JPH07260714A - X-ray analyzer - Google Patents

Abstract

PURPOSE:To make it possible to execute fine regulation of an optical element for convergence of an X ray easily and in a short time by a method wherein a two-dimensional image detector for detecting a sectional image of a convergent X ray is disposed on the optical axis of the X ray. CONSTITUTION:An image detector 1 and a sample support stage 5 are disposed for the main body of equipment through the intermediary of a moving mechanism 2 or 7 so that they can be inserted into and removed from the focal position of an X ray in a replacing manner. In the case when an imaging system of an optical element 9 is regulated, the sample support stage 5 is withdrawn from the focal position by operating the moving mechanism 7 and then the image detector 1 is inserted into the focal position by operating the moving mechanism 2. Information on a two-dimensional image detected by the image detector 1 is processed by using an image processing device 3 and then displayed as a sectional image of a convergent X ray on the screen of a monitor thereof. By operating a controller 11 while observing the sectional image of the convergent X ray, accordingly, a manufacturer or a user of the equipment can regulate the optical element 9 finely to be in the optimum condition through the intermediary of a regulating mechanism 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an X-ray analysis apparatus including an optical element for condensing a line and an adjusting mechanism for adjusting the condensing and imaging performance of the optical element.

[0002]

2. Description of the Related Art With the high integration of semiconductor integrated circuits and the increase in capacity of magnetic disks and the like, there is an increasing need to control the physical properties of materials within a minute region. For this kind of physical property control,
Local information on the structure, chemical state, and electronic state of materials is essential. The local analysis technique using focused X-rays (X-ray microbeam) has an advantage that necessary information can be obtained with less irradiation damage, as compared with the local analysis technique using other particle beams.

The spatial resolution (size of the analyzable area) of the X-ray analyzer is mainly determined by the diameter and shape of the focused X-ray. Therefore, to improve the spatial resolution,
Condensing X with smaller diameter and more symmetrical shape
Need to use lines. Due to the progress of processing technology in recent years, it is possible to manufacture an optical element for X-ray focusing with extremely high accuracy. However, the optical element of the X-ray analysis apparatus, which is the target of local analysis, requires an accuracy of about the same as the wavelength of X-rays (0.1 nm to 10 nm),
It is difficult to completely avoid the production error. Therefore, after assembling the X-ray analysis apparatus or whenever the apparatus is used, it is necessary to finely adjust and optimize the condensing and imaging performance of the optical element each time.

The fine adjustment of the optical element is usually performed by actually observing the diameter and shape of the generated condensed X-ray, and as a concrete means, a method using a knife edge has been conventionally used. (See, for example, "Advances in X-ray analysis", Vol. 23 (1992), pages 239-253). This method observes passing X-rays while mechanically moving the knife edge in the direction perpendicular to the focused X-rays, and differentiates the intensity change at the knife edge position to determine the shape of the focused X-rays. And to find the diameter. However, there is a problem in that it takes at least about 20 minutes for the knife edge to finish crossing the X-ray, and the cross-sectional shape of the focused X-ray cannot be observed without waiting for that. . For this reason, in addition to the adjustment of the optical element in each xyz axis direction, several days are required when adjusting the optical element at the rotation angle (tilt angle) about the x-axis center and the rotation angle (rotation angle) about the z-axis center. It was not unusual for it to cost.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an improved X-ray which enables easy fine adjustment of the X-ray focusing optical element in a short time. It is to provide an analyzer.

[0006]

The above-mentioned problems of the present invention can be solved by disposing a two-dimensional image detector for detecting a sectional image of condensed X-rays on the optical axis. . This type of image detector can be used by arranging it on the optical axis of either the front stage (optical element side) or the rear stage (side opposite to the optical element) of the X-ray focal point position.

When the image detector is arranged in front of the focus position of the X-ray, it should be detachable with respect to the optical axis in order to avoid the detector from interfering with the X-ray analysis. It is desirable to arrange the detector via a suitable moving mechanism. On the other hand, when arranging the image detector at the focal position of the X-ray, in order to avoid the detector and the sample support from interfering with each other, it is appropriate to replace the focal position so that it can be inserted and removed. It is desirable to dispose both via a moving means. Further, when the image detector is arranged at the subsequent stage of the X-ray focal point position, it should be possible to insert and remove it with respect to the optical axis in order to avoid disturbing the sample support table when adjusting the optical element. It is desirable to dispose the support base via an appropriate moving mechanism.

As the optical element for the local analysis by the converging X-ray, a diffractive optical element using a zone plate, a transmissive diffraction grating or the like, an ellipsoidal mirror, a spherical mirror or a Walter type reflecting mirror in which these are combined is used. , A reflection type optical element using a Schwarzschild type reflection mirror or a Kirkpatrick Betz type reflection mirror, or an optical element having a multilayer film formed on the surface of these reflection mirrors for improving the X-ray reflectance, Known optical elements can be appropriately combined and used.

Further, as a two-dimensional image detector for observing a cross-sectional image of condensed X-rays, in addition to a position-sensitive detector using a microchannel plate and a charge-coupled device, a fluorescent plate and a television camera are combined. It is possible to use a known photoelectric conversion means as appropriate. The position resolution of the image detector is preferably at least about 1/10 of the diameter of the focused X-ray to be measured, but a resolution lower than this can be used depending on the conditions for the reasons described below.

[0010]

By arranging the two-dimensional image detector on the optical axis of the X-ray, the two-dimensional intensity distribution in the cross section of the focused X-ray can be instantaneously obtained without using mechanical means such as knife edge. And it becomes possible to detect electrically. Therefore, by displaying the signal detected by the two-dimensional image detector on the monitor, the optical element is finely adjusted while directly observing the cross-sectional image of the generated focused X-ray, and the diameter and shape of the focused X-ray are determined. Can be optimized. Further, by additionally providing means for processing the detected two-dimensional image information, it is possible to automatically control the adjusting mechanism of the optical element using the means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments shown in the drawings. The same symbols in FIGS. 1 to 4 represent the same or similar items.

<Embodiment 1> In the X-ray analysis apparatus of this embodiment, as shown in FIG. 1, the image detector 1 and the sample support 5
Of the apparatus main body (not shown) via the moving mechanism 2 or the moving mechanism 7 so as to be replaceable with respect to the focal point position of the X-ray and removable.
It was installed in. The image detector 1 is composed of a known position sensitive detector using a multi-channel plate. X
Although the optical element 9 for condensing the line is not shown in detail,
It was configured with a known reflection type optical element, and was similarly installed in the main body of the apparatus via the adjusting mechanism 10. The adjusting mechanism 10
The manipulator is composed of a translation mechanism for xyz in each axial direction and a rotation mechanism for centering the x axis and the z axis, and finely adjusts the condensing and imaging performance of the optical element 9 under the control of the controller 11. .

As the sample support base 5, one having a minute moving mechanism 6 for adjusting the X-ray irradiation position on the sample 4 is used, and as in the conventional case, the two generated from the sample 4 by the X-ray irradiation are used. A particle observation device 12 for detecting secondary particles (electrons, ions, fluorescent X-rays, photons such as ultraviolet rays and visible rays) was arranged at a predetermined position. 8 is an electronic computer for analyzing the secondary particles detected by the particle observation device 12, 13
Is a controller for setting the observation conditions of the particle observation device 12.

When the image forming system of the optical element 9 is adjusted, the moving mechanism 7 is operated to move the sample support 5 away from the focus position, and then the moving mechanism 2 is operated to move the image detector 1 to the focus position. insert. The two-dimensional image information detected by the image detector 1 is processed by the image processing device 3 and then displayed as a cross-sectional image of condensed X-rays on the monitor screen of the device. Therefore, the maker or the user of the apparatus operates the controller 11 while directly observing the cross-sectional image of the condensed X-ray to adjust the adjusting mechanism 1.
The optical element 9 can be finely adjusted to the optimum condition via 0. After the adjustment of the optical element 9 is completed, the moving mechanism 2
Is operated to move the image detector 1 to a position where it does not interfere with sample analysis, and then the moving mechanism 7 is operated to insert the sample support base 5 again into the focal position. Normal X-ray analysis can be performed in this state.

<Embodiment 2> In this embodiment, as shown in FIG. 2, the sample support 5 is fixedly arranged at the focal position of the X-ray, while it can be inserted and removed on the optical axis in front of the focal position. The difference from the first embodiment is that the image detector 1 is arranged in this way. In the present embodiment, in order to avoid absorption of X-rays by the atmosphere and surface contamination of the sample 4, the optical system from the X-ray source 14 to the sample support 5 is housed in the vacuum housing 15, and the vacuum exhaust means is used. 16 is used to exhaust the gas in the same housing. Such a configuration is necessary when performing local analysis using soft X-rays.

In the case of this embodiment, since the image detector 1 is arranged at a position deviated from the focal position of the X-ray, the optical element 9 can be accurately positioned by observing only the sectional image of the condensed X-ray. Adjusting is difficult. However, if the X-ray cross-sectional image obtained at the arrangement position of the image detector 1 when the optimized optical element 9 is used is previously stored as a reference image in the image processing device 3, the stored reference image is stored. By finely adjusting the position, rotation, and the like of the optical element 9 so that the actual observed image approaches, it is possible to optimize the condensing and imaging performance. Further, when the structure of the present embodiment is adopted, the optical element 9 can be adjusted while the sample support base 5 is still installed at the predetermined position (focal position), and the position resolution of the image detector 1 is improved. Even if is relatively low, the optical element 9 can be precisely finely adjusted.

<Embodiment 3> In this embodiment, the present invention is applied to the case where an X-ray analysis is carried out in a state where the sample 4 is tilted with respect to the optical axis, and as shown in FIG. Detector 1
Are arranged on the optical axis with a tilt corresponding to the tilt angle of the sample 4. According to this configuration, the optical element 9 can be accurately adjusted while observing the cross-sectional image of the focused X-ray that should be irradiated on the tilted sample 4.

In the case of the present embodiment, the X-ray is focused by using the pinhole 18 provided in the stainless steel plate 17, and then the X-ray
A structure is adopted in which the optical element 9 collects a line to a diameter on the order of 1 μm and irradiates the image detector 1 or the sample 4. Further, although not shown in detail, the moving mechanism 2 of the image detector 1 and the moving mechanism 7 of the sample support base 5 have a tilting mechanism constituted by a pulse motor and a piezo element. Other structures are substantially the same as those in the first embodiment.

<Embodiment 4> In the embodiment shown in FIG. 4, the sample support base 5 is arranged at the focal position of the X-ray, and the image detector 1 is fixedly arranged at the subsequent stage. On the other hand, the sample support base 5 is moved by the moving mechanism 7 when adjusting the optical element 9.
The structure is such that the image detector 1 is moved to a position that does not interfere with the observation of condensed X-rays. Further, the image detector 1 is installed via the tilting mechanism 19 so that the sample support base 5
The tilt angle with respect to the optical axis can be adjusted in conjunction with the moving mechanism 7 of FIG.

In the case of the present embodiment, although not shown in detail, the image detector 1 is constructed with a fluorescent screen and a television camera, and the image processing device 3 is linked with the adjusting mechanism 10 of the optical element 9. , So that it functions as a control device of the same mechanism. As a result, the image processing apparatus 3 causes the reference cross-sectional image (the image detector 1 when the optimized optical element 9 is used to store the cross-sectional image of the focused X-ray captured by the image detector 1 in advance. The X-ray cross-sectional image obtained at the arrangement position of 1) is controlled to control the adjusting mechanism 10 to adjust the optical element 9 so as to approach the reference cross-sectional image.

[0021]

According to the present invention, the position and rotation angle of the optical element can be adjusted while directly observing the diameter and shape of the focused X-ray, so that it can be compared with the conventional method using a knife edge. As a result, the adjustment time of the optical element can be significantly shortened.

[Brief description of drawings]

FIG. 1 is a device configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... Two-dimensional image detector, 2 ... Image detector moving mechanism, 3 ...
Image processing device, 4 ... Sample, 5 ... Sample support base, 7 ... Sample support base moving mechanism, 9 ... Optical element, 10 ... Optical element adjusting mechanism, 11 ... Adjusting mechanism controller, 19 ... Image detector tilting mechanism

Claims (5)

[Claims] 1. An optical element for converging X-rays, an adjusting mechanism for adjusting an image forming system of the optical element, a sample support base for positioning a sample at a focal position of X-rays, In an X-ray analyzer having at least an observation device for observing secondary particles generated from a sample, a two-dimensional image detector for directly observing a cross-sectional image of condensed X-rays is arranged on the optical axis. An X-ray analyzer characterized by the above. 2. The sample support base is arranged at a focal point position of X-rays, and the image detector is insertable / removable with respect to an optical axis at a front stage (optical element side) of the X-ray focal point. The device is arranged in the vehicle through a moving means.
The X-ray analysis apparatus described in 1. 3. The both of the image detector and the sample support base are arranged via moving means so that they can be inserted and removed alternately with respect to the X-ray focal point position. The X-ray analysis apparatus according to claim 1. 4. The image detector is arranged on the optical axis in the latter stage of the X-ray focus (on the side opposite to the optical element), and the sample support is arranged with respect to the focal position of the focused X-ray. The X-ray analysis apparatus according to claim 1, wherein the X-ray analysis apparatus is arranged so that it can be inserted and removed through a moving unit. 5. The apparatus further comprises means for processing the two-dimensional image information detected by the image detector, and the adjusting mechanism of the optical element is configured to be controlled by the image processing means. Claim 1 characterized in that
~ The X-ray analysis apparatus according to claim 4.