Thickness measurement method, x-ray analysis device, information processing device, and computer program

Abstract

Provided are a thickness measurement method, an X-ray analysis device, an information processing device, and a computer program with which it is possible to measure the thickness of each layer of a multi-layer sample that is difficult to measure in the prior art. In the thickness measurement method, a sample including a plurality of layers is irradiated with X-rays so that the X-rays pass through the plurality of layers, fluorescent X-rays generated from the sample are detected, transmitted X-rays that have passed through the sample are detected, and the X-rays are measured. Creating a first relational expression indicating the relationship between the detected intensity of the transmitted X-rays and the thickness of each layer, and a second relational expression indicating the relationship between the theoretical ratio of the intensity of the fluorescent X-rays and the intensity of the transmitted X-rays and the ratio of the detected intensity of the fluorescent X-rays and the intensity of the transmitted X-rays according to the thickness of each layer; and calculating the thickness of each layer which simultaneously meets the first relational expression and the second relational expression.

Description

Technical Field

[0001] The present invention relates to a thickness measurement method, an X-ray analysis device, an information processing device, and a computer program for measuring the thickness of each layer included in a multi-layer sample. Background Art

[0002] Sometimes, it is desired to measure the thickness of each layer included in a multilayer sample. As a method for measuring the thickness of each layer of a multilayer sample, there is a method of irradiating the multilayer sample with X-rays, detecting fluorescent X-rays generated from the multilayer sample, and measuring the thickness of each layer based on the fluorescent X-rays. In addition, there is a method of detecting transmitted X-rays that have passed through the multilayer sample and measuring the thickness of each layer based on the transmitted X-rays. Patent Document 1 discloses a technique for measuring the thickness of a sample based on transmitted X-rays. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Publication No. 11-287643 Summary of the invention Technical Problems to be Solved by the Invention

[0004] In the method of measuring thickness based on fluorescent X-rays, the intensity of fluorescent X-rays generated from a part far from the surface becomes smaller, so there is a limit to the thickness that can be measured. Information related to the transmission X-rays after passing through a multi-layer sample becomes a superposition of information related to multiple layers. Therefore, it is difficult to measure the thickness of each layer based on transmission X-rays alone.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thickness measurement method, an X-ray analysis device, an information processing device, and a computer program capable of measuring the thickness of each layer of a multilayer sample which is difficult to measure in the prior art. Technical solutions for solving technical problems

[0006] A thickness measurement method according to one embodiment of the present invention is characterized in that a sample including multiple layers is irradiated with X-rays in such a manner that the X-rays pass through the multiple layers, fluorescent X-rays generated from the sample are detected, and transmitted X-rays after passing through the sample are detected, and a first relationship expression representing the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer and a second relationship expression representing the relationship between the theoretical ratio of the intensity of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the ratio of the intensity of the detected fluorescent X-rays and the transmitted X-rays are prepared, and the thickness of each layer that satisfies both the first relationship expression and the second relationship expression is calculated.

[0007] In one embodiment of the present invention, a sample including a plurality of layers is irradiated with X-rays, and fluorescent X-rays and transmitted X-rays are detected. The thickness of each layer is calculated so as to simultaneously satisfy a first relational expression representing the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer, and a second relational expression representing the relationship between the ratio of the theoretical intensity of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the ratio of the intensity of the detected fluorescent X-rays and the transmitted X-rays. Compared with the prior art that uses only the detection results of the fluorescent X-rays, a greater thickness can be measured. In addition, by using both the fluorescent X-rays and the transmitted X-rays, the thickness of each of the plurality of layers can be easily measured.

[0008] In one embodiment of the thickness measurement method of the present invention, it is characterized in that the sample includes more than three layers, the first relationship related to a specific first energy, the second relationship related to a specific second energy, and the first relationship or the second relationship related to other energies different from the first energy or the second energy are prepared, and the thickness of each layer that simultaneously satisfies the first relationship related to the first energy, the second relationship related to the second energy, and the first relationship or the second relationship related to the other energies is calculated.

[0009] In one embodiment of the present invention, the thickness of each layer is calculated to simultaneously satisfy a first relational expression associated with a first energy, a second relational expression associated with a second energy, and a first relational expression or a second relational expression associated with other energies. By using three or more relational expressions, the thickness of each layer can be measured even when the sample includes more than three layers.

[0010] A thickness measurement method according to one embodiment of the present invention is characterized in that a sample including multiple layers is irradiated with X-rays in such a manner that the X-rays pass through the multiple layers, fluorescent X-rays generated from the sample are detected, and transmitted X-rays after passing through the sample are detected. A plurality of relationship equations are prepared from a first relationship equation representing a relationship between the intensity of the detected transmitted X-rays and the thickness of each layer, a third relationship equation representing a relationship between the theoretical intensity of the fluorescent X-rays corresponding to the thickness of each layer and the intensity of the detected fluorescent X-rays, and a fourth relationship equation representing a relationship between the theoretical intensity of the transmitted X-rays corresponding to the thickness of each layer and the intensity of the detected transmitted X-rays, and the thickness of each layer that simultaneously satisfies the plurality of relationship equations is calculated.

[0011] In one embodiment of the present invention, the thickness of each layer is calculated so as to simultaneously satisfy multiple relationship expressions among the first relationship expression, the third relationship expression indicating the relationship between the theoretical intensity of fluorescent X-rays and the intensity of detected fluorescent X-rays, and the fourth relationship expression indicating the relationship between the theoretical intensity of transmitted X-rays and the intensity of detected transmitted X-rays. Even in this method, the thickness of each of the multiple layers can be easily measured.

[0012] In one embodiment of the thickness measurement method of the present invention, the sample includes more than three specific number of layers, and the specific number of relationship expressions are prepared from the first relationship expression related to a specific first energy, the third relationship expression related to a specific second energy, the fourth relationship expression related to a specific third energy, and the first relationship expression, the third relationship expression or the fourth relationship expression related to other energies different from the first energy, the second energy or the third energy, and the thickness of each layer that simultaneously satisfies the prepared specific number of relationship expressions is calculated.

[0013] In one embodiment of the present invention, the thickness of each layer is calculated so as to simultaneously satisfy the first relational expression, the third relational expression, the fourth relational expression, and a relational expression of a specific number among the first relational expression, the third relational expression, or the fourth relational expression related to other energies. By using three or more relational expressions of specific numbers, when the sample includes a specific number of layers, the thickness of each layer can be measured.

[0014] A thickness measurement method according to one embodiment of the present invention is characterized in that, in the absence of the sample, X-rays to be irradiated to the sample are generated and detected with an output lower than when irradiating the sample, and the first relationship is a relationship between the ratio of the detected intensity of the transmitted X-rays and the detected intensity of the X-rays and the thickness and density of each layer and the mass absorption coefficient of the X-rays in each layer.

[0015] In one embodiment of the present invention, X-rays to be irradiated to a sample are detected in a state without a sample. By detecting X-rays in a state without a sample, X-rays can be detected at a high count rate. By using the intensity of the detected X-rays as the intensity of the X-rays irradiated to the sample, a first relational expression can be prepared. In addition, by adjusting the output of the X-rays to be lower, the detector can be protected.

[0016] A thickness measurement method according to one embodiment of the present invention is characterized in that the first relationship is prepared using the intensity of the transmitted X-ray at an energy that does not correspond to the position of the peak of the fluorescent X-ray included in the spectrum of the fluorescent X-ray and the mass absorption coefficient of the X-ray at the energy.

[0017] In one embodiment of the present invention, the first relational expression is prepared using the intensity of the transmitted X-ray at an energy that does not correspond to the position of the peak included in the spectrum of the fluorescent X-ray and the mass absorption coefficient of the X-ray at the energy. When the intensity of the fluorescent X-ray is included in the intensity of the detected transmitted X-ray, the relationship between the intensity of the transmitted X-ray and the thickness of each layer deviates from the first relational expression. By using the energy that does not correspond to the position of the peak of the fluorescent X-ray, the intensity of the fluorescent X-ray included in the intensity of the transmitted X-ray becomes smaller, and the first relational expression is established.

[0018] A thickness measurement method according to one embodiment of the present invention is characterized in that the second relationship is prepared using the theoretical intensities of the fluorescent X-rays and the transmitted X-rays at an energy corresponding to the position of the peak of the fluorescent X-rays contained in the spectrum of the fluorescent X-rays, and the detected intensities of the fluorescent X-rays and the transmitted X-rays at the energy.

[0019] In one embodiment of the present invention, the second relational expression is prepared using the theoretical intensities of the fluorescent X-ray and the transmitted X-ray at the energy corresponding to the position of the peak included in the spectrum of the fluorescent X-ray and the detected intensities of the fluorescent X-ray and the transmitted X-ray at the energy. By using the energy corresponding to the position of the peak of the fluorescent X-ray, the intensity of the detected fluorescent X-ray becomes larger. By using the large intensity of the fluorescent X-ray, the second relational expression can be correctly calculated.

[0020] A thickness measurement method according to one embodiment of the present invention is characterized in that the third relationship is prepared using the theoretical fluorescent X-rays at an energy corresponding to the position of the peak of the fluorescent X-rays contained in the spectrum of the fluorescent X-rays and the intensity of the detected fluorescent X-rays at the energy.

[0021] In one embodiment of the present invention, the third relational expression is prepared using the theoretical intensity of fluorescent X-rays at an energy corresponding to the position of a peak included in the spectrum of fluorescent X-rays and the intensity of detected fluorescent X-rays at the energy. By using a large intensity of fluorescent X-rays, the third relational expression can be accurately calculated.

[0022] In the thickness measurement method according to one aspect of the present invention, the peak of the fluorescent X-ray is a peak of the fluorescent X-ray caused by an element contained in a layer through which the X-ray first transmits among the plurality of layers.

[0023] In one embodiment of the present invention, fluorescent X-rays generated by elements contained in the layer through which the X-rays first pass are used. The intensity of the fluorescent X-rays generated from the first layer is large and can be used to create a relational expression.

[0024] An X-ray analysis device according to one embodiment of the present invention is characterized in that it comprises: an irradiation unit for irradiating a sample including a plurality of layers with X-rays in such a manner that the X-rays pass through the plurality of the layers; a fluorescence X-ray detector for detecting the fluorescence X-rays generated from the sample; a transmission X-ray detector for detecting the transmission X-rays after passing through the sample; and an analysis unit for preparing a first relationship expressing the relationship between the intensity of the detected transmission X-rays and the thickness of each layer, and a second relationship expressing the relationship between the theoretical ratio of the intensity of the fluorescence X-rays to the transmission X-rays corresponding to the thickness of each layer and the ratio of the intensity of the detected fluorescence X-rays to the transmission X-rays, and calculating the thickness of each layer that satisfies both the first relationship and the second relationship.

[0025] An X-ray analysis device according to one embodiment of the present invention is characterized in that it comprises: an irradiation unit for irradiating a sample including a plurality of layers with X-rays in such a manner that the X-rays pass through the plurality of layers; a fluorescence X-ray detector for detecting the fluorescence X-rays generated from the sample; a transmission X-ray detector for detecting the transmission X-rays after passing through the sample; and an analysis unit for preparing a plurality of relationship equations from a first relationship equation representing a relationship between the intensity of the detected transmission X-rays and the thickness of each layer, a third relationship equation representing a relationship between the theoretical intensity of the fluorescence X-rays corresponding to the thickness of each layer and the intensity of the detected fluorescence X-rays, and a fourth relationship equation representing a relationship between the theoretical intensity of the transmission X-rays corresponding to the thickness of each layer and the intensity of the detected transmission X-rays, and calculating the thickness of each layer that simultaneously satisfies the plurality of relationship equations.

[0026] In one embodiment of the present invention, an X-ray analyzer irradiates a sample including a plurality of layers with X-rays, and detects fluorescent X-rays and transmitted X-rays. An analyzer included in the X-ray analyzer calculates the thickness of each layer so as to simultaneously satisfy a plurality of relational expressions representing the relationship between the intensity of the transmitted X-rays and the thickness of each layer, and the relationship between the theoretical intensity of the fluorescent X-rays or transmitted X-rays corresponding to the thickness of each layer and the intensity of the detected fluorescent X-rays or transmitted X-rays. By utilizing both the fluorescent X-rays and the transmitted X-rays, the thickness of each of the plurality of layers can be easily measured.

[0027] An information processing device according to one embodiment of the present invention is characterized in that it comprises: an acquisition unit for acquiring detection results of fluorescent X-rays generated from a sample including multiple layers by irradiating the X-rays to the sample in a manner such that the X-rays pass through the multiple layers, and detection results of transmitted X-rays after passing through the sample; a relationship generation unit for generating a first relationship expressing the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer, and a second relationship expressing the relationship between the theoretical ratio of the intensities of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the ratio of the intensities of the detected fluorescent X-rays and the transmitted X-rays; and a calculation unit for calculating the thickness of each layer that satisfies both the first relationship and the second relationship.

[0028] An information processing device according to one embodiment of the present invention is characterized in that it comprises: an acquisition unit for acquiring detection results of fluorescent X-rays generated from a sample including multiple layers by irradiating the sample with X-rays in a manner such that the X-rays pass through the multiple layers, and detection results of transmitted X-rays after passing through the sample; a relationship generation unit for generating multiple relationship equations from a first relationship equation representing the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer, a third relationship equation representing the relationship between the theoretical intensity of the fluorescent X-rays corresponding to the thickness of each layer and the intensity of the detected fluorescent X-rays, and a fourth relationship equation representing the relationship between the theoretical intensity of the transmitted X-rays corresponding to the thickness of each layer and the intensity of the detected transmitted X-rays; and a calculation unit for calculating the thickness of each layer that simultaneously satisfies multiple of the relationship equations.

[0029] A computer program according to one embodiment of the present invention is characterized in that it causes a computer to perform the following processing: creating a first relationship expression and a second relationship expression, wherein the first relationship expression represents the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer based on the detection result of the transmitted X-rays after the sample including multiple layers is irradiated with the X-rays in a manner that allows the X-rays to pass through the multiple layers, and the second relationship expression represents the relationship between the theoretical ratio of the intensity of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the ratio of the intensity of the detected fluorescent X-rays and the transmitted X-rays based on the detection result of the fluorescent X-rays generated from the sample and the detection result of the transmitted X-rays; and calculating the thickness of each layer that satisfies both the first relationship expression and the second relationship expression.

[0030] A computer program according to one embodiment of the present invention is characterized in that it causes a computer to perform the following processing: preparing a plurality of relationship expressions from a first relationship expression, a second relationship expression, and a fourth relationship expression, wherein the first relationship expression represents a relationship between the intensity of the detected transmission X-ray and the thickness of each layer based on a detection result of a transmission X-ray after the transmission X-ray is transmitted through the sample including a plurality of layers by irradiating the X-ray to the sample in a manner such that the X-ray transmits the plurality of the layers, the second relationship expression represents a relationship between the theoretical intensity of the fluorescence X-ray corresponding to the thickness of each layer and the intensity of the detected fluorescence X-ray based on a detection result of a fluorescence X-ray generated from the sample, the fourth relationship expression represents a relationship between the theoretical intensity of the transmission X-ray corresponding to the thickness of each layer and the intensity of the detected transmission X-ray; and calculating the thickness of each layer that simultaneously satisfies a plurality of the relationship expressions.

[0031] In one embodiment of the present invention, the thickness of each layer is calculated so as to simultaneously satisfy multiple relational expressions representing the relationship between the intensity of the transmission X-ray after passing through a sample including multiple layers and the thickness of each layer, and the relationship between the theoretical intensity of the fluorescent X-ray or transmission X-ray corresponding to the thickness of each layer and the intensity of the detected fluorescent X-ray or transmission X-ray. By using both the fluorescent X-ray and the transmission X-ray, multiple respective thicknesses can be easily measured. Effects of the Invention

[0032] The present invention has excellent effects such as being able to measure the thickness of each layer included in a larger number of multilayer samples than before. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a block diagram showing an example of the functional configuration of an X-ray analysis device. Figure 2 This is a block diagram showing an example of the internal configuration of the analysis unit. Figure 3 is a schematic cross-sectional view of the specimen. Figure 4 It is a diagram showing examples of spectra of transmission X-rays and fluorescent X-rays. Figure 5 This is a flowchart showing an example of the steps of a process for measuring the thickness of each layer of a sample executed by the X-ray analyzer. Figure 6 This is a schematic cross-sectional view showing an example of a sample according to the third embodiment. DETAILED DESCRIPTION

[0034] Hereinafter, the present invention will be described in detail based on the drawings showing embodiments of the present invention. <Implementation Method 1> Figure 11 is a block diagram showing an example of the functional configuration of an X-ray analyzer 100. The X-ray analyzer 100 includes: an irradiation unit 21 for irradiating a sample 3 with X-rays; a fluorescent X-ray detector 22 for detecting fluorescent X-rays generated from the sample 3 irradiated with X-rays; and a transmission X-ray detector 23 for detecting transmission X-rays after passing through the sample 3. The sample 3 is a multilayer sample including a plurality of stacked layers. The X-ray analyzer 100 performs a thickness measurement method for measuring the thickness of a layer included in the sample 3. The irradiation unit 21 includes an X-ray source for generating X-rays. The X-ray source is, for example, an X-ray tube. Figure 1 In the figure, arrows are used to indicate the X-rays, fluorescent X-rays, and transmitted X-rays irradiated to the sample 3 .

[0035] The fluorescent X-ray detector 22 and the transmission X-ray detector 23 are radiation detectors having radiation detection elements formed using semiconductors. For example, the fluorescent X-ray detector 22 and the transmission X-ray detector 23 are SDDs (Silicon Drift Detectors). The surface of the sample 3 irradiated with X-rays from the irradiation unit 21 is referred to as the surface. The surface on the opposite side to the surface is referred to as the back surface. The fluorescent X-ray detector 22 is arranged so as to be opposite to the surface of the sample 3. By irradiating the sample 3 with X-rays from the irradiation unit 21, fluorescent X-rays are generated in the sample 3. Fluorescent X-rays are radiated from the surface of the sample 3 and are incident on the fluorescent X-ray detector 22. The fluorescent X-ray detector 22 detects the incident fluorescent X-rays and outputs a signal of an intensity corresponding to the energy of the fluorescent X-rays.

[0036] The transmission X-ray detector 23 is arranged at a position opposite to the irradiation unit 21. In a state where the sample 3 is arranged between the irradiation unit 21 and the transmission X-ray detector 23, the sample 3 is irradiated with X-rays from the irradiation unit 21. At this time, the irradiation unit 21 is opposite to the surface of the sample 3, and the transmission X-ray detector 23 is opposite to the back surface of the sample 3. A part of the X-rays irradiated from the irradiation unit 21 to the sample 3 passes through the sample 3. The X-rays that have passed through the sample 3 are called transmission X-rays. The transmission X-rays are incident on the transmission X-ray detector 23. The transmission X-ray detector 23 detects the incident transmission X-rays and outputs a signal of an intensity corresponding to the energy of the transmission X-rays.

[0037] The fluorescent X-ray detector 22 is connected to a first signal processing unit 24, and the transmission X-ray detector 23 is connected to a second signal processing unit 25. The first signal processing unit 24 and the second signal processing unit 25 are connected to the analysis unit 1. The analysis unit 1 is configured using a computer. The analysis unit 1 is connected to a display unit 27 such as a liquid crystal display or an EL display (Electroluminescent Display). The irradiation unit 21, the first signal processing unit 24, the second signal processing unit 25, and the analysis unit 1 are connected to a control unit 26.

[0038] The control unit 26 controls the operation of the irradiation unit 21, the first signal processing unit 24, the second signal processing unit 25, and the analysis unit 1. The control unit 26 is configured using a computer including a computing unit that performs operations for controlling each unit. The control unit 26 may be configured to receive an operation from a user and control each unit of the X-ray analysis device 100 according to the received operation. The control unit 26 and the analysis unit 1 may also be configured integrally.

[0039] The fluorescent X-ray detector 22 outputs a signal having an intensity corresponding to the energy of the fluorescent X-ray, and the first signal processing unit 24 receives the signal output by the fluorescent X-ray detector 22. The first signal processing unit 24 detects the intensity of the received signal to detect a signal value corresponding to the energy of the fluorescent X-ray detected by the fluorescent X-ray detector 22. The first signal processing unit 24 counts the signal according to the signal value, and outputs data indicating the relationship between the signal value and the count value to the analysis unit 1.

[0040] The transmission X-ray detector 23 outputs a signal having an intensity corresponding to the energy of the transmission X-ray, and the second signal processing unit 25 receives the signal output by the transmission X-ray detector 23. The second signal processing unit 25 detects the intensity of the received signal to detect a signal value corresponding to the energy of the transmission X-ray detected by the transmission X-ray detector 23. The second signal processing unit 25 counts the signal according to the signal value, and outputs data indicating the relationship between the signal value and the count value to the analysis unit 1.

[0041] The analysis unit 1 receives data indicating the relationship between the signal value and the count value output by the first signal processing unit 24. The analysis unit 1 generates a spectrum of fluorescent X-rays detected by the fluorescent X-ray detector 22 based on the data from the first signal processing unit 24. The signal value corresponds to the energy of the fluorescent X-rays, and the count value corresponds to the number of times the fluorescent X-rays are detected, that is, the intensity of the fluorescent X-rays. Therefore, based on the relationship between the signal value and the count value, a spectrum of fluorescent X-rays indicating the relationship between the energy and the intensity of the fluorescent X-rays is obtained.

[0042] In addition, the analysis unit 1 receives data indicating the relationship between the signal value and the count value output by the second signal processing unit 25. The analysis unit 1 generates a spectrum of the transmitted X-ray detected by the transmission X-ray detector 23 based on the data from the second signal processing unit 25. The signal value corresponds to the energy of the transmitted X-ray, and the count value corresponds to the number of times the transmitted X-ray is detected, that is, the intensity of the transmitted X-ray. Therefore, based on the relationship between the signal value and the count value, a spectrum of the transmitted X-ray indicating the relationship between the energy and the intensity of the transmitted X-ray is obtained.

[0043] The process of counting the signals outputted by the fluorescent X-ray detector 22 and the transmission X-ray detector 23 according to the signal values ​​may be performed by the analysis unit 1 instead of the first signal processing unit 24 and the second signal processing unit 25. The generation of the spectrum of the fluorescent X-ray may be performed by the first signal processing unit 24, and the generation of the spectrum of the transmission X-ray may be performed by the second signal processing unit 25. The analysis unit 1 stores spectral data representing the spectrum of the fluorescent X-ray and spectral data representing the spectrum of the transmission X-ray. The display unit 27 displays the spectrum of the fluorescent X-ray or the transmission X-ray. The user can confirm the spectrum of the fluorescent X-ray from the sample 3 or the spectrum of the transmission X-ray after passing through the sample 3. In addition, the analysis unit 1 performs information processing based on the spectrum of the fluorescent X-ray and the transmission X-ray. More specifically, the analysis unit 1 performs information processing in order to measure the thickness of each layer included in the sample 3. The analysis unit 1 corresponds to an information processing device that performs information processing for measuring the thickness of each layer included in the sample 3.

[0044] Figure 2 1 is a block diagram showing an example of the internal structure of the analysis unit 1. The analysis unit 1 is composed of a computer such as a personal computer. The analysis unit 1 includes a computing unit 11, a memory 12, a reading unit 13, a storage unit 14, and an operating unit 15. The computing unit 11 is composed of, for example, a CPU (central processing unit), a GPU (graphics processing unit), or a multi-core CPU. The computing unit 11 can also be composed of a quantum computer. The memory 12 stores temporary data generated by the calculation. The memory 12 is, for example, a RAM (Random Access Memory). The reading unit 13 reads information from a recording medium 10 such as an optical disk or a removable memory. The storage unit 14 is non-volatile, for example, a hard disk or a non-volatile semiconductor memory. The operating unit 15 receives input of information such as text by receiving operations from the user. The operating unit 15 is, for example, a touch panel, a keyboard, or a pointing device. The user inputs various instructions to the analysis unit 1 by operating the operating unit 15. The analysis unit 1 receives instructions input using the operating unit 15.

[0045] The operation unit 11 causes the reading unit 13 to read the computer program 141 recorded on the recording medium 10, and stores the read computer program 141 in the storage unit 14. The operation unit 11 executes the processing required by the analysis unit 1 according to the computer program 141. In addition, the computer program 141 may also be downloaded from the outside of the analysis unit 1. Alternatively, the computer program 141 may also be stored in the analysis unit 1 in advance. In these cases, the analysis unit 1 may not have the reading unit 13. In addition, the analysis unit 1 may also be composed of a plurality of computers.

[0046] The analysis unit 1 is connected to a display unit 27, a first signal processing unit 24, a second signal processing unit 25, and a control unit 26. The display unit 27 displays an image. The analysis unit 1 outputs information required for information processing by causing the display unit 27 to display an image containing information. The analysis unit 1 receives signals from the first signal processing unit 24 and the second signal processing unit 25, and receives control signals from the control unit 26. In addition, the analysis unit 1 and the control unit 26 may be composed of the same computer.

[0047] The storage unit 14 stores an element database, which records data required for element analysis. Information representing the characteristics of multiple elements is recorded in the element database. For example, the position of the peak contained in the fluorescence X-ray spectrum of each element, the intensity ratio of multiple peaks, the mass absorption coefficient and the density are recorded in the element database. The peak contained in the spectrum of X-rays refers to the peak caused by X-rays, not the peak caused by noise. The position of the peak is represented by the energy of X-rays. In addition, the element database can also be set outside the analysis unit 1. For example, the element database is stored in a storage device connected to the analysis unit 1 via a communication network. The element database can also be constructed using a cloud. The operation unit 11 accesses the element database via the communication network and performs processing with reference to the data recorded in the element database.

[0048] Figure 3 : is a schematic cross-sectional view of the sample 3. The sample 3 is composed of a first layer 31 and a second layer 32 stacked together. The thickness of the first layer 31 is set to t1, and the thickness of the second layer 32 is set to t2. The thickness t1 of the first layer 31 is smaller than the thickness t2 of the second layer 32. For example, the second layer 32 is a base material, and the first layer 31 is a covering film covering the base material. For example, the sample 3 is a part of a plate-shaped raw material. The analysis unit 1 performs information processing for measuring the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. Figure 3 As shown, the sample 3 is irradiated with X-rays in such a manner that the X-rays are transmitted in the order of the first layer 31 and the second layer 32. Fluorescent X-rays are generated from the first layer 31 irradiated with X-rays. The fluorescent X-rays detected by the fluorescent X-ray detector 22 are mainly fluorescent X-rays generated from the first layer 31. The fluorescent X-rays generated from the second layer 32 are absorbed by the first layer 31 and are hardly detected by the fluorescent X-ray detector 22.

[0049] Figure 4This is a diagram showing examples of spectra of transmitted X-rays and fluorescent X-rays. The upper side shows the spectrum of transmitted X-rays, and the lower side shows the spectrum of fluorescent X-rays. The horizontal axis of the upper diagram shows the energy of the transmitted X-rays, and the vertical axis shows the intensity of the transmitted X-rays. The horizontal axis of the lower diagram shows the energy of the fluorescent X-rays, and the vertical axis shows the intensity of the fluorescent X-rays. For example, the intensity of the X-rays is represented by a count value per unit time. Two different energies of the transmitted X-rays for obtaining the spectrum are set as E1 and E2. The first energy E1 is set to an energy that does not correspond to the position of the peak contained in the spectrum of the fluorescent X-rays generated from the sample 3. The second energy E2 is set to an energy that corresponds to the position of the peak contained in the spectrum of the fluorescent X-rays generated from the first layer 31.

[0050] The intensity of the X-rays at the energy E1 irradiated to the sample 3 is denoted as I0(E1). The intensity of the X-rays I0(E1) is the intensity of the X-rays that should be irradiated to the sample 3 when the sample 3 is not irradiated. It is the intensity of the X-rays that are irradiated from the irradiation unit 21 and detected by the transmission X-ray detector 23 when there is no sample 3. The intensity of the X-rays at the energy E1 irradiated to the sample 3 and detected by the transmission X-ray detector 23 is denoted as I0(E1). T (E1).

[0051] The mass absorption coefficient of X-rays at energy E1 of the first layer 31 is μ1(E1). The mass absorption coefficient of X-rays at energy E1 of the second layer 32 is μ2(E1). The density of the first layer 31 is ρ1, and the density of the second layer 32 is ρ2. The intensity I of the transmitted X-ray at energy E1 is T (E1) can be expressed by the following formula (1). I T (E1)=I0(E1)exp(-μ1(E1)ρ1t1-μ2(E1)ρ2t2)…(1)

[0052] By rearranging equation (1), the following equation (2) can be obtained. Equation (2) represents the intensity I at the energy E1 of the transmitted X-ray. T (E1) is a first relational expression for the relationship between the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. In addition, the expression (2) is a first relational expression for the first energy E1. μ1(E1)ρ1t1+μ2(E1)ρ2t2+ln(I T (E1) / I0(E1))=0…(2)

[0053] The intensity of the X-rays irradiated to the sample 3 at the energy E2 is denoted as I0(E2). The intensity of the fluorescent X-rays irradiated to the sample 3 at the energy E2 and detected by the fluorescent X-ray detector 22 is denoted as I0(E2). F(E2). The intensity of the transmission X-ray detected by the transmission X-ray detector 23 at the energy E2 is set to I T (E2). The intensity of the detected transmitted X-ray I T (E2) also includes the intensity of the fluorescent X-ray generated from the first layer 31 and transmitted through the first layer 31 and the second layer 32. In addition, the intensity of the fluorescent X-ray at the energy E2 calculated theoretically based on the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 is set to I F ~(E2,t1,t2), the theoretical intensity of the transmitted X-ray at energy E2 is set to I T ~(E2,t1,t2).

[0054] The theoretical intensity of fluorescent X-rays and the theoretical intensity of transmitted X-rays are calculated based on the information about the X-ray analyzer 100 and the sample 3. The intensity of X-rays incident on the surface of the sample 3 is calculated based on the intensity of X-rays generated by the irradiation unit 21, the solid angle of the X-rays irradiated from the irradiation unit 21 to the sample 3, the X-ray absorption coefficient of air, the density of air, and the distance from the irradiation unit 21 to the sample 3. The intensity of X-rays incident on the surface of the sample 3 can also be obtained by experiment. Based on the intensity of X-rays incident on the surface of the sample 3, the incident angle, the mass absorption coefficient of the sample 3 for X-rays, and the density of the sample 3, the intensity of X-rays at an arbitrary depth from the surface of the sample 3 is calculated. Based on the concentration of each element contained in the sample 3 and the mass absorption coefficient of each element for X-rays, the proportion of each element absorbing X-rays in a tiny portion at an arbitrary depth from the surface of the sample 3 is calculated.

[0055] Based on the ratio of X-rays absorbed by the element being absorbed by each electron shell, the ratio of electrons emitting fluorescent X-rays by transitioning to each electron shell, and the ratio of fluorescent X-rays of a specific species in the emitted fluorescent X-rays, the ratio of fluorescent X-rays of a specific species emitted from the element to X-rays absorbed by the element is calculated. Based on the distance from the sample 3 to the fluorescent X-ray detector 22, the solid angle at which the generated fluorescent X-rays enter the fluorescent X-ray detector 22 is calculated. Based on the mass absorption coefficient of the sample 3 for the fluorescent X-rays, the density of the sample 3, and the emission angle of the fluorescent X-rays that can enter the fluorescent X-ray detector 22, the ratio of the fluorescent X-rays generated at an arbitrary depth from the surface of the sample 3 to the surface of the sample 3 that pass through the sample 3 is calculated. In addition, based on the incident angle of the X-rays and the emission angle of the fluorescent X-rays, the intensity of the fluorescent X-rays is converted into an intensity perpendicular to the direction in which the fluorescent X-rays are detected. Based on the values ​​obtained above, the intensity of the fluorescent X-rays generated from a tiny portion at an arbitrary depth from the surface of the sample 3 and reaching the surface of the sample 3 is calculated.

[0056] The calculated intensity of the fluorescent X-ray is integrated with respect to the energy of the irradiated X-ray and further integrated with respect to the depth from the surface of the sample 3, thereby obtaining the intensity of the fluorescent X-ray emitted from the surface of the sample 3 as a function of the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. In this way, the theoretical intensity I of the fluorescent X-ray at the energy E2 is obtained. F ~(E2,t1,t2). F ~(E2,t1,t2) is a function of t1 and t2.

[0057] Energy E2 is energy corresponding to the peak of fluorescent X-rays, so fluorescent X-rays are mixed in the transmission X-rays at energy E2. The intensity of X-rays incident on the surface of sample 3 is calculated as described above. The intensity of the incident X-rays when passing through sample 3 is calculated using the same formula as formula (1). As described above, the intensity of X-rays at any depth from the surface of sample 3, the ratio of X-ray absorption by each element in a tiny portion at any depth from the surface of sample 3, and the ratio of fluorescent X-rays of a specific species emitted from an element to X-rays absorbed by the element are calculated. Based on the depth of the tiny portion and the distance from sample 3 to transmission X-ray detector 23, the solid angle at which the generated fluorescent X-rays are incident on transmission X-ray detector 23 is calculated. Based on the mass absorption coefficient of each layer of sample 3 for fluorescent X-rays and the density of each layer, the ratio of fluorescent X-rays passing through sample 3 to the back of sample 3 is calculated. The calculated ratio is obtained as a function of the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. Based on the values ​​obtained above, the intensity of the fluorescent X-ray generated from a tiny portion at an arbitrary depth from the surface of the sample 3 and emitted from the back side of the sample 3 is calculated.

[0058] The calculated intensity of the fluorescent X-ray is integrated with respect to the energy of the irradiated X-ray and further integrated with respect to the depth from the surface of the sample 3, thereby obtaining the intensity of the fluorescent X-ray emitted from the back side of the sample 3 as a function of the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. Based on the intensity of the incident X-ray when it passes through the sample 3 and the intensity of the fluorescent X-ray emitted from the back side of the sample 3, the theoretical intensity I of the transmitted X-ray at the energy E2 is obtained. T ~(E2,t1,t2). T ~(E2,t1,t2) is a function of t1 and t2.

[0059] The information required for calculating the theoretical intensity of fluorescent X-rays and transmitted X-rays is pre-stored in the storage unit 14 or pre-recorded in the element database. For example, the intensity of X-rays generated by the irradiation unit 21, the solid angle of X-rays irradiated from the irradiation unit 21 to the sample 3, the X-ray absorption coefficient of air, the density of air, the distance from the irradiation unit 21 to the sample 3, and the distance from the sample 3 to the fluorescent X-ray detector 22 are pre-stored in the storage unit 14. For example, the mass absorption coefficient of each element, the density of each element, the ratio of X-rays absorbed by each element to be absorbed by each electron shell, the ratio of electrons transitioning to each electron shell and emitting fluorescent X-rays through the transition, and the ratio of fluorescent X-rays of a specific line in the emitted fluorescent X-rays are pre-recorded in the element database.

[0060] The specific calculation method of the theoretical intensity of fluorescent X-rays and transmitted X-rays can be roughly based on the method described above. As a detailed correction method for the theoretical intensity of fluorescent X-rays and transmitted X-rays, various methods known in the past can be used. For example, as a method for correcting the theoretical intensity of fluorescent X-rays and transmitted X-rays based on the absorption of X-rays by air, the sensitivity of the fluorescent X-ray detector 22 or the transmitted X-ray detector 23, or the influence of coexisting elements, any one of various methods known in the past that are different from each other can be used.

[0061] The theoretical intensity of the fluorescent X-ray can be considered to be F ~(E2,t1,t2) and the theoretical intensity of transmitted X-rays I T The ratio of ~(E2, t1, t2) to the intensity of the detected fluorescent X-ray I F (E2) and the intensity of the detected transmitted X-ray I T Therefore, the following formula (3) holds. I F ~(E2,t1,t2) / I T ~(E2,t1,t2)-I F (E2) / I T (E2) = 0...(3)

[0062] Formula (3) is a second relational expression that represents the relationship between the theoretical ratio of the intensity of fluorescent X-rays and transmitted X-rays corresponding to the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 and the ratio of the intensity of the detected fluorescent X-rays and transmitted X-rays. In addition, formula (3) is a second relational expression related to the second energy E2. Formula (2) and formula (3) both include the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 as variables. By determining t1 and t2 in a manner that satisfies formula (2) and formula (3) at the same time, the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 can be obtained.

[0063] In addition, as the intensity of the transmitted X-ray, a value obtained by subtracting the background may be used. T (E2) is a value obtained by subtracting the intensity of the X-rays from the irradiation unit 21 after passing through the sample 3 from the intensity of the transmitted X-rays at energy E2 detected by the transmitted X-ray detector 23 at energy E2. T (E2) is the intensity of the fluorescent X-ray generated inside the sample 3 detected by the transmission X-ray detector 23. In addition, as the theoretical transmission X-ray intensity I T ~(E2, t1, t2), does not include the intensity of the X-rays from the irradiation unit 21 after passing through the sample 3, and only the intensity of the fluorescent X-rays generated inside the sample 3 is calculated. Even in this case, by calculating I F ~(E2,t1,t2) and the theoretical intensity of transmitted X-rays I T ~(E2,t1,t2), and I F (E2) and the intensity I of the detected transmitted X-ray T (E2), formula (3) also holds true.

[0064] Figure 51 is a flowchart showing an example of a processing step for measuring the thickness of each layer of the sample 3 performed by the X-ray analysis device 100. Hereinafter, the step is referred to as S. The analysis unit 1 performs processing by executing information processing according to the computer program 141 by the operation unit 11. The irradiation unit 21 generates X-rays in a state without the sample 3, and detects the X-rays through the X-ray detector 23 (S1). In S1, the irradiation unit 21 generates X-rays with a lower output than when irradiating the sample 3 with X-rays. For example, the control unit 26 reduces the current flowing through the X-ray tube provided in the irradiation unit 21. By adjusting the output of the X-rays to be lower, the transmission X-ray detector 23 is protected. In addition, the transmission X-ray detector 23 can detect X-rays at a high count rate by detecting X-rays in a state without the sample 3. The transmission X-ray detector 23 outputs a signal of an intensity corresponding to the energy of the detected X-rays to the second signal processing unit 25, and the second signal processing unit 25 counts the signal according to the signal value, and outputs data indicating the relationship between the signal value and the count value to the analysis unit 1.

[0065] The analysis unit 1 obtains the detection result of the X-ray by receiving the data from the second signal processing unit 25 (S2). The analysis unit 1 generates a spectrum of the X-ray and stores the spectrum data in the storage unit 14. Through the processing of S1 to S2, the analysis unit 1 obtains the intensity of the X-ray that should be irradiated to the sample 3 when the sample 3 is not irradiated. In addition, the intensity of the X-ray when the sample 3 is not irradiated is pre-stored in the storage unit 14, and the processing of S1 to S2 can also be omitted.

[0066] In the presence of sample 3, the irradiation unit 21 generates X-rays and irradiates the sample 3 with X-rays (S3). In S3, the irradiation unit 21 generates X-rays with a higher output than in S1. For example, the control unit 26 increases the current flowing through the X-ray tube provided in the irradiation unit 21. The sample 3 is held in the X-ray analysis device 100 in such a manner that the X-rays pass through the first layer 31 and the second layer 32 in the order of the first layer 31 and the second layer 32. The first layer 31 corresponds to the layer through which the X-rays first pass among the multiple layers included in the sample 3. Fluorescent X-rays are generated from the sample 3 by irradiation with X-rays. The fluorescent X-ray detector 22 detects the fluorescent X-rays (S4). The transmission X-ray detector 23 detects the transmission X-rays after passing through the sample 3 (S5).

[0067] The fluorescent X-ray detector 22 outputs a signal of intensity corresponding to the energy of the fluorescent X-ray to the first signal processing unit 24, and the first signal processing unit 24 counts the signal according to the signal value, and outputs data indicating the relationship between the signal value and the count value to the analysis unit 1. The transmission X-ray detector 23 outputs a signal of intensity corresponding to the energy of the transmission X-ray to the second signal processing unit 25, and the second signal processing unit 25 counts the signal according to the signal value, and outputs data indicating the relationship between the signal value and the count value to the analysis unit 1. The analysis unit 1 obtains the detection results of the fluorescent X-ray and the transmission X-ray by receiving the data from the first signal processing unit 24 and the second signal processing unit 25 (S6). The analysis unit 1 generates spectra of the fluorescent X-ray and the transmission X-ray, and stores the spectral data in the storage unit 14. The processing of S6 corresponds to the acquisition unit.

[0068] The analysis unit 1 determines the elements included in each layer (S7). The elements included in the first layer 31 and the second layer 32 are pre-stored in the storage unit 14. In S7, the operation unit 11 determines the elements included in the first layer 31 and the second layer 32 by reading the data representing the elements included in the first layer 31 and the second layer 32 stored in the storage unit 14. In S7, the user operates the operation unit 15 to input information representing the elements included in the first layer 31 and the second layer 32, and the operation unit 11 can determine the elements included in the first layer 31 and the second layer 32 as the elements represented by the input information. The processing of S7 can also be omitted.

[0069] The analysis unit 1 determines a plurality of energies (S8). Specifically, two energies E1 and E2 are determined. An energy E1 that does not correspond to the position of a peak included in the spectrum of fluorescent X-rays is determined, and an energy E2 that corresponds to the position of a peak included in the spectrum of fluorescent X-rays is determined. The values ​​of the energies E1 and E2 are pre-stored in the storage unit 14, and in S8, the operation unit 11 determines the energies E1 and E2 by reading the values ​​of E1 and E2 stored in the storage unit 14. In S8, the user inputs the values ​​of the energies E1 and E2 by operating the operation unit 15, and the operation unit 11 can determine the values ​​of the energies E1 and E2 as the input values. Alternatively, the values ​​of E1 and E2 can be stored in the storage unit 14 in association with the elements, and the operation unit 11 determines the energies E1 and E2 by reading the values ​​of E1 and E2 associated with the determined elements.

[0070] The analysis unit 1 determines the mass absorption coefficient of X-rays of each layer and the density of each layer (S9). The values ​​of the mass absorption coefficients μ1(E1), μ1(E2), μ2(E1), and μ2(E2) of the X-rays of the first layer 31 and the second layer, and the values ​​of the densities ρ1 and ρ2 of the first layer 31 and the second layer 32 are stored in advance in the storage unit 14. In S9, the operation unit 11 determines the mass absorption coefficient and the density of X-rays of the first layer 31 and the second layer by reading the values ​​of μ1(E1), μ1(E2), μ2(E1), μ2(E2), ρ1, and ρ2 stored in the storage unit 14. In S9, the user operates the operation unit 15 to input the values ​​of μ1(E1), μ1(E2), μ2(E1), μ2(E2), ρ1, and ρ2, and the operation unit 11 can determine the values ​​of μ1(E1), μ1(E2), μ2(E1), μ2(E2), ρ1, and ρ2 as the input values.

[0071] Alternatively, the compositions of the first layer 31 and the second layer may be pre-stored in the storage unit 14. In S9, the operation unit 11 may read the mass absorption coefficient of X-rays associated with the compositions of the first layer 31 and the second layer 32 from a database storing the compositions of substances in association with the mass absorption coefficient of X-rays, thereby determining the mass absorption coefficient of X-rays of the first layer 31 and the second layer. The operation unit 11 may also read the density associated with the compositions of the first layer 31 and the second layer 32 from a database storing the compositions of substances in association with the density, thereby determining the density of the first layer 31 and the second layer.

[0072] The analysis unit 1 generates a plurality of relational expressions representing the relationship between the intensity of the transmitted X-ray or fluorescent X-ray and the thickness of each layer (S10). In S10, the calculation unit 11 generates a first relational expression representing the relationship between the intensity of the transmitted X-ray and the thickness of each layer. Specifically, the calculation unit 11 generates a first relational expression representing the intensity I of the transmitted X-ray at the energy E1. TThe first relational expression is the expression (2) showing the relationship between (E1) and the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. The calculation unit 11 uses the intensity of the X-ray at the energy E1 obtained by the processing of S1 to S2 as I0(E1) included in the expression (2). By using the intensity of the X-ray detected in the state without the sample 3 as the intensity of the X-ray irradiated to the sample 3, the expression (2) showing the relationship between the ratio of the intensity of the transmitted X-ray and the intensity of the irradiated X-ray and the thickness, density and mass absorption coefficient of each layer can be prepared. By using the intensity of the X-ray detected in the state without the sample 3 as the intensity of the X-ray irradiated to the sample 3, the intensity of the X-ray measured at a high count rate can be used as the intensity of the X-ray irradiated to the sample 3. The intensity of the X-ray irradiated to the sample 3 is the intensity measured at a high count rate, so it is highly accurate and the ratio of the intensity of the transmitted X-ray to the intensity of the irradiated X-ray can be accurately obtained. The expression (2) includes the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 as variables.

[0073] In addition, in S10, the analysis unit 1 generates a second relational expression representing the relationship between the theoretical intensity ratio of the fluorescent X-ray and the transmitted X-ray corresponding to the thickness of each layer and the detected intensity ratio of the fluorescent X-ray and the transmitted X-ray. Specifically, the calculation unit 11 calculates the theoretical intensity I of the transmitted X-ray at the energy E2. T ~(E2,t1,t2) and the theoretical intensity I of the fluorescent X-ray at energy E2 F ~(E2, t1, t2). The information required to calculate the theoretical intensity of fluorescent X-rays and transmitted X-rays is pre-stored in the storage unit 14, or pre-recorded in the element database. In addition, the calculation unit 11 creates the equation (3) representing the relationship between the ratio of the theoretical intensity of fluorescent X-rays and transmitted X-rays corresponding to the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 and the ratio of the detected intensity of fluorescent X-rays and transmitted X-rays as a second relational equation. The equation (3) includes the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 as variables. The processing of S10 corresponds to the relational equation creation unit.

[0074] The analysis unit 1 determines the thickness of each layer that satisfies the generated equations (2) and (3) by optimization calculation, thereby calculating the thickness of each layer (S11). In S11, the operation unit 11 calculates the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 by performing optimization calculation according to a prescribed algorithm. For example, the operation unit 11 determines the value of the thickness t1 of the first layer 31 as a specific initial value, substitutes the value of t1 into equation (2), calculates the value of the thickness t2 of the second layer 32, substitutes the values ​​of t1 and t2 into equation (3), and calculates the left side of equation (3). Based on the calculation result of the left side of equation (3), the operation unit 11 changes the value of t1 so that the calculation result of the left side of equation (3) approaches zero. The operation unit 11 repeatedly calculates the value of t2 corresponding to the value of t1, calculates the left side of equation (3), and changes the value of t1 until the calculation result of the left side of equation (3) is sufficiently close to zero.

[0075] For example, when the absolute value of the calculation result on the left side of equation (3) is below a predetermined threshold, the operation unit 11 determines that the calculation result on the left side of equation (3) is sufficiently close to zero. The threshold is pre-stored in the storage unit 14. The values ​​of t1 and t2 at this moment substantially satisfy equations (2) and (3) at the same time. When the calculation result on the left side of equation (3) is sufficiently close to zero, the operation unit 11 ends the calculation and uses the values ​​of t1 and t2 at this moment as the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. In this way, the analysis unit 1 calculates the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. Other methods may also be used as optimization calculations. The processing of S11 corresponds to the calculation unit.

[0076] The analysis unit 1 outputs the calculated thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 (S12). In S12, the operation unit 11 outputs the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 by causing the display unit 27 to display the calculated values ​​of the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. The operation unit 11 stores the values ​​of the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 in the storage unit 14. After S12 ends, the analysis unit 1 ends the process for measuring the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32. The X-ray analysis device 100 measures the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 through the processes of S1 to S12.

[0077] As described in detail above, the X-ray analysis device 100 irradiates the sample 3 with X-rays and detects fluorescent X-rays and transmitted X-rays. The analysis unit 1 calculates the thickness of each layer in a manner that satisfies both the formula (2) representing the relationship between the intensity of the detected transmitted X-rays and the thickness of each layer, and the formula (3) representing the relationship between the theoretical ratio of the intensity of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the ratio of the intensity of the detected fluorescent X-rays and the transmitted X-rays. In the prior art that uses only the detection results of fluorescent X-rays, there is a limit to the thickness that can be measured. In contrast, in the present embodiment, a greater thickness can be measured. In addition, compared with the prior art that uses only the detection results of transmitted X-rays, in the present embodiment, by using both fluorescent X-rays and transmitted X-rays, the thickness of each of the multiple layers can be measured more easily. Therefore, for multi-layer samples that are difficult to measure in the prior art, the present invention can measure the thickness of each layer.

[0078] In this embodiment, the intensity of the transmitted X-ray at the energy E1 which does not correspond to the position of the peak included in the spectrum of the fluorescent X-ray and the mass absorption coefficient of the X-ray at the energy E1 are used to prepare the formula (2). The formula (2) is a relationship formula that represents the relationship between the intensity of the transmitted X-ray and the thickness of the first layer 31 and the second layer 32. In the case where the intensity of the fluorescent X-ray is included in the intensity of the detected transmitted X-ray, the relationship between the intensity of the transmitted X-ray and the thickness of the first layer 31 and the second layer 32 deviates from the formula (2). By using the energy E1 which does not correspond to the position of the peak of the fluorescent X-ray, the fluorescent X-ray included in the intensity of the transmitted X-ray disappears, and the formula (2) is established.

[0079] Energy E1 only needs to not correspond to the position of the peak of the fluorescent X-ray, so it is possible to select energy E1 that makes the intensity of the detected transmitted X-ray as large as possible. For example, energy higher than the position of the peak of the fluorescent X-ray can be selected as E1. Since the intensity of the transmitted X-ray is large, the SN ratio (signal-to-noise ratio) becomes large, and the calculation of formula (2) can be performed correctly. In addition, since the intensity of the transmitted X-ray is large, the thickness can be measured even when the thickness of the sample 3 is large. Therefore, the thickness of each layer of the sample 3 that is thicker than before can be measured.

[0080] In this embodiment, the intensities of the theoretical fluorescent X-rays and the transmitted X-rays at the energy E2 corresponding to the position of the peak included in the spectrum of the fluorescent X-rays, and the intensities of the detected fluorescent X-rays and the transmitted X-rays at the energy E2 are used to generate equation (3). Equation (3) is a relational expression that represents the relationship between the ratio of the theoretical intensity of the fluorescent X-rays and the transmitted X-rays and the ratio of the detected intensity of the fluorescent X-rays and the transmitted X-rays. By using the energy E2 corresponding to the position of the peak of the fluorescent X-rays, the intensity of the detected fluorescent X-rays increases, and the SN ratio increases. By using the intensity of the fluorescent X-rays with a large SN ratio, the calculation of equation (3) can be performed correctly.

[0081] In the above description, an example is shown in which the sample 3 is composed of the first layer 31 and the second layer 32, but the X-ray analysis device 100 may also be a method of measuring the thickness of each layer included in the sample 3 including three or more layers stacked. Assume that the sample 3 includes three or more specific number of layers, and each layer is set to be the first layer 31, the second layer 32, the third layer 33, .... The thickness of each layer is set to t1, t2, t3, ..., the density is set to ρ1, ρ2, ρ3, ..., and the mass absorption coefficient is set to μ1, μ2, μ3, .... The analysis unit 1 creates a relational expression of the specific number in the process of S10.

[0082] In S10 , the analysis unit 1 generates the following equation (4) as a first relational expression in the same manner as equation (2). μ1(E1)ρ1t1+μ2(E1)ρ2t2+μ3(E1)ρ3t3+…+ln(I T (E1) / I0(E1))=0……(4)

[0083] In addition, the analysis unit 1 generates the following equation (5) as a second relational expression in the same manner as equation (3). I F ~(E2,t1,t2,t3,…) / I T ~(E2,t1,t2,t3,…)-I F (E2) / I T (E2) = 0...(5)

[0084] In addition, the analysis unit 1 creates another relational expression. For example, the analysis unit 1 creates an energy E1 different from the first energy E1. (2) The first relation of , or setting the energy to E2 which is different from the second energy E2 (2) The second relation of . Let the energy be E1 (2) The first relational equation is expressed by the following equation (6), where the energy is set to E2 (2) The second relational equation is expressed as the following equation (7). Equation (6) is related to the energy E1 (2)The first relation, (7) is related to the energy E2 (2) The second relation of . μ1(E1 (2) )ρ1t1+μ2(E1 (2) )ρ2t2+μ3(E1 (2) )ρ3t3+…+ln(I T (E1 (2) ) / I0(E1 (2) ))=0……(6) I F ~(E2 (2) ,t1,t2,t3,…) / I T ~(E2 (2) ,t1,t2,t3,…)-I F (E2 (2) ) / I T (E2 (2) )=0……(7)

[0085] For example, the analysis unit 1 may create a second relational expression using the theoretical intensity of the fluorescent X-ray generated from the second layer 32 and the detected intensity. If the energy corresponding to the peak position of the fluorescent X-ray generated from the second layer 32 is E2 (3) , then the second relationship is expressed by the following equation (8). I F ~(E2 (3) ,t1,t2,t3,…) / I T ~(E2 (3) ,t1,t2,t3,…)-I F (E2 (3) ) / I T (E2 (3) )=0……(8)

[0086] When the overall thickness of the sample 3 is known, the analysis unit 1 can generate a relational expression between the thickness of each layer and the overall thickness. If the overall thickness of the sample 3 is D, the relational expression between the thickness of each layer and the overall thickness is expressed by the following equation (9). t1+t2+t3+…=D…(9)

[0087] In S10, for example, when the sample 3 is composed of three layers, the analysis unit 1 creates three relational expressions. In S11, the analysis unit 1 determines the thickness of each layer that satisfies the relational expressions of the specific number created in S10 by optimization calculation, thereby calculating the thickness of each layer. In this way, the X-ray analysis device 100 measures the thickness of each layer included in the sample 3 through the processing of S1 to S12. By creating three or more relational expressions using relational expressions such as the first relational expression or the second relational expression related to energy different from E1 or E2, the thickness of each layer can be measured even when the sample 3 includes three or more specific number of layers.

[0088] <Implementation Method 2> The configuration of the X-ray analysis device 100 of the second embodiment is the same as that of the first embodiment. In the second embodiment, the analysis unit 1 does not use the second relational expression representing the relationship between the theoretical ratio of the intensity of the fluorescent X-ray and the intensity of the transmitted X-ray and the ratio of the intensity of the detected fluorescent X-ray and the transmitted X-ray. Instead, the analysis unit 1 uses the third relational expression representing the relationship between the theoretical intensity of the fluorescent X-ray and the intensity of the detected fluorescent X-ray corresponding to the thickness of each layer, and the fourth relational expression representing the relationship between the theoretical intensity of the transmitted X-ray and the intensity of the detected transmitted X-ray corresponding to the thickness of each layer.

[0089] If the theoretical intensity of the fluorescent X-ray is calculated correctly, the theoretical intensity of the fluorescent X-ray is equal to the intensity of the detected fluorescent X-ray. F ~(E2,t1,t2) and the intensity of the detected fluorescent X-ray I F The third relational expression of the relationship between the energy E2 and the second energy E2 is as follows: the following equation (10) holds. The equation (10) is the third relational expression related to the second energy E2. I F ~(E2,t1,t2)=I F (E2)……(10)

[0090] If the theoretical intensity of the transmitted X-ray is calculated correctly, the theoretical intensity of the transmitted X-ray is equal to the intensity of the detected transmitted X-ray. The third energy is set to E3. As the theoretical intensity of the transmitted X-ray corresponding to the thickness of each layer, T ~(E3,t1,t2) and the intensity of the detected transmitted X-ray I T The fourth relational expression of the relationship (E3) holds true for the following equation (11). I T ~(E3,t1,t2)=I T (E3)……(11)

[0091] Formula (11) is a fourth relational formula related to the third energy E3. E3 may be different from E2. In addition, preferably, E3 is different from E1. Formula (10) and Formula (11) both include the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 as variables.

[0092] In order to measure the thickness of each layer of the sample 3, the X-ray analysis device 100 performs the processing of S1 to S12. The X-ray analysis device 100 performs the processing of S1 to S7 in the same manner as in the first embodiment. In S8, the analysis unit 1 determines two energies among the first energy E1, the second energy E2, or the third energy E3. The X-ray analysis device 100 performs the processing of S9 in the same manner as in the first embodiment. In S10, the analysis unit 1 creates two relational expressions from equations (2), (10), and (11). In S11, the analysis unit 1 determines the thickness of each layer that satisfies the two created relational expressions through optimization calculation, thereby calculating the thickness of each layer. The X-ray analysis device 100 performs the processing of S12 in the same manner as in the first embodiment, and ends the processing.

[0093] Even in the second embodiment, the X-ray analysis device 100 detects fluorescent X-rays and transmitted X-rays, and calculates the thickness of each layer so as to simultaneously satisfy a plurality of relational expressions representing the relationship between the intensity of the detected transmitted X-rays or fluorescent X-rays and the thickness of each layer of the sample 3. Even in the second embodiment, a greater thickness can be measured compared to the prior art, and the thickness of each of the plurality of layers can be measured more easily. Therefore, the present invention can measure the thickness of each layer of a multi-layer sample that is difficult to measure in the prior art.

[0094] Even in the second embodiment, the X-ray analysis device 100 may be a method of measuring the thickness of each layer included in the sample 3 including three or more layers stacked. The sample 3 includes three or more specific number of layers. The analysis unit 1 generates a relational expression of the specific number in the process of S10. For example, when the sample 3 is composed of three layers, the analysis unit 1 generates equations (2), (10), and (11) in S10, and calculates the thickness of each layer in S11 so as to simultaneously satisfy the three generated relational expressions.

[0095] In S10, the analysis unit 1 may generate another relational expression. For example, the analysis unit 1 may generate an energy E1 different from the first energy E1. (2) For example, the analysis unit 1 may also generate a first relational expression in which the energy is set to E2 different from the second energy E2. (2) or create a third relational expression in which the energy is set to be different from the third energy E3. (2)For example, the analysis unit 1 may also create a third relationship using the theoretical intensity of the fluorescent X-ray generated from the second layer 32 and the detected intensity. When the overall thickness of the sample 3 is known, the analysis unit 1 may also create a relationship between the thickness of each layer and the overall thickness.

[0096] In S11, the analysis unit 1 determines the thickness of each layer that satisfies the specific number of relational expressions prepared in S10 by optimization calculation, thereby calculating the thickness of each layer. In this way, even in the second embodiment, the X-ray analysis device 100 can measure the thickness of each layer by preparing three or more relational expressions even when the sample 3 includes three or more specific number of layers.

[0097] <Implementation Method 3> In the third embodiment, an example is shown in which the thickness of a part of the plurality of layers included in the sample 3 is known. The configuration of the X-ray analysis apparatus 100 of the third embodiment is the same as that of the first embodiment. Figure 6 : is a schematic cross-sectional view showing an example of a sample 3 according to Embodiment 3. The sample 3 includes a first layer 31 and a second layer 32, and a third layer 33 sandwiched between the first layer 31 and the second layer 32. X-rays irradiated to the sample 3 pass through the sample 3 in the order of the first layer 31, the third layer 33, and the second layer 32.

[0098] The thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 are unknown, but the thickness of the third layer 33 is known. Let the known thickness of the third layer 33 be t (3) For example, the first layer 31 and the second layer 32 are metal layers containing platinum, the third layer 33 is an organic film, and the sample 3 is a part of the material of the electrode of the fuel cell.

[0099] In the third embodiment, the following equation (12) is used as the first relational expression. The equation (12) is obtained by setting the number of layers in equation (4) to three and replacing t3 with t which is a known constant. (3) And get. μ1(E1)ρ1t1+μ2(E1)ρ2t2+μ3(E1)ρ3t (3) +ln(I T (E1) / I0(E1))=0……(12)

[0100] As the second relational expression, the following equation (13) is used. The equation (13) is obtained by setting the number of layers in equation (5) to three and replacing t3 with t which is a known constant. (3) And get. I F ~(E2,t1,t2,t (3) ) / I T ~(E2,t1,t2,t(3) )-I F (E2) / I T (E2) = 0...(13)

[0101] In the case where the first layer 31 and the second layer 32 have the same composition, there is a possibility that the detected fluorescent X-rays contain fluorescent X-rays from the second layer 32 in addition to the fluorescent X-rays from the first layer 31. Therefore, it is preferable that the energy E2 is energy corresponding to the position of the peak contained in the spectrum of the fluorescent X-ray and is the energy of the fluorescent X-ray generated from the second layer 32 and blocked as much as possible by the first layer 31 or the third layer 33. For example, in the case where the first layer 31 and the second layer 32 are metal layers containing platinum, the energy E2 is the energy of the M line of platinum. By using such energy E2, the correct formula (13) can be obtained, and the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32 can be correctly calculated.

[0102] Even in the third embodiment, the X-ray analysis device 100 executes S1 to S12. In S10, the analysis unit 1 creates equation (12) as the first relational expression and creates equation (13) as the second relational expression. In S11, the analysis unit 1 determines the thickness of each layer that satisfies equations (12) and (13) created in S10 by optimization calculation, thereby calculating the thickness t1 of the first layer 31 and the thickness t2 of the second layer 32.

[0103] As described above, even in the third embodiment, the X-ray analysis device 100 can measure the thickness of each layer even when the thickness of a portion of the multiple layers included in the sample 3 is known. Similarly, when the sample 3 includes more than three layers and the thickness of any one of the layers is known, the thickness of each layer can be measured by using an equation obtained by replacing the thickness of any one of the layers with a known value in equations (4) and (5), and by using an equation obtained by replacing the thickness of any one of the layers with a known value in any one of equations (6) to (9) as needed.

[0104] In Embodiments 1 to 3, the fluorescent X-ray detector 22 and the transmission X-ray detector 23 are radiation detectors having radiation detection elements formed using semiconductors. The fluorescent X-ray detector 22 and the transmission X-ray detector 23 may also be radiation detectors having radiation detection elements other than radiation detection elements formed using semiconductors. The fluorescent X-ray detector 22 and the transmission X-ray detector 23 may also be detectors having multiple channels. For example, the fluorescent X-ray detector 22 and the transmission X-ray detector 23 may also be strip detectors, pixel array detectors, or linear sensors, or may be composed of a plurality of detectors arranged in an array. When a detector having multiple channels is used, a high count rate measurement can be performed compared to the case of using a detector having a single channel.

[0105] The fluorescent X-ray detector 22 and the transmission X-ray detector 23 are not limited to energy dispersive detectors, and any detector that can detect the intensity of X-rays of a specific energy may be used. For example, the fluorescent X-ray detector 22 and the transmission X-ray detector 23 may be formed using a CCD (Charge Coupled Device) optical sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) optical sensor, or may be formed using a combination of a photomultiplier tube and a scintillator. Such a detector may be combined with a filter that allows X-rays of a specific energy to pass through, or an element that focuses X-rays of a specific energy by diffracting them.

[0106] In the first to third embodiments, an example in which the horizontal axis of the X-ray spectrum is energy is shown, but the X-ray analysis device 100 may also be a method of processing a spectrum in which a value other than energy, such as wavelength or wave number, is used as the horizontal axis. In this method, the analysis unit 1 may also use two wavelengths or wave numbers corresponding to two energies to perform processing to calculate the thickness of each layer of the sample 3.

[0107] The present invention is not limited to the contents of the above-mentioned embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

[0108] The matters described in each embodiment can be combined with each other. In addition, the independent claims and dependent claims described in the claims can be combined with each other in all combinations regardless of the reference form. In addition, the form of recording and citing two or more other claims (multiple claims form) is used in the claims, but it is not limited to this. It is also possible to record in the form of recording multiple claims (multiple citing multiple claims) that at least one multiple claim is cited. Description of reference numerals:

[0109] 100: X-ray analysis device; 1: analysis unit; 10: recording medium; 141: computer program; 21: irradiation unit; 22: fluorescent X-ray detector; 23: transmission X-ray detector; 3: sample; 31: first layer; 32: second layer.

Claims

1. A thickness measurement method, characterized in that: irradiating the X-ray to a sample including a plurality of layers in such a manner that the X-ray is transmitted through the plurality of layers, detecting fluorescent X-rays generated from the sample, detecting the transmitted X-rays after passing through the sample, A first relational expression indicating the relationship between the intensity of the detected transmission X-ray and the thickness of each layer, and a second relational expression indicating the relationship between the ratio of the theoretical intensity of the fluorescent X-ray and the transmission X-ray corresponding to the thickness of each layer and the ratio of the detected intensity of the fluorescent X-ray and the transmission X-ray are prepared, The thickness of each layer that satisfies both the first relational expression and the second relational expression is calculated.

2. The thickness measurement method according to claim 1, characterized in that: The sample includes three or more layers, preparing the first relational expression related to a specific first energy, the second relational expression related to a specific second energy, and the first relational expression or the second relational expression related to other energies different from the first energy or the second energy, The thickness of each layer that simultaneously satisfies the first relational expression related to the first energy, the second relational expression related to the second energy, and the first relational expression or the second relational expression related to the other energy is calculated.

3. A thickness measurement method, characterized in that: irradiating the X-ray to a sample including a plurality of layers in such a manner that the X-ray is transmitted through the plurality of layers, detecting fluorescent X-rays generated from the sample, detecting the transmitted X-rays after passing through the sample, A plurality of relational expressions are prepared from a first relational expression indicating the relationship between the intensity of the detected transmission X-ray and the thickness of each layer, a third relational expression indicating the relationship between the theoretical intensity of the fluorescent X-ray corresponding to the thickness of each layer and the detected intensity of the fluorescent X-ray, and a fourth relational expression indicating the relationship between the theoretical intensity of the transmission X-ray corresponding to the thickness of each layer and the detected intensity of the transmission X-ray, The thickness of each layer that satisfies a plurality of the above relationship expressions is calculated.

4. The thickness measurement method according to claim 3, characterized in that: The sample includes three or more specific number of layers, The relational expression of the specific number is produced from the first relational expression related to a specific first energy, the third relational expression related to a specific second energy, the fourth relational expression related to a specific third energy, and the first relational expression, the third relational expression or the fourth relational expression related to other energies different from the first energy, the second energy or the third energy, The thickness of each layer that simultaneously satisfies the prepared relational expression of the specific number is calculated.

5. The thickness measurement method according to any one of claims 1 to 4, characterized in that: In the absence of the sample, the X-rays to be irradiated to the sample are generated and detected at a lower output than when irradiating to the sample, The first relational expression is an expression expressing the relationship between the ratio of the detected intensity of the transmitted X-ray and the detected intensity of the X-ray, and the thickness and density of each layer and the mass absorption coefficient of the X-ray in each layer.

6. The thickness measurement method according to claim 5, characterized in that: The first relational expression is prepared using the intensity of the transmitted X-ray at an energy not corresponding to the position of the peak of the fluorescent X-ray included in the spectrum of the fluorescent X-ray and the mass absorption coefficient of the X-ray at the energy.

7. The thickness measurement method according to claim 1 or 2, characterized in that: The second relational expression is prepared using the theoretical intensities of the fluorescent X-rays and the transmitted X-rays at an energy corresponding to the position of the peak of the fluorescent X-rays included in the spectrum of the fluorescent X-rays and the detected intensities of the fluorescent X-rays and the transmitted X-rays at the energy.

8. The thickness measurement method according to claim 3 or 4, characterized in that: The third relational expression is created using the theoretical fluorescent X-rays at an energy corresponding to the position of the peak of the fluorescent X-rays included in the spectrum of the fluorescent X-rays and the intensity of the detected fluorescent X-rays at the energy.

9. The thickness measurement method according to claim 7 or 8, characterized in that: The peak of the fluorescent X-ray is a peak of the fluorescent X-ray caused by an element contained in a layer through which the X-ray first transmits among the plurality of layers.

10. An X-ray analysis device, characterized in that: The X-ray analysis device comprises: an irradiation unit that irradiates the X-ray to a sample including a plurality of layers in such a manner that the X-ray passes through the plurality of layers; a fluorescent X-ray detector for detecting fluorescent X-rays generated from the sample; a transmission X-ray detector for detecting the transmission X-rays after passing through the sample; as well as Analytics Department, The analysis unit generates a first relational expression indicating the relationship between the intensity of the detected transmission X-ray and the thickness of each layer, and a second relational expression indicating the relationship between the ratio of the theoretical intensity of the fluorescent X-ray and the transmission X-ray corresponding to the thickness of each layer and the ratio of the detected intensity of the fluorescent X-ray and the transmission X-ray, The thickness of each layer that satisfies both the first relational expression and the second relational expression is calculated.

11. An X-ray analysis device, characterized in that: The X-ray analysis device comprises: an irradiation unit that irradiates the X-ray to a sample including a plurality of layers in such a manner that the X-ray passes through the plurality of layers; a fluorescent X-ray detector for detecting fluorescent X-rays generated from the sample; a transmission X-ray detector for detecting the transmission X-rays after passing through the sample; as well as Analytics Department, The analyzing unit generates a plurality of relational expressions from a first relational expression indicating a relationship between the intensity of the detected transmission X-ray and the thickness of each layer, a third relational expression indicating a relationship between the theoretical intensity of the fluorescent X-ray corresponding to the thickness of each layer and the detected intensity of the fluorescent X-ray, and a fourth relational expression indicating a relationship between the theoretical intensity of the transmission X-ray corresponding to the thickness of each layer and the detected intensity of the transmission X-ray, The thickness of each layer that satisfies a plurality of the above relationship expressions is calculated.

12. An information processing device, characterized in that: The information processing device comprises: an acquisition unit that acquires detection results of fluorescent X-rays generated from a sample including a plurality of layers by irradiating the sample with X-rays in such a manner that the X-rays pass through the plurality of layers, and detection results of transmission X-rays that pass through the sample; a relational expression preparation unit for preparing a first relational expression indicating a relationship between the detected intensity of the transmission X-ray and the thickness of each layer, and a second relational expression indicating a relationship between a theoretical ratio of the intensity of the fluorescent X-ray to the transmission X-ray corresponding to the thickness of each layer and a ratio of the intensity of the detected fluorescent X-ray to the transmission X-ray; as well as The calculation unit calculates the thickness of each layer that satisfies both the first relational expression and the second relational expression.

13. An information processing device, characterized in that: The information processing device comprises: an acquisition unit that acquires detection results of fluorescent X-rays generated from a sample including a plurality of layers by irradiating the sample with X-rays in a manner that allows the X-rays to pass through the plurality of layers, and detection results of transmission X-rays that pass through the sample; a relational expression preparation unit that prepares a plurality of relational expressions from a first relational expression that expresses a relationship between the detected intensity of the transmission X-ray and the thickness of each layer, a third relational expression that expresses a relationship between the theoretical intensity of the fluorescent X-ray corresponding to the thickness of each layer and the detected intensity of the fluorescent X-ray, and a fourth relational expression that expresses a relationship between the theoretical intensity of the transmission X-ray corresponding to the thickness of each layer and the detected intensity of the transmission X-ray; and The calculation unit calculates the thickness of each layer that satisfies a plurality of the relational expressions simultaneously.

14. A computer program, characterized in that The computer program causes the computer to execute the following processing: Prepare a first relational expression and a second relational expression, the first relational expression representing a relationship between the intensity of the detected transmission X-ray and the thickness of each layer based on a detection result of a transmission X-ray after the sample including a plurality of layers is transmitted through the sample by irradiating the X-ray to the sample in a manner such that the X-ray transmits the plurality of the layers, and the second relational expression representing a relationship between a theoretical ratio of the intensity of the fluorescent X-ray to the transmission X-ray corresponding to the thickness of each layer and a ratio of the intensity of the detected fluorescent X-ray to the transmission X-ray based on a detection result of a fluorescent X-ray generated from the sample and a detection result of the transmission X-ray; as well as The thickness of each layer that satisfies both the first relational expression and the second relational expression is calculated.

15. A computer program, characterized in that The computer program causes the computer to execute the following processing: preparing a plurality of relationship equations from a first relationship equation, a second relationship equation, and a fourth relationship equation, the first relationship equation representing a relationship between the intensity of the detected transmission X-ray and the thickness of each layer based on a detection result of a transmission X-ray after the transmission X-ray passes through the sample by irradiating the sample with the X-ray in such a manner that the X-ray passes through the multiple layers, the second relationship equation representing a relationship between the theoretical intensity of the fluorescence X-ray corresponding to the thickness of each layer and the detected intensity of the fluorescence X-ray based on a detection result of the fluorescence X-ray generated from the sample, and the fourth relationship equation representing a relationship between the theoretical intensity of the transmission X-ray corresponding to the thickness of each layer and the detected intensity of the transmission X-ray; and The thickness of each layer that satisfies a plurality of the above relationship expressions is calculated.

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