JP2015065246A - Optical device, optical system, exposure device, and manufacturing method for article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device having advantage in deforming an optical surface of an optical element.SOLUTION: An optical device includes: a plurality of first actuators 4 individually including a magnet 41 and coil 42, either one of which is arranged on a surface on the side opposite to an optical surface 2a of an optical element 2 and the other of which is arranged on a base plate 3, to deform the optical surface; a second actuator 5 for applying force to the surface on the opposite side of the optical surface of the optical element; a detection unit 8 for detecting a value of induced electromotive force generated in each of the plurality of first actuators; and a processing unit 10 for correcting an instruction value for driving each of the plurality of first actuators in a reference state, on the basis of a variation amount of a value of the induced electromotive force obtained by the detection unit detecting the value of the induced electromotive force generated in each of the plurality of first actuators when driving the second actuator by a unit amount.

Description

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

  In astronomical observations using astronomical equipment such as ground telescopes, star image blur due to air fluctuations becomes a problem. Therefore, in such a telescope, a variable mirror with a variable surface (reflecting surface) called a wavefront compensation optical system is used to correct the air fluctuation measured by the wavefront sensor and reduce star image blur. ing.

  In addition, when manufacturing a semiconductor device, in a photolithography process in which a reticle (mask) pattern is transferred onto a substrate, an image of a very fine pattern is formed on the substrate. Become. Even in such a case, like the wavefront compensation optical system described above, the imaging characteristics can be improved by using a variable optical element that deforms the lens or mirror of the optical system of the exposure apparatus.

  In general, the variable optical element controls the shape by deforming the optical element itself by driving a large number of actuators arranged in the optical element. A piezoelectric actuator, a voice coil motor (VCM), a linear motor, a solenoid, or the like is used as the actuator.

  Actuators that use electromagnetic force, such as VCM and linear motor, have a feature that the stator and the mover are not in contact with each other, so that they are not easily affected by deformation or vibration of the structure on the stator side when the optical element is driven. Have. Therefore, an actuator such as a VCM is advantageous from the viewpoint of avoiding thermal deformation and vibration of peripheral components when controlling the shape of the optical element with high accuracy. In addition, since an actuator using an electromagnetic force drives an optical element with a force, it is necessary to measure the force generated by the actuator, but it is not essential to measure the displacement of the actuator. Therefore, in contrast to piezo actuators and ball screws that require measurement of displacement, displacement sensors can be omitted in actuators that use electromagnetic force, which contributes to cost reduction.

  However, in an actuator that uses an electromagnetic force, the magnetic flux density of the magnet changes due to the heat generation of the coil due to energization of the coil and the temperature change of the magnet due to the ambient temperature change. Thus, in an actuator using electromagnetic force, the thrust depends on the temperature of the magnet, and in order to stabilize the thrust, it is necessary to consider the influence of the temperature of the magnet. For example, with respect to the temperature dependence of VCM thrust, a technique has been proposed in which a table representing the relationship between magnet temperature and thrust is prepared in advance, and thrust is corrected according to the magnet temperature (Patent Document 1). reference).

JP-A-9-51700

  In Patent Document 1, in response to a change in thrust due to a change in temperature of the magnet, the temperature of the magnet is measured using a thermometer arranged on the magnet, and the change in thrust is corrected based on the measurement result. However, in the variable optical element, since a large number of magnets are attached to the optical element, disposing a thermometer on these magnets causes a driving error and an increase in cost.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an optical device that is advantageous in deforming the optical surface of an optical element.

  In order to achieve the above object, an optical device according to one aspect of the present invention is an optical device that deforms an optical surface of an optical element, and is either a base plate or one of the optical elements opposite to the optical surface. A plurality of first actuators for deforming the optical surface, and applying a force to the surface opposite to the optical surface of the optical element. A second actuator, a detection unit that detects a value of an induced electromotive force generated in each of the plurality of first actuators, and a case where the plurality of first actuators are in a reference state and a first state changed from the reference state In each case, when the second actuator is driven by a unit amount, the value of the induced electromotive force generated in each of the plurality of first actuators is A command value for driving each of the plurality of first actuators in the reference state is detected based on the amount of change in the value of the induced electromotive force detected in the reference state and the first state. And a processing unit that determines a correction command value to be corrected and given to each of the plurality of first actuators in the first state.

  Further objects and other aspects of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, for example, it is possible to provide an optical device that is advantageous in deforming the optical surface of an optical element.

It is the schematic which shows the structure of the optical apparatus in the 1st Embodiment of this invention. 3 is a flowchart for explaining the operation of the optical device shown in FIG. 1. It is the schematic which shows the structure of the optical apparatus in the 2nd Embodiment of this invention. It is the schematic which shows the structure of the optical apparatus in the 3rd Embodiment of this invention. It is the schematic which shows the structure of the optical apparatus in the 4th Embodiment of this invention. It is the schematic which shows the structure of the optical apparatus in the 5th Embodiment of this invention. It is the schematic which shows the structure of the optical apparatus in the 6th Embodiment of this invention. It is the schematic which shows the structure of the exposure apparatus as 1 side surface of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  In each of the following embodiments, a mirror will be described as an example of an optical element. However, the mirror may be replaced with another optical element (lens, parallel plate glass, prism, Fresnel zone plate, kinoform, binary optics, hologram), or the like. Is possible. Also, a voice coil motor (VCM) will be described as an example of an actuator for deforming the optical surface of the optical element (for driving the optical element), but it is replaced with an actuator using electromagnetic force such as a linear motor or solenoid. It is also possible. Such an actuator includes a magnet and a coil, one of which is disposed on the surface opposite to the optical surface of the optical element and the other of which is disposed on the base plate, and deforms the optical surface of the optical element by passing an electric current through the coil. .

<First Embodiment>
FIG. 1 is a schematic diagram showing a configuration of an optical device 1 according to the first embodiment of the present invention. The optical device 1 is a device that deforms the reflecting surface (optical surface) 2 a of the mirror 2. The optical device 1 includes a mirror holding member 21, a base plate 3, a plurality of voice coil motors (VCM) 4, a reference voice coil motor (reference VCM) 5, a detection unit 8, a command value determination unit 6, and actuator control. A processing unit 10 including a unit 7.

  The mirror 2 is supported on the base plate 3 via the mirror holding member 21. The base plate 3 is attached to a housing (not shown) of the optical device 1. The optical device 1 is used in combination with, for example, a light receiving element or another optical system.

  The optical device 1 includes a plurality of VCMs (a plurality of first actuators) 4 as actuators for deforming (driving) the mirror 2 and a reference VCM (second actuator) 5. The VCM 4 includes a mover 41 disposed on a surface (back surface) 2 b opposite to the reflection surface 2 a of the mirror 2 and a stator 42 disposed on the base plate 3. In the present embodiment, the movable element 41 is a magnet and the stator 42 is a coil so that an additional object such as a wiring is not arranged on the movable mirror 2. Similarly, in this embodiment, the reference VCM 5 includes a magnet as the mover 51 disposed on the back surface 2b of the mirror 2 and a coil as the stator 52 disposed on the base plate 3, and the back surface 2b of the mirror 2 Force on. The number of VCMs 4 and the number of reference VCMs 5 are not limited, and may be arbitrarily set according to the shape accuracy required for the reflection surface 2a of the mirror 2.

  The reference VCM 5 may not be used as an actuator for deforming the mirror 2 (that is, it may not be driven when the mirror 2 is deformed). However, when the reference VCM 5 is used as an actuator for deforming the mirror 2, it is necessary to arrange the reference VCM 5 at a position where the thrust is stable so that the reference VCM 5 can be used as a standard for calibrating the VCM 4. For example, the reference VCM 5 has a low rigidity in the reflection surface of the mirror 2 and a position where the displacement sensitivity of the movable element 51 is high with respect to a command value for driving the reference VCM 5, specifically, the outer peripheral side of the mirror 2. It is good to arrange at the position. In this case, a magnet as the mover 51 is disposed on the outer peripheral portion of the back surface 2 b of the mirror 2, and a coil as the stator 52 is disposed on the base plate 3 correspondingly. As described above, by arranging the reference VCM 5 at a position where the displacement sensitivity of the mover 51 is high, the command value for obtaining a predetermined displacement can be lowered, and the fluctuation of the thrust of the magnet due to the heat generation of the coil is suppressed. be able to. In the layout design of the reference VCM 5, the level of thrust fluctuation at a level that can use the reference VCM 5 as a standard for calibrating the VCM 4 is obtained, a position that is equal to or less than the thrust fluctuation is searched, and the reference VCM 5 is detected at the position. May be arranged.

  On the other hand, when the reference VCM 5 is not used as an actuator for deforming the mirror 2, the reference VCM 5 is arranged at a position that can be used as a reference for calibrating the VCM 4 even if the thrust fluctuates due to a temperature change due to an external factor. do it.

  For example, the detection unit 8 is provided corresponding to each of the plurality of VCMs 4 and the reference VCM 5 and detects the value of the induced electromotive force generated in each of the plurality of VCMs 4 and the value of the induced electromotive force generated in the reference VCM 5. As will be described later, in the present embodiment, the thrust fluctuation of each of the plurality of VCMs 4 is corrected based on the amount of change in the value of the induced electromotive force generated in each of the plurality of VCMs 4 detected by the detection unit 8.

  The processing unit 10 includes a CPU, a memory, and the like, and controls the entire optical device 1. In this embodiment, the processing unit 10 includes a command value determination unit 6 that determines a command value for driving each of the plurality of VCMs 4 and an actuator control unit 7 that drives (controls) the plurality of VCMs 4. The actuator control unit 7 applies each command value of the plurality of VCMs 4 determined by the command value determination unit 6 to each of the plurality of VCMs 4 to drive each VCM 4, thereby deforming the reflecting surface 2 a of the mirror 2. Can do.

  With reference to FIG. 2, the operation of the optical device 1, that is, the operation for deforming the reflecting surface 2a of the mirror 2 will be described. Before such operation is started, the processing unit 10 acquires the relationship between the command value given to the reference VCM 5 and the drive amount of the reference VCM 5 (displacement of the movable element 51) as reference VCM calibration data. . In addition, it is assumed that the processing unit 10 also acquires a relationship between a command value given to each of the plurality of VCMs 4 and each driving amount (displacement of the movable element 41) of the plurality of VCMs 4.

  In S201, before the reflecting surface 2a of the mirror 2 is deformed into a predetermined shape, the detection unit 8 detects the value of the induced electromotive force generated in each of the plurality of VCMs 4 when the reference VCM 5 is driven by a unit amount. When the reference VCM 5 is driven by a unit amount, the mirror 2 (the reflection surface 2a thereof) is deformed by driving the reference VCM 5, and the movable elements 41 of the plurality of VCMs 4 are also displaced. Due to the displacement of the mover 41, an induced electromotive force is generated in each of the plurality of VCMs 4. Further, the state before the reflecting surface 2a of the mirror 2 is deformed to a predetermined shape means a state before driving the plurality of VCMs 4, that is, the plurality of VCMs 4 are in the reference state.

  In S202, the value of the induced electromotive force generated in each of the plurality of VCMs 4 detected in S201 is recorded, for example, in the memory of the processing unit 10 as initial induced electromotive force data of each VCM 4.

  In S203, each of the plurality of VCMs 4 is driven to deform the reflecting surface 2a of the mirror 2 into a predetermined shape. Specifically, the command value determining unit 6 calculates the drive amount of each of the plurality of VCMs 4 required to deform the reflecting surface 2a of the mirror 2 into a predetermined shape, and the command value corresponding to the drive amount. Is determined for each of the plurality of VCMs 4. At this time, the command value determination unit 6 determines each command value of the plurality of VCMs 4 with reference to, for example, the relationship between the command value given to each of the plurality of VCMs 4 and the drive amount of each of the plurality of VCMs 4. Then, the actuator control unit 7 applies the command value determined by the command value determination unit 6 to each of the plurality of VCMs 4 to drive each VCM 4. However, when the reflecting surface 2a of the mirror 2 is deformed into a predetermined shape, the temperature of the magnet as the mover 41 fluctuates due to the input of disturbance or the driving of each VCM 4 itself, and the thrust (driving amount) for the command value of the VCM 4 ) May change. In other words, the plurality of VCMs 4 may be in a state (first state) changed from the reference state. In such a case, even if the command value determined by the command value determination unit 6 is given to each VCM 4 to drive each VCM 4, the reflecting surface 2a of the mirror 2 cannot be deformed into a predetermined shape.

  In S204, it is determined whether or not to correct the command value given to each of the plurality of VCMs 4. For example, as a result of driving each of the plurality of VCMs 4 in S203, if the reflection surface 2a of the mirror 2 is deformed into a predetermined shape (or if the difference from the predetermined shape is within an allowable range), There is no need to correct the command value given to each of the VCMs 4. However, if the reflecting surface 2a of the mirror 2 is not deformed into a predetermined shape, it is necessary to correct the command value given to each of the plurality of VCMs 4 so that the reflecting surface 2a of the mirror 2 is deformed into a predetermined shape. is there. If the command value given to each of the plurality of VCMs 4 is not corrected, the operation is terminated. On the other hand, when the command value given to each of the plurality of VCMs 4 is corrected, the process proceeds to S205.

  In S205, the driving of each of the plurality of VCMs 4 is stopped. In other words, in S205, the state after driving each of the plurality of VCMs 4 is returned to the state before driving each of the plurality of VCMs 4, that is, the state of S201.

  In S206, after S205 (that is, in a state after driving and stopping the plurality of VCMs 4), the value of the induced electromotive force generated in each of the plurality of VCMs 4 when the reference VCM 5 is driven by a unit amount is detected. Detect by.

  In S207, the command value determining unit 6 calculates the amount of change in the value of the induced electromotive force generated in each of the plurality of VCMs 4 detected in S206 from the initial induced electromotive force data of each VCM 4 recorded in S202. In other words, the difference between the value of the induced electromotive force generated in each of the plurality of VCMs 4 detected in S201 and the value of the induced electromotive force generated in each of the plurality of VCMs 4 detected in S206 is calculated.

  In S208, the command value determining unit 6 corrects the command value for driving each of the plurality of VCMs 4 based on the change amount of the dielectric electromotive force of each VCM 4 calculated in S207, and gives the correction values to the plurality of VCMs 4 Determine the command value. For example, if the value of the induced electromotive force detected in S206 is 1/3 times the value of the induced electromotive force detected in S201, the command value determination unit 6 uses the command value given to the VCM 4 in S203. The tripled value is determined as the correction command value.

  When the correction command value to be given to each VCM 4 is determined by the command value determining unit 6, the process proceeds to S203, and each of the plurality of VCMs 4 is driven. At this time, the actuator control unit 7 applies the correction command value determined by the command value determination unit 6 to each of the plurality of VCMs 4 to drive each VCM 4.

  Here, the unit amount drive (S201 and S206) of the reference VCM5 will be described. The unit amount driving of the reference VCM 5 in S201 and S206 is driving of the reference VCM 5 when a predetermined unit command value (unit current) is given to the reference VCM 5. The unit current includes a pulsed current signal and a periodic current signal, but the periodic current signal is more effective because it can reduce the cause of disturbance error. In the present embodiment, the unit current as a unit command value for driving the reference VCM 5 by a unit amount in S201 and S206 is set to the same value. This is because the driving current (displacement speed) of the reference VCM in S201 is reproduced in S206 by making the driving current of the reference VCM5 in S201 and the driving current of the reference VCM5 in S206 the same. The unit current may be determined with reference to the reference VCM calibration data.

  Further, the number of reference VCMs 5 is not limited to one. For example, in the region between the back surface 2b of the mirror 2 and the base plate 3, the reference VCMs 5 are arranged at a plurality of locations, and the plurality of reference VCMs 5 are driven by a unit amount to improve the accuracy of command value correction for each VCM 4. Can do. This is because the mirror 2 can be largely deformed by driving a plurality of reference VCMs 5 by a unit amount, and a greater induced electromotive force can be generated in each VCM 4 by increasing the displacement speed of the mover 51. Because it can. When the value of the induced electromotive force generated in each VCM 4 increases, the influence of noise or the like becomes relatively small, so that the accuracy of calibrating each VCM 4 can be improved.

  Further, when a plurality of reference VCMs 5 are arranged, it is preferable that the deformation of the mirror 2 (the reflection surface 2a thereof) by unit amount driving of the reference VCM 5 can be maximized. For example, in this embodiment, another reference VCM 5 is arranged on the opposite side of the reference VCM 5 shown in FIG. 1 on the opposite side rotated by 180 degrees around the mirror holding member 21 that holds the center of the mirror 2 as a unit. The deformation of the mirror 2 can be increased by driving the amount. In this case, it becomes more effective by reversing the direction of displacement by unit amount driving of the two reference VCMs 5 and deforming the mirror 2 so that the mirror 2 tilts around the mirror holding member 21.

  Next, the criteria for determining whether to correct the command value given to each of the plurality of VCMs 4 (S204) will be described. For example, in S <b> 204, a change in the temperature inside the optical device 1, specifically, the temperature around the plurality of VCMs 4 can be used as a determination criterion. The temperature around the plurality of VCMs 4 is measured by a thermometer or the like disposed inside the optical device 1, and it is determined that the command value given to each of the plurality of VCMs 4 is corrected when the temperature changes by a predetermined amount. In other words, each time the temperature around the plurality of VCMs 4 changes by a predetermined amount, the command value given to each of the plurality of VCMs 4 is corrected to determine the correction command value. When the relationship between the operating time of the optical device 1 (that is, the driving time of the plurality of VCMs 4) and the temperature of the magnet that is the mover 41 of each VCM 4 is obtained, in S204, the operating time of the optical device 1 is set. It can also be used as a criterion for determination. Each time the operating time of the optical device 1 (driving time of the plurality of VCMs 4) elapses, a command value given to each of the plurality of VCMs 4 is corrected to determine a correction command value.

  In the optical device 1 of the present embodiment, the induced electromotive force generated in each VCM 4 when the reference VCM 5 is driven by a unit amount in each of the case where the plurality of VCMs 4 are in the reference state and the state where the VCM 4 is changed from the reference state. Detect value. Based on the detected amount of change in the induced electromotive force, the command value for driving each VCM 4 is corrected to determine the corrected command value. Thereby, since the optical apparatus 1 can correct | amend the fluctuation | variation of the thrust (driving amount) by the temperature change of each VCM4, it can deform | transform the reflective surface 2a of the mirror 2 into a defined shape.

<Second Embodiment>
FIG. 3 is a schematic diagram showing the configuration of the optical device 1 according to the second embodiment of the present invention. In the present embodiment, the reference VCM 5 is driven by a unit amount in consideration of fluctuations in thrust (drive amount) due to changes in the temperature of the reference VCM 5 itself. In the present embodiment, the optical device 1 further includes a temperature measurement unit 91 disposed on a magnet that is the mover 51 of the reference VCM 5 as illustrated in FIG. 3. The temperature measurement unit 91 includes, for example, a thermometer, and measures the temperature of the reference VCM 5, specifically, the temperature of the magnet that is the mover 51 of the reference VCM 5.

  An operation of the optical device 1, that is, an operation for deforming the reflecting surface 2a of the mirror 2 will be described. In the present embodiment, the processing unit 10 acquires in advance, as reference VCM calibration data, a relationship between a command value given to the reference VCM 5, a driving amount of the reference VCM 5 (displacement of the mover 51), and a temperature of the reference VCM 5. It shall be.

  In each of S201 and S206 shown in FIG. 2, the temperature measurement unit 91 measures the temperature of the mover 51 when the reference VCM 5 is driven by a unit amount. In S206, the thrust (drive amount) of the reference VCM5 at the temperature of the mover 51 of the reference VCM5 measured in S206 is obtained using the reference VCM calibration data. Then, the unit command value for driving the reference VCM 5 by a unit amount is corrected so as to return the change in the thrust (drive amount) of the reference VCM 5. In other words, a unit command for driving the reference VCM 5 by a unit amount so that the driving amount of the reference VCM 5 is always equal based on the temperature difference of the mover 51 of the reference VCM 5 measured in S201 and S206. The correction unit command value is determined by correcting the value.

  In the optical apparatus 1 according to the present embodiment, even when a temperature change occurs in the reference VCM 5, the reference VCM 5 can be accurately driven by a unit amount. Therefore, the reference VCM 5 is used as a standard for calibrating each VCM 4. be able to. Accordingly, the optical device 1 can determine the correction command value by reducing the correction error of the command value of each VCM 4 due to the temperature change (unit amount drive error) of the reference VCM 5.

<Third Embodiment>
FIG. 4 is a schematic diagram showing the configuration of the optical device 1 according to the third embodiment of the present invention. In the present embodiment, the optical device 1 further includes a speed measuring unit 92 as shown in FIG. The speed measuring unit 92 measures the driving speed (displacement speed) of the reference VCM 5, specifically, the driving speed of the magnet that is the mover 51 of the reference VCM 5. The speed measurement unit 92 may include a non-contact type speedometer. Examples of the non-contact type speedometer include a laser displacement meter, a capacitance sensor, and an overcurrent sensor. An accelerometer can also be used as the speed measuring unit 92. In this case, the driving speed of the reference VCM 5 is obtained by integrating the acceleration measured by the accelerometer.

  An operation of the optical device 1, that is, an operation for deforming the reflecting surface 2a of the mirror 2 will be described. In this embodiment, the drive speed (displacement speed) of the reference VCM 5 when the reference VCM 5 is driven by a unit amount in each of S201 and S206 is controlled. As the unit amount drive of the reference VCM 5, there are step-like drive and periodic drive, but the periodic drive is more effective because it can reduce the cause of disturbance error.

  In S201 shown in FIG. 2, the speed measurement unit 92 measures the driving speed of the reference VCM 5 when the reference VCM 5 is driven by a unit amount. In S206, the unit command value for driving the reference VCM5 by the unit amount is set so that the driving speed of the reference VCM5 when the reference VCM5 is driven by the unit amount is equal to the driving speed of the reference VCM5 measured in S201. Correct and determine the correction unit command value. In this manner, the reference VCM 5 is driven by a unit amount so as to reproduce the driving speed of the reference VCM 5 measured by the speed measuring unit 92 in S201 and S206.

  In the optical device 1 of the present embodiment, the driving speed when the reference VCM 5 is driven by a unit amount can be reproduced regardless of the change in thrust (drive amount) due to the temperature change of the reference VCM 5 or the like. The reference VCM 5 can be used as a standard for calibrating. Therefore, the optical device 1 can determine the correction command value by reducing the correction error of the command value of each VCM 4 due to the difference in driving speed when the reference VCM 5 is driven by a unit amount.

<Fourth Embodiment>
FIG. 5 is a schematic diagram showing the configuration of the optical device 1 according to the fourth embodiment of the present invention. In this embodiment, the optical device 1 has a rigid actuator 53 that functions as a reference actuator instead of the reference VCM 5 as shown in FIG. The rigid actuator 53 is disposed on the base plate 3 and supports the mirror 2. The rigid actuator 53 is configured by an actuator that drives without moving the movable side and the fixed side, such as a piezo actuator, a shape memory alloy actuator, a bimetal, a pneumatic actuator, a hydraulic actuator, and a ball screw. In the present embodiment, the rigid actuator 53 is configured by a piezo actuator.

  The rigid actuator 53 can obtain a larger thrust than a non-contact type actuator such as a VCM. Therefore, by using the rigid actuator 53 as a reference actuator, a large induced electromotive force can be generated in each VCM 4, so that the accuracy of calibrating each VCM 4 can be improved while suppressing the influence of noise and the like.

  Regarding the operation of the optical device 1, that is, the operation for deforming the reflecting surface 2a of the mirror 2, the reference VCM 5 may be replaced with the rigid actuator 53, and thus detailed description thereof is omitted here. As in the third embodiment, the rigid actuator 53 is used as a reference for calibrating each VCM 4 by reproducing the driving speed when the rigid actuator 53 is driven by a unit amount in S201 and S206 shown in FIG. Can do.

<Fifth Embodiment>
FIG. 6 is a schematic diagram showing the configuration of the optical device 1 according to the fifth embodiment of the present invention. In the present embodiment, as shown in FIG. 6, the optical device 1 causes the rigid actuator 53 to function not only as a reference actuator but also as a mirror holding member 21. The rigid actuator 53 is disposed between the center portion of the back surface 2 b of the mirror 2 and the base plate 3. Thereby, the mirror 2 is supported by the base plate 3 via the rigid actuator 53.

  Regarding the operation of the optical device 1, that is, the operation for deforming the reflecting surface 2a of the mirror 2, the reference VCM 5 may be replaced with the rigid actuator 53, and thus detailed description thereof is omitted here. As in the fourth embodiment, the rigid actuator 53 is used as a reference for calibrating each VCM 4 by reproducing the driving speed when the rigid actuator 53 is driven by a unit amount in S201 and S206 shown in FIG. Can do.

<Sixth Embodiment>
FIG. 7 is a schematic diagram showing the configuration of the optical device 1 according to the sixth embodiment of the present invention. In the present embodiment, as shown in FIG. 7, the optical device 1 includes a plurality of rigid body actuators 53, and the plurality of rigid body actuators 53 not only function as reference actuators but also function as mirror holding members 21. . The plurality of rigid actuators 53 are arranged at a plurality of locations between the back surface 2 b of the mirror 2 and the base plate 3. The mirror 2 supported by the plurality of rigid body actuators 53 can be tilted by changing the drive amount of each rigid body actuator 53. The number of rigid actuators 53 is two in FIG. 7, but is not limited to this, and may be three or more.

  Regarding the operation of the optical device 1, that is, the operation for deforming the reflecting surface 2a of the mirror 2, the reference VCM 5 may be replaced with the rigid actuator 53, and thus detailed description thereof is omitted here. However, in the unit amount driving of the rigid actuator 53 in S201 and S206, if the driving amounts of the two rigid actuators 53 are equal, the mirror 2 can be displaced in the vertical direction as in the fifth embodiment.

  Further, when the displacement directions by the unit amount driving of the two rigid actuators 53 are reversed, the mirror 2 tilts. In this case, since the driving speed (displacement speed) of the VCM 4 arranged on the outer peripheral portion of the mirror 2 is increased, a larger induced electromotive force can be generated. When the value of the induced electromotive force generated in each VCM 4 increases, the influence of noise or the like becomes relatively small, so that the accuracy of calibrating each VCM 4 can be improved.

<Seventh Embodiment>
FIG. 8 is a schematic diagram showing a configuration of an exposure apparatus 500 as one aspect of the present invention. The exposure apparatus 500 is a lithography apparatus that transfers (forms) a mask pattern onto a substrate. The exposure apparatus 500 includes an illumination optical system IL, a projection optical system PO, a mask stage MS that moves while holding a mask 550, and a substrate stage WS that moves while holding a substrate 560. In addition, the exposure apparatus 500 includes a control unit 510 that controls processing for exposing the substrate 560.

  Light emitted from a light source (not shown) forms, for example, an arc-shaped exposure region that is long in the Y direction on the mask 550 by a slit (not shown) included in the illumination optical system IL. Each of the mask 550 and the substrate 560 is held by the mask stage MS and the substrate stage WS, and is disposed at an optically conjugate position (the object plane and the image plane of the projection optical system PO) via the projection optical system PO. . The projection optical system PO is an optical system that has a predetermined projection magnification (for example, ½ times) and projects the pattern of the mask 550 onto the substrate 560. The mask stage MS and the substrate stage WS are scanned in a direction (for example, the X direction) parallel to the object plane of the projection optical system PO at a speed ratio corresponding to the projection magnification of the projection optical system PO. Thereby, the pattern of the mask 550 can be transferred to the substrate 560.

  For example, as shown in FIG. 8, the projection optical system PO includes a plane mirror 520, a concave mirror 530, and a convex mirror 540. The light emitted from the illumination optical system IL and passed through the mask 550 has its optical path bent by the first surface 520a of the plane mirror 520 and is incident on the first surface 530a of the concave mirror 530. The light reflected by the first surface 530 a of the concave mirror 530 is reflected by the convex mirror 540 and enters the second surface 530 b of the concave mirror 530. The light reflected by the second surface 530 b of the concave mirror 530 is bent on the optical path by the second surface 520 b of the flat mirror 520 and forms an image on the substrate 560. In the projection optical system PO configured in this way, the surface of the convex mirror 540 becomes an optical pupil.

  In the exposure apparatus 500, the optical apparatus 1 of each embodiment described above is used as an apparatus that deforms the reflecting surface of the concave mirror 530 as the mirror 2, for example. By using the optical apparatus 1 for the exposure apparatus 500, the reflecting surfaces (the first surface 530a and the second surface 530b) of the concave mirror 530 can be deformed into a predetermined shape, and the aberration of the projection optical system PO is highly accurate. Can be corrected. Therefore, the exposure apparatus 500 can provide a high-quality device (semiconductor device, liquid crystal display device, flat panel display (FPD), etc.) with high throughput and high economic efficiency. Note that the control unit 510 in the exposure apparatus 500 may be configured to include the processing unit 10 in the optical apparatus 1.

  The method for manufacturing an article according to an embodiment of the present invention is suitable, for example, for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. In the method for manufacturing an article according to the present embodiment, a latent image pattern is formed on the photosensitive agent applied to the substrate using the above-described scanning exposure apparatus (a step of exposing the substrate), and the latent image pattern is formed in this step. Developing the processed substrate. Further, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

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

Claims (13)

An optical device for deforming an optical surface of an optical element,
A base plate;
A plurality of first actuators, each of which includes a magnet and a coil disposed on a surface opposite to the optical surface of the optical element and the other disposed on the base plate, and deforms the optical surface;
A second actuator for applying a force to a surface of the optical element opposite to the optical surface;
A detection unit for detecting a value of an induced electromotive force generated in each of the plurality of first actuators;
Occurs in each of the plurality of first actuators when the second actuator is driven by a unit amount when each of the plurality of first actuators is in a reference state and when the first actuator is changed from the reference state. The value of the induced electromotive force is detected by the detection unit, and each of the plurality of first actuators in the reference state is detected based on the amount of change in the value of the induced electromotive force detected in the reference state and the first state. A processing unit for correcting a command value for driving and determining a correction command value to be given to each of the plurality of first actuators in the first state;
An optical device comprising: The reference state is a state before driving the plurality of first actuators,
The optical device according to claim 1, wherein the first state is a state after driving the plurality of first actuators and stopping the driving. A temperature measuring unit for measuring the temperature of the second actuator;
The processing unit measures the temperature of the second actuator by the temperature measurement unit when the plurality of first actuators are in a reference state and when the first actuator is in a first state changed from the reference state, A corrected unit command value to be given to the second actuator by correcting a unit command value for driving the second actuator by a unit amount based on a temperature difference between the state and the second actuator measured in the first state. The optical device according to claim 1, wherein the optical device is determined. A speed measuring unit for measuring the driving speed of the second actuator;
In the processing unit, when the plurality of first actuators are in the first state, the driving speed measured by the speed measuring unit when the second actuator is driven by a unit amount is the plurality of first actuators. Is a unit command value for driving the second actuator by a unit amount so as to be equal to the driving speed measured by the speed measuring unit when the second actuator is driven by a unit amount when the second actuator is in the reference state. The optical apparatus according to claim 1, wherein a correction unit command value to be applied to the second actuator is determined by correcting the correction.   2. The second actuator includes a magnet and a coil, one of which is disposed on an outer peripheral portion of a surface opposite to the optical surface of the optical element and the other of which is disposed on the base plate. 5. The optical device according to any one of items 4 to 4.   5. The optical device according to claim 1, wherein the second actuator includes a rigid actuator that is disposed on the base plate and supports the optical element. 6.   The optical device according to claim 6, wherein the second actuator is disposed between a center portion of a surface of the optical element opposite to the optical surface and the base plate.   The said 2nd actuator is arrange | positioned in multiple places between the surface on the opposite side of the said optical surface of the said optical element, and the said base plate, The any one of Claims 1 thru | or 5 characterized by the above-mentioned. Optical device.   The processing unit determines the correction command value to be given to each of the plurality of first actuators each time a driving time of the plurality of first actuators elapses for a predetermined time. The optical apparatus of any one of them.   The processing unit determines the correction command value to be given to each of the plurality of first actuators every time a temperature around the plurality of first actuators changes by a predetermined amount. The optical apparatus of any one of these. An optical element;
The optical device according to any one of claims 1 to 10, which deforms an optical surface of the optical element;
An optical system comprising: An illumination optical system for illuminating the mask;
A projection optical system for projecting the pattern of the mask onto the substrate;
Have
The projection optical system is
An optical element;
The optical device according to any one of claims 1 to 10, which deforms an optical surface of the optical element;
An exposure apparatus comprising: Exposing the substrate using the exposure apparatus according to claim 12;
Developing the exposed substrate;
A method for producing an article comprising:

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