JP2005128013A - Fluorescence x-ray analyzing method and fluoroscence x-ray analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescence X-ray analyzing method capable of rapidly analyzing/evaluating a plurality of the samples formed on one substrate by a fluorescence X-ray method and capable of analyzing all of the samples accumulated on the substrate under the same condition at the same time, and an fluoroscence X-ray analyzer. <P>SOLUTION: The surface of the substrate, on which a plurality of samples are formed, is irradiated with X-rays at an incident angle θ from a value satisfying the formula (I): tanθ=h/i (wherein h is the height from the substrate of the samples and l is the distance between the samples measured along a vector wherein an incident X-ray vector is projected on the surface of the substrate) to a value satisfying the formula (II):H=L sinθ+h cosθ (wherein H is the beam width of incident X-rays, L is the distance between the lowermost part of the sample present on the most upstream side to the downstream end part of the sample present on the most downstream side and h is the height from the substrate of the sample) and the fluorescence X-rays generated from the respective sample regions are simultaneously detected by a detection means constituted by gathering at least individual detection parts aimed at the respective sample regions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The invention of this application relates to a fluorescent X-ray analysis method and an apparatus therefor. More specifically, the invention of this application relates to a plurality of samples formed on one substrate, for example, combinatorial samples of inorganic compounds, semiconductors, metals, etc. synthesized or prepared on a substrate by a combinatorial material synthesis method. An analysis method for analyzing by the X-ray method, wherein fluorescent X-rays emitted from different sample regions can be detected at the same time, and the structure and composition of the sample regions can be analyzed at the same time. It relates to the device.

  In recent years, in the development of semiconductor materials and inorganic oxides used in electronic devices, combinatorial material synthesis methods have been actively performed in order to efficiently search for useful new substances and materials. This is a method of simultaneously synthesizing substances (samples) with different synthesis conditions such as composition and temperature on a single micro substrate in parallel, and picking out necessary materials and substances with excellent characteristics from them, Future development is expected. As such a combinatorial material synthesis method, specifically, a combinatorial material is produced while controlling the supply of multiple types of raw materials and the movement of the mask on the substrate, and a multi-component sample with a composition gradient is synthesized. The method of doing is illustrated.

  When the synthesis is performed by the combinatorial material synthesis method in this way, a substance having a large number of synthesis conditions can be produced in a shorter time and more efficiently than in the past.

However, the sample produced by the combinatorial material synthesis method is still evaluated by the conventional method, and each part with different synthesis conditions is individually evaluated, so there is a problem that it takes a long time. . Therefore, the fact is that the evaluation has not caught up even if the synthesis is performed at high speed.
JP 2000-55842 A ED Isaacs et al., Applied Physics Letters, 1998, Vol. 73, No. 13, 1820-1822 Kenji Sakurai et al., Analytical Chemistry, Vol. 75, 355-359

  On the other hand, the fluorescent X-ray analysis method can elucidate the composition of a substance, and if an X-ray absorption spectrum called a fluorescent XAFS method is used to indirectly measure the X-ray absorption spectrum by the fluorescent X-ray intensity, Since even the arrangement is known, it is very important in material evaluation. However, X-ray fluorescence analysis is generally premised on homogeneous materials having a uniform composition and structure, and for objects whose composition or structure changes in a narrow area. It cannot be applied as it is.

  Therefore, when observing the composition distribution on the surface of the material, as a so-called scanning X-ray fluorescence analysis method, an X-ray beam or an electron beam is irradiated, and the X-ray fluorescence is scanned while scanning the irradiation position with respect to the material surface. A mapping method has been performed by observing. Regarding the evaluation of the above-described combinatorial sample using fluorescent X-rays, it is attempted to analyze by irradiating only a specific sample portion on the substrate by focusing synchrotron radiation to a small beam size (for example, Non-Patent Document 1).

However, such a scanning X-ray fluorescence analysis method has a problem that it takes a long time to evaluate all of the plurality of samples formed on the substrate, resulting in poor efficiency. There is also a problem that the analysis conditions may change due to changes in measurement conditions and environment due to the time required.

  On the other hand, the inventors of this application have provided an X-ray imaging analysis method and apparatus capable of imaging and analyzing the positional distribution of elements existing on the surface of a substance with high accuracy and in a short time. Patent Document 1) finds that imaging of fluorescent X-rays can be realized without scanning a sample or a beam. However, the actual situation is that the method of simultaneously measuring a plurality of samples formed on one substrate like a combinatorial material in a short time has not been clarified.

  Therefore, in view of the circumstances as described above, the invention of this application is capable of promptly analyzing and evaluating a plurality of samples formed on one substrate by the fluorescent X-ray method. It is an object of the present invention to provide a fluorescent X-ray analysis method capable of simultaneously analyzing a sample under the same conditions and an apparatus therefor.

  The invention of this application is a method for simultaneously performing a fluorescent X-ray analysis on a plurality of samples formed on one substrate, in order to solve the above-described problems, and for a substrate surface on which a plurality of samples are formed. And the following formula (I)

(Where h represents the height of the sample from the substrate, and l represents the distance between the samples measured along the vector obtained by projecting the incident X-ray vector onto the substrate surface)
If the value meets or exceeds the following formula (II)

(Where H represents the beam width of the incident X-ray, L represents the distance from the lowest part of the sample on the most upstream side to the downstream end of the sample on the most downstream side, and h represents the distance from the substrate of the sample. Represents height)
X-rays are irradiated at an incident angle θ equal to or less than a value satisfying the above, and the fluorescent X-rays generated from each sample region are simultaneously detected by a detection means configured by a collection of individual detection units that are aimed at at least each sample region. An X-ray fluorescence analysis method (Claim 1) is provided, wherein the incident angle θ of X-rays is 0.1 to 5 ° with respect to the substrate (Claim 2). The line has a single color or a narrow energy width and is in an energy region including absorption edges of elements constituting a plurality of samples formed on one substrate (Claim 3), or on one substrate. The plurality of samples formed in the above are used as combinatorial samples formed by a combinatorial material synthesis method (Claim 4), and the detection means includes at least a detection unit disposed near the substrate, a substrate, Fluorescent X-ray angle between detection unit The angle divergence limiting means for limiting the divergence (Claim 5), and the angle divergence limiting means is an individual collimator in which at least each one is aimed one-on-one in each sample region (Aspect 6), and the detection unit is a one-dimensional or two-dimensional detector (Claim 7).

The invention of this application can at least fix an X-ray source and a substrate on which a plurality of samples are formed, and adjust an incident angle and an incident direction when irradiating the surface of the substrate with X-rays from the X-ray source. X-ray fluorescence analysis characterized by comprising a sample stage capable of detecting and X-ray fluorescence generated from each sample region, and a detection means configured by a collection of individual detection units aiming at each sample region An apparatus (Claim 8) is also provided, and the X-ray source is an X-ray source in an energy region having a single color or a narrow energy width and including absorption edges of elements constituting a plurality of samples formed on one substrate. And the energy region can be varied (Claim 9), and the detection means is at least between the detection unit disposed close to the substrate and the substrate and the detection unit. Yes, to limit the angular divergence of fluorescent X-rays The angle divergence limiting means is composed of at least one collimator that is aimed at each sample area on a one-to-one basis. (Claim 11), and the detection means is a one-dimensional or two-dimensional detector (Claim 12).

  The “X-ray with a narrow energy width” means an X-ray with an energy width that can provide a spectrum with sufficient resolution in XAFS observation or the like. For example, in the example of manganese in FIG. In the case of XANES and EXAFS at the absorption edge, the energy width is typically about 1 to 20 keV.

  In the fluorescent X-ray analysis method of the invention of this application, it is possible to simultaneously perform a parallel X-ray fluorescence analysis on a plurality of samples formed on one substrate, for example, a combinatorial sample. In addition, by adjusting the incident angle of the irradiated X-rays to the substrate, a wide area on the substrate can be irradiated, and at the same time, the irradiated X-rays can enter the sample with a sufficient penetration depth, It is possible to generate fluorescent X-rays by exciting not only the sample surface but also elements present in the lower part of the sample. In addition, if the substrate is placed so that the respective sample regions are not shaded from each other with respect to the irradiated X-rays, the fluorescent X-rays can be generated by exciting the elements present in the lower part of the sample more easily and reliably. it can. Further, in the fluorescent X-ray analysis method of the invention of this application, since the detection means can be brought close to the sample without interfering with the optical path of the X-ray, it is possible to simultaneously perform fluorescent X-ray analysis of a plurality of samples with high accuracy. It becomes possible. Furthermore, the detection means is provided between the substrate and the detection unit, and has angle divergence limiting means for limiting the angle divergence of the fluorescent X-rays, and each of the angle divergence limiting means is provided in each sample region. When configured by an assembly of individual collimators that are aimed one-on-one, the detected X-ray intensity is remarkably improved, the imaging time is greatly shortened, and highly reliable fluorescent X-ray information can be obtained.

  As described above, the invention of this application enables simultaneous detection of fluorescent X-rays generated from different sample regions in fluorescent X-ray analysis of a plurality of samples formed on one substrate.

  The inventors of this application have focused on the fact that a wide area on the substrate can be irradiated if the X-ray incident angle is shallow with respect to the substrate. And by the earnest research, they found the fluorescent X-ray analysis method of the invention of this application.

  Specifically, individual detection units that irradiate each sample on the substrate with X-rays and aim the fluorescent X-rays emitted from each sample close to the substrate and aim at each sample region are assembled. By detecting with the detecting means configured as described above, it becomes possible to perform fluorescent X-ray analysis on a plurality of samples formed on one substrate. Therefore, it is desirable that the incident angle of the irradiated X-rays be as shallow as possible even when the detecting means is brought close to the substance without obstructing the optical path of the X-rays.

However, if the incident angle is too small at this time, among the plurality of samples formed on the substrate, the lower part of the sample on the downstream side of the incident X-ray becomes the shadow of the sample on the more upstream side, and the lower part It becomes impossible to observe fluorescent X-rays from nearby elements. Therefore, it is necessary to make the incident angle of the X-rays to be radiated appropriately. When the incident angle is set to an appropriate size, the effect that the irradiated X-rays can enter the sample with a sufficient penetration depth is also generated, and the sample surface exists in the lower part of the sample as well as the sample surface. It is also possible to generate fluorescent X-rays by exciting elements.

  FIG. 1 and FIG. 2 show schematic schematic diagrams for explaining the incident angle θ of irradiated X-rays in the fluorescent X-ray analysis method of the invention of this application. X-ray fluorescence is generated when each element contained in a sample is excited when the substrate is irradiated with X-rays. In the X-ray fluorescence analysis method of the invention of this application, the incident angle, that is, irradiation X-rays. The angle (θ) of (1) with respect to the substrate (2) is defined within the following range.

  That is, the incident angle (θ) is expressed by the following formula (I)

By setting the value to a value that satisfies the above relationship, a plurality of samples (31, 32,
It is possible to irradiate not only the surface (41) of 33) but also the low part (42).

In the above formula (I), h is the substrate (2) of the sample (31, 32, 33) as shown in FIG.
Where l is the sample in the direction of the projected vector on the substrate of the incident X-ray (1) vector (31,
32, 33). When θ is smaller than a value satisfying the above equation, the sample on the downstream side (for example, 33) is shadowed by the sample on the upstream side (for example, 32) with respect to the incident X-ray (1), and the X-ray is sufficiently obtained. (1) is not irradiated. For example, X-ray fluorescence analysis is not possible for the lower part (42) of the sample (eg 33).

  The incident angle (θ) is expressed by the following formula (II)

By making the value less than or equal to the value satisfying the above relationship, it is possible to irradiate the entire sample on the substrate even with a narrow incident X-ray. In the above formula (II), H represents the width of the incident X-ray (1) as shown in FIG. 2 representing the state where the condition of the formula (II) is satisfied, and L is the most upstream sample ( 31 represents the distance from the lowest part (311) of 31) to the downstream end part (332) of the sample (33) located on the most downstream side, and h represents the height of the sample from the substrate. When θ is larger than the value satisfying the above formula, the irradiation region of incident X-rays becomes smaller than the region of the entire sample, and X-rays cannot be completely bathed for all samples.

  Accordingly, θ is not less than a value satisfying the relationship of the above formula (II) while being not less than a value satisfying the relationship of the above formula (II). Further, in order to obtain θ that satisfies both formula (I) and formula (II) at the same time, θ is obtained by substituting θ uniquely determined by formula (I) from the structure of the sample into formula (II), and The width of the incident X-ray may be adjusted to realize this H.

  In the above formula (II), H is expressed as the sum of H1 and H2 in FIG.

Thus, θ can be calculated. θ needs to satisfy the above conditions, and a specific value of θ can be set to 0.1 to 5 °, for example.

In the fluorescent X-ray analysis method of the invention of this application, “a plurality of samples formed on one substrate” to be measured is preferably a combinatorial material formed by a combinatorial material synthesis method. Specifically, as schematically shown in FIGS. 1 and 2, there are samples (31, 32, 33) having a height on the substrate (2), but for each sample (31, 32, 33). May be different in height, or may have irregularities on the surface of each sample, so that the height (thickness) is not constant. If the height (h) of the sample (31, 32, 33) differs greatly depending on the location of each sample (31, 32, 33) or sample (31, 32, 33), each sample (31 or 32) Or 33) or a part, h, distances on the substrate between each sample or each part and the upstream end of the downstream sample, H, H2 (in FIG. 3, each sample or the sample most downstream from each part ( 33) If the distance to the downstream end (332) is m, H2 = (hm · tan θ) · cos θ) is obtained, and the incident angle (θ) between the obtained lower limit value and the upper limit value is obtained. Can be determined.

In the fluorescent X-ray analysis method of the invention of this application, the substrate (2) to be used is not particularly limited, but a substrate having high heat resistance or a sample (31) depending on the preparation method of the sample (31, 32, 33), etc. , 32, 33) should be selected. Specific examples include alumina, synthetic quartz glass, sapphire substrate, silicon wafer, and the like. For example, when a semiconductor device, an artificial lattice, or the like is manufactured by epitaxial growth using the MBE method or the like, a material of the same kind or a similar crystal lattice may be selected so that the crystal orientation grows in a uniform manner.

In the fluorescent X-ray analysis method of the invention of this application, in order to further irradiate the lower part (42) of the sample (31, 32, 33) with the X-ray (1), an incident X-ray vector is used. It is desirable to place the substrate (2) so that each sample region (34) (see FIG. 6) is not shaded with respect to the direction. That is, FIG. 4 is a schematic diagram showing an example of the fluorescent X-ray analysis apparatus of the invention of this application. The substrate (2) on which a plurality of samples (for example, 31, 32, 33) in FIG. As shown in FIG. 5, the samples (32, 33) on the downstream side with respect to the vector direction of the incident X-ray (1)
All samples (3) by placing them so that they are not shaded by the samples (31) on the upstream side
X-rays (1) can be reliably irradiated to all parts of the device to generate fluorescent X-rays.

  For example, each sample (31, 32, 33) has the following formula (III) as shown in FIG.

For the incident direction of the X-ray (1) with respect to the sample region (30) on the substrate (2), the above formula (III) and the following formula (IV)

It is considered that the irradiation is performed at an angle ψ that satisfies the above relationship.

The fluorescent X-ray analysis method of the invention of this application uses a plurality of samples (on a single substrate (2)).
For example, 31, 32, 33), for example, the above-mentioned combinatorial sample can be qualitatively analyzed by observing fluorescent X-rays from its constituent elements, and quantified by measuring the intensity of emitted fluorescent X-rays. Analysis can be performed to determine the content and content ratio of the constituent elements. That is, the composition analysis can be simultaneously performed on a plurality of samples (3) formed on one substrate (2). At this time, when observing X-ray fluorescence from an arbitrary element, the irradiated X-ray (1) is necessary for the absorption edge of the element (in the absorption spectrum, the inner shell electrons jump out as photoelectrons). It must have a higher energy (lower limit of energy). When a sample contains a plurality of elements, the X-rays generated by irradiating the X-rays on the high energy side and the low energy side of the absorption edge are observed, and the target element is calculated by performing calculations. Qualitative analysis and quantitative analysis are possible.

  Furthermore, in the fluorescent X-ray analysis method of the invention of this application, an X-ray direct detection type charge-coupled device (CCD) is used as the detection unit (71), and the element is identified by selecting the fluorescent X-ray energy. Can do. Since the amount of charge generated in a charge-coupled device by fluorescent X-rays varies depending on the energy of X-rays, a single photon of fluorescent X-rays is detected, and if the energy is selected, the fluorescent X-ray intensity is observed for each element. It can be done.

Therefore, in the fluorescent X-ray analysis method of the invention of this application, for example, fluorescent X-rays are observed for combinatorial samples with different synthesis conditions, and qualitative analysis, quantitative analysis, and composition analysis are simultaneously performed for each sample (3). Is possible.

In the fluorescent X-ray analysis method of the invention of this application, a plurality of samples (3) formed on one substrate (2), for example, a combinatorial material, in an energy region including an absorption edge of an element constituting the sample. An X-ray absorption fine structure spectrum can also be obtained at the same time by measuring the fluorescent X-ray intensity with respect to the energy of the irradiated X-rays. The X-ray absorption fine structure (XAFS) is a fine structure that appears from the vicinity of the absorption edge peculiar to each element to the high energy side in the X-ray absorption spectrum. Paying attention to the near-line-absorption fine structure (XANES), information on the electronic state and valence of the atom, the symmetry of the electron arrangement and the bond, and the like can be obtained.

Further, from the fine structure appearing on the high energy side by several tens eV or more from the absorption edge, that is, the wide-area X-ray absorption fine structure, the atomic species, the number of atoms, and the interatomic distance around the atom can be determined. Both have the feature that the structure can be determined for amorphous substances and fine particles that cannot be observed for X-ray diffraction. In the fluorescent X-ray analysis method of the invention of this application, a specific sample (for example, 31) is handled from fluorescent X-ray intensities measured simultaneously on a plurality of samples (3) formed on one substrate (2). By extracting the signal portion and graphing the change of the intensity with respect to the irradiation X-ray energy, a fluorescence X-ray absorption fine structure (fluorescence XAFS) spectrum can be obtained. Therefore, by applying the fluorescent X-ray analysis method of the invention of this application to a combinatorial sample, a fluorescent XAFS spectrum can be obtained for each sample (3) with different synthesis conditions, and the electronic state and valence of the constituent elements for each sample are obtained. It is possible to simultaneously analyze the number, local structure around the constituent elements, and the like.

Furthermore, in the fluorescent X-ray analysis method of the invention of this application, the detection means (7) includes at least an individual detection unit (71) aiming at each sample region (for example, 31, 32, 33). The detection means (7) further includes a detection unit (71) disposed close to the substrate (2), and between the substrate (2) and the detection unit (71). There is preferably an angle divergence limiting means (8) for limiting the angle divergence of fluorescent X-rays.

The state in which the detector (71) and the angle divergence limiting means (8) are brought close to the sample (3) refers to a state as close as possible within a range that does not interfere with the incident optical path of the irradiated X-ray (1). By setting such a state, the generation position of fluorescent X-rays that diverge from any position on the sample (3) is specified, and the angular divergence from that position is suppressed, thereby spreading the fluorescent X-rays. Can be suppressed, and sufficient strength can be secured. Therefore, each of the plurality of samples (3) formed on one substrate (2) can be analyzed. By taking a closer arrangement, both the fluorescent X-ray detection efficiency and the position resolution are improved.

At this time, the distance between the detection unit (71) and the sample (3) can be set to 0.5 to 5 mm, for example. In such an arrangement, the X-ray (1) irradiating the sample must be irradiated at a shallow incident angle (θ) that satisfies the conditions of the above formulas (I) and (II) so as to pass through the gap. However, as described above, when the X-ray (1) is incident on the substrate sample at a shallow angle, the optical axis direction of the X-ray (1) spreads on the substrate (2) and the width of the beam cross section is narrow. Even using lines, a large area on the substrate can be irradiated and excited at once. For example, when an incident X-ray having a width of 100 μm is incident on the substrate at an incident angle of 10 mrad (about 0.57 °), the substrate (2)
Above it spreads out to a width of 10 mm. Therefore, it is possible to irradiate the entire surface of a combinatorial sample of about 10 mm.

Furthermore, in the fluorescent X-ray analysis method of the invention of this application, the detection means (7) is configured by assembling individual detection units (71) aiming at each sample region (3). In this case, the detection unit may be a one-dimensional or two-dimensional detector.

When a two-dimensional detector is used as the detector (71), a planar two-dimensional detector can be installed on the planar combinatorial sample via the angle divergence limiting means (8) configured in a planar shape. Therefore, the X-ray (1) can be made to approach the gap between the sample (3) and the angle divergence limiting means (8) without leaving a useless interval. A charge coupled device (CCD camera) is exemplified as a two-dimensional detector configured by assembling individual detection units (71) each aiming at each sample region. In this case, the detection unit (71) includes a plurality of detection units (71). That is a pixel. Since these individual detection units (71) are assembled, each detection unit (71) observes fluorescent X-rays from different sample regions (3), and a plurality of detection units (71) on the substrate (2). The sample (3) can be analyzed simultaneously.

A charge-coupled device has a pixel size of several μm to several tens of μm, and has excellent resolution. The entire size of the device (the size of an image that can be captured at one time) is about several to several tens of square mm. It is. For example, when a combinatorial sample is used as a plurality of samples formed on one substrate (2), the size of the substrate (2) of the combinatorial sample is about several to several tens of mm square for ease of handling during synthesis work. Therefore, a CCD camera is preferable as the observation area size.

  If a charge-coupled device of the X-ray direct detection type is used, it is possible to detect single photons of fluorescent X-rays and select their energy, so that it is possible to observe the fluorescent X-ray intensity for each element. preferable. In addition, an imaging plate, a multi-wire X-ray detector, etc. are considered as a two-dimensional detector.

On the other hand, examples of the angle divergence limiting means (8) include a fine tube and a tubular collimator. When the detector (71) is combined with a two-dimensional detector or the like constituted by an assembly, a fine tube assembly can be adopted. This fine tube aggregate is made of, for example, a material in which X-rays can be blocked (such as a glass plate) is precisely and regularly drilled, or glass in which fine pipes are regularly arranged and integrated. It can be a board. Such a microtubule aggregate is generally known as a “collimator plate” or “capillary plate”, but various microtubule assemblies may be used as long as they have a function of limiting the angle divergence of fluorescent X-rays. These means or means newly prepared to have the function can be used as the angle divergence limiting means (8).

Furthermore, in the invention of this application, the individual detection means (7) includes a plurality of samples (3) on the substrate (2).
), The angle divergence limit level corresponding to the sample distribution, resolution, element size, and arrangement may be specially provided.

The resolution of the fluorescent X-ray image determined by the angle divergence limiting means (8) is calculated as follows.
When the angle divergence limiting means (8) is, for example, a fine tube having an inner diameter of 6 μm and a length of 1 mm, fluorescent X
The angle divergence of the line is limited to 6/1000 rad (radians). If the distance between the sample (3) surface (41) and the detection element is 3 mm, the resolution of the image is 18 μm because the product of the angle divergence and (distance between the sample surface and the detection element). . However, for example, in the case of a combinatorial sample in which synthesis conditions are uniform in a 1 mm size sample region (for example, 31) and samples having different conditions (for example, 31, 32, and 33) are arranged at intervals of 1 mm, dozens of μm The resolution is over-spec, and in practice, it is sufficient to have a structure that can distinguish at least each sample unit and observe signals from each as individual signals. That is, for example, when the angle divergence limiting means (8) is a microtubule assembly, it is sufficient and wasteful to receive fluorescent X-rays generated from one sample (for example, 31) with one or a few specific microtubules. It is only necessary to provide an angle divergence limiting means (8) that suppresses divergence to the outside and suppresses fluorescent X-rays from another sample (for example, 32) from being mixed.

In some cases, the combinatorial sample can be sufficiently evaluated if it can be analyzed with a resolution of 1 mm or the like. In such a case, for example, an inner diameter of 300 is used as the angle divergence limiting means (8).
If a micro tube of μm and a length of 1 mm is selected, the resolution is about 0.9 mm when the distance between the sample surface and the detection element is 3 mm. In particular, when the combinatorial sample is composed of sample units that are independent and separated from each other, if the resolution is smaller than the distance between each other, the separated signal can be observed. is there.

Furthermore, according to the sample distribution on the combinatorial sample, micro tubes and tubular collimators are arranged one by one at intervals to be evaluated on the combinatorial sample, or according to the arrangement of the sample (3) on the combinatorial sample, Place and arrange micro tubes and tubular collimators one by one directly above each sample (eg 31, 32, 33), and install so that only each sample (eg 31, 32, 33) can be seen You can also

  If the detector (71) is a two-dimensional detector, the imaging resolution determined by its own element size or the like is selected according to the sample, or a zero-dimensional (no position resolution) detector, for example, A plurality of scintillation counters or semiconductor detectors having an appropriate light receiving window size can be arranged and handled as a two-dimensional detector. The arrangement at this time can be adjusted to the optimum positional relationship according to the arrangement of the sample (3) on the combinatorial sample.

In general, in the detection of a signal, improving the resolution will lower the detection efficiency. Even in the angle divergence limiting means (8), the strict angle divergence limitation is caused by the fact that the fluorescent X-ray components excluded by the limitation are not. Since it means an increase, the angle divergence limit more than necessary leads to a simple loss of the fluorescent X-ray signal. Therefore, by selecting a resolution that matches the distribution of the sample (3) on the substrate (2) as much as possible, the number of effective fluorescent X-rays that reach the detector is increased, which is preferable from the viewpoint of fluorescent X-ray observation efficiency.

  Here, an example using a particularly preferred angle divergence limiting means (8) is shown.

  In this example, as the angle divergence limiting means (8) constituting the detection means (7), each one is directly above each of the samples (3) in accordance with the arrangement of the samples (3) on the combinatorial sample. Use a collimator placed so that only the area of sample (3) is expected. Here, one collimator has a single tubular shape. Accordingly, the angle divergence limiting means (8) is an aggregate of tubular collimators as many as the number of samples (3), and the fluorescent X-rays generated from one sample (3) are received by one collimator so as not to diverge outside. The angle divergence limiting means (8) suppresses the fluorescent X-ray from another sample (3) so as not to be mixed.

As a result of such angle divergence limiting means (8), the intensity of the fluorescent X-rays reaching the detector (71) is remarkably improved, and the time required to capture the fluorescent X-ray image is greatly reduced. . In addition, fluorescent X-rays that can be observed with high accuracy from a very small amount of sample such as a combinatorial sample can be made to reach the detection unit (71), and sufficiently strong and reliable fluorescent X-ray information can be obtained. become able to.

In the invention of this application, one substrate (1) is also obtained by the fluorescent X-ray analysis method as described above.
The fluorescent X-ray analyzer for simultaneously performing the fluorescent X-ray analysis of the plurality of samples (3) formed in (1) is also provided. Specifically, such an apparatus comprises at least (a) an X-ray source (5) and (b)
An incident angle (θ) when a substrate (2) on which a plurality of samples (3) are formed can be fixed and the surface of the substrate (2) is irradiated with X-rays (1) from an X-ray source (5) And a sample stage (6) that can adjust the incident direction (ψ), and (c) an individual detector (71) that can detect fluorescent X-rays generated from each sample (3) and is aimed at each sample (3) ) Are included in the detection means (7).
Further, the X-ray source (5) has a single color or a narrow energy width, and includes X-rays in an energy region including absorption edges of elements constituting a plurality of samples (3) formed on one substrate (2). (1) can be irradiated and the energy range can be changed, as described above, qualitative analysis, quantitative analysis and sample composition analysis of the target element contained in the sample (3) can be performed simultaneously. In addition, it is possible to simultaneously analyze the electronic state, valence, local structure around the constituent element, etc. of each constituent element by fluorescent XAFS.

In the fluorescent X-ray analysis apparatus of the invention of this application, the detection means (7) further includes a detection unit (71) disposed close to the substrate (2), a substrate (2), and the detection unit (71). Fluorescence X
The above-described configuration including the angle divergence limiting means (8) for limiting the angle divergence of the line is preferable, and the detection unit (71) may be a one-dimensional or two-dimensional detector.

From the above, the fluorescent X-ray analysis method of the invention of this application is reduced in the measurement time and efficiency by simultaneous analysis, compared with the conventional method in which each sample portion on the combinatorial sample is individually targeted. Are better. In addition, since a plurality of samples (3) are analyzed simultaneously, there is also an advantage that the measurement conditions in the sample region (30) are equal.

  Hereinafter, embodiments will be described with reference to the accompanying drawings, and embodiments of the present invention will be described in more detail.

<Example 1>
FIG. 4 is a schematic diagram showing an example of a fluorescent X-ray analyzer according to the invention of this application.

In the fluorescent X-ray analyzer of FIG. 4, X-rays (1) that have been made monochromatic by a Si (111) double crystal monochromator (51) and passed through an entrance slit (52) having a width of 0.6 mm and a length of 20 mm are obtained. The combinatorial sample (3) produced on the substrate (2) was irradiated at an incident angle (θ) of about 3.5 °.

A glass collimator plate (8) having a hole diameter of 6 μmφ regularly and two-dimensionally formed in a glass plate having a thickness of 1 mm and a diameter of 25 mm and having an aperture ratio of 55% or more at an effective diameter of 20 mm is incorporated. A CCD camera (7) was placed directly above the combinatorial sample (3) in the vertical direction. By adjusting the height of the combinatorial sample (3) or CCD camera (7), the CCD camera (7) has a gap that allows the incident X-ray (1) to irradiate the sample (3).
The light-receiving window was able to be as close as possible to the combinatorial sample (3). The size of the charge coupled device (71), which is a component of the CCD camera (7) and serves as an X-ray detector, is 8 m.
The number of pixels is 1000 × 1000 at the m-square.

  The combinatorial sample was obtained by arranging samples having different synthesis conditions of manganese and cobalt in a 3 × 3 arrangement in a 8.5 mm square area on a flat alumina substrate in a unit (pixel) form (FIG. 7). ).

About this sample (3), it analyzed using the synchrotron radiation experiment facility BL-16A1 of a high energy accelerator research organization using said fluorescence X-ray-analysis apparatus. The incident X-ray energy was 6.57 keV, and the image was taken with a CCD camera (7) with an exposure time of 1 second.

  As shown in FIG. 8, fluorescent X-rays from each sample unit were observed in the 8 mm square region corresponding to the combinatorial sample.

  Further, the monochromator (51) was adjusted to observe the X-ray fluorescence at the energy above and below the absorption edge for each of the manganese K absorption edge and the cobalt K absorption edge. The intensity was integrated.

  For the inside of the square frame in FIG. 8C, the counts in each pixel of the CCD were summed, and the results are shown in Table 1. The jump at the bottom of Table 1 was regarded as the intensity of K fluorescent rays from manganese and cobalt, respectively.

  However, since the K fluorescent line generated from cobalt has higher energy than the K absorption edge of manganese, it was confirmed that a part was absorbed by manganese coexisting in the sample and became weak. Strict correction is required for accurate quantitative analysis, but the cobalt to manganese jump ratio was 0.63 / 0.35 = 1.8. Considering that the fluorescent line from cobalt is absorbed by manganese and is observed to be weak, it is suggested that the composition of manganese: cobalt is approximately 1: 2. Therefore, an approximate composition ratio of the obtained combinatorial material could be obtained.

<Example 2>
With respect to the combinatorial sample of Example 1, the dependency of the fluorescent X-ray intensity on the incident X-ray energy was examined using the fluorescent X-ray analyzer shown in FIG.

  By scanning the angle of the monochromator, the incident X-ray energy was changed from the bottom to the top of the manganese K absorption edge, and the fluorescent X-ray intensity was measured with an exposure time of 1 second.

  The X-ray fluorescence intensity is integrated for each of the LL, UL, UR, LR, and C regions in FIG. 8, and the X-ray energy is normalized on the horizontal axis and the normalized X-ray fluorescence intensity is on the vertical axis. XANES spectra were obtained (Figure 9). The valence and chemical state of manganese were confirmed from the energy and spectral shape of the absorption edge.

  From the above, it has been clarified that when the nitric acid concentration is high, the valence of manganese increases even when heated at 220 ° C. (LR) or 350 ° C. (UR). On the other hand, when nitric acid is not added or when the nitric acid concentration is low, the valence of manganese does not increase by heating at 220 ° C. (LL) or 285 ° C. (C), but it is heated at 350 ° C. even when nitric acid is not added. It has been shown that the valency of (UL) manganese increases.

The time required for this measurement was about 13 minutes, which was equivalent to the time required for measuring a normal XAFS spectrum for one sample. However, since the spectra for 9 samples could be obtained at the same time, the total time was significantly reduced.
<Example 3>
As shown in FIG. 10 and FIG. 11, a collimator plate A (81) having a thickness of 1 mm with a hole having a diameter of 2 mm so as to be close to the combinatorial sample substrate (2), and an inner diameter of 1. A collimator plate B (82) with a thickness of 1 mm with a 5 mm hole is provided, and the fluorescent X-rays from each sample (3) are received by a pair of holes in the two collimator plates A (81) and B (82). To reach the detector (71) (by placing two collimator plates close to each other, one collimator plate facing each sample has a simple annular structure. The angle divergence limiting effect is similar to that of

X-rays from the bending magnet of the synchrotron radiation experimental facility BL-4A at the High Energy Accelerator Research Organization were monochromatized to 9.3 keV by the Si (111) double crystal monochromator (51), and incident with a width of 0.6 mm and a length of 20 mm A CCD having a charge coupled device (71) of 1000 × 1000 pixels through the slit (52) and irradiating the copper foil sample on the substrate (2) through the collimator plates A (81) and B (82). X-ray fluorescence was observed with a camera (7). A circular fluorescent X-ray spot reflecting the shape of the holes in the collimator plates A (81) and B (82) is observed as an image on the CCD, corresponding to the fluorescent X-ray signal from one sample (3). X-ray intensity was examined for 3000 pixels in a circle.

As a result, the imaging time is 0.25 seconds, the average count per pixel is 15837, the average count per pixel per second is 63348, the imaging time is greatly reduced, and reliability with sufficient strength High fluorescence X-ray information was obtained.

  As described above in detail, according to the present invention, fluorescent X-rays from a plurality of samples formed on one substrate are observed in parallel, and the composition and element chemistry of samples with different synthesis conditions are obtained with high accuracy and in a short time. A new fluorescent X-ray analysis method and apparatus for analyzing the state and structure simultaneously are provided.

  By using this fluorescent X-ray analysis method and apparatus, the material evaluation in the combinatorial material synthesis method can proceed at a high speed, and as a result, both the synthesis and the evaluation can be efficiently performed and a large number of systems and substances can be screened. become. Therefore, further development of the combinatorial material synthesis method can be achieved.

It is a schematic diagram explaining the lower limit of the incident angle (θ) of irradiated X-rays in the fluorescent X-ray analysis method of the invention of this application. It is a schematic diagram explaining the upper limit of the incident angle ((theta)) of the irradiation X-ray in the fluorescent-X-ray-analysis method of invention of this application. In the fluorescent X-ray analysis method of the invention of this application, it is a schematic diagram illustrating the incident angle (θ) of irradiated X-rays when the height of a sample is not constant. It is a principal part block diagram which showed an example of the fluorescent-X-ray-analysis apparatus of invention of this application. It is the schematic schematic which showed an example of the installation method of the sample in the fluorescent-X-ray-analysis method of invention of this application. It is the schematic schematic diagram which showed an example of the installation method of a sample and the incident direction ((psi)) of irradiation X-ray in the fluorescent X-ray-analysis method of invention of this application. In Example 1 of this invention, it is a figure replaced with the photograph which showed the produced combinatorial sample. In Example 1 of this invention, it is the figure which showed the fluorescence X-ray image obtained by injecting a monochromatic X-ray of 6.57 keV. In Example 2 of this invention, it is a XANES spectrum which measured the fluorescence X-ray integrated intensity from each sample unit of a combinatorial sample near manganese K absorption edge. In Example 3 of this invention, it is the figure which showed the collimator board used for the angle divergence limiting means. It is the schematic diagram which showed the incident X-ray in Example 3 of this invention, the board | substrate which has a sample, an angle divergence limiting means, a fluorescent X-ray, and a detection part.

Explanation of symbols

1 X-ray
11 Incident X-ray vector 2 Substrate 3 Sample
30 Sample area
31 samples (upstream side)
311 lowest part
32 samples (near the center)
33 Sample (downstream side)
331 top
332 Downstream end
34 Sample areas
41 surface
42 Lower part 5 X-ray source
51 Double crystal monochromator
52 Entrance slit 6 Sample stage 7 Detection means, CCD camera
71 detector, charge coupled device 8 angle divergence limiting means, collimator plate
81, 82 Collimator plate

Claims (12)

A method of performing X-ray fluorescence analysis simultaneously on a plurality of samples formed on one substrate, wherein the following formula (I) is applied to the substrate surface on which the plurality of samples are formed:

(Where h represents the height of the sample from the substrate, and l represents the distance between the samples measured along the vector obtained by projecting the incident X-ray vector onto the substrate surface)
If the value meets or exceeds the following formula (II)
(Where H represents the beam width of the incident X-ray, L represents the distance from the lowest part of the sample on the most upstream side to the downstream end of the sample on the most downstream side, and h represents the distance from the substrate of the sample. Represents height)
X-rays are irradiated at an incident angle θ equal to or less than a value satisfying the above, and the fluorescent X-rays generated from each sample region are simultaneously detected by a detection means configured by a collection of individual detection units that are aimed at at least each sample region. X-ray fluorescence analysis method characterized by detecting.   The X-ray fluorescence analysis method according to claim 1, wherein an incident angle θ of the X-ray is 0.1 to 5 ° with respect to the substrate.   3. The fluorescent X-ray according to claim 1, wherein the X-ray has a monochromatic or narrow energy width and has an energy region including absorption edges of elements constituting a plurality of samples formed on one substrate. Line analysis method.   4. The fluorescent X-ray analysis method according to claim 1, wherein the plurality of samples formed on one substrate are combinatorial samples formed by a combinatorial material synthesis method.   The detection means includes at least a detection unit disposed in the vicinity of the substrate, and an angle divergence limiting unit for limiting the angle divergence of fluorescent X-rays between the substrate and the detection unit. Item 5. The fluorescent X-ray analysis method according to any one of Items 1 to 4.   6. The fluorescent X-ray analysis method according to claim 5, wherein the angle divergence limiting means comprises at least a collection of individual collimators each aiming at one-to-one with each sample region.   The fluorescent X-ray analysis method according to claim 5 or 6, wherein the detection unit is a one-dimensional or two-dimensional detector. at least,
An X-ray source;
A sample stage capable of fixing a substrate on which a plurality of samples are formed and adjusting an incident angle and an incident direction when irradiating the surface of the substrate with X-rays from an X-ray source;
A fluorescent X-ray analyzer characterized by having a detecting means configured to collect individual detection units that are capable of detecting fluorescent X-rays generated from each sample region and at least aiming at each sample region.   The X-ray source has a single color or a narrow energy width, can irradiate X-rays in an energy region including absorption edges of elements constituting a plurality of samples formed on one substrate, and can vary the energy region. The fluorescent X-ray analyzer according to claim 8, which can be performed.   The detection means includes at least a detection unit disposed in the vicinity of the substrate, and an angle divergence limiting unit for limiting the angle divergence of fluorescent X-rays between the substrate and the detection unit. Item 8. The fluorescent X-ray analyzer according to item 8 or 9.   11. The fluorescent X-ray analysis apparatus according to claim 10, wherein the angle divergence limiting means includes at least one set of individual collimators each aiming one-to-one with each sample region. The fluorescent X-ray analysis apparatus according to claim 10 or 11, wherein the detection unit is a one-dimensional or two-dimensional detector.