Inspection device and inspection method

Abstract

An inspection device according to the present embodiment comprises: an illumination optical system (100) for illuminating an object (400) with illumination light (L10); an imaging optical system (220a) that includes a condensing member (210) for condensing light (L20) from the object (400) illuminated with the illumination light (L10), and images the light (L20) condensed by the condensing member (210) onto a light detection unit (230); and a processing unit (300) that inspects the object (400) on the basis of the image imaged on the light detection unit (230). When an object plane (410) is set between the object (400) and the condensing member (210), the object plane (410) has: a condensing region (520) including a first condensing region and a second condensing region; and an illumination light region (510) surrounded by the second condensing region. The first condensing region is associated with regular reflection light (L21), and the second condensing region is associated with high-order diffraction light (L22). The first condensing region is surrounded by the second condensing region.

Description

Technical Field

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[0001] The present disclosure relates to an inspection apparatus and an inspection method.

Background Art

[0002] With the miniaturization of semiconductor processes, the patterns and defect sizes of photomasks are also expected to be miniaturized.

[0003] Patent Document 1 describes a technique for inspecting defects in a mask formed with a pattern using EUV (Extreme Ultraviolet) light.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In mask inspection using EUV light, it is required to further improve the resolution.

[0006] The present disclosure has been made in view of such problems, and provides an inspection apparatus and an inspection method capable of improving the resolution.

Means for Solving the Problems

[0007] An inspection apparatus according to one aspect of this embodiment includes an illumination optical system for illuminating an object with illumination light, an imaging optical system including a light-collecting member for collecting light from the object illuminated by the illumination light, and for forming an image of the light collected by the light-collecting member on a light-detecting unit, and a processing unit for inspecting the object based on the image formed on the light-detecting unit, wherein when an object plane parallel to the object is set between the object and the light-collecting member, the object plane has a focusing region that shows the luminous beam of the light collected by the light-collecting member, and a front of the illumination optical system The imaging optical system has an illumination light region that shows the luminous beam of illumination light that illuminates an object, and the focusing region includes a first focusing region that shows the luminous beam of specularly reflected light from the illumination light that illuminates the object, and a second focusing region that shows the luminous beam of higher-order diffracted light from the illumination light that illuminates the object, wherein the second focusing region has a shape with a gap due to shielding by the illumination light region or the components of the illumination optical system, and the imaging optical system images at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region onto the light detection unit.

[0008] In the inspection apparatus described above, the second focusing region may include a portion opposite to the illumination light region when viewed from the first focusing region, and a portion opposite to the first focusing region when viewed from the illumination light region.

[0009] In the inspection apparatus described above, the first focusing region may be surrounded by the second focusing region.

[0010] In the inspection apparatus described above, the illumination light area may be surrounded by the light-gathering area.

[0011] In the inspection apparatus described above, the second focusing region is defined by a first line connecting the center of the illumination light region and the center of the first focusing region. axis of symmetry A line-symmetrical design would also be acceptable.

[0012] In the inspection apparatus described above, the illumination light area and the first light-gathering area may each be formed as only one section on the plane of the object.

[0013] In the inspection apparatus described above, the first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region, and the region enclosed by the outer edge of the light-gathering region is defined by a first line connecting the center of the illumination light region and the center of the first light-gathering region. axis of symmetry It can also be symmetrical.

[0014] In the inspection apparatus described above, the centroid of the area of ​​the light-gathering region may coincide with the center of the first light-gathering region.

[0015] In the above inspection apparatus, the center of the light-gathering region does not overlap with the center of the first light-gathering region. The center of the light-gathering region may be closer to the illumination light region than the center of the first light-gathering region.

[0016] In the inspection apparatus described above, the region enclosed by the outer edge of the light-gathering region is divided into two by a second line perpendicular to the first line connecting the center of the illumination light region and the center of the first light-gathering region, and the second line passing through the center of the first light-gathering region. The portion of the light-gathering region on the side where the illumination light region is located is designated as the first portion, and the portion of the light-gathering region opposite to the first portion is designated as the second portion. In this case, the first portion may be larger than the second portion.

[0017] In the inspection apparatus described above, the second focusing region may include the portion between the illumination light region and the first focusing region.

[0018] In the inspection apparatus described above, the light-gathering member may relay the specularly reflected light and the higher-order diffracted light to an optical element located outside the space extending the second light-gathering region in a direction perpendicular to the plane of the object.

[0019] In the inspection apparatus described above, at least one of the illumination light region and the first focusing region may have an elongated shape in a direction perpendicular to the first line connecting the center of the illumination light region and the center of the first focusing region.

[0020] In the inspection apparatus described above, the first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region, and the region enclosed by the outer edge of the light-gathering region is defined by a first line connecting the center of the illumination light region and the center of the first light-gathering region. axis of symmetry It is symmetrical with respect to the line, and is a second line perpendicular to the first line, and the second line passing through the center of the first light-gathering region is the axis of symmetry It can also be symmetrical.

[0021] An inspection method according to one aspect of this embodiment comprises the steps of: illuminating an object with illumination light using an illumination optical system; forming an image of the light from the object illuminated with the illumination light onto a light detection unit using an imaging optical system; and inspecting the object with a processing unit based on the image formed on the light detection unit, wherein the step of forming an image of the light onto the light detection unit using the imaging optical system includes the step of focusing the light with a light-gathering member included in the imaging optical system, and in the step of illuminating with illumination light and the step of focusing the light with a light-gathering member, when an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous beam of the light focused by the focusing member, and an illumination light region showing the luminous beam of the illumination light that illuminates the object by the illumination optical system, wherein the focusing region includes a first focusing region showing the luminous beam of specularly reflected light from the illumination light that illuminates the object, and a second focusing region showing the luminous beam of higher-order diffracted light from the illumination light that illuminates the object, wherein the second focusing region has a shape with a gap due to shielding by the illumination light region or components of the illumination optical system, and the imaging optical system images at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region onto the light detection unit.

[0022] In the inspection method described above, in the steps of illuminating with the illumination light and focusing the light with the light-gathering member, the second light-gathering region may include the portion opposite to the illumination light region when viewed from the first light-gathering region and the portion opposite to the first light-gathering region when viewed from the illumination light region.

[0023] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the first condensing region may be surrounded by the second condensing region.

[0024] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the illumination light region may be surrounded by the condensing region.

[0025] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the second condensing region may be line-symmetric with respect to a first line connecting the center of the illumination light region and the center of the first condensing region. axis of symmetry

[0026] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, only one illumination light region and the first condensing region may be formed respectively on the object plane.

[0027] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the first condensing region is arranged at the center of the region surrounded by the outer edge of the condensing region, and the region surrounded by the outer edge of the condensing region may be line-symmetric with respect to a first line connecting the center of the illumination light region and the center of the first condensing region. axis of symmetry

[0028] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the centroid of the area of the condensing region excluding the illumination light region may overlap with the center of the first condensing region.

[0029] In the above inspection method, in the step of illuminating with the illumination light and the step of condensing by the condensing member, the center of the condensing region may not overlap with the center of the first condensing region, and the center of the condensing region may be closer to the illumination light region than the center of the first condensing region.

[0030] ​​ In the above inspection method, in the steps of illuminating with the illumination light and focusing the light with the light-gathering member, the region enclosed by the outer edge of the light-gathering region is divided into two by a second line perpendicular to the first line connecting the center of the illumination light region and the center of the first light-gathering region, and the second line passing through the center of the first light-gathering region. The portion of the light-gathering region on the side where the illumination light region is located is designated as the first portion, and the portion of the light-gathering region opposite to the first portion is designated as the second portion. In this case, the first portion may be larger than the second portion.

[0031] In the inspection method described above, in the steps of illuminating with the illumination light and focusing the light with the light-gathering member, the second light-gathering region may include the portion between the illumination light region and the first light-gathering region.

[0032] In the inspection method described above, in the step of focusing light with the focusing member, the focusing member may relay the specular reflected light and the higher-order diffracted light to an optical element located outside the space extended from the focusing region in a direction perpendicular to the plane of the object.

[0033] In the inspection method described above, in the steps of illuminating with the illumination light and focusing the light with the light-gathering member, at least one of the illumination light area and the first light-gathering area may have an elongated shape in a direction perpendicular to the first line connecting the center of the illumination light area and the center of the first light-gathering area.

[0034] In the above inspection method, in the steps of illuminating with the illumination light and focusing the light with the light-gathering member, the first light-gathering region is positioned in the center of the region enclosed by the outer edge of the light-gathering region, and the region enclosed by the outer edge of the light-gathering region is defined by a first line connecting the center of the illumination light region and the center of the first light-gathering region. axis of symmetry It is symmetrical with respect to the line, and is a second line perpendicular to the first line, and the second line passing through the center of the first light-gathering region is the axis of symmetry It can also be symmetrical. [Effects of the Invention]

[0035] This disclosure provides an inspection apparatus and inspection method that can further improve resolution. [Brief explanation of the drawing]

[0036] [Figure 1] This is a diagram illustrating an inspection device according to Embodiment 1. [Figure 2] This is a plan view illustrating the illumination light area and the light focusing area on the plane of the object in the inspection apparatus according to Embodiment 1. [Figure 3] This is a plan view illustrating the illumination light area and the light focusing area on the plane of the object in an inspection device according to a modified example 1 of Embodiment 1. [Figure 4] This is a diagram illustrating an inspection device according to a modified example 2 of Embodiment 1. [Figure 5] This flowchart illustrates an inspection method using the inspection device according to Embodiment 1. [Figure 6] This is a plan view illustrating the illumination light area and the light focusing area in an inspection apparatus according to a modified example 3 of Embodiment 1. [Figure 7] This is a diagram illustrating the inspection measures according to Embodiment 2. [Figure 8] This is a plan view illustrating the illumination light area and the light focusing area on the plane of the object in the inspection apparatus according to Embodiment 2. [Figure 9] This graph illustrates the relationship between the symmetry of the focusing region and phase defects in the inspection apparatus according to Embodiment 1. The horizontal axis shows the amount of shift between the center of the first focusing region and the center of the focusing region, and the vertical axis shows the roughness. [Figure 10] This figure illustrates the illumination light area and the light focusing area in an inspection device according to a modified example of Embodiment 2. [Figure 11] This is a plan view illustrating the illumination light area and the light focusing area on the plane of the object in the inspection apparatus according to Embodiment 3. [Figure 12] This figure illustrates the illumination light area and the light focusing area in an inspection device according to a modified example of Embodiment 3. [Figure 13]This figure illustrates the illumination light area and the light focusing area in the inspection apparatus according to Embodiment 5. [Modes for carrying out the invention]

[0037] 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.

[0038] <Embodiment 1> An inspection apparatus and inspection method according to Embodiment 1 will be described. Figure 1 is a configuration diagram illustrating an inspection apparatus according to Embodiment 1. As shown in Figure 1, the inspection apparatus 1 according to this embodiment includes an illumination optical system 100, a detection optical system 200, and a processing unit 300. The detection optical system 200 includes an imaging optical system 220a and a light detection unit 230. The imaging optical system 220a includes a light-gathering member 210. The imaging optical system 220a may also include a light-gathering member 210 and a relay system 220. The detection optical system 200 may include a light-gathering member 210, a relay system 220, and a light detection unit 230. In addition to the components described above, the inspection apparatus 1 may further include optical components such as mirrors and lenses, or some of the components described above may be omitted. For example, if the light reflected from the light-gathering member 210 is directly incident on the light detection unit 230, the relay system can be omitted. The inspection apparatus 1 inspects an object 400.

[0039] The illumination optical system 100 illuminates the object 400 with illumination light L10. The illumination optical system 100 may include a light source 110. The illumination optical system 100 may also draw illumination light L10 from a light source 110 provided separately from the inspection device 1, as long as it can illuminate the object 400 with illumination light L10. The illumination optical system 100 may include optical components such as mirrors and lenses, which are not shown in the illustration. The hole 212 formed in the collector mirror 211, described later, is provided to illuminate the object 400 with illumination light L10. Therefore, the hole 212 may be included as an aperture in the optical component 120 of the illumination optical system 100. For example, the illumination light L10 generated by the light source 110 illuminates the object 400 by passing through the illumination optical system 100, including the hole 212 in the collector mirror 211, etc.

[0040] Here, for the sake of explaining the inspection device 1, we introduce an XYZ Cartesian coordinate system. The plane tangent to the illuminated surface of the object 400 illuminated by the illumination light L10 is defined as the XY plane, and the two directions parallel to the XY plane and mutually orthogonal to each other are defined as the X-axis and Y-axis directions. The direction perpendicular to the XY plane is defined as the Z-axis direction. The illumination light L10 illuminates the object 400 from, for example, the +Z-axis side. Therefore, the illumination light L10 travels such that it has a component in the -Z-axis direction.

[0041] The light-gathering member 210 is positioned, for example, on the +Z axis side of the object 400. The light-gathering member 210 includes a collector mirror 211. The collector mirror 211 may include an elliptical mirror. The collector mirror 211 may also include a concave mirror and a plane mirror. The light-gathering member 210 gathers the light L20 from the object 400 illuminated by the illumination light L10. The light L20 from the object 400 illuminated by the illumination light L10 may include specular reflected light (0th-order diffracted light) L21 and higher-order diffracted light L22. The collector mirror 211 gathers the light L20, including the specular reflected light L21 and higher-order diffracted light L22, and reflects it to the relay system 220 or the light detection unit 230. The collector mirror 211 may have a hole 212. As described above, the illumination light L10 may illuminate the object 400 by passing through the hole 212. An object plane 410 may be set between the object 400 and the light-gathering member 210. The object plane 410 is parallel to the object 400. The object plane 410 may also be parallel to the irradiation surface of the object 400.

[0042] Figure 2 is a plan view illustrating the illumination light area 510 and the light-gathering area 520 on the object plane 410 in the inspection apparatus 1 according to Embodiment 1. As shown in Figure 2, the object plane 410 may have an illumination light area 510 and a light-gathering area 520. The light-gathering area 520 includes a first light-gathering area 521 and a second light-gathering area 522.

[0043] The illumination light region 510 corresponds to the illumination light L10. The illumination light region 510 represents the luminous beam of the illumination light L10 that illuminates the object 400 by the illumination optical system 100. In other words, the illumination light region 510 includes the region through which the luminous beam of illumination light L10 has passed in the object plane 410. In the object plane 410, the outer edge of the illumination light region 510 corresponds to the outer edge of the luminous beam of illumination light L10. The plane containing the optical axis of the illumination light L10 and the optical axis of the specularly reflected light L21 is defined as the optical axis plane. For example, the optical axis plane intersects with the first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first focusing region 521, and is perpendicular to the object plane 410. The optical axis plane is a plane containing the principal optical axis of the illumination light L10 and the principal optical axis of the specularly reflected light L21, and may also be a plane containing the normal to the principal surface of the object 400. In the optical axis plane, the sine of the angle between the optical axis of the illumination light L10 and the outer edge of the illumination light L10 corresponds to the numerical aperture (NA) of the illumination light L10.

[0044] In Figure 2, the illumination light region 510 is surrounded by the focusing region 520 and the second focusing region 522. However, the illumination light region 510 does not have to be entirely surrounded by the second focusing region 522. In other words, a part of the illumination light region 510 does not have to be surrounded by the second focusing region 522. The following explanation will follow the example shown in the figure. The illumination light region 510 is located inside the outer edge of the focusing region 520 and the outer edge of the second focusing region. The illumination optical system 100 illuminates the object 400 with illumination light L10 that has passed through the illumination light region 510 on the object plane 410.

[0045] The focusing region 520 represents the luminous beam of light focused by the focusing member 210. The first focusing region 521 represents the luminous beam of specular reflected light L21 from the illumination light L10 that illuminated the object 400. The first focusing region 521 is associated with the specular reflected light L21 from the illumination light L10 that illuminated the object 400. In other words, the first focusing region 521 includes the region through which the luminous beam of specular reflected light L21 has passed in the object plane 410. In the object plane 410, the outer edge of the first focusing region 521 corresponds to the outer edge of the luminous beam of specular reflected light L21. In the optical axis plane, the sine of the angle between the optical axis of specular reflected light L21 and the outer edge of specular reflected light L21 corresponds to the NA of specular reflected light L21.

[0046] The first condensing region 521 is positioned so as to be surrounded by the second condensing region 522. The first condensing region 521 is positioned inward from the outer edge of the condensing region 520 and the outer edge of the second condensing region 522. The imaging optical system 220a images the light L20, which includes specularly reflected light L21 that has passed through the first condensing region 521, onto the light detection unit 230 in the object plane 410.

[0047] The second focusing region 522 represents the luminous beam of higher-order diffracted light L22 caused by the illumination light L10 that illuminated the object 400. The second focusing region 522 is associated with the higher-order diffracted light L22 caused by the illumination light L10 that illuminated the object 400. In other words, the second focusing region 522 includes the region through which the luminous beam of higher-order diffracted light L22 has passed in the object plane 410. In the object plane 410, the outer edge of the second focusing region 522 corresponds to the outer edge of the luminous beam of higher-order diffracted light L22 that can be received by the focusing member 210. In the optical axis plane, the sine of the angle between the optical axis of the higher-order diffracted light L22 and the outer edge of the higher-order diffracted light L22 corresponds to the NA of the higher-order diffracted light L22 that can be received by the focusing member 210.

[0048] The second focusing region 522 may be formed to surround the illumination light region 510. That is, by forming the second focusing region 522 to surround the illumination light region 510, the second focusing region 522 may have a shape that includes a gap due to the shielding of the illumination light region 510 or components of the illumination optical system 100. The second focusing region 522 includes a region outside at least a portion of the outer edge of the illumination light region 510 in a direction perpendicular to the optical axis plane. The second focusing region 522 is also formed to surround the first focusing region 521. The outer edge of the second focusing region 522 is formed outside the illumination light region 510 and the first focusing region 521. In this embodiment, the illumination light region 510 can also be said to be the gap 511 in the second focusing region 522. The focusing region 520 is the region obtained by removing the gap 511 from the first focusing region 521 and the second focusing region 522. The imaging optical system 220a images the light L20, which includes the higher-order diffracted light L22 that has passed through the second focusing region 522, onto the photodetector 230 in the object plane 410. As mentioned above, the second focusing region 522 does not need to be formed to surround the illumination light region 510. The second focusing region 522 includes a portion opposite to the illumination light region 510 when viewed from the first focusing region 521, and a portion opposite to the first focusing region 521 when viewed from the illumination light region 510. The imaging optical system 220a then images at least a portion of the first light L21 in the first focusing region 521 and at least a portion of the second light L22 in the second focusing region 522 onto the photodetector 230.

[0049] The second focusing region 522 is formed by a first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first focusing region 521. axis of symmetry A line-symmetric shape is also acceptable. The higher-order diffracted light L22 may contain noise with a component having the opposite phase on the opposite side of the optical axis of the higher-order diffracted light L22. Therefore, by making the second focusing region 522 a line-symmetric shape, such noise can be mutually canceled out, thereby reducing noise.

[0050] The illumination light area 510 and the first light-gathering area 521 may each be formed as only one section on the object plane 410. This increases the intensity of specular reflected light L21 and improves resolution. Furthermore, this configuration simplifies the structure of the inspection device 1.

[0051] The light-gathering member 210 may relay the specularly reflected light L21 and the higher-order diffracted light L22 to an optical element located outside the space extending the light-gathering region 520 in the Z-axis direction perpendicular to the object plane 410. For example, the relay system 220 is located outside the space extending the light-gathering region 520 in the Z-axis direction. The light-gathering member 210 guides the specularly reflected light L21 and the higher-order diffracted light L22 to the relay system 220. With this configuration, the light L20 emitted from the object 400 can be focused by the light-gathering member 210 without being blocked by other members, thus maintaining the intensity of the light L20. Therefore, the resolution can be improved.

[0052] In contrast, for example, the Schwarzschild optical system described in Patent Document 1 includes a concave mirror that receives either specularly reflected light L21 or higher-order diffracted light L22 from an object 400, and a convex mirror that guides the specularly reflected light L21 or higher-order diffracted light L22 reflected by the concave mirror to a photodetector 230. In the Schwarzschild optical system, the convex mirror is positioned inside a space that extends the light-collecting region of the light received by the concave mirror in the Z-axis direction. When detecting higher-order diffracted light L22, the Schwarzschild optical system places a recessed mirror directly below the convex mirror so that the higher-order diffracted light L22 is incident on the entire surface of the concave mirror. In this case, since the convex mirror is positioned between the irradiation position of the illumination light L10 and the concave mirror, specularly reflected light L21 cannot be incident on the concave mirror. On the other hand, when detecting specularly reflected light L21, the Schwarzschild optical system shifts the recessed mirror away from directly below the convex mirror so that the specularly reflected light L21 is incident on half of the concave mirror. In this case, since the recessed mirror is positioned between the illumination position of the illumination light L10 and the remaining half of the concave mirror, higher-order diffracted light L22 that can be incident on the convex mirror cannot be incident on the concave mirror.

[0053] The focusing member 210 may include a transmitting member such as a lens and a prism. The transmitting member in the focusing member 210 may focus light L20, which includes specularly reflected light L21 and higher-order diffracted light L22, and guide it to the relay system 220 or the photodetector 230. Furthermore, the focusing member 210 may be positioned on the -Z axis side of the object 400. In that case, the light L20 from the object 400 illuminated by illumination light L10 includes transmitted light and higher-order diffracted light L22. The focusing member 210 focuses light L20, which includes transmitted light and higher-order diffracted light L22, and guides it to the relay system 220 or the photodetector 230. The light L20 focused by the focusing member 210 is incident on the relay system 220 or the photodetector 230. The focusing member 210 is included in the imaging optical system 220a.

[0054] The imaging optical system 220a includes a light-gathering member 210. The imaging optical system 220a may also include other optical elements such as mirrors. The imaging optical system 220a forms an image of the light L20 focused by the light-gathering member 210 onto the light detection unit 230. The imaging optical system 220a may form an image of the light L20 focused by the light-gathering member 210 onto the light detection unit 230 by the light-gathering member 210, or it may form an image onto the light detection unit 230 by an optical element such as a mirror relayed from the light-gathering member 210 (relay system 220). The relay system 220 may include a concave mirror and a plane mirror. The light detection unit 230 detects the image formed by the imaging optical system 220a. The light detection unit 230 outputs information including the detected image to the processing unit 300.

[0055] The processing unit 300 is connected to the photodetector 230 in a manner that enables information transmission. The processing unit 300 receives information including an image from the photodetector 230. The processing unit 300 inspects the object 400 based on the image formed on the photodetector 230. The processing unit 300 may also be connected to the illumination optical system 100 and the detection optical system 200 in a manner that enables information transmission. The processing unit 300 may acquire various data from the illumination optical system 100 and the detection optical system 200. The processing unit 300 may control the illumination optical system 100 and the detection optical system 200 based on the acquired data.

[0056] <Example 1> Next, Modification 1 will be described. In this modification, the shapes of the illumination light area 510 and the light-gathering area 520 differ from those of Embodiment 1 described above. The shapes of the illumination light area 510 and the light-gathering area 520 can be set by adjusting the shape and arrangement of optical components such as the light-gathering member 210 in the illumination optical system 100 and the detection optical system 200. Figure 3 is a plan view illustrating the illumination light area 510 and the light-gathering area 520a on the object plane 410 in the inspection apparatus 1a according to Modification 1 of Embodiment 1.

[0057] As shown in Figure 3, the illumination light area 510 and the first focusing area 521 may be elongated in shape extending in the Y-axis direction perpendicular to the first line 531. For example, the illumination light area 510 and the first focusing area 521 may be ellipses with the Y-axis direction perpendicular to the first line 531 as their major axis. This reduces the portion shielded by the illumination light area 510, even if the second focusing area 522 includes the illumination light area 510 and the first focusing area 521, thereby improving resolution. It also allows for space to be secured between the illumination light area 510 and the first focusing area 521. The same effect can be obtained even if at least one of the illumination light area 510 and the first focusing area 521 is elongated.

[0058] As described above, the illumination light region 510 and the first focusing region 521 may be spaced apart. In other words, the illumination light region 510 and the first focusing region 521 do not overlap. As a result, the illumination light L10 and the specular reflected light L21 do not block each other, and thus the resolution can be improved. Furthermore, the second focusing region 522 may include the portion between the illumination light region 510 and the first focusing region 521. In other words, the second focusing region 522 is formed to connect to both the illumination light region 510 and the first focusing region 521. Higher-order diffracted light L22 due to defects contained in the object 400 may have a high intensity even when emitted in the same direction as the specular reflected light L21. Therefore, a portion of the high-order diffracted light L22 due to defects with high intensity is distributed around the first focusing region 521. Therefore, by including the portion between the illumination light region 510 and the first illumination light region 521 in the second focusing region 522, more of the higher-order diffracted light L22 from defects can be captured without being blocked by the illumination light region 510, thereby improving the resolution of defects contained in the object 400.

[0059] <Modification 2> Next, a modified example 2 will be described. In the inspection apparatus 1b of this modified example, the collector mirror 211 does not have a hole 212. Figure 4 is a configuration diagram illustrating an inspection apparatus 1b according to modified example 2 of Embodiment 1. As shown in Figure 4, in the inspection apparatus 1b of this modified example, the illumination optical system 100 may include a mirror 121 as an optical member 120. The mirror 121 is positioned between the light-gathering member 210 and the object 400. The mirror 121 reflects the illumination light L10 emitted from the light source 110 to illuminate the object 400. Therefore, the collector mirror 211 does not need to have a hole 212. The optical path of the illumination light L10 from the mirror 121 to the object 400 may be the same as a part of the optical path that goes to the object 400 through the aforementioned hole 212. In the inspection apparatus 1b of this modified example, the shapes of the illumination light area 510 and the light-gathering area 520 may be the same as those of Embodiment 1 described above. However, a portion of the luminous flux of the higher-order diffracted light L22 from the illumination light L10 that illuminates the object 400 is shielded by the mirror 121 and not focused by the light-gathering member 210. Therefore, in the inspection apparatus 1b of this modified example, the second light-gathering region 522 has a shape that has a gap due to shielding by the components of the illumination optical system 100. In addition, the illumination light region 510 is the same as the gap 511, but depending on the effective area of ​​the mirror 121, the illumination light region 510 may also be included in the gap 511.

[0060] In this embodiment, the inspection device 1b allows for easy modification of the illumination position of the illumination light L10 by changing the angle of the reflective surface of the mirror 121. By forming the members supporting the mirror 121, such as bridges, in a thin linear shape, the effect of shielding by bridges, etc., can be reduced.

[0061] <Testing Method> Next, the inspection method will be described. Figure 5 is a flowchart illustrating the inspection method using the inspection device 1 according to Embodiment 1. As shown in Figure 5, the inspection method of this embodiment comprises the steps of: illuminating the object 400 with illumination light L10 in step S11; focusing the light L20 from the object 400 in step S12; forming an image of the light L20 on the light detection unit 230 in step S13; and inspecting the object 400 in step S14.

[0062] In step S11, the object 400 is illuminated with illumination light L10 by the illumination optical system 100.

[0063] In step S12, the light L20 from the object 400 illuminated by the illumination light L10 is focused by the light-gathering member 210. The light L20 from the object 400 may include specularly reflected light L21 reflected by the object 400 and higher-order diffracted light L22 diffracted by the object 400.

[0064] In steps S11 and S12, an object plane 410 may be set between the object 400 and the light-gathering member 210. In this case, the object plane 410 may have a light-gathering region 520 including a first light-gathering region 521 and a second light-gathering region 522, and an illumination light region 510 surrounded by the second light-gathering region 522. Note that a part of the illumination light region 510 does not need to be surrounded by the second light-gathering region 522. The light-gathering region 520 represents the luminous beam of light focused by the light-gathering member 210. The first light-gathering region 521 represents the luminous beam of specularly reflected light L21 from the illumination light L10 that illuminated the object 400. In other words, the first light-gathering region 521 corresponds to the specularly reflected light L21 from the illumination light L10 that illuminated the object 400. The second light-gathering region 522 represents the luminous beam of higher-order diffracted light L22 from the illumination light L10 that illuminated the object 400. In other words, the second focusing region 522 corresponds to the higher-order diffracted light L22 produced by the illumination light L10 that illuminated the object 400. Here, the first focusing region 521 is positioned so as to be surrounded by the second focusing region 522.

[0065] In steps S11 and S12, the second focusing region 522 has a first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first focusing region 521. axis of symmetryLine symmetry is also acceptable. The illumination light region 510 and the first focusing region 521 may each be formed as only one section in the object plane 410. At least one of the illumination light region 510 and the first focusing region 521 may be elongated in a direction perpendicular to the first line 531. The illumination light region 510 and the first focusing region 521 may be spaced apart. Furthermore, the second focusing region 522 may include the portion between the illumination light region 510 and the first focusing region 521.

[0066] In step S11, the illumination optical system 100 illuminates the object 400 with illumination light L10 that has passed through the illumination light region 510.

[0067] In step S12, the light-gathering member 210 may relay the specularly reflected light L21 and the higher-order diffracted light L22 to an optical element located outside the space in which the light-gathering region 520 is extended in a direction perpendicular to the object plane 410.

[0068] Next, in step S13, the light L20 focused by the light-gathering member 210 is imaged onto the light-detecting unit 230 by the imaging optical system 220a. The imaging optical system 220a images the light L20, which includes specularly reflected light L21 (first light) that has passed through the first light-gathering region 521 and higher-order diffracted light L22 (second light) that has passed through the second light-gathering region 522, onto the light-detecting unit 230.

[0069] Next, in step S14, the processing unit 300 inspects the object 400 based on the image formed by the light detection unit 230.

[0070] In addition, in steps S11 and S12, the shape of the light-gathering region 520a may be as shown in Modification 1. Also, in step S11, a mirror 121 may be used as the optical element 120.

[0071] Next, the effects of this embodiment will be described. In the inspection apparatus 1, 1a and 1b of this embodiment, the imaging optical system 220a images the light L20, which includes specular reflected light L21 that has passed through the first focusing region 521 and higher-order diffracted light L22 that has passed through the second focusing region 522, onto the photodetector 230. Therefore, the photodetector 230 detects not only the specular reflected light L21 but also the higher-order diffracted light L22, thereby improving the resolution.

[0072] <Variation 3> Figure 6 shows a modification 3 of Embodiment 1. Based on this, variations in the absence of the second focusing region 522 will be explained. Figure 6 is a plan view illustrating the illumination light region 510, the first focusing region 521 (solid line), and the second focusing region 522 (dotted line) in the inspection apparatus 601 according to modification 3 of Embodiment 1. As a means of improving the resolution of the inspection apparatus 601, it is conceivable to image more of the scattered light components, including the higher-order diffracted light L22, by expanding the NA of the imaging optical system 220a. On the other hand, since the reflectance of EUV light in the EUV multilayer constituting the EUV photomask is angle-dependent (for example, the reflectance is maximum when the incident angle is 6°), the introduction path of the illumination light L10 is almost uniquely determined in actinic inspection. For this reason, if the focusing region 520 with respect to the NA of the imaging optical system 220a is to be expanded, the illumination light region 510 and the second focusing region 522 will spatially overlap, as shown in Figure 6. Therefore, the illumination light area 510 acts as an obstruction to the second light-gathering area 522. Nevertheless, since it is advantageous to have a wide second light-gathering area 522, in the inspection apparatus 601 according to this modified example, the second light-gathering area 522 is given a shape that has a gap due to the illumination light area 510. As a result, the light detection unit 230 can detect not only specular reflected light L21 but also more higher-order diffracted light L22, thereby improving the resolution. In this case, the gap 511 is represented by a diagonal line. That is, in this modified example, the second light-gathering area 522 has a shape that has a gap due to the obstruction of the illumination light area 510 or the components of the illumination optical system 100, but it does not surround the illumination light area 510, which is different from the embodiment described above.

[0073] Returning to the main point, in this embodiment, the illumination light area 510 is positioned within the focusing area 520. This makes it possible to further image the light L20, which has passed through both the first focusing area 521 associated with specular reflected light L21 and the second focusing area 522 associated with higher-order diffracted light L22, onto the photodetector 230. The illumination light area 510 acts as an obstruction to the focusing area 520, but rather, the outer edge of the NA of the focusing area 520 is made large enough to surround the illumination light area 510, including that portion. For example, if the focusing area 520 surrounds the outside of the illumination light area 510 all around, including an area larger than the area obstructed by the illumination light area 510 and the components of the illumination optical system, the amount of light imaged onto the photodetector 230 can be increased, and the resolution can be improved.

[0074] <Embodiment 2> Next, an inspection apparatus according to Embodiment 2 will be described. In this embodiment, the first focusing region 521 through which specular reflected light L21 passes is positioned in the center of the second focusing region 522 through which higher-order diffracted light L22 passes. Figure 7 is a configuration diagram illustrating the inspection apparatus 2 according to Embodiment 2. Figure 8 is a plan view illustrating the illumination light region 510 and the focusing region 520b on the object plane 410 in the inspection apparatus 2 according to Embodiment 2.

[0075] As shown in Figures 7 and 8, the first focusing region 521 in this embodiment is located in the center of the region enclosed by the outer edge of the second focusing region 522. Therefore, the first focusing region 521 is located in the center of the region enclosed by the outer edge of the focusing region 520b. For example, the center C20 of the region enclosed by the outer edge of the focusing region 520b may overlap with the center C21 of the first focusing region. The focusing member 210 in this embodiment is configured such that the first focusing region 521 is located in the center of the region enclosed by the outer edge of the second focusing region 522. The focusing member 210 that determines the NA of the higher-order diffracted light L22 is configured such that the central region of the reflecting surface of the focusing member 210 includes the optical axis of the specularly reflected light L21, and the peripheral region around the central region includes the light beam of the higher-order diffracted light L22.

[0076] Furthermore, the region enclosed by the outer edge of the light-gathering region 520b is defined by the first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first light-gathering region 521. axis of symmetry It is symmetrical in this respect. In addition, the region enclosed by the outer edge of the light-gathering region 520b is a second line 532 that is perpendicular to the first line 531, and the second line 532 passes through the center C21 of the first light-gathering region 521. axis of symmetry It can also be symmetrical.

[0077] In the inspection method of this embodiment, in steps S11 and S12, the first light-gathering region 521 is positioned in the center of the region enclosed by the outer edge of the light-gathering region 520b. The region enclosed by the outer edge of the light-gathering region 520b is defined by the first line 531. axis of symmetry It is symmetrical with respect to the second line 532. axis of symmetry Make it symmetrical with respect to the line.

[0078] Next, the effects of this embodiment will be explained. The inspection apparatus 2 of this embodiment can obtain a high signal-to-noise ratio (SNR). In general, as the NA of the focusing region 520b is increased, minute phase defects (ML roughness) on the surface of the EUV multilayer are also resolved and become noise. As a result, there is a problem of reducing the SNR. These minute phase defects can be reduced by increasing the symmetry of the focusing region 520b.

[0079] Figure 9 is a graph illustrating the relationship between the symmetry of the focusing region 520b and phase defects in the inspection apparatus 1 according to Embodiment 1. The horizontal axis represents the amount of shift between the center of the first focusing region 521 and the center of the focusing region 520, and the vertical axis represents roughness. As shown in Figure 9, the smaller the amount of shift, the better the symmetry of the focusing region 520b can be, and the less roughness can be reduced. Thus, the inspection apparatus 2 of this embodiment can reduce noise caused by phase defects and obtain a high signal-to-noise ratio by forming the first focusing region 521 in the center of the focusing region 520b. Other configurations and effects are described in Embodiment 1 and each of its modifications.

[0080] <Variation> Figure 10 is a diagram illustrating the illumination light region 510 and the focusing region 520b in an inspection apparatus 2a according to a modified example of Embodiment 2. As shown in Figure 10, the second focusing region 522 has a shape that is missing due to shielding by the illumination light region 510 or components of the illumination optical system 100. However, the second focusing region 522 differs from Embodiment 2 in that it does not surround the illumination light region 510. In this modified example, the first focusing region 521 through which specular reflected light L21 passes is positioned in the center of the second focusing region 522 through which higher-order diffracted light L22 passes. The region enclosed by the outer edge of the focusing region 520b is defined by the first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first focusing region 521. axis of symmetry It is symmetrical in this respect. However, since the second focusing region 522 does not surround the illumination region 510, the region enclosed by the outer edge of the focusing region 520b is the second line 532 which is perpendicular to the first line 531, and the second line 532 passing through the center C21 of the first focusing region 521 axis of symmetry It is not symmetrical with respect to this. Other configurations and effects are described in Embodiment 2.

[0081] <Embodiment 3> Next, an inspection apparatus according to Embodiment 3 will be described. Figure 11 is a plan view illustrating the illumination light area 510 and the light-gathering area 520c in the object plane 410 of the inspection apparatus 3 according to Embodiment 3. As shown in Figure 11, in the object plane 410, the centroid G20 of the area of ​​the light-gathering area 520c, excluding the illumination light area 510 (missing portion 511), may coincide with the center C21 of the first light-gathering area 521. Note that in the object plane 410, the centroid G20 of the area of ​​the light-gathering area 520c, excluding the illumination light area 510 (missing portion 511), may coincide with the centroid G21 of the area of ​​the first light-gathering area 521.

[0082] Furthermore, the region enclosed by the outer edge of the focusing region 520c is divided in two by a second line 532 that is perpendicular to the first line 531 connecting the center C10 of the illumination light region 510 and the center C21 of the first focusing region 521, and passes through the center C21 of the first focusing region 521. If the part of the focusing region 520c on the side where the illumination light region 510 is located is designated as the first part, and the part of the focusing region 520c on the opposite side of the first part is designated as the second part, the first part may be larger than the second part. The area of ​​the focusing region 520c excluding the illumination light region 510 may be equal to the area of ​​the first part and the area of ​​the second part.

[0083] In the inspection method of this embodiment, in steps S11 and S12, the centroid G20 of the area of ​​the light-gathering region 520c, excluding the illumination light region 510 (missing portion 511), is made to coincide with the center C21 of the first light-gathering region 521. Furthermore, the area enclosed by the outer edge of the light-gathering region 520c is divided in two by the second line 532, and the first portion of the light-gathering region 520c where the illumination light region 510 is located is made larger than the second portion on the opposite side of the first portion.

[0084] According to this embodiment, the centroid G20 of the area of ​​the focusing region 520c, excluding the illumination light region 510 (missing portion 511), coincides with the center C21 of the first focusing region 521. Therefore, the symmetry of the focusing region 520 can be improved, and roughness can be reduced. Thus, noise caused by phase defects can be reduced, and a high signal-to-noise ratio can be obtained. Furthermore, by making the first portion larger than the second portion, the focusing region 520c includes an area larger than the area shielded by the illumination light region 510, thus improving the resolution. Other configurations and effects are included in Embodiments 1 and 2 and their respective modifications.

[0085] <Variation> Figure 12 illustrates the illumination light area 510 and the focusing area 520c in an inspection apparatus 3a according to a modified example of Embodiment 3. As shown in Figure 12, the second focusing area 522 has a shape that is missing due to shielding by the illumination light area 510 or components of the illumination optical system 100. However, it differs from Embodiment 3 in that the second focusing area 522 does not surround the illumination light area 510. Other configurations and effects are described in Embodiment 3.

[0086] <Embodiment 4> The inspection apparatus of this embodiment may include an illumination optical system 100, an imaging optical system 220a, and a processing unit 300. The illumination optical system 100 may irradiate the object 400 with illumination light L10 in the EUV range at an angle tilted in a predetermined direction from the normal to the main surface of the object 400. The imaging optical system 220a includes a light-gathering member 210 that collects light from the object 400 illuminated by the illumination light L10. The imaging optical system 220a images the light collected by the light-gathering member 210 onto a light-detection unit 230. The processing unit 300 inspects the object 400 based on the image formed on the light-detection unit 230.

[0087] In the inspection apparatus of this embodiment, the focusing pupil distribution of the imaging optical system 220a on the object 400 may include a first focusing region showing the luminous flux of specularly reflected light from the illumination light L10 that illuminates the object 400, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light L10 that illuminates the object 400. The imaging optical system 220a may image at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region onto the light detection unit 230. The second focusing region may have a portion on the side of a predetermined direction.

[0088] The second focusing region may have a shape that includes the illumination pupil distribution of the illumination optical system 100 on the object 400 or a gap due to the shielding of components of the illumination optical system 100. The second focusing region may also include the portion outside the maximum angular area on a predetermined direction in the illumination pupil distribution of the illumination optical system 100 on the object 400.

[0089] The inspection method of this embodiment comprises an illumination step, an imaging step, and an inspection step. In the illumination step, the illumination optical system 100 illuminates the object 400 with illumination light L10 in the EUV range at an angle tilted in a predetermined direction from the normal to the main surface of the object 400. In the imaging step, the light from the object 400 illuminated by the illumination light L10 is imaged onto the photodetector 230 by the imaging optical system 220a. In the inspection step, the object 400 is inspected based on the image formed on the photodetector 230.

[0090] The imaging step includes focusing the light from the object 400 illuminated by the illumination light L10 using a light-gathering member 210 included in the imaging optical system 220a. In the illumination step and the step of focusing the light with the light-gathering member 210, the focusing pupil distribution of the imaging optical system 220a on the object 400 includes a first focusing region showing the luminous flux of specularly reflected light from the illumination light L10 that illuminated the object 400, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light L10 that illuminated the object 400. The imaging optical system 220a images at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region onto the light detection unit 230. The second focusing region may have a portion on the side of a predetermined direction.

[0091] The second focusing region may have a shape that includes the illumination pupil distribution of the illumination optical system 100 on the object 400 or a gap due to the shielding of components of the illumination optical system 100. The second focusing region may also include the portion outside the maximum angular area on a predetermined direction in the illumination pupil distribution of the illumination optical system 100 on the object 400.

[0092] <Embodiment 5> Figure 13 shows the illumination light area in the inspection apparatus 5 according to Embodiment 5. 510The figure also illustrates the light-gathering region 520d. As shown in Figure 13, in this embodiment, the center position C20 of the light-gathering region 520d (light-gathering pupil distribution), which includes the first light-gathering region 521 and the second light-gathering region 522, does not overlap with the center position C21 of the first light-gathering region 521. The center position C20 of the light-gathering region 520d (light-gathering pupil distribution) is closer to the illumination light region 510 (illumination pupil distribution) than the center position C21 of the first light-gathering region 521.

[0093] The focusing region 520d (focusing pupil distribution) does not have any gaps due to shielding by the illumination light region 510 (illumination pupil distribution) or components of the illumination optical system. The shape of each pupil may be circular or non-circular. Also, the entirety of the first focusing region 521 does not have to be included in the second focusing region 522. The maximum angle of the luminous beam of illumination light L10 passing through the illumination light region 510 with respect to the normal of the main surface of the object 400 is preferably less than or equal to the angle that ensures a reflectivity of illumination light L10 on the object 400 that is above the desired level, for example, 12 degrees or less. Furthermore, the focusing region 520d (focusing pupil distribution) may be formed to include the normal of the main surface of the object 400 (or an intermediate position between the center position of the illumination light region 510 (illumination pupil distribution) and the center position C21 of the first focusing region 521). The center position may be appropriately interpreted as the centroid (centroid of the figure). Furthermore, in the inspection apparatus 5 according to Embodiment 5, the light-gathering region 520d (light-gathering pupil distribution) is formed so as not to include the region outside the outer edge of the illumination light region 510 in a direction perpendicular to the optical axis plane, and to include the normal to the main surface of the object 400 (or an intermediate position between the center position of the illumination light region 510 (illumination pupil distribution) and the center position C21 of the first light-gathering region 521).

[0094] 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 also fall within the scope of the technical concept of this disclosure.

[0095] This application claims priority based on Japanese Patent Application No. 2024-161143, filed on 18 September 2024, and incorporates all of its disclosures herein.

[0096] The following notes also fall within the scope of the technical concept of this disclosure.

[0097] [Note 1] An illumination optical system that illuminates an object with illumination light, An imaging optical system includes a light-collecting member that collects light from the object illuminated by the aforementioned illumination light, and an imaging optical system that forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, When an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous flux of the light focused by the focusing member, and an illumination region showing the luminous flux of the illumination light that illuminates the object by the illumination optical system, The light-gathering region includes a first light-gathering region that shows the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second light-gathering region that shows the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The second focusing region includes a region outside at least a portion of the outer edge of the illumination region in a direction perpendicular to the optical axis plane, which is a plane containing the principal optical axis of the illumination light and the principal optical axis of the specular reflection light, and which contains the normal to the principal surface of the object. The imaging optical system causes the light detection unit to image at least a portion of the first light within the first light-gathering region and at least a portion of the second light within the second light-gathering region. Inspection device.

[0098] [Note 2] An illumination optical system that illuminates an object with illumination light, An imaging optical system includes a light-collecting member that collects light from the object illuminated by the aforementioned illumination light, and an imaging optical system that forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, When an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous flux of the light focused by the focusing member, and an illumination region showing the luminous flux of the illumination light that illuminates the object by the illumination optical system, The light-gathering region includes a first light-gathering region that shows the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second light-gathering region that shows the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The center position or centroid of the light-gathering region does not overlap with the center position or centroid of the first light-gathering region, and the center position or centroid of the light-gathering region is closer to the illumination light region than the center position or centroid of the first light-gathering region. The imaging optical system causes the light detection unit to image at least a portion of the first light within the first light-gathering region and at least a portion of the second light within the second light-gathering region. Inspection device.

[0099] [Note 3] An illumination optical system that illuminates an object with illumination light, An imaging optical system includes a light-collecting member that collects light from the object illuminated by the aforementioned illumination light, and an imaging optical system that forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, When an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous flux of the light focused by the focusing member, and an illumination region showing the luminous flux of the illumination light that illuminates the object by the illumination optical system, The light-gathering region includes a first light-gathering region that shows the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second light-gathering region that shows the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The second focusing region is a plane containing the principal optical axis of the illumination light and the principal optical axis of the specular reflection light, and in a direction perpendicular to the optical axis plane which is a plane containing the normal to the principal surface of the object, it does not include the region outside the outer edge of the illumination light region, but includes the normal to the principal surface of the object. The imaging optical system causes the light detection unit to image at least a portion of the first light within the first light-gathering region and at least a portion of the second light within the second light-gathering region. Inspection device. [Explanation of Symbols]

[0100] 1, 1a, 1b, 2, 3, 5 Inspection device 100 Illumination optical system 110 Light source 120 Optical components 121 Mirror 200 detection optics 210 Light-gathering member 211 Collector Mirror 212 holes 220 Relay System 220a Imaging Optical System 230 Light detection unit 300 Processing Unit 400 Objects 410 Object Plane 510 Illumination light area 511 Missing parts 520, 520a, 520b, 520c, 520d focusing area 521 1st focusing area 522 Second focusing area 531 First Line 532 Second Line 601 Inspection equipment C10, C20, C21 center G20, G21 center of gravity L10 illumination light L20 light L21 Specular reflection light L22 High-order diffracted light

Claims

1. An illumination optical system that illuminates an object with illumination light, An imaging optical system includes a light-collecting member that collects light from an object illuminated by the aforementioned illumination light, and which forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, When an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous flux of the light focused by the focusing member, and an illumination region showing the luminous flux of the illumination light that illuminates the object by the illumination optical system, The light-gathering region includes a first light-gathering region that shows the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second light-gathering region that shows the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The second light-gathering region has a shape that includes a gap due to the shielding of the illumination light region or the components of the illumination optical system. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first light-gathering region and at least a portion of the second light in the second light-gathering region. Inspection device.

2. The second focusing region includes a portion opposite to the illumination light region when viewed from the first focusing region, and a portion opposite to the first focusing region when viewed from the illumination light region. The inspection apparatus according to claim 1.

3. The first light-gathering region is surrounded by the second light-gathering region. The inspection apparatus according to claim 1 or 2.

4. The illumination light region is surrounded by the light-gathering region. The inspection apparatus according to claim 1 or 2.

5. The second focusing region is symmetrical with respect to a first line connecting the center of the illumination light region and the center of the first focusing region. The inspection apparatus according to claim 1 or 2.

6. The illumination light region and the first light-gathering region are each formed in only one section on the object plane. The inspection apparatus according to claim 1 or 2.

7. The first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region. The region enclosed by the outer edge of the light-gathering region is symmetrical with respect to the first line connecting the center of the illumination light region and the center of the first light-gathering region. The inspection apparatus according to claim 1 or 2.

8. The centroid of the area of ​​the light-gathering region coincides with the center of the first light-gathering region. The inspection apparatus according to claim 1 or 2.

9. The center of the light-gathering region does not overlap with the center of the first light-gathering region. The center of the light-gathering region is closer to the illumination light region than the center of the first light-gathering region. The inspection apparatus according to claim 1 or 2.

10. When the region enclosed by the outer edge of the light-gathering region is divided into two by a second line perpendicular to the first line connecting the center of the illumination light region and the center of the first light-gathering region, and the second line passing through the center of the first light-gathering region, with the portion of the light-gathering region on the side where the illumination light region is located being designated as the first portion and the portion of the light-gathering region opposite to the first portion being designated as the second portion, the first portion is larger than the second portion. The inspection apparatus according to claim 8.

11. The second light-gathering region includes the portion between the illumination light region and the first light-gathering region. The inspection apparatus according to claim 1 or 2.

12. The light-gathering member relays the specularly reflected light and the higher-order diffracted light to an optical element located outside the space extending the second light-gathering region in a direction perpendicular to the plane of the object. The inspection apparatus according to claim 1 or 2.

13. At least one of the illumination light region and the first focusing region is elongated in a direction perpendicular to the first line connecting the center of the illumination light region and the center of the first focusing region. The inspection apparatus according to claim 1 or 2.

14. The first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region. The region enclosed by the outer edge of the light-gathering region is symmetrical with respect to a first line connecting the center of the illumination light region and the center of the first light-gathering region, and is also symmetrical with respect to a second line perpendicular to the first line and passing through the center of the first light-gathering region. The inspection apparatus according to claim 4.

15. An illumination optical system that irradiates an object with illumination light in the EUV range at an angle tilted in a predetermined direction from the normal to the main surface of the object, An imaging optical system includes a light-collecting member that collects light from an object illuminated by the aforementioned illumination light, and which forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, The focusing pupil distribution of the imaging optical system on the object includes a first focusing region showing the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region. The second light-gathering region has a portion on the side in the predetermined direction, The second light-gathering region has a shape that includes the illumination pupil distribution of the illumination optical system on the object or a gap due to the shielding of components of the illumination optical system. Inspection device.

16. An illumination optical system that irradiates an object with illumination light in the EUV range at an angle tilted in a predetermined direction from the normal to the main surface of the object, An imaging optical system includes a light-collecting member that collects light from an object illuminated by the aforementioned illumination light, and which forms an image of the light collected by the light-collecting member on a light-detecting unit, A processing unit that inspects the object based on the image formed on the light detection unit, Equipped with, The focusing pupil distribution of the imaging optical system on the object includes a first focusing region showing the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region. The second light-gathering region has a portion on the side in the predetermined direction, The second light-gathering region includes the portion of the illumination pupil distribution of the illumination optical system on the object that is outside the maximum angle region on the predetermined direction side, Inspection device.

17. The steps include: illuminating an object with illumination light using an illumination optical system, The steps include: forming an image of the light from the object illuminated by the aforementioned illumination light onto a light detection unit using an imaging optical system; The steps include: inspecting the object by a processing unit based on the image formed on the light detection unit; Equipped with, The step of forming an image of the light on the light detection unit using the imaging optical system includes the step of focusing the light with a light-gathering member included in the imaging optical system, In the steps of illuminating with the aforementioned illumination light and concentrating the light with a light-gathering member, When an object plane parallel to the object is set between the object and the light-gathering member, The object plane has a focusing region showing the luminous flux of the light focused by the focusing member, and an illumination region showing the luminous flux of the illumination light that illuminates the object by the illumination optical system, The light-gathering region includes a first light-gathering region that shows the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second light-gathering region that shows the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The second light-gathering region has a shape that includes a gap due to the shielding of the illumination light region or the components of the illumination optical system. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first light-gathering region and at least a portion of the second light in the second light-gathering region. Testing method.

18. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The second focusing region includes a portion opposite to the illumination light region when viewed from the first focusing region, and a portion opposite to the first focusing region when viewed from the illumination light region. The inspection method according to claim 17.

19. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The first light-gathering region is surrounded by the second light-gathering region. The inspection method according to claim 17 or 18.

20. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The illumination light region is surrounded by the light-gathering region. The inspection method according to claim 17 or 18.

21. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The second focusing region is symmetrical with respect to a first line connecting the center of the illumination light region and the center of the first focusing region. The inspection method according to claim 17 or 18.

22. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The illumination light region and the first light-gathering region are each formed in only one form on the object plane. The inspection method according to claim 17 or 18.

23. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region. The region enclosed by the outer edge of the light-gathering region is symmetrical with respect to the first line connecting the center of the illumination light region and the center of the first light-gathering region. The inspection method according to claim 17 or 18.

24. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The centroid of the area of ​​the light-gathering region, excluding the illumination light region, is to coincide with the center of the first light-gathering region. The inspection method according to claim 17 or 18.

25. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The center of the light-gathering region is set so as not to overlap with the center of the first light-gathering region. The center of the light-gathering region is closer to the illumination light region than the center of the first light-gathering region. The inspection method according to claim 17 or 18.

26. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, When the region enclosed by the outer edge of the light-gathering region is divided into two by a second line perpendicular to the first line connecting the center of the illumination light region and the center of the first light-gathering region, and passing through the center of the first light-gathering region, with the portion of the light-gathering region on the side where the illumination light region is located being designated as the first portion and the portion of the light-gathering region on the opposite side of the first portion being designated as the second portion, the first portion is larger than the second portion. The inspection method according to claim 23.

27. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The second light-gathering region includes the portion between the illumination light region and the first light-gathering region. The inspection method according to claim 17 or 18.

28. In the step of concentrating light using the aforementioned light-collecting member, The light-gathering member relays the specularly reflected light and the higher-order diffracted light to an optical element located outside the space extending the light-gathering region in a direction perpendicular to the plane of the object. The inspection method according to claim 17 or 18.

29. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, At least one of the illumination light region and the first focusing region is elongated in a direction perpendicular to the first line connecting the center of the illumination light region and the center of the first focusing region. The inspection method according to claim 17 or 18.

30. In the step of illuminating with the aforementioned illumination light and the step of concentrating the light with the light-collecting member, The first light-gathering region is located in the center of the region enclosed by the outer edge of the light-gathering region. The region enclosed by the outer edge of the light-gathering region is symmetrical with respect to a first line connecting the center of the illumination light region and the center of the first light-gathering region, and is also symmetrical with respect to a second line perpendicular to the first line and passing through the center of the first light-gathering region, The inspection method according to claim 20.

31. The steps include: irradiating an object with EUV illumination light using an illumination optical system at an angle inclined toward a predetermined direction from the normal to the main surface of the object; The steps include: forming an image of the light from the object illuminated by the aforementioned illumination light onto a light detection unit using an imaging optical system; The steps include: inspecting the object based on the image formed on the light detection unit; Equipped with, The step of forming an image of the light on the light detection unit using the imaging optical system includes the step of focusing the light with a light-gathering member included in the imaging optical system, In the irradiating step and the step of focusing the light with the light-collecting member, The focusing pupil distribution of the imaging optical system on the object includes a first focusing region showing the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region. The second light-gathering region has a portion on the side in the predetermined direction, The second light-gathering region has a shape that includes the illumination pupil distribution of the illumination optical system on the object or a gap due to the shielding of components of the illumination optical system. Testing method.

32. The steps include: irradiating an object with EUV illumination light using an illumination optical system at an angle inclined toward a predetermined direction from the normal to the main surface of the object; The steps include: forming an image of the light from the object illuminated by the aforementioned illumination light onto a light detection unit using an imaging optical system; The steps include: inspecting the object based on the image formed on the light detection unit; Equipped with, The step of forming an image of the light on the light detection unit using the imaging optical system includes the step of focusing the light with a light-gathering member included in the imaging optical system, In the irradiating step and the step of focusing the light with the light-collecting member, The focusing pupil distribution of the imaging optical system on the object includes a first focusing region showing the luminous flux of specularly reflected light from the illumination light that illuminates the object, and a second focusing region showing the luminous flux of higher-order diffracted light from the illumination light that illuminates the object. The imaging optical system causes the light detection unit to image at least a portion of the first light in the first focusing region and at least a portion of the second light in the second focusing region. The second light-gathering region has a portion on the side in the predetermined direction, The second light-gathering region includes the portion of the illumination pupil distribution of the illumination optical system on the object that is outside the maximum angle region on the predetermined direction side, Testing method.