JPH0627297A - Nonchromatic same phase x-ray condenser - Google Patents

Abstract

PURPOSE:To eliminate influence for scattering X-rays and the like caused by total reflection as much as possible in the case where X-rays are made incident at a low incident angle not much exceeding a critical angle for a crystalline material for the purpose of obtaining good monochromatic same phase X-rays. CONSTITUTION:An angle between a cut face 12 and a diffraction face 12 of a crystalline material 10 is moved and formed in order that the cut face side of an incident angle alpha of X-rays 13 close to a critical angle for a crystalline material 10 may be larger than the diffraction side thereof. Thereby scattering X-rays are lessened, a background at the incident angle alpha a little exceeding the critical angle of the crystalline material 10 is reduced sharply and the X-rays whose monochrome is good and phase is complete can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectroscopic device for injecting X-rays at an incident angle close to the critical angle of a substance so that the X-rays are reflected and interfered to collect monochromatic X-rays of the same phase. It relates to a monochromatic in-phase X-ray concentrator.

[0002]

2. Description of the Related Art Generally, X-rays have a short wavelength (several 10 Å ~
The index of refraction of the material is almost equal to 1. When such X-rays are incident on the solid surface at a grazing angle, total reflection occurs. The critical angle θc is usually about 10 to 30 ′, and the longer the wavelength of X-ray, the larger. A curved mirror is used for light collection by utilizing this total reflection. Also, X
The lines show interference phenomena like light, and when the phases are aligned, the waves strengthen each other. By the way, as shown in FIG. 4, when the X-ray 1 is incident on the surface of the substance 3 on the substrate 2 at a grazing incidence angle α, the wave reflected on the substance 3 surface and the wave reflected on the substrate 2 surface are different from each other. , The phases are aligned at a certain angle α ₁ having a relationship as shown in FIG. This occurs when the optical path difference between the two X-rays equals an integer multiple of the incident X-ray wavelength. If the film thickness of the substance 3 is not more than 1000Å, the X-ray 1 does not reach the substrate 2 and this phenomenon does not occur. The substance 3 may be crystalline or amorphous, and the point is that it is uniform.

By the way, if the film thickness of the substance 3 is less than 1000 Å and it is provided with a multi-layer structure, the above interference effect is increased. However, the layers must be mirror-finished. However, according to the current manufacturing technology, it is possible to provide several thin film layers uniformly. For example, LB
GaAs provided by film or MBE (Molecular Beam Epitaxy)
It is possible with semiconductors such as. When the incident angle α is α ₁ , the reflected X-rays are monochromatic (spectralized) according to the above-mentioned principle and have the same phase.

[0004]

However, in reality, as shown in FIG. 6, at the incident angle α ₁ , in addition to the monochromatic and in-phase X-ray components, the wavelength and the phase of the substance 3 scattered by the surface of the substance 3 and the like are scattered. Different X-ray components (shown by hatching in the figure) also occur at the same time, and they are not separated into X-rays of perfect monochromatic / in-phase.

[0005]

According to a first aspect of the present invention, the crystalline substance is cut so that the incident angle of X-rays close to the critical angle with respect to the crystalline substance is larger on the cut surface side than on the diffraction surface side. It was formed by shifting the angle between the plane and the diffraction plane. In this case, in the invention of claim 2, the curved crystalline material is used, in the invention of claim 3, the surface roughness of the crystalline material is 3 to 10Å, and in the invention of claim 4, the crystalline material is crystalline. The material has a multi-layer structure with a large difference in density.

[0006]

[Function] The diffractive surface of the crystalline material = atomic surface and the cut surface = surface are slightly deviated from each other, and the cut surface is X
Since the incident angle of the rays is slightly large, the scattered X-rays are small, and the background at the incident angle slightly exceeding the critical angle of the crystalline substance is greatly reduced, resulting in good monochromaticity and phase. X-rays with a uniform distribution can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. In this embodiment, a crystalline substance for condensing X-rays as monochromatic in-phase X-rays is devised. As shown in FIG. 1, a crystalline substance 10 has a diffractive surface (= atomic plane) 11 Cut surface (= incident surface) 12 and slightly (3
The angle of incidence of the X-ray 13 which is formed by shifting (asymmetrical cut) about 0 ′) and is incident at a small angle (2 ° or less) that is about the critical angle of the crystalline material 10 is closer to the cut surface 12 side than to the diffraction surface 11 side. Is also set to be large. At this time, in order to reduce scattered light, it is preferable that the cut surface 12 be somewhat rough (roughness due to unevenness of about 3 to 10 Å). If the angle by which the diffractive surface 11 and the cut surface 12 are displaced is made smaller, the incident angle α moves toward the direction of total reflection, so the incident angle α is made larger. The crystalline material 10 may be curved to increase the incident angle α. Since the diffractive surface 11 for diffracting may be a single crystal surface or a surface in which molecules are laminated in layers such as an LB film, the expression "crystalline substance" is used in the present invention. is there. It should be noted that the materials to be laminated are not the same but have different densities.
If more than one type of material is stacked, the interference effect will increase,
X-rays with high intensity can be obtained. The material of the substrate 14 for the crystalline substance 10 is glass, S
It is not particularly limited to i, SiO ₂ , metal thin plate and the like.

As a manufacturing method, as illustrated in FIG.
Material layers A, B made of different atoms or different molecules on the substrate 14
May be laminated as A, B, A, B ,. Here, the material layers A and B may have the same film thickness or different film thicknesses. When the film thickness is different, two vibrations having different peak periods are generated, so that the film thickness relationship may be A = 2B. For the same reason, a structure in which three or more layers are sequentially stacked or a structure including only the A layer may be used. Further, in the material layers A and B, it is preferable that the difference in density between the two is large because the vibration (peak) increases. The thickness of the crystalline substance 10 as a whole may be 5000 Å or less, which does not permeate, though it depends on the atomic species used. If the thickness of each layer itself becomes too thin, the vibration cycle becomes smaller, so
About 0 to 500Å is suitable. As described above, it is preferable that the cut surface 12 is rough to about 3 to 10 liters because scattered light is reduced. It is preferable that the incident angle α of the X-ray 13 is as close to the critical angle as possible and that the peak appears. At this time, the longer the wavelength of the X-ray 13 is, the larger the incident angle α can be made, which facilitates the setting.

As a result of the method of this embodiment, the influence of scattered X-rays and the like as shown by hatching in FIG.
The characteristics as shown in FIG. 3 are obtained, and the X-ray becomes excellent in monochromatic in-phase property.

Now, a specific example will be described. First, S
Using an ion beam sputtering device on the i-wafer substrate,
The following conditions Target: Si, Fe Substrate heating: None Ionized gas: Ar (99.999%) Ion gun current x voltage: 3 mA x 9 kV Ion incident angle: 30 ° Base pressure: 3 x 10 to ⁷ Torr Target-substrate Distance: 15 mm (however, target and substrate are parallel) Substrate size: 30 × 30 mm ² Film thickness of each layer: 200 Å (1 for both Si and Fe)
0 layers each) The outermost surface was made of Si, and two crystalline materials having a laminated film thickness of about 4000 Å were prepared.

Then, in order to cut one side of the substrate a little diagonally with the same ion beam sputtering device, one of them is made to obliquely enter an Ar ion beam on the surface under the above-mentioned conditions to form the outermost Si layer. It was cut diagonally and its surface roughness was set to about 4Å.

With respect to the crystalline material having such a multilayer film structure, an X-ray apparatus RU-300 manufactured by Rigaku Co., Ltd. was used (target is Cu), and Cu was dispersed by Si (111).
When the relationship between the incident angle of Kα rays and the intensity was obtained, a large peak was obtained when the incident angle was about 7 mrad.
In this case, the background (the shaded area shown in Fig. 6)
Was almost zero. Also, when the width of the X-ray 13 was measured with an X-ray film, it was found to have decreased from 1 mm width to 0.2 mm width.

The relationship between the incident angle and the intensity was similarly obtained for the other one whose surface was not abraded by the Ar ion beam. The peak position at about 7 mrad was similar, but the intensity was obtained by abrading the surface. (The surface was inclined with respect to the layer surface)
It was confirmed that the scattered X-rays were overlapped to a greater extent than the case of one crystalline substance formed by the multilayer film (showing characteristics like the shaded portion in FIG. 6). The width of the X-ray was reduced from 1 mm width to 0.6 mm width. The peak was measured using an SSD (semiconductor detector) having a resolution of 144 eV. The peak width is
The former case, in which the interface between the Si layer and the Fe layer and the surface (cut surface) are different, was reduced to about half and the monochromaticity was improved. Further, the reduction of the background as shown in FIG. 2 shows the improvement of the in-phase X-ray ratio.

By the way, unless X-rays are incident at an incident angle very close to the critical angle of the crystalline substance, it is necessary to form the crystal plane (diffraction plane) and the cut surface of the crystal so as to be offset from each other.
This is conventionally known as "Bragg case asymmetric reflection". That is, as shown in FIG. 7, a crystalline substance 20 having a single crystal structure is formed by displacing its atomic plane 21 and cut surface 22, and X-ray 23 is incident on the cut surface 22 as shown in FIG. This is used to increase the width of the reflected X-ray, and to reduce the width of the reflected X-ray by making the X-ray 23 incident on the cut surface as shown in FIG. That is, the X-ray 23 is the atomic plane (diffraction plane) 21.
Similar to the case of the method of the present invention, the light is reflected by and the interference is caused when the Bragg condition is satisfied. However, since it is used at an incident angle larger than the critical angle, the total reflection that is the premise of the present invention is irrelevant, and there is no problem of reducing the total reflected light.

The device of the present invention which functions as an X-ray spectroscope is called an X-ray concentrator for the following reason. At present, X-rays can be obtained only by divergent light, and those using general X-ray tubes and rotor targets, those using plasma, and those using radiant light are all divergent. In the case of spectral separation, in the case of FIG. 7A, the beam width becomes wider, whereas in the case of FIG. 7B, only the light satisfying the diffraction condition is reflected, so that the beam width of the incident beam is increased. Since the beam width is narrower than the width, the beam width can be narrowed by the spectrum itself. However, according to the configuration of this embodiment, the beam width is narrowed to a narrower state and reflected. It was done.

Further, the reflecting mirror for soft X-rays (wavelength of 3 to 100Å) is used as a reflecting mirror at a larger angle (about 45 °) by laminating two kinds of materials having a large difference in density. However, if this embodiment is applied, it can be applied to a larger angle.

[0017]

As described above, according to the present invention, the cut surface and the diffractive surface of the crystalline material are arranged so that the incident angle of the X-ray near the critical angle with respect to the crystalline material is larger on the cut surface side than on the diffractive surface side. Since it is formed by shifting the angle with respect to, the amount of scattered X-rays can be reduced, and the background at an incident angle slightly exceeding the critical angle of the crystalline substance can be significantly reduced. It is possible to obtain X-rays having good properties and uniform phases.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a laminated structure.

FIG. 3 is an incident angle-X-ray intensity characteristic diagram.

FIG. 4 is a schematic diagram showing the principle of low incidence angle X-ray intensity measurement.

FIG. 5 is an incident angle-X-ray intensity characteristic diagram.

FIG. 6 is an incident angle-X-ray intensity characteristic diagram showing an extracted single-color in-phase portion.

FIG. 7 is a schematic diagram showing the principle of asymmetric reflection in the case of a conventional high incidence angle method.

[Explanation of symbols]

 10 Crystalline substance 11 Diffraction surface 12 Cut surface 13 X-ray

Claims (4)

[Claims] 1. An X-ray incident angle close to a critical angle with respect to a crystalline substance is set so that the cut surface side is larger than the diffraction surface side.
A monochromatic in-phase X-ray concentrator, which is formed by shifting the angle between the cut surface and the diffraction surface of the crystalline material. 2. The monochromatic in-phase X-ray concentrator according to claim 1, which is made of a curved crystalline material. 3. The monochromatic in-phase X according to claim 1 or 2, wherein the surface roughness of the crystalline substance is 3 to 10 liters.
Line concentrator. 4. The monochromatic in-phase X-ray concentrator according to claim 1, wherein the crystalline substance has a multi-layer structure having a large density difference.