, a pair of X-direction restraining bearing members 7 are arranged on the side surface of the Y guide bar 6 with a gap of several im so as to sandwich the Y guide bar 6 in the X direction. The Z floating bearing plate 14 (see Fig. 1) is fixed to the bottom surface of the constraining bearing member 7, and the sample stage 15 is fixed to the upper surface of the X-direction constraining bearing member 7, not shown on the sample stage 15. The wafer W to be exposed to which the resist is applied is held via the wafer holder. In this example, a Y stage is composed of a pair of X-direction constrained bearing members 7, a Z floating bearing plate 14, and a sample stage 15.

In this case, on the bottom surface of the Z-floating bearing plate 14 (the surface facing the surface plate 3), there is an air ejection part that constitutes an air bearing, and a vacuum pocket ゃ More than three sets of pressure devices are incorporated, and the weight of the Y stage is supported in a non-contact manner by an air-bearing system. In addition, a pair of X-direction restraint bearings 7 blast air toward the Y guide bar 6, respectively, and the Y stage is fixed to the Y guide bar 6 by balancing the air pressure generated by both. Constrain in the X direction without contact while maintaining. Thus, the Y stage can move in the Y direction along the Y guide bar 6 while being restrained in a non-contact manner in the X direction and the Z direction.

In order to drive the Y stage, a pair of X guide restraint bearing members 7 are connected in parallel to the Y direction so that Y guide bar carriers 5 and 8 (see Fig. 1) are connected to both sides. The stators 16 A and 16 B with coils are installed. + A plurality of U-shaped permanent magnets sandwich the stator 16 A on the outer surface of the X-direction restraining bearing member 7 on the X-direction side. The mover 17 A with the permanent magnet is fixed, and the mover (not shown) with a plurality of permanent magnets is fixed on the outer surface of the X-direction constrained bearing member 7 on the X direction side so as to sandwich the stator 16 B. It has been. The stators 16A and 16B and the corresponding movers 17A and the like constitute the two-axis moving magnet type Y-axis linear motors 26A and 26B, respectively. The Y stage is driven in the Y direction by axis linear motors 26A and 26B.

In FIG. 2, the sample stage 15 above the X-direction constraining bearing member 7 in the Y stage is capable of correcting the position in the Z direction (focus position) and the tilt angle around the X axis and the Y axis. The X-axis movable mirror 19 X and the Y-axis movable mirror 19 Y are fixed to the end in the −X direction and the end in the + Y direction on the sample table 15, respectively. In addition, the two-axis X-axis laser interferometers 21 XA and 21 XB attached to the support member 25 fixed to the X-direction side surface of the platen 3 are parallel to the X-axis to the moving mirror 19 X Is irradiated with a laser beam, and a laser mirror 19 X (sample stage 15) is moved by a laser interferometer 2 IXA and 21 XB. The X coordinates XW1 and XW2 of are measured. For example, one X coordinate XW1 is the X coordinate of the sample stage 15, and the rotation angle of the sample stage 15 is calculated from the difference between the two X coordinates XW1 and XW2.

The laser beam from the Y-axis laser interferometer 21 Y attached to the support member 25 is reflected by a mirror 20 attached to an optical system support frame (not shown) attached to the support member 25, and The moving mirror 19Y is irradiated parallel to the axis, and the Y coordinate YW of the moving mirror 19Y (sample stage 15) is measured by the laser interferometer 21Y.

Referring back to FIG. 1, a projection optical system PL and a reticle R are sequentially arranged above the wafer W, and the projection optical system PL is supported by a column (not shown) fixed to the surface plate 3, and the reticle R is It is held on a reticle stage 22 movably mounted on a reticle base 23 fixed to a column. In addition, a fly-eye lens at the top of the column, for example, for uniformizing the illuminance distribution of exposure light from an exposure light source installed outside the chamber in which the projection exposure apparatus is housed, a variable field stop (reticle blind), An illumination optical system 24 including a condenser lens and the like is arranged, and at the time of exposure, the exposure light IL from the illumination optical system 24 illuminates the pattern area of the reticle R with, for example, a rectangular illumination area elongated in the X direction. As the exposure light IL, excimer laser light such as KrF (wavelength 248 nm) or ArF (wavelength 193 nm), and soft X-rays are used in addition to bright lines such as i-line of a mercury lamp. it can.

In addition, a laser interferometer (not shown) for measuring the two-dimensional position of the reticle stage 22 is also provided. The laser interferometer measures the measured values of the laser interferometer and commands from the main control system 51 for controlling the overall operation of the apparatus. Accordingly, stage control system 52 controls the operation of reticle stage 22 in a linear mode. Similarly, the measured values of the laser interferometers 21XA, 21XB, and 21Y in FIG. 2 are also supplied to the stage control system 52 in FIG. 1, and the measured values and the main control system 51 The stage control system 52 controls the operations of the two-axis X-axis linear motors 10A and 10B on the wafer stage side and the two-axis Y-axis linear motors 26A and 26B in response to the command from the CPU. That is, at the time of exposure, when exposure to one shot area on the wafer W is completed, the X-axis linear motors 1OA and 10B and the Y-axis linear motors 26A and 26B are stepped and driven to the next step. After moving the shot area to the scanning start position, the reticle R and the wafer W are projected by driving the Y-axis linear motors 26A and 26B at a constant speed and driving the reticle stage 22 in synchronization. The operation of synchronously scanning the optical system PL in the Y direction with the projection magnification as a speed ratio is repeated in a step-and-scan manner, and each shot area of the wafer W is exposed. The present invention is also applied to a case where a batch exposure system such as a stepper is used as the projection exposure apparatus instead of the step-and-scan system as in this embodiment.

As shown in FIG. 2, the sample stage 15 (wafer W) of the wafer stage of this example is driven by two X-axis linear motors 10 A and 10 B in the X direction, and in the Y direction. Are also driven by two Y-axis linear motors 26A and 26B. When the sample stage 15 is driven in the X direction, for example, the accelerations (including deceleration) targeted by the movers 118 and 11B of the corresponding X-axis linear motors 10A and 108 are included. The thrust is proportional to the thrust force. At that time, a force of the same magnitude (hereinafter referred to as "reaction force") is applied to the corresponding stators 12A and 12B by the reaction in the opposite direction. Similarly, when the test stand 15 is driven in the Y direction, a thrust proportional to the target acceleration is applied to the mover 17 A of the corresponding Y-axis linear motors 26 A and 26 B, and the thrust is applied. And the same magnitude of reaction force acts on the corresponding stators 16A and 16B. Therefore, if there is no braking mechanism, those reaction forces act on the platen 3 from the stators 12A, 12B, or 16A, 16B to generate vibration. The vibration remains after the acceleration / deceleration of the sample stage 15 is completed, and the positioning accuracy of the sample stage 15 or the constant speed controllability during scanning exposure is deteriorated.

In order to prevent such deterioration in positioning accuracy and constant speed controllability, the wafer stage of the projection exposure apparatus of the present example is provided with X-axis and Y-axis braking mechanisms. First, as shown in Fig. 2, a part of the X-axis braking mechanism is movable in the direction in which the reaction force is generated by the stators 128, 12B of the X-axis linear motors 10A, 108A. Are the linear motion guides 13A and 13B. A braking frame 35 is fixed to the side of the base 1 in the —X direction. The braking frame 35 has almost the stator 12 A, at the ends of the stators 12 A and 12 B in the —X direction. Convex portions 35a and 35b facing the upper surface of 12B are provided, and convex portions 35a and 3b are provided.

The X-brake members 36 A and 36 B, which have coils on the bottom surface of the X-axis linear motors 10 A and 10 B, respectively, with almost the same configuration as the movers 11 A and 11 B, respectively Are fixed, and the tip portions of the X braking members 36A and 36B are inserted into the U-shaped stators 12A and 12B in a non-contact manner, respectively. The above linear motion guides 13 A, 13 B, brake frame 35, and X brake member 3

6A and 36B constitute an X-axis braking mechanism. The X-braking members 36A and 36B are provided with desired linear control over the stators 12A and 12B in a linear motor system. Generate power.

FIG. 5 shows the detailed configuration of the stage control system 52 shown in FIG. 1. In FIG. 5, the stage control system 52 includes a wafer stage drive system 53 and a reticle stage drive system 54. And various drivers. Then, the measured values of the three-axis laser interferometers 21 XA, 21 XB and 21 Y on the wafer stage side are supplied to the wafer stage drive system 53, and the wafer stage drive system 53 further has a main control system. Command values such as target position and moving speed of the wafer stage (sample stage 15) are supplied from 51. In response to this information, the wafer stage drive system 53 is driven by the X-axis linear motor 10 A, shown in FIG. 10 Set the thrust generated in the B and Y axis linear motors 26 mm and 26 mm, and supply the information of these thrusts to the drivers 55 mm, 55 mm and 56 mm, 56 mm in the feedforward system. The wafer stage drive system 53 supplies synchronization information to a reticle stage drive system 54, and the reticle stage drive system 54 drives the reticle stage in synchronization with the wafer stage. Drivers 55 ドライバ, 55Β and 56A, 56Β on the wafer stage are equipped with coils for the movers 11A, 11 1 and the stators 16Α, 16Β that correspond to generate the set thrust. Supply drive current to the coil. At this time, the information of the X-axis thrust to the X-axis drivers 55Α and 55Β is also supplied to the X-axis control drivers 57Α and 57Β, and the drivers 57Α and 57Β are driven by the corresponding X-brake member 36 部材. , 36 mm coil is supplied with a current to generate a thrust in the opposite direction with the same magnitude as its X-axis thrust.

FIG. 6 is a simplified side view of the wafer stage in FIG. 2 as viewed in one direction. In FIG. 6, in order to temporarily drive the sample stage 15 in FIG. When thrust FXA in the X direction is applied to the mover 1 1 Α of the X axis linear motor 10 10 in the X direction, the corresponding stator 12 A is subjected to anti-car FXA (reaction force FXA in the X direction). At the same time, the braking force DXA acting on the stator 12A from the X-braking member 36A becomes a thrust FXA in the X-direction, which has the same magnitude in the opposite direction to the reaction force. No force acts on the stator 12A, and the stator 12A remains stationary. In particular, in this example, since the reaction force FXA and the braking force DXA are substantially on the same straight line, no moment or force for deforming the stator 12 A is generated, and the movable element 11 A There is no generation of minute vibration during acceleration / deceleration.

Also, the timing when the braking force is applied to the stator 12A by the X braking member 36A is compared with the timing when the thrust is applied to the mover 11A. Is slightly deviated, or even if the magnitude of the braking force applied to the stator 12A by the X braking member 36A is slightly different from the magnitude of the reaction force generated in the stator 12A, Since the stator 1 2 A is displaced in the X direction by the moving guide 13 A, the surface plate 3 does not vibrate. Therefore, the surface plate 3 is stationary regardless of the acceleration / deceleration of the X stage (movable elements 11A and 11B), and the position control and speed control of the X stage are performed with high accuracy.

Returning to Fig. 2, during the period when the X-axis linear motors 10A and 10B are not driven, as an example, the stators 11A and 11B are usually kept stationary by the X-braking members 36A and 36B, for example. Keep it. Although not shown, an encoder of an optical type or a capacitance type for roughly detecting the relative position of the stators 12A and 12B and the surface plate 3 in the X direction is arranged. The measured value of this encoder is also supplied to the wafer stage drive system 53 in FIG. Then, for example, during a period in which the X-axis linear motors 10A and 10B are not driven, the relative positions of the stators 12A and 12B and the platen 3 in the X direction deviate from a predetermined target range. During this operation, the wafer stage control system 53 drives the X braking members 36A and 36B via a control line (not shown) so that the relative position is within the target range. As a result, the positions of the stators 12A and 12B do not gradually shift.

Next, the Y-axis braking mechanism will be described. First, as shown in FIG. 1, a mover 32 having a coil is fixed to a connecting member 9 that moves in the X direction together with the Y guide bar transporter 5 so as to cover the tip of the mover 32 in a non-contact manner. A stator 33 having a U-shaped cross section is arranged along the X direction, and the stator 33 is fixed to two braking frames 34 A, 34 B fixed to the side of the base 1 in the + Y direction. The mover 32 and the stator 33 constitute a Y braking mode 31 as a Y-axis braking mechanism. As shown in FIG. 2, a part of the stator 33 is cut away, and the stator 33 is moved in the X direction. Mover 3 in It is arranged to cover the mover 32 in the entire movement range of 2.

FIG. 3A is a partially cutaway plan view showing a Y braking motor 31 composed of the mover 32 and the stator 33 shown in FIG. 1, and FIG. 3B is a side view of FIG. 3A. As shown in FIG. 3B, the stator 33 is fixed on one inner surface of the three yokes 37, 38A and 38B fixed in a U-shape so that the polarity is reversed in the Y direction. The magnets 39A and 39B are fixed, and the permanent magnets 39C and 39D are fixed to the other inner surface with the polarity attracting the permanent magnets 39A and 39B. Therefore, the direction of the magnetic flux generated between one pair of permanent magnets 39A and 39C is opposite to the direction of the magnetic flux generated between the other pair of permanent magnets 39B and 39D. The mover 32 is inserted in a non-contact manner between the pair of permanent magnets.

As shown in FIG. 3A, inside the mover 32, a coil 32a is wound a plurality of times in a rectangular shape. In this case, the current IY flowing through the coil 32a is opposite between the pair of permanent magnets 39A and 39C and the other pair of permanent magnets 39B and 390 in the + direction or the -X direction. If a braking force DY / 2, which is a Lorentz force, is applied to the mover 32 in the Y direction between the permanent magnets 39A and 39C, the movable element 32 will move between the permanent magnets 39B and 39D. In the Y direction, a braking force DYZ 2 composed of a mouth-to-Lenz force acts. Since the Lorentz force is proportional to the current I Y, the direction and magnitude of the DY braking force can be arbitrarily controlled in total by controlling the current I Y.

Therefore, in FIG. 5, the information on the thrust supplied from the wafer stage drive system 53 to the Y-axis drivers 56 A and 56 B is also supplied to the driver 58. The driver 58 acts on the mover 32 according to the total value FY of the thrusts applied to the movers 168 and 16B of the two-axis Y-axis linear motors 26A and 268 by the braking force DY composed of the mouth-to-Lenz force. The power supplied to the coil 32a of the mover 32 is such that the direction is opposite to the reaction force and the size is the same. Set the flow IY.

As a result, in Fig. 1, assuming that thrust FY acts on the mover 17 7 etc. (sample stage 15) in the によって direction by the Υ-axis linear motors 26, and 26 Β (see Fig. 2), The stator 16 A, 16 B (see Fig. 2) and the movable member 3 2 of the Y braking motor 31 via the connecting member 9 have the anti-car FY (the size in the Y direction is FY). Work). Correspondingly, the braking force DY in the Y direction, which is opposite in direction to the reaction force, acts on the mover 3 2 by the Y braking mode 3 1, so that the mover 3 2 Panel 3 does not vibrate in the Y direction. Also in the Y-axis braking mechanism, the reaction force generated by the Y-axis linear motors 26A and 26B and the braking force applied by the Y-braking motor 31 are substantially on the same plane. There is no deformation force.

In this case, in FIG. 2, even if the position of the sample table 15 in the X direction changes, the mover 32 is still in the stator 33, and the mover 32 always has the Y direction. Braking force that offsets the reaction force to the vehicle. Therefore, irrespective of the position of the X stage in the X direction, the surface plate 3 is stationary even when the Y stage is accelerated or decelerated in the Y direction, and the position control and the speed control of the Y stage and, consequently, the sample stage 15 are performed. Performed with high precision.

In the Y braking motor 31 of FIGS. 3A and 3B, the permanent magnet and the coil may be reversed as shown in FIGS. 4A and 4B.

That is, FIG. 4A is a plan view showing another example of the configuration of the Y braking motor 31, and FIG. 4B is a side view thereof. As shown in FIG. 2A is provided with permanent magnets 42A, 42B on one inner surface of three yokes 40, 41A, 41B fixed in a U-shape so that the polarity is reversed in the Y direction. The permanent magnets 42C and 42D are fixed on the other inner surface with the polarity that attracts them so as to face the permanent magnets 42A and 42B. And Between these two pairs of permanent magnets, a stator 33A long in the X direction is inserted in a non-contact manner so as to cover the entire moving range of the mover 32A.

As shown in FIG. 4A, a coil 33Aa is wound a plurality of times in a rectangular shape inside the stator 33A. Therefore, even in this modification, when the coil 33 Aa is energized, the mouth force generated in the stator 33 A between the permanent magnets 42 A and 42 C and the stator 33 A between the permanent magnets 42 B and 42 D The force is the same as the mouth-to-lentz force generated in the armature, and the reaction force of the total Lorentz force acts as a braking force on the mover 32A. By canceling the reaction force FY acting on the mover 32 A with the braking force, vibration in the Y direction can be suppressed. In the above-described embodiment, the X braking members 36A and 36B equivalent to the movers 118 and 11B of the X axis linear motors 10A and 108 are used as the X axis braking mechanism. Since the stators 12 A and 12 B to which the bearings are attached are movably connected in the X-direction to the platen 3 via the linear motion guides 13 A and 13 B, the X-axis linear motors 10 A and 10 B Even if the difference between the thrust applied from B to the X stage and the braking force applied from the X braking members 36A and 36B to the stators 12A and 12B and the amount of timing deviation increase, the surface plate 3 Does not act in the X direction. Therefore, a more flexible or inexpensive configuration can be adopted. Hereinafter, other embodiments of the X-axis brake mechanism will be described. For convenience of description, only a mechanism that brakes the stator 12A of one X-axis linear motor 10A will be described.

[Second embodiment]

FIG. 7 shows a second embodiment of the X-axis braking mechanism. In FIG. 7, in which parts corresponding to FIG. 6 are denoted by the same reference numerals, one X-axis linear motor 1 OA The stator 12A (see FIG. 2) is mounted on the surface plate 3 so as to be movable in the X direction via the linear motion guide 13A. Then, a cylindrical insulator 62 extending in the X direction is fixed to one end of the stator 12A in the X direction, A coil 63 is wound around the insulator 62, and a cylindrical permanent magnet 61 is inserted into the insulator 62 in a non-contact manner. The permanent magnet 61 is fixed to the base 1 on a braking frame. Fixed at 35 A. In this example, the permanent magnet 61 and the coil 63 constitute a voice coil motor as a braking mechanism. The voice coil motor applies a braking force FXA that cancels the anti-car FXA acting on the stator 12A. You. Thus, the embodiment using the voice coil motor as the X-axis braking mechanism is particularly effective when a moving magnet type linear motor is used as the X-axis driving mechanism.

[Third embodiment]

FIG. 8 shows a third embodiment of the X-axis braking mechanism. In FIG. 8, parts corresponding to FIG. 6 are denoted by the same reference numerals, and in FIG. 8, the stator 12 A of the X-axis linear motor is shown. A rod 64 B made of, for example, a metal, which is elastically deformable and extends in the X direction, is fixed to one end in the X direction. The braking frame 35 A fixed to the base 1 also has the rod 6 4 An elastically deformable rod 64 A made of, for example, a metal extending in the X direction is fixed to face B, and a viscoelastic body 65 is interposed between the rods 64 A and 64 B. . In this example, the rods 64 A and 64 B can rotate to some extent within the range of elastic deformation and extend and contract in the X direction, and the viscoelastic body 65 It plays a role in improving the gaps between the disc-shaped tips of 4A and 64B, the position in the direction perpendicular to the X-axis, and the parallelism of those tips.

Therefore, for example, when a reaction force in the X direction acts on the stator 12 A, the braking frame 35 A is applied to the braking frame 35 A via the braking mechanism including the rods 64 A and 64 B and the viscoelastic body 65. The reaction force is transmitted, and as the reaction, a braking force having substantially the same magnitude acts on the stator 12A in the + X direction, and the stator 12A hardly moves in the X direction, and No vibration or the like occurs in the panel 3. In this example, when the stator 12 A and the braking frame 35 A are connected only with the rods 64 A and 64 B made of elastic material, the stator 1 2 during floor vibration and acceleration / deceleration of the X stage 1 2 The reaction force to A is transmitted to the braking frame 35 A, and the vibration of the braking frame 35 A is transmitted to the stator 12 A in reverse. Also, the stator 1 2 A can freely move with respect to the surface plate 3. The vibration in the X direction is not transmitted to the surface plate 3, but the vibration in the Y direction and the Z direction is transmitted to the surface plate 3. On the other hand, in the present example, the vibration components in the Y direction and the Z direction can be reduced through the viscoelastic body 65.

[Fourth embodiment]

FIG. 9 shows a fourth embodiment of the X-axis braking mechanism. In FIG. 9, parts corresponding to FIG. 6 are denoted by the same reference numerals. An elastically deformable, e.g., metal rod 67 extending in the X direction is connected to the end of A in the X direction via a rotatable ball joint 66 B, and the other end of the rod 67 is rotatable. The braking frame 35 A is fixed to the base 1 via a simple ball joint 66 A.

Also in this example, the reaction force generated in the stator 12 A is transmitted to the brake frame 35 A via the rod 67 and is canceled out by the reaction of the brake frame 35 A. Maintain almost stationary. Moreover, since the mouth 67 is connected via rotatable pole joints 66A and 66B, the vibration components in the Y and Z directions can be reduced.

[Fifth Embodiment]

FIG. 10 shows a fifth embodiment of the X-axis braking mechanism. In FIG. 10, in which parts corresponding to FIG. 6 are denoted by the same reference numerals, FIG. One end of the bellows 69 that can be extended and retracted in the X direction is fixed to the end of the 12 A in the X direction, and the other end of the bellows 69 is fixed on the base 1 Fix to frame 35 A. Further, a liquid such as oil is sealed in the bellows 69, and an intermediate portion of the bellows 69 is supported by a bellows holder 68 fixed to the surface plate 3.

In this example, when a reaction force in the X direction is applied to the stator 12 A, the pressure of the liquid inside the bellows 69 changes, but the pressure of the liquid acting on the bellows 69 changes in the Y direction and the Z direction. The directions are balanced, and only the force in the X direction is transmitted to the braking frame 35A. Therefore, the reaction force of the stator 12 A in the X direction is not transmitted to the platen 3, and the stator 12 A does not largely move in the X direction.

It should be noted that the present invention is not limited to the above-described embodiment, and can take various configurations without departing from the spirit of the present invention.

For example, the stage device of the above embodiment can be applied to a reticle stage of a projection exposure apparatus. FIG. 11 is a modification of the projection exposure apparatus of FIG. 1, in which not only the wafer stage but also the reticle stage is provided with a non-contact X-drive linear motor. A braking mechanism that provides a braking force that offsets the reaction force applied to the stator during driving is provided to prevent vibration.

In this case, three columns 88 are fixed at appropriate positions on the base 1, and at the upper end of these columns 88, three vibration isolation tables 2 each consisting of an air damper, elastic panel or oil damper are provided. Fixed. The lens barrel base 83 is installed on the column 88 via these vibration isolating tables 2. The projection optical system PL is supported by a barrel base 83, and the reticle base 103 on which the reticle stage 122 is mounted is mounted on a frame 84 provided on the barrel base 83. Supported. The wafer surface plate 3 on which the wafer stage 15 is mounted is suspended and fixed to the lens barrel surface plate 83 via a frame 86. The structure of the drive mechanism of the wafer stage 15 is the same as that shown in FIGS. 1 and 2. Therefore, the same portions are denoted by the same reference numerals, and redundant description will be omitted. The illumination optical system 24 is supported by a frame 82 provided on a lens barrel base 83.

X-axis linear motors 10 A and 10 B consisting of stators 1 12 A and 1 12 B and movers 11 A and 11 B are arranged on reticle surface plate 103. . The movers 11 A and 11 B are connected to a reticle stage 122 via a connecting member 9. The reticle stage 122 is guided by a linear motion guide (not shown) in the X-axis direction, and is driven by the X-axis linear motors 10A and 10B to smoothly move back and forth in the X direction. The position of the reticle stage 122 in the X direction is determined by moving the laser beam 1 19 fixed on the reticle stage 122 and the laser beam parallel to the X axis supported by the reticle surface plate 103. It is detected by the laser interferometer 1 21 irradiating the movable mirror 1 19.

The stators 11 A and 11 B are guided by the linear motion guides 13 A and 13 B, and are slidable back and forth in the X direction. The braking frames 35 fixed to the base 1 are provided with X braking members 36A and 36B for applying a braking force to the stators 111A and 112B in a non-contact manner.

The reticle stage control system 54, based on the output of the laser interferometer 121 and the command from the main control system 51, uses the reticle stage movers 11A and 11B and the X braking member 3 Controls the supply of drive current to 6 A and 36 B. The device configuration for controlling the movers 11A and 11B and the X braking members 36A and 36B on the reticle stage side is the same as that of the wafer stage shown in FIG. At this time, since drive control in the Y direction is not performed, the driver for the movers 11 A and 1 IB of the reticle stage corresponding to the drivers 56 A and 56 B and the drivers 57 A and 5 in FIG. A reticle stage X-braking member for 7BX and a driver for 36A and 36B will be added, and these will be connected to the reticle stage control system 54. In the above apparatus, when thrust in the X direction is applied to the movers 11 A and 11 B to drive the reticle stage 122 in the + X direction, the corresponding stators 1 12 A and A reaction force acts on 1 1 2 B. At the same time, the braking force acting on the stators 1 12 A and 1 12 B from the X braking members 36 A and 36 A is a thrust in the X direction that is the opposite direction to the reaction force and has the same magnitude. However, no force in the X direction acts on the stators 1 1 2 A and 1 1 2 B, and the stators 1 1 2 A and 1 1 2 B remain stationary. At this time, since the reaction force and the braking force are substantially on the same straight line, no moment or force for deforming the stators 112A and 112B is generated. Since no minute vibration or the like occurs during acceleration and deceleration of A and 12B, the reticle can be precisely driven to a desired position in the X direction.

Claims

The scope of the claims

1. A stage driving method for driving a movable table movably mounted on a surface plate in a predetermined direction with respect to the surface plate using a non-contact type driving means in the predetermined direction,

When a thrust is applied to the movable table in the predetermined direction in a state where the stator of the non-contact type driving means is movably supported on the surface plate, a braking force is applied to the stator. A stage driving method, comprising:

2. The stage driving method according to claim 1, wherein

A stage driving method, wherein the braking force applied to the stator is provided in a non-contact manner by an electromagnetic force.

3. The stage driving method according to claim 1, wherein

A stage driving method, wherein a braking force is applied to the stator by a feed-forward system based on a command value of a position and a moving speed of the movable table.

4. The stage driving method according to claim 1, wherein

A stage driving method, wherein a relative displacement of the stator with respect to the surface plate is corrected when the non-contact type driving means is not operating.

5. The stage driving method according to claim 1, wherein

A second non-contact type driving means is provided in the second direction with respect to the movable table, the second non-contact type driving means being movably installed in the second direction crossing the predetermined direction with respect to the movable table. When driving using the movable table, a braking force in the second direction is applied to the movable member that moves in the predetermined direction together with the movable table over the moving range of the movable member in the predetermined direction. A stage driving method.

6. The surface plate and A movable table installed movably in a predetermined direction with respect to the surface plate; non-contact type driving means for driving the movable table in the predetermined direction with respect to the surface plate;

Supporting means for movably supporting the stator of the non-contact type driving means in the predetermined direction with respect to the surface plate;

A braking member that is provided on a predetermined base and applies a braking force to the stator;

A stage device comprising:

7. The stage device according to claim 6, wherein

The stator of the non-contact type driving means is supported so as not to move in a direction perpendicular to the predetermined direction with respect to the surface plate, and the braking member provided on the base is provided on the base. And a thrust generator attached to the frame for applying a braking force consisting of an electromagnetic force to a stator of the non-contact type driving means. A stage device, wherein a thrust that substantially cancels a reaction force acting on the stator when the movable table is driven via a contact-type driving unit is generated as the braking force.

8. The stage device according to claim 6, wherein

A stage device, further comprising control means for controlling the braking member to apply a braking force to the stator in a feedforward system based on command values of the position and the moving speed of the movable table. .

9. The stage device according to claim 8, wherein

A stage device for controlling the braking member to correct a relative displacement of the stator with respect to the surface plate when the non-contact type driving unit is not operating; .

10. The stage device according to claim 6, wherein The stator of the non-contact type driving unit is supported so as not to move in a direction orthogonal to the predetermined direction with respect to the surface plate, and the braking member provided on the base is configured to include the base A stage device comprising: a frame provided thereon; and a passive brake attached to the frame and providing mechanical control to a stator of the non-contact driving means.

11. The stage device according to claim 10, wherein:

The stage device, wherein the passive damper has a pair of metal rods extending on the same straight line in the predetermined direction, and a viscoelastic body sandwiched between tips of the pair of metal rods.

1 2. The stage device according to claim 10, wherein:

The stage device, wherein the passive damper includes an elastically deformable metal rod extending in the predetermined direction, and ball joints provided at both ends of the metal rod.

13. The stage device according to claim 10, wherein

A stage device, wherein the passive brake is a device in which a liquid is sealed in a telescopic bellows.

14. The stage device according to claim 6, wherein

A second movable table movably installed in a second direction intersecting the predetermined direction with respect to the movable table; and a second movable table in the second direction with respect to the movable table. A second non-contact type driving means for driving; a movable member attached to the movable table and moving in the predetermined direction together with the movable table; a first direction of the movable member fixed on a predetermined base. And a braking member that applies a thrust to the movable member in the second direction over the range of movement of the stage device.

15. The stage device according to claim 14, wherein The braking member has a fixed member disposed so as to face the movable member over the entire moving range of the movable member in the predetermined direction, and between the movable member and the fixed member, A stage apparatus for generating a thrust that substantially cancels a reaction force acting on the movable member when the second movable table is driven via a non-contact type driving means.

16. An exposure apparatus for projecting, via a projection lens, a pattern formed on an illuminated mask onto a substrate mounted on the stage apparatus according to claim 6.

17. An exposure apparatus that illuminates a mask mounted on the stage device according to claim 6, and projects a pattern formed on the mask onto a substrate on a substrate stage via a projection lens.