JP4586367B2 - Stage apparatus and exposure apparatus - Google Patents

Description

  The present invention relates to a stage apparatus for precisely positioning an object to be processed and an exposure apparatus including the stage apparatus, and is suitable for use in a lithography process for manufacturing, for example, a semiconductor element, a liquid crystal display element, a thin film magnetic head, and the like. The present invention relates to a stage apparatus and an exposure apparatus.

2. Description of the Related Art Conventionally, in a lithography process, which is one of semiconductor device manufacturing processes, a circuit pattern formed on a mask or reticle (hereinafter referred to as a reticle) is applied to a wafer or glass plate coated with a resist (photosensitive agent). Various exposure apparatuses that transfer onto a photosensitive substrate are used.
For example, as an exposure apparatus for semiconductor devices, a reticle pattern is projected onto a wafer using a projection optical system in accordance with the miniaturization of the minimum line width (device rule) of a pattern accompanying the recent high integration of integrated circuits. A reduction projection exposure apparatus that performs reduction transfer is mainly used.

  As this reduction projection exposure apparatus, a step-and-repeat type static exposure type reduction projection exposure apparatus (so-called stepper) that sequentially transfers a reticle pattern to a plurality of shot areas (exposure areas) on a wafer, and this stepper Is a step-and-scan type scanning exposure apparatus (so-called scanning stepper) that transfers the reticle pattern to each shot area on the wafer by synchronously moving the reticle and wafer in a one-dimensional direction. It has been known.

  By the way, the exposure apparatus described above repeats exposure to other shot areas after exposure to a certain shot area on the wafer. Therefore, a wafer stage (in the case of a stepper) or a reticle stage and wafer stage ( (In the case of a scanning stepper), the relative vibration between the projection optical system and the wafer, etc. caused by the vibration and bias load caused by the movement of the projection, and the pattern is transferred to a position different from the design value on the wafer. If the error includes a vibration component, there is a possibility of causing image blur (increase in pattern line width). For this reason, conventionally, measures such as increasing the strength of members that generate vibrations and reducing the number of places that become sources of vibrations have been taken, but this measure causes problems such as increasing the weight and size of the device. Occurs.

  For this reason, Patent Document 1 discloses a stage apparatus in which a stage main body and a drive frame that are levitated and supported on a base are provided, and the drive frame moves backward as a counter mass by a reaction force accompanying the forward movement of the stage main body. According to this technology, the law of conservation of momentum works between the stage body and the drive frame, and the position of the center of gravity of the device on the base is maintained, resulting in vibration without increasing the weight and size of the device. It is possible to prevent a decrease in exposure accuracy.

  On the other hand, in the stage body, a cable for supplying electric power to driving means such as a motor arranged inside the stage body, a coolant pipe for cooling the motor, a coolant pipe for maintaining the substrate stage at a predetermined temperature, Connected to power supply members for supplying various powers (hereinafter these cables and pipes are collectively referred to as cables) such as vacuum pipes for evacuating the vacuum suction holes provided on the substrate mounting surface. Has been. These power supply members may give a tensile force as the stage main body moves, or may generate a slight vibration by the reaction force, thereby causing an error in the synchronization accuracy of the stage main body. Conventionally, the synchronization error caused by this fine vibration has been ignored. However, in recent years, it has been necessary to take measures against this error as the exposure accuracy increases with the miniaturization of the pattern.

Also in this regard, Patent Document 1 discloses that the mover provided on the stage main body and the mover provided on the carrier / follower to which the cable as the power supply member is connected have the same magnetic force as the stator. A technique is disclosed in which the magnetic flux is simultaneously generated from the track so that the carrier / follower moves following the movement of the stage body, and the tensile force applied to the stage body by the cable is removed.
JP-A-8-63231

However, if the stage body has a coarse movement stage that moves with a long stroke and a fine movement stage that moves with a fine stroke relative to the coarse movement stage, the position of the fine movement stage has conventionally been measured using a laser interferometer or the like. Although detected in both the scanning direction and the non-scanning direction (direction orthogonal to the scanning direction), the position of the coarse movement stage is detected only in the scanning direction.
Further, the movement of the stage body in the non-scanning direction has a short stroke and the reaction force has not been considered so much. However, in recent years, as the pattern line width to be transferred becomes fine, the non-scanning direction It is also considered to apply a reaction force process to the movement of. For this purpose, it is necessary to detect the position of the coarse movement stage in the non-scanning direction. However, when an expensive measuring instrument such as a laser interferometer is used, there is a problem that the cost increases.

  On the other hand, if the acceleration of the stage body increases to improve throughput, the carrier connected to the power supply member needs to follow (synchronously move) the stage body, so the same thrust as the stage body is required. As a result, there has been a problem that the drive device for driving the carrier is increased in size and price.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a stage apparatus and an exposure apparatus that can detect position information in the non-scanning direction of the coarse movement stage without increasing the price. To do.
Another object of the present invention is to provide a stage apparatus and an exposure apparatus capable of following and moving a carrier that relays a utility supply member with respect to a stage main body without causing an increase in cost.

In order to achieve the above object, the present invention adopts the following configuration corresponding to FIGS. 1 to 10 showing the embodiment.
The stage apparatus of the present invention is a stage apparatus having a first moving body that holds a substrate and moves in a first direction and a second direction with respect to a base, wherein the first moving body includes the first moving body. An encoder scale of an encoder system for measuring a direction and a position in the second direction is provided extending in the first direction, and an encoder head of the encoder system is provided in the first direction on the first moving body. It is provided at two locations facing each other while moving relative to the encoder scale at a predetermined interval, and relays a power supply member connected to the first moving body, and synchronizes with the first moving body. A second moving body that moves in the first direction, and the encoder head is disposed between the first moving body and the second moving body in the second direction. that you are It is an feature.

  Therefore, in the stage apparatus of the present invention, the position of the stage main body (MST) in the first direction and the second direction is determined by measuring the detection target part (74) with either one of the pair of detection heads (73). It can be detected. Further, by using the difference between the measurement results of the pair of detection heads (73), the position of the stage main body (MST) in the axial direction (θZ) perpendicular to the first direction and the second direction can be detected. That is, in the present invention, it is possible to easily detect the position of the stage main body (MST) with three degrees of freedom.

Further, the stage apparatus of the present invention is connected to a power supply member (CB) for supplying power, and holds the substrate (M) and moves in the first direction (Y-axis direction) ( first moving body (MST)). a stage device having (1), first mobile relaying the utilities supply member (CB) (MST) and a second movable body that moves in synchronization with the first direction (CS), the second And a driving device (64) for moving the moving body (CS) synchronously with an acceleration smaller than that of the first moving body (MST).

  Therefore, in the stage apparatus of the present invention, the sub-stage (CS) is placed on the stage by suspending the utility supply member (CB) between the stage main body (MST) and the sub-stage (CS) with a margin. It is not necessary to follow the main body (MST) completely, and the acceleration can be set small. Therefore, it becomes possible to reduce the thrust of the drive device (64) that drives the substage (CS), and it is possible to prevent an increase in price.

  The exposure apparatus according to the present invention includes a mask stage in an exposure apparatus (EX) that exposes a pattern of a mask (M) held on a mask stage (MST) onto a substrate (P) held on a substrate stage (PST). The stage apparatus (1) according to any one of claims 1 to 12 is used as at least one of the (MST) and the substrate stage (PST).

  Therefore, in the exposure apparatus of the present invention, the positions of the mask stage (MST) and the substrate stage (PST) can be easily detected with three degrees of freedom, and the working force for supplying working force to the mask stage (MST) or the substrate stage (PST). It is possible to reduce the thrust of the drive device (64) that drives the substage (CS) that relays the supply member (CB), thereby preventing an increase in price. In addition, in order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings representing one embodiment, but it goes without saying that the present invention is not limited to the embodiment.

In the present invention, it is possible to detect the position information of the stage body in the first direction and the second direction with a simplified and low-cost system.
Further, according to the present invention, when the substage is provided, the substage can be driven with a small thrust, which contributes to downsizing and cost reduction of the apparatus.

Embodiments of a stage apparatus and an exposure apparatus according to the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic block diagram showing an embodiment of an exposure apparatus provided with the stage apparatus of the present invention as a mask stage. Here, the exposure apparatus EX in the present embodiment transfers the pattern provided on the mask M onto the photosensitive substrate P via the projection optical system PL while moving the mask (substrate) M and the photosensitive substrate P synchronously. This is a so-called scanning stepper. In the following description, the direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, and the synchronous movement direction (scanning direction) in the plane perpendicular to the Z-axis direction is the Y-axis direction. A direction perpendicular to the axial direction and the Y-axis direction (non-scanning direction) will be described as the X-axis direction as the second direction. In addition, the “photosensitive substrate” herein includes a semiconductor wafer coated with a resist, and the “mask” includes a reticle on which a device pattern to be reduced and projected on the photosensitive substrate is formed.

  In FIG. 1, an exposure apparatus EX is a stage apparatus having a mask stage (reticle stage) MST as a stage body that holds and moves a mask (reticle) M, and a mask surface plate 3 as a base that supports the mask stage MST. 1, an illumination optical system IL having a light source and illuminating the mask M supported by the mask stage MST with exposure light, a substrate stage PST that holds and moves the photosensitive substrate P, and supports the substrate stage PST. A stage apparatus 2 having a substrate surface plate 4, a projection optical system PL that projects a pattern image of the mask M illuminated by the exposure light EL onto the photosensitive substrate P supported by the substrate stage PST, the stage apparatus 1 and the projection optics The reaction frame 5 that supports the system PL and the control unit CONT that controls the operation of the exposure apparatus EX are provided. To have. The reaction frame 5 is installed on a base plate 6 placed horizontally on the floor surface, and step portions 5a and 5b projecting inward are formed on the upper side and the lower side of the reaction frame 5, respectively. Yes.

  The mask surface plate 3 of the stage apparatus 1 is supported almost horizontally on the step portion 5a of the reaction frame 5 through the vibration isolation unit 8 at each corner, and an opening 3a through which the pattern image of the mask M passes at the center portion. It has. The mask stage MST is provided on the mask surface plate 3, and has an opening K that communicates with the opening 3a of the mask surface plate 3 and through which the pattern image of the mask M passes. A plurality of air bearings 9 which are non-contact bearings are provided on the bottom surface of the mask stage MST, and the mask stage MST is supported by the air bearing 9 so as to be levitated with a predetermined clearance from the mask surface plate 3.

FIG. 2 is a schematic perspective view of the stage apparatus 1 having the mask stage MST.
As shown in FIG. 2, the stage apparatus 1 (mask stage MST) includes a ceramic coarse movement stage 16 provided on the mask surface plate 3 and formed in an L shape in plan view, and a voice coil motor 17Y described later. , 17X, and a ceramic fine movement stage (substrate holding part) 18 formed in a rectangular frame shape coupled to the coarse mask movement stage 16 via the 17X, and the coarse movement stage 16 on the mask surface plate 3 with the Y axis A pair of Y linear motors 20A and 20B that can move in a predetermined stroke in the direction and a pair of Y that finely moves the fine movement stage 18 on the coarse movement stage 16 in the Y axis direction and in the θZ direction (rotation direction around the Z axis). A voice coil motor 17Y and an X voice coil motor 17X that finely moves the fine movement stage 18 in the X-axis direction are provided. In FIG. 1, the coarse movement stage 16 and the fine movement stage 18 are simplified and illustrated as one stage.

  The Y voice coil motor 17Y is provided at a predetermined interval in the X-axis direction, which is the non-scanning direction, and both generate substantially the same thrust to move the fine movement stage 18 in the Y-axis direction with respect to the coarse movement stage 16. The fine movement stage 18 is driven in the θZ direction by driving and different thrusts. These three fine movement voice coil motors 17Y and 17X are each configured as an MM type (moving magnet type) in which the permanent magnet unit is fixed to the fine movement stage 18 side and the coil unit is fixed to the coarse movement stage 16 side. However, this is not necessarily essential, and in some cases, it may be an MC (moving coil) type in which the arrangement of the magnet unit and the coil unit is reversed for all or a part of the three.

As the Y linear motors 20A and 20B, cylindrical stators 21A and 21B extending in the Y-axis direction in which a large number of disk-like or donut-shaped strong permanent magnets are stacked in the Y direction in a cylindrical case; Movable that moves on the mask surface plate 3 through a plurality of air pads 19 (only a part of which is shown in FIG. 2) that accommodates coil windings that wrap around the stators 21A and 21B in an annular shape. A shaft type linear motor in which the elements 22A and 22B are respectively combined is used. Such a shaft type linear motor has a simple coil winding structure as a mover, and it is easy to assemble a magnet array in the stator, and the coil winding structure is simple. The structure of the internal circulation path when supplying the gas into the movers 22A and 22B can be simplified, and the cooling efficiency can be increased.
The stators 21A and 21B and the movers 22A and 22B constitute moving coil type linear motors 20A and 20B. A coarse movement stage 16 is provided between the movable elements 22A and 22B, and the movable elements 22A and 22B are driven by electromagnetic interaction with the stators 21A and 21B, thereby causing the coarse movement stage 16 (mask stage). MST) moves in the Y-axis direction.

Both ends of the stators 21A and 21B are supported by the support devices 23A and 23B disposed outside the mask surface plate 3 (on the reaction frame 5) so as to be movable in the Y-axis direction without contact with each other. For this reason, the stators 21A and 21B move in the −Y direction according to the movement of the coarse movement stage 16 in the + Y direction, for example, according to the law of conservation of momentum. The movement of the stators 21A and 21B cancels the reaction force accompanying the movement of the coarse movement stage 16, and can prevent the change in the position of the center of gravity.
The linear motors 20A and 20B are provided with trim motors 27A and 27B for returning the stators 21A and 21B moved (as counter masses) to the neutral position according to the law of conservation of momentum.

  The fine movement stage 18 sucks and holds the mask M via the vacuum chuck 24. A pair of Y moving mirrors 25A and 25B made of a corner cube is fixed to the end portion of the fine movement stage 18 in the -Y direction, and an X portion made of a plane mirror extending in the Y-axis direction is attached to the end portion of the fine movement stage 18 in the -X direction. The movable mirror 26 is fixed. Then, three laser interferometers (all of which are not shown) that irradiate the measurement beams to the movable mirrors 25A, 25B, and 26 measure the distances from the movable mirrors, whereby the X axis of the mask stage MST, The Y axis and the position in the θZ direction are detected with high accuracy. The control device CONT drives each motor including the Y linear motors 20A, 20B, the X voice coil motor 17X, and the Y voice coil motor 17Y based on the detection results of these laser interferometers, and is supported by the fine movement stage 18. The position of the mask M (mask stage MST) is controlled.

  The coarse movement stage 16 (and the fine movement stage 18) includes a cable for supplying power to driving means such as a motor, a coolant pipe for cooling the motor, and a coolant pipe for maintaining the substrate stage at a predetermined temperature. , A power supply member for supplying various powers such as a vacuum pipe for evacuating a vacuum suction hole provided on the substrate mounting surface (hereinafter, these cables and pipes are collectively referred to as cables) CB (Note that although many cables CB are connected, only three cables are shown in the present embodiment for ease of illustration). Specific examples of the cables CB include a pipe for supplying and discharging a temperature adjusting refrigerant, a pipe for supplying air used for an air bearing (helium in the case of using a helium bearing), and for sucking the mask M under a negative pressure. Piping for supplying negative pressure (vacuum), wiring for supplying electric power to various sensors, system wiring for supplying various control signals and detection signals, and the like are provided for various drive devices and control devices. Also, as these cables CB, in order to satisfy the requirements for chemical clean, a cable having a large thickness or a hardened material having a double structure and having flexibility is used.

  The stage apparatus 1 is provided with a cable stage (substage) CS that relays the cables CB connected to the coarse movement stage 16 and moves synchronously with the coarse movement stage 16. The cable stage CS includes a mover 62 that moves along a stator 61 arranged in parallel with the stator 21B of the Y linear motor 20B, and a support plate 63 that is provided on the mover 62 and supports the cables CB. It is configured. As with the Y linear motors 20A and 20B, the stator 61 and the mover 62 constitute a moving coil type shaft type linear motor (drive device) 64, and the drive thereof is controlled by the control device CONT.

  The stator 61 of the linear motor 64 is supported so as to be movable in the Y-axis direction in a non-contact manner by support devices 65 arranged at both ends outside the mask surface plate 3 (on the reaction frame 5). For this reason, the stator 61 moves in the −Y direction according to the movement of the mover 62 and the support plate 63 in the + Y direction, for example, according to the law of conservation of momentum. By the movement of the stator 61, the reaction force accompanying the movement of the mover 62 and the support plate 63 is canceled, and the change in the position of the center of gravity can be prevented. The mover 62 moves on the plate 70 suspended between the support devices 65, 65 via a plurality of air pads 71 (see FIG. 1) that are non-contact bearings.

  As shown in FIG. 3, a stator 67 of a trim motor 66 composed of a voice coil motor is attached (connected) to the −X direction side of the mover 62. The trim motor 66 is interposed between the mover 22B of the Y linear motor 20B and the mover 62 of the linear motor 64, and the mover 68 is provided on the mover 22B. For this reason, the reaction force when the fine movement stage 18 is driven in the X direction by the voice coil motor 17X is a reaction frame 8 that is vibrationally separated from the mask stage MST via the support device 65 by the trim motor 66 as a transmission device. And further transmitted to the base plate 10 via the reaction frame 8, it is possible to prevent vibration from being transmitted to the mask surface plate 3.

Further, as shown in the partial plan view of FIG. 4, the length of the stator 67 in the Y-axis direction is set to be larger than the movable element 68 by a predetermined length. Specifically, when the movers 62 and 68 are synchronously moved, even if they move relative to each other, the electromagnetic interaction is maintained, and the reaction force accompanying the movement of the mask stage MST is transmitted to the reaction frame 8 to a length that can be transmitted. Is set.
The movers 62 and 68 are connected with a predetermined amount of free movement by a wire (wire) 69 as a restraining device, and even if at least one of the movers 62 and 68 runs away for some reason, the movers 62 and 68 are restrained by the other. It is the composition which becomes.

  The support plate 63 has a substantially L-shaped cross section (see FIG. 3), and supports a plurality of cables CB at the bottom 63a. More specifically, when the movers 62 and 68 are moved synchronously, even if they move relative to each other, the support plate is arranged so that a large load is not applied to the cables CB (connection portion between the cables CB and the coarse movement stage 16). 63 supports and holds the cables CB with the coarse movement stage 16 with a predetermined amount of play (bending).

Further, in stage apparatus 1 according to the present embodiment, coarse movement stage 16 can be moved by a minute amount by a reaction force accompanying movement of mask stage MST in the X-axis direction, so that the position of coarse movement stage can be freely set in three degrees. A detection device 72 is provided for detection at a degree.
The detection device 72 includes a pair of encoders (detection heads) 73 provided at predetermined intervals in the Y-axis direction at the lower end of the mover 22B of the Y linear motor 20B as a drive unit (see FIG. 3). A scale (encoder scale, lattice member) 74 serving as a detection target portion provided at a position facing the encoder 73 at the + X side end of the mask surface plate 3.

  As the encoder 73, a two-dimensional sensor is used, and the scale 74 is detected in two dimensions. The result detected by the encoder 73 is output to the control device CONT. The control device CONT controls the position of the coarse movement stage 16 by driving the trim motor 66 based on the detection result of the encoder 73.

  As shown in FIG. 5, an X origin 75, a Y origin 76, and a grid 77 are formed on the upper surface (the surface on the + Z side) of the scale 74, respectively. The X origin 75 serves as an origin when detecting position information in the X direction, and is formed in the vicinity of the −X side edge of the scale 74 in a band shape along the Y axis direction as the scanning direction. . The Y origin 76 serves as an origin when detecting position information in the Y direction, and is formed near the + Y side edge of the scale 74. The grid 77 indicates position information in the X direction and the Y direction, and a plurality of grids 77 are arranged at intervals in the X direction and the Y direction.

  These grids 77 are arranged in a detectable range of the encoder 73 in the X direction, and in the Y direction, a range that can be detected even when the encoder 73 moves in the Y axis direction together with the coarse movement stage 16 (movable element 22B). It is arranged over. Similarly to the grid 77, the X origin 75 is formed over a range that can be detected even when the encoder 73 moves in the Y-axis direction together with the coarse movement stage 16 (movable element 22B). Note that the grids 77 are actually arranged in a large number of lattices at a minute pitch, but in FIG. 5, the number of the grids 77 is reduced in order to facilitate understanding.

Returning to FIG. 1, the illumination optical system IL includes a mirror, a variable dimmer, a beam shaping optical system, an optical integrator, a condensing optical system, a vibrating mirror, an illumination system aperture stop plate, a beam arranged in a predetermined positional relationship. A splitter, a relay lens system, a blind mechanism (setting device), and the like are provided and supported by a support column 7 fixed to the upper surface of the reaction frame 5. The blind mechanism includes a fixed blind having an opening of a predetermined shape that defines an illumination area on the reticle R, and a fixed reticle blind by a movable blade at the start and end of scanning exposure to prevent exposure of unnecessary portions. And a movable blind that further restricts the illumination area on the mask M defined by.
As the exposure light EL emitted from the illumination optical system IL, for example, far ultraviolet light (g-line, h-line, i-line) emitted from a mercury lamp and far ultraviolet light (wavelength 248 nm) such as KrF excimer laser light (wavelength 248 nm). DUV light), vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F ₂ laser light (wavelength 157 nm), or the like is used.

  The pattern image of the mask M that has passed through the opening K and the opening 3a in the mask stage MST is incident on the projection optical system PL. Projection optical system PL is composed of a plurality of optical elements, and these optical elements are supported by a lens barrel. The projection optical system PL is a reduction system having a projection magnification of, for example, 1/4 or 1/5. The projection optical system PL may be either an equal magnification system or an enlargement system. A flange portion 10 integrated with the lens barrel is provided on the outer periphery of the lens barrel of the projection optical system PL. In the projection optical system PL, the flange portion 10 is engaged with the lens barrel surface plate 12 supported substantially horizontally by the step portion 5b of the reaction frame 5 via the vibration isolation unit 11.

  The stage apparatus 2 supports the substrate stage PST, the substrate surface plate 4 that supports the substrate stage PST so as to be movable in a two-dimensional direction along the XY plane, and the substrate stage PST that is movable while being guided in the X-axis direction. An X guide stage 35, an X linear motor 40 provided on the X guide stage 35 and capable of moving the substrate stage PST in the X axis direction, and a pair of Y linear motors 30 capable of moving the X guide stage 35 in the Y axis direction, 30. The substrate stage PST has a substrate holder PH that holds the photosensitive substrate P such as a wafer by vacuum suction, and the photosensitive substrate P is supported by the substrate stage PST via the substrate holder PH. A plurality of air bearings 37 that are non-contact bearings are provided on the bottom surface of the substrate stage PST, and the substrate stage PST is supported in a non-contact manner with respect to the substrate surface plate 4 by these air bearings 37. The substrate surface plate 4 is supported substantially horizontally above the base plate 6 via a vibration isolation unit 13.

  A mover 34a of an X trim motor 34 is attached to the + X side of the X guide stage 35 (see FIG. 6). A stator (not shown) of the X trim motor 34 is provided on the reaction frame 5. Therefore, the reaction force when driving the substrate stage PST in the X-axis direction is transmitted to the base plate 6 via the X trim motor 34 and the reaction frame 5.

FIG. 6 is a schematic perspective view of the stage apparatus 2 having the substrate stage PST.
As shown in FIG. 6, the stage apparatus 2 can move the substrate stage PST in the X axis direction with a predetermined stroke while being guided by the X guide stage 35 having an elongated shape along the X axis direction. An X linear motor 40 and a pair of Y linear motors 30 and 30 provided at both ends in the longitudinal direction of the X guide stage 35 and capable of moving the X guide stage 35 together with the substrate stage PST in the Y-axis direction are provided.

  The X linear motor 40 includes a stator 41 including a coil unit provided on the X guide stage 35 so as to extend in the X-axis direction, and a magnet unit provided corresponding to the stator 41 and fixed to the substrate stage PST. The movable element 42 which consists of these is provided. The stator 41 and the mover 42 constitute a moving magnet type linear motor 40, and the substrate stage PST is moved in the X-axis direction by driving the mover 42 by electromagnetic interaction with the stator 41. Moving. Here, the substrate stage PST is supported in a non-contact manner by a magnetic guide including a magnet and an actuator that maintain a predetermined amount of gap in the Z-axis direction with respect to the X guide stage 35. The substrate stage PST is moved in the X-axis direction by the X linear motor 40 while being supported by the X guide stage 35 in a non-contact manner. In place of the magnetic guide, an air guide may be used for non-contact support.

  Each of the Y linear motors 30 includes a mover 32 as a moving body including a magnet unit provided at both ends of the X guide stage 35 in the longitudinal direction, and a stator 31 including a coil unit provided corresponding to the mover 32. And. Here, the stators 31 and 31 are provided on support portions 36 and 36 (see FIG. 1) protruding from the base plate 6. In FIG. 1, the stator 31 and the mover 32 are illustrated in a simplified manner. The stator 31 and the mover 32 constitute a moving magnet type linear motor 30, and the mover 32 is driven by electromagnetic interaction with the stator 31, whereby the X guide stage 35 is moved in the Y-axis direction. Move to. Further, the X guide stage 35 can be rotated in the θZ direction by adjusting the driving of the Y linear motors 30 and 30. Therefore, the Y linear motors 30 and 30 enable the substrate stage PST to move in the Y axis direction and the θZ direction almost integrally with the X guide stage 35.

  Returning to FIG. 1, an X moving mirror 51 extending along the Y-axis direction is provided at the −X side edge of the substrate stage PST, and a laser interferometer 50 is disposed at a position facing the X moving mirror 51. Is provided. The laser interferometer 50 irradiates laser light (detection light) toward each of the reflection surface of the X movable mirror 51 and the reference mirror 52 provided at the lower end of the projection optical system PL, and the reflected light and the incident light are incident thereon. By measuring the relative displacement between the X moving mirror 51 and the reference mirror 52 based on the interference with light, the position of the substrate stage PST and thus the photosensitive substrate P in the X-axis direction is detected in real time with a predetermined resolution. Similarly, a Y moving mirror 53 (not shown in FIG. 1, see FIG. 6) extending along the X-axis direction is provided on the side edge on the + Y side on the substrate stage PST. A Y laser interferometer (not shown) is provided at the facing position, and the Y laser interferometer is a reference mirror (not shown) provided at the reflecting surface of the Y movable mirror 53 and the lower end of the projection optical system PL. And the relative displacement between the Y moving mirror and the reference mirror based on the interference between the reflected light and the incident light, thereby measuring the substrate stage PST and eventually the photosensitive substrate P. A position in the Y-axis direction is detected in real time with a predetermined resolution. The detection result of the laser interferometer is output to the control device CONT, and the control device CONT controls the position of the substrate stage PST via the linear motors 30 and 40 based on the detection result of the laser interferometer.

Next, the operation of the stage apparatus 1 in the exposure apparatus EX configured as described above will be described below.
In the alignment operation of the mask M and the like, when the mask M is moved in the X-axis direction via the fine movement stage 18 by driving the X voice coil motor 17X, the reaction force accompanying the movement of the fine movement stage 18 is the coarse movement stage 16. To the movers 22A and 22B of the Y linear motors 20A and 20B. Since the movers 22A and 22B are not positioned rigidly with respect to the stators 21A and 21B but can move relative to each other in a minute amount in the X-axis direction, the movers 22A and 22B move with a reaction force accompanying the movement of the fine movement stage 18.

At this time, the position of the mover 22B (that is, the coarse movement stage 16) in the X-axis direction is detected by measuring the grid 77 with reference to the X origin 75 of the scale 74 by the encoder 73 of the detection device 72 and is sent to the control device CONT. Is output. Further, the position of the mover 22B (that is, the coarse movement stage 16) in the direction around the θZ axis is detected by obtaining a difference between detection results of the pair of encoders 73.
The control device CONT controls the position of the coarse movement stage 16 by driving the trim motor 66 based on the detection result of the encoder 73. As a result, the reaction force accompanying the movement of the fine movement stage 18 is transmitted to the reaction frame 8 by the trim motor 66 via the movable element 62, the stator 61, the support device 65, and the plate 70, and vibrates to the mask surface plate 3. Can be prevented from being transmitted.

  On the other hand, when the coarse movement stage 16 (and the fine movement stage 18, that is, the mask stage MST) is moved in the Y-axis direction (for example, + Y direction) by driving the Y linear motors 20A and 20B, the movers 22A and 22B are moved. The stators 21A and 21B move in the reverse direction (−Y direction) due to the reaction force accompanying. Therefore, the law of conservation of momentum works, the reaction force during acceleration / deceleration of the mask stage MST is absorbed by the movement of the stators 21A and 21B, and the position of the center of gravity in the stage apparatus 1 is substantially fixed in the Y direction.

  The weight ratio between the mover side (mask stage MST, movers 22A, 22B, etc.) and the stator side (stator 21A, 21B, etc.) is obtained by coupling the movers 22A, 22B and the stators 21A, 21B. If the stators 21A and 21B do not move to the base positions, the law of conservation of momentum is not maintained, and the position of the center of gravity in the stage device 1 changes. Therefore, in the present embodiment, when the stators 21A and 21B move due to the reaction force, the trim motors 27A and 27B are driven while monitoring the positions of the stators 21A and 21B, so that the stator block 21A is driven. The position of the center of gravity of the stage apparatus 1 is maintained by adjusting the position of 21B.

  Further, in the present embodiment, as described above, when the mask stage MST is moved by driving the Y linear motors 20A and 20B, the cable stage CS follows and moves in synchronization. That is, when the mask stage MST is moved in the Y-axis direction, the cable stage CS is synchronously moved in the Y-axis direction together with the mask stage MST by driving the X linear motor 64 under the control of the control device CONT. At this time, the control device CONT controls the driving of the Y linear motors 20A and 20B and the linear motor 64 so that the cable stage CS moves with a smaller acceleration than the mask stage MST.

  In this case, if the mask stage MST and the cable stage CS are moved in the same time, the cable stage CS cannot follow the mask stage MST and the relative positional relationship changes. However, since the displacement is small, both stages MST, The tensile load and compression load associated with the deformation of the cables CB stretched between the CSs are also very small. Also, the vibration associated with the deformation of the cables CB is a low frequency vibration, which is generated by rubbing or hitting the cables, and is not a high frequency vibration that adversely affects the movement of the mask stage MST, thereby hindering the movement control of the stage. It is not a thing.

  Here, when the synchronous movement of the mask stage MST and the cable stage CS is repeated, the displacement between the mask stage MST and the cable stage CS may be integrated and become large. Therefore, in this embodiment, in order to suppress the displacement amount of both stages, (1) the moving time of the cable stage CS is increased (2) the moving amount of the cable stage CS is made smaller than the moving amount of the mask stage MST. Measures are taken.

(1) Increasing the moving time of the cable stage CS In this method, as shown in the time chart relating to acceleration in FIG. 7, the cable stage CS is started to accelerate before the mask stage MST is accelerated, The acceleration is terminated after the acceleration is completed. Similarly, regarding the deceleration, the deceleration of the cable stage CS is started before the mask stage MST starts decelerating, and the movement (deceleration) of the cable stage CS is terminated after the deceleration of the mask stage MST is completed. As described above, by moving the cable stage CS, there is a time during which the both stages are slightly displaced during the synchronous movement. However, when considering one scanning operation, the cable stage CS is moved to the mask stage MST. Therefore, even when the synchronous movement is repeated, the displacement between both stages does not increase.

(2) Making the moving amount of the cable stage CS smaller than the moving amount of the mask stage MST In this method, as shown in FIG. 8A, the mask stage MST and the cable stage CS are moved synchronously in the + Y-axis direction, for example. (In FIGS. 8A and 8B, the mask stage MST is not shown, but for the sake of convenience, the movable element 22B of the Y linear motor 20B will be described as the mask stage MST.) Before the acceleration of the mask stage MST starts, the cable stage CS is positioned in advance in the movement direction.
At the end of the synchronous movement, as shown in FIG. 8B, the cable stage CS is stopped on the rear side in the movement direction from the stop position of the mask stage MST. As a result, the movement amount of the cable stage CS becomes smaller than the movement amount of the mask stage MST, and even when the cable stage CS is driven with an acceleration smaller than that of the mask stage MST, the movement can be followed, and the synchronous movement is repeated. Even in this case, the displacement between both stages does not increase.

  Note that the wire 69 stretched between the movable elements 22B and 62 is not pulled by each other because even if a predetermined displacement occurs between both stages, the wire 69 is provided with a deflection that can absorb this displacement. There is no adverse effect on the driving of each other due to the displacement between the two stages.

  Further, when the mask stage MST is moved in the Y-axis direction, the encoder 77 of the detection device 72 measures the grid 77 with reference to the Y origin 76 of the scale 74, thereby detecting the position in the Y-axis direction and the control device CONT. Is output. At this time, the mover 22B is moved while detecting the X origin 75 by the encoder 73 (at least one of them). Thereby, the displacement (running accuracy) in the X-axis direction when the mover 22B, that is, the mask stage MST moves in the Y-axis direction, can be detected during stage driving. The control device CONT controls the driving of the X voice coil motor 17X so as to correct the detected running accuracy, thereby preventing a reduction in accuracy due to a running accuracy error, so-called cosine error.

  Further, when an unexpected situation occurs and one of the mask stage MST (Y linear motors 20A and 20B) and the cable stage CS (linear motor 64) goes out of control, the wire 69 functions as a stopper. Since the uncontrollable stage is restrained by the normal stage, it is possible to prevent other components from being damaged by the runaway of the stage.

Next, an exposure operation in the exposure apparatus EX having the above configuration will be described.
Preparatory work such as reticle alignment and baseline measurement using a reticle microscope and off-axis alignment sensor is performed, and then fine alignment (EGA; enhanced global alignment, etc.) of the photosensitive substrate P using the alignment sensor is completed. Then, the arrangement coordinates of a plurality of shot areas on the photosensitive substrate P are obtained. Then, while monitoring the measurement value of the laser interferometer 50 based on the alignment result, the linear motors 30 and 40 are controlled to move the substrate stage PST to the scanning start position for the exposure of the first shot of the photosensitive substrate P. . Then, scanning in the Y direction of the mask stage MST and the substrate stage PST is started via the linear motors 20 and 30, and when both the stages MST and PST reach their target scanning speeds, they are set by driving the blind mechanism. The pattern area of the mask M is illuminated by the exposure illumination light, and scanning exposure is started.

  During this scanning exposure, the moving speed in the Y direction of the mask stage MST and the moving speed in the Y direction of the substrate stage PST are speed ratios corresponding to the projection magnification (1/5 or 1/4) of the projection optical system PL. Thus, the mask stage MST and the substrate stage PST are synchronously controlled via the linear motors 20 and 30 so as to be maintained. Then, different areas of the pattern area of the mask M are sequentially illuminated with illumination light, and the illumination of the entire pattern area is completed, whereby the scanning exposure of the first shot on the photosensitive substrate P is completed. Thereby, the pattern of the mask M is reduced and transferred to the first shot area on the photosensitive substrate P via the projection optical system PL.

As described above, in the present embodiment, the position of the mask stage MST (coarse movement stage 16) is detected with three degrees of freedom by the detection device 72 including the encoder 73 and the scale 74, so that an interferometer or the like is used. Therefore, it is possible to easily construct a simplified system without requiring a long moving mirror, thereby contributing to cost reduction.
Further, in the present embodiment, since a running error can be detected while the mask stage MST is moving and the error can be corrected quickly, the mask stage MST can be driven stably and with high accuracy.

On the other hand, in the present embodiment, the cable stage CS that relays and synchronizes with the cables CB connected to the mask stage MST is driven with a smaller acceleration than the mask stage MST, and therefore the linear motor 64 with a small thrust is provided. It can be used, and can contribute to downsizing and cost reduction. In particular, in this embodiment, the cable stage CS is moved by following the movement of the cable stage CS by adopting a simple method of increasing the movement time of the cable stage CS or reducing the movement amount of the cable stage CS with respect to the mask stage MST. Thus, the acceleration of the cable stage CS can be easily reduced without complicating the apparatus configuration or complicating the sequence.
Furthermore, in the present embodiment, the relative positional relationship between the mask stage MST and the cable stage CS is constrained by the wire 69, so that even if one of the stages runs away, damage to other components is prevented with a simple system. be able to.
In addition, the acceleration of the coarse movement stage 16 may be made smaller than the acceleration of the fine movement stage 18. Thereby, the influence of the heat generation of the Y linear motor 20 can be reduced, and the Y linear motor 20 can be reduced in size.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above embodiment, the wire is used as a restraining device that restrains the relative movement between the mask stage MST and the cable stage CS. However, the present invention is not limited to this. For example, as shown in FIG. When the mover (second member) 68 provided on the stage MST moves in the Y-axis direction within the groove 67a of the stator (first member) 67 provided on the cable stage CS, the Y-axis of the groove 67a A closing member 78 that closes both ends in the direction may be provided as a restraining device.

  Also in this case, the movement stroke of the mover 68 in the Y-axis direction is restricted by the closing member 78, so that the relative movement of both the stages MST and CS can be restricted by a simple system. In addition to being able to prevent damage to the device, the stator 67 and the mover 68 are not in contact with each other during normal operation, so that a minute vibration is applied to the mask stage MST via the wire as if connected by a wire. This can eliminate the possibility of adversely affecting the pattern transfer accuracy.

  Further, in the above-described embodiment, the description has been given of the configuration in which all the cables CB connected to the mask stage MST are relayed to the cable stage CS (support plate 63). However, the present invention is not limited to this. It is also possible to adopt a configuration in which only those having a large vibration (power system piping such as a hose) applied to the mask stage MST are relayed to the cable stage CS, and cables that do not generate much vibration are not relayed to the cable stage CS.

In particular, a signal cable or the like for transmitting an electrical signal originally has a small weight, and when relayed to the cable stage CS, the linear motors 20B and 64 (movable elements 22B and 62) and the trim motor 66 are always integrated. Therefore, there is a possibility that the influence of the electromagnetic wave generated when the motor is driven may remain as noise. Therefore, if the configuration is configured such that the influence of the noise is suppressed without being relayed to the cable stage CS and directly connected to the mask stage MST. Reliability can be increased.
Thus, it is preferable to select the cables to be relayed to the cable stage CS based on the characteristics of the power to be supplied to the mask stage MST.

  In the above embodiment, the stage apparatus of the present invention is applied to the stage apparatus 1 (mask stage MST side) in the exposure apparatus EX. However, it goes without saying that the stage apparatus can be applied to the stage apparatus 2 (substrate stage PST side).

  The substrate P in each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus EX, in addition to the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by moving the mask M and the substrate P synchronously, the mask M and the substrate P Can be applied to a step-and-repeat type projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while the substrate P is stationary and the substrate P is sequentially moved stepwise. The present invention can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on the substrate P.

  The present invention can also be applied to a twin stage type exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 10-163099, Japanese Patent Application Laid-Open No. 10-214783, and Japanese Translation of PCT International Publication No. 2000-505958.

  The type of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). ) Or an exposure apparatus for manufacturing reticles or masks.

  When using a linear motor (see USP5,623,853 or USP5,528,118) for the substrate stage PST and mask stage MST, use either an air levitation type using air bearings or a magnetic levitation type using Lorentz force or reactance force. Also good. Each stage PST, MST may be a type that moves along a guide, or may be a guideless type that does not have a guide.

  As a driving mechanism for each stage PST, MST, a planar motor that drives each stage PST, MST by electromagnetic force with a magnet unit having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil facing each other is provided. It may be used. In this case, either one of the magnet unit and the armature unit may be connected to the stages PST and MST, and the other of the magnet unit and the armature unit may be provided on the moving surface side of the stages PST and MST.

As described in JP-A-8-166475 (USP 5,528,118), the reaction force generated by the movement of the substrate stage PST is not transmitted to the projection optical system PL, and mechanically using a frame member. You may escape to (earth).
As described in JP-A-8-330224 (USP 5,874,820), the reaction force generated by the movement of the mask stage MST is not transmitted to the projection optical system PL. You may escape to (earth). Further, as described in JP-A-8-63231 (USP 6,255,796), the reaction force may be processed using a momentum conservation law.

  The exposure apparatus EX according to the embodiment of the present application is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 10, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate as a substrate of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic block diagram which shows one Embodiment of the exposure apparatus provided with the stage apparatus of this invention. It is a schematic perspective view which shows one Embodiment of a stage apparatus which has a mask stage. It is the elements on larger scale which show the principal part of a Y linear motor and a cable stage. It is a fragmentary top view which shows the principal part of Y linear motor and a cable stage. It is a top view which shows the principal part of a detection apparatus. It is a schematic perspective view which shows one Embodiment of a stage apparatus which has a substrate stage. It is a time chart figure regarding the acceleration of a mask stage and a cable stage. (A), (b) is a figure for demonstrating that the movement amount of a cable stage is smaller than the movement amount of a mask stage. It is an external appearance perspective view which shows another form of a restraint apparatus. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

CB cables (utility supply members)
CS cable stage (substage)
EX exposure equipment M Mask (substrate, reticle)
MST mask stage (reticle stage, stage body)
P Photosensitive substrate PST Substrate stage 1 Stage device 3 Mask surface plate (base)
18 Fine movement stage (substrate holder)
20B Y linear motor (drive unit)
21B Stator 22B Movable element 64 Linear motor (drive device)
66 Trim motor (transmission device)
67 Stator (first member)
67a Groove 68 Movable element (second member)
69 Wire (restraint device, wire)
72 Detection Device 73 Encoder (Detection Head)
74 Scale (grid member, detection target part)
78 Closure member (restraint device)

Claims (13)

A stage apparatus having a first moving body that holds a substrate and moves in a first direction and a second direction with respect to a base,
An encoder scale of an encoder system for measuring positions of the first moving body in the first direction and the second direction is provided extending in the first direction;
The first moving body is provided so that the encoder head of the encoder system is opposed to the encoder scale while moving relative to the encoder scale at two positions with a predetermined interval in the first direction,
A second moving body that relays the power supply member connected to the first moving body and moves in the first direction in synchronization with the first moving body;
The stage apparatus , wherein the encoder head is disposed between the first moving body and the second moving body in the second direction . The stage apparatus according to claim 1, wherein
The encoder scale is connected to the base, and the stage device. The stage apparatus according to claim 1 or 2,
A stage device characterized in that a grid is formed on the encoder scale in a lattice shape . The stage apparatus according to any one of claims 1 to 3,
The stage apparatus characterized in that the encoder scale is positioned below a guide surface of the first moving body in the base . The stage apparatus according to any one of claims 1 to 4,
The stage apparatus is characterized in that the first moving body is provided in a vibrationally separated manner against a reaction force generated when the second moving body is moved in the first direction . A stage apparatus having a first moving body connected to a power supply member for supplying power and holding the substrate and moving in a first direction,
A second movable body that moves in synchronization with the first direction and the first moving body by relaying the for power supply member,
Stage apparatus characterized by comprising a drive device for the synchronous movement the second moving body in the first smaller acceleration than the moving body. The stage apparatus according to claim 6, wherein
The stage device characterized in that the driving device causes the second moving body to move synchronously with a smaller moving amount than the first moving body . The stage apparatus according to claim 6 or 7 ,
A stage apparatus, wherein a power supply member to be relayed to the second moving body is selected based on the characteristics of the power. The stage apparatus according to claim 8, wherein
The stage apparatus characterized in that the power is an electrical signal. The stage apparatus according to any one of claims 6 to 9,
A stage device comprising a restraining device for restraining a relative positional relationship between the first moving body and the second moving body with a predetermined amount of play. The stage apparatus according to claim 10, wherein
The stage device is characterized in that the restraining device is a wire connecting the first moving body and the second moving body . The stage apparatus according to claim 10, wherein
One of the first moving body and the second moving body is provided with a first member having a groove extending in the first direction,
The other of the first moving body and the second moving body is provided with a second member that moves in the groove in the first direction,
The stage device is characterized in that the restraining device is a closing member that closes both ends of the groove. In an exposure apparatus that exposes a mask pattern held on a mask stage onto a substrate held on a substrate stage,
An exposure apparatus using the stage apparatus according to any one of claims 1 to 12, as at least one of the mask stage and the substrate stage.

Images