JPH08334480A - X-ray fluorescence analytical device - Google Patents

Abstract

PURPOSE: To make analysis possible to be performed in a short time using a simple mechanism at high resolution by eliminating the necessity of a two-dimensional drive mechanism for excitation X-rays, a sample and a detector in analyzing the two-dimensional distribution of elements on the surface of the sample using fluorescent X-ray spectrometry. CONSTITUTION: This X-ray fluorescence analytical device is provided with an excitation source from which an exciting beam L0 is applied to the surface S of a sample, an image focusing means 1 by which fluorescent X-rays LS, LX emitted from the sample by the application of the exciting beam LO are focused, and a fluorescent X-ray detector 2 for recording the two-dimensional intensity distribution of a fluorescent X-ray image IX formed by the image focusing means 1. Preferably, a pinhole 1A is provided as the image focusing means 1 and an imaging plate as the fluorescent X-ray detector 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray fluorescence analyzer for obtaining two-dimensional distribution information of constituent elements on a sample surface.

[0002]

2. Description of the Related Art In X-ray fluorescence analysis, a sample to be measured is usually excited by X-rays, and an electromagnetic wave (fluorescent X-ray) having an energy peculiar to the element emitted from the sample by the excitation is generated. By detecting, qualitative or quantitative analysis of the elements contained in the sample is performed.
In this case, an energy dispersive type detector such as a semiconductor detector (SSD) or a wavelength dispersive type detector using a diffraction crystal has been conventionally used as a device for detecting fluorescent X-rays.

The following two methods are generally used as methods for obtaining the two-dimensional distribution of elements on the sample surface by such fluorescent X-ray analysis. That is, in the first method, as shown in FIG. 9, the irradiation range S _L is limited by using an X-ray beam that is narrowed down as the excitation X-ray L ₀ . Further, the sample S is moved relative to the X-ray beam L ₀ ,
The irradiation range S _L of the X-ray beam L ₀ is the surface of the sample S, x,
Two-dimensional scanning is performed in the y direction. Then, the fluorescent X-ray L _S emitted from the sample S is detected by the detector 20. In this case, the visual field range for detection may be wide.

As a second method, as shown in FIG. 10, a detector 20 having a narrow visual field range or a limited visual field range is used. Then, the sample S or the detector 20 is moved so that the observation site is relatively two-dimensionally scanned in the x and y directions on the surface of the sample S. Then, the fluorescent X-ray L _S emitted from the sample S is detected by the detector 20.
In this case, the excited X-ray L ₀ may irradiate a wide irradiation area S _L.

[0005]

However, in any of the conventional methods, it is necessary to two-dimensionally move the relative position between the excited X-ray L ₀ and the sample S or the detector 20. However, there is a problem that a complicated drive mechanism for that is required.

Further, in the case of the above-mentioned first method, it is not possible to use the total reflection condition which can make the surface sensitive.
This is because under the condition of total internal reflection, the excited X-rays must be obliquely incident on the sample surface at an angle of a very small milliradian order, but it is difficult to accurately align the irradiation position for this purpose. This is because the beam spot inevitably spreads on the irradiation surface, and the excitation X-ray cannot be narrowed down.

On the other hand, when the visual field is limited by the second method, the total reflection condition can be used. However, when the field of view is limited by this method, the resolution matches the width of the field of view. Therefore, if the field of view is narrowed to improve the position resolution, the number of measurement points per the same measurement area will increase sharply.
In addition, the fluorescent X-ray intensity per point becomes weak, and therefore the time required for measurement becomes much longer than the improvement in resolution. Further, at the time of measurement, all fluorescent X-rays emitted from areas other than the visual field range are wasted, so there is a problem that the higher the resolution, the greater the loss of fluorescent X-rays. Therefore, the resolution of a typical commercially available device that measures contamination on the surface of a Si wafer is only about 1 cm.

As the X-ray fluorescence analyzer, an incident pinhole for passing the X-ray fluorescence emitted from the sample on the sample, a zone plate for separating and condensing the X-ray fluorescence, and an output pinhole. An apparatus has been proposed in which X and Y are sequentially arranged and fluorescent X-rays that have passed through the emission pinhole are detected by an X-ray detector (Japanese Patent Laid-Open No. 6-003294). However, in this apparatus, an optical system including an incident pinhole, a zone plate and an outgoing pinhole is used as a spectroscopic element, and these cannot immediately obtain a two-dimensional distribution of elements on the sample surface. Therefore,
In order to analyze the two-dimensional distribution of elements on the sample surface, a mechanism for driving the sample two-dimensionally is required. Therefore, the problem that the drive mechanism is complicated has not been solved even by this device.

Further, according to the apparatus disclosed in Japanese Patent Laid-Open No. 6-003294, the spatial resolution is several tens of μm × number 1
It is said that it can be increased to about 0 μm. However, this device is basically included in the above-described method of limiting the visual field, and has the same problem as the method of limiting the visual field. Therefore, it is unavoidable that the number of measurement points per the same measurement area becomes enormous due to the increased spatial resolution.

The present invention is intended to solve the problems of the prior art as described above, and in analyzing the two-dimensional distribution of elements on the sample surface by fluorescent X-ray analysis, the excitation X
Shortening the measurement time by eliminating the need for a two-dimensional drive mechanism for lines and samples, enabling a simple mechanism with high resolution, and making the field of view during measurement much wider than the resolution. The purpose is to measure.

[0011]

The inventor of the present invention has no problem by forming an image of a fluorescent X-ray emitted from a sample on a detector serving as a two-dimensional sensor by using an image forming means such as a pinhole. It is possible to immediately form a two-dimensional image by fluorescent X-rays from the sample surface without the need for the two-dimensional driving mechanism described above. By using the method of total reflection fluorescent X-ray analysis that is sensitive to the surface state of the sample, At the same time, they have found that the two-dimensional distribution of elements on the sample surface can be analyzed, and have completed the present invention.

That is, according to the present invention, an excitation source for irradiating a sample surface with an excitation beam, an image forming means for forming an image of fluorescent X-rays emitted from the sample by the irradiation of the excitation beam, and a fluorescent X-ray image by the image forming means. And an X-ray fluorescence detector for recording the two-dimensional intensity distribution of the X-ray fluorescence detector.

The present invention will be described below in detail with reference to the drawings. In each drawing, the same reference numerals represent the same or equivalent constituent elements.

FIG. 1 is a system configuration diagram of a basic aspect of the present invention. The apparatus shown in the figure is an apparatus for performing surface analysis of a sample by a total reflection X-ray fluorescence analysis method,
_A is provided so as to be located above the sample S, and an imaging plate 2 _A is further provided above it. Here, the pinhole 1 _A is provided as the image forming means 1 of the present invention, and the imaging plate 2 _A is provided as the fluorescent X-ray detector 2. In addition, this device
It has a sample holder 3 for mounting a sample holder, a sample holder up-and-down mechanism 4, an up-and-down fine adjustment mechanism 5, and a swivel mechanism 6 for changing the irradiation angle of the excitation X-ray L ₀ , and further has an excitation X-ray source as an excitation source. (Not shown), whereby the excitation X-ray L ₀ as an excitation beam irradiates the entire surface of the sample S mounted on the sample holder 3 or a predetermined region S _{L of a} part thereof. In addition, the entire apparatus is preferably placed in a vacuum chamber in order to prevent interference by scattering of air molecules and generation of fluorescence.

Here, the pinhole 1 _A is an image I of the fluorescent X-ray L _S emitted from the sample surface on the imaging plate 2 _A as the fluorescent X-ray detector 2 by the principle of the needle hole camera.
To form an image. The pinhole 1 _A can be composed of a plate 1 _{p made} of a material (for example, lead, tantalum, molybdenum, etc.) that blocks fluorescent X-rays and has a minute opening (that is, the pinhole 1) formed therein.

Thus, using the pinhole 1 _A , fluorescence X
When a line image is formed on the fluorescent X-ray detector 2, the visual field range of the entire apparatus covers a wide range of the sample S irradiated with the excitation light, but the resolution is higher than this visual field range. It can be much smaller. here,
If the diameter of the pinhole is 2R, the distance from the sample to the pinhole is d ₁ , and the distance from the pinhole to the image plane is d ₂ , the resolution is approximately expressed by the following equation (1).

[0017]

[Equation 1] Can be estimated at.

When a fluorescent X-ray image is formed on the fluorescent X-ray detector 2 using the pinhole 1 _A as described above, the positional relationship among the sample S, the pinhole 1 A and the fluorescent X-ray detector 2 is obtained. Image I does not blur even when the
It is possible to obtain a line image. Further, it becomes possible to form a fluorescent X-ray image at a low cost with a simple device configuration.

On the other hand, in this apparatus, the imaging plate 2 _A provided as the fluorescent X-ray detector 2 is
It is also called a stimulable phosphor sheet. Since the imaging plate 2 _A can record a fluorescent X-ray image with high sensitivity according to the intensity of the fluorescent X-ray reaching the imaging plate 2 _A , use of the imaging plate makes it possible to compare with conventional imaging media such as X-ray film. Therefore, the analysis time can be shortened. Further, since the imaging plate 2 _A has a wide dynamic range and the image recorded here is obtained as digital data, the image quality is not deteriorated. Further, it is possible to easily perform processing such as image sharpening, contour extraction, noise removal, etc. by using a known digital image processing method.

The excitation X-ray source used in the apparatus of FIG. 1 is not particularly limited, and various sources can be used as long as they emit excitation X-rays capable of exciting the element to be detected. For example, iron, nickel, chromium, copper,
When detecting a metal element such as zinc, a rotating anticathode light source using a tungsten target can be used. Further, when it is desired to obtain a distribution image for each element present on the sample surface, synchrotron radiation that can obtain a predetermined irradiation intensity while changing the wavelength of the excitation X-ray is used to perform an analysis process as described later. It is desirable to do.

When irradiating the surface of the sample S with the excited X-ray L ₀ from the excited X-ray source, it is preferable that the excited X-ray L ₀ can irradiate the entire surface of the sample or a predetermined region with a uniform intensity. For this purpose, a collimator can be provided between the excitation X-ray source and the sample.

As a method of using the apparatus shown in FIG. 1, for example,
When analyzing the surface contaminant element of the sample S, first, the sample S is placed on the sample holder 3 and the sample S is irradiated with the excitation X-ray L ₀ having a predetermined wavelength from the excitation X-ray source. In this case, the irradiation angle is adjusted to a predetermined angle by the swivel mechanism 6, and the vertical position of the sample is adjusted by the vertical mechanism 4 and the vertical fine adjustment mechanism 5 to optimize each. Note that once these are adjusted, it is not necessary to readjust these until the end of analysis to obtain a two-dimensional distribution image of the surface contamination element. This is a significant difference from the conventional X-ray fluorescence analyzer that requires a two-dimensional driving mechanism to obtain a two-dimensional distribution image.

When the sample S is irradiated with the excited X-rays L ₀ , the main element constituting the sample S (for example, when a silicon wafer is used as the sample, S is irradiated from the irradiation region S _L of the sample S).
X) fluorescent X-ray L _S from i), fluorescent X-ray L from pollutant element X
_X and scattered X-rays L ₁ of the excitation X-rays are emitted, and those passing through the pinhole 1 _A reach the imaging plate 2 _A. Here, among the regions of the imaging plate 2 _A where these X-rays have reached, the regions where the fluorescent X-rays L _x from the contaminating element X reach and the regions other than that have a difference in the reaching X-ray dose. since, the imaging plate 2 _a two-dimensional image I _x according to the pollution distribution by contaminating elements X are formed, the imaging plate 2 _a becomes possible to record this image.

[0024] In forming the fluorescent X-ray image I _x in this way imaging plate 2 _A, pinholes 1 and the distance d ₁ between the sample S, and pinholes 1 and the imaging plate 2 a distance d ₂ between _A is It can be arbitrarily changed by means not shown. Therefore, the fluorescent X-ray image I _x of the contaminant element can be obtained at an arbitrary magnification (d ₂ / d ₁ ) with respect to the actual contamination distribution. The resolution is as described above.

The image I _x of the contamination distribution recorded on the imaging plate 2 _A can be read at any time using a known reader. In this case, the read image information is
Since it is obtained as digital data, it can be processed by a known image processing method.

As described above, when the surface contamination distribution of the sample is analyzed using the apparatus of FIG. 1, a fluorescent X-ray image corresponding to the intensity of the fluorescent X-ray from the sample S is displayed on the imaging plate 2 _A. Although recorded, the wavelength of the fluorescent X-ray emitted from the sample S is unknown. This is because this device has a sample S and fluorescent X
This is because no spectroscopic device is provided between the line detector 2. Therefore, in the apparatus of the same figure, when an excited X-ray source that emits excited X-rays of only a certain wavelength is used, the type of contaminant element cannot be directly specified.

On the other hand, when it is necessary to specify the type of pollutant element, rather than performing wavelength dispersion or energy dispersion of the fluorescent X-ray, the fact that the minimum excitation energy differs depending on each element is used. It is preferable to specify the type of contaminant element by changing the wavelength of the excited X-ray.
That is, two digital images corresponding to excited X-rays having energies before and after the lowest excitation energy of each element are obtained, and a distribution image of each element is obtained by calculating a difference between these digital images.
A specific example in the case of identifying the type of the contaminant element in this way will be described based on FIG.

In FIG. 2, (a) shows a silicon wafer S.
_The sample S in which iron X _Fe and zinc X _Zn are distributed as contaminant elements on _Si is shown. Here, the lowest energy E _Si of _silicon is 1.84 keV, the lowest excitation energy E _Fe of _iron is 7.11 keV, and the lowest excitation energy E _Zn of _zinc is 9.66 keV. _Si <E _Fe <E _Zn . Therefore, when this sample S is irradiated with excited X-rays having an energy E of excited X-rays of E ≧ E _Zn , the obtained fluorescent X-ray image shows an image of iron and zinc as shown in (b). Distribution image I _Fe of both pollutant elements,
It contains I _Zn . Also, the energy E of the excited X-ray
However, when excited X-rays _satisfying E _Fe ≦ E <E _Zn are applied, the fluorescent X-ray image obtained does not include the zinc distribution image as shown in (c). The energy E of the excited X-ray is E
_When excited X-rays _{satisfying Si} ≤ E <E _Fe are irradiated, neither the distribution image of iron nor the distribution image of zinc is obtained as shown in (d), and only the image of the silicon wafer is obtained. Therefore, by taking the difference between the image data of (b) and (c), (e)
As shown in, a zinc distribution image I _Zn can be obtained,
By taking the difference between the image data of (c) and (d), the iron distribution image I _Fe can be obtained as shown in (f).

As described above, in order to change the energy of the excited X-rays for analysis, it is desirable to use synchrotron radiation as the excited X-rays and select the wavelength with a monochromator for use. Moreover, in addition to the basic system shown in FIG.
It is preferable to additionally provide a reading device for the fluorescent X-ray image recorded on the imaging plate, a calculation device for calculating difference data of the read image data, and a display device for displaying an image based on the difference data. However, the reading device, the arithmetic device, and the display device do not necessarily have to be integrated with the basic system of FIG. 1 and can be placed separately from the measuring device. Therefore, this device is easy to handle even in a synchrotron radiation facility where space is limited.

According to the apparatus of the present invention, as described above, the kind of surface contamination element of the sample can be obtained without the need of the two-dimensional driving mechanism on the side of the excitation X-ray irradiation and the side of the fluorescent X-ray detector. However, in the case of further accurately quantifying the pollutant element, first, the distribution area of the pollutant element is grasped by the device of the present invention, and then the conventional semiconductor detector is used. It is preferable to perform a quantitative analysis of pollutant elements using a fluorescent X-ray analyzer of the type. For example, as shown in FIG. 3, a distribution image I of the pollutant element X is obtained by the apparatus of the present invention.
_x is obtained ((a) in the same figure), and the coordinates of the distribution area of the contaminating element X in the sample S are determined based on it ((b) in the same figure). Then, the semiconductor detector 7 is brought close to the coordinate and quantitative analysis of the pollutant element is performed ((c) of the same figure). This enables efficient quantitative analysis of polluting elements.

The apparatus of the present invention is not limited to the embodiment shown in FIG. 1 and can take various forms. For example, in the apparatus shown in FIG. 1, an X-ray source that emits excited X-rays is used as the excitation source, but the excitation source is not limited to this in the present invention. That is, the fluorescent X-ray analysis detects and analyzes the fluorescent X-rays emitted when the element on the sample surface is excited and returns to the ground state. Therefore, if the element to be analyzed can be excited as such. The excitation means is not particularly limited. Therefore, as the excitation beam, an electron beam, an ion beam, or the like can be used instead of the X-ray. 4, using electron beam L _E as an excitation beam to the diffraction image (RHEED image) reflection high-energy electron diffraction to form a (RHEED) apparatus 10, the provided pinhole 1 _A, the fluorescent X-ray image I is It is an apparatus block diagram when it is made to obtain in the fluorescence X detector 2.

Although the pinhole 1 _A is used as the image forming means 1 in the apparatus shown in FIG. 1, a zone plate may be used instead of the pinhole 1 _A.

FIG. 5 shows a zone plate 1 as an image forming means.
It is a device block diagram at the time of using _B. In this case, the distance between the sample S and the zone plate 1 _B is d ₁ , the distance between the zone plate 1 _B and the fluorescent X-ray detector 2 is d _2, and the focal length of the zone plate 1 _B with respect to the fluorescent X-ray is f. Then, the zone plate 1 _B is arranged at a position satisfying (1 / d1) + (1 / d2) = (1 / f). As a result, even with the same resolution, the numerical aperture can be made larger than that of the pinhole, and the formation sensitivity and resolution of the fluorescent X-ray image I can be improved.

Furthermore, in the apparatus shown in FIG.
Although the individual pinholes 1 _A are provided, a plurality of pinholes 1 _A may be provided in the plate 1 _p as shown in FIG. In this case, as the X-ray image having passed through another pinhole do not overlap, provided the material of the plate 11 which does not transmit X-rays in contact with the imaging plate 2 _A,
The space from the pinhole 1 _A to the fluorescent X-ray detector 2 is divided into a plurality of cells 12. Further, by making the distance d ₁ from the sample to the pinhole the same as the distance d ₂ from the pinhole to the image plane, it becomes possible to cover the sample surface without missing or overlapping the fields of view. . _A fluorescent X-ray image I formed on the imaging plate 2 _A when the image forming means including a large number of pinholes is used.
For example, if the surface of the sample S has a fluorescent X-ray intensity distribution as shown in FIG. 7A, an image as shown in FIG. Therefore, when the fluorescent X-ray image I is read and analyzed, a point symmetry conversion process of the image (a 180 ° rotation process of the image of each cell) is performed for each cell 12. As a result, the original image as shown in FIG.

When the fluorescent X-ray image is formed using the plurality of pinholes 1 _A as described above, it is possible to obtain the advantage that the detection intensity of the fluorescent X-ray image I on the imaging plate 2 _A can be increased. That is, as shown in FIG. 1, when the fluorescent X-ray image I is formed by providing one pinhole 1 _A on the sample S, from the point of vertically dropping from the pinhole 1 _A to the sample surface. As the detection site on the sample surface becomes farther away, the distance between the pinhole and the detection site becomes longer, and the detection intensity of the fluorescent X-rays emitted from the peripheral region of the detection site becomes weaker, so the detection sensitivity also decreases and the imaging plate 2 _A However, there is a problem in that the entire surface of the image cannot be exposed with uniform sensitivity. However, when a fluorescent X-ray image is formed using a plurality of pinholes 1 _A as shown in FIG.
It is possible to shorten the distance between the pinhole 1 _A for each two and the detection site, and it is possible to keep the detection intensity uniform over the entire measurement visual field without degrading the image resolution.

Further, in the apparatus shown in FIG. 1, the imaging plate 2 _A is used as the fluorescent X detector 2. However, in the apparatus of the present invention, in addition to the imaging plate 2 _A , the nuclear dry plate and the X-ray are used. Any two-dimensional line sensor such as a television can be used as the fluorescent X-ray detector.

The device of the present invention can be used for surface analysis of samples in various fields. For example, by using the device of the present invention to analyze contaminants on the surface of a sample, it is possible to quickly identify the type of contaminant element and to know its distribution, so that product contamination can be efficiently controlled and quality can be improved. It becomes possible to improve.

[0038]

According to the apparatus of the present invention, since image forming means such as a pinhole is provided between the sample and the fluorescent X-ray detector in the fluorescent X-ray analysis, no two-dimensional driving mechanism is required. Immediately, a two-dimensional image of fluorescent X-rays emitted from the sample surface can be formed on the fluorescent X-ray detector. Therefore, it becomes possible to analyze the distribution of the elements constituting the sample surface with a simplified device configuration.

In particular, in the apparatus of the present invention, the energy of the excitation beam is changed, and the difference image between the fluorescent X-ray images by the excitation beams of different energies is obtained to specify the kind of the element existing on the sample surface, and to specify it. It is also possible to obtain a distribution image only for the selected elements.

Further, by using an imaging plate as the fluorescent X-ray detector, a fluorescent X-ray image can be obtained with high sensitivity and image information can be obtained as digital data. Image processing can be easily performed.

The resolution of the apparatus of the present invention can be variously changed depending on the pinhole size and the positional relationship between the sample, the pinhole and the detector. When the diameter of the pinhole is 2R, the distance from the sample to the pinhole is d ₁ , and the distance from the pinhole to the image plane is d ₂ , the resolution is approximately the following equation (1).

[0042]

[Equation 2] Given in.

When it is desired to examine the approximate state of element distribution over a wide range of the sample in a short time, the pinhole size may be increased to some extent. For example, in the measurement examples shown in the following examples, the measurement is performed under the condition that the pinhole size is 0.3 mm, d ₁ is 5 cm, and d ₂ is 2.5 cm, and the resolution is 1 mm or less. Further, in order to further improve the resolution, if the intensity of the excitation light source is sufficient, the pinhole may be made smaller, d ₁ may be made smaller, and d ₂ may be made larger. Here, when the resolution of the imaging plate itself is about 100 μm, d ₁
By setting / d ₂ to about 1 to 10, a resolution of several tens of μm can be obtained.

[0044]

EXAMPLES The present invention will be specifically described below based on examples.

Example 1 In the apparatus configuration shown in FIG. 1, an opening having a diameter of 0.3 mm formed on a lead plate having a thickness of 0.7 mm was provided as a pinhole 1 _A , and the excitation beam was synchrotron radiation light. We have assembled a device that uses a single color with a monochromator.

On the other hand, as shown in FIG. 7, a droplet 13 of a solution of Zn dissolved in hydrochloric acid (Zn concentration 1 mg / 1 ml).
Is dropped on the silicon wafer S _Si and evaporated to dryness (diameter D
₁ = 8 mm), which was used as a sample for observing the uneven distribution of the dried solid matter (FIG. 2 (b)).

This sample was subjected to fluorescent X-ray analysis with the above-mentioned device,
When the digital image data of the fluorescent X-ray image formed on the imaging plate was output to the screen, the image as shown in FIG. 7C was obtained. In this case, the analysis conditions are as follows: excited X-ray energy 12 keV, pinhole size 0.3 mm, distance d ₁₅ between sample S _Si and pinhole 1 _A.
cm, the distance d ₂ between the pinhole 1 _A and the image plane was 2.5 cm, and the exposure time was 5 minutes. When measured by the conventional method, the resolution is 1 m even if the measurement range is limited to 1 cm x 1 cm.
When trying to image with m, the number of measurement points becomes 100 or more, and in this case, the measurement time per point cannot be shortened. Therefore, it is estimated that the measurement for a much longer time is required as compared with the present invention.

Example 2 With the same apparatus configuration as in Example 1, the types of contaminant elements (chromium and zinc) were distinguished as follows based on the principle shown in FIG. S
The i-wafer sample S _Si was intentionally contaminated with different kinds of metal elements (chromium and zinc) to obtain a sample. In this case, a standard solution for atomic absorption (each converted to a metal element, 1 mg / 1 ml) is used as a pollution source, and S is used as shown in FIG.
Cr, Zn, and Cr were contaminated on the i-wafer S _{Si in} the order of 3 points (distance D ₂ = 6 mm between Cr contamination point and Zn contamination point, distance D ₃ = 5 mm between Zn contamination point and Cr contamination point). ).

In this case, two analytical conditions were used: exposure X-ray energy of 12 keV and exposure time of 30 minutes, and excitation X-ray energy of 7 keV and exposure time of 30 minutes. As a result, when 12 keV excitation is performed, the result of FIG.
As shown in (b), contamination images of Cr and Zn were observed. In addition, when 7 keV excitation is performed, as shown in FIG.
As shown in (c), only the Cr contamination image was observed.
This is because the lowest excitation energy of Zn is 9.66 keV and Cr is 5.99 keV with respect to the K series.
It is considered that both Cr and Zn were excited by the 2 keV excitation, and only Cr was excited by the 7 keV excitation.

According to the second embodiment, it was confirmed that the Cr contamination point and the Zn contamination point Cr can be distinguished according to the principle of FIG.

[0051]

According to the present invention, by fluorescent X-ray analysis,
In analyzing the two-dimensional distribution of elements on the sample surface, a mechanism for driving the excitation X-ray, the sample, and the field of view of the detector in two dimensions is not necessary, and the analysis can be performed with a simple mechanism and high resolution. Further, it becomes possible to shorten the measurement time as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an apparatus of the present invention.

FIG. 2 is an explanatory diagram of a method for identifying the type of element by the difference between image data of fluorescent X-ray images having different excitation energies.

FIG. 3 is an explanatory diagram of a method for quantitatively analyzing an element by combining the apparatus of the present invention and a fluorescent X-ray analysis apparatus using a conventional semiconductor detector.

FIG. 4 is a system configuration diagram of an apparatus of the present invention using an electron beam as an excitation beam.

FIG. 5 is a system configuration diagram of an apparatus of the present invention in which a zone plate is provided as an image forming unit.

FIG. 6 is a system configuration diagram of an apparatus of the present invention in which a plurality of pinholes are provided as an image forming unit.

FIG. 7 is an explanatory diagram of a sample used in an example and a fluorescent X-ray image obtained thereby.

FIG. 8 is an explanatory diagram of a sample used in an example and a fluorescent X-ray image obtained by the sample.

FIG. 9 is an explanatory diagram of a conventional fluorescent X-ray analysis method.

FIG. 10 is an explanatory diagram of a conventional fluorescent X-ray analysis method.

[Explanation of symbols]

I fluorescent X-ray image I _x contaminating elements of the fluorescent X-ray L ₀ excitation X-ray L ₁ induced X-ray scattering X-ray L _S key element samples constituting the (e.g., in the case where the silicon wafer and sample, Si ) Fluorescent X-ray from L _x Fluorescent X-ray from contaminant element S Sample S _L Sample irradiation area X Contaminating element 1 Imaging means 1 _A Pinhole 1 _B Zone plate 2 Fluorescent X-ray detector 2 _A Imaging plate 3 Sample Holder 4 Vertical mechanism 5 Vertical fine adjustment mechanism 6 Swivel mechanism

Claims (7)

[Claims] 1. An excitation source for irradiating a sample surface with an excitation beam, and fluorescence X emitted from the sample by irradiation with the excitation beam.
An X-ray fluorescence analyzer comprising: an image forming means for forming an image of a line; and a fluorescent X-ray detector for recording a two-dimensional intensity distribution of the fluorescent X-ray image by the image forming means. 2. The fluorescent X according to claim 1, wherein the image forming means comprises a pinhole arranged between the sample and the fluorescent X-ray detector.
Line analyzer. 3. An X-ray fluorescence analyzer according to claim 1, wherein the image forming means comprises a zone plate arranged between the sample and the X-ray fluorescence detector. 4. The X-ray fluorescence analyzer according to claim 1, wherein the X-ray fluorescence detector comprises an imaging plate. 5. The fluorescence according to claim 1, wherein the relative distance between the sample, the imaging means and the fluorescent X-ray detector is variable so that a fluorescent X-ray image can be obtained at an arbitrary magnification. X-ray analyzer. 6. The X-ray fluorescence analyzer according to claim 1, wherein the excitation source is a beam source capable of irradiating the excitation beam with variable energy. 7. An arithmetic device for calculating difference image data between fluorescent X-ray images formed by excitation beams having mutually different energies, and a display device for displaying a difference image based on the difference image data. X-ray fluorescence analyzer.