JP2012002760A - X-ray waveguide and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray waveguide that can simultaneously confine X-rays having different energies or incident angles and guide the X-rays, and a method of manufacturing the X-ray waveguide.SOLUTION: An X-ray waveguide includes a core part for wave-guiding of an X-ray and a clad part for confining the X-ray in the core part. The clad part is a periodic structure including a material having a different refraction index real part. The periodic structure includes two or more meso structure body films having different structure periods. A method of manufacturing the X-ray waveguide includes the steps of: forming a first meso structure body film; forming a second and subsequent meso structure films having different structure periods on the first meso structure body film; and configuring the X-ray waveguide by providing the first meso structure film and second and subsequent meso structure films in the core part.

Description

  The present invention relates to an X-ray waveguide using a mesostructured material for a clad portion and a method for manufacturing the same.

X-rays are widely used in fields such as medical care, nondestructive inspection, and crystal structure analysis. The difference in refractive index between different substances with respect to electromagnetic waves with a short wavelength of several tens nm or less such as X-rays is as small as about 10 ⁻⁵ or less. Therefore, in order to control such electromagnetic waves, a large spatial optical system is used. Recently, studies have been conducted on X-ray waveguides that confine electromagnetic waves in thin films and multilayers and propagate them in order to reduce the size and increase the functionality of such optical systems, which are the mainstream. Non-Patent Document 1 discloses a thin film waveguide in which a waveguide layer is sandwiched between two layers of a one-dimensional periodic structure.

Physical Review B, Volume 67, Issue 23, p. 233303 (2003)

  The waveguide disclosed in Non-Patent Document 1 uses X-rays as a core part by using Bragg reflection in a cladding part having a one-dimensional periodic structure in which two kinds of materials having different refractive indexes are alternately laminated in a direction perpendicular to the substrate. It is the structure which is confined in and guided. However, in this configuration, since the X-rays confined are limited to energy corresponding to Bragg reflection caused by the periodic structure, further improvement is required.

  Therefore, the present invention provides an X-ray waveguide capable of confining and guiding X-rays having different energies or X-rays having different incident angles, and a manufacturing method thereof.

  An X-ray waveguide that solves the above problem is an X-ray waveguide that has a core part for guiding X-rays and a cladding part for confining the X-rays in the core part, wherein the cladding part has a refractive index. The real part is a periodic structure composed of different materials, and the periodic structure is composed of a plurality of mesostructured films having different structural periods.

  An X-ray waveguide manufacturing method that solves the above problems includes a step of forming a first mesostructured film, and second and subsequent mesostructured films having different structural periods on the first mesostructured film. And a step of forming an X-ray waveguide by providing the first mesostructured film and the second and subsequent mesostructured films in a core portion.

  According to the present invention, it is possible to provide an X-ray waveguide capable of simultaneously confining and guiding X-rays having different energies or X-rays having different incident angles, and a manufacturing method thereof.

It is a key map showing one embodiment of an X-ray waveguide concerning the present invention. It is the graph which showed the energy (horizontal axis) dependence of the X-ray transmittance (vertical axis) of the material used for the hole or organic compound site | part of a material with a low electron density or a mesostructured body. It is a graph which shows the X-ray energy (horizontal axis) dependence of the intensity | strength (vertical axis) of the X-ray which guides the X-ray waveguide of the Example and comparative example of this invention. It is a graph which shows the incident angle (horizontal axis) dependence of the X-ray of the intensity | strength (vertical axis) of the X-ray which guides the X-ray waveguide of the Example and comparative example of this invention. It is a graph which shows the X-ray energy (horizontal axis) dependence of the reflectance (vertical axis) of the clad part comprised from the several mesostructure film | membrane from which a structural period differs in an X-ray waveguide.

(First embodiment: X-ray waveguide)
FIG. 1 is a conceptual diagram showing an embodiment of an X-ray waveguide according to the present invention. In FIG. 1, reference numeral 1000 denotes a clad portion composed of a plurality of mesostructured films having different structural periods, 1010 denotes a core part for guiding X, and 1020 denotes mesostructured films having different structural periods. . 1030 is an incident X-ray, 1040, 1050 and 1060 are X-rays having different energies. Here, 1070 is a wall portion of the mesostructured film, 1080 is a hole or an organic compound portion of the mesostructured film, and 1090 is an X-ray incident angle.

  The X-ray waveguide according to this embodiment includes a core portion 1010 for guiding X-rays, and a cladding portion 1000 for confining the X-rays in the core portion. The cladding part 1000 is a periodic structure composed of materials having different real refractive index parts, and this periodic structure is composed of a plurality of mesostructured films 1020 having different structural periods.

  In the X-ray waveguide according to the present embodiment, Bragg angles corresponding to X-rays having different energies can be used by forming the clad portion from mesostructured films having different structural periods. Thus, it is possible to provide an X-ray waveguide that can confine and guide X-rays having different energies at the same time, which has been difficult in the past.

The X-ray waveguide according to the present embodiment will be described in the following items (1) to (4).
(1) About X-ray (2) About core part (3) About clad part (4) About effect

(1) About X-ray The X-ray in the present invention means an X-ray band electromagnetic wave in which the real part of the refractive index of the substance is 1 or less. The X-ray band electromagnetic wave specifically refers to an electromagnetic wave having a wavelength of 100 nm or less including extreme ultraviolet light (Extreme Ultra Violet (EUV) light).

It is known that such a short-wavelength electromagnetic wave has a high frequency and the outermost electrons of the substance cannot respond, so that the real part of the refractive index of the substance is smaller than 1 unlike visible light and infrared rays. The refractive index n of a substance with respect to electromagnetic waves in the X-ray band is generally 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 called the imaginary part of the refractive index.

(2) About core part The core part in this invention bears the function which guides an X-ray in the X-ray waveguide of this invention. Although the material which comprises this core part does not receive a restriction | limiting in particular, From the viewpoint of guiding an X-ray, the material with the high X-ray permeability is preferable. Specifically, a gas such as air (vacuum if necessary), an organic substance (particularly a polymer), and an inorganic substance made of a light element can be used.

  About the shape of a core part, it does not receive a restriction | limiting in particular, A shape can be freely selected according to a use. Specific examples of the shape include a cylindrical shape and a rectangular parallelepiped. Further, it is possible to select a bent shape or a shape whose width has changed as required, and this makes it possible to bend the X-ray, change the spot size, and change the mode. Conventional semiconductor processes can be applied to these manufacturing methods. As a formation region of the core portion, a periodic structure of the cladding portion may be used.

(3) About the clad part The clad part in the X-ray waveguide of the present invention acts to confine the X-rays in the core part. The clad part in this invention is comprised from the periodic structure comprised from the material from which a refractive index real part differs. The real part of the refractive index of a material becomes smaller as the material has a higher electron density. For this reason, materials having different electron densities may be used as the two materials having different real parts of the refractive index. For X-rays, the phenomenon of reflection and refraction appears at the interface between two materials with different real parts of the refractive index. Therefore, even when a periodic structure is formed of these materials, reflection and refraction occur repeatedly, and multiple interference occurs in the periodic structure. As a result, Bragg reflection is developed.

  The periodic structure constituting the cladding portion in the present invention is characterized by being composed of mesostructured films having different structural periods. The mesostructure has a large reciprocal lattice point compared to a normal crystal. Therefore, by using the mesostructure for the clad portion, the wavelength range of the X-ray reflected by Bragg reflection becomes wider than that of a normal crystal. This can provide an X-ray waveguide having a relatively wide wavelength range to be selected.

  The periodic structure may be one-dimensional, two-dimensional, or three-dimensional. Examples of each include a lamellar structure as one dimension, a two-dimensional hexagonal structure as two dimensions, and a three-dimensional hexagonal structure as three dimensions. When the periodic structure of the cladding part is a two-dimensional or three-dimensional structure, Bragg reflection is expressed two-dimensionally and three-dimensionally, and the mode and propagation direction of the X-ray formed in the core part are two-dimensionally and three-dimensionally expressed. Can be controlled. In any of the above mesostructures, the surface normal vector of the periodic structure is perpendicular to the substrate used for preparation.

Hereinafter, the description will be divided into the following items.
(3-1) About periodic structure (3-1-1) About mesostructured film (3-1-2) About a plurality of mesostructured films having different structure periods (3-1-3) A plurality of mesostructures About arrangement order of body membrane

(3-1) Periodic structure The periodic structure in the present invention is characterized by being composed of mesostructured films having different structural periods. This is described below.

(3-1-1) About mesostructured membranes Porous materials are classified according to their pore diameters by IUPAC (International Union of Pure and Applied Chemistry). Porous materials with pore diameters of 2 to 50 nm are mesoporous. being classified. 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.

  Here, the mesostructured film of the present invention includes the following (A) mesoporous film, (B) a mesoporous film in which pores are mainly filled with an organic compound, (C) a mesostructured film having a lamellar structure, Means. These are described below.

(A) About mesoporous film A porous material having a pore diameter of 2 to 50 nm and the material of the wall portion is not particularly limited, but examples thereof include manufacturability, and the periodic structure has a different refractive index real part. An inorganic oxide is mentioned from a viewpoint of comprising from a substance. Examples of the inorganic oxide include silicon oxide, tin oxide, zirconia oxide, titanium oxide, niobium oxide, tantalum oxide, aluminum oxide, tungsten oxide, hafnium oxide, and zinc oxide. These materials all have a real part of a refractive index of 0.999997 or less for an X-ray of 10 keV, for example. Therefore, when a periodic structure is formed with an organic substance (having a real part of refractive index of about 0.9999998) and air (having a real part of refractive index of about 1) described later, the refractive index is set. A periodic structure composed of substances having different real parts can be formed. 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 include ionic and nonionic surfactants. Examples of the ionic surfactant include a halide salt of trimethylalkylammonium ion. Examples of the chain length of the alkyl chain include 10 to 22 carbon atoms. As an example of a nonionic surfactant, what contains polyethyleneglycol as a hydrophilic group can be mentioned. Specific examples of the surfactant containing polyethylene glycol as a hydrophilic group include polyethylene glycol alkyl ether and polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymers. Examples of the chain length of the polyethylene glycol alkyl ether include 10 to 22 carbon atoms, and examples of the polyethylene glycol repeating number include 2 to 50. 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. Examples of the additive for adjusting the structure period include hydrophobic substances. Examples of the hydrophobic substance include alkanes and aromatic compounds not containing a hydrophilic group, and specific examples thereof include octane.

Examples of inorganic oxide precursors include silicon and metal element alkoxides and chlorides. More specific examples include alkoxides and chlorides of Si, Sn, Zr, Ti, Nb, Ta, Al, W, Hf, and Zn. Examples of the alkoxide include methoxide, ethoxide, propoxide, or one in which a part thereof is substituted with an alkyl group.

Examples of the film forming method include a dip coating method, a spin coating method, and a hydrothermal synthesis method.
Examples of the template molecule removal method include baking, extraction, ultraviolet irradiation, and ozone treatment.

(B) About mesoporous film in which pores are mainly filled with an organic compound As the material of the wall, the same materials as those described in the section (A) can be used. 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). Examples of a material in which a part having a function of forming a molecular assembly forms a wall or a material bonded to a precursor of a material that forms a wall include an alkoxysilane having an alkyl group and an alkyl group. The oligosiloxane compound which has can be mentioned. Examples of the chain length of the alkyl chain include 10 to 22 carbon atoms.

  The inside of the hole may contain an organic solvent, a salt, or the like as needed or as a result of the material to be used or the 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.

(3-1-2) About a plurality of mesostructured films having different structure periods The periodic structure of the present invention is composed of a plurality of mesostructured films having different structure periods. The plurality is two or more, preferably three or more. This structural period basically changes stepwise. It is preferable that a plurality of mesostructured films having different structure periods have three or more periods.

The X-ray waveguide of the present invention reflects X-rays mainly by Bragg diffraction of a periodic structure constituting the cladding part and confines it in the core part. This Bragg diffraction condition is given by the following equation (1).
nλ = 2d sin θ (1)
(N: order, λ: wavelength of incident X-ray, d: structural period, θ: incident angle)

For this reason, in the periodic structure of the present invention, the number of X-ray wavelengths corresponding to Bragg diffraction increases as the number of mesostructured films having different periods increases, assuming that the angle is constant. When the wavelength is considered constant, there is an effect that the number of incident angles corresponding to Bragg diffraction increases as the number of mesostructured films having different periods increases. On the other hand, when the number of layers is increased, although it is relatively small, the X-rays cannot reach the deep part due to absorption of the material of the cladding part, and there are problems in that the manufacturing process is complicated and the cost is increased accordingly. The number of layers is set in accordance with the use of the waveguide in consideration of these.

(3-1-3) Arrangement order of a plurality of mesostructured films A preferred arrangement order of the layers of the mesostructured film having a plurality of layers having different structure periods according to the present invention increases as the period approaches the core part. Preferably it is. This can be explained as follows. X-ray permeability increases with increasing energy. Therefore, in the mesostructured film, the arrangement that reflects the high-energy X-rays with high permeability at a position away from the core part, and reflects the low-energy X-rays with low permeability at a position close to the core part. This is advantageous when the reflection efficiency is considered. From the equation (1), since the structure period and the wavelength are in a proportional relationship, a high energy X-ray, that is, a short wavelength X-ray, corresponds to a small period, and a low energy X-ray, that is, a long wavelength X-ray, has a large period. Correspond. Therefore, it is preferable that the preferable arrangement order of the plurality of layers of the mesostructured film of the present invention increases as the period approaches the core portion.

(4) Effects (4-1) X-ray waveguide capable of guiding X-rays having different energies The X-ray waveguide of the present invention uses a plurality of mesostructured films having different structural periods as cladding portions. If the angle is considered constant as described in Equation 1, X-rays with different energies can be confined in the core portion by Bragg reflection. Thus, by selecting a combination of periods, for example, it is possible to selectively guide a plurality of specific X-rays with different wavelengths. In addition, for example, X-rays having a continuous wavelength can be guided by the relatively ambiguous Bragg diffraction caused by the relatively large reciprocal lattice points specific to the mesostructured film.

(4-2) X-ray waveguide capable of guiding X-rays with different incident angles In the X-ray waveguide according to the present invention, a plurality of mesostructured films having different structural periods are used for the cladding portion, which is described in Equation 1. As described above, when the wavelength is considered constant, X-rays having different incident angles can be confined in the core portion by Bragg reflection. Thus, by selecting a combination of periods, for example, it is possible to selectively guide X-rays incident at a plurality of specific apart angles. In addition, a relatively ambiguous Bragg diffraction due to a relatively large reciprocal lattice point unique to mesostructured films, for example, to provide a waveguide with a wide incident angle tolerance that guides X-rays in a wide incident angle range. Is possible.

(4-3) Waveguide with Reduced Absorption Loss in Reflection by Cladding Part In the X-ray waveguide of Non-Patent Document 1, nickel is used as a material with a high electron density, and carbon is used as a low material as a material having a different real part of refractive index. ing. However, the X-ray absorption capacity of carbon is so high that it cannot be ignored, and causes an increase in absorption loss during Bragg reflection in the cladding. In the mesostructured film of the present invention, holes or an organic compound is used as a material corresponding to the material having a low electron density. For this reason, it becomes possible to reduce the absorption loss of this X-ray, and the reflectance of Bragg reflection in a clad part can be increased.

An example of this absorption effect is given in FIG. FIG. 2 shows the energy (horizontal axis) dependence of the X-ray transmittance (vertical axis) when the thickness of the material used for the hole or organic compound portion of the material having a low electron density or mesostructure film is 1 mm. It is a graph. In the figure, 2000 indicates pores (nitrogen), and 2010 indicates a surfactant polyoxyethylene alkyl ether. 2020, shown substantially overlapping with 2010, is the surfactant poly (ethylene glycol) (20) -block-poly (propylene glycol) (70) -block-poly (ethylene glycol) (20): (20) PO (70) EO (20)). The number in parentheses is the number of repetitions of each block. 2030 indicates carbon (graphite). For this reason, the hole or organic compound part of the mesostructured film of the present invention exhibits a higher transmittance than carbon (graphite) described in Non-Patent Document 1. Therefore, X-ray absorption loss can be reduced, and the reflectance of Bragg reflection in the cladding can be increased.
In addition, a more preferable embodiment of the mesostructured film of the present invention is a mesoporous film that absorbs less X-rays than an organic compound.

(Second Embodiment: X-ray Waveguide Manufacturing Method)
The manufacturing method of the X-ray waveguide according to this embodiment includes at least the following three steps. That is, a step of forming a first mesostructured film, a step of forming second and subsequent mesostructured films having different structural periods, and a first and second and subsequent mesostructured films are provided in the core portion. This is a step of constructing an X-ray waveguide.

Hereinafter, the description will be divided into the following items (1) to (4).
(1) Step of forming first mesostructured film (2) Step of forming second and subsequent mesostructured films on first mesostructured film (3) Removing amphiphile Step (4) Each step of forming an X-ray waveguide using the first mesostructured film and the second and subsequent mesostructured films

(1) Step of Forming First Mesostructured Film In order to explain the step of forming the first mesostructured film, an example in which an inorganic oxide is used as the wall of the mesostructured film is described below. The process will be described separately.
(1-1) A step of preparing a reaction solution containing an inorganic oxide precursor substance and an amphiphilic substance.
(1-2) A step of bringing the reaction solution into contact with the substrate.
(1-3) A step of forming a mesostructured film including an aggregate of amphiphilic substances in the pores.

A first mesostructured film is formed through the above steps. The reason why such a structure is formed is that the amphiphile self-assembles to form an aggregate (micelle).
Here, the step (1-2) may be performed substantially as the same step as the step (1-3).
These steps are described in detail below.

(1-1) Step of Preparing a Reaction Solution Containing an Inorganic Oxide Precursor Material and an Amphiphile The reaction solution contains an inorganic oxide precursor, an amphiphile, and a solvent. Moreover, you may add another substance as needed. Although the small process which comprises this process is not specifically limited, For example, the substance which comprises the other reaction solution in a solvent is thrown in and it stirs. These steps can be performed by controlling the atmosphere, temperature, humidity, stirring intensity, and the like as necessary. Moreover, small processes, such as a ultrasonic treatment and filtration, can be added as needed.

As the precursor of the inorganic oxide and the amphiphilic substance, those described in the first embodiment (3-1-1) (A) can be used.
As the solvent for the reaction solution, a solvent capable of dissolving an inorganic oxide precursor and an amphiphilic substance is used. Examples of this include water and alcohol. Examples of this alcohol include ethanol, propanol, methanol, butanol and the like. A mixture of two or more solvents may be used.

  If necessary, other substances can be added to the reaction solution. For example, water is added that reacts with the precursor of the inorganic oxide, hydrolyzes it, and finally gives the inorganic oxide. Further, a substance for adjusting the acidity and basicity of the reaction solution may be added. Examples of the substance for adjusting the acidity and basicity include acids such as hydrochloric acid and bases such as ammonium hydroxide. These are often added to control the hydrolysis and condensation reaction rate of the precursor material.

(1-2) Step of bringing the reaction solution into contact with the substrate The method used in this step differs in the content actually performed depending on the method of generating the inorganic oxide. For example, the hydrothermal synthesis method includes immersing the substrate in a reaction solution, and the sol-gel method includes applying the reaction solution to the substrate.

(1-2-1) Substrate The substrate used in the present invention can be used without particular limitation as long as it can form the mesostructured film of the present invention. Illustratively, examples of the material include silicon, quartz, glass, metal, and polymer. The shape can be selected without particular limitation as long as it satisfies the characteristics required for the waveguide. Examples include flat surfaces and curved surfaces. When using the substrate, it is preferable to sufficiently clean the substrate to expose a clean surface. Examples of this cleaning method include organic solvent cleaning, water cleaning, acid, and UV-ozone treatment. For the waveguide of the present invention, the mesostructured film may be formed using a material constituting the core of the waveguide as a substrate.

(1-2-2) Step of contacting the reaction solution with the substrate As a step of applying the reaction solution to the substrate, a general coating method can be used. Examples of this include dip coating, casting, spin coating, spray coating, ink jet, and pen lithography.
Among these, the dip coating method is effective as a coating method that can easily form a uniform film. In the application method by the dip coating method, the substrate is immersed in a reaction solution, and the substrate is pulled up to apply the solution onto the substrate. This application amount can be controlled by application conditions. Typical conditions include solution composition and substrate pulling rate. For example, the amount of coating (film thickness) is generally decreased by increasing the solvent in the reaction solution and decreasing the pulling rate.
This application is affected by the surrounding environment. Therefore, the atmosphere, temperature, humidity, solvent concentration in the atmosphere, and the like can be controlled as necessary.

(1-3) Step of forming a mesostructured film including an aggregate of amphiphilic substances in the pores The actual contents of this step differ depending on the method of generating the inorganic oxide. For example, in the case of the hydrothermal synthesis method, the substrate is kept immersed in the reaction solution, and in the case of the sol-gel method, the reaction solution applied to the substrate is dried.

  This step is performed following the step (1-2). Although these two steps are described separately, it is considered that the formation of the mesostructured film is basically started from the time when the reaction solution comes into contact with the substrate.

A specific example of this step in the sol-gel method includes evaporating a reaction solution (particularly a solvent) on a substrate and generating an inorganic oxide in a controlled environment. As an example of using the dip coating method, as the solvent and hydrogen chloride are lost from the solution after coating on the substrate, the reaction between water and the precursor of the inorganic oxide proceeds, and the inorganic oxide film becomes What is formed is mentioned. Examples of the environmental control items include temperature and humidity. By controlling the temperature condition and the humidity condition, the hydrolysis and condensation rate of the precursor substance is controlled, and the regularity of the arrangement of the amphiphilic substance aggregate is changed. For example, excessive temperature rise leads to remarkable acceleration of the condensation reaction, which may impair uniform thin film formation. On the other hand, if the temperature is too low, the solvent evaporation rate is lowered, and there is a problem that it takes time to form a thin film. As a specific example, the temperature includes a range of 0 ° C. to 50 ° C. and a relative humidity of 0% to 50%. The holding time, which is the time for holding the film under this temperature and humidity condition, is determined in accordance with the reactivity, temperature and humidity of the precursor material used. A specific example is a range of 30 minutes to 4 weeks.

  Although the thickness of the porous membrane which passed through this process is not specifically limited, As an example, the value of 0.005 micrometer-10 micrometers is mentioned. For example, in the case of the dip coating method, a film having a thickness of about 0.05 μm to 3 μm can be formed.

(2) Step of forming second and subsequent mesostructure films on the first mesostructure film The X-ray waveguide manufacturing method of the present invention further includes a structural period on the first mesostructure film. The method includes a step of forming different second and subsequent mesostructured films. The process for forming the second and subsequent mesostructured films is the method for preparing the first mesostructured film according to (1) except that the process is performed on the first mesostructured film on the substrate. The same process can be used. Further, if necessary, a pretreatment can be performed prior to the step (2). Examples of this pretreatment include a process for stabilizing the first mesostructured film and a process for improving the adhesion between the first mesostructured film and the second mesostructured film. As a specific example of the former, heat treatment may be performed after the first mesostructured film is prepared. As a specific example of the latter, surface treatment such as UV-O ₃ may be performed after preparing the first mesostructured film.

  In the X-ray waveguide manufacturing method of the present invention, it is preferable that after the second mesostructured film is formed, a third mesostructured film is further formed on the second mesostructured film. Done. Furthermore, in order to obtain the target performance, fourth, fifth, and subsequent multi-stage layers may be formed according to the design.

(3) Step of removing amphiphile In addition to the above steps, if necessary, the following steps further remove the amphiphile to form a mesoporous film having a hollow hole. be able to. This (3) process may be performed before the process of (4) mentioned later, and may be performed collectively after performing the process of (4).

The method for removing the amphiphile is not particularly limited, and methods such as decomposition removal and extraction can be used. Examples of the former include baking, UV irradiation, and a method using O ₃ , and examples of the latter include a method using a solvent and a supercritical fluid.

  The removal of the amphiphile by baking can remove the amphiphile from the porous film almost completely. The firing temperature and time vary depending on the type of amphiphile retained inside. Specific examples include a range of 300 ° C. to 600 ° C. as the temperature and 15 minutes to 24 hours as the time. When the solvent extraction method is used, it is difficult to remove 100% of the amphiphile, but it is significant in terms of maintaining the structure when removing the template.

The firing process has the above-mentioned features, but on the other hand, the structure regularity of the mesoporous film may be disturbed and the structure may be destroyed. This is considered to be because the structure of the inorganic oxide changes depending on the high temperature environment during firing. In order to prevent this, it is considered effective to reinforce the pore walls of the mesostructured film and / or suppress the growth of inorganic oxide crystals. As an example of this specific method, there is a method in which an inorganic oxide precursor such as silicon oxide is reacted after formation of a mesostructured film of an inorganic oxide to partially form an inorganic oxide such as silicon oxide. Can be mentioned. By using this method, it is possible to suppress disturbance of the structural regularity of the mesostructured film while removing the surfactant by calcination and crystallizing the inorganic oxide. When preparing an inorganic oxide mesoporous film, this method can be applied as necessary.

(4) About the process of constructing an X-ray waveguide using the first mesostructured film and the second mesostructured film The X-ray waveguide manufacturing method of the present invention comprises the first mesostructured film. And an X-ray waveguide using the second mesostructured film. The process of constructing this X-ray waveguide can be broadly divided into the following three methods.

(A) A core part is formed on a film composed of a first mesostructured film and a second mesostructured film, and a second mesostructured film and a first mesostructured film are further formed on the core part. (B) Method of forming the second mesostructured film and the first mesostructured film across the core part on the core part (C) The first mesostructured film and the second mesostructured film Method for Opposing and Fixing a Membrane Constructed from Mesostructured Film The following three methods are described below.

(A) A core part is formed on a film composed of a first mesostructured film and a second mesostructured film, and a second mesostructured film and a first mesostructured film are further formed on the core part. After forming the second mesostructured film on the first mesostructured film in (2), a core is formed on the second mesostructured film, and the core The second mesostructured film and the first mesostructured film are formed on the substrate.

  The method for forming the core part is not particularly limited, and a conventional coating and film forming method is selected according to the material used for the core part. For example, in the case of an organic compound, a method such as dip coating, spin coating, or bar coating may be used after dissolving in a solvent, or the film may be formed directly by a method such as vacuum deposition. For example, in the case of an inorganic material, a preparation method under vacuum such as sputtering or vacuum deposition may be used, and a preparation method under normal pressure such as a sol-gel method may be used.

  When the mesostructured film is further formed on the core portion, pretreatment as described in the step (2) can be performed as necessary. Moreover, as a process of forming the mesostructured film, the methods described in (1) and (2) can be used.

(B) Method of forming the second mesostructured film and the first mesostructured film across the core part on the core part. In this method, first, the material of the core part is prepared, This is a method of forming a second mesostructured film and a first mesostructured film.

  The material and shape used for this core part are not particularly limited, and those described in (2) of the first embodiment can be used. Moreover, as a process of forming the mesostructured film, the methods described in (1) and (2) can be used.

(C) Method of opposingly fixing a film composed of a first mesostructured film and a second mesostructured film In this method, the first mesostructured film and the second mesostructured previously formed This is a method in which a film composed of a structure film is fixed oppositely with a core portion interposed therebetween. As an example of this method, a spacer is provided on at least one of the films composed of the first mesostructured film and the second mesostructured film so as to sandwich the cavity serving as the core portion, and the other There is a method of facing a film composed of the first mesostructured film and the second mesostructured film. The material used as the spacer is not particularly limited, but examples include metal, inorganic and organic fine particles that can be controlled to a thickness of about several hundreds of nanometers, and organic substances (especially polymers) containing these. Can be mentioned.
Examples of methods for fixing these films include a method of fusing and adhering using the material used for the spacer, and a method of fixing using a fixture from the outside. This method (C) has a feature that the core portion can be a gas such as air, or can be evacuated as necessary.

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.
The embodiment will be described in the following items (1) to (5).
(1) Function as an X-ray waveguide for guiding X-rays with different energies (2) Function as an X-ray waveguide for guiding X-rays with different incident angles (3) Effect of arrangement order of a plurality of layers having different structure periods (4) Effect of material constituting wall portion of mesostructured film (5) Method of manufacturing X-ray waveguide

(1) Function as an X-ray waveguide for guiding X-rays having different energies In this item, it is shown that the X-ray waveguide of the present invention has a function of guiding X-rays having different energies at a single incident angle.

  FIG. 3 shows a schematic diagram of the X-ray energy (horizontal axis) dependence of the intensity (vertical axis) of the X-ray guided through the X-ray waveguide under the following conditions. Each of these X-ray waveguides has a structure in which the surface normal vector of the periodic structure is perpendicular to the substrate and is composed of a plurality of mesostructured films having different structural periods.

(Common conditions)
Wall part of mesostructured film: silicon oxide (SiO ₂ )
Pore or organic compound part of mesostructured film: Nitrogen incident angle: 0.5 degree Ratio (thickness) of hole or organic compound part occupied in mesostructured film: 0.7
Core part: Nitrogen (Invention: dotted line)
Number of layers: 6
Structure period: 5.0, 4.8, 4.6, 4.4, 4.2, 4.0 nm from the core side
Number of periods: 20, 21, 22, 23, 24, 25 (the order corresponds to the order of description of the structure period)
(Comparative example: Solid line)
Number of layers: 1
Structure period: 4.4 nm
Number of cycles: 23

  From this figure, it is shown that when an X-ray waveguide composed of a clad portion composed of a plurality of mesostructured films having different structural periods is used, it functions as an X-ray waveguide for guiding X-rays having different energies.

(2) Function as X-ray waveguide for guiding X-rays with different incident angles In this item, it is shown that the X-ray waveguide of the present invention has a function of guiding X-rays with different incident angles.

  FIG. 4 shows the strength of X-rays guided through an X-ray waveguide composed of a clad portion composed of a plurality of mesostructured films having different structural periods under the same conditions as in (1) (both the present invention and comparative examples). The schematic diagram of the incident angle (horizontal axis) dependence of the X-ray of (vertical axis) is shown.

(Common conditions) Incident X-ray energy: 16 keV
(Invention: dotted line, comparative example: solid line)
From this figure, when an X-ray waveguide consisting of a clad part composed of a plurality of mesostructured films with different structural periods is used, it functions as an X-ray waveguide that guides X-rays with different incident angles with respect to the incident X-ray. Is shown to do. Further, it is shown that it can function as an X-ray waveguide that guides X-rays in a wide angle range and has a wide allowable range of reflection angles.

(3) Effect of Arrangement Order of Multiple Layers with Different Structural Periods In this item, the reflectivity of the clad portion composed of multiple mesostructured films with different structural periods of the present invention Show the effect.

FIG. 5 shows the calculated value of the dependence of the reflectance (vertical axis) on the X-ray energy (horizontal axis) of the clad portion composed of a plurality of mesostructured films having different structural periods under the following conditions.
(Common conditions)
Number of layers: 3
Wall part of mesostructured film: silicon oxide (SiO ₂ )
Pore or organic compound part of mesostructured membrane: surfactant (EO (20) PO (70) EO (20))
Incident angle: Ratio of pores or organic compound sites in the mesostructured film of 0.5 degree (thickness): 0.7
(Invention 1: dotted line)
Number of layers: 3
Structure period: 10.0, 7.0, 4.0 nm from the X-ray incident side (the side that becomes the core side when the waveguide is constructed)
Number of periods: 30, 43, 75 (the order corresponds to the order of the structure periods)
(Invention 2: Solid line)
Number of layers: 3
Structure period: 4.0, 7.0, 10.0 nm from the X-ray incident side (the side that becomes the core side when the waveguide is constructed)
Number of periods: 75, 43, 30 (the order corresponds to the order of description of the structure period)

  In this figure, the reflectance of the present invention 1 shows a larger value than the reflectance of the present invention 2 near 7.6 keV. On the other hand, in the vicinity of 14.5 keV, the reflectance of the present invention 2 shows a larger value than the reflectance of the present invention 1. The ratio of ((smaller value) / (larger value)) in the vicinity of 7.6 and 14.5 keV is 0.680 and 0.940, respectively. At least simply judging from the ratio, it is shown that the arrangement of the present invention 1 showing a high value in the vicinity of 7.6 keV is more advantageous.

As shown in FIG. 2, the X-ray transmission power increases as the energy increases. Therefore, an arrangement in which a structure having a long period (10 nm in this example) corresponding to low energy on the side closer to the X-ray incident surface is a structure having a short period (4 nm in this example) corresponding to high energy on the far side. Is effective.
That is, it is preferable that the X-ray waveguide cladding has a long period corresponding to low energy on the side close to the core part side and a short period corresponding to high energy on the far side. By arranging in this way, X-rays can be effectively confined and guided in the core portion.

(4) Effect of material constituting the wall portion of the mesostructured film In this item, the effect of the material constituting the wall part of the mesostructured film used for the cladding portion of the X-ray waveguide of the present invention is shown.

Table 1 shows the peak values calculated when the energy dependency of the reflectance of the clad portion composed of a plurality of mesostructured films having different structural periods is calculated under the following conditions.
(Common conditions)
Number of layers: 3
Pore or organic compound part of mesostructured film: Nitrogen incident angle: 0.5 degree Ratio (thickness) of hole or organic compound part occupied in mesostructured film: 0.7
Structure period: 10, 7, 4 nm from X-ray incident side
Number of cycles: 4 for each cycle
Incident X-ray energy: 5-24 keV

(Invention 1)
Wall part of mesostructured film: silicon oxide (SiO ₂ )
(Invention 2)
Wall portion of mesostructured film: titanium oxide (TiO ₂ )
(Invention 3)
Wall part of mesostructured film: tin oxide (SnO ₂ )

  The interaction of a substance with x-rays increases with the electron density of the substance. Among the materials used here, tin oxide exhibits high reflectivity due to its high density (approximately proportional to the electron density). When using a plurality of mesostructured films having different structure periods as the cladding part of the X-ray waveguide, as in the condition of this example, when the number of periods is small, the material of the wall part of the mesostructured film is It greatly affects the reflectivity. In such a condition, it is effective to use a wall material having a high density.

(5) Manufacturing method of X-ray waveguide (5-1) In this item, an X-ray having a silicon oxide mesostructured film 3 layer having a two-dimensional hexagonal structure prepared on a flat substrate as a cladding part and a polymer as a core part A method for manufacturing the waveguide will be described.

(A) Preparation of precursor solution of mesostructured film A silicon oxide mesostructured film having a two-dimensional hexagonal structure is prepared by a dip coating method. A precursor solution of a mesostructure is prepared by dissolving a block polymer in an ethanol solvent, adding ethanol, water, hydrochloric acid, and tetraethoxysilane, and stirring at 70 ° C. for 1 hour. 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, block polymer: 0.001, water: 8, hydrochloric acid: 0.01, ethanol: 40.

  The block polymer includes a first mesostructured film: EO (20) PO (30) EO (20), a second mesostructured film: EO (26) PO (39) EO (26), a third meso Structure film: EO (20) PO (70) EO (20) is used.

(B) Formation of Mesostructured Film After the silicon substrate is washed, dip coating is performed at a pulling rate of 0.5 to 2 mms ⁻¹ using a dip coating apparatus. The temperature at this time is 25 ° C., and the relative humidity is 40%. After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 24 hours. When the layers are subsequently stacked, the second and third mesostructured films are formed in the same process.

(C) Film formation of core part A core part is prepared by spin-coating the chloroform solution of polystyrene after forming the 1st-3rd mesostructure film | membrane. Polystyrene is dissolved in chloroform at an appropriate concentration, and a film is formed using a spin coater under conditions of 1000 to 5000 rpm and 10 to 60 seconds. After film formation, it is allowed to stand at room temperature for 12 hours.

(D) Formation of Mesostructured Film After the formation of the core part, the third to first mesostructured films are sequentially formed on the core part. The method for preparing the mesostructure is the same as the method (b).

(E) Evaluation X-ray diffraction analysis of Bragg-Brentano arrangement is performed on the first to third mesostructured films formed independently for reference. As a result, it is confirmed that this mesostructured film has high ordering in the normal direction of the substrate surface, and the plane spacing is 7.8, 8.8, and 9.6 nm.

  When a white X-ray is incident on the X-ray waveguide made of this silicon oxide mesostructure film at an incident angle of 0.5 degrees, X-ray wave-guiding with a peak of 9.2, 8.1, and 7.4 keV is confirmed. The From this, it is shown that the silicon oxide mesostructured film of this example functions as a waveguide corresponding to X-rays having different energies.

(5-2) In this item, a method for manufacturing an X-ray waveguide using four layers of a mesostructured film having a lamellar structure prepared on a curved substrate as a clad part and a polymer as a core part will be described.
(A) Preparation of precursor solution of mesostructured film A mesostructured film having a lamellar structure is prepared by spin coating. The precursor solution is prepared by dissolving n-decyltrimethoxysilane, tetramethoxysilane, water and hydrochloric acid in a tetrahydrofuran solvent and stirring at room temperature for a predetermined time. The mixing ratio (molar ratio) is n-decyltrimethoxysilane: 1, tetramethoxysilane: 4, water: 19, hydrochloric acid: 0.01, and tetrahydrofuran: 20.
The stirring time is set as follows: first mesostructured film: 6 hours, second mesostructured film: 1 hour, and third mesostructured film: 0.5 hour.

(B) Formation of Mesostructured Film After a convex lens substrate having a large curvature radius is washed, coating is performed using a spin coater under conditions of 3000 rpm and 10 seconds. The temperature at this time is 25 ° C., and the relative humidity is 40%. After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 4 weeks. Thereafter, when the layers are stacked, an upper layer is formed on the above-described substrate in the same process.

(C) Film formation of core part A core part is prepared by spin-coating a nitrobenzene solution of polypropylene after forming the first to third mesostructured film. Polypropylene is dissolved in nitrobenzene at an appropriate concentration, and a film is formed using a spin coater at 1000-5000 rpm for 10 to 60 seconds. After film formation, it is allowed to stand at room temperature for 12 hours.

(D) Formation of Mesostructured Film After the formation of the core part, the third to first mesostructured films are sequentially formed on the core part. The method for preparing the mesostructure is the same as the method (b).

(E) Evaluation X-ray diffraction analysis of Bragg-Brentano arrangement is performed on the first to third mesostructured films formed independently for reference. As a result, it is confirmed that this mesostructured film has a high order in the normal direction of the substrate surface, and the surface spacing is 3.46, 3.76, and 3.88 nm.

  When an X-ray of 2 keV is incident on the X-ray waveguide made of this silicon oxide mesostructure film, X-ray waveguides having peaks at incident angles of 5.14, 4.73, and 4.58 degrees are confirmed. From this, it is confirmed that the mesostructured film of this example functions as an X-ray waveguide that guides X-rays having different incident angles.

  (5-3) In this item, a method for manufacturing an X-ray waveguide using a three-layer mesostructured film as a cladding part and a polymer as a core part will be described. Here, the three-layer mesostructured film refers to a titanium oxide having a three-dimensional cubic structure on a film having two layers made of a silicon oxide mesostructure having a two-dimensional hexagonal structure prepared on a flat substrate. A mesostructured film is formed.

(A1) Manufacture of silicon oxide mesostructured film A silicon oxide mesostructured film having a two-dimensional hexagonal structure is the solution of the second mesostructured film, the solution of the third mesostructured film, and the method of (5-1) It is prepared using.

(A2) Preparation of Titanium Oxide Mesostructured Film Precursor Solution After the block polymer is dissolved in an ethanol solvent, titanium (IV) chloride is added dropwise. Prepare by adding water and stirring. The mixing ratio (molar ratio) is titanium chloride (IV): 1, block polymer: 0.005, water: 10, ethanol: 40. As the block polymer, EO (106) PO (70) EO (106) is used.

(B) Film formation of mesostructured film 0.5-2 mms using a dip coater on the first and second mesostructured films made of silicon oxide prepared using the conditions of (5-1). Dip coat at a pulling speed of ^-1 . The temperature at this time is 25 ° C., and the relative humidity is 40%. After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 2 weeks.

(C) Film formation of a core part A core part performs film formation using the conditions as described in the term of (5-1).
(D) Evaluation X-ray diffraction analysis of Bragg-Brentano arrangement is performed on the mesostructured film formed independently for reference. As a result, these films are highly ordered in the normal direction of the substrate surface, and the distance between the surfaces is the first layer: 8.8 nm, the second layer: 9.6 nm, and the third layer made of titanium oxide. Layer of 10.1 nm.

  When a white X-ray is incident on the mesostructured film at an incident angle of 0.5 degrees, X-ray waveguiding with a peak of 8.1, 7.4, 7.0 keV is confirmed. From this, it is shown that the mesostructured film of this example functions as a waveguide corresponding to X-rays having different energies.

  (5-4) In this item, an X-ray waveguide manufacturing method using a nanofiber as a core part and a silicon oxide two-layer having a two-dimensional hexagonal structure around the nanofiber as a cladding part will be described.

(A) Preparation of Mesostructured Precursor Solution The precursor solution of the mesostructured film is prepared by the method described in the first and third mesostructured films in (5-1).

(B) Film formation of mesostructured membrane Nylon nanofibers having a single yarn diameter of 100 nm are immersed in the precursor solution of the first mesostructured body, and are lifted at a speed of 0.5 to 2 mms ⁻¹ using a dip coater. Dip coat. The temperature at this time is 25 ° C., and the relative humidity is 40%. After film formation, the film is held in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 24 hours. When the layers are subsequently stacked, the second mesostructure is formed in the same process.

(E) Evaluation The X-ray diffraction analysis of the Bragg-Brentano arrangement is performed on the first and second mesostructured films formed independently for reference. As a result, it is confirmed that this mesostructured film has a high order in the normal direction of the substrate surface, and the plane spacing is 7.8, 9.6 nm.

  When a white X-ray is incident on an X-ray waveguide in which a silicon oxide mesostructure layer is coated on the surface of the nanofiber at an incident angle of 0.5 degrees, X-ray waveguide having a peak at 9.2, 7.4 keV is confirmed. Is done. This shows that the nanofibers coated with the silicon oxide mesostructure of this example function as waveguides corresponding to X-rays of different energies.

  (5-5) In this item, a spacer is formed on a film having two layers made of a silicon oxide mesoporous film having a two-dimensional hexagonal structure prepared on a flat substrate, and arranged to be opposed to form an air core part. A method for manufacturing the X-ray waveguide will be described.

(A) Preparation of Mesostructured Precursor Solution The precursor solution of the mesostructured film is prepared by the method described in the first and third mesostructured films in (5-1).

(B) Film formation of mesostructured film Film formation is performed using the conditions described in (5-1).
(C) Firing After forming the first to third mesostructured films, the mesostructured film is baked in air at 400 ° C. for 10 hours to remove the block polymer inside the pores.

(D) Formation of spacer A mask that covers the entire longitudinal direction of the central portion is placed on the baked mesoporous thin film to secure a space as a core portion, and then titanium is sputtered to 10 to 100 nm. After sputtering, the mask is removed. The formed titanium is used as a spacer.

(E) Substrate facing step The substrates on which the spacers are formed face each other and are fixed together with a SUS jig to form a waveguide.

(F) Evaluation The X-ray diffraction analysis of Bragg-Brentano arrangement is performed on the first and second mesostructured films formed independently for reference. As a result, it is confirmed that this mesostructured film has a high order in the normal direction of the substrate surface, and the surface spacing is 5.2, 6.4 nm.

  When a white X-ray is incident on the X-ray waveguide at an incident angle of 0.5 degrees, X-ray waveguide having peaks at 11.1 and 13.7 keV is confirmed. From here, the X-ray waveguide formed by forming a spacer on the film having two layers made of the silicon oxide mesoporous film of the present embodiment and arranging the spacers to oppose each other, and the X-ray waveguide corresponding to the X-rays having different energies. As shown.

  Since the X-ray waveguide of the present invention can simultaneously confine and guide X-rays having different energies or different incident angles, the X-ray waveguide can be used for an imaging apparatus, an analysis apparatus, and the like using X-rays.

1000 Cladding portion 1010 Core portion 1020 Mesostructured film with different structural period 1030 Incident X-ray 1040, 1050, 1060 X-ray with different energy 1070 Wall portion 1080 Hole or organic compound part of mesostructured film 1090 Incident angle of X-ray

Claims (5)

  An X-ray waveguide having a core part for guiding X-rays and a clad part for confining the X-rays in the core part, wherein the cladding part is made of a material having a different refractive index real part. An X-ray waveguide, wherein the periodic structure is composed of a plurality of mesostructured films having different structural periods.   2. The X-ray waveguide according to claim 1, wherein the plurality of mesostructured films having different structure periods have three or more kinds of periods.   The X-ray waveguide according to claim 1, wherein the arrangement of the plurality of mesostructured films having different structural periods increases as the structural period approaches the core.   The X-ray waveguide according to claim 1, wherein the mesostructured film is a mesoporous film.   A step of forming a first mesostructured film, a step of forming second and subsequent mesostructured films having different structure periods on the first mesostructured film, and the first mesostructured film A method for manufacturing an X-ray waveguide, comprising: providing a second mesostructure film or subsequent mesostructure film on a core portion to form an X-ray waveguide.

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