JP4623243B2 - Electromagnetic actuator and stage device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic actuator and a stage device, and more particularly to an electromagnetic actuator that obtains a driving force by a force due to electromagnetic interaction and a stage device that drives a stage by the electromagnetic actuator.
[0002]
[Prior art]
Conventionally, in a lithography process for manufacturing a semiconductor element, a liquid crystal display element or the like, a resist or the like is applied to a pattern formed on a mask or a reticle (hereinafter, collectively referred to as “reticle”) via a projection optical system. An exposure apparatus that transfers onto a substrate such as a wafer or a glass plate (hereinafter referred to as “sensitive substrate or wafer” as appropriate) is used. As such an exposure apparatus, a stationary exposure type projection exposure apparatus such as a so-called stepper and a scanning exposure type projection exposure apparatus such as a so-called scanning stepper are mainly used. In these types of projection exposure apparatuses, since a pattern formed on a reticle needs to be sequentially transferred to a plurality of shot areas on a wafer, a wafer stage that holds the wafer and can move two-dimensionally is provided. In the case of a scanning exposure type projection exposure apparatus, the reticle stage that holds the reticle is also movable in the scanning direction.
[0003]
In recent projection exposure apparatuses, electromagnetic actuators such as so-called linear motors and voice coil motors are used as drive sources for reticle stages, wafer stages, and the like. This is because the electromagnetic actuator has a simple structure, requires a small number of parts, has a low frictional resistance in driving, has high operation accuracy, and can be moved quickly because it is linearly driven directly. This is because it is suitable for meeting demands for improving the throughput and positioning accuracy related to the reticle stage, wafer stage, and the like.
[0004]
When a current is passed through a coil that is a component of such an electromagnetic actuator, heat is generated by the internal resistance of the coil itself. As a result, the internal resistance value of the coil itself changes with temperature, and the generated heat causes air fluctuations in the surrounding space or is transmitted to peripheral devices and causes thermal deformation. Therefore, in an exposure apparatus that performs precise position measurement using an optical interferometer and performs precise positioning, a device for effectively cooling an electromagnetic actuator such as a drive mechanism of a stage on which a reticle, a wafer or the like is placed has been devised. ing. For example, there have been proposed a system in which a coil cooling refrigerant flows around the coil and a system in which a heat insulating material is disposed between the coil and the peripheral member (Japanese Patent No. 2661902).
[0005]
[Problems to be solved by the invention]
By the way, in a reticle stage or wafer stage in a projection exposure apparatus, it is required to position the lens at a predetermined position in as short a time as possible in order to improve throughput. It is necessary to provide high rigidity so as not to generate vibration. For this reason, the mass of the stage has to be large, and the electromagnetic actuator used for driving the stage is required to have a thrust performance that can drive a heavy stage with a large acceleration. In order to improve the thrust performance of the electromagnetic actuator in response to such a request, it is necessary to generate a large electromagnetic force. For example, when the Lorentz electromagnetic force method is adopted, the current flowing through the current path that generates the Lorentz electromagnetic force is increased, the length of the current path intersecting the magnetic flux, that is, the effective wire length is increased, or the magnetic flux density is increased. It is possible to do. Even when the variable magnetoresistive method is adopted, in order to increase the generated force, the coil current of the electromagnet is increased, the number of turns of the coil is increased to increase the magnetic force of the electromagnet, or the opposing magnetic poles It is conceivable to increase the magnetic flux density in the field gap.
[0006]
Here, in order to increase the magnetic flux density in the field gap, it is conceivable to increase the magnetic force of each field magnet or to narrow the width of the field gap. However, the magnetic force of the field magnet is increased to the maximum in view of the physical properties of the material selected from the viewpoint of mass productivity, and when the width of the field gap is reduced, the cross-sectional area of the refrigerant path is reduced, A sufficient amount of refrigerant cannot be ensured, leading to a decrease in cooling capacity, resulting in a decrease in position measurement accuracy and a decrease in exposure accuracy as described above.
[0007]
Therefore, it is realistic to increase the current flowing through the coil or increase the effective wire length of the coil, but in such a case, the amount of heat generated by the coil also increases. Therefore, if the current flowing through the coil is increased or the effective wire length of the coil is increased while maintaining the same electromagnetic actuator configuration as before, the amount of heat generated in the coil to the surroundings will increase. As a result, the gas in the surrounding atmosphere fluctuates to cause a change in the refractive index, or a large amount of heat is transmitted to the peripheral members to cause thermal expansion of the stage. In order to prevent this, if the flow path of the refrigerant is increased or a sufficient heat insulating material is inserted, the electromagnetic actuator is increased in size.
[0008]
The present invention has been made under such circumstances, and a first object thereof is to provide a linear actuator capable of efficiently cooling an armature unit and reducing heat transfer to the surroundings. There is.
[0009]
A second object of the present invention is to provide a stage apparatus capable of controlling the position with high accuracy.
[0010]
[Means for Solving the Problems]
  The first electromagnetic actuator of the present invention has an internal space, and an armature coil (84A) is provided in the internal space.₁... 84B₁In the electromagnetic actuator including an armature unit for storing the armature unit, a cooling space (83A) in which at least a part of the internal space is cooled, and a heat insulating space (83B) that insulates the cooling space and the external space. And a partition member (81) forming the armature coil (84A).₁... 84B₁,... Are housed in the cooling space, and the inside of the heat insulating space and the inside of the cooling space serve as passages for the flow of the heat insulating refrigerant and the flow of the cooling refrigerant, respectively. To do. The second electromagnetic actuator according to the present invention is an electromagnetic actuator having an internal space and an armature unit that houses an armature coil in the internal space, and at least a part of the internal space is cooled. Cooling space,in frontA heat insulating space that insulates the cooling space from the external space;To partition the cooling space and the heat insulation spaceA partition member disposed between the cooling space and the heat insulating space,The armature coil is accommodated in the cooling space,The inside of the heat insulating space and the inside of the cooling space serve as passages for the flow of heat insulating refrigerant and the flow of cooling refrigerant, respectively.
[0011]
  According to this, the armature coil is mainly cooled in the cooling space, and the heat generated in the armature coil by the heat insulation space is thermally insulated from the external space around the armature unit. That is, regarding the cooling function and the heat insulation function to be performed in the armature unit, the cooling function is performed in the cooling space, andNohSince the functions to be performed mainly for each space are shared, the heat generated in the armature coil can be efficiently removed and insulated.In addition, since the inside of the heat insulation space and the inside of the cooling space are passages for the flow of heat insulation refrigerant and the flow of cooling refrigerant, respectively.For example, a coolant having an excellent cooling function is supplied to the cooling space, and a fluid having a heat insulating function is supplied to the heat insulating space.PayThus, the cooling and heat insulation can be performed more efficiently than the conventional case where the internal space in which the armature coil is accommodated is not partitioned and the cooling and heat insulation are performed using one kind of refrigerant flow. Therefore, it is possible to reduce the width of the armature unit in the magnetic field, increase the effective wire length of the armature coil, Increase the supply current toStoryThus, thrust performance can be improved.
[0012]
In the electromagnetic actuator according to the present invention, the cooling space is a space extending in a predetermined direction, and the cooling space is surrounded by the at least one heat insulating space when viewed in an arbitrary cross section orthogonal to the predetermined direction. It is desirable that In such a case, since a heat insulating space is always interposed between the cooling space and the storage member in the direction orthogonal to the predetermined direction, it is more effectively achieved that the heat generated by the armature coil is not leaked to the outside. The
[0013]
  In the electromagnetic actuator of the present invention,,in frontThe wall surface on the cooling space side of the partition member is at least in front of the wall surface.ColdIt is desirable that the surface of the medium has a turbulent surface roughness. In such a case, since the turbulent flow of the refrigerant in the cooling space is promoted, the heat generated in the armature coil can be efficiently transmitted to the refrigerant, so that the armature coil is efficiently cooled by the refrigerant. can do.
[0014]
In the electromagnetic actuator of the present invention, it is desirable that the wall surface of the partition member on the heat insulating space side is mirror-finished when the refrigerant is supplied to the heat insulating space. In such a case, since it becomes easy to make the flow of the refrigerant in the heat insulation space into a laminar flow, the heat insulation function by the flow of the refrigerant can be easily achieved. Furthermore, an effective heat insulating function against radiant heat can be achieved by laminar flow.
[0015]
The electromagnetic actuator of the present invention may be a linear actuator whose driving direction is a predetermined axial direction, or a planar actuator whose driving direction is a two-dimensional direction. Further, the driving force generation method may be a Lorentz electromagnetic force method or a variable magnetoresistive method.
[0016]
In addition, the refrigerant used mainly for cooling the coil preferably has a large thermal conductivity, specific heat, and heat capacity, and the refrigerant used mainly for heat insulation of the generated heat of the coil is compared with the refrigerant. Those having low thermal conductivity, specific heat, and heat capacity are preferred.
[0017]
  The stage apparatus of the present invention is a stage apparatus that moves the stage (38) along a predetermined moving surface, and drives the stage (38).The present inventionA drive device (10) including the electromagnetic actuators (24, 26, 32, 34); and the cooling space (83A) and the heat insulation space (83B) of the electromagnetic actuators (24, 26, 32, 34), respectively. And a refrigerant supply device (71A, 71B) for supplying the refrigerant.
[0018]
  According to this, since the refrigerant supply device supplies the refrigerant to the cooling space and the heat insulation space of the present invention, and the driving device generates a driving force for moving the stage by the electromagnetic actuator of the present invention, The coil is efficiently cooled and insulated, and the stage can be driven while suppressing air fluctuations and thermal expansion of the stage in the air around the stage. Therefore, the position control of the stage can be performed with high accuracy.
  In this case, the refrigerant supplied to the cooling space and the refrigerant supplied to the heat insulation space can have different physical properties. The refrigerant supply device can also supply the refrigerant at different flow rates to the cooling space and the heat insulation space..
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of the overall configuration of an exposure apparatus 100 according to the present embodiment. The exposure apparatus 100 is a so-called step-and-scan exposure type projection exposure apparatus.
[0020]
The exposure apparatus 100 includes an illumination system IOP, a reticle stage RST that holds a reticle R, a projection optical system PL, a wafer stage apparatus 15 as a stage apparatus that drives a wafer W in an XY two-dimensional direction in the XY plane, and controls thereof. System.
[0021]
The illumination system IOP includes a light source unit, a shutter, a secondary light source forming optical system, a beam splitter, a condensing lens system, a reticle blind, an imaging lens system, and the like (all not shown). The configuration of the illumination system IOP is disclosed in, for example, JP-A-9-320956. The illumination light IL output from the illumination system 10 illuminates a rectangular (or arc-shaped) illumination area on the reticle R held on the reticle stage RST after being reflected by the bending mirror 62.
[0022]
On reticle stage RST, reticle R is fixed, for example, by vacuum suction. A movable mirror 64 that reflects a laser beam from a reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 66 is fixed on the reticle stage RST, and the position of the reticle stage RST in the stage moving plane is fixed to the reticle stage RST. By the interferometer 66, it is always detected with a resolution of about 0.5 to 1 nm, for example.
[0023]
Position information of reticle stage RST from reticle interferometer 66 is sent to stage control system 68 and main controller 60 via this, and stage control system 68 responds to instructions from main controller 60 in accordance with the position of reticle stage RST. Based on the information, reticle stage RST is driven via a reticle drive unit (not shown).
[0024]
The projection optical system PL is disposed below the reticle stage RST in FIG. 1, and the direction of the optical axis AX (coincident with the optical axis IX of the illumination optical system) is the Z-axis direction. Here, a refracting optical system composed of a plurality of lens elements arranged at a predetermined interval along the optical axis AX direction is used so as to provide a telecentric optical arrangement on both sides. The projection optical system PL is a reduction optical system having a predetermined projection magnification, for example, 1/5 (or 1/4). For this reason, when the illumination region of the reticle R is illuminated by the illumination light IL from the illumination optical system, the illumination light IL that has passed through the reticle R causes the circuit of the reticle R in the illumination region to pass through the projection optical system PL. A reduced image (partial inverted image) of the pattern is formed in an exposed region conjugate to the illumination region on the wafer W having a photoresist coated on the surface.
[0025]
The wafer stage device 15 includes a driving device 10, a wafer stage 36, a cooling controller 71A, and a cooling controller 71B.
[0026]
As shown in FIG. 2, the driving device 10 has a surface plate 12, an X guide 14 fixed on the surface plate 12, and a movement movable in the X direction along the upper surface of the surface plate 12 and the X guide 14. Body 16.
[0027]
As the surface plate 12, for example, a rectangular plate made of alumina ceramics that is lighter and less likely to be scratched than iron is used. The upper surface of the surface plate 12 is a reference surface.
[0028]
As said X guide 14, the thing made from alumina ceramics is used, for example. The X guide 14 is disposed in the vicinity of one end surface in the Y direction on the surface plate 12 along the X direction. The surface on the other end side in the Y direction of the X guide 14 is a reference surface.
[0029]
The movable body 16 includes a first Y guide transport body 18 made of an L-shaped cross section disposed along the X direction on the surface plate 12 in the vicinity of the X guide 14, and the first Y guide transport. A second Y guide transport body 20 composed of an elongated plate-like member disposed on the surface plate 12 at a predetermined distance from the body 18 in parallel with the first Y guide transport body 18, and the first and second The Y guide 22 is extended between the Y guide carriers 18 and 20 and extends in the Y direction.
[0030]
On one side of the X guide 14 on the surface plate 12 in the Y direction, an armature unit 24A as a stator of the first X linear motor 24 extends in the X direction in the vicinity of the X guide 14. . Further, an armature unit 26A as a stator of the second X linear motor 26 is provided on the other side in the Y direction of the second Y guide conveyance body 20 in the vicinity of the other end portion in the Y direction on the surface plate 12. It extends in the X direction. That is, in the present embodiment, so-called moving magnet type linear motors are used as the first and second X linear motors 24 and 26.
[0031]
A magnetic pole unit (movable element) 24 </ b> B as a magnetic field generating unit of the first X linear motor 24 is connected to one end of the Y guide 22 via a connecting member 28, and the magnetic pole unit 26 </ b> B of the second X linear motor 26. Is connected to the other end of the Y guide 22 via a connecting member 30. For this reason, the moving body 16 is driven in the X direction by the movement of the movers 24B and 26B of the first and second X linear motors 24 and 26.
[0032]
On one side and the other side of the Y guide 22 in the X direction, armature units (stator) 32A, 34A of the first and second Y linear motors 32, 34 are arranged along the Y direction. It is suspended between the second Y guide transport bodies 18 and 20. However, in FIG. 2, the magnetic pole unit of the second Y linear motor on the back side is not shown. As the first and second Y linear motors, moving magnet type linear motors are used.
[0033]
The wafer stage 36 includes a top plate 38 and a bottom plate 40 arranged in parallel to each other with the Y guide 22 sandwiched from above and below and substantially parallel to the upper surface (reference surface) of the surface plate 12, and the top plate 38 and A pair of Y-direction bearing bodies 42, 42 that connect the bottom plate 40 to each other on both sides of the Y guide 22 are provided. These Y-direction bearing bodies 42 and 42 are arranged in parallel to the Y guide 22 in a state where a predetermined gap is formed between the Y-direction bearing bodies 42 and 42. The magnetic pole units 32B and 34B (34B not shown) of the first and second Y linear motors 32 and 34 described above are attached to the outer surfaces of these Y-direction bearing bodies 42 and 42, respectively. The wafer stage 36 is driven in the Y direction by the movement of the armature units 32B, 34B of the linear motors 32, 34. Further, an air blowing portion (not shown) is provided on the inner surface of the Y-direction bearing body 42. Furthermore, the dimension in the height direction of these Y-direction bearing bodies 42 is set to be larger than that of the Y guide 22.
[0034]
The top plate 38 also serves as a substrate table. The top plate 38 is radiated from the X-coordinate measurement laser interferometer 44 and the Y-coordinate measurement laser interferometer 46 fixed on the surface plate 12. An X moving mirror 48, a Y moving mirror 50, and a wafer W that reflect the laser beam are mounted. The wafer W is actually mounted on the top plate 38 via a Z leveling stage (not shown) that can move up and down (Z direction) and rotate around the X, Y, and Z axes. The position of the top plate 38 in the stage moving surface is always detected by the X coordinate measuring laser interferometer 44 and the Y coordinate measuring laser interferometer 46 with a resolution of about 0.5 to 1 nm, for example.
[0035]
Returning to FIG. 1, the position information of the top plate 38 from the X-coordinate measuring laser interferometer 44 and the Y-coordinate measuring laser interferometer 46 (not shown in FIG. 1, see FIG. 2) is obtained from the stage control system 68 and this. In response to an instruction from the main control device 60, the stage control system 68 sends the above armature units 24 </ b> A, 26 </ b> A from the current drive device 70 based on the position information of the top plate 38. The drive device 10 is controlled by adjusting the direction and magnitude of the current supplied to 32A and 34A.
[0036]
Here, when current is supplied from the current driving device 70 to the armature units 24A, 26A, 32A, and 34A, the armature units 24A, 26A, 32A, and 34A generate heat. Therefore, in order to cool the armature units 24A, 26A, 32A, and 34A, pure water (specific resistance is 18 MΩ / cm) as the first refrigerant.²The above is supplied from the cooling controller 71A to the driving device 10, and Fluorinert FC-77 (manufactured by Sumitomo 3M Co., Ltd., fluorine-based inert liquid) as the second refrigerant is supplied from the cooling controller 71B. It is supplied to the driving device 10. The pure water and Fluorinert FC-77 via the driving device 10 are returned to the cooling controller 71A and the cooling controller 71B, respectively. However, the coolant after heat absorption may be discharged to the outside without necessarily configuring such a circulation path of the coolant (pure water and Fluorinert FC-77).
[0037]
Further, the wafer stage device 15 is provided with vacuum preload type static pressure air bearings having an air ejection portion and a vacuum preload portion at various places, and an air pump (not shown) is used for controlling the air pressure. 15 is connected.
[0038]
Further, the apparatus shown in FIG. 1 includes an oblique incident light type focus detection system (focus detection system) for detecting the position in the Z direction (optical axis AX direction) of the exposure area portion on the surface of the wafer W and the vicinity thereof. ) Is a multipoint focus position detection system (not shown). The detailed configuration of this multipoint focus position detection system is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-283403.
[0039]
In exposure apparatus 100 of the present embodiment configured as described above, reticle R is illuminated with a rectangular (slit-shaped) illumination region having a longitudinal direction in a direction perpendicular to the scanning direction of reticle R. Then, the reticle R and the wafer W are synchronously moved in opposite directions, whereby the entire pattern formed in the pattern area of the reticle R is transferred to the shot area on the wafer W with an accurate projection magnification.
[0040]
Next, the linear motors 24, 26, 32, and 34 mounted on the wafer stage apparatus 15 shown in FIG. 2 will be described with reference to FIGS. Since the linear motors 24, 26, 32, and 34 are configured in the same manner, the linear motor 24 will be described below as an example.
[0041]
As described above, the linear motor 24 includes the armature unit 24A and the magnetic pole unit 24B.
[0042]
As shown in FIG. 3, the magnetic pole unit 24 </ b> B is made of a magnetic material, and has a U-shaped end surface and a magnetic pole base 72 extending in the stroke direction (X-axis direction). The field magnet group 74 is embedded on one side of the inner walls facing each other, and the field magnet group 76 is embedded on the other side of the inner walls facing each other. Here, the magnet group 74 is configured such that a field magnet 74N having an exposed magnetic pole surface of N poles and a field magnet 74S having an exposed magnetic pole surface of S poles are alternately arranged in the stroke direction. The exposed magnetic pole surface of the field magnet 74N and the exposed magnetic pole surface of the field magnet 74S have the same shape and have a width (l) in the stroke direction. The field magnet 74N and the field magnet 74S are arranged with a space having a width (L-1) in the stroke direction. The field magnet group 76 is configured by alternately arranging field magnets 76S having an exposed magnetic pole surface of S poles and field magnets 74N having an exposed magnetic pole surface of N poles in the stroke direction. The exposed magnetic pole surface of the field magnet 74N and the exposed magnetic pole surface of the field magnet 74S have the same shape as the exposed magnetic pole surface of the field magnet 74N or the exposed magnetic pole surface of the field magnet 74S. The field magnet 74N and the field magnet 76S are arranged so that the field magnet 74N and the field magnet 76S face each other with a gap.
[0043]
For this reason, the space between the field magnet group 74 and the field magnet group 76 has a period L along the stroke direction and a field in which an alternating magnetic flux in the direction perpendicular to the stroke direction (Y-axis direction) is generated. It is a void. The field magnet group 74, the field magnet group 76, the magnetic pole base 72, and the field gap constitute a magnetic circuit.
[0044]
In the magnetic pole unit 24B of the present embodiment, the field magnet group 74 and the field magnet group 76 are embedded in the magnetic pole base 72. However, the opposing inner wall of the magnetic pole base 72 is a flat surface, and the field magnet group 74 and the field magnet The magnetic pole unit can be configured by adhering the magnet group 76 to the opposing inner wall of the magnetic pole base 72 with an adhesive or the like.
[0045]
A schematic configuration of the armature unit 24A is shown in FIG. Here, FIG. 4A is a cross-sectional view of the armature unit 24A taken along a plane parallel to the XZ plane, and FIG. 4B is a cross-sectional view taken along the line AA in FIG.
[0046]
As shown in FIG. 4, the armature unit 24 </ b> A has an armature base 78 made of a non-magnetic metal or resin and a non-magnetic material, and has an open surface on one side of a hollow rectangular parallelepiped. And the opening is provided with a can 80 fixed to the surface on the + Z direction side of the armature base 78.
[0047]
A closed space formed by the armature base 78 and the can 80 is partitioned into a cooling space 83A and a heat insulating space 83B by a partition member 81 as a partition member. Here, when a cross section perpendicular to the stroke direction is viewed, as shown in FIG. 4B, the cooling space 83A is surrounded by the heat insulating space 83B. The partition member 81 is made of a metal such as SUS (stainless steel), which is a non-magnetic material, a resin such as a non-conductive plastic, or a ceramic, and both ends in the longitudinal direction are fixed to the can 80 with an adhesive or the like. The wall surface on the 83A side is processed to have a surface roughness that makes the flow of pure water turbulent along the wall surface. The wall surface of the partition member 81 on the heat insulating space 83B side is mirror-finished. Then, N flat coils 84A are provided in the cooling space 83A.₁... 84A_NFlat coil group 84A and N flat coils 84B (not shown) on the + Y direction side of the flat coil group 84A.₁... 84B_NA flat coil group 84 </ b> B is arranged.
[0048]
Each flat coil 84A_i84B_i(I = 1 to N) (hereinafter, arbitrary one is referred to as “flat coil 84”) is configured in the same manner, and its schematic configuration is shown in FIG. Here, when the flat coil 84 is viewed from the front side of the sheet of FIG. 4A, the front view is shown in FIG. 5A, the right side view is shown in FIG. The figure is shown in FIG. FIG. 5 shows a case where the number of turns is 3 for the purpose of drawing. Usually, since the electric wire is sufficiently thin compared to the width L / 3, the number of turns is larger than 3. Become.
[0049]
As comprehensively apparent from FIGS. 5A to 5C, the flat coil 84 is a planar coil having a hexagonal shape with a predetermined width in a front view. More specifically, the electric wire 90 is wound in a hexagonal shape in which both ends in the Z-axis direction are two apexes when viewed from the front, and is approximately 1/3 (= L) of the period L of the alternating magnetic flux in the magnetic pole unit 24B. / 3), and the maximum width in the stroke direction (X-axis direction) of the hollow portion is approximately 2L / 3. Further, the flat coil 84 is configured to form a hexagon that is substantially line symmetric with respect to an axis extending in the stroke direction passing through the coil center.
[0050]
As a result, the flat coil 84 is disposed in the field gap in which the alternating magnetic flux having the period L along the stroke direction formed by the magnetic pole unit 72 is generated, and the current (I) is supplied from the current driver 70 to the flat coil 84. Is supplied, only a force parallel to the stroke direction acts on the entire flat coil as a resultant force of Lorentz electromagnetic force generated on each side. The direction and magnitude of the force acting on the flat coil 84 is determined by the direction and magnitude of the current supplied from the current driving device 70 to the flat coil 84 and the flat coil, the alternating magnetic field, and the positional relationship.
[0051]
Further, the flat coil 84 is folded at both ends in the Z-axis direction, but is gently bent so that the electric wire 90 is not disconnected at the folded portion. As a result, as clearly shown particularly in FIG. 5B, in each of the folded portions, a space 92 extending in the stroke direction therein.₁, 92₂Is formed.
[0052]
The flat coil 84 as described above can be manufactured by winding a coil electric wire 90, producing a coil having a hexagonal column shape in the hollow portion, and then crushing the coil into a flat shape.
[0053]
Returning to FIG. 4, the flat coil group 84 </ b> A includes the flat coil 84 </ b> A configured as described above._iHowever, along the stroke direction, the flat coil 84A_iAre arranged in order so that sides parallel to the Z-axis are adjacent to each other. The flat coil group 84A includes each flat coil 84A._iSpace 92₁Support wire 86A as a linear support member penetrating through₁And each flat coil 84A_iSpace 92₂Support wire 86A as a linear support member penetrating through₂Is supported by. And support wire 86A₁86A₂One end is fixed to the can 80 via a spacer 82A, and the other end is fixed to the can 80 via a spacer 82B.
[0054]
Further, the flat coil group 84B is similar to the flat coil group in that the flat coil 84B._iHowever, along the stroke direction, the flat coil 84B_iAre arranged in order so that sides parallel to the Z-axis are adjacent to each other. The flat coil group 84B, like the flat coil group, has one end fixed to the can 80 via the spacer 82A and the other end fixed to the can 80 via the spacer 82B.₁, 86B₂Is supported by.
[0055]
In addition, support wire 86A₁86A₂, 86B₁, 86B₂The can 80 may be fixed directly by welding or the like without using the spacers 82A and 82B. In addition, support wire 86A₁86A₂, 86B₁, 86B₂With the tension applied to the support wire 86A₁86A₂, 86B₁, 86B₂May be fixed to the can 80.
[0056]
Support wire 86A₁86A₂, 86B₁, 86B₂The material is preferably a metal having high rigidity and low thermal conductivity, a resin such as ceramic or plastic. For example, there are high tension wires (spring steel, piano wire, etc.), coated conductors, nylon wires, metal strands, and the like. Also, using a Peltier element, support wire 86A₁86A₂, 86B₁, 86B₂It is also possible to provide a cooling function. In addition, support wire 86A₁86A₂, 86B₁, 86B₂If a shape memory alloy is used, the holding state of the flat coil 84 can be adjusted in accordance with the temperature of the refrigerant inside the can or the operating temperature of the coil.
[0057]
Furthermore, conductive support wire 86A₁86A₂, 86B₁, 86B₂Can be used as electrical wiring to each flat coil 84. In this case, separate electric wiring can be simplified inside the can.
[0058]
In addition, the can 80 is provided with an inlet 88A for supplying pure water, which is a refrigerant having a high cooling effect, to the cooling space 83A and an outlet 89A for discharging pure water from the cooling space 83A. Then, pure water is fed from the cooling controller 71A shown in FIG. 1 into the cooling space 83A via the inflow port 88A, and when passing through the cooling space 83A, the flat coil 84A._i84B_iExchange heat with In such heat exchange, the side wall surface of the cooling space 83A of the partition member 81 is processed to have a surface roughness so that the pure water flow becomes turbulent as described above, so that the number of Ray nozzles of the pure water flow is larger than the critical Reynolds number. Prone to large turbulence. When the pure water flow is turbulent, the heat transfer coefficient between the solid and the liquid is larger (ten to several tens of times) than that of the laminar flow, and rapid heat removal is performed. Flat coil 84A_i84B_iThe pure water that has become a high temperature by absorbing the heat generated in the above is discharged to the outside through the outlet 89A. Thus, the pure water discharged through the outlet 89A is returned to the cooling controller 71A through the liquid passage, where it is cooled again and sent into the cooling space 83A.
[0059]
Further, the can 80 is provided with an inlet 88B for supplying Florinart FC-77 to the heat insulating space 83B and an outlet 89B for discharging pure water from the heat insulating space 83B. Then, Fluorinert FC-77 is sent from the cooling controller 71B shown in FIG. 1 to the heat insulating space 83B via the inlet 88B, and performs heat exchange with the partition member 81 when passing through the heat insulating space 83B. . The side wall surface of the heat insulating space 83B of the partition member 81 is mirror-finished as described above, and it is difficult for turbulent flow to occur in the flow of Fluorinert FC-77 in the heat insulating space 83B, so that the heat absorbed from the partition member 81 is Before reaching the can 80, Fluorinert FC-77 is discharged from the outlet 89B. Thus, Fluorinert FC-77 discharged through the outlet 89B is returned to the cooling controller 71B via the liquid passage, where it is cooled again and sent into the cooling space 83A.
[0060]
In the linear motor 24, each flat coil 84A of the armature unit 24A._i84B_iThe current driver 70 controls the current supplied to the flat coil 84A._i84B_iThe magnetic pole unit 24 </ b> B is driven by the reaction force of the Lorentz electromagnetic force generated in the magnetic field. In driving the magnetic pole unit 24B, the flat coils 84A of the flat coil groups 84A and 84B are used._i84B_iSince the width L / 3 of the current path side is approximately 1/3 of the period L of the alternating magnetic flux in the magnetic pole unit 24B, the flat coils 84A arranged sequentially in the stroke direction_iOr flat coil 84B_iA three-phase current is supplied by the current driving device 70 to the flat coil group consisting of three continuous coils.
[0061]
In the linear motor 24 of the present embodiment configured as described above, each flat coil 84A of the armature unit 24A._i84B_iEach flat coil 84A is supplied to the cooling space 83A of the armature unit 24A while supplying current to the armature unit 24A._i84B_iIn addition to supplying pure water, which is a cooling refrigerant, the flat coils 84A are provided in the heat insulating spaces 83B._i84B_iBy supplying Fluorinert FC-77, which is a refrigerant for heat insulation of the heat generated in step 1, cooling and heat insulation can be performed efficiently. Therefore, desired cooling and heat insulation can be efficiently performed while narrowing the flow path of the refrigerant.
[0062]
For this reason, when the magnetic pole unit 24B is configured in the same manner as in the prior art and the width of the field gap is also the same as in the prior art, the coil 84A of the armature unit 24A can be obtained without reducing the magnetic flux density in the field gap._i84B_iThe number of turns of the electric wire can be increased, and the effective electric wire length can be increased. On the other hand, the flat coil 84A of the armature unit 24A._i84B_iWhen the number of turns of the electric wire is the same as that of the conventional wire, the width of the field gap can be reduced, and the magnetic flux density of the field gap can be increased without shortening the effective wire length. Therefore, the thrust performance of the linear motor can be improved.
[0063]
In addition, since the closed space formed by the armature base 78 and the can 80 is partitioned by the partition member 81 so that the cooling space 83A is surrounded by the heat insulating space 83B when the cross section perpendicular to the stroke direction is viewed. The flat coil 84A in the direction orthogonal to the stroke direction_i84B_iIt is possible to effectively reduce the leakage of heat generated in the outside.
[0064]
Therefore, in the wafer stage device 15 of this embodiment that uses the linear motor 24 and the linear motors 26, 32, and 34 configured in the same manner as a source of driving force, the cause of the decrease in position detection accuracy by the optical interferometer As a result, it is possible to effectively suppress fluctuations due to heat in the air around the wafer stage apparatus 15 and thermal expansion of the constituent members of the exposure apparatus 100 including the members constituting the wafer stage apparatus 15 itself. Therefore, the position control of the wafer W mounted on the wafer stage device 15 can be performed with high accuracy.
[0065]
Then, according to the projection exposure apparatus 100 of the present embodiment configured as described above, the wafer stage apparatus 15 controls the position of the wafer W with high accuracy, so that the exposure accuracy is improved and the wafer R is formed on the reticle R. The formed pattern can be transferred to the shot area of the wafer W.
[0066]
In the above embodiment, pure water is used as the cooling refrigerant supplied to the cooling space 83A. However, the cooling refrigerant has a high thermal conductivity, a large specific heat, and a large heat capacity, that is, a cooling medium. Any refrigerant that is highly effective can be used. In addition, although Fluorinert FC-77 is used as a heat insulating refrigerant supplied to the heat insulating space 83B, any refrigerant can be used as long as it has a low thermal conductivity, a low specific heat, and a small heat capacity, that is, a high heat insulating effect. . Note that the cooling refrigerant and the heat insulating refrigerant can be made the same refrigerant by adjusting the flow velocity and the like. Further, in the above-described embodiment, the cooling liquid is used for cooling the armature coil. However, it is possible to use a gaseous refrigerant as long as the fluid is a refrigerant.
[0067]
In the above-described embodiment, pure water is supplied as a refrigerant in cooling the cooling space 83A. However, the cooling space 83A is disposed in other heat exchange means, for example, the partition member 81 around the cooling space 83A. It is also possible to cool the inside of the cooling space 83A with a heat pipe or the like.
[0068]
In the above-described embodiment, the linear motor in which the flat coil is supported by the linear support member is applied to the wafer stage device 15. However, a linear motor having the same configuration as these can also be applied to the reticle stage RST. is there. In this case, it is possible to drive with a large thrust while suppressing the fluctuation of the air around the reticle stage RST due to heat and the thermal expansion of the members constituting the reticle stage RST. Therefore, the reticle mounted on reticle stage RST can be quickly moved in the Y-axis direction, and reticle R can be positioned with high accuracy.
[0069]
In the above embodiment, in the configuration of the linear motor, the armature unit is a stator and the magnetic pole unit is a mover. However, the armature unit can be a mover and the magnetic pole unit can be a stator. is there.
[0070]
In the above embodiment, the shape of the flat coil is a hexagonal shape, but other shapes are possible as long as the shape can be arranged in the stroke direction. Furthermore, the width of the current path side of the flat coil is set to 1/3 of the period of the alternating magnetic flux by the magnetic pole unit, and the three-phase current is supplied. However, the width of the current path side is set to 1 of the period of the alternating magnetic flux by the magnetic pole unit. The thrust performance can be improved even when n / n (n is an integer other than 2 and 3) and n-phase current is supplied.
[0071]
In the above embodiment, a flat coil is used. However, instead of the flat coil, for example, a coil wound around a winding bobbin can be used. Furthermore, the coil support member is not limited to a linear member, and may be, for example, a plate member.
[0072]
Moreover, in said embodiment, although it was one member 81 as a partition member, and the cross-sectional shape used the closed figure, the division by a partition member is not limited to this. In other words, the armature unit may be a section that forms a heat insulating space between the cooling space and the can in a direction in which the heat insulating function needs to be enhanced due to circumstances such as the need to narrow the width or the width of the refrigerant flow path cannot be taken. That's fine. For example, when it is desired to reduce the width of the refrigerant flow path in the magnetic flux direction, as shown in FIG.₁, 81₂The cooling space 83A and the two heat insulation spaces 83B₁, 83B₂It is also possible to partition it into In this case, the two heat insulating spaces 83B₁, 83B₂Each refrigerant inlet 88B₁88B₂In addition, it is necessary to provide an outlet (not shown).
[0073]
In the above embodiment, a permanent magnet is used as the field magnet of the magnetic pole unit. However, an electromagnet that generates lines of magnetic force in the same direction as the permanent magnet can be used instead of the permanent magnet.
[0074]
The present invention is not limited to the case where the Lorentz electromagnetic force is used as the driving force, and can be applied to an electromagnetic actuator using an armature coil such as a variable magnetoresistive method.
[0075]
The present invention also relates to a reduction projection exposure apparatus that uses ultraviolet light as a light source, a reduction projection exposure apparatus that uses soft X-rays having a wavelength of around 10 nm as a light source, an X-ray exposure apparatus that uses light as a wavelength around 1 nm, an EB (electron beam), It can be applied to all types of wafer exposure devices such as ion beam exposure devices, liquid crystal exposure devices, and the like. Step and repeat machines, step and scan machines, and step and stitching machines may be used.
[0076]
Furthermore, the present invention is not limited to application to an exposure apparatus, but is applicable to various apparatus driving devices such as a moving system of a three-dimensional measuring instrument that three-dimensionally measures the shape of an object, and various apparatuses using coils. Can also be applied.
[0077]
【The invention's effect】
As described above in detail, according to the electromagnetic actuator of the present invention, in the internal section of the armature unit, the cooling space and the heat insulating space for housing the armature coil are formed by the partition member. The heat generated in the armature coil is removed, and the heat generated in the armature coil can be effectively removed and insulated by mainly performing heat insulation between the internal space and the external space in the heat insulation space.
[0078]
Further, according to the stage apparatus of the present invention, the stage driving force is generated by the electromagnetic actuator of the present invention, so that the stage is driven while suppressing air fluctuation and thermal expansion of the stage surrounding air. Can do. Therefore, the position control of the stage can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a view showing a schematic configuration of an exposure apparatus according to an embodiment.
2 is a diagram for explaining a detailed configuration of a driving device and a wafer stage that constitute the wafer stage device of the apparatus of FIG. 1; FIG.
3 is a view showing a schematic configuration of a magnetic motor magnetic pole unit used in the wafer stage apparatus of FIG. 2;
4 is a diagram showing a schematic configuration of an armature unit of a linear motor used in the wafer stage apparatus of FIG. 2 (A, B).
5 is a diagram for explaining a configuration of a flat coil used in the armature unit of FIG. 4 (A to C);
FIG. 6 is a diagram illustrating a schematic configuration of an armature unit of a linear motor according to a modification.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Drive apparatus, 15 ... Wafer stage apparatus (stage apparatus), 24, 26, 32, 34 ... Linear motor (electromagnetic actuator), 24A, 26A, 32A, 34A ... Armature unit, 24B, 26B, 32B, 34B ... Magnetic pole unit, 36 ... wafer stage (stage), 71A, 71B ... cooling controller (refrigerant supply device), 81 ... partition material (partition member), 83A ... cooling space, 83B ... insulation space, 84A_i84B_i... flat coil (armature coil).

Claims (8)

In an electromagnetic actuator comprising an armature unit having an internal space and storing an armature coil in the internal space,
A partition member that forms a cooling space in which at least a part of the internal space is cooled and a heat insulating space that insulates the cooling space and the external space is disposed in the internal space,
The armature coil is housed in the cooling space,
The electromagnetic actuator characterized in that the inside of the heat insulation space and the inside of the cooling space serve as passages for the heat insulation refrigerant flow and the cooling refrigerant flow, respectively. In an electromagnetic actuator comprising an armature unit having an internal space and storing an armature coil in the internal space,
In the internal space, a cooling space in which at least a part thereof is cooled, a heat insulating space that insulates the cooling space and the external space, and the cooling space and the heat insulating space to partition the cooling space and the heat insulating space. A partition member disposed between the heat insulating space and
The armature coil is accommodated in the cooling space,
The electromagnetic actuator characterized in that the inside of the heat insulation space and the inside of the cooling space serve as passages for the heat insulation refrigerant flow and the cooling refrigerant flow, respectively.   The cooling space is a space extending in a predetermined direction, and the cooling space is surrounded by the heat insulation space when viewed in at least an arbitrary cross section orthogonal to the predetermined direction. 2. The electromagnetic actuator according to 2.   The wall surface on the cooling space side of the partition member has at least a surface roughness at which the flow of the refrigerant along the wall surface becomes a turbulent flow. Electromagnetic actuator.   The electromagnetic actuator according to claim 1, wherein a wall surface of the partition member on the heat insulating space side is mirror-finished. A stage device for moving a stage along a predetermined moving surface,
A drive device including the electromagnetic actuator according to claim 1 and driving the stage;
A stage device comprising: a refrigerant supply device that supplies refrigerant to the cooling space and the heat insulation space of the electromagnetic actuator.   The stage apparatus according to claim 6, wherein the refrigerant supplied to the cooling space and the refrigerant supplied to the heat insulation space have different physical properties.   The stage device according to claim 6 or 7, wherein the refrigerant supply device supplies refrigerant to the cooling space and the heat insulation space at different flow rates.

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