JPH04204297A - Multiple wavelength spectral diffraction element - Google Patents

Abstract

PURPOSE:To extract X-ray light beams of more than two wave length, simultane ously with one element by constituting the element with a multitude of crystal layers having flat crystal surface causing Bragg's reflection and arranging each crystal surface to be in poly type relation of the same component or to be in the relation of super lattice structure due to the substitution of part of atoms. CONSTITUTION:A spectral diffraction element consists from the surface, of the first crystal layer 1 with lattice coefficient of d1, the second crystal layer 2 with lattice coefficient of d2 and the third crystal layer 3 with lattice coefficient of d3 in turn, the lattice coefficients d1, d2 and d3 are preferred to be in the relation of d1>d2>d3. And for each crystal layer 1, 2 and 3, ones with crystal structures in poly type relation are used. The poly type relation is obtained by constituting crystal structure of layered basic structures such as SiC, CdI2, ZnS, etc. When white X-ray comes in the surface of spectral diffraction element, mixed beams of X-ray with wavelengths lambda1, lambda2 and lambda3 separated by the Bragg's condition of 2d1 sintheta=lambda1 2d2sintheta=lambda2, 2d3sintheta=lambda3 are emitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-wavelength spectroscopic element that can simultaneously extract X-ray beams of two or more wavelengths.

[Prior art and problems to be solved by the invention] An X-ray spectrometer (monochromator) black-reflects incident X-rays and extracts a monochromatic X-ray beam. Flat or curved crystals), mosaic crystals, etc. are used.

Various types of these spectroscopic elements have been proposed, but all conventional spectroscopic elements have the function of extracting an X-ray beam of only one wavelength.

On the other hand, the anomalous dispersion method is an effective method for structural analysis of crystals and amorphous materials. Scattering factor of each atom (X-ray scattering power)
changes significantly depending on the wavelength of each absorption edge (abnormal dispersion). Therefore, by performing multiple measurements using a wavelength near the absorption edge of each atom that makes up the substance as the wavelength of the X-rays to be measured.

Enough information can be obtained to analyze the position of each atom within the material.

However, when performing diffraction measurements using X-rays of two different wavelengths, the same X-ray diffraction measurements must be performed twice by changing the X-ray source. Furthermore, there are various difficulties such as the X-ray diffraction measurement requires a long time to measure weak diffraction intensity and the substance changes during the measurement.

Furthermore, attempts have been made to use X-rays for photolithography such as microfabrication. Even in photolithography using X-rays, the efficiency can be greatly improved by using a beam containing X-rays with two or more desired wavelengths.

However, if a known X-ray spectroscopic element is used, even if a white X-ray beam is irradiated, the X-ray beam extracted by black reflection from this X-ray spectroscopic element is of one wavelength. It has been desired to solve the above problems.

The present invention was made in view of the actual state of the prior art, and it is an object of the present invention to provide a multi-wavelength spectroscopic element that can simultaneously extract light beams containing X-rays of two or more wavelengths with a single element.

[Means to solve the problem]

In order to achieve the above object, the present invention comprises a plurality of crystal layers with flat crystal planes that cause black reflection,
A multi-wavelength spectroscopic element is provided in which each crystal layer has a polymorphic relationship with the same composition or a superlattice structure relationship due to partial substitution of atoms.

[For production]

When white X-rays are incident on the element surface, XJi of a wavelength that satisfies Black's condition is generated on the surface of each crystal layer that has a polymorphic relationship or a superlattice structure relationship due to partial substitution of atoms.
is diffracted, and a parallel beam of light mixed with X-rays of wavelengths corresponding to the number of crystal layers is extracted.

〔Example〕

The present invention will be explained in detail below with reference to Examples.

FIG. 1 is a conceptual diagram of a multi-wavelength (three-wavelength) spectroscopic element according to an embodiment of the present invention, and from the surface side, a first crystal layer 1 with a lattice constant d, a second crystal layer 2 with a lattice constant d2, and a second crystal layer 2 with a lattice constant d2. It has a structure in which third crystal layers 3 having a lattice constant d3 are sequentially laminated.

It is desirable that d, d2 and d3 have a relationship of d>d2>d3. Each crystal layer 1, 2.3 has a crystal structure having a polytype relationship. Polymorphisms are well known in SiC, Cdl□, ZnS, etc., and when creating a crystal structure by stacking basic layered structures, there are various synchronizations (lattice constants) in the stacking direction depending on the stacking rules. It is a phenomenon in which things can appear,
It is known from the research of Zhdanov, Ramspur et al.

) Here, in order to simplify the explanation, a case will be described as an example in which a ZnS polymorphism is used in a two-wavelength spectroscopic element. This is a spectroscopic element constructed by stacking layers made of ZnS tetrahedrons, but the first layer of the spectroscopic element is ^BCABC・,
It is assumed that the second layer is a stacked crystal layer of ABAB^6. That is, if the structure of each crystal layer is described using Ramspur symbols, it is 3C and 2H. In this case, the lattice constant d of the first layer.

The ratio of the lattice constant d2 in FIG. 2 is d+/dt=3/2, and a two-wavelength spectroscopic element is constructed.

The spectroscopic element of the embodiment shown in FIG. 1 applies the principle of the above two-wavelength spectroscopic element to the first crystal layer 1 and the second crystal layer 2, and the second crystal layer 2 and the third crystal layer 3. With this configuration, when white X-rays are incident on the surface of the spectroscopic element of this embodiment, 2dlsin IJ =λ1.2d2. sinθ
:^2.2d3+inθ2λ3 A light beam containing a mixture of X-rays of wavelengths 1, λ2, and λ3 separated by Black's condition is emitted.

In addition, in the above example, a three-wavelength spectroscopic element was illustrated, but
The present invention can be applied to a spectroscopic element with two wavelengths or four or more wavelengths using the same principle.

Furthermore, in the above embodiment, polymorphism of ZnS was exemplified, but Si
Polymorphisms such as C, C(112, mica, etc.) can also be used, and by using these polymorphisms, it is possible to design multi-wavelength spectroscopic elements with various combinations of lattice constants.

Furthermore, in the above embodiment, a crystal structure having a polymorphic relationship was used for each crystal layer, but instead of this, a layer having a superlattice structure due to the substitution of some atoms may also be used to achieve the desired results. can achieve the objectives of

[Effect of the invention 3] According to the present invention, because of the target configuration, multi-wavelength spectroscopy is possible, so an X-ray beam composed of a line spectrum can be obtained, and application to evaluation of crystals and measurement of physical properties is possible. It can also be applied to odolithography (by increasing the efficiency of photochemical reactions, etc.).

In addition, since layer interfaces are formed using a polymorphism in the multilayer structure or a superlattice structure by substituting some atoms, the layer interfaces are continuous, making it an excellent spectroscopic element.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a multi-wavelength spectroscopy element according to an embodiment of the present invention. 1...First crystal layer 2...Second crystal layer 3...Third
Crystal layer patent applicant Rico Co., Ltd. - Agent
Patent attorney Toshiaki Ikeura (and 1 other person) Figure 1

Claims (3)

[Claims] (1) It is composed of multiple crystal layers with flat crystal planes that cause black reflection, and each crystal layer has a polymorphic relationship with the same composition or a superlattice structure relationship due to partial substitution of atoms. Characteristic multi-wavelength spectroscopic element. (2) The multi-wavelength spectroscopic element according to claim 1, wherein there is no lattice constant misfit at the crystal layer interface, but the lattice constant of each crystal layer changes in the direction perpendicular to the interface. . (3) The multi-wavelength spectroscopic element according to claim 1 or 2, characterized in that the lattice constant of the crystal layer on the surface side becomes sequentially larger than the lattice constant of the crystal layer on the inner side.