JP2003149184A - Analyzer with CCD camera - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable crystal orientation analysis and spectroscopic analysis to be performed by one measurement system. An unequally-spaced diffraction grating (8) for diffracting characteristic X-rays from a sample irradiated with an electron beam, a light-receiving surface at a position where the diffraction lines diffracted by the unequally-spaced diffraction grating are incident, and CC for detecting a reflected electron beam from the sample on the light receiving surface
A D camera (7) is provided to perform crystal orientation analysis based on the diffraction pattern of the reflected electron beam recorded by the CCD camera, and to perform elemental analysis by receiving diffraction lines from unequally spaced diffraction gratings. is there.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer using a CCD camera which can be used for X-ray fluorescence spectroscopy, crystal orientation analysis and the like.

[0002]

2. Description of the Related Art Conventionally, a crystalline sample is irradiated with an electron beam, a diffraction pattern of the reflected electron beam is photographed and recorded by a CCD camera, and the crystal orientation is analyzed. Further, a sample is irradiated with an electron beam, characteristic X-rays generated from the sample are separated by a curved diffraction grating arranged on a Rowland circle, condensed on a CCD camera, and elemental analysis is performed from the spectrum.

[0003]

As described above, conventionally, the crystal orientation analysis and the spectroscopic analysis have been performed by independent measurement systems. Until now, no proposal has been made to use one of these measurement systems. However, even if the crystal orientation analysis and the spectroscopic analysis are performed by one measurement system, the X-ray generation source and the diffraction grating are used in the spectroscopic analysis. Since the CCD camera has to be positioned on the Rowland circle, the device becomes large in size, and it has been difficult to detect reflected electrons with this CCD camera and perform crystal orientation analysis.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and an object of the present invention is to enable crystal orientation analysis and spectroscopic analysis to be performed with a single compact measuring system. Therefore, the present invention has a non-equidistant diffraction grating that diffracts characteristic X-rays from a sample irradiated with an electron beam, and a light-receiving surface at a position where a diffraction line diffracted by the non-equidistant diffraction grating enters. A CCD camera for detecting reflected electron beams from the sample on the light receiving surface is provided, crystal orientation analysis is performed from the diffraction pattern of the reflected electron beams recorded by the CCD camera, and diffraction lines from the non-equidistant diffraction grating are received. It is characterized by performing elemental analysis. Further, according to the present invention, the capillary lens on which the characteristic X-ray from the sample irradiated with the electron beam is incident, and the characteristic X emitted from the capillary lens.
A diffraction grating that diffracts a line and a CCD camera that has a light receiving surface at a position where the diffraction line diffracted by the diffraction grating is incident and that detects a reflected electron beam from a sample on the light receiving surface are provided. The crystal orientation is analyzed from the recorded diffraction pattern of the backscattered electron beam, and the characteristic X emitted from the capillary lens and diffracted through the diffraction grating is also analyzed.
It is characterized in that it receives a line and performs elemental analysis.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram when a crystal orientation analysis is performed by the analyzer of the present invention. When the sample 1 is irradiated with the incident electron beam 2, the reflected electron beam 4 and the characteristic X-ray 5 are generated from the irradiation point 3. Of the reflected electron beams 4 radiated in various directions, those reflected by the CCD camera 7 enter the CCD camera 7 and are detected. The information on the detected backscattered electron beam is stored in the memory of the analysis system 9 and processed by the CPU to obtain a diffraction pattern of crystal orientation as shown on the monitor screen. Sample 1 and CCD
A shutter plate 6 is arranged between the cameras, and the shutter plate 6 is inserted into and removed from the path of the reflected electron beam toward the CCD camera by the shutter moving mechanism 10. Shutter plate 6
Is in the position indicated by the solid line, the reflected electron beam can be incident on the CCD camera 7, and the characteristic X-ray traveling from the sample to the diffraction grating 8 is blocked by the shutter plate 6.
It cannot reach the diffraction grating 8.

On the other hand, when the shutter plate 6 is at the position indicated by the broken line, the reflected electron beam is blocked by the shutter plate 6 and C
The characteristic X-rays 5 that cannot enter the CD camera 7 and travel from the sample to the diffraction grating 8 can reach the diffraction grating 8 as shown by a broken line without being blocked by the shutter plate 6.

In this way, when the shutter plate 6 is removed from the path of the reflected electron beam from the sample to the CCD camera, C
The reflected electron beam can be detected by the CD camera 7,
On the contrary, when the shutter plate 6 is inserted into the path of the reflected electron beam from the sample to the CCD camera, the CCD camera 7 can detect the characteristic X-rays dispersed by the diffraction grating 8.

When detecting a backscattered electron beam, a characteristic X-ray that follows the same path as that of the backscattered electron beam also enters the CCD camera, but since it is not spectrally separated, it is simply detected as background noise. And can be removed by image processing.

In the example of FIG. 1, when the shutter plate 6 is removed from the path of the reflected electron beam from the sample to the CCD camera, the shutter plate 6 passes through the path of the characteristic X-ray from the sample to the diffraction grating 8. Due to consideration so as to block, the characteristic X-rays do not reach the diffraction grating 8 and, as a result, the X-rays passing through the diffraction grating 8
It is possible to prevent the lines from being detected by the CCD camera. When detecting the backscattered electron beam with a CCD camera,
When the X-rays that have passed through the diffraction grating do not have much adverse effect on the CCD, when the shutter plate 6 is removed from the path of the reflected electron beam from the sample to the CCD camera, the shutter plate 6 is removed from the sample. It is not necessary to consider blocking the passage of the characteristic X-ray toward the diffraction grating 8.

FIG. 2 is an explanatory diagram when elemental analysis is performed by the analyzer of the present invention. In the measurement system shown in FIG. 2, the shutter moving mechanism 1 is operated by the CPU of the analysis system 9.
By operating 0, the shutter 6 is moved to the position shown by the broken line in FIG. 1, whereby the backscattered electron beam is blocked, while the characteristic X-rays 5 generated from the irradiation point 3 may enter the non-equidistant diffraction grating 8. it can. The unequal-spaced diffraction grating 8 has scribed lines (grooves) arranged at unequal intervals in the X-ray incident direction. In the type that uses an evenly spaced diffraction grating, the detector moves in a complicated manner on the Rowland circle, and the diffraction line is significantly obliquely incident on the light receiving surface of the detector. The type is known to be easy to move the detector and to allow the diffraction line to enter the detector perpendicularly (Maruzen Experimental Physics Course 8 Spectroscopic Measurement 1999 9
Issued on page 94). Further, the unequal-spaced diffraction grating can realize an image plane perpendicular to the diffracted light, and when the incident angle is 87 °, the image plane is almost perpendicular to the plane including the diffraction grating,
A region with a length of about 25 mm, which can be regarded as an almost flat surface, appears, which is a region corresponding to the spectral wavelength of 5.0 nm to 20.0 nm. By placing a position-sensitive detector here, the spectrum in this wavelength range can be obtained. It is reported that it is possible to measure at once (Tohoku University Institute of Scientific and Instrument Research Vol. 42 No. 1 23-37 (1993)).

Thus, the X-rays incident at a high angle are diffracted by the diffraction grating 8 and the diffraction lines diffracted at a low angle with respect to the diffraction grating surface make the light receiving surface perpendicular to the surface including the diffraction grating. The light enters the CCD camera 7 almost vertically. The X-ray thus detected is stored in the memory of the analysis system 9, and C
The image is processed by the PU and its spectrum is displayed on the monitor screen. In this case as well, the slit is not always necessary, but it is preferable to dispose the slit in order to reduce background noise.

In the present invention, since the diffraction grating and the light receiving surface of the CCD camera do not need to be placed on the Rowland circle by using the non-uniform diffraction grating, the light receiving surface of the CCD camera is the surface of the non-uniform diffraction grating. The measurement system can be set up so that it can be efficiently detected by arranging it vertically so that the reflected electron beam is incident on its light-receiving surface almost vertically. And characteristic X-rays can be detected. On the other hand, with an equally-spaced diffraction grating, the detector moves in a complicated manner on the Rowland circle, and the diffraction line enters the light-receiving surface of the detector at a significantly oblique angle. I can't.

In the above example, the diffraction grating and the C
The characteristic X-rays are selected and diffracted by the slit without moving the position or angle of the CD camera, but the angle of the diffraction grating may be changed or the position of the CCD camera may be moved. By doing so, it is possible to perform wider-band spectroscopy. For example, when the diffraction grating 8 itself is provided with a tilt mechanism so that the incident angle of the X-rays on the diffraction grating 8 can be changed, a spectrum spectrum having a different wavelength range depending on the tilt angle can be acquired through a CCD camera. it can. Also, equipped with multiple diffraction gratings with different surface spacing,
If a mechanism that can be switched and arranged in the X-ray optical path is provided, characteristic X-rays in a wide wavelength range can be measured.

Further, the above-mentioned unequal-interval diffraction grating has a single-layer structure and can perform one-dimensional or two-dimensional spectroscopy. However, a multi-layer dispersive crystal is used, and the angle of the crystal plane and the lattice spacing in the crystal depth direction are used. By changing, it is possible to perform three-dimensional diffraction and perform spectroscopy.

FIG. 3 is an explanatory view of an analyzer using a capillary lens, which is different from that of FIG. 3 in that it does not use an unequal-spaced diffraction grating but uses a capillary lens and a diffraction grating at equal intervals. 1, the same as in the case of FIG. In the figure, the position of the slit 6 is moved and the irradiation point 3
The characteristic X-ray 5 from is incident on the diffraction grating 21 through the capillary lens 20 and is imaged on the light receiving surface of the CCD camera 7. The capillary lens 20 is a bundle of thin tubes that totally reflects incident X-rays on the inner surface and emits it from the exit surface. One thin tube is called a single capillary lens, and the bundled one is called a polycapillary lens. It is a lens capable of focusing on X-rays by curving the shape of.

The image plane formed by the capillary lens 20 is C
By matching the light receiving surface of the CD camera 7 and splitting the light by the diffraction grating 21, the diffracted X-rays can be received without placing the diffraction grating and the light receiving surface of the CCD camera on the Rowland circle. Further, if the position of the slit is moved, the reflected electron beam can be detected by this CCD camera. That is,
By only placing the CCD camera 7 at a position determined by the focal length of the capillary lens 20, elemental analysis and crystal orientation analysis can be performed with one measurement system.

In the above example, the light receiving surface of the CCD camera 7 is made to coincide with the image forming surface of the capillary lens 20, but it is not always necessary. For example, as shown by the broken line in FIG. 3, even if the CCD camera 7 is arranged at a position that does not coincide with the image plane, the dispersed X-rays can be detected, and the spectrum peak appears in the image data obtained from the CCD camera. It is sufficient to perform data processing for separating the.

[0018]

As described above, according to the present invention, the X-ray analysis and the crystal orientation analysis can be performed only by image-processing the analysis of the pattern recorded by the same CCD camera, and the diffraction grating and the CCD camera can be analyzed. Since it is not necessary to place it on the Roland circle, the entire apparatus becomes compact, the cost can be reduced as compared with the conventional one, and an X-ray fluorescence analyzer having a simple operation can be obtained. It is also possible to achieve high resolution as a soft X-ray spectrometer. In addition, by using a multi-layer dispersive crystal, it is possible to deal with high energy X-rays.

[Brief description of drawings]

FIG. 1 is an explanatory diagram in the case of performing a crystal orientation analysis by an analyzer of the present invention.

FIG. 2 is an explanatory diagram when performing elemental analysis by the analyzer of the present invention.

FIG. 3 is an explanatory diagram of an analyzer using a capillary lens.

[Explanation of symbols]

1 ... Sample, 2 ... Incident electron beam, 3 ... Irradiation point, 4 ... Reflection electron beam, 5 ... Characteristic X-ray, 6 ... Shutter, 7 ... CCD camera,
8 ... Unequally spaced diffraction grating, 9 ... Analysis system, 10 ... Slit moving mechanism, 20 ... Capillary lens, 21 ... Diffraction grating,

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Eiichi Watanabe             3-12 Musashino, Akishima-shi, Tokyo Japan             Electronic Engineering Co., Ltd. F-term (reference) 2G001 AA03 BA05 BA15 BA18 CA01                       CA03 DA01 DA09 FA09 GA01                       GA13 JA04 JA06 KA01 KA08                       SA01 SA04

Claims (3)

[Claims] 1. A non-equidistant diffraction grating that diffracts characteristic X-rays from a sample irradiated with an electron beam, and a light-receiving surface at a position where a diffraction line diffracted by the non-equidistant diffraction grating is incident, and the light-receiving surface CCD that detects the reflected electron beam from the sample on the surface
A CCD camera, comprising: a camera, which performs crystal orientation analysis from a diffraction pattern of a backscattered electron beam recorded by the CCD camera, and receives elemental analysis by receiving diffraction lines from a non-equidistant diffraction grating. Analyzer. 2. A capillary lens into which characteristic X-rays from a sample irradiated with an electron beam are incident, a diffraction grating that diffracts characteristic X-rays emitted from the capillary lens, and a diffraction line diffracted by the diffraction grating is incident. C having a light-receiving surface at a position and detecting a reflected electron beam from the sample at the light-receiving surface C
A CD camera is provided, and the crystal orientation analysis is performed from the diffraction pattern of the backscattered electron beam recorded by the CCD camera, and the characteristic X-rays emitted from the capillary lens and diffracted through the diffraction grating are received to perform elemental analysis. An analyzer using a CCD camera, characterized in that 3. The analyzer according to claim 1, further comprising a shutter that is removably provided in a passage of the reflected electron beam toward the CCD camera.