KR20170089767A - Optical device, exposure apparatus, and article manufacturing method - Google Patents

Abstract

The present invention provides an optical device effective in improving the performance of an optical system. According to the prevent invention, a variable mirror device for deforming the reflecting surface of a mirror is provided. The device comprises a voice coil motor having a magnet mounted on the opposing surface of the reflecting surface and a coil disposed at a position facing the magnet, a reference base for holding and supporting the coil, a heat transfer bar connected to the coil held and supported by the reference base, and a flow path for recovering heat from the heat transfer bar. The heat transfer bar has a free end at the end of a heat conducting unit facing the end connected to the coil.

Description

OPTICAL DEVICE, EXPOSURE APPARATUS, AND ARTICLE MANUFACTURING METHOD Technical Field [1] The present invention relates to an optical device,

The present invention relates to an optical device, an exposure apparatus, and a method of manufacturing an article.

There is an optical device in which aberration in the optical system can be corrected by using a mirror having a reflective surface having a variable shape. In order to adjust the shape of the mirror, the mirror is attached to the back surface of the mirror, and the voice coil motor is driven in a state in which the coil is disposed at a position facing the magnet with a minute interval from the magnet. Has been proposed.

In this method, the coils and the magnets are inevitably disposed adjacent to each other. Then, the heat generated by the coil at the time of driving is transmitted from the coil to the magnet via the air layer, and is transferred from the magnet to the mirror. Therefore, it may be difficult to deform the mirror into the desired shape. A coil is provided at the end of the copper bar attached to the cooling plate, and then the heat generated by the coil is recovered from the copper bar to reduce the temperature rise of the mirror. &Quot; VLT Deformable Secondary Mirror: integration and electromechanical tests results "by R. Biasi et al., Proc. SPIE 8447, Adaptive Optics Systems III, 84472G (September 13, 2012).

egg. In the configuration disclosed in non-patent documents such as Via City, the coil is held only by the copper bar extending in the normal direction of the mirror. A distance sensor is provided in the reference base corresponding to each voice coil motor to measure the distance between the reference base and the mirror, and the shape of the mirror is controlled based on the measured value. egg. In the case of a configuration disclosed in non-patent documents such as Via City, it is necessary to provide a distance sensor to each voice coil motor, and when the mirror has a large diameter, more than 100 distance sensors are required. Thus, this can lead to an increase in cost. Therefore, a configuration in which the number of distance sensors is reduced is required. When the distance sensor is removed from each voice coil motor, it is necessary to control the shape of the mirror by generating a desired force in a feed-forward manner. However, al. In the case of the configuration disclosed in Non-Patent Documents such as Via City, the thermal expansion of the copper bar changes the distance between the coil and the magnet and changes the thrust constant so that the voice coil motor is driven in a feed- Can not be generated. It is necessary to fix the coil to the reference base in order to reduce the change in the distance between the coil and the magnet. In this case, the reference base is configured to be coupled to the cooling plate via the coil and the copper bar. Therefore, when the copper bar and the cooling plate are thermally deformed, the reference base is also deformed by the force received from the deformed copper bar and the cooling plate, and the position of the coil is shifted to change the thrust constant. Thus, in a configuration in which the coil of the voice coil motor is fixed to the reference plate, there is a demand for a configuration that reduces the influence due to the thermal deformation provided on the reference plate while the coil can be cooled.

The present invention provides an optical device advantageous in terms of, for example, improving the performance of an optical system.

An optical device according to an aspect of the present invention is an optical device for deforming a reflecting surface of an optical element, the device including an actuator having a magnet mounted on an opposing surface of a reflecting surface and a coil disposed at a position facing the magnet, And a cooling unit for recovering heat from the heat conduction unit, wherein the heat conduction unit comprises a heat conduction unit which is opposed to the end connected to the coil And has a free end at its end.

Additional features of the present invention will become apparent from the following detailed description of illustrative embodiments with reference to the accompanying drawings.

1A to 1C are schematic views showing the basic structure of an optical device.
2 is a schematic view showing a configuration of an optical device according to the first embodiment.
3 is a schematic view showing a configuration of an optical device according to the second embodiment.
4 is a schematic view showing a configuration of an optical device according to the third embodiment.
5 is a schematic view showing a configuration of an optical device according to the fourth embodiment.
6 is a schematic view showing the configuration of an exposure apparatus to which an optical device is applied.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and the like.

(Embodiment 1)

FIG. 1A is a sectional view showing an exemplary basic configuration of a variable mirror device 100. FIG. The variable mirror device 100, which is referred to as an optical device, is configured to change the shape of the reflecting surface of the mirror 101 which is an optical element. 1 to 5, the X-axis is set as a direction perpendicular to the reflecting surface of the mirror 101 before deformation, and the Y-axis and Z-axis are set in a plane perpendicular to the X-axis Parallel planes). The mirror 101 is a thin mirror and has a back surface (hereinafter, referred to as "reflection back surface") of the reflection surface fixed to the reference base 121 by the mirror fixing portion 102. A coating suitable for the wavelength of the light used is applied on the reflecting surface of the mirror 101. [ In order to suppress the generation of the shape error due to thermal distortion, in this embodiment, the low thermal expansion optical glass is set as the material of the mirror 101. [ Further, in the present embodiment, there is no limitation on the size of the mirror in particular, but the mirror is generally about several mm to several cm thick for an outer diameter of about 0.1 m to 2 m. For example, the mirror 101 has an outer diameter of about 1 m and a thickness of about 1 cm.

The reference base 121, which is referred to as a base plate, holds a mirror 101, a displacement sensor 123, and an actuator fixing holder 122. Further, the reference base 121 holds the coil 105 via the holder 122. The mirror 101 is held on the reference base 121 via the mirror fixing portion 102. The displacement sensor 123 held on the reference base 121 measures the shape of the surface of the mirror 101. In this embodiment, the material of the reference base 121 is set as the low thermal expansion material in order to reduce the deterioration of the measurement precision due to the thermal distortion caused by the heat from the actuator or the like.

The mirror fixing portion 102 has a cylindrical shape, and fixes the mirror 101 and the reference base 121. In this embodiment, the mirror fixing portion 102 is arranged so that the center line of the mirror 101 and the mirror fixing portion 102 coincide with each other. However, the present embodiment is not limited to this configuration, and accordingly, the position, shape, and number of the mirror fixing portions 102 can be changed when they are in this context. It is preferable that the material of the mirror fixing portion 102 has a low thermal expansion property in order to reduce the influence of thermal distortion. In the present embodiment, the same thermal expansion material as the reference base 121 is used as the material of the mirror fixing portion 102, . The voice coil motor 103 is driven so that the mirror 101 is deformed into the target shape but since the mirror fixing portion 102 fixes the mirror 101 so as not to be displaced, the mirror 101 is not translated in the X direction Nor rotated about an axis perpendicular to the X direction. For example, when the voice coil motor 103 is driven, the total force generated by the voice coil motor 103 does not necessarily become zero. However, a moment against the moment caused by the voice coil motor 103 is generated in the mirror fixing portion 102, so that the mirror 101 does not rotate. As a result, the posture of the mirror 101 can be maintained within the required accuracy range, and it is not necessary to control the posture of the mirror 101. [

The voice coil motor 103 is an actuator unit composed of a magnet 104 and a coil 105. [ 1B is an example showing the arrangement of the magnets 104 in the mirror back surface according to the present embodiment. The magnet 104 referred to as a movable unit is radially disposed on a surface opposite to the reflecting surface of the mirror 101 and the coil 105 referred to as a fixed unit is disposed at a small distance from the magnet 104 122 to the reference base 121. The arrangement and the number of the voice coil motors 103 can be determined by the target shape of the mirror 101 and the required accuracy. The voice coil motor 103 generates a Lorentz force in the direction of the axis crossing the magnet and the coil by applying a current to the coil 105. [ The voice coil motor 103 has a thrust and a driving amount capable of deforming the reflecting surface of the mirror 101 to a desired shape. For example, neodymium with a high magnetic flux density can be used as the magnet 104. The larger the gap between the coil 105 and the magnet 104 is, the smaller the thrust is, and thus the coil 105 and the magnet 104 are moved from the end face of the magnet 104, .

The pack 106 is disposed between the magnet 104 and the mirror 101 and an adhesive fixes a portion between the pack 106 and the magnet 104 and a portion between the pack 106 and the mirror 101. [ The pack 106 is disposed between the mirror 101 and the magnet 104 to thereby reduce the influence of the thermal distortion of the magnet 104 relative to the mirror 101. [ The material of the pack 106 is a low thermal expansion material which is the same as the material of the mirror 101. [ The holder 122 is a holding unit for fixing the coil 105 to the reference base 121. [

A plurality of displacement sensors 123, which are referred to as measurement units, are arranged at positions facing the rear surface of the mirror on the reference base 121. [ The shape information of the mirror is acquired by setting the reference base 121 as a reference and measuring the distance from the reference base 121 to the back of the mirror. 1B, the displacement sensor 123 is arranged radially, but its arrangement and number can be determined by the target shape of the mirror 101 and the required accuracy. In this embodiment, the exemplary configuration is shown such that the number of the displacement sensors 123 is smaller than the number of the actuator units, that is, the number of the coils 105, from the viewpoint of cost reduction, but the embodiment is not limited thereto.

The heat transfer bar 124 is a thermal conductor (thermal conduction unit) coupled to couple the coil 105 and the cooling plate 125 and transfers the heat of the coil to the cooling plate 125. The heat transfer bar 124 is secured to the cooling plate 125 by a screw 127 via a thermal conductive grease. The heat transfer bar 124 is, for example, a unit made of copper, aluminum having a high thermal conductivity, or a heat pipe having a high thermal conductivity. The length and thickness of the heat transfer bar 124 are determined by the calorific value of the coil and the required thermal resistance value. Further, the coil 105 and the heat transfer bar 124 are attached via an adhesive.

The cooling plate (plate) 125 is disposed apart from the end of the heat transfer bar 124 which is connected to the coil 105, and a flow passage 126 called a cooling unit is formed therein. In the flow path 126, a temperature-controlled refrigerant supplied from a temperature controller (not shown) flows. 1C is a view showing an example of the heat transfer bar 124 and the flow path 126 attached to the cooling plate 125. Fig. The heat of the coil 105 recovered by the heat transfer bar 124 is recovered in the flow path 126 formed in the cooling plate 125. The cooling plate 125 may be made of a material having high thermal conductivity such as copper or aluminum. The flow rate of the refrigerant and the shape of the flow path 126 can be determined from the heat resistance required to recover the heat of the coil, the pressure loss of the refrigerant, and the like. In this embodiment, a plurality of flow paths 126 are arranged and the flow paths are arranged in a parallel configuration in order to reduce the pressure loss. Further, the cooling plate 125 may be configured to be divided in consideration of the assemblability.

The voice coil motor 103 has a structure that generates a thrust by applying a current to the coil 105, so that the coil 105 generates heat when driven. The heat of the coil is transferred from the coil 105 through the air layer to the magnet 104 and from the magnet 104 through the pack 106 to the mirror 101. And then, the mirror 101 undergoes thermal deformation, thereby making it impossible to deform and control the mirror 101 into a desired shape. When the heat of the coil causes thermal deformation of the reference base 121 via the holder 122, the positional relationship between the mirror 101 and the reference base 121 is changed. In addition, when the reference base 121 is thermally deformed, the position of the displacement sensor 123 is shifted, whereby it is impossible to measure the shape of the mirror 101 accurately. It is necessary to recover the heat of the coil 105 by the cooling plate 125 through the heat transfer bar 124 to reduce thermal deformation of the reference base 121 and the mirror 101. [

However, the heat transfer bar 124 is thermally expanded due to the heat recovery of the coil 105. In particular, since the heat transfer bar 124 is often made of copper or aluminum as its material and has a large linear expansion coefficient and a large Young's modulus, the heat transfer bar 124 produces a large thermal stress. Since both ends of the heat transfer bar 124 are fixed to the cooling plate 125 and the reference base 121 respectively, the heat transfer bar 124 is configured to restrict the force due to the thermal expansion to the reference base 121 and the cooling plate 125 . In particular, when a force is applied to the reference base 121 via the holder 122, the reference base 121 is deformed, and it is impossible to deform and control the mirror 101 into a desired shape.

Therefore, the present embodiment provides a configuration in which deformation of the reference base 121 caused by thermal deformation of the heat transfer bar 124 is reduced. Hereinafter, with reference to Fig. 2, the cooling configuration of the coil 105 in the present embodiment will be described in detail. 2 is a schematic cross-sectional view of the variable mirror device 300 according to the first embodiment. The thickness of the cooling plate 125 is several mm to several tens mm. The variable mirror device 300 of this embodiment has a heat transfer bar 124 and a cooling plate 125 spaced apart from each other and has an air layer 301 provided between the heat transfer bar 124 and the cooling plate 125 ). The distance between the heat transfer bar 124 and the cooling plate 125 is, for example, from several micrometers to several millimeters. The heat transfer efficiency between the heat transfer bar 124 and the cooling plate 125 is proportional to the facing area between the cooling plate 125 and the heat transfer bar 124 coupled to the cooling plate 125. In addition, it is inversely proportional to the thickness of the air layer 301. Therefore, the thickness of the air layer 301 and the facing area of the coupling portion can be determined according to the heating value of the coil and the allowable temperature of the mirror 101. The facing area can be adjusted by the thickness of the cooling plate 125 and the diameter of the heat transfer bar 124. The gas constituting the air layer 301 is not limited to air, and may be a single component gas.

The heat transfer bar 124 has a free end on the cooling plate 125 side and is therefore thermally expanded freely from the end coupled to the coil 105 as a starting point. Accordingly, the heat transfer bar 124 can reduce the deformation amount of the reference base 121 without applying a large force to the reference base 121. [ Therefore, the change in the distance between the coil 105 and the magnet 104 is reduced, and the variation in the thrust constant of the voice coil motor 103 can also be made acceptable for this embodiment. Thus, by using this embodiment, the voice coil motor 103 under feed-forward control can be used to create the desired force and control the shape of the mirror.

Further, since the heat transfer bar 124 is disposed apart from the cooling plate 125, it is possible to prevent the vibration of the cooling plate 125 from being transmitted to the reference base 121 through the copper bar 124. Further, in this embodiment, the assembly is easily performed without attaching the heat transfer bar 124 to the cooling plate 125 using screws 127 or the like. For example, after assembling the coil 105 and the heat transfer bar 124 in the reference base 121, the cooling plate 125 may also be assembled to align with the heat transfer bar 124. At this time, when the cooling plate 125 is configured to be divided, the assembly is further facilitated. Further, after the cooling plate 125 is aligned with respect to the reference base 121, the holder 122 also inserts the heat transfer bar 124 from the cooling plate 125 into the reference base 121, 125 can be fixed to the reference base 121 by aligning the heat transfer bar 124 with respect to the base plate 121. In this case, it becomes easy to manage the thickness of the air layer 301. The reference base 121 and the cooling plate are fixed by a barrel (not shown).

The variable mirror device 300 of the present embodiment is configured such that they are thermally attached across the air layer 301 even though the cooling plate 125 and the heat transfer bar 124 are not directly attached to each other . Thus, the heat generated by the coil 105 through the heat transfer bar 124 is recovered in the cooling plate 125, and at the same time, the deformation of the reference base 121 caused by the thermal expansion of the heat transfer bar 124 The accuracy of shape control of the optical device can be improved.

(Second Embodiment)

Referring to Fig. 3, another embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be given the same reference numerals as those in the above embodiment, and the description thereof will be simplified or omitted. 3 is a schematic cross-sectional view of a variable mirror device 400 according to the second embodiment. The heat transfer bar 124 of the present embodiment has a frusto-shaped rigid body 401 having a low rigidity near its end. The cooling plate 125 also has a truncated cone-shaped hole 402 which is the same as the elastic body 401 at a position corresponding to the heat transfer bar 124 so that the elastic body 401 can engage with it. The hole 402 can be formed smaller than the elastic body 401, so that the elastic body 401 can be contacted with the hole 402 without any gap.

In this embodiment, the gap between the heat transfer bar 124 and the cooling plate 125 is filled with the elastic body 401. When a resin, a rubber, or a heat transfer sheet is used as the material of the elastic body 401, its thermal conductivity is several tens to several hundred times larger than the thermal conductivity of air 0.026 W / mK (23 DEG C). Therefore, even if the gap (the thickness of the elastic body 401) between the heat transfer bar 124 and the cooling plate 125 is set to be equal to or several times larger than that of the first embodiment, the heat transfer bar 124 ) To the cooling plate 125 can be improved.

Here, the heat transfer bar 124 is thermally expanded by the heat of the coil 105. However, in the present embodiment, since the elastic body 401 is elastically deformed due to the thermal expansion of the heat transfer bar 124, the heat transfer bar 124 is thermally expanded from the end coupled to the coil 105 as a starting point , The force received by the reference base 121 due to thermal expansion of the heat transfer bar 124 is reduced. That is, by applying the elastic body 401 having a sufficiently low rigidity, deformation of the reference base 121 can be reduced within an allowable range. The elastic body 401 may have a Young's modulus of 10 GPa or less, and the material may be, for example, resin, rubber, or the like. At this time, it is also possible to set the variation value of the thrust constant of the voice coil motor 103 to be also allowable, to generate the desired force using the voice coil motor 103 under the feed-forward control, Can be controlled.

Further, since the clearance between the heat transfer bar 124 and the cooling plate 125 can be larger than that of the air layer, when the variable mirror device 400 is assembled, the heat transfer bar 124 and the cooling plate 125 are easily aligned. That is, even if the center of the hole 402 of the heat transfer bar 124 and the cooling plate 125 is shifted, the elastic body 401 is elastically deformed so that the elastic body 401 and the cooling plate 125 are in close contact with each other . As described above, the variable mirror device 400 according to the present embodiment is configured to move the heat transfer bar 124 from the heat transfer bar 124 to the cooling plate 125 by interposing the elastic body 401 to attach the heat transfer bar 124 to the cooling plate 125. [ The heat transfer efficiency to the heat transfer member 125 can be improved. It is also possible to reduce deformation of the reference base 121 due to thermal expansion of the heat transfer bar 124 by interposing the elastic body 401 in the gap between the heat transfer bar 124 and the cooling plate 125, The shape control precision can be improved.

(Third Embodiment)

Hereinafter, another embodiment will be described with reference to Fig. In the following description, the same or equivalent components as those in the above-described embodiment will be given the same reference numerals as in the previous embodiments, and the description thereof will be simplified or omitted. 4 is a schematic cross-sectional view of a variable mirror device 500 according to the third embodiment. In the interior of the reference base 501 of the present embodiment, a flow path 502 called a cooling unit is formed. Therefore, the variable mirror device 500 according to the present embodiment does not have a separate form of the cooling plate 125 used in the first and second embodiments. The flow path 502 is disposed between the heat transfer bars 124. The diameter and length of the flow path can be determined according to the heat generation amount of the coil or the required thermal resistance value. The flow path 502 can be disposed in the vicinity of the heat transfer bar 124, thereby improving the cooling efficiency. Further, in this embodiment, a plurality of flow paths 502 exist, and the flow paths are arranged in a parallel configuration. By shortening the lengths of the respective flow paths in the parallel construction, the pressure loss can be reduced, and the lowering of the cooling ability due to the temperature rise of the refrigerant can be suppressed. The diameter of the heat transfer bar 124 of this embodiment is configured such that the air layer 503, which is referred to as the gap between the reference base 501 and the heat transfer bar 204, is about several micrometers to several millimeters.

Next, the effect of this embodiment will be explained. The variable mirror device 500 further conveys the heat generated in the coil 105 to the reference base 501 via the heat transfer bar 124 and the air layer 503, Can be recovered. Since the reference base 501 has a thickness thicker than that of the cooling plate 125 of the first and second embodiments, the present embodiment is different from the first and second embodiments in that the reference base 501 is provided with the heat transfer bar 124 ), Thereby improving heat transfer efficiency. In addition, the heat transfer bar 124 is thermally expanded from the end coupled to the coil 105 as a starting point, so that deformation of the reference base 501 can be suppressed without being subjected to a large force.

In this embodiment, since there is no separate form of the cooling plate 125, the variable mirror device can be miniaturized as compared with the first and second embodiments. Also, the assembly is easy due to the simple structure. The temperature of the reference base 501 substantially becomes the temperature of the refrigerant and the temperature of the reference base 501 is maintained even if the temperature in the environment of the variable mirror device 500 changes. The temperature fluctuation of the substrate W is reduced. In this embodiment, even if the gap between the heat transfer bar 124 and the reference base 501 is the air layer 503, an elastic body similar to that of the second embodiment can be inserted. As described above, in the variable mirror device 500 of this embodiment, the flow passage 502 is formed in the reference base 501 and the heat transfer bar 124 and the cooling plate 125 are disposed through the air layer 503 The deformation of the reference base 501 due to thermal expansion of the heat transfer bar 124 can be reduced.

(Fourth Embodiment)

Hereinafter, description of another embodiment will be provided with reference to Fig. In the following description, elements identical or equivalent to those of the above-described embodiment will be given the same reference numerals as those of the previous embodiment, and the description thereof will be simplified or omitted. 5 is a schematic cross-sectional view of a variable mirror device 600 according to the fourth embodiment. The difference between the variable mirror device 600 of the present embodiment and the variable mirror device 500 of the third embodiment is that the variable mirror device 600 of the present embodiment does not include the heat transfer bar 124 and does not include the reference base 501, And a flow passage 602, which is referred to as a cooling unit disposed in each of the coils 105, is disposed between the coils 105. The diameter and length of the flow path 602 can be determined according to the heat generation amount of the coil 105 and the required thermal resistance value. The flow path 602 may be disposed in the vicinity of the coil 105 to improve the cooling efficiency. In this embodiment, a plurality of flow paths 602 exist and the flow paths are arranged in a parallel configuration like the flow paths 502 of the third embodiment. By shortening the lengths of the respective flow paths 602 in the parallel configuration, the pressure loss can be reduced and the lowering of the cooling ability due to the temperature rise of the refrigerant can be suppressed. In this embodiment, the holder 122, which is referred to as a heat conduction unit, is a material with high thermal conductivity.

Next, a description of the effect of this embodiment will be provided. The variable mirror device 600 can transfer the heat generated in the coil 105 to the reference base 501 via the holder 122 and recover the heat by the flow path 602. In addition, since the variable mirror device 600 of the present embodiment does not have a heat transfer bar, the reference base 501 can suppress deformation of the reference base 501 without receiving large force. Further, in the present embodiment, the holder 122 may be extended away from the coil 105, and the contact area between the holder 122 and the reference base 501 may be increased. In this configuration, heat transfer efficiency can be further improved.

Since the present embodiment does not have a separate form of the cooling plate 125, the size of the constitution can be reduced as compared with the first and second embodiments. Also, the assembly is easy due to the simple structure. Since the flow passage 602 is formed in the reference base 501, the temperature of the reference base 501 substantially becomes the temperature of the refrigerant. Therefore, even if the temperature of the environment of the variable mirror device 600 changes, the change in the temperature of the reference base 501 is reduced. As described above, the variable mirror device 600 of this embodiment can transfer the heat generated in the coil 105 to the reference base 501 via the holder 122 and recover the heat in the flow path 602 Thus, no heat transfer bar is required and therefore, deformation of the reference base 501 due to thermal expansion of the heat transfer bar can be suppressed.

(Embodiment of Exposure Apparatus)

6 is a schematic view showing a configuration of an exposure apparatus to which an optical device according to one of the first to fourth embodiments is applied. The exposure apparatus 50 includes an illumination optical system IL, a projection optical system PO, a movable mask stage MS holding a mask 55, a movable substrate stage WS holding a substrate 56, And a control unit 51 for controlling the exposure processing of the substrate 56. [ The Z-axis is set parallel to the optical axis of the light emitted from the illumination optical system IL, and the X-axis and the Y-axis are set perpendicular to each other in a plane perpendicular to the Z-axis. The illumination optical system IL includes a light source and a slit (both not shown). The light emitted from the light source included in the illumination optical system IL can be formed on the mask 55 by using, for example, a slit included in the illumination optical system IL, an exposure area of a long circular arc shape in the XY directions. The mask 55 and the substrate 56 are held by the mask stage MS and the substrate stage WS respectively and are held at substantially the optical conjugate position (the object plane of the projection optical system PO The position of the image plane). The projection optical system PO has a predetermined projection magnification and projects a pattern formed on the mask 55 onto the substrate 56. [ The mask stage MS and the substrate stage WS are moved in the direction parallel to the object plane of the projection optical system PO (for example, in the XY direction) with a speed ratio corresponding to the projection magnification of the projection optical system PO do. As a result, the pattern formed on the mask 55 can be transferred to the substrate 56.

The projection optical system PO is configured to include a trapezoidal mirror 52, a concave mirror 53, and a convex mirror 54. The optical path of the exposure light emitted from the illumination optical system IL and transmitted through the mask 55 is bent by the first surface 52a of the trapezoidal mirror 52. [ Then, the exposure light is incident on the first surface 53a of the concave mirror 53. The exposure light reflected by the reflective surface 53a of the concave mirror 53 is reflected by the convex mirror 54 and is incident on the reflective surface 53a of the concave mirror 53. [ The optical path of the exposure light reflected by the reflecting surface 53a of the concave mirror 53 is bent by the second surface 52b of the trapezoidal mirror 52 and the exposure light is imaged on the substrate. In the projection optical system PO configured in this manner, the surface of the convex mirror 54 is set as an optical pupil.

In the above-described configuration of the exposure apparatus 50, the optical device described in one of the first to fourth embodiments can be used in the projection optical system as an apparatus for deforming the reflecting surface of the concave mirror 53, for example. The reflective surface 53a of the concave mirror 53 can be deformed and the optical aberration in the projection optical system PO can be corrected by using the optical device of any one of the first to fourth embodiments in the exposure apparatus 50. [ Can be corrected accurately.

In the above embodiment, an example applied to the exposure apparatus has been described, but an apparatus to which the optical device according to any one of the above-described embodiments is applicable includes, for example, a lithographic apparatus that forms a resist latent image pattern on a substrate. The optical device can also be applied to a laser processing apparatus, an eye fundus photographing apparatus, a telescope, a projection optical system, and the like.

(Embodiment of article manufacturing method)

The article manufacturing method according to the embodiment of the present invention is preferable for manufacturing, for example, microdevices such as semiconductor devices and articles such as elements having a fine structure. The article manufacturing method includes a step of forming a latent image pattern on an object (exposure step) using the above-described exposure apparatus, and a step of developing an object on which the latent image pattern is formed in the previous step. In addition, the article manufacturing method may include other well-known processes (oxidation, deposition, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of an article as compared with the conventional device manufacturing method.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. The scope of the following claims should be accorded the broadest interpretation so as to encompass all such modifications and equivalent structural examples and functional examples.

This application claims priority from Japanese Patent Application No. 2016-013620, filed January 27, 2016, and Japanese Patent Application No. 2016-231794, filed November 29, 2016, the entirety of which is incorporated herein by reference. I argue.

Claims (20)

An optical device for deforming a reflecting surface of an optical element,
An actuator having a magnet mounted on an opposite surface of the reflecting surface, and a coil disposed at a position facing the magnet,
A base plate for holding the coil,
A heat conduction unit connected to the coil held on the base plate,
And a cooling unit for recovering heat from the heat conduction unit,
Wherein the heat conduction unit has a free end at an end of the heat conduction unit facing an end connected to the coil. The method according to claim 1,
Wherein the heat conduction unit and the cooling unit are disposed apart from each other. The method according to claim 1,
Wherein the cooling unit is a flow path included in a plate arranged so as to be spaced apart from the heat conduction unit at a position spaced apart from an end of the heat conduction unit in which refrigerant flows and is connected to the coil. The method according to claim 1,
Wherein the cooling unit is a flow path through which the refrigerant flows and is contained in the base plate. The method according to claim 1,
And an elastic body having thermal conductivity between the heat conduction unit and the cooling unit. 6. The method of claim 5,
Wherein the elastic member has a Young's modulus smaller than that of the heat conduction unit. 6. The method of claim 5,
Wherein the elastic body is a resin. 6. The method of claim 5,
Wherein the elastic body is rubber. The method of claim 3,
Wherein the plurality of flow paths exist and are arranged in a parallel configuration. 5. The method of claim 4,
Wherein the plurality of flow paths exist and are arranged in a parallel configuration. An optical device for deforming a reflecting surface of an optical element,
An actuator having a magnet mounted on an opposite surface of the reflecting surface, and a coil disposed at a position facing the magnet,
A base plate for holding the coil, and
And a cooling unit provided on the base plate for recovering heat from the coil. 12. The method of claim 11,
Wherein the cooling unit is a flow path through which the refrigerant flows and is contained in the base plate. 12. The method of claim 11,
And a heat conduction unit between the cooling unit and the coil,
Wherein the heat conduction unit conveys heat from the coil to the cooling unit. 12. The method of claim 11,
Wherein the cooling unit is disposed in proximity to the coil within the base plate. The method according to claim 1,
Further comprising a measurement unit which is disposed on the base plate and acquires shape information of the optical element by measuring a distance between the base plate and the opposing surface of the reflection surface,
Wherein the number of the measurement units is smaller than the number of the actuators. 12. The method of claim 11,
Further comprising a measurement unit which is disposed on the base plate and acquires shape information of the optical element by measuring a distance between the base plate and the opposing surface of the reflection surface,
Wherein the number of the measurement units is smaller than the number of the actuators. 17. A projection optical system comprising an optical device according to any one of claims 1 to 16. An illumination optical system for illuminating a mask, and a projection optical system according to claim 17 for projecting a pattern formed on the mask onto a substrate. A method of manufacturing an article,
Exposing the substrate to an exposure apparatus, the exposure apparatus comprising: an exposure step having an illumination optical system for illuminating a mask, and a projection optical system for projecting a pattern formed on the mask onto the substrate;
And developing the exposed substrate,
Wherein the projection optical system includes an optical device for deforming a reflecting surface of the optical element,
An actuator having a magnet mounted on an opposite surface of the reflecting surface, and a coil disposed at a position facing the magnet,
A base plate for holding the coil,
A heat conduction unit connected to the coil held on the base plate,
And a cooling unit for recovering heat from the heat conduction unit,
Wherein the heat conduction unit has a free end at an end of the heat conduction unit opposite the end connected to the coil. A method of manufacturing an article,
Exposing the substrate to an exposure apparatus, the exposure apparatus comprising: an exposure step having an illumination optical system for illuminating a mask, and a projection optical system for projecting a pattern formed on the mask onto the substrate;
And developing the exposed substrate,
Wherein the projection optical system includes an optical device for deforming a reflecting surface of the optical element,
An actuator having a magnet mounted on an opposite surface of the reflecting surface, and a coil disposed at a position facing the magnet,
A base plate for holding the coil, and
And a cooling unit included in the base plate and recovering heat from the coil.

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