JP5919733B2 - Moving table device, exposure device, and air pad - Google Patents

Description

  The present invention relates to a moving table device, an exposure device, and an air pad.

  An example of a conventional linear motion table device is shown in FIG. This linear motion table device includes a moving table 101, a table base 102, a ball screw 103, and four linear guides 104. The ball screw 103 and the linear guide 104 are provided between the moving table 101 and the table base 102, but the ball screw 103 is arranged at the center in the table width direction (direction perpendicular to the linear motion direction). The linear guides 104 are disposed at both ends in the table width direction and between the linear guides 104 and the ball screws 103 at both ends. On the moving table 101, a fixed body or a moving body 105 (for example, a moving table having a moving direction different from that of the moving table 101) is placed.

  In such a linear motion table device, since the moving table 101 is supported by the four linear guides 104, it is not easily deformed by its own weight or the load of the load, and the moving table 101 is moved along with the movement of the moving body 105. It is hard to be deformed by movement of the center of gravity. Accordingly, since the core height of the ball screw 103 hardly changes due to the deformation of the moving table 101, the moving table 101 can be moved in a stable posture. However, since it is necessary to accurately adjust the height and moving direction of the four linear guides 104, there is a problem that it is very difficult to adjust the linear motion table device during assembly.

  Therefore, a linear motion table device in which such a problem is unlikely to occur is proposed in Patent Document 1 (see FIG. 9). The linear motion table device disclosed in Patent Document 1 is the same as the linear motion table device in FIG. 8, instead of providing two linear guides 104 between the linear guide 104 and the ball screw 103 at both ends in the table width direction. The moving table 101 is provided with an air pad 106 that blows air toward the table base 102 from the 101 side.

  By adjusting the air blowing pressure of the air pad 106 according to the weight of the moving table 101 and the mass of the load, the center part in the table width direction of the moving table 101 is lifted upward, and the moving table 101 and the table base 102 are The interval (vertical distance) can be constant over the entire surface of the moving table 101. Thereby, even if the position of the center of gravity moves due to the movement of the moving body 105 loaded on the moving table 101, the moving table 101 is hardly deformed. In addition, since the number of linear guides 104 is two, there is almost no problem that adjustment during assembly is very difficult unlike the linear motion table device of FIG.

JP-A-11-277351 JP 2006-281426 A

However, since the air pad 106 is fixed to the moving table 101, if the accuracy of the plane of the table base 102, which is the bearing guide surface of the static pressure gas bearing, is poor, the distance between the air pad 106 and the bearing guide surface (vertical direction) The distance) is not constant, and varies depending on the location of the bearing guide surface.
For this reason, the force that lifts the moving table 101 from the table base 102 (that is, the force applied to the moving table 101 by the static pressure gas bearing) fluctuates, so the distance between the moving table 101 and the table base 102 (vertical direction). The distance) cannot be made constant over the entire surface of the moving table 101, and the moving table 101 may be deformed. As a result, the core height of the ball screw 103 is changed, and there is a possibility that the moving table 101 cannot be moved in a stable posture.

If the linear guide is used instead of the hydrostatic bearing as in the technique disclosed in Patent Document 2, the influence of surface accuracy can be eliminated, but the minute vibration generated from the linear guide is transmitted to the moving table. There is a possibility that a problem such as friction becomes a disturbance force with respect to the positioning of the moving table.
Accordingly, the present invention solves the problems of the prior art as described above, and even if the accuracy of the bearing guide surface of the static pressure gas bearing is insufficient, the movable table is hardly deformed and the movable table is in a stable posture. It is an object of the present invention to provide a moving table device, an exposure device, and an air pad that can be moved at a high speed.

  In order to solve the above problems, an aspect of the present invention has the following configuration. That is, the moving table device according to one aspect of the present invention includes a base having a bearing guide surface of a static pressure gas bearing, a moving table that linearly moves or rotates on the base, and the base and the moving table. And a guide mechanism that guides linear movement or rotation of the moving table while supporting the moving table on the base, and a gas bearing surface on which a jet port for jetting gas is formed An air pad capable of constituting a static pressure gas bearing between the bearing guide surface and the gas bearing surface by jetting gas from the gas bearing surface toward the bearing guide surface facing through the bearing gap The gas bearing surface is fixed to a surface facing the base of the moving table with the gas bearing surface facing the bearing guide surface, and the air pad includes a bearing portion provided with the gas bearing surface. A housing portion fixed to the movable table and holding the bearing portion, the housing portion having a recess for accommodating the bearing portion so that the gas bearing surface is exposed, and the gas bearing surface The bearing portion is held in the recess so as to be able to advance and retreat in the vertical direction, and the air pad advances and retreats the bearing portion in the vertical direction of the gas bearing surface, so that the vertical position between the moving table and the base is An advance / retreat mechanism that keeps the directional distance constant is provided.

  In such a moving table device, the advance / retreat mechanism is disposed between the housing part and the bearing part, and applies a biasing force in a direction perpendicular to the gas bearing surface to the housing part and the bearing part. It is preferable that More preferably, the spring is at least one of a coil spring and an air spring. Moreover, it is preferable that the advance / retreat mechanism includes an adjustment mechanism that adjusts an urging force of the spring.

An exposure apparatus according to another aspect of the present invention includes a positioning device that moves an object to be exposed and moves and positions the object to be exposed, and irradiates exposure light to the positioned object to be exposed. An exposure apparatus for forming a pattern, wherein the moving table device is used as the positioning device.
Furthermore, an air pad according to another aspect of the present invention includes a gas bearing surface in which an outlet for ejecting gas toward the bearing guide surface is formed, and a static pressure is provided between the bearing guide surface and the gas bearing surface. A bearing portion that can constitute a gas bearing and a recess that accommodates the bearing portion so that the gas bearing surface is exposed, and the bearing portion is held in the recess so as to be able to advance and retreat in a direction perpendicular to the gas bearing surface. And a forward / backward mechanism arranged between the housing portion and the bearing portion for moving the bearing portion forward and backward in a direction perpendicular to the gas bearing surface.

  In such an air pad, it is preferable that the advance / retreat mechanism is a spring that applies a biasing force in a direction perpendicular to the gas bearing surface to the housing portion and the bearing portion. More preferably, the spring is at least one of a coil spring and an air spring. Moreover, it is preferable that the advance / retreat mechanism includes an adjustment mechanism that adjusts an urging force of the spring.

Since the moving table device of the present invention includes an air pad having an advance / retreat mechanism that keeps the vertical distance between the moving table and the base constant, the accuracy of the bearing guide surface of the static pressure gas bearing is insufficient. However, the moving table is hardly deformed, and the moving table can be moved in a stable posture.
Moreover, since the exposure apparatus of the present invention can move the moving table in a stable posture, the exposure material is accurately positioned.

  Furthermore, the air pad according to the present invention has a bearing portion provided with a gas bearing surface formed with a jet port for ejecting gas toward the bearing guide surface of the static pressure gas bearing in a direction perpendicular to the housing. Since the advance / retreat mechanism for advancing and retreating is provided, the vertical distance between the member to which the housing portion is attached and the bearing guide surface can be kept constant even if the accuracy of the bearing guide surface is insufficient.

It is a front view which shows the structure of the XY table apparatus which is one Embodiment of the movement table apparatus which concerns on this invention. It is sectional drawing which shows the air pad of the XY table apparatus of FIG. It is sectional drawing which shows the air pad of a 1st modification. It is sectional drawing which shows the air pad of a 2nd modification. It is sectional drawing which shows the air pad of the 2nd modification at the time of non-air supply. It is sectional drawing which shows the air pad of a 3rd modification. It is sectional drawing which shows the air pad of a 4th modification. It is a front view which shows the structure of the conventional XY table apparatus. It is a front view which shows the structure of another conventional XY table apparatus.

Embodiments of a moving table device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing a structure of an XY table device which is an embodiment of a moving table device according to the present invention. FIG. 2 is a cross-sectional view of an air pad used in the XY table device of FIG.
Two linear motion guide devices 4 and 4 are fixed side by side on the upper surface of the flat base 2 so as to be parallel to each other. On the two linear motion guide devices 4 and 4, a rectangular flat plate-like moving table 1 is placed and fixed. The longitudinal direction of the moving table 1 and the axial direction of the linear motion guide device 4 (hereinafter sometimes referred to as “X direction”) are parallel to each other.

More specifically, the guide rails 4a and 4a of the linear motion guide devices 4 and 4 are fixed to the upper surface of the base 2, and the linear motion guide devices 4 and 4 attached to the guide rails 4a and 4a so as to be movable in the axial direction. Sliders 4b and 4b are attached to both ends in the width direction of the lower surface of the moving table 1, respectively.
Therefore, the linear guide devices 4 and 4 arranged between the base 2 and the moving table 1 function as a guide mechanism for guiding the linear movement of the moving table 1 while supporting the moving table 1 on the base 2. Since the number of the linear motion guide devices 4 is two, there is almost no problem that adjustment during assembly as in the linear motion table device of FIG. 8 is very difficult.

  A ball screw 3 is attached to the center of the lower surface of the moving table 1 in the width direction. The axial direction of the ball screw 3 is parallel to the longitudinal direction of the moving table 1. The ball screw 3 is connected to a driving device (not shown) such as a motor that rotationally drives the screw shaft. Therefore, when the screw shaft is rotated by the driving device, the nut of the ball screw 3 moves in the X direction, so that the moving table 1 is guided by the linear motion guide devices 4 and 4 and moves on the base 2 in the X direction. It becomes.

Further, a plurality of air pads 6 are attached to the lower surface of the moving table 1 facing the upper surface of the base 2. More specifically, the plurality of air pads 6 are attached in a line along the entire length of the moving table 1 at a position between the linear motion guide device 4 and the ball screw 3 in the width direction of the moving table 1. .
The air pad 6 includes a gas bearing surface 10 a in which a jet port 10 b for ejecting a gas such as air is formed, and the bearing guide surface 2 a of the static pressure gas bearing in which the gas bearing surface 10 a is formed on the upper surface of the base 2. Is attached to the lower surface of the movable table 1. Therefore, the gas bearing surface 10a of the air pad 6 is opposed to the bearing guide surface 2a of the base 2 via a gap (bearing gap), and if gas is ejected from the gas bearing surface 10a toward the bearing guide surface 2a, A static pressure gas bearing (non-contact bearing) is configured between the bearing guide surface 2a and the gas bearing surface 10a.

  Here, the structure of the air pad 6 will be described in more detail with reference to FIG. The air pad 6 includes a substantially cylindrical bearing portion 10 and a housing portion 11 having a substantially cylindrical concave portion 11 a having a shape substantially corresponding to the outer diameter shape of the bearing portion 10. The housing portion 11 is fixed to the lower surface of the moving table 1 with the recess 11a facing the lower bearing guide surface 2a, and the bearing portion 10 is accommodated in the recess 11a of the housing portion 11.

  One of the two parallel planes of the substantially cylindrical bearing portion 10 faces the bottom surface of the recess 11 a of the housing portion 11. The other of the two parallel planes is exposed to the outside of the recess 11a and faces the bearing guide surface 2a, forming a gas bearing surface 10a that is a component of the hydrostatic gas bearing. The gas bearing surface 10 a is formed with a plurality of ejection ports 10 b that eject gas toward the bearing guide surface 2 a of the static pressure gas bearing formed on the upper surface of the base 2.

  The gas ejected from the ejection port 10b is introduced into the air pad 6 from an air supply port 13 opened on the outer surface of the housing part 11, and is formed in the air pad 6 (the housing part 11 and the bearing part 10). 14 is supplied to the spout 10b. That is, the air passage 14 of the housing portion 11 passes through the inside of the housing portion 11 to reach the bottom surface of the concave portion 11a and is connected to the air passage 14 of the bearing portion 10 that opens in a plane facing the bottom surface of the concave portion 11a of the housing portion 11. To do. In order to prevent gas leakage, a seal such as an O-ring 15 is attached to the connection portion between the air passages 14 and 14. The air passage 14 of the bearing portion 10 passes through the inside of the bearing portion 10 and is connected to a jet port 10b formed in the gas bearing surface 10a. The gas may be directly introduced into the bearing portion 10 without passing through the housing portion 11.

  Further, the air passage 14 of the bearing portion 10 branches inside the bearing portion 10 and opens to the cylindrical surface of the bearing portion 10. That is, a jet port 10c for jetting gas is also formed on the cylindrical surface of the bearing portion 10, and the gas is jetted to the cylindrical surface of the concave portion 11a of the housing portion 11 that faces the cylindrical surface of the bearing portion 10 through a gap. Thus, a static pressure gas bearing (non-contact bearing) is formed between both cylindrical surfaces. As for the static pressure gas bearing between the two cylindrical surfaces, the bearing clearance is set wide and the bearing rigidity is low so as not to disturb the advance and retreat of the bearing portion 10 and to convey the influence of the inclination direction of the bearing guide surface 2a. Is preferred. However, if the bearing rigidity is too low, a resonance phenomenon may occur. Therefore, it is necessary to set the bearing rigidity to a level that does not cause the resonance phenomenon.

  Further, the housing portion 11 is provided with a through hole 16 (for example, a through hole extending in a direction parallel to the gas bearing surface 10a) that communicates the inner peripheral surface and the outer peripheral surface of the recess 11a. The gas ejected from the ejection port 10c formed in the cylindrical surface toward the cylindrical surface of the concave portion 11a of the housing portion 11 is opened downward (the cylindrical surface of the bearing portion 10 and the concave portion of the housing portion 11). 11a and the cylindrical surface of 11a) and the through hole 16 are also discharged to the outside of the air pad 6.

  Further, a bottomed hole 22 is formed at the center of the bottom surface of the recess 11a of the housing part 11, and an advancing / retreating mechanism for advancing and retracting the bearing part 10 in the direction perpendicular to the gas bearing surface 10a in the bottomed hole 22. The spring which comprises is arrange | positioned. That is, the bearing portion 10 is held in the recess 11a of the housing portion 11 so as to be able to advance and retract in the direction perpendicular to the gas bearing surface 10a. In the example of FIG. 2, a coil spring 20 is arranged as an advance / retreat mechanism, and this coil spring 20 applies a biasing force in the vertical direction of the gas bearing surface 10 a to the housing portion 11 and the bearing portion 10. More specifically, the coil spring 20 applies a biasing force directed upward in the vertical direction of the gas bearing surface 10a to the housing portion 11, and applies a biasing force directed downward in the vertical direction of the gas bearing surface 10a to the bearing portion 10. The spring constant of the coil spring 20 may be appropriately selected according to the strength of the urging force to be applied to the housing portion 11 (that is, the force to be applied to the moving table 1).

  A magnet 23 is attached to the outer peripheral portion of the bottom surface of the recess 11 a of the housing portion 11, and the bearing portion 10 is drawn toward the bottom surface side of the housing portion 11 by the magnetic force of the magnet 23. A biasing force directed downward in the vertical direction of the gas bearing surface 10a is applied to the bearing portion 10 by the coil spring 20, but since it is attracted by the magnet 23, the hydrostatic gas bearing is not operated (for example, during maintenance). The bearing portion 10 does not fall off the housing portion 11.

  Further, on the moving table 1, the moving direction is a direction orthogonal to the moving direction of the moving table 1 (that is, the width direction of the moving table 1 and may be referred to as “Y direction” hereinafter). A moving table 5 is provided. Although not shown, a linear motion guide device and a ball screw are arranged between the moving table 1 and the moving table 5, and the above-described mechanism provided between the base 2 and the moving table 1 By the same mechanism, the moving table 5 is guided by the linear motion guide device and moves on the moving table 1 in the Y direction. That is, the moving table 1 is a moving body that moves on the base 2 and at the same time has the role of the base of the moving table 5.

  Although not shown, a plurality of air pads are also attached to the lower surface of the moving table 5. Since the configuration of this air pad is exactly the same as that of the air pad 6, the bearing guide surface formed on the upper surface of the moving table 1 and the gas bearing surface of the air pad of the moving table 5 by the same mechanism as the air pad 6 of the moving table 1. A static pressure gas bearing (non-contact bearing) is formed between the two.

  Next, the operation of the XY table device of this embodiment will be described. When the gas is introduced into the air pad 6 from the air supply port 13, the gas is ejected from the outlet 10 b formed in the gas bearing surface 10 a of the bearing portion 10 toward the bearing guide surface 2 a of the base 2, and the bearing portion 10. Gas is ejected from the jet outlet 10c formed on the cylindrical surface of the cylindrical portion toward the cylindrical surface of the recess 11a of the housing portion 11. As a result, a static pressure gas bearing is formed between the gas bearing surface 10a of the bearing portion 10 and the bearing guide surface 2a of the base 2, and the cylindrical surface of the bearing portion 10 and the cylindrical surface of the recess 11a of the housing portion 11 A static pressure gas bearing is formed between the two.

  Since a static pressure gas bearing is formed between both cylindrical surfaces, the bearing portion 10 and the housing portion 11 are maintained in a non-contact state on both cylindrical surfaces, and the bearing portion 10 can smoothly advance and retract. Further, since a static pressure gas bearing is configured between the gas bearing surface 10a of the bearing portion 10 and the bearing guide surface 2a of the base 2, a force directed upward in the vertical direction of the gas bearing surface 10a is applied to the bearing portion 10. Thus, the non-contact state between the gas bearing surface 10a of the bearing portion 10 and the bearing guide surface 2a of the base 2 is maintained.

As described above, the bearing portion 10 is applied with a biasing force directed downward in the vertical direction of the gas bearing surface 10a by the coil spring 20 (that is, a preload is applied to the bearing portion 10 by the coil spring 20). The bearing portion 10 is held in the concave portion 11 a of the housing portion 11 at a height position where the urging force by 20 and the force by the static pressure gas bearing are balanced.
The movable table 1 is supported by linear motion guide devices 4 and 4 at both ends in the width direction, and the central portion in the width direction is not supported. Therefore, the movable table 1 receives a load due to the weight of the movable table 1 and the mass of the load. However, since a force directed upward in the vertical direction acts on the central portion in the width direction of the movable table 1 by forming the static pressure gas bearing, the central portion in the width direction of the movable table 1 is upward. Lifted.

  Therefore, if the gas ejection pressure from the gas bearing surface 10a of the air pad 6 is set according to the weight of the moving table 1 and the mass of the load, etc., and the coil spring 20 that gives an appropriate urging force is selected, The central part of the moving table 1 in the table width direction is lifted upward, and the bending deformation due to the weight of the moving table 1 and the load of the load is suppressed. Alternatively, bending deformation of the moving table 1 due to movement of a load such as the moving table 5 loaded on the moving table 1 can also be suppressed.

  Therefore, the distance (vertical direction distance) between the moving table 1 and the base 2 can be made constant over the entire width direction of the moving table 1. In addition, since the air pads 6 are attached in a straight line over the entire longitudinal direction (moving direction) of the moving table 1, the distance (vertical distance) between the moving table 1 and the base 2 is set to the entire surface of the moving table 1. Can be constant over time.

Further, when the width of the moving table 1 is large, the moving table 1 is likely to be bent and deformed, but even in such a case, it is not necessary to increase the thickness of the moving table 1 in order to suppress the bending deformation. Therefore, even when the width of the moving table 1 is large, the XY table device can be made thin.
In the conventional product that does not have the above-mentioned advance / retreat mechanism in the air pad, if the accuracy of the bearing guide surface of the base is low, the clearance (bearing clearance) between the gas bearing surface and the bearing guide surface increases as the moving table moves. May fluctuate. For example, when the bearing gap increases, the force directed upward in the vertical direction of the gas bearing surface applied to the bearing portion by the static pressure gas bearing decreases, so the force directed upward in the vertical direction applied to the moving table also decreases, There is a risk that the moving table may bend downward and deform. In addition, when the bearing gap is reduced, the force directed upward in the vertical direction of the gas bearing surface applied to the bearing portion by the static pressure gas bearing increases, so the force directed upward in the vertical direction applied to the moving table also increases. There is a risk that the moving table may bend upward and deform.

  However, since the XY table device of the present embodiment includes an advance / retreat mechanism that advances and retracts the bearing portion 10 in the direction perpendicular to the gas bearing surface 10a, the accuracy of the bearing guide surface 2a of the base 2 is low and the movement table 1 can be moved. Accordingly, even if the size of the gap (bearing gap) between the gas bearing surface 10a and the bearing guide surface 2a fluctuates, the movable table 1 hardly undergoes bending deformation, and the distance between the movable table 1 and the base 2 (vertical) Directional distance) is kept constant. Therefore, since the change in the core height of the ball screw 3 due to the deformation of the moving table 1 hardly occurs, the moving table 1 can be moved in a stable posture.

  This mechanism will be described in detail below. For example, if the bearing clearance is increased due to insufficient accuracy of the bearing guide surface 2a of the base 2, the force directed upward in the vertical direction of the gas bearing surface 10a applied to the bearing portion 10 by the static pressure gas bearing is reduced. Then, the balance between the biasing force by the coil spring 20 and the force by the static pressure gas bearing is lost, and the bearing portion 10 is moved downward by the biasing force of the coil spring 20 directed downward in the vertical direction of the gas bearing surface 10a (that is, The vertical length of the air pad 6 is increased). And the bearing part 10 is hold | maintained in the recessed part 11a of the housing part 11 in the height position where the urging | biasing force by the coil spring 20 and the force by a static pressure gas bearing balance.

  On the contrary, when the bearing clearance is reduced, the force directed upward in the vertical direction of the gas bearing surface 10a applied to the bearing portion 10 by the static pressure gas bearing is increased, but in this case, the biasing force and the static pressure gas by the coil spring 20 described above are increased. The balance with the force by the bearing is lost, and the bearing portion 10 moves upward by the force directed upward in the vertical direction of the gas bearing surface 10a applied to the bearing portion 10 by the static pressure gas bearing (that is, the vertical length of the air pad 6). Is smaller). And the bearing part 10 is hold | maintained in the recessed part 11a of the housing part 11 in the height position where the urging | biasing force by the coil spring 20 and the force by a static pressure gas bearing balance.

  Thus, when the bearing gap increases, the vertical length of the air pad 6 increases due to the bearing 10 moving downward, and when the bearing gap decreases, the air pad 6 moves upward due to the bearing 10 moving upward. Therefore, even if the bearing gap fluctuates with the movement of the moving table 1, the gas bearing surface of the air pad 6 that is initially set according to the weight of the moving table 1, the mass of the load, etc. The distance (vertical direction distance) between the moving table 1 and the base 2 is kept constant without adjusting the gas ejection pressure from 10a according to the variation of the bearing gap. Therefore, the movable table 1 can always be moved in a stable posture without being affected by the accuracy of the bearing guide surface 2a.

  In addition, about the advance / retreat mechanism, the following modifications can be employed. For example, the advance / retreat mechanism may include an adjustment mechanism that adjusts the biasing force of the spring. FIG. 3 shows an example (first modification) in which a spacer 21 is used as the adjustment mechanism. That is, if the compression amount of the coil spring 20 is adjusted by arranging, for example, an annular spacer 21 between the bottom of the bottomed hole 22 and the coil spring 20, the strength of the urging force can be adjusted. Further, the strength of the biasing force can be adjusted by adjusting the thickness of the spacer 21 and the vertical position where the spacer 21 is provided. In addition, illustration of the movement table 1 is abbreviate | omitted in FIGS.

  Moreover, as shown in FIG. 4, the coil spring 20 and the air spring by gas supply can also be used together as an advancing / retreating mechanism (2nd modification). If the bottomed hole 22 provided with the coil spring 20 is sealed with an O-ring 17 or the like, and the gas is supplied to the space of the sealed bottomed hole 22 to make a positive pressure, the housing portion is applied by the biasing force of the coil spring 20 and the air spring. 11 and the bearing portion 10 can be applied with an urging force in the vertical direction of the gas bearing surface 10a. Further, by adjusting the pressure in the space of the bottomed hole 22, the strength of the urging force in the vertical direction of the gas bearing surface applied to the housing part 11 and the bearing part 10 can be reduced without using the spacer 21. Can be adjusted.

  Further, if the attraction force of the magnet 23 is larger than the biasing force of the coil spring 20, the bearing portion 10 is in contact with the bottom surface of the recess 11 a of the housing portion 11 when the gas is not supplied to the bottomed hole 22. (See FIG. 5). Then, since a large gap can be provided between the gas bearing surface 10a of the bearing portion 10 and the bearing guide surface 2a of the base 2, the movable table 1 is moved even in a situation where the static pressure gas bearing is not functioning. be able to. Therefore, it is possible to manually move the moving table 1 during maintenance of the XY table device. However, when it is difficult to weaken the urging force of the coil spring 20, the bearing portion 10 is moved upward by moving the bearing portion 10 upward by making the space of the bottomed hole 22 negative pressure. It is good also as the state which contacted the bottom face of the recessed part 11a.

  In addition, since supply of the gas to the space of the bottomed hole 22 may not be stable and the pressure in the space of the bottomed hole 22 may become unstable, it is applied to the housing portion 11 and the bearing portion 10. In order to stabilize the strength of the urging force in the vertical direction of the gas bearing surface 10a, it is preferable to apply the urging force with the coil spring 20 as a main component. Further, when the XY table device is used under a positive pressure or negative pressure condition, the pressure in the space of the bottomed hole 22 may fluctuate, so that the gas applied to the housing part 11 and the bearing part 10 In order to stabilize the strength of the urging force in the vertical direction of the bearing surface 10a, it is preferable to apply the urging force with the coil spring 20 as a main component.

  Furthermore, as shown in FIG. 6, the advance / retreat mechanism can be configured by only an air spring by gas supply without using the coil spring 20 (third modification). If a bottomed hole 24 is provided in the center of the bottom surface of the recess 11a of the housing part 11 and a gas is supplied to the space of the bottomed hole 24 sealed with an O-ring 25 or the like to generate a positive pressure, the housing part 11 and the bearing part 10 can be applied with a biasing force in the vertical direction of the gas bearing surface 10a.

  Further, by adjusting the pressure in the space of the bottomed hole 24, the strength of the urging force in the vertical direction of the gas bearing surface 10a applied to the housing portion 11 and the bearing portion 10 can be adjusted. Furthermore, the strength of the urging force can be dynamically adjusted by adjusting the pressure in the space of the bottomed hole 24. This dynamic adjustment of the strength of the urging force is also possible in the second modification. Furthermore, since the coil spring 20 is not provided, when the gas is not supplied to the bottomed hole 22, the bearing portion 10 can be brought into contact with the bottom surface of the concave portion 11 a of the housing portion 11 by the attractive force of the magnet 23. .

  Furthermore, as shown in FIG. 7, it can also be set as the structure which does not use the magnet 23 in a 3rd modification (4th modification). When the XY table device of the fourth modification is used with the gas bearing surface 10a of the bearing portion 10 facing downward in the direction of gravity, in order to prevent the bearing portion 10 from falling off during maintenance of the XY table device. The space of the bottomed hole 24 is preferably a negative pressure. Further, the XY table device of the fourth modification is suitable for use when the gas bearing surface 10a of the bearing portion 10 is directed upward in the gravity direction. When the gas bearing surface 10a of the bearing portion 10 is used facing upward in the direction of gravity, the means for preventing the drop-out of the bearing portion 10 is unnecessary, and therefore the space of the bottomed hole 24 does not need to be set to a negative pressure.

Such an XY table apparatus of this embodiment is used in an exposure apparatus (for example, a semiconductor exposure apparatus for forming a pattern on a flat substrate such as a semiconductor wafer or a liquid crystal panel), an assembly apparatus, an inspection apparatus, a precision machine tool, or the like. It can be used as a positioning device to be used.
For example, an exposure apparatus that exposes a semiconductor wafer to form a pattern places a semiconductor wafer, which is a material to be exposed, and moves the wafer to position the semiconductor wafer, and irradiates the positioned semiconductor wafer with exposure light. An optical system and a control device for controlling them are provided. As the positioning device, the XY table device of this embodiment is preferably used.

After driving the XY table device on which the wafer is placed on the moving table and moving the wafer to a predetermined position, exposure is performed by irradiating the wafer with exposure light from the light source of the optical system to form a pattern on the wafer. . When the exposure is completed, the XY table device is driven to move another wafer to a predetermined position, and exposure is performed in the same manner as described above to form a pattern on the wafer.
In the XY table device of the present embodiment used as a positioning device in such an exposure apparatus, the movable table is less likely to be deformed, and the movable table can be moved in a stable posture. It is.

  In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, the XY table device has been described as an example of the moving table device. However, the present invention is not limited to this, and the present invention is a linear table device that linearly moves the moving table in one direction. It can also be applied to. The present invention can also be applied to a rotary table device that rotates a movable table supported on a base by a guide mechanism that guides the rotation of the movable table.

In this embodiment, the ball screw 3 is used as a feed mechanism for moving the movable table 1, but the feed mechanism is not limited to the ball screw.
Furthermore, the type of spring is not limited to a coil spring or an air spring, and other types of springs such as a leaf spring can be used. Also, a spring made of a lump of elastic material such as rubber can be used. Furthermore, the material of the coil spring and the leaf spring is not limited to metal, and resin material, wood, bamboo, or the like can also be used.

  In addition to the self-contained throttles shown in FIGS. 2-7, there are other types of throttles for hydrostatic gas bearings, such as orifice throttles, surface throttles, and porous throttles. Any type can be used in the present invention. is there. However, among these, the self-contained drawing is preferable because it uses a drill hole as a drawing and is easy to manufacture.

DESCRIPTION OF SYMBOLS 1 Moving table 2 Base 2a Bearing guide surface 3 Ball screw 4 Linear motion guide device 4a Guide rail 4b Slider 5 Moving table 6 Air pad 10 Bearing part 10a Gas bearing surface 10b Outlet 11 Housing part 11a Concave 20 Coil spring 21 Spacer 22 Bottomed Hole 24 Bottomed hole

Claims (11)

A base having a bearing guide surface of a hydrostatic gas bearing; a moving table that linearly moves or rotates on the base; and the movable table arranged between the base and the moving table while supporting the moving table on the base A moving table device comprising a guide mechanism for guiding linear movement or rotation of the moving table,
The bearing guide surface and the gas bearing surface are provided by having a gas bearing surface formed with an ejection port for ejecting gas, and ejecting gas from the gas bearing surface toward the bearing guide surface facing through a bearing gap. An air pad capable of constituting a static pressure gas bearing is fixed to a surface facing the base of the moving table with the gas bearing surface facing the bearing guide surface,
The air pad includes a bearing portion including the gas bearing surface, and a housing portion that is fixed to the moving table and holds the bearing portion, and the housing portion is configured such that the gas bearing surface is exposed. Having a recess for accommodating the portion, holding the bearing portion in the recess so as to be movable back and forth in a direction perpendicular to the gas bearing surface,
Further, the air pad includes an advance / retreat mechanism that advances and retracts the bearing portion in the vertical direction of the gas bearing surface to maintain a constant vertical distance between the moving table and the base ,
The retractable mechanism, Ri Oh spring for imparting a biasing force in the vertical direction of the gas bearing surface and the bearing portion and the housing portion disposed between said housing portion and the bearing portion,
The moving table device, wherein the advance / retreat mechanism includes an adjustment mechanism for adjusting an urging force of the spring. The moving table device according to claim 1 , wherein the spring is at least one of a coil spring and an air spring. The moving table device according to claim 1, wherein a magnet that attracts the bearing portion to the bottom surface side of the concave portion of the housing portion by a magnetic force is attached to the bottom surface of the concave portion of the housing portion. The moving table device according to claim 3, wherein the spring is a coil spring, and the attracting force of the magnet is larger than the biasing force of the coil spring. The spring is an air spring, and the air spring is configured by providing a bottomed hole in the center of the bottom surface of the concave portion of the housing part, and supplying a gas to the space of the bottomed hole to make a positive pressure.
The said adjustment mechanism is a movement table apparatus as described in any one of Claims 1-3 comprised by adjustment of the pressure of the space of the said bottomed hole. An exposure apparatus that includes a positioning device that places and moves the exposed material and positions the exposed material, and irradiates exposure light onto the positioned exposed material to form a pattern, the positioning device An exposure apparatus using the moving table device according to any one of claims 1 to 5 . A bearing portion having a gas bearing surface formed with a jet port for ejecting gas toward the bearing guide surface, and capable of forming a static pressure gas bearing between the bearing guide surface and the gas bearing surface;
A housing portion for accommodating the bearing portion so that the gas bearing surface is exposed, and a housing portion for holding the bearing portion in the recess so as to be movable back and forth in a direction perpendicular to the gas bearing surface;
An advancing / retreating mechanism arranged between the housing part and the bearing part for advancing and retracting the bearing part in a direction perpendicular to the gas bearing surface;
Equipped with a,
The retractable mechanism, Ri Oh spring for imparting a biasing force in the vertical direction of the gas bearing surface and the housing portion and the bearing portion,
The air pad, wherein the advance / retreat mechanism includes an adjustment mechanism for adjusting an urging force of the spring.   The air pad according to claim 7, wherein the spring is at least one of a coil spring and an air spring. The air pad according to claim 7 or 8, wherein a magnet for attracting the bearing portion to the bottom surface side of the concave portion of the housing portion by a magnetic force is attached to the bottom surface of the concave portion of the housing portion. The air pad according to claim 9, wherein the spring is a coil spring, and the attraction force of the magnet is greater than the urging force of the coil spring. The spring is an air spring, and the air spring is configured by providing a bottomed hole in the center of the bottom surface of the concave portion of the housing part, and supplying a gas to the space of the bottomed hole to make a positive pressure.
The air pad according to any one of claims 7 to 9, wherein the adjustment mechanism is configured by adjusting a pressure in a space of the bottomed hole.

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