WO2020137047A1

WO2020137047A1 - X-ray guide tube production method, x-ray guide tube, and analysis device

Info

Publication number: WO2020137047A1
Application number: PCT/JP2019/037472
Authority: WO
Inventors: 肇二位
Original assignee: 株式会社堀場製作所
Priority date: 2018-12-28
Filing date: 2019-09-25
Publication date: 2020-07-02
Also published as: JPWO2020137047A1; JP7264917B2

Abstract

The present invention increases X-ray transmission efficiency in an X-ray guide tube. This X-ray guide tube production method produces an X-ray guide tube 29 for emitting X-rays incident from an X-ray source, and comprises the following steps: a step for preparing a capillary body 29a that has an internal capillary space 32 to which X-rays are incident; and a step for forming a thin metal film 33 on an inner circumferential surface 32a by using atomic layer deposition.

Description

X-ray conduit manufacturing method, X-ray conduit, and analyzer

The present invention relates to an X-ray conduit manufacturing method, an X-ray conduit, and an analyzer.

Conventionally, an analyzer called an X-ray analysis microscope is known in which X-rays emitted from an X-ray source are narrowed down by an X-ray conduit to irradiate a sample with a minute spot diameter (for example, patents). Reference 1).
The X-ray conduit is an optical component that focuses X-rays from the other end of the glass tube and reflects the X-rays incident from the X-ray source on the inner surface of the glass tube. The shape of the inner surface of the glass tube of the X-ray conduit is, for example, cylindrical, conical, spheroidal, or paraboloidal.

Patent No.

　The conventional X-ray conduit has a problem that the passage efficiency is reduced. The reason is that since the X-ray conduit is a glass thin tube, the total reflection critical angle θc is small, and therefore the solid angle for capturing X-rays at the incident side end is small, and therefore a large amount of X-rays are collected. This is because it cannot be sent to the output side end. It should be noted that the above reduction in passage efficiency becomes remarkable as the total reflection critical angle θc becomes smaller as the X-ray energy becomes higher.

The purpose of the present invention is to improve the X-ray passage efficiency in the X-ray conduit.

A plurality of modes will be explained below as means for solving the problems. These aspects can be arbitrarily combined as needed.

A method according to one aspect of the invention is a method of manufacturing an X-ray conduit for emitting X-rays incident from an X-ray source, comprising the steps of:
◎Step of preparing a capillary main body having an inner space of the capillary where X-rays are incident ◎Step of forming a metal thin film on the inner wall surface of the capillary by an atomic layer deposition method

In this method, since the metal thin film is formed on the inner wall surface of the capillary of the X-ray conduit, the X-ray passing efficiency can be improved.
Furthermore, since the metal thin film is formed by the atomic layer deposition method, the film thickness is uniform even in the space inside the elongated capillary.
For example, a glass capillary for guiding X-rays is manufactured by a method in which liquid glass is poured into a mold to form a capillary shape, and then heat treatment is performed, or liquid glass is drawn to form a capillary shape. It Since the capillary manufactured by such a manufacturing method has a very small surface roughness, the scattering loss of X-rays can be reduced when used as an X-ray conduit. On the other hand, the atomic layer deposition method is capable of forming a film having a surface roughness approximately the same as the surface roughness of the substrate because of the characteristic that the layers can be formed one by one. Therefore, by applying the present invention, it is possible to form a metal film having a surface roughness almost equal to the small surface roughness of the glass capillary.

The aspect ratio of the capillary body may be in the range 500-10000.
In this method, since the metal thin film is formed by the atomic layer deposition method, the film thickness is uniform even in the space inside the elongated capillary.

An X-ray conduit according to another aspect of the present invention is for collecting and emitting X-rays incident from an X-ray source, and includes a capillary body and a metal thin film.
The capillary body has a space inside the capillary into which X-rays are incident.
The metal thin film is formed on the inner wall surface of the capillary by the atomic layer deposition method.
For example, a glass capillary for guiding X-rays is manufactured by a method in which liquid glass is poured into a mold to form a capillary shape, and then heat treatment is performed, or liquid glass is drawn to form a capillary shape. It Since the capillary manufactured by such a manufacturing method has a very small surface roughness, the scattering loss of X-rays can be reduced when used as an X-ray conduit. On the other hand, the atomic layer deposition method is capable of forming a film having a surface roughness approximately the same as the surface roughness of the substrate because of the characteristic that the layers can be formed one by one. Therefore, by applying the present invention, it is possible to form a metal film having a surface roughness almost equal to the small surface roughness of the glass capillary.

In this X-ray conduit, since the metal thin film is formed on the inner wall surface of the capillary of the X-ray conduit, the X-ray passage efficiency can be improved.
Moreover, since the metal thin film is formed by the atomic layer deposition method, the film thickness is uniform even in the elongated capillary inner space.

The aspect ratio of the capillary body may be in the range 500-10000.
In this X-ray conduit, since the metal thin film is formed by the atomic layer deposition method, the film thickness is uniform even in the elongated capillary inner space.

An analysis apparatus according to another aspect of the present invention includes an X-ray conduit and an X-ray source that irradiates the X-ray conduit with X-rays.
The above effect can be obtained with this analyzer.

The analyzer may have a plurality of X-ray conduits of different types.
The analyzer may further include a switching device that switches a plurality of X-ray conduits according to the purpose of use.
In this analyzer, the X-ray conduit can be switched according to the purpose of use.

The X-ray conduit manufacturing method, the X-ray conduit, and the analyzer according to the present invention can improve the X-ray passage efficiency.

The block diagram which shows the schematic structure of an analyzer. FIG. 3 is a partial cross-sectional view of an X-ray conduit. The schematic diagram of a film-forming apparatus. The flowchart of the film-forming method.

1. First Embodiment (1) Schematic Description of Analytical Apparatus The analytical apparatus 1 will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of an analyzer.
The analyzer 1 is an X-ray analysis microscope that performs qualitative/quantitative analysis of the physical properties of the sample S by irradiating the sample S with primary X-rays and measuring the fluorescent X-rays generated at that time.

The analyzer 1 includes a sample box 3 in which a sample S to be analyzed is stored, an X-ray tube 5 that generates X-rays that irradiate the sample S, and a vacuum disposed between the X-ray tube 5 and the sample box 3. And a box 7.
The X-ray tube 5 is attached to the upper surface of the vacuum box 7 via a communication part 9. The vacuum box 7 is attached to the upper surface of the sample box 3 via a communication part provided with an X-ray transmission window 11 that allows X-rays to pass satisfactorily.

A sample stage 13 is installed at a predetermined position in the sample box 3, and a sample S is placed on it. An optical element unit 21 (described later) is arranged at a predetermined position in the vacuum box 7. With such a configuration, the X-rays generated by the X-ray tube 5 enter the vacuum box 7 through the communicating portion 9, pass through the optical element unit 21 in the vacuum box 7, and further pass through the X-ray transmission window 11. The light enters the sample box 3 through the sample and is irradiated onto the sample S on the sample stage 13.
The sample stage 13 is driven by the sample stage drive unit 56 in the X-ray irradiation direction (vertical direction in FIG. 1) and in two directions orthogonal to each other in the plane orthogonal to the irradiation direction (for example, the horizontal direction and the depth in FIG. 1). Direction) and can be moved. The sample stage drive unit 56 is provided inside or outside the sample box 3.

The vacuum box 7 is provided with the X-ray detector 35 that detects the fluorescent X-rays generated from the sample S when the sample S is irradiated with the X-rays as described above. In the example shown in FIG. 1, the X-ray detector 35 is attached to the vacuum box 7 with the detection surface for detecting fluorescent X-rays facing the X-ray transmission window 11.
An observation unit 57 such as a CCD (Charge Coupled Device) camera or an optical microscope is attached to the vacuum box 7. As will be described later, the optical element unit 21 in the vacuum box 7 has a mirror 28, and the observation section 57 is arranged so as to face the mirror 28.

The optical element unit 21 narrows the beam diameter and irradiates the sample S with X-rays generated by the X-ray tube 5. The optical element unit 21 is configured by mounting a plurality of

X-ray conduits

29, 31 as optical elements on an optical element switching stage 27. The optical element switching stage 27 is a member for switching the plurality of

X-ray conduits

29, 31 according to the purpose of use.
The

X-ray conduits

29 and 31 emit the X-rays generated by the X-ray tube 5 and incident on the inside of the vacuum box 7. The

X-ray conduits

29 and 31 are, for example, capillaries formed of glass in a tubular shape, and guide the X-rays incident from one end while reflecting the X-rays on the inner surface and emit the X-rays from the other end.

By using the

X-ray conduits

29 and 31, a thin and high-intensity X-ray beam system can be realized, and therefore, a minute area can be measured and analyzed at high speed.
In addition to the

X-ray conduits

29 and 31, the mirror 28 is attached to the optical element switching stage 27.

The optical element switching stage 27 is configured to be movable in two directions orthogonal to each other in a plane orthogonal to the X-ray irradiation direction (vertical direction in FIG. 1) by the switching stage drive unit 55. The switching stage drive unit 55 is configured by using, for example, a stepping motor.
By moving the optical element switching stage 27 by the switching stage drive unit 55, the positions of the

X-ray conduits

29 and 31 and the mirror 28 are switched, and the

X-ray conduits

29 and 31 arranged at predetermined positions are used. The X-rays generated by the X-ray tube 5 are delivered to the sample S.
The X-rays emitted from the

X-ray conduits

29 and 31 arranged at predetermined positions pass through the X-ray transmission window 11 and are irradiated onto the upper surface of the sample S, and the X-ray irradiation generates fluorescent X-rays from the sample S. To do. The fluorescent X-rays generated from the sample S reach the X-ray detector 35 through the X-ray transmission window 11 and are detected by the X-ray detector 35.

The X-ray detector 35 is a device that detects fluorescent X-rays generated by irradiating the sample S with X-rays, and outputs a signal proportional to the energy of the detected fluorescent X-rays. To the X-ray detector 35, a signal processing unit 52 that processes the signal output by the X-ray detector 35 is connected. The signal processing unit 52 counts the signals of the respective values output by the X-ray detector 35, and performs the process of generating the relationship between the energy of the fluorescent X-rays and the count number, that is, the spectrum of the fluorescent X-rays. An analysis unit 53 is connected to the signal processing unit 52. The signal processing unit 52 outputs the data indicating the generated spectrum to the analysis unit 53. The analysis unit 53 is configured to include a calculation unit that performs calculation and a memory that stores data. The analysis unit 53 performs qualitative analysis or quantitative analysis of elements contained in the sample S based on the spectrum indicated by the data input from the signal processing unit 52.

The X-ray tube 5, the signal processing unit 52, the analysis unit 53, the display unit 54, the switching stage drive unit 55, and the sample stage drive unit 56 are connected to the control unit 51. The control unit 51 is composed of a computer including a calculation unit and a memory. The control unit 51 controls the operations of the X-ray tube 5, the signal processing unit 52, the analysis unit 53, the display unit 54, the switching stage drive unit 55, and the sample stage drive unit 56. The control unit 51 may be configured to receive an instruction from the user and control the operation of each unit of the analyzer 1 according to the received instruction. The display unit 54 may display the spectrum generated by the signal processing unit 52 or the analysis result by the analysis unit 53. Further, the control unit 51 and the analysis unit 53 may be configured by the same computer.

(2) Detailed description of X-ray conduit The

X-ray conduits

29 and 31 are thin tubular ones having a hollow parabolic surface or a cylindrical reflecting surface as a hollow inner surface, and a primary X-ray introduced from the base end is used. , Is emitted from the tip and is irradiated or narrowed down on the sample S with different spot diameters.
The

X-ray conduits

29 and 31 have capillary

bodies

29a and 31a. The

capillary bodies

29a and 31a are cylindrical tubes made of glass. That is, the

capillary bodies

29a and 31a have the capillary inner space 32 (FIG. 2) which is a hollow hole into which X-rays are incident. The

capillary bodies

29a and 31a have mutually different lengths, and in this example, the capillary body 29a is long and the capillary body 31a is short.

The length of the

capillary bodies

29a and 31a is, for example, in the range of 50 to 100 mm.
The diameter of the capillary is, for example, in the range of 10 to 400 μm.

The aspect ratio of the

capillary bodies

29a and 31a is, for example, in the range of 500 to 10,000. Here, the aspect ratio is the ratio (h/w) between the height (h) of the inner surface shape of the capillary inner space 32 and the diameter (w) of the circular cross section or a shape close to the circle.

Each of the

X-ray conduits

29 and 31 has, for example, the same outer diameter and different inner diameter. With this configuration, the diameter of the X-rays emitted from each of the

X-ray conduits

29 and 31 on the sample surface (spot diameter ) Can be different. In the capillary body 29a, the inner diameter of the capillary inner space 32 is small (for example, 10 μm), so that the X-ray conduit 29 has a small focused spot diameter. The capillary body 31a has a large inner diameter of the capillary inner space 32 (for example, 100 μm), and therefore the X-ray conduit 31 has a large focused spot diameter. That is, the X-ray conduit 29 collects and irradiates X-rays in a narrower area, so that analysis can be performed with higher resolution. On the other hand, the X-ray conduit 31 makes it possible to irradiate more intense X-rays, and to perform measurement faster.

As shown in FIG. 2, a metal thin film 33 is formed on the inner peripheral surface 32a of the capillary inner space 32 of the capillary body 29a (an example of the inner wall surface of the capillary). FIG. 2 is a partial cross-sectional view of the X-ray conduit. A base material (for example, Cr) may be formed between the glass and the metal thin film.
The metal thin film 33 is made of, for example, silver, gold or platinum. Further, the metal thin film 33 is formed with a uniform thickness. The thickness of the metal thin film 33 is, for example, several tens nm to several μm, preferably 0.1 to 3 μm.

By providing the metal thin film 33, the critical angle θc can be increased as compared with the case where the inner peripheral surface is, for example, glass. As a result, the solid angle for capturing X-rays on the incident side end face becomes wider, and more X-rays can be collected and sent to the emission side end face. As a result, the passage efficiency is significantly improved even with high-energy X-rays, and a sufficiently large X-ray intensity can be obtained at the exit-side end face.

The significance of the effect of this embodiment will be described in more detail.
The formula for obtaining the critical angle θc is as follows.
θc=1.64×10 ⁻³ λ√ρ (θc: critical angle, ρ: density of inner wall material of capillary, λ: wavelength of incident X-ray)
Conventionally, when a capillary is brought closer to the X-ray source in order to capture more X-rays emitted from the X-ray source into the capillary, the X-ray with a large incident angle inside the capillary is incident than the critical angle inside the capillary. Since the corner becomes large, it may penetrate through the inside of the capillary. This phenomenon becomes particularly noticeable with high-energy X-rays. The reason for this is that the energy is inversely proportional to the wavelength λ in the above equation, so that the higher the energy, the smaller the critical angle, and the more the X-ray dose that penetrates inside the capillary. Although this phenomenon occurs in both types of monocapillaries and polycapillaries, this phenomenon is remarkable because the inner wall of the capillary is generally thinner in the polycapillary than in the monocapillary.
In the case of the

X-ray conduits

29 and 31 in the present embodiment, the metal thin film 33 is formed on the inner peripheral surface 32a (capillary inner wall surface) of the capillary main body 29a, so that it is more critical than the conventional glass capillary tube. The angle θc can be set large.

As shown in the table below, when Pt is used as the metal thin film on the inner wall surface of the capillary as an example of the present embodiment, compared with the case where the inner wall surface of the conventional capillary is SiO ₂ , the same energy is applied. It can be seen that the critical angle and the solid angle are large.

Since the metal thin film 33 is formed by the atomic layer deposition method as described later, the film thickness in the elongated capillary inner space 32 is more uniform than in the case of being formed by another manufacturing method (for example, plating). ing.
The X-ray conduit 29 and the X-ray conduit 31 may have different materials for the metal thin film depending on the analysis target. For example, in selecting the X-ray conduit, an X-ray conduit formed with a metal thin film having a fluorescent X-ray peak that does not overlap with the fluorescent X-ray peak of the target measurement object in the fluorescent X-ray energy spectrum can be selected.

(3) Film Forming Apparatus A film forming apparatus 71 for manufacturing the X-ray conduit 29 will be described with reference to FIG. FIG. 3 is a schematic diagram of a film forming apparatus. The following description is the same for the X-ray conduit 31.
The film forming apparatus 71 uses the ALD method. The ALD (Atomic Layer Deposition) method is a film forming method for forming a thin film by chemical substitution through periodic supply of each reactant.

The film forming apparatus 71 has a film forming chamber 72. In the film forming chamber 72, the capillary main body 29 a is mounted on the mounting table 73. The mounting table 73 is supported by the supporting portion 75. The film forming chamber 72 is provided with a reactive gas (H ₂ O) inlet port 77, a source gas inlet port 79 as a raw material of a metal compound, and a purge gas inlet port 81. An exhaust port 83 for exhausting the gas in the film forming chamber 72 is provided on the right side surface of the film forming chamber 72.

(4) Film Forming Method A film forming method for forming the metal thin film 33 on the wall surface of the capillary inner space 32 by the atomic layer deposition method will be described with reference to FIG. FIG. 4 is a flowchart of the film forming method.
In step S1, after the capillary main body 29a is installed in the film forming chamber 72, a raw material gas that is a raw material of the metal thin film 33 is supplied to the capillary main body 29a.

In step S2, the raw material A in the reaction chamber is exhausted by purging the inert gas.
In step S3, the reactive gas is supplied to the film forming chamber 72. As the reactive gas, oxygen, water vapor or the like can be used. As a result, an atomic layer of oxygen is formed on the atomic layer made of the raw material.
In step S4, in order to remove by-products and reactive gas generated in the gas phase, the gas is exhausted by purging with an inert gas.

The above-mentioned S1 to S4 are repeated to form the metal thin film 33.
Then, in step S5, a film thickness measuring device (not shown) provided in the film forming device 71 confirms whether the metal thin film 33 has reached a predetermined film thickness.
The above film forming method further has an advantage that the film forming raw material is a gas, so that the raw material can be reliably sent to the inner space of the capillary even if the capillary is thin. On the other hand, in the vapor deposition method and the plating method, in the case of a thin capillary, it is difficult to enter the film-forming raw material because the capillary has a narrow inlet, and therefore it is difficult to form a film.

2. Other Embodiments One embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. In particular, the plurality of embodiments and modifications described in the present specification can be arbitrarily combined as needed.
Although the monocapillary has been described as the X-ray conduit in the above embodiment, a polycapillary may be used. However, from the viewpoint that a higher X-ray emission intensity is required, the advantage of the present invention is greater in the case of the monocapillary.
The number of X-ray conduits provided in the analyzer may be one or three or more.

The present invention can be widely applied to an X-ray conduit used for focusing or collimating X-rays in an X-ray analyzer or the like that uses X-rays for analysis.

1: Analysis device 21: Optical element unit 29: X-ray conduit 29a: Capillary main body 31: X-ray conduit 31a: Capillary main body 33: Metal thin film 35: X-ray detector 71: Film-forming device S: Sample

Claims

A method of manufacturing an X-ray conduit for emitting X-rays incident from an X-ray source, comprising:
A step of preparing a capillary main body having a space inside the capillary into which X-rays are incident,
A step of forming a metal thin film on the inner wall surface of the capillary by an atomic layer deposition method,
An X-ray conduit manufacturing method comprising:
The method for manufacturing an X-ray conduit according to claim 1, wherein the aspect ratio of the capillary body is in the range of 500 to 10,000.
An X-ray conduit for emitting X-rays incident from an X-ray source,
A capillary body having a space inside the capillary into which X-rays are incident;
A metal thin film formed by an atomic layer deposition method on the inner wall surface of the capillary,
X-ray conduit with.
The X-ray conduit according to claim 3, wherein the aspect ratio of the capillary body is in the range of 500 to 10,000.
An X-ray conduit according to claim 3 or 4,
An X-ray source for irradiating the X-ray conduit with X-rays;
Analyzer equipped with.
Having a plurality of X-ray conduits of different types,
The analyzer according to claim 5, further comprising a switching device that switches the plurality of X-ray conduits according to a purpose of use.