Alignment method for opposed X-ray composite mirrors

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 back surface of one mirror base body opposite the x-ray reflective surface thereof has a reference surface lying having a defined relative angle with respect to a flat area on a front surface thereof.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 8(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 8(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 order to collect more light, it has been proposed to arrange mirrors facing each other on both sides of the focusing optical system and imaging optical system (see Figure 9). Figure 9(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 have the same shape, which increases the amount of light. Figure 9(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 9(b), it is possible to magnify 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, 7:46358, (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, A reference surface having a relative angle with respect to the flat area of ​​the surface is defined on the back surface opposite to the X-ray reflecting surface of the mirror base. A paired X-ray composite mirror characterized by:

[0014] (2) The opposed X-ray composite mirror according to (1), wherein in the at least one mirror body, either the flat area or the reference surface, or both, are mirror surfaces, and have a surface capable of reflecting evaluation light of at least one wavelength in the wavelength range of 0.1 nm to 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 side of the mirror substrate, and a reference surface is formed on the back side, for the purpose of being able to evaluate the angle of the evaluation light incident from the back side to the front side of the mirror substrate with respect to the optical axis.

[0016] (4) An opposed X-ray composite mirror according to (3), wherein the mirror substrate on which the reference surface is formed is made of a glass material, and the tilt component a of the profile Y=aX+An (n is 1, 2, . . . n, and X is the coordinate in the optical axis direction of the X-ray) of the flat area relative to the back surface can be evaluated from either the front or back surface of the mirror substrate using at least a part of the flat area and the reference surface, and the angle of the flat area is evaluated from the reference surface side.

[0017] (5) The opposed X-ray composite mirror according to (4), wherein the mirror substrate is formed of a glass material, the flat area is provided with a metal coating having a thickness of 20 to 500 nm, and the reference surface is provided with a coating that is semi-transparent to the evaluation light.

[0018] (6) The opposed X-ray composite mirror according to any one of (1) to (5), wherein the reference surface and the location of the flat area in the mirror substrate on which the reference surface is formed are both located at approximately the same distance from an end face of the mirror substrate that is perpendicular to the optical axis direction of the X-rays.

[0019] (7) The flat areas of the two mirror substrates, whose X-ray reflecting surfaces are arranged opposite each other, are positioned at approximately the same distance from the light source or the sample position to be measured in the direction of the X-ray optical axis. The opposed X-ray composite mirror according to any one of (1) to (6), wherein:

[0020] (8) The opposed X-ray composite mirror according to any one of (1) to (7), 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 region from 1 mm to an effective length.

[0021] (9) An opposed X-ray composite mirror according to any one of (1) to (8), 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.

[0022] (10) 10. The opposed X-ray composite mirror according to claim 9, 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.

[0023] (11) The opposed X-ray composite mirror according to (9) or (10), 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.

[0024] (12) In the opposed type X-ray composite mirror according to any one of (9) to (11), One side of the mirror substrate is placed on the flat substrate; an autocollimator disposed at a position facing the reference surface is used to adjust the angle of each of the mirror bodies by reflection of the evaluation light on the flat region and the reference surface, and then each of the mirror bodies is fixed to the flat substrate; An alignment device for an opposed type X-ray composite mirror, characterized by the above.

[0025] (13) An alignment device for an opposed type X-ray composite mirror according to (12), in which, with one side of the mirror substrate placed on the planar substrate, the positions of the two opposing mirror substrates relative 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.

[0026] In the present invention, the "evaluation light" refers to a light beam that serves as a reference for a measuring instrument, such as a parallel beam from an autocollimator. In the present invention, the "substantially same distance" refers to the position where the evaluation light intersects with the optical axis direction of the evaluation light when the evaluation light is incident at a right angle on either the front or back surface of the mirror substrate. [Effects of the Invention]

[0027] According to the opposed-type X-ray composite mirror of the present invention, at least one mirror has a flat area adjacent to the reflective surface that reflects X-rays. The relative shape of the reflective surface and the flat area is accurately created, and the tilt relationship between the mirror's surface on the X-ray reflective side (hereinafter referred to as the mirror surface) and its back surface is evaluated in advance using a three-dimensional measuring device or autocollimator, allowing the relative angle of the X-ray reflective surface to be recognized from the back surface. Furthermore, the other mirror also has a flat area on the X-ray reflective side. By accurately positioning the flat area on one side of the two opposing mirror substrates relative to the back surface of the other, it is possible to accurately position at least two reflective surfaces facing each other. Because the reflective surface and the 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 the relative shape can be accurately created by repeated measurement and processing. Furthermore, there is a gap between the flat areas of the mirror substrate, which allows for easy adjustment even if there is a protrusion between the mirrors.

[0028] If the mirror substrate is made of glass, the relative angle between the flat area and the reference surface can be evaluated using a three-dimensional measuring device and an autocollimator. When evaluating with an autocollimator, the reference surface must be coated with a semi-transparent coating to the evaluation light. By positioning the reference surface and the flat area at approximately the same distance from the mirror end face, the relative angle between the flat area on the front surface and the mirror substrate can be evaluated from the back surface using an autocollimator. Furthermore, evaluation can be performed without shifting the position of the autocollimator, resulting in higher accuracy. [Brief explanation of the drawings]

[0029] [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] 1 is a plan view showing an embodiment of an opposed X-ray composite mirror of the present invention. [Figure 5] FIG. 10 is an explanatory diagram for evaluating the angle between the flat area of ​​the mirror substrate and the reference plane in the opposed X-ray composite mirror of the present invention using an autocollimator. [Figure 6] 1A and 1B are explanatory plan views showing an example of evaluating the relative angle between substrates 1 and 2 in an opposed-type X-ray composite mirror of the present invention using an autocollimator, where (a) shows a state in which the normal direction of the planar area of ​​one mirror substrate is aligned with the evaluation light of the autocollimator, and (b) shows a state in which the angle of the reference surface of the other mirror substrate relative to the evaluation light is adjusted. [Figure 7] 1 is a perspective view showing an embodiment of an alignment device for a paired X-ray composite mirror of the present invention. [Figure 8] 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 9]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

[0030] 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.

[0031] 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.

[0032] 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.

[0033] In order to accurately determine the relative positioning of the first mirror substrate 1 and the second mirror substrate 2 using the respective flat areas 5, 6 of the first mirror substrate 1 and the second mirror substrate 2, it is necessary that parts of the flat areas 5, 6 of the mirror substrates 1, 2 are positioned to face each other, and a gap is provided between the flat areas 5, 6 of the mirror substrates 1, 2. In the present invention, alignment is performed using the flat area 6 of the second mirror substrate 2 and a reference plane 7 formed on part of the back surface 12 of the first mirror substrate 1, whose relative angle is defined with respect to the flat area 5 of the front surface 11.

[0034] 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.

[0035] In this case, the relationship between the flat area 5 and the X-ray reflecting surface 3 on the first mirror substrate 1, and further the relationship between the flat area 6 and the X-ray reflecting surface 4 on the second mirror substrate 2, can be derived separately by shape measurement methods such as an interferometer or a three-dimensional measuring device. In addition, the relationship between the reference surface 7 on the back surface 12 of the first mirror substrate 1 and the flat area 5 on the front surface 11 can be evaluated by a three-dimensional measuring device. As a result, by evaluating the reference surface 7 on the back surface 12 of the first mirror substrate 1 and the X-ray reflecting surface 4 or the flat area 6 of the second mirror substrate 2 with a three-dimensional measuring device, the relationship between the X-ray reflecting surfaces 3 and 4 of the mirror substrates 1 and 2 can also be derived.

[0036] The flat areas 5 and 6 of the two mirror substrates 1 and 2 and the reference surface 7 formed on a partial area of ​​the back surface 12 of the first mirror substrate 1 are preferably mirror surfaces. The mirror surfaces allow the shapes of the flat areas 5 and 6, the X-ray reflecting surfaces 3 and 4, and the reference surface 7 to be accurately evaluated for relative angles using various measuring instruments. It is more preferable that the flat areas 5 and 6 of the two mirror substrates 1 and 2 and the reference surface 7 formed on a partial area of ​​the back surface 12 of the first mirror substrate 1 are flat, and it is even more preferable that the slope error of the flat area be 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 to be less than 10 μrad RMS, taking into account 3σ. Furthermore, it is preferable that the flat area of ​​at least one of the mirror substrates has a mirror surface capable of reflecting light of at least one wavelength between 0.1 nm and 1000 nm.

[0037] Furthermore, if the first mirror substrate 1 is made of a glass material, the relationship between the flat area 5 and the X-ray reflecting surface 3, and further the relationship between the flat area 6 and the X-ray reflecting surface 4 of the second mirror substrate 2, can be derived separately using shape measurement methods such as an interferometer or a three-dimensional measuring device, as described above, and the relationship between the reference surface 7 on the back surface 12 of the first mirror substrate 1 and the flat area 5 can be measured using an autocollimator 8. Here, as shown in FIG. 6(a), the second mirror substrate 2 and the autocollimator are first installed and the angle is adjusted, and then, as shown in FIG. 6(b), the first mirror substrate 1 is installed between the autocollimator 8 and the second mirror substrate 2. If the angle between the flat area 5 on the front surface 11 of the first mirror substrate 1 and the reference surface 7 on the back surface 12 is known, the relative relationship between the mirror substrates 1 and 2 can be evaluated using the autocollimator by measuring the reference surface 7 on the back surface 12. Specifically, first, the normal direction of the planar region 6 of one of the second mirror substrates 2 is aligned with the optical axis direction Q of the evaluation light of the autocollimator 8 (see Figure 6(a)), and then the angle of the reference surface 7 of the other first mirror substrate 1 relative to the optical axis direction Q of the evaluation light is adjusted (see Figure 6(b)), thereby allowing the relative angle between the X-ray reflecting surface 3 of the first mirror substrate 1 and the X-ray reflecting surface 4 of the second mirror substrate 2 to be accurately adjusted as designed.

[0038] FIG. 5 shows a method for evaluating the angle between the flat area 5 on the front surface 11 of the first mirror substrate 1 and the reference surface 7 on the back surface 12. If the first mirror substrate 1 is made of a glass material and light incident from the back surface 12 is reflected by the flat area 5 on the front surface 11, and the reflected light returns to the same location, then the relative tilt between the flat area 5 on the mirror substrate 1 and the reference surface 7 is θ', assuming that the angle of incidence is θ and the angle of refraction is θ'. In this case, according to Snell's law, where n is the refractive index of the glass material, n × sinθ' = 1 × sinθ, and θ' = arcsin(sinθ / n). Furthermore, when the angle of reflection on the back surface is measured, if the angle of incidence is θ, then the angle on the back surface is shifted by 2θ.

[0039] From the above, if the refractive index of the glass material is known in advance, and the 2θ component due to reflection from the back surface can be evaluated, the tilt θ' of the base can be recognized.

[0040] Furthermore, in the case of a glass material, it is preferable that the flat areas 5 and 6 are coated with a metal, and that the reference surface 7 on the back surface 12 of the substrate is coated with a semi-transparent coating. Although the evaluation position of the autocollimator 8 can be changed using a stage, the angle changes when the evaluation location is changed due to distortion of the stage, etc. For this reason, it is preferable to fix the installation location. Therefore, as shown in Figure 6, by having the flat areas 5 and 6 and the reference surface 7 each located at approximately the same position with respect to the optical axis direction Q of the autocollimator 8, it becomes possible to evaluate the installation angle of the mirror substrate with the location of the autocollimator 8 fixed.

[0041] The autocollimator 8 can be adjusted on a stage, so evaluation is possible even if the distance from the optical axis is not the same.

[0042] The method for evaluating the relative angle between the mirror substrates 1 and 2 is to first evaluate the flat area 6 of the second mirror substrate 2 with an autocollimator 8 and adjust it so that it forms a predetermined angle with respect to the optical axis direction P of the X-rays. Thereafter, the first mirror substrate 1 is positioned so that it blocks the optical axis direction Q of the autocollimator 8, and the reference surface 7 on its back surface 12 is evaluated, and the angle of the flat area 5 is evaluated from 2θ to confirm that it is at the predetermined angle.

[0043] 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 7, 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. Note that the first mirror substrate 1 having the planar region 5 and reference surface 7, the second mirror substrate 2 having the planar region 6, the autocollimator 8, the planar substrate 9, and the X-axis adjustment jig 10 constitute an alignment device for an opposed-type X-ray composite mirror. 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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]

[0054] 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 Reference plane 8 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 alignment method for an opposed type X-ray composite mirror, comprising a first mirror substrate and a second mirror substrate, each of which has at least a front surface and an opposing back surface, and has a one-dimensional X-ray reflecting surface that is either concave or convex, or both, on a part of the front surface, and which is arranged with its X-ray reflecting surface facing each other, comprising: the first mirror substrate has a flat area on a part of its surface on the same side as the X-ray reflecting surface, and has a reference surface on its back surface on the opposite side to the X-ray reflecting surface, the reference surface having a defined relative angle with respect to the flat area on the surface; the second mirror substrate has a flat area on a part of its surface on the same side as the X-ray reflecting surface; After arranging the second mirror substrate so that the normal direction of the planar area thereof coincides with the direction of the optical axis of the evaluation light of the autocollimator, the angle of the reference surface of the first mirror substrate relative to the direction of the optical axis of the evaluation light is adjusted and arranged, a gap is provided between the planar area of ​​the first mirror substrate and the planar area of ​​the second mirror substrate, and the relative angle between the X-ray reflecting surface of the first mirror substrate and the X-ray reflecting surface of the second mirror substrate is adjusted.

1. A method for aligning an opposed type X-ray composite mirror, comprising:

2. 2. The method for aligning an opposed type X-ray composite mirror according to claim 1, wherein either or both of the planar region and the reference surface of the first mirror body are mirror surfaces and have a surface capable of reflecting evaluation light of at least one wavelength in the wavelength range of 0.1 nm to 1000 nm.

3. A method for aligning an opposed type X-ray composite mirror as described in claim 1 or 2, wherein the first mirror substrate is formed of a glass material, the flat area is coated with a metal coating having a thickness of 20 to 500 nm, and the reference surface is coated with a coating that is semi-transparent to the evaluation light, and the relative angle of the reference surface to the flat area is determined from the angle of incidence when the reflected light returns to the same place when the evaluation light incident from the reference surface on the back side is reflected by the flat area on the front side.

4. An alignment method for an opposed type X-ray composite mirror as described in claim 1, wherein the locations of the reference surface and the flat area in the first mirror substrate are both positioned at approximately the same distance from the end face of the first mirror substrate that is perpendicular to the optical axis direction of the X-rays.

5. 5. The alignment method for an opposed type X-ray composite mirror according to claim 4, wherein the planar regions of the first mirror substrate and the second mirror substrate, whose X-ray reflecting surfaces are arranged opposite to each other, are arranged at positions approximately the same distance from the light source or the sample position to be measured in the optical axis direction of the X-rays.

6. 2. The alignment method for an opposed type X-ray composite mirror according to claim 1, wherein the first mirror substrate and the second mirror substrate extend along the optical axis direction of the X-rays and have side surfaces perpendicular to the surface, and with one side of the first mirror substrate and one side of the second mirror substrate placed on a planar substrate, the positions of the two opposing mirror substrates with respect to the optical axis direction of the X-rays are determined by using a fixing device or an adjustment jig to determine the position of the first mirror substrate with reference to an end face of the second mirror substrate perpendicular to the optical axis direction of the X-rays.

7. 7. The method for aligning an opposed type X-ray composite mirror according to claim 6, wherein the perpendicularity between the X-ray reflecting surface and both opposing side surfaces of the first mirror substrate and the second mirror substrate extending along the optical axis direction of the X-rays is 100 seconds or less.

8. 8. The method for aligning an opposed type X-ray composite mirror according to claim 6, wherein the parallelism of opposing side surfaces of the first mirror substrate and the second mirror substrate extending along the optical axis direction of the X-rays is 100 seconds or less.

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