JP6016433B2 - Positioning apparatus, exposure apparatus, and device manufacturing method - Google Patents

Description

  The present invention relates to a positioning device including a scale and an encoder. The present invention also relates to an exposure apparatus using such a positioning apparatus. Furthermore, the present invention relates to a device manufacturing method using such an exposure apparatus.

  Projection exposure equipment that forms an image of a circuit pattern formed on an original on a substrate via a projection optical system has been used in the past. In recent years, higher resolution and more economical exposure equipment are increasingly required. Has been. One of the important performances of such an exposure apparatus is the overlay accuracy when a circuit pattern is imaged on a substrate. Normally, a plurality of circuit patterns are formed in multiple layers on a substrate, but an electronic circuit cannot be established unless the plurality of circuit patterns are aligned with a predetermined accuracy.

  Therefore, a technique for accurately aligning the substrate during exposure is important. As one technique for aligning substrates, a positioning device including a scale and an encoder has been proposed.

  Patent Document 1 describes a positioning device including a scale fixed to a lens barrel surface plate and an encoder fixed on a stage. In addition, this document describes that a scale is coupled to a lens barrel surface plate through a flexible element.

  In this positioning device, a plurality of flexure elements are arranged on a virtual circle centered on the central axis of the lens barrel. Since each flexible element has flexibility in the radial direction, the scale is prevented from being displaced even if the lens barrel surface plate is deformed by temperature fluctuation.

JP 2009-004737 A

  In the conventional exposure apparatus, the lens barrel surface plate is supported on the floor surface via a vibration isolator such as an air mount, and the vibration transmitted from the floor to the lens barrel surface plate is treated as negligible. However, in recent years, the accuracy required for the exposure apparatus has increased, and there is a concern about vibrations that cannot be completely removed by the air mount and are transmitted to the lens barrel surface plate.

  In particular, in a positioning device including a scale and an encoder, the scale is often mounted on a structure such as a lens barrel surface plate, and there is a concern that this vibration is transmitted to the scale. In particular, since the scale has a structure that is easily deformed in the thickness direction, the amount of deformation increases when vibration is transmitted in this direction. At this time, even when the frequency of vibration is sufficiently smaller than the natural frequency of the scale, there is a risk that deformation of the scale may increase due to the inertial force corresponding to the acceleration generated in the scale acting on the scale.

  In the positioning device of Patent Document 1, the deflection element is flexible in the radial direction, but the plate thickness direction of the scale is not taken into consideration, and the lens platen from the lens barrel surface plate to the scale in the plate thickness direction via the deflection element. The structure is easy to transmit vibration.

The present invention has been made in view of the above, and an object thereof is to provide an advantageous measuring apparatus in terms of measurement accuracy.

The present invention is a measuring device for measuring the position of an object,
An encoder provided on the object;
A scale irradiated with light from the encoder and having a thickness in the direction of gravity;
A structure having a scale supported on the floor via a vibration isolator that reduces vibration transmitted from the floor ;
A support unit provided in the structure and supporting the scale in the direction ;
Oite Before SL direction, a measuring device for measuring the position of the scale relative to the supported member to the structure or the structure,
Based on the output of the measuring instrument, comprising: a drive portion for moving the scale in front SL direction, and
The support unit includes a spring element having a spring constant that reduces, in the direction, vibration transmitted from the floor to the scale via the vibration isolation device and the structure.
The mass of the object including the scale and supported by the support unit is m, the spring constant is k, and the frequency fc of the support unit in the direction fc = (1 / 2π) · (√ (| k | / m )) Has 10 Hz or less,
The spring constant is negative;
The servo control frequency of the drive unit is 1 to 10 times the frequency fc.

According to the present invention, it is possible to provide a measurement device that is advantageous in terms of measurement accuracy.

Schematic of an immersion exposure apparatus to which the present invention is applied (A) is a bottom view of the scale in the present invention, (b) is a top view of the scale in the present invention. (A), (b) is the schematic of the support apparatus in this invention Example of scale deformation Scale top view in the present invention Schematic of the support device in the present invention The figure which shows the vibration transmitted to the scale from the lens barrel surface plate via the support device for each frequency.

[Example 1]
An exposure apparatus according to the first embodiment will be described with reference to the drawings. In the drawings, constituent elements indicated by reference numerals with alphabets are part of constituent elements indicated by the same reference numerals without alphabets. Further, the optical axis direction of the exposure light of the exposure apparatus is defined as the Z direction, the directions orthogonal to the Z direction and the directions orthogonal to each other are defined as the X direction and the Y direction.

  FIG. 1 is a diagram illustrating an immersion exposure apparatus 80 according to the first embodiment. A pattern formed on the original (not shown) is imaged (exposed) on the substrate 30 via the projection optical system 10 (a member supported by the structure). In the immersion exposure apparatus, exposure is performed in a state where the space between the projection optical system 10 and the substrate is filled with the liquid 31. An original plate is a general term for members on which a pattern is formed, and is, for example, a mask or a reticle. The substrate is a general term for members to be exposed, and is, for example, a wafer or a glass substrate. The substrate 30 is mounted on a substrate stage (moving body), and the substrate stage is positioned by a positioning device including a driving device and a position measurement system described later. The projection optical system 10 includes a plurality of optical elements and a lens barrel that surrounds the optical elements, and is supported by the lens barrel surface plate 9 (structure) via the vibration isolation device 22. The lens barrel surface plate is sometimes referred to as a support that supports the projection optical system. As the plurality of optical elements, for example, a lens, a mirror, or a combination of both can be applied. The lens barrel surface plate 9 is supported on the columnar member 44 fixed to the floor 43 via the vibration isolation device 20. The vibration isolation devices 20 and 22 are provided so as to suppress transmission of vibration or deformation. For example, a mount using air pressure, a mechanism for generating force using electricity or magnetism, an elastic member, or the like is applied. sell. The vibration isolation table may be a passive type or an active type.

  In the present embodiment, the substrate stage includes a coarse movement stage 41 that can move with a long stroke in the XY directions with respect to the base surface plate 42. Further, a fine movement stage that is movable in the X, Y, Z directions and rotational directions ωx, ωy, ωz directions (hereinafter referred to as six-axis directions) around an axis parallel to each direction in a short stroke with respect to the coarse movement stage 41. 40 is also provided. However, the substrate stage is not limited to this, and the substrate stage may be configured by one stage that serves both as the coarse movement stage and the fine movement stage. The driving device 45 (driving unit) is provided to drive the substrate stage (in the figure, for coarse movement stage and fine movement stage, respectively), and for example, a linear motor is preferably used. The driving device 45 is controlled by the control unit 100. The control unit 100 can be configured from a CPU or MPU, ROM, RAM, recording unit, driver, and the like, and the configuration is not particularly limited.

  The position of the substrate stage in the six axis directions is measured by a position measurement system.

  The position measurement system includes an encoder 7 mounted on a substrate stage and a scale 1 supported by a lens barrel base plate 9. As the scale 1, various scales in a known position measurement system can be applied. In this embodiment, the scale 1 includes a diffraction grating 2. The diffraction grating 2 may be directly formed on a plate-like member, or the member on which the diffraction grating is formed may be attached to the plate-like member. Using the encoder 7 and the scale 1, the relative position of the substrate stage with respect to the scale 1 can be measured. Then, the driving device 45 is controlled to drive the substrate stage based on the output of the encoder 7. For example, feedback control using known PID compensation can be applied.

  Further, the position measurement system includes a support device (support unit) 3 that supports the scale 1 in a non-contact manner with respect to the lens barrel base plate 9 and a drive that drives the scale 1 with respect to the lens barrel base plate 9 in six axial directions. A device 4 (drive unit) is provided. Further, a position sensor 5 (measuring instrument) that measures the relative position of the scale 1 in the six-axis direction with respect to the projection optical system 10 is provided. In the figure, one sensor 5, a part of the encoder 7, and the measurement optical axis 6 and the measurement optical axis 8 are shown as an example.

  FIG. 2A is a bottom view of the scale 1 (viewed from the −Z direction). In this embodiment, the scale 1 includes four plates 2a, 2b, 2c, and 2d (indicated by reference numeral 2 in FIG. 1) on which diffraction gratings are formed, and a plate-like member to which these plates are attached, including. The light from the encoder 7 is applied to the diffraction grating, and the position of the substrate stage corresponding to the diffracted light is measured by a light receiving element (not shown).

  FIG. 2B is a top view of the scale 1 (viewed from the + Z direction). On the scale 1, position sensors 5a to 5d (indicated by reference numeral 5 in FIG. 1) are mounted. For example, a capacitance sensor, an interferometer, or a linear encoder can be used as the position sensors 5a to 5d. Each of the position sensors 5a and 5b can measure the position of the scale 1 in the X direction and the Z direction with respect to the projection optical system 10, and each of the position sensors 5c and 5d can measure the Y direction of the scale 1 with respect to the projection optical system 10 and The position in the Z direction can be measured. The rotation direction (θx, θy, θz directions) can be obtained from the difference between the two outputs of the position sensor. Further, an average value of outputs of redundant position sensors may be used as a measurement value. The number and the arrangement of the position sensors are not limited to this, and it is sufficient that the position of the scale 1 with respect to the projection optical system 10 in the six-axis directions can be measured. Note that the position measurement of the scale 1 is described in Japanese Patent Laid-Open No. 2009-27141.

  Further, the scale 1 and the lens barrel surface plate 9 are provided with drive devices 4a to 4h (indicated by reference numeral 4 in FIG. 1) and support devices 3a to 3d (indicated by reference numeral 3 in FIG. 1). The driving devices 4 a to 4 h are configured to drive the scale 1 with respect to the lens barrel surface plate 9. As the driving devices 4a to 4h, non-contact type devices having a vibration isolation effect are suitably applied. Examples of such a driving device include a Lorentz type linear motor and an electromagnet actuator. The driving devices 4a to 4h are controlled by the control unit 100. Control of the driving devices 4a to 4h will be described later. Furthermore, you may provide the cooling part which cools a drive device.

  Fig.3 (a) is a figure which shows the detail of the support apparatus 3a, FIG.3 (b) is the perspective view. Since the configuration of the support devices 3b, 3c, and 3d is the same as that of the support device 3a, description thereof is omitted.

  The support device 3 a includes a pair of magnets 32 fixed to the lens barrel surface plate 9 via a support member 31 and a magnet 34 fixed to the scale 1 via a support member 33. The pair of magnets 32 are disposed so as to face each other with a gap therebetween, and the magnet 34 is disposed between the pair of magnets 32 in a non-contact manner. That is, the magnets are arranged on the lens barrel base plate 9 side (structure side) and the scale 1 side. Each magnet is a permanent magnet and is magnetized in the magnet thickness direction, that is, in the X direction, and the magnet 32 and the magnet 34 are arranged so that the same poles face each other.

  The support device 3 a preferably includes yokes 35 and 36 for strengthening the magnetic flux of the magnetic circuit formed by the magnet 32. As a material of the yoke, for example, a soft magnetic material such as iron is used.

  Due to the magnetic repulsion between the pair of magnets 32 and 34, a levitation force in the + Z direction acts on the magnet 34. The repulsive force in the X direction that acts between one magnet of the magnet 32 and the magnet 34 is offset by the repulsive force that acts between the other magnet and the magnet 34.

  The number and arrangement of the support device and the drive device are not limited to the illustrated form. In this embodiment, linear motors (4e, 4f) that can be driven in the X direction are arranged symmetrically with respect to the Y axis passing through the center of gravity of the scale 1. Further, linear motors (4g, 4h) that can be driven in the Y direction are arranged symmetrically with respect to the X axis passing through the center of gravity of the scale 1. Linear motors (4 a to 4 d) that can be driven in the Z direction are arranged at the four corners of the scale 1. In order to apply a symmetrical force to the scale 1, it is preferable that both the support device and the drive device have symmetry with respect to the scale 1. By providing symmetry, deformation can be suppressed, or deformation can be predicted and corrected easily.

  Hereinafter, the characteristics of the support device of the present embodiment will be described. The support device of the present embodiment has the following three features.

  The first feature is that the scale 1 is supported in a non-contact manner with respect to the lens barrel surface plate. Since the support device described in Japanese Patent Application Laid-Open No. 2009-004737 is supported through the deflection element, the temperature fluctuation of the lens barrel surface plate 9 is transmitted to the scale 1 through the deflection element. When the measurement error of the position measurement system is set to 0.1 nm or less, it is necessary to suppress the temperature change of the scale 1 to the order of 1 to 10 mK. Since the lens barrel surface plate used in the exposure apparatus has a very large surface area compared to the scale, a temperature change of the order of 100 mK occurs due to a temperature fluctuation in the surrounding environment. In addition, since the lens barrel surface plate itself is large, it is difficult to precisely adjust the temperature.

  In this embodiment, since the scale 1 is supported in a non-contact manner with respect to the lens barrel base plate 9, the temperature fluctuation of the lens barrel base plate 9 is not easily transmitted to the scale 1, and the deformation due to the temperature fluctuation of the scale 1 is reduced. be able to.

  The second feature is that the support device 3a (the same applies to 3b to 3d) has a negative spring characteristic in the plate thickness direction (Z direction) of the scale 1 and supports the scale 1 at a position where the negative spring constant is obtained. It is to be configured. By making the positional relationship between the magnet 32 and the magnet 34 a predetermined relationship, the support device 3a has a negative spring characteristic. Here, the “negative spring characteristic” is a characteristic in which a spring force does not act at a balanced position when an object is supported, but a force is generated in a direction away from the balanced position when the object deviates from the balanced position. In contrast, the “positive spring characteristic” is a characteristic in which a spring force does not act at a balanced position when an object is supported, but generates a force that attempts to return to the balanced position when it deviates from the balanced position.

  The support device described in Japanese Patent Application Laid-Open No. 2009-004737 uses a flexure element, and resonance due to the mass of the flexure element (spring element) itself and the spring constant becomes a problem. In the conventional example, even if the spring constant of the flexure element is made as small as possible, a plurality of natural frequencies (resonance frequencies) exist from several tens of Hz due to the mass of the flexure element itself, and vibration in the thickness direction transmitted from the lens barrel base plate 9 Will be amplified. Such vibration causes deformation of the scale 1.

  In this embodiment, since the support device has a negative spring characteristic, there is no problem of resonance, and deformation of the scale 1 can be reduced.

  The third feature is that the absolute value of the spring constant in the plate thickness direction (Z direction) of the scale is very small. Preferably, the absolute value of the spring constant in the 6-axis direction is very small. In other words, the scale 1 is supported in a vibrationally insulated state.

  Since the scale 1 is plate-shaped, deformation is most likely to occur due to inertial force acting in the thickness direction of the scale 1 in terms of material mechanics. FIG. 4 shows the shape of the scale 1 when vibration is transmitted from the lens barrel surface plate in the support device that rigidly supports (fixes) the scale 1 in the thickness direction. Forces F1 to F4 are applied to the scale 1 at the support portions 108a to 108d, and the acceleration is generated in the entire scale 1 by the force, and the inertial force F5 is applied. As a result, deformation as shown in FIG. 4 occurs.

  The inertial force F5 generated in the scale 1 is represented by [scale mass] × [vibration amplitude] × [angular frequency of vibration] ^ 2. That is, while the inertial force is proportional to the vibration amplitude, the inertial force is also proportional to the angular frequency [rad / s] of vibration or the square of the vibration frequency [Hz] that is proportional to each frequency. Therefore, reducing high-frequency vibration transmitted to the scale 1 is effective for reducing the deformation amount of the scale 1.

  A support device having a negative spring characteristic does not have a general natural frequency because the spring constant is defined as negative. Accordingly, the following frequency fc is defined as the frequency corresponding to the natural frequency.

(Expression 1) is a modification of an expression representing a general natural frequency, and the spring constant k in the expression representing the natural frequency is an absolute value. m is the mass of the scale 1 or the total mass of the objects mounted on the scale 1 and the scale 1. Since the resonance phenomenon does not occur in the case of the negative spring characteristic, the frequency fc does not mean the frequency that causes resonance. However, (Equation 1) can be a guideline for knowing how much vibration is difficult to be transmitted due to the effect of the inertial force acting on the supported object or how much spring force acts on the supported object.

  In recent exposure apparatuses, since the accuracy of about 0.1 nm is required for measuring the position of the substrate stage, the deformation amount of the scale 1 needs to be 0.1 nm or less. According to the analysis result, when the thickness of the scale 1 is several tens of millimeters, the thickness of the support device 3 is controlled in order to suppress the amount of deformation of the scale 1 due to vibration in the thickness direction to 0.1 nm or less. The direction frequency fc may be 10 Hz or less. Here, when the scale 1 is rigidly supported in the thickness direction, the frequency fc is 100 Hz or more, which is not preferable. In the present embodiment, the frequency fc is set to 10 Hz or less by supporting the scale 1 with the support device 3 using the repulsive force of the magnet.

  As a result, it is possible to significantly reduce deformation of the scale 1 due to vibration transmission from the lens barrel surface plate to the scale 1.

  Next, positioning control of the scale 1 using the driving device 4 in the driving device of the present embodiment will be described. Since the support device 3 of the present embodiment has a negative spring constant and a small absolute value of the spring constant, acceleration is unlikely to occur in the scale 1, but on the other hand, the position stability of the scale 1 is low. It gets worse. For example, the scale 1 may be displaced due to the influence of the wind pressure accompanying the movement of the substrate stage. Therefore, in the driving device 4 of this embodiment, both the position stability of the scale 1 and the suppression of the acceleration generated in the scale 1 are made compatible.

  In order to describe the positioning control of the present embodiment in detail, first, the relationship between the support device 3 and the positioning control will be described.

  In this embodiment, the relative position of the scale 1 with respect to the projection optical system 10 in the six-axis direction is measured by the position sensor 5, and the drive device 4 is moved in the six-axis direction so that the relative position has a predetermined relationship based on the measurement result. To control. Specifically, feedback control using PID compensation is applied.

  When the support device has a positive spring characteristic, there is a concern that the positioning control of the scale 1 amplifies the vibration. Usually, positioning control is difficult in the region of 1/2 to √2 times the natural frequency.

  On the other hand, when the support device has a negative spring characteristic, the resonance phenomenon does not occur at the frequency corresponding to the natural frequency, and the servo control frequency of the positioning control of the scale 1 is set near the frequency fc. However, the positioning control does not become unstable. However, since the force acts in the direction away from the balance position in the negative spring characteristic, it is necessary to adjust the servo control frequency so as to secure a control driving force that can overcome this force at least. Although depending on the assumed relative displacement between the scale 1 and the lens barrel surface plate 9, the positioning control is usually possible if the servo control frequency is one or more times the frequency fc corresponding to the natural frequency. In other words, if positioning control is performed at a servo control frequency smaller than 1 times the frequency fc, the control driving force may be lost to the force generated by the negative spring, and the positioning control tends to become unstable.

  On the other hand, the positioning control of the scale 1 has a function of causing the scale 1 to follow the movement of the projection optical system 10, so that if the scale 1 is positioned and controlled at a high servo control frequency, the vibration of the projection optical system 10 is excessively transmitted. become.

  FIG. 7 is a diagram illustrating the relationship between the servo control frequency of the positioning control of the scale 1 and the vibration energy applied to the scale 1. FIG. 7A shows a case where the support device 3 has a positive spring characteristic, and FIG. 7B shows a case where the support device 3 has a negative spring characteristic.

  The horizontal axis represents the frequency ratio, which is the ratio between the servo control frequency and the natural frequency or frequency fc.

  The vertical axis indicates the vibration energy ratio, and the square of the amplitude when the scale 1 vibrates due to the force transmitted from the support device 3 or the control driving force is supported by the support device having a positive spring characteristic with a natural frequency of 2 Hz. In addition, the values are normalized with the values when the servo control is not performed. Since it is normalized, the vibration energy ratio is 1.0 when the servo control frequency is 0 (when servo control is not performed). This graph can be interpreted as a graph obtained by normalizing vibration energy applied to the scale 1 when positioning control is performed at each servo control frequency.

  As shown in FIG. 7 (a), the support device having the positive spring characteristic reduces the vibration energy applied to the scale 1 when the servo control frequency is set to about 2 to 4 times the natural frequency. I understand that it is expensive. Also, if the servo control frequency is set to 10 times or more of the natural frequency, the vibration energy applied to the scale 1 is increased and the vibration suppression effect is worse than the positioning control at the servo control frequency near the natural frequency. I understand that.

  From FIG. 7 (b), it can be understood that the vibration energy applied to the scale 1 increases and the vibration suppression effect deteriorates as the servo control frequency is increased in the support device having the negative spring characteristic. It can also be seen that the vibration suppressing effect is high when the servo control frequency is set to about 1 to 3 times the frequency fc. When the servo control frequency is set to 10 times or more of fc, the vibration suppressing effect is not different from the case of the support device having the positive spring characteristic.

  In summary, it can be seen that in the support device 3 having negative spring characteristics, it is preferable to set the servo control frequency of the positioning control of the scale 1 to 1 to 10 times the frequency fc. Furthermore, it is more preferable to set it to 1 to 3 times the frequency fc.

  In this embodiment, as an example, the frequency fc of the support device is set to about 2 Hz in all six axis directions, and the servo control frequency is set to about 3 to 5 Hz.

  The “servo control frequency” (also referred to as a servo control band) is defined by the zero cross frequency in the open characteristic, and serves as an index indicating the boundary of whether or not the follow-up control functions sufficiently. In other words, when the servo control frequency is set to 5 Hz, the control does not function for the movement of the frequency of 5 Hz or more, but the control functions for the movement of the lens tube of the frequency of 5 Hz or less, and the low frequency band at the scale 1 position. Drift can be prevented.

  The support device 3 of the present embodiment has a negative spring characteristic in the support device in the thickness direction of the scale 1, and further, the servo control frequency for positioning control of the scale 1 is not less than 1 times and not more than 10 times the frequency fc. Is set. Thereby, the inertial force generated in the scale 1 by the positioning control of the scale 1 can be suppressed, and the deformation of the scale 1 in the plate thickness direction due to vibration can be greatly reduced.

  In the present embodiment, position measurement in the 6-axis direction and driving in the 6-axis direction are described as preferred examples, but position measurement only in the plate thickness direction of the scale 1 and drive in the plate thickness direction may be used. Further, in this embodiment, the position sensor 5 measures the position of the scale 1 with respect to the projection optical system 10 (member supported by the structure). The position of the scale 1 with respect to) may be measured.

  In this embodiment, the scale 1 is supported by the lens barrel base plate 9, but may be supported by a structure other than the lens barrel base plate 9. Also in that case, the structure is supported via the vibration isolation device.

  The configuration of the exposure apparatus 80 in the present embodiment is an example, and the configuration may be different without departing from the spirit of the invention. For example, it is not limited to any of the step-and-scan method, the step-and-repeat method, and other methods, and is not limited to the wavelength of a predetermined light source, and is not limited to either the liquid immersion method or the non-liquid immersion method. Further, the present invention is not limited to an exposure apparatus, and can be applied to, for example, a charged particle beam drawing apparatus that does not use an original plate, an imprint apparatus, a digital microscope, and a positioning apparatus used in a machine tool.

  When the above-described position measurement system is applied to a charged particle beam drawing apparatus, an electron optical system for deflecting or shaping a charged particle beam can be applied instead of the projection optical system.

  When the above-described position measurement system is applied to the imprint apparatus, a pattern on which a pattern is formed or a support that supports the mold can be applied instead of the projection optical system.

  When the above-described position measurement system is applied to a digital microscope, an optical system constituting the microscope can be applied instead of the projection optical system.

[Example 2]
A position measurement system according to the second embodiment will be described. An acceleration sensor 60 (acceleration measuring means) is added on the scale 1 with respect to the configuration of the first embodiment, and the output of the acceleration sensor 60 is used for controlling the driving device 4. In the following description, portions different from those in the first embodiment will be described, and description of portions having functions similar to those in the first embodiment will be omitted.

  FIG. 5 is a top view of the scale 1 of the second embodiment. In the figure, portions having the same functions as those in the first embodiment are denoted by the same reference numerals.

  In the scale 1, acceleration sensors 60a to 60d that detect acceleration in the thickness direction of the scale 1 are arranged. The control unit controls the driving devices 4a to 4h so as to cancel the acceleration generated in the scale 1 based on the acceleration detected by the acceleration sensors 60a to 60d. That is, the drive device is controlled so that the outputs of the acceleration sensors 60a to 60d become zero.

  In this embodiment, the acceleration sensor detects the acceleration in the plate thickness direction of the scale 1, but may detect the acceleration in other directions (for example, the 6-axis direction), and in that case, the plate generated in the scale 1 The acceleration other than the thickness direction can be canceled out.

  The above-described acceleration control in the second embodiment is performed together with the position control for preventing the drift in the first embodiment. Since the servo control frequency of the acceleration control is not limited as in the position control, the deformation of the scale 1 can be further reduced by setting it as high as possible.

  The driving devices 4a to 4d are preferably arranged in the vicinity of the supporting devices 3a to 3d. Furthermore, the acceleration sensors 60a to 60d are preferably arranged in the vicinity of the supporting devices 3a to 3d and the driving devices 4a to 4d that drive in the plate thickness direction. With such an arrangement, when the force transmitted from the support devices 3a to 3d to the scale 1 is canceled by the force generated by the drive devices 4a to 4d, local deformation of the scale 1 caused by the difference in the point of action of each force is prevented. Can be reduced.

[Example 3]
A position measurement system according to the third embodiment will be described. The support device of Example 1 is different from the non-contact type in that the support device of Example 3 is a contact type. Since the first feature in the first embodiment is not provided, the temperature fluctuation of the scale 1 is likely to occur as compared with the configuration of the first embodiment. However, the deformation of the scale 1 is reduced by providing the second and third features. Can be made. In the following description, portions different from those in the first embodiment will be described, and description of portions having functions similar to those in the first embodiment will be omitted.

  FIG. 6A shows a support device in the second embodiment. Although one supporting device is shown in the figure, the position measurement system includes a plurality of supporting devices as in the first embodiment, and other supporting devices not shown in the figure have the same configuration.

  The support device includes a magnet 72 a fixed to the lens barrel base plate 9, a magnet 72 b fixed to the scale 1 so as to face the magnet 72 a, and a coil spring 71 that connects the lens barrel base plate 9 and the scale 1. With. The magnets 72a and 72b are permanent magnets. The coil spring 71 may have other configurations as long as it acts as a spring element.

  The scale 1 is supported by a supporting force determined by a magnetic repulsive force acting between the magnet 72 a and the magnet 72 b and a restoring force of the coil spring 71. The magnets 72a and 72b generate a non-linear spring force with respect to the displacement of the scale 1, and the coil spring 71 is configured to generate a linear spring force. By adjusting the spring force and the support position of the scale 1, the scale 1 can be supported in the negative spring characteristic.

  Further, the adjustment can provide a support force for supporting the scale 1 and can suppress the amount of elongation of the coil spring 71 with respect to the displacement in the vicinity of the balanced position. This reduces the distance between the scale 1 and the lens barrel surface plate 9 and saves space. Furthermore, the absolute value of the spring constant at the balanced position can be reduced by adjustment.

  FIG. 6B is a modification of FIG. The support device illustrated in FIG. 6B uses an air spring (Bellofram) 73 instead of the coil spring 71. Further, magnets 72c to 72f are used in place of the magnets 72a and 72b. The magnets 72c to 72f are different from the support device of FIG. 6A in that magnetic attraction is used.

(Device manufacturing method)
Next, a method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. A semiconductor device is manufactured through a pre-process for producing an integrated circuit on a wafer and a post-process for completing an integrated circuit chip on the wafer produced in the pre-process as a product. The pre-process includes a step of exposing a wafer coated with a photosensitive agent using the above-described exposure apparatus, and a step of developing the wafer. The post-process includes an assembly process (dicing and bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured through a process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied using the above-described exposure apparatus, and a glass substrate. The process of developing is included. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Scale 3 (3a-3d) Support apparatus 4 (4a-4h) Drive apparatus 5, 7 Sensor 32, 34 Magnet 40, 41 Substrate stage 45 Drive apparatus 60a-60d Acceleration sensor 80 Exposure apparatus 100 Control part

Claims (8)

A measuring device for measuring the position of an object,
An encoder provided on the object;
A scale irradiated with light from the encoder and having a thickness in the direction of gravity;
A structure supported on the floor via a vibration isolator that reduces vibration transmitted from the floor ;
A support unit provided in the structure and supporting the scale in the direction ;
Oite Before SL direction, a measuring device for measuring the position of the scale relative to the supported member to the structure or the structure,
Based on the output of the measuring instrument, comprising: a drive portion for moving the scale in front SL direction, and
The support unit includes a spring element having a spring constant that reduces, in the direction, vibration transmitted from the floor to the scale via the vibration isolation device and the structure.
The mass of the object including the scale and supported by the support unit is m, the spring constant is k, and the frequency fc of the support unit in the direction fc = (1 / 2π) · (√ (| k | / m )) Has 10 Hz or less,
The spring constant is negative;
The servo control frequency of the drive unit, the measurement device wherein the or less and 10 times 1x frequency fc. The measuring apparatus according to claim 1 , wherein the support unit supports the scale in a non-contact manner. The support unit, measuring apparatus according to claim 1 or 2, characterized in Tei Rukoto is configured to reduce vibrations transmitted to the scale Te 6 axially smell. The support unit has a pair of first permanent magnets attached to one of the scale and the structure, and a second permanent magnet attached to the other,
Wherein at least one of the first and second permanent magnets before SL are magnetized in a direction orthogonal to the direction, and said the force acting between said first permanent magnet and the second permanent magnet measurement apparatus according to any one of 3 claims 1, characterized in that for supporting the scale. Comprises acceleration measuring means for detecting an acceleration of the scale,
The drive unit of the previous SL measuring device according to any one of claims 1 to 4 also based on the output of the acceleration measuring means, characterized in that moving the scale. An exposure apparatus which exposes a substrate, according to claim 1 to comprise a measuring device according to any one of 5, the measuring exposure apparatus and performs positioning of the substrate on the basis of the output of the device . The exposure apparatus according to claim 6, wherein the measurement apparatus measures a position of a stage on which the substrate is mounted. A step of exposing a substrate using an exposure apparatus according to claim 6 or 7, device manufacturing method and a step of developing the exposed substrate.

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