Analysis method and analysis device

Abstract

To provide an analyzing method capable of easily acquiring a spectrum map using a wavelength-dispersive x-ray spectrometer.SOLUTION: An analyzing method uses an analyzer in which a wavelength-dispersive X-ray spectrometer, which has a spectroscopic element to disperse an X-ray emitted from a specimen and detects a X-ray of energy corresponding to a position of the spectroscopic element, is mounted. The analyzing method includes the steps of: acquiring a plurality of pieces of map data by repeatedly performing map analysis for acquiring map data by fixing the position of the spectroscopic element to detect an X-ray of specific energy while scanning the specimen with an electron beam, while changing the position of the spectroscopic element; and generating, on the basis of the plurality of pieces of map data, a spectrum map in which a position on the specimen and an X-ray spectrum are associated with each other.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an analytical method and an analytical device. [Background technology]

[0002] A wavelength-dispersive X-ray spectrometer (WDS) performs elemental analysis by dispersing the characteristic X-rays emitted from a sample. Compared to an energy-dispersive X-ray spectrometer (EDS), a WDS has higher energy resolution and can accurately separate characteristic X-rays with similar energies to identify elements. Furthermore, a WDS has a better signal-to-noise ratio than an EDS, making it possible to detect trace elements.

[0003] Patent Document 1 discloses an analytical device equipped with five WDSs. In map analysis using WDSs, only one energy value can be analyzed for each WDS. The analytical device disclosed in Patent Document 1 is equipped with five WDSs, so map analysis of five elements can be performed simultaneously. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-018222 Summary of the Invention [Problem to be solved by the invention]

[0005] With EDS, all elements can be measured simultaneously, making it easy to obtain X-ray spectra. Therefore, with EDS, it is easy to obtain a spectral map that associates the X-ray spectrum with the position on the sample. It is desirable for WDS to also be able to easily obtain a spectral map. [Means for solving the problem]

[0006] One aspect of the analysis method according to the present invention is An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while fixing the position of the spectroscopic element while scanning the sample with an electron beam, and changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including fruit, correcting a spectral shift caused by a deviation in height of the sample in the X-ray spectrum stored in each pixel of the spectral map; In the step of correcting the spectral shift, the spectral shift is corrected based on information indicating a relationship between the deviation amount of the height of the sample and the spectral shift amount. . One aspect of the analysis method according to the present invention is An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while fixing the position of the spectroscopic element while scanning the sample with an electron beam, and changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; a step of comparing the X-ray spectrum stored in each pixel of the spectrum map with a reference spectrum to determine a spectral shift amount; creating a map relating positions on the sample to heights of the sample based on the amount of spectral shift; Includes: One aspect of the analysis method according to the present invention is An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while fixing the position of the spectroscopic element while scanning the sample with an electron beam, and changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, In the step of acquiring the plurality of map data, the sample is scanned with the electron beam by deflecting the electron beam with a deflector; correcting a spectral shift caused by deflection of an electron beam in the X-ray spectrum stored in each pixel of the spectral map; In the step of correcting the spectral shift, the spectral shift is corrected based on information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift. One aspect of the analysis method according to the present invention is An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while fixing the position of the spectroscopic element while scanning the sample with an electron beam, and changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, In the step of acquiring the plurality of map data, the sample is scanned with the electron beam by deflecting the electron beam with a deflector; correcting a decrease in X-ray intensity caused by deflection of an electron beam in the X-ray spectrum stored in each pixel of the spectrum map; In the step of correcting the decrease in X-ray intensity, the decrease in X-ray intensity is corrected based on information indicating the relationship between the amount of deflection of the electron beam and the decrease rate of the X-ray intensity. One aspect of the analysis method according to the present invention is An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while fixing the position of the spectroscopic element while scanning the sample with an electron beam, and changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, acquiring information about elements contained in the sample, In the step of acquiring the plurality of map data, an interval for changing the position of the light separating element is set based on the information.

[0007] In this analysis method, a spectral map can be obtained using a wavelength dispersive X-ray spectrometer. Furthermore, in this analysis method, map analysis is repeated while changing the position of the dispersing element to obtain multiple map data, and a spectral map is generated based on the multiple map data. This makes it easier to obtain a spectral map than when a spectral map is generated by obtaining X-ray spectra by point analysis at each analysis point on the sample.

[0008] One aspect of the analysis device according to the present invention is an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses the X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Do stomach, and a storage unit that stores information indicating the relationship between the deviation in height of the sample and the amount of spectrum shift. . One aspect of the analysis device according to the present invention is an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses the X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and the electron optical system includes a deflector that deflects an electron beam; The device includes a storage unit that stores information indicating the relationship between the amount of deflection of the electron beam and the amount of spectrum shift. One aspect of the analysis device according to the present invention is an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses the X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; Based on the plurality of map data, the position on the sample and the X-ray spectrum are associated with each other. generating a spectral map; and the electron optical system includes a deflector that deflects an electron beam; The device includes a storage unit that stores information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity. One aspect of the analysis device according to the present invention is an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses the X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and the control unit performs a process of acquiring information about elements contained in the sample; The control unit sets an interval for changing the position of the light separating element based on the information.

[0009] In such an analytical instrument, a spectral map can be obtained using a wavelength dispersive X-ray spectrometer. Furthermore, in such an analytical instrument, multiple map data are obtained by repeating map analysis while changing the position of the dispersing element, and a spectral map is generated based on the multiple map data. This makes it easier to obtain a spectral map than when a spectral map is generated by obtaining an X-ray spectrum by point analysis at each analysis point on the sample. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the configuration of an analysis device used in an analysis method according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of an analysis device used in an analysis method according to a first embodiment. [Figure 3] FIG. 1 is a diagram for explaining a method for acquiring a spectrum in WDS. [Figure 4] FIG. 1 is a diagram for explaining map analysis in WDS. [Figure 5] FIG. 1 is a diagram for explaining spectral imaging. [Figure 6] 3 is a flowchart showing an example of an analysis method according to the first embodiment. [Figure 7] 10 is a flowchart showing an example of a spectral imaging process performed by a control unit. [Figure 8] 10 is a flowchart showing an example of a method for determining the relationship between the amount of deviation in height of a sample and the amount of spectrum shift. [Figure 9] 10 is a graph showing the relationship between the deviation in height of a sample and the amount of spectrum shift. [Figure 10] 10 is a graph showing the relationship between spectral position and spectral shift amount. [Figure 11] FIG. 10 is a diagram for explaining a method for determining the relationship between the deviation in height of a sample and the amount of spectrum shift in Sc-Kα radiation. [Figure 12] 1 is a graph showing the relationship between the deviation in height of a sample and the amount of spectrum shift for Sc-Kα radiation. [Figure 13]10 is a flowchart showing an example of a correction process for a spectrum shift caused by a deviation in height of a sample in a control unit. [Figure 14] FIG. 1 shows multiple spectra obtained by performing point analysis on a sample containing Sc while changing the sample height. [Figure 15] FIG. 10 shows the results of correcting the spectral shift caused by the deviation of the sample height in each Sc spectrum. [Figure 16] A comparison of the results of map analysis using beam scanning at 500x magnification and the results of map analysis using stage scanning of the field of view corresponding to the beam scanning. [Figure 17] 10 is a flowchart showing an example of a method for determining the relationship between the amount of deflection of an electron beam and the amount of spectrum shift. [Figure 18] FIG. 1 is a diagram showing a schematic diagram of how an electron beam is deflected by a deflector. [Figure 19] 10 is a graph showing the relationship between the deflection amount of an electron beam and the amount of spectrum shift. [Figure 20] 10 is a graph showing the relationship between spectral position and spectral shift amount. [Figure 21] FIG. 10 is a diagram for explaining a method for determining the relationship between the amount of deflection of an electron beam and the amount of spectral shift in Sc-Kα radiation. [Figure 22] 1 is a graph showing the relationship between the amount of deflection of an electron beam and the amount of spectral shift in Sc-Kα radiation. [Figure 23] 10 is a flowchart showing an example of a correction process for a spectral shift caused by deflection of an electron beam in a control unit. [Figure 24] FIG. 10 shows multiple spectra obtained by performing point analysis on a sample containing Sc while changing the deflection amount of the electron beam. [Figure 25] FIG. 10 shows the results of correcting the spectral shift caused by the deflection of the electron beam in each Sc spectrum. [Figure 26] 10 is a flowchart showing an example of a method for determining the relationship between the amount of deflection of an electron beam and the rate of decrease in X-ray intensity. [Figure 27] 1 is a graph showing the relationship between the amount of deflection of an electron beam and the rate of decrease in X-ray intensity. [Figure 28] 10 is a graph showing the relationship between deflection distance and correction value for correcting X-ray intensity. [Figure 29] 10 is a graph showing the relationship between spectral position and correction value. [Figure 30] 10 is a graph showing the relationship between the amount of deflection of an electron beam and a correction value for Sc-Kα rays. [Figure 31] 10 is a flowchart showing an example of a correction process for a decrease in X-ray intensity caused by deflection of an electron beam in a control unit. [Figure 32] Image of Sc-Kα line map data at 200x magnification. [Figure 33] An illustration of map data after correcting the spectral shift caused by electron beam deflection. [Figure 34] An illustration of map data corrected for the spectral shift caused by electron beam deflection and the decrease in X-ray intensity caused by electron beam deflection. [Figure 35] 10 is a flowchart showing an example of an analysis method according to the third embodiment. [Figure 36] FIG. 4 is a diagram for explaining a method for setting the movement interval of the light separating element. [Figure 37] 10 is a flowchart showing an example of a spectral imaging process performed by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0012] 1. First embodiment 1.1. Analyzer First, an analytical device used in the analytical method according to the first embodiment will be described with reference to the drawings. FIGS. 1 and 2 are diagrams showing the configuration of an analytical device 100 used in the analytical method according to the first embodiment. The analytical device 100 is a scanning electron microscope equipped with multiple wavelength dispersive X-ray spectrometers (WDS). The analytical device 100 may also be an electron probe microanalyzer (EPMA) equipped with multiple WDS.

[0013] 1 and 2, the analytical device 100 includes an electron optical system 10, a sample stage 20, an electron detector 30, an energy dispersive X-ray spectrometer (EDS) 40, WDSs 50a, 50b, 50c, 50d, and 50e, a control unit 60, an operation unit 70, a display unit 72, and a storage unit 74. For convenience, only the electron optical system 10, WDSs 50a, 50b, 50c, 50d, and 50e are shown in FIG.

[0014] The electron optical system 10 irradiates the electron beam EB onto the sample S. The electron optical system 10 includes an electron gun 12, a focusing lens 14, a deflector 16, and an objective lens 18.

[0015] The electron gun 12 emits an electron beam EB. The electron gun 12 is accelerated by a predetermined acceleration voltage. The electron beam EB is emitted toward the sample S.

[0016] The focusing lens 14 focuses the electron beam EB emitted from the electron gun 12. The deflector 16 deflects the electron beam EB two-dimensionally. The deflector 16 allows the electron probe to scan the sample S (beam scan). The objective lens 18 focuses the electron beam EB on the sample S. By focusing the electron beam EB with the focusing lens 14 and the objective lens 18, an electron probe can be formed.

[0017] The sample stage 20 supports the sample S. The sample S is placed on the sample stage 20. Although not shown, the sample stage 20 is equipped with a movement mechanism for moving the sample S. By moving the sample S on the sample stage 20, the sample S can be scanned with an electron probe (stage scan).

[0018] The electron detector 30 is a detector for detecting electrons emitted from the sample S. A scanning electron microscope image (SEM image) can be obtained by detecting electrons emitted from the sample S with the electron detector 30 while scanning the sample S with an electron beam EB. The electron detector 30 may be a backscattered electron detector that detects backscattered electrons, or a secondary electron detector that detects secondary electrons.

[0019] The EDS 40 uses a semiconductor detector to detect and energy-disperse the characteristic X-rays emitted from the sample S. By detecting the characteristic X-rays with the EDS 40, an X-ray spectrum can be obtained.

[0020] The analytical device 100 is equipped with five WDSs (WDS 50a, WDS 50b, WDS 50c, WDS 50d, and WDS 50e). Note that the number of WDSs equipped in the analytical device 100 is not particularly limited.

[0021] The WDS 50a includes a spectroscopic element 52 and an X-ray detector 54. In the WDS 50a, the spectroscopic element 52 disperses characteristic X-rays generated from the sample S, and the X-ray detector 54 detects the dispersed X-rays.

[0022] The dispersing element 52 is, for example, a dispersing crystal for performing dispersive analysis using the diffraction phenomenon of X-rays. The WDS 50a includes a plurality of dispersing elements 52 having different crystal plane spacings. That is, the plurality of dispersing elements 52 have different spectral wavelength ranges. Examples of the dispersing elements 52 include PET (pentaerythritol), LiF (lithium fluoride), TAP (thallium acid phthalate), and STE (stearate). The X-ray detector 54 detects the characteristic X-rays dispersed by the dispersing elements 52.

[0023] The WDS 50a includes a drive unit for moving the spectroscopic element 52 and the X-ray detector 54. The drive unit moves the spectroscopic element 52 and the X-ray detector 54 by, for example, motor drive. This allows the spectroscopic element 52 and the X-ray detector 54 to be positioned as desired. The WDS 50a can detect X-rays with energy that corresponds to the position of the spectroscopic element 52.

[0024] As shown in Fig. 2, the analytical device 100 is equipped with WDSs 50a, 50b, 50c, 50d, and 50e. The WDSs 50b, 50c, 50d, and 50e have the same configuration as the WDS 50a. Each of the five WDSs has a plurality of spectroscopic elements 52. Since the analytical device 100 is equipped with five WDSs, it can simultaneously perform map analysis (area analysis) of five elements.

[0025] The operation unit 70 receives an operation signal corresponding to an operation by a user and transmits the signal to the control unit 60. The operation unit 70 is, for example, a button, a key, a touch panel display, a microphone, or the like.

[0026] The display unit 72 displays the image generated by the control unit 60. The display unit 72 is, for example, a display such as an LCD (liquid crystal display).

[0027] The storage unit 74 stores programs and data for the control unit 60 to perform various calculation processes and control processes. The storage unit 74 is also used as a work area for the control unit 60. The storage unit 74 is, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), or a hard disk.

[0028] The functions of the control unit 60 can be realized by executing programs stored in the storage unit 74 using various processors (such as a CPU (Central Processing Unit)).

[0029] The control unit 60 controls each part constituting the analyzer 100. For example, the control unit 60 controls the electron optical system 10 and the WDSs 50a, 50b, 50c, 50d, 50e. The control unit 60 controls the electron optical system 10 and the WDSs 50a, 50b, 50c, 50d, 50e to perform a process of executing spectral imaging. Details of the process of the control unit 60 will be described later.

[0030] 1.2. Analysis method 1.2.1. Point analysis (qualitative analysis) FIG. 3 is a diagram for explaining a method of acquiring a spectrum in the WDS.

[0031] In the WDS, the analysis point (electron beam irradiation position) on the sample S, the spectroscopic element 52, and the X-ray detector 54 are arranged on the Rowland circle circumference so as to satisfy the Bragg law for the light collection condition. The spectroscopic element 52 moves on a straight line inclined by the extraction angle φ from the analysis point. Also, as the spectroscopic element 52 moves, the X-ray detector 54 also moves. The distance between the analysis point and the spectroscopic element 52 is equal to the distance between the spectroscopic element 52 and the X-ray detector 54.

[0032] Here, when the position of the spectroscopic element 52 (spectroscopic position L) is changed while the position of the sample S (analysis point) is fixed, the incident angle θ of the X-ray with respect to the spectroscopic element 52 changes. The spectroscopic position L is represented by the distance between the sample S (analysis point) and the spectroscopic element 52.

[0033] In the example shown in FIG. 3, the spectroscopic element 52 is moved from the spectroscopic position L1 where the distance between the sample S and the spectroscopic element 52 is L1 to the spectroscopic position L2 where the distance between the sample S and the spectroscopic element 52 is L2 (L1 < L2). Thereby, the incident angle θ changes from θ1 to θ2 (θ1 < θ2).

[0034] According to Bragg's law, changing the incident angle θ changes the energy (wavelength) of the X-rays detected by the X-ray detector 54. Therefore, by fixing the position of the sample S and changing the spectral position L, it is possible to obtain an X-ray spectrum (hereinafter simply referred to as "spectrum") in which the horizontal axis represents energy (wavelength, spectral position L) and the vertical axis represents X-ray intensity.

[0035] From the spectrum thus obtained, qualitative analysis can be performed.

[0036] 1.2.2. Map analysis (area analysis) FIG. 4 is a diagram for explaining map analysis in WDS.

[0037] To obtain map data representing the distribution of intensity of a specific element, i.e., characteristic X-rays of a specific energy, the electron beam EB is scanned on the sample S while the spectroscopic position L is fixed. At this time, the spectroscopic element 52 is fixed to a spectroscopic position L corresponding to the energy of the characteristic X-ray to be analyzed. With the spectroscopic position L fixed in this manner, the sample S is scanned with the electron probe, thereby making it possible to obtain information on the X-ray intensity at each analysis point on the sample S. Note that scanning of the sample S with the electron beam EB can be performed by beam scanning or stage scanning.

[0038] Map analysis can obtain map data that associates positions on the sample S with X-ray intensities of specific energies. In the map data, the coordinates (position) of each pixel correspond to a position on the sample S. Information on the X-ray intensity obtained at each analysis point is stored in each pixel.

[0039] From the map data obtained as a result of the map analysis, information on the distribution of elements can be obtained.

[0040] 1.2.3. Spectral Imaging FIG. 5 is a diagram for explaining spectral imaging.

[0041] Spectral imaging is a technique for obtaining a spectral map SM, which is a map that associates spectra with positions on a sample S.

[0042] In the analysis method according to the first embodiment, map analysis is performed to acquire map data with the spectral position L fixed, and multiple map data are acquired by repeating this process while changing the spectral position L, and a spectral map SM is generated based on the multiple acquired map data.

[0043] FIG. 6 is a flowchart showing an example of the analysis method according to the first embodiment.

[0044] First, a map analysis is performed on the sample S at the spectroscopic position L1, and map data M L1 (S10).

[0045] Specifically, the spectral position L is fixed at the spectral position L1, and map analysis is performed on the sample S. As a result, map data M L1 Map data M L1 In the map data M, the coordinates of each pixel are expressed as X and Y coordinates. L1 Each pixel in the map data M stores information on the X-ray intensity acquired at the analysis point corresponding to the coordinates of each pixel. L1 Each pixel stores information about the X-ray intensity of the energy corresponding to the spectral position L1.

[0046] Next, the light-splitting element 52 is moved a predetermined distance (S20). As a result, the light-splitting position L is changed from light-splitting position L1 to light-splitting position L2. The interval at which the position of the light-splitting element 52 is changed is, for example, constant. That is, the interval between light-splitting position L1 and light-splitting position L2 is equal to the interval between light-splitting position L2 and light-splitting position L3. The interval at which the position of the light-splitting element 52 is changed can be changed as appropriate.

[0047] Next, a map analysis is performed on the sample S at the spectroscopic position L2, and map data M L2 (S30).

[0048] Specifically, the spectral position L is fixed at the spectral position L2, and map analysis is performed on the sample S. As a result, map data M L2 Map data M L2 Each pixel stores information about the X-ray intensity of the energy corresponding to the spectral position L2.

[0049] Next, map data M L1 and Map Data M L2 are combined (S40).

[0050] Map Data M L1 and Map Data M L2 X-ray intensity information is extracted from each corresponding pixel in the spectrum to generate a single piece of map data. This allows a spectral map to be created. Here, each pixel of the spectral map stores spectral data including information on the X-ray intensity at spectral position L1 and the X-ray intensity at spectral position L2.

[0051] The step S20 of moving the spectroscopic element 52, the step S30 of performing the map analysis, and the step S40 of combining the map data are repeated to obtain the map data M L3 , Map Data M L4 ,...,Map data M LN When N map data have been acquired (Yes in S50), the spectral imaging is terminated.

[0052] As shown in FIG. 5, each pixel constituting the spectral map SM is assigned to N different spectral positions L (spectral position L1, spectral position L2, . . . , spectral position L N 5, the horizontal axis of the spectrum represents the spectral position L, but the horizontal axis of the spectrum may also represent the energy (wavelength) of the X-ray.

[0053] Since the analytical device 100 is equipped with five WDSs, it can simultaneously acquire five spectrum maps SM.

[0054] The spectrum map SM includes not only the peak position but also the data before and after it. Therefore, various analyses can be performed after acquiring the spectrum map SM. For example, because the spectrum map SM includes background data, it is possible to obtain information by subtracting the background intensity from the peak intensity. Furthermore, with the spectrum map SM, it is not necessary to specify a specific energy (element); it is sufficient to specify the measurement energy range. Therefore, analysis is possible even if the sample S contains an unknown element.

[0055] Furthermore, the spectrum map SM can correct for a spectrum shift caused by a deviation in the height of the sample S, a spectrum shift caused by the deflection of the electron beam EB, and a decrease in X-ray intensity caused by the deflection of the electron beam EB. These corrections will be described later.

[0056] 1.3. Control section processing FIG. 7 is a flowchart showing an example of the spectral imaging process of the control unit 60.

[0057] The control unit 60 receives the settings of the analysis conditions for spectral imaging (S100).

[0058] The user sets the area where spectral imaging of the sample S is to be performed, the conditions of the electron optical system 10, and the conditions of each WDS. The WDS conditions include the type of spectroscopic element 52, the measurement energy range, and the measurement energy interval.

[0059] For example, the user moves the field of view to the area where spectral imaging of the sample S is to be performed. The user also sets the acceleration voltage and irradiation current as conditions for the electron optical system 10. The user also selects the type of spectroscopic element 52 for each of the five WDSs and sets the measurement energy range and measurement energy interval. These conditions are set by the user operating the operation unit 70. The control unit 60 accepts the setting of analysis conditions via the operation unit 70. After setting these conditions, the user inputs an instruction to start the analysis via the operation unit 70.

[0060] The control unit 60 places the light separating element 52 at the initial position for each of the five WDSs (S 102).

[0061] The control unit 60 moves the light-splitting element 52 of the WDS 50a in accordance with the measurement energy range set for the WDS 50a, and sets the light-splitting position L as the initial position. Similarly, the control unit 60 moves the light-splitting element 52 of the WDS 50b in accordance with the measurement energy range set for the WDS 50b, and sets the light-splitting position L as the initial position. The control unit 60 similarly sets the light-splitting position L as the initial position for the WDS 50c, WDS 50d, and WDS 50e.

[0062] Next, the control unit 60 performs a map analysis (S104).

[0063] The control unit 60, for example, causes the electron optical system 10 to deflect the electron beam EB and scan the electron beam EB over the sample S, while causing the WDS 50a to fix the position of the spectroscopic element 52 and detect X-rays of a specific energy. This makes it possible to acquire map data of energy corresponding to the spectroscopic position L. Similarly, the control unit 60 causes the WDS 50b to fix the position of the spectroscopic element 52 and detect X-rays of a specific energy. Similarly, the control unit 60 causes the WDSs 50c, WDS 50d, and WDS 50e to fix the positions of the spectroscopic elements 52 and detect X-rays of a specific energy.

[0064] The analytical device 100 has five WDSs, and therefore can simultaneously acquire five map data with different energies. The acquired five map data are stored in the memory unit 74. Note that, here, the electron beam EB is deflected by the electron optical system 10 and scanned over the sample S with the electron beam EB (beam scanning), but the sample S may also be moved on the sample stage 20 and the electron beam EB may be scanned over the sample S (beam scanning).

[0065] Next, the control unit 60 moves the spectroscopic element 52 based on the set measurement energy interval (S106).

[0066] The control unit 60 moves the light-splitting element 52 of the WDS 50a by a distance corresponding to the measurement energy interval set in the WDS 50a. As a result, the light-splitting position L is changed from the initial position by a distance corresponding to the measurement energy interval. Similarly, the control unit 60 moves the light-splitting element 52 of the WDS 50b by a distance corresponding to the measurement energy interval set in the WDS 50b. Similarly, the control unit 60 moves the light-splitting element 52 of the WDS 50c, WDS 50d, and WDS 50e by a distance corresponding to the measurement energy interval.

[0067] Next, the control unit 60 performs a map analysis (S108).

[0068] The map analysis is performed in the same manner as in step S104 described above. This makes it possible to acquire energy map data corresponding to the spectral position L that has been moved from the initial position by the set measurement energy interval. The acquired five map data are stored in the storage unit 74.

[0069] Next, the control unit 60 combines the map data (S110).

[0070] The control unit 60 combines the map data stored in the memory unit 74. The map data is combined for each WDS. This allows five spectral maps to be generated. Here, map analysis is performed twice, so each pixel of the spectral map stores spectral data containing information on X-ray intensities acquired at two analysis points.

[0071] Next, the control unit 60 determines whether or not the spectral imaging is completed (S112).

[0072] The control unit 60 determines that spectral imaging is complete when map analysis of the set measurement energy ranges is complete for all five WDSs. Note that if map analysis of the set measurement energy ranges is complete for WDS 50a but map analysis of the measurement energy ranges for the other WDSs is not complete, processing for WDS 50a is stopped and processing for the other WDSs is continued. In this way, when map analysis of the set measurement energy ranges is complete for all five WDSs, the control unit 60 determines that spectral imaging is complete.

[0073] If the control unit 60 determines that spectral imaging is not complete (No in S112), it returns to step S106 and performs step S106 to move the spectroscopic element 52, step S108 to perform map analysis, and step S110 to combine the map data.

[0074] The control unit 60 repeats the process S106 of moving the spectroscopic element 52, the process S108 of performing map analysis, and the process S110 of combining the map data, until it is determined that spectral imaging is complete.

[0075] When it is determined that the spectral imaging is completed (Yes in S112), the control unit 60 ends the spectral imaging process. Five spectral maps can be obtained through the above process.

[0076] 1.4. Correction method 1.4.1. Correction of spectral shifts caused by sample height deviation In map analysis, the analysis point on the sample S may deviate from the Rowland circle due to the unevenness or inclination of the sample surface, which may result in the focusing condition not being met. If the focusing condition is not met, the spectrum will shift.

[0077] Therefore, in the analysis method according to the first embodiment, the spectral shift caused by the deviation of the sample S from the Rowland circle in the height direction (Z direction) (hereinafter simply referred to as "sample height deviation") is corrected in the spectral map. The sample height deviation can also be said to be the deviation of the sample height from the height that satisfies the focusing condition. The height direction of the sample S is along the Z axis. The Z axis is an axis parallel to the optical axis of the electron optical system 10.

[0078] The spectral shift caused by the deviation in height of the sample is corrected based on information indicating the relationship between the deviation in height of the sample and the amount of spectral shift.

[0079] <Method for determining the relationship between the deviation in sample height and the amount of spectrum shift> The analysis method according to the first embodiment includes a step of acquiring information indicating the relationship between the amount of deviation in sample height and the amount of spectral shift. In this step, first, a standard sample is irradiated with an electron beam EB without any deviation in sample height, and the X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a reference spectrum. Next, the standard sample is irradiated with an electron beam EB while a deviation in sample height exists, and the X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a comparison spectrum. This analysis is repeated while changing the amount of deviation in sample height to acquire multiple comparison spectra. Next, the reference spectrum is compared with each comparison spectrum to acquire information indicating the relationship between the amount of deviation in sample height and the amount of spectral shift.

[0080] 8 is a flowchart showing an example of a method for determining the relationship between the deviation in height of the sample and the amount of spectrum shift. In the following, a case where a PET crystal is used as the spectroscopic element 52 will be described.

[0081] First, a plurality of standard samples are prepared (S200).

[0082] The standard sample is, for example, a sample consisting of a single element of interest. When a PET crystal is used as the spectroscopic element 52, the standard sample may be, for example, a Ti standard sample, a Cd standard sample, a Mo standard sample, or a Si standard sample. The standard sample is appropriately selected depending on the type of spectroscopic element 52. The standard sample is selected from standard samples containing elements that can be measured by the selected spectroscopic element 52.

[0083] Next, point analysis is performed on the standard sample to obtain a reference spectrum (S202).

[0084] First, one standard sample is selected from multiple standard samples. In this example, a Ti standard sample is selected. The order in which the standard samples are selected is not particularly limited; for example, they may be selected in order of atomic number. The selected Ti standard sample is placed on the sample stage 20, and the Z-direction position (height) of the standard sample is adjusted using the sample stage 20 so that the standard sample is in focus. For example, by placing the standard sample at a position where it is in focus, the standard sample can be positioned on the Rowland circle. At this time, the analysis point on the sample S is set to the center of the observation field. That is, the electron beam EB is irradiated onto the standard sample along the optical axis of the electron optical system 10 without being deflected by the deflector 16. In this state, point analysis is performed to obtain a reference spectrum of Ti. The reference spectrum is a spectrum acquired when the focusing conditions are met. That is, the reference spectrum is a spectrum acquired when there is no deviation in the height of the sample.

[0085] Next, the standard sample is moved a predetermined distance in the Z direction (S204). This causes a shift in the height of the standard sample. Point analysis is performed in this state, and a comparison spectrum of Ti is obtained (S206). The comparison spectrum is a spectrum obtained with the sample height shift.

[0086] Next, the reference spectrum and the comparison spectrum are compared to determine the amount of spectral shift (S208). Specifically, the amount of shift of the Ti peak position in the comparison spectrum relative to the Ti peak position in the reference spectrum is determined. This makes it possible to determine the amount of spectral shift when the sample height is shifted by a predetermined amount.

[0087] Next, it is determined whether or not the point analysis has been performed a preset number of times (S210). The number of repetitions can be changed as appropriate depending on the required accuracy of correction.

[0088] If point analysis has not been performed the preset number of times (No in S210), the process returns to step S204, the standard sample is moved in the Z direction (S204), a comparison spectrum of Ti is obtained (S206), and the amount of spectral shift is calculated (S208).

[0089] In this way, step S204 of moving the standard sample in the Z direction, step S206 of performing point analysis, and step S208 of determining the amount of spectral shift are repeated until the predetermined number of point analyses have been performed. This allows a table of the amount of sample height deviation and the amount of spectral shift for the Ti spectrum to be obtained.

[0090] When point analysis has been performed the set number of times (Yes in S210), it is determined whether or not analysis has been performed on all standard samples (S212).

[0091] If analysis has not been performed on all standard samples (No in S212), return to step S202, select a Cd standard sample, and perform steps S202, S204, S206, S208, and S210 to obtain a table of sample height deviation and spectral shift amount for the Cd spectrum.

[0092] In this manner, steps S202, S204, S206, S208, and S210 are repeated to analyze the Ti standard sample, the Cd standard sample, the Mo standard sample, and the Si standard sample. As a result, a table of the sample height deviation and the spectrum shift amount can be obtained for the Ti spectrum, the Cd spectrum, the Mo spectrum, and the Si spectrum.

[0093] When all the standard samples have been analyzed (Yes in S212), the relationship between the deviation in height of the sample and the amount of spectral shift is determined (S214).

[0094] Figure 9 is a graph showing the relationship between the deviation in sample height and the amount of spectral shift for each of the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum. The horizontal axis of the graph shown in Figure 9 represents the deviation in sample height, and the vertical axis represents the amount of spectral shift. The amount of spectral shift is expressed as the difference (mm) between the peak position of the reference spectrum and the peak position of the comparison spectrum at the spectral position L.

[0095] The graph shown in Fig. 9 can be created from a table of the sample height deviation and the spectral shift for the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum. As shown in Fig. 9, the relationship between the sample height deviation and the spectral shift is determined for each element, i.e., for each energy (spectral position L).

[0096] Through the above steps, the relationship between the deviation in height of the sample and the amount of spectrum shift can be determined.

[0097] FIG. 10 is a graph showing the relationship between the spectral position L (energy of characteristic X-rays) and the amount of spectral shift for each amount of deviation in the height of the sample.

[0098] The graph shown in Fig. 10 is obtained from the graph shown in Fig. 9. Specifically, the items (elements) of the graph shown in Fig. 9 are converted into the horizontal axis of the graph shown in Fig. 10. At this time, the items (elements) of the graph shown in Fig. 9 are represented by the spectroscopic position L on the horizontal axis of the graph shown in Fig. 10. Furthermore, the deviation amount of the height of the sample shown on the horizontal axis of the graph shown in Fig. 9 is converted into the items of the graph shown in Fig. 10.

[0099] In this way, from the relationship between the deviation in sample height and the amount of spectral shift calculated for each element, as shown in FIG. 9, it is possible to obtain the relational expression between the spectral position L and the amount of spectral shift for each deviation in sample height, as shown in FIG. 10.

[0100] Information showing the relationship between the deviation amount of the sample height and the amount of spectrum shift for each element shown in Fig. 9 and information showing the relationship between the spectral position L and the amount of spectrum shift for each deviation amount of the sample height shown in Fig. 10 are stored in the storage unit 74. The relationship shown in Fig. 9 and the relationship shown in Fig. 10 are expressed differently, and it is sufficient if either the information on the relationship shown in Fig. 9 or the information on the relationship shown in Fig. 10 is stored in the storage unit 74.

[0101] <Method for correcting the spectral shift caused by the difference in sample height> Next, a method for correcting the spectral shift caused by the deviation of the sample height will be described. As an example of the correction of the spectral shift caused by the deviation of the sample height, the correction of the shift of the Sc-Kα line caused by the deviation of the sample height will be described below.

[0102] First, the relationship between the deviation in height of the sample and the amount of spectrum shift for Sc-Kα radiation is found from the relational expression shown in FIG.

[0103] FIG. 11 is a diagram for explaining a method for determining the relationship between the deviation amount of the height of the sample and the amount of spectrum shift in Sc-Kα radiation from the relational expression shown in FIG.

[0104] As shown in Figure 11, a line is drawn at the spectral position L = 97.08 mm, which is the peak position of the Sc-Kα line, and the intersection point of the relational expression between the spectral position L and the amount of spectral shift, which is plotted for each deviation in sample height, is found. The intersection points found are plotted on a graph with the horizontal axis representing the deviation in sample height and the vertical axis representing the amount of spectral shift. This makes it possible to find the relational expression between the deviation in sample height and the amount of spectral shift for Sc-Kα line.

[0105] FIG. 12 is a graph showing the relationship between the deviation in height of a sample and the amount of spectrum shift in Sc-Kα radiation.

[0106] Next, the spectral shift of the Sc peak in the spectrum stored in each pixel of the spectral map is corrected using the relational expression shown in Fig. 12. Specifically, first, the amount of spectral shift is calculated from the height of the sample at each pixel using the relational expression shown in Fig. 12. The information on the height of the sample at each pixel can be, for example, the measurement results of the height of the sample measured in advance using a laser microscope or the like.

[0107] Next, for each pixel, the Sc peak of the X-ray spectrum is shifted based on the calculated amount of spectrum shift.

[0108] By the above steps, the spectral shift caused by the deviation in the height of the sample can be corrected.

[0109] In the above, the number of peaks to be corrected is one, but there may be multiple peaks to be corrected. In this case, the above-described correction may be performed on each of the multiple peaks to be corrected.

[0110] <Correction process for spectrum shift caused by deviation in sample height> FIG. 13 is a flowchart showing an example of a correction process performed by the control unit 60 to correct a spectrum shift caused by a deviation in the height of the sample.

[0111] The control unit 60 receives a specification of a peak to be corrected (S300).

[0112] The peak may be expressed by the spectral position L or by the energy (wavelength) of the X-rays. The control unit 60 reads out the relational expression shown in Fig. 9 stored in advance in the storage unit 74, and obtains information indicating the relationship between the amount of deviation in height of the sample at the specified peak position and the amount of spectral shift based on the relational expression (S302). This makes it possible to obtain information indicating the relationship between the amount of deviation in height of the sample at the specified peak position and the amount of spectral shift.

[0113] Next, the control unit 60 corrects the spectrum stored in each pixel of the spectrum map for the spectral shift based on the information indicating the relationship between the deviation amount of the sample height and the spectral shift amount (S304).

[0114] By the above process, the spectral shift caused by the deviation in the height of the sample can be corrected.

[0115] <Experimental Example> Point analysis was performed while changing the height of the sample, and multiple Sc spectra were obtained.

[0116] FIG. 14 shows a plurality of Sc spectra obtained by performing point analysis on a sample containing Sc while changing the height of the sample. The Sc spectrum was acquired at positions where the sample height was shifted by +100 μm, +200 μm, -100 μm, and -200 μm from the focal position. At the focal position, the analysis point on the sample was located on the Rowland circle, satisfying the focusing condition. The multiple Sc spectra shown in Figure 14 reveal that the greater the deviation in sample height, the greater the spectral shift.

[0117] The spectral shift caused by the deviation in the height of the sample was corrected for the multiple Sc spectra shown in Fig. 14. Specifically, the spectral shift amount for each spectrum was calculated from the height of the sample when each spectrum was acquired using the relational expression between the deviation in height of the sample and the spectral shift amount shown in Fig. 12. Then, the spectrum was shifted based on the calculated spectral shift amount for each spectrum.

[0118] FIG. 15 shows the results of correcting the spectrum shift caused by the deviation in the height of the sample in each Sc spectrum shown in FIG.

[0119] As shown in Figure 15, as a result of the correction, the peak positions of the spectra acquired under different sample height deviation conditions were aligned. Therefore, the spectral shift caused by the sample height deviation was accurately corrected.

[0120] Z-map As shown in Figure 14, if there is a deviation in the sample height, the amount of spectral shift will change depending on the magnitude of the deviation. Therefore, by comparing the reference spectrum with the spectrum stored in each pixel of the spectrum map to determine the amount of spectral shift, it is possible to determine the sample height at each pixel. This makes it possible to create a Z map that shows the distribution of sample heights. A Z map is a map that associates positions on the sample with the sample height.

[0121] In this way, information about the topography of the sample surface can be obtained from the spectral map.

[0122] In the analytical device 100, the control unit 60 performs processing to obtain the height of the sample at each pixel by comparing the reference spectrum with the spectrum stored in each pixel of the spectrum map to obtain the amount of spectrum shift, and thereby create a Z map.

[0123] Effects The analysis method according to the first embodiment is an analysis method using an analysis device 100 equipped with a WDS 50a that has a spectroscopic element 52 that disperses X-rays emitted from a sample S and detects X-rays with energies according to the position of the spectroscopic element 52. The analysis method according to the first embodiment also includes the steps of: acquiring map data by fixing the position of the spectroscopic element 52 and detecting X-rays with specific energies while scanning the sample S with an electron beam EB, and repeating this map analysis while changing the position of the spectroscopic element 52 to acquire multiple pieces of map data; and generating a spectrum map that associates positions on the sample S with X-ray spectra based on the multiple pieces of map data.

[0124] Therefore, in the analysis method according to the first embodiment, a spectrum map can be easily obtained using WDS.

[0125] For example, when performing point analysis at each analysis point on a sample to acquire a spectrum and obtain a spectrum map, the spectroscopic element 52 must be moved by the amount of the measurement energy range for each analysis point. In other words, the operation of moving the spectroscopic element 52 by the amount of the measurement energy range must be performed as many times as there are analysis points. In contrast, in the analysis method according to the first embodiment, the operation of moving the spectroscopic element 52 by the amount of the measurement energy range can be performed once. That's fine.

[0126] Here, the movement of the spectroscopic element 52 is performed by mechanical driving such as motor driving, and the movement (scanning) of the electron beam EB is performed by electrical driving such as deflector 16. Therefore, the analysis method in the analysis device 100 can obtain a spectrum map in a shorter time than when a spectrum map is obtained by performing point analysis on each analysis point.

[0127] In the analysis method according to the first embodiment, multiple WDSs are installed in the analysis device 100, and the process of acquiring multiple map data and the process of generating a spectral map are performed for each WDS. In this way, in the analysis method according to the first embodiment, spectral maps can be simultaneously acquired for as many WDSs as there are WDSs installed in the analysis device 100.

[0128] The analysis method according to the first embodiment includes a step of correcting a spectral shift caused by a deviation in the height of the sample in the spectrum stored in each pixel of the spectral map. The step of correcting the spectral shift includes correcting the spectral shift based on information indicating the relationship between the deviation in the height of the sample and the amount of the spectral shift. Therefore, the analysis method according to the first embodiment can easily correct the spectral shift caused by a deviation in the height of the sample.

[0129] The analytical method according to the first embodiment includes a step of acquiring information indicating the relationship between the amount of deviation in sample height and the amount of spectrum shift. In the step of acquiring the information, an analysis is performed in which an electron beam EB is irradiated onto a standard sample without any deviation in sample height, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a reference spectrum, and an analysis in which an electron beam EB is irradiated onto the standard sample with a deviation in sample height, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a comparison spectrum. This analysis is repeated while changing the amount of deviation in sample height to acquire multiple comparison spectra, and the reference spectrum is compared with each comparison spectrum to acquire the information.

[0130] Therefore, in the analysis method according to the first embodiment, information indicating the relationship between the amount of deviation in height of the sample and the amount of spectrum shift can be obtained.

[0131] The analysis method according to the first embodiment includes the steps of: determining the amount of spectral shift by comparing the spectrum stored in each pixel of the spectral map with a reference spectrum; and creating a Z-map that associates positions on the sample with the height of the sample based on the amount of spectral shift. Therefore, the analysis method according to the first embodiment can obtain information about the shape of the sample surface from the spectral map.

[0132] The analytical device 100 includes an electron optical system 10 that irradiates an electron beam EB onto a sample S, a WDS 50a that has a spectroscopic element 52 that disperses X-rays emitted from the sample S and detects X-rays of an energy corresponding to the position of the spectroscopic element 52, and a control unit 60 that controls the electron optical system 10 and the WDS 50a. The control unit 60 also performs map analysis to acquire map data by causing the WDS 50a to detect X-rays of a specific energy while fixing the position of the spectroscopic element 52 while scanning the sample S with the electron beam EB, and repeats this while changing the position of the spectroscopic element 52 to acquire multiple map data, and generates a spectrum map that associates positions on the sample S with X-ray spectra based on the multiple map data.

[0133] Therefore, in the analysis device 100, a spectrum map can be easily obtained using the WDS 50a.

[0134] In the analysis device 100, a plurality of WDSs are installed, and the process of acquiring a plurality of map data is performed. The process of generating the spectral map is performed for each WDS, so that the analysis device 100 can simultaneously obtain multiple spectral maps.

[0135] The analysis device 100 includes a storage unit 74 that stores information indicating the relationship between the amount of deviation in height of the sample S and the amount of spectral shift. Therefore, the analysis device 100 can correct the spectral shift caused by the deviation in height of the sample S for the spectrum stored in each pixel of the spectral map.

[0136] 2. Second embodiment 2.1. Analyzer Next, an analysis method according to a second embodiment will be described. Below, differences from the analysis method according to the first embodiment will be described, and a description of similarities will be omitted.

[0137] The analysis device used in the analysis method according to the second embodiment is the same as the analysis device 100 shown in FIGS. 1 and 2, and a description thereof will be omitted.

[0138] 2.2. Low-magnification map analysis The analysis device 100 can perform map analysis using two methods: stage scanning, in which the sample stage 20 is moved to scan the sample S while the irradiation position of the electron beam EB is fixed, and beam scanning, in which the sample stage 20 is fixed and the electron beam EB is deflected two-dimensionally to scan the sample S.

[0139] For example, when the observation magnification is low (less than 3000x), map analysis is performed using stage scanning, and when the observation magnification is 3000x or higher, beam scanning is used. This is because when beam scanning is performed at low magnification, the analysis point (the electron beam irradiation position) deviates from the Rowland circle, which does not satisfy the WDS focusing conditions, resulting in a spectral shift and a decrease in X-ray intensity.

[0140] Figure 16 compares the results of map analysis at a magnification of 500x using beam scanning with the results of map analysis of a field of view corresponding to beam scanning using stage scanning. The two maps shown in Figure 16 are maps of Si measured using a TAP crystal as the spectroscopic element 52. In Figure 16, the lower the X-ray intensity, the darker the image. As shown in Figure 16, with beam scanning, a decrease in X-ray intensity is observed in the edge regions of the observation field, i.e., in the region where the electron beam EB is significantly deflected.

[0141] However, map analysis using stage scanning takes longer than beam scanning. Because spectral imaging requires multiple map analyses, beam scanning is preferable even at low magnifications.

[0142] In the analysis method according to the second embodiment, spectral imaging is performed to acquire a spectral map in a manner similar to that of the measurement method according to the first embodiment shown in FIG. 6. However, the observation magnification is set to low, and the electron beam EB scans the sample S by beam scanning. In the measurement method according to the second embodiment, the spectrum stored in each pixel of the spectral map acquired in this manner is corrected for spectral shifts and reductions in X-ray intensity that occur in low-magnification map analysis using beam scanning.

[0143] 2.3. Correction method 2.3.1. Correction of spectral shift caused by electron beam deflection In the analysis method according to the second embodiment, the spectrum stored in each pixel of the spectrum map is corrected for a spectral shift caused by the deflection of the electron beam. The resulting spectral shift is corrected based on information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift.

[0144] <Method for determining the relationship between the amount of deflection of an electron beam and the amount of spectral shift> The analysis method according to the second embodiment includes a step of acquiring information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift. In this step, first, a standard sample is irradiated with an electron beam without deflection, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a reference spectrum. Next, the standard sample is irradiated with the electron beam while deflecting the electron beam, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a comparison spectrum. This analysis is repeated while changing the amount of deflection of the electron beam to acquire multiple comparison spectra. Next, the reference spectrum is compared with each comparison spectrum to acquire information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift.

[0145] Fig. 17 is a flowchart showing an example of a method for determining the relationship between the amount of deflection of an electron beam and the amount of spectrum shift. Below, a case where a PET crystal is used as the spectroscopic element 52 will be described. Also, a description of the same points as those in the process shown in Fig. 8 above will be omitted.

[0146] First, a plurality of standard samples are prepared (S400).

[0147] As the standard sample, for example, a Ti standard sample, a Cd standard sample, a Mo standard sample, and a Si standard sample can be used.

[0148] Next, point analysis is performed on a standard Ti sample to obtain a reference spectrum (S402).

[0149] Step S402 of acquiring a reference spectrum is performed in the same manner as step S202 of acquiring a reference spectrum shown in Fig. 8. Here, the reference spectrum of Ti is acquired. The reference spectrum is acquired in a state where the focusing condition is satisfied, and the deflection amount of the electron beam is zero.

[0150] Next, the electron beam EB is deflected by a predetermined deflection amount by the deflector 16 (S404).

[0151] Fig. 18 is a diagram showing a schematic diagram of the deflection of the electron beam EB by the deflector 16. As shown in Fig. 18, the electron beam EB is deflected in a direction perpendicular to the short side of the spectroscopic element 52. In this state, point analysis is performed to obtain a spectrum of Ti (comparison spectrum) (S406). The comparison spectrum is a spectrum obtained in a state in which the electron beam is deflected.

[0152] Next, the reference spectrum and the comparison spectrum are compared to determine the amount of spectral shift (S408). Specifically, the amount of shift of the Ti peak position in the comparison spectrum relative to the Ti peak position in the reference spectrum is determined. This makes it possible to determine the amount of spectral shift of the comparison spectrum relative to the reference spectrum. In other words, it is possible to determine the amount of spectral shift when the electron beam EB is deflected by a predetermined deflection amount.

[0153] Next, it is determined whether point analysis has been performed a preset number of times (S410). If point analysis has not been performed a preset number of times (No in S410), the process returns to step S404, where the electron beam EB is deflected (S404), a comparative spectrum of Ti is obtained (S406), and the amount of spectral shift is calculated (S408). In step S404 of deflecting the electron beam EB, for example, the amount of deflection of the electron beam is increased according to the number of repetitions.

[0154] In this way, the step S404 of deflecting the standard sample, the step S404 of acquiring a comparison spectrum of Ti, and the step S405 of acquiring a spectrum are repeated until the point analysis is performed a preset number of times. Step S408 for calculating the amount of deflection of the electron beam and the amount of spectral shift is repeated. This makes it possible to obtain a table of the amount of deflection of the electron beam and the amount of spectral shift for the Ti spectrum.

[0155] When point analysis has been performed the set number of times (Yes in S410), it is determined whether or not analysis has been performed on all standard samples (S412).

[0156] If analysis has not been performed on all standard samples (No in S412), return to step S402, select a Cd standard sample, and perform steps S402, S404, S406, S408, and S410 to obtain a table of the electron beam deflection amount and spectral shift amount for the Cd spectrum.

[0157] In this way, analyses are performed on a standard sample of Ti, a standard sample of Cd, a standard sample of Mo, and a standard sample of Si. As a result, tables of the electron beam deflection and spectral shift amounts can be obtained for the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum.

[0158] When all the standard samples have been analyzed (Yes in S412), the relationship between the deflection amount of the electron beam and the amount of spectral shift is determined (S414).

[0159] Figure 19 is a graph showing the relationship between the deflection amount of the electron beam and the spectral shift amount for each of the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum. The horizontal axis of the graph shown in Figure 19 represents the deflection amount of the electron beam, and the vertical axis represents the spectral shift amount. The deflection amount on the horizontal axis is expressed as the deflection distance, which is the distance between the center of the observation field on the sample and the analysis point (the position irradiated with the electron beam). The deflection distance is zero when the analysis point is at the center of the observation field. The spectral shift amount is expressed as the difference in spectral position L (mm).

[0160] From the table of the deflection amount of the electron beam and the spectral shift amount for each of the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum, the graph shown in Fig. 19 can be created. As shown in Fig. 19, the relationship between the deflection amount of the electron beam and the spectral shift amount is found for each element, i.e., for each energy (spectral position L).

[0161] Through the above steps, the relationship between the amount of deflection of the electron beam and the amount of spectrum shift can be obtained.

[0162] FIG. 20 is a graph showing the relationship between the spectral position L and the amount of spectral shift for each deflection amount (deflection distance) of the electron beam.

[0163] The graph shown in Fig. 20 is obtained from the graph shown in Fig. 19. Specifically, the items (elements) of the graph shown in Fig. 19 are converted into the horizontal axis of the graph shown in Fig. 20. At this time, the items (elements) of the graph shown in Fig. 19 are represented by the spectral position L on the horizontal axis of Fig. 20. Furthermore, the deflection distance shown on the horizontal axis of the graph shown in Fig. 19 is converted into the items of the graph shown in Fig. 20.

[0164] In this way, from the relationship between the deflection amount of the electron beam and the spectral shift amount calculated for each element shown in FIG. 19, the relational expression between the energy (spectral position L) of the characteristic X-rays and the spectral shift amount for each deflection amount of the electron beam shown in FIG. 20 can be calculated.

[0165] Information showing the relationship between the deflection amount of the electron beam and the amount of spectral shift for each element shown in Fig. 19 and information showing the relationship between the energy of the characteristic X-ray and the amount of spectral shift for each deflection amount of the electron beam shown in Fig. 20 are stored in the storage unit 74. The relationships shown are just different ways of expressing them, and it is sufficient that either the relationship information shown in FIG. 19 or the relationship information shown in FIG.

[0166] <Method for correcting spectral shift caused by electron beam deflection> Next, a method for correcting a spectral shift caused by deflection of an electron beam will be described. As an example of correcting a spectral shift caused by deflection of an electron beam, a case of correcting a shift of Sc-Kα radiation caused by deflection of an electron beam will be described below.

[0167] First, the relationship between the deflection amount of the electron beam and the spectral shift amount in the Sc-Kα ray is found from the relational expression shown in FIG.

[0168] FIG. 21 is a diagram for explaining a method for determining the relationship between the deflection amount of an electron beam and the spectral shift amount in Sc-Kα radiation from the relational expression shown in FIG.

[0169] As shown in Figure 21, a line is drawn at the spectral position L = 97.08 mm, which is the peak position of Sc-Kα radiation, and the intersection point of the relational expression between the spectral position L and the amount of spectral shift, plotted for each deflection amount of the electron beam, is found. The intersection points found are plotted on a graph with the horizontal axis being the deflection distance and the vertical axis being the amount of spectral shift. This makes it possible to find the relational expression between the amount of deflection of the electron beam and the amount of spectral shift for Sc-Kα radiation.

[0170] FIG. 22 is a graph showing the relation between the deflection amount (deflection distance) of an electron beam and the amount of spectral shift in Sc-Kα radiation.

[0171] Next, the spectral shift of the Sc peak of the spectrum stored in each pixel of the spectrum map is corrected using the relational expression shown in Fig. 22. Specifically, first, the spectral shift amount is calculated from the deflection amount (deflection distance) of the electron beam at each pixel using the relational expression shown in Fig. 22. The deflection amount (deflection distance) of the electron beam can be calculated, for example, from the coordinates of each pixel. Next, at each pixel, the Sc peak of the X-ray spectrum is shifted based on the calculated spectral shift amount.

[0172] By the above steps, the spectral shift caused by the deflection of the electron beam can be corrected.

[0173] In the above, the number of peaks to be corrected is one, but the number of peaks to be corrected may be multiple. In this case, the above-described correction may be performed on each of the multiple peaks to be corrected.

[0174] <Correction process for spectral shift caused by electron beam deflection> FIG. 23 is a flowchart showing an example of a correction process for a spectral shift caused by deflection of the electron beam in the control unit 60.

[0175] The control unit 60 receives the specification of the peak to be corrected (S500). The control unit 60 reads out the relational expression shown in Fig. 19 stored in advance in the storage unit 74, and obtains information indicating the relationship between the deflection amount of the electron beam and the amount of spectral shift at the specified peak position based on the relational expression (S502). This makes it possible to obtain information indicating the relationship between the deflection amount of the electron beam and the amount of spectral shift at the specified peak position.

[0176] Next, the control unit 60 corrects the spectrum stored in each pixel of the spectrum map for the spectral shift based on the information indicating the relationship between the deflection amount of the electron beam and the spectral shift amount (S504).

[0177] By the above processing, the spectral shift caused by the deflection of the electron beam can be corrected.

[0178] <Experimental Example> Point analysis was performed while changing the deflection amount of the electron beam to obtain the Sc spectrum.

[0179] Figure 24 shows multiple Sc spectra obtained by performing point analysis on a sample containing Sc while varying the deflection amount of the electron beam. Here, Sc spectra were obtained when the analysis point (the irradiation position of the electron beam) was located at the center of the observation field, the left edge of the observation field at a magnification of 300x (deflection amount: 0.21333 mm), the left edge of the observation field at a magnification of 200x (deflection amount: 0.32 mm), the right edge of the observation field at a magnification of 300x, and the right edge of the observation field at a magnification of 200x. When the analysis point was located at the center of the observation field, the analysis point on the sample was located on the Rowland circle, satisfying the focusing condition. The multiple Sc spectra shown in Figure 24 reveal that the greater the deflection amount of the electron beam, the greater the spectral shift.

[0180] In each spectrum of Sc shown in Fig. 24, the spectral shift caused by the deflection of the electron beam was corrected. Specifically, the amount of spectral shift in each spectrum was calculated from the amount of deflection of the electron beam when each spectrum was acquired, using the relational expression between the amount of deflection of the electron beam and the amount of spectral shift shown in Fig. 22. Then, the spectrum was shifted based on the amount of spectral shift calculated for each spectrum.

[0181] Fig. 25 shows the results of correcting the spectral shift caused by the deflection of the electron beam in each spectrum of Sc shown in Fig. 24. As shown in Fig. 25, as a result of the correction, the peak positions of the spectra acquired with different amounts of deflection of the electron beam were consistent. Therefore, the spectral shift caused by the deflection of the electron beam was accurately corrected.

[0182] 2.3.2. Correction of X-ray intensity reduction due to electron beam deflection In the analysis method according to the second embodiment, the spectrum stored in each pixel of the spectrum map is corrected for a decrease in X-ray intensity due to the deflection of the electron beam, based on information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity.

[0183] <Method for determining the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity> The analysis method according to the second embodiment includes a step of acquiring information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity. In this step of acquiring information, first, a standard sample is irradiated with an electron beam without deflection, and the X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a reference spectrum. Next, the standard sample is irradiated with the electron beam while deflecting, and the X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element 52 to acquire a comparison spectrum. This analysis is repeated while changing the amount of deflection of the electron beam to acquire multiple comparison spectra. Next, the reference spectrum is compared with each comparison spectrum to acquire information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity.

[0184] Fig. 26 is a flowchart showing an example of a method for determining the relationship between the amount of deflection of an electron beam and the rate of decrease in X-ray intensity. The following describes a case where a PET crystal is used as the spectroscopic element 52. Furthermore, explanations of the same points as those in the correction process shown in Fig. 17 above will be omitted.

[0185] First, a plurality of standard samples are prepared (S600).

[0186] As the standard sample, for example, a Ti standard sample, a Cd standard sample, a Mo standard sample, and a Si standard sample can be used.

[0187] Next, point analysis is performed on a standard Ti sample to obtain a reference spectrum (S602).

[0188] Step S602 of acquiring a reference spectrum is performed in the same manner as step S402 of acquiring a reference spectrum shown in Fig. 17. Here, the reference spectrum of Ti is acquired. The reference spectrum is acquired in a state where the focusing condition is satisfied, and the deflection amount of the electron beam is zero.

[0189] Next, the electron beam EB is deflected by a predetermined deflection amount by the deflector 16 (S604).

[0190] 18, point analysis is performed with the electron beam EB deflected in a direction perpendicular to the short side of the spectroscopic element 52 to obtain a spectrum of Ti (comparison spectrum) (S606). The comparison spectrum is a spectrum obtained with the electron beam deflected.

[0191] Next, the X-ray intensity of the reference spectrum is compared with the X-ray intensity of the comparison spectrum to determine the reduction rate of the X-ray intensity (S608). Specifically, the ratio of the X-ray intensity of the Ti peak in the comparison spectrum to the X-ray intensity of the Ti peak in the reference spectrum is determined. This makes it possible to determine the reduction rate of the X-ray intensity when the electron beam EB is deflected by a predetermined deflection amount.

[0192] Next, it is determined whether point analysis has been performed a preset number of times (S610). If point analysis has not been performed a preset number of times (No in S610), the process returns to step S604, where the electron beam EB is deflected (S604), a comparative spectrum of Ti is obtained (S606), and the rate of decrease in X-ray intensity is calculated (S608). In step S604 of deflecting the electron beam EB, for example, the amount of deflection of the electron beam is increased according to the number of repetitions.

[0193] In this way, step S604 of deflecting the electron beam, step S606 of performing the point analysis, and step S608 of determining the rate of decrease in X-ray intensity are repeated until the point analysis has been performed a preset number of times. This makes it possible to obtain a table of the electron beam deflection amount and the rate of decrease in X-ray intensity for the Ti spectrum.

[0194] When point analysis has been performed the set number of times (Yes in S610), it is determined whether or not analysis has been performed on all standard samples (S612).

[0195] If analysis has not been performed on all standard samples (No in S612), return to step S602, select a Cd standard sample, and perform steps S602, S604, S606, S608, and S610 to obtain a table of the electron beam deflection amount and the rate of decrease in X-ray intensity for the Cd spectrum.

[0196] In this way, analyses are performed on a standard sample of Ti, a standard sample of Cd, a standard sample of Mo, and a standard sample of Si. As a result, tables of the electron beam deflection amount and the rate of decrease in X-ray intensity can be obtained for the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum.

[0197] When all the standard samples have been analyzed (Yes in S612), the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity is determined (S614).

[0198] Fig. 27 is a graph showing the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity for each of the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum. The horizontal axis of the graph shown in Fig. 27 represents the amount of deflection of the electron beam, and the vertical axis represents the rate of decrease in X-ray intensity. The decrease rate of X-ray intensity is the ratio of the X-ray intensity in the comparison spectrum to the X-ray intensity in the reference spectrum. The deflection amount of the electron beam on the horizontal axis is expressed as the deflection distance.

[0199] The graph shown in FIG. 27 can be created from a table of the electron beam deflection amount and the rate of decrease in X-ray intensity for each of the Ti spectrum, Cd spectrum, Mo spectrum, and Si spectrum.

[0200] Through the above steps, the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity can be obtained.

[0201] FIG. 28 is a graph showing the relationship between the deflection distance and the correction value for correcting the X-ray intensity.

[0202] From the graph shown in Fig. 27, a graph showing the relationship between deflection distance and correction value, shown in Fig. 28, is created. The correction value is a coefficient for making the X-ray intensity reduced by the deflection of the electron beam the same as the X-ray intensity of the reference spectrum. The X-ray intensity can be corrected by multiplying the X-ray intensity of the spectrum by the correction value. As shown in Fig. 28, the correction value is expressed as a function that increases as the amount of deflection of the electron beam increases.

[0203] FIG. 29 is a graph showing the relationship between the spectral position L and the correction value for each deflection amount of the electron beam.

[0204] The items of the graph shown in Fig. 28 are converted into the horizontal axis of the graph shown in Fig. 29, and the horizontal axis of the graph shown in Fig. 28 is converted into the items of the graph shown in Fig. 29. In this way, the relational expression between the spectral position L and the correction value can be obtained for each deflection amount of the electron beam shown in Fig. 29.

[0205] Information showing the relationship between the deflection amount of the electron beam and the reduction rate of X-ray intensity for each element shown in Fig. 27, information showing the relationship between the deflection distance and the correction value for each element shown in Fig. 28, and information showing the relationship between the spectral position L and the correction value for each deflection amount of the electron beam shown in Fig. 29 are stored in the storage unit 74. Note that the relationship shown in Fig. 27, the relationship shown in Fig. 28, and the relationship shown in Fig. 29 are expressed differently, and it is sufficient that one of the relationship shown in Fig. 27, the relationship shown in Fig. 28, and the relationship shown in Fig. 29 is stored in the storage unit 74.

[0206] <Method for correcting the decrease in X-ray intensity caused by electron beam deflection> Next, a method for correcting a decrease in X-ray intensity due to deflection of an electron beam will be described. As an example of correcting a decrease in X-ray intensity due to deflection of an electron beam, a case of correcting a decrease in X-ray intensity of an Sc-Kα line peak due to deflection of an electron beam will be described below.

[0207] First, the relationship between the amount of deflection of the electron beam for Sc-Kα radiation and the correction value is found from the relational expression shown in Fig. 29. Specifically, in the graph shown in Fig. 29, a line is drawn at the spectral position L = 97.08 mm, which is the peak position of Sc-Kα radiation, and the intersection point of the relational expression between the spectral position L and the correction value, drawn for each amount of deflection of the electron beam, is found. The found intersection point is plotted on a graph with the deflection distance on the horizontal axis and the correction value on the vertical axis. This makes it possible to find the relational expression between the amount of deflection of the electron beam for Sc-Kα radiation and the correction value.

[0208] FIG. 30 is a graph showing the relationship between the amount of deflection of an electron beam and the correction value for Sc-Kα radiation.

[0209] Next, the X-ray intensity of the Sc peak of the spectrum stored in each pixel of the spectrum map is corrected using the relational expression shown in Figure 30. Specifically, first, a correction value is found for each pixel from the deflection amount (deflection distance) of the electron beam using the relational expression shown in Figure 30. Next, for each pixel, the intensity of the Sc peak of the X-ray spectrum is multiplied by the found correction value. This makes it possible to correct the decrease in X-ray intensity of the Sc peak caused by the deflection of the electron beam.

[0210] By the above steps, the decrease in X-ray intensity caused by the deflection of the electron beam can be corrected.

[0211] In the above, the number of peaks to be corrected is one, but the number of peaks to be corrected may be multiple. In this case, the above-described correction may be performed on each of the multiple peaks to be corrected.

[0212] <Correction process for reduction in X-ray intensity caused by electron beam deflection> FIG. 31 is a flowchart showing an example of a process performed by the control unit 60 to correct a decrease in X-ray intensity caused by deflection of the electron beam.

[0213] First, the control unit 60 accepts the specification of a peak to be corrected (S700). The control unit 60 reads out the relational expression shown in Fig. 27 stored in advance in the storage unit 74, and obtains information indicating the relationship between the amount of deflection of the electron beam at the specified peak position and the correction value (the rate of decrease in X-ray intensity) based on the relational expression (S702). This makes it possible to obtain information indicating the relationship between the amount of deflection of the electron beam at the specified peak position and the correction value (the rate of decrease in X-ray intensity).

[0214] Next, the control unit 60 corrects the X-ray intensity for the spectrum stored in each pixel of the spectrum map based on the relationship between the deflection amount of the electron beam and the correction value (the rate of decrease in X-ray intensity) (S704).

[0215] By the above processing, the decrease in X-ray intensity caused by the deflection of the electron beam can be corrected.

[0216] <Experimental Example> Each spectrum of Sc shown in FIG. 24 was acquired, and map data of Sc-Kα radiation at an observation magnification of 200 times was created based on each spectrum of Sc shown in FIG.

[0217] FIG. 32 is an image of map data of Sc-Kα rays at an observation magnification of 200 times.

[0218] The map data shown in Figure 32 reproduces map analysis using beam scanning. In the map data shown in Figure 32, if the peak intensity (maximum X-ray intensity) of the spectrum acquired at the center of the observation field of view is set to 100, the X-ray intensity (minimum X-ray intensity) at the edge of the observation field of view is 11.9. As such, the X-ray intensity at the edge of the observation field of view is significantly reduced due to the spectral shift and reduction in X-ray intensity caused by the deflection of the electron beam.

[0219] Next, the map data shown in Fig. 32 was corrected for the spectral shift caused by the deflection of the electron beam. Specifically, the spectrum stored in each pixel of the map data shown in Fig. 32 was shifted based on the relationship between the deflection amount of the electron beam and the spectral shift amount shown in Fig. 22.

[0220] FIG. 33 is an image diagram of map data in which the spectral shift caused by the deflection of the electron beam has been corrected.

[0221] In the map data shown in Figure 33, when the peak intensity (maximum X-ray intensity) of the spectrum acquired at the center of the observation field of view was set to 100, the X-ray intensity (minimum X-ray intensity) at the edge of the observation field of view was 88.5. In this way, by correcting the spectral shift, the X-ray intensity could also be corrected.

[0222] Next, the map data shown in Fig. 33 was corrected for the decrease in X-ray intensity caused by the deflection of the electron beam. Specifically, based on the relationship between the deflection amount of the electron beam and the correction value (decrease rate of X-ray intensity) shown in Fig. 30, the X-ray intensity of the spectrum stored in each pixel of the map data shown in Fig. 33 was corrected. The intensity was corrected.

[0223] FIG. 34 is an image diagram of map data corrected for the spectral shift caused by the deflection of the electron beam and the decrease in X-ray intensity caused by the deflection of the electron beam.

[0224] In the map data shown in Figure 34, if the peak intensity (maximum X-ray intensity) of the spectrum acquired at the center of the observation field of view is set to 100, the X-ray intensity (minimum X-ray intensity) at the edge of the observation field of view is 96.7. By correcting the spectral shift and X-ray intensity in this way, the error in X-ray intensity over the entire observation field of view was kept to approximately ±3%. Therefore, the spectral shift and decrease in X-ray intensity caused by electron beam deflection were accurately corrected.

[0225] Effects In the analysis method according to the second embodiment, in the step of acquiring a plurality of map data, the electron beam EB is deflected by the deflector 16 so as to scan the electron beam EB over the sample S. The analysis method according to the second embodiment also includes a step of correcting a spectral shift caused by the deflection of the electron beam in the spectrum stored in each pixel of the spectral map, and in the step of correcting the spectral shift, the spectral shift is corrected based on information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift.

[0226] As described above, in the analysis method according to the second embodiment, the sample S can be scanned by beam scanning, and therefore map analysis can be performed in a shorter time than when the sample S is scanned by stage scanning. Therefore, in the analysis method according to the second embodiment, spectral imaging can be performed in a shorter time. Furthermore, in the analysis method according to the second embodiment, spectral shifts caused by deflection of the electron beam can be corrected.

[0227] The analytical method according to the second embodiment includes a step of acquiring information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift. In the step of acquiring the information, the following analysis is repeated while changing the amount of deflection of the electron beam: irradiating a standard sample with an electron beam without deflecting the electron beam, detecting X-rays emitted from the standard sample while changing the position of the spectroscopic element 52 to acquire a reference spectrum; irradiating the standard sample with the electron beam while deflecting the electron beam, detecting X-rays emitted from the standard sample while changing the position of the spectroscopic element 52 to acquire a comparison spectrum; and acquiring a plurality of comparison spectra by determining the amount of spectral shift of each comparison spectrum relative to the reference spectrum, thereby acquiring the information.

[0228] Therefore, in the analysis method according to the second embodiment, information indicating the relationship between the amount of deflection of the electron beam and the amount of spectrum shift can be obtained.

[0229] The analysis method according to the second embodiment includes a step of correcting a decrease in X-ray intensity due to deflection of the electron beam in the X-ray spectrum stored in each pixel of the spectrum map. Furthermore, in the step of correcting the decrease in X-ray intensity, the decrease in X-ray intensity is corrected based on information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity. Therefore, the analysis method according to the second embodiment can correct the decrease in X-ray intensity due to deflection of the electron beam.

[0230] The analysis method according to the second embodiment includes a step of acquiring information indicating the relationship between the deflection amount of the electron beam and the rate of decrease in X-ray intensity. The step of acquiring the information further includes: irradiating a standard sample with an electron beam without deflecting the electron beam, detecting the X-rays emitted from the standard sample while changing the position of the spectroscopic element 52 to acquire a reference spectrum; irradiating the standard sample with the electron beam while deflecting the electron beam, detecting the X-rays emitted from the standard sample while changing the position of the spectroscopic element 52 to acquire a comparison spectrum; and repeating this analysis while changing the deflection amount of the electron beam to acquire multiple comparison spectra, and comparing the X-ray intensity of the reference spectrum with the X-ray intensity of each comparison spectrum. , and obtain the information.

[0231] Therefore, in the analysis method according to the second embodiment, it is possible to obtain information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity.

[0232] As described above, the analysis method according to the second embodiment can correct the spectral shift caused by the deflection of the electron beam and the decrease in X-ray intensity caused by the deflection of the electron beam. Therefore, the analysis method according to the second embodiment can perform low-magnification map analysis using beam scanning. Therefore, the analysis method according to the second embodiment can acquire a low-magnification spectral map in a short time.

[0233] The analysis device 100 includes a storage unit 74 that stores information indicating the relationship between the amount of deflection of the electron beam and the amount of spectral shift. Therefore, the analysis device 100 can correct the spectrum stored in each pixel of the spectrum map for the spectral shift caused by the deflection of the electron beam.

[0234] The analysis device 100 includes a storage unit 74 that stores information indicating the relationship between the amount of deflection of the electron beam and the rate of decrease in X-ray intensity. Therefore, the analysis device 100 can correct the decrease in X-ray intensity caused by the deflection of the electron beam for the spectrum stored in each pixel of the spectrum map.

[0235] 3. Third embodiment 3.1. Analyzer Next, an analysis method according to a third embodiment will be described. Below, differences from the analysis method according to the first embodiment and the analysis method according to the second embodiment will be described, and a description of similarities will be omitted.

[0236] The analysis device used in the analysis method according to the third embodiment is the same as the analysis device 100 shown in FIGS. 1 and 2, and a description thereof will be omitted.

[0237] 3.2. Spectral Imaging In spectral imaging, map analysis is performed for each analysis point of the X-ray spectrum stored in each pixel, which means that spectral imaging has the problem of taking a long time to complete the analysis.

[0238] Therefore, in the analysis method according to the third embodiment, information about the elements contained in the sample S is acquired in advance, and the interval for changing the position of the spectroscopic element 52 is set based on the information about the elements contained in the sample S. This makes it possible to reduce the number of times map analysis is performed in the analysis method according to the third embodiment. Therefore, the analysis method according to the third embodiment makes it possible to perform spectral imaging in a short time.

[0239] Fig. 35 is a flowchart showing an example of an analysis method according to the third embodiment. The analysis method according to the third embodiment is similar to the analysis method according to the first embodiment shown in Fig. 6 described above, except that it includes a step of acquiring information about elements contained in the sample S and that the interval at which the position of the spectroscopic element 52 is changed is set based on the information about the elements contained in the sample S. Below, differences from the analysis method according to the first embodiment will be described, and a description of similarities will be omitted.

[0240] In step S2 of acquiring information about the elements contained in the sample S, the sample S is measured using an X-ray fluorescence spectrometer (XRF) to acquire information about the elements contained in the sample S. Information about the elements contained in the sample S can be acquired from the analysis results by XRF. Although not shown, the analysis device 100 may include an XRF.

[0241] Here, because XRF uses X-ray excitation, it generates less continuous X-rays and has a lower background than methods such as EDS, which use electron beam excitation. Therefore, XRF can perform highly sensitive analysis in a short time. Furthermore, XRF can simultaneously detect elements contained in the area where WDS performs map analysis. In this way, XRF can obtain information on trace elements in a short time.

[0242] Here, we have described the case where information about the elements contained in the sample S is obtained using XRF, but the method for obtaining information about the elements contained in the sample S is not limited as long as the information about the elements contained in the sample S can be easily obtained.

[0243] For example, information on elements contained in the sample S may be obtained using the EDS 40. The EDS 40 can obtain information on elements contained in the sample S in a shorter time than the WDS. Furthermore, information on elements contained in the sample S may be obtained by setting analysis conditions that enable measurement in a short time in spectral imaging using five WDSs mounted on the analysis device 100. For example, spectral imaging can be performed in a short time by reducing the number of pixels in map analysis. Furthermore, spectral imaging can be performed in a short time by shortening the dwell time per point in map analysis.

[0244] In step S20 of moving the spectroscopic element 52, the interval at which the position of the spectroscopic element 52 is changed is set based on the information about the elements contained in the sample S acquired in step S2. For example, the position of a peak specific to the element is identified based on the information about the elements contained in the sample S, and the movement interval of the spectroscopic element 52 when measuring the spectral background is set to be larger than the movement interval when measuring the peak position.

[0245] Fig. 36 is a diagram for explaining a method for setting the movement interval of the dispersive element 52. Fig. 36 shows spectral data of the entire observation field of the sample S acquired using a LiF crystal. In Fig. 36, the peak position and the area around it are hatched.

[0246] 36, the movement interval of the spectroscopic element 52 is set to be smaller than that of the non-hatched background area. This makes it possible to reduce the number of map analyses compared to when the movement interval of the spectroscopic element 52 is constant over the entire measurement energy range. Therefore, the time required for spectral imaging can be shortened.

[0247] For example, in a background region between adjacent peak regions, the movement interval of the spectroscopic element 52 may be set so that map analysis is performed only at the midpoint between the adjacent peaks. In other words, the number of measurement points in the background region may be set to one.

[0248] 3.3. Control section processing Fig. 37 is a flowchart showing an example of the spectral imaging process of the control unit 60. The process of the control unit 60 is similar to the spectral imaging process of the control unit 60 shown in Fig. 7 described above, except that the control unit 60 performs a process of receiving information about elements contained in the sample S and sets an interval for changing the position of the spectroscopic element 52 based on the information about the elements contained in the sample S. Below, differences from the spectral imaging process of the control unit 60 shown in Fig. 7 will be described, and a description of similarities will be omitted.

[0249] After step S100 of receiving the setting of the analysis conditions for spectral imaging, the control unit 60 acquires information on elements contained in the sample S (S101).

[0250] The control unit 60 receives the results of the qualitative analysis of the sample S by XRF (not shown), and Information about the elements contained in the sample S is obtained from the analysis results. The control unit 60 may also receive the results of qualitative analysis of the sample S by the EDS 40 and obtain information about the elements contained in the sample S from the results of the qualitative analysis. Alternatively, the control unit 60 may also receive information about the elements contained in the sample S input by the user via the operation unit 70.

[0251] In step S106 of moving the spectroscopic element 52, the control unit 60 sets the interval for changing the position of the spectroscopic element 52 based on information about the elements contained in the sample S. For example, the control unit 60 identifies the position of a peak specific to the element based on the information about the elements contained in the sample S, and sets the movement interval of the spectroscopic element 52 when measuring the background of the spectrum to be larger than the movement interval when measuring the peak.

[0252] Effects The analysis method according to the third embodiment includes a step of acquiring information about elements contained in the sample S, and in the step of acquiring a plurality of map data, an interval for changing the position of the spectroscopic element 52 is set based on the information about the elements contained in the sample S. Therefore, the analysis method according to the third embodiment can reduce the number of times map analysis is performed. Therefore, the analysis method according to the third embodiment can perform spectral imaging in a short time.

[0253] In the analysis method according to the third embodiment, information on the elements contained in the sample S is obtained by analysis using XRF or EDS. Therefore, in the analysis method according to the third embodiment, information on the elements contained in the sample S can be obtained in a short time.

[0254] In the analytical instrument 100, the control unit 60 performs a process to acquire information about elements contained in the sample, identifies the position of a peak specific to the element in the X-ray spectrum based on the information, and sets the interval for measuring the background of the X-ray spectrum to be larger than the interval for measuring the peak. This allows the analytical instrument 100 to reduce the number of times map analysis is performed. Therefore, the analytical instrument 100 can perform spectral imaging in a short time.

[0255] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0256] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes configurations that are substantially identical to the configurations described in the embodiments. A substantially identical configuration means, for example, a configuration with the same function, method, and result, or a configuration with the same purpose and effect. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments. [Explanation of symbols]

[0257] 10...electron optical system, 12...electron gun, 14...focusing lens, 16...deflector, 18...objective lens, 20...sample stage, 30...electron detector, 40...EDS, 50a...WDS, 50b...WDS, 50c...WDS, 50d...WDS, 50e...WDS, 52...spectroscopic element, 54...X-ray detector, 60...control unit, 70...operation unit, 72...display unit, 74...storage unit, 100...analytical device

Claims

1. An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energies corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while scanning the sample with an electron beam and fixing the position of the spectroscopic element, while changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, correcting a spectral shift caused by a deviation in height of the sample in the X-ray spectrum stored in each pixel of the spectral map; In the step of correcting the spectral shift, the spectral shift is corrected based on information indicating a relationship between the amount of deviation in height of the sample and the amount of spectral shift.

2. In claim 1, obtaining the information; In the step of acquiring the information, irradiating a standard sample with an electron beam without deviation in the height of the sample, detecting X-rays emitted from the standard sample while changing the position of the spectroscopic element, and acquiring a reference spectrum; an analysis in which an electron beam is irradiated onto the standard sample in a state where there is a height deviation of the sample, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element to obtain a comparison spectrum, and the analysis is repeated while changing the amount of deviation in the height of the sample to obtain a plurality of comparison spectra; The method of analysis includes comparing the reference spectrum with each of the comparison spectra to obtain the information.

3. An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer that has a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energy corresponding to the position of the spectroscopic element. So, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while scanning the sample with an electron beam and fixing the position of the spectroscopic element, while changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; a step of comparing the X-ray spectrum stored in each pixel of the spectrum map with a reference spectrum to determine a spectral shift amount; creating a map relating positions on the sample to heights of the sample based on the amount of spectral shift; Analytical methods, including:

4. An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energies corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while scanning the sample with an electron beam and fixing the position of the spectroscopic element, while changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, In the step of acquiring the plurality of map data, the sample is scanned with the electron beam by deflecting the electron beam with a deflector; correcting a spectral shift caused by deflection of an electron beam in the X-ray spectrum stored in each pixel of the spectral map; In the step of correcting the spectral shift, the spectral shift is corrected based on information indicating a relationship between an amount of deflection of an electron beam and an amount of spectral shift.

5. In claim 4, obtaining the information; In the step of acquiring the information, irradiating a standard sample with an electron beam without deflecting the electron beam, detecting X-rays emitted from the standard sample while changing the position of the spectroscopic element, and obtaining a reference spectrum; an analysis in which the standard sample is irradiated with an electron beam while the electron beam is deflected, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element to obtain a comparison spectrum, and this analysis is repeated while changing the deflection amount of the electron beam to obtain a plurality of comparison spectra; The analysis method includes obtaining the information by determining a spectral shift amount of each of the comparison spectra relative to the reference spectrum.

6. An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energies corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while scanning the sample with an electron beam and fixing the position of the spectroscopic element, while changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, In the step of acquiring the plurality of map data, the sample is scanned with the electron beam by deflecting the electron beam with a deflector; a step of correcting a decrease in X-ray intensity caused by deflection of an electron beam in the X-ray spectrum stored in each pixel of the spectrum map; In the step of correcting the decrease in X-ray intensity, the decrease in X-ray intensity is corrected based on information indicating a relationship between an amount of deflection of an electron beam and a rate of decrease in the X-ray intensity.

7. In claim 6, obtaining the information; In the step of acquiring the information, irradiating a standard sample with an electron beam without deflecting the electron beam, detecting X-rays emitted from the standard sample while changing the position of the spectroscopic element, and obtaining a reference spectrum; an analysis in which the standard sample is irradiated with an electron beam while the electron beam is deflected, and X-rays emitted from the standard sample are detected while changing the position of the spectroscopic element to obtain a comparison spectrum, and this analysis is repeated while changing the deflection amount of the electron beam to obtain a plurality of comparison spectra; The analysis method includes comparing the X-ray intensities of the reference spectrum with the X-ray intensities of each of the comparison spectra to obtain the information.

8. An analytical method using an analytical device equipped with a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from a sample and detects X-rays with energies corresponding to the position of the spectroscopic element, a step of acquiring a plurality of map data by repeating a map analysis in which map data is acquired by detecting X-rays of a specific energy while scanning the sample with an electron beam and fixing the position of the spectroscopic element, while changing the position of the spectroscopic element; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; Including, acquiring information about elements contained in the sample, In the step of acquiring the plurality of map data, an interval for changing the position of the light separating element is set based on the information.

9. In claim 8, An analysis method, wherein in the step of acquiring the information, the information is acquired by analysis using an X-ray fluorescence spectrometer or an energy dispersive X-ray spectrometer.

10. In claim 8 or 9, In the step of acquiring the plurality of map data, Identifying the location of peaks specific to the element in the X-ray spectrum based on the information; An analytical method, wherein the interval when measuring the background of the X-ray spectrum is set to be larger than the interval when measuring the characteristic peak.

11. In any one of claims 1 to 9, A plurality of wavelength dispersive X-ray spectrometers are mounted, an analysis method, wherein the step of acquiring the plurality of map data and the step of generating the spectral map are performed for each wavelength dispersive X-ray spectrometer;

12. an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and An analytical device including a storage unit that stores information indicating the relationship between the amount of deviation in height of the sample and the amount of spectrum shift.

13. an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and the electron optical system includes a deflector that deflects an electron beam; An analyzing apparatus including a storage unit that stores information indicating the relationship between the amount of deflection of an electron beam and the amount of spectrum shift.

14. an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and the electron optical system includes a deflector that deflects an electron beam; An analyzing apparatus including a storage unit that stores information indicating the relationship between the amount of deflection of an electron beam and the rate of decrease in X-ray intensity.

15. an electron optical system that irradiates an electron beam onto a sample; a wavelength dispersive X-ray spectrometer having a spectroscopic element that disperses X-rays emitted from the sample and detects X-rays with energies corresponding to the position of the spectroscopic element; a control unit that controls the electron optical system and the wavelength dispersive X-ray spectrometer; Including, The control unit a process of acquiring map data by scanning the sample with an electron beam and detecting X-rays of a specific energy with the spectroscopic element of the wavelength dispersive X-ray spectrometer fixed in position, and repeating this process while changing the position of the spectroscopic element of the wavelength dispersive X-ray spectrometer, thereby acquiring a plurality of map data; generating a spectral map that associates positions on the sample with X-ray spectra based on the plurality of map data; and the control unit performs a process of acquiring information about elements contained in the sample; The control unit sets an interval for changing the position of the spectroscopic element based on the information.

16. In claim 15, The control unit Identifying the location of peaks specific to the element in the X-ray spectrum based on the information; An analytical apparatus in which the interval when measuring the background of the X-ray spectrum is set to be larger than the interval when measuring the characteristic peak.

17. In any one of claims 12 to 16, A plurality of wavelength dispersive X-ray spectrometers are mounted, an analysis apparatus, wherein the process of acquiring the plurality of map data and the process of generating the spectral map are performed for each wavelength dispersive X-ray spectrometer;

Images