JP2007019429A - Stage equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rigidly couple an XY table which rotatably supports a wafer holding plate holding a wafer and the wafer holding plate, and to reduce an error when the wafer holding plate rotates. <P>SOLUTION: Stage equipment 10 includes the wafer holding plate 14, the XY table 20 supporting the wafer holding plate 14 via bearing 18, a θz driving actuator 22 rotating the wafer holding plate 14 in the θz direction, and a flat spring 36 to energize the bearing 18. Moreover, the stage equipment 10 has an electrostatic chuck 60 which absorbs the wafer holding plate 14 whose rotation position is adjusted; and a fluctuation control unit 62 which inhibits the movement in the thrust direction of the wafer holding plate 14 to control the fluctuation of the wafer holding plate 14, and allows rotation around a Z axis of the wafer holding plate 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stage apparatus, and more particularly to a stage apparatus configured to precisely position a rotation position around a Z-axis of a holding plate that holds an object.

  In the field of semiconductor device manufacturing, various types of stage apparatuses are used. For example, a stage device for mounting a wafer employed in an electron beam exposure apparatus combines a coarse movement stage device that operates during wafer transfer and chip-to-chip movement and a fine movement stage device that performs positioning of several nanometers to 10 nm. Many configurations are employed (see, for example, Patent Document 1).

In this type of stage apparatus, when the wafer as an object is transported and held on the holding plate, the holding plate is rotated in the θz direction around the Z axis in order to accurately position the wafer with respect to the exposure apparatus. Thus, an adjustment process for adjusting the position of the wafer is performed. Therefore, the rotating shaft extending below the holding plate is rotatably supported by the ball bearing. Further, the positioning of the wafer is performed, for example, by rotating the holding plate by a small angle so that the position of the alignment marker provided on the peripheral edge of the wafer becomes the reference position.
Japanese Patent Laid-Open No. 7-115057

  In the stage apparatus, when the position of the wafer mounted by rotating the holding plate is adjusted in the θz direction, it is important to accurately stop at the position where the wafer is positioned. However, when the brake mechanism that brakes the rotating shaft is provided so that the position of the holding plate does not shift, the weight increases and the overall size of the apparatus increases.

  Further, in the configuration in which the rotating shaft of the holding plate is rotatably supported by the ball bearing as described above, since the metal ball (ball) interposed between the inner ring and the outer ring has a bearing structure, the metal ball is Since the contacted part is elastically deformed to generate contact pressure, there is a limit to increasing the rigidity in a limited space, and it is easily affected by disturbances such as vibration and thermal deformation. There is a problem that sufficient bearing accuracy cannot be obtained.

  Accordingly, an object of the present invention is to provide a stage apparatus that solves the above-described problems.

  In order to solve the above problems, the present invention has the following means.

  According to the first aspect of the present invention, an XY table that moves in the horizontal direction, an XY table driving unit that drives the XY table, a holding plate that is provided on the XY table and holds an object, In a stage apparatus having a bearing that rotatably supports a rotation shaft about the Z axis in the vertical direction and a holding plate driving means for rotating the holding plate about the Z axis, the stage device is rotated by the holding plate driving means. An adsorbing means for adsorbing the holding plate whose position has been adjusted, and restricting the movement of the holding plate in the thrust direction to restrict the swinging of the holding plate and allowing the holding plate to rotate about the Z axis And a swing restricting means.

  According to a second aspect of the present invention, the swing restricting means includes a lower annular member fixed to the upper surface of the XY table, and an upper annular member fixed to the lower surface of the holding plate, and the lower annular member The upper surface of the member and the lower surface of the upper annular member are brought into surface contact.

  The invention described in claim 3 is characterized in that the attracting means is an electrostatic chuck.

  The invention described in claim 4 is characterized in that the suction means is a vacuum chuck or an electromagnetic chuck.

  The invention according to claim 5 is characterized in that the swing restricting means comprises an electrostatic chuck in which the upper annular member holds the upper annular member, and also serves as the attracting means.

  The invention described in claim 6 is characterized in that an urging member for applying an urging force in a thrust direction to the bearing is provided between the holding plate and the bearing plate.

  According to a seventh aspect of the present invention, the biasing member is a leaf spring inserted between the lower surface of the holding plate and the rotating shaft, and extends in the radial direction to apply a thrust force in the thrust direction. A plurality of pressing portions are arranged radially.

  The invention according to claim 8 is characterized in that the biasing force of the biasing member is adjusted by a height adjusting shim.

  According to a ninth aspect of the present invention, the XY table driving means includes an X direction driving means for moving the XY stage in the X direction, a Y direction driving means for moving the XY stage in the Y direction, and the XY stage as Z. And θz direction driving means for rotating about the axis.

  According to the present invention, the suction means for sucking the holding plate whose rotational position is adjusted by the holding plate driving means, the movement of the holding plate in the thrust direction is restricted, and the swinging of the holding plate is restricted. Swing control means that allows rotation around the Z axis, so that when the rotation position around the Z axis is adjusted, the holding plate is rotated in a stable state and swinging is prevented. When the rotation position of the rotation is adjusted, the holding plate can be sucked and held at the positioned position, reducing the error of the holding plate and enabling stable adjustment even when higher accuracy is required. Become.

  Further, according to the present invention, the position of the thrust direction is adjusted by bringing the lower annular member fixed on the upper surface of the XY table and the upper annular member fixed on the lower surface of the holding plate into surface contact with each other. In addition to being able to guide stably, it has the strength to withstand even if the load in the thrust direction increases, so it can cope with an increase in the size of the holding plate. In addition, since the attractive force acts equally over the entire circumference, the coupling force between both members is strong, and an error occurs due to relative displacement between the two members regardless of the horizontal direction of the XY table. Can be prevented.

  Further, according to the present invention, the holding plate can be securely held on the XY table by using an electrostatic chuck or a vacuum chuck as the attracting means, and the apparatus can be made thinner and thinner in order to save space. Can contribute to downsizing.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a stage apparatus according to the present invention. FIG. 2 is a plan view of the stage apparatus shown in FIG. As shown in FIGS. 1 and 2, the stage apparatus 10 is installed, for example, in a chamber (not shown) of a semiconductor exposure apparatus, and a predetermined mask pattern is transferred by irradiation with an electron beam or X-ray. A wafer 12 is placed. The wafer 12 is made of a substrate formed in a disk shape, is automatically transferred by a transfer mechanism (not shown), and is placed on a wafer holding plate 14 positioned at the uppermost stage of the stage apparatus 10. The wafer holding plate 14 is provided with an electrostatic chuck for attracting the wafer 12, and the wafer 12 is attracted and held at a predetermined mounting position until the exposure processing is completed after positioning. The means for adsorbing the wafer 12 may be a vacuum chuck or an electromagnetic chuck.

  Here, the configuration of the stage apparatus 10 will be described. The stage apparatus 10 includes the wafer holding plate 14, a bearing 18 that supports the rotating shaft 16 of the wafer holding plate 14 so as to be rotatable about the Z axis, and an XY table 20 that supports the wafer holding plate 14 via the bearing 18. And a θz driving actuator (holding plate driving means) 22 for rotating the wafer holding plate 14 in the θz direction around the Z axis.

  The XY table 20 is provided with an X mirror 30 for reflecting laser light emitted from an X laser interferometer (not shown) at the Y direction edge of the upper surface, and a Y laser interferometer at the X direction edge of the upper surface. A Y mirror 32 for reflecting the laser light emitted from (not shown) is provided. Therefore, the XY table 20 measures the positions of the X mirror 30 and the Y mirror 32 by the X laser interferometer and the Y laser interferometer so that the center position coincides with the optical axis of the exposure apparatus. Will be adjusted.

  The wafer holding plate 14 is formed in a disk shape having a larger diameter than the wafer 12, a chuck surface for adsorbing the wafer 12 is formed on the upper surface, and an annular groove 34 for fixing the upper annular member 72 on the lower surface side. And a spring mounting portion 38 for attaching a leaf spring (biasing member) 36 that biases the bearing 18. The upper annular member 72 is fixed to the annular groove 34 via the washer 35.

  The leaf spring 36 has a center portion 36a fastened to the upper surface of the rotating shaft 16 by screws 40 and spring retainers 41, and a plurality of arm portions 36b extending in the radial direction from the outer periphery of the center portion 36a. The arm portions 36 b are provided radially at intervals of 60 degrees in the circumferential direction, and the tip portions thereof are fastened to the spring mounting portions 38 by screws 42. Therefore, the rotating shaft 16 is coupled to the wafer holding plate 14 via the leaf spring 36, and a substantially uniform urging force is applied in the circumferential direction by bending a plurality of radially provided arm portions 36b. .

  A height adjusting shim 44 made of a thin metal plate is inserted between the plate spring 36 and the upper surface of the rotary shaft 16. Since the amount of bending of the arm portion 36b is adjusted by changing the number of inserted height adjusting shims 44, the leaf spring 36 is adjusted in magnitude.

  The bearing 18 is a ball bearing that guides the radial direction (radial direction) of the rotary shaft 16, and is attached so as to be interposed between the outer periphery of the rotary shaft 16 and the central hole 46 of the XY table 20. The outer ring is fitted to the outer periphery of the rotation shaft 16, and the outer ring is fitted to the inner periphery of the center hole 46. The inner and outer rings of the bearing 18 are held in contact with the inner ring retainer 48 and the outer ring retainer 49 whose lower ends are in contact with the rotating shaft 16 and the stepped portion of the central hole 46 and whose upper ends are fastened by screws 47.

  The bearing 18 has a metal ball inserted between the outer ring and the inner ring so as to be able to roll, and guides the relative displacement in the circumferential direction between the outer ring and the inner ring with low friction when adjusting the position in the θz direction. It is configured as follows.

  Therefore, when adjusting the position in the θz direction, the vibration from the bearing 18 is reduced to the extent that it does not act as a disturbance, and the position adjustment in the θz direction can be performed more precisely.

  The θz drive actuator 22 is composed of, for example, an ultrasonic motor, and is configured to slightly move the drive shaft 22a in the θz direction, and is supported by a bracket 50 fixed to the lower surface of the XY table 20. The drive shaft 22a of the θz drive actuator 22 extends in the vertical direction, passes through the hole 52 of the XY table 20, and protrudes to the upper surface side of the XY table 20. The θz drive actuator 22 may be configured using a ball screw.

  Further, the drive shaft 22 a of the θz drive actuator 22 is inserted into the hole 54 a of the connecting member 54 fixed to the lower surface of the wafer holding plate 14. The drive shaft 22a is pressed and held on the inner wall of the hole 54a by being pressed by a lock pin 56 screwed from the side. Accordingly, the θz drive actuator 22 rotates the wafer holding plate 14 in the θz direction by driving the drive shaft 22a in the θz direction, thereby finely adjusting the position of the wafer 12 mounted on the wafer holding plate 14 in the θz direction. adjust. The wafer positioning in the θz direction by the θz drive actuator 22 is performed after the respective positions in the X, Y, Z, θx, θy, and θz directions of the XY table 20 by the tilt mechanism 80 and the XY table drive mechanism 90 are adjusted as described later. Done.

  Further, the positioning of the wafer 12 mounted on the wafer holding plate 14 is performed by, for example, positioning the wafer holding plate 14 at a minute angle so that the position of the alignment marker provided on the peripheral portion of the wafer 12 matches the reference position. This is done by turning.

  The stage device 10 includes an electrostatic chuck (suction means) 60 that sucks the wafer holding plate 14 whose rotational position is adjusted, and a wafer holding plate that restricts the movement of the wafer holding plate 14 in the thrust direction (Z-axis direction). 14 has a swing restricting portion (swing restricting means) 62 that restricts the swing of the wafer holding plate 14 around the Z axis while restricting the swing of the 14 in the θx axis direction and the θy axis direction.

  The swing restricting portion 62 is configured such that a lower annular member 70 fixed to the upper surface of the XY table 20 and an upper annular member 72 fixed to the lower surface of the wafer holding plate 14 are opposed to each other. The upper surface of the lower annular member 70 and the lower surface of the upper annular member 72 are combined so as to be in surface contact with each other, thereby restraining the movement of the wafer holding plate 14 in the thrust direction and swinging the wafer holding plate 14. It functions to regulate and allow the wafer holding plate 14 to rotate in the θz direction.

  The lower annular member 70 and the upper annular member 72 have a longitudinal cross-sectional shape formed in a flat plate shape, and are formed in an annular shape (ring shape) when viewed from above. The lower annular member 70 and the upper annular member 72 are made of conductive ceramics, and the upper and lower surfaces are subjected to planar polishing.

  Furthermore, the lower annular member 70 and the upper annular member 72 have the same inner and outer radial dimensions, and are in surface contact over the entire circumference. The load on the wafer holding plate 14 fluctuates as a restraining force in the thrust direction. It acts on the entire circumference of the movement restricting portion 62. Therefore, when the wafer holding plate 14 is rotated in the θz direction, the contact surfaces of the lower annular member 70 and the upper annular member 72 slide with each other, the inclination in the thrust direction is restricted, and the sliding is performed. The friction caused by the above acts as a braking force.

  In addition, since the lower annular member 70 and the upper annular member 72 are in surface contact over the entire circumference, they can stably guide the position in the thrust direction and can withstand the strength even if the load in the thrust direction increases. Have. Therefore, it is possible to cope with the case where the diameter of the wafer 12 is increased and the holding plate 14 is enlarged. Furthermore, it is possible to suppress the occurrence of errors due to inertial force when the wafer holding plate 14 is rotated to adjust the position in the θz direction.

  The electrostatic chuck 60 has a configuration in which electrodes are provided on either the lower annular member 70 or the upper annular member 72 described above. In this embodiment, an electrode is provided on the upper annular member 72 to function as an electrostatic chuck, and the lower annular member 70 is configured to function as an attracted ring to be attracted. Then, after positioning in the θz-axis direction, a voltage is applied to the internal electrode embedded in the upper annular member 72, whereby the upper annular member 32 attracts the lower annular member 70 and fixes the wafer holding plate 14. Is configured to do. That is, the electrostatic chuck 60 of the present embodiment restrains the movement of the wafer holding plate 14 in the thrust direction by adsorbing means for sucking the wafer holding plate 14 and the movement of the wafer holding plate 14 in the θx axis direction and θy axis direction. It has a structure that also serves as a rocking regulating means for regulating movement.

  Further, in this embodiment, since the electrostatic chuck is used as the attracting means, the wafer holding plate 14 can be securely attracted and held on the XY table 20, and the apparatus can be made thin in order to save space. Can contribute to downsizing and downsizing.

  Furthermore, since the electrostatic chuck 60 has a configuration in which the lower annular member 70 and the upper annular member 72 formed in an annular shape are in surface contact over the entire circumference, the brake that applies a braking force to the XY table 20 from the outside. The XY table 20 is not deformed by the action of the braking force as compared with the case where the mechanism is provided separately, and the error of the wafer holding plate 14 due to the distortion of the XY table 20 is reduced.

  Further, when the XY table 20 is coarsely moved, horizontal acceleration due to acceleration and deceleration of the wafer holding plate 14 is applied. However, in the electrostatic chuck 60 of this embodiment, since the attracting force acts uniformly over the entire circumference, the coupling force between both members is strong, and the wafer holding plate 14 and the XY table 20 are integrated. It is possible to perform a coarse motion operation in the state that has been performed. Therefore, even if the XY table 20 moves in any direction in the horizontal direction, it is possible to prevent the occurrence of errors due to the relative displacement between both members.

  The stage apparatus 10 includes a tilt mechanism 80 that adjusts the vertical position of the XY table 20 and an XY table drive mechanism (XY table drive means) 90 that adjusts the position of the XY table 20 in the X, Y, and θz directions.

  Hereinafter, the tilt mechanism 80 and the XY table drive mechanism 90 will be described with reference to FIGS. 3 to 11. The stage device 10 is a fine movement stage device and can be used alone, but is normally mounted on a coarse movement stage device (not shown). The coarse movement stage device includes an X table movable in the X-axis direction and a Y table movable in the Y-axis direction. For example, the X table is configured to be movable on the Y table. Of course, the Y table may be configured to be movable on the X table. The stage apparatus 10 of the present embodiment is mounted on the X table or the Y table in the coarse movement stage apparatus.

  The stage apparatus 10 is configured by combining the XY stage 20 with a tilt mechanism 80 constructed on a base plate 100.

  First, the tilt mechanism 80 will be described. FIG. 3 is a side view for explaining the tilt mechanism 80. FIG. 4 is a side view of the tilt mechanism 80 as viewed from the Y direction. FIG. 5 is a side view of the tilt mechanism 80 as viewed from the X direction. FIG. 6 is a plan view showing a tilt mechanism 80 disposed on the base plate 100. 3 to 5, the XY table 20 is illustrated, but the wafer holding plate 14 on the XY table 20 is not illustrated. In FIG. 6, the XY table 20 and the tilt plate 201 are not shown.

  As shown in FIGS. 3 to 6, the tilt mechanism 80 includes a tilt plate 201 on which the XY table 20 is mounted. This tilt plate 201 is composed of two sets and two sets of piezoelectric actuators (piezo actuator elements) Z1-1, Z1-2, Z2-1, Z2- arranged on the base plate 100 so as to extend in parallel with each other. 2, Z3-1, Z3-2 and a wedge stage, which will be described later, are driven in a direction perpendicular to the base plate 100 (Z-axis direction or up-down direction). Hereinafter, a combination of the piezoelectric actuators Z1-1 and Z1-2 is referred to as a Z1 axis, a combination of the piezoelectric actuators Z2-1 and Z2-2 is referred to as a Z2 axis, and a combination of the piezoelectric actuators Z3-1 and Z3-2 is referred to as a Z3 axis.

  FIG. 7 is a longitudinal sectional view showing the configuration of one of the three axes constituting the tilt mechanism 80. FIG. 8 is a perspective view showing a tilt mechanism 80 disposed on the base plate 100. FIG. 9 is a perspective view showing the tilt mechanism 80 and the tilt plate 201 disposed on the base plate 100.

  With reference to FIG. 7 thru | or FIG. 9, the detail of a structure and operation | movement is demonstrated about Z3 axis | shaft. A piezo fixing block 223 is installed on the base plate 100. The piezo actuator Z 3-2 is fixed at one end to the piezo fixing block 223 and is connected to the piezo actuator Z 3-1 via the piezo base 224. Thus, the drive stroke of the piezo actuator Z3-2 and the drive stroke of the piezo actuator Z3-1 are added, and the wedge stage 225 is driven with the added drive stroke.

  As is well known, the wedge stage is for converting horizontal movement into vertical movement. In this example, the wedge stage 225 has a 45-degree orthogonal transformation mechanism so that the horizontal displacement input by the two piezo actuators Z3-1 and Z2-2 and the vertical displacement output of the wedge stage 225 are 1: 1. It is configured. The orthogonal transformation mechanism is configured by combining an inclined block 225-1 having a 45-degree inclined surface on the upper surface side and an inclined block 225-2 having a 45-degree inclined surface on the lower surface side. The inclined block 225-1 has a guide part for guiding the inclined block 225-2. The inclined block 225-2 is slidable along the inclined surface of the inclined block 225-1 in a state where the inclined surface is guided by the guide portion. As a result, when the inclined block 225-1 is displaced in the horizontal direction, the inclined block 225-2 slides along with it and is displaced in the vertical direction.

  By such a wedge stage 225, the tilt hinge 226 fixed to the vertical motion portion is driven in the Z-axis direction. Then, the tilt plate 201 fixed to the tip of the tilt hinge 226 is driven in the Z-axis direction. The tilt plate 201 has an opening 201a (see FIG. 9) in the center. An XY plate 301 (see FIG. 4) is combined in the opening 201a. An XY table 20 (see FIG. 7) is fixed to the XY plate 301.

  The Z1 axis and the Z2 axis have the same configuration as the Z3 axis. That is, the Z1 axis has the piezo fixing block 203, the piezo base 204, and the wedge stage 205, and the Z2 axis has the piezo fixing block 213, the piezo base 214, and the wedge stage 215. In particular, the Z1 axis wedge stage 205, the Z2 axis wedge stage 215, and the Z3 axis wedge stage 225 are arranged on the same circumference (indicated by a one-dot chain line in FIG. 4).

  In particular, in this embodiment, the wedge stages 205, 215, and 225 are arranged at positions corresponding to the vertices of the equilateral triangle, that is, at an angular interval of 120 degrees. These three-axis vertical motion parts can be displaced in the same direction. As a result, the tilt plate 201 performs a translational motion in the Z-axis direction, and when a differential operation, that is, a difference in displacement amount of each axis is given, the tilt plate 201 rotates in the θx-axis direction and the θy-axis direction.

  Here, it goes without saying that the rotational motion in the θx-axis direction means rotational motion around the X-axis, and the rotational motion in the θy-axis direction means rotational motion around the Y-axis. Further, the rotational movement in the θz-axis direction, which will be described later, means rotational movement around the Z-axis.

  Here, the position in the Z-axis direction is measured by a capacitance sensor. The capacitance sensor is disposed between the XY table 20 that is the final movable unit and the base plate 100 above the tilt plate 201. Hereinafter, the Z1-axis capacitance sensor is referred to as a Z1 sensor 207, the Z2-axis capacitance sensor as a Z2 sensor 217, and the Z3-axis capacitance sensor as a Z3 sensor 227. The sensors 207, 217, and 227 are installed at positions adjacent to the wedge stages 205, 215, and 225, respectively. The measurement principle of a capacitance sensor is well known, but simply speaking, a minute displacement in the Z-axis direction can be detected as a change in capacitance.

  In this embodiment, the height of the XY table 20 that is the final movable portion is measured by the Z1 sensor 207, the Z2 sensor 217, and the Z3 sensor 227, and the position control (full closed control) of the XY table 20 is performed based on the measurement result. Done.

  Normally, in the tilt stage, the height position of the tilt plate 201 from the base plate 100 is measured, and position control (semi-closed control) is performed based on the measurement result. However, this method cannot measure the position error in the Z-axis direction when the XY stage moves. This means that the positions of the XY table 20 in the Z-axis direction, θx-axis direction, and θy-axis direction cannot be controlled. However, the arrangement of the Z-axis direction position measurement system according to the present embodiment enables position control of the XY table 20 in the Z-axis direction, θx-axis direction, and θy-axis direction.

  The guide system for the tilt stage is a leaf spring that can be displaced only in the Z-axis direction and is mounted between the tilt hinges 206, 216, and 226 attached to the wedge stages 205, 215, and 225, and the base plate 100 and the tilt plate 201. 208, 218, 228 (see FIGS. 6 and 9). These plate springs 208, 218, and 228 constitute a high-rigidity guide system that restrains the movement of the tilt plate 201 in the XY plane, which cannot be realized only by the guide part of the wedge stage. The leaf springs 208, 218, 228 are installed via spring mounting portions 208-1, 218-1, 228-1, respectively, provided on the base plate 100.

  FIG. 10 is a perspective view showing the XY table driving mechanism 90 incorporated in the XY plate 301.

  Next, the XY table driving mechanism 90 will be described with reference to FIGS. 3 to 5 and FIG. The XY table 20 is fixed to the XY plate 301. The XY plate 301 is incorporated in the opening 201 a at the center of the tilt plate 201. The XY plate 301 can be displaced in the Z-axis direction, θx-axis direction, and θy-axis direction together with the tilt plate 201, but can be displaced in the X-axis direction, Y-axis direction, and θz-axis direction independently of the tilt plate 201. Has been. In other words, the XY plate 301 is driven by two X1 piezo actuators 302 and X2 piezo actuators 303 extending in parallel to each other in the X axis direction in the X axis direction.

  The X1 piezoactuator 302 and the X2 piezoactuator 303 are provided at regular intervals, each having one end fixed to the tilt plate 201 and the other end connected to the XY plate 301. On the other hand, the XY plate 301 is driven by one Y piezo actuator 304 extending in the Y axis direction in the Y axis direction. The Y piezo actuator 304 also has one end fixed to the tilt plate 201 and the other end connected to the XY plate 301. The X1 piezo actuator 302, X2 piezo actuator 303, and Y piezo actuator 304 constitute an XY table drive mechanism 90.

  The guide system (transmission mechanism) of the XY table drive mechanism 90 is as follows. As shown in FIG. 4, in the guide system in the XY plane, an X1 hinge 312 fixed to one end of the X1 piezo actuator 302 is fixed to the tilt plate 201 and X1 fixed to the other end of the X1 piezo actuator 302. A hinge 311 is connected to the XY plate 301. Similarly, an X2 hinge 314 fixed to one end of the X2 piezo actuator 303 is fixed to the tilt plate 201, and an X2 hinge 313 fixed to the other end of the X2 piezo actuator 303 is connected to the XY plate 301. On the other hand, a Y hinge 316 fixed to one end of the Y piezo actuator 304 is fixed to the tilt plate 201, and a Y hinge 315 fixed to the other end of the Y piezo actuator 304 is connected to the XY plate 301.

  The guide system in the Z-axis direction is realized by three main link hinges 321, 322 and 323 and two sub link hinges 324 and 325 installed between the XY plate 301 and the tilt plate 201. One of these link hinges, for example, the main link hinge 321 will be described with reference to FIG.

  A link hinge block 321-1 is provided on the tilt plate 201 so as to extend vertically downward. The link hinge block 321-1 is provided with a hinge 321-2 extending upward therefrom and connected to the XY plate 301. The hinge 321-2 has a well-known ball joint joint, and supports the XY plate 301 so that it can be displaced in the XY plane, but exhibits high rigidity in the Z-axis direction. The main link hinges 322 and 323 and the sub link hinges 324 and 325 have exactly the same structure. FIG. 10 shows a main link hinge 322 composed of a link hinge block 322-1 and a hinge 322-2.

  As shown in FIG. 4, the three main link hinges 321, 322, and 323 are installed at positions corresponding to the vertices of a triangle, here an isosceles triangle, and the two secondary link hinges 324 and 325 are It is installed on both sides of the main link hinge 321. The main link hinges 321 to 323 and the sub link hinges 324 and 325 have a function of allowing the XY plate 301 to be freely displaced in the XY plane, and have a large rigidity in the Z-axis direction. Thereby, the rigidity is greatly improved as compared with the conventional fine movement stage device.

  Here, the operation of the XY table driving mechanism 90 will be described. When the X1 piezo actuator 302 and the X2 piezo actuator 303 operate in the same X-axis direction, the XY plate 301 performs translational motion in the X-axis direction. When the X1 piezo actuator 302 and the X2 piezo actuator 303 are operated differentially, that is, so as to cause a difference in displacement, the XY plate 301 operates in the θz-axis direction. On the other hand, when the Y piezo actuator 304 operates, the XY plate 301 translates in the Y-axis direction.

  As shown in FIG. 4, the position of the XY plate 301 in the X-axis direction is determined by two electrostatic capacity sensors 326 and 327 (hereinafter referred to as “X1 sensor, X2” disposed between the tilt plate 201 and the XY plate 301. Called a "sensor"). The position of the XY plate 301 in the Y-axis direction is measured by one capacitance sensor 328 (hereinafter referred to as “Y sensor”) disposed between the tilt plate 201 and the XY plate 301. Semi-closed position control of the XY table 2-2 is performed based on position information in the XY plane measured by the X1 sensor 326, X2 sensor 327, and Y sensor 328.

  In this embodiment, as described above, the XY plate 301 on which the XY table 20 is mounted can be moved in the X axis direction, the Y axis direction, and the θz axis direction by the XY table drive mechanism 90. Further, the tilt plate 201 whose height positions at three points are adjusted by the tilt mechanism 80 can be displaced in the Z-axis direction, the θx-axis direction, and the θy-axis direction. In addition, the XY plate 301 can be displaced together with the tilt plate 201 and can be displaced in the X axis direction, the Y axis direction, and the θz axis direction independently of the tilt plate 201. As a result, the XY table 20 can move in six degrees of freedom (X-axis direction, Y-axis direction, Z-axis direction, θx-axis direction, θy-axis direction, and θz-axis direction). Therefore, the tilt plate 201 and the XY plate 301 are adjusted in the positions of the six axes by the tilt mechanism 80 and the XY table driving mechanism 90, so that the wafer holding plate 14 is interposed via the XY table 20 fixed to the XY plate 301. It is possible to adjust the position of the wafer 12 held on the 6-axis direction.

  Note that the position measurement of the XY stage 20 (X-axis direction, Y-axis direction, θz-axis direction) is performed by an X mirror 30 (see FIGS. 1 and 3) attached to the XY table 20 and extending in the Y-axis direction. This is performed by a Y mirror 32 (see FIGS. 1 and 5) extending in the axial direction and a laser interferometer (not shown). Based on the position information obtained by this position measurement, full-closed control with six degrees of freedom (X-axis direction, Y-axis direction, Z-axis direction, θx-axis direction, θy-axis direction, and θz-axis direction) is performed.

  FIG. 11 is a longitudinal sectional view showing a modification of the stage apparatus. As shown in FIG. 11, the stage device 400 according to the modification has a configuration in which a vacuum chuck 410 is used instead of the electrostatic chuck 60. The vacuum chuck 410 sucks the wafer holding plate 14 by a pressure difference from the atmospheric pressure applied to the wafer holding plate 14 by introducing a negative pressure from a vacuum generator 420 installed outside.

  A vacuum line 430 from the vacuum generator 420 communicates with an annular recess 440 formed on the upper surface of the XY stage 20. The lower annular member 70 fixed so as to close the annular recess 440 is provided with a plurality of through holes 70a penetrating in the Z-axis direction.

  In the vacuum generator 420, when the built-in valve is switched and the air in the annular recess 440 is sucked and a negative pressure is introduced, the upper annular member 72 facing the lower annular member 70 through the through hole 70a. Apply negative pressure. Thereby, the upper annular member 72 is adsorbed by the lower annular member 70 over the entire circumference by the adsorption force due to the pressure difference between the atmospheric pressure in the chamber and the negative pressure of the annular recess 440 and is firmly held.

  In the vacuum generator 420, when the built-in valve is switched and air is supplied to the annular recess 440 and returned to the atmospheric pressure, the suction force to the wafer holding plate 14 is lost, and the holding of the wafer holding plate 14 is released. The

  It should be noted that the chamber in which the stage device 400 of this modification is installed must be filled with air or gas instead of vacuum.

  In the above embodiment, the stage apparatus installed in the chamber of the semiconductor exposure apparatus has been described as an example. However, the present invention is not limited to this, and a stage apparatus used in combination with a processing apparatus or inspection apparatus other than the semiconductor exposure apparatus. Of course, the present invention can also be applied.

  In the above embodiment, the object held on the holding plate has been described as a wafer. However, the present invention is not limited to this, and the object may be a precision processed product (for example, a liquid crystal glass substrate) that requires more precise positioning accuracy. Needless to say, the present invention can also be applied to an apparatus having a configuration that holds the above.

  Moreover, although the case where the stage apparatus 10 is used as a fine movement stage apparatus has been described as an example in the above embodiment, it is needless to say that the present invention can be applied to the case where the stage apparatus 10 is used as a coarse movement stage apparatus.

  Further, in the above embodiment, the electrostatic chuck formed in a ring shape serves as both the attracting means and the swing restricting means, but is not limited thereto, for example, a swing restricting portion formed in a ring shape, It goes without saying that a plurality of small electrostatic chucks may be arranged in the circumferential direction.

It is a longitudinal cross-sectional view which shows one Example of the stage apparatus which becomes this invention. It is a top view of the stage apparatus shown in FIG. 4 is a side view for explaining a tilt mechanism 80. FIG. FIG. 5 is a side view seen from the Y direction for explaining the tilt mechanism 80. FIG. 6 is a side view seen from the X direction for explaining the tilt mechanism 80. 4 is a plan view showing a tilt mechanism 80 disposed on a base plate 100. FIG. 4 is a longitudinal sectional view showing the configuration of one of the three axes constituting the tilt mechanism 80. FIG. 3 is a perspective view showing a tilt mechanism 80 disposed on a base plate 100. FIG. 2 is a perspective view showing a tilt mechanism 80 and a tilt plate 201 disposed on a base plate 100. FIG. It is a perspective view which shows the XY table drive mechanism 90 integrated in the XY plate 301. FIG. It is a longitudinal cross-sectional view which shows the modification of the stage apparatus which becomes this invention.

Explanation of symbols

10,400 Stage device 14 Wafer holding plate 16 Rotating shaft 18 Bearing 20 XY table 22 θz drive actuator 36 Leaf spring 44 Height adjustment shim 60 Electrostatic chuck 62 Swing restricting portion 70 Lower annular member 72 Upper annular member 80 Tilt mechanism 90 XY table drive mechanism 100 base plate 201 tilt plate 301 XY plate 410 vacuum chuck 420 vacuum generator

Claims (9)

An XY table that moves horizontally;
XY table driving means for driving the XY table;
A holding plate that is provided on the XY table and holds an object;
A bearing that rotatably supports the rotation axis of the holding plate about the Z axis in the vertical direction;
In a stage device having a holding plate driving means for rotating the holding plate around the Z axis,
Suction means for sucking the holding plate whose rotational position is adjusted by the holding plate driving means;
A rocking restricting means for restricting the movement of the holding plate in the thrust direction and restricting the rocking of the holding plate, and allowing the holding plate to rotate around the Z axis;
The stage apparatus characterized by providing. The swing restricting means is
A lower annular member fixed to the upper surface of the XY table;
An upper annular member fixed to the lower surface of the holding plate,
The stage apparatus according to claim 1, wherein an upper surface of the lower annular member and a lower surface of the upper annular member are brought into surface contact.   The stage apparatus according to claim 1, wherein the suction unit is an electrostatic chuck.   The stage apparatus according to claim 1, wherein the suction unit is a vacuum chuck or an electromagnetic chuck.   The stage apparatus according to claim 2, wherein the swing restricting unit includes an electrostatic chuck in which the upper annular member holds the upper annular member, and also serves as the attracting unit.   The stage apparatus according to claim 1, wherein a biasing member that applies a biasing force in a thrust direction to the bearing is provided between the bearing plate and the holding plate.   The urging member is a leaf spring inserted between the lower surface of the holding plate and the rotating shaft, and a plurality of pressing portions that extend in the radial direction and apply a urging force in the thrust direction are arranged radially. The stage apparatus according to claim 1, wherein the stage apparatus is provided.   The stage device according to claim 7, wherein the biasing force of the biasing member is adjusted by a height adjusting shim. The XY table driving means includes
An X direction driving means for moving the XY stage in the X direction;
Y direction driving means for moving the XY stage in the Y direction;
Θz direction driving means for rotating the XY stage around the Z axis;
The stage apparatus according to claim 1, further comprising:

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