TW201802607A - Optical device, projection optical system, exposure apparatus, and article manufacturing method - Google Patents

Abstract

There is provided a deformable mirror device for deforming a reflecting surface of a mirror, the device comprising: a voice coil motor with a magnet mounted on a surface opposed to the reflecting surface and a coil disposed at a position facing the magnet; a reference base which holds the coil; a heat transfer bar connected to the coil held in the reference base; and a flow path which collects heat from the heat transfer bar. The heat transfer bar has a free end at an end portion of the heat conducting unit opposed to an end portion connected to the coil.

Description

Optical device, projection optical system, exposure device, and article manufacturing method

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

It is known to have an optical device in which aberrations in the optical system can be corrected by using a mirror having a deformable shape on the reflecting surface. Such a mirror is disposed on the optical path of the optical system, and in order to adjust the shape of the mirror, there has been proposed a method using a voice coil motor in which the voice coil motor is bonded to the back of the mirror and the coil is It is driven in a state where the magnet is slightly spaced apart from the position of the counter magnet.

This method makes it necessary for the coil and the magnet to be placed adjacent to each other. Then, the heat generated by the coil during driving is transferred from the coil to the magnet via the air layer and from the magnet to the mirror. Therefore, it is difficult to deform the mirror into a desired shape. "VLT Deformable Secondary Mirror: integration and electromechanical tests" by R. Biasi et al. A configuration is disclosed in "Property", Proc. SPIE 8447, Adaptive Optics Systems III, 84472G (September 13, 2012), in which a coil is disposed at an end of a copper rod joined to a cooling plate, and then, The heat generated by the coil is collected into the copper rod to reduce the temperature rise of the mirror.

In the configuration disclosed by R. Biasi et al., the coil is only held by a copper rod that extends in the normal direction of the mirror. A distance sensor is disposed 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. In the case of the configuration disclosed by R. Biasi et al., it is necessary to provide a distance sensor in each voice coil motor, and then, if the mirror has a large diameter, 100 or more distance sensors are required. . Therefore, this may result in an increase in cost. Therefore, there is a need for a configuration that reduces the number of distance sensors. If the individual distance sensors are removed from the individual voice coil motors, the feed forward mode is required to produce the desired force and control the shape of the mirror. However, in the case of the structure disclosed by R. Biasi et al., the thermal expansion of the copper rod changes the distance between the coil and the magnet, and changes the thrust constant so that the voice coil motor cannot generate the target force in the feedforward manner. . In order to reduce the change in the distance between the coil and the magnet, it is necessary to fix the coil on the reference base. In this case, the reference base is configured to be coupled to the cooling plate via a coil and a copper rod. Therefore, if the copper rod and the cooling plate are thermally deformed, the reference base is also deformed by the force received from the deformed copper rod and the cooling plate, and the position of the coil is shifted, which will change the thrust constant. Therefore, in the configuration in which the coil of the voice coil motor is fixed to the reference plate, there is a need for a configuration that can be used in the coil It is sufficient to be cooled while reducing the effects due to the thermal deformation provided to the reference plate.

The present invention provides, for example, an optical device that is advantageous in terms of performance improvement of an optical system.

An optical device according to the present invention is an optical device for deforming a reflecting surface of an optical element, the optical device comprising: an actuator having a magnet mounted on a face relative to the reflecting surface, and being disposed a coil at a position facing the magnet; a bottom plate holding the coil; a heat transfer unit connected to the coil held in the bottom plate; and a cooling unit collecting heat from the heat transfer unit, wherein the heat transfer unit is connected to The end of the coil has a free end at the end of the opposite heat conducting unit.

Further features of the present invention will become apparent from the following description of exemplary embodiments.

50‧‧‧Exposure equipment

51‧‧‧Control unit

52‧‧‧ ladder mirror

52a‧‧‧ first side

52b‧‧‧ second side

53‧‧‧ concave mirror

53a‧‧‧ first side

54‧‧‧ convex mirror

55‧‧‧Photomask

56‧‧‧Substrate

100‧‧‧ deformable mirror device

101‧‧‧Mirror

102‧‧‧Mirror Fixing Department

103‧‧‧ voice coil motor

104‧‧‧ Magnet

105‧‧‧ coil

106‧‧‧Component

121‧‧‧Datum base

122‧‧‧keeper

123‧‧‧ Displacement Sensor

124‧‧‧heat transfer rod

125‧‧‧Cooling plate

126‧‧‧flow path

127‧‧‧ screws

300‧‧‧ deformable mirror device

301‧‧ Air layer

400‧‧‧ deformable mirror device

401‧‧‧ Elastomers

402‧‧‧ hole

500‧‧‧ deformable mirror device

501‧‧‧ benchmark base

502‧‧‧flow path

503‧‧‧ air layer

600‧‧‧ deformable mirror device

602‧‧‧Flow

IL‧‧‧Lighting Optical System

MS‧‧‧mask table

PO‧‧‧Projection Optical System

WS‧‧‧ substrate table

1A to 1C are schematic views showing a basic configuration of an optical device.

Fig. 2 is a schematic view showing the configuration of an optical device according to the first embodiment.

Fig. 3 is a schematic view showing the configuration of an optical device according to a second embodiment.

4 is a view showing the construction of an optical device according to a third embodiment Schematic diagram of the creation.

Fig. 5 is a schematic view showing the configuration of an optical device according to a fourth embodiment.

Fig. 6 is a schematic view showing the configuration of an exposure apparatus to which an optical device is applied.

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment)

FIG. 1A is a cross-sectional view showing an exemplary basic configuration of a deformable mirror device 100. The deformable mirror device 100, called an optical device, is configured to allow the shape of the reflecting surface of the mirror 101 as an optical element to be changed. In FIGS. 1A to 5, the X-axis system is set to be perpendicular to the reflection surface of the mirror 101 before deformation, and the Y-axis and the Z-axis are set to be perpendicular to the X-axis (ie, before deformation). The plane in which the reflecting surfaces of the mirror 101 are parallel is perpendicular to each other. The mirror 101 is a thin mirror, and the center of the back surface of the reflecting surface (hereinafter referred to as "mirror back") is fixed to the reference base 121 by the mirror fixing portion 102. A coating suitable for the wavelength of the light to be used is applied to the reflective surface of the mirror 101. In order to suppress the occurrence of a shape error due to heat distortion, the low thermal expansion optical glass is set as the material of the mirror 101 in the present embodiment. Further, in the present embodiment, although the size of the mirror is not particularly limited, the mirror is usually for about 0.1 to 2 meters. The outer diameter has a thickness of about several millimeters to several centimeters. For example, the mirror 101 has an outer diameter of about 1 meter and a thickness of about 1 centimeter.

A reference base 121 called a bottom plate holds a mirror 101, a displacement sensor 123, and a holder 122 for fixing the actuator. Further, the reference base 121 holds the coil 105 via the holder 122. The mirror 101 is held in the reference base 121 via the mirror fixing portion 102. The displacement sensor 123 held in the reference base 121 measures the surface shape of the mirror 101. In order to reduce the decrease in measurement accuracy caused by thermal deformation caused by heat from an actuator or the like, in the present embodiment, the material of the reference base 121 is set as a low thermal expansion material.

The mirror fixing portion 102 has a cylindrical shape and fixes the mirror 101 and the reference base 121. In the present embodiment, the mirror fixing portion 102 is disposed such that the center line of the mirror 101 and the center line of the mirror fixing portion 102 match. However, the present embodiment is not limited to such a configuration, and therefore, the position, shape, and number of the mirror fixing portions 102 can be changed if it is within the scope of the present document. The material of the mirror fixing portion 102 preferably has low thermal expansion to reduce the influence of thermal deformation, and in the present embodiment, the same low 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 such that the mirror 101 is deformed into a target shape, however, since the mirror fixing portion 102 fixes the mirror 101 so as not to be displaced, the mirror 101 does not translate in the X direction nor around the X direction. The vertical axis rotates. For example, when the voice coil motor 103 is driven, the total force generated by the voice coil motor 103 is not necessarily zero. However, a moment that cancels the torque of the voice coil motor 103 is generated at the mirror fixing portion 102, and thus the mirror 101 does not rotate. As a result, the posture of the mirror 101 can be maintained within the required accuracy range, and thus the posture of the mirror 101 is not required to be controlled.

The voice coil motor 103 is an actuator unit composed of a magnet 104 and a coil 105. FIG. 1B is an example showing the arrangement of the magnets 104 in the back surface of the mirror according to the present embodiment. A magnet 104 called a movable unit is radially placed on a face opposite to the reflecting surface of the mirror 101, and a coil 105 called a fixed unit is held in the reference base 121 via the holder 122, so that the coil 105 is slightly spaced from the magnet 104. The number and setting of the voice coil motor 103 can be determined according to 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 intersecting the magnet and the coil by applying a current to the coil 105. Further, the voice coil motor 103 has a thrust and a driving amount capable of deforming the reflecting surface of the mirror 101 into a desired shape. For example, a crucible having a high magnetic flux density can be used as the magnet 104. The thrust decreases as the gap between the coil 105 and the magnet 104 increases, and therefore it is necessary to bring the coil 105 close to the magnet 104, for example, from about 0.1 mm to several millimeters from the end face of the magnet 104.

A pack 106 is disposed between the magnet 104 and the mirror 101, and a portion between the adhesive fixing assembly 106 and the magnet 104, and a portion between the assembly 106 and the mirror 101. The assembly 106 is disposed between the mirror 101 and the magnet 104 to reduce the effect of thermal deformation of the magnet 104 on the mirror 101. The material of assembly 106 is the same low thermal expansion material as 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, referred to as measurement units, are disposed at positions on the back surface of the mirror on the reference base 121. The shape information of the mirror is obtained by setting the reference base 121 as a reference and measuring the distance from the reference base 121 to the back of the mirror. The displacement sensor 123 in FIG. 1B is radially disposed, however, the setting and number of the displacement sensors 123 can be determined according to the target shape of the mirror 101 and the required accuracy. In the present embodiment, an exemplary configuration in which the number of the displacement sensors 123 is made smaller than the number of actuator units (i.e., the number of the coils 105) is shown from the viewpoint of cost reduction, however, this embodiment does not Limited to this.

The heat transfer rod 124 is a heat conductor (heat transfer unit) that is coupled to couple the coil 105 and the cooling plate 125 and transfer the heat of the coil to the cooling plate 125. The heat transfer rod 124 is fixed to the cooling plate 125 by a heat conductive grease by a screw 127. The heat transfer rod 124 is, for example, made of copper or aluminum having a high thermal conductivity, or is a unit such as a heat transfer tube having a high thermal conductivity. The length and thickness of the heat transfer rod 124 are determined based on the amount of heating of the coil and the desired thermal resistance value. Further, the coil 105 and the heat transfer rod 124 are joined via an adhesive.

A cooling plate (plate) 125 is provided spaced apart from an end of the heat transfer rod 124 connected to the coil 105, and a flow path 126 called a cooling unit is formed in the cooling plate 125. The coolant is controlled to flow in the flow path 126 from a temperature supplied from a temperature controller (not shown). FIG. 1C is a view showing an example of the heat transfer rod 124 and the flow path 126 joined to the cooling plate 125. The heat of the coil 105 collected by the heat transfer rod 124 is collected into the flow path 126 formed in the cooling plate 125. The cooling plate 125 can be made of copper or Made of aluminum with high thermal conductivity. The shape of the flow path 126 and the flow rate of the coolant can be determined according to the thermal resistance value required to collect the heat of the coil, the pressure loss of the coolant, and the like. In the present embodiment, the number of flow paths 126 is plural, and a plurality of flow paths are arranged in a parallel configuration to reduce pressure loss. Further, the cooling plate 125 may be configured to be separated in consideration of the assembly characteristics of the cooling plates.

The voice coil motor 103 has a structure for generating a thrust by applying a current to the coil 105, and therefore, the coil 105 generates heat upon driving. The heat of the coil is transferred from the coil 105 to the magnet 104 via the air layer and from the magnet 104 to the mirror 101 via the assembly 106. And then, the mirror 101 undergoes thermal deformation, and thus the mirror 101 cannot be deformed and controlled to a desired shape. Further, if 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 changes. Further, if the reference base 121 is thermally deformed, the position of the displacement sensor 123 is shifted, and thus the shape of the mirror 101 cannot be accurately measured. Therefore, it is necessary to collect the heat of the coil 105 through the heat transfer rod 124 by the cooling plate 125, and to reduce the thermal deformation of the reference base 121 and the mirror 101.

However, the heat transfer rod 124 thermally expands due to the collection of heat from the coil 105. In particular, since the heat transfer rod 124 is usually made of copper or aluminum as a material and has a large linear expansion coefficient and a large Young's modulus, the heat transfer rod 124 generates a large thermal stress. Since both ends of the heat transfer rod 124 are fixed to the cooling plate 125 and the reference base 121, respectively, the heat transfer rod 124 applies a force to the reference base 121 and the cooling plate 125 in accordance with thermal expansion. Especially, such as The force is applied to the reference base 121 via the holder 122, and the reference base 121 is deformed, and the mirror 101 cannot be deformed and controlled to a desired shape.

Therefore, the present embodiment provides a configuration in which the deformation of the reference base 121 caused by the thermal expansion of the heat transfer rod 124 is reduced. Hereinafter, the cooling configuration of the coil 105 in the present embodiment will be specifically described with reference to FIG. FIG. 2 is a schematic cross-sectional view of a deformable mirror device 300 in accordance with a first embodiment. The thickness of the cooling plate 125 is several millimeters to several tens of millimeters. The deformable mirror device 300 of the present embodiment has a heat transfer rod 124 and a cooling plate 125 which are disposed apart from each other, and has an air layer 301 disposed between the heat transfer rod 124 and the cooling plate 125. The distance between the heat transfer rod 124 and the cooling plate 125 is, for example, several micrometers to several millimeters. The heat transfer efficiency between the heat transfer rod 124 and the cooling plate 125 is proportional to the facing area between the heat transfer rod 124 and the cooling plate 125 that is engaged to the cooling plate 125. Further, the heat transfer efficiency between the heat transfer rod 124 and the cooling plate 125 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 fitting portion can be determined according to the heating amount of the coil and the allowable temperature rise value 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 rod 124. The gas constituting the air layer 301 is not limited to air, and may be a single component gas.

The heat transfer rod 124 has a free end on the side of the cooling plate 125, and thus is freely thermally expanded from the end coupled to the coil 105 as a starting point. Therefore, the heat transfer rod 124 can reduce the amount of deformation of the reference base 121 without applying a large force to the reference base 121. Therefore, coil 105 and magnetic The change in the distance between the bodies 104 is reduced, and the amount of change in the thrust constant of the voice coil motor 103 also becomes acceptable for the present embodiment. Therefore, by using the present embodiment, the voice coil motor 103 can be used under the feedforward control to generate a desired force and control the shape of the mirror.

Further, since the heat transfer rod 124 and the cooling plate 125 are spaced apart, it is possible to prevent the vibration of the cooling plate 125 from being transmitted to the reference base 121 via the heat transfer rod 124. Further, in the present embodiment, the assembly can be easily performed without using the screws 127 or the like to join the heat transfer rod 124 to the cooling plate 125. For example, after the coil 105 and the heat transfer rod 124 are assembled in the reference base 121, the cooling plate 125 can also be assembled to align with the heat transfer rod 124. At this time, if the cooling plate 125 is configured to be separated, it will further facilitate assembly. In addition, after the cooling plate 125 is aligned with the reference base 121, the holder 122 can also be fixed to the reference base 121 by inserting the heat transfer rod 124 from the cooling plate 125 into the reference base 121 and aligning the heat transfer rod 124 based on the cooling plate 125. . In this case, it is easy to manage the thickness of the air layer 301. The reference base 121 and the cooling plate are fixed by a lens barrel not shown.

As described above, the deformable mirror device 300 in the present embodiment is configured such that although the cooling plate 125 and the heat transfer rod 124 are not directly engaged with each other, they are thermally joined by the air layer 301. Therefore, it is possible to enhance the shape of the optical device by collecting the heat generated by the coil 105 through the heat transfer rod 124 into the cooling plate 125 while reducing the deformation of the reference base 121 caused by the thermal expansion of the heat transfer rod 124. control precision.

(Second embodiment)

Another embodiment will be described with reference to FIG. 3. In the following description, the same or equivalent components as those of the above embodiment will be given the same reference numerals as in the above embodiment, and the description thereof will be omitted or simplified. FIG. 3 is a schematic cross-sectional view of a deformable mirror device 400 in accordance with a second embodiment. The heat transfer rod 124 of the present embodiment has a low-rigidity elastic body 401 having a truncated cone shape near its end. Further, the cooling plate 125 has the same truncated cone shape hole 402 as the elastic body 401 at a position corresponding to the heat transfer rod 124 to allow the elastic body 401 to be fitted into the hole 402. The aperture 402 can be formed smaller than the elastomer 401 such that the elastomer 401 can contact the aperture 402 without any gap.

In the present embodiment, the gap between the heat transfer rod 124 and the cooling plate 125 is filled with the elastic body 401. If a resin, a rubber or a heat transfer sheet is used as the material of the elastic body 401, the thermal conductivity of the elastic body 401 is several tens to several hundreds times larger than the thermal conductivity of air of 0.026 W/mK (23 ° C). Therefore, even if the gap between the heat transfer rod 124 and the cooling plate 125 (the thickness of the elastic body 401) is set equal to or larger than the air layer in the first embodiment, The heat transfer efficiency of the air layer can improve the heat transfer efficiency from the heat transfer rod 124 to the cooling plate 125.

Here, the heat transfer rod 124 thermally expands due to the heat of the coil 105. However, in the present embodiment, since the elastic body 401 is elastically deformed by the thermal expansion of the heat transfer rod 124, the heat transfer rod 124 thermally expands from the end coupled to the coil 105 as a starting point, and is thermally expanded by the heat transfer rod 124. The force received by the reference base 121 is reduced. In other words, The elastic body 401 having a sufficiently low rigidity is used to reduce the deformation of the reference base 121 to an allowable range. The elastic body 401 may have a Young's modulus of 10 GPa or less, and may be made of, for example, a resin, a 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 acceptable, and use the voice coil motor 103 to generate a desired force under the feedforward control, and to control the shape of the mirror.

Further, since the gap between the heat transfer rod 124 and the cooling plate 125 can be made larger than the gap between the heat transfer rod 124 and the cooling plate 125 in the case of the air layer, if the deformable mirror device 400 is assembled, heat transfer is performed. The rod 124 and the cooling plate 125 are easily aligned. In other words, even if the center of the heat transfer rod 124 and the center of the hole 402 of the cooling plate 125 are displaced, the elastic body 401 is elastically deformed, and thus the elastic body 401 and the cooling plate 125 can be in close contact with each other. As described above, by inserting the elastic body 401 for joining the heat transfer rod 124 to the cooling plate 125, the deformable mirror device 400 according to the present embodiment can improve the heat transfer efficiency from the heat transfer rod 124 to the cooling plate 125. Further, by inserting the elastic body 401 into the gap between the heat transfer rod 124 and the cooling plate 125, deformation of the reference base 121 due to thermal expansion of the heat transfer rod 124 can be reduced and the shape control accuracy of the optical device can be improved.

(Third embodiment)

Hereinafter, another embodiment will be described with reference to FIG. 4. In the following description, the same or equivalent components as those of the above-described embodiments are given the same reference numerals as in the previous embodiments, and are omitted or simplified. Its description. FIG. 4 is a schematic cross-sectional view of a deformable mirror device 500 in accordance with a third embodiment. A flow path 502 called a cooling unit is formed in the reference base 501 of the present embodiment. Therefore, the deformable mirror device 500 according to the present embodiment does not have the cooling plate 125 in the separated form used in the first embodiment and the second embodiment. The flow path 502 is disposed between the heat transfer rods 124. The diameter and length of the flow path can be determined according to the amount of heating of the coil or the required thermal resistance value. The flow path 502 can be disposed in the vicinity of the heat transfer rod 124 to improve the cooling efficiency. Further, in the present embodiment, there are a plurality of flow paths 502, and the flow paths are arranged in a parallel configuration. By shortening the length of each flow path of the parallel structure, the pressure loss can be reduced, and the decrease in the cooling ability due to the temperature rise of the coolant can be suppressed. The diameter of the heat transfer rod 124 in this embodiment is configured such that the air layer 503 called the gap between the reference base 501 and the heat transfer rod 124 is about several micrometers to several millimeters.

Next, a description will be given of the effect of the present embodiment. The deformable mirror device 500 can transfer heat generated in the coil 105 to the heat transfer rod 124, further to the reference base 501 via the air layer 503, and collect heat in the flow path 502. Since the reference base 501 has a thicker thickness than the thickness of the cooling plate 125 in the first embodiment and the second embodiment, the present embodiment has the reference base 501 facing the transmission with respect to the first embodiment and the second embodiment. The larger area of the hot rod 124 enhances heat transfer efficiency. Further, the heat transfer rod 124 thermally expands from the end coupled to the coil 105 as a starting point, and thus deformation of the reference base 501 can be suppressed without receiving a large force.

In this embodiment, there is no separate form of cooling The plate 125, the deformable mirror device can be made smaller than the first embodiment and the second embodiment. In addition, its assembly is facilitated by the simplified construction. Since the flow path 502 is formed in the reference base 501, the temperature of the reference base 501 substantially becomes the temperature of the coolant, and even if the ambient temperature of the deformable mirror device 500 changes, the temperature change of the reference base 501 is reduced. In the present embodiment, although the gap between the heat transfer rod 124 and the reference base 501 is the air layer 503, an elastic body similar to that in the second embodiment can be inserted. As described above, since the flow path 502 is formed in the reference base 501 in the deformable mirror device 500 of the present embodiment, and the heat transfer rod 124 and the cooling plate 125 are disposed with the air layer 503 therebetween, the transmission can be reduced. Deformation of the reference base 501 caused by thermal expansion of the hot rod 124.

(Fourth embodiment)

Hereinafter, a description will be given of another embodiment with reference to FIG. 5. In the following description, the same or equivalent components as those of the above embodiment will be given the same reference numerals as in the previous embodiment, and the description thereof will be omitted or simplified. FIG. 5 is a schematic cross-sectional view of a deformable mirror device 600 in accordance with a fourth embodiment. The difference between the deformable mirror device 600 in the present embodiment and the deformable mirror device 500 in the third embodiment is that the deformable mirror device 600 in the present embodiment does not include the heat transfer rod 124 and is set A flow path 602 called a cooling unit in the reference base 501 is disposed between the respective coils 105. The diameter and length of the flow path 602 can be determined according to the amount of heating of the coil 105 and the required thermal resistance value. Flow path 602 can be placed close to coil 105 to increase cooling efficiency. In addition, in this embodiment In the flow path 502 in the third embodiment, there are a plurality of flow paths 602, and the flow paths are arranged in a parallel configuration. By shortening the length of each flow path 602 of the parallel structure, the pressure loss can be reduced, and the decrease in the cooling ability due to the temperature rise of the coolant can be suppressed. The holder 122, which is referred to as a heat conduction unit in this embodiment, is made of a material having high thermal conductivity.

Next, a description will be given of the effect of the present embodiment. The deformable mirror device 600 can transfer heat generated in the coil 105 to the reference base 501 via the holder 122, and collect heat by the flow path 602. Further, since the deformable mirror device 600 in the present embodiment does not have the heat transfer rod, the reference base 501 can suppress the deformation of the reference base 501 without receiving a large force. Further, in the present embodiment, the holder 122 may extend spaced apart from the coil 105 and increase the contact area of the holder 122 and the reference base 501. In this configuration, the heat transfer efficiency can be further improved.

Since this configuration does not have the cooling plate 125 in a separate form, the present embodiment can reduce the size of the configuration with respect to the first embodiment and the second embodiment. In addition, its assembly is facilitated by the simplified construction. Since the flow path 602 is formed in the reference base 501, the temperature of the reference base 501 substantially becomes the temperature of the coolant. And, therefore, even if the ambient temperature of the deformable mirror device 600 changes, the temperature change of the reference base 501 is reduced. As described above, since the deformable mirror device 600 in the present embodiment can transfer the heat generated in the coil 105 to the reference base 501 via the holder 122 and collect heat in the flow path 602, the heat transfer rod is unnecessary. And, therefore, deformation of the reference base 501 caused by thermal expansion of the heat transfer rod can be suppressed.

(Example of exposure device)

Fig. 6 is a schematic view showing the configuration of an exposure apparatus to which an optical apparatus according to an embodiment 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 table MS that holds the mask 55, a movable substrate stage WS that holds the substrate 56, and a control unit 51 that controls the exposure processing of the substrate 56. The Z axis is set to be 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 to be 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). Light emitted from a light source included in the illumination optical system IL may be formed by a slit included in the illumination optical system IL, for example, a long curved exposure region in the XY direction is formed on the photomask 55. The mask 55 and the substrate 56 are respectively held by the mask stage MS and the substrate stage WS, and are disposed at substantially optically conjugated positions of the projection optical system PO (positions of the object surface and the image plane of the projection optical system PO) At the office. The projection optical system PO has a predetermined projection magnification, and the pattern formed on the photomask 55 is projected onto the substrate 56. Next, the mask stage MS and the substrate stage WS are scanned in a direction parallel to the object plane of the projection optical system PO (for example, the XY direction) at a speed ratio corresponding to the projection magnification of the projection optical system PO. As a result, the pattern formed on the photomask 55 can be transferred onto 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 first surface 52a of the trapezoidal mirror 52 causes the light path of the exposure light emitted from the illumination optical system IL and transmitted through the mask 55 Bend. Then, the exposure light is incident on the first surface 53a of the concave mirror 53. The exposure light reflected by the reflecting surface 53a of the concave mirror 53 is reflected by the convex mirror 54 and incident on the reflecting 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 constructed in this manner, the surface of the convex mirror 54 is set as a pupil.

In the configuration of the exposure apparatus 50 described above, it is possible to use in the projection optical system, for example, the optical apparatus described in one of the first to fourth embodiments as the reflection surface of the concave mirror 53. Deformed device. By using the optical device in any one of the first to fourth embodiments in the exposure device 50, the reflecting surface 53a of the concave mirror 53 can be deformed and the optical image in the projection optical system PO can be accurately corrected. difference.

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

(Example of article manufacturing method)

An article manufacturing method according to an embodiment of the present invention is preferably used for manufacturing, for example, a micro device such as a semiconductor device or the like, Items such as components with micro structures. The article manufacturing method may include a step of forming a latent image pattern on the object using the aforementioned exposure apparatus (for example, an exposure process); and a step of developing an object on which the latent image pattern has been formed in the previous step. In addition, the article manufacturing method can include other known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, cutting, bonding, encapsulation, etc.). The article manufacturing method of the present embodiment has an advantage in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional device manufacturing method.

While the invention has been described with reference to the preferred embodiments thereof, it is understood that the invention is not limited to the illustrative embodiments disclosed. The scope of the following claims is to be accorded the breadth of

The present application claims priority from Japanese Patent Application No. 2016-013620, filed on Jan. 27,,,,,,,,,,,,, The citation is incorporated.

101‧‧‧Mirror

102‧‧‧Mirror Fixing Department

103‧‧‧ voice coil motor

104‧‧‧ Magnet

105‧‧‧ coil

106‧‧‧Component

121‧‧‧Datum base

122‧‧‧keeper

123‧‧‧ Displacement Sensor

124‧‧‧heat transfer rod

125‧‧‧Cooling plate

300‧‧‧ deformable mirror device

301‧‧ Air layer

Claims (19)

An optical device for deforming a reflective surface of an optical element, the optical device comprising: an actuator having a magnet mounted on a face relative to the reflective surface, and a position disposed facing the magnet a coil at the bottom; holding the coil; a heat conducting unit connected to the coil held in the bottom plate; and a cooling unit collecting heat from the heat conducting unit, wherein the heat conducting unit is connected to the The end of the coil opposite the end of the heat conducting unit has a free end. The optical device of claim 1, wherein the heat transfer unit and the cooling unit are disposed apart from each other. The optical device of claim 1, wherein the cooling unit is a flow path for flowing a coolant, and the flow path is included in a plate at the end of the heat conduction unit connected to the coil The spaced apart locations are spaced apart from the thermally conductive unit. The optical device of claim 1, wherein the cooling unit is a flow path through which the coolant flows, and the flow path is included in the bottom plate. The optical device of claim 1, further comprising an elastomer having thermal conductivity between the heat transfer unit and the cooling unit. An optical device as claimed in claim 5, wherein the bomb The trait has a Young's modulus of 10 GPa or less. The optical device of claim 5, wherein the elastomer is a resin. The optical device of claim 5, wherein the elastomer is rubber. An optical device according to claim 3, wherein a plurality of the flow paths are present, and the plurality of flow paths are arranged in a parallel configuration. The optical device of claim 4, wherein a plurality of the flow paths are present, and the plurality of flow paths are disposed in a parallel configuration. An optical device according to claim 1, further comprising a measuring unit disposed in the bottom plate and obtaining the optical element by measuring a distance between the bottom plate and the face relative to the reflecting surface Shape information, wherein the number of measurement units is less than the number of actuators. An optical device for deforming a reflective surface of an optical element, the optical device comprising: an actuator having a magnet mounted on a face relative to the reflective surface, and a position disposed facing the magnet a coil at the bottom; a bottom plate that holds the coil; and a cooling unit included in the bottom plate and collecting heat from the coil. The optical device of claim 12, wherein the cooling unit is a flow path through which the coolant flows, and the flow path is included in the bottom plate. An optical device according to claim 12, comprising a heat conducting unit between the cooling unit and the coil, wherein the heat conducting unit transfers heat from the coil to the cooling unit. The optical device of claim 12, wherein the cooling unit is disposed adjacent to the coil in the bottom plate. An optical device according to claim 12, further comprising a measuring unit disposed in the bottom plate and obtaining the optical element by measuring a distance between the bottom plate and the face relative to the reflecting surface Shape information, wherein the number of measurement units is less than the number of actuators. A projection optical system comprising the optical device according to any one of claims 1 to 16. An exposure apparatus having an illumination optical system for illuminating a reticle, and a projection optical system according to claim 17, wherein the projection optical system projects a pattern formed on the reticle onto the substrate. An article manufacturing method comprising: exposing a substrate using an exposure apparatus as claimed in claim 18; and developing the exposed substrate.