Optical device and method for controlling the optical device

Abstract

To provide an optical device and a method for controlling the optical device with which it is possible to grasp the light-emission state of illumination light in greater detail and facilitate more elaborately controlling the light source of illumination light.SOLUTION: An optical device 1 according to the present embodiment illuminates an object 50 with illumination light L10. The optical device 1 comprises: a first mirror unit 11 for reflecting a first portion L11 of generated light L0 from a light-emitting point LP of generated light L0 in which illumination light L10 is included; a second mirror unit 12 for reflecting a second portion L12 of generated light L0; an optical element 10 for reflecting generated light L0; a first detection unit 21 for detecting the first portion L11 reflected by the first mirror unit 11; and a second detection unit 22 for detecting the second portion L12 reflected by the second mirror unit 12. The generated light L0 includes the first portion L11, the second portion L12, and a primary portion LM, and at least some of the primary portion LM reflected by the optical element 10 is the illumination light L10 that illuminates the object 50.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present disclosure relates to an optical device and a method for controlling an optical device. 【Background Art】 【0002】 Patent Document 1 discloses a technique for extracting a part from a light beam of extreme ultraviolet (EUV) light and monitoring the intensity distribution of the EUV light. 【0003】 Patent Document 2 discloses a technique for surrounding EUV light with a sensor having a cavity in the center and monitoring the state of the EUV light. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent No. 6249513 【Patent Document 2】 Japanese Translation of PCT International Publication No. 2023-515488 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, when a temporal intensity change of EUV light is observed by a monitor, it may be difficult to determine whether this is due to the movement of the light emission point of the EUV light, the blinking (light quantity change) of the light emission point, defocusing, or some other reason. It is desired to be able to grasp the light emission state of EUV light in more detail and enable more fine-tuned control of the light source of EUV light. 【0006】 The present disclosure has been made in view of such problems, and provides an optical device and a method for controlling an optical device that can grasp the light emission state of illumination light in more detail and facilitate more fine-tuned control of the light source of illumination light. 【Means for Solving the Problems】 【0007】 An optical device according to one aspect of this embodiment is an optical device for illuminating an object with illumination light, comprising: a first mirror portion that reflects a first portion of generated light from a light-emitting point that includes the illumination light; a second mirror portion that reflects a second portion of the generated light; an optical element that reflects the generated light; a first detection unit that detects the first portion reflected by the first mirror portion; and a second detection unit that detects the second portion reflected by the second mirror portion, wherein the generated light includes the first portion, the second portion, and a main portion, and at least a portion of the main portion reflected by the optical element is the illumination light that illuminates the object. 【0008】 In the optical device described above, the first mirror portion may separate the first portion from the optical path of the main portion, and the second mirror portion may separate the second portion from the optical path of the main portion. 【0009】 The optical device described above may further include an acquisition unit that acquires first output information from the first detection unit at multiple sampling times and second output information from the second detection unit at multiple sampling times, and a determination unit that determines the state of the light-emitting point based on the changes in the first output information and the changes in the second output information. 【0010】 In the optical apparatus described above, the determination unit may determine the movement of the light-emitting point in the optical axis direction of the generated light and the movement of the light-emitting point in an orthogonal direction perpendicular to the optical axis direction, based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. 【0011】 In the optical apparatus described above, the determination unit may determine the change in light emission intensity at the light emission point based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. 【0012】 In the optical device described above, the determination unit may determine that a change in light emission intensity has occurred at the light emission point if at least one of a change in the intensity of the light emission point based on the first output information and a change in the intensity of the light emission point based on the second output information is detected, and neither a movement of the light emission point based on the first output information nor a movement of the light emission point based on the second output information is detected. 【0013】 In the optical device described above, the acquisition unit may acquire a first image from the first output information that captures the light-emitting point and has a horizontal direction and a vertical direction perpendicular to the horizontal direction, and may also acquire a second image from the second output information that captures the light-emitting point and has the horizontal direction and the vertical direction. 【0014】 In the optical device described above, when the light-emitting point moves in the optical axis direction, the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions. When the light-emitting point moves in the orthogonal direction, the light-emitting point in the first image and the light-emitting point in the second image may move such that they have the same component in at least one of the horizontal and vertical directions. 【0015】 In the optical device described above, the determination unit may determine that the light-emitting point has moved in the optical axis direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions, and may determine that the light-emitting point has moved in the orthogonal direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in the same direction in at least one of the horizontal and vertical directions. 【0016】 In the optical device described above, the first detection unit and the second detection unit may be positioned at optically conjugate positions with respect to the object. 【0017】 In the above optical device, the generated light further includes a third part, and further includes a third mirror part that reflects the third part, and a third detection part that detects the third part reflected by the third mirror part. The acquisition part may acquire the third output information of the third detection part, and based on the acquired third output information, acquire the intensity distribution of the generated light. 【0018】 In the above optical device, the third part may be closer to the optical axis of the main part than the first part and the second part. 【0019】 In the above optical device, the illumination light may be critical illumination. 【0020】 The above optical device includes a mirror that reflects the generated light generated at the light emitting point, and the first part, the second part, and the main part may be the generated light reflected by the mirror. 【0021】 In the above optical device, the illumination light may include the wavelength of EUV. 【0022】 In the above optical device, the first detection part and the second detection part may detect light having a wavelength different from the wavelength of the illumination light. 【0023】 In the above optical device, the first mirror part and the second mirror part may be arranged at substantially the same optical path position on the optical axis of the main part. 【0024】 In the above optical device, the first mirror part and the second mirror part may be arranged at positions facing each other across the optical axis of the main part. 【0025】 The above optical device may further include a fourth detection part that detects the illumination light including the main part reflected by the object, and a processing part that processes an image of the object based on the fourth output information of the fourth detection part. 【0026】 In the above optical device, the object may include a photomask. 【0027】 In the above optical device, it further includes a fourth detection unit that detects light from an observation object disposed on the optical path of the main part, and a processing unit that processes an image of the observation object based on the fourth output information of the fourth detection unit, and the object may include the fourth detection unit. 【0028】 In the above optical device, the illumination light includes exposure light for exposing a wafer, and the object may include a wafer having a region activated based on light from a photomask disposed on the optical path of the exposure light. 【0029】 In the above optical device, the illumination light includes exposure light for exposing a wafer, and the object may include a photomask for forming a pattern on the wafer. 【0030】 A control method for an optical device according to an aspect of the present embodiment is a control method for an optical device that illuminates an object with illumination light. The optical device includes a first mirror unit that reflects a first portion of the generated light from the light emission point of the generated light including the illumination light, a second mirror unit that reflects a second portion of the generated light, an optical element that reflects the generated light, a first detection unit that detects the first portion reflected by the first mirror unit, a second detection unit that detects the second portion reflected by the second mirror unit, and an image processing unit including an acquisition unit and a determination unit. The generated light includes the first portion, the second portion, and a main portion. The control method for the optical device includes illuminating the object with the illumination light including at least a part of the main portion reflected by the optical element, causing the acquisition unit to acquire the first output information of the first detection unit and the second output information of the second detection unit at a plurality of sampling times, and causing the determination unit to determine the state of the light emission point based on the change in the first output information and the change in the second output information. 【Effect of the Invention】 【0031】 According to this disclosure, it is possible to provide an optical device and a control method for the optical device that can understand the emission state of illumination light in more detail and facilitate more precise control of the illumination light source. [Brief explanation of the drawing] 【0032】 [Figure 1] This is a plan view illustrating an optical device according to Embodiment 1. [Figure 2] This is a side view illustrating an optical device according to Embodiment 1. [Figure 3] This is a cross-sectional view illustrating the generated light and illumination light of the optical device according to Embodiment 1, showing the cross-section along line III-III in Figure 1. [Figure 4] This is a block diagram illustrating the image processing unit in the optical device according to Embodiment 1. [Figure 5] This figure illustrates the output information of the first detection unit and the output information of the second detection unit acquired by the acquisition unit in the image processing unit of the optical device according to Embodiment 1. [Figure 6] This figure illustrates the output information of the first detection unit and the output information of the second detection unit acquired by the acquisition unit in the image processing unit of the optical device according to Embodiment 1. [Figure 7] This figure illustrates the output information of the first detection unit and the output information of the second detection unit acquired by the acquisition unit in the image processing unit of the optical device according to Embodiment 1. [Figure 8] This figure illustrates the output information of the first detection unit and the output information of the second detection unit acquired by the acquisition unit in the image processing unit of the optical device according to Embodiment 1. [Figure 9] This figure illustrates the output information of the first detection unit and the output information of the second detection unit acquired by the acquisition unit in the image processing unit of the optical device according to Embodiment 1. [Figure 10] This is a flowchart illustrating a control method for an optical device according to Embodiment 1. [Figure 11] This is a plan view illustrating an optical device according to Embodiment 2. [Figure 12]This is a diagram illustrating an inspection device according to Embodiment 3. [Figure 13] This is a block diagram illustrating the image processing unit in the inspection apparatus according to Embodiment 3. [Figure 14] This is a diagram illustrating an inspection device according to Embodiment 4. [Figure 15] This is a diagram illustrating the configuration of the monitoring unit in the inspection device according to Embodiment 4. [Figure 16] This is a diagram illustrating an inspection device according to Embodiment 5. [Modes for carrying out the invention] 【0033】 Embodiments of the present disclosure will be described below with reference to the drawings. The following description illustrates preferred embodiments of the present disclosure and does not limit the scope of the present disclosure to the following embodiments. In the following description, the same reference numerals indicate substantially the same thing. 【0034】 <Embodiment 1> An optical device according to Embodiment 1 will now be described. Figure 1 is a plan view illustrating the optical device 1 according to Embodiment 1. Figure 2 is a side view illustrating the optical device 1 according to Embodiment 1. Figure 3 is a cross-sectional view illustrating the generated light L0 and illumination light L10 of the optical device 1 according to Embodiment 1, showing the cross-section along line III-III in Figure 1. As shown in Figures 1 to 3, the optical device 1 is a device that illuminates an object 50 with illumination light L10 contained in the generated light L0. The illumination light L10 may illuminate the object 50 through several optical members after passing through a focal point LS. The optical device 1 may also be an inspection device that inspects an object 50 with illumination light L10, or an exposure device that exposes an object to be exposed using illumination light L10 as exposure light, or an exposure device that exposes an object 50 with exposure light. 【0035】 The object 50 may include, for example, a photomask. However, the object 50 is not limited to a photomask and may include other components such as a semiconductor substrate. The optical device 1 comprises an optical element 10, a first mirror section 11, a second mirror section 12, a first detection section 21, a second detection section 22, and an image processing section 30. 【0036】 The generated light L0, including the illumination light L10, is generated at the emission point LP and emitted from the emission point LP. The emission point LP includes, for example, a bright spot in the plasma generated by irradiating a target material with excitation light. In this case, the generated light L0 and illumination light L10 include EUV light generated from the plasma. Therefore, the generated light L0 and illumination light L10 include wavelengths of EUV. 0 The illumination light L10 may also include UV light, visible light, and infrared (IR) light of wavelengths other than EUV. Furthermore, the generated light L0 and the illumination light L10 may include at least one wavelength of EUV light, UV light, visible light, and IR light. The generated light L0, including the illumination light L10, travels from the light emission point LP towards the object 50. The generated light L0 emitted from the light emission point LP travels as a beam of light. The generated light L0 travels while spreading out from the light emission point LP. The generated light L0 is incident on the optical element 10. 【0037】 The optical element 10 reflects the generated light L0. The optical element 10 includes, for example, a mirror. The optical element 10 may also include a concave mirror such as an ellipsoidal mirror. In that case, the optical element 10 reflects the generated light L0, which is incident while spreading out, so as it travels while being focused. In other words, the optical element 10 reflects the generated light L0, which is incident as divergent light, as focused light. 【0038】 Here, for the sake of explaining the optical device 1, we introduce the XYZ Cartesian coordinate system and the αβγ Cartesian coordinate system. As shown in Figure 2, the direction of the optical axis C1 of the generated light L0 emitted from the light emission point LP is defined as the Z axis direction, and the two directions perpendicular to the Z axis direction are defined as the X axis direction and the Y axis direction. Directions within the XY plane are called orthogonal directions. Also, as shown in Figures 1 to 3, the direction of the optical axis C2 of the generated light L0 reflected by the optical element 10 is defined as the γ axis direction, and the two directions perpendicular to the direction of the optical axis C2 are defined as the α axis direction and the β axis direction. 【0039】 For example, the light emission point LP is located in a direction having components in the +γ axis direction and the -β axis direction of the optical element 10. The optical axis C1 of the generated light L0 traveling from the light emission point LP to the optical element 10 extends in a direction having components in the -γ axis direction and the +β axis direction. 【0040】 The generated light L0 reflected by the optical element 10 travels in the +γ direction so as to be focused at the focal point LS. The generated light L0 includes a first part L11, a second part L12, and a main part LM. For example, the first part L11 includes the portion of the generated light L0 on the +α direction side, and the second part L12 includes the portion of the generated light L0 on the -α direction side. Therefore, the first part L11 and the second part L12 are spaced apart in the α direction with respect to the optical axis C2 of the generated light L0. The first part L11 and the second part L12 may include EUV light, UV light, visible light, and IR light, etc. 【0041】 The first portion L11 and the second portion L12 are preferably the regions furthest from the optical axis C2 in the generated light L0. Furthermore, the first portion L11 and the second portion L12 preferably include the portions on both sides of the optical axis C2 in the generated light L0 that are furthest apart. This improves the sensitivity with which the first detection unit 21 and the second detection unit 22 can detect changes in the position of the light emission point LP. 【0042】 Furthermore, the first part L11 and the second part L12 are not limited to being separated in the α-axis direction, but may also be separated in the β-axis direction, or in directions inclined from the α-axis and β-axis directions. Also, the first part L11 and the second part L12 are not limited to being separated on opposite sides of the optical axis C2 of the generated light L0. For example, the first part L11 and the second part L12 may be positioned so as to be a part on the +α-axis side and a part on the +β-axis side, respectively, without straddling the optical axis C2 of the generated light L0. 【0043】 First part L of generated light L0 11 It is incident on the first mirror section 11. Also, the second portion L of the generated light L0 12 The light is incident on the second mirror section 12. The main portion LM of the generated light L0 may include portions other than the first portion L11 and the second portion L12. The main portion LM is focused at the focal point LS. At least a portion of the main portion LM reflected by the optical element 10 is illumination light L10 that illuminates the object 50. For example, the main portion LM may illuminate the object 50 from the focal point LS through several optical members. The main portion LM of the illumination light L10 may illuminate the object 50 in such a way that it is focused at the object 50. In this way, the illumination light L10 may be critical illumination. The main portion LM has the same optical axis as the optical axis C2 of the illumination light L10. 【0044】 The first mirror section 11 is the first portion L of the generated light L0. 11 It reflects the second mirror part 12 of the second portion L of the generated light L0. 12It reflects light. For example, the first mirror section 11 is positioned on the +α axis side of the optical axis C2 of the generated light L0. The second mirror section 12 is positioned on the -α axis side of the optical axis C2 of the generated light L0. Therefore, the first mirror section 11 and the second mirror section 12 are spaced apart in the α axis direction with the optical axis C2 of the generated light L0 in between. The first mirror section 11 and the second mirror section 12 are positioned at approximately the same optical path position on the optical axis C2 of the main portion LM of the generated light L0. In other words, the first mirror section 11 and the second mirror section 12 are located on the same plane perpendicular to the optical axis C2. Furthermore, the first mirror section 11 and the second mirror section 12 are positioned opposite each other with the optical axis C2 of the main portion LM in between. Alternatively, the first mirror section 11 and the second mirror section 12 may be integrated. 【0045】 Furthermore, the first mirror section 11 and the second mirror section 12 may be positioned at different locations on the optical axis C2. That is, the plane perpendicular to the optical axis C2 on which the first mirror section 11 is located and the plane perpendicular to the optical axis C2 on which the second mirror section 12 is located may be different. Also, the first mirror section 11 and the second mirror section 12 may be positioned not only spaced apart in the α-axis direction, but also spaced apart in the β-axis direction, or spaced apart in directions inclined from the α-axis and β-axis directions. Moreover, the first mirror section 11 and the second mirror section 12 are not limited to being positioned spaced apart on opposite sides of the optical axis C2 of the generated light L0. For example, the first mirror section 11 and the second mirror section 12 may be positioned spaced apart so as not to straddle the optical axis C2 of the generated light L0, such that they are located on the +α-axis side and the +β-axis side, respectively. 【0046】 The first mirror section 11 reflects the first portion L11 of the generated light L0, for example, in the +α axis direction. The first portion L11 reflected by the first mirror section 11 propagates in the +α axis direction. The second mirror section 12 reflects the second portion L12 of the generated light L0, for example, in the -α axis direction. The second portion L12 reflected by the second mirror section 12 propagates in the -α axis direction. In Figure 2, the directions in which the first portion L11 and the second portion L12 propagate are different from those in Figure 1. That is, as shown in Figure 2, the first mirror section 11 may reflect the first portion L11 of the generated light L0 in directions having components in the +α axis direction, the -β axis direction, and the -γ axis direction. The second mirror section 12 may reflect the second portion L12 of the generated light L0 in directions having components in the -α axis direction, the -β axis direction, and the -γ axis direction. 【0047】 The first mirror section 11 separates the first portion L11 from the optical path of the main portion LM. The second mirror section 12 separates the second portion L12 from the optical path of the main portion LM. 【0048】 The first detection unit 21 detects the first portion L11 reflected by the first mirror unit 11. The first detection unit 21 may be positioned at an optically conjugate position with respect to the light emission point LP, the light focusing point LS, and the object 50. This allows the first detection unit 21 to obtain the detection result of the generated light L0 as critical illumination. The first detection unit 21 may detect EUV light, UV light, visible light, IR light, etc., contained in the first portion L11. The first detection unit 21 may detect light with approximately the same wavelength as the main portion LM, which is the illumination light L10, or it may detect light with a different wavelength. The first detection unit 21 outputs the detection result of the first portion L11 as output information to the image processing unit 30. The output information of the first detection unit 21 may be called the first output information. 【0049】 The second detection unit 22 detects the second portion L12 reflected by the second mirror unit 12. The second detection unit 22 may be positioned at an optically conjugate position with respect to the light emission point LP, the light focusing point LS, and the object 50. This allows the second detection unit 22 to obtain the detection result of the generated light L0 as critical illumination. The second detection unit 22 may detect EUV light, UV light, visible light, IR light, etc., contained in the second portion L12. The second detection unit 22 may detect light with approximately the same wavelength as the main portion LM, which is the illumination light L10, or it may detect light with a different wavelength. The wavelength of the light detected by the second detection unit 22 may be approximately the same as the wavelength of the light detected by the first detection unit 21. The second detection unit 22 outputs the detection result of the second portion L12 as output information to the image processing unit 30. The output information of the second detection unit 22 is sometimes called the second output information. 【0050】 The first detection unit 21 and the second detection unit 22 may be integrated. For example, the optical device 1 may include a detection device. The detection device may include the first detection unit 21 and the second detection unit 22. The optical path of the first part L11 from the first mirror unit 11 to the detection device and the optical path of the second part L12 from the second mirror unit 12 to the detection device may be adjusted as appropriate by optical members and guided to the inspection device. This reduces the number of detection units and lowers costs. 【0051】 The image processing unit 30 is connected to the first detection unit 21 and the second detection unit 22 via signal lines or wirelessly, enabling information transmission. The image processing unit 30 receives output information from the first detection unit 21 and the second detection unit 22. The output information includes image data of the light-emitting point LP. The image processing unit 30 processes the image data of the light-emitting point LP received from the first detection unit 21 and the second detection unit 22 as a two-dimensional image. 【0052】 Figure 4 is a block diagram illustrating the image processing unit 30 in the optical device 1 according to Embodiment 1. As shown in Figure 4, the image processing unit 30 has an acquisition unit 31 and a determination unit 32. The acquisition unit 31 and the determination unit 32 have the functions of an acquisition means and a determination means. The acquisition unit 31 acquires first output information from the first detection unit 21 at multiple sampling times, and second output information from the second detection unit 22 at multiple sampling times. 【0053】 The determination unit 32 determines the state of the light-emitting point LP based on the changes in the first output information of the first detection unit 21 at multiple sampling times and the changes in the second output information of the second detection unit 22 at multiple sampling times. The state of the light-emitting point LP may include the state of the position of the light-emitting point LP. The state of the light-emitting point LP includes focus shift due to movement of the light-emitting point LP in the direction of the optical axis C1, position shift due to movement of the light-emitting point LP in a direction perpendicular to the optical axis C1, and blinking due to an increase or decrease in the intensity of the light-emitting point LP. 【0054】 Figures 5 to 9 illustrate the first output information of the first detection unit 21 and the second output information of the second detection unit 22 acquired by the acquisition unit 31 in the image processing unit 30 of the optical device 1 according to Embodiment 1. As shown in Figure 5, the acquisition unit 31 acquires the first image G11 from the first output information. The first image G11 is an image having a horizontal and vertical direction in which the light-emitting point LP is captured. The vertical direction is the direction that intersects the horizontal direction. For example, the vertical direction is perpendicular to the horizontal direction. In this case, the first image G11 is rectangular. Here, the horizontal direction is defined as the H direction, the right side as the +H direction, and the left side as the -H direction. Also, the vertical direction is defined as the V direction, the upward direction as the +V direction, and the downward direction as the -V direction. 【0055】 The acquisition unit 31 acquires the first image G11 and also acquires the second image G12 from the second output information. The second image G12 is an image having both horizontal and vertical dimensions, capturing the light-emitting point LP. The second image G12 is, for example, rectangular. 【0056】 The acquisition unit 31 acquires the position information of the light-emitting point LP on the first image G11 from the first output information of the first detection unit 21. The acquisition unit 31 acquires the position information of the light-emitting point LP on the second image G12 from the second output information of the second detection unit 22. 【0057】 When the light emission point LP is located at a predetermined reference position at sampling time t0, the acquisition unit 31, as shown in Figure 5, uses the first output information of the first detection unit 21 at sampling time t=t0 to determine the predetermined position of the first image G11 (for example, 1 An image is acquired in which the light emission point LP is located at the center of image G11. Furthermore, if the light emission point LP is located at a predetermined reference position at sampling time t=t0, the acquisition unit 31 uses the second output information of the second detection unit 22 at sampling time t0 to determine the predetermined position of the second image G12 (for example, 2nd An image is obtained in which the light source LP is located at the center of image G12. 【0058】 Thus, in this embodiment, the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22 determine the predetermined positions of the first image G11 and the second image G12 (for example, when the light emission point LP is located at a predetermined reference position) 1 Image G11 and 2nd The light-emitting point LP is positioned so as to be imaged at the center of image G12. For example, the positions of the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22 are set in advance so that when the light-emitting point LP is positioned at a predetermined reference position, the light-emitting point LP is positioned at predetermined positions in the first image G11 and the second image G12. 【0059】 As shown in Figure 6, when the light emission point LP moves orthogonally from the reference position (direction within the XY plane) at sampling time t=t1, the acquisition unit 31, from the first output information of the first detection unit 21, determines that the light emission point LP has moved in the -H direction from the center of the first image G11. 1 Image G11 is acquired. The acquisition unit 31 also determines from the second output information of the second detection unit 22 that the light emission point LP has moved in the -H direction from the center of the second image G12. 2ndGet image G12. 【0060】 Thus, in this embodiment, the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22 are arranged such that when the light-emitting point LP moves in an orthogonal direction (direction within the XY plane), the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move while having components in at least one of the H direction and the V direction. With this arrangement, when the light-emitting point LP moves in an orthogonal direction (direction within the XY plane), the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move while having components in at least one of the H direction and the V direction. Here, the orthogonal direction, as described above, is a direction within the XY plane perpendicular to the optical axis C1, and includes a direction having components in at least one of the X-axis direction and the Y-axis direction. 【0061】 For example, the angle between the reflective surface of the first mirror section 11 and the optical axis C2 is made the same as the angle between the reflective surface of the second mirror section 12 and the optical axis C2. The orientation of the reflective surface of the first mirror section 11 with respect to the optical axis C2 and the orientation of the reflective surface of the second mirror section 12 with respect to the optical axis C2 are arranged symmetrically with respect to the optical axis C2. In addition, the optical path of the first section L11 from the first mirror section 11 to the first detection section 21 and the optical path of the second section L12 from the second mirror section 12 to the second detection section 22 are arranged symmetrically with respect to the optical axis C2. 【0062】 By configuring it in this way, when the light source LP moves in an orthogonal direction, the light source LP in the first image G11 and the light source in the second image G12 LP This means that the light-emitting point LP can move in the same direction in at least one of the H and V directions. Furthermore, the configuration for moving the light-emitting point LP in the first image G11 and the second image G12 as described above when the light-emitting point LP moves in an orthogonal direction is not limited to the above configuration; the angle of the reflective surface and the number of optical elements may be changed as appropriate. 【0063】 The determination unit 32 determines the movement of the light emission point LP in the optical axis C1 direction and the movement of the light emission point LP in the orthogonal direction based on the change in the first output information of the first detection unit 21 and the change in the second output information of the second detection unit 22 between predetermined sampling times t=t0 and t=t1. Here, sampling time t=t1 is a time after the predetermined sampling time t=t0. The optical axis C1 direction is the optical axis C1 direction of the generated light L0 emitted from the light emission point LP at the predetermined sampling time t=t0. 【0064】 Specifically, the determination unit 32 determines that the light-emitting point LP has moved in an orthogonal direction when the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move such that they have components in the same direction in at least one of the H direction and the V direction. 【0065】 As shown in Figure 7, if the light emission point LP moves in a different orthogonal direction from the reference position at sampling time t=t1 than in Figure 6, the acquisition unit 31, based on the first output information of the first detection unit 21, determines that the light emission point LP has moved in the -V direction from the center of the first image G11. 1 Image G11 is acquired. The acquisition unit 31 determines from the second output information of the second detection unit 22 that the light emission point LP has moved in the -V direction from the center of the second image G12. 2nd Get image G12. 【0066】 As described above, the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22, when the light-emitting point LP moves in an orthogonal direction, detect the light-emitting point LP in the first image G11 and the light-emitting point in the second image G12. LP The two are arranged to move while having components in the same direction in at least one of the H direction and the V direction. Therefore, when the light-emitting point LP moves in an orthogonal direction, as shown in Figure 7, the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move while having components in the same direction in at least one of the H direction and the V direction. However, in Figure 7, the movement is in a different orthogonal direction than in Figure 6. 【0067】 The determination unit 32 determines that the light-emitting point LP has moved in a direction different from that of Figure 6 if the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 have moved such that they have the same component in at least one of the H direction and V direction that is different from that of Figure 6. 【0068】 For example, the movement and amount of movement of the light-emitting point LP in the X-axis and Y-axis directions in the orthogonal direction are determined in advance, 1 Image G11 and 2nd The movement of the light-emitting point LP on image G12 in the H and V directions, and the amount of movement, may be associated with this. This allows the determination unit 32 to determine that 1 Image G11 and 2nd From the movement and amount of movement of the light-emitting point LP on image G12, the actual direction and amount of movement of the light-emitting point LP can be determined. 【0069】 As shown in Figure 8, when the light emission point LP moves from the reference position in the direction of the optical axis C1 (Z axis direction) at sampling time t=t1, the acquisition unit 31, from the first output information of the first detection unit 21, determines that the light emission point LP has moved in the +H direction from the center of the first image G11. 1 Image G11 is acquired. The acquisition unit 31 also acquires an image from the second output information of the second detection unit 22 in which the light emission point LP has moved in the -H direction from the center of the second image G12. 【0070】 Thus, in this embodiment, when the light-emitting point LP moves in the direction of the optical axis C1, the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22 detect the light-emitting point LP in the first image G11 and the light-emitting point in the second image G12. LP This arrangement means that, for example, the light-emitting points LP are positioned to move in at least one of the H and V directions while having components in opposite directions. With this arrangement, when the light-emitting point LP moves in the direction of the optical axis C1, the light-emitting point LP of the first image G11 and the light-emitting point LP of the second image G12 move in at least one of the H and V directions while having components in opposite directions. 【0071】 The determination unit 32 determines that the light-emitting point LP has moved in the direction of the optical axis C1 if the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 have components in opposite directions in at least one of the H direction and the V direction. 【0072】 For example, the first mirror section 11 and the second mirror section 12 are positioned symmetrically with respect to the optical axis C2. Also, the detection surface of the first detection section 21 and the detection surface of the second detection section 22 are positioned opposite each other. In this case, if the light emission point LP moves along the optical axis C1, a focus shift occurs at the condensation point LS. 【0073】 Then the focusing point LS is +γ shaft Direction or -γ shaft It moves in the direction. Therefore, the focusing point on the detection surface in the first detection unit 21 is +γ on the detection surface. shaft Direction or -γ shaft It moves in the direction. The focusing point on the detection surface in the second detection unit 22 is +γ on the detection surface. shaft Direction or -γ shaft It moves in the direction of the optical axis C1. In this way, when the light-emitting point LP moves in the direction of the optical axis C1, the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move such that they have components in opposite directions in at least one of the H direction and the V direction. Note that the configuration in which the light-emitting point LP in the first image G11 and the second image G12 move as described above when the light-emitting point LP moves in the direction of the optical axis C1 is not limited to the configuration described above, and the angle of the reflective surface and the number of optical elements may be changed as appropriate. 【0074】 For example, the amount of movement of the light-emitting point LP in the direction of the optical axis C1, 1 Image G11 and image 2nd The amount of movement of the light-emitting point LP on the image G12 in the H direction and the V direction may be associated with this. This allows the determination unit 32 to determine that 1 Image G11 and 2nd The amount of movement of the light-emitting point LP in the reverse direction on image G12 can be used to determine the actual amount of movement of the light-emitting point LP in the direction of the optical axis C1. 【0075】 Furthermore, the determination unit 32 determines if the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move such that they have components in opposite directions in at least one of the H direction and the V direction, and then determines the light-emitting point LP in the first image G11 and the second image G12.G12 The average position of the light-emitting point LP and the position of the other point may be calculated. Furthermore, the average position of the light-emitting point LP may be associated with the actual positional displacement of the light-emitting point LP in the optical axis C1 direction. This allows the determination unit 32 to determine the actual positional displacement of the light-emitting point LP in the optical axis C1 direction and the movement in the orthogonal direction from the calculated average value when the points move to have components in opposite directions. 【0076】 As shown in Figure 9, if the light emission point LP does not move from the reference position at sampling time t=t1, the acquisition unit 31 determines from the first output information of the first detection unit 21 that the light emission point LP does not move in any direction from the center of the first image G11. 1 Image G11 is acquired. The acquisition unit 31 also acquires an image from the second output information of the second detection unit 22 in which the light emission point LP does not move in any direction from the center of the second image G12. 【0077】 Thus, in this embodiment, the first mirror unit 11, the second mirror unit 12, the first detection unit 21, and the second detection unit 22 detect the light-emitting point LP in the first image G11 and the light-emitting point in the second image G12 when the light-emitting point LP does not move in either the direction of the optical axis C1 or the orthogonal direction. LP The light source is positioned so as not to move in either the H or V direction. With this arrangement, when the light source LP does not move in either the direction of the optical axis C1 or the direction perpendicular to it, the light source LP in the first image G11 and the light source LP in the second image G12 do not move in either the H or V direction. 【0078】 The determination unit 32 determines that the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 have not moved in either the H direction or the V direction, and that the light-emitting point LP has not moved in either the optical axis C1 direction or the orthogonal direction. 【0079】 For example, if the intensity of the light-emitting point LP in the first image G11 or the second image G12 has changed from that at sampling time t=t0, possible reasons include movement of the light-emitting point LP in the direction of the optical axis C1 (so-called defocus), a change in the light emission intensity at the light-emitting point LP, or both. As described above, the determination unit 32 can determine the movement of the light-emitting point LP in the direction of the optical axis C1. Therefore, as shown in Figure 9, if the intensity of the light-emitting point LP in the first image G11 or the second image G12 has changed from that at sampling time t=t0, and the determination unit 32 does not detect movement of the light-emitting point LP (more specifically, movement in a manner corresponding to the determination of movement of the light-emitting point LP in the direction of the optical axis C1), then it can be determined that the change in the intensity of the illumination light L10 is predominantly due to a change in the light emission intensity at the light-emitting point LP. Among the changes in light emission intensity at the light-emitting point LP, possible causes of a decrease in light emission intensity include a temporary shortage of target material or a temporary decrease in the output of the excitation laser. Therefore, the determination unit 32 may continue to perform control to address these issues. Conversely, if the intensity of the light-emitting point LP in the first image G11 or the second image G12 has changed (for example, decreased) from that at sampling time t=t0, and the determination unit 32 detects movement of the light-emitting point LP (more specifically, movement in a manner corresponding to the determination of movement of the light-emitting point LP in the direction of the optical axis C1), then it can be determined that one of the reasons for the change (for example, decrease) in the intensity of the illumination light L10 is that movement of the light-emitting point LP in the direction of the optical axis C1 (so-called defocus) has occurred. 【0080】 Next, the control method for the optical device 1 will be described. Figure 10 is a flowchart illustrating the control method for the optical device according to Embodiment 1. As shown in step S11 of Figure 10, the object 50 is illuminated by at least a portion of the main part LM of the generated light L0 reflected by the optical element 10. 【0081】 Next, as shown in step S12, the acquisition unit 31 is made to acquire first output information from the first detection unit 21 that detected the first portion L11 of the generated light L0 and second output information from the second detection unit 22 that detected the second portion L12 at multiple sampling times. The first mirror unit 11 reflects the first portion L11 of the generated light L0, and the first portion L11 is made to the main portion LM It separates from the optical path. The second mirror section 12 reflects the second portion L12 of the generated light L0, and the second portion L12 is separated from the main portion LM The optical path is separated. In step S12, the acquisition unit 31 is instructed to acquire a first image G11 of the light-emitting point LP from the first output information. The acquisition unit 31 is also instructed to acquire a second image G12 of the light-emitting point LP from the second output information. 【0082】 Next, as shown in step S13, the determination unit 32 is made to determine the state of the light-emitting point LP based on the changes in the first output information and the changes in the second output information. For example, the determination unit 32 is made to determine the movement of the light-emitting point LP in the direction of the optical axis C1, the movement of the light-emitting point LP in the orthogonal direction, and the change in intensity due to the blinking of the light-emitting point LP, based on the changes in the first output information and the changes in the second output information between predetermined sampling times t=t0 and t=t1. 【0083】 Specifically, the determination unit 32 determines that the light-emitting point LP has moved in the direction of the optical axis C1 if the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move such that they have components in opposite directions in at least one of the horizontal and vertical directions. On the other hand, the determination unit 32 determines that the light-emitting point LP has moved in an orthogonal direction if the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 move such that they have components in the same direction in at least one of the horizontal and vertical directions. Furthermore, the determination unit 32 determines that a change in light intensity due to the blinking of the light-emitting point LP has occurred if, when the intensity of the illumination light L10 changes, the light-emitting point LP in the first image G11 and the light-emitting point LP in the second image G12 do not move in either the horizontal or vertical directions. By determining the state of the light-emitting point LP in this way, the optical device 1 can be controlled. 【0084】 Next, the effects of this embodiment will be described. The optical device 1 of this embodiment includes a first detection unit 21 and a second detection unit 22 that detect a first portion L11 and a second portion L12 of the generated light L0. In this way, by detecting light from at least two locations of the generated light L0, the state of the light emission point LP can be determined, so the state of the light emission point LP can be understood in more detail, and more precise control of the illumination light source L10 can be facilitated. 【0085】 The determination unit 32 determines the data acquired by the acquisition unit 31. 1 Image G11 and 2nd By observing the movement of the light-emitting point LP on image G12, the movement of the light-emitting point LP in the direction of the optical axis C1 and its movement in the orthogonal direction can be determined. This allows for three-dimensional monitoring of the position of the light-emitting point LP. Therefore, the position of the light-emitting point LP can be determined in detail. 【0086】 For example, when a decrease in the brightness of the light-emitting point LP or a decrease in the intensity of the illumination light L10 is detected, it may be necessary to determine whether these decreases are due to a focus shift caused by movement of the light-emitting point LP in the direction of the optical axis C1, a positional shift of the light-emitting point LP in the orthogonal direction, or flickering due to an increase or decrease in the output of the light-emitting point LP. The determination unit 32 of this embodiment is: 1 Image G11 and 2nd By moving the position of the light-emitting point LP on image G12, it is possible to distinguish between a decrease in intensity, etc. due to movement of the light-emitting point LP in the direction of the optical axis C1, a decrease in intensity, etc. due to movement in the orthogonal direction, and a decrease in intensity, etc. due to the blinking of the light-emitting point LP. Therefore, the intensity, etc. of the light-emitting point LP decline It is possible to distinguish the cause. 【0087】 The first detection unit 21 and the second detection unit 22 are positioned optically conjugate to the object 50, and the illumination light L10 is critical illumination. Therefore, the state of the illumination light L10 can be understood in more detail. 【0088】 <Embodiment 2> Next, the optical device 2 of Embodiment 2 will be described. Figure 11 is a plan view illustrating the optical device 2 according to Embodiment 2. As shown in Figure 11, in the optical device 2 of this embodiment, the generated light L0 also includes a first part L11, a second part L12, and a main part LM. The first mirror part 11 reflects the first part L11 of the generated light L0 directed from the light emission point LP toward the object 50. The second mirror part 12 reflects the second part L12 of the generated light L0 directed from the light emission point LP toward the object 50. The optical element 10 reflects only the main part LM of the generated light L0. The main part reflected by the optical element 10 LM At least a portion of the light illuminates the object 50. In this embodiment as well, the optical device 2 can be controlled by determining the state of the light-emitting point LP. The point designated as the light-emitting point LP is not limited to this, but may also be a point where the generated light L0 is focused by an optical member, for example, a focal point LS1 (see Figure 12) where the generated light L0 is focused by an ellipsoidal mirror. 【0089】 According to this embodiment, the arrangement of the optical element 10, the first mirror section 11, and the second mirror section 12 can be changed as appropriate. Therefore, the degree of freedom in the arrangement of each component of the optical device 2 can be improved. Other configurations and effects are described in Embodiment 1. 【0090】 <Embodiment 3> Next, an optical device according to Embodiment 3 will be described. This embodiment describes an inspection device as an example of an optical device. In the inspection device of this embodiment, the object 50 may include, for example, a photomask. 【0091】 Figure 12 is a diagram illustrating an inspection device 3 according to Embodiment 3. In addition to the configurations of the optical devices 1 and 2 described above, the inspection device 3 includes an illumination optical system 60 and an imaging optical system 70. The illumination optical system 60 illuminates the object 50 using illumination light L10. The illumination optical system 60 includes, for example, a light source 61, an ellipsoidal mirror 62, an ellipsoidal mirror 63, and a recessed mirror 64. The imaging optical system 70 captures an image of the object 50 illuminated by the illumination light L10. The imaging optical system 70 includes, for example, a perforated concave mirror 71, a convex mirror 72, and a main detection unit 73. The perforated concave mirror 71 and the convex mirror 72 constitute a Schwarzschild magnification optical system. In addition to the above configurations, the illumination optical system 60 and the imaging optical system 70 may further include optical components, or any of the above optical components may be omitted. 【0092】 The object 50 is, for example, placed on the stage 52. The inspection device 3 is a device for inspecting the object 50 for defects, contamination, etc. The object 50 is, for example, an EUV mask that corresponds to EUV light. However, the object 50 is not limited to an EUV mask; it may also be a photomask that corresponds to illumination light L10 having a different wavelength. Furthermore, the object 50 is not limited to a photomask; it may also be a semiconductor substrate or the like. 【0093】 The light source 61 generates generated light L0. For example, generated light L0 is generated from the aforementioned light emission point LP. The generated light L0 includes, for example, EUV light of 13.5 nm, which is the same as the exposure wavelength of the EUV mask, which is the object 50. The light source 61 may also include light of other wavelengths as generated light L0. The generated light L0 generated from the light source 61 is reflected by the ellipsoidal mirror 62. The generated light L0 reflected by the ellipsoidal mirror 62 travels while being focused and is focused at the focal point LS1. The focal point LS1 is positioned conjugate to the upper surface 51 of the object 50. 【0094】 The first mirror section 11 reflects the first portion L11 of the generated light L0 between the ellipsoidal mirror 62 and the focal point LS1. As a result, the first detection unit 21 detects the first portion L11 reflected by the first mirror section 11. The second mirror section 12 reflects the second portion L12 of the generated light L0 between the ellipsoidal mirror 62 and the focal point LS1. As a result, the second detection unit 22 detects the second portion L12 reflected by the second mirror section 12. 【0095】 The arrangement of the first mirror section 11 and the second mirror section 12 is not limited to the space between the ellipsoidal mirror 62 and the focusing point LS1. The arrangement of the first mirror section 11 and the second mirror section 12 may be any space between the light-emitting point LP and the object 50, for example, between the ellipsoidal mirror 63 and the recessed mirror 64. 【0096】 The illumination light L10, including the main portion LM, passes through the focal point LS1, then spreads out as it travels and enters a reflecting mirror such as an ellipsoidal mirror 63. The illumination light L10 that enters the ellipsoidal mirror 63 is reflected by the ellipsoidal mirror 63, and as it travels, it is focused and enters the recessed mirror 64. In other words, the ellipsoidal mirror 63 causes the illumination light L10 to enter the recessed mirror 64 as a focused beam. The recessed mirror 64 is positioned above the object 50. The illumination light L10 that enters the recessed mirror 64 and is reflected enters the object 50. That is, the recessed mirror 64 causes the illumination light L10 to enter the object 50. 【0097】 The ellipsoidal mirror 63 focuses the illumination light L10 onto the object 50. The illumination optical system 60 is positioned so that when the illumination light L10 illuminates the object 50, the image of the light source LP is projected onto the upper surface 51 of the object 50. In this way, the illumination optical system 60 provides critical illumination. Thus, the illumination optical system 60 illuminates the object 50 using critical illumination provided by the illumination light L10 generated by the light source 61. 【0098】 The illumination light L10, including the main portion LM, is incident on the object 50 from a direction inclined from the normal direction to the stage surface on the stage 52. In other words, the illumination light L10 is incident at an oblique angle to illuminate the object 50. 【0099】 Stage 52 is a three-dimensional drive stage. By moving Stage 52 in a direction parallel to the stage surface, a desired area of ​​the object 50 can be illuminated. Furthermore, by moving Stage 52 in the direction normal to the stage surface, focus adjustment can be performed. Stage 52 may also be rotated around three axes such as the X, Y, and Z axes. Alternatively, instead of moving and rotating Stage 52, the illumination optical system 60 and the imaging optical system 70 may be moved and rotated. 【0100】 Illumination light L10 from light source 61 illuminates the inspection area of ​​object 50. Illumination light L10, which is incident from a direction inclined with respect to the normal direction of the stage surface and reflected by object 50, enters the perforated concave mirror 71. A hole 71a is provided in the center of the perforated concave mirror 71. 【0101】 The illumination light L10 reflected by the perforated concave mirror 71 is incident on the convex mirror 72. The convex mirror 72 reflects the illumination light L10 incident from the perforated concave mirror 71 toward the hole 71a of the perforated concave mirror 71. The illumination light L10 that has passed through the hole 71a is detected by the main detection unit 73. The main detection unit 73 may be a detector including a TDI (Time Delay Integration) sensor. The main detection unit 73 detects the illumination light L10 including the main portion LM reflected from the object 50. The main detection unit 73 may include a plurality of image sensors arranged in a line in one direction. Linear image data captured by a plurality of image sensors arranged in a line is called one-dimensional image data, or one frame. The main detection unit 73 acquires a plurality of one-dimensional image data by scanning in a direction orthogonal to one direction. The image sensor is, for example, a CCD (Charge Coupled Device). However, the image sensor is not limited to a CCD. 【0102】 In this manner, the imaging optical system 70 collects the illumination light L10 reflected from the illuminated object 50, and the main detection unit 73 detects the collected illumination light L10 to acquire image data of the object 50. 【0103】 The illumination light L10 reflected from the object 50 contains information about defects in the object 50. The specularly reflected light of the illumination light L10 incident on the object 50 from a direction tilted relative to the stage surface is detected by the imaging optical system 70. If a defect exists in the object 50, the defect is observed as a dark image. This observation method is called bright-field observation. The output information of the object 50 acquired by the main detection unit 73 is output to the image processing unit 30. 【0104】 The image processing unit 30 is connected to the imaging optical system 70 in a manner that allows for information transmission via signal lines or wirelessly. The image processing unit 30 receives image data of the object 50 from the main detection unit 73 in the imaging optical system 70. 30 The main detection unit 73 processes the image data of the object 50 received from the main detection unit 73 as a two-dimensional captured image. The image processing unit 30 inspects the object 50 using the processed captured image. 【0105】 Figure 13 is a block diagram illustrating the image processing unit 30 in the inspection apparatus 3 according to Embodiment 3. As shown in Figure 13, the image processing unit 30 may further include a processing unit 33 in addition to the acquisition unit 31 and the determination unit 32. The acquisition unit 31 acquires output information from the main detection unit 73. The output information includes, for example, one-dimensional image data of the object 50. The acquisition unit 31 may acquire an image of the object 50 from the output information of the main detection unit 73. The processing unit 33 processes the image of the object 50. The processing unit 33 inspects the object 50 based on the processed image. 【0106】 The inspection apparatus 3 of this embodiment includes a main detection unit 73 that detects illumination light L10 reflected from the object 50, and a processing unit 33 that processes an image of the object 50 based on the output information of the main detection unit 73. The state of the light emission point LP and the illumination light L10 is determined by the determination unit 32. As a result, the processing unit 33 can process an image of the object 50 based on the determination result of the determination unit 32, thereby improving the accuracy of the inspection of the object 50. Other configurations and effects are described in Embodiments 1 and 2. 【0107】 <Embodiment 4> Next, an optical device according to Embodiment 4 will be described. The optical device of this embodiment is an inspection device and includes a monitoring unit that monitors generated light L0 including illumination light L10. Figure 14 is a configuration diagram illustrating an inspection device 4 according to Embodiment 4. As shown in Figure 14, the inspection device 4 further includes a monitoring unit 15. The monitoring unit 15 further includes a third mirror unit 13, a concave mirror 14, and a third detection unit 23. The generated light L0 includes a first part L11, a second part L12, and a main part LM, as well as a third part L13. 【0108】 Figure 15 is a diagram illustrating the configuration of the monitor unit 15 in the inspection apparatus 4 according to Embodiment 4. Figure 15 also shows an enlarged view of the vicinity of the concave mirror 14. As shown in Figures 14 and 15, the third mirror unit 13 of the monitor unit 15 is positioned between the ellipsoidal mirror 63 and the recessed mirror 64, and extracts the third portion L13 of the generated light L0 between the ellipsoidal mirror 63 and the recessed mirror 64. The third mirror unit 13 reflects the third portion L13 so as to slightly cut out a part of the beam of generated light L0. 【0109】 The position of the third mirror section 13 is not limited to between the ellipsoidal mirror 63 and the recessed mirror 64. The position of the third mirror section 13 may be anywhere between the light-emitting point LP and the object 50, for example, between the ellipsoidal mirror 62 and the focusing point LS. 【0110】 In the cross-sectional area of ​​the section perpendicular to the optical axis C2 of the generated light L0 at the position where the third mirror section 13 is positioned, the cross-sectional area of ​​the third portion L13 reflected by the third mirror section 13 is smaller than the cross-sectional area of ​​the main portion LM. 【0111】 For example, if the cross-sectional area of ​​the generated light L0 perpendicular to the optical axis C2 at the position where the third mirror section 13 is located is 100, then the cross-sectional area of ​​the third section L13 is approximately 1. The extraction angle of the generated light L0 extracted from the light source 61 in the direction perpendicular to the optical axis C2 is, for example, ±7°. The range used as illumination light L10 for the EUV mask of the object 50 is, for example, ±6°. Even if a small portion of the generated light L0 beam is extracted for use in the monitor section 15, the amount of illumination light L10 on the EUV mask does not decrease significantly. Therefore, a decrease in the inspection accuracy of the object 50 can be suppressed. 【0112】 The third mirror unit 13 is positioned, for example, near the pupil in the illumination optical system 60. By extracting the generated light L0 with the third mirror unit 13 at a position near the pupil in the illumination optical system 60, a good correlation can be obtained between the image data acquired by the main detection unit 73 and the image data acquired by the third detection unit 23. Even if the numerical aperture (NA) for the main detection unit 73 and the NA for the third detection unit 23 are different, and the point spreading function (PSF) is different, the difference in NA does not affect this embodiment because the plasma size is sufficiently large compared to the PSF size. 【0113】 The third mirror section 13 reflects the third portion L13 in the generated light L0. This separates the third portion L13 from the optical path of the main portion LM. It is preferable that the third mirror section 13 is positioned closer to the optical axis C2 of the main portion LM than the first mirror section 11 and the second mirror section 12. That is, the third portion L13 is closer to the optical axis C2 of the main portion LM than the first portion L11 and the second portion L12. This ensures that the first portion L11 and the second portion L12 are reflected by the first mirror section 11 and the second mirror section 12. 【0114】 The third portion L13, reflected by the third mirror 13, travels while being narrowed and focuses at the focal point LS2. After that, the third portion L13 expands as it enters the concave mirror 14. 【0115】 The concave mirror 14 and several other mirrors (not shown) magnify the third portion L13 of the generated light L0 extracted by the third mirror section 13. The distance L1 is between the focusing point LS2 and the concave mirror 14, and the distance L2 is between the focusing point LS2 and the third detection section 23. The image data acquired by the third detection section 23 can also be magnified to a high level. However, to obtain a high magnification (~500), the distance L2 must be made very large. For example, if the distance L1 is ~5 mm, the distance L2 should be ~2500 mm to obtain a magnification of 500x. For example, a magnification of 500x can be achieved by using multiple mirrors. 【0116】 In this embodiment, the magnification of the image data of the intensity distribution of generated light L0 acquired by the monitor unit 15 is the same as the magnification of the image data of the object 50 acquired by the imaging optical system 70. However, the magnification of the image data of the intensity distribution acquired by the monitor unit 15 may be lower than the magnification of the image data of the object 50 acquired by the imaging optical system 70. The solid angle required for extraction is the square of the ratio of the magnifications. For example, if the magnification of the main detection unit 73 is 20x and the magnification of the third detection unit 23 is 2x, the solid angle required for extraction by the third mirror unit 13 is 1 / 100 of the solid angle of extraction from the light source 61. Converted using NA, it is 1 / 10. 【0117】 The third portion L13, which is incident on the concave mirror 14 and reflected by the concave mirror 14, is detected by the third detection unit 23. That is, the third detection unit 23 detects the third portion L13 reflected by the third mirror unit 13. The third detection unit 23 includes, for example, a TDI sensor. The third detection unit 23 acquires a monitor image such as the intensity distribution of the generated light L0. The third detection unit 23 includes a plurality of image sensors arranged in a line in one direction. The linear image data captured by the plurality of image sensors arranged in a line is called one-dimensional image data, or one frame, as is the case with the main detection unit 73. The third detection unit 23 acquires a plurality of one-dimensional image data by scanning in a direction orthogonal to one direction. The one-dimensional image data acquired by the third detection unit 23 shows the intensity distribution including the power fluctuation and brightness distribution of the generated light L0. The image sensor is, for example, a CCD (Charge Coupled Sensor). d It is a device. Note that the image sensor is not limited to a CCD. 【0118】 for example ,raw The optical system is arranged so that the image of the light-emitting point LP of the generated light L0 is formed on the third detection unit 23. As a result, the monitor unit 15 illuminates the third detection unit 23 by critical illumination using the third portion L13 of the generated light L0. The monitor unit 15 then acquires image data of the intensity distribution of the detected generated light L0. Therefore, the intensity distribution, including power fluctuations and luminance distribution, can be detected with high accuracy. 【0119】 In this manner, the monitor unit 15 focuses the third portion L13 of the generated light L0, and the focused third portion L13 is detected by the third detection unit 23. The third detection unit 23 outputs output information to the image processing unit 30, which includes power fluctuations and intensity distribution information including luminance distribution of the detected generated light L0. The output information includes image data detected by the third detection unit 23. The output information is output to the image processing unit 30 and processed into two-dimensional image data. In the image processing unit 30, the acquisition unit 31 acquires the output information from the third detection unit 23 and acquires the intensity distribution of the generated light L0 based on the acquired output information. 【0120】 According to this embodiment, the monitor unit 15 acquires the power fluctuation and intensity distribution including the luminance distribution of the generated light L0, so that the state of the light emission point LP and the illumination light L10 can be acquired with even higher precision. Other configurations and effects are described in Embodiments 1 to 3. 【0121】 <Embodiment 5> Next, an optical device according to Embodiment 5 will be described. The optical device of this embodiment is an inspection device, and the object 50 includes a main detection unit 73. Figure 16 is a configuration diagram illustrating an inspection device 5 according to Embodiment 5. In the above-described embodiment, the object 50 is, for example, a photomask placed on the stage 52. Therefore, the first mirror unit 11 and the second mirror unit 12 are arranged on the optical path of the generated light L0 between the light emission point LP and the object 50 on the stage 52. On the other hand, in this embodiment, since the object 50 is the main detection unit 73, at least one of the first mirror unit 11 and the second mirror unit 12 may be arranged on the optical path of the generated light L0 between the light emission point LP and the main detection unit 73. 【0122】 For example, as shown in Figure 16, in this embodiment, the first mirror section 11 and the second mirror section 12 may be arranged on the optical path of the generated light L0 between the convex mirror 72 and the main detection section 73. An object to be observed 50a, such as a photomask, is placed on the stage 52. Thus, the inspection apparatus 5 of this embodiment includes a main detection section 73 that detects light from the object to be observed 50a placed on the optical path of the main portion LM of the generated light L0, and a processing section 33 that processes an image of the object to be observed 50a based on the output information of the main detection section 73. The object 50 is the main detection section 73. The main detection section 73 may be, for example, a detection section that detects illumination light L10 reflected or transmitted from the object to be observed 50a, such as a photomask, placed on the stage 52. 【0123】 According to this embodiment, the first mirror section 11 and the second mirror section 12 can separate the first part L11 and the second part L12 from the generated light L0, which includes the illumination light L10 immediately before it enters the main detection section 73. This allows for more detailed detection of the state of the illumination light L10 detected by the main detection section 73. Other configurations and effects are described in Embodiments 1 to 4. 【0124】 Furthermore, the configurations of the optical devices 1 and 2, and the inspection devices 3 to 5 described above can be applied to an exposure apparatus. For example, the illumination light L10 may include exposure light for exposing the wafer. The object 50 may include a wafer having a region that is activated based on light from a photomask placed on the optical path of the exposure light. In that case, at least one of the first mirror portion 11 and the second mirror portion 12 may be placed on the optical path of the exposure light between the light-emitting point LP and the wafer. 【0125】 Furthermore, the object 50 may include a photomask for forming a pattern on the wafer. In that case, the first mirror portion 11 and the second mirror portion 12 are arranged on the optical path of the exposure light between the light-emitting point LP and the photomask. 【0126】 While embodiments of this disclosure have been described above, this disclosure includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the embodiments described above. Furthermore, combinations of the configurations of Embodiments 1 to 5 are also within the scope of the technical concept of this disclosure. In addition, the following configurations are also within the scope of the technical concept of the embodiments. 【0127】 (Note 1) A control method for an optical device that illuminates an object with illumination light, The optical device is A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, An image processing unit including an acquisition unit and a determination unit, It has, The generated light includes the first part, the second part, and the main part. A method for controlling an optical device, The steps include illuminating the object with the illumination light, which includes at least a portion of the main part reflected by the optical element, The steps include causing the acquisition unit to acquire the first output information of the first detection unit and the second output information of the second detection unit at multiple sampling times, A step of causing the determination unit to determine the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, A method for controlling an optical device. (Note 2) The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion. A control method for the optical device described in Appendix 1. (Note 3) In the step of having the determination unit make a determination, The determination unit is instructed to determine, based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time, the movement of the light-emitting point in the optical axis direction of the generated light and the movement of the light-emitting point in an orthogonal direction perpendicular to the optical axis direction. A control method for the optical device described in Appendix 1. (Note 4) In the step of having the determination unit make a determination, Based on the changes in the first output information of the first detection unit and the changes in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time, the determination unit determines the movement of the light emission point in the optical axis direction of the generated light, and the position of the light emission point. Luminous To distinguish between changes in intensity, A control method for the optical device described in Appendix 1. (Note 5) In the step of having the determination unit make a determination, The determination unit is instructed to determine the change in light emission intensity at the light emission point based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. A control method for the optical device described in Appendix 3. (Note 6) In the step of having the determination unit make a determination, The determination unit is instructed to determine that a change in light intensity has occurred at the light source if at least one of a change in the intensity of the light source based on the first output information and a change in the intensity of the light source based on the second output information is detected, and neither a movement of the light source based on the first output information nor a movement of the light source based on the second output information is detected. A control method for the optical device described in Appendix 5. (Note 7) In the step of having the acquisition unit acquire the data, The acquisition unit is instructed to acquire a first image from the first output information that captures the light-emitting point and has a horizontal direction and a vertical direction perpendicular to the horizontal direction, and to acquire a second image from the second output information that has a horizontal direction and a vertical direction that captures the light-emitting point. A control method for the optical device described in Appendix 4. (Note 8) When the light-emitting point moves in the optical axis direction, the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions. When the light-emitting point moves in the orthogonal direction, the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in the same direction in at least one of the horizontal and vertical directions. A control method for the optical device described in Appendix 7. (Note 9) In the step of having the determination unit make a determination, The determination unit is instructed to determine that the light-emitting point has moved in the optical axis direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions, and to determine that the light-emitting point has moved in the orthogonal direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in the same direction in at least one of the horizontal and vertical directions. A control method for the optical device described in Appendix 7. (Note 10) The first detection unit and the second detection unit are positioned at optically conjugate positions with respect to the object, A control method for the optical device described in Appendix 1. (Note 11) The generated light further comprises a third part, The optical device is A third mirror portion that reflects the aforementioned third portion, A third detection unit for detecting the third portion reflected by the third mirror unit, Furthermore, The acquisition unit further includes the step of causing the acquisition unit to acquire the third output information of the third detection unit, and to acquire the intensity distribution of the generated light based on the acquired third output information. A control method for the optical device described in Appendix 3. (Note 12) The third part is closer to the optical axis of the main part than the first and second parts, A control method for the optical device described in Appendix 11. (Note 13) The aforementioned illumination light is critical illumination. A control method for the optical device described in Appendix 1. (Note 14) The system includes a mirror that reflects the generated light generated at the light-emitting point, The first part, the second part, and the main part are the generated light reflected by the mirror. A control method for the optical device described in Appendix 1. (Note 15) The illumination light includes wavelengths of EUV, A control method for the optical device described in Appendix 1. (Note 16) The first detection unit and the second detection unit detect light with a wavelength different from the wavelength of the illumination light. A control method for the optical device described in Appendix 1. (Note 17) The first mirror section and the second mirror section are arranged at substantially the same optical path position on the optical axis of the main section. A control method for the optical device described in Appendix 1. (Note 18) The first mirror portion and the second mirror portion are positioned opposite each other across the optical axis of the main portion. Control method for the optical device described in Appendix 17. (Note 19) The optical device is A fourth detection unit detects the illumination light, including the main portion, that has been reflected by the object; A processing unit that processes an image of the object based on the fourth output information of the fourth detection unit, It also has, A control method for the optical device described in Appendix 1. (Note 20) The aforementioned object includes a photomask, Control method for the optical device described in Appendix 18. (Note 21) The optical device is A fourth detection unit that detects light from an object to be observed, which is positioned on the optical path of the main part, A processing unit that processes the image of the object to be observed based on the fourth output information of the fourth detection unit, Furthermore, The object includes the fourth detection unit, A control method for the optical device described in Appendix 1. (Note 22) The illumination light includes exposure light for exposing the wafer, The object is the aforementioned exposure light A wafer having a region that is activated based on light from a photomask placed on the optical path, A control method for the optical device described in Appendix 1. (Note 23) The illumination light includes exposure light for exposing the wafer, The object includes a photomask for forming a pattern on a wafer. A control method for the optical device described in Appendix 1. [Explanation of symbols] 【0128】 1, 2 Optical equipment 3, 4, 5 Inspection equipment 10 Optical elements 11. First Mirror Section 12. Second Mirror Section 13. Third Mirror Section 14 concave mirror 15 Monitor section 21 First detection unit 22 Second detection unit 23 Third detection unit 30 Image Processing Unit 31 Acquisition Department 32 Judgment section 33 Processing Unit 50 Objects 50a Subject of observation 51 Top side 52 stages 60 Illumination optical system 61 Light source 62 Ellipsoidal mirror 63 Ellipsoidal mirror 64 Recessed Mirror 70 Imaging optical system 71. Perforated concave mirror 71a Hole 72 Convex mirror 73 Main detection unit C1, C2 optical axis G11 Image 1 G12 Image 2 L10 illumination light L11 Part 1 L12 2nd part L13 3rd part LM main parts LP light source LS, LS1, LS2 focal point

Claims

[Claim 1] An optical device that illuminates an object with illumination light, A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, Equipped with, The generated light includes the first part, the second part, and the main part. At least a portion of the main part reflected by the optical element is the illumination light that illuminates the object, An acquisition unit that acquires first output information from the first detection unit at multiple sampling times, and second output information from the second detection unit at multiple sampling times, A determination unit that detects the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Furthermore, The determination unit detects the movement of the light-emitting point in the optical axis direction of the generated light and the movement of the light-emitting point in an orthogonal direction perpendicular to the optical axis direction, based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. optical equipment. [Claim 2] An optical device that illuminates an object with illumination light, A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, Equipped with, The generated light includes the first part, the second part, and the main part. At least a portion of the main part reflected by the optical element is the illumination light that illuminates the object, An acquisition unit that acquires first output information from the first detection unit at multiple sampling times, and second output information from the second detection unit at multiple sampling times, A determination unit that detects the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Furthermore, The determination unit detects a change in the light emission intensity at the light emission point based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. The determination unit determines that a change in light emission intensity has occurred at the light emission point if at least one of a change in the intensity of the light emission point based on the first output information and a change in the intensity of the light emission point based on the second output information is detected, and neither movement of the light emission point based on the first output information nor movement of the light emission point based on the second output information is detected. optical equipment. [Claim 3] The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion. The optical apparatus according to claim 1 or 2. [Claim 4] An optical device for illuminating an object with illumination light, A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, Equipped with, The generated light includes the first part, the second part, and the main part. At least a portion of the main part reflected by the optical element is the illumination light that illuminates the object, The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion, An acquisition unit that acquires first output information from the first detection unit at multiple sampling times, and second output information from the second detection unit at multiple sampling times, A determination unit that detects the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Furthermore, The determination unit detects the movement of the light-emitting point in the optical axis direction of the generated light and the movement of the light-emitting point in an orthogonal direction perpendicular to the optical axis direction, based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. optical equipment. [Claim 5] An optical device for illuminating an object with illumination light, A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, Equipped with, The generated light includes the first part, the second part, and the main part. At least a portion of the main part reflected by the optical element is the illumination light that illuminates the object, The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion, An acquisition unit that acquires first output information from the first detection unit at multiple sampling times, and second output information from the second detection unit at multiple sampling times, A determination unit that detects the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Furthermore, The determination unit detects a change in the light emission intensity at the light emission point based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. optical equipment. [Claim 6] The determination unit determines that a change in light emission intensity has occurred at the light emission point if at least one of a change in the intensity of the light emission point based on the first output information and a change in the intensity of the light emission point based on the second output information is detected, and neither movement of the light emission point based on the first output information nor movement of the light emission point based on the second output information is detected. The optical apparatus according to claim 5. [Claim 7] The acquisition unit acquires a first image from the first output information that captures the light-emitting point and has a horizontal direction and a vertical direction perpendicular to the horizontal direction, and acquires a second image from the second output information that has a horizontal direction and a vertical direction that captures the light-emitting point. The optical apparatus according to claim 4. [Claim 8] When the light-emitting point moves in the optical axis direction, the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions. When the light-emitting point moves in the orthogonal direction, the light-emitting point in the first image and the light-emitting point in the second image move such that they have the same component in at least one of the horizontal and vertical directions. The optical apparatus according to claim 7. [Claim 9] The determination unit determines that the light-emitting point has moved in the optical axis direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in opposite directions in at least one of the horizontal and vertical directions, and determines that the light-emitting point has moved in the orthogonal direction if the light-emitting point in the first image and the light-emitting point in the second image move such that they have components in the same direction in at least one of the horizontal and vertical directions. The optical apparatus according to claim 7. [Claim 10] The first detection unit and the second detection unit are positioned at optically conjugate positions with respect to the object. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 11] The generated light further comprises a third portion, A third mirror portion that reflects the aforementioned third portion, A third detection unit for detecting the third portion reflected by the third mirror unit, Furthermore, The acquisition unit acquires the third output information of the third detection unit, and acquires the intensity distribution of the generated light based on the acquired third output information. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 12] The third portion is closer to the optical axis of the main portion than the first and second portions. The optical apparatus according to claim 11. [Claim 13] The aforementioned illumination light is critical illumination. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 14] The system includes a mirror that reflects the generated light generated at the light-emitting point, The first part, the second part, and the main part are the generated light reflected by the mirror. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 15] The illumination light includes wavelengths of EUV, The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 16] The first detection unit and the second detection unit detect light with a wavelength different from the wavelength of the illumination light. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 17] The first mirror section and the second mirror section are arranged at substantially the same optical path position on the optical axis of the main section. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 18] The first mirror portion and the second mirror portion are positioned opposite each other across the optical axis of the main portion. The optical apparatus according to claim 17. [Claim 19] A fourth detection unit detects the illumination light, including the main portion, that has been reflected by the object, A processing unit that processes an image of the object based on the fourth output information of the fourth detection unit, It also has, The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 20] The aforementioned object includes a photomask, The optical apparatus according to claim 18. [Claim 21] A fourth detection unit that detects light from an object to be observed, which is positioned on the optical path of the main part, A processing unit that processes the image of the object to be observed based on the fourth output information of the fourth detection unit, Furthermore, The object includes the fourth detection unit, The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 22] The illumination light includes exposure light for exposing the wafer, The object includes a wafer having a region that is activated based on light from a photomask placed on the optical path of the exposure light, The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 23] The illumination light includes exposure light for exposing the wafer, The object includes a photomask for forming a pattern on the wafer. The optical apparatus according to any one of claims 1, 2, 4 to 9. [Claim 24] A control method for an optical device that illuminates an object with illumination light, The optical device is A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, An image processing unit including an acquisition unit and a determination unit, It has, The generated light includes the first part, the second part, and the main part. A method for controlling an optical device, The steps include illuminating the object with the illumination light, which includes at least a portion of the main part reflected by the optical element, The steps include causing the acquisition unit to acquire the first output information of the first detection unit and the second output information of the second detection unit at multiple sampling times, A step of causing the determination unit to determine the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Equipped with, The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion, In the step of having the determination unit make a determination, the determination unit is instructed to detect the movement of the light-emitting point in the optical axis direction of the generated light and the movement of the light-emitting point in an orthogonal direction perpendicular to the optical axis direction, based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. A method for controlling optical devices. [Claim 25] A control method for an optical device that illuminates an object with illumination light, The optical device is A first mirror portion that reflects a first portion of the generated light from the light emission point of the generated light which includes the illumination light, A second mirror portion that reflects the second portion of the generated light, An optical element that reflects the generated light, A first detection unit for detecting the first portion reflected by the first mirror unit, A second detection unit for detecting the second portion reflected by the second mirror unit, An image processing unit including an acquisition unit and a determination unit, It has, The generated light includes the first part, the second part, and the main part. A method for controlling an optical device, The steps include illuminating the object with the illumination light, which includes at least a portion of the main part reflected by the optical element, The steps include causing the acquisition unit to acquire the first output information of the first detection unit and the second output information of the second detection unit at multiple sampling times, A step of causing the determination unit to determine the state of the light-emitting point based on the changes in the first output information and the changes in the second output information, Equipped with, The first mirror portion separates the first portion from the optical path of the main portion, The second mirror portion separates the second portion from the optical path of the main portion, In the step of having the determination unit make a determination, the determination unit is instructed to detect a change in the light emission intensity at the light emission point based on the change in the first output information of the first detection unit and the change in the second output information of the second detection unit between a predetermined sampling time and a sampling time after the predetermined sampling time. A method for controlling optical devices.

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