JP2013057628A - Manufacturing method of x-ray wave guide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray waveguide which wave-guides an in-phase X-ray with high propagation efficiency by arranging a flattening layer between a core and a cladding and thereby reducing loss due to scattering of the X-ray in an interface of the flattening layer and the cladding.SOLUTION: The manufacturing method of the X-ray waveguide having the core and the cladding includes the steps of: forming the flattening layer on a surface of the core which has a periodic structure containing a plurality of materials with different refraction factor real parts in a direction perpendicular to the waveguide direction of the X-ray, and forming the cladding on the flattening layer.

Description

  The present invention relates to a method for manufacturing an X-ray waveguide.

X-rays are widely used in the fields of medicine, nondestructive inspection, crystal structure analysis, and the like. Since the refractive index difference between different substances for electromagnetic waves with a short wavelength of several tens of nm or less such as X-rays is as small as 10 ⁻⁵ or less, a large spatial optical system is used to control such electromagnetic waves. It has been. In recent years, research has been conducted on X-ray waveguides that confine electromagnetic waves in thin films and multilayer films for the purpose of reducing the size and increasing the functionality of such optical systems. Non-Patent Document 1 discloses an X-ray waveguide made of a Ni / carbon multilayer film.

Physical Review B, Volume 62, p. 16939 (2000)

  Non-Patent Document 1 describes a method of manufacturing an X-ray waveguide having a clad made of nickel and a core made of carbon. The X-ray waveguide described in Non-Patent Document 1 functions as a stacked waveguide in which X-rays are confined by total reflection at the carbon / nickel interface and guided. For this reason, a combination of cores sandwiched between clads can guide X-rays having a larger light quantity than a set of waveguides (hereinafter referred to as “single-layer waveguides”).

  However, Non-Patent Document 1 describes a method of manufacturing an X-ray waveguide that has a step of flattening the interface between the core and the cladding, thereby reducing propagation loss due to X-ray scattering at the interface between the core and the cladding. Absent. In the X-ray waveguide described in Non-Patent Document 1, each of the laminated waveguide structures (a set of a core and a clad sandwiching the core) functions as a separate single-layer waveguide. For this reason, there has been a problem that the effects of the single-layer waveguide such as the light condensing and the divergence suppressing effect that the phases of X-rays emitted as a whole are aligned are reduced.

  The present invention has been made in view of the above problems, and is a method of manufacturing an X-ray waveguide having a core and a clad, and a plurality of real parts different in refractive index in a direction perpendicular to the X-ray waveguide direction. The present invention relates to a method for manufacturing an X-ray waveguide, comprising: a step of forming a planarization layer on a surface of a core having a periodic structure containing a substance; and a step of forming the clad on the planarization layer.

  According to the present invention, by providing a planarization layer between the core and the clad, loss due to X-ray scattering at the interface between the planarization layer and the clad is reduced, and X-rays with high propagation efficiency and the same phase are obtained. Can be manufactured.

One embodiment of the present invention (Example 2) Conceptual diagram of X-ray waveguide manufactured by the manufacturing method of the present invention Conceptual diagram of effective propagation angle θ One embodiment of the present invention (Example 1) One embodiment of the present invention (Example 3) One embodiment of the present invention (Example 4) One embodiment of the present invention (Example 5)

  The X-ray waveguide manufacturing method of the present invention will be described in detail below.

  The X-ray waveguide manufactured by the manufacturing method of the present invention is an X-ray waveguide that includes a clad and a core and confines X-rays in the core by total reflection at the interface between the planarization layer (or core) and the clad. The X-ray waveguide has a core in which a plurality of substances having different real parts of the refractive index are periodically arranged. In such an X-ray waveguide, a mode in which X-rays guided through the core cause multiple interference and efficiently guide in accordance with this periodic structure is selected, so that the phase of a large amount of light can be efficiently achieved. It becomes possible to guide the X-rays with the same number.

  The X-ray waveguide manufacturing method of the present invention is characterized in that a clad is formed after providing a planarizing layer on a core. Moreover, it is preferable to planarize the planarization layer after providing the planarization layer on the core. An outline of a method for manufacturing an X-ray waveguide according to the present invention will be described with reference to FIG. A clad 102 is formed on the substrate 100 (1-b), and a core 101 is formed on the clad 102 (1-c). After the planarization layer 110 is formed on the formed core 101, the planarization layer 110 is planarized (1-d). Next, the clad 103 is formed on the planarized planarization layer 110 (1-e). In FIG. 1, although the manufacturing method which planarizes only the upper planarization layer was described, the lower planarization layer can also be planarized. The X-ray waveguide manufactured by the manufacturing method of the present invention has a flat interface between the flattening layer (or core) and the clad, and a flattening layer (or core) in which incident X-rays are flattened. By being effectively confined by the interface with the cladding, X-rays can be guided with high propagation efficiency. Here, FIG. 1 is a schematic diagram, and the irregularities on the core surface are exaggerated.

  Next, regarding the X-ray waveguide manufacturing method of the present invention, (1) X-ray waveguide, (2) core forming step, (3) flattening layer flattening step (4) cladding forming step Separately described.

(1) X-ray waveguide In the present invention, X-rays are electromagnetic waves in a wavelength band in which the real part of the refractive index of a substance is 1 or less. Specifically, the X-ray in the present invention refers to an electromagnetic wave having a wavelength of 100 nm or less including extreme ultraviolet light (Extreme Ultra Violet (EUV) light). In this specification, an electromagnetic wave having a wavelength of 1 pm to 100 nm is referred to as X-ray. Further, in the specification, when the electromagnetic wave is simply referred to, it may be used synonymously with the X-ray.

  The frequency of electromagnetic waves with short wavelengths such as X-rays is very high, and the outermost shell electrons of the substance cannot respond. Therefore, unlike the frequency band of electromagnetic waves (visible light and infrared rays) having a wavelength longer than the wavelength of ultraviolet light, X It is known that the real part of the refractive index of a substance is smaller than 1 for a line. The refractive index n of a substance with respect to such X-rays is generally obtained by using a deviation δ from the real part 1 and β ′ of the imaginary part related to absorption as represented by the following formula (1). It is expressed as

δ is proportional to the electron density [rho _e substance, the real part of the larger material as the refractive index of the electron density is reduced. The real part n ′ of the refractive index is 1−δ. Furthermore, ρ _e is proportional to the atomic density ρ _a and the atomic number Z. As described above, the refractive index of a substance with respect to X-rays is represented by a complex number. In this specification, the real part is referred to as the real part of the refractive index or the real part of the refractive index, and the imaginary part is the imaginary part of the refractive index or the refractive index. Called the imaginary part. For example, X-rays have a maximum real part of refractive index when propagating in a vacuum, and have a maximum real part of refractive index of air for almost all substances that are not gases under general circumstances. In this specification, the term “substance” includes air and vacuum. Therefore, even when the mesostructure and the mesoporous are composed of a single material, the mesostructure and the mesoporous are composed of a plurality of substances because they have portions having different refractive indexes including air and vacuum.

  Next, the X-ray waveguide manufactured by the manufacturing method of the present invention will be described. The X-ray waveguide of the present invention confins X-rays to the core by total reflection at the clad and guides the X-rays, and the core has a periodic structure including a plurality of substances having different real refractive indices. Thus, a periodic resonant waveguide mode described later is developed. At this time, when the roughness of the interface between the core, the planarization layer (or core) and the clad is large, the confinement efficiency of X-rays to the core is lowered, and as a result, the propagation efficiency of X-rays is also lowered. In order to effectively confine X-rays by this total reflection, the X-ray waveguide manufacturing method of the present invention includes a step of forming a planarization layer between the core and the clad. And In the present invention, it is preferable to planarize the planarization layer after forming the planarization layer.

  Before describing the process of forming a planarizing layer characteristic of the present invention, the basic principle of an X-ray waveguide that exhibits a periodic resonance waveguide mode will be described. In order to help understanding the principle, this section uses an X-ray waveguide having an ideal (smooth) core-cladding interface and no planarization layer. An X-ray waveguide that expresses a periodic resonant waveguide mode forms a waveguide mode by confining the X-ray in the core having a periodic structure by total reflection at the interface between the core and the cladding, and propagates the X-ray. . This waveguide is characterized in that the total reflection critical angle at the interface between the core and the clad is larger than the Bragg angle resulting from the periodicity of the periodic structure of the core. FIG. 2 shows a conceptual diagram of this X-ray waveguide. This X-ray waveguide has a form in which a core 201 is sandwiched between a clad 202 and a clad 203. The core 201 is formed by laminating a basic structure including a material layer 205 having a high refractive index real part and a material layer 206 having a low refractive index real part. The periodic structure of the core of the X-ray waveguide according to the present invention may be any one of the one-dimensional to three-dimensional periodic structures, but will be described below using a one-dimensional periodic structure such as a multilayer film as an example. do. Reference numeral 207 denotes a critical angle for total reflection at the interface between the clad and core, 208 denotes a Bragg angle, and 209 denotes a critical angle for total reflection at the material interface in the basic structure.

In FIG. 2, the total reflection critical angle θ _{c-total at} the interface between the clad and the core, the total reflection critical angle θ _c-multi at the interface of each layer constituting the basic structure in the multilayer film, and the Bragg due to the periodicity of the multilayer film. An example of the angle θ _B is shown. In the present specification, these angles are expressed by assuming that the direction parallel to the plane of the film is 0 °. The advancing direction of the arrow X-ray in the figure is shown.

The total reflection critical angle θ from the direction parallel to the film surface, where n _{clad is} the real part of the refractive index of the material on the clad side and n _core is the real part of the refractive index of the material on the core side at the interface between the clad and the core _c-total (°) is expressed by the following formula (2) where n _clad <n _core.

It is represented by

When the period of the one-dimensional periodic structure of the core is d and the real part of the average refractive index of the periodic structure that is the core is n _avg , it is approximately as shown in the following formula (3) regardless of the presence or absence of multiple diffraction in the core. Bragg angle θ _B (°) is defined.

  Here, m is a constant, and λ is the wavelength of X-rays.

  The physical property parameter of the substance constituting the X-ray waveguide, the structural parameter of the waveguide, and the wavelength of the X-ray are designed to satisfy the following formula (4).

By satisfying Equation (4), the waveguide mode with an effective propagation angle such as the Bragg angle due to the periodicity of the core, which is a periodic structure, is always confined in the core by the cladding, contributing to the propagation of X-rays. Can be made. Here, in this specification, the effective propagation angle θ ′ (°) is expressed by the following equation (5) using the wave number vector (propagation constant) k _z in the propagation direction of the waveguide mode and the wave number vector k ₀ in vacuum. It shall be represented by Since k _z is constant at the interface of each layer due to the continuous condition, as shown in FIG. 3, the effective propagation angle θ ′ (°) is the propagation constant k _z of the fundamental wave of the waveguide mode and the wave number vector k _{0 in} vacuum. The angle at which the fundamental wave of the guided mode travels in a vacuum. Since this can be considered to roughly represent the propagation angle of the fundamental wave of the guided mode in the core, it will be used for future explanation.

Here, the periodic structure that forms the core is assumed to be a multilayered film in which films of a plurality of substances having different real parts of the refractive index are periodically stacked. At this time, the total reflection critical angle due to the difference in the real part of the refractive index exists at the adjacent film interface. This is defined as θ _c-multi (°).

  When the critical angle for total reflection in the multilayer film is smaller than the Bragg angle due to the periodicity of the multilayer film as shown in the above formula (6), it is incident on the interface in the multilayer film at an angle greater than or equal to the Bragg angle. The X-rays that are generated do not cause total reflection, but cause partial reflection or refraction. Since the multilayer film is composed of a plurality of periodically laminated films having different real refractive indexes, there are a plurality of interfaces in the stacking direction, and X-rays inside the multilayer film are repeatedly reflected and refracted at these interfaces. It becomes. Such repeated reflection and refraction of X-rays within the multilayer film causes multiple interference. As a result, an X-ray having a condition capable of resonating with the periodic structure of the multilayer film, that is, a propagation mode that can exist inside the multilayer film is formed. As a result, a waveguide mode is formed in the core of the X-ray waveguide structure. It will be. This is referred to as a periodic resonance waveguide mode.

  Each of such periodic resonant waveguide modes has an effective propagation angle, and the effective propagation angle of the periodic resonant waveguide mode having the smallest effective propagation angle appears in the vicinity of the Bragg angle of the multilayer film. Since the periodic resonant waveguide mode is a mode that resonates with the periodicity of the periodic structure, it is referred to as a periodic resonant waveguide mode in this specification. This corresponds to a propagation mode that satisfies the lowest order band when the multi-layer film is considered as a one-dimensional photonic crystal with an infinite number of cycles. This propagation mode is confined by total reflection at the interface between the cladding and the core. Become.

  In an actual one-dimensional periodic structure, since the number of periods is finite, the photonic band structure deviates from the photonic band structure of the one-dimensional periodic structure with an infinite period. However, the waveguide mode increases as the number of periods increases. The characteristic approaches that on a photonic band with an infinite period. The Bragg reflection is caused by the effect of the photonic band gap due to periodicity, and the Bragg angle, which is the angle that gives the Bragg reflection, is slightly larger than the effective propagation angle of the periodic resonant waveguide mode.

  In a photonic band structure having a periodic structure, a waveguide mode that resonates with the periodic structure exists at the end of the photonic band gap. When the effective propagation angle of the waveguide mode is considered with the X-ray energy constant, the waveguide mode having a relatively small effective propagation angle among these waveguide modes is the lowest-order periodic resonant waveguide mode. . In the spatial distribution profile of the electric field intensity in the periodic resonant waveguide mode, the number of antinodes of the electric field intensity basically matches the number of periods of the multilayer film. The position of the antinode of the higher-order periodic resonant waveguide mode having an effective propagation angle corresponding to the higher-order Bragg angle is basically a natural number multiple of 2 or more of the number of periods.

  In a multilayer film having a finite number of periods, there may be a waveguide mode that propagates at an angle other than the effective propagation angle of the periodic resonance waveguide mode as described above. These are waveguide modes that exist when the entire multilayer film, which is not a periodic resonant waveguide mode, is considered as a uniform medium with the real part of the refractive index averaged. The influence of periodicity is small. On the other hand, in the periodic resonant waveguide mode realized by this X-ray waveguide configuration, as the number of periods of the periodic structure increases, the electric field concentrates at the center of the core, which is a multilayer film, and the seepage into the cladding decreases. Thus, the X-ray propagation loss is reduced. In addition, the envelope curve of the electric field intensity distribution has a shape biased toward the center of the core, and the loss due to the seepage into the clad is further reduced. Furthermore, the phase of the periodic resonant waveguide mode used in this X-ray waveguide is uniform in the direction with high periodicity, that is, in the direction perpendicular to the interface between the cladding and the core and perpendicular to the waveguide direction. Can have typical coherence. Here, the fact that the waveguide modes are in phase not only corresponds to the fact that the phase difference of the electromagnetic field in the plane perpendicular to the waveguide direction is zero, but also corresponds to the spatial refractive index distribution of the periodic structure. This also means that the phase difference of the electromagnetic field periodically changes between −π and + π. In this periodic resonant waveguide mode, the phase of the electric field changes between −π and + π in the direction perpendicular to the waveguide direction at the same period as the period of the periodic structure.

(2) Core formation process The core used in the core formation process of the present invention will be described. In the present invention, the core has a periodic structure made of a plurality of substances having different real parts of the refractive index. In the present invention, the plurality of substances having different real parts of refractive index are often two or more kinds of substances having different electron densities. The periodic structure may be a one-dimensional to three-dimensional periodic structure, but has a periodicity in a plane perpendicular to the X-ray waveguide direction. Such a periodic structure can also be produced by a conventional semiconductor process such as photolithography, electron beam lithography, etching process, lamination or bonding. For example, when the periodic structure is one-dimensional, the periodic structure can be configured as a multilayer film. In this case, as a method of forming the multilayer film, there are alternating vapor deposition and sputtering.

Such a substance having a different real part of the refractive index forming the core may be a gas or a vacuum in addition to an inorganic or organic solid material. A combination of these substances is also preferably used. Examples of inorganic materials include boron, boron compounds, beryllium, carbon, nitrides, oxides, and phosphorus. Specifically, Be, B, C, B ₄ C, BN, SiC, Si ₃ N ₄ , SiN, Al ₂ O ₃ , MgO, TiO ₂ , SiO ₂ , and P can be used. By using an inorganic material as the material for forming the core, established processes such as conventional sputtering, vapor deposition, and crystal growth can be used, and a structure resistant to heat and external force can be obtained. Examples of organic substances include polymers and low molecular compounds. By using an organic substance, propagation loss due to X-ray absorption can be reduced. A gas or vacuum is preferable because this loss can be further reduced.

  Further, as a material for forming the periodic structure, a material manufactured by a self-organized formation mechanism different from a normal semiconductor process may be used. An example of this is a mesostructured film formed by self-assembly of a surfactant or the like or an amphiphile. The mesostructured film is preferably used for the periodic structure in the present invention. This is described below.

(Mesostructured film)
The porous material is classified according to its pore diameter by IUPAC (International Union of Pure and Applied Chemistry), and the porous material having a pore diameter of 2 to 50 nm is classified as mesoporous. In recent years, research on this mesoporous material has been actively conducted, and it has become possible to obtain a structure in which mesopores with uniform diameters are regularly arranged by using a surfactant aggregate as a template. In this specification, the mesostructured film includes (A) mesoporous film, (B) mesoporous film mainly filled with organic compounds, and (C) mesostructured film having a lamellar structure. It is. Each will be described in detail below.

(A) Mesoporous film A porous material having a pore size of 2 to 50 nm, and the material of the wall portion is not particularly limited, but examples thereof include substances having different real parts of refractive index and manufacturability and periodic structures. An oxide is mentioned from a viewpoint of comprising more. Examples of the oxide include silicon oxide, tin oxide, zirconia, titanium oxide, niobium oxide, tantalum oxide, aluminum oxide, tungsten oxide, hafnium oxide, and zinc oxide. These substances have, for example, a real part of refractive index of 0.999997 or less for X-rays of 10 keV, for example, organic substances (having a real part of refractive index of about 0.999998) described later, air (same as above) , Having a real part of refractive index of approximately 1) and a periodic structure, it is possible to form a periodic structure made of materials having different real parts of refractive index. The above oxide may contain an organic component in its skeleton. The surface of the wall portion may be modified as necessary. For example, hydrophobic molecules may be modified to suppress water adsorption.

  The method for preparing the mesoporous film is not particularly limited, but for example, it can be prepared by the following method. An inorganic oxide precursor is added to a solution of an amphiphile in which the aggregate functions as a template, a film is formed, and an inorganic oxide formation reaction proceeds. Thereafter, the template molecule is removed to obtain a porous material.

  The amphiphile is not particularly limited, but a surfactant is suitable. Examples of the surfactant molecule include ionic and nonionic surfactants. Examples of the ionic surfactant include a halide salt of trimethylalkylammonium ion. The chain length of this alkyl chain is preferably 10 to 22 carbon atoms. As the nonionic surfactant, one containing polyethylene glycol as a hydrophilic group can be used. As the surfactant containing polyethylene glycol as a hydrophilic group, polyethylene glycol alkyl ether and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymers can be used. The chain length of this alkyl chain of the polyethylene glycol alkyl ether is preferably 10 to 22 carbon atoms, and the repeating number of polyethylene glycol is preferably 2 to 50 carbon atoms. It is possible to change the structural period by changing the hydrophobic group and the hydrophilic group. In general, it is possible to enlarge the pore diameter by increasing the hydrophobic group and hydrophilic group. In addition to the surfactant, an additive for adjusting the structural period may be added. As an additive for adjusting the structure period, a hydrophobic substance can be used. As this hydrophobic substance, alkanes and aromatic compounds not containing a hydrophilic group can be used, and specifically, octane can be used.

  As the precursor of the inorganic oxide, silicon or metal element alkoxide or chloride can be used. More specifically, alkoxides and chlorides of Si, Zr, Ti, Nb, Al, Zn, and Sn can be used. As the alkoxide, methoxide, ethoxide, propoxide, or one in which a part thereof is substituted with an alkyl group can be used. As the film forming method, a dip coating method, a spin coating method, or a hydrothermal synthesis method can be used. As a method for removing the template molecule, baking, extraction, ultraviolet irradiation, or ozone treatment can be used.

(B) The mesoporous film whose pores are mainly filled with an organic compound The same material as described in the section (A) can be used as the wall material. The substance filling the pores is not particularly limited as long as it is mainly composed of an organic compound. The meaning of “main” means 50% or more by volume ratio. Examples of the organic compound include a surfactant and a material in which a site having a function of forming a molecular assembly is bonded to a material forming a wall or a precursor of a material forming a wall. Examples of this surfactant include the surfactants described in the section (A). In addition, the material having a function of forming a molecular assembly is a material that forms a wall portion or a material that is bonded to a precursor of a material that forms a wall portion. Siloxane compounds can be used. The chain length of this alkyl chain is preferably 10 to 22 carbon atoms.

  The inside of the hole may contain water, an organic solvent, a salt, or the like as necessary or as a result of a material to be used or a process. Examples of the organic solvent include alcohol, ether and hydrocarbon.

  The method for preparing the mesoporous membrane whose pores are mainly filled with an organic compound is not particularly limited. For example, the steps prior to the removal of the template in the method for preparing the mesoporous membrane described in the section (A) are performed. Can be mentioned.

(C) Mesostructured film having a lamellar structure The mesostructured film of the present invention includes a mesostructured film having a lamellar structure in addition to (A) and (B). This lamellar structure refers to a lamellar structure composed of the material for the wall portion described in (B) and the substance that fills the holes described in (B). These two kinds of materials (substances) may be bonded by chemical bonds as necessary in order to obtain desired properties. An example of this bonded compound is trialkoxyalkylsilane.

(3) Step of forming flattening layer The flattening layer formed in the present invention will be described. The X-ray waveguide manufactured by the present invention guides the X-ray by confining the X-ray in the core by total reflection at the cladding interface. If the scattering loss at the time of total reflection by the clad at this time is small, the X-ray confinement efficiency in the core is improved, and the X-ray propagation efficiency is improved. The total reflection of X-rays is very sensitive to the roughness of the total reflection interface, and its scattering loss decreases with decreasing roughness. As a result of examining various X-ray waveguide configurations, the inventors have confirmed that the propagation efficiency is improved in some X-ray waveguides by reducing the roughness of the interface between the core and the cladding. did.

  In the method for manufacturing an X-ray waveguide according to the present invention, in order to reduce the roughness of the interface, a “flattening layer” is introduced between the core and the clad to achieve flattening. As a result of various studies, it was concluded that a flattening layer having the following characteristics is suitable.

  First, the planarization layer is examined from the viewpoint of refractive index. The planarization layer introduced for the purpose of reducing the roughness of the interface is preferably a medium having X-ray waveguide characteristics that are the same as or close to the core, based on the principle of the X-ray waveguide. The X-ray waveguide manufactured by the manufacturing method of the present invention utilizes phenomena such as refraction and interference caused by X-rays at the interface of different substances, and a substance recognized by X-rays when these phenomena occur. This difference is mainly due to the difference in electron density. The electron density is determined by the atomic number Z of the material constituting the planarization layer and the atomic density of the planarization layer. The planarization layer preferably has the same or near X-ray wave guiding characteristics as the core, but there may be a case where the difference in electron density between the planarization layer and the core is large. In this case, the volume of the planarization layer finally remaining in the X-ray waveguide is preferably kept to the minimum possible with respect to the core volume. Further, when the flattening layer can be completely removed to flatten the interface between the core and the clad, the formed flattening layer can be completely removed.

  Second, the formation and planarization of the planarization layer will be examined from the viewpoint of the planarization effect. As the material used for the planarization layer, a material that can be formed so as to reduce the roughness of the core surface and a material that has favorable physical properties with respect to the planarization process subsequent to the formation are selected.

  The substance used for the planarization layer is not particularly limited as long as it has the above properties. Although the substance used for the planarization layer depends on the substance constituting the core, inorganic substances, organic substances, and these inorganic / organic composite materials can be used. As examples of inorganic substances, oxides, light metals, and carbon can be used. Among these, oxides are preferably used from the viewpoint of adhesion because a strong layer can be easily formed by a coating and drying method. As a specific material, an oxide containing Si, Al, Ti, Zn, Nb, Zr, and Sn having the above properties is selected. A porous body may be used for these oxides. Moreover, it is preferable to use the same material as the core as the material used for the planarization layer.

  Examples of the method for forming the planarizing layer include a general sputtering method, a CVD (chemical vapor deposition) method, a vapor deposition method, and a coating from a solution system (by a sol-gel method) for inorganic materials. If it is an organic substance, the application from a solution system, vapor deposition, etc. are mentioned. If it is a composite material, application | coating from a solution system is mentioned.

  As an example of a method for forming a planarizing layer particularly preferably used in the present invention, a method for forming Si oxide by coating from a solution system will be described in detail. For example, a commercially available material called spin-on-glass (SOG) is used as the coating solution after diluting with a suitable solvent in accordance with the desired flattening layer thickness. In addition to inorganic materials such as tetraalkoxysilane and perhydrosilazane, inorganic / organic composite materials such as alkylalkoxysilane, siloxane, and organosilsesquioxane are used as precursors for Si oxides in SOG materials. Can be mentioned. As a diluting solvent, a solvent used for various SOG materials such as alcohols, ethers, and xylenes may be appropriately selected.

  The above SOG material is applied on a core formed by spin coating, dip coating, spraying, or the like, and dried to obtain Si oxide. In addition to the element in which the SOG material in the liquid state flows into the recess having the roughness on the core surface, the SOG material flows and flattens the surface during the condensation of the Si precursor in the subsequent drying step. Drying is performed at normal temperature and pressure, drying, heating, firing, or in some cases, in an inert gas atmosphere or under reduced pressure (for example, when the amount of water is adjusted and the hydrolysis condensation reaction of the precursor is desired). select.

  Here, the Si oxide is described in detail as an example. However, as described above, the present invention is not limited to the Si oxide, and other materials can be formed by a similar method.

  Next, the planarization step after the planarization layer is formed will be described. In the X-ray waveguide manufacturing method of the present invention, a step of further planarizing the formed planarization layer can be performed. Specifically, the planarization layer is removed by chemical etching or physical polishing. Planarization methods include liquid phase etching, plasma processing etching, mechanical polishing with abrasives (mechanical polishing), and chemical mechanical polishing (hereinafter referred to as chemical mechanical polishing) that combines chemicals that react chemically with the planarization layer with abrasives. (Referred to as CMP).

  In the planarization step, part or all of the formed planarization layer can be removed. When a part of the planarization layer is removed, the clad is in contact with the planarization layer (and the core). Further, when all of the planarizing layer is removed, the clad is in contact with the core.

  At the interface between the planarization layer (or core) and the clad, the surface roughness of the planarization layer (or core) is preferably 5 nm or less, more preferably 3 nm or less in terms of root mean square. Therefore, in the planarization step, the surface roughness of the planarization layer (or core) is preferably 5 nm or less, preferably 3 nm or less in terms of root mean square. When these conditions are satisfied, propagation loss due to X-ray scattering at the interface between the planarization layer or the core and the cladding can be further reduced, and the planarization layer or core and the cladding can be strongly bonded.

  The thickness range of the planarized layer thus formed is in the range of 1 nm to 5 μm, and preferably in the range of 3 nm to 100 nm. Note that the thickness of the planarizing layer referred to here refers to the thickness from the surface of a material serving as a base when the formed layer is viewed from the cross-sectional direction. When the ground surface has irregularities, the thickness is determined from the lowest position.

(4) Cladding The X-ray waveguide according to the present invention guides the X-ray by confining the X-ray in the core (and the flattening layer) by total reflection at the cladding. In the X-ray region, a substance having a higher electron density has a smaller real part of the refractive index. Therefore, it is preferable to use a metal having a high density as the material used for the cladding. Specifically, a simple substance of Os, Ir, Pt, Au, W, Ta, Hg, Ru, Rh, Pd, Pb, and Mo, or a material containing these elements can be used. The X-ray waveguide according to the present invention is designed so as to satisfy the above-mentioned formulas (2) to (4) between the material forming the core and the material used for the cladding. There is. A clad using such a material can be formed by sputtering, vapor deposition, or the like. Although the thickness of this clad varies depending on the material, it is required to be thick enough to sufficiently confine X-rays in the core and thin from the viewpoint of cost and manufacturing. The thickness of the cladding is preferably 1 nm to 300 nm, and more preferably 1 nm to 50 nm. The clad is preferably formed with a film thickness distribution in the X-ray waveguide. For example, for the purpose of positively incident from the cladding surface, a thin film is formed in the incident region to improve introduction efficiency, while in other regions, a thick film is formed to enhance the X-ray confinement effect. Is preferably performed.

  According to the method of manufacturing an X-ray waveguide of the present invention, the planarization layer is used to smooth the core / cladding interface, thereby increasing the total reflection efficiency at the cladding interface, and the core (or the planarizing layer). ) Can be guided with high propagation efficiency. As a result, a waveguide that can effectively use the characteristics of the periodic resonant waveguide mode, such as a reduction in propagation loss due to the concentration of the electric field at the center of the core and the presence of spatial coherence, is manufactured. be able to.

  The present invention will be described in more detail with reference to the following examples. However, the method of the present invention is not limited to these examples.

Example 1
(1-1) Production of Waveguide In Example 1, an X-ray waveguide having a configuration of (3-f) in FIG. 4 in which a planarization layer is formed between clads on both sides of the core will be described. The X-ray waveguide manufactured in this embodiment is formed by laminating a cladding 402 made of W (tungsten), a planarization layer 409, a core 401, a planarization layer 410, and a cladding 403 in this order on a Si substrate 400. Has been. The core 401 is a silicon oxide mesostructured film. In this mesostructured film, holes made of an organic substance are two-dimensionally arranged to form a periodic structure in the film thickness direction. In this embodiment, a silicon oxide mesostructured film is also used for the planarizing layer. The mesostructured film used for the planarization layer has a smooth surface although it has a structure with less periodicity than that formed on the core. A method for manufacturing the X-ray waveguide according to the present embodiment will be described below in order with reference to FIG.

(1-1-1) Formation of cladding (FIG. 4-b)
A clad 402 made of W (tungsten) is formed on a Si substrate to a thickness of about 15 nanometers by sputtering.

(1-1-2) Formation of planarization layer (FIG. 4-b)
(1-1-2-1) Precursor Solution Preparation of Mesostructured Film A silicon oxide mesostructured film 409 as a planarizing layer is prepared by a dip coating method. The mesostructure precursor solution was prepared by mixing and stirring tetragoxysilane 2.6 g, block copolymer (Pluronic P123, manufactured by BASF) 0.7 g, 1-propanol 13 g, and 0.01M hydrochloric acid aqueous solution 1.35 g. did.

(1-1-2-2) Formation of Mesostructured Film A dip coating is performed on the cleaned substrate using a dip coating apparatus at a pulling rate of 0.5 mms ⁻¹ . After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 40% for 2 weeks and at 80 ° C. for 24 hours. The mesostructured film formed as a planarization layer has a structure with a lower periodicity than that formed on the core. (Flatness is improved by giving distribution to the periodicity of the structure.) The formed planarization layer 409 is formed to have a thickness of 100 nm.

(1-1-3) Formation of core (production of silicon oxide mesostructured film) (FIG. 4-c)
(1-1-3-1) Preparation of precursor solution of mesostructured film A silicon oxide mesostructured film 301 having a 2D hexagonal structure is prepared by a dip coating method. The precursor solution of the mesostructure is prepared by adding an ethanol solution of a block polymer to a solution obtained by adding ethanol, 0.01M hydrochloric acid, and tetraethoxysilane and mixing for 20 minutes, and stirring for 3 hours. As a block polymer, ethylene oxide (20) propylene oxide (70) ethylene oxide (20) (hereinafter referred to as EO (20) PO (70) EO (20) (in parentheses are the number of repetitions of each block)) Can be used. It is also possible to use methanol, propanol, 1,4-dioxane, tetrahydrofuran, or acetonitrile instead of ethanol. The mixing ratio (molar ratio) is tetraethoxysilane: 1.0, hydrochloric acid: 0.0011, ethanol: 5.2, block polymer: 0.0096, and ethanol: 3.5. The solution is appropriately diluted and used for the purpose of adjusting the film thickness.

(1-1-3-2) Formation of Mesostructured Film A dip coating is performed on the cleaned substrate at a lifting speed of 0.5 mms ⁻¹ using a dip coating apparatus. After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 40% for 2 weeks and at 80 ° C. for 24 hours. From the X-ray diffraction analysis of the adjusted mesostructured film using the Bragg-Brentano configuration, this mesostructured film has a high order in the normal direction of the substrate surface, and its plane spacing, that is, in the confinement direction. It is confirmed that the period is 10 nm. Its film thickness is approximately 500 nanometers.

(1-1-4) Formation of planarization layer (FIG. 4-d)
The silicon oxide mesostructured film 410 as the planarizing layer was formed with a thickness of 100 nm by the same method as (1-1-2).

(1-1-5) Formation of cladding (FIG. 4-f)
A clad 403 made of W (tungsten) is formed on the surface of the core (and made of a buffer material). This clad was formed with a thickness of approximately 15 nanometers by sputtering.

(1-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The mesostructured film, which is the core when the steps (1-1-2) and (1-1-4) are omitted and the planarizing layer is not formed for the X-ray waveguide formed in Example 1. The surface roughness 401 is approximately 12 nm in terms of root mean square. The roughness of the surface of the planarization layer 410 on the core 401 formed by the manufacturing method of Example 1 using the planarization layer is about 1 nm.

  The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.

  The X-ray waveguide of Example 1 shows a value approximately three times that of an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer. This suggests that the X-ray confinement effect by the clad of the X-ray waveguide is improved by the flattening by the flattening layer.

(1-3) Waveguide characteristics A 10 keV X-ray was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is approximately six times as high is observed. This high waveguide strength is considered to be achieved by improving the X-ray confinement efficiency of the X-ray waveguide of the present invention by flattening with the flattening layer.

Example 2
(2-1) Production of Waveguide In this example, an X-ray waveguide having a configuration of (1-e) in FIG. 1 is described in which a planarization layer is formed between clads on one side with respect to the core. The X-ray waveguide manufactured in this embodiment is formed by laminating a clad 102 made of W (tungsten), a core 101, a planarizing layer 110, and a clad 103 in this order on a Si substrate 100. The core 101 is a silicon oxide mesostructured film. In this mesostructured film, holes made of an organic substance are two-dimensionally arranged to form a periodic structure in the film thickness direction. Example 2 also uses a silicon oxide mesostructured film for the planarization layer. The mesostructured film used for the planarization layer has a smooth surface although it has a structure with less periodicity than that formed on the core. A method for manufacturing the X-ray waveguide of Example 2 will be described below in order with reference to FIG.

(2-1-1) Formation of cladding (FIG. 1-b)
The clad is formed using the same method as in (1-1-1).

(2-1-2) Formation of core (production of silicon oxide mesostructured film) (FIG. 1-c)
The mesostructured film is formed using the same method as in (1-1-3).

(2-1-3) Formation of planarization layer (FIG. 1-d)
The mesostructured film is formed using the same method as in (1-1-4). The thickness of the formed planarization layer is 100 nm.

(2-1-4) Formation of cladding (FIG. 1-e)
A clad 103 made of tungsten is formed on the planarizing layer. This clad was formed with a thickness of approximately 15 nanometers by sputtering.

(2-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The surface roughness of the mesostructured film 110, which is the core prepared in the process (2-1-2), is approximately 12 nm in terms of the root mean square value, and the planarized layer is planarized in the process (2-1-3). The surface roughness consisting of is about 1 nm.

  The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.

  The X-ray waveguide of Example 2 shows a value approximately three times that of an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer. This suggests that the X-ray confinement effect by the clad of the X-ray waveguide is improved by the flattening by the flattening layer.

(2-3) Waveguide characteristics An X-ray of 10 keV was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a flattening layer, a waveguide strength that is approximately 10 times that of the X-ray waveguide is observed. This high waveguide strength is considered to be achieved by improving the X-ray confinement efficiency of the X-ray waveguide of the present invention by flattening with the flattening layer.

Example 3
(3-1) Production of Waveguide In Example 3, the planarization layer was formed between the clads on one side of the core and then further planarized by etching (5-f) in FIG. An X-ray waveguide having the following structure will be described. The X-ray waveguide manufactured in this embodiment is formed by laminating a clad 502 made of W (tungsten), a core 501, a planarizing layer 510, and a clad 503 in this order on a Si substrate 500. The core 501 is a silicon oxide mesostructured film. In this mesostructured film, holes made of an organic substance are two-dimensionally arranged to form a periodic structure in the film thickness direction. In this embodiment, a silicon oxide film is used for the planarizing layer. The manufacturing method of the X-ray waveguide of the present embodiment will be described in order below with reference to FIG.

(3-1-1) Formation of cladding (FIG. 5-b)
The clad is formed using the same method as in (1-1-1).

(3-1-2) Formation of core (silicon oxide mesostructured film) (FIG. 5-c)
The mesostructured film is formed using the same method as in (1-1-3).

(3-1-3) Formation of planarization layer (FIG. 5-d)
The planarization layer 510 made of silicon oxide was formed by spin coating an SOG material. As the SOG material, NAX120 manufactured by AZ Electronic Materials Co., Ltd. was applied on the substrate by spin coating. The substrate after application is held for 24 hours in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 40%. The thickness of the formed planarization layer is 400 nm.

(3-1-4) Planarization Processing Subsequently, reactive ion etching (RIE) is performed on the formed planarization layer. Using a dry etching apparatus, the film thickness corresponding to the planarization layer 280 nm was removed by this process, and finally the planarization layer 510 having a thickness of 120 nm was formed on the mesostructured film 501 as the core. .

(3-1-5) Formation of clad A clad 503 made of tungsten is formed on the planarization layer. This clad is formed with a thickness of approximately 15 nanometers by sputtering. The clad is formed in close contact with the surface made of the planarizing layer 510.

(3-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The surface roughness of the mesostructured film 510, which is the core prepared in the step (3-1-2), is approximately 12 nm in terms of root mean square value, and (3-1-3) and (3- The roughness of the surface flattened in the process 1-4) is about 2 nm.
The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.
The X-ray waveguide of Example 3 shows a value approximately 2.5 times that of an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer. This suggests that the X-ray confinement effect by the clad of the X-ray waveguide is improved by the flattening by the flattening layer.

(3-3) Waveguide characteristics A 10 keV X-ray was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared with an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is approximately twice as high is observed. This high waveguide strength is considered to be achieved by improving the X-ray confinement efficiency of the X-ray waveguide of the present invention by flattening with the flattening layer.

Example 4
(4-1) Production of Waveguide In this example, after a flattening layer is formed between clads on one side of the core, a further flattening process is performed by polishing, and the surface comprising the core and the flattening layer is clad. An X-ray waveguide having the configuration (5-f) in FIG.

  The X-ray waveguide manufactured in this embodiment is formed by laminating a clad 602 made of W (tungsten), a core 601, a planarizing layer 610, and a clad 603 in this order on a Si substrate 600. The core 601 is a silicon oxide mesostructured film. In this mesostructured film, holes made of an organic substance are two-dimensionally arranged to form a periodic structure in the film thickness direction. In this embodiment, a silicon oxide film is used for the planarizing layer. A method for manufacturing the X-ray waveguide according to the present embodiment will be described below step by step with reference to FIG.

(4-1-1) Formation of cladding (FIG. 6b)
The clad is formed using the same method as in (1-1-1).

(4-1-2) Formation of core (silicon oxide mesostructured film) (FIG. 6-c)
The mesostructured film is formed using the same method as in (1-1-3).

(4-1-3) Formation of planarization layer (FIG. 6-d)
The planarization layer 610 made of silicon oxide was formed by spin coating an SOG material. As the SOG material, NAX120 manufactured by AZ Electronic Materials Co., Ltd. was applied on the substrate by spin coating. The substrate after application is held for 24 hours in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 40%. The thickness of the formed planarization layer is 200 nm.

(4-1-4) Planarization Process Subsequently, further planarization is performed by polishing the formed planarization layer. Using a CMP apparatus (manufactured by MTT), polishing was performed with a polishing solution manufactured by BUEHLER in which colloidal silica particles having a diameter of 5 nmΦ were dispersed in water. The film thickness corresponding to 200 nm was removed by this step by adjusting the polishing time. When the cross section of the formed substrate was analyzed with a transmission electron microscope (TEM), most of the planarization layer formed in the process of 1-1-4 was removed, the core material was partially exposed to the surface, and the others A smooth surface was formed in such a form that the material used for the flattening layer was filled in this area. (Fig. 6-e)

(4-1-5) Formation of clad A clad 603 made of tungsten is formed on the planarization layer. This clad is formed with a thickness of approximately 15 nanometers by sputtering. The clad is formed in close contact with the surface composed of the core 601 and the planarizing layer 610.

(4-2) Relationship between surface roughness and X-ray reflectance The surface roughness is evaluated using a surface roughness meter. The surface roughness of the mesostructured film 5010, which is the core prepared in the step (4-1-2), is approximately 12 nm in terms of root mean square value, and (4-1-3) and (4- The roughness of the surface flattened in the process 1-4) is about 0.8 nm.
The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.
The X-ray waveguide of Example 4 shows a value approximately three times that of an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer. This suggests that the X-ray confinement effect by the clad of the X-ray waveguide is improved by the flattening by the flattening layer.

(4-3) Waveguide characteristics A 10 keV X-ray was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is about 12 times as high is observed. This high waveguiding strength enables the X-ray waveguide of the present invention to planarize using a planarizing layer, and more effectively use the regular periodicity of the core by partially removing the planarizing layer. As a result, it is considered to have been achieved.

Example 5
(5-1) Production of Waveguide In this example, after the planarization layer was formed between the clads on one side with respect to the core, the planarization layer was removed by polishing, and a part of the core was also removed. An X-ray waveguide having the configuration (7-f) in FIG. 7 in which a cladding is formed on the surface of the core will be described.

  The X-ray waveguide manufactured in this embodiment is formed on a Si substrate 700 in the order of a clad 702 made of W (tungsten), a core 701, and a clad 703. The core 701 is a silicon oxide mesostructured film. In this mesostructured film, holes made of an organic substance are two-dimensionally arranged to form a periodic structure in the film thickness direction. In this embodiment, a silicon oxide film is used for the planarizing layer. A method for manufacturing the X-ray waveguide according to the present embodiment will be described in order with reference to FIG.

(5-1-1) Formation of cladding (FIG. 7-b)
The clad is formed using the same method as in (1-1-1).

(5-1-2) Formation of core (silicon oxide mesostructured film) (FIG. 7-c)
The mesostructured film is formed using the same method as in (1-1-3).

(5-1-3) Formation of planarization layer (FIG. 7-d)
A silicon oxide film is formed by a method similar to (4-1-3).

(5-1-4) Planarization treatment Subsequently, further planarization is performed by polishing the formed planarization layer. Polishing was performed with a polishing solution manufactured by BUEHLER in which colloidal silica particles having a diameter of 60 nmΦ were dispersed, using a CMP apparatus (manufactured by MTT). The film thickness corresponding to 250 nm was removed by this step by adjusting the polishing time. When the cross section of the formed substrate is analyzed by a transmission electron microscope (TEM), the planarization layer formed in the step 5-3-1 is removed, and the thickness of the core material formed in the step 5-1-2 is further increased. It decreased by about 50 nm (meaning that the polishing progressed to the core layer after the planarization layer was removed), and the surface of the core was planarized. (Fig. 7-e)

(5-1-5) Formation of clad A clad 703 made of tungsten is formed on the planarization layer. This clad is formed with a thickness of approximately 15 nanometers by sputtering. The clad is formed in close contact with the surface comprising the core 701.

(5-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The surface roughness of the mesostructured film 6010, which is the core formed in the process of (5-1-2), is approximately 12 nm in terms of root mean square value, and (5-1-3) and (5- The roughness of the core surface flattened in the process 1-4) is about 2 nm.
The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.
The X-ray waveguide of Example 5 shows a value approximately twice that of an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer. This suggests that the X-ray confinement effect by the clad of the X-ray waveguide is improved by the flattening process using the flattening layer.

(5-3) Waveguide characteristics An X-ray of 10 keV was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is about eight times as high is observed. This high waveguide strength effectively utilizes the regular periodicity of the core by removing the planarization layer after the X-ray waveguide of the present invention performs planarization using the planarization layer. As a result, it is considered to have been achieved.

Example 6
(6-1) Preparation of Waveguide In Example 6, an X-ray waveguide having a configuration in which a planarization layer is formed by the same method as in Example 3 and only the thickness of the planarization layer is changed to 20 nm is described. To do.

(6-1-1) Formation of clad A clad is formed using the same method as in (3-1-1).

(6-1-2) Formation of Core (Silicon Oxide Mesostructure Film) The mesostructure film is formed using the same method as in (3-1-3).

(6-1-3) Formation of planarization layer A silicon oxide film is formed in the same manner as in (3-1-3).

(6-1-4) Planarization Processing Subsequently, reactive ion etching (RIE) is performed on the formed planarization layer. Using a dry etching apparatus, the film thickness corresponding to the planarization layer of 380 nm was removed by this step, and finally the planarization layer having a thickness of 20 nm was formed on the mesostructured film as the core.

(6-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The roughness of the surface flattened by the steps (6-1-3) and (6-1-4) using the flattening layer is about 2 nm in terms of the root mean square value.
The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.
In the X-ray waveguide of Example 6, a good reflectance equivalent to that of the X-ray waveguide formed in Example 3 was obtained.

(6-3) Waveguide characteristics An X-ray of 10 keV was incident on this waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is about eight times as high is observed. This high waveguide strength is due to the fact that the X-ray waveguide of the present invention is improved in the X-ray confinement efficiency by the flattening by the flattening layer, and the thickness of the flattening layer is more optimized than in the third embodiment. It is thought that it was achieved.

Example 7
(7-1) Preparation of Waveguide In this example, an X-ray waveguide formed by the same method as in Example 2 and having a configuration in which only the material of the planarizing layer is changed to titanium oxide will be described.

(7-1-1) Formation of clad A clad is formed using the same method as in (2-1-1).

(7-1-2) Formation of Core (Silicon Oxide Mesostructured Film) The mesostructured film is formed using the same method as (2-1-3).

(7-1-3) Formation of planarization layer (titanium oxide) The planarization layer made of titanium oxide is prepared by a spin coating method. The precursor solution is prepared by adding acetic acid, 1-propanol, ethanol and water to titanium tetraisopropoxide and performing ultrasonic treatment for 15 minutes. The volume ratio of the reagents used is titanium tetraisopropoxide: 2.5, acetic acid: 5, 1-propanol: 5, ethanol: 15, and water: 1. The solution is appropriately diluted and used for the purpose of adjusting the film thickness. A film is formed on the mesostructured film prepared in the previous step using a spin coater. Then, it was kept in a constant temperature and humidity chamber at 25 ° C. and 40% relative humidity for 24 hours to form titanium oxide having a thickness of 15 nm.

(7-2) Relationship between surface roughness and X-ray reflectivity Surface roughness is evaluated using a surface roughness meter. The roughness of the surface flattened by the step (6-1-3) using the flattening layer is about 3 nm in terms of the root mean square value.
The reflectance when the X-ray waveguide clad is irradiated with X-rays is compared and evaluated. Using 10 keV X-rays, near the Bragg angle (θ = 0.36 °) corresponding to the periodic structure of the core, at an angle from which Bragg reflection is removed (θ = 0.3 °: within the total reflection region of the cladding) The X-ray reflectivity when incident is measured.
The X-ray waveguide of Example 7 had a 2.5 times higher reflectance than the X-ray waveguide formed by a manufacturing method that does not use a planarizing layer.

(7-3) Waveguide characteristics A 10 keV X-ray was incident on the waveguide, and the intensity of the X-ray guided by the periodic resonance waveguide mode was measured. Compared to an X-ray waveguide formed by a manufacturing method that does not use a planarizing layer, a waveguide strength that is about four times as high is observed. This high waveguide strength is considered to be achieved by improving the X-ray confinement efficiency of the X-ray waveguide of the present invention by flattening with the flattening layer.

  The X-ray waveguide of the present invention can be used for components used in an X-ray optical system in imaging, exposure, analysis and the like using X-rays.

100 substrate 101 core 102 clad 103 clad 109 flattened layer 110 flattened layer 201 core 202 clad 203 clad 204 unit structure 205 material having a high refractive index real part 206 material having a low refractive index real part 207 at the interface between the clad and the core Total reflection critical angle 208 Bragg angle 209 Total reflection critical angle at the material interface in the basic structure

Claims (8)

A method of manufacturing an X-ray waveguide having a core and a cladding,
Forming a planarization layer on the surface of the core having a periodic structure including a plurality of substances having different real refractive index parts in a direction perpendicular to the X-ray waveguide direction;
Forming the clad on the planarizing layer. A method for producing an X-ray waveguide, comprising:   The method of manufacturing an X-ray waveguide according to claim 1, further comprising a step of flattening the flattening layer after the step of forming the flat layer.   3. The X-ray according to claim 1, wherein the critical angle of total reflection at the interface between the planarization layer and the clad is larger than the Bragg angle due to the periodic structure of the core. A method for manufacturing a waveguide.   4. The X-ray waveguide according to claim 1, wherein a surface roughness of the planarizing layer at an interface between the planarizing layer and the core is 5 nm or less in terms of a root mean square. 5. Manufacturing method.   The method of manufacturing an X-ray waveguide according to claim 1, wherein the core is a mesostructure.   6. The method of manufacturing an X-ray waveguide according to claim 1, wherein the planarizing layer is made of the same material as that constituting the core.   The method for producing an X-ray waveguide according to claim 1, wherein the step of forming the planarizing layer forms a planarizing layer having a thickness of 3 nm to 100 nm.   The method of manufacturing an X-ray waveguide according to claim 2, further comprising a step of flattening the flattening layer and a step of flattening the core.

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