Spectrum processing device, sample analysis device, 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 analyzing apparatus, and a spectrum processing method. [Background technology]

[0002] Scanning electron microscopes equipped with X-ray detectors such as energy dispersive X-ray spectrometers (EDS) and wavelength dispersive X-ray spectrometers (WDS) can obtain spectral imaging data that associates positions on a sample with X-ray spectra. Phase analysis is known as a method for determining the distribution of compounds using spectral imaging data.

[0003] For example, Patent Document 1 discloses a phase analyzer that displays a phase map showing the distribution of compounds as well as a graph showing 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 compound composition. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-200270 A Summary of the Invention [Problem to be solved by the invention]

[0005] One method for generating a phase map from spectral imaging data is to use a representative spectrum. Specifically, a representative spectrum that represents the characteristics of the material contained in the analysis region is selected from the spectral imaging data, and the abundance of the representative spectrum is calculated for each pixel of the spectral imaging data. This abundance is used as the pixel value to generate a phase map that shows the distribution of phases (compounds). The phase composition of the generated phase map is obtained by qualitative and quantitative analysis of the representative spectrum.

[0006] The spectrum stored in each pixel of the spectral imaging data has a low signal amount and low S / N ratio due to the short measurement time. Therefore, the representative spectrum selected from the spectral imaging data has a low S / N ratio. Therefore, even if the representative spectrum is qualitatively and quantitatively analyzed, the phase composition may not be accurately identified. [Means for solving the problem]

[0007] One aspect of the spectrum processing device according to the present invention is 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 extracting unit that compares, for each of the pixels, the pixel spectrum with a representative spectrum selected from the spectral imaging data, and extracts a plurality of the pixel spectra from the spectral imaging data based on a comparison result; A spectrum generating unit that generates a phase spectrum based on the extracted pixel spectra; Includes.

[0008] Such a spectral processing device can generate phase spectra with high signal-to-noise ratios, allowing accurate identification of phase composition.

[0009] One aspect of the sample analyzer according to the present invention is The above-mentioned spectrum processing device is included.

[0010] One aspect of the spectrum processing method according to the present invention comprises: 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; comparing, for each of the pixels, 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 a comparison result; generating a phase spectrum based on the extracted plurality of pixel spectra; Includes.

[0011] Such a spectral processing method can generate phase spectra with high signal-to-noise ratios, allowing accurate identification of phase compositions. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing the configuration of a sample analyzer including a spectral processing device according to a first embodiment. [Diagram 2] FIG. 1 is a diagram for explaining spectral imaging data. [Diagram 3] FIG. 1 is a diagram showing the configuration of a spectrum processing apparatus according to a first embodiment. [Figure 4] 11 is a flowchart showing an example of the flow of a phase map generation process. [Diagram 5] FIG. 4 is a diagram showing an example of a first phase map. [Figure 6] 11 is a flowchart showing an example of the flow of a phase spectrum generation process. [Figure 7] FIG. 4 is a diagram for explaining first pixel data. [Figure 8] 11A and 11B are diagrams for explaining a process of excluding pixel spectra extracted from the same pixel. [Figure 9] FIG. 4 is a diagram showing an example of a first pixel map. [Figure 10] FIG. 4 is a diagram showing the first pixel map superimposed on an electron microscope image. [Figure 11] FIG. 13 is a diagram showing a state in which a first pixel map is superimposed on a first phase map. [Figure 12] FIG. 13 is a diagram showing the configuration of a spectrum processing device according to a second embodiment. [Figure 13] 11 is a flowchart showing an example of the flow of a phase spectrum generation process. [Figure 14] FIG. 13 is a diagram showing the configuration of a spectrum processing device according to a third embodiment. [Figure 15] 11 is a flowchart showing an example of the flow of a phase spectrum generation process. [Figure 16] FIG. 13 is a diagram showing the configuration of a spectrum processing apparatus according to a fourth embodiment. [Figure 17] 11 is a flowchart showing an example of the flow of a phase spectrum generation process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are necessarily essential components of the present invention.

[0014] 1. First embodiment 1.1. Sample analysis equipment First, the spectral processing device 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 spectral processing device 80 according to the first embodiment.

[0015] 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 device 80. The sample analyzer 100 is a scanning electron microscope equipped with the X-ray detector 70.

[0016] The electron gun 10 emits an electron beam. For example, the electron gun 10 accelerates electrons emitted from a cathode at an anode to emit 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 movement mechanism for moving the sample S.

[0018] The secondary electron detector 60 detects secondary electrons emitted from the sample S when the sample S is irradiated with the electron beam. A secondary electron image can be obtained 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.

[0019] The backscattered electron detector 62 detects backscattered electrons emitted from the sample S when the sample S is irradiated with the electron beam. A backscattered electron image can be obtained 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.

[0020] The X-ray detector 70 detects characteristic X-rays emitted from the sample S when the sample S is irradiated with the electron beam. The X-ray detector 70 is, for example, an energy dispersive X-ray detector. The X-ray detector 70 may also be a wavelength dispersive X-ray spectrometer. Spectral imaging data can be acquired 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.

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

[0022] FIG. 2 is a diagram for explaining the spectral imaging data 2. The spectral imaging data 2 is data in which positions (coordinates) on the sample S correspond to spectra based on signals from the sample S. Here, the signals from the sample S are characteristic X-rays emitted from the sample S. The spectral imaging data 2 has a plurality of pixels 2a corresponding to 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 X-rays generated at the positions on the sample S indicated by the pixels 2a.

[0023] In the main body 101 of the sample analysis apparatus 100, the sample S is scanned with an electron probe EP while X-rays are detected by the X-ray detector 70, and the positions (coordinates) on the sample S are associated with the X-ray spectrum and stored, thereby obtaining spectral imaging data 2.

[0024] The spectrum processing device (information processing device) 80 performs phase analysis using the spectrum imaging data 2, and generates a phase map as a result of the phase analysis. The spectrum processing device 80 also generates a phase spectrum for identifying the composition of a phase. A phase map is a map that shows the distribution of phases (compounds or simple substances). A phase spectrum is a spectrum used to identify the composition of a phase. A phase map and a phase spectrum are generated for each phase.

[0025] FIG. 3 is a diagram showing the configuration of the spectrum processing device 80. As shown in FIG.

[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 allows 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, a button, a touch panel, or a touch pad.

[0028] The display unit 820 displays the image generated by the processing unit 800, and the function thereof 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 unit of the processing unit 800. The storage unit 830 also functions as a work area for the processing unit 800. The functions of the storage unit 830 can be realized by a hard disk, a RAM (Random Access Memory), or the like.

[0030] The processing unit 800 executes a program stored in the storage unit 830, thereby functioning 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 executing the program using hardware such as various processors (CPU, DSP, etc.) and ASIC (gate array, etc.). The processing unit 800 includes the data acquisition unit 801, the representative spectrum selection unit 802, the phase analysis unit 803, the extraction unit 804, the spectrum generation unit 805, the display control unit 806, and the composition analysis unit 807.

[0031] The data acquisition unit 801 acquires spectral imaging data 2 obtained by measuring a sample S with the sample analysis apparatus 100. The spectral processing device 80 is connected to the main body 101 of the sample analysis apparatus 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 processing device 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 a phase. The representative spectrum is one of a plurality of pixel spectra 4 stored in the spectral imaging data 2. The representative spectrum selection unit 802 selects one representative spectrum for one phase. The representative spectrum selection unit 802 selects the 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. 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 performs phase analysis by analyzing the spectral imaging data 2. The phase analysis refers to analyzing the spectral imaging data 2 to create an equivalent spectrum, that is, a spatial distribution (phase map) of substances having an equivalent composition and the spectrum (phase spectrum).

[0034] The phase analysis unit 803 compares the pixel spectrum 4 with the representative spectrum for each pixel 2a of the spectral imaging data 2, for example, 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 that associates the abundance with the coordinates of the pixel 2a. The abundance is a coefficient when the pixel spectrum 4 is expressed based on the representative spectrum. For example, the pixel spectrum 4 and the representative spectrum are each regarded as vectors, and the pixel spectrum relative to the representative spectrum is calculated. The abundance can be calculated by a projection operation of the tor 4. In addition, for example, the coefficient of each representative spectrum when the pixel spectrum 4 is fitted using all the representative spectra may be regarded as the abundance.

[0035] The phase analysis unit 803 creates a phase map based on data associating the abundance with the coordinates of the pixel 2a. The phase analysis unit 803 creates a phase map, for example, with the abundance as a pixel value (brightness value). That is, in the phase map created by the phase analysis unit 803, the pixel value of each pixel is a value according to the abundance calculated in 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 the same number of phase maps as the number of selected representative spectra.

[0036] The extraction unit 804 and the spectrum generation unit 805 perform processing to generate a phase spectrum.

[0037] 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.

[0038] Specifically, first, the extraction unit 804 sets a threshold for extracting the pixel spectrum 4 from the spectral imaging data 2. The extraction unit 804 accepts a threshold designated by a user and sets the threshold. For example, when a user operates the operation unit 810 to designate a threshold, the extraction unit 804 accepts information on the threshold designated by the user from the operation unit 810 and sets the threshold. The user may designate the threshold by operating the operation unit 810 to input an arbitrary numerical value, or may designate the threshold by selecting one of options displayed on a GUI (Graphical User Interface). The extraction unit 804 may set the threshold by reading out information on the threshold previously stored in the storage unit 830. The threshold may be set to a different value for each phase, or the same value may be set 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 a threshold. The extraction unit 804 extracts the pixel spectrum 4 stored in the pixel 2a whose abundance is greater than the threshold. The pixel spectrum 4 can be extracted by the above process.

[0040] The extraction unit 804 performs a process of extracting the pixel spectrum 4 for each phase. If a pixel spectrum 4 of the same pixel 2a is extracted in a different phase from the pixel spectrum 4 extracted for each phase, the extraction unit 804 excludes the pixel spectrum 4. This makes it possible to extract a pixel spectrum 4 in which the phase composition is purely expressed.

[0041] The spectrum generating unit 805 generates a phase spectrum based on the pixel spectrum 4 extracted by the extraction unit 804. The spectrum generating unit 805 adds or averages the multiple pixel spectra 4 extracted for each phase to generate a phase spectrum for each phase. That is, the spectrum generating unit 805 generates the same number of phase spectra as 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 (hereinafter also referred to as "extracted pixel") in which the extracted pixel spectrum 4 is stored. The extracted pixel 2a is a pixel in which the spectrum used to generate the phase spectrum is stored among the pixels 2a of the spectral imaging data 2. 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 on the display unit 820. The display control unit 806 also causes the display unit 820 to display an image of the sample S, such as a secondary electron image or a backscattered electron image, and the generated pixel map in a superimposed manner.

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

[0044] 1.2. Spectral processing methods 1.2.1. Generation of phase maps Next, a description will be given of a spectrum processing method using the spectrum processing device 80. First, the phase map generation process of the spectrum processing device 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 device 80.

[0046] First, data acquisition unit 801 acquires spectral imaging data 2 obtained by measuring sample S in main body 101 of 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 the positions on the sample S are associated with the X-ray spectrum and stored, thereby obtaining the spectral imaging data 2 shown in Fig. 2. When the spectral imaging data 2 is obtained in the main body 101, the spectral imaging data 2 is sent from the main body 101 to the spectral processing device 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 known method such as VCA (Vertex Component Analysis), PPI (Pixel Purely Index), or N-FINDR. The representative spectrum selection unit 802 selects a representative spectrum for each of the first to nth phases (n is an integer of 2 or more) which are different from each other. Hereinafter, the representative spectrum for the mth phase (m is an integer of 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 in which the abundance is 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 will be 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 in which the pixel value is a value according to the abundance. The phase analysis unit 803 similarly calculates the abundance of the third representative spectrum and thereafter, performs processing to create a phase map, 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 brightness value of each pixel represents the abundance calculated for each pixel.

[0054] 1.2.2. Generation of phase spectra Next, a description will be given of a process for generating a phase spectrum by the spectrum processing device 80. Fig. 6 is a flow chart showing an example of the flow of a process for generating a phase spectrum by the spectrum processing device 80.

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

[0056] 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 pixel spectra 4 whose abundance is greater than a first threshold (S102). This makes it possible to extract pixel spectra 4 whose abundance is greater than the first threshold from the spectral imaging data 2. The extraction unit 804 creates first pixel data D-1 that associates the extracted pixel spectrum 4 with the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored (the coordinates of the extracted pixel 2a), and stores the first pixel data D-1 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 extraction unit 804 stores the extracted pixel spectrum 4 in the pixel 6a corresponding to the pixel 2a. As a result, the extracted pixel spectrum 4 and information on the coordinates of the pixel 2a in which the extracted pixel spectrum 4 is stored are registered in the first pixel data D-1.

[0058] Although the first pixel data D-1 is represented in map format here, the first pixel data D-1 may 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 judges whether or not the process of extracting pixel spectra 4 for all phases has been performed (S104). That is, the extraction unit 804 judges whether or not m=n is satisfied. When the extraction unit 804 judges that m=n is not satisfied (No in S104), the extraction unit 804 sets a second threshold for generating a phase spectrum of the second phase, with m=1+1 (S100). The extraction unit 804 may set the second threshold by accepting a second threshold designated by a user, or may set the second threshold by reading information on the second threshold recorded in advance in the storage unit 830. In addition, the extraction unit 804 may set the second threshold to the same value as the first threshold. That is, the first threshold to the n-th threshold set in the process S100 may be the same value.

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

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

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

[0063] Fig. 8 is a diagram for explaining the 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 contain the pixel spectrum 4 extracted from the same pixel 2a in 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. This makes it possible to extract the pixel spectrum 4 in which the phase composition is purely expressed.

[0064] Here, we have described the case where pixel spectra 4 extracted from the same pixel 2a are excluded from two pieces of pixel data. However, if pixel spectra 4 extracted from the same pixel 2a are included in three or more pieces of pixel data, the pixel spectra 4 extracted from the same pixel 2a are similarly excluded from each piece of pixel data.

[0065] Next, the spectrum generating 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 spectra 4 from the first pixel data D-1, and generates a phase spectrum of the first phase by adding or averaging the extracted pixel spectra 4. In this way, since a phase spectrum is generated by adding or averaging a plurality of pixel spectra 4, the S / N ratio of the phase spectrum can be improved compared to when a single pixel spectrum 4 is used as the phase spectrum.

[0067] Similarly, the spectrum generating unit 805 acquires information on pixel spectra 4 extracted from the second pixel data D-2, and adds or averages the extracted pixel spectra 4 to generate the phase spectrum of the second phase. The spectrum generating unit 805 generates the phase spectra of the third to nth phases in the same manner as the phase spectrum of the first phase. The phase spectra of the first to nth phases generated by the spectrum generating 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 generates the third to n-th 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 n-th 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 showing the positions of the pixels 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 pixels corresponding to the extracted pixels 2a are shown in red, and the pixels 2a other than the extracted pixels 2a, i.e., the pixels 2a in the spectral imaging data 2 from which the pixel spectrum 4 was not extracted, are shown in black. The first pixel map Mp1 makes it 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 the first pixel map Mp1 superimposed on the scanning electron microscope image SI. 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 is superimposed on a scanning electron microscope image SI, such as a secondary electron image or a backscattered electron image. In this manner, the display control unit 806 may cause the first pixel map Mp1 and the pixels of the sample S to be superimposed and displayed.

[0072] Fig. 11 is a diagram showing a state in which the first pixel map Mp1 is superimposed on the first phase map M1. 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 displays the second to n-th pixel maps in the same manner as the first pixel map Mp1. After the processing unit 800 causes the display unit 820 to display the first to n-th pixel maps, the processing unit 800 ends the phase spectrum generation process.

[0074] Although the case where a pixel map is displayed as information on the positions of the extracted pixels 2a has been described here, the method of displaying the information on the positions of the extracted pixels 2a is not limited to a pixel map. For example, a list of the coordinates of the extracted pixels 2a may be displayed on the display unit 820 as information indicating the positions of the extracted pixels 2a.

[0075] The user checks the phase spectra of the first to n-th phases displayed on the display unit 820 to check whether the S / N ratios of the phase spectra are sufficient. For example, if the user determines that the S / N ratio of the phase spectrum of the first phase is insufficient, the user sets the first threshold to a low value and causes the spectrum processing device 80 to execute the phase spectrum generation process shown in FIG. 6 again. This makes it possible to obtain a phase spectrum of the first phase with a high S / N ratio. If the user determines that the S / N ratios of the phase spectra of the second to n-th phases are also insufficient, the user sets the threshold to a low value and causes the spectrum processing device 80 to execute the phase spectrum generation process shown in FIG. 6 again.

[0076] When the user judges that the S / N ratios of the phase spectra of all phases are sufficient, the user checks the first to n-th pixel maps displayed on the display unit 820 and checks whether each pixel map contains an area where other phases are mixed. For example, when the first pixel map Mp1 contains an area where the second phase is mixed, the user specifies the first threshold value to be high and causes the spectrum processing device 80 to execute the phase spectrum generation process shown in FIG. 6 again. This makes it possible to obtain a phase spectrum in which the composition of the first phase is purely expressed. When the second to n-th pixel maps also contain areas where other phases are mixed, the user specifies the threshold value to be high and causes the spectrum processing device 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 that each pixel map does not include an area where other phases are mixed, the user causes the composition analysis unit 807 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, the user causes the composition analysis unit 807 to perform qualitative and quantitative analysis on the phase spectrum of each of the third to nth phases to identify the composition of each of the phases. This makes it possible to identify the composition of each of the phases from the first to nth phases.

[0078] Effects The spectrum processing device 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 that represents a position on the sample S, an extraction unit 804 that compares the pixel spectrum 4 with a representative spectrum selected from the spectrum imaging data 2 for each pixel 2a and extracts multiple pixel spectra 4 from the spectrum imaging data 2 based on the comparison result, and a spectrum generation unit 805 that generates a phase spectrum based on the extracted multiple pixel spectra 4. The apparatus 80 can generate phase spectra with high signal-to-noise ratios, allowing accurate identification of phase composition.

[0079] Generally, the pixel spectrum 4 stored in the pixel 2a of the spectral imaging data 2 has a smaller signal amount and a lower S / N ratio due to a shorter measurement time compared to a spectrum obtained by point analysis in which a single point on the sample S is irradiated. In phase analysis, a phase map can be created from the abundance of a representative spectrum for the pixel spectrum 4, so that even if the S / N ratio of the pixel spectrum 4 is low, a phase map reflecting the distribution of phases can be obtained.

[0080] However, when identifying the phase composition, the representative spectrum consisting of the pixel spectrum of one pixel has a low S / N ratio, and therefore the phase composition cannot be accurately identified. The S / N ratio of the representative spectrum can be improved, for example, by lengthening the measurement time for obtaining the spectral imaging data 2 or by increasing the amount of irradiation current of the electron probe EP irradiated to the sample S. However, this would result in a longer measurement time or greater damage to the sample S.

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

[0082] In the spectrum 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 a threshold value. Therefore, in the spectrum processing device 80, it is possible to reduce the dependency of the identification result of the phase composition on the user.

[0083] For example, a method for improving the S / N ratio of a phase spectrum can be conceived in which a user specifies an area on the spectral imaging data 2, extracts pixel spectra 4 recorded in multiple pixels 2a contained in the specified area, and adds or averages the extracted pixel spectra 4 to generate a phase spectrum. However, this method is user-dependent because the user specifies the area. Also, with this method, when materials are present separately and apart, such as particles that are sparsely present on the analysis field of view, it is difficult for the user to specify an area on the spectral imaging data 2, and the pixel spectra 4 cannot be appropriately extracted.

[0084] In contrast, the spectrum processing device 80 extracts pixel spectra 4 whose abundance is greater than a threshold value, so that the identification result of the phase composition can be made less dependent on the user. Furthermore, even if materials are present separately and apart, the pixel spectra 4 recorded in the pixels 2a corresponding to the materials present separately can be appropriately extracted.

[0085] In the spectrum processing device 80, the extraction unit 804 accepts a threshold value designated by the user and sets the threshold value. Therefore, in the spectrum processing device 80, the user can designate the threshold value.

[0086] The spectrum processing device 80 includes a display control unit 806 that 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. The display control unit 806 also generates a pixel map indicating the position of the extracted pixel 2a, and causes the pixel map to be displayed on the display unit 820. Therefore, in the spectrum processing device 80, the user can check the validity of the phase spectrum.

[0087] For example, if the phase spectrum generated by the spectrum generating unit 805 includes a peak of an unexpected element, it is possible to determine whether the peak of the unexpected element is a contribution from another substance by checking the pixel map. For example, if the pixel 2a extracted from the pixel map is a peak of another substance, If the presence of the unexpected element at the boundary or in the region close to the boundary is confirmed, it suggests the possibility that the unexpected element is a contribution from another substance.

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

[0089] In the spectrum processing device 80, the spectrum generating unit 805 generates a phase spectrum by adding or averaging the extracted multiple pixel spectra 4. Therefore, the spectrum processing device 80 can generate a phase spectrum with a high S / N ratio.

[0090] The spectrum processing device 80 includes a composition analysis unit 807 that identifies the composition of a phase from the phase spectrum. Since the spectrum processing device 80 can generate a phase spectrum with a high S / N ratio, the composition analysis unit 807 can accurately identify the composition of the phase.

[0091] The spectrum processing device 80 includes a representative spectrum selection unit 802 that selects a representative spectrum from the spectral imaging data 2. Therefore, the spectrum processing device 80 can automatically select a representative spectrum.

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

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

[0094] 2. Second embodiment 2.1. Spectral Processing Equipment Next, a spectrum processing device 80 according to a second embodiment will be described with reference to the drawings. Fig. 12 is a diagram showing the configuration of the spectrum processing device 80 according to the second embodiment. Hereinafter, in the spectrum processing device 80 according to the second embodiment, components having the same functions as those of the spectrum processing device 80 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0095] As shown in Fig. 12, the spectrum 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 judged is a spectrum obtained by adding the extracted pixel spectra 4, whether the S / N ratio is sufficient or not can be judged from the total count number of the signal amount of the phase spectrum, the count number of the maximum peak of the phase spectrum, the flatness (variation in the count number) in the region without peaks of the phase spectrum, etc. Also, for example, when the phase spectrum to be judged is a spectrum obtained by averaging the extracted pixel spectra 4, whether the S / N ratio is sufficient or not can be judged from the flatness in the region without peaks of the phase spectrum, etc.

[0097] In the spectrum processing device 80 according to the second embodiment, the threshold value is automatically set. The other configuration of the sample analyzer 100 according to the present embodiment is similar to that of the sample analyzer 100 according to the first embodiment, and therefore a description thereof will be omitted.

[0098] 2.2. Spectral processing methods Fig. 13 is a flowchart showing an example of the flow of a phase spectrum generation process of the spectrum processing device 80 according to the second embodiment. Below, differences from the phase spectrum generation process shown in Fig. 6 described above will be described, and a description of similarities will be omitted.

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

[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 pixel spectra 4 whose abundance is greater than a first threshold (S202). The extraction unit 804 creates the first pixel data D-1 shown in FIG.

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

[0102] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S204), it 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). In this way, phase spectra for 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 ratios, for example, in the order from the phase spectrum of the first phase to the phase spectrum of the nth phase. The order of evaluating the S / N ratios of the phase spectra 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 the S / N ratio is sufficient based on whether the total count number of the signal amount of the phase spectrum of the first phase exceeds a threshold value. The S / N ratio evaluation unit 808 may determine whether the S / N ratio is sufficient based on whether the count number of the maximum peak of the phase spectrum of the first phase exceeds a threshold value, or may determine whether the S / N ratio is sufficient based on whether the variation in the count number in a region without a peak of 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 (S214). Specifically, the extraction unit 804 changes the first threshold to a value lower than the first threshold before the change. The extraction unit 804 rewrites the information of the first threshold stored in the storage unit 830 to change the first threshold.

[0106] The extraction unit 804 returns to the process S200 and resets the first threshold (S200). The extraction unit 804 reads out the information on the changed first threshold stored in the storage unit 830, and resets the first threshold.

[0107] The extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts pixel spectra 4 whose abundance is greater than the reset first threshold (S202). As a result, the first pixel data D-1 is recreated. Because the first threshold has been changed to a value lower than the first threshold before the change, the number of pixel spectra 4 included in the recreated first pixel data D-1 is greater than the number of pixel spectra 4 included in the first pixel data D-1 before it was recreated.

[0108] The extraction unit 804 repeats the processes S200, S202, and S204 to generate the first through n-th pixel data. Here, the second through n-th thresholds are not changed, so the second through n-th pixel data are not changed. Therefore, the extraction unit 804 may omit the processes S200, S202, and S204 for generating the second through n-th pixel data.

[0109] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S204), it 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). In this way, phase spectra for 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 ratios in this order from the phase spectrum of the first phase to the phase spectrum of the nth phase. If 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 or not the S / N ratios of all phase spectra have been evaluated (S216). If the S / N ratio evaluation unit 808 determines that the S / N ratios of all phase spectra have not been evaluated (No in S216), it returns to the 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 (S214). Specifically, the extraction unit 804 changes the second threshold to a value lower than the second threshold before the change. The extraction unit 804 changes the second threshold, for example, by rewriting the information on the second threshold stored in the storage unit 830.

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

[0113] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S204), it 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). In this way, phase spectra for the first to nth phases are generated.

[0114] The processing unit 800 repeats steps S212, S214, S216, S200, S202, S204, S206, S208, and S210 to evaluate the S / N ratios of the phase spectra of the first to n-th phases. If the S / N ratio evaluation unit 808 determines that the S / N ratios of all phase spectra have been evaluated (Yes in S216), the display control unit 806 causes the display unit 820 to display information on the position of the extracted pixel 2a (S218). After causing the display unit 820 to display information on the position of the extracted pixel 2a, the processing unit 800 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. If 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 pixel spectra 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.

[0116] 3. Third embodiment 3.1. Spectral Processing Equipment Next, a spectrum processing device 80 according to a 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, components having the same functions as those of the spectrum processing device 80 according to the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be 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 judges 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 obtains information on the position of the extracted pixel 2a from the first pixel data D-1.

[0118] The pixel evaluation unit 809 judges whether the position of the extracted pixel 2a is appropriate or not 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, the probability that the extracted pixel 2a appears in the region where the substance exists 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 whose composition changes gradually, the amount of phases present also changes gradually. Therefore, the probability that the extracted pixel 2a appears is not constant. That is, when the composition is not uniform and whose composition changes gradually, the density of the extracted pixel 2a is not constant. Therefore, it is possible to judge whether the position of the extracted pixel 2a is appropriate or not based on the density of the extracted pixel 2a.

[0119] For example, a process of determining whether or not the extracted pixel 2a is included within a predetermined region centered on the extracted pixel 2a of interest in the spectral imaging data 2 is performed for all extracted pixels 2a. If it is determined that 90% or more of the extracted pixels 2a are included within the predetermined region, the density is determined to be uniform and the position of the extracted pixel 2a is determined to be appropriate.

[0120] Furthermore, the pixel evaluation unit 809 may compare the position of the extracted pixel 2a with the position of the reflected electron image 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 values ​​of the pixels of the reflected electron image corresponding to the extracted pixel 2a included in the first pixel data D-1 are obtained, and a histogram of the luminance values ​​is created. If the histogram of the luminance values ​​has one peak, 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 inappropriate.

[0121] In the spectrum processing device 80 according to the third embodiment, the threshold value is automatically set, similarly to the spectrum processing device 80 according to the second embodiment. The other configurations of the sample analyzer 100 according to the third embodiment are similar to those of the sample analyzer 100 according to the first embodiment, and therefore description thereof will be omitted.

[0122] 3.2. Spectral processing methods FIG. 15 is a flow chart showing a phase spectrum generation process of the spectrum processing device 80 according to the third embodiment. 13. The following describes the differences from the phase spectrum generation process shown in FIGS. 6 and 13, and a description of the similarities will be omitted.

[0123] The extraction unit 804 sets an m-th threshold for generating a phase spectrum of the m-th phase (S300). Here, m=1, and the extraction unit 804 sets a first threshold for generating a phase spectrum of the first phase. The extraction unit 804 reads out information on the first threshold recorded in advance in the storage unit 830 and sets the first threshold.

[0124] 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 pixel spectra 4 whose abundance is greater than a first threshold (S302). The extraction unit 804 creates the first pixel data D-1 shown in FIG.

[0125] The extraction unit 804 determines whether or not the process of extracting pixel spectra 4 has been performed for all phases (S304). The extraction unit 804 repeats the process S300, the process S302, and the process S304 until it is determined that the process of extracting pixel spectra 4 has been performed for all phases, and creates the first to n-th pixel data.

[0126] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S304), it excludes the pixel spectra 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 spectra 4 (S308). In this way, phase spectra for the first to nth phases are generated.

[0127] Next, the pixel evaluation unit 809 evaluates the position of the extracted pixel 2a (S310).

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

[0129] When the pixel evaluation unit 809 determines that the position of the extracted pixel 2a of the first phase is not appropriate (No in S312), the extraction unit 804 changes the first threshold (S314). Specifically, the extraction unit 804 changes the first threshold to a value higher than the first threshold before the change. The extraction unit 804 changes the first threshold, for example, by rewriting the information on the first threshold stored in the storage unit 830.

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

[0131] The extraction unit 804 calculates the abundance of the first representative spectrum in the pixel spectrum 4 for each pixel 2a, and extracts pixel spectra 4 whose abundance is greater than the reset first threshold (S302). As a result, the first pixel data D-1 is recreated. Because the first threshold has been changed to a value higher than the first threshold 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 it was recreated.

[0132] The extraction unit 804 repeats the process S300, the process S302, and the process S304 to obtain the first 1 to n-th pixel data. Here, since the second to n-th thresholds are not changed, the extraction unit 804 may omit the process S300, the process S302, and the process S304 for creating the second to n-th pixel data.

[0133] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S304), it excludes the pixel spectra 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 spectra 4 (S308). In this way, phase spectra for 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 the order from the first phase to the nth phase. If 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 or not the positions of the extracted pixel 2a in all phases have been evaluated (S316). If the pixel evaluation unit 809 determines that the positions of the extracted pixel 2a in all phases have not been evaluated (No in S316), the process returns to S310 and the pixel evaluation unit 809 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 of 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 a value higher than the second threshold before the change. The extraction unit 804 changes the second threshold, for example, by rewriting the information on the second threshold stored in the storage unit 830.

[0136] The extraction unit 804 repeats the processes S300, S302, and S304 to generate the first to n-th pixel data. Here, since the first threshold value and the third to n-th threshold values ​​are not changed, the extraction unit 804 may omit the processes S300, S302, and S304 for generating the first pixel data D-1 and the third to n-th pixel data.

[0137] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S304), it excludes the pixel spectra 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 spectra 4 (S308). In this way, phase spectra for the first to nth phases are generated.

[0138] The processing unit 800 repeats steps S312, S314, S316, S300, S302, S304, S306, S308, and S310 to evaluate the positions of the extracted pixels 2a of the first to n-th phases. If the pixel evaluation unit 809 determines that the extracted pixels 2a of all phases have been evaluated (Yes in S316), the display control unit 806 causes the display unit 820 to display information on the positions of the extracted pixels 2a (S318). After causing the display unit 820 to display information on the positions of the extracted pixels 2a, the processing unit 800 ends the phase spectrum generation process.

[0139] Effect The spectrum processing device 80 includes a pixel evaluation unit 809 that judges whether the position of the pixel 2a in which the extracted pixel spectrum 4 is stored is appropriate or not. If the pixel evaluation unit 809 judges 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 in which the abundance is greater than the threshold value. Therefore, the spectrum processing device 80 can set an appropriate threshold value and extract a pixel spectrum 4 in which the phase composition is more purely expressed. Therefore, the phase composition can be identified more accurately.

[0140] 4. Fourth embodiment 4.1. Spectral Processing Equipment Next, a spectrum processing device 80 according to a fourth embodiment will be described with reference to the drawings. Fig. 16 is a diagram showing the configuration of the spectrum processing device 80 according to the fourth embodiment. Hereinafter, in the spectrum processing device 80 according to the fourth embodiment, components having the same functions as those of the spectrum processing device 80 according to the first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0141] The spectrum processing device 80 according to the fourth embodiment includes a threshold evaluation unit 811, as shown in Fig. 16. 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 or not, for example, in a similar manner to the S / N ratio evaluation unit 808 described above. The threshold evaluation unit 811 also determines whether the position of the extracted pixel 2a is appropriate or not, in a similar manner to the pixel evaluation unit 809 described above.

[0142] The threshold evaluation unit 811 determines that the S / N ratio is insufficient and that the position of the extracted pixel 2a is inappropriate when it determines that the S / N ratio is insufficient and that the position of the extracted pixel 2a is appropriate when it determines that the S / N ratio is sufficient and that the position of the extracted pixel 2a is inappropriate when it determines that the threshold is inappropriate. Also, the threshold evaluation unit 811 determines that the S / N ratio is sufficient and that the position of the extracted pixel 2a is appropriate when it determines that the threshold is appropriate.

[0143] In the spectrum processing device 80 according to the fourth embodiment, the threshold value is automatically set, as in the spectrum processing device 80 according to the second and third embodiments. The other configurations of the sample analyzer 100 according to the fourth embodiment are similar to those of the sample analyzer 100 according to the first embodiment, and therefore description thereof will be omitted.

[0144] 4.2. Spectral processing methods Fig. 17 is a flowchart showing an example of the flow of a phase spectrum generation process of the spectrum processing device 80 according to the fourth embodiment. In the following, differences from the phase spectrum generation process shown in Figs. 6, 13, and 15 described above will be described, and a description of similarities will be omitted.

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

[0146] 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 pixel spectra 4 whose abundance is greater than a first threshold (S402). The extraction unit 804 creates the first pixel data D-1 shown in FIG.

[0147] The extraction unit 804 determines whether or not the process of extracting pixel spectra 4 has been performed for all phases (S404). The extraction unit 804 repeats the process S400, the process S402, and the process S404 until it is determined that the process of extracting pixel spectra 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 pixel spectra 4 has been performed for all phases (Yes in S404), it 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 spectra 4 (S408). In this way, phase spectra for the first to nth phases are generated.

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

[0150] The threshold evaluation unit 811 evaluates the thresholds in this order, for example, from the first threshold to the n-th threshold. The order in which the thresholds are evaluated 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 by the threshold evaluation unit 811. For example, when it is determined that the S / N ratio is insufficient and the position of the extracted pixel 2a is appropriate, the extraction unit 804 changes the first threshold to a value lower than the first threshold before the change. When it is determined that the S / N ratio is sufficient and the position of the extracted pixel 2a is inappropriate, the extraction unit 804 changes the first threshold to a value higher than the first threshold before the change. When it is determined that the S / N ratio is insufficient and the position of the extracted pixel 2a is inappropriate, the extraction unit 804 calculates an optimal first threshold that provides a relatively high S / N ratio and a high density of the extracted pixels 2a, and changes the first threshold. If it is determined that the S / N ratio is insufficient and that the position of the extracted pixel 2a is not appropriate, the extraction unit 804 may change the first threshold to a lower value to prioritize the S / N ratio, or may change the first threshold to a higher value to prioritize the position of the extracted pixel 2a. The user may be able to select whether to prioritize the S / N ratio or the position of the extracted pixel 2a.

[0153] The extraction unit 804 returns to the process S400 and resets the first threshold (S400). The extraction unit 804 reads out the information on 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 whose abundance is greater than the reset first threshold value (S402). As a result, the first pixel data D-1 is recreated.

[0155] The extraction unit 804 repeats the processes S400, S402, and S404 to generate the first through n-th pixel data. Here, since the second through n-th thresholds are not changed, the extraction unit 804 may omit the processes S400, S402, and S404 for generating pixel data using the second through n-th thresholds.

[0156] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S404), it 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 spectra 4 (S408). In this way, phase spectra for the first to nth phases are generated.

[0157] Next, the threshold evaluation unit 811 evaluates the thresholds (S410). The threshold evaluation unit 811 evaluates the thresholds in order from the first threshold to the n-th threshold. If the threshold evaluation unit 811 determines that the first threshold is appropriate (Yes in S412), it determines whether or not all thresholds have been evaluated (S416). If the threshold evaluation unit 811 determines that all thresholds have not been evaluated (No in S416), it returns to processing S410 and evaluates the second threshold (S410).

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

[0159] The extraction unit 804 repeats the processes S400, S402, and S404 to generate the first to n-th pixel data. Here, since the first threshold value and the third to n-th threshold values ​​are not changed, the extraction unit 804 may omit the processes S400, S402, and S404 for generating the first pixel data D-1 and the third to n-th pixel data.

[0160] When the extraction unit 804 determines that the process of extracting pixel spectra 4 has been performed for all phases (Yes in S404), it 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 spectra 4 (S408). In this way, phase spectra for the first to nth phases are generated.

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

[0162] Effect The spectrum processing device 80 includes a threshold evaluation unit 811 that evaluates a threshold based on the S / N ratio of the phase spectrum and the position of the extracted pixel 2a. If the threshold evaluation unit 811 determines that the threshold is inappropriate, the extraction unit 804 sets a threshold based on the evaluation result of the threshold evaluation unit 811, and extracts pixel spectra 4 whose abundance is greater than the threshold. Therefore, the spectrum processing device 80 can set an appropriate threshold and generate a phase spectrum with a high S / N ratio.

[0163] 5. Variations 5.1. First variant 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, but the method of creating a 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, the phase analysis unit 803 calculates the similarity between the pixel spectrum 4 and the representative spectrum for each pixel 2a of the spectral imaging data 2, and creates data that associates the similarity with the coordinates of the pixel 2a. The similarity can be calculated, for example, from cosine similarity or Euclidean distance. The phase analysis unit 803 creates a phase map based on the data that associates the similarity with the coordinates of the pixel 2a. The phase analysis unit 803 creates a phase map, for example, by using the similarity as a pixel value.

[0164] Furthermore, the extraction unit 804 calculates the abundance of the representative spectrum in the pixel spectrum 4 for each pixel 2a and extracts pixel spectra 4 whose abundance is greater than a threshold, but the method of extracting the pixel spectra 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 pixel spectra 4 whose similarity is greater than a threshold. The similarity can be calculated, for example, from cosine similarity or Euclidean distance.

[0165] In the spectrum processing device 80, even when a pixel spectrum 4 having a similarity degree greater than a threshold value is extracted from the spectrum imaging data 2, the above-mentioned spectrum imaging data The same effect can be obtained as when pixel spectrum 4 having an abundance greater than a threshold is extracted from pixel spectrum 2.

[0166] 5.2. Second variant In the above-described first to fourth embodiments, the representative spectrum selection unit 802 selects a representative spectrum from the spectral imaging data 2, but the method of selecting a representative spectrum is not limited to this. For example, a user may select a representative spectrum. A 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 a pixel 2a of the spectral imaging data 2 by specifying 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 the representative spectrum based on the secondary electron image, backscattered electron image, element map, etc. An element map indicates 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 variant In the above-described first to fourth embodiments, the spectral processing device 80 is included in the sample analyzer 100, but the spectral processing device 80 does not have to be included in the sample analyzer 100. The spectral processing device 80 may acquire the spectral imaging data 2 by, for example, reading out the spectral imaging data 2 stored in an information storage medium, or may acquire the spectral imaging data 2 from a server (not shown) or the like via a network.

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

[0170] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiment and modifications can be appropriately combined.

[0171] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment. A substantially identical configuration is, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention also includes a configuration that has the same action and effect as the configuration described in the embodiment, or a configuration that can achieve the same purpose. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment. [Explanation of symbols]

[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... storage 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 that represents a position on the sample; an extracting unit that compares, for each of the pixels, the pixel spectrum with a representative spectrum selected from the spectral imaging data, and extracts a plurality of the pixel spectra from the spectral imaging data based on a comparison result; A spectrum generating unit that generates a phase spectrum based on the extracted pixel spectra; A spectrum processing device comprising:

2. In claim 1, The extraction unit calculates an abundance of the representative spectrum in the pixel spectrum or a similarity between the pixel spectrum and the representative spectrum for each of the pixels, and extracts the pixel spectrum in which the abundance or the similarity is greater than a threshold.

3. In claim 2, The extraction unit receives a threshold value designated by a user and sets the threshold value.

4. In claim 2, an S / N ratio evaluation unit for determining 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 insufficient, the extraction unit sets the threshold low and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold.

5. In claim 2, a pixel evaluation unit that judges whether the position of the pixel at 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 high and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold.

6. In claim 2, a threshold evaluation unit that evaluates the threshold based on an S / N ratio of the generated phase spectrum and a position of the pixel at which the extracted pixel spectrum is stored; The extraction unit sets the threshold based on a result of the evaluation of the threshold by the threshold evaluation unit, and extracts the pixel spectrum in which the abundance or the similarity is greater than the threshold.

7. In any one of claims 1 to 6, a display control unit that causes a display unit to display information about the position of the pixel at which the extracted pixel spectrum is stored.

8. In claim 7, The display control unit generates a map indicating positions of the pixels at which the extracted pixel spectra are stored, and causes the display unit to display the map.

9. In claim 8, The display control unit causes the image of the sample and the map to be displayed on the display unit in an overlapping manner.

10. In any one of claims 1 to 6, The spectrum generation unit adds or averages the extracted pixel spectra to generate the phase spectrum.

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

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

13. A sample analysis device comprising the spectral processing device according to claim 1.

14. 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; comparing, for each of the pixels, 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 a comparison result; generating a phase spectrum based on the extracted plurality of pixel spectra; A spectrum processing method comprising:

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