Opposed X-ray composite mirror and its alignment device

Abstract

To provide an opposing-type x-ray composite mirror which significantly reduces the time required to adjust alignment of mirrors, in a state of being completely aligned without using a special measurement device or X-ray beams.SOLUTION: An opposing-type x-ray composite mirror comprises at least two or more mirror base bodies, each having a one-dimensional x-ray reflective surface formed thereon, in which at least two x-ray reflective surfaces face each other. An x-ray reflective surface and a flat area are formed on a surface of each mirror base body. A flat area of at least one mirror base body of the two mirror base bodies with opposing x-ray reflective surfaces is positioned on the outer side than an end face of the other mirror base body in an X-ray optical axis direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an opposed X-ray composite mirror and an alignment device therefor, and more particularly to an opposed X-ray composite mirror used in an X-ray grazing incidence optical system and an alignment device therefor. [Background technology]

[0002] X-ray mirrors using an elliptical shape are currently used in many synchrotron radiation facilities as Kirkpatric-Baez (KB) mirrors, and are characterized by not only being able to obtain a small focused diameter but also having a higher light focusing efficiency than other focusing optical systems (Non-Patent Document 1). Another feature is the absence of chromatic aberration, and the focal position does not change even when the energy changes, making them suitable for use in imaging applications.

[0003] For example, many synchrotron radiation facilities use an X-ray focusing optical system in which a pair of elliptical mirrors 101 and 102 are arranged vertically and horizontally (KB mirror arrangement) as shown in Figure 6(a), or an X-ray imaging optical system in which a pair of elliptical mirrors 101 and 102 and a pair of hyperbolic mirrors 103 and 104 are arranged in a KB mirror arrangement as shown in Figure 6(b), but these are used on only one side of the X-ray beam in the vertical and horizontal directions.

[0004] However, in recent years, in focusing and imaging optical systems, it has been proposed to place mirrors facing each other on both sides in order to collect more light (see Figure 7). Figure 7(a) shows a focusing optical system with two pairs of elliptical mirrors 105, 105 and 106, 106 arranged in a KB mirror configuration. The opposing elliptical mirrors 105, 105 and 106, 106 are identical in shape, which increases the amount of light. Figure 7(b) shows an imaging optical system with two pairs of concave mirrors 107, 108 and convex mirrors 109, 110 arranged facing each other and offset in the optical axis direction (Patent Document 1, Non-Patent Document 2). Here, the concave mirrors 107, 108 are elliptical mirrors, and the convex mirrors 109, 110 are hyperbolic mirrors. This allows the principal plane of the optical system to be shifted toward the sample, thereby making the entire optical system more compact. By using the imaging optical system shown in Figure 7(b), it is possible to enlarge and observe fine structures of about several tens of nanometers, even without a large-scale facility such as a synchrotron radiation facility.

[0005] As mentioned above, optical systems with opposing mirror reflective surfaces have excellent properties, but because the mirrors are facing each other, they must be manufactured separately. The relative positions of these mirrors must be precisely aligned, which requires the use of synchrotron X-rays, special measuring equipment, or fixing the mirrors with UV-curable resin after adjustment. Fixing with UV-curable resin, however, is subject to the effects of adhesive shrinkage during curing and temperature drift due to UV irradiation, making it difficult to achieve when high precision is required.

[0006] Until now, opposing mirror pairs have been realized by either (1) assembling them separately on a stage, or (2) gluing them to a substrate and then assembling them on a stage. However, method (1) requires highly precise alignment technology, and there are concerns about usability, long-term stability, and vibration. Method (2) has concerns about alignment changes and shape deformation due to adhesion, and there are also issues with adhesives that cannot be used in high vacuums, and the mirrors must be peeled off every time maintenance is performed. In either case, special measuring equipment is required that can measure opposing mirrors with an accuracy of 100 nm or 10 μrad, which is extremely difficult.

[0007] A one-dimensional Wolter mirror has been provided in which an elliptical mirror and a hyperbolic mirror are built into a single mirror substrate (Patent Document 2). Because an elliptical mirror and a hyperbolic mirror are built into a single mirror, alignment adjustment of the mirrors is much easier than when each mirror is built separately. However, when used for imaging, the magnification is limited, which remains an issue. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. WO2017 / 051890 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-006457 [Non-patent literature]

[0009] [Non-Patent Document 1] Satoshi Matsuyama, et.al, Scientific Reports, 7:5,63,48, (2017). [Non-patent document 2] Jumpei Yamada,et.al, Applied Optics, Vol.56,No.4, p.967 (2017). Summary of the Invention [Problem to be solved by the invention]

[0010] Optical systems in which the reflective surfaces of mirrors face each other have excellent properties as mentioned above, but because the mirrors face each other, they must be manufactured separately. The relative positions of these mirrors must then be aligned with high precision, which requires the use of synchrotron X-rays, and requires the use of the special measuring equipment mentioned above, or fixing the mirrors with UV-curable resin after adjustment. Fixing with UV-curable resin, however, is subject to the effects of adhesive shrinkage during curing and temperature drift due to UV irradiation, making it difficult to achieve when high precision is required.

[0011] In view of the above situation, the present invention aims to solve the problem by providing an opposed X-ray composite mirror and its alignment device that significantly reduces the time required to align the mirrors by using an X-ray beam generated by a commercially available X-ray generator, an autocollimator, a 3D measuring device, and the like. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the present invention provides the following opposed X-ray composite mirror and its alignment device.

[0013] (1) An X-ray composite mirror having two or more one-dimensional X-ray reflecting surfaces and used in an X-ray grazing incidence optical system, There are at least two mirror substrates each having at least a front surface and a back surface opposite thereto, a one-dimensional X-ray reflecting surface having either a concave or a convex shape, or both, on a part of the surface of each of the mirror substrates, and a flat area on a part of the surface on the same side as the X-ray reflecting surface; In an opposed type X-ray composite mirror having a structure in which a relative position of another mirror substrate is determined based on at least a part of the planar region of the mirror substrate, and at least two X-ray reflecting surfaces are opposed to each other, the planar region of at least one of the two mirror substrates whose X-ray reflecting surfaces face each other is located at an outer position along the optical axis direction of the X-rays than the end face of the other mirror substrate; A paired X-ray composite mirror characterized by:

[0014] (2) The opposed type X-ray composite mirror according to (1), wherein the flat area of ​​the at least one mirror substrate is a mirror surface and has a surface capable of reflecting light of at least one wavelength between 0.1 nm and 1000 nm.

[0015] (3) An opposed X-ray composite mirror according to (1) or (2), wherein at least one of the mirror substrates is made of silicon or glass material, and an X-ray reflecting surface and a flat area are formed on the front surface side of the mirror substrate in order to enable evaluation of the angle of the evaluation light incident from the back surface side to the front surface side of the mirror substrate with respect to the optical axis.

[0016] (4) The opposed X-ray composite mirror according to any one of (1) to (3), wherein the shape error of the X-ray reflecting surface from the ideal shape is 0.1 nm RMS or more and 2 nm RMS or less in a spatial frequency domain from 1 mm to an effective length.

[0017] (5) The opposed X-ray composite mirror according to any one of (1) to (4), wherein each of the mirror substrates extends along the optical axis direction of the X-rays, has a side surface perpendicular to the surface, and the side surface of each mirror substrate is present on a planar substrate and is arranged on the same plane.

[0018] (6) The opposed X-ray composite mirror according to (5), wherein the perpendicularity between the X-ray reflecting surface and both opposing side surfaces of the mirror base extending along the optical axis direction of the X-rays is 100 seconds or less.

[0019] (7) The opposed X-ray composite mirror according to (5) or (6), wherein the parallelism of the opposing side surfaces of the mirror substrate extending along the optical axis direction of the X-rays is 100 seconds or less.

[0020] (8) In the opposed type X-ray composite mirror described in any one of (5) to (7), placing one side surface of the mirror substrate on the flat substrate; an optical path changing element having a function of internally reflecting incident light two or more times, inverting the incident light 180 degrees, and emitting or reflecting the light from a position a predetermined distance away, and an optical angle measuring device capable of optically measuring the angle of the plane, are arranged at positions facing each other in the optical axis direction of the X-rays, and a first mirror substrate and an optical path changing element are also arranged; a step of adjusting the angle of the first mirror substrate by causing the evaluation light incident from the optical angle measurement device to be incident on a planar area of ​​the first mirror substrate via an optical path changing element; adjusting the angle of the second mirror substrate by irradiating evaluation light directly from the optical angle measurement device onto a planar area of ​​the second mirror substrate; An alignment device for an opposed X-ray composite mirror, comprising:

[0021] (9) 9. An alignment device for an opposed type X-ray composite mirror as described in claim 8, wherein, with one side of the mirror substrate placed on the planar substrate, the positions of the two opposing mirror substrates with respect to the optical axis direction of the X-rays are determined using an end face of one mirror substrate that is perpendicular to the optical axis direction of the X-rays as a reference, and the position of the other mirror substrate is determined using a fixing device or an adjustment jig.

[0022] (10) An alignment device for an opposed type X-ray composite mirror according to (8) or (9), wherein the optical path changing element is composed of at least one of a right-angle prism, a Dove prism, a retroreflector prism, a retroreflector mirror (corner cube), a hollow roof mirror, and a combination of multiple pentaprisms.

[0023] (11) The alignment device for an opposed type X-ray composite mirror according to (8) or (9), wherein the optical path changing element is a right-angle prism, and the optical angle measuring device is an autocollimator.

[0024] (12) The evaluation light of the autocollimator is reflected onto the flat area of ​​the first mirror substrate via the right-angle prism, and the flat area is adjusted so that the direction of the optical axis of the evaluation light is perpendicular to the direction of the optical axis of the evaluation light. An alignment device for an opposed type X-ray composite mirror according to (11), wherein the flat area of ​​the second mirror substrate is positioned so as to directly intersect with the evaluation light of the autocollimator, and the angle of the reflected light reflected by the flat area is measured to evaluate the relative angle of both flat areas.

[0025] (13) The opposed X-ray composite mirror and alignment device according to (11) or (12), wherein, when the light source or the sample point is used as the reference point, the position coordinate B of the planar area of ​​the second mirror substrate is expressed as A+D or AD, where A is the position coordinate of the planar area of ​​the first mirror substrate and D is the distance of the light ray traveling in the optical axis direction of the X-ray within the rectangular prism. [Effects of the Invention]

[0026] According to the opposed-type X-ray composite mirror and its alignment device of the present invention, at least one mirror substrate has a flat area adjacent to the X-ray reflecting surface that reflects X-rays. By using an optical angle measurement device and an optical path changing element, even opposing mirror substrates can be accurately positioned relative to each other's optical axis direction, thereby enabling at least two X-ray reflecting surfaces to be accurately aligned. Because the X-ray reflecting surface and flat area are located on the same side of the mirror substrate, they are within the scope of application of high-precision interferometers and three-dimensional measuring devices, and repeated measurement and processing allows for accurate creation of relative shapes. Furthermore, there is a gap between the flat areas of the mirror substrate, which allows for easy alignment even if there is a protrusion between the mirrors. Furthermore, if the optical path changing element is a right-angle prism and the optical angle measurement device is an autocollimator, the alignment device can be constructed relatively inexpensively. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view showing an embodiment of a counter-type X-ray composite mirror of the present invention. [Figure 2] 1A and 1B are six-view diagrams, taken through a third angle projection, of a mirror base 1 in a paired X-ray composite mirror of the present invention. [Figure 3] 2 is a six-view diagram of a mirror base 2 in the opposed X-ray composite mirror of the present invention, using a third angle projection method. FIG. [Figure 4] 1A and 1B are explanatory plan views showing an example of adjusting the relative angle between substrates 1 and 2 in an opposed-type X-ray composite mirror of the present invention using a prism and an autocollimator, where (a) shows a state in which the normal direction of the flat area of ​​one mirror substrate is aligned with the evaluation light of the autocollimator reflected by the prism, and (b) shows a state in which the normal direction of the flat area of ​​the other mirror substrate is aligned with the evaluation light before it enters the prism. [Figure 5] 1 is a perspective view showing an embodiment of an alignment device for a paired X-ray composite mirror of the present invention. [Figure 6] 1A and 1B show a conventional example, in which (a) is an explanatory diagram showing a light-collecting optical system with a KB mirror arrangement, and (b) is an explanatory diagram showing an imaging optical system with an AKB mirror arrangement. [Figure 7] Fig. 1 shows a conventional example, where (a) is an explanatory diagram showing a focusing optical system in which two pairs of opposing elliptical mirrors are arranged in a KB mirror configuration, and (b) is an explanatory diagram showing a compact imaging optical system in which two elliptical concave mirrors and two hyperbolic convex mirrors are arranged in a KB mirror configuration. DETAILED DESCRIPTION OF THE INVENTION

[0028] Next, the present invention will be described in more detail based on the embodiments shown in the accompanying drawings. Figures 1 to 7 show an embodiment of an opposed type X-ray composite mirror of the present invention, in which reference numeral 1 indicates a first mirror substrate and 2 indicates a second mirror substrate. Note that, although this embodiment shows a case where the number of mirror substrates is two, three or more may be used.

[0029] The first mirror substrate 1 and the second mirror substrate 2 have a rectangular parallelepiped shape extending in the X-ray propagation direction (for convenience, represented as the optical axis direction P). The first mirror substrate 1 has a front surface 11 along the X-ray propagation direction, a back surface 12 facing the front surface 11, side surfaces 13 and 14 on both sides, and end surfaces 15 and 16 intersecting the X-ray propagation direction. Similarly, the second mirror substrate 2 has a front surface 21, a back surface 22, both side surfaces 23 and 24, and both end surfaces 25 and 26. However, even if the front surface 11 and back surface 12 of the first mirror substrate 1 or the front surface 21 and back surface 22 of the second mirror substrate 2 are precisely machined and polished, they cannot be expected to be completely flat and parallel due to limitations in accuracy. 2 and 3, in the six-sided views by the third angle projection method, the surfaces 11 and 21 correspond to a front view, the back surfaces 12 and 22 correspond to a rear view, the side surfaces 13 and 23 correspond to a bottom view (lower view), the side surfaces 14 and 24 correspond to a plan view, the end surfaces 15 and 25 correspond to a left side view, and the end surfaces 16 and 26 correspond to a right side view.

[0030] The present invention is an X-ray composite mirror for use in an X-ray grazing incidence optical system, comprising two or more one-dimensional X-ray reflecting surfaces 3, 4, characterized in that there are at least two or more mirror substrates 1, 2, the first mirror substrate 1 has a one-dimensional X-ray reflecting surface 3 of either a concave or convex shape or both in a portion of its surface 11, and a flat area 5 in a portion of its surface 11 on the same side as the X-ray reflecting surface 3, and the second mirror substrate 2 has a one-dimensional X-ray reflecting surface 4 of either a concave or convex shape or both in a portion of its surface 21, and a flat area 6 in a portion of its surface 21 on the same side as the X-ray reflecting surface 4, and the relative positions of the first mirror substrate 1 and the second mirror substrate 2 are accurately determined using both flat areas 5, 6 so that the at least two X-ray reflecting surfaces 3, 4 are arranged opposite each other. In other words, the relative position of one mirror substrate is determined using a portion of the flat area of ​​another mirror substrate as a reference. Here, the X-rays are reflected by the opposing X-ray reflecting surfaces 3 and 4 and pass between the mirror substrates 1 and 2.

[0031] As a method for accurately determining the relative positioning of the first mirror body 1 and the second mirror body 2 using the respective flat areas 5, 6 of the first mirror body 1 and the second mirror body 2, it is necessary that parts of the flat areas 5, 6 of the mirror bodies 1, 2 are arranged in positions facing each other and are spaced apart along the optical axis direction P of the X-rays, and that a gap is provided between the flat areas 5, 6 of the mirror bodies 1, 2. In the present invention, alignment is performed using the flat area 5 of the first mirror body 1 and the flat area 6 of the second mirror body 2, an optical path changing element 7 having the function of inverting incident light 180 degrees and emitting or reflecting it from a position a predetermined distance away, and an optical angle measuring device 8.

[0032] The mirror substrates 1 and 2 have X-ray reflecting surfaces 3 and 4 of one-dimensional shape, which are either elliptical, parabolic, or hyperbolic, on a part of the surface 11 and 21, and have flat areas 5 and 6 on a part of the surface 11 and 12 on the same side as the X-ray reflecting surfaces 3 and 4, respectively, when the shape profiles of the X-ray reflecting surfaces 3 and 4 of the mirror substrates 1 and 2 are each expressed by a polynomial. Y=Fn(X) (n is 1, 2, . . . n, X is the coordinate in the optical axis direction of the X-ray, and the rear surface 12, 22 of the substrate is set to zero) It is expressed as The shape profile of the planar regions 5 and 6 of the mirror substrates 1 and 2 is approximately Y=aX+An (n is 1, 2, . . . n, and the rear surfaces 12 and 22 of the substrate are set to zero) In the present invention, the shapes of the X-ray reflecting surfaces 3 and 4 need not be limited, and any shape may be used.

[0033] In this case, the relationship between the flat area 5 on the first mirror substrate 1 and the X-ray reflecting surface 3, and further the relationship between the flat area 6 on the second mirror substrate 2 and the X-ray reflecting surface 4, can be derived separately using a shape measurement method such as an interferometer or a three-dimensional measuring device.

[0034] It is preferable that the flat areas 5, 6 of the two mirror substrates 1, 2 are mirror surfaces. The mirror surfaces allow the shapes of the flat areas 5, 6, the X-ray reflecting surfaces 3, 4, and the back surfaces 12, 22 to be accurately evaluated for relative angles using various measuring instruments. It is even more preferable that the flat areas 5, 6 of the two mirror substrates 1, 2 are flat, and it is even more preferable that the slope error of the flat areas is less than 10 μrad RMS. The angular error measured in the optical axis direction of each flat area is approximately 30 μrad. In other words, when converted to a slope error, it is preferable to design it so that it is 10 μrad RMS or less, taking into account 3σ. Furthermore, it is preferable that the flat areas of at least one of the mirror substrates have a mirror surface that is capable of reflecting light of at least one wavelength between 0.1 nm and 1000 nm.

[0035] Examples of optical path changing elements 7 that have the function of inverting incident light 180 degrees and outputting or reflecting it from a position a predetermined distance away include the right-angle prism, Dove prism, retroreflector prism, retroreflector mirror (corner cube), hollow roof mirror, and a combination of multiple pentaprisms, and it is also possible to configure a composite optical element by combining multiple of these. In any optical path changing element 7, the position of the output light or reflected light is a predetermined distance away from the incident light in the optical axis direction P of the X-ray. Here, the error accuracy of the relative angle between the incident light and the output light of the optical path changing element 7 is required to be ±10 seconds, and more preferably ±3 seconds.

[0036] In this embodiment, a method for achieving accurate alignment will be described, utilizing the planar area 5 of the first mirror substrate 1 and the planar area 6 of the second mirror substrate 2, using a right-angle prism as the optical path changing element 7 and an autocollimator as the optical angle measuring device 8. As shown in Fig. 4 and Fig. 5, it is preferable that the first mirror substrate 1 and the autocollimator 8 are located in the same normal direction to the optical axis of the X-ray (represented as optical axis direction P), and that the autocollimator 8 and the right-angle prism 7 are installed at positions facing each other across the optical axis.

[0037] At this time, the right-angle prism 7 has the function of reflecting the light incident at right angles on the inclined surface 7A twice at the right-angle constituent surfaces 7B and 7C inside the prism 7, and emitting the light in the opposite direction by approximately 180 degrees from the inclined surface 7A at a position parallel to the optical axis direction P of the X-rays and separated by a distance D.

[0038] First, as shown in Figure 4(a) where the optical axis direction of the evaluation light of the autocollimator 8 is indicated as Q, incident light Q1 that is incident at a right angle on the inclined surface 7A of the right-angle prism 7 is reflected by one right-angle constituent surface 7B, and then reflected by the other right-angle constituent surface 7C that is a distance D away, and is emitted at a right angle from the inclined surface 7A, and the emitted light Q2 is reflected by the flat area 5 of the first mirror substrate 1, and the evaluation light reflected by the flat area 5 is again incident on the inclined surface 7A of the right-angle prism 7 as incident light Q3, is reflected by the right-angle constituent surface 7C and the right-angle constituent surface 7B, and is emitted from the inclined surface 7A, and the first mirror substrate 1 is adjusted so that the emitted light Q4 overlaps with the incident light Q1 of the autocollimator 8.

[0039] Next, as shown in FIG. 4(b), the flat area 6 of the second mirror 2 is positioned directly opposite the autocollimator 8. Light reflected from the flat area 6 is incident on the light-receiving section of the autocollimator 8, allowing the relative angle between the flat areas 5 and 6 to be evaluated. To adjust the relative angle between the flat areas 5 and 6 to zero, i.e., to make the flat areas 5 and 6 parallel, the second mirror substrate 2 is positioned so that the flat area 6 blocks the incident light Q1 of the autocollimator 8, and the reflected light Q5 reflected by the flat area 6 overlaps the incident light Q1. In this way, by adjusting the optical axis direction Q of the evaluation light of the autocollimator 8 and the flat areas 5 and 6 to be perpendicular, the flat areas 5 and 6 become parallel, and the X-ray reflecting surfaces 3 and 4, which are precisely manufactured based on the flat areas 5 and 6, face each other at the designed relative angle. Note that, in FIG. 4(b), it is also possible to adjust the reflected light Q5 to have a predetermined angle with respect to the incident light Q1.

[0040] Generally, if the relationship between the X-ray reflecting surfaces 3, 4 and the flat areas 5, 6 of each mirror substrate 1, 2 is evaluated in advance using a three-dimensional measuring device or an interferometer, the angle of the second mirror substrate 2 can be adjusted so that the X-ray reflecting surfaces 3, 4 have the desired relative angle based on the measurement results of the relative angle between the flat areas using an autocollimator 8.

[0041] To enable such alignment, it is necessary that the planar region of at least one of the two mirror substrates be positioned outward along the optical axis direction P of the X-rays from the end face of the other mirror substrate. In this embodiment, an example is shown in which the planar region 6 of the second mirror substrate 2 is displaced toward the X-ray source side from the end face 16 of the first mirror substrate 1, but it may also be displaced toward the sample side. In other words, in FIG. 4, the optical axis direction P remains the same, and the mirror substrates 1 and 2, the rectangular prism 7, and the autocollimator 8 are arranged upside down.

[0042] In other words, as shown in Figure 4, when the location in the optical axis direction of the X-ray in each flat area of ​​the opposing mirrors is based on the light source or the sample point, if the position coordinate of the flat area 5 of the first mirror body 1 is A and the ray distance traveling in the optical axis direction P of the X-ray within the rectangular prism 7 is D, the position coordinate B of the flat area 6 of the second mirror body 2 is expressed as A+D or AD.

[0043] Although the evaluation position of the autocollimator 8 can be changed by using the stage, when the evaluation location is changed, the angle changes due to distortion of the stage, etc. Therefore, it is preferable to fix the installation location. Furthermore, it is preferable that the flat areas 5 and 6 are metal coated.

[0044] As described above, the alignment device for an opposed type X-ray composite mirror of the present invention is characterized by including the steps of placing one side surface 13, 23 of the mirror substrates 1, 2 on the planar substrate 10, and arranging, at positions facing each other in the optical axis direction P of the X-rays, an optical path changing element 7 having the function of internally reflecting incident light two or more times, inverting it 180 degrees, and emitting or reflecting it from a position a predetermined distance away, and an optical angle measurement device 8 capable of optically measuring the angle of the plane, and similarly arranging a first mirror substrate 1 and the optical path changing element 7, and adjusting the angle of the first mirror substrate 1 by having evaluation light incident from the optical angle measurement device 8 enter the planar area 5 of the first mirror substrate 1 via the optical path changing element 7, and adjusting the angle of the second mirror substrate 2 by having evaluation light directly enter the planar area 6 of the second mirror substrate 2 from the optical angle measurement device 8.

[0045] The position along the optical axis direction P can be fixed using a fixing or adjusting jig, with the end face of one mirror substrate as the reference. For example, as shown in Figure 5, with one side surface 13, 23 of two mirror substrates 1, 2 resting on a planar substrate 9, the first mirror substrate 1 is moved only in the optical axis direction P using a fixing or adjustable jig 10 of a predetermined length, with the end face 25 of the second mirror substrate 2 as the reference. These methods make it possible to adjust the angle between the mirror substrates and the optical axis direction P. The alignment device for an opposed-type X-ray composite mirror includes the first mirror substrate 1 having the planar region 5 and the second mirror substrate 2 having the planar region 6, as well as a right-angle prism 7, an autocollimator 8, a planar substrate 9, and an X-axis adjustment jig 10. After alignment, the opposed-type X-ray composite mirror is provided to the consumer in a state where both mirror substrates 1, 2 are fixed in position on the planar substrate 9.

[0046] Since X-rays are the target here, the shape error from the ideal shape of the reflecting surfaces 3 and 4 is required to be 0.1 nm RMS or more and 2 nm RMS or less in the spatial frequency range from 1 mm to the effective length.

[0047] Typically, the mirror substrates 1 and 2 are manufactured using rectangular parallelepiped substrate materials such as silicon single crystal or quartz glass. Specifically, the mirror substrates 1 and 2 are manufactured by rough processing such as mechanical polishing or cutting to form the flat areas 5 and 6 and the reflective surfaces 3 and 4, respectively, using the back surfaces 12 and 22 of the substrate material as a reference, and then precisely machining them using precision processing methods such as EEM (Elastic Emission Machining), CARE (Catalyst Referred Etching), and PCVM (Plasma Chemical Vaporization Machining). Because the reflective surfaces and flat areas are fabricated on the same substrate material over the entire surface using the back surface as a reference, it is easy to achieve a relative accuracy of 100 nm and 10 μrad between the reflective surfaces and the flat areas.

[0048] EEM is a processing method that achieves a PV value of 1 nm by placing the workpiece in a suspension of fine particles and creating a shear flow along the surface of the workpiece. When the fine particles adhering to the surface of the workpiece are removed by the shear flow, the surface atoms bonded to the fine particles are also removed.

[0049] CARE is an ultimate processing method that can achieve a PV value of 0.7 nm by moving a catalytic pad (coated with a catalyst such as Pt or Ni) over the target using ultrapure water as the processing fluid, chemically removing only the protrusions on the surface and flattening various materials on an atomic scale.

[0050] PCVM is a processing method that achieves highly efficient and distortion-free processing through chemical etching using high-pressure plasma at 1 atmosphere. It can easily create aspherical shapes that are difficult to achieve through mechanical processing, and by using the shape of the electrode that generates the plasma, it is possible to process only the required areas of the workpiece surface using numerical control.

[0051] The perpendicularity between both side surfaces 13, 14 of the mirror substrate 1 and the X-ray reflecting surface 3 is required to be 100 arcseconds or less. Similarly, the perpendicularity between both side surfaces 23, 24 of the mirror substrate 2 and the X-ray reflecting surface 4 is required to be 100 arcseconds or less. The side surfaces of the mirror substrates 1, 2 are often used as references during alignment adjustment, so high precision is required. If the perpendicularity exceeds 100 arcseconds, the required precision cannot be ensured.

[0052] Furthermore, the parallelism of both side surfaces 13, 14 of the mirror substrate 1 is required to be 100 seconds or less. Similarly, the parallelism of both side surfaces 23, 24 of the mirror substrate 2 is required to be 100 seconds or less. The side surfaces of the mirror substrates 1, 2 are often used as references during alignment adjustment, so high precision is required. If the parallelism exceeds 100 seconds, the required precision cannot be ensured.

[0053] After the relative positions of the X-ray reflecting surfaces 3 and 4 of the mirror substrates 1 and 2 are adjusted with high precision using the alignment device, it is desirable to fix the mirror substrates 1 and 2 in this state using some fixing means, such as applying an external stress to the extent that it allows deformation of the mirror substrates 1 and 2, or fixing the joint ends with a UV-curable resin.

[0054] In the present invention, "X-ray reflecting surfaces facing each other" is not limited to the case where the X-ray reflecting surfaces 3 and 4 are misaligned while partially overlapping on the upstream and downstream sides of the X-ray optical axis direction P, as in this embodiment, but is a broad concept including the case where the X-ray reflecting surfaces 3 and 4 completely face each other, or the case where the X-ray reflecting surfaces 3 and 4 are completely separated in the X-ray optical axis direction P.

[0055] In the present invention, the shapes of the X-ray reflecting surface 3 of the mirror substrate 1 and the X-ray reflecting surface 4 of the mirror substrate 2 are not limited, and various shapes and combinations of convex and concave surfaces are possible. [Explanation of symbols]

[0056] 1 First mirror substrate 2 Second mirror substrate 3 X-ray reflective surface 4 X-ray reflective surface 5 Planar area 6 Planar area 7. Optical path changing element (right-angle prism) 8 Optical angle measuring device (autocollimator) 9 Planar board 10 Optical axis direction adjustment jig PX-ray optical axis direction Q Optical axis direction of autocollimator 11,21 surface 12,22 Back side 13,14,23,24 Side 15,16,25,26 End face 101,102 Elliptical mirror 103,104 Hyperbolic mirror 105 elliptical mirror 106 Elliptical Mirror 107,108 Concave mirror 109,110 Convex mirror

Claims

1. An X-ray composite mirror having two or more one-dimensional X-ray reflecting surfaces and used in an X-ray grazing incidence optical system, There are at least two mirror substrates each having at least a front surface and a back surface opposite thereto, a one-dimensional X-ray reflecting surface having either a concave shape or a convex shape, or both, on a part of the surface of each of the mirror substrates, and a flat area on a part of the surface on the same side as the X-ray reflecting surface; In an opposed type X-ray composite mirror having a structure in which a relative position of another mirror substrate is determined based on at least a part of the planar region of the mirror substrate, and at least two X-ray reflecting surfaces are opposed to each other, a flat surface region of at least one of the two mirror substrates having the X-ray reflecting surfaces facing each other is disposed at an outer position along the optical axis direction of the X-rays than an end face of the other mirror substrate; 1. An opposed type X-ray composite mirror.

2. 2. The opposed type X-ray composite mirror according to claim 1, wherein the flat regions of the at least two mirror substrates are mirror surfaces and have surfaces capable of reflecting light of at least one wavelength in the wavelength range of 0.1 nm to 1000 nm.

3. 3. The opposed-type X-ray composite mirror according to claim 1, wherein at least one of the mirror substrates is made of a silicon or glass material, and an X-ray reflecting surface and a flat area are formed on the front surface side of the mirror substrate in order to enable evaluation of the angle of evaluation light incident from the back surface side to the front surface side of the mirror substrate with respect to the optical axis.

4. 4. The opposed X-ray composite mirror according to claim 1, wherein a shape error from an ideal shape of the X-ray reflecting surface is 0.1 nm RMS or more and 2 nm RMS or less in a spatial frequency region from 1 mm to an effective length.

5. 5. The opposed X-ray composite mirror according to claim 1, wherein each of the mirror substrates extends along the optical axis direction of the X-rays and has a side surface perpendicular to the surface, and the side surface of each mirror substrate is present on a planar substrate and is arranged on the same plane.

6. 6. The opposed type X-ray composite mirror according to claim 5, wherein the perpendicularity between the X-ray reflecting surface and both opposing side surfaces of the mirror base extending along the optical axis of the X-rays is 100 seconds or less.

7. 7. The opposed type X-ray composite mirror according to claim 5, wherein the parallelism of the opposing side surfaces of the mirror substrate extending along the optical axis direction of the X-rays is 100 seconds or less.

8. The opposed X-ray composite mirror according to any one of claims 5 to 7, placing one side surface of the mirror substrate on the flat substrate; an optical path changing element having a function of internally reflecting incident light two or more times, inverting the incident light by 180 degrees, and emitting or reflecting the light from a position a predetermined distance away, and an optical angle measuring device capable of optically measuring the angle of the plane, are arranged at positions facing each other in the optical axis direction of the X-rays, and a first mirror substrate and the optical path changing element are also arranged; a step of adjusting the angle of the first mirror substrate by causing the evaluation light incident from the optical angle measurement device to be incident on a planar area of ​​the first mirror substrate via an optical path changing element; a step of adjusting the angle of the second mirror substrate by irradiating evaluation light from the optical angle measurement device directly onto a planar area of ​​the second mirror substrate; An alignment device for an opposed type X-ray composite mirror, comprising:

9. 9. An alignment device for an opposed type X-ray composite mirror according to claim 8, wherein, with one side of the mirror substrate placed on the planar substrate, the positions of the two opposing mirror substrates with respect to the optical axis direction of the X-rays are determined using an end face of one mirror substrate perpendicular to the optical axis direction of the X-rays as a reference, and the position of the other mirror substrate is determined using a fixing tool or an adjustment jig.

10. 10. An alignment device for an opposed type X-ray composite mirror according to claim 8 or 9, wherein the optical path changing element is composed of at least one of a right-angle prism, a Dove prism, a retroreflector prism, a retroreflector mirror (corner cube), a hollow roof mirror, and a combination of multiple pentaprisms.

11. 10. An alignment device for an opposed type X-ray composite mirror according to claim 8, wherein the optical path changing element is a right-angle prism, and the optical angle measuring device is an autocollimator.

12. The evaluation light of the autocollimator is reflected onto the flat area of ​​the first mirror substrate via the rectangular prism, and the flat area is adjusted so that the direction of the optical axis of the evaluation light is perpendicular to the direction of the optical axis of the evaluation light.

12. An alignment device for an opposed type X-ray composite mirror according to claim 11, wherein the flat area of ​​the second mirror substrate is positioned so as to directly intersect with the evaluation light of the autocollimator, and the angle of the reflected light reflected by the flat area is measured to evaluate the relative angle between the two flat areas.

13. 13. The opposed X-ray composite mirror and alignment device according to claim 11 or 12, wherein, when a light source or a sample point is used as a reference, a position coordinate B of the planar region of the second mirror substrate is expressed as A+D or A-D, where A is the position coordinate of the planar region of the first mirror substrate and D is the distance of a ray traveling in the optical axis direction of the X-ray within a rectangular prism.

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