JPH05142396A - X-ray reflecting mirror, x-ray image forming device and x-ray condensing device - Google Patents

Abstract

PURPOSE:To provide a multi-film type X-ray reflecting mirror which is excellent in thickness and flexibility, easy to process multiple nesting, and is also so excellent in lightness as to be formed into a curved article such as a cylinder and the like, and thereby provide a X-ray image forming device and a X-ray condensing device in which the aforesaid X-ray reflecting mirror is incorporated. CONSTITUTION:A X-ray image forming device or a X-ray condensing device includes a multi-film type X-ray reflecting mirror where more than two kinds of thin films 21 and 22 which are different in refractive index against X-rays, are laminated 3 in cycles over a flexible substrate 1, a nesting type X-ray reflecting mirror where the X-ray reflecting mirror is in a curved condition, and a curved conditional or a nesting type X-ray reflecting mirror. The X-ray image forming device which is excellent in condensing efficiency, are therefore provided, an artificial satellite can be easily launched because a X-ray telescope can be made light in weight, an high-volume production capacity can thereby be enhanced, which enables each product in continuous length with a large area to be easily manufactured continuously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer film type X-ray reflecting mirror which is flexible and can be easily processed into a curved shape, and an X-ray telescope and an X-ray microscope using the same. X-ray imaging device,
And an X-ray condensing device used for an X-ray lithography device, an X-ray laser device, and the like.

[0002]

2. Description of the Related Art Heretofore, there has been known an X-ray reflecting mirror in which a large number of thin layers of heavy elements and thin layers of light elements are alternately laminated on a glass plate or a silicon wafer whose surface is precisely polished. This utilizes Bragg reflection by a multilayer film provided on a glass plate or the like. Such a multilayer film type X-ray reflecting mirror can enter the reflecting surface at a larger angle (smaller incident angle) than the conventional total reflection type X-ray reflecting mirror, and is necessary for reflecting the X-ray beam. This has the advantage that the specific area can be made small and the X-ray reflecting mirror can be made compact.

That is, in a multilayer film type X-ray reflecting mirror, X
The wavelength of the line is λ, the thickness of the reflective layer, that is, the total thickness of each thin layer of heavy and light elements, is d, and the angle of incidence on the reflective surface is θ.
In such a case, strong X-ray reflection can be obtained in the direction satisfying the Bragg condition represented by the formula: mλ = 2d sin θ. Note that m in the above formula is a positive integer.

On the other hand, in the case of a total reflection type X-ray reflecting mirror utilizing the fact that the refractive index of a substance for X-rays is slightly smaller than 1, the critical angle thereof is 88 to 8 when the wavelength is a few nm.
The angle is 9 degrees, and in order to totally reflect the X-ray, it is necessary to make the incident angle to the reflecting surface at a shallow angle of 2 to 1 degree, which is shallower than that of the multilayer film type. It is necessary to make it incident. Therefore, a larger area is required to reflect the X-ray beam. However, it is difficult to form such a large area total reflection type X-ray reflecting mirror.

Incidentally, the refractive index (n) for X-rays
Is generally represented by n = 1-δ-iβ, and δ and β are small values and change depending on the wavelength of the X-ray. Specifically, for example,
The δ and β of the X-ray wavelength 1.54 Å, respectively tungsten 4.5 / 10 ^5, 3.7 / 10 ^6, respectively carbon 7.2 / 10 ^6, 1.1 / 10 ^8.

As described above, the multilayer film type X-ray reflecting mirror is advantageous over the total reflection type X-ray reflecting mirror in terms of downsizing, but in the case of a hard X-ray having a wavelength of several Å or less, Even if the layer thickness (d) is thinned to an interatomic distance, the incident angle (θ) needs to be shallow, and the effective reflection area is reduced.

On the other hand, there is known a grazing-incidence type reflecting mirror in which a curved reflecting mirror having a different diameter is overlapped with the inside of a cylindrical body to form a nesting shape to increase the effective reflection area. However, even if a glass plate is used as the substrate, the thickness must be 2 to 3 cm from the viewpoint of the strength required for polishing and the accuracy of the reflection mirror, and the upper limit of the number of layers that can be nested is limited. As little as four layers,
There is a problem that the effective reflection area cannot be increased sufficiently.

Further, there are problems that the entire reflecting mirror becomes heavy due to its own weight of the glass substrate, and that it is difficult to precisely form the glass surface into a smooth curved surface, thus making it difficult to form a curved surface. .. Further, in the case of obtaining a tubular X-ray reflecting mirror as in an X-ray telescope, there is a problem in that it is substantially difficult to form a multilayer film in which each layer thickness is highly controlled inside a glass tube or the like. It was

[0009]

DISCLOSURE OF THE INVENTION The present invention is excellent in thinness and easy to perform multiple nesting processing, and also has flexibility and can easily form a curved form including a tubular body and the like. The development of a multilayer film type X-ray reflecting mirror, which is also excellent, is an issue.

[0010]

The present invention is a multilayer film type characterized in that two or more thin layers having different refractive indices for X-rays are periodically laminated on a flexible substrate. X-ray reflecting mirror, and a nesting type X-ray reflecting mirror in which the X-ray reflecting mirror is in a curved state, and an X-ray reflecting mirror in a curved state or in a nesting type.
A line imaging device or an X-ray focusing device is provided.

[0011]

By using the flexible substrate, it is possible to form a thin and light multilayer film type X-ray reflecting mirror. Further, a nesting process of several hundreds or more is easy, and a bright image can be formed by increasing the effective reflection area. Further, bending and the like are easy, and various curved forms including a cylindrical body and its curved body can be easily formed.

[0012]

EXAMPLE An X-ray reflecting mirror of the present invention is a flexible substrate,
It is a multi-layer film type in which two or more thin layers having different refractive indices for X-rays are periodically laminated. An example thereof is shown in FIG. Reference numeral 1 is a flexible substrate, and 2 is a set of layers which is a basic unit of lamination, and two kinds of thin layers 21 and 2 having different refractive indices for X-rays.
It consists of two.

Examples of the flexible substrate include a film made of plastic such as polyethylene terephthalate and polyimide, and a metal foil. The surface on which the set of layers is provided is preferably as smooth as possible from the viewpoint of improving the reflection efficiency of Bragg reflection by preventing scattering and layer thickness disorder. In particular, the surface roughness (difference between a convex portion and a concave portion) is 1 of the thickness of the layer set, that is, the thickness of a repeating repeating unit composed of a laminate of two or more thin layers having different refractive indices for X-rays. /
It is preferably 3 or less.

The plastic film having a smooth surface can be obtained by, for example, a method of casting a plastic solution on a table having a highly smooth surface, if necessary under pressure treatment. The thickness of the flexible substrate may be appropriately determined according to the flexibility required for processing into a curved shape or the like. Generally, those having a thickness of about 10 μm to 1 mm are used.

As described above, the layer set (2), which is a repeating unit of superposition, is formed of a laminate of two or more kinds of thin layers having different refractive indices for X-rays. The number of thin layers forming each set of layers is generally 2 to 5 but is not limited to this. Therefore, the X-ray reflecting mirror of the present invention can be formed, for example, by periodically laminating each thin layer on a flexible substrate. The number of layers to be overlapped is arbitrary, and it is possible to set the number of layers to be more than several hundred. In general, the number of layers is 1,000 or less, especially about 2 to 100, from the viewpoint of flexibility of the obtained X-ray reflecting mirror or bending workability.

The lamination process may be carried out by an appropriate method such as a sputtering method, an ion beam sputtering method, a vacuum evaporation method or the like. It is preferable that the thickness of each thin layer is smaller than that of achieving a large angle of incidence (θ), as is clear from the Bragg conditions described above. Therefore, it is appropriately determined according to the formation accuracy of the uniform layer, and generally 10 nm or less, especially 1
Below nm. In addition, each layer (21, 22) of two or more kinds of thin layers having different refractive indices for X-rays, which is a forming unit of the layer set (2), may have different thicknesses.

The material used to form each thin layer is
As a substance that gives a small refractive index, for example, a heavy element such as platinum, gold, iridium, iron, nickel, tungsten, molybdenum, tantalum, or a substance having a high density can be given, and as a substance that gives a large refractive index, for example, carbon, silicon or beryllium. Examples include light elements with low X-ray absorption, or low density elements. Further, alloys or compounds containing the above elements can also be used, and the substances used are not particularly limited. For X-rays having a wavelength of several nm or less, it is customary to use a combination of platinum and carbon, or a combination of tungsten and carbon.

Due to its flexibility, the X-ray reflecting mirror of the present invention can be easily processed into a curved shape including a cylindrical body or a curved body thereof. Therefore, it can be used in an appropriate processing form. Further, the nesting process can be easily performed in an appropriate form such as a form in which the X-ray reflecting mirrors are superposed in a curved state. FIG. 2 shows an example of nesting in a cylindrical form. Reference numeral 1 is a flexible substrate, and 3 is a multi-layered film including an overlapping layer of a set of layers.

The X-ray reflecting mirror of the present invention or its nesting object is an X-ray imaging device such as an X-ray telescope or an X-ray microscope, or a reflecting mirror or a condensing device such as an X-ray lithography device or an X-ray laser device. Can be used preferably.

FIG. 3 illustrates an X-ray focusing device. this is,
A cylindrical body 4 obtained by processing the X-ray reflecting mirror of the present invention into a cylindrical shape is further curved along a paraboloid of revolution and arranged on the object with respect to the optical axis A, and the parallel X-ray beam incident on the cylindrical body 4 is focused on the focal plane. In B, the light is reflected and condensed in a point shape as much as possible. The application to the X-ray imaging apparatus can be easily performed by the method of replacing the X-ray reflecting mirror of the present invention or its nesting object with the conventional X-ray reflecting mirror.

Example 1 Using a sputtering apparatus having tungsten and carbon as targets in a vacuum chamber and also having a film winding apparatus, a polyimide film having a thickness of 125 μm was formed by reciprocating the film over two types of targets. On the polyethylene terephthalate film, a carbon layer having a thickness of 3.8 nm and a tungsten layer having a thickness of 5.7 nm were alternately formed by nine layers each to obtain a multilayer film type X-ray reflecting mirror.

For the multilayer film of the X-ray reflecting mirror obtained above,
An X-ray with a wavelength of 1.54Å was made incident, and the relationship between the incident angle and the reflection intensity was investigated. The results are shown in the graphs of FIGS. The reflection intensity in the graph is shown on a logarithmic scale. Further, the horizontal axis represents a deviation angle, that is, an angle formed by the X-ray incident direction and the reflection direction. FIG. 4 shows the case where a polyimide film is used for the substrate, and reflected light having a satisfactory intensity can be obtained even in the case of a high deflection angle of more than 1 degree. The portion where the declination angle is close to 0 degree is a peak based on total reflection.

On the other hand, FIG. 5 shows the case where a polyethylene terephthalate film is used for the substrate, and it is possible to obtain a reflected light of a sufficient intensity with a deviation angle of more than 1 degree in which the contribution of total reflection is not considered. By multiplexing by nesting, stronger reflected light can be obtained.

[0024]

According to the present invention, it is possible to obtain a thin, light and flexible multilayer film type X-ray reflecting mirror.
In addition, multiple nesting processing in excess of several hundreds can be easily performed, and a large effective area forms a bright image.
It is possible to obtain a line imaging device or an X-ray focusing device having excellent focusing efficiency. Further, bending work is easy, and various curved forms such as a cylinder can be easily formed. In addition, the lightness makes it possible to reduce the weight of the X-ray telescope and also has the advantage of facilitating the launch of an artificial satellite. Further, it also has an advantage of being excellent in mass productivity such that a long-sized body having a large area can be easily continuously manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an X-ray reflecting mirror.

FIG. 2 is a sectional view of an example in a nesting form.

FIG. 3 is an explanatory diagram of an embodiment of an X-ray focusing device.

FIG. 4 is a graph showing the relationship between the deflection angle and the reflection intensity in Example 1.

FIG. 5 is a graph showing the relationship between other deflection angles and reflection intensity in Example 1.

[Explanation of symbols]

 1: Flexible substrate 2: Layer set 21, 22: Thin layer having different refractive index for X-ray 3: Multilayer film consisting of superposed layers of layer set 4: Cylindrical processed X-ray mirror

Claims (4)

[Claims] 1. A multilayer film type X-ray reflecting mirror comprising a flexible substrate and two or more thin layers having different refractive indices for X-rays, which are periodically laminated. 2. A nesting type X-ray reflecting mirror in which the X-ray reflecting mirror according to claim 1 is in a curved state. 3. An X-ray imaging apparatus comprising the X-ray reflecting mirror according to claim 1 or the X-ray reflecting mirror according to claim 2 in a curved state. 4. An X-ray condensing device comprising the X-ray reflecting mirror according to claim 1 or the X-ray reflecting mirror according to claim 2 in a curved state.