JP2003194743A - Fixed goniometer and fluorescent x-ray analyzer equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixed goniometer that has a simple structure and can take out fluorescent X-rays from a minute portion of a sample with a sufficient intensity, and to provide a fluorescent X-ray analyzer equipped with the goniometer. <P>SOLUTION: The diaphragm 8 of the goniometer which transmits fluorescent X-rays generated from the minute portion 2 of the sample 1 is composed of a straight pipe. The surface of the minute portion 2 has the maximum width D<SB>max</SB>of ≤3 mm. The distance L<SB>1</SB>from one end of the straight pipe 8 on the sample 1 side to the surface 2a of the minute portion 2 along the center line of the pipe 8 is adjusted to ≤1/6 of the length L<SB>2</SB>of the pipe 8. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed goniometer for detecting fluorescent X-rays generated from a predetermined element in a sample and a fluorescent X-ray analyzer equipped therewith.

[0002]

2. Description of the Related Art Conventionally, an X-ray fluorescence analyzer equipped with a fixed goniometer for detecting a fluorescent X-ray generated from a predetermined element in a sample has been used to detect a minute portion of a sample ( A small part of the sample surface and its vicinity in the depth direction. In addition, when analyzing the entire sample when the sample itself is very small), the primary X-rays that irradiate the sample are analyzed. Often, only a small area is irradiated with a narrowed beam, but when the diameter of the surface of the small area is about 3 mm or less, the intensity of the primary X-rays to be irradiated is drastically reduced, and the intensity of fluorescent X-rays to be measured is also drastically reduced. Accurate analysis becomes difficult.

Therefore, FIG. 13 of JP-A-8-313459 is used.
As described above, in the focusing optical system, a field limiting slit may be provided in front of the divergence slit, and the fluorescent X-rays may be narrowed down so that only the surface of the minute portion is seen. However, the intensity of the fluorescent X-ray to be measured is still insufficient because it has to pass through a divergence slit hole having a minute diameter for forming a focal point of the optical path and diverging the fluorescent X-ray. Also,
In a parallel method optical system mainly used in a scanning X-ray fluorescence analyzer, it is conceivable to limit the field of view by using a cone-shaped or straight tubular diaphragm as in JP-A-5-126998. As is clear from FIG. 2, the field of view cannot be limited and the structure becomes complicated unless this diaphragm is combined with a solar slit.

The present invention has been made in view of the conventional problems described above. In a fixed goniometer and an X-ray fluorescence analyzer equipped with the fixed goniometer, the X-ray fluorescence from a minute portion of a sample has a sufficient intensity with a simple structure. The purpose is to provide something that can be taken out at.

[0005]

In order to achieve the above object, the first invention of the present application is a fixed goniometer for detecting a fluorescent X-ray generated from a predetermined element in a sample. A diaphragm for passing fluorescent X-rays generated from a minute portion of a sample, a spectroscopic element for spectroscopically analyzing fluorescent X-rays generated by the predetermined element upon incidence of the fluorescent X-rays passing through the diaphragm, and the spectroscopic element. A single detector for detecting the fluorescent X-rays upon which the spectral X-rays are incident is provided. The maximum width of the surface of the minute portion is 3 mm or less, the diaphragm is a straight tube, and the distance from the one end on the sample side of the straight tube to the surface of the minute portion in the central axis is:
It is 1/6 or less of the length of the straight pipe.

According to the first invention of the present application, by such a configuration, it is possible to limit the field of view to a minute portion only by the diaphragm without using a solar slit, and further, the minute portion corresponding to the inner width (inner diameter) of the diaphragm. It can be almost equal to the width of the surface. Therefore, with a simple structure, the maximum width of the surface is 3 m.
Fluorescent X-rays from a minute portion having a size of m or less can be extracted with sufficient intensity.

The second invention of the present application is a fixed goniometer for detecting a fluorescent X-ray generated from a predetermined element in a sample, wherein the fluorescent X-ray generated from a minute portion of the sample.
A diaphragm that allows the light to pass therethrough, the fluorescent X-rays that have passed through the diaphragm are incident, and the spectroscopic element that disperses the fluorescent X-rays generated from the one predetermined element, and the fluorescent X-rays that are spectroscopically dispersed by the spectroscopic element are incident. , And a single detector for detecting the fluorescent X-rays. And the maximum width of the surface of the minute portion is 3 m
m or less, the diaphragm is configured by using two plate-shaped field limiting slits having a single diaphragm hole, and the distance from the sample-side field limiting slit to the surface of the minute portion on the central axis of the diaphragm. However, it is 1/6 or less of the distance between both field limiting slits. The same effects as those of the first invention of the present application can be obtained by the second invention of the present application.

A third invention of the present application is an X-ray fluorescence analyzer equipped with the fixed goniometer of the first or second invention of the present application. According to the third invention of the present application, the same operational effects as those of the first and second inventions of the present application can be obtained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A fluorescent X-ray analyzer according to a first embodiment of the present invention will be described below. First, the configuration of this device will be described with reference to FIG. This device
An X-ray fluorescence analyzer equipped with a fixed goniometer 6 for a sample 1 such as a semiconductor wafer mounted on a sample table 3.
An X-ray source 4 such as an X-ray tube for irradiating the next X-ray 5 is provided.
The fixed goniometer 6 (the housing is shown in cross section) detects fluorescent X-rays emitted from a predetermined element in the sample 1, and first, the fluorescent X-rays emitted from the microscopic portion 2 of the sample 1 are detected.
A diaphragm 8 (shown in cross section) for passing the line 7 and the diaphragm 8
The fluorescent X-rays 9 that have passed through are incident, the spectroscopic element 10 that disperses the fluorescent X-rays 11 generated from the predetermined one element, and the fluorescent X-rays 11 that are spectroscopically dispersed by the spectroscopic element 10 are incident.
A single detector 12 for detecting the fluorescent X-ray 11 is provided.

Then, the X-ray optical path from the surface 2a of the minute portion to the passage of the diaphragm 8 is enlarged and upward (see FIG. 1).
2) as seen in FIG. 2)
The maximum width D _{max of} a (this portion is viewed from directly above in FIG. 1) is 3 mm or less, for example, 1 mm,
The diaphragm 8 is a straight tube, more specifically, a circular tube having an inner diameter d, which is an oblique view of the minute portion surface 2a having an elliptical shape with a major axis D _max and a minor axis D (see FIG. 1). A distance L ₁ from one end of the circular tube 8 on the sample side to the minute portion surface 2a on the central axis C is 1/6 or less, for example, 1/6 of the length L ₂ of the circular tube 8.

The size and shape of the diaphragm 8 are derived as follows. That is, in FIG. 2, the fluorescence X from the minute portion 2 is expected by just looking at the minute portion surface 2a.
If only the line is incident on the detector 12 (FIG. 1), the following equation (1) is established from the geometrical relation.

D = {L ₂ / (2L ₁ + L ₂ )} D ...
(1)

In order to obtain a fluorescent X-ray with a practical intensity even when D _max is 3 mm or less and up to about 0.5 mm, it is empirically preferable that the following expression (2) is established.

D ≧ 0.75D (2)

From the equations (1) and (2), the following equation (3) is obtained.

[0016] _{L 1 ≦ L 2/6 ...} (3)

The reason why the diaphragm 8 is a circular tube is for easy production. In this case, the minute portion surface 2a seen from an oblique direction has a substantially elliptical shape. However, when the sample is rotated, or when the surface of a micro-site that is common to a plurality of diaphragms is to be viewed as described later, it is preferable to more precisely see the same micro-site surface. It is preferable that the aperture is a circular shape, and the diaphragm is an elliptic tube in which the circular shape is viewed obliquely. It should be noted that the fluorescent light X that is going to travel toward the spectroscopic element 10 (FIG. 1) through the outside of the diaphragm 8.
The line is blocked by the housing of the fixed goniometer 6.

According to the fluorescent X-ray analysis apparatus of the first embodiment having the above-described structure, the field of view for the minute portion 2 can be limited only by the diaphragm 8 without using the solar slit, and the diaphragm 8 can be used. The inner diameter d can be 75% of the width D of the corresponding minute portion surface 2a, that is, substantially the same. Therefore, the maximum width D _max of the surface is 1 mm with a simple structure.
It is possible to take out the fluorescent X-ray from the minute portion 2 having such a sufficient intensity.

Next, an X-ray fluorescence analyzer according to the second embodiment of the present invention will be described. As shown in FIG. 3, which is a view of the X-ray optical path from the surface 2a of a minute portion to passing through the diaphragms 8A, 8B, 8C, as shown in FIG.
The apparatus of the first embodiment is that A, 8B, 8C are plural, for example, three, and are arranged radially, and the fluorescent X-rays 9A, 9B, 9C to be passed through each are generated from a common minute portion 2 in the sample 1. However, the description is omitted because the other configurations are the same. In FIG. 3, the radiation states of the diaphragms 8A, 8B, and 8C are exaggerated for easy understanding and illustration, but in reality, the minute portion surface 2a is shown.
Is much smaller and the apertures 8A, 8B,
Since 8C is also much thinner, the diaphragms 8A, 8B and 8C can be arranged in a state of being more parallel.

In the apparatus of the second embodiment, each diaphragm 8
Strictly different, the minute portion surface 2a expected by A, 8B, and 8C can be configured so as to be substantially overlapped, and fluorescent X-rays 9A, 9B, and 9C generated from the substantially common minute portion 2 are used as apertures 8A, 8B, 8C can be passed. In order to make the surfaces of the minute portions more strictly overlap, as described above, it is preferable that the surfaces of the minute portions are circular and the diaphragm is an elliptic tube that allows the circles to be viewed in an oblique direction. Also,
The three fluorescent X-rays 11A, 11B, 11C traveling radially are directed to the detector 12 (FIG. 1).
Since the entrance of is spread in the direction in which the three fluorescent X-rays 11A, 11B, and 11C are arranged (the direction perpendicular to the paper surface of FIG. 1),
It can be captured without waste. Therefore, according to the X-ray fluorescence analyzer of the second embodiment, the X-ray fluorescence from the minute portion 2 can be extracted with a sufficient intensity, which is three times that of the apparatus of the first embodiment.

Further, as shown in FIG. 4, a plurality of, in this case, two diaphragms 8D and 8E may be arranged in directions in which the extraction angles of the fluorescent X-rays 7D and 7E generated from the minute portion 2 of the sample 1 are different. . That is, a plurality of diaphragms 8 are radially arranged along the paper surface of FIG.
You may arrange D, 8E. In this case, fluorescent X-ray 7
Since the extraction angles of D and 7E are different from each other, a plurality of spectroscopic elements 10D and 10E are used, or a plurality of fluorescent X-rays 9D and
It is necessary to use a curved spectroscopic element corresponding to 9E. Further, it is also possible to arrange a plurality of apertures as shown in FIG. 3 along the plane perpendicular to the paper surface of FIG. 4 for each take-out angle.

Next, an X-ray fluorescence analyzer according to the third embodiment of the present invention will be described. In this apparatus, as shown in FIG. 5, the diaphragm 18 is configured by using two plate-shaped field limiting slits 18a and 18b having single diaphragm holes 19a and 19b. Aperture 1
The dimensions 9a and 19b are common, and X from the surface 2a of the minute portion to the aperture 18 is the same as in FIG.
As shown in FIG. 6 in which the line optical path is viewed, the aperture holes 19a and 19b are formed.
Is a circular shape in which the minute portion surface 2a having the same size and shape as in the case of the first embodiment is viewed obliquely, and the central axis C of the diaphragm 18 is
In the above, the distance L ₃ from the field limiting slit 18a on the side of the sample 1 to the minute portion surface 2a is equal to
1/6 or less of the distance L ₄ between a and 18b, for example, 1/6
It is different from the device of the first embodiment in that
The other configurations are the same, and the description thereof will be omitted.

The fact that the diaphragm 18 can be made to have such a size and shape is that L ₁ is replaced by L ₃ and L ₂ is replaced by L ₄ in the expressions (1) to (3) by comparing FIG. 6 with FIG. From that,
it is obvious. For the same reason as described above, it is preferable that the surface of the minute portion is circular and the aperture is an elliptical shape in which the circular shape is viewed obliquely. Further, as shown in FIG. 7, the field limiting slit 18b on the side of the spectroscopic element 10b.
Can also be used as masking for the spectroscopic element 10 by bringing it into close contact with the spectroscopic element 10. In this case, the size and shape of the diaphragm holes 19a and 19b of the field limiting slits 18a and 18b are not common.

According to the X-ray fluorescence analyzer of the third embodiment, it is possible to limit the visual field to the minute portion 2 only by the diaphragm 18 without using a solar slit, and moreover, the inner diameter d of the diaphragm hole 19 (the spectroscopic element 10). When the field limiting slit 18b on the side is brought into close contact with the spectroscopic element 10, the surface of the minute portion 2a corresponding to the ellipse of the diaphragm hole 19b)
The width D can be made 75%, that is, substantially the same. Therefore, with a simple structure, fluorescent X-rays from the minute portion 2 having a maximum surface width D _max of 1 mm can be extracted with sufficient intensity.

Next, a fluorescent X-ray analyzer according to the fourth embodiment of the present invention will be described. This device is similar to that shown in FIG.
As shown in FIG. 8 in which the X-ray optical path before passing through the optical path is shown, a plurality of, for example, three diaphragms 18A, 18B, and 18C are radially arranged and the diaphragm 1
Partition plates 20B and 20C are provided between 8A, 18B and 18C, and fluorescent X-rays 9A, 9B and 9C are passed through the partition plates 20B and 20C, respectively.
Is different from the device of the third embodiment in that it is generated from a common minute portion 2 in the sample 1, but the other configurations are the same and the description thereof will be omitted. As in the case of FIG. 3, the radiation states of the diaphragms 18A, 18B and 18C are exaggerated in FIG. 8 for easy illustration and understanding.

In the apparatus of the fourth embodiment, each diaphragm 18
Strictly different from each other, the minute portion surfaces 2a expected by A, 18B, and 18C can be configured so as to substantially overlap with each other, and the fluorescent X-rays 9A, 9B, and 9C generated from the substantially common minute portion 2 are used as apertures 18A, 18B, and 18C can be passed. To make the surfaces of the minute parts more strictly overlap,
As described above, it is preferable that the surface of the minute portion is circular, and the aperture is an elliptical shape that allows the circular shape to be viewed in an oblique direction. In addition, three fluorescent X-rays 11A, which travel radially,
11B and 11C are directed to the detector 12 (FIG. 5), the entrance of the detector 12 has three fluorescent X-rays 11A,
Since 11B and 11C are spread in the direction in which they are aligned (the direction perpendicular to the paper surface of FIG. 5), they can be taken in without waste. Therefore, according to the fluorescent X-ray analysis apparatus of the fourth embodiment, the fluorescent X-rays from the minute portion 2 can be extracted with a sufficient intensity, which is three times that of the apparatus of the third embodiment.

Also in the fourth embodiment, the second
Similar to FIG. 4 in the embodiment, the arrangement directions of the plurality of diaphragms 18 may be directions in which the extraction angles of the fluorescent X-rays 7 generated from the minute portions 2 of the sample 1 are different. Further, it is also possible to arrange a plurality of diaphragms as shown in FIG. 8 along the plane perpendicular to the paper surface of FIG. 4 for each take-out angle.

In the present invention, since the fluorescent X-rays that have been made sufficiently thin and parallelized by the diaphragm are taken out, the flat spectroscopic element 10 can be used as in each of the above-mentioned embodiments, but of course a curved spectroscopic element can also be used. Good. Further, if a solar slit or a light receiving slit is provided in front of the detector as in an optical system of a normal parallel method or a focusing method, the resolution can be improved.

[0029]

As described in detail above, according to the present invention, in the fixed goniometer and the fluorescent X-ray analyzer equipped with the fixed goniometer, the fluorescent X-rays from the microscopic portion of the sample are sufficiently suffied with a simple structure. It can be taken out with strength.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a fluorescent X-ray analysis apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of the X-ray optical path from the surface of a minute portion to the passage of a diaphragm in the same apparatus, as seen from above.

FIG. 3 is an enlarged view of an X-ray optical path from the surface of a minute portion to a stop passing through the diaphragm and seen from above in the fluorescent X-ray analysis apparatus according to the second embodiment of the present invention.

FIG. 4 is a schematic view showing an example in which the arrangement directions of a plurality of diaphragms are changed in the same apparatus.

FIG. 5 is a schematic diagram showing a fluorescent X-ray analysis apparatus according to a third embodiment of the present invention.

FIG. 6 is an enlarged view of the X-ray optical path from the surface of a minute portion to the passage through the diaphragm in the same apparatus as seen from above.

FIG. 7 is a diagram showing an example in which the field limiting slit on the spectroscopic element side is closely attached to the spectroscopic element in the same apparatus.

FIG. 8 is an enlarged view of an X-ray optical path from the surface of a minute portion to a stop passing through the diaphragm and seen from above in the fluorescent X-ray analyzer of the fourth embodiment of the present invention.

[Explanation of symbols]

1 ... sample, 2 ... micro part of sample, 2a ... micro part surface,
6, 16 ... Fixed goniometer, 7 ... Fluorescent X-ray generated from a minute portion of the sample, 8, 18 ... Aperture (straight tube, two field limiting slits), 9 ... Fluorescent X-ray passing through the aperture, 10 ...
Spectroscopic element 11, ... Fluorescent X-rays spectrally separated by the spectroscopic element, 12
... detector, 19 ... throttle hole, 20 ... partition plate, C ... central axis of the diaphragm, D _max ... maximum width of the micro site surface, L _1, L ₃ ... small from one end of the sample side of the aperture at the center axis of the aperture Distance to the surface of the part, L ₂ , L ₄ ... Length of diaphragm.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Kenichi Nakano             14-8 Akaoji-cho, Takatsuki-shi, Osaka Rigaku Denki             Industry Co., Ltd. F term (reference) 2G001 AA01 BA04 CA01 EA02 EA08                       KA01 LA11 MA05 SA02 SA07                       SA30

Claims (7)

[Claims] 1. A fixed goniometer for detecting fluorescent X-rays generated from a predetermined element in a sample, comprising: a diaphragm for passing fluorescent X-rays generated from a minute portion of the sample; and a diaphragm passing through the diaphragm. A spectroscopic element that disperses the fluorescent X-rays generated from the predetermined one element when the fluorescent X-rays are incident, and a single detection that detects the fluorescent X-rays that the spectroscopic X-rays dispersed by the spectroscopic element are incident. A maximum width of the surface of the minute portion is 3 mm or less, the diaphragm is a straight tube, and the distance from the sample-side end of the straight tube to the surface of the minute portion in the central axis is the straight tube. Fixed goniometer that is less than 1/6 of the length of the. 2. The fixed goniometer according to claim 1, wherein the plurality of diaphragms are provided, and the fluorescent X-rays to be passed through each are generated from a common minute portion in the sample. 3. The fixed goniometer according to claim 1 or 2, wherein the diaphragm is an elliptical tube that obliquely looks at the surface of the minute portion having a circular shape. 4. A fixed goniometer for detecting fluorescent X-rays generated from a predetermined element in a sample, comprising: a diaphragm for passing fluorescent X-rays generated from a minute portion of the sample; A spectroscopic element that disperses the fluorescent X-rays generated from the predetermined one element when the fluorescent X-rays are incident, and a single detection that detects the fluorescent X-rays that the spectroscopic X-rays dispersed by the spectroscopic element are incident. And a maximum width of the surface of the minute portion is 3 mm or less, the diaphragm is configured by using two plate-shaped field limiting slits having a single diaphragm hole, and a sample is provided at the center axis of the diaphragm. A fixed goniometer in which the distance from the side visual field limiting slit to the surface of the minute portion is 1/6 or less of the distance between the visual field limiting slits. 5. The fluorescent X according to claim 4, wherein the plurality of diaphragms are provided, and a partition plate is provided between the diaphragms in order to make each optical path independent, and the fluorescent X to pass through each diaphragm.
A fixed goniometer in which the lines originate from a common microportion in the sample. 6. The fixed goniometer according to claim 4 or 5, wherein the aperture has an elliptical shape in which the surface of the minute portion having a circular shape is viewed obliquely. 7. An X-ray fluorescence analyzer provided with the fixed goniometer according to claim 1.