Spectrum processing apparatus, sample analysis apparatus, and spectrum processing method

Abstract

To provide a spectrum processing device with which it is possible to generate a phase spectrum of high S / N ratio.SOLUTION: A spectrum processing device according to the present invention comprises: a data acquisition unit for acquiring spectrum imaging data in which a pixel spectrum based on a signal from a sample is stored for each pixel representing a position in the sample; an extraction unit for comparing, for each pixel, the pixel spectrum with a representative spectrum selected from the spectrum imaging data, and extracting a plurality of pixel spectra from the spectrum imaging data on the basis of the comparison result; and a spectrum generation unit for generating a phase spectrum on the basis of the plurality of extracted pixel spectra.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a spectrum processing apparatus, a sample analysis apparatus, and a spectrum processing method.

Background Art

[0002] In a scanning electron microscope equipped with an X-ray detector such as an energy dispersive X-ray spectrometer (EDS) or a wavelength dispersive X-ray spectrometer (WDS), spectrum imaging data associating the position on a sample with an X-ray spectrum can be acquired. As a method for obtaining the distribution of a compound using the spectrum imaging data, phase analysis is known.

[0003] For example, Patent Document 1 discloses a phase analysis apparatus that displays a phase map showing the distribution of a compound and a graph representing the X-ray intensity of each element and the concentration of each element as an area, making it easy to grasp the characteristics of the composition of the compound.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One method for generating a phase map from spectrum imaging data is a method using a representative spectrum. Specifically, a representative spectrum representing the characteristics of substances contained in an analysis region is selected from the spectrum imaging data, and the abundance of the representative spectrum is obtained for each pixel of the spectrum imaging data. Using this abundance as a pixel value, a phase map showing the distribution of a phase (compound) is generated. The phase composition of the generated phase map is obtained by qualitatively and quantitatively analyzing the representative spectrum.

[0006] The spectra stored in each pixel of the spectral imaging data have a low signal amount and a low S / N ratio due to the short measurement time. Therefore, the representative spectra selected from the spectral imaging data have a low S / N ratio. Accordingly, there are cases where the composition of the phase cannot be accurately identified even when qualitative analysis and quantitative analysis are performed on the representative spectra.

Means for Solving the Problem

[0007] One aspect of the spectral processing apparatus according to the present invention is a data acquisition unit that acquires spectral imaging data in which pixel spectra based on signals from the sample are stored for each pixel representing a position on the sample; an extraction unit that compares the pixel spectrum with a representative spectrum selected from the spectral imaging data for each pixel and extracts a plurality of the pixel spectra from the spectral imaging data based on the comparison result; a spectrum generation unit that generates a phase spectrum based on the plurality of extracted pixel spectra; and includes.

[0008] In such a spectral processing apparatus, a phase spectrum with a high S / N ratio can be generated, and the composition of the phase can be accurately identified.

[0009] One aspect of the sample analysis apparatus according to the present invention is including the above spectral processing apparatus.

[0010] One aspect of the spectral processing method according to the present invention is a step of acquiring spectral imaging data in which pixel spectra based on signals from the sample are stored for each pixel representing a position on the sample; a step of comparing the pixel spectrum with a representative spectrum selected from the spectral imaging data for each pixel and extracting a plurality of the pixel spectra from the spectral imaging data based on the comparison result; a step of generating a phase spectrum based on the plurality of extracted pixel spectra; including

[0011] In such a spectrum processing method, a phase spectrum with a high S / N ratio can be generated, and the phase composition can be accurately identified.

Brief Description of Drawings

[0012]

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Embodiments for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0014] 1. First Embodiment 1.1. Sample Analyzer First, the spectrum processing apparatus according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of a sample analyzer 100 including a spectrum processing apparatus 80 according to the first embodiment.

[0015] As shown in FIG. 1, the sample analyzer 100 includes an electron gun 10, a condenser lens 20, a scanning coil 30, an objective lens 40, a sample stage 50, a secondary electron detector 60, a backscattered electron detector 62, an X-ray detector 70, and a spectrum processing apparatus 80. The sample analyzer 100 is a scanning electron microscope equipped with an X-ray detector 70.

[0016] The electron gun 10 emits an electron beam. The electron gun 10, for example, accelerates electrons emitted from a cathode with an anode and emits an electron beam. The condenser lens 20 and the objective lens 40 focus the electron beam emitted from the electron gun 10 to form an electron probe EP. The condenser lens 20 can control the probe diameter and the probe current. The scanning coil 30 deflects the electron probe EP two-dimensionally. By deflecting the electron probe EP two-dimensionally with the scanning coil 30, the sample S can be scanned with the electron probe EP.

[0017] The sample stage 50 holds the sample S. The sample stage 50 has a moving mechanism for moving the sample S.

[0018] The secondary electron detector 60 detects secondary electrons emitted from the sample S when the electron beam irradiates the sample S. By scanning the sample S with the electron probe EP and detecting the secondary electrons emitted from the sample S with the secondary electron detector 60, a secondary electron image can be obtained.

[0019] The backscattered electron detector 62 detects backscattered electrons emitted from the sample S when the electron beam irradiates the sample S. By scanning the sample S with the electron probe EP and detecting the backscattered electrons emitted from the sample S with the backscattered electron detector 62, a backscattered electron image can be obtained.

[0020] The X-ray detector 70 detects characteristic X-rays emitted from the sample S when the electron beam irradiates the sample S. The X-ray detector 70 is, for example, an energy-dispersive X-ray detector. Note that the X-ray detector 70 may be a wavelength-dispersive X-ray spectrometer. By scanning the sample S with the electron probe EP and detecting the characteristic X-rays emitted from the sample S with the X-ray detector 70, spectral imaging data can be obtained.

[0021] The electron gun 10, the condenser lens 20, the scanning coil 30, the objective lens 40, the sample stage 50, the secondary electron detector 60, the backscattered electron detector 62, and the X-ray detector 70 constitute the main body 101 of the sample analyzer 100.

[0022] Figure 2 is a diagram for explaining the spectral imaging data 2. The spectral imaging data 2 is data that associates the position (coordinates) on the sample S with the spectrum based on the signal from the sample S. Here, the signal from the sample S is the characteristic X-ray emitted from the sample S. The spectral imaging data 2 has a plurality of pixels 2a corresponding to the positions on the sample S. Each pixel 2a stores a pixel spectrum 4. The pixel spectrum 4 is an X-ray spectrum obtained by detecting the X-rays generated at the position on the sample S indicated by the pixel 2a.

[0023] In the main body 101 of the sample analysis device 100, while scanning the sample S with the electron probe EP, the X-ray detector 70 detects X-rays, and by associating and storing the position (coordinates) on the sample S with the X-ray spectrum, the spectral imaging data 2 can be obtained.

[0024] The spectrum processing device (information processing device) 80 performs phase analysis using the spectral imaging data 2 and generates a phase map as a result of the phase analysis. Further, the spectrum processing device 80 generates a phase spectrum for identifying the composition of the phase. The phase map is a map showing the distribution of the phase (compound or single substance). The phase spectrum is a spectrum used for identifying the composition of the phase. The phase map and the phase spectrum are generated for each phase.

[0025] Figure 3 is a diagram showing the configuration of the spectrum processing device 80.

[0026] As shown in FIG. 3, the spectrum processing device 80 includes a processing unit 800, an operation unit 810, a display unit 820, and a storage unit 830.

[0027] The operation unit 810 is for the user to input operation information and outputs the input operation information to the processing unit 800. The functions of the operation unit 810 can be realized by input devices such as a keyboard, a mouse, buttons, a touch panel, and a touch pad.

[0028] The display unit 820 displays the image generated by the processing unit 800, and its functions can be realized by a display such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube).

[0029] The storage unit 830 stores programs and various data for causing a computer to function as each part of the processing unit 800. Further, the storage unit 830 also functions as a work area of the processing unit 800. The functions of the storage unit 830 can be realized by a hard disk, a RAM (Random Access Memory), etc.

[0030] By executing the program stored in the storage unit 830, the processing unit 800 functions as a data acquisition unit 801, a representative spectrum selection unit 802, a phase analysis unit 803, an extraction unit 804, a spectrum generation unit 805, a display control unit 806, and a composition analysis unit 807, which will be described below. The functions of the processing unit 800 can be realized by hardware such as various processors (CPU, DSP, etc.) and ASIC (gate array, etc.) by executing a program. The processing unit 800 includes a data acquisition unit 801, a representative spectrum selection unit 802, a phase analysis unit 803, an extraction unit 804, a spectrum generation unit 805, a display control unit 806, and a composition analysis unit 807.

[0031] The data acquisition unit 801 acquires the spectral imaging data 2 obtained by measuring the sample S with the sample analyzer 100. The spectral processor 80 is connected to the main body 101 of the sample analyzer 100. When the spectral imaging data 2 is acquired by the main body 101, the spectral imaging data 2 is sent from the main body 101 to the spectral processor 80.

[0032] The representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2. The representative spectrum is a spectrum that represents the characteristics of the phase. The representative spectrum is one of the plurality of pixel spectra 4 stored in the spectral imaging data 2. The representative spectrum selection unit 802 selects one representative spectrum for each phase. The representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2 using a well-known method such as VCA (Vertex Component Analysis), PPI (pixel purely index), N-FINDR, etc. At this time, the number of representative spectra (number of phases) to be selected may be specified by the user, or may be calculated by the representative spectrum selection unit 802 based on the spectral imaging data 2.

[0033] The phase analysis unit 803 analyzes the spectral imaging data 2 to perform phase analysis. Phase analysis refers to analyzing the spectral imaging data 2 to create the spatial distribution (phase map) of substances having the same spectrum, that is, the same composition, and its spectrum (phase spectrum).

[0034] For example, the phase analysis unit 803 compares the pixel spectrum 4 with the representative spectrum for each pixel 2a of the spectral imaging data 2, and creates a phase map based on the comparison result. The phase analysis unit 803 calculates the abundance of the representative spectrum in the pixel spectrum 4 for each pixel 2a, and creates data associating the abundance with the coordinates of the pixel 2a. The abundance is a coefficient when representing the pixel spectrum 4 with reference to the representative spectrum. For example, considering the pixel spectrum 4 and the representative spectrum as vectors respectively, the abundance can be calculated by the projection operation of the pixel spectrum 4 with respect to the representative spectrum. Also, for example, the coefficient of each representative spectrum when fitting the pixel spectrum 4 using all the representative spectra may be used as the abundance. The phase analysis unit 803 creates a phase map based on the data associating the abundance with the coordinates of the pixel 2a. For example, the phase analysis unit 803 creates a phase map using the abundance as a pixel value (luminance value). That is, in the phase map generated by the phase analysis unit 803, the pixel value of each pixel becomes a value corresponding to the abundance calculated at the corresponding pixel 2a. The phase analysis unit 803 creates a phase map for each selected representative spectrum. That is, the phase analysis unit 803 creates as many phase maps as the number of selected representative spectra.

[0035] The extraction unit 804 and the spectrum generation unit 805 perform a process of generating a phase spectrum.

[0036] The extraction unit 804 compares the pixel spectrum 4 with the representative spectrum for each pixel 2a, and extracts the pixel spectrum 4 from the spectral imaging data 2 based on the comparison result.

[0037]

[0038] ​Specifically, first, the extraction unit 804 sets a threshold value for extracting the pixel spectrum 4 from the spectral imaging data 2. The extraction unit 804 receives the user's specification of the threshold value and sets the threshold value. For example, when the user operates the operation unit 810 to specify the threshold value, the extraction unit 804 receives the information of the threshold value specified by the user from the operation unit 810 and sets the threshold value. The user may specify the threshold value by operating the operation unit 810 to input an arbitrary numerical value, or may specify the threshold value by selecting one from the options displayed on the GUI (Graphical User Interface). Note that the extraction unit 804 may set the threshold value by reading out the information of the threshold value stored in the storage unit 830 in advance. Different values may be set for each phase, or the threshold values may be set to be the same for a plurality of phases.

[0039] Next, the extraction unit 804 calculates the abundance of the representative spectrum in the pixel spectrum 4 for each pixel 2a, and identifies the pixel 2a whose abundance is greater than the threshold value. The extraction unit 804 extracts the pixel spectrum 4 stored in the pixel 2a whose abundance is greater than the threshold value. Through the above processing, the pixel spectrum 4 can be extracted.

[0040] The extraction unit 804 performs the process of extracting the above pixel spectrum 4 for each phase. Here, in the pixel spectrum 4 extracted for each phase, when the pixel spectra 4 of the same pixel 2a in different phases are extracted, the extraction unit 804 excludes the pixel spectrum 4. Thereby, the pixel spectrum 4 in which the phase composition is purely represented can be extracted.

[0041] The spectrum generation unit 805 generates a phase spectrum based on the pixel spectrum 4 extracted by the extraction unit 804. The spectrum generation unit 805 adds or averages a plurality of pixel spectra 4 extracted for each phase to generate a phase spectrum for each phase. That is, the spectrum generation unit 805 generates a phase spectrum for the number of representative spectra.

[0042] The display control unit 806 causes the display unit 820 to display information on the position of the pixel 2a in which the extracted pixel spectrum 4 is stored (hereinafter also referred to as "extracted pixel"). The extracted pixel 2a is a pixel in the pixel 2a of the spectral imaging data 2 in which the spectrum used for generating the phase spectrum is stored. The display control unit 806 generates, for example, a pixel map indicating the position of the extracted pixel 2a, and causes the display unit 820 to display the generated pixel map. Further, the display control unit 806 causes the display unit 820 to display, by overlapping, an image of the sample S such as a secondary electron image or a reflected electron image and the generated pixel map.

[0043] The composition analysis unit 807 performs qualitative analysis and quantitative analysis on the phase spectrum to identify the composition of the phase. The composition analysis unit 807 performs qualitative analysis and quantitative analysis on each phase spectrum to identify the composition of each phase.

[0044] 1.2. Spectrum processing method 1.2.1. Generation of phase map Next, a spectrum processing method using the spectrum processing apparatus 80 will be described. Here, first, the generation process of the phase map of the spectrum processing apparatus 80 will be described.

[0045] FIG. 4 is a flowchart showing an example of the flow of the phase map generation process of the spectrum processing apparatus 80.

[0046] First, the data acquisition unit 801 acquires the spectral imaging data 2 obtained by measuring the sample S with the main body 101 of the sample analyzer 100 (S10).

[0047] In the main body 101, while scanning the sample S with the electron probe EP, the X-ray detector 70 detects X-rays, and by associating and storing the position on the sample S and the X-ray spectrum, the spectral imaging data 2 shown in FIG. 2 can be acquired. When the spectral imaging data 2 is acquired in the main body 101, the spectral imaging data 2 is sent from the main body 101 to the spectrum processing apparatus 80.

[0048] Next, the representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2 acquired by the data acquisition unit 801 (S20).

[0049] The representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2 using a well-known method such as VCA (Vertex Component Analysis), PPI (pixel purely index), or N-FINDR. The representative spectrum selection unit 802 selects representative spectra for each of the first to nth phases (n is an integer of 2 or more), which are different phases from each other. Hereinafter, the representative spectrum of the mth phase (m is an integer from 1 to n) is referred to as the mth representative spectrum. The representative spectrum selection unit 802 selects the first to nth representative spectra.

[0050] Next, the phase analysis unit 803 compares the pixel spectrum 4 with the representative spectrum for each pixel 2a, and creates a phase map based on the comparison result (S30).

[0051] The phase analysis unit 803 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a, and creates a first phase map with the abundance as the pixel value. The first phase map is a phase map showing the distribution of the first phase. Hereinafter, the phase map showing the distribution of the mth phase is referred to as the mth phase map.

[0052] Next, the phase analysis unit 803 calculates the abundance of the second representative spectrum in the pixel spectrum 4 for each pixel 2a, and creates a second phase map with a value corresponding to the abundance as the pixel value. The phase analysis unit 803 also performs a process of calculating the abundance and creating a phase map for the representative spectra after the third representative spectrum, and creates the third to nth phase maps. In this way, the phase analysis unit 803 creates the first to nth phase maps.

[0053] FIG. 5 is a diagram showing an example of the first phase map M1. As shown in FIG. 5, in the first phase map M1, the luminance value of each pixel represents the abundance calculated for each pixel.

[0054] 1.2.2. Generation of Phase Spectrum Next, the generation process of the phase spectrum by the spectrum processing device 80 will be described. FIG. 6 is a flowchart showing an example of the flow of the phase spectrum generation process of the spectrum processing device 80.

[0055] The extraction unit 804 sets a first threshold for generating the phase spectrum of the m-th phase (S100). Here, assuming m = 1, the extraction unit 804 sets the first threshold for generating the phase spectrum of the first phase. The extraction unit 804 may receive the designation of the first threshold by the user and set the first threshold, or may read out the information of the first threshold recorded in the storage unit 830 in advance and set the first threshold.

[0056] Next, for each pixel 2a of the spectral imaging data 2, the extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4, and extracts the pixel spectrum 4 whose abundance is greater than the first threshold (S102). As a result, the pixel spectrum 4 whose abundance is greater than the first threshold can be extracted from the spectral imaging data 2. The extraction unit 804 creates first pixel data D-1 in which the extracted pixel spectrum 4 is associated with the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored (coordinates of the extracted pixel 2a), and stores it in the storage unit 830.

[0057] FIG. 7 is a diagram for explaining the first pixel data D-1. As shown in FIG. 7, the first pixel data D-1 has a plurality of pixels 6a corresponding to a plurality of pixels 2a of the spectral imaging data 2. In the example shown in FIG. 7, the pixel 6a in which the extracted pixel spectrum 4 is stored is hatched. When the extraction unit 804 extracts the pixel spectrum 4 from the pixel 2a, the extracted pixel spectrum 4 is stored in the pixel 6a corresponding to the pixel 2a. As a result, the first pixel data D-1 is registered with the extracted pixel spectrum 4 and the information of the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored.

[0058] Here, the first pixel data D-1 is represented in a map format. However, the first pixel data D-1 may also be represented as a list of the extracted pixel spectrum 4 and the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored.

[0059] The extraction unit 804 determines whether the process of extracting the pixel spectrum 4 has been performed for all phases (S104). That is, the extraction unit 804 determines whether m = n is satisfied. If the extraction unit 804 determines that m = n is not satisfied (No in S104), it sets m = 1 + 1, and the extraction unit 804 sets a second threshold value for generating the second phase spectrum (S100). The extraction unit 804 may receive the designation of the second threshold value by the user and set the second threshold value, or may read the information of the second threshold value recorded in the storage unit 830 in advance and set the second threshold value. Further, the extraction unit 804 may set the same value as the first threshold value as the second threshold value. That is, the first threshold value to the n-th threshold value set in the process S100 may be the same value.

[0060] For each pixel 2a, the extraction unit 804 calculates the abundance of the second representative spectrum in the pixel spectrum 4, and extracts the pixel spectrum 4 whose abundance is greater than the second threshold value (S102). The extraction unit 804 creates second pixel data in which the extracted pixel spectrum 4 and the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored are associated, and stores it in the storage unit 830.

[0061] In this way, the extraction unit 804 repeats the processes S100, S102, and S104 until it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases. The extraction unit 804 creates the first to n-th pixel data by repeating the processes S100, S102, and S104.

[0062] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S104), it excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to n-th pixel data (S106).

[0063] FIG. 8 is a diagram for explaining a process of excluding the pixel spectrum 4 extracted from the same pixel 2a. As shown in FIG. 8, when the first pixel data D-1 and the second pixel data D-2 include the pixel spectrum 4 extracted from the same pixel 2a of the spectral imaging data 2, the pixel spectrum 4 extracted from the same pixel 2a is excluded from the first pixel data D-1 and the second pixel data D-2. Thereby, the pixel spectrum 4 in which the phase composition is purely represented can be extracted.

[0064] Here, the case where the pixel spectrum 4 extracted from the same pixel 2a is excluded from two pixel data has been described. However, when there is a pixel spectrum 4 extracted from the same pixel 2a in three or more pixel data, the pixel spectrum 4 extracted from the same pixel 2a is similarly excluded from each pixel data.

[0065] Next, the spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S108).

[0066] The spectrum generation unit 805 acquires information on the extracted pixel spectrum 4 from the first pixel data D-1, adds or averages the extracted pixel spectrum 4, and generates a phase spectrum of the first phase. In this way, since a plurality of pixel spectra 4 are added or averaged to generate a phase spectrum, the S / N ratio of the phase spectrum can be improved as compared with the case where one pixel spectrum 4 is used as the phase spectrum.

[0067] Similarly, the spectrum generation unit 805 acquires information on the pixel spectrum 4 extracted from the second pixel data D-2, adds or averages the extracted pixel spectrum 4, and generates a phase spectrum of the second phase. The spectrum generation unit 805 generates phase spectra of the third phase to the nth phase in the same manner as the phase spectrum of the first phase. The phase spectra of the first phase to the nth phase generated by the spectrum generation unit 805 are displayed on the display unit 820.

[0068] The display control unit 806 causes the display unit 820 to display information on the position of the pixel 2a (extracted pixel 2a) in which the extracted pixel spectrum 4 is stored (S110).

[0069] The display control unit 806 generates a first pixel map indicating the position of the extracted pixel 2a from the first pixel data D-1. Similarly, the display control unit 806 generates a second pixel map indicating the position of the extracted pixel 2a from the second pixel data D-2. The display control unit 806 also generates the third to nth pixel maps in the same manner as the first pixel map. The display control unit 806 causes the display unit 820 to display the first to nth pixel maps.

[0070] FIG. 9 is a diagram showing an example of the first pixel map Mp1. The first pixel map Mp1 is a map indicating the position of the pixel 2a in which the pixel spectrum 4 used to generate the phase spectrum of the first phase is stored. In the first pixel map Mp1 shown in FIG. 9, the pixel corresponding to the extracted pixel 2a is shown in red, and the pixels 2a other than the extracted pixel 2a, that is, the pixels 2a of the spectral imaging data 2 for which the pixel spectrum 4 was not extracted, are shown in black. From the first pixel map Mp1, it is possible to know at which position on the sample S the pixel spectrum 4 used to generate the phase spectrum of the first phase was detected.

[0071] FIG. 10 shows a state in which the first pixel map Mp1 is superimposed on the scanning electron microscope image SI and displayed. As shown in FIG. 10, the display control unit 806 may cause the display unit 820 to display an image SI+Mp1 in which the first pixel map Mp1 and a scanning electron microscope image SI such as a secondary electron image or a backscattered electron image are superimposed. In this way, the display control unit 806 may superimpose and display the first pixel map Mp1 and the pixels of the sample S.

[0072] FIG. 11 is a diagram showing a state in which the first pixel map Mp1 is superimposed on the first phase map M1 and displayed. As shown in FIG. 11, the display control unit 806 may cause the display unit 820 to display an image M1+Mp1 in which the first pixel map Mp1 and the first phase map M1 are superimposed.

[0073] The display control unit 806 also displays the second to nth pixel maps in the same manner as the first pixel map Mp1. After the processing unit 800 causes the first to nth pixel maps to be displayed on the display unit 820, it ends the phase spectrum generation process.

[0074] Here, the case of displaying the pixel map has been described as the information on the position of the extraction pixel 2a, but the display method of the information on the position of the extraction pixel 2a is not limited to the pixel map. For example, as the information indicating the position of the extraction pixel 2a, a list of the coordinates of the extraction pixel 2a may be displayed on the display unit 820.

[0075] The user checks the first to nth phase spectra displayed on the display unit 820 to check whether the S / N ratio of the phase spectra is sufficient. For example, if the user determines that the S / N ratio of the first phase spectrum is not sufficient, the user specifies a lower first threshold value and causes the spectrum processing apparatus 80 to execute the phase spectrum generation process shown in FIG. 6 again. Thereby, a first phase spectrum with a high S / N ratio can be obtained. If the user determines that the S / N ratios of the second to nth phase spectra are also not sufficient, the user specifies a lower threshold value and causes the spectrum processing apparatus 80 to execute the phase spectrum generation process shown in FIG. 6 again.

[0076] When the user determines that the S / N ratios of the phase spectra of all phases are sufficient, the user checks the first to nth pixel maps displayed on the display unit 820 to check whether there are any regions in each pixel map where other phases are mixed. For example, if the first pixel map Mp1 contains a region where the second phase is mixed, the user specifies a higher first threshold value and causes the spectrum processing apparatus 80 to execute the phase spectrum generation process shown in FIG. 6 again. Thereby, a phase spectrum in which the composition of the first phase is purely represented can be obtained. If the second to nth pixel maps also contain regions where other phases are mixed, the user specifies a higher threshold value and causes the spectrum processing apparatus 80 to execute the phase spectrum generation process shown in FIG. 6 again.

[0077] When the user determines that the S / N ratio of the phase spectrum is sufficient and each pixel map does not contain an area where other phases are mixed, the composition analysis unit 807 is made to perform qualitative and quantitative analysis on the phase spectrum of the first phase to identify the composition of the first phase. Similarly, the user causes the composition analysis unit 807 to perform qualitative and quantitative analysis on the phase spectrum of the second phase to identify the composition of the second phase. Similarly for the third phase to the nth phase, the user causes the composition analysis unit 807 to perform qualitative and quantitative analysis on the phase spectrum of each phase to identify the composition of each phase. Thereby, the composition of each phase from the first phase to the nth phase can be identified.

[0078] 1.3. Effect The spectrum processing apparatus 80 includes a data acquisition unit 801 that acquires spectrum imaging data 2 in which a pixel spectrum 4 is stored for each pixel 2a representing a position on the sample S, and for each pixel 2a, compares the pixel spectrum 4 with a representative spectrum selected from the spectrum imaging data 2, and based on the comparison result, extracts a plurality of pixel spectra 4 from the spectrum imaging data 2, and a spectrum generation unit 805 that generates a phase spectrum based on the plurality of extracted pixel spectra 4. Therefore, in the spectrum processing apparatus 80, a phase spectrum with a high S / N ratio can be generated, and the composition of the phase can be accurately identified. Generally, the pixel spectrum 4 stored in the pixel 2a of the spectrum imaging data 2 has a shorter measurement time, a smaller signal amount, and a lower S / N ratio compared to the spectrum obtained by point analysis that irradiates a single point of the sample S. In phase analysis, since a phase map can be created from the abundance of the representative spectrum with respect to the pixel spectrum 4, even if the S / N ratio of the pixel spectrum 4 is low, a phase map reflecting the distribution of the phase can be obtained.

[0079]

[0080] ​However, when identifying the composition of a phase, the representative spectrum consisting of the pixel spectrum for one pixel has a low S / N ratio, so the composition of the phase cannot be accurately identified. The S / N ratio of the representative spectrum can be improved, for example, by increasing the measurement time for obtaining the spectral imaging data 2 or by increasing the irradiation current amount of the electron probe EP irradiated on the sample S. However, the measurement time becomes long or the damage to the sample S becomes large.

[0081] In contrast, the spectral processing device 80 can generate a phase spectrum with a high S / N ratio without causing such problems.

[0082] In the spectral processing device 80, the extraction unit 804 calculates the abundance of the representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts the pixel spectrum 4 whose abundance is greater than the threshold value. Therefore, in the spectral processing device 80, it is possible to reduce the dependence of the identification result of the phase composition on the user.

[0083] For example, as a method for improving the S / N ratio of the phase spectrum, a method is conceivable in which a user designates a region on the spectral imaging data 2, extracts the pixel spectra 4 recorded in a plurality of pixels 2a included in the designated region, and adds or averages the extracted pixel spectra 4 to generate a phase spectrum. However, in this method, since the user designates a region, there is user dependence. Further, in this method, when substances are sparsely present, such as particles sparsely present on the analysis field of view, it is difficult for the user to designate a region on the spectral imaging data 2, and the pixel spectra 4 cannot be appropriately extracted.

[0084] In contrast, in the spectral processing device 80, since the pixel spectrum 4 whose abundance is greater than the threshold value is extracted, it is possible to reduce the dependence of the identification result of the phase composition on the user. Further, even when substances are sparsely present, the pixel spectra 4 recorded in the pixels 2a corresponding to the sparsely present substances can be appropriately extracted.

[0085] In the spectrum processing device 80, the extraction unit 804 receives the threshold value specified by the user and sets the threshold value. Therefore, in the spectrum processing device 80, the user can specify the threshold value.

[0086] The spectrum processing device 80 includes a display control unit 806 that causes the display unit 820 to display the position information of the pixel 2a (extracted pixel 2a) in which the extracted pixel spectrum 4 is stored. Further, the display control unit 806 generates a pixel map indicating the position of the extracted pixel 2a and causes the display unit 820 to display the pixel map. Therefore, in the spectrum processing device 80, the user can confirm the validity of the phase spectrum.

[0087] For example, when the phase spectrum generated by the spectrum generation unit 805 includes a peak of an unexpected element, by checking the pixel map, it is possible to determine whether the peak of the unexpected element is a contribution from another substance. For example, if it can be confirmed from the pixel map that the extracted pixel 2a exists in the boundary and the region near the boundary with another substance, it is suggested that the unexpected element may be a contribution from another substance. If it is confirmed that the extracted pixel 2a exists in the boundary and the region near the boundary with another substance, it is suggested that the unexpected element may be a contribution from another substance.

[0088] In the spectrum processing device 80, the display control unit 806 causes the display unit 820 to display the image of the sample S and the pixel map superimposed. Therefore, in the spectrum processing device 80, the user can easily confirm the validity of the phase spectrum.

[0089] In the spectrum processing device 80, the spectrum generation unit 805 adds or averages the extracted plurality of pixel spectra 4 to generate a phase spectrum. Therefore, in the spectrum processing device 80, a phase spectrum with a high S / N ratio can be generated.

[0090] The spectrum processing device 80 includes a composition analysis unit 807 that identifies the phase composition from the phase spectrum. In the spectrum processing device 80, since a phase spectrum with a high S / N ratio can be generated, the phase composition can be accurately identified in the composition analysis unit 807.

[0091] In the spectral processing device 80, a representative spectrum selection unit 802 that selects a representative spectrum from the spectral imaging data 2 is included. Therefore, in the spectral processing device 80, the representative spectrum can be automatically selected.

[0092] The sample analyzer 100 includes the spectral processing device 80. Therefore, in the sample analyzer 100, a phase spectrum with a high S / N ratio can be generated, and the composition of the phase can be accurately identified.

[0093] The spectral processing method in the first embodiment includes a step of acquiring spectral imaging data 2 in which a pixel spectrum 4 is stored for each pixel 2a representing a position on the sample S, a step of comparing, for each pixel 2a, the pixel spectrum 4 with a representative spectrum selected from the spectral imaging data 2, and extracting a plurality of pixel spectra 4 from the spectral imaging data 2 based on the comparison result, and a step of generating a phase spectrum based on the plurality of extracted pixel spectra 4. Therefore, in the spectral processing method in the first embodiment, a phase spectrum with a high S / N ratio can be generated, and the composition of the phase can be accurately identified.

[0094] 2. Second Embodiment 2.1. Spectral Processing Device Next, the spectral processing device 80 according to the second embodiment will be described with reference to the drawings. FIG. 12 is a diagram showing the configuration of the spectral processing device 80 according to the second embodiment. Hereinafter, in the spectral processing device 80 according to the second embodiment, members having the same functions as the constituent members of the spectral processing device 80 according to the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0095] As shown in FIG. 12, the spectral processing device 80 according to the second embodiment includes an S / N ratio evaluation unit 808. The S / N ratio evaluation unit 808 evaluates the S / N ratio of the generated phase spectrum. The S / N ratio evaluation unit 808 determines, for example, whether the S / N ratio of the phase spectrum is sufficient.

[0096] When the phase spectrum to be determined is the spectrum obtained by adding the extracted pixel spectra 4, whether the S / N ratio is sufficient can be determined from the total count of the signal amount of the phase spectrum, the count of the maximum peak of the phase spectrum, the flatness (variation in count) in the region without peaks in the phase spectrum, etc. Further, for example, when the phase spectrum to be determined is the spectrum obtained by averaging the extracted pixel spectra 4, whether the S / N ratio is sufficient can be determined from the flatness in the region without peaks in the phase spectrum, etc.

[0097] In the spectrum processing apparatus 80 according to the second embodiment, the threshold value is automatically set. In the second The other configurations of the sample analyzer 100 according to the second embodiment are the same as those of the sample analyzer 100 according to the first embodiment, and the description thereof is omitted.

[0098] 2.2. Spectrum Processing Method FIG. 13 is a flowchart showing an example of the flow of the phase spectrum generation process of the spectrum processing apparatus 80 according to the second embodiment. Hereinafter, the differences from the phase spectrum generation process shown in FIG. 6 described above will be described, and the description of the same points will be omitted.

[0099] The extraction unit 804 sets a first threshold value for generating the phase spectrum of the m-th phase (S200). Here, taking m = 1, the extraction unit 804 sets a first threshold value for generating the phase spectrum of the first phase. The extraction unit 804 reads out the information of the first threshold value recorded in the storage unit 830 in advance and sets the first threshold value.

[0100] Next, the extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a of the spectral imaging data 2, and extracts the pixel spectrum 4 whose abundance is greater than the first threshold value (S202). The extraction unit 804 creates the first pixel data D-1 shown in FIG. 7 and stores it in the storage unit 830.

[0101] The extraction unit 804 determines whether or not the process of extracting the pixel spectrum 4 has been performed for all phases (S204). The extraction unit 804 repeats the processes S200, S202, and S204 until it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases, and creates the first to nth pixel data.

[0102] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S204), the extraction unit 804 excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to nth pixel data (S206). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S208). Thereby, the phase spectra of the first to nth phases are generated.

[0103] Next, the S / N ratio evaluation unit 808 evaluates the S / N ratio of the generated phase spectrum (S210).

[0104] The S / N ratio evaluation unit 808 evaluates the S / N ratio, for example, in this order from the phase spectrum of the first phase to the phase spectrum of the nth phase. Note that the order of evaluating the S / N ratio of the phase spectrum is not particularly limited. When evaluating the S / N ratio of the phase spectrum of the first phase, the S / N ratio evaluation unit 808 determines whether or not the S / N ratio is sufficient based on whether or not the total count number of the signal amounts of the phase spectrum of the first phase exceeds a threshold value. Note that the S / N ratio evaluation unit 808 may determine whether or not the S / N ratio is sufficient based on whether or not the count number of the maximum peak of the phase spectrum of the first phase exceeds a threshold value, or may determine whether or not the S / N ratio is sufficient based on whether or not the variation in the count number in the region without a peak in the phase spectrum of the first phase is equal to or less than a threshold value.

[0105] When the S / N ratio evaluation unit 808 determines that the S / N ratio of the phase spectrum of the first phase is not sufficient (No in S212), the extraction unit 804 changes the first threshold value (S214). Specifically, the extraction unit 804 changes the first threshold value to be lower than the first threshold value before the change. The extraction unit 804 rewrites the information on the first threshold value stored in the storage unit 830 to change the first threshold value.

[0106] The extraction unit 804 returns to process S200 and re - sets the first threshold value (S200). The extraction unit 804 reads out the information of the changed first threshold value stored in the storage unit 830 and re - sets the first threshold value.

[0107] For each pixel 2a, the extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4, and extracts the pixel spectrum 4 whose abundance is greater than the re - set first threshold value (S202). Thereby, the first pixel data D - 1 is re - created. Since the first threshold value is changed to be lower than the first threshold value before the change, the number of pixel spectra 4 included in the re - created first pixel data D - 1 is larger than the number of pixel spectra 4 included in the first pixel data D - 1 before being re - created.

[0108] The extraction unit 804 repeats process S200, process S202, and process S204 to create the first to nth pixel data. Here, since the second to nth threshold values are not changed, the second to nth pixel data are not changed. Therefore, the extraction unit 804 may omit process S200, process S202, and process S204 for creating the second to nth pixel data.

[0109] When it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S204), the extraction unit 804 excludes the pixel spectra 4 extracted from the same pixel 2a from the first to nth pixel data (S206). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectra 4 (S208). Thereby, the phase spectra of the first to nth phases are generated.

[0110] Next, the S / N ratio evaluation unit 808 evaluates the S / N ratio of the generated phase spectrum (S210). The S / N ratio evaluation unit 808 evaluates the S / N ratio in order from the phase spectrum of the first phase to the phase spectrum of the nth phase. When the S / N ratio evaluation unit 808 determines that the S / N ratio of the phase spectrum of the first phase is sufficient (Yes in S212), it determines whether the S / N ratios of all the phase spectra have been evaluated (S216). When the S / N ratio evaluation unit 808 determines that the S / N ratios of all the phase spectra have not been evaluated (No in S216), it returns to process S210 and evaluates the S / N ratio of the phase spectrum of the second phase (S210).

[0111] When the S / N ratio evaluation unit 808 determines that the S / N ratio of the phase spectrum of the second phase is not sufficient (No in S212), the extraction unit 804 changes the second threshold value (S214). Specifically, the extraction unit 804 changes the second threshold value to be lower than the second threshold value before the change. The extraction unit 804 changes the second threshold value, for example, by rewriting the information on the second threshold value stored in the storage unit 830.

[0112] The extraction unit 804 repeats processes S200, S202, and S204 to create the first to nth pixel data. Here, since the first threshold value and the third to nth threshold values are not changed, the extraction unit 804 may omit processes S200, S202, and S204 for creating the first pixel data D-1 and the third to nth pixel data.

[0113] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S204), it excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to nth pixel data (S206). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S208). Thereby, the phase spectra of the first phase to the nth phase are generated.

[0114] The processing unit 800 repeats processing S212, processing S214, processing 216, processing S200, processing S202, processing S204, processing S206, processing S208, and processing S210 to evaluate the S / N ratio of the phase spectra from the first phase to the nth phase. When the S / N ratio evaluation unit 808 determines that it has evaluated the S / N ratio of all the phase spectra (Yes in S216), the display control unit 806 causes the display unit 820 to display the information on the position of the extracted pixel 2a (S218). After the processing unit 800 causes the display unit 820 to display the information on the position of the extracted pixel 2a, it ends the phase spectrum generation process.

[0115] 2.3. Effects The spectrum processing device 80 includes an S / N ratio evaluation unit 808 that determines whether the S / N ratio of the generated phase spectrum is sufficient. When the S / N ratio evaluation unit 808 determines that the S / N ratio is not sufficient, the extraction unit 804 sets a low threshold value and extracts the pixel spectrum 4 whose abundance is greater than the threshold value. Therefore, in the spectrum processing device 80, an appropriate threshold value can be set, and a phase spectrum with a high S / N ratio can be generated.

[0116] 3. Third Embodiment 3.1. Spectrum Processing Device Next, the spectrum processing device 80 according to the third embodiment will be described with reference to the drawings. FIG. 14 is a diagram showing the configuration of the spectrum processing device 80 according to the third embodiment. Hereinafter, in the spectrum processing device 80 according to the third embodiment, members having the same functions as the constituent members of the spectrum processing device 80 according to the first and second embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0117] As shown in FIG. 14, the spectrum processing device 80 according to the third embodiment includes a pixel evaluation unit 809. The pixel evaluation unit 809 determines whether the position of the pixel (extracted pixel) 2a in which the extracted pixel spectrum 4 is stored is appropriate. The pixel evaluation unit 809 evaluates the position of the extracted pixel 2a for each phase. When evaluating the position of the extracted pixel 2a in the first phase, the pixel evaluation unit 809 acquires the information on the position of the extracted pixel 2a from the first pixel data D-1.

[0118] The pixel evaluation unit 809 determines whether the position of the extracted pixel 2a is appropriate based on, for example, the density of the extracted pixel 2a. The density of the extracted pixel 2a is the number of extracted pixels 2a contained per unit area. In the case of a substance with a uniform composition, in the region where the substance exists, the probability of the appearance of the extracted pixel 2a is constant. That is, the density of the extracted pixel 2a is constant. On the other hand, in a sample whose composition is not uniform and gradually changes, the abundance of the phase also gradually changes. Therefore, the probability of the appearance of the extracted pixel 2a is not constant either. That is, when the composition is not uniform and gradually changes, the density of the extracted pixel 2a is not constant. Therefore, based on the density of the extracted pixel 2a, it is possible to determine whether the position of the extracted pixel 2a is appropriate.

[0119] For example, in the spectral imaging data 2, for all the extracted pixels 2a, a process of determining whether the extracted pixel 2a is included in a predetermined region centered on the extracted pixel 2a of interest is performed. When it is determined that 90% or more of the extracted pixels 2a are included in the predetermined region, the density is regarded as uniform, and it is determined that the position of the extracted pixel 2a is appropriate.

[0120] Further, the pixel evaluation unit 809 may compare the reflected electron image with the position of the extracted pixel 2a to determine whether the position of the extracted pixel 2a is appropriate. The luminance value of the reflected electron image depends on the average atomic number. Therefore, for example, the luminance value of the pixel of the reflected electron image corresponding to the extracted pixel 2a included in the first pixel data D-1 is acquired, and a histogram of the luminance values is created. If there is one peak in this histogram of luminance values, it can be determined that the position of the extracted pixel 2a is appropriate, and if there are two or more peaks, it can be determined that the position of the extracted pixel 2a is not appropriate.

[0121] In the spectral processing apparatus 80 according to the third embodiment, the threshold value is automatically set in the same manner as in the spectral processing apparatus 80 according to the second embodiment. Other configurations of the sample analyzer 100 according to the third embodiment are the same as those of the sample analyzer 100 according to the first embodiment, and the description thereof is omitted.

[0122] 3.2. Spectrum processing method FIG. 15 is a flowchart showing an example of the phase spectrum generation process of the spectrum processing apparatus 80 according to the third embodiment. Hereinafter, differences from the phase spectrum generation processes shown in FIGS. 6 and 13 described above will be described, and descriptions of the same points will be omitted. The extraction unit 804 sets a first threshold value for generating the phase spectrum of the m-th phase (S300). Here, assuming m = 1, the extraction unit 804 sets the first threshold value for generating the phase spectrum of the first phase. The extraction unit 804 reads the information of the first threshold value recorded in the storage unit 830 in advance and sets the first threshold value.

[0123] Next, for each pixel 2a of the spectral imaging data 2, the extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4, and extracts the pixel spectrum 4 whose abundance is greater than the first threshold value (S302). The extraction unit 804 creates the first pixel data D-1 shown in FIG. 7 and stores it in the storage unit 830.

[0124] The extraction unit 804 determines whether the process of extracting the pixel spectrum 4 has been performed for all phases (S304). The extraction unit 804 repeats processes S300, S302, and S304 until it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases, and creates the first to n-th pixel data.

[0125] If the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S304), the extraction unit 804 excludes the pixel spectra 4 extracted from the same pixel 2a from the first to n-th pixel data (S306). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S308). As a result, the phase spectra of the first to n-th phases are generated.

[0126] Next, the pixel evaluation unit 809 evaluates the position of the extracted pixel 2a (S310).

[0127] ​

[0128] The pixel evaluation unit 809 evaluates the positions of the extracted pixels 2a in order from the first phase to the nth phase, for example. Note that the order of evaluating the positions of the extracted pixels 2a is not particularly limited. When evaluating the position of the extracted pixel 2a in the first phase, the pixel evaluation unit 809 acquires information on the position of the extracted pixel 2a in the first phase from the first pixel data D-1, and determines whether the position of the extracted pixel 2a is appropriate based on the density of the extracted pixel 2a. Note that the pixel evaluation unit 809 may compare the reflected electron image with the extracted pixel 2a to determine whether the position of the extracted pixel 2a is appropriate.

[0129] When the pixel evaluation unit 809 determines that the position of the extracted pixel 2a in the first phase is inappropriate (No in S312), the extraction unit 804 changes the first threshold value (S314). Specifically, the extraction unit 804 changes the first threshold value to be higher than the first threshold value before the change. The extraction unit 804 changes the first threshold value, for example, by rewriting the information on the first threshold value stored in the storage unit 830.

[0130] The extraction unit 804 returns to the process S300 and resets the first threshold value (S300). The extraction unit 804 reads out the information on the changed first threshold value stored in the storage unit 830 and resets the first threshold value.

[0131] The extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts the pixel spectrum 4 in which the abundance is greater than the reset first threshold value (S302). Thereby, the first pixel data D-1 is recreated. Since the first threshold value is changed to be higher than the first threshold value before the change, the number of pixel spectra 4 included in the recreated first pixel data D-1 is smaller than the number of pixel spectra 4 included in the first pixel data D-1 before being recreated.

[0132] The extraction unit 804 repeats the processes S300, S302, and S304, and the first ~Create the first to nth pixel data. Here, since the second to nth thresholds have not been changed, the extraction unit 804 may omit the processes S300, S302, and S304 for creating the second to nth pixel data.

[0133] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S304), it excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to nth pixel data (S306). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S308). Thereby, the phase spectra of the first to nth phases are generated.

[0134] Next, the pixel evaluation unit 809 evaluates the position of the extracted pixel 2a (S310). The pixel evaluation unit 809 evaluates the position of the extracted pixel 2a in this order from the first phase to the nth phase. When the pixel evaluation unit 809 determines that the position of the extracted pixel 2a in the first phase is appropriate (Yes in S312), it determines whether the positions of the extracted pixels 2a in all phases have been evaluated (S316). When the pixel evaluation unit 809 determines that the positions of the extracted pixels 2a in all phases have not been evaluated (No in S316), it returns to process S310 and evaluates the position of the extracted pixel 2a in the second phase (S310).

[0135] When the pixel evaluation unit 809 determines that the position of the extracted pixel 2a in the second phase is not appropriate (No in S312), the extraction unit 804 changes the second threshold (S314). Specifically, the extraction unit 804 changes the second threshold to be higher than the second threshold before the change. The extraction unit 804 changes the second threshold, for example, by rewriting the information of the second threshold stored in the storage unit 830.

[0136] The extraction unit 804 repeats processes S300, S302, and S304 to create the first to nth pixel data. Here, since the first threshold and the third to nth thresholds have not been changed, the extraction unit 804 may omit the processes S300, S302, and S304 for creating the first pixel data D-1 and the third to nth pixel data.

[0137] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S304), it excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to nth pixel data (S306). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S308). Thereby, the phase spectra of the first to nth phases are generated.

[0138] The processing unit 800 repeats the processes S312, S314, 316, S300, S302, S304, S306, S308, S310 to evaluate the positions of the extracted pixels 2a of the first to nth phases. When it is determined that the pixel evaluation unit 809 has evaluated the extracted pixels 2a of all phases (Yes in S316), the display control unit 806 causes the display unit 820 to display the information on the positions of the extracted pixels 2a (S318). After the processing unit 800 causes the display unit 820 to display the information on the positions of the extracted pixels 2a, it ends the phase spectrum generation process.

[0139] 3.3. Effects The spectrum processing device 80 includes a pixel evaluation unit 809 that determines whether the position of the pixel 2a in which the extracted pixel spectrum 4 is stored is appropriate. Further, when the pixel evaluation unit 809 determines that the position of the extracted pixel 2a is not appropriate, the extraction unit 804 sets a high threshold value and extracts a pixel spectrum 4 whose abundance is greater than the threshold value. Therefore, in the spectrum processing device 80, an appropriate threshold value can be set, and a pixel spectrum 4 in which the composition of the phase is more purely represented can be extracted. Accordingly, the composition of the phase can be identified more accurately.

[0140] 4. Fourth Embodiment 4.1. Spectrum Processing Device Next, the spectrum processing apparatus 80 according to the fourth embodiment will be described with reference to the drawings. FIG. 16 is a diagram showing the configuration of the spectrum processing apparatus 80 according to the fourth embodiment. Hereinafter, in the spectrum processing apparatus 80 according to the fourth embodiment, members having the same functions as the constituent members of the spectrum processing apparatus 80 according to the first to third embodiments are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0141] As shown in FIG. 16, the spectrum processing apparatus 80 according to the fourth embodiment includes a threshold evaluation unit 811. The threshold evaluation unit 811 evaluates a threshold based on the S / N ratio of the phase spectrum and the position of the extracted pixel 2a. The threshold evaluation unit 811 determines whether the S / N ratio is sufficient by, for example, the same method as the S / N ratio evaluation unit 808 described above. Further, the threshold evaluation unit 811 determines whether the position of the extracted pixel 2a is appropriate by the same method as the pixel evaluation unit 809 described above.

[0142] When the threshold evaluation unit 811 determines that the S / N ratio is not sufficient and the position of the extracted pixel 2a is not appropriate, when it determines that the S / N ratio is not sufficient and the position of the extracted pixel 2a is appropriate, when it determines that the S / N ratio is sufficient and the position of the extracted pixel 2a is not appropriate, it determines that the threshold is not appropriate. Also, when the threshold evaluation unit 811 determines that the S / N ratio is sufficient and the position of the extracted pixel 2a is appropriate, it determines that the threshold is appropriate.

[0143] In the spectrum processing apparatus 80 according to the fourth embodiment, the threshold is automatically set in the same manner as in the spectrum processing apparatuses 80 according to the second and third embodiments. The other configuration of the sample analysis apparatus 100 according to the fourth embodiment is the same as that of the sample analysis apparatus 100 according to the first embodiment, and the description thereof is omitted.

[0144] 4.2. Spectrum Processing Method FIG. 17 is a flowchart showing an example of the flow of the phase spectrum generation process of the spectrum processing apparatus 80 according to the fourth embodiment. Hereinafter, differences from the phase spectrum generation processes shown in FIGS. 6, 13, and 15 described above will be described, and descriptions of the same points will be omitted.

[0145] The extraction unit 804 sets a first threshold value for generating the phase spectrum of the m-th phase (S400). Here, assuming m = 1, the extraction unit 804 sets a first threshold value for generating the phase spectrum of the first phase. The extraction unit 804 reads the information of the first threshold value recorded in the storage unit 830 in advance and sets the first threshold value.

[0146] Next, for each pixel 2a of the spectral imaging data 2, the extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4, and extracts the pixel spectrum 4 whose abundance is greater than the first threshold value (S402). The extraction unit 804 creates the first pixel data D-1 shown in FIG. 7 and stores it in the storage unit 830.

[0147] The extraction unit 804 determines whether the process of extracting the pixel spectrum 4 has been performed for all phases (S404). The extraction unit 804 repeats processes S400, S402, and S404 until it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases, and creates the first to n-th pixel data.

[0148] When the extraction unit 804 determines that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S404), the extraction unit 804 excludes the pixel spectra 4 extracted from the same pixel 2a from the first to n-th pixel data (S406). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectra 4 (S408). Thereby, the phase spectra of the first to n-th phases are generated.

[0149] Next, the threshold evaluation unit 811 evaluates the threshold value (S410).

[0150] The threshold evaluation unit 811 evaluates thresholds in order from the first threshold to the nth threshold, for example. Note that the order of evaluating the thresholds is not particularly limited. When evaluating the first threshold, the threshold evaluation unit 811 evaluates the first threshold based on the S / N ratio of the phase spectrum of the first phase and the position of the extracted pixel 2a of the first phase.

[0151] When the threshold evaluation unit 811 determines that the first threshold is not appropriate (No in S412), the extraction unit 804 changes the first threshold (S414).

[0152] The extraction unit 804 changes the first threshold based on the evaluation result of the first threshold in the threshold evaluation unit 811. For example, when it is determined that the S / N ratio is not sufficient and the position of the extracted pixel 2a is appropriate, the extraction unit 804 changes the first threshold to be lower than the first threshold before the change. Also, when it is determined that the S / N ratio is sufficient and the position of the extracted pixel 2a is not appropriate, the extraction unit 804 changes the first threshold to be higher than the first threshold before the change. Also, when it is determined that the S / N ratio is not sufficient and the position of the extracted pixel 2a is not appropriate, the extraction unit 804 calculates, for example, an optimal first threshold with a relatively high S / N ratio and a high density of the extracted pixel 2a, and changes the first threshold. Note that when it is determined that the S / N ratio is not sufficient and the position of the extracted pixel 2a is not appropriate, the extraction unit 804 may give priority to the S / N ratio and change the first threshold to be lower, or may give priority to the position of the extracted pixel 2a and change the first threshold to be higher. Whether to give priority to the S / N ratio or the position of the extracted pixel 2a may be selectable by the user.

[0153] The extraction unit 804 returns to process S400 and resets the first threshold (S400). The extraction unit 804 reads out the information of the changed first threshold stored in the storage unit 830 and resets the first threshold.

[0154] The extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts the pixel spectrum 4 in which the abundance is greater than the reset first threshold value (S402). Thereby, the first pixel data D-1 is recreated.

[0155] The extraction unit 804 repeats the processes S400, S402, and S404 to create the first to nth pixel data. Here, since the second to nth threshold values are not changed, the extraction unit 804 may omit the processes S400, S402, and S404 for creating pixel data using the second to nth threshold values.

[0156] When it is determined that the process of extracting the pixel spectrum 4 has been performed for all phases (Yes in S404), the extraction unit 804 excludes the pixel spectra 4 extracted from the same pixel 2a from the first to nth pixel data (S406). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S408). Thereby, the phase spectra of the first to nth phases are generated.

[0157] Next, the threshold evaluation unit 811 evaluates the threshold value (S410). The threshold evaluation unit 811 evaluates the threshold values in order from the first threshold value to the nth threshold value. When the threshold evaluation unit 811 determines that the first threshold value is appropriate (Yes in S412), it determines whether all the threshold values have been evaluated (S416). When the threshold evaluation unit 811 determines that not all the threshold values have been evaluated (No in S416), it returns to the process S410 and evaluates the second threshold value (S410).

[0158] When the threshold evaluation unit 811 determines that the second threshold value is not appropriate (No in S412), the extraction unit 804 changes the second threshold value (S414). The extraction unit 804 changes the second threshold value, for example, by rewriting the information of the second threshold value stored in the storage unit 830.

[0159] The extraction unit 804 repeats process S400, process S402, and process S404 to create the first to nth pixel data. Here, since the first threshold value and the third to nth threshold values are not changed, the extraction unit 804 may omit process S400, process S402, and process S404 for creating the first pixel data D-1 and the third to nth pixel data.

[0160] When it is determined that the extraction unit 804 has performed the process of extracting the pixel spectrum 4 for all phases (Yes in S404), the extraction unit 804 excludes the pixel spectrum 4 extracted from the same pixel 2a from the first to nth pixel data (S406). The spectrum generation unit 805 generates a phase spectrum based on the extracted pixel spectrum 4 (S408). Thereby, the phase spectra of the first to nth phases are generated.

[0161] The processing unit 800 repeats process S412, process S414, process 416, process S400, process S402, process S404, process S406, process S408, and process S410 in this order from the phase spectrum of the first phase to the phase spectrum of the nth phase. When it is determined that the threshold evaluation unit 811 has evaluated all the threshold values (Yes in S416), the display control unit 806 causes the display unit 820 to display the information on the position of the extracted pixel 2a (S418). After the processing unit 800 causes the display unit 820 to display the information on the position of the extracted pixel 2a, the phase spectrum generation process ends.

[0162] 4.3. Effects The spectrum processing device 80 includes a threshold evaluation unit 811 that evaluates a threshold value based on the S / N ratio of the phase spectrum and the position of the extracted pixel 2a. Further, when the threshold evaluation unit 811 determines that the threshold value is not appropriate, the extraction unit 804 sets the threshold value based on the threshold evaluation result in the threshold evaluation unit 811 and extracts the pixel spectrum 4 whose abundance is greater than the threshold value. Therefore, the spectrum processing device 80 can set an appropriate threshold value and generate a phase spectrum with a high S / N ratio.

[0163] 5. Modification Examples 5.1. First Modification Example In the above-described first to fourth embodiments, the phase analysis unit 803 calculates the abundance of the representative spectrum in the pixel spectrum 4 to create a phase map. However, the method for creating the phase map is not limited to this. For example, the phase analysis unit 803 may calculate the similarity between the pixel spectrum and the representative spectrum to create a phase map. Specifically, for each pixel 2a of the spectral imaging data 2, the phase analysis unit 803 calculates the similarity between the pixel spectrum 4 and the representative spectrum, and creates data associating the similarity with the coordinates of the pixel 2a. The similarity can be calculated from, for example, the cosine similarity or the Euclidean distance. The phase analysis unit 803 creates a phase map based on the data associating the similarity with the coordinates of the pixel 2a. The phase analysis unit 803 creates a phase map, for example, using the similarity as the pixel value.

[0164] Further, the extraction unit 804 calculates the abundance of the representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts the pixel spectrum 4 whose abundance is greater than the threshold value. However, the method for extracting the pixel spectrum 4 is not limited to this. For example, the extraction unit 804 may calculate the similarity between the pixel spectrum 4 and the representative spectrum for each pixel 2a, and extract the pixel spectrum 4 whose similarity is greater than the threshold value. The similarity can be calculated from, for example, the cosine similarity or the Euclidean distance.

[0165] Even when the spectral processing device 80 extracts the pixel spectrum 4 whose similarity is greater than the threshold value from the spectral imaging data 2, it can achieve the same effects as when extracting the pixel spectrum 4 whose abundance is greater than the threshold value from the above-described spectral imaging data 2.

[0166] 5.2. Second Variant Example In the above-described first to fourth embodiments, the case where the representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2 has been described. However, the method for selecting a representative spectrum is not limited to this. For example, a user may select a representative spectrum. The user may select a representative spectrum by selecting a pixel 2a from the spectral imaging data 2. In this case, the pixel spectrum 4 recorded in the selected pixel 2a is selected as the representative spectrum.

[0167] The user may select the pixel 2a of the spectral imaging data 2 by designating a position on an image of the sample S such as a secondary electron image or a backscattered electron image. In this case, the pixel spectrum 4 stored in the pixel 2a corresponding to the selected position in the image of the sample S is selected as the representative spectrum. The user can select a representative spectrum using a secondary electron image, a backscattered electron image, an elemental map, etc. as a reference material. An elemental map shows the distribution of X-ray intensity or concentration for each element and can be obtained from the spectral imaging data 2.

[0168] 5.3. Third Modification In the above-described first to fourth embodiments, the case where the spectral processing device 80 is included in the sample analyzer 100 has been described. However, the spectral processing device 80 may not be included in the sample analyzer 100. The spectral processing device 80 may acquire the spectral imaging data 2, for example, by reading out the spectral imaging data 2 stored in an information storage medium, or may acquire the spectral imaging data 2 via a network from a server (not shown) or the like.

[0169] 5.4. Fourth Modification In the above-described first to fourth embodiments, the case where the sample analyzer 100 is a scanning electron microscope equipped with an X-ray detector 70 has been described. However, the sample analyzer 100 is not limited thereto. For example, the sample analyzer 100 may be any device that can obtain a spectrum based on signals (such as X-rays, electrons, ions, etc.) from the sample S. The sample analyzer 100 may be, for example, a transmission electron microscope equipped with an energy-dispersive X-ray spectrometer or a wavelength-dispersive X-ray spectrometer, an electron probe microanalyzer, an Auger microprobe, a photoelectron spectrometer, a focused ion beam device, or the like.

[0170] Note that the above-described embodiments and modified examples are merely examples and are not necessarily limited thereto. For example, the embodiments and each modified example can be combined as appropriate.

[0171] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiments. Substantially the same configuration means, for example, a configuration having the same functions, methods, and results, or a configuration having the same purpose and effects. Further, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiments is replaced. Further, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiments or a configuration that can achieve the same purpose. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiments.

Description of Reference Numerals

[0172] 2…Spectral imaging data, 2a…Pixel, 4…Pixel spectrum, 6a…Pixel, 10…Electron gun, 20…Condenser lens, 30…Scanning coil, 40…Objective lens, 50… Sample stage, 60... Secondary electron detector, 62... Backscattered electron detector, 70... X-ray detector, 80... Spectrum processing device, 100... Sample analysis device, 101... Main body, 800... Processing unit, 801... Data acquisition unit, 802... Representative spectrum selection unit, 803... Phase analysis unit, 804... Extraction unit, 805... Spectrum generation unit, 806... Display control unit, 807... Composition analysis unit, 808... S / N ratio evaluation unit, 809... Pixel evaluation unit, 810... Operation unit, 811... Threshold evaluation unit, 820... Display unit, 830... Memory unit

Claims

1. A data acquisition unit that acquires spectral imaging data in which a pixel spectrum based on a signal from the sample is stored for each pixel representing a position on the sample; An extraction unit that compares the pixel spectrum with a representative spectrum selected from the spectral imaging data for each pixel, and extracts a plurality of the pixel spectra from the spectral imaging data based on the comparison result; A spectrum generation unit that generates a phase spectrum based on the plurality of extracted pixel spectra; A spectral processing apparatus comprising:

2. In Claim 1, The extraction unit calculates the abundance of the representative spectrum in the pixel spectrum or the similarity between the pixel spectrum and the representative spectrum for each pixel, and extracts the pixel spectrum in which the abundance or the similarity is greater than a threshold value. A spectral processing apparatus.

3. In Claim 2, The extraction unit receives a designation of the threshold value by a user and sets the threshold value. A spectral processing apparatus.

4. In Claim 2, Comprising an S / N ratio evaluation unit that determines whether the S / N ratio of the generated phase spectrum is sufficient, When the S / N ratio evaluation unit determines that the S / N ratio is not sufficient, the extraction unit sets the threshold value low and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold value. A spectral processing apparatus.

5. In Claim 2, Comprising a pixel evaluation unit that determines whether the position of the pixel in which the extracted pixel spectrum is stored is appropriate, When it is determined that the position of the pixel is not appropriate, the extraction unit sets the threshold value high and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold value. A spectral processing apparatus.

6. In Claim 2, Comprising a threshold value evaluation unit that evaluates the threshold value based on the S / N ratio of the generated phase spectrum and the position of the pixel in which the extracted pixel spectrum is stored, The extraction unit sets the threshold value based on the evaluation result of the threshold value in the threshold value evaluation unit, and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold value. A spectral processing apparatus.

7. In any one of Claims 1 to 6, A spectral processing apparatus including a display control unit that causes a display unit to display information on the position of the pixel in which the extracted pixel spectrum is stored.

8. In claim 7, The display control unit generates a map indicating the position of the pixel in which the extracted pixel spectrum is stored, and causes the display unit to display the map. A spectral processing apparatus.

9. In claim 8, The display control unit causes the display unit to display the image of the sample and the map superimposed on each other. A spectral processing apparatus.

10. In any one of claims 1 to 6, The spectral generation unit generates the phase spectrum by adding or averaging a plurality of the extracted pixel spectra. A spectral processing apparatus.

11. In any one of claims 1 to 6, A spectral processing apparatus including a composition analysis unit that identifies the composition of the phase from the phase spectrum.

12. In any one of claims 1 to 6, A spectral processing apparatus including a representative spectrum selection unit that selects the representative spectrum from the spectral imaging data.

13. A sample analysis apparatus including the spectral processing apparatus according to claim 1.

14. A step of acquiring spectral imaging data in which a pixel spectrum based on a signal from the sample is stored for each pixel representing a position on the sample; For each pixel, comparing the pixel spectrum with a representative spectrum selected from the spectral imaging data, and extracting a plurality of the pixel spectra from the spectral imaging data based on the comparison result; A step of generating a phase spectrum based on a plurality of the extracted pixel spectra; A spectral processing method including:

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