JPH04204399A - Soft x-rays converging device - Google Patents

Abstract

PURPOSE:To provide applicability for analysis of an element of fine amount and analysis of a light element of low detection efficiency while reducing attenuation of X-ray intensity in an X-ray detection surface by inserting a hollow fine X-ray guide pipe interposed between an X-ray generating source and a detector. CONSTITUTION:X-rays 2, generated from an X-ray generating device l, are irradiated to an opposedly provided sample 3, and fluorescence X8, generated from the sample 3, is guided to an X-ray detector 7 through an X-ray guide pipe 5. As the detector 7, an Si semiconductor detector, having energy resolution, and a gas flow type proportional counter are used. An amount of the fluorescence X-rays 8 is incident upon the detector 7 as a total amount of X-rays of direct fluorescence X-ray light and X-rays fully reflected by an internal wall of the hollow fine X-ray guide pipe 5, and X-ray intensity is in inverse proportion to a square of a distance between an X-ray generated position and a detection surface of the detector 7, so that the closer to a generating source of the fluorescence X-ray is a point end of the X-ray guide pipe 5 the larger the X-ray intensity is increased.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method for focusing soft X (8) generated from a sample during X-ray analysis using an X-ray generator, an electron beam generator, etc. It is related to light equipment.

[Summary of the Invention] The present invention provides: 1) A soft X-ray concentrator characterized in that a hollow thin X-ray conduit is inserted between a source of soft X-rays to be detected and a detector.

2) The inner surface of the hollow thin tube X-ray conduit is a smooth surface that causes total reflection, and the inner shape is cylindrical, conical, elliptical, or hyperbolic, and is composed of one type or a combination of two or more of these types. A soft X-ray condenser according to claim 1, characterized in that:

3) The X-ray conduit in the hollow tube moves minutely, and the
The soft X-ray condenser according to claim 1, characterized in that the soft X-ray concentrator has positional resolution by guiding the rays to a detector.

4) The soft X-ray concentrator according to claim 1, wherein the soft X-rays condensed using a hollow thin tube X-ray conduit have a wavelength of 1 angstrom or more.

In order to obtain sufficient intensity of the soft X-rays to be detected, the soft XI emitted from the X-ray generation source in all directions is placed in a space away from the X-ray generation position. In order to increase the amount of X-rays taken into the X-ray detector, a hollow thin X-ray conduit is inserted between the X-ray source and the X-ray detector. Furthermore, by moving the X-ray tube minutely and guiding the X-rays at each position to the detector,
A detection system that enables position resolution is constructed. This makes it possible to introduce sufficient X-ray intensity to the X-ray detector for analysis of trace elements and analysis of light elements such as carbon and boron, which have low detection sensitivity, thereby improving detection efficiency. It is.

[Prior Art] Conventionally, X-rays are emitted in all directions from the source to be detected, but only a small portion of the X-rays are emitted at a certain position in space away from the X-ray generation position. Analyze it with a semiconductor detector such as a Si (Li) detector or Ge detector or a proportional counter that has energy resolution, or use a crystal, total reflection mirror, artificial multilayer film, organic crystal, or diffraction detector in front of the Xu detector. It was analyzed using a spectroscopic element such as a grating.

[Problem to be solved by the invention] However, since x#IA to be detected is emitted in all directions from the X-ray generation source, in a space far from the X-ray generation value 1, the x#IA is not the same as the X-ray generation position. The X-ray intensity ratio decreases in inverse proportion to the square of the distance to the detection surface. Usually, in an X-ray analyzer that analyzes X-rays generated from a sample, the geometrical conditions on the device.

Due to the operability of the device, the size of the X-ray detector, etc., it is not possible to move the detector close to the X-ray generation position and obtain sufficient X-ray intensity. Therefore, there have been problems with X-ray analysis of trace elements and analysis of light elements such as carbon and boron with insufficient detection sensitivity.

[Means for Solving the Problems] The present invention is intended to solve the above-mentioned conventional problems, and its purpose is to reduce the attenuation of X-ray intensity due to the distance between the X-rays to be detected and the detector. The aim is to make the size of the element as small as possible and improve the analysis and detection efficiency of trace elements.

The X-rays to be detected are excited and generated by electron beams, X-rays, or the like. The generated X-rays are emitted in all directions and have an attenuation in intensity ratio inversely proportional to the square of the distance between the X-ray source and the detection surface of the X-ray detector. Therefore, the closer the detection surface is to the X-ray source, the smaller the attenuation of the X-ray intensity will be. By inserting a hollow thin X-ray conduit between the X-ray source and the X-ray detector, it is possible to bring the X-ray detection surface substantially closer to the X-ray source, reducing the amount of attenuation of the X-ray intensity. It is possible to reduce the

[For use] In order to achieve the above purpose, by inserting a hollow thin X-ray conduit between the X-ray ordering source and the detector, the X-ray intensity at the X-ray detection surface can be reduced as compared to the conventional technology. The aim of this method is to reduce the attenuation of light and apply it to the analysis of trace elements and the analysis of light elements with low detection efficiency.

[Example] Hereinafter, an example of the soft X-ray condenser of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is an overall configuration diagram showing the configuration of an embodiment of the present invention. X-rays 2 generated from the X-ray generator 1 and a sample 3 are arranged opposite each other, and X-rays (fluorescent X-rays) 8 generated from the sample 3 are guided to an X-ray detector 7 via an X-ray conduit 5. In this Example 1, a 5i (Li) semiconductor detector with energy resolution and a gas flow type proportional counter were used. The amount of fluorescent X-rays 8 is incident on the X-ray detector as the total amount of direct fluorescent X-ray light and X-rays totally reflected on the inner wall of the hollow thin tube X-ray conduit 5. Since the X-ray intensity is inversely proportional to the square of the distance between the X-ray generation position and the detection surface of the X-ray detector, the closer the tip of the X-ray tube is to the source of fluorescent X-rays, the more
The line strength is large. The distance between the X-ray source and the tip of the X-ray conduit is 1
It is mm.

In order to obtain an X-ray conduit with the desired inner shape, a glass material (Pyrex glass) was used, and its shape was 0.1 mm in diameter at one end, 4 mm in diameter at the other end, and 50 mm in length.
It has a conical shape. The 4 mm diameter side is connected to the X-ray detection surface.

FIG. 3 is a diagram showing the reflectance at various xi wavelengths and the critical angle of total reflection with respect to the oblique incidence angle when the X-ray to be detected is reflected by the inner wall of the X-ray conduit.

The critical angle and reflectance of total reflection of X1lil are determined by the X-ray wavelength, the material of the reflecting surface, etc. FIG. 3 shows the critical angle of total reflection and reflectance when Pyrex glass is used as a reflective surface. Generally, X-rays with long wavelengths have a large critical angle for total reflection, and a high reflectance can be obtained. The above-mentioned X-ray conduit was designed with these considerations in mind, and the diameter of one end was 0.1 mmφ.
When the other end diameter is 4mmφ and the length is 50mm, the intensity ratio at the detection surface of the X-ray detector when no X-ray conduit is attached is 1st.
It is as shown in the table.

As shown in Table 1 of X-rays in 1, the oblique incidence angle of 0.6 degrees is
Used for line wavelengths. Furthermore, for the soft X&l wavelength,
The X-ray intensity was increased by increasing the oblique incidence angle to 25 degrees (FKa or higher) and 4.6 degrees (CKa). As a result, the soft X-ray concentrator of the present invention can achieve a
A 5-fold improvement in strength was confirmed. When measuring soft XFa, since X-ray absorption by air is large, the measurement system was replaced with He in the air and in a vacuum state of 0.1 Torr or less.

Furthermore, the X-ray conduit is scanned by a micro-moveable manipulator 6. Through this positional control, positional analysis information on the sample surface can be obtained.

(Embodiment 2) FIG. 2 is an overall configuration diagram showing the configuration of Embodiment 2 of the present invention. In the case of semiconductor wafers having a thickness of about 0.1 to 1 mm, it is applied to transmitted fluorescent X-ray analysis. X-rays 2 generated by the X-ray generator 1 are irradiated from the back side of the sample wafer, and fluorescent X-rays 8 excited from near the surface are
The radiation is led to an X-ray detector via a radiation conduit 5. In this case, 1,/manufacturer. = e−0 Here, engineering. is the incident X-ray intensity, ■. is the X-ray intensity transmitted through a material having a thickness of X, μ is a linear absorption coefficient, and X is the thickness of a sample material.

Because of the transmission, the transmitted X-rays were removed by a shield 9 except for the XI conduit section 5. The inner surface of the X-ray conduit was conical, and its tip diameter was 0.03 mmφ. The tip of the X-ray tube is 10 μm to 1 μm relative to the mirror surface of the wafer.
00 μm and guide the generated fluorescent light to the detector. In this case, the positional resolution is approximately equal to the tip diameter of the Xla tube, which can be achieved at around 30 um, and the intensity obtained from that area is compared to the case where no X-ray tube is used.
Shown in the table.

As shown in Table 2, the X-ray intensity incident on the X49 detector is improved by a factor of 10-9° compared to the case without the xMA conduit.

Although the above embodiments have been explained using an X-ray generator, the soft X-ray concentrator of the present invention is also effective in devices that can excite characteristic X-rays from a sample, such as an electron beam or an ion source. . Furthermore, the material of the hollow thin tube X-ray conduit used is not limited to glass, but can also be made of metals, alloys, organic materials, etc., and paulownia.

[Effects of the Invention] As described above, when the soft X-ray condenser of the present invention is used, it is possible to prevent the attenuation of the X-ray intensity that is inversely proportional to the square of the distance from the X-ray generation position of the X-ray to be detected. It is possible to analyze trace elements and light elements such as carbon and boron, which have poor detection efficiency.

The excellent effects described above can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing the configuration of Embodiment 1 of the present invention.
FIG. 2 is an overall configuration diagram showing the configuration of Embodiment 2 of the present invention.
FIG. 3 is a characteristic explanatory diagram showing the reflectance due to total reflection on the inner surface of the glass. l...X-ray generator 2...Primary X-thread spring 3...Sample 4...Sample holder 5...X-ray conduit 6...Minimum movement manipulator 7...X-ray detector 8...・Secondary X-rays (fluorescent X-rays) 9...Shielding plate and above Applicant Seiko Electronic Industries Co., Ltd. Agent Patent attorney Toshiyuki Hayashi Toichitsu Sukeki's Ichimimikago [jtf] To J Hon Me 2 1st Roy 3 + 1 Fl Execution/Execution Frame l Lateral to the entire side 2 younger brother 2 Figure Oblique incidence angle (degrees) is the reflectance of the lath (7) M-1 raw rough figure Figure 3

Claims (1)

[Scope of Claims] 1) A soft X-ray concentrator characterized in that an X-ray conduit in the form of a hollow tube is inserted between a source of soft X-rays to be detected and a detector. 2) The inner surface of the hollow tube is a smooth surface that causes total reflection, and the inner shape is cylindrical, conical, elliptical, or hyperbolic, and is characterized by being composed of one type or a combination of two or more of these types. A soft X-ray condenser according to claim 1. 3) The soft X-ray collection according to claim 1, characterized in that the hollow thin tube X-ray guide moves minutely and guides X-rays at each position to a detector, thereby providing positional resolution. Light device. 4) The soft X-ray concentrator according to claim 1, wherein the soft X-rays condensed using a hollow thin tube X-ray conduit have a wavelength of 1 angstrom or more.