JPH06216221A - Positioning apparatus - Google Patents

Abstract

PURPOSE:To eliminate probable deformation of mirror reflective surface due to a stress, by installing magnets on three sides of mirrors, the sides being not parallel mutually, and fixing the mirrors on an X-Y stage from three directions with no contact using magnetic attraction means which is opposite to the magnetic attraction surface integrally installed on the X-Y stage and jets a gas. CONSTITUTION:Mirrors 2 and 3 are attracted to the surfaces of attraction devices 6 and 7 by attraction force of a magnetic circuit formed by permanent magnets of the mirrors 2 and 3 opposite to the attraction devices 6 and 7 and the attraction devices 6 and 7. At the same time, the mirrors 2 and 3 are floated from the surfaces of the attraction devices 6 and 7 by the static pressure of pressurized air jetted from openings of the attraction devices 6 and 7. In such a manner, three sides of the mirrors 2 and 3, the sides being not parallel mutually, are fixed in a predetermined position of an X-Y stage 1 with no contact by the magnetic attraction force and the static pressure of the pressurized air. Thus, like the case using a leaf spring, etc., a stress due to a local pressure does not occur and a measuring error caused by the deformation of the mirrors 2 and 3 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning apparatus for positioning a substrate such as a wafer to be exposed or a workpiece with respect to exposure light or a tool in a semiconductor exposure apparatus, a precision machine tool or the like. .

[0002]

2. Description of the Related Art In semiconductor exposure apparatuses, precision machine tools, etc., substrates such as wafers (hereinafter,
It is called "substrate". ) And a work piece are required to be positioned with high precision, and a positioning device using a laser interferometer has been developed for this purpose. This is because a mirror having a high degree of flatness is fixed to an XY stage on which a substrate or a work piece is mounted, laser light is reflected by the mirror, and the reflected laser light is introduced into a laser interferometer, where it is introduced. The amount of positional deviation of the XY stage is measured by the obtained interference fringes, and the XY stage is moved based on the obtained measurement value. In such a positioning device, if the flatness of the mirror that reflects the laser light is low, a large error will occur in the measurement value of the laser interferometer due to the reflected light, so that the mirror surface of the mirror is technically limited. It is performed with high accuracy close to. In addition, various methods have been devised for fixing the mirror to the XY stage.
There have been developed one that presses a mirror against an abutting surface or the like provided on the Y stage, and one that attracts the mirror to the XY stage by a vacuum suction force or the like.

[0003]

However, according to the above-mentioned conventional technique, in the method of fixing the mirror to the XY stage by the leaf spring, the mirror is deformed by the local pressing force of the leaf spring, and the reflection surface thereof is changed. There is a risk that the curvature will cause a loss of flatness and cause a large error in the measurement value of the laser interferometer, which will significantly reduce the positioning accuracy.
Further, in the method using the vacuum suction force, not only the reflecting surface of the mirror but also the contact surface between the mirror and the XY stage is required to have high flatness, which causes an increase in manufacturing cost. Furthermore, in any of the above methods, when the temperature of the XY stage rises,
Stress may be generated in the mirror due to the dimensional change due to the thermal expansion of the XY stage, and as a result, the mirror may be deformed and the positioning accuracy may be significantly reduced as in the above case.

Further, a method of correcting the output of the laser interferometer by measuring in advance a measurement error caused by such a reduction in flatness due to the deformation of the mirror and unevenness of the reflecting surface due to the technical limit of mirroring the mirror. Is also being developed. This method
An inspection glass substrate provided with an inspection pattern instead of the substrate or the work piece is adsorbed to the adsorption surface of the XY stage, and the pattern displacement is detected by observing the pattern through a projection lens system. And this,
By comparing the amount of positional deviation of the XY stage obtained from the interference fringes of the laser interferometer, the measurement error of the laser interferometer due to the irregularities and curvature of the reflecting surface of the mirror is detected, and the output of the laser interferometer is corrected. is there. However, this correction method requires focusing of the inspection glass substrate and the projection lens system, which reduces throughput. In addition, since the weight of the glass substrate for inspection is much larger than that of the substrate to be exposed, the driving device of the XY stage becomes large, heavy and complicated.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and reduces the measurement error of the laser interferometer due to the unevenness and the curvature of the reflecting surface of the mirror and improves the positioning accuracy. It is an object of the present invention to provide a positioning device capable of performing the above.

[0006]

In order to achieve the above object, a positioning device of the present invention comprises an XY stage having a mirror and a measuring means for measuring the position of the XY stage by the reflected light of the mirror. In the positioning device, the mirrors have magnetic bodies or magnets on three side surfaces that are not parallel to each other, and are biased by the magnetic attraction surface of the magnetic attraction means integrally provided on the XY stage. The magnetic attraction means has a gas ejection means for ejecting gas between the side surface of the mirror and the magnetic attraction surface.

Further, an XY stage having a mirror, a measuring means for measuring the position of the XY stage by the reflected light of the mirror, and a long length having a plurality of reference marks arranged at a predetermined interval on one straight line. Of the reference member, fixing means for removably fixing the reference member to the XY stage along the mirror, observing means for observing the reference mark, and observing the reference mark by the observing means. Further, it is characterized by comprising storage means for storing the deviation of the measured value of the measuring means.

[0008]

According to the above apparatus, the magnetic attraction means for ejecting the gas can fix the mirror on the XY stage from the three directions in a non-contact manner. Therefore, there is no possibility that a large stress will occur in the fixed mirror and the reflecting surface of the mirror will be deformed. Further, even if the dimensions of the XY stage change due to thermal expansion or the like, there is no possibility that the mirror will be deformed.

Further, an XY stage having a mirror, a measuring means for measuring the position of the XY stage by the reflected light of the mirror, and a long length having a plurality of reference marks arranged at a predetermined interval on one straight line. Of the reference member, fixing means for removably fixing the reference member to the XY stage along the mirror, observing means for observing the reference mark, and observing the reference mark by the observing means. If the storage means stores the deviation of the measurement value of the measuring means, the measurement error due to the unevenness or the curvature of the reflecting surface of the mirror is detected in advance by using the reference member, and the output of the measuring means is corrected based on these. be able to.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a first embodiment. A positioning apparatus E ₁ of this embodiment is used for positioning a substrate such as a wafer of a semiconductor exposure apparatus with respect to exposure light. , Two axes orthogonal to each other (hereinafter, "X
Axis, Y axis ". XY that can be reciprocally moved in any direction in a plane including) and rotatable about an axis perpendicular to the plane (hereinafter, referred to as “Z axis”).
Stage 1 and drive device for moving it (not shown)
A rod-shaped first mirror 2 extending in the X-axis direction, a rod-shaped second mirror 3 extending in the Y-axis direction, and a reflecting surface 2a of the first mirror 2 arranged on the outer peripheral edge of the XY stage 1. The first laser interferometer 4 which is the first measuring means for irradiating the laser light and obtaining the interference fringes by the reflected light and the reflecting surface 3a of the second mirror 3 are irradiated with the laser light, and the reflected light It has a second laser interferometer 5 which is a second measuring means for obtaining interference fringes, and an adsorption chuck 1a for adsorbing the wafer W ₁ is arranged at the center of the XY stage 1. The first mirror 2 and the second mirror 3 are fixed to the XY stage 1 by attraction devices 6 and 7 which are magnetic attraction means. The suction device 6 for fixing the first mirror 2 includes a pair of first support pads 6a and 6b facing the side surface 2b of the first mirror 2 opposite to the reflection surface 2a, and as shown in FIG. A pair of second support pads 6c and 6d facing the side surface 2c facing the surface of the XY stage 1 and both end surfaces 2
The second mirror 3 has a third support pad 6e facing the end surface 2d of the d and 2e, which is closer to the second mirror 3.
Similarly, the suction device 7 for fixing the pair of first support pads 7a and 7b facing the side surface 3b of the second mirror 3 opposite to the reflecting surface 3a, and the side surface facing the surface of the XY stage 1. A pair of second support pads 7c, 7d facing each other (not shown) and a third support pad 7e facing the end surface 3d closer to the first mirror 2 among the end surfaces 3d, 3e.
Have.

The first support pads 6a and 6b of the suction device 6 for fixing the first mirror 2 are fixed to plate-like stands 8a and 8b integrally provided with the XY stage with an adhesive or screws. The second support pad 6
c and 6d are directly fixed to the upper surface of the XY stage 1 with an adhesive or screws. Regarding the suction device 7 for fixing the second mirror 3, similarly, the first support pads 7a and 7b are respectively on the same stands 9a and 9b as the stands 8a and 8b, and the second support pad 7 is also provided.
c and 7d are directly fixed to the upper surface of the XY stage 1 with an adhesive or screws. Furthermore, the third support pads 6e and 7e of the suction devices 6 and 7 are the XY stage 1
The columnar stand 10 integrally provided on the above is fixed to the mutually orthogonal side surfaces 10a and 10b by the same method as described above.

Further, as shown in FIG. 2, the first mirror 2
The permanent magnets 11, which are magnets, are embedded in the side surfaces 2b to 2d of the first mirror 2 that face the support pads 6a to 6e of the adsorption device 6 that supports the magnets 6 and 6 and are fixed by an adhesive or screws. Similarly, the second facing the support pads 7a to 7e of the suction device 7 that supports the second mirror 3.
Permanent magnets (not shown) are also embedded in the side surfaces 3b to 3d of the mirror 3. If necessary, after fixing each permanent magnet 11 to each mirror 2 and 3, the reflecting surface of each mirror 2 and 3 is polished to correct its flatness.

Since all of the support pads 6a to 6e and 7a to 7e have the same structure, one of the first support pads 6a and 6b of the suction device 6 for fixing the first mirror 2 is one of the support pads 6a. Only will be described.

The support pad 6a has a main body 61 made of a magnetic material in the form of a flat plate, and the surface 61a which is the magnetic attraction surface of the main body 61 facing the first mirror 2 has, for example, one side of about 5 mm. It has a square smooth surface and has a plurality of openings 62 that are gas ejection means that open toward the first mirror 2. Each opening 62 is connected to a pressurized air supply line (not shown) through an internal pipe 63. There is. The first mirror 2 is attracted to the surface of the support pad 6a by the magnetic attraction force of the magnetic circuit formed by the permanent magnet 11 facing the support pad 6a and the main body 61 of the support pad 6a, and at the same time, from each opening 62. The static pressure of the jetted pressurized air causes the surface of the support pad 6a to float.

The first mirror 2 and the second mirror 3 have their three non-parallel side surfaces acting in opposite directions to each of the support pads 6a to 6e and 7a to 7e. It is supported in a non-contact manner by the magnetic attraction force and the static pressure of pressurized air, and is fixed at a predetermined position on the XY stage 1. Therefore, unlike the case where a leaf spring or the like is used, stress due to local pressing force is not likely to occur, and even if the size of the XY stage 1 changes due to temperature change, this causes the first mirror. 2 and the second mirror 3
There is no fear of causing great stress. as a result,
There is no possibility of causing a measurement error due to the deformation of the first mirror 2 and the second mirror 3.

The first and second mirrors 2 and 3 are supported by the support pads 6a to 6e and 7a to 7 by applying only the magnetic attraction force.
If the first mirror 2 and the second mirror 3 are not likely to be greatly deformed even if they are adsorbed on the surface of e, the supply of the pressurized air to the support pads 6a to 6e and 7a to 7e is stopped. Then, the first mirror 2 and the second mirror 3 are firmly fixed to the XY stage 1 only by the magnetic attraction force, and only when a temperature change or the like exceeding a preset range is detected. Support pads 6a-6e, 7 of
a to 7e or a part thereof is supplied with pressurized air, and the static pressure of all the supporting pads 6a to 6e, 7a to 7
e or the part thereof, the first mirror 2 and the second mirror 3 are levitated, and the first mirror 2 and the second mirror 3 are levitated for thermal expansion or the like.
It is desirable to release the stress generated in the second mirror 3 and then stop the supply of the pressurized air and firmly fix them to the XY stage 1 only by the magnetic attraction force.

Incidentally, all the support pads 6a to 6e, 7
When pressurized air is supplied to a part of the adsorbing devices 6 and 7, instead of a to 7e, the first and second support pads 6 of the adsorbing devices 6 and 7 are provided.
a to 6d, 7a to 7d, a third support pad 6e,
The compressed air is supplied only to the first and second support pads 6b, 7b and 6d, 7d located farther from 7e, and the first mirror 2 and the second mirror 3 facing each other are pressurized. It is effective to release stress from the free end.

It is also possible to form the main body of each support pad by a permanent magnet and use a magnetic material instead of the permanent magnet of each mirror. Further, each mirror may be made of a magnetic material.

3 and 4 show a modification of the first embodiment. In this modification, the support pads 6a to 6e and 7a to 7e of the first embodiment are connected to the XY stage 1 or the stand 8a. , 8b, 10 directly, instead of being fixed directly with an adhesive, screws, etc., at least one small-diameter column 1
By interposing 2, the support pads 6a to 6e,
7a to 7e are XY stage 1 or stands 8a and 8
It is configured such that it can be elastically displaced or deformed with respect to b and 10. Each column 12 is made of a magnetic material or a magnet, and each stand 8 is made of a screw or the like.
a, 8b, 10 or the upper surface of the XY stage 1 is integrally connected. Further, the number is one that supports each of the first support pads 6a and 6b and the third support pad 6e of the suction device 6 that fixes the first mirror 2.
It is desirable to select such that the total number of the devices that support the second support pads 6c and 6d is three. The same applies to the suction device 7 that fixes the second mirror 3.

Each support column 12 includes support pads 6a-6e, 7
a-7e, and the support pads 6a-6e and 7a-7e are attracted by the magnetic attraction force of the magnetic circuit formed by the permanent magnets 11 of the first mirror 2 and the second mirror 3, and this is absorbed by the XY stage. 1 or stand 8a,
8b and 10 are integrally connected.

The support pads 6a to 6e and 7a to 7e are
The support pads 6a can be displaced or deformed freely within the range allowed by the elastic deformation of the columns 12.
6e and 7a to 7e are permanent magnets 1 due to the magnetic attraction force.
When it is adsorbed on No. 1, it is possible to freely displace or deform it according to the shape of its surface, so that it is not necessary to finish the facing surfaces of the two with high flatness.

The support pads 6a to 6e and 7a to 7 are provided.
For e, by using a body in which, for example, an iron plate having a thickness of about 0.5 mm and having openings formed by etching is laminated and laminated, a product having particularly low bending rigidity and easily deformed is produced. can do. Further, it is desirable that the surface of each column that is in contact with the support pad be covered with a sprayed film of tungsten carbide to increase the friction coefficient.

FIG. 5 is a plan view showing a second embodiment. The positioning apparatus E ₂ of this embodiment exposes a substrate such as a wafer of a semiconductor exposure apparatus like the positioning apparatus E ₁ of the first embodiment. Positioning with respect to light, as shown in FIG. 5 (a), it is reciprocally movable in any direction within a plane including the X axis and the Y axis, and is rotatable about the Z axis. A certain XY stage 21, a drive device (not shown) for moving the same, a rod-shaped first mirror 22 extending in the X-axis direction, which is arranged on the outer peripheral edge of the XY stage 21, and Y
A rod-shaped second mirror 23 extending in the axial direction, a laser interferometer 24a which is a first measuring means for irradiating the reflecting surface 22a of the first mirror 22 with laser light, and obtaining interference fringes by the reflected light, A laser interferometer 25, which is a second measuring means for irradiating the reflecting surface 23a of the second mirror 23 with laser light and obtaining an interference fringe by the reflected light, and a first laser interferometer 24a, a predetermined amount in the X-axis direction. It has a laser interferometer 24b which is a third measuring means similar to this, which is separated by a distance,
On the upper surface of the XY stage 21, a suction chuck 21a for adsorbing the wafer W _2, a first reference member 33 and the second respectively detachably held to the two pairs of fixing means the reference member 34 to be described later holding device 35 to 38 are provided, and the holding devices 35 to 38 are configured such that the first reference member 33 and the second reference member 34 held by them are substantially parallel to the first mirror 2 and the second mirror 3, respectively. It is arranged at such a position.

As shown in FIG. 5B, a projection lens system D for condensing the exposure light on the wafer W ₂ attracted by the adsorption chuck 21a is provided above the XY stage 21, and the side thereof is provided. An optical microscope F, which is an observing means, is arranged in the.

Each of the holding devices 35 to 38 includes the XY stage 2.
Substantially L-shaped bases 35a to 38a fixed to the surface of No. 1
And the spring members 35b to 38b held in a cantilever state on the rising portion thereof. Each of the bases 35a to 38a has, on its upper surface, one or two columns 35c to 38c that support the lower surfaces of the reference members 33 and 34, respectively. It is set to be supported by three columns. That is,
A pair of holding devices 35, 3 for holding the first reference member 33
6, the holding device 35 on the left side in the drawing has one support column 35c, the holding device 36 on the right side in the drawing has two support columns 36c spaced apart from each other in the Y-axis direction, and the second reference member 34 is The pair of holding devices 37 and 38 to hold are the holding device 3 on the upper side in the drawing.
7 has two columns 37c spaced apart from each other in the X-axis direction,
The holding device 38 on the lower side of the drawing has one column 38c.
In addition, the spring members 35b to 38b are the columns 35c to 38c.
The protruding portion 35 that is gently pressed against the upper surfaces of the first reference member 33 and the second reference member 34 whose lower surfaces are supported by
d to 38d (only the protrusion 38d is shown in FIG. 5B)
Have. That is, the holding devices 35 and 36 for holding the first reference member 33 support the lower surface of the first reference member 33 only by a total of three columns 35c and 36c, and the spring members 35b and 36b are gently attached to the upper surface thereof. The first reference member 33 is detachably fixed to the surface of the XY stage 21 by pressing the second reference member 34.
The same applies to the holding devices 37 and 38 that hold the.

Each of the first reference member 33 and the second reference member 34 is a rod-shaped body having reflection surfaces 33a and 34a having extremely high flatness on its side surface, and the upper surface of the rod-shaped body is Reference marks 33b and 34b are provided on the center line in the vertical axis direction at predetermined intervals. In this embodiment E ₂ , the first reference member 33 and the second reference member 34 are used in advance by the method described later, and the projections and depressions of the reflecting surfaces 22a and 23a of the first mirror 22 and the second mirror 23 are previously formed. The measurement error caused by the curvature and the curvature is detected, and the detected measurement error is stored in the first to third storage devices M which are storage means respectively connected to the first to third laser interferometers 24a, 24b and 25. _The correction values are stored in _{1 to} M ₃ .

The first laser interferometer 24a and the second laser interferometer 25 measure the positions of the XY stage 21 in the Y-axis direction and the X-axis direction, respectively, and the third laser interferometer 24b is The rotation angle of the XY stage 21 around the Z-axis is detected by the difference in output from the first laser interferometer 24a. If the measured values of the laser interferometers 24a, 24b, 25 are corrected by the above-mentioned correction values, the reflecting surfaces 22 of the first mirror 22 and the second mirror 23 respectively.
Even if the a and 23a have irregularities or curves, there is no possibility of causing the measurement error.

Next, a method of using the first reference member 33 to detect a measurement error in advance due to unevenness or curvature of the reflecting surface 22a of the first mirror 22 will be described.

First, as shown in FIGS. 5A and 5B, while observing the upper surface of the first reference member 33 with the optical microscope F, the XY stage 1 is moved to move the first reference member 33. After arranging any one of the reference marks 33b on the optical axis of the optical microscope F, the reflecting surface 22a of the first mirror 22 is irradiated with laser light from the first laser interferometer 24a, A measurement value of the position of the reflecting surface 22a of the first mirror 22 in the Y-axis direction is obtained from the interference fringes due to the reflected light. Next, the XY stage 21 is moved to position the other reference mark 33b of the first reference member 33 on the optical axis of the optical microscope F, and then the measurement of the first laser interferometer 24a is performed in the same manner as above. Get the value. After obtaining the measurement values of the first laser interferometer 24a for all the reference marks 33b of the first reference member 33 by the same method, the deviation of each measurement value from the predetermined reference value is calculated, and this is calculated as Mirror 2 in 1
As the correction value for correcting the measurement error due to the unevenness or the curvature of the second reflecting surface 22a, the first and third positions are obtained together with the position of the reflecting surface 22a of the first mirror 22 in the X-axis direction that has obtained each measured value.
In the memory devices M ₁ and M ₃ of.

When positioning the XY stage 21 in the Y-axis direction, the measurement value obtained by irradiating the reflecting surface 22a of the first mirror 22 with the laser beam from the first laser interferometer 24a is stored in the first memory. It is corrected by the correction value stored in the device M ₁ . Therefore, even if the reflecting surface 22a of the first mirror 22 has unevenness or curvature, the XY stage 2 is
There is no fear that the positioning accuracy of No. 1 in the Y-axis direction will be significantly impaired.

Next, as shown in FIGS. 6A and 6B, the XY stage 1 is moved in the Y-axis direction while observing the upper surface of the second reference member 34 with the optical microscope F, and After arranging any one of the reference marks 34b of the second reference member 34 on the optical axis of the optical microscope F,
The reflection surface 23a of the second mirror 23 is irradiated with laser light from the second laser interferometer 25, and the measurement value of the position of the reflection surface 23a of the second mirror 23 in the X-axis direction is obtained from the interference fringes due to the reflection light. obtain. Then, the XY stage 21 is moved to position the other reference mark 34b of the second reference member 34 on the optical axis of the optical microscope F, and then the measurement of the second laser interferometer 25 is performed as described above. Get the value. The measured value obtained by repeating such a measuring process is compared with a predetermined reference value to calculate the deviation between the measured value and the second reference value.
In the memory device M ₂ of.

When positioning the XY stage 21 in the X-axis direction, the measurement value of the second laser interferometer 25 is corrected by the correction value stored in the _second storage device M ₂ as in the positioning in the X-axis direction. To do.

Each of the reference members 33 and 34 is made of a light material in the form of a rod having a small cross section, so that the weight can be easily reduced. Unlike the conventional case where a glass substrate is attracted to an adsorption chuck of an XY stage, XY is used. Since there is no danger of causing the stage drive device to become large or complicated, the reference mark is observed with an optical microscope.
It does not require complicated focusing as in the case of using a projection lens system.

As described above, when the reference members 33 and 34 detect the measurement error due to the unevenness and the curvature of the reflecting surfaces 22a and 23a of the mirrors 22 and 23, the following errors occur in the detected values. .

(1) During observation with the optical microscope F, XY
An error caused by the rotation of the stage 21 around the Z axis.

(2) The reference members 33 and 34 are used for the mirrors 2.
Error caused by not being parallel to 2, 23.

(3) An error caused by the displacement of the reference marks 33b and 34b in the horizontal axis direction with respect to the center line of the upper surfaces of the reference members 33 and 34 in the vertical axis direction.

The error (1) is caused by the output of the third laser interferometer 24b of the first laser interferometer 24a while the reference marks 33b and 34b of the reference members 33 and 34 are observed by the optical microscope F. The rotation angle θ around the Z axis of the XY stage 21 is monitored by comparing with the output, and X
By controlling the drive device of the Y stage 21, it is possible to solve the problem by preventing the fluctuation of the rotation angle θ.

The error (2) can be eliminated by approximating the deviation of the measurement values obtained by the reference marks 33b and 34b of the reference members 33 and 34 by the least square method.

The error (3) can be obtained by using the auxiliary device K which is the detecting means shown in FIG.
It is possible to measure each 4b, store it in the fourth storage device M ₄ which is the second storage means, and cancel it in each storage device M ₁ , M ₂ , M ₃ . The method will be described below.

The auxiliary device K includes a pair of holding devices 40 supported by the movable base 39, and the reflecting surfaces 33a of the first reference member 33 or the second reference member 34 supported by both of them.
A fourth laser interferometer 41 for irradiating 34a with laser light to obtain interference fringes, and a second optical microscope F for observing the upper surface of the first reference member 33 or the second reference member 34,
Each holding device 40 has the same configuration in all respects as the holding devices 35 to 38 described above. While holding the first reference member 33 in the holding device 40 and observing each reference mark 33b of the first reference member 33 with the second optical microscope F, the movable table 39 is moved to move the first reference member 33. When one of the reference marks 33b of 33 matches the optical axis of the second optical microscope F, the measurement value by the laser interferometer 41 is obtained. The measured values are obtained for all the reference marks 33b of the first reference member 33, the deviations thereof are calculated, and stored in the _fourth storage device M ₄ . The same measurement is performed on the second reference member 34, and the deviation of each reference mark 34b is calculated and stored in the fourth storage device M ₄ .

[0043]

Since the present invention is configured as described above, it has the following effects.

In the positioning device for positioning the XY stage by measuring the position of the XY stage by the reflected light of the mirror, it is possible to reduce the measurement error due to the unevenness and the curvature of the reflecting surface of the mirror and improve the positioning accuracy.

The invention according to claim 1 reduces the measurement error due to the deformation of the mirror.

According to the third aspect of the present invention, a measurement error due to unevenness or curvature of the reflecting surface of the mirror is detected, and the measurement value of the position of the XY stage is corrected.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a first embodiment.

2 is a partially enlarged cross-sectional view showing a part of the device of FIG. 1 in a cross section taken along line AA.

FIG. 3 is a schematic plan view showing a modification of the first embodiment.

4 is a partially enlarged cross-sectional view showing a part of the device of FIG. 3 in a cross section taken along line BB.

5A and 5B show a second embodiment, in which FIG. 5A is a plan view and FIG. 5B is an elevation view.

6A and 6B show a state in which an XY stage of the apparatus shown in FIG. 5 is moved in the X-axis direction, in which FIG. 6A is a plan view and FIG. 6B is an elevation view.

FIG. 7 is an elevational view illustrating an auxiliary device.

[Explanation of symbols]

1, 21 XY stage 2, 22 1st mirror 3, 23 2nd mirror 4, 24a 1st laser interferometer 5, 25 2nd laser interferometer 24b 3rd laser interferometer 6, 7 Adsorption device 6a 6e, 7a to 7e Support pad 11 Permanent magnet 12 Support 33 First reference member 34 Second reference member 33b, 34b Reference mark 35-38 Holding device 41 Fourth laser interferometer D Projection lens system F Optical microscope H Second optical microscope M ₁ First storage device M ₂ Second storage device M ₃ Third storage device M ₄ Fourth storage device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01S 3/00 F 8934-4M

Claims (4)

[Claims] 1. A positioning device comprising: an XY stage having a mirror; and a measuring means for measuring the position of the XY stage by reflected light from the mirror, wherein the mirror has magnetic surfaces on three side surfaces which are not parallel to each other. It has a body or a magnet, and is biased by the magnetic attraction surface of the magnetic attraction means integrally provided on the XY stage, and the magnetic attraction means is provided between the side surface of the mirror and the magnetic attraction surface. A positioning device having a gas ejecting means for ejecting gas therebetween. 2. The positioning device according to claim 1, wherein the magnetic attraction means comprises a plurality of support pads fixed to the XY stage via at least one support having a small cross section. 3. An XY stage having a mirror, measuring means for measuring the position of the XY stage by the reflected light of the mirror, and a long length having a plurality of reference marks arranged at a predetermined interval on one straight line. Of the reference member, fixing means for removably fixing the reference member to the XY stage along the mirror, observing means for observing the reference mark, and observing the reference mark by the observing means. A positioning device comprising storage means for storing the deviation of the measured values of the measuring means. 4. A detection means for detecting a positional deviation of each reference mark on one straight line of the reference member with respect to the straight line, and a second storage means for storing the output thereof. The positioning device according to item 3.