JPH07209216A - Total reflection fluorescent x-ray analyzer - Google Patents

Abstract

PURPOSE:To analyze a large number of elements in one sample easily and quickly by a structure wherein a plurality of polarization elements having different lattice plane interval are shifted through a shifting means. CONSTITUTION:A control section controls a drive motor 24 to shift a shifting part 20 by a predetermined distance along a rack 28 and stop any one of polarization elements 1A-1C at an incident point IN. Since the incident angle alpha of first-order X-rays B2 to a sample is very small and the allowance is limited severely, the angles of the elements 1A-1C around a pin 31, i.e., the angles with respect to incident X-rays B1, are adjusted finely by means of an adjusting screw. When the moving part 20 is moved and the element 1A is stopped at the incident point IN, only the characteristic X-rays among the incident X-rays B1 from a target material are diffracted by the element 1A to produce first- order X-rays B2 which impinge on a sample 2 at an incident angle a and reflected totally thereon. Consequently, a plurality of elements can be measured for one sample without shifting an X-ray source or a sample stage by simply shifting the elements 1A-1C through the shifting means 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a surface of a sample with a primary X-ray at a minute incident angle to cause fluorescence X 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 analyzer is known as an apparatus for detecting impurities contained in a surface layer of a sample. FIG. 8 shows an example of a conventional total reflection X-ray fluorescence analyzer (for example, JP-A-63-78056).

In the figure, the target material 51 of the X-ray source 5 is shown.
An X-ray B1 emitted from the curved spectroscopic element (dispersive crystal) 1
Head to A. Characteristic X-rays of a predetermined wavelength among the X-rays B1 are diffracted by the spectroscopic element 1A to be monochromatic, and the diffraction X
Line (primary X-ray) B2 is sample 2 such as a silicon wafer
Incident angle α (for example, 0.05 ° to 0.20 ° on the surface 2a of the
Is irradiated.

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

In this type of total reflection X-ray fluorescence analyzer, the incident angle α of the diffracted X-rays (primary X-rays) B2 to the sample 2 is small, and the reflected light beam B4 and the scattered X-rays are the X-ray detector 3. Hard to enter. Therefore, the 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, and therefore the analysis sensitivity is good and, for example, a small amount of impurities are contained. Even if it is detected, it can be detected.

By the way, the spectroscopic element 1A produces diffraction only when a characteristic X-ray is incident at a constant angle (θ) determined by the wavelength (λ) of the characteristic X-ray and the lattice spacing (2d) of the element (well known). Bragg's equation: 2d · sin θ = nλ). On the other hand, the element is excited only by characteristic X-rays having a wavelength shorter than its absorption edge wavelength.

Therefore, when measuring various elements having greatly different absorption edge wavelengths for the same sample 2, it is necessary to use characteristic X-rays of 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 = 94.2Å for α and 2d = 80 for Lβ
Å and Lγ are diffracted by a spectroscopic element having a lattice plane spacing of 2d = 68.4Å.

[0008]

However, the conventional device has the following problems. As described above, when many elements are measured for the same sample 2, the spectroscopic element must be replaced, but at this time, the incident angle to 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 and angle, or the sample table 7
It is difficult to adjust the position and angle of the so as to be within the above 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 analyzer 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 spectroscope includes a plurality of spectroscopic elements having different lattice plane intervals, and a moving unit that moves the spectroscopic elements to obtain the predetermined incident angle with respect to a desired primary X-ray.

Further, in the total reflection X-ray fluorescence analyzer according to a second aspect, the spectroscope moves the spectroscopic element and the spectroscopic element in which the intervals of the lattice plane intervals are set different along the spectral plane. Therefore, a moving means for obtaining the above-mentioned predetermined incident angle with respect to a desired primary X-ray is provided.

[0012]

According to the total reflection X-ray fluorescence analyzer of claim 1,
A predetermined incident angle with respect to a desired primary X-ray can be obtained without moving the positions of the X-ray source and the sample stage by simply moving the plurality of spectroscopic elements having different lattice plane intervals by the moving means.

Further, according to the total reflection X-ray fluorescence analyzer of the second aspect, the X-axis can be moved only by moving the spectroscopic element in which the period of the lattice plane interval is set to be different along the spectral plane by the moving means. It is possible to obtain a predetermined incident angle with respect to a desired primary X-ray without moving the positions of the radiation source and the sample stage.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic side view of a total reflection X-ray fluorescence analyzer according to an embodiment of the present invention. This device has a plurality of artificial multilayer gratings (1A, 1
B, 1C), and a moving means 1 for moving these artificial multilayer film lattices 1A to 1C in a direction perpendicular to the plane of the drawing.
0 and a control unit 14 that controls the moving means 10. The position and mounting angle of the sample 2 and the X-ray source 5 are fixed. The other configurations are the same as those of the conventional example of FIG. 7, and the same portions or corresponding portions are denoted by the same reference numerals,
The detailed description is omitted.

FIG. 2 is a schematic front view of the moving means 10, and FIG.
The schematic side view is shown in FIG. In FIG. 2, the moving means 10
Has a fixed frame 12 and a moving part 20.
The moving part 20 is provided with four lattice support parts 22 protruding downward, and the artificial multilayer film lattices 1A to 1C are attached between the adjacent lattice support parts 22. In FIG. 3, an attachment groove 30 is formed on the lower surface of the lattice support portion 22, and the pin 31 fixed to the artificial multilayer film lattices 1A to 1C is attached to the attachment groove 30.
And is fixed by being tightened with bolts 32 via a contact plate 33. Further, a pinion 27 is fixed to a projecting end 26a of a drive shaft 26 of a drive motor 24 mounted on the moving unit 20, and the pinion 27 engages with a rack 28 provided on the main body 12 side.

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

In FIG. 2, the control unit 14 (see FIG. 1)
Controls the drive motor 24 to move the moving unit 20 along the rack 28 by a predetermined distance, and the artificial multilayer film lattices 1A to
Any one of 1C is stopped at the incident point IN.

As described above, in FIG. 1, since the incident angle α of the primary X-ray B2 to the sample 2 is minute and the permissible range is narrow, the angle around the pin 31 of the artificial multilayer lattices 1A to 1C,
That is, it is necessary to finely adjust the angle with respect to the incident X-ray B1. Therefore, in FIG. 3, the moving unit 20 is provided with an adjusting screw 40 which is an example of an angle adjusting unit.

The adjusting screw 40 is a protrusion 21 of the moving part 20.
And the tip 40a thereof is provided on the artificial multilayered film lattices 1A to 1A.
Mounting bracket 42 provided at one end (left end) of C
Is in contact with. In addition, one end of a leaf spring 44, which is an example of an elastic member, is fixed to the recess 23 between the lattice support portions 22, 22, and the other end is the other end (right end) of the artificial multilayer film lattices 1A to 1C. Is in contact with. Therefore, the artificial multilayer film lattices 1A to 1C are tilted in the Z2 direction when the adjustment screw 40 is tightened, and tilted in the Z1 direction when loosened, and the angles thereof are adjusted.

For example, in FIG. 2, the moving unit 20 is X1.
Moved in the -X2 direction and moved to the incident point IN at the artificial multilayer film grating 1A.
When is stopped, the artificial X-ray lattice 1A diffracts the characteristic X-ray Lα of the X-ray B1 of Au from 51,
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 film grating 1A are θ1. At this diffraction angle θ1, the primary X-ray B2
Has an incident angle of α on the sample 2 and is totally reflected on the surface 2 a of the sample 2.

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

In each of FIGS. 4A to 4C, the incident point IN of the X-ray B1 to the artificial multilayer film lattices 1A to 1C is deviated in the front-rear direction (left-right direction in the drawing).

As described above, the present apparatus can move the artificial multilayered film lattices 1A to 1C by the moving means 10 and the X
It is possible to measure a plurality of elements for the same sample without moving the radiation source 5 and the sample table 7.

FIG. 5 shows a second embodiment. This moving means 50 is provided with a rotating body 52 in which a plurality of artificial multilayer film lattices (three in this example, 1A, 1B and 1C) similar to those shown in FIGS. 1 to 4 are arranged on the circumference. There is. The rotating shaft 54 of the rotating body 52 is rotated by a predetermined angle by a drive motor (not shown), and an artificial multilayer film lattice (1C in this figure) is placed at the diffraction position O.
Are moved and each characteristic X-ray is diffracted.

Next, FIG. 6 shows a third embodiment. Figure 6
In (A), the non-equidistant elements 6 in which the lattice plane spacing continuously changes in the front-back direction between the lattice support portions 64 of the moving means 60.
2, the unequal spacing element 62 is moved by the drive motor 24 in the front-back direction (Y
1-Y2 direction). In FIG. 6B, the lattice support portion 65 is formed with the shaft holes 66, and the non-equidistant elements 62 are formed.
A pin 67 fixed to the shaft is rotatably fitted in the shaft hole 66. A driven gear 76 is attached to one of the pins 67. The angle adjusting motor 68 is controlled by the control unit 70.
Is controlled, and the drive gear 72 fixed to the rotation shaft of the angle adjusting motor 68 rotates the driven gear 76 via the intermediate gear 74 supported by the moving portion 63. The characteristic X-rays Lα, Lβ, and Lγ are diffracted by adjusting the angle in the R1-R2 direction.

In this embodiment, the target material 51
Although Au is used for the above, other 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 shown in FIG.

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

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

[0030]

As described above, according to the first aspect of the present invention, the plurality of spectroscopic elements having different lattice plane intervals are moved by the moving means without moving the positions of the X-ray source and the sample stage. Therefore, it is possible to obtain a predetermined incident angle with respect to a desired primary X-ray. As a result, it is possible to provide a total reflection X-ray fluorescence analyzer that easily and quickly analyzes many elements in the same sample.

According to the second aspect of the invention, the spectroscopic elements, which are set such that the periods of the lattice plane intervals are different along the spectral plane, are moved by the moving means to move the X-ray source and the sample stage. It is possible to obtain a predetermined incident angle with respect to a desired primary X-ray without moving the position.

[Brief description of drawings]

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

FIG. 2 is a schematic plan view showing a moving means of the above-mentioned total reflection X-ray fluorescence analyzer.

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

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

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

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

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

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

[Explanation of symbols]

1A, 1B, 1C ... Spectroscopic element (artificial multilayer film grating), 2 ...
Sample, 3 ... X-ray detector, 4 ... Multiple wave height analyzer, 5 ... X
Radiation source, 7 ... Sample stage, 10 ... Moving means, 14 ... Control unit, B
1 ... Characteristic X-ray, B2 ... Primary X-ray, B5 ... Fluorescent X-ray.

Claims (2)

[Claims] 1. An X-ray source for generating X-rays, a spectroscope for injecting primary X-rays diffracted from the X-rays and monochromated toward the sample surface at a minute predetermined incident angle, and the sample surface. An X-ray detector for detecting fluorescent X-rays from the sample that has received the above-mentioned primary X-rays, and total reflection fluorescence X for analyzing the fluorescent X-rays based on the detection result of this X-ray detector. In the line analysis device, the spectroscope includes a plurality of spectroscopic elements having different lattice plane intervals,
A total reflection fluorescent X-ray analysis apparatus comprising: a moving unit that obtains the predetermined incident angle with respect to a desired primary X-ray by moving these spectroscopic elements. 2. The total reflection X-ray fluorescence analyzer according to claim 1, wherein the spectroscope is configured to move the spectroscopic element and the spectroscopic element in which the intervals of the lattice plane intervals are set different along the spectroscopic plane. And a moving means for obtaining the above-mentioned predetermined incident angle with respect to a desired primary X-ray.