X-ray analysis device

Abstract

An x-ray analysis device according to the present invention is to analyze the elements included in a measurement sample transported in a prescribed direction and comprises an x-ray irradiation unit that radiates x-rays toward the measurement sample, an x-ray detection unit that faces the measurement sample and detects x-ray fluorescence produced from the measurement sample, and a standard sample that has a known element content and is provided in a region of overlap between a region irradiated with the x-rays radiated from the x-ray irradiation unit and a region in which x-ray fluorescence can be detected by the x-ray detection unit.

Description

X-ray analyzer

[0001] The present invention relates to an X-ray analysis apparatus.

[0002] Conventionally, a method for quantitatively or qualitatively analyzing elements in a transported sample has been to use an X-ray fluorescence analyzer, as disclosed in Patent Document 1. This X-ray fluorescence analyzer irradiates the transported sample with X-rays from an X-ray source and detects the fluorescent X-rays emitted from the sample with an X-ray detector, thereby determining the composition ratio, film thickness, etc. of the sample.

[0003] Japanese Patent Application Laid-Open No. 2022-13497

[0004] However, when calibrating an X-ray detector, a separate measurement for calibration must be performed, separate from the normal measurement, using a standard sample whose components and concentrations are known at the measurement position. In the case of an X-ray analyzer that analyzes transported samples as described above, the standard sample must be placed next to the process line, and during calibration, the X-ray analyzer must be temporarily moved to measure the standard sample. This means that measurements of test samples cannot be performed while the standard sample is being measured, resulting in periods of missing measurement data. Furthermore, when a process line is operating for a long period of time, the calibration interval becomes longer, and even if a deviation in the measurement value occurs during that time, the deviation cannot be detected.

[0005] The present invention has been made to solve all of the above problems at once, and its main objective is to enable calibration work to be performed simultaneously while analyzing a transported measurement sample in an X-ray fluorescence analyzer that analyzes the measurement sample.

[0006] That is, the X-ray analysis apparatus according to the present invention analyzes elements contained in a measurement sample transported in a predetermined direction, and is characterized by comprising an X-ray irradiation unit that irradiates X-rays toward the measurement sample, an X-ray detection unit that faces the measurement sample and detects fluorescent X-rays generated from the measurement sample, and a standard sample whose contained elements are known and that is placed in an overlapping area between an irradiation area of ​​X-rays irradiated from the X-ray irradiation unit and an area where fluorescent X-rays can be detected by the X-ray detection unit.

[0007] With this configuration, a standard sample containing known elements is placed in the overlapping region between the irradiation region of X-rays irradiated from the X-ray irradiation unit and the detectable region of fluorescent X-rays by the X-ray detection unit, so that the X-ray detection unit can simultaneously detect the fluorescent X-rays emitted from the measurement sample and the standard sample. This makes it possible to calibrate the X-ray detection unit while analyzing the measurement sample. For example, energy calibration of the X-ray analysis device can be performed by pre-storing information about the fluorescent X-ray energy of the elements contained in the standard sample, comparing the energy of the elements contained in the standard sample with the peak position of the element in a spectrum generated based on the output of the X-ray detection unit, and calculating the amount of deviation.

[0008] A specific embodiment of the X-ray analysis apparatus further includes a spectrum generation unit that generates a measured spectrum, which is a spectrum of fluorescent X-rays emitted from the measurement sample, based on the output of the X-ray detection unit, an element information storage unit that stores first energy information related to the energy of fluorescent X-rays specific to a first element contained in the standard sample, a peak detection unit that analyzes the generated measured spectrum and detects a peak corresponding to the first element, and a calibration unit that performs energy calibration based on the first energy information stored in the element information storage unit and information related to the position of the peak of the first element detected by the peak detection unit. With this type of apparatus, it is possible to grasp the amount of deviation between the first energy information and the position of the peak of the first element by comparing them, and thereby perform energy calibration of the X-ray analysis apparatus.

[0009] In addition, it is preferable that the X-ray analysis apparatus be configured such that the standard sample or the measurement sample contains a second element different from the first element, the element information storage unit stores second energy information relating to the energy of fluorescent X-rays specific to the second element, the peak detection unit analyzes the measured spectrum to detect a peak corresponding to the second element, and the calibration unit performs energy calibration based on the first energy information and second energy information stored in the element information storage unit and information on the positions of the peaks of the first element and the second element detected by the peak detection unit. In this way, energy calibration of the X-ray analysis apparatus can be performed more accurately by using information on the positions of two peaks in the fluorescence spectrum.

[0010] In order to enable intensity calibration of the X-ray analysis device simultaneously with the analysis of the measurement sample, the element information storage unit may further store standard intensity information regarding the intensity of the fluorescent X-rays originating from the first element, which information has been obtained in advance by irradiating the standard sample with X-rays, and the calibration unit may perform intensity calibration based on the standard intensity information stored in the element information storage unit and information regarding the peak intensity of the first element detected by the peak detection unit.

[0011] In the X-ray analysis apparatus, the spectrum generation unit generates, as the measured spectra, an analytical spectrum to be used for analyzing the measurement sample and a calibration spectrum to be used for calibration in the calibration unit, and it is preferable that the number of spectrum integrations when generating the calibration spectrum is greater than the number of spectrum integrations when generating the analytical spectrum. In this way, quantitative analysis of the measurement sample is performed at short intervals using an analytical spectrum with a relatively small number of integrations, while calibration is performed using a calibration spectrum with a larger number of integrations and a relatively large S / N ratio than the analytical spectrum, thereby enabling accurate calibration work.

[0012] It is preferable that the spectrum generating unit generates the calibration spectrum by integrating, from among a plurality of most recently generated measured spectra, a plurality of measured spectra having fewer noise components near the peak corresponding to the first element. In this way, by integrating spectra having fewer noise components (background) near the peak corresponding to the first element, it is possible to generate a more accurate calibration spectrum to be compared with the first energy information.

[0013] The X-ray analysis apparatus preferably further includes a reference spectrum storage unit that stores a reference spectrum for determining the timing of calibration by the calibration unit, and a spectrum comparison unit that compares the stored reference spectrum with the measured spectrum generated by the spectrum generation unit to determine whether they are similar to each other. If the spectrum comparison unit determines that the measured spectrum and the reference spectrum are similar, the peak detection unit performs analysis of the measured spectrum. This configuration allows calibration to be performed only when the measured spectrum is highly similar to the pre-stored reference spectrum, thereby enabling calibration to be performed at an appropriate time without receiving external instructions. This configuration is particularly effective when the measurement sample is one in which different states repeatedly occur, such as a substrate intermittently coated with a coating.

[0014] A specific embodiment of the X-ray analysis device is one in which the measurement sample repeatedly exhibits multiple states in which the constituent elements are different from one another in the overlapping region as it is transported, and the reference spectrum is a spectrum generated based on the output of the X-ray detection unit in one of the multiple states.

[0015] The peak position of the detected first element gradually fluctuates due to temperature changes in the surrounding environment, etc., and therefore rarely fluctuates suddenly during analysis. Therefore, in the X-ray analysis apparatus, it is preferable that the element information storage unit stores, as the first energy information, a reference peak position, which is a peak position corresponding to the energy of fluorescent X-rays specific to the first element, and the calibration unit performs energy calibration when the deviation between the peak position of the first element detected by the peak detection unit and the reference peak position stored in the element information storage unit is equal to or greater than a predetermined value. In this manner, energy calibration is not performed every time a measured spectrum is analyzed and a peak position is detected, but rather when the peak position of the first element contained in the standard sample gradually fluctuates and deviates from the reference peak position to an extent that may affect measurement accuracy. This reduces the calibration frequency while maintaining measurement accuracy and improves the processing speed of the calibration unit.

[0016] In the X-ray analysis apparatus, it is preferable that the peak detection unit detects the peak corresponding to the first element from the measured spectrum by referring to information about the reference peak position stored in the element information storage unit. In this way, the peak detection unit searches for the peak of the first element starting from the vicinity of the reference peak position where the peak of the first element is likely to exist, thereby reducing the time required for peak detection.

[0017] To detect only the fluorescent X-rays originating from the measurement sample in the X-ray detection unit and reduce noise components, it is desirable that the overlap area between the X-ray irradiation area by the X-ray irradiation unit and the detectable area by the X-ray detection unit be formed only near the surface of the measurement sample. However, in the case of analyzing a transported measurement sample as in the present invention, if the measurement sample is transported, for example, on a conveyor belt or in the form of a film transported roll-to-roll, the measurement sample flutters during transport. If a standard sample is placed in the overlap area formed near the surface of the measurement sample, the fluttering measurement sample may come into contact with the standard sample. Therefore, in the X-ray analysis device, in consideration of the fluttering of the measurement sample, it is desirable to set the overlap area not only near the surface of the measurement sample but also at a sufficient distance (safety distance) from the surface, and to place the standard sample in the overlap area at the safety distance. This safety distance is a distance that does not interfere with (reach) the transported measurement sample even if it flutters.

[0018] A more specific embodiment of the X-ray analysis apparatus is one that further includes a housing that houses the X-ray irradiator and the X-ray detector, and has an opening formed in one side wall through which X-rays generated from the X-ray irradiator and fluorescent X-rays generated from the measurement sample pass, and the standard sample is placed in the overlapping area set near the opening in the housing. With this configuration, by providing an overlapping area within the housing and placing the standard sample in the overlapping area within the housing, it is possible to bring the X-ray irradiator and the X-ray detector as close as possible to the surface of the measurement sample while placing the standard sample at a safe distance.

[0019] Specific examples of the standard sample include those in the form of a wire, mesh, ring, or film. If the standard sample has such a configuration, even when placed in the overlapping region, it will be able to easily pass most of the X-rays irradiated from the X-ray irradiation unit and directed toward the measurement sample, and also pass most of the fluorescent X-rays generated from the measurement sample and directed toward the X-ray detection unit, making it possible to perform calibration work without interfering with the analysis of the measurement sample.

[0020] According to the present invention as described above, in an X-ray fluorescence spectrometer that analyzes a transported measurement sample, it is possible to perform calibration work while analyzing the measurement sample.

[0021] The present invention relates to an X-ray analysis apparatus and an X-ray analyzer, and an X-ray analyzer for use in an X-ray analysis of an X-ray source.

[0022] An X-ray analysis apparatus 100 according to an embodiment of the present invention will be described below with reference to the drawings.

[0023] 1 , the X-ray analysis apparatus 100 of this embodiment is a so-called fluorescent X-ray analysis apparatus that irradiates X-rays (also called primary X-rays) toward a measurement sample W being transported in a predetermined transport direction (left-right direction on the page) and detects fluorescent X-rays (also called secondary X-rays) generated from the measurement sample W, thereby quantitatively or qualitatively analyzing elements contained in the measurement sample W. As will be described in detail below, the X-ray analysis apparatus 100 of this embodiment is configured to calibrate the X-ray detection unit 2 while simultaneously analyzing the elements contained in the transported measurement sample W (i.e., while the measurement sample W is being transported).

[0024] The measurement sample W in this embodiment is formed by applying a film material W2 to one surface of a film-like substrate W1, and is transported along the transport direction at a substantially constant speed, for example, by a roll-to-roll transport mechanism (not shown). The film material W2 constituting the measurement sample W is applied to the surface of the substrate W1 at substantially constant intervals along the transport direction. The X-ray analysis device 100 is positioned so as to irradiate X-rays onto the film material W2 of the measurement sample W and detect the generated secondary X-rays.

[0025] Specifically, this X-ray analysis device 100 includes an X-ray irradiation unit 1 that irradiates a measurement sample W with primary X-rays, an X-ray detection unit 2 that detects secondary X-rays generated from the measurement sample W, and an information processing device 4 that analyzes the measurement sample W based on the output from the X-ray detection unit 2.

[0026] The X-ray irradiation unit 1 includes an X-ray source and a collimator. The X-ray source includes an X-ray tube, and generates primary X-rays by exciting a target metal with thermoelectrons generated from a filament. The collimator has a passage window that allows the primary X-rays generated by the X-ray source to pass through, and the passage window narrows the irradiation angle of the primary X-rays.

[0027] The X-ray irradiation unit 1 of this embodiment configured as described above irradiates radial primary X-rays that spread at a predetermined radiation angle θ1 toward the measurement sample W. In this embodiment, the X-ray source is disposed so that the central axis A1 of the radiated primary X-rays is perpendicular to the surface of the measurement sample W.

[0028] The X-ray detection unit 2 includes an X-ray detector 21 and a signal processing unit 22 that processes signals from the X-ray detector 21 and outputs the processed signals to the information processing device 4 .

[0029] The X-ray detector 21 is configured using, for example, an X-ray detection element such as a Si element (e.g., a silicon drift detector (SDD)). The field of view θ2 of this X-ray detector 21, at which secondary X-rays can be detected, is set within a predetermined range, and the detector 21 can detect secondary X-rays generated within the field of view. The X-ray detector 21 is disposed so that the central axis A2 of its detection field of view is inclined with respect to the surface of the measurement sample W.

[0030] The signal processing unit 22 detects the integrated amount of charge output when fluorescent X-rays generated from the measurement sample W are incident on the X-ray detector 21 and converts the integrated amount into an integrated signal (voltage signal) corresponding to the integrated amount. The signal processing unit 22 then shapes the integrated signal into a trapezoidal pulse signal having a peak value corresponding to the energy of the fluorescent X-rays, detects the peak value of the pulse signal, and outputs the detected peak value to the information processing device 4. The signal processing unit 22 of this embodiment pre-stores a calibration coefficient (hereinafter also referred to as a first calibration coefficient) for energy calibration and calculates the calibrated peak value by multiplying the detected peak value by the first calibration coefficient. The signal processing unit 22 then counts the calibrated peak values ​​by peak height using a multichannel analyzer and outputs peak-height count data indicating the count number for each peak height to the information processing device 4. The signal processing unit 22 accumulates and integrates the count number for each peak height output from the multichannel analyzer for a predetermined period of time and outputs the count data to the information processing device 4 as peak-height count data.

[0031] The X-ray irradiator 1 and the X-ray detector 2 are housed in a housing 3. An opening 3a is formed in one side wall 31 of the housing 3, and primary X-rays emitted from the X-ray irradiator 1 at a radiation angle θ1 pass through the opening 3a and are irradiated onto the measurement sample W. Secondary X-rays generated from the measurement sample W also pass through the opening 3a and are detected by the X-ray detector 21.

[0032] An irradiation area 1R of the primary X-rays irradiated from the X-ray irradiator 1 and a detectable area 2R in which secondary X-rays can be detected by the X-ray detector 21 are arranged in the housing 3 so as to overlap at least on the surface of the measurement sample W. As shown in Figure 1, the irradiation area 1R of the X-ray irradiator 1 and the detectable area 2R of the X-ray detector also overlap near the opening 3a in the housing 3.

[0033] 2, the information processing device 4 is a computer having a CPU, memory, an input / output interface, a display, input means, etc., and performs the functions of at least a spectrum generation unit 41 that generates a fluorescent X-ray spectrum based on the output of the X-ray detection unit 2 (i.e., the calibrated pulse height value), and an analysis unit 42 that performs qualitative or quantitative analysis of elements contained in the measurement sample W based on the fluorescent X-ray spectrum. The fluorescence spectrum displays the intensity of secondary X-rays (the number of counts per second) as a function of energy.

[0034] The spectrum generation unit 41 generates an X-ray spectrum based on the pulse height-specific count data output from the X-ray detection unit 2. The spectrum generation unit 41 of this embodiment stores in advance a calibration coefficient (hereinafter also referred to as a second calibration coefficient) for performing intensity calibration, and outputs a calibrated X-ray spectrum (hereinafter also referred to as a measured spectrum) obtained by multiplying the X-ray intensity of the generated X-ray spectrum by the second calibration coefficient. The spectrum generation unit 41 of this embodiment is configured to generate measured spectra at predetermined time intervals (for example, every 3 seconds) and output them to the analysis unit 42 sequentially.

[0035] Thus, the X-ray analysis apparatus 100 of this embodiment is provided with a standard sample 5 placed at a predetermined position (calibration position) in the overlapping region between the irradiation region 1R of X-rays irradiated from the X-ray irradiation unit 1 and the detectable region 2R of fluorescent X-rays by the X-ray detection unit 2, so that the X-ray detection unit 2 can be calibrated while analyzing the transported measurement sample W. This standard sample 5 is used for calibrating the X-ray detection unit 2, and contains one or more elements of known concentrations (none of which are elements contained in the measurement sample W). The standard sample 5 of this embodiment contains Mo (hereinafter referred to as the first element) as an element of known concentration.

[0036] Although placed in the overlapping region, the standard sample 5 has the property of passing most (e.g., 90% or more) of the X-rays irradiated from the X-ray irradiation unit 1 and directed toward the measurement sample W, and passing most (e.g., 90% or more) of the fluorescent X-rays generated from the measurement sample W and directed toward the X-ray detection unit 2. The standard sample 5 in this embodiment is specifically a single metal wire, and as shown in Fig. 3, is arranged along the direction in which the X-ray source and the X-ray detector 21 are aligned when viewed from the measurement sample W side, and more specifically, is arranged so as to coincide with the line connecting the central axis A1 of the X-ray source and the central axis A2 of the detection field of view of the X-ray detector 21.

[0037] Furthermore, the standard sample 5 is placed in a position where it will not interfere with the measurement sample W even if the transported measurement sample W flaps. Specifically, the standard sample 5 is placed at a safety distance from the surface of the measurement sample W, which is a distance that will not reach the measurement sample W even if the transported measurement sample W flaps. More specifically, in this embodiment, the positions and orientations of the X-ray irradiation unit 1 and the X-ray detection unit 2 are set so that an overlapping region is formed within the housing 3, and the standard sample 5 is placed in the overlapping region near the opening 3 a of the housing 3.

[0038] The information processing device 4 of this embodiment further functions as an element information storage unit 43, a peak detection unit 44, and a calibration unit 46.

[0039] The element information storage unit 43 stores in advance first energy information relating to the energy of fluorescent X-rays specific to a first element contained in the standard sample 5, and second energy information relating to the energy of fluorescent X-rays specific to a second element different from the first element. This second element is an element contained in the standard sample 5 or the measurement sample W, and in this embodiment, the element contained in the measurement sample W is defined as the second element.

[0040] The element information storage unit 43 also stores standard intensity information regarding the intensity of fluorescent X-rays originating from the first element, which is previously obtained by irradiating X-rays from the X-ray irradiation unit 1 onto the standard sample 5 set at the calibration position.

[0041] The peak detection section 44 analyzes the measured spectrum generated by the spectrum generation section 41 according to a predetermined algorithm such as a peak fitting method, and detects peaks corresponding to the first element and the second element.

[0042] The calibration unit 46 is configured to perform energy calibration of the X-ray detection unit 2 based on the first energy information and second energy information stored in the element information memory unit 43 and information regarding the positions of the peaks of the first element and the second element detected by the peak detection unit 44.

[0043] Specifically, the calibration unit 46 calculates the amount of deviation between the fluorescent X-ray energies indicated by the detected peak positions of the first and second elements and the fluorescent X-ray energies indicated by the first energy information and the second energy information, and performs energy calibration of the X-ray detection unit 2 to eliminate these deviations. More specifically, the first calibration coefficient pre-stored in the signal processing unit 22 of the X-ray detection unit 2 is updated to eliminate the calculated deviations. More specifically, as shown in FIG. 4 , the measured spectrum generated by the spectrum generation unit 41 contains a peak due to the first element contained in the standard sample 5 and a peak due to the second element contained in the measurement sample W. The calibration unit 46 performs energy calibration by comparing the energies indicated by the positions of these two peaks with the fluorescent X-ray energies indicated by the first energy information and the second energy information (more specifically, the stored first calibration coefficient is updated).

[0044] Furthermore, the calibration unit 46 of this embodiment is configured to perform intensity calibration based on the standard intensity information stored in the element information storage unit 43 and information related to the peak intensity of the first element detected by the peak detection unit 44. Specifically, the calibration unit 46 compares the intensity of the fluorescent X-rays derived from the first element stored in the standard intensity information with the detected peak intensity of the first element to calculate the amount of deviation, and updates the second calibration coefficient stored in the spectrum generation unit 41 so as to eliminate the amount of deviation.

[0045] In addition, in the X-ray analysis apparatus 100 of this embodiment, the information processing device 4 further functions as a reference spectrum storage unit 47 and a spectrum comparison unit 48 so that the calibration operation by the calibration unit 46 can be performed at an appropriate timing.

[0046] The reference spectrum storage unit 47 stores in advance a reference spectrum for determining the timing of calibration by the calibration unit 46. As described above, as the measurement sample W of this embodiment is transported, the surface of the film material W2 and the surface of the substrate W1 appear alternately in the overlap region, causing the measurement sample W to repeatedly exhibit various states (specifically, two states) of different constituent elements. This reference spectrum is a fluorescent spectrum obtained by irradiating X-rays onto the measurement sample W, which has been set to be in one of the multiple states before the start of analysis. In this embodiment, the spectrum of fluorescent X-rays generated from the substrate W1 is used as the reference spectrum, but this is not limited to this.

[0047] The spectrum comparison unit 48 compares the reference spectrum stored in the reference spectrum storage unit 47 with the measured spectrum generated by the spectrum generation unit 41 to determine whether they are similar to each other. Specifically, the spectrum comparison unit 48 calculates the similarity between the reference spectrum and the measured spectrum based on a predetermined known algorithm, and determines that they are similar to each other if the similarity is equal to or greater than a predetermined value.

[0048] If the spectrum comparison unit 48 determines that the measured spectrum and the reference spectrum are similar, the calibration unit 46 performs a calibration operation. Specifically, when the spectrum comparison unit 48 determines that the measured spectrum and the reference spectrum are similar, this triggers the peak detection unit 44 to analyze the measured spectrum and detect the peaks of the first and second elements, and then the calibration unit 46 performs a calibration operation (energy calibration and / or intensity calibration).

[0049] Furthermore, in this embodiment, in order to speed up the peak detection operation by the peak detection unit 44 and thereby speed up the calibration operation, the peak detection unit 44 detects peaks corresponding to the first element and the second element from the measured spectrum by referring to the first energy information and the second energy information stored in the element information storage unit 43. Specifically, in this embodiment, the element information storage unit 43 stores, as the first energy information and the second energy information, a first reference peak position and a second reference peak position, which are peak positions corresponding to the fluorescent X-ray energies specific to the first element and the second element, respectively. Then, the peak detection unit 44 detects the peaks of the first element and the second element from the newly generated measured spectrum using the first reference peak position and the second reference peak position as references.

[0050] Furthermore, in this embodiment, the calibration unit 46 is configured to compare the peak position of the first element detected by the peak detection unit 44 from the newly generated measured spectrum with the first reference peak position stored in the element information storage unit 43, and perform energy calibration of the X-ray detection unit 2 if the amount of deviation is equal to or greater than a predetermined value.

[0051] According to the X-ray analysis apparatus 100 of this embodiment configured as described above, the standard sample 5 containing known elements is placed in the overlapping region between the irradiation region 1R of X-rays irradiated from the X-ray irradiation unit 1 and the detectable region 2R of fluorescent X-rays by the X-ray detection unit 2. This allows the X-ray detection unit 2 to simultaneously detect the fluorescent X-rays emitted from the measurement sample W and the standard sample 5, making it possible to calibrate the X-ray detection unit 2 while analyzing the measurement sample W. For example, energy calibration of the X-ray detection unit 2 can be performed by pre-storing information regarding the fluorescent X-ray energy of the elements contained in the standard sample 5, comparing the energy of the element contained in the standard sample 5 with the peak position of the element in a spectrum generated based on the output of the X-ray detection unit 2, and calculating the amount of deviation.

[0052] The present invention is not limited to the above-described embodiment. For example, the metal wire serving as the standard sample 5 in the above-described embodiment is arranged along the direction in which the X-ray source and the X-ray detector 21 are aligned, but this is not limiting. In other embodiments, the metal wire serving as the standard sample 5 may be arranged along a direction intersecting the direction in which the X-ray source and the X-ray detector 21 are aligned. In this case, multiple metal wires may be arranged side by side in the direction in which the X-ray source and the X-ray detector 21 are aligned.

[0053] In other embodiments, the standard specimen 5 is not limited to a metal wire, but may be, for example, a mesh or film. When the standard specimen 5 is in a film form, it may be a thin film that is easily permeable to X-rays, such as a resin film of polyimide or the like, rolled beryllium foil, or graphene film, on which a metal layer is vapor-deposited.

[0054] In the above embodiment, the second element is contained in the measurement sample W, but this is not limiting. In other embodiments, the second element may be contained in the standard sample 5.

[0055] Furthermore, in the X-ray analysis apparatus 100 of the above embodiment, the calibration unit 46 calibrates the X-ray detector 21 based on information on the two peaks of the first element and the second element, but this is not limiting. In other embodiments, the calibration unit 46 may calibrate the X-ray detector 21 using only information on the peak of the first element, without using information on the peak of the second element.

[0056] Furthermore, the X-ray analysis apparatus 100 of another embodiment does not need to have the functions of the reference spectrum storage unit 47 and the spectrum comparison unit 48. The X-ray analysis apparatus 100 of one embodiment can perform energy calibration and / or intensity calibration as long as it can perform the functions of the spectrum generation unit 41, the element information storage unit 43, the peak detection unit 44, and the calibration unit 46.

[0057] Furthermore, the measured spectrum generated by the spectrum generation unit 41 may have the same or different number of spectrum integration times (or integration time) for the spectrum used for quantitative analysis in the analysis unit 42 and the spectrum used for various calibrations in the calibration unit 46. For example, when generating a measured spectrum (calibration spectrum) used for various calibrations in the calibration unit 46, the spectrum may be integrated more times (or the integration time may be longer) than when generating a measured spectrum (analysis spectrum) used for quantitative analysis in the analysis unit 42. This allows accurate calibration work while performing quantitative analysis at short intervals. For example, a calibration spectrum may be generated by integrating the analysis spectrum obtained every three seconds by integrating the spectrum for three seconds, and then integrating the most recent spectra multiple times.

[0058] Furthermore, when generating a calibration spectrum, the spectrum generating unit 41 preferably integrates, from among a plurality of analytical spectra generated most recently, a plurality of analytical spectra that have fewer noise components near the peak corresponding to the first element. Examples of "noise components near the peak corresponding to the first element" include those originating from the first element contained in the measurement sample rather than the standard sample, and those due to scattered X-rays. In other words, an "analytical spectrum with fewer noise components near the peak corresponding to the first element" refers to a spectrum in which the peak originating from the first element contained in the calibration sample is easy to detect.

[0059] Furthermore, it is more preferable that the spectrum generation unit 41 generates a calibration spectrum by integrating, from among a plurality of analytical spectra most recently generated, a plurality of analytical spectra in which noise components are small near the peak corresponding to the first element and in which a peak corresponding to the second element appears.

[0060] Furthermore, in order to determine whether the generated analytical spectrum is an "analytical spectrum with few noise components near the peak corresponding to the first element," the spectrum generating unit 41 may refer to the similarity with the reference spectrum calculated by the spectrum comparing unit 48. For example, if the similarity with the reference spectrum is equal to or greater than a predetermined value, a flag may be set for the analytical spectrum whose similarity has been calculated, indicating that the analytical spectrum is an "analytical spectrum suitable for integration to generate a calibration spectrum."

[0061] In another embodiment, the X-ray analysis apparatus 100 may include a distance measurement sensor that measures the distance between the measurement sample W and the measurement sample W that has entered the overlapping region, or an imaging device that images the measurement sample W that has entered the overlapping region. The spectrum generation unit 41 may determine whether the generated analysis spectrum is an "analysis spectrum with few noise components near the peak corresponding to the first element" based on information output from the distance measurement sensor or the imaging device. The spectrum generation unit 41 may also determine whether the generated analysis spectrum is an "analysis spectrum with few noise components near the peak corresponding to the first element" based on various information output from the transport mechanism (e.g., information related to the transport speed, time, etc.). For example, in the above embodiment, if the measurement sample W is a film-like substrate W1 with a film material W2 intermittently applied to one surface thereof, only the analysis spectrum generated based on the fluorescent X-rays emitted from the film material W2 may be flagged as an "analysis spectrum suitable for integration for generating a calibration spectrum" by referring to information output from the distance measurement sensor, the imaging device, or the transport mechanism.

[0062] In the X-ray analysis apparatus 100 of the above embodiment, the X-ray detection unit 2 stores the first calibration coefficients for performing energy calibration, and the X-ray detection unit 2 performs the energy calibration, but this is not limiting. In other embodiments, the information processing device 4 may store the first calibration coefficients, and the information processing device 4 (e.g., the spectrum generation unit 41) may perform the energy calibration.

[0063] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention.

[0064] According to the present invention, in an X-ray fluorescence spectrometer that analyzes a measurement sample being transported, calibration work can be performed simultaneously while analyzing the measurement sample.

[0065] REFERENCE SIGNS LIST 100: X-ray analysis apparatus 1: X-ray irradiation unit 1R: irradiation area 2: X-ray detection unit 2R: detectable area 5: standard sample W: measurement sample

Claims

1. An X-ray analysis device for analyzing elements contained in a measurement sample transported in a specified direction, comprising: an X-ray irradiation unit that irradiates X-rays towards the measurement sample; an X-ray detection unit that faces the measurement sample and detects fluorescent X-rays generated from the measurement sample; and a standard sample whose contained elements are known, positioned in an overlapping area between an irradiation area of ​​X-rays irradiated from the X-ray irradiation unit and an area where fluorescent X-rays can be detected by the X-ray detection unit.

2. The X-ray analysis apparatus of claim 1, further comprising: a spectrum generation unit that generates a measured spectrum, which is a spectrum of fluorescent X-rays generated from the measurement sample, based on an output of the X-ray detection unit; an element information storage unit that stores first energy information regarding the energy of fluorescent X-rays specific to a first element contained in the standard sample; a peak detection unit that analyzes the generated measured spectrum and detects a peak corresponding to the first element; and a calibration unit that performs energy calibration based on the first energy information stored in the element information storage unit and information regarding the position of the peak of the first element detected by the peak detection unit.

3. The X-ray analysis apparatus of claim 2, wherein the standard sample or the measurement sample contains a second element different from the first element, the element information storage unit stores second energy information relating to the energy of fluorescent X-rays specific to the second element, the peak detection unit analyzes the measured spectrum to detect a peak corresponding to the second element, and the calibration unit performs energy calibration based on the first energy information and second energy information stored in the element information storage unit and information relating to the positions of the peaks of the first element and the second element detected by the peak detection unit.

4. An X-ray analysis apparatus as described in claim 2 or 3, wherein the elemental information storage unit further stores standard intensity information regarding the intensity of fluorescent X-rays originating from the first element, which has been acquired in advance by irradiating the standard sample with X-rays, and the calibration unit performs intensity calibration based on the standard intensity information stored in the elemental information storage unit and information regarding the peak intensity of the first element detected by the peak detection unit.

5. An X-ray analysis apparatus as claimed in any one of claims 2 to 4, wherein the spectrum generation unit generates, as the actual measured spectrum, an analytical spectrum to be used in the analysis of the measurement sample and a calibration spectrum to be used for calibration in the calibration unit, and the number of times the spectrum is accumulated when the calibration spectrum is generated is greater than the number of times the spectrum is accumulated when the analytical spectrum is generated.

6. An X-ray analysis apparatus as described in claim 5, wherein the spectrum generation unit generates the calibration spectrum by integrating a plurality of measured spectra having less noise components near a peak corresponding to a first element from among a plurality of recently generated measured spectra.

7. An X-ray analysis apparatus as described in any one of claims 2 to 6, further comprising: a reference spectrum memory unit that pre-stores a reference spectrum for determining the timing of calibration by the calibration unit; and a spectrum comparison unit that compares the reference spectrum stored in the reference spectrum with a measured spectrum generated by the spectrum generation unit and determines whether they are similar to each other, wherein when the spectrum comparison unit determines that the measured spectrum and the reference spectrum are similar, the peak detection unit executes an analysis of the measured spectrum.

8. An X-ray analysis apparatus as described in claim 7, wherein the measurement sample repeatedly exhibits a plurality of states in which the constituent elements are different from one another in the overlapping region as the measurement sample is transported, and the reference spectrum is a spectrum generated based on the output of the X-ray detection unit in one of the plurality of states.

9. An X-ray analysis apparatus as claimed in any one of claims 2 to 8, wherein the elemental information storage unit stores, as the first energy information, a reference peak position which is a peak position corresponding to the energy of fluorescent X-rays specific to the first element, and the calibration unit performs energy calibration when a deviation between the peak position of the first element detected by the peak detection unit and the reference peak position stored in the elemental information storage unit is equal to or greater than a predetermined value.

10. An X-ray analysis apparatus as described in claim 9, wherein the peak detection unit detects a peak corresponding to the first element from the measured spectrum by referring to information regarding the reference peak position stored in the element information storage unit.

11. An X-ray analysis apparatus according to any one of claims 1 to 10, wherein the standard sample is placed in an area at a safety distance from the surface of the measurement sample being transported to ensure that the standard sample does not come into contact with the surface.

12. An X-ray analysis apparatus according to any one of claims 1 to 11, further comprising a housing that houses the X-ray irradiation unit and the X-ray detection unit, and has an opening formed in one side wall through which the X-rays generated from the X-ray irradiation unit and the fluorescent X-rays generated from the measurement sample pass, and the standard sample is placed in the overlapping area set in the vicinity of the opening in the housing.

13. An X-ray analysis apparatus according to any one of claims 1 to 12, wherein the standard sample is in the form of a wire, mesh, ring or film.

14. The X-ray analysis apparatus according to any one of claims 1 to 13, wherein the elements contained in the standard sample are different from the elements contained in the measurement sample.

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