JPH0915392A - X-ray analyzer - Google Patents

Abstract

PURPOSE: To detect incident X-ray in an irradiation region equalized for sample surface by changing the slit width of at least one of incidence and emission limiting slits in accordance with the incidence angle or emission angle of X-ray to or from the sample. CONSTITUTION: An incident X-ray width limiting slit 2 limits the width and height of the X-ray from an X-ray source and introduces as incidence light 3 with width T on a sample 5 with an incidence angle (ω) and width (t). Here, T=t/sinω. Emission X-ray 6 reflected and diffracted at the irradiated emission region 4 and generated fluorescence X-ray 11 are limited in width and height with emission limiting slits 7, 9 and individually measured with X-ray detectors 8, 10. If the slit 2 width is varied in accordance with the incidence angle ωat this moment, the dependency on incidence angle in the measuring region is eliminated. Similarly, if the width of slits 7, 9 is varied in accordance with the emission angle, the dependency of emission angle in the measuring region is eliminated. In this manner, the intensity of diffracted, reflected and fluorescent X-ray from an equal sample area can be measured with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray analysis apparatus.

[0002]

2. Description of the Related Art X-ray diffraction has been used for structural analysis of many materials. Such measurement includes (1) measuring the relationship between the diffraction / reflection intensity and the emission angle (2θ) by injecting X-rays on the sample, fixing the sample and moving the detector (θ scan), (2). X-ray is incident on the sample, the detector is fixed and the sample is moved, and the relationship between the diffraction / reflection intensity and the incident angle (ω) is measured (ω scan, rocking curve measurement), (3)
X-rays are incident on the sample, the sample and the detector are coaxial, and the detector is moved by twice the sample tilt angle, and the relationship between the diffraction / reflection intensity and the incident angle (ω) is measured (ω-2θ scan). )
It is done in.

In recent years, a method of analyzing the structure of a multilayer film from the periodicity of diffraction from a periodic thin film multilayer film and the diffuse scattering intensity in the vicinity of diffraction, and from the interference pattern of totally reflected X-rays A method for obtaining the film thickness and the density is disclosed. These incident X-rays on the surface of the sample and measure the intensity of low-angle diffracted X-rays and reflected X-rays, and nondestructively analyze the structure and constituent elements near the sample surface and the film structure of the thin film multilayer film. It is a technique. In addition, X-rays are made to grazing the surface of the sample, the fluorescent X-rays generated therefrom are measured by using the incident angle dependence of the penetration depth of the X-rays, and the constituent elements and film structure near the sample surface are measured. Research using techniques such as X-rays that are grazingly incident on the sample surface is being actively conducted.

When the X-ray intensity is measured in conjunction with the incident angle or the emission angle, if the incident angle or the emission angle is changed, the incident X-ray irradiation area or the detected X-ray emission area becomes smaller. Change. In the conventional measurement of the intensity of diffracted X-rays having an incident angle and an outgoing angle of 10 ° or more, the incident X-ray irradiation area and the X-ray outgoing area hardly change.

[0005]

However, the diffracted X-rays, the reflected X-rays, or the fluorescent X-rays of the X-rays that have just been incident on the sample.
When measuring an X-ray in conjunction with an incident angle or an emission angle, if the incident angle or the emission angle is changed, the irradiation area of the incident X-ray on the sample surface or the emission area of the detected X-ray greatly changes. . When the irradiation area of incident X-rays or the emission area of detected X-rays changes, the measurement area changes. This means that if the sample is curved, the in-plane structure is non-uniform, or the sample is small, the measurement result is affected, and high-precision measurement cannot be performed. Therefore, according to the present invention, even if the incident angle of the X-ray to the sample or the emission angle is changed, the incident X-ray is changed.
X-ray that can detect X-rays so that the irradiation area of the rays is constant on the sample surface or emitted from a constant sample area
It is to provide a line analysis device.

[0006]

In an X-ray analysis apparatus including an X-ray source, an incident X-ray limiting slit, a sample stage, an outgoing X-ray limiting slit, and an X-ray detector, diffraction of X-rays incident on a sample is performed. When measuring X-rays, reflected X-rays, or fluorescent X-rays in conjunction with the incident angle or the emission angle, the irradiation area of the incident X-rays is kept constant on the sample surface, or is emitted from a fixed sample area. As described above, in order to detect X-rays, the width of at least one of the entrance or exit limiting slits changes in association with the incident angle or the exit angle to the sample.
An X-ray analysis apparatus having a slit capable of varying the width of an X-ray or an emitted X-ray.

The incident X-ray or outgoing X-ray width variable slit is characterized in that the curved surface sides of a pair of cylinders are arranged to face each other and the X-ray width is limited between them. slit.

Further, the incident X-ray or outgoing X-ray width variable slit is rotated by the entire slit in association with the incident angle of the X-ray to the sample or the outgoing angle of the X-ray from the sample. Of the X-ray so that the X-ray irradiation area becomes constant on the sample surface and the X-ray emitted from the constant sample surface enters the detector. Slit with variable width.

Further, the incident X-ray or outgoing X-ray width variable slit is a slit capable of varying the X-ray width, characterized in that a pair of slit blades are arranged facing each other and the X-ray width is limited between them.

The incident X-ray or outgoing X-ray width variable slit moves one or both of the slit blades in association with the incident angle of the X-ray to the sample or the outgoing angle of the X-ray from the sample. By changing the width of the X-ray, the slit width is changed so that the irradiation area of the X-ray becomes constant on the sample surface or the X-ray emitted from the constant sample surface enters the detector. A slit that can change the width of X-rays.

Further, in the X-ray analysis apparatus, the intensity change of the incident X-ray or the output X-ray due to the change of the slit width of the incident X-ray or the output X-ray width variable slit depends on the incident angle dependence of the incident X-ray intensity. The present invention relates to an X-ray analysis apparatus, characterized in that the output angle dependence of the output X-ray intensity is measured in advance and the intensity is standardized by the measurement result.

[0012]

The width T of the X-ray incident on the sample on the sample surface can be expressed by the equation (1), where t ₁ is the width of the incident X-ray and ω is the incident angle from the sample surface.

T = t ₁ / sin (ω) (1) The width t of the incident X-ray required to keep the width T of the X-ray on the sample surface constant can be expressed as in equation (2).

T ₁ = Tsin (ω) (2) By changing the width of the incident X-ray limiting slit in accordance with the incident angle according to the equation (2), the irradiation area of the incident X-ray is made constant on the sample surface. It becomes possible to become.

On the other hand, the width t ₂ of the emitted X-ray is the width T of the X-ray incident on the sample on the sample surface, and the emission angle from the sample surface is 2.
If it is set to θ, it can be expressed as in Expression (3).

T ₂ = Tsin (2θ) (3) By changing the width of the emission X-ray limiting slit in accordance with the emission angle according to the equation (3), X-rays are emitted as if they were emitted from a fixed sample area. It becomes possible to detect.

Further, the slit having variable widths of the incident X-rays or the outgoing X-rays is characterized in that the curved surface sides of a pair of cylinders are arranged to face each other and the X-ray width is limited between them.
In the variable line width slit, the width of the slit is changed by rotating the entire slit in conjunction with the incident angle of the X-ray to the sample, so that the incident X-ray irradiation area becomes constant on the sample surface, or It becomes possible to detect X-rays as if they were emitted from a fixed sample area.

Further, in the slit in which the width of the incident X-rays or the emitted X-rays can be varied, a pair of slit blades are arranged facing each other, and in the slits for limiting the X-ray width between them, the incident angle of the X-rays to the sample is set. In conjunction with this, the slit width is changed by moving one or both of the slit blades so that the incident X-ray irradiation area is constant on the sample surface or the X-ray is emitted from a constant sample area. Can be detected.

Further, the intensity change of the incident X-ray or the emitted X-ray due to the change of the slit width of the slit whose width of the incident X-ray or the emitted X-ray can be varied depends on the incident angle dependence of the incident X-ray or the emitted X-ray. It is possible to measure the exit angle dependence of the line intensity in advance and correct the intensity with the measurement result.

Further, when measuring the X-ray reflectance, since the slit width in the total reflection angle region is small, the X-ray intensity detected in the total reflection angle region is small, and the apparent dynamic range of the X-ray detector is small. Can be widened.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual block diagram of an embodiment of the present invention. The X-rays generated by the X-ray source 1 are incident X-rays 3 whose width and height are limited by the incident X-ray width limiting slit 2. This incident X
The line 3 is made incident on the sample 5 at an incident angle ω. On the sample surface, the width T of the incident X-ray is T = t / sin, where t is the width of the incident X-ray.
(ω). The outgoing X-ray 6 reflected or diffracted in the outgoing region 4 irradiated with the incoming X-ray is limited in angular spread by the outgoing X-ray width limiting slit 7 and measured by the X-ray detector 8. Further, the fluorescent X-rays 11 generated in the emission region 4 are also limited in angular spread by the emission X-ray width limiting slit 9 and are energy dispersive X-rays.
The line detector 10 measures intensity and energy. At this time, when t = 50 μm and ω = 0.2 °, T spreads to about 15 mm, and when ω = 2.0 °, T decreases to T = 0.6 mm. By changing the width of the incident X-ray width limiting slit 2 at the incident angle ω and therefore t = Tsin (ω) so that the change of T is eliminated, the incident angle dependency of the measurement region is eliminated.

Further, this incident X-ray 3 is applied to the sample 5 at an incident angle ω.
When the outgoing X-rays 6 and fluorescent X-rays 11 which are incident on the sample and are reflected or diffracted on the sample surface are measured at the position of the outgoing angle 2θ, the outgoing X-rays 6 and fluorescent X-rays 11 are enhanced by the outgoing X-ray width limiting slit 7. And the width is limited and it enters the detector. The width of the emission X-ray width limiting slit 7 or the fluorescent X-ray width limiting slit is t, and the emission X-ray width limiting slit is
If the extraction angle of the X-ray or the fluorescent X-ray is 2θ, the width of the emitted X-ray 6 and the fluorescent X-ray 11 detected by the X-ray detector 8 or the energy dispersive X-ray detector 10 is T = t / sin (2θ )
Only the X-rays emitted from the sample surface area 4 of At this time, when t = 50 μm and 2θ = 0.2 °, T is about 15 mm, and when 2θ = 2.0 °, T = 0.6 mm.
The width of the slit 7 or the slit 9 is changed at t = Tsin (2θ) according to the emission angle 2θ so that the change of T is eliminated, and the emission angle or the extraction angle dependency of the measurement region can be eliminated. .

If the width of at least one of the entrance limiting slit 2 or the exit limiting slits 7 and 9 changes in association with the incident angle or the outgoing angle to the sample,
Even if the X-ray intensity generated by the X-ray source 1 is the same, the X-ray intensity detected by the X-ray detectors 8 and 10 changes. This intensity change measures the angle dependence of the X-ray intensity in advance, and corrects the measured reflection, diffraction, and fluorescent X-ray intensity according to the angle dependence of the X-ray intensity to obtain diffraction from a fixed sample area, It became possible to measure reflection and fluorescent X-ray intensity with high accuracy.

FIG. 2 is an overall configuration diagram of an embodiment of the present invention. The fluorescent X-ray width limiting slit (width variable slit) and the energy dispersive X-ray detector are not shown. The X-ray generated by the X-ray source is 50 μm wide at the incident X-ray width variable slit 12.
The incident X-ray 3 has a strip shape of m and a height of 5 mm. This incident X
The line 3 is incident on the sample 5. Sample 5 is a goniometer 14
It is located on the ω axis. The 2θ axis coaxial with the ω axis serves as an axis for moving the exit X-ray width variable slit 13 and the X-ray detector 8 arranged on the 2θ arm 15. When measuring fluorescent X-rays, the 2θ arm 15 is extended to the vicinity of the sample, and a fluorescent X-ray width limiting slit (width variable slit) and an energy dispersive X-ray which are not shown are provided at a position near the sample.
Place the line detector. Each axis of the goniometer 14 is driven by a pulse motor, and its control is controlled by a computer 20 via a driver and a controller unit 17. Also, the incident X-ray width variable slit 12, the exit X
The variable line width slit 13 and the fluorescent X-ray width variable slit are also driven by the pulse motor, and are controlled by the computer 20 via the driver and the controller unit 16. Also X
X measured by X-ray detector 8 and energy dispersive X-ray detector
The line intensity is taken into the computer 20 via the scaler and the channel analyzer 18, and the result is shown in the image display unit 19.

An X-ray reflectance measurement will be shown as one of the examples. Incident X-ray 3 is incident on the sample (ω <
The emitted X-ray 6 from the sample 5 is measured by the X-ray detector 8. In the measurement, the incident angle ω was increased from 0.1 ° to 1.2 °, the output angle 2θ of the X-ray detector 8 was twice the incident angle ω,
The intensity of the reflected X-ray is measured while moving from 0.2 ° to 2.2 °. The width of the incident X-ray width limiting slit 2 is 50μ.
When m and the incident angle ω = 0.2 °, the width of the incident surface X on the sample surface irradiation region 4 is about 15 mm. When the incident angle ω = 1.0 °, the width of the sample surface irradiation area 4 decreases to about 1.2 mm. Slit width required to keep the width of the incident X-ray irradiation area 4 on the sample surface constant at about 15 mm {15 x sin (ω) [m
[m]} is calculated by the computer 20 and the width of the incident X-ray width variable slit 12 is controlled according to the incident angle ω, whereby the width of the sample surface irradiation region 4 can be made constant. At this time, the incident X-ray intensity changes as the width of the incident X-ray width limiting slit 12 changes. Therefore, the relationship between ω and the incident X-ray intensity is measured in advance, and the measured X
The X-ray intensity obtained from the relationship between the line intensities I _r (ω) and ω and the incident X-ray intensity is I ₀ (ω), and the reflectance R = I _r (ω) / I ₀ (ω)
The reflectance is obtained by normalizing as. In this method, since the incident X-ray intensity is reduced in the total reflection area on the side where the incident angle is low, the X-ray detector 8 is not saturated because the X-ray intensity is strong in the total reflection area, and the X-ray detection is performed. The same effect that the dynamic range of the container 8 is widened is obtained.

Next, the case where the exit X-ray width limiting slit is used will be described. In the same manner as described above, the incident X-ray 3 is made to enter the sample smoothly (ω <0.2 °), and the emitted X-ray 6 from the sample 5 is measured by the X-ray detector 8. In the measurement, the incident angle ω was increased from 0.1 ° to 1.2 °, and the emission angle 2θ of the X-ray detector 8 was twice as much as the incident angle ω, and was emitted while moving from 0.2 ° to 2.2 °. The intensity of X-ray 6 is measured. When the width of the incident X-ray width limiting slit 2 is 50 μm and the incident angle ω = 0.2 °, the width of the incident surface X on the sample surface irradiation region 4 is about 15 mm. When the incident angle ω = 1.0 °, the width of the sample surface irradiation area 4 is reduced to about 1.2 mm. The width of the X-ray emission area 4 on the sample surface counted by the X-ray detector 8 is also reduced from about 15 mm to about 1.2 mm. The slit width required to keep the width of the emission area 4 in which the detected X-rays are emitted from a constant sample area constant at about 1.2 mm {1.2 x sin (2θ) [m
m]} is calculated by the computer 20 and the slit drive unit 1
By controlling the width of 3 according to the incident angle ω, the width of the sample surface emission area 4 can be made constant. At this time, the incident X-ray intensity changes as the width of the incident X-ray width limiting slit changes. Therefore, the relationship between ω and the incident X-ray intensity is measured in advance, and the measured X-ray intensity I
_The X-ray intensity obtained from the relationship between _r (ω), ω and the incident X-ray intensity is I ₀ (ω), and the reflectance is normalized by the reflectance R = I _r (ω) / I ₀ (ω). The rate can be calculated.

FIG. 3 shows an embodiment of an X-ray width variable slit. Two cylindrical slit blades 21 with a diameter of about 1 cm
Are placed in parallel with an interval of 500 μm. These cylinders are placed on the slit rotation shaft 22 and are rotated by driving the slit rotation shaft 22 by a slit driving unit 23 configured by a pulse motor 23. When the radius of the cylinder is r, the blade width is w, and the rotation angle of the slit is α, the width t of the incident X-ray can be expressed by equation (4).

T = {w + 2r-2r / cos (α)} (4) According to this formula, the rotation angle α is adjusted so that the slit width becomes t = Tsin (ω) or t = Tsin (2θ). This makes it possible to control the width of the X-ray, which can be
By using as the variable line width slit 12 or the outgoing X-ray width variable slit 13, the X-rays are emitted so that the incident area 4 of the incident X-rays is constant on the sample surface or emitted from the constant outgoing area 4. It can be detected.

FIG. 4 is a block diagram of another embodiment of the variable X-ray width slit. Two 1 mm thick slit blades 24
Are placed in parallel with an interval of 500 μm. The slit width of these slit blades can be changed by a driving unit 25 including a micrometer and a pulse motor. The same effect can be obtained with a structure in which one blade is fixed and the other blade is moved to change the slit width, or a structure in which both blades are mirror-image moved to change the slit width. The slit width is controlled so that the slit width is t = Tsin (ω), t = Tsin (2θ) where T is the width of the X-ray on the sample surface, ω is the incident angle, and 2θ is the emission angle. As a result, X-rays can be detected such that the incident X-ray irradiation area 4 is constant on the sample surface or is emitted from the constant emission area 4.

[0031]

According to the present invention, when measuring the diffracted X-rays, reflected X-rays, or fluorescent X-rays of the X-rays incident on the sample in conjunction with the incident angle or the outgoing angle, the incident or outgoing limiting slits. The width of at least one of the slits changes in association with the incident angle or the outgoing angle to the sample, so that the incident X-ray irradiation area becomes constant on the sample surface. Alternatively, X-rays can be detected as if they were emitted from a fixed sample area. Further, a change in the detected X-ray intensity due to a change in the width of at least one of the entrance or exit limiting slits in association with the incident angle or the exit angle to the sample depends on the angular dependence of the X-ray intensity in advance. Is measured and corrected, it becomes possible to measure diffraction, reflection, and fluorescent X-ray intensity from a fixed sample area with high accuracy.

Further, when measuring the X-ray reflectance, since the slit width in the total reflection angle region is small, the X-ray intensity detected in the total reflection angle region is small, and the apparent dynamic range of the X-ray detector is small. Is widened, and highly accurate X-ray reflectance measurement is possible.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of the present invention.

FIG. 2 is an overall configuration diagram of an embodiment of the present invention.

FIG. 3 is an example of an X-ray width variable slit.

FIG. 4 is another example of the variable X-ray width slit.

[Explanation of symbols]

1 ... X-ray source, 2 ... Incident X-ray width limiting slit, 3 ... Incident X
Lines, 4 ... Incident X-ray irradiation region and X-ray emission region, 5 ... Sample, 6 ... Emission X-ray, 7 ... Emission X-ray width limiting slit, 8 ...
X-ray detector, 9 ... Fluorescent X-ray width limiting slit, 10 ... Energy dispersive X-ray detector, 11 ... Fluorescent X-ray, 12 ... Incident X-ray width variable slit, 13 ... Outgoing X-ray width variable slit,
14 ... Goniometer, 15 ... Counter arm, 16
... Pulse motor driver and controller for X-ray width variable slit, 17 ... Pulse motor driver and controller for goniometer, 18 ... Scaler and channel analyzer, 19 ... Image output device, 20 ... Computer,
21 ... Cylindrical slit blade, 22 ... Slit rotating shaft, 23 ... Slit drive unit, 24 ... Slit blade,
25 ... Micrometer and drive unit.

Claims (8)

[Claims] 1. An X-ray analyzer comprising an X-ray source, an incident X-ray limiting slit, a sample stage, an outgoing X-ray limiting slit and an X-ray detector, wherein the X-ray diffracted and reflected by the X-ray incident on the sample. X
When measuring X-rays or fluorescent X-rays in conjunction with the incident angle or the emission angle, the X-rays are emitted in order to make the irradiation area of the incident X-rays constant on the sample surface or as if they were emitted from a fixed sample area. In order to detect, the width of at least one of the entrance or exit limiting slits has a slit capable of varying the width of the incident X-ray or the exit X-ray that changes in association with the incident angle or the exit angle of the sample. Characteristic X-ray analysis device. 2. The slit according to claim 1, wherein the slits capable of varying the width of the X-ray are arranged such that curved surface sides of a pair of cylinders face each other,
A slit capable of varying the width of X-rays, which is characterized by limiting the width of X-rays. 3. The slit according to claim 2, wherein the slit capable of varying the width of the X-ray changes the width of the X-ray by rotating the entire slit in association with the incident angle of the X-ray to the sample.
A slit capable of varying the width of X-rays, characterized in that the irradiation area of the rays is constant on the sample surface. 4. The slit according to claim 2, wherein the slit capable of varying the width of the X-ray is interlocked with an emission angle of the X-ray from the sample,
A slit capable of varying the width of the X-ray, wherein the width of the X-ray is changed so that the X-ray emitted from a constant sample surface enters the detector by rotating the entire slit. 5. The X-ray according to claim 1, wherein the slit capable of varying the width of the incident X-ray has a pair of slit blades arranged to face each other, and the X-ray width is limited between them.
A slit with variable line width. 6. The slit according to claim 5, wherein the slit capable of varying the width of the X-ray changes the width of the X-ray by moving one or both of the slit blades in association with the incident angle of the X-ray to the sample. A slit capable of varying the width of X-rays, characterized in that the irradiation area of X-rays is changed to be constant on the sample surface. 7. The slit according to claim 5, wherein the slit capable of varying the width of the X-ray is interlocked with an emission angle of the X-ray from the sample,
A slit capable of varying the width of the X-ray, wherein one or both of the slit blades is moved to change the slit width so that the X-ray emitted from a fixed sample surface enters the detector. 8. The X-ray analysis apparatus according to claim 1, wherein the incident X-ray is caused by a change in slit width of the variable X-ray width slit.
The change in the intensity of the X-ray or the emitted X-ray is characterized in that the incident angle dependency of the incident X-ray intensity or the emitted angle dependency of the emitted X-ray intensity is measured in advance and the intensity is standardized by the measurement result. X-ray analyzer.