JP2664632B2 - Total reflection X-ray fluorescence analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for irradiating a sample surface with primary X-rays at a very small incident angle to obtain a fluorescent X-ray from a surface layer of the sample.
The present invention relates to a total reflection X-ray fluorescence analyzer for analyzing rays.

[0002]

2. Description of the Related Art Generally, a total reflection X-ray fluorescence spectrometer is known as a device for detecting impurities contained in a surface layer of a sample. FIG. 8 shows an example of a conventional total reflection X-ray fluorescence spectrometer (for example, JP-A-63-78056).

In FIG. 1, a target material 51 of an X-ray source 5 is shown.
X-rays B1 emitted from the light source are curved-type spectroscopic elements (spectral crystals) 1
Head to A. Among the X-rays B1, characteristic X-rays having a predetermined wavelength are diffracted by the spectral element 1A to be monochromatic, and the diffracted X-rays are obtained.
The line (primary X-ray) B2 is a sample 2 such as a silicon wafer.
Incident angle α (eg, 0.05 ° to 0.20 °) on the surface 2a of
Degree).

A part of the diffracted X-ray B2 incident on the sample 2 is totally reflected and becomes a reflected light beam B4, and the other part excites the sample 2 as a primary X-ray and is unique to the element constituting the sample 2. Of the fluorescent X-ray B5 is generated. The fluorescent X-ray B5 is incident on the X-ray detector 3 arranged opposite to the sample surface 2a.
The incident fluorescent X-ray B5 is detected by the X-ray detector 3.
After the X-ray intensity is detected, the target X-ray spectrum is obtained by the multiplex height analyzer 4 based on the detection signal a from the X-ray detector 3.

In this type of total reflection X-ray fluorescence spectrometer, the angle of incidence α of the diffracted X-rays (primary X-rays) B2 on the sample 2 is small, and the reflected light B4 and the scattered X-rays Difficult to enter. For this reason, noise is smaller than the output level of the fluorescent X-ray B5 detected by the X-ray detector 3, that is, a large S / N ratio is obtained, so that the analysis sensitivity is good and, for example, a small amount of impurities is contained. It can be detected even if it is.

Incidentally, the spectroscopic element 1A generates diffraction only when the characteristic X-ray enters at a fixed angle (θ) determined by the wavelength (λ) of the characteristic X-ray and the lattice spacing (2d) of the element (known). Brad's equation: 2d · sin θ = nλ). On the other hand, an element is only excited by characteristic X-rays having a wavelength shorter than its absorption edge wavelength.

Accordingly, when measuring various elements having significantly different absorption edge wavelengths for the same sample 2, it is necessary to use characteristic X-rays having different wavelengths. The element needs to be replaced. For example, when Au is used for the X-ray source 5, the characteristic X-ray L
2d = 94.2 ° for α, 2d = 80 for Lβ
Å and Lγ are diffracted by a spectroscopic element having a lattice spacing of 2d = 68.4 °.

[0008]

However, the conventional apparatus has the following problems. As described above, the spectroscopic element must be replaced when many elements are measured for the same sample 2. At this time, the angle of incidence on the sample 2 is small and the allowable range is narrow due to the necessity of total reflection. For,
Each time the spectroscopic element is replaced, its position or angle, or the sample stage 7
It is difficult to adjust the position and angle of the sample so as to be within the allowable range, and it takes time to analyze the sample.

An object of the present invention is to solve the above problems and to provide a total reflection X-ray fluorescence spectrometer capable of easily and quickly analyzing many elements in the same sample.

[0010]

In order to achieve the above object, a total reflection X-ray fluorescence analyzer according to claim 1 of the present invention comprises:
The lattice spacings are different from each other.
Position on the plane containing the path of the primary X-rays leading to the
A plurality of spectroscopic elements fixed to the X-ray source and the sample, and by moving these spectroscopic elements in a direction orthogonal to the plane, the primary X-rays are separated by a desired spectroscopic element.
And a moving means for obtaining a constant angle of incidence on the sample for all the spectroscopic elements .

According to a second aspect of the present invention, there is provided a total reflection X-ray fluorescence spectrometer , wherein the spectroscope has a lattice spacing fixed on the circumference of the rotating body.
Rotating the rotating body with a plurality of spectral elements different from each other
By causing any one of the spectroscopic elements to emit the primary X-ray.
Primary X-rays with the desired spectral element
Moving means for obtaining a constant angle of incidence on the sample for all the spectroscopic elements, wherein the axis of the rotating body is an X-ray source
Plane containing the path of primary X-rays from the instrument to the sample through the spectrometer
Position above is fixed relative to the x-ray source and the sample
ing.

[0012] The total reflection X-ray fluorescence spectrometer according to the third aspect is characterized in that:
When the optical device continuously changes the period of the lattice spacing along the spectral surface,
And a single spectroscopic element set to
The primary X-ray path from the X-ray source through the spectrometer to the sample
Desired primary X-rays by translating on the plane containing
Moving means for obtaining a constant incident angle with respect to

[0013]

According to the total reflection X-ray fluorescence analyzer of the first aspect,
A plurality of spectroscopic elements having different lattice spacings are connected to a primary X-ray path.
Position on the plane containing the X-ray source and the sample
In a fixed state, the plane is perpendicular to the plane by the moving means .
By moving the that direction, desired spectral primary X-rays
Since the light is split by the element, it is possible to target the primary X-ray to the sample.
It is possible to obtain a constant angle of incidence.

Further, according to the total reflection X-ray fluorescence spectrometer of the present invention, a plurality of components having different lattice spacings on the circumference are different.
The rotating body to which the optical element is fixed is rotated by the moving means,
Position one of the spectral elements on the path of the primary X-ray
By doing so, the primary X-rays are dispersed by a desired spectral element.
At the same time, the axis of the rotating body moves along the path of the primary X-ray.
Position on the plane including the X-ray source and the sample
Because it is fixed , the sample
A constant angle of incidence can be obtained.

According to the total reflection X-ray fluorescence analyzer of claim 3,
If the period of the lattice spacing varies continuously along the spectral plane
To the primary X-ray path
By moving it in parallel on the plane
Primary X-rays are separated by a desired spectroscopic element.
Constant angle of incidence of primary X-rays on the sample
You.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of a total reflection X-ray fluorescence spectrometer according to an embodiment of the present invention. This device, the grating surface
A plurality of (three in this example, 1A, 1B, and 1C) artificial multilayer gratings, which are dispersive elements having different intervals, are provided, and a moving unit 10 that moves these artificial multilayer gratings 1A to 1C in a direction perpendicular to the paper surface. And a control unit 14 for controlling the moving means 10. Artificial multilayer gratings 1A-1C and
The spectroscope 8 is constituted by the moving means 10. The above artificial multilayer film
The gratings 1A to 1C are connected to the sample 2 from the X-ray source 5 via the spectroscope 8.
On the plane H (FIG. 2) including the path of the primary X-ray B2 leading to
The position of the sample 2 is fixed with respect to the X-ray source 5 and the sample 2 . The other configuration is the same as that of the conventional example shown in FIG. 7, and the same or corresponding portions are denoted by the same reference characters and detailed description thereof will not be repeated.

FIG. 2 is a schematic front view of the moving means 10, and FIG.
Figure 2 shows a schematic side view. In FIG. 2, the moving means 10
Has a fixed frame 12 and a moving part 20 ,
The artificial multilayer gratings 1A to 1C are moved in a direction orthogonal to the plane H.
Move. The moving unit 20 includes four lattice support parts 22 protruding downward, and the artificial multilayer film lattices 1 </ b> A to 1 </ b> C are attached between adjacent lattice support parts 22. In FIG. 3, a mounting groove 30 is formed on the lower surface of the lattice support portion 22, and a pin 31 fixed to the artificial multilayer film lattices 1 </ b> A to 1 </ b> C is fitted into the mounting groove 30, and
It is tightened and fixed at 2. Further, a protruding end 26 a of the drive shaft 26 of the drive motor 24 mounted on the moving portion 20 is provided.
, A pinion 27 is fixed, and this pinion 27 is engaged with a rack 28 provided on the main body 12 side.

Therefore, the moving unit 20 is provided with a driving motor 24
As the pinion 27 rotates, the pinion 27 linearly moves on the rack 28, and the guides 34, 3 fixed to the frame 12 are rotated.
6 along the frame 12 in a direction perpendicular to the paper surface (X in FIG. 2).
1-X2 direction). In addition, artificial multilayer film lattice 1A
Is for characteristic X-ray Lα, 1B is for Lβ, and 1C is for Lγ.

In FIG. 2, a control unit 14 (see FIG. 1)
Controls the driving motor 24 to move the moving unit 20 a predetermined distance along the rack 28, and
1C is stopped at the incident point IN.

As described above, in FIG. 1, since the angle of incidence α of the primary X-ray B2 on the sample 2 is very small and the allowable range is narrow, the angle around the pin 31 of the artificial multilayer gratings 1A to 1C,
That is, it is necessary to finely adjust the angle with respect to the incident X-ray B1. For this reason, in FIG. 3, the moving part 20 is provided with an adjusting screw 40 which is an example of an angle adjusting means.

The adjusting screw 40 is connected to the projection 21 of the moving unit 20.
, And the tip 40a of the artificial multilayered lattice 1A-1
Mounting bracket 42 provided at one end (left end) of C
Is in contact with One end of a leaf spring 44, which is an example of an elastic member, is fixed to the concave portion 23 between the lattice support portions 22, 22, and the other end is the other end (right end) of the artificial multilayer lattices 1A to 1C. Is in contact with Therefore, the artificial multilayer lattices 1A to 1C are inclined in the Z2 direction when the adjusting screw 40 is tightened, and inclined in the Z1 direction when the adjusting screw 40 is loosened, and the angles thereof are adjusted.

For example, in FIG.
The artificial multilayer grating 1A is moved in the -X2 direction to the incident point IN.
Is stopped, the characteristic X-ray Lα out of the Au X-ray B1 from 51 is diffracted by the artificial multilayer lattice 1A,
It becomes the primary X-ray B2. At this time, as shown in FIG. 4A, the incident angle and the diffraction angle of the X-ray B1 on the artificial multilayer grating 1A are θ1. At this diffraction angle θ1, the primary X-ray B2
Has an incident angle α on the sample 2 and is totally reflected on the surface 2 a of the sample 2.

When the artificial multilayer grating 1B is moved to the incident point IN, the characteristic X-ray Lβ is diffracted, and as shown in FIG. 4B, the angle of incidence of the X-ray B1 on the artificial multilayer grating 1B. ,
The diffraction angle is θ2. At this time, similarly, the incident angle of the primary X-ray B2 on the sample 2 is α. Further, as shown in FIG. 4C, when the artificial multilayer lattice 1C is moved, the characteristic X
The line Lγ is diffracted, and the incident angle and the diffraction angle on the artificial multilayer grating 1C are θ3. Also at this time, the sample 2 of the primary X-ray B2
Is similarly α, and is totally reflected by the surface 2 a of the sample 2.

In each of FIGS. 4A to 4C, the incident point IN of the X-ray B1 on the artificial multilayer gratings 1A to 1C is shifted in the front-back direction (the left-right direction in the drawing).

As described above, the present apparatus moves the artificial multilayered gratings 1A to 1C by the moving means 10, and
A plurality of elements can be measured for the same sample without moving the radiation source 5 and the sample stage 7.

FIG. 5 shows a second embodiment. This spectroscope 4
Reference numeral 8 denotes a plurality of artificial multilayer film gratings (spectral elements) 1A similar to those shown in FIGS. 1 to 4 fixed on the circumference of the rotating body 52 .
~ 1 C, by rotating the rotating body 52
One of the artificial multilayer gratings 1A to 1C is converted to a primary X-ray B2.
The primary X-ray B2 is located on the path and
Spectroscopy with all the artificial multilayer gratings 1A
A moving hand that obtains a constant angle of incidence α on sample 2 for ~ 1C
And a step 50. At the same time, the rotating body 52
The axis 54a of the rotating shaft 54 is connected to the spectroscope 48 from the X-ray source 5.
On the plane H including the path of the primary X-ray B2 reaching the sample 2 via
Is fixed with respect to the X-ray source 5 and the sample 2.
Have been. The rotating shaft 54 of the rotating body 52 is rotated by a predetermined angle by a driving motor (not shown), the artificial multilayer grating (1C in this figure) is moved to the diffraction position O, and each characteristic X-ray is diffracted. .

FIG. 6 shows a third embodiment. FIG.
In (A), the spectroscope 58 has a period of the lattice spacing.
Single set to be continuously different along the spectral plane
The irregularly-spaced element (spectral element) 62 and the irregularly-spaced element 62 are attached between the lattice support portions 64 to separate the light from the X-ray source 5.
Including the path of the primary X-ray B2 to the sample 2 via the detector 48
Desired by parallel movement on plane H (FIG. 2B)
Means for obtaining a constant incident angle α with respect to the primary X-ray B2
60.

The unequally-spaced element 62 is a moving means of FIG.
10, the drive motor 24 causes the front-rear direction (Y1
−Y2 direction). In FIG. 6B, a shaft hole 66 is formed in the lattice support portion 65, and a pin 67 fixed to the unequally spaced element 62 is rotatably fitted into the shaft hole 66. A driven gear 76 is attached to one of the pins 67. The rotation of the angle adjustment motor 68 is controlled by the control unit 70, and the drive gear 72 fixed to the rotation shaft of the angle adjustment motor 68 is connected to the intermediate gear 7 supported by the moving unit 63.
By rotating the driven gear 76 through 4,
The unequally spaced elements 62 are angle adjusted in the R1-R2 directions,
Each characteristic X-ray Lα, Lβ, Lγ is diffracted.

In this embodiment, the target material 51
Is used, but another target material 51 such as platinum (Pt) may be used.

As a result of the analysis using the characteristic X-rays as described above, it becomes possible to analyze the elements as shown in FIG.

In the first and second embodiments, three artificial multilayer lattices are used. However, the present invention is not limited to this, and two or more artificial lattices may be used.

In this embodiment, the characteristic X-rays Lα and Lα
Although β and Lγ are used, the present invention is not limited thereto, and for example, Kα, Kβ, Kγ, etc. can be used.

[0033]

As described above, according to the first aspect of the present invention, a plurality of spectroscopic elements having different lattice spacings can be used for the primary X-rays.
The position on the plane containing the path is relative to the X-ray source and the sample.
While being fixed with said plane and straight by moving means
The primary X-rays are moved to the desired
Since the dispersed by the spectroscopic element, trial for the desired primary X-rays
A constant angle of incidence on the material can be obtained. This allows
A total reflection X-ray fluorescence spectrometer capable of easily and quickly analyzing many elements in the same sample can be provided.

According to the second aspect of the present invention ,
Fixing multiple spectroscopy elements with different lattice spacings
The rotating body is rotated by the moving means, and any one of
By placing the element on the path of the primary X-ray, the primary
X-rays are dispersed by a desired spectral element, and
The axis of the body is on a plane including the path of the primary X-ray.
The position is fixed relative to the X-ray source and the sample
Thus, it is possible to obtain a constant incident angle on the sample with respect to a desired primary X-ray.

According to the third aspect of the present invention, the circumference of the lattice spacing is
The periods are set so that they differ continuously along the spectral plane.
One spectroscopic element is connected to the sample from the X-ray source through the spectrometer.
Translate by the moving means on the plane including the path of the next X-ray
This allows the primary X-rays to be separated by the desired spectral element.
Since the morphism constant input to the sample relative to the desired primary X-rays
You can get the corner.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a total reflection X-ray fluorescence spectrometer according to one embodiment of the present invention.

Figure 2 is a schematic positive elevation view showing a moving means of total reflection X-ray fluorescence spectrometer described above.

FIG. 3 is a schematic side view showing the moving means.

FIG. 4 is a side view showing a state of diffraction of the artificial multilayer grating.

FIG. 5 is a side view showing a moving unit according to another embodiment.

FIG. 6 is a side view showing a moving unit according to another embodiment.

FIG. 7 is a diagram showing elements that can be analyzed.

FIG. 8 is a schematic side view of a conventional total reflection X-ray fluorescence spectrometer.

[Explanation of symbols]

1A, 1B, 1C ... Spectroscopy element (artificial multilayer grating), 2 ...
Sample, 3 ... X-ray detector, 4 ... Multiple height analyzer, 5 ... X
Source: 7, Sample table, 8 , 48 , 58 Spectroscope, 10 , 5
0,60 : moving means, 14: control unit, B1: characteristic X-ray,
B2: primary X-ray, B5: fluorescent X-ray.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-7991 (JP, A) JP-A-3-209156 (JP, A) JP-A-63-167250 (JP, A) 111799 (JP, A) JP-A-63-61200 (JP, A) JP-A-2-33399 (JP, U) JP-A-47-25594 (JP, Y2)

Claims (3)

(57) [Claims] 1. An X-ray source for generating X-rays, a spectroscope for diffracting the X-rays to make monochromatic primary X-rays incident on a sample surface at a small, constant incident angle, and the sample surface An X-ray detector that detects fluorescent X-rays from a sample that has received the primary X-rays, and that analyzes the fluorescent X-rays based on the detection result of the X-ray detector. In the X-ray spectrometer, the spectroscopes have different lattice spacings, and are separated from an X-ray source.
On the plane containing the path of primary X-rays to the sample via the spectrometer
A plurality of spectral elements fixed with respect to the X-ray source and the sample, and these spectral elements are orthogonal to the plane.
Primary X-ray by moving it in the desired direction
Spectroscopy with all spectroscopic elements
A total reflection X-ray fluorescence spectrometer, comprising: moving means for obtaining a constant angle of incidence. 2. An X-ray source for generating X-rays, and the X-ray source
The primary X-ray that has been folded and converted to monochromatic
A spectroscope for incidence at a constant angle of incidence and the sample surface
Detects fluorescent X-rays from the sample facing and receiving the primary X-rays
And an X-ray detector for detecting the detection result of the X-ray detector.
Total reflection X-ray fluorescence analysis for analyzing the above-mentioned X-ray fluorescence based on
In the apparatus, the spectroscope has a lattice spacing fixed on the circumference of the rotating body.
Rotating the rotating body with a plurality of spectral elements different from each other
By causing any one of the spectroscopic elements to emit the primary X-ray.
Primary X-rays with the desired spectral element
It is allowed, and a moving means for obtaining said constant angle of incidence to all the spectral element samples, the axis of the rotating body reaches the sample through a spectroscope from the X-ray source
The position on the plane containing the path of the primary X-ray
And a total reflection X-ray fluorescence analyzer fixed to the sample . 3. An X-ray source for generating X-rays, and the X-ray source
The primary X-ray that has been folded and converted to monochromatic
A spectroscope for incidence at a constant angle of incidence and the sample surface
Detects fluorescent X-rays from the sample facing and receiving the primary X-rays
And an X-ray detector for detecting the detection result of the X-ray detector.
Total reflection X-ray fluorescence analysis for analyzing the above-mentioned X-ray fluorescence based on
In the apparatus, in the spectroscope, the period of the lattice plane interval is continuously along the spectral plane.
And a single spectroscopic element set differently
The optical element is used to convert the primary X-rays from the X-ray source through the spectrometer to the sample.
By moving in parallel on the plane containing the path,
Moving means for obtaining the above-mentioned constant incident angle with respect to the next X-ray.
A total reflection X-ray fluorescence analyzer.