JPH07161799A - Stage device - Google Patents

Abstract

PURPOSE:To lessen a work in amount of deviation in a lateral direction when the work is corrected in gradient. CONSTITUTION:A wafer 21 is placed on a gradient correction table 23 through the intermediary of a wafer chuck 22, a ring-shaped plate spring 25 is mounted on a gradient correction table 23 through the intermediary of mounting screws 28D to 28F, and the ring-shaped plate spring 25 is mounted on projections 24a and 24c of a base plate 24 through the intermediary of mounting screws 28A to 28C. A wafer 21 is corrected in angle of inclination and height by displacing three pivots 32A to 32C provided to the base of the gradient correction table 23 with a vertical drive means 26A provided onto the base plate 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage device for correcting the height and inclination of a workpiece or an object to be measured, for example, a projection exposure apparatus for manufacturing semiconductor elements or an inspection apparatus for semiconductor elements. Etc., it is suitable for application to an inclination correction stage mounted on an XY stage for correcting the inclination angle of a wafer.

[0002]

2. Description of the Related Art In a projection exposure apparatus used for manufacturing a semiconductor device or the like by a lithography process, it is necessary to match an exposure surface of a wafer on which a pattern of a photomask or a reticle is exposed with an image surface of a projection optical system. Therefore, for adjusting the position (focus position) of the wafer in the optical axis direction of the projection optical system on the XY stage for positioning the wafer in the two-dimensional plane (referred to as “XY plane”). A Z stage and an inclination correction stage (leveling stage) for finely adjusting the inclination angle of the wafer are mounted. In this case, the tilt angle of the wafer can be separated into a rotation angle θ _X around the X axis and a rotation angle θ _Y around the Y axis.

Similarly, for example, an inspection apparatus for inspecting a semiconductor element formed on a wafer also uses an inclination correction stage for finely adjusting the inclination angle of the surface of the wafer. In the following, the tilt correction stage used in the projection exposure apparatus will be described as an example. FIG. 7 shows a conventional tilt correction stage (for example, Japanese Patent Laid-Open No. 62-27420).
In this FIG. 7, the leaf spring 4A is fixed on the convex portion 3a on the surface of the base plate 3 by the set screw 7A, and the flexible portion at the central portion of the plate spring 4A is inserted via the set screw 8A. Arm 5A is attached. Figure 7
8, which is a cross-sectional view taken along the line AA, is provided with a vertical drive means 10A composed of a piezo element or the like via a cylindrical pivot 6A as a fulcrum at the bottom of the leaf spring 4A. Further, the position of the leaf spring 4A can be finely moved in the vertical direction with respect to the base plate 3 by the vertical drive means 10A.

Similarly, in FIG. 7, the base plate 3
Arms 5B and 5C are attached to the other two convex portions 3b and 3c on the surface of the base plate 3 via the leaf springs 4B and 4C, respectively, so as to be finely movable in the vertical direction with respect to the base plate 3. The leaf springs 4B and 4C are also pivoted 6B, respectively.
The vertical movement of the base plate 3 is made possible by the vertical drive means, the vertical drive means, and the pivot 6C and the vertical drive means. The center of the three pivots 6A-6C is 1
It is set to a position that divides one circle into three equal parts, and three arms 5
The wafer chuck 2 is moved to the base plate 3 by A to 5C.
The wafer 1 is supported on a wafer chuck 2 at a predetermined distance (the distance varies), and the wafer 1 is held on the wafer chuck 2 by, for example, vacuum suction.

In this conventional example, the height and inclination angle of the center of the surface of the wafer 1 are determined by three pivots 6A to 6C located at positions that divide one circumference into three equal parts.
The inclination angle of the surface is corrected by vertically driving two or more pivots of the three pivots 6A to 6C. Further, the correction of the height of the surface of the wafer 1 is theoretically performed by vertically driving the three pivots 6A to 6C in parallel, but in reality, the movement stroke of the pivots 6A to 6C is Since it is small, the height of the surface of the wafer 1 is corrected by another Z stage.

In the conventional example, the wafer chuck 2 serving as a table to be corrected has three leaf springs 4A-4C centered on a position where one circumference is divided into three equal parts via three arms 5A-5C. Although fixed, these three leaf springs 4
A to 4C are used as guide means for minimizing the amount of horizontal displacement between the base plate 3 and the wafer chuck 2. These three leaf springs 4A-4C
Are installed so that the vertical rigidity is weak and the horizontal rigidity is strong.

Further, a movable mirror 9X having a reflecting surface parallel to the Y axis and a movable mirror 9Y having a reflecting surface parallel to the X axis are fixed to the end portion on the base plate 3 so as to be orthogonal to each other.
An X-axis interferometer 11X and a Y-axis interferometer 11Y are installed so as to face the movable mirrors 9X and 9Y, respectively. Generally, the base plate 3 is mounted on an XY stage configured to be movable in the XY plane, and the X coordinate and the Y coordinate of the base plate 3 are respectively interferometers 11X.
And, it can be measured by the interferometer 11Y.
Therefore, conventionally, the movement of the wafer chuck 2, which is the table to be corrected, cannot directly be measured, and the two-dimensional coordinates of the wafer chuck 2, and thus the wafer W, are indirectly measured from the movement of the base plate 3. I was able to do it.

[0008]

When the conventional tilt correction table as described above is used in the conventional projection exposure apparatus for semiconductor manufacturing, it has a good tilt control accuracy that can easily satisfy the required stage accuracy. Had. However, in recent years, as the design rule of the pattern of the semiconductor element has become finer and finer, the tilt control accuracy required for the tilt correction table has become more severe, and the conventional tilt correction table cannot cope with it. . Specifically, the conventional tilt correction table has the following disadvantages in improving the tilt control accuracy.

In the conventional tilt correction table, as shown in FIG. 7, the leaf springs 4A to 4C are installed compactly on the pivots 6A to 6C.
In order to achieve the purpose of guiding the wafer chuck 2 so that the wafer chuck 2 is not displaced, A to 4C are partially provided with mounting screws (7
(A, etc.) on the base plate 3 side, and at another part, on the wafer chuck 2 side by a mounting screw (8 A, etc.). However, since the vertical drive amount required for the pivots 6A to 6C is too large for the size of the leaf springs 4A to 4C, the planes of the leaf springs 4A to 4C, especially the mounting screws (7A, 8A, etc.) Large stress is generated in the mounting part. In other words, the mounting screw (7A,
8A, etc.) may generate a large reaction force that opposes the fastening force, and the reaction force may cause a “slip” of the order of nm (nanometers) at the fastening portion with the mounting screws of the leaf springs 4A to 4C. There was a nature.

The position measuring system using the interferometers 11X and 11Y is constructed outside the wafer chuck 2 as a table to be corrected. Therefore, even if the "slip" as described above occurs in the leaf spring portion on the base plate 3 and the position of the wafer chuck 2 is displaced, the interferometers 11X, 1
Depending on 1Y, the position shift cannot be detected and the exposure position of the wafer 1 shifts from its original position.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a stage device capable of suppressing a lateral shift amount of a workpiece when correcting the inclination of the workpiece.
It is another object of the present invention to provide a stage device that can accurately detect the amount of lateral deviation of a workpiece when correcting the inclination of the workpiece.

[0012]

A stage device according to the present invention, as shown in FIG. 1 and FIG.
1) In a stage device for correcting the height and inclination of (including an object to be measured), a correction table (23) on which the workpiece is placed and a first set of correction table (23) One or more mounting points (28D-28F)
Attached to the leaf spring (25) via a leaf spring (25) attached via a second set and one or a plurality of attachment points (28A to 28C) of the second set other than the attachment point of the first set. A base member (24) and three or more fulcrums (32A to 32C) other than the second set of attachment points (28A to 28C) on the leaf spring (25) are supported with respect to the base member (24). A plurality of supporting members (39A to 39C) and driving means (26A to 26A) for displacing two or more supporting points of the three or more supporting points with respect to the base member (24).
C) and.

In this case, when the number of fulcrums is 3,
Those three fulcrums (32A to 32) on the leaf spring (25)
It is desirable to arrange the center P of the circumference passing through C) near the center of gravity of the correction table (23). Also, for example, in FIG.
As shown in, the first set of attachment points (28D-28F)
And the number of mounting points (28A to 28C) of the second set are equal, and the mounting points (28D to 28F) of the first set and the mounting points (28) of the second set on the leaf spring (25A).
A to 28C) are arranged in close proximity to each other, and a slit (38A) is provided between the first set of attachment points (28D to 28F) and the second set of attachment points (28A to 28C) on the leaf spring (25A).
~ 38C) may be provided.

Further, the base member (25) is fixed on a positioning stage which is movable in a two-dimensional plane,
Two movable mirrors (27X, 27Y) each made of a flat mirror and having reflecting surfaces orthogonal to each other are fixed on the correction table (23), and the measuring optical beams are respectively attached to the two movable mirrors outside the positioning stage. Interferometer (3
It is desirable to install 7X) and measure the coordinates of the two moving mirrors using this interferometer.

[0015]

In the present invention, the correction table (23)
Is driven by displacing two or more fulcrums of the three or more fulcrums (32A to 32C) with respect to the base member (24). Then, one leaf spring (25) is used as a guide means for minimizing the amount of deviation between the correction table (23) and the base member (24) in the direction perpendicular to the displacement direction of the fulcrums. However, the fulcrum has a weak rigidity in the displacement direction and a strong rigidity in the direction perpendicular to the displacement direction.

In this case, the correction table (23) as a whole is provided with the base member (24) via the one leaf spring (25).
The leaf spring (25) has a size so as to cover the whole of three or more fulcrums (32A to 32C) because it is attached to the conventional leaf spring (for example, leaf springs 4A to 4C in FIG. 7).
It is about 10 times larger than C). Therefore, the first set of attachment points (28D to 28F), which are the attachment points of the leaf spring (25) to the correction table (23),
When the distance between the leaf spring (25) and the second set of attachment points (28A to 28C), which are attachment points to the base member (24), is the same as that of the fulcrum, as in the conventional example. It is about 5 times wider than, for example.

Therefore, when two or more fulcrums are driven, the stress generated in the plane of the leaf spring (25) becomes considerably small. Since the stress is small, the reaction force generated at the attachment points (28D to 28F) of the first set and the attachment points (28A to 28C) of the second set of the leaf spring (25) is naturally small. Therefore, it becomes possible to fix the leaf spring (25) with sufficient attachment force at those attachment points, and the leaf spring (25) in the plane of the leaf spring (25) that should not occur at those attachment points. The "slip" is suppressed to a negligible level. That is, the lateral shift amount of the workpiece becomes negligible.

Further, the three fulcrums (32) of the leaf spring (25)
A-32C), the center of the circumference passing through the correction table (2
In the case of arranging in the vicinity of the center of gravity of 3), harmful vibration when driving a predetermined fulcrum of these three fulcrums to perform tilt correction is efficiently removed. Alternatively, when the base member (24) is mounted on, for example, an XY stage and the XY stage is driven to move the base member (24), harmful vibrations are efficiently removed. It

Further, as shown in FIG. 5, for example, the first set of attachment points (28D to 28F) on the leaf spring (25).
And the slits (38A to 38C) between the second set of attachment points (28A to 28C), the first set of attachment points (28D to 28F) and the second set of attachment points. Even if it approaches (28A to 28C), large stress does not occur in the leaf spring (25) due to the driving of the fulcrum, and the “slip” of the leaf spring (25) becomes small. Furthermore, the degree of freedom of arrangement of attachment points and the like increases.

When two moving mirrors (27X, 27Y) are installed on the correction table (23) and an interferometer (37X) for irradiating the moving mirrors with a light beam is provided, a fulcrum (32A) Even if a slight "slip" occurs in the leaf spring (25) due to the driving of the disk drive (.about.32C), the lateral deviation amount of the work piece due to the "slip" is directly measured in real time by the interferometer (37X). The measurement resolution of the interferometer (37X) depends on the resolution of the interferometer system used and the reliability of the measured values, but if the latest interferometer is used, the measurement accuracy of the interferometer is 1 nm or less. The precision is a sufficient value for the required stage precision. Therefore, a positioning error exceeding the allowable value does not occur in the work piece.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the stage device according to the present invention will be described below with reference to FIGS. In this embodiment, the present invention is applied to a correction tilt stage (leveling stage) for correcting the tilt of a wafer in a projection exposure apparatus for manufacturing a semiconductor device or the like.

FIG. 1 shows the use state of the tilt correction stage of the present embodiment. In FIG. 1, the tilt correction stage is
It is installed under the projection optical system 31. Projection optical system 31
A mask (not shown) on which a transfer pattern is formed is installed above the wafer, and the pattern of the mask on the wafer 21 coated with the photoresist through the projection optical system 31 under the exposure light. Each shot area is projected and exposed. At this time, the tilt correction stage of the present embodiment operates so that the exposure surface of the wafer 21 is aligned with the image plane of the projection optical system 31.

The wafer 21 is held on a disk-shaped wafer chuck 22 fixed on a substantially square plate-shaped tilt correction table 23 by vacuum suction, electrostatic suction or the like. The Z axis is taken parallel to the optical axis of the projection optical system 31, the X axis is taken in the direction perpendicular to the Z axis and parallel to the paper surface of FIG. 1, and the Y axis is taken in the direction perpendicular to the paper surface of FIG. In this case, a movable mirror 27X having a reflection surface substantially perpendicular to the X axis is fixed to one end in the X direction on the tilt correction table 23, and a measurement light beam is provided outside the movable mirror 27X in parallel to the X axis. An interferometer 37X for X-axis irradiation is arranged. Further, as shown in FIG. 2A, which is a plan view of the tilt correction stage of this example, a movable mirror 27Y having a reflecting surface substantially perpendicular to the Y axis is fixed to one end of the tilt correction table 23 in the Y direction. , Which irradiates the movable mirror 27Y with a light beam for measurement parallel to the Y-axis
An interferometer (not shown) for the axis is arranged. An X-axis interferometer 37X and a Y-axis interferometer are used to move the X of the tilt correction table 23 via the movable mirrors 27X and 27Y, respectively.
Coordinates and Y coordinates are constantly measured.

Returning to FIG. 1, diagonally above the wafer 21,
A light transmitting system 29 that irradiates a parallel light beam obliquely with respect to the optical axis of the projection optical system 31 on the exposure surface of the wafer 21, and a light beam reflected from the exposure surface is condensed, and the light is condensed at the position of this condensing point. A tilt angle detection system including a light receiving system 30 that generates a corresponding signal is arranged. This tilt angle detection system detects the amount of deviation of the tilt angle of the exposure surface of the wafer 21 with respect to the image plane of the projection optical system 31. The tilt correction stage of this embodiment corrects the tilt angle of the wafer 21 so that the deviation amount of the tilt angle becomes zero.

2A and BB in FIG. 2A
As shown in FIG. 2B, which is a cross-sectional view taken along the line, a substantially square plate-shaped base plate 24 is arranged on the bottom surface side of the tilt correction table 23 with a certain gap, and the base plate 24 is not It is mounted on the XY stage shown. Three convex portions 24a to 24c of the base plate 24
However, each of the three through holes in the tilt correction table 23 projects from the upper surface of the tilt correction table 23. And
By attaching screws 28D to 28F on the three convex portions on the outer peripheral portion of the upper surface of the tilt correction table 23, a ring-shaped 1
The bottom surface of the plate spring 25 is fixed, and the other three positions on the bottom surface of the plate spring 25 are fixed to the upper ends of the convex portions 24a to 24c of the base plate 24 by the mounting screws 28A to 28C, respectively. The leaf spring 25 is formed of a metal plate such as a steel plate, and the wafer chuck 2 is provided inside the leaf spring 25.
2 is located.

The three mounting screws 28D to 28F are arranged at positions that divide the same circumference centered on the center P of the tilt correction table 23 into three equal parts, and the other three mounting screws 2D.
8A to 28C are also arranged at positions that divide another circumference centered on the center P into three equal parts, and further mounting screws 28D to 28F.
Are mounting screws 28A-
It is arranged at a position shifted by 60 ° with respect to 28C. Further, on the bottom surface side of the tilt correction table 23, the circumference centering on the center P is divided into three equal parts, and the mounting screw 28
Spherical pivots 32A, 32B, and 32C as fulcrums are embedded in positions near F, 28E, and 28D in a rotatable state.

Of the three pivots 32A to 32C, the pivot 32A is supported by a vertical drive means 26A fixed on the base plate 24 via a column 39A. Similarly, the other pivots 32B and 32C are also connected to the base plate 24 through the columns as shown in FIG.
It is supported by vertical drive means 26B and 26C fixed above. The pivots 32A to 32C are supported by vertical drive means 26A to 26C so as to be independently displaceable in the vertical direction (Z direction) with respect to the base plate 24. At least two of the pivots 32A to 32C
By adjusting the amount of displacement in the two Z directions, the tilt correction table 23, and thus the wafer 2 on the wafer chuck 22 is adjusted.
The tilt angle θ _X around the X axis of 1 and the tilt angle θ _Y around the Y axis are adjusted.

The three pivots 32A to 32A are also provided.
The center P, which is the center of the circumference passing through C, is also the center of gravity of the entire tilt correction table 23. In this case, two movable mirrors 27X and 27X are provided at the upper end of the tilt correction table 23.
Since Y is fixed so as to be orthogonal to each other, the center of gravity of the entire tilt correction table 23 is set to the center P.
As shown in, the position of the center Q of the wafer chuck 22 fixed on the tilt correction table 23 is displaced in the opposite direction with respect to the movable mirrors 27X and 27Y.

An example of the construction of the vertical drive means 26A to 26C used in this embodiment will be described with reference to FIG. 6 is a sectional view of the vertical drive means 26A. In FIG. 6, the drive mechanism housing 49 is fixed on the base plate (see FIG. 2), and the feed screw 46 is rotatably housed in the drive mechanism housing 49. A rotary motor 44 is connected to the left end of the feed screw 46 via a coupling 45A, and a rotary encoder 48 for detecting a rotation angle is connected to the right end of the feed screw 46 via a coupling 45B. In addition, the nut 5 is attached to the feed screw 46.
0 is screwed, and the upper end of the slope portion 4 is slanted to the nut 50 via the strut 47 (this corresponds to the strut 39A in FIG. 2).
The pivot 41 (which corresponds to the pivot 32A in FIG. 2) is in contact with the upper end of the slope portion 42.
The inclined surface portion 42 is supported so as to be movable along the linear guide 43 in a direction parallel to the feed screw 46.

In this case, when the rotary motor 44 is driven to rotate the feed screw 46, the nut 50 moves the feed screw 46.
Since it moves along the ridge, the slope portion 42 also moves along the feed screw 46 accordingly. Therefore, the pivot 41 contacting the upper end of the slope portion 42 is displaced in the vertical direction (Z direction in FIG. 2) with respect to the drive mechanism housing 49 while rotating. Further, the amount of vertical displacement of the pivot 41 is detected by measuring the rotation angle of the feed screw 46 by the rotary encoder 48. The vertical drive means 26A can drive the pivot 41 in the vertical direction with a high resolution of about 1 μm or less and a stroke of about 2 mm. The other vertical drive means 26B and 26C have the same structure. The vertical driving means 26A to 26C may be composed of, for example, a piezo element or the like other than FIG.

Now, returning to FIGS. 1 and 2, the operation of this embodiment will be described. First, the vertical drive means 26A to 26C
The driving amount of each of the pivots 32A to 32C by
It is determined according to the deviation amount of the tilt angle calculated based on the signal output from the light receiving system 30 of the tilt angle detection system. Then, the pivot 32 is moved through the vertical driving means 26A to 26C.
By displacing A to 32C, the inclination angle of the inclination correction table 23 is controlled. At this time, since the tilt correction table 23 is fixed to the base plate 24 via the leaf spring 25, the lateral shift amount of the tilt correction table 23 in the XY plane is extremely small.

When the tilt angle of the tilt correction table 23 changes, stress is generated in the plane of the leaf spring 25. However, unlike the conventional method, in the leaf spring 25 of this embodiment, the positions of the mounting screws 28A to 28C to the base plate 24 and the mounting screws 28D to 28D to the tilt correction table 23 are set.
Since the position of 8F is far away, the stress generated is small, and the possibility that "slip" of the leaf spring 25 in the X direction and the Y direction at the fastening portions of the mounting screws 28A to 28F is extremely small.

Even if a "slip" occurs in the leaf spring 25 in the X direction and the Y direction, the amount of slip is equal to that of the movable mirror 27X.
And 27Y, the slip amount is measured in real time and with high accuracy by the X-axis interferometer 37X and the Y-axis interferometer. Therefore, by finely moving the base plate 24 by the XY stage below the base plate 24 so as to cancel the slip amount, the position of the wafer 21 is returned to the same position as before the correction of the tilt angle, and thus each shot of the wafer 21. The overlay accuracy between the area and the image of the mask pattern to be exposed is high.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, as the detection system on the exposure surface side of the wafer 21, a focus position detection system is additionally provided in addition to the tilt angle detection system. In FIG. 3, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals, the wafer 21 is arranged below the projection optical system 31, and the tilt angle detection including the light transmitting system 29 and the light receiving system 30 is obliquely above the wafer 21. The system is located. Furthermore, a projection projecting, for example, a slit pattern image obliquely on the optical axis of the projection optical system 31 at a measurement point on the exposure surface of the wafer 21 located at the center of the exposure field of the projection optical system 31 diagonally above the wafer 21. The system 33 and the condensing system 3 that generates a focus signal according to the lateral shift amount of the slit pattern image re-formed by the reflected light from the exposure surface.
A focus position detection system composed of 4 and 4 is arranged.

The focus signal is a position (focus position) in the optical axis direction of the projection optical system 31 on the exposure surface of the wafer 21.
Is a signal according to the amount of deviation of the projection optical system 31 from the image plane, and in the present embodiment, the tilt angle of the exposure surface of the wafer 21 is determined based on the output signal of the tilt angle detection system. The wafer 21 on the basis of the focus signal.
The focus position of the exposure surface is adjusted to the focus position of the image forming surface. As a result, the exposure surface of the wafer 21 perfectly matches the image formation surface of the projection optical system 31.

In this case, the wafer 21 is the wafer chuck 2
2 is mounted on the tilt correction table 23, and the tilt correction table 23 is connected to the Z stage 35 (which corresponds to the base plate 24 in FIG. 1) via the leaf spring 25 as in the first embodiment. . Then, the tilt angle of the wafer 21 is corrected by driving at least two vertical drive means of the three vertical drive means 26A to 26C on the Z stage 35. Further, the Z stage 35 is mounted on the XY stage 37 via the vertical drive means 36. The vertical drive means 36 has substantially the same structure as the vertical drive means 26A shown in FIG. 6, but one rotary motor simultaneously moves up and down three pivots in parallel in the Z direction. Focusing system 34 of focus position detection system of FIG.
By controlling the drive amount of the up-and-down drive means 36 based on the focus signal of
The stage 35 moves in the Z direction, and the focus position at the measurement point on the exposure surface of the wafer 21 matches the image plane.

Next, a third embodiment of the present invention will be described with reference to FIG. As described above, according to the configuration of the above-described embodiment, the stress generated in the leaf spring 25 can be considerably reduced. If this is used in reverse, even if the amount of deformation in the leaf spring 25 is larger than in the conventional case, the mounting screws 28A to
It means that there is a margin in the amount of “slip” of the leaf spring 25 at the fastening portions of 28C and 28D to 28F.

Therefore, in the third embodiment, the displacement amounts of the three pivots in the Z direction are increased and the focus position is corrected by the tilt correction stage. On the other hand, the second embodiment of FIG. 3 is an example in which the tilt correction mechanism and the focus position adjustment mechanism (Z stage mechanism) are divided.

FIG. 4, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals, shows the structure of the tilt correction stage of the third embodiment. In FIG. 4, three vertical driving means 26A to 26A.
Similar to the first embodiment, at least two of 26C are driven to match the inclination angle of the exposure surface of the wafer 21 with the inclination angle of the image forming surface of the projection optical system 31. Further, in the present embodiment, in FIG. 4, the three vertical drive means 26A to 26C are driven in parallel by the same amount in accordance with the detection result of the focus position detection system including the projection system 33 and the light collection system 34. As a result, the focus position of the exposure surface of the wafer 21 is aligned with the focus position of the image forming surface of the projection optical system 31.
As a result, the function of the Z stage is also realized. Moreover,
This embodiment is smaller in size and lower in manufacturing cost than the second embodiment shown in FIG.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, unlike the leaf spring 25 used in the above-mentioned embodiment, a leaf spring 25A provided with a slit is used. Further, in FIG. 5, parts corresponding to those in FIG. 2 are denoted by the same reference numerals and detailed description thereof will be omitted.
5A is a plan view of the tilt correction table of the present embodiment, and FIG. 5B is a sectional view taken along the line CC of FIG. 5A, which are shown in FIGS. 5A and 5B. As described above, the base plate 24 is arranged on the bottom surface side of the tilt correction table 23 with a certain gap therebetween, and the three convex portions 24 a to 24 c of the base plate 24 respectively pass through the through holes in the tilt correction table 23. And protrudes from the upper surface of the tilt correction table 23. Then, one leaf spring 25A is attached to the convex portion on the upper surface of the tilt correction table 23 by the mounting screws 28D to 28F.
The bottom surface of is fixed. The leaf spring 25A has an annular shape and is provided with three arc-shaped slits 38A to 38C so as to pass near the fastening portions of the mounting screws 28D to 28F at equal angular intervals with respect to the center P. In addition, the leaf spring 2 is provided by the attachment screws 28A to 28C provided at positions facing the attachment screws 28D to 28F with the slits 38A to 38C of the leaf spring 25A interposed therebetween.
The bottom surface of 5A has convex portions 24a to 24c of the base plate 24.
It is fixed at the top of.

The three mounting screws 28D to 28F are arranged at positions that divide the same circumference about the center P of the tilt correction table 23 into three equal parts, and the mounting screws 28A to 28F.
C also has mounting screws 28D to
It is arranged at the same angular position as 28F. Further, on the bottom surface side of the tilt correction table 23, the circumference centered on the center P is divided into three equal parts, and three slits 38 of the leaf spring 25A are formed.
Spherical pivots 32A, 32B, and 32C, which serve as fulcrums, are embedded in intermediate positions A to 38C in a rotatable state.

The three pivots 32A to 32C are
The base plate 24 through the columns (39A etc.)
It is supported by vertical drive means (26A, etc.) fixed above. By adjusting the displacement amount in at least two Z directions (directions perpendicular to the paper surface of FIG. 5A) of the pivots 32A to 32C, the tilt correction table 23, and by extension, the tilt angle of the wafer 21 on the wafer chuck 22. Is adjusted. Further, the focus position of the wafer 21 is adjusted by driving the three vertical drive means 26A to 26C in parallel and moving the three pivots 32A to 32C up and down simultaneously in the Z direction by the same amount.

In this case, according to the present embodiment, the leaf spring 25
Fastening portions of mounting screws 28D to 28F for fixing A to the tilt correction table 23 and mounting screws 28A to 28 for fixing the leaf spring 25A to the base plate 24.
Slits 38A to 38C are provided between the C fastening portions.
Is cut. As a result, the mounting screw 28D
Since the fastening portions of ~ 28F and the fastening portions of the mounting screws 28A to 28C can be easily displaced independently in the direction perpendicular to the plane of the leaf spring 25A (Z direction), the pivots 32A to 32C are moved up and down to attach the mounting screws 28D. Even if the fastening portions of ~ 28F are moved up and down, the stress generated in the leaf spring 25A is extremely small.

In other words, by using the leaf spring 25A provided with the slit, the inclination correction table 23
To the base plate 24 (mounting screws 28A to 28F).
Even if they are brought close to C), the generated stress is reduced and the “slip” of the leaf spring 25A is also reduced. Therefore, the degree of freedom in arranging the fastening portions on the tilt correction table 23 and the base plate 24 in the leaf spring 25A is increased, and the lateral deviation amount of the wafer 21 when the tilt correction or the focus position correction of the wafer 21 is performed becomes small. ing. On the contrary, if the same "slip" as in the above-described embodiment is allowed, the diameter of the leaf spring 25A can be made smaller than the diameter of the leaf spring 25 in FIG.

The embodiment shown in FIG. 5 uses a leaf spring 25A with slits instead of the leaf spring 25 in the embodiment shown in FIGS. 1 and 2, but the embodiment shown in FIGS. Also, the leaf spring 25A having slits can be used. The present invention is not limited to the above embodiment,
It goes without saying that various configurations can be taken without departing from the scope of the present invention.

[0046]

According to the present invention, since the correction table is attached to the base member via one leaf spring,
The stress between the leaf spring when the correction table is tilted can be reduced by increasing the distance between the attachment point of the leaf spring on the correction table and the attachment point on the base member. Therefore, the amount of "slip" at the attachment point of the leaf spring is small, the amount of lateral displacement of the work piece when the inclination angle of the work piece is changed is small, and the positioning accuracy is improved.

Further, it is possible to increase the amount of vertical movement of the fulcrum by taking advantage of the fact that the stress generated in the plane of the leaf spring due to the vertical movement of the fulcrum becomes much smaller than in the conventional case. Therefore, there is an advantage that the correction range of the inclination angle of the workpiece can be increased as compared with the conventional example. Further, since the movement stroke of each fulcrum is long, the height of the workpiece can be adjusted by moving the three fulcrums in parallel by the same long stroke. That is, there is an advantage that the inclination angle and height of the workpiece can be corrected with a simple configuration.

Further, the number of fulcrums is three, and when the center of the circumference passing through these three fulcrums on the leaf spring is arranged near the center of gravity of the correction table, the vibration or Vibrations that occur when the base member itself is moved via, for example, the bottom XY stage have the advantage that the stability of the position is high. Further, the number of attachment points of the first set is equal to the number of attachment points of the second set, and the attachment points of the first set and the attachment points of the second set are arranged close to each other on the leaf spring. However, if a slit is provided between the mounting point of the first set and the mounting point of the second set on the leaf spring, the stress in the leaf spring becomes small, and the amount of "slip" that occurs in the leaf spring. Also becomes smaller. Therefore, there are advantages that the degree of freedom in arranging the attachment points on the leaf spring is increased, and the lateral deviation amount when performing the inclination correction or the height adjustment of the workpiece is further reduced.

Further, the base member is fixed on a positioning stage which is movable in a two-dimensional plane, and two movable mirrors each made of a plane mirror and having reflecting surfaces orthogonal to each other are fixed on the correction table. If an interferometer that irradiates the moving mirrors with a light beam for measurement is installed outside the positioning stage, even if lateral displacement occurs in the workpiece, the lateral displacement amount can be measured accurately and in real time by the interferometer. Is measured. Therefore, by correcting the measured lateral deviation amount, the lateral deviation amount of the workpiece can be made smaller as a whole.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a tilt correction stage as a first embodiment of a stage device according to the present invention.

2A is a plan view of the tilt correction stage of the first embodiment, and FIG. 2B is a sectional view taken along line BB of FIG. 2A.

FIG. 3 is a partially cutaway front view showing a second embodiment of the present invention. .

FIG. 4 is a partially cutaway front view showing a third embodiment of the present invention. .

5A is a plan view of an inclination correction stage according to a fourth embodiment of the present invention, and FIG. 5B is a sectional view taken along the line CC of FIG. 5A.

FIG. 6 is a partial cross-sectional view showing an example of the vertical drive means 26A used in the embodiment.

FIG. 7 is a plan view showing a configuration of a conventional tilt correction stage.

8 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

 21 Wafer 22 Wafer Chuck 23 Tilt Correction Table 24 Base Plate 25, 25A Leaf Springs 26A, 26B, 26C Vertical Driving Means 27X, 27Y Moving Mirror 28A-28C Mounting Screws for Base Plate 28D-28F Mounting Screws 29 for Tilt Correction Table 29 Tilt Angle Transmitting system of detection system 30 Receiving system of tilt angle detection system 31 Projection optical system 32A, 32B, 32C Pivot 33 Projection system of focus position detection system 34 Focusing system of focus position detection system 35 Z stage 36 Vertical drive means 37X Interference Total 41 Pivot 42 Slope 43 Straight guide 44 Rotary motor 45A, 45B Coupling 46 Feed screw 47 Support 48 Sensor 49 Drive mechanism housing

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G01B 11/26 GH01L 21/027 21/66 D 7630-4M

Claims (4)

[Claims] 1. A stage device for correcting the inclination of a workpiece, comprising: a correction table on which the workpiece is placed; and a first set of one or a plurality of attachment points on the correction table. A leaf spring attached to the leaf spring, a base member attached to the leaf spring via one or more attachment points of a second set other than the attachment points of the first set, and the first member on the leaf spring. Three or more support members that support three or more fulcrums other than two sets of attachment points with respect to the base member, and two or more fulcrums of the three or more fulcrums with respect to the base member A drive unit for displacing the stage device. 2. The number of the fulcrums is three, and the center of a circle passing through the three fulcrums on the leaf spring is arranged near the center of gravity of the correction table. 1. The stage device according to 1. 3. The number of attachment points of the first set and the number of attachment points of the second set are equal, and the attachment points of the first set and the attachment points of the second set on the leaf spring. 3. The stage apparatus according to claim 1 or 2, characterized in that a slit is formed between the attachment points of the first set and the attachment point of the second set on the leaf spring in close proximity to each other. . 4. The base member is fixed on a positioning stage configured to be movable in a two-dimensional plane, and two movable mirrors each made of a flat mirror and having reflecting surfaces orthogonal to each other are fixed on the correction table. An interferometer for irradiating the two movable mirrors with a measuring light beam is installed outside the positioning stage, and the interferometer is used to measure the coordinates of the two movable mirrors. The stage device according to claim 1, 2, or 3.