JPH0634107B2 - Multi-layer film mirror for X-ray - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to X-rays widely used as an optical system for soft X-rays such as X-ray linography, X-ray microscope, synchrotron radiation spectroscopy and X-ray laser. Multi-layered film reflective mirror for X-rays, which reflects X-rays near normal incidence with high reflectance,
The present invention relates to an X-ray multilayer mirror having high X-ray resistance.

[Conventional technology]

Conventionally, such multilayer mirrors for X-rays have been combined with Au / C or Re / C for 180 Å soft X-rays (Scholarship Grant Research Report 1984 (Research issue number 5835000).
1)), 160.1Å, 170.4Å, 228Å soft X-ray Mo / S
Combinations of i (Applied Optics 24 (1985), 883) and other combinations of MO / C, Ta / C, W / C, AuPd / C, ReW / C, etc. have been reported.

[Problems to be solved by the invention]

However, if the previously known one is used as a combination of two substances having different refractive indices, 100 Å
For the soft X-rays in the vicinity, not only the difference in the refractive index of the two substances does not become large, but also the absorptance is large. number%
Can only obtain 20% reflectance, and 80Å under the same conditions
For soft X-rays of a certain degree, only a reflectance of several% to 10% can be obtained.

When creating an image forming system using a reflecting mirror, some require several reflecting mirrors. Therefore, the imaging system as a whole comes into play by multiplying the reflectance of one reflecting mirror. Therefore, the low reflectance of the multilayer-film reflective mirror is very problematic.

Further, the large absorption not only causes a decrease in reflectance, but also causes a large amount of heat generated by the incidence of soft X-rays and causes deterioration, which causes a decrease in X-ray resistance. Furthermore, when Au or the like is used as one of the substances, the X-ray resistance is not sufficient due to its low melting point.

The present invention has been made in view of the problems of the above-mentioned conventional example, and the object thereof is to solve the problems of the above-mentioned conventional examples and to achieve a wavelength of 80 to 12
An object of the present invention is to provide a multilayer film reflection mirror for X-rays, which has a high reflectance and a small absorption coefficient even for soft X-rays of 0Å and has a high melting point.

[Means for solving problems]

The above object of the present invention is to provide a first layer having a film thickness of 10 Å or more composed of one or more kinds of white metal and a second layer having a film thickness of 10 Å or more composed of one or more elements of Be, B, C and Si. This is achieved by a multilayer film reflection mirror for X-rays in which the above layers are alternately laminated.

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, the multilayer mirror for X-rays according to the present invention is formed by alternately laminating first layers 2 and second layers 3 on a flat or curved substrate 1.

The film thicknesses d ₁ , d ₂ ... Of the respective layers are 10 Å or more, and the film thicknesses are alternately equal (d ₁ = d ₃ = ..., d ₂ = d ₄ =
...) is acceptable even if all film thicknesses are changed, but the amplitude is reduced by absorption of soft X-rays in each layer and the reflected light is strengthened by the phase overlap of the reflected light at the interface of each layer. In consideration of both of the above, it is preferable to set the thickness such that the highest reflectance can be obtained as the entire multilayer-film reflective mirror. When the thickness of each layer is less than 10Å, it is not preferable because a high reflectance cannot be obtained as a reflecting mirror due to the effect of diffusion of two substances at the interface. The number of layers is set to several to several tens.

The first layer 2 is made of one or more of white metal, Ru, R
h and Pd are preferably used. The second layer 3 is Be, B, C
And one or more of Si are used.

It is better to use the uppermost layer of the alternately stacked layers as the first layer.
The vacuum and the first layer are better than the case where the uppermost layer of the alternating layers is the second layer.
Since the reflectance at the interface of the layer is higher than the reflectance at the interface between the vacuum and the second layer, a large reflectance can be obtained, which is more preferable.

A protective film may be further laminated on the uppermost layer of the alternately laminated layers, and as a material for the protective layer, oxides, borides, carbides, nitrides or B, C, Si having a high melting point are used. Is.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

<Multilayer film mirror for X-rays with a wavelength of 114.0Å> Example 1 41 layers are laminated with the first substance of FIG. 1 as Ru and the second substance as Si, and the film thickness of 36.4Å and 23.5Å respectively. As a result, a reflectance of 38.6% was obtained at an incident angle of 0 °. As a result of stacking C as a protective film on the 5Å uppermost layer, it was 37.9 at an incident angle of 0 °.
% Reflectance was obtained. Each film thickness is 39.1Å, 25.2
As Å, by stacking 41 layers, 40.1 at an incident angle of 20 °
% Reflectance was obtained. As a result of laminating C as a protective film on the 5Å uppermost layer, a reflectance of 39.4% was obtained at an incident angle of 20 °.

Example 2 Pd was used as the first substance and Si was used as the second substance.
By laminating 41 layers with 31.3Å and 28.0Å, a reflectance of 26.1% was obtained at an incident angle of 0 °. 3 for each film thickness
By setting 3.3Å and 30.1Å, a reflectance of 26.7% was obtained at an incident angle of 20 °.

<Multilayer Film Mirror for X-Rays with Wavelength 112.7Å> Example 3 The first substance is Ru and the second substance is Be, and each film thickness is 2
With 6.6Å and 30.6Å, by laminating 41 layers, a reflectance of 77.2% was obtained at an incident angle of 0 °. 2 for each film thickness
Incident angle 20 by stacking 41 layers as 7.4Å and 33.4Å
A reflectance of 79.9% was obtained at °.

<Multilayer Film Mirror for X-Rays with Wavelength 108.7Å> Example 4 The first material is Rh and the second material is Si, and the respective film thicknesses are
As 33.4Å and 23.4Å, by laminating 41 layers, a reflectance of 33.2% was obtained at an incident angle of 0 °. Each film thickness is 4
Incident angle 20 by stacking 41 layers as 8.2Å and 28.8Å
A reflectance of 38.7% was obtained at °.

<Multilayer Film Mirror for X-Rays with Wavelength 82.1Å> Example 5 With Ru as the first substance and B as the second substance, the respective film thicknesses are
Incident angle 0 by stacking 41 layers as 20.1Å and 21.8Å
A reflectance of 18.0% was obtained at °. Each film thickness is 21.3
With 41 layers as Å and 23.4Å, the incident angle is 20 °
A reflectance of 21.6% was obtained.

Example 6 With the first substance being Rh and the second substance being B, the respective film thicknesses were
Incident angle is 0 by stacking 41 layers as 20.0Å and 21.9Å
A reflectance of 15.7% was obtained at °. Each film thickness is 21.0
With 41 layers as Å and 23.6Å, the incident angle is 20 °
A reflectance of 18.8% was obtained.

Example 7 With the first substance as Pd and the second substance as B, the respective film thicknesses are
Incident angle of 0 by stacking 41 layers as 19.4Å and 22.4Å
A reflectance of 13.2% was obtained at °. Each film thickness is 20.6
With 41 layers as Å and 24.0Å, the incident angle is 20 °
A reflectance of 15.7% was obtained.

〔The invention's effect〕

As described above, the multilayer mirror for X-rays according to the present invention is 80 to 120 Å
Since it has a high reflectance also for X-rays of the wavelength of, and has a low reflectance in the conventional multilayer film reflecting mirror for X-rays, it can be suitably used in the field of using an X-ray laser in a wavelength range which has not been applied.

Further, the multilayer film reflecting mirror for X-rays of the present invention has a small absorptivity and therefore a small amount of heat storage by heating, and has a high melting point of the constituent material of each layer, and thus has a high X-ray resistance. For this reason, it is suitable as a reflecting mirror for a resonator of an X-ray laser.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an X-ray multilayer mirror according to the present invention. 1: substrate 2: first layer 3: second layer 4: protective layer

Claims (2)

[Claims] 1. A first layer containing at least one of white metal and a second layer containing at least one element of Be, B, C and Si.
A multilayer film reflection mirror for X-rays, characterized in that the above layers are alternately laminated. 2. The multilayer film reflecting mirror for X-rays according to claim 1, wherein the layer thickness of the first layer and the second layer is 10 Å or more.