JPH04299240A - Spectroscopic diffraction apparatus for laser plasma soft x-rays - Google Patents

Abstract

PURPOSE:To enable measurement of the quantity of light for every wavelength at one time by condensing soft X-rays linearly in a wavelength scattering direction in cooperation between a toroidal reflection mirror and a diffraction grating on a sample to be measured. CONSTITUTION:Soft X-rays generated from a laser plasma soft X-rays generating means 1 are condensed linearly at the position 3 of a slit for removing aberration with atoroidal reflection mirror 2 and scattered by a diffraction grating 4 in a wavelength-wise direction to be condensed linearly in the position of a sample 5 to be measured. The soft X-rays condensed at the slit position 3 are scattered with the grating 4 in the direction of the wavelength scattering and then, reflected from the sample 5 to be condensed in a spot by a quantity of light measuring means 6 for every wavelength. Thus, the quantity of light for very wavelength can be measued at one time.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to nanometer (10-
The present invention relates to a laser plasma soft X-ray spectroscopic diffraction device that can be used for fine structural analysis of structural materials, etc. (9 nm) size.

0002

[Conventional technology]

[0003] For structural analysis of nanometer-sized structural materials, the wavelengths generated from conventional electron tubes are 0.2 to 1.
There is a method of structural analysis using small-angle scattering, which uses 0 Å X-rays to obtain information about nanometer-sized structures from regions with small diffraction angles, and a method of analyzing soft X-rays from synchrotron radiation to make them monochromatic, that is, monochromatic. One wavelength, one wavelength
There is a method of structural analysis using soft X-rays of 0 to 200 Å. Both are under Bragg's diffraction condition (2d・sinθ=n
Structural analysis is performed using λ, d: lattice constant, θ: scattering angle, λ: wavelength).

In diffraction by small-angle scattering, the wavelength of the irradiated X-rays is very short compared to the d value, which is the lattice constant of the nanometer-structured material, so the scattering angle that satisfies Bragg's diffraction condition becomes small, and the dispersion power decreases. Because the angle of incidence is low and the angle of incidence is small, it is easily affected by the surface shape of the sample being measured.
There was a problem that the diffracted light did not sufficiently reflect the internal structure of the sample to be measured. In addition, in measurements using synchrotron reflected light, soft X
In order to obtain the lines, relatively large-scale equipment of which there are only a few in Japan is required, such as KEK in Tsukuba and IMS in Okazaki.
It was difficult to use it easily. In addition, since the intensity of soft X-rays is low, structural analysis requires exposure for microseconds or more, which makes it difficult to observe structural changes due to exposure of the sample to be measured during structural analysis and dynamic observation in microseconds or less. There were some problems.

[0005] Therefore, attempts have been made to analyze the structure by diffraction using laser plasma soft X-rays, which can obtain soft X-rays with higher intensity than synchrotron radiation. For example, by separating laser plasma soft X-rays with a diffraction grating,
After making it monochromatic with a pinhole or slit, a part of the light is converted into a parallel beam using a collimator and directed to the sample to be measured.
There is a report that measured the reflectance of a multilayer film by irradiating the remaining light onto a measuring device and comparing the amount of reflected light from the former with the measured amount of light from the latter.

[0006] In this method, only a part of the soft X-rays made monochromatic by a pinhole etc. are irradiated onto the sample to be measured, and the amount of light is insufficient. In addition, this method uses Bragg diffraction of a single wavelength. However, since the amount of diffracted light for multiple wavelengths cannot be measured at once, there is a problem in that irradiation must be repeated for each wavelength and the amount of diffracted light must be measured.

[0007]

[Problems to be Solved by the Invention] An object of the present invention is to provide a simple method that can measure the light intensity of multiple wavelengths at once when performing structural analysis by spectroscopic diffraction of nanometer-sized structural materials using laser plasma soft X-rays. Laser plasma soft X
An object of the present invention is to provide a line spectroscopic diffraction device.

[0008]

[Means for Solving the Problems] The present inventors have repeatedly conducted systematic experiments and theoretical analyzes in order to develop a new laser plasma soft As a result, we developed an optical system designed to wavelength-disperse the soft X-rays by combining a condensing optical means and a diffraction grating, and condense the soft X-rays linearly in the direction of the wavelength dispersion on the sample to be measured. When used, the amount of light per unit area for each wavelength can be increased, and the spectral diffraction caused by diffraction of multiple wavelengths can be
They discovered that this can be achieved by irradiating laser plasma with soft X-rays twice, and completed the present invention. (Configuration of the first invention)

The spectroscopic diffraction apparatus for laser plasma soft X-rays according to the first aspect of the present invention includes a laser plasma soft X-ray generating means and a condensing mirror having a toroidal reflecting mirror that condenses the generated soft X-rays linearly at two locations. an optical means, an aberration removing means installed in the first linear condensing section, a sample holding means for holding a sample to be measured installed in the second linear condensing section, A light amount measuring means is installed between the aberration removing means and the sample to be measured, and the light amount measuring means is installed between the aberration removing means and the sample to be measured, wavelength-dispersing the soft X-rays, and dispersing the soft It consists of a diffraction grating that linearly focuses light in the direction perpendicular to the
The method is characterized in that soft X-rays are linearly focused in the wavelength dispersion direction on the sample to be measured by the cooperation of the toroidal reflecting mirror and the diffraction grating. (Configuration of second invention)

A spectroscopic diffraction apparatus for laser plasma soft X-rays according to the second invention includes a laser plasma soft X-ray generating means and a condensing optical system having a cylindrical reflecting mirror or a spherical mirror that condenses the generated soft X-rays into a line. an aberration removing means installed in the linear condensing section, a light amount measuring means for measuring the amount of soft X-rays diffracted by the sample to be measured, and installed between the aberration removing means and the sample to be measured. a diffraction grating that wavelength-disperses the soft X-rays and focuses the soft X-rays linearly for each wavelength in a direction perpendicular to the wavelength dispersion direction on the light amount measuring means; It is characterized by comprising a linear irradiation slit having an elongated hole in the wavelength dispersion direction for linear irradiation in the wavelength dispersion direction.

[0011]

[Function] (Function of the first invention) The structure and principle of the laser plasma soft X-ray spectroscopic diffraction apparatus of the first invention will be explained with reference to FIG. 1, which is a schematic diagram.

The first feature of the present invention is that a toroidal reflecting mirror is used as the condensing optical means. The toroidal reflector has different curvatures along two different axes and has the function of linearly focusing light at two locations. That is, the first linear condensing section linearly condenses light in the horizontal direction with respect to the reflective mirror surface, and the second linear condensing section condenses linear light in the vertical direction with respect to the reflective mirror surface. In the present invention, an aberration removing means for cutting off an aberration component caused by the toroidal reflecting mirror is arranged in the first linear light collecting section in the linear light collecting direction. Aberration components appear as background etc. when soft X-rays are imaged onto a light intensity measurement means, and thus interfere with accurate determination of the profile. However, this aberration removal means prevents the generation of background etc. and facilitates analysis. ability can be improved. Further, a sample to be measured is installed in the second linear light condensing section.

A second feature of the present invention is that a diffraction grating is used in combination with the toroidal reflecting mirror. The grating shape and the like of the diffraction grating are determined so as to cause wavelength dispersion in a direction perpendicular to the grating plane, and soft X-rays incident on the diffraction grating are wavelength dispersed. This wavelength-dispersed soft X-ray is incident on the sample to be measured, and as described above, the sample to be measured is installed in the second linear condensing part of the toroidal reflecting mirror, On its surface, soft X-rays are linearly focused in a direction perpendicular to the toroidal reflector. Therefore, by adjusting the distance between the toroidal reflecting mirror and the diffraction grating, the inclination of the diffraction grating surface, etc., it becomes possible to linearly focus the soft X-rays in the wavelength dispersion direction on the surface of the sample to be measured. In this way, according to the apparatus of the present invention, it has become possible to focus and diffract soft X-rays for each wavelength on the sample to be measured.

Further, the diffraction grating controls the radius of curvature of the grating surface, the distance between the diffraction grating, the aberration removing means, the sample to be measured, the light amount measuring means, etc., so that the diffracted light from the diffraction grating is transmitted to the light amount measuring means. The light is linearly focused for each wavelength in a direction perpendicular to the wavelength dispersion direction on the surface of the light source. On the other hand, soft X-rays are linearly condensed in the wavelength dispersion direction by a toroidal reflecting mirror on the surface of the sample to be measured, and enter the surface of the light amount measuring means 10 while maintaining almost the same shape. Because of the linear focusing effect in the direction perpendicular to the wavelength dispersion direction, the soft X-rays are focused at each wavelength in the wavelength dispersion direction. Therefore, diffraction for each wavelength, that is, spectral diffraction becomes possible.

Furthermore, since the soft X-rays are focused for each wavelength on the sample to be measured and the light amount measuring means, the amount of light per unit area can be extremely increased.

In the diffraction device according to the first aspect of the present invention, the amount of light at each wavelength is determined with respect to the angle of incidence on the sample to be measured, and from the angle of incidence at which each wavelength is reflected most strongly, the grating spacing is determined according to Bragg's diffraction conditions. A certain d value can be determined. Furthermore, by plotting the amount of light against the angle of incidence for each wavelength and drawing a curve, the half-width, etc. can be determined, and the crystal state, etc. of the sample to be measured can be estimated. (Action of the second invention)

As shown in the schematic diagram of FIG. 2, the diffraction apparatus of the second invention does not linearly condense soft X-rays on the surface of the sample to be measured, but uses cylindrical reflection as a condensing optical means. The feature is that a mirror or a spherical mirror is used in combination with a slit for linear irradiation to perform linear irradiation. The configuration and operation other than this are almost the same as the device of the first invention, so the differences will be mainly explained.

Cylindrical reflecting mirrors and spherical mirrors are
In either case, the light is condensed in a line parallel to the reflecting mirror surface at one point, and then becomes a diverging light. An aberration removing means is installed in this condensing section. The diffraction grating has the same configuration as that used in the first invention, and wavelength-disperses the soft X-rays in a direction perpendicular to the diffraction grating surface, and also disperses each wavelength of the soft X-rays wavelength-dispersed on the surface of the light amount measuring means. The light is focused linearly in the direction perpendicular to the wavelength dispersion direction. In the diffraction apparatus of the second invention, before the wavelength-dispersed soft X-rays enter the sample to be measured, a linear irradiation slit with an elongated hole in the wavelength dispersion direction is installed, and only the portion of this hole is exposed. Soft X-rays are allowed to pass through, and the surface of the sample to be measured is irradiated with soft X-rays with linear wavelength dispersion. The amount of the irradiated and reflected soft X-rays is measured by a measuring means. On the surface of this measuring means, each of the wavelength-dispersed wavelengths is focused to a point in the direction perpendicular to the direction of wavelength dispersion, due to the linear focusing action of the diffraction grating, similar to the device of the first invention.

[Effect of the invention] (Effect of the first invention)

Since a toroidal reflector is used as the condensing optical means, the soft X-rays wavelength-dispersed by the diffraction grating can be linearly focused in the direction of wavelength dispersion on the surface of the sample to be measured. The soft X-rays reflected on the surface can also be focused on a point on the light amount measuring means due to the linear focusing action of the diffraction grating. Therefore, the amount of light per unit area for each wavelength increases, and sufficient analysis sensitivity can be obtained. In addition, whereas conventional equipment measures the amount of light for each single wavelength,
One irradiation with laser plasma soft X-rays makes it possible to measure the light intensity of multiple wavelengths, that is, spectroscopic diffraction becomes possible, and the labor of repeating measurements for each wavelength as in the conventional method can be significantly reduced. (Effect of the second invention)

[0020] An optical system that combines a cylindrical reflecting mirror or a spherical mirror and a slit for linear irradiation can irradiate the surface of a sample to be measured with linearly wavelength-dispersed soft X-rays, which can be focused linearly on the sample surface. Compared to the diffraction device of the first invention, the amount of light per unit area is slightly smaller, but compared to the conventional device that irradiates only a part of the single-wavelength soft X-ray to the sample to be measured, it is more effective for structural analysis. The intensity of the available soft X-ray light is much higher, and it is possible to obtain sufficient analysis sensitivity. Therefore, like the diffraction device of the first invention, the amount of light for each wavelength can be measured with high sensitivity by one irradiation of laser plasma soft X-rays.

[0021]

EXAMPLES (Specific Examples of the Present Invention) Specific examples that further embody the first and second inventions will be described.

The means for generating laser plasma soft X-rays is not particularly limited, and any device that is normally used for generating soft X-rays may be used. When a laser beam generated by a laser generator is introduced into a vacuum chamber and irradiated onto a target such as aluminum, soft X-rays are generated.

[0023] Soft X-rays are generated when a solid target is irradiated with a laser beam, and the elements constituting the solid target are ionized or excited and placed at a higher level than the ground state. It occurs when trying to return to the original position or when colliding with an ion. The shape of this laser plasma soft X-ray can be changed depending on the shape of the target and the shape of the irradiation beam, so that the soft X-rays can be emitted in various directions.

The aberration removing means used in this specific example usually uses a slit. The soft X-rays that are incident on a condensing optical means such as a toroidal reflector and reflected are condensed into a line parallel to the reflective mirror surface at a condensing section. In reality, due to the aberration of the reflecting mirror,
The linear light collection has a width, and the aberration component is focused away from the center of the optical axis.

Therefore, a slit is placed near the center of the condensing section in a direction parallel to the mirror surface to cut out soft X-rays with large aberrations. Soft X-rays with large aberrations are cut by adjusting the slit width. In addition, the reason for condensing the light into a line in this way is to irradiate the entire surface of the diffraction grating with the light transmitted through the slit, and by narrowing the light with the slit, the resolution of the image formed by the diffraction grating on the surface of the light amount measuring means is increased. can be raised.

The diffraction grating is provided between the light amount adjusting means and the sample to be measured. It can be either an oblique incidence type or a transmission type, but the grating surface has a spherical surface, or it is flat and has a specific grating spacing, and wavelength dispersion occurs in the direction perpendicular to the grating surface, and wavelength dispersion occurs on the surface of the light amount measuring means. It is preferable to use one that has the function of condensing light for each wavelength in a direction perpendicular to the direction.

[0027] The sample to be measured is fixed to the sample holder,
The sample holder is equipped with a mechanism that can freely change the incident angle of the soft X-rays on the sample surface, and an adjustment mechanism that allows the reflected light reflected at the same angle as the incident angle to be directed toward the light amount measuring means. It is being

Furthermore, as the light amount measuring means, any of a soft X-ray film, an imaging plate, or a fixed detector can be used.

When a soft X-ray film is used as the light amount measuring means, the amount of light at each wavelength can be determined from the density of the exposed area corresponding to each wavelength position. Furthermore, with the imaging plate, the amount of light at each wavelength can be determined by using a reader linked to a computer. In addition, when using a solid-state detector, by using the solid-state detector and computer in conjunction, it is possible to measure the light intensity at the same time.
Since reflectance can be obtained, it can be used as a practical evaluation device for optical elements.

[0030] Furthermore, the soft The reflectance of soft X-rays in the measurement sample can be determined.

Separation of the irradiated light and the direct light may be performed by (1) laser plasma soft This may be done between different samples. The configuration of the system in case (1) is shown in FIG. 3, which requires a condensing optical means for direct light, an aberration removing means, a diffraction grating, and a light amount measuring means.

Since the direct light condensing optical means does not need to condense the light on the sample to be measured, a cylindrical reflecting mirror or a spherical mirror is used, and the curvature of the mirror is made linear at the position of the slit for removing aberrations. Design to focus light. Further, if the light source size is small and a sufficient amount of light can be secured, a cylindrical reflecting mirror or the like can be omitted.

In the case of (2) and (3), a reflecting mirror is inserted into the optical path of the soft X-rays to change the optical path of a part of the soft X-rays, thereby directing the light to the sample to be measured. Separate into irradiated light. In the case of (2), the apparatus can be simplified in that there is only one condensing optical means, but since the soft X-rays reflected by the condensing optical means are divided into two, the amount of light for each is reduced. There is. In the case of (3), a part of the soft X-rays wavelength-dispersed by the diffraction grating is changed in its optical path using a reflecting mirror, and is separated into direct light and irradiation light. In this case, there is an advantage that only one diffraction grating is required, but the amount of light is even smaller than in case (2). (Example 1)

In this example, the sample to be measured is RF
Molybdenum and silicon are alternately deposited on a silicon substrate by magnetron sputtering, with a layer thickness of approximately 11 nm.
A multilayer film of 30 layers was used.

Furthermore, in order to generate laser plasma soft X-rays, aluminum is used as a target,
The laser beam used was a double harmonic of a YAG laser (wavelength: about 0.5 μm), a pulse width of 6 to 8 nanoseconds, and an irradiation energy of 0.8 Joule.

FIG. 4 shows a schematic diagram of the laser plasma soft X-ray generating means. The laser beam is focused by a quartz lens 10 with a focal length of 200 mm installed in a chamber 9, and is perpendicular to the surface of the target 11. was irradiated. Therefore, soft X-rays generated from the target surface irradiated with the laser beam are radiated axially symmetrically with respect to the laser beam.

Furthermore, an optical system 12 for obtaining direct light;
By providing the optical system 13 for obtaining the irradiation light to the sample to be measured at a position axially symmetrical with respect to the laser beam, the amount of light of each wavelength in the two optical systems was made comparable. FIG. 1 shows the configuration of an optical system for irradiating a sample to be measured. 1 is a laser plasma soft X-ray generating means; 2
is a toroidal reflector for focusing light. The soft X-rays are linearly condensed at an aberration removal slit position 3 by a toroidal reflector, dispersed in the wavelength direction by a diffraction grating 4, and further focused in the direction of wavelength dispersion by the toroidal reflector at a sample position 5 for measurement. Focuses light into a line. In addition, in the wavelength dispersion direction, after the soft X-rays focused at the slit position 3 are dispersed by the diffraction grating 4, they are reflected by the sample to be measured 5, and are focused at a point by the light amount measuring means 6 for each wavelength. It is structured to do this. The distance between the laser plasma soft X-ray generating means 1 and the toroidal reflecting mirror 2 is U, the distance between the toroidal reflecting mirror 2 and the aberration removal slit 3 is V, the distance between the slit 3 and the diffraction grating 4 is W, and the diffraction grating 4 and the distance between the sample to be measured 5 is X, and the distance between the sample to be measured 5 is
The distance between and the light amount measuring means 6 is Y, the radius of curvature of the toroidal reflecting mirror in the wavelength dispersion direction is R, the radius of curvature in the direction perpendicular to the wavelength dispersion direction is r, the radius of curvature of the diffraction grating is L, and the radius of curvature of the toroidal reflecting mirror in the direction of wavelength dispersion is R. Assuming that the incident angle of the soft X-rays is θ and the incident angle of the soft X-rays to the diffraction grating is Θ, these have the following relationship.

1/U+1/V=2/Rcos(90-θ)...
(1)

1/U+1/(V+W+X)=2cos(90−θ
)/r...(2)

1/W+1/(X+Y)=2/Lcos(90−Θ
)...(3)

In this embodiment, each distance, U
=1095mm, V=95mm, W=237mm, X=
200mm, Y=35mm, each radius of curvature, R=50
00 mm, r=26 mm, L=5649 mm, each incident angle, θ=2°, Θ=2.4°.

When the light source size of the laser plasma soft X-ray generating means 1 is about 60 μm, the condensing width at the slit part is about 5 μm.
．． 2 μm (=60×95/1095), and the focusing width at the sample to be measured is approximately 336 μm (=60×(95+237+2)
00)/95), and the spectrum width on the light amount measuring means is approximately 5.16 μm (=5.2×235/237). Therefore, the width of the reflected light from the sample to be measured on the light amount measuring means is about 336 μm, and the size of the point condensed light on the light amount measuring means is about 5.16×336 μm. Also, the angular resolution of the diffracted light is approximately 0.04°=0.71 mrad (=
0.34/(2π×75)).

FIG. 3 shows the configuration of an optical system for direct light measurement. The direct light dispersed by the laser plasma soft X-ray generating means 1 is incident on a cylindrical reflecting mirror 7 for condensing light. The soft X-rays are focused by a cylindrical reflecting mirror 7 on a slit position 3 in the direction of wavelength dispersion, and after passing through the slit 3, the soft X-rays are wavelength-dispersed by a diffraction grating 4 and can be measured by a light quantity measuring means 6. The distance between the laser plasma soft X-ray generating means 1 and the cylindrical reflecting mirror 7 is u, the distance between the cylindrical reflecting mirror 7 and the slit 3 is v, the distance between the slit and the diffraction grating 4 is w, and the diffraction grating 4 and the light amount measuring means 6 is the distance to When Θ is, these have the following relationship.

1/u+1/v=2/Rcos(90−θ)...
(4)

1/w+1/x=2/Lcos(90−Θ)...
(3)

In this example, the values are each distance, u=10
95mm, v=95mm, w=237mm, x=235
mm, each radius of curvature, R = 5000 mm, L = 564
9 mm, and each incident angle was set to θ=2° and Θ=2.4°.

The spectrum of the direct light of soft X-rays generated from the aluminum target irradiated with laser light is shown in FIG.
As shown in Figure 2, several strong line spectra are observed in the wavelength range from 8 nm to 16 nm. In FIG. 5, the horizontal axis is the wavelength, and the vertical axis is the optical density (logI0/I, I: transmitted intensity, I0: incident intensity). This soft X-ray was subjected to wavelength dispersion using a diffraction grating, and was made incident on a multilayer film having a periodic structure of 11 nm. FIG. 6 shows an X-ray photograph of reflected light obtained using a soft X-ray film when the incident angle was changed from 22.8° to 44.5°. Soft X-rays with a wavelength of 8.8 nm have the strongest reflected light when the incident angle is 24.6° and 25.5°.
Soft X-rays with a wavelength of 10.8 nm have the strongest reflected light when the angle of incidence is 29.1°, and soft X-rays with a wavelength of 13 nm have the strongest reflected light when the angle of incidence is 34.
When the angle was 5°, the reflected light was the strongest. From the sensitivity characteristics of the film measured in advance, the amount of reflected light was calculated and the relationship with the angle of incidence was determined, and as a result, the result shown in FIG. 7 was obtained. FIG. 7 shows only soft X-rays with a wavelength of 13 nm. From the angular distribution of reflection intensity at such wavelengths, characteristics such as the dimensions of the periodic structure, variations between layers, and surface conditions of the sample to be measured can be evaluated. Furthermore, by comparing the intensity of direct light, it was measured that the peak reflectance was about 10%. The apparatus of this embodiment has a major feature of being able to determine the reflectance for each wavelength.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a spectroscopic diffraction apparatus for laser plasma soft X-rays according to the present invention in which a toroidal reflecting mirror is used as a condensing optical means.

FIG. 2 is a schematic diagram of a spectroscopic diffraction apparatus for laser plasma soft X-rays according to the present invention in which a cylindrical reflecting mirror is used as a condensing optical means.

FIG. 3 is a schematic diagram of a laser plasma soft X-ray spectroscopic diffraction apparatus according to the present invention when measuring the amount of direct light.

FIG. 4 is a schematic diagram of a laser plasma soft X-ray generating means used in Example 1 of the present invention.

FIG. 5 is a diagram showing the spectrum of direct light obtained in Example 1 of the present invention.

FIG. 6 is an X-ray photograph obtained in Example 1 of the present invention.

FIG. 7 is a diagram showing the incident angle dependence of the amount of reflected light of soft X-rays obtained in Example 1 of the present invention.

[Explanation of symbols]

1... Laser plasma soft X-ray generating means 2... Toroidal reflecting mirror 3... Aberration removing means 4... Diffraction grating 5... Sample to be measured 6... Light amount measuring means 7... Cylindrical reflecting mirror 8...Slit for linear irradiation 9...Chamber 10...Condensing lens 11...Target 12...Optical system 13 for obtaining direct light...For obtaining reflected light optical system

Claims (2)

[Claims] [Claim 1] Laser plasma soft X-ray generating means;
A condensing optical means having a toroidal reflecting mirror that linearly condenses the generated soft X-rays at two locations, an aberration removing means installed in the first linear condensing section, and a second linear condensing section. sample holding means for holding a sample to be measured installed in the sample to be measured; light amount measuring means for measuring the amount of light of soft X-rays diffracted by the sample to be measured; and installed between the aberration removing means and the sample to be measured. It consists of a diffraction grating that wavelength-disperses the soft X-rays and focuses the light in a line perpendicular to the wavelength dispersion direction for each wavelength on the light amount measuring means, and performs diffraction with the toroidal reflecting mirror on the sample to be measured. A spectroscopic diffraction device for laser plasma soft X-rays, which is characterized by linearly focusing soft X-rays in the wavelength dispersion direction through cooperation with a grating. [Claim 2] Laser plasma soft X-ray generating means;
a condensing optical means having a cylindrical reflecting mirror or a spherical mirror that condenses the generated soft X-rays into a linear shape; an aberration removing means installed in the linear condensing section; a sample holding means that holds a sample to be measured; a light amount measuring means for measuring the light amount of soft X-rays diffracted by the sample to be measured; A diffraction grating that linearly condenses light in a direction perpendicular to the wavelength dispersion direction for each wavelength, and a wavelength division for linearly irradiating soft X-rays incident on the sample to be measured from the diffraction grating in the wavelength dispersion direction. A spectroscopic diffraction device for laser plasma soft X-rays, comprising a linear irradiation slit having an elongated hole in the soft direction.