JP2005285881A - Stage device and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage device capable of reducing the heat produced when driving a coarse motion stage and of replacing a fine motion stage, and to provide an exposure apparatus. <P>SOLUTION: The stage device comprises a first stage 63A that moves in a first direction, and a second stage 83A that moves in the first direction and a second direction different from the first direction. It further comprises a first stator 112A provided on the first stage 63A along the first direction, a first movable unit 111A which is provided on the second stage 83A and is opened along the first direction, a first driving device for transferring the first stage 83A to the first direction, a second stator 102A provided on the first stage 63A along the first direction, a second movable unit 101A which is provided on the second stage 83A and is opened along the first direction, and a second driving device for transferring the second stage 83A to the second direction. When the first stage 63A is transferred along the first direction, the first stage 63A can be separated from the second stage 83A. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stage apparatus and an exposure apparatus.

  Conventionally, various exposure apparatuses have been used when manufacturing semiconductor elements (integrated circuits), liquid crystal display elements, and the like in a lithography process. In recent years, along with the high integration of semiconductor elements, a step-and-repeat reduction projection exposure apparatus (so-called stepper) and a step-and-scan scanning projection exposure apparatus (so-called stepper) in which this stepper has been improved. Sequentially moving projection exposure apparatuses such as scanning steppers are the mainstream.

  Since this type of projection exposure apparatus is mainly used as a mass-production machine for semiconductor elements and the like, it is possible to improve the throughput, that is, the throughput of how many wafers can be exposed within a certain period of time. Is inevitably requested.

  In this type of projection exposure apparatus, three main operations are repeatedly performed using one wafer stage as follows: wafer exchange → alignment (search alignment, fine alignment) → exposure → wafer exchange. Therefore, if the above three operations, ie, wafer exchange, alignment, and exposure operations, can be processed partially or simultaneously in parallel, the throughput is improved compared to the case where these operations are performed sequentially. Can be made. However, no exposure is performed during wafer exchange and alignment. To shorten the process time, that is, to improve throughput, for example, the wafer exchange and alignment stage and the exposure stage are controlled independently at the same time. A way to do this is conceivable.

In this regard, for example, Patent Document 1 discloses a first guide bar and a second guide bar that can be moved in the Y-axis direction by a Y-axis linear motor, along the first guide bar and the second guide bar in the X-axis direction. The movable first and second wafer stages are provided, and the two wafer stages are independently XY-dimensionally arranged at the exposure position and alignment position directly below the projection optical system and alignment optical system arranged along the X-axis direction. A stage apparatus that is driven in parallel with a direction is disclosed.
In this stage apparatus, each wafer stage is provided with an air pad (gas static pressure bearing), and a coarse motion stage (first stage) that is supported in a non-contact manner with a small gap on the guide bar by the static pressure of the pressurized gas. Each substrate has a fine movement stage (second stage) that holds a substrate such as a wafer and is supported in a cantilevered state with respect to the coarse movement stage.
JP 2003-17404 A

  In the above technique, the relative movable range of the fine movement stage with respect to the coarse movement stage is limited to the clearance range between the movable element and the stator in the X fine movement mechanism and the Y fine movement mechanism. Specifically, the movable range in the X direction of the fine movement stage relative to the coarse movement stage is limited to the clearance range between the movable element and the stator in the X fine movement mechanism, and the movable range in the Y direction is fixed to the movable element in the Y fine movement mechanism. Limited to clearance with child. Usually, since these clearances are set to about 1 mm, it is necessary to drive the coarse movement stage with almost the same acceleration profile as that of the fine movement stage. Occurs. In addition, since the relative position fluctuation between the coarse movement stage and the fine movement stage is limited within the clearance range between the mover and the stator in the fine movement mechanism, the coarse movement stage requires a corresponding control response characteristic. Is done. Accordingly, not only the fine movement stage but also the coarse movement stage needs to be reduced in weight according to the driving profile, and there is a problem that the degree of freedom in design is limited.

  In recent years, it has been studied to increase production efficiency by carrying out exposure processing and alignment processing in parallel. Furthermore, as one of means for realizing this parallel processing, a configuration in which the fine movement stage is exchanged between a plurality of stages has been studied, but in this case as well, the limitation due to the clearance between the movable element and the stator in the fine movement mechanism is rough. It becomes an obstacle to exchange between the moving stage and the fine moving stage.

  The present invention has been made in consideration of the above points, and can reduce the heat generated by the driving of the coarse movement stage, increase the degree of freedom in design, and allow the fine movement stage to be replaced. An object of the present invention is to provide a stage apparatus and an exposure apparatus.

In order to achieve the above object, the present invention employs the following configuration.
The stage apparatus according to the present invention includes a first stage (63A, 63B) that moves in a first direction along the surface (44a) of the surface plate (44), and a first direction with respect to the first stage (63A, 63B). And a stage device (12) having a second stage (83A, 83B) moving in a second direction different from the first direction, provided on the first stage (63A, 63B) along the first direction. The first stator (112A, 112B) and the first mover (111A, 111B) provided on the second stage (83A, 83B) and opened along the first direction, and the second stage First driving devices (110A, 110B) that move (83A, 83B) in the first direction, and second stators (102A, 102B) provided on the first stage (63A, 63B) along the first direction And the second stay (83A, 83B) and second movable elements (101A, 101B) opened in the first direction and moving the second stage (83A, 83B) in the second direction. (100A, 100B), and the first stage (63A, 63B) and the second stage (83A, 83B) can be separated when the first stage (63A, 63B) is moved along the first direction. It is characterized by being.

Therefore, in the stage apparatus of the present invention, the second stage (83A, 83B) is moved in the first direction by the first driving device (110A, 110B), and the second stage is driven by the second driving device (100A, 100B). When moving (83A, 83B) in the second direction, the first mover (111A, 111B) and the second mover (101A, 101B) are opened in each direction, so that the movement is restricted. Absent. Therefore, it is not necessary to drive the first stage (63A, 63B) with the same acceleration profile when the second stage (83A, 83B) is moved, the amount of heat generation can be suppressed, and the design freedom is limited. Can also be relaxed.
In the present invention, the second stage (83A, 83B) can be exchanged by moving the second stage (83A, 83B) in the first direction and separating it from the first stage (63A, 63B). become.

  The exposure apparatus of the present invention exposes the pattern of the mask (R) held on the mask stage (RST) onto the substrate (W, W1, W2) held on the substrate stage (12). And the stage apparatus as described in any one of Claim 1-9 is used as at least one stage (12) of a mask stage and a substrate stage.

  Therefore, in the exposure apparatus of the present invention, the amount of heat generated when the mask (R) and the substrate (W, W1, W2) are moved can be suppressed, and the pattern transfer accuracy can be improved by suppressing air fluctuation caused by the heat generation. It becomes possible to prevent the decrease. Further, by making the mask stage and the substrate stage replaceable, parallel processing can be performed and productivity can be improved.

  In the present invention, it is possible to suppress the heat generated by driving the stage, and when applied to an exposure apparatus, adverse effects on exposure accuracy (pattern transfer accuracy) caused by heat generation, such as air fluctuation, can be reduced. It becomes possible. Further, in the present invention, the stage can be easily replaced, which can contribute to the improvement of production efficiency.

Embodiments of the stage apparatus and exposure apparatus of the present invention will be described below with reference to FIGS.
Here, as an exposure apparatus, for example, a description will be given using an example in which a scanning stepper is used that transfers a circuit pattern of a semiconductor device formed on a reticle onto a wafer while moving the reticle and the wafer synchronously. In this exposure apparatus, the stage apparatus of the present invention will be described as applied to a wafer stage.

FIG. 1 shows a schematic configuration of an exposure apparatus 10 according to an embodiment.
The exposure apparatus 10 includes a light source (not shown) and an illumination unit ILU. The illumination system illuminates a reticle R as a mask from above with exposure illumination light. The reticle R is mainly set in a predetermined scanning direction, here a first direction. , A reticle driving system for driving in the Y-axis direction (left and right direction in FIG. 1), a projection optical system PL disposed below the reticle R, and a wafer W1, W2 (substrates) disposed below the projection optical system PL. Stage device 12 as a substrate stage including wafer stages WST1 and WST2 independently holding and moving independently in an XY two-dimensional plane, and arranged on the −Y side of projection optical system PL. Alignment optical system ALG and the like. Among these components, the above-described parts other than the light source (not shown) are housed in an environmental control chamber (hereinafter referred to as “chamber”) 14 that is installed on the floor surface of an ultra-clean room and in which temperature, humidity, etc. are accurately controlled. Yes.

  The optical axis AX (see FIG. 11) of the projection optical system PL is disposed at the + Y side position of the stage surface plate 44, and the optical axis SX (see FIG. 11) of the alignment optical system ALG is − It is arranged at a position on the Y side. Therefore, the + Y side of the stage surface plate 44 is used as an exposure area, and an exposure process is performed on the wafer stage located in this area. The −Y side of the stage surface plate 44 is used as an alignment area, and the wafer stage located in this area. Is aligned.

As shown in FIG. 1, the stage apparatus 12 is installed inside a chamber 42 that forms a wafer chamber 40 therein. On the upper wall of the chamber 42, the vicinity of the lower end of the lens barrel of the projection optical system PL is joined without a gap.
The stage apparatus 12 is levitated and supported via a stage surface plate 44 accommodated in the wafer chamber 40, and a vacuum preload type gas static pressure bearing device (not shown) that is a non-contact bearing above the stage surface plate 44, and Y Two wafer stages WST1 and WST2 that can be moved two-dimensionally independently in the axial direction (left and right direction in FIG. 1) and the X direction (second direction in FIG. 1), which is the second direction, and these wafer stages WST1 , WST2, a stage driving system, and a wafer interferometer system that measures the positions of wafer stages WST1, WST2.

The wafer chamber 40 is filled with clean helium gas (He) or dry nitrogen gas (N ₂ ) with an air (oxygen) concentration of several ppm. In addition, the wafer 42 forming the wafer chamber 40 is not loaded / unloaded at the position of the −Y side half (right half in FIG. 1) on the −X side (front side in FIG. 1) of the chamber 42. The illustrated wafer loader is provided.

  FIG. 2 is a schematic perspective view of the stage apparatus 12 housed in the chamber 42. As shown in FIGS. 2 and 1, the stage device 12 is horizontally supported at three or four points via a vibration isolation unit (not shown) on a base plate BP installed on the inner bottom surface of the chamber 42. A stage surface plate (surface plate) 44, a coarse movement stage (first stage) 63A that moves along an X guide stage 61A that is connected to wafer stage WST1 and extends in the X direction, and is connected to wafer stage WST2 and extends in the X direction. Wafer stages WST1 and WST2 are driven in the Y-axis direction via coarse movement stage (first stage) 63B, coarse movement stages 63A and 63B, and X guide stages 61A and 61B moving along existing X guide stage 61B. Wafer stages WST1, WST2 via Y linear motors 65A, 65B and coarse movement stages 63A, 63B X linear motors 67A for driving the X-axis direction each have a 67B.

  A plurality of vacuum preload type air bearings 60A and 60B, which are non-contact bearings, are provided below both ends of the X guide stages 61A and 61B, respectively, and pressure is blown out from the bearing surfaces of the air bearings 60A and 60B. The X guide stages 60A and 60B are the upper surface of the stage surface plate 44 due to the balance between the static pressure of gas (for example, air, helium, or nitrogen gas) and the own weight of the X guide stages 61A and 61B and the vacuum suction force. The moving surface 44a is supported in a non-contact manner through a clearance of about several microns.

The Y linear motor 65A is provided at both ends of the stator 58A disposed along the Y-axis direction on both outer sides in the X-axis direction of the stage surface plate 44 and the X guide stage 61A, respectively, between the stator 58A. The movable member 62A is driven in the Y-axis direction along the stator 58A by electromagnetic interaction. These stators 58A are respectively supported by support blocks 64A provided separately in the X-axis direction of the stage surface plate 44.
Similarly, the Y linear motor 65B includes a stator 58B disposed on both outer sides of the stage base plate 44 in the Y-axis direction along the Y-axis direction, and a stator by electromagnetic interaction between the stator 58B and the stator 58B. A movable element 62B driven in the Y-axis direction along 58B. These stators 58B are supported by the support block 64B, respectively.

  The support blocks 64A and 64B positioned on the + X side are respectively provided with Y guides 68A and 68B along the Y direction. The movers 62A and 62B positioned on the + X side are provided with the Y guides 68A and 68B. Y guide stages 69A and 69B to be fitted and guided are provided.

  The stators 58A and 58B each have an air bearing such as an air pad, and are supported so as to be movable in a non-contact manner in the Y direction with respect to the support blocks 64A and 64B. Accordingly, the reaction force accompanying the movement of the movers 62A and 62B (wafer stages WST1 and WST2) in the Y-axis direction is absorbed by the movement of the stators 58A and 58B, so the momentum applied to the base plate BP is theoretically large. The position of the center of gravity in the stage device 12 is substantially fixed in the Y direction.

  The movers 62A and 62B are provided with electromagnets 81A and 81B (not shown in FIG. 2, refer to FIG. 12) on the surfaces facing the stators 58A and 58B, respectively. The stators 58A and 58B are electromagnets 81A and 58B, respectively. An iron plate (not shown) is provided on the surface facing 81B. Then, by appropriately adjusting the magnetic attractive force of the electromagnets 81A and 81B under the control of the control device CONT (see FIG. 12), the coarse movement stages 63A and 63B and the wafer stages WST1 and WST2 are moved in the X direction. Reaction force can be offset.

  Next, coarse movement stages 63A and 63B and wafer stages WST1 and WST2 will be described with reference to FIGS. Since wafer stages WST1 and WST2 have the same configuration, only wafer stage WST1 and coarse movement stage 63A will be typically described below, and wafer stage WST2 and coarse movement stage 63B are denoted by reference numerals (mainly in FIG. Only subscript B is added).

  As shown in FIG. 3, wafer stage WST1 includes coarse movement stage 63A described above and a fine movement stage that is interchangeably connected to the -Y side of coarse movement stage 63A (in the case of coarse movement stage 63B, the + Y side). (Second stage) 83A. Fine movement stage 83A includes a table unit 70A having wafer holder WHA for sucking and holding wafer W1, and a support unit for supporting table unit 70A from below by air cylinder 82A (the + Y side air cylinder is not shown in FIG. 3). 84A. The air cylinder 82A supports the table unit 70A with substantially zero air spring rigidity so as to cancel the weight of the table unit 70A under the control of the control device CONT.

The support unit 84A includes a bearing plate 71A provided with a plurality of vacuum preload type air bearings 73A (see FIGS. 4 and 5) which are non-contact bearings on the bottom surface, and the air cylinder 82A provided upright on the bearing plate 71A. A support plate 72A is provided which stands on the bearing plate 71A and supports the air cylinder 82A. Then, fine movement stage 83A has a balance between the static pressure of pressurized gas (for example, air, helium, or nitrogen gas) blown out from the bearing surface of air bearing 73A, and the total weight and vacuum suction force of fine movement stage 83A. The moving surface 44a, which is the upper surface of the stage surface plate 44, is supported without contact through a clearance of about several microns.
Further, scales (position index portions) 74A and 75A of linear encoders used when measuring the relative displacement of the fine movement stage 83A with respect to the coarse movement stage 63A are provided on the upper surface of the bearing plate 71A. Details of the linear encoder including the scales 74A and 75A will be described later.

  The table unit 70A has the above-described wafer holder WHA that holds the wafer (substrate) W by suction means such as vacuum suction on the upper surface of the table body 76A, and extends in the Y-axis direction at one end (−X side end) in the X-axis direction. An X moving mirror 77X and a Y moving mirror 77Y extending in the X axis direction are provided at one end (+ Y side end) in the Y axis direction. Further, a reference mark plate FM whose surface is set to be substantially the same as the height of the wafer W is fixed to the upper surface of the table body 76A. This reference mark plate FM is used, for example, when detecting the reference position of wafer stage WST1 (fine movement stage 83A).

The body 85A below the table body 76A is provided with a mover of a linear motor that moves the fine movement stage 83A with six degrees of freedom with respect to the coarse movement stage 63A.
More specifically, as shown in FIG. 4, the mover of the X motor (second drive device) 100A that drives the fine movement stage 83A in the X-axis direction, which is the second direction, is located at the center in the X-axis direction of the body 85A. A (second mover) 101A is provided. The mover 101A is composed of a pair of magnetism bodies (magnets) extending in the X-axis direction with a gap in the Z-direction so as to be opened along the Y-axis direction.

  On both sides of the mover 101A in the X-axis direction, a Y motor (first drive device) 110A that drives the fine movement stage 83A in the Y-axis direction and the Zθ direction (rotation direction around the Z-axis) as the first direction is movable. A child (first mover) 111A is provided. The mover 111A is composed of a pair of magnetic generators that are spaced along the Z direction on each side so as to be opened along the Y axis direction, and extend in the Y axis direction as shown in FIG. Has been.

  Also, below the mover 111A, a Z motor that drives the fine movement stage 83A in the third direction, ie, the Z-axis direction, the Xθ direction (the rotation direction around the X axis), and the Yθ direction (the rotation direction around the Y axis). (Third drive unit) A movable element (third movable element) 121A of 120A is provided. The mover 121A is composed of a pair of magnetomotive members extending on each side with a gap in the Z direction so as to be opened along the Y-axis direction. These movers 121A are provided at a total of three locations, one at the center in the Y-axis direction (not shown in FIGS. 3 and 5) on the −X side, and two on both sides in the Y-axis direction with a gap on the + X side. (See FIG. 5).

  As shown in FIG. 3, the coarse movement stage 63A includes a stator (second stator) 102A of the X motor 100A, a stator (first stator) 112A of the Y motor 110A, and a Z motor 120A. A stator (third stator) 122A protrudes along the Y-axis direction (−Y side, the stators 102B, 112B, and 122B of the coarse movement stage 63B are on the + Y side). The stator 102A incorporates a coil unit, and is provided at a position to be inserted into the gap between the pair of movers 101A when the fine movement stage 83A is mounted on the coarse movement stage 63A along the Y-axis direction. The stator 112A also includes a coil unit, and is provided at a position where the fine movement stage 83A is inserted into the gap between the pair of movable elements 111A when the fine movement stage 83A is mounted on the coarse movement stage 63A along the Y-axis direction. . Similarly, the stator 122A incorporates a coil unit, and is provided at a position where the fine movement stage 83A is inserted into the gap between the pair of movable elements 111A when the fine movement stage 83A is mounted on the coarse movement stage 63A along the Y-axis direction. Yes. The stator 122A is provided at one position on the −X side and at two positions on the + X side with a gap in the Y-axis direction corresponding to the mover 121A provided at three positions. Driving of the motors 100A, 110A, and 120A by the stators 102A, 112A, and 122A (coil units) is controlled by the control device CONT (not shown in FIG. 3, see FIG. 12).

  Therefore, by controlling the driving of the X motor 100A by the control device CONT, the fine movement stage 83A can be moved relative to the coarse movement stage 63A in the X-axis direction. Further, the control device CONT controls the drive of the Y motor 110A to drive the movable elements 111A on both sides in the same size and direction, so that the fine movement stage 83A is relative to the coarse movement stage 63A in the Y-axis direction. The fine movement stage 83A can be moved relative to the coarse movement stage 63A in the Zθ direction by making it possible to move, and by making the drive amounts of the movable elements 111A on both sides different.

  Further, the control device CONT controls the driving of the Z motor 120A to drive the three movable elements 121A in the same size and direction, so that the fine movement stage 83A is relative to the coarse movement stage 63A in the Z-axis direction. Can be moved. Further, by driving the two movable elements 121A on the + X side in the same size and direction, and by making the driving amount of the movable element 121A on the −X side different, the fine movement stage 83A is moved to Yθ with respect to the coarse movement stage 63A. It can be moved relative to the direction. Further, by varying the drive amount of the two movers 121A on the + X side, the fine movement stage 83A can be moved relative to the coarse movement stage 63A in the Xθ direction. Accordingly, by driving the X motor 100A, the Y motor 110A, and the Z motor 120A, the fine movement stage 83A is moved to the coarse movement stage 63A in the X axis direction, the Y axis direction, the Z axis direction, the Xθ direction, the Yθ direction, and the Zθ direction. It can be moved with a degree of freedom.

The driving principle of the configuration of the Z motor 120A will be described with reference to FIG.
As shown in this figure, the mover 121A made of a magnet generator is such that the magnetic poles of the magnets adjacent to the upper and lower yokes 123 are opposite to each other, and the magnetic poles of the magnets facing vertically are the same. Is arranged.
In the Z motor 120A having this configuration, a stator (coil unit) 122A is disposed in the gap between the mover 121A. For example, in FIG. 6, a current in a direction toward the front side of the sheet is supplied to a coil located on the + Y side, and −Y By causing a current in the direction toward the back side of the drawing to flow through the coil located on the side, a thrust force that moves the mover 121A (that is, fine movement stage 83A) to the + Z side can be generated. Further, by reversing the direction in which the current flows, it is possible to generate a thrust that moves the mover 121A (that is, fine movement stage 83A) to the −Z side. That is, by adjusting the direction and magnitude of the current flowing through the stator 122A, the mover 121A (fine movement stage 83A) can be moved in the Z direction in an arbitrary direction and magnitude.

  Wafer stage WST1 is provided with a linear encoder for measuring the relative positional relationship between fine movement stage 83A and coarse movement stage 63A in the X-axis direction, Y-axis direction, and Zθ direction. FIG. 7 is a diagram showing a state in which the fine movement stage 83A and the coarse movement stage 63A are in a connected state and a part of the air cylinder 82A and the support plate 72A are removed. As shown in this figure, the linear encoder includes the above-described scales 74A and 75A provided on the upper surface of the bearing plate 71A in the support unit 84A, and measurement heads (measurement units) 94A and 95A that measure the scales 74A and 75A. It is composed of The scales 74A and 75A are provided in pairs on the + Y side edge and the −Y side edge of the bearing plate 71A, respectively.

As shown in FIG. 8A, the scale 74A has line and space marks formed at a predetermined pitch in the X-axis direction. The scale 75A is formed with line-and-space (that is, lattice-like) marks at a predetermined pitch in each of the X-axis direction and the Y-axis direction. As shown in FIG. 8B, the measurement heads 94A and 95A (shown by reference numerals 94 and 95 in FIG. 8B for convenience) are spaced above the scales 74A and 75B in the Z direction. Protruding so as to face each other.
In this linear encoder, the displacement in the X-axis direction can be measured by measuring the scale 74A with the measurement head 94A, and the displacement in the X-axis direction and the Y-axis direction can be measured by measuring the scale 75A with the measurement head 95A. Therefore, the relative displacement of the fine movement stage 83A and the coarse movement stage 63A in the X axis direction, the Y axis direction, and the Zθ direction can be measured from the measurement results of the measurement heads 94A and 95A. The measurement result by the linear encoder (measuring heads 94A, 95A) is output to the control device CONT (see FIG. 12).

  A plurality of vacuum preload type air bearings 78A (see FIG. 8B), which are non-contact bearings, are provided on the bottom surface of the coarse movement stage 63A. Then, due to the balance between the static pressure of the pressurized gas blown out from the bearing surface of the air bearing 78A, the total weight of the coarse movement stage 63A and the vacuum suction force, the coarse movement stage 63A moves on the upper surface of the stage surface plate 44. The surface 44a is supported without contact through a clearance of about several microns. Accordingly, the coarse movement stage 63A and the fine movement stage 83A are supported on the same support surface 44a by the air bearings 78A and 73A. Usually, in order to obtain measurement accuracy of about 1 μm with respect to the linear encoder, it is necessary to limit the clearance between the scales 74A and 75A and the measurement heads 94A and 95A to several μm to several tens μm or less. The bearing plate 71A (fine movement stage 83A) provided with 74A and 75A and the coarse movement stage 63A are supported and restrained in the Z-axis direction by the air bearings 78A and 73A on the same support surface 44a as described above. The clearance between the scales 74A and 75A and the measurement heads 94A and 95A can be managed to be about several μm (for example, 2 to 3 μm).

  1 and 2, the position of the wafer stage located in the exposure area in the Y-axis direction is provided on the + Y side outside of the stage surface plate 44, and a laser interferometer 32 (which irradiates the moving mirror 77Y with laser light) The position in the X-axis direction is measured by a laser interferometer 33 (see FIG. 2) that is provided outside the −X side of the stage surface plate 44 and emits laser light to the movable mirror 77X. The measurement is performed and the result is output to the control device CONT (see FIG. 12). The position of the wafer stage located in the alignment area in the Y-axis direction is suspended substantially at the center of the stage surface plate 44 (see FIG. 1), and a laser interferometer 34 (FIG. 1) irradiates the movable mirror 77Y with laser light. 1) and the position in the X-axis direction is provided by a laser interferometer 35 (see FIG. 2) that is provided outside the -X side of the stage surface plate 44 and irradiates the moving mirror 77X with laser light. The measurement is performed and the result is output to the control device CONT (see FIG. 12).

  On the other hand, a fixing device for fixing the fine movement stages 83A and 83B separated from the coarse movement stages 63A and 63B to the stage surface plate 44 is provided on the stage surface plate 44 immediately below the laser interferometer 34. FIG. 9 is a partially enlarged view showing a main part of the fixing device. As shown in this figure, a pedestal 86 is provided at substantially the center of the stage surface plate 44, and a fixing device 87 is provided on the pedestal 86. The fixing device 87 is a plate-like holding portion 88 fixed along the Y-axis direction at the + X side end of the pedestal 86 in the vicinity of the fixing position of the fine movement stage 83A, along the X-axis direction with respect to the holding portion 88. From an electromagnetic actuator such as an air cylinder or solenoid having a guide portion 89 that holds and holds the cam follower 91 provided on the fine movement stage 83A with the holding portion 88 when it advances and retracts toward the holding portion 88. The driving unit 90 is roughly configured. The drive of the drive unit 90 is controlled by a control device CONT as a drive control device.

  As shown in FIGS. 3 to 5, the cam followers 91 are suspended downward in pairs (a total of four) at both ends in the X-axis direction of the body 85A of the fine movement stage 83A at intervals in the Y-axis direction. ing. FIG. 10 is a schematic plan view showing the fixing device 87 on the pedestal 86. As shown in this figure, the guide portion 89 is formed with a V-groove 92 that fits the cam follower 91 at a position facing the cam follower 91 when the fine movement stage 83A is in the fixed position. Although not shown in FIGS. 9 and 10, the fixing device 87 is installed on the opposite side across the Y axis, and the two fine movement stages 83 </ b> A and 83 </ b> B can be fixed simultaneously. It has become.

Returning to FIG. 1, a pulsed laser light source that outputs pulsed ultraviolet light in the vacuum ultraviolet region, such as an F ₂ laser light source (output wavelength 157 nm) or an ArF excimer laser light source (output wavelength 193 nm), is used here. ing. This light source is installed in a service room with a low degree of cleanness different from the ultra clean room in which the chamber 14 is installed, or in a utility space below the clean room floor, and the illumination unit ILU in the chamber 14 is routed through a routing optical system (not shown). It is connected to the. The light source has a configuration in which a repetition frequency (oscillation frequency) of pulse emission, pulse energy, and the like are controlled by a laser control device 18 (not shown in FIG. 1 but see FIG. 12) under the control of the control device CONT. ing.

The illumination unit ILU includes an illumination system housing 20 that is hermetically sealed with respect to outside air, and a secondary light source forming optical system, a beam splitter, and a light collecting unit that are housed in the illumination system housing 20 in a predetermined positional relationship. The illumination optical system includes a lens system, a reticle blind, an imaging lens system (all not shown), and the like, and a rectangular (or arc-shaped) illumination area IAR (see FIG. 11) on the reticle R is uniformly formed. Illuminate with illuminance. As the illumination optical system, one having the same configuration as that disclosed in, for example, JP-A-9-320956 is used. The illumination system housing 20 is filled with clean helium gas (He) or dry nitrogen gas (N ₂ ) whose concentration of air (oxygen) is less than several ppm.

The reticle drive system is accommodated in a reticle chamber 22 shown in FIG. A light transmission window made of fluorite or the like is formed at a connection portion between the reticle chamber 22 and the illumination system housing 20. The reticle chamber 22 is filled with clean helium gas (He) or dry nitrogen gas (N ₂ ) whose concentration of air (oxygen) is about several ppm. The reticle drive system includes a reticle stage (mask stage) RST that can move in an XY two-dimensional plane while holding the reticle R on the reticle base board 24 shown in FIG. 1, and a reticle stage RST (not shown) that drives the reticle stage RST. A drive unit 26 (not shown in FIG. 1, refer to FIG. 12) including a linear motor and the like, and a reticle interferometer system 28 for managing the position of the reticle stage RST are provided.

  More specifically, the reticle stage RST is actually levitated and supported on the reticle base board 24 via a non-contact bearing (not shown), for example, a vacuum preload type gas static pressure bearing device, and a linear motor (not shown). Accordingly, a coarse reticle stage that is driven in a predetermined stroke range in the Y axis direction that is the scanning direction, and a drive mechanism that includes a voice coil motor or the like with respect to the reticle coarse stage, the X axis direction, the Y axis direction, and the θZ direction ( And a reticle fine movement stage that is slightly driven in the rotation direction around the Z-axis). The reticle R is attracted and held on the reticle fine movement stage via an electrostatic chuck or a vacuum chuck (not shown). As described above, reticle stage RST is actually composed of two stages, but in the following, for convenience, reticle stage RST is driven by drive unit 26 in the X-axis and Y-axis directions, and in the θZ direction. In the following description, it is assumed that the stage is a single stage that can perform micro-rotation and scanning in the Y-axis direction. The drive unit 26 is a mechanism that uses a linear motor, a voice coil motor, or the like as a drive source, but is shown as a simple block in FIG. 12 for convenience of illustration.

  On the reticle stage RST, as shown in FIG. 11, a movable mirror 30 made of the same material (for example, ceramic) as the reticle stage RST is extended in the Y axis direction at one end portion in the X axis direction. A reflecting surface is formed on one surface of the movable mirror 30 in the X-axis direction by mirror finishing. The interferometer beam from the interferometer system 28 is irradiated toward the reflecting surface of the movable mirror 30, and the interferometer receives the reflected light and measures the relative displacement with respect to the reference surface to thereby position the reticle stage RST. Is measured. Here, the interferometer 28 actually has two interferometer optical axes that can be measured independently, and can measure the position of the reticle stage RST in the X-axis direction and the yawing amount. ing. The interferometer 28 is configured to cancel the relative rotation (rotation error) of the reticle and the wafer based on the yawing information and Y position information of the wafer stages WST1 and WST2 from the interferometers 32 and 34 on the wafer stage side. It is used for controlling rotation of the stage RST and performing X-direction synchronization control (position alignment). In FIG. 11, the coarse movement stages 63A and 63B in the wafer stages WST1 and WST2 are not shown.

  On the other hand, a pair of corner cube mirrors 36A and 36B are installed on one side in the Y-axis direction, which is the scanning direction (scanning direction) of reticle stage RST. Then, an interferometer beam is irradiated from the double-pass interferometer 37 to the corner cube mirrors 36A and 36B, and is returned from the corner cube mirrors 36A and 36B to a reflection surface (not shown) provided on the reticle base board 24. Then, each reflected light reflected there returns on the same optical path, and is received by each double path interferometer 37, and from the reference position (reflecting surface on the reticle base board 24 at the reference position) of each corner cube mirror 36A, 36B. Relative displacement is measured. Then, the measurement values of these double path interferometers 37 are supplied to the control device CONT (not shown in FIG. 1, refer to FIG. 12), and the position of the reticle stage RST in the Y-axis direction is measured based on the average value. . The information on the Y-axis direction position is obtained by calculating the relative position between reticle stage RST and wafer stage WST1 or WST2 based on the measurement value of the wafer-side interferometer, and based on this, the scanning direction (Y-axis direction) during scanning exposure This is used for synchronous control of the reticle and wafer.

In addition, it is necessary to use the material of the glass substrate which comprises the reticle R properly by the light source to be used. For example, synthetic quartz in the case of using a vacuum ultraviolet light source such as F ₂ laser light source as a light source, magnesium fluorspar and fluoride, the fluoride crystal such as lithium fluoride, or a hydroxyl group concentration of 100ppm or less, and containing fluorine It is necessary to use (fluorine-doped quartz) or the like, and when using an ArF excimer laser light source or a KrF excimer laser light source, it is possible to use synthetic quartz in addition to the above materials.

  Returning to FIG. 1, the projection optical system PL is joined to the reticle chamber 22 with no gap near the upper end of the lens barrel. Here, as the projection optical system PL, a reduction system having a 1/4 (or 1/5) reduction magnification in which both the object plane (reticle R) side and the image plane (wafer W) side are telecentric is used. For this reason, when the reticle R is irradiated with illumination light (ultraviolet pulse light) from the illumination unit ILU, an imaging light beam from a portion illuminated by the ultraviolet pulse light in the circuit pattern area on the reticle R is projected into the projection optical system. A partial inverted image of the circuit pattern is incident on the PL and is confined to a slit shape or a rectangular shape (polygonal shape) at the center of the field on the image plane side of the projection optical system PL for each pulse irradiation of ultraviolet pulsed light. Imaged. Thereby, the partially inverted image of the projected circuit pattern is reduced and transferred to the resist layer on the surface of one of the plurality of shot areas on the wafer W arranged on the imaging plane of the projection optical system PL. .

  An off-axis type alignment optical system ALG is installed at a position a predetermined distance away from the optical axis center of the projection optical system PL (which coincides with the projection center of the reticle pattern image) on the + Y side. This alignment optical system ALG has three types of alignment sensors, an LSA (Laser Step Alignment) system, an FIA (Filed Image Alignment) system, and an LIA (Laser Interferometric Alignment) system. It is possible to measure the position of the alignment mark on the wafer in the X and Y two-dimensional directions.

  Here, the LSA system is the most versatile sensor that irradiates a mark with a laser beam and measures the mark position using diffracted / scattered light, and has been conventionally used for a wide variety of process wafers. The FIA system is a sensor that measures the mark position by illuminating the mark with broadband light such as a halogen lamp and processing the image of the mark, and is effectively used for asymmetric marks on the aluminum layer and wafer surface. The In addition, the LIA system is a sensor that irradiates a diffraction grating mark with laser light having a slightly different frequency from two directions, causes the generated two diffracted lights to interfere, and detects the position information of the mark from the phase. Yes, it can be used effectively for low step and rough wafers. In the present embodiment, these three types of alignment sensors are properly used according to the purpose, so-called search alignment in which the approximate position of the wafer is measured by detecting the position of three-dimensional marks on the wafer, or on the wafer. Fine alignment or the like for performing accurate position measurement of each shot area is performed.

  Further, in the exposure apparatus 10 of the present embodiment, although not shown in FIG. 1, the reticle is provided above the reticle R via the projection optical system PL disclosed in, for example, Japanese Patent Laid-Open No. 7-176468. A pair of reticles comprising a TTR (Through The Reticle) alignment optical system using an exposure wavelength for simultaneously observing reticle marks on R (not shown) and marks on reference mark plates FM1 and FM2 (see FIG. 11). Alignment microscopes 138A and 138B (see FIG. 12) are provided. Detection signals from these reticle alignment microscopes 138A and 138B are supplied to the control device CONT.

  Although not shown in FIG. 1, each of the projection optical system PL and the alignment optical system ALG has an autofocus / autoleveling measurement mechanism (hereinafter referred to as “AF / AL system”) for checking the in-focus position. Each). As described above, the configuration of the exposure apparatus provided with the auto focus / auto leveling measurement mechanism in each of the projection optical system PL and the alignment optical system ALG is disclosed in detail in, for example, Japanese Patent Laid-Open No. 10-214783, and is publicly known. Therefore, further explanation is omitted here. Therefore, in the present embodiment, as in the exposure apparatus described in the above-mentioned Japanese Patent Application Laid-Open No. 10-214783, when the alignment sensor is measured by the alignment optical system ALG, auto / automatic AF / AL measurement and control similar to those during exposure are performed. By measuring the position of the alignment mark while performing focus / auto-leveling, highly accurate alignment measurement is possible. In other words, an offset (error) due to the posture of the stage does not occur between exposure and alignment.

FIG. 12 shows the main configuration of the control system of the exposure apparatus 10 according to this embodiment. This control system is composed of a control device CONT that controls the entire device in an integrated manner, various measuring devices that output measurement results to the control device CONT, and various drive devices that are driven based on these measurement results. .
In the following description, the description of the point that the various drive devices are driven by the control of the control device CONT is omitted.

Subsequently, the operation of the stage apparatus 12 in the exposure apparatus 10 according to the present embodiment will be described. Since operations of wafer stages WST1 and WST2 are the same, here, description will be given using an example of one wafer stage WST1.
When wafer stage WST1 is moved in the Y-axis direction by exposure operation or alignment operation, control device CONT drives Y linear motor 65A along guide portion 68A with a long stroke and finely drives Y motor 110A.
Further, when moving wafer stage WST1 in the X-axis direction by step movement or the like, control device CONT drives X linear motor 67A along X guide stage 61A with a long stroke, and minutely drives X motor 100A.

When moving wafer stage WST1, movers 101A, 111A, 121A of motors 100A, 110A, 120A connecting fine movement stage 83A and coarse movement stage 63A are arranged with a clearance in the Z-axis direction. Therefore, the movable range when the fine movement stage 83A is moved in the X-axis direction or the Y-axis direction with respect to the coarse movement stage 63A is restricted by the clearance amount between the movable elements 101A, 111A, 121A and the stators 102A, 112A, 122A. However, the thrust guarantee range as a linear motor in the X-axis direction or the range in which the stators 102A, 112A, 122A and the body 85A do not mechanically interfere with each other, and the movers 101A, 111A, 121A are in the Y-axis direction. Since each is open along the Y-axis direction, It becomes thrust guarantee range as Amota, becomes considerably large as compared with the case that is bound to the amount of clearance in the motor.
Therefore, in this embodiment, it is not necessary to drive the coarse movement stage 63A with the same acceleration profile as that of the fine movement stage 83A, and both stages 63A and 83A can be driven with different accelerations under the control of the control device CONT. it can. Specifically, the coarse movement stage 63A can be driven with a smaller acceleration with respect to the fine movement stage 83, and the heat generation associated with the driving (acceleration) of the coarse movement stage 63A can be suppressed.

  Next, of the operations of the stage apparatus 12 in the exposure apparatus 10 according to the present embodiment, the operation of switching (switching) the wafer stages WST1 and WST2 between the exposure area and the alignment area will be described with reference to FIGS. I will explain. In FIGS. 13 to 15, the stage constituent members are illustrated in a simplified manner, and only those that are particularly related to the operations described with reference to the drawings are denoted by reference numerals.

  FIG. 13A shows a wafer stage WST1 subjected to exposure processing in the exposure area (upper side in the drawing) and a wafer stage WST2 subjected to alignment processing in the alignment area (lower side in the drawing). It is a figure which shows the state moved to the exchange position about the X-axis direction by the drive of linear motor 67A, 67B. Wafer stages WST1 and WST2 have been moved in advance by driving Y linear motors 65A and 65B to positions in the Y-axis direction that do not interfere with each other even when moved in the X-axis direction.

  Next, as shown in FIG. 13B, the Y linear motors 65A and 65B are driven so that the wafer stages WST1 and WST2 approach each other, and the fine movement stages 83A and 83B sandwich the fixing device 87 in the X-axis direction. Move it to the exchange position. As the fine movement stages 83A and 83B move in the Y-axis direction, the cam follower 91 provided on the fine movement stages 83A and 83B enters between the holding portion 88 and the guide portion 89 in the fixing device 87, as shown in FIG. .

  At this time, the control device CONT controls the drive unit 90 so that the cam follower 91 can smoothly enter, and retracts the guide unit 89 to a position where it does not interfere with the cam follower 91 as shown by a two-dot chain line in FIG. deep. Further, the control device CONT advances the guide portion 89 toward the holding portion 88 when the fine movement stages 83A and 83B reach the replacement position, holds the cam follower 91 between the holding portion 88 and the air by the V groove 92. The driving of the cylinders 82A and 82B is stopped. Thereby, the fine movement stages 83A and 83B are positioned and fixed to the stage surface plate 44 in the X-axis direction and the Y-axis direction by fixing the fixing device 87, and the table units 70A and 70B in the fine movement stages 83A and 83B are Z-axis by their own weight. The position of the direction is fixed. That is, the fine movement stages 83A and 83B are fixed in the X, Y, and Z axis directions and maintained in their postures even when the servo control by the coarse movement stages 63A and 63B is not performed.

  When the positions of fine movement stages 83A and 83B are fixed, control device CONT stops driving of X motors 100A and 100B, Y motors 110A and 110B, and Z motors 120A and 120B, and coarse movement stages 63A and 63B are fine movement stages. Even in the case of relative movement in the X-axis direction with respect to 83A and 83B, any of the stators 102A, 102B, 112A, 112B, 122A, 122B (hereinafter, these are illustrated and described as stator groups 132A, 132B). As shown in FIG. 14A, the Y linear motors 65A and 65B are driven to move the coarse movement stages 63A and 63B in the Y-axis direction to positions where they do not interfere with the bodies 85A and 85B (see FIG. 3). Thereby, coarse movement stages 63A and 63B and fine movement stages 83A and 83B are separated.

  Subsequently, the control device CONT drives the X linear motors 67A and 67B, and as shown in FIG. 14B, the coarse movement stage 63A faces the fine movement stage 83B, and the coarse movement stage 63B and the fine movement stage 83A. The stator group 132A and the movers 101B, 111B, and 121B (hereinafter, illustrated and described as the mover group 131B) of the fine movement stage 83B are connected to each other at the facing position, more specifically, in the X-axis direction. The coarse movement stages 63A and 63B are moved to positions where 132B and the movable elements 101A, 111A, and 121A (hereinafter, illustrated and described as the movable element group 131A) of the fine movement stage 83A are connected.

  Thereafter, the control device CONT drives the Y linear motors 65A and 65B to move the coarse movement stages 63A and 63B in a direction approaching the fine movement stages 83B and 83A, and the stator group 132A and the movable element group 131B are fixed. The child group 132B and the movable element group 131A are connected to each other (see FIG. 15A). When fine movement stages 83B and 83A are mounted on coarse movement stages 63A and 63B, respectively, control device CONT drives drive unit 90 to release holding of cam follower 91 by holding unit 88 and guide unit 89, and an air cylinder 82A and 82B are driven and the support to the table units 70A and 70B is resumed. Then, the control device CONT measures the scales 74B, 75B and 74A, 75A with the measurement heads 94A, 95A and 94B, 95B shown in FIG. The relative position in each direction of Zθ and the relative position in each direction of X, Y, Zθ between coarse movement stage 63B and fine movement stage 83A are detected, and X motor 100A, Y motor 110A and Z motor are detected based on the detection results. By driving 120A, the relative position between coarse movement stage 63A and fine movement stage 83B and the relative position between coarse movement stage 63B and fine movement stage 83A are adjusted.

Then, the control device CONT drives the Y linear motors 65A and 65 to bring the coarse movement stage 63A and the fine movement stage 83B into the exposure processing preparation position and move the coarse movement stage 63B and the fine movement as shown in FIG. The stage 83A is moved to the alignment processing preparation position.
In this way, the exchange process of fine movement stages 83A and 83B is completed.

Next, parallel processing using two wafer stages will be described.
For example, while performing an exposure operation as described later on the wafer W1 on the wafer holder WHA via the projection optical system PL in the exposure area, the wafer loader and the wafer stage WST2 are placed at predetermined loading positions in the alignment area. The wafer is exchanged by a delivery mechanism (not shown), and the wafer W2 is loaded on the wafer holder WHB. Next, the control unit CONT controls the Y linear motor 65B and the X linear motor 67B while monitoring the measurement values of the interferometers 34 and 35, thereby positioning the wafer stage WST2 at the alignment reference position. During the movement of wafer stage WST2, the exposure operation is continued on wafer stage WST1 side. The alignment reference position is a position where the first reference mark (not shown) on the reference mark plate FM2 of the wafer stage WST2 comes directly under the alignment optical system ALG.

  Subsequently, on the wafer stage WST2 side, after performing the search alignment, fine alignment is performed in which the arrangement of each shot area on the wafer W2 is obtained using, for example, EGA. That is, while aligning the position of wafer stage WST2 based on the measurement values of interferometers 34 and 35, alignment of a predetermined sample shot on wafer W2 is performed based on design shot arrangement data (alignment mark position data). The mark position is measured by an FIA sensor or the like of the alignment optical system ALG, and all shot arrangement data is calculated by statistical calculation by the least square method based on the measurement result and shot arrangement design coordinate data. Thereby, the coordinate position of each shot is calculated on the alignment stage coordinate system. Then, the control device CONT calculates the relative positional relationship of each shot with respect to the first reference mark by subtracting the above-described coordinate position of the first reference mark from the coordinate position of each shot.

  On the other hand, in the exposure area, the position of wafer stage WST1 is controlled on the stage coordinate system during exposure, and the reference mark plate FM1 on wafer stage WST1 is positioned at the exposure reference position at which the reticle pattern image is projected. . When wafer stage WST1 is positioned at this exposure reference position, control unit CONT uses a pair of reticle alignment microscopes (not shown) to expose a pair of second reference marks on reference mark plate FM1 and corresponding to them. The relative position of the projected image on the wafer surface of the mark on the reticle is detected, that is, the image signal of each mark image is captured by the reticle alignment microscope. As a result, the coordinate position of the pair of second reference marks on the reference mark plate FM1 in the stage coordinate system during exposure and the projected image coordinate position of the mark on the reticle R on the wafer surface are detected. A relative positional relationship between the position (projection center of the projection optical system PL) and the coordinate position of the pair of second reference marks on the reference mark plate FM1 is obtained.

  In the main control unit CONT, the relative positional relationship of each shot on the wafer W1 with respect to the first reference mark on the reference mark plate FM1 obtained in the alignment process, and the exposure position and a pair of first marks on the reference mark plate FM1. The relative position relationship between the exposure position and each shot is finally calculated from the relative position relationship with the coordinate position of the two reference marks. Based on the calculation result, the EI cores 84a to 84c and the voice coil motors 85a to 85c are driven to finely position the wafer holder WHA, and the wafer is positioned at the scanning start position for exposure of the shot area on the wafer W1. While the stage WST1 is sequentially positioned, scanning exposure is performed by relatively scanning the reticle stage RST and the wafer stage WST1 in the scanning direction in synchronism with each shot area exposure. Of course, in parallel with the exposure operation on the wafer W1 side, on the wafer stage WST2 side, the wafer is replaced, and subsequently, the wafer stage WST2 is moved to the alignment reference position, search alignment, and fine alignment are performed as described above. . Thereafter, as described above, the two wafer stages WST1 and WST2 are switched (switched) while moving independently in the two-dimensional direction, the exposure sequence for the wafer on one wafer stage, and the wafer exchange for the other wafer. And the parallel processing with the alignment sequence is repeatedly performed.

  As described above, in the present embodiment, the movable range when fine movement stages 83A and 83B are moved in the X-axis direction or the Y-axis direction is restricted by the clearance amount between the stator and the mover in the motor. Since the coarse movement stages 63A and 63B are driven with a smaller acceleration than the fine movement stages 83A and 83B, the coarse movement stages 63A and 63B have the same acceleration profile as the fine movement stages 83A and 83B. This eliminates the need for driving, can suppress heat generation associated with driving (acceleration) of the coarse movement stages 63A and 63B, and can reduce adverse effects on exposure accuracy (pattern transfer accuracy) due to heat generation, such as air fluctuations. become. In the present embodiment, the relative position variation between the coarse movement stages 63A and 63B and the fine movement stages 83A and 83B is not limited by the clearance amount, so that the degree of freedom in designing the control response characteristic can be increased.

  In this embodiment, the movers 101A, 101B, 111A, 111B, 121A, 121B of the X motors 100A, 100B, the Y motors 110A, 110B, and the Z motors 120A, 120B are opened along the Y-axis direction. Therefore, the fine movement stages 83A and 83B can be easily exchanged by moving in the Y-axis direction. Therefore, it becomes possible to easily execute the parallel processing of the exposure processing and the alignment processing, which can contribute to the improvement of production efficiency.

  Furthermore, in this embodiment, since the relative positional relationship between the coarse movement stages 63A and 63B and the fine movement stages 83A and 83B is detected by the linear encoder, the measurement of the laser interferometers 32 to 35 is performed when the fine movement stages 83A and 83B are exchanged. Even when out of the possible range, the positions of the fine movement stages 83A and 83B can be monitored. In this embodiment, the bearing plates 71A and 71B provided with the scales 74A and 75A of the linear encoder and the coarse movement stages 63A and 63B provided with the measuring heads 94A and 95A are the same by the air bearings 73A and 78A. Therefore, the clearance between the scales 74A and 75A and the measurement heads 94A and 95A can be maintained at a minute amount, and the position information of the fine movement stages 83A and 83B is measured with high accuracy. It becomes possible.

  In the present embodiment, when fine movement stages 83A and 83B are replaced, fine movement stages 83A and 83B are fixed on stage surface plate 44 by fixing device 87, so that fine movement stages 83A and 83B are held in a predetermined posture. And stable exchange processing is possible.

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 such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, in the above embodiment, the fine movement stages 83A and 83B are fixed on the stage surface plate 44 by the fixing device 87, but in addition to this, air bearings 73A and 73B provided on the fine movement stages 83A and 83B. The fine movement stages 83A and 83B may be placed on and fixed to the stage surface plate 44 by stopping the driving of.
In the above embodiment, the scales 74A and 75A are provided on the fine movement stages 83A and 83B, and the measurement heads 94A and 95A are provided on the coarse movement stages 63A and 63B. However, the scales 74A and 75A are provided on the coarse movement stages. The measurement heads 94A and 95A may be provided on the fine movement stages 83A and 83B.

Further, in the above embodiment, two wafer stages are provided and each moves independently (double stage method). However, the present invention is not limited to this, and three or more wafer stages are provided. A configuration or a configuration in which one wafer stage is provided (single stage method) may be used.
Furthermore, in the above embodiment, the stage apparatus of the present invention is applied to the wafer stage, but it can also be applied to the reticle stage RST.

  In the above embodiment, the illumination unit ILU has the housing 20, the reticle stage RST is accommodated in the reticle chamber 22, the stage device 12 is installed in the chamber 42, the housing 14, the chamber 22, the chamber 42, and the projection. The case where an inert gas such as helium gas is filled in the lens barrel of the optical system PL has been described. However, the present invention is not limited to this, and the entire components of the exposure apparatus are accommodated in a single chamber. It doesn't matter.

  In the above embodiment, the case where the wafer is exchanged, aligned, etc. on the other wafer stage while the exposure is performed using the pattern of one reticle on one wafer stage has been described. For example, as disclosed in Japanese Patent Application Laid-Open No. 10-214783, double exposure is performed by using a reticle stage on which two reticles can be mounted and using a pattern of two reticles on one wafer stage. During the process, wafer exchange, alignment, etc. may be performed in parallel on the other wafer stage. In this way, high resolution and an improved DOF (depth of focus) can be obtained by double exposure without significantly reducing the throughput by simultaneous parallel processing.

  In the above embodiment, the stage apparatus according to the present invention is illustrated as being applied to a scanning stepper. However, the scope of the present invention is not limited to this, and the stage apparatus according to the present invention is The present invention can also be suitably applied to a stationary exposure apparatus such as a stepper that performs exposure while the mask and the substrate are stationary. Even in such a case, since the position controllability of the substrate stage holding the substrate can be improved by the stage device, the positioning accuracy of the substrate held on the stage is improved and the positioning settling time is shortened. This makes it possible to improve exposure accuracy and throughput.

  The stage apparatus according to the present invention can also be suitably applied to a proximity exposure apparatus that transfers a mask pattern onto a substrate by closely contacting the mask and the substrate without using a projection optical system.

  Of course, the present invention is not limited to an exposure apparatus used for manufacturing a semiconductor element, but also used for manufacturing a display including a liquid crystal display element, a plasma display, and the like. The present invention can also be applied to an exposure apparatus for transferring a device pattern onto a ceramic wafer, an exposure apparatus used for manufacturing an image pickup device (CCD, etc.), etc.

  In addition to a micro device such as a semiconductor element, a glass substrate is used to manufacture a reticle or mask used in an optical exposure apparatus, EUV (Extreme Ultraviolet) exposure apparatus, X-ray exposure apparatus, and electron beam exposure apparatus. Alternatively, the present invention can also be applied to an exposure apparatus that transfers a circuit pattern to a silicon wafer or the like. Here, in an exposure apparatus using DUV (far ultraviolet) light, VUV (vacuum ultraviolet) light, or the like, a transmission type reticle is generally used. As a reticle substrate, quartz glass, fluorine-doped quartz glass, fluorite, Magnesium fluoride or quartz is used. A proximity type X-ray exposure apparatus or electron beam exposure apparatus uses a transmission mask (stencil mask, membrane mask), an EUV exposure apparatus uses a reflection mask, and the mask substrate is a silicon wafer or the like. Is used.

  Further, the stage apparatus according to the present invention is not limited to the exposure apparatus, but can be widely applied to other substrate processing apparatuses (for example, a laser repair apparatus, a substrate inspection apparatus, etc.), or a sample positioning apparatus in other precision machines. .

As the projection optical system PL, when an ArF excimer laser light source or a KrF excimer laser light source is used as a light source, a refraction system consisting only of a refractive optical element (lens element) is mainly used, but an F ₂ laser light source, Ar ₂ laser is used. When a light source or the like is used, a so-called catadioptric system (catadioptric refraction and refraction) in which a refractive optical element and a reflective optical element (such as a concave mirror or a beam splitter) are combined as disclosed in, for example, Japanese Patent Laid-Open No. 3-282527. System), or a reflective optical system consisting only of reflective optical elements is mainly used. However, it is possible to use a refraction system when using an F ₂ laser light source.

In the above-described embodiment, the case where the reduction system is used as the projection optical system has been described. However, the projection optical system may be either a unity magnification system or an enlargement system. Further, the catadioptric projection optical system is not limited to the one described above. For example, it has a circular image field, and both the object plane side and the image plane side are telecentric, and the projection magnification is 1/4. Alternatively, a reduction system that is 1/5 times may be used. Further, in the case of a scanning exposure apparatus provided with this catadioptric projection optical system, the illumination light irradiation area is substantially centered on the optical axis in the field of view of the projection optical system, and substantially in the scanning direction of the reticle or wafer. It may be a type defined as a rectangular slit extending along a direction orthogonal to each other. According to the scanning exposure apparatus provided with such a catadioptric projection optical system, a fine pattern of about 100 nm L / S pattern can be formed on the wafer with high accuracy even when, for example, F ₂ laser light with a wavelength of 157 nm is used as illumination light for exposure Can be transferred to.

The exposure optical system in the exposure apparatus according to the present invention is not limited to the projection optical system, and a charged particle beam optical system such as an X-ray optical system or an electron optical system can also be used. For example, in the case of using an electron optical system, the optical system can be configured to include an electron lens and a deflector. As an electron gun, a thermionic emission type lanthanum hexabolite (LaB ₆ ), Yunthal (Ta) Can be used. Needless to say, the optical path through which the electron beam passes is in a vacuum state.

  Furthermore, when the present invention is applied to an exposure apparatus that uses an electron optical system, a configuration using a mask may be used, or a pattern may be formed on a substrate by direct drawing using an electron beam without using a mask. That is, the present invention is an electron beam exposure apparatus that uses an electron optical system as an exposure optical system, and is any of a pencil beam method, a variable shaped beam method, a cell projection method, a blanking / aperture method, and an EBPS type. Even if it is, it can be applied.

In the exposure apparatus according to the present invention, EUV light in a soft X-ray region having a wavelength of about 5 to 30 nm may be used as exposure illumination light, not limited to the above-described far ultraviolet light and vacuum ultraviolet light. For example, ArF excimer laser light, F ₂ laser light, or the like is used as vacuum ultraviolet light. However, the present invention is not limited to this, and a single wavelength laser in the infrared region or visible region oscillated from a DFB semiconductor laser or fiber laser is used. For example, harmonics obtained by amplifying light with a fiber amplifier doped with, for example, erbium (or both erbium and yttrium) and converting the wavelength into ultraviolet light using a nonlinear optical crystal may be used.

For example, if the oscillation wavelength of a single wavelength laser is in the range of 1.51 to 1.59 μm, the generated wavelength is in the range of 189 to 199 nm, the eighth harmonic, or the generated wavelength is in the range of 151 to 159 nm. A 10th harmonic is output. In particular, when the oscillation wavelength is in the range of 1.544 to 1.553 μm, an 8th harmonic wave having a generated wavelength in the range of 193 to 194 nm, that is, ultraviolet light having substantially the same wavelength as the ArF excimer laser light is obtained. When the wavelength is in the range of 1.57 to 1.58 μm, the tenth harmonic wave in the range of 157 to 158 nm, that is, ultraviolet light having substantially the same wavelength as the F ₂ laser light is obtained.

Further, if the oscillation wavelength is in the range of 1.03 to 1.12 μm, the seventh harmonic whose output wavelength is in the range of 147 to 160 nm is output, and in particular, the oscillation wavelength is in the range of 1.099 to 1.106 μm. If it is inside, the 7th harmonic in the range of 157 to 158 μm, that is, ultraviolet light having substantially the same wavelength as the F ₂ laser light is obtained. In this case, for example, an yttrium-doped fiber laser can be used as the single wavelength oscillation laser.

  When a linear motor is used for the substrate stage or the reticle stage as in the above embodiment, it is not limited to an air levitation type using an air bearing, and a magnetic levitation type using Lorentz force may be used. Each stage may be a type that moves along a guide, or may be a guideless type that does not have a guide.

  The reaction force generated by the movement of the substrate stage may be released mechanically to the floor (ground) using a frame member as described in JP-A-8-166475. The reaction force generated by the movement of the reticle stage may be mechanically released to the floor (ground) using a frame member as described in JP-A-8-330224.

  As described above, the exposure apparatus of the embodiment of the present application maintains various mechanical 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. Manufactured by assembling. 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. 16, the semiconductor device has a step 201 for designing the function / performance of the device, a step 202 for producing a mask (reticle) based on the design step, and a step 203 for producing a substrate as a base material of the device. The substrate is manufactured through the substrate processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, the device assembly step (including the dicing process, bonding process, and package process) 205, the inspection step 206, and the like.

1 is a schematic block diagram of an exposure apparatus according to the present invention. It is an external appearance perspective view of a stage apparatus. It is a perspective view which shows the schematic structure of a wafer stage. It is a front view of a fine movement stage. It is a right view of a fine movement stage. It is a figure for demonstrating the drive principle of Z motor. It is a figure which shows the state where the fine movement stage and the coarse movement stage are in a connected state and a part of the air cylinder and the support plate are removed. (A) which shows the structure of a linear encoder is a top view, (b) is a front view. It is the elements on larger scale which show the structure of a fine movement stage and a fixing device. It is a top view which shows the principal part of a fixing device. It is a perspective view showing a positional relationship between a reticle stage, two wafer stages, a projection optical system, and an alignment system. It is a control block diagram which shows the main structures of the control system of exposure apparatus. It is a figure which shows the procedure which replace | exchanges a fine movement stage. It is a figure which shows the procedure which replace | exchanges a fine movement stage. It is a figure which shows the procedure which replace | exchanges a fine movement stage. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

CONT control device (drive control device)
R reticle (mask)
RST reticle stage (mask stage)
W, W1, W2 Wafer (substrate)
10 Exposure Equipment 12 Stage Equipment (Substrate Stage)
44 Stage surface plate (surface plate)
44a Surface 63A, 63B Coarse movement stage (first stage)
73A, 73B Air bearing (Non-contact bearing)
74A, 74B, 75A, 75B scale (position indicator)
83A, 83B Fine movement stage (second stage)
87 Fixing device 88 Holding unit 90 Drive unit 94A, 94B, 95A, 95B Measuring head (measuring unit)
100A, 100B X motor (second drive unit)
101A, 101B mover (second mover)
102A, 102B Stator (second stator)
110A, 110B Y motor (first drive)
111A, 111B mover (first mover)
112A, 112B Stator (first stator)
120A, 120B Z motor (third drive)
121A, 121B mover (third mover)
122A, 122B Stator (third stator)

Claims (10)

A first stage that moves in a first direction along the surface of the surface plate; and a second stage that moves in the first direction and a second direction different from the first direction with respect to the first stage. A stage device,
A first stator provided on the first stage along the first direction; and a first mover provided on the second stage and opened along the first direction; A first drive for moving the stage in the first direction;
A second stator provided on the first stage along the first direction; and a second mover provided on the second stage and opened along the first direction. A second drive device for moving the stage in the second direction,
A stage apparatus characterized in that the first stage and the second stage can be separated when the first stage is moved along the first direction. The stage apparatus according to claim 1, wherein
A third stator provided on the first stage along the first direction; and a third mover provided on the second stage and opened along the first direction. A stage device comprising a third driving device for moving the stage in a third direction substantially perpendicular to the surface of the surface plate. The stage apparatus according to claim 2, wherein
The stage device characterized in that the first, second and third driving devices move the second stage with respect to the first stage with six degrees of freedom. In the stage apparatus as described in any one of Claim 1 to 3,
One of the first stage and the second stage has a position index portion of the first stage and the second stage with respect to the first direction and the second direction,
The other of the first stage and the second stage has a measuring unit that measures the position index unit at a predetermined interval in a third direction substantially orthogonal to the surface of the surface plate. . The stage apparatus according to claim 4, wherein
The stage device, wherein the first stage and the second stage are supported on the surface of the surface plate via non-contact bearings, respectively. In the stage apparatus as described in any one of Claim 1 to 5,
A stage device comprising: a control device that moves the first stage and the second stage at different accelerations in at least one of the first direction and the second direction. In the stage apparatus as described in any one of Claim 1 to 6,
A stage device comprising: a fixing device for fixing the second stage separated from the first stage to the surface plate. The stage apparatus according to claim 7, wherein
The fixing device includes a holding portion fixed in the vicinity of a fixing position of the second stage, and can move forward and backward with respect to the holding portion, and between the holding portion when advanced toward the holding portion. A stage device comprising: a drive unit that holds a second stage; and a drive control device that controls the drive unit based on a position of the second stage. In the stage device according to any one of claims 1 to 8,
A stage device comprising a plurality of the first stage and the second stage. An exposure apparatus that exposes a mask pattern held on a mask stage onto a substrate held on a substrate stage,
An exposure apparatus, wherein the stage apparatus according to claim 1 is used as at least one of the mask stage and the substrate stage.

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