Information processing system and phase analysis system

Abstract

To provide an information processing system and a phase analysis system capable of accurately measuring the electromagnetic field of a measurement target even when the structure of the sample changes.SOLUTION: The information processing system and the phase analysis system include: an input unit for inputting the structure distribution of a sample and the first-phase distribution of the electron beam, X-ray, light, or neutron beam that has passed through the sample; a processing unit that calculates the second-phase distribution based on the structure distribution, and based on the first-phase distribution and the second-phase distribution, calculates the electromagnetic field components of the sample; and output unit that outputs the magnetic field components.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an information processing system and a phase analysis system.

Background Art

[0002] An electron microscope is a device that can observe and analyze the structure of substances at the atomic resolution level, and is used in various fields from physical property research to the bio field. In particular, in order to perform observation at the atomic level, a scanning transmission electron microscope that uses an electron beam with a short wavelength by accelerating electrons at an acceleration voltage of 100 kV or more, narrowing the electron beam thinly, scanning the electron beam, and detecting transmitted electrons to obtain an image of the sample is used.

[0003] With the practical application of aberration correctors in recent years, in aberration-corrected electron microscopes, atomic resolution can be obtained even at an acceleration voltage of about 30 kV, and the acceleration voltage of the microscope can be selected according to the observation purpose. An observation method that has attracted attention in recent years in this scanning transmission electron microscope is the differential phase contrast method (see Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the differential phase contrast method, it is difficult to accurately measure the phase change derived from the potential or the phase change derived from the magnetic field that is desired to be measured in a measurement target in which the phase (structural phase) derived from the structure changes due to a change in the sample structure.

[0006] The objective of the present invention is to accurately measure the electromagnetic field of a sample in an information processing system, even when the structure of the sample changes. [Means for solving the problem]

[0007] An information processing system according to one aspect of the present invention is characterized by comprising: an input unit that receives the structural distribution of a sample and a first phase distribution of an electron beam, X-ray, light, or neutron beam transmitted through the sample; a processing unit that calculates a second phase distribution based on the structural distribution and calculates the electromagnetic field component of the sample based on the first phase distribution and the second phase distribution; and an output unit that outputs the magnetic field component. [Effects of the Invention]

[0008] According to one aspect of the present invention, in an information processing system, the electromagnetic field of the object to be measured can be measured with high accuracy even when the structure of the sample changes. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of an example of a differential phase-contrast scanning transmission electron microscope. [Figure 2A] This is a schematic diagram showing the phase change of the electron beam due to the sample. [Figure 2B] This is a schematic diagram showing the differential phase difference. [Figure 3] This is a schematic diagram of the sample. [Figure 4A] This is a schematic diagram of the phase change due to the potential distribution. [Figure 4B] This is a schematic diagram of the phase change due to the average internal potential. [Figure 4C] This is a schematic diagram of the total phase change. [Figure 5] This is a schematic diagram of the phase profile of the phase change due to the potential distribution, the phase change due to the average internal potential, and the total phase change. [Figure 6] This is a schematic diagram of the phase differential profile of the phase change due to the potential distribution, the phase change due to the average internal potential, and the total phase change. [Figure 7]It is a schematic diagram showing a phase analysis system combined with an electron microscope according to Example 1. [Figure 8] It is a schematic diagram of the intensity profile of an ADF image. [Figure 9] It is a schematic diagram showing the profile of the Z signal calculated from the ADF intensity. [Figure 10] It is a schematic diagram showing the relationship between the Z signal and the phase change. [Figure 11] It is a schematic diagram showing the structural phase calculated from the structural information. [Figure 12] It is a schematic diagram showing the derivative of the structural phase calculated from the structural information. [Figure 13] It is a schematic diagram showing the derivative of the phase change due to the potential distribution obtained by removing the structural phase calculated from the structural information from the differential phase obtained by the DPC method. [Figure 14] It is a schematic diagram showing the flow of data analysis. [Figure 15] It is a schematic diagram showing an example of a GUI for data analysis. [Figure 16A] It is a schematic diagram showing a phase analysis system combined with an electron microscope with changeable measurement conditions according to Example 2. [Figure 16B] It is a schematic diagram showing a phase analysis system combined with an electron microscope with changeable measurement conditions according to Example 2. [Figure 16C] It is a schematic diagram showing a phase analysis system combined with an electron microscope with changeable measurement conditions according to Example 2. [Figure 17] It is a schematic diagram showing a phase analysis system combined with an electron microscope having an energy dispersive X-ray spectrometer (EDX) according to Example 3. [Figure 18] It is a schematic diagram showing the flow of data analysis using EDX data as structural information. [Figure 19] It is a schematic diagram showing an interference optical system in the case of measuring the phase of a sample by electron beam holography according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not to be construed as being limited to the embodiments described below. It will be readily apparent to those skilled in the art that the specific configuration can be modified without departing from the spirit or essence of the present invention.

[0011] Furthermore, in the configuration of the invention described below, the same reference numerals may be used in common across different drawings for identical parts or parts having similar functions, and redundant explanations may be omitted.

[0012] First, embodiments of the present invention will be described.

[0013] This invention relates to a phase measurement method for measuring electromagnetic fields, and more particularly to an electron microscope that irradiates a sample with a focused electron beam and scans the electron beam to obtain an image of the sample. It also relates to a microscope device that observes the electromagnetic field information of a sample by detecting and analyzing the transmitted electron beam. Since electromagnetic field measurement can also be performed by phase measurement of synchrotron radiation and neutron beams in addition to electron beams, this invention is also applicable to electromagnetic field measurement methods other than electron beams.

[0014] Figure 1 shows a schematic diagram of differential phase contrast (DPC) scanning transmission electron microscopy.

[0015] The electron wave (electron beam) 2 emitted from the electron source 1 travels as shown in the diagram. The focusing angle of the electron beam 2 is adjusted by the irradiation electron lens 3 and the objective lens 4. A sample 5 is placed between the objective lens 4 and the ADF (Annular Dark Field) magnifying lens 6, and the focused electron beam 2 irradiates the sample 5.

[0016] The electron beam 2 that passes through sample 5 is magnified by the action of the ADF projection lens 6 and the magnifying lens 7, and the electron beam 2 is detected by the detector (camera) 10 on the observation surface 8. When an electromagnetic field is present in sample 5, a phase change φ (rad) of the electron beam occurs at each position, as shown in Figure 2A.

[0017] As a simple explanation, if we consider a sample where the phase change occurs only in the x-direction along the horizontal axis, the differential phase dφ / dx (rad / nm) relative to the x-axis position is shown as in Figure 2B. For example, when observing a magnetic thin film with a saturation magnetization of 2T (thin film sample thickness 50nm), a phase gradient of 0.152 rad / nm occurs. This phase gradient can be correlated to the deflection angle θ of the electron beam affected by the sample using the following equation (Equation 1).

[0018] θ = dφλ / 2π / dx (Equation 1) Here, λ is the wavelength of the electron beam.

[0019] If there is a differential phase difference due to the electromagnetic field effect of sample 5, the position where electrons are detected by detector 10 changes, and a change in the position of the electron beam 12 is detected.

[0020] Figure 3 shows a model diagram of the sample structure and charge distribution assumed to be the model for measurement.

[0021] Sample 5 is composed of material 101 and material 102, and is a sample in which electrons are accumulated between the two materials (interface). In this case, there are two factors that cause the phase of electron beam 2 to change when it passes through sample 5. One is the potential distribution due to electrons accumulated at the interface, and the other is the phase change due to the structure (structural phase) caused by the influence of the mean inner potential (MIP), which changes the phase of the electron wave when it passes through the material. Here, the information that the measurer wants to obtain is the potential distribution generated by charge accumulation at the interface.

[0022] Figure 4A shows the phase change due to the potential distribution generated by electrons accumulated at the interface, Figure 4B shows the phase change due to the average internal potential, and Figure 4C shows the total phase change, which is the sum of these two values.

[0023] Figure 5 shows the phase profiles for the region indicated by the white line in Figure 4, which represents the interface region.

[0024] The phase change due to the potential distribution to be measured is affected by the phase change originating from the structure at the interface, which alters the total phase change. As a result, the profile of the differential value of the phase obtained by the DPC method is as shown in Figure 6.

[0025] The derivative of the phase change due to the potential distribution that we originally wanted to measure is affected by the derivative of the total phase change actually measured by DPC, which is influenced by the derivative of the phase change due to the structure, which varies depending on the average internal potential of the material.

[0026] Therefore, with conventional methods, if there was a change in the sample structure, the measurement would be affected by the phase change caused by the structural change, making it impossible to measure the potential that was to be measured.

[0027] Figure 3 illustrates a model where the sample thickness is constant. However, even with the same material, if the sample thickness changes, the phase change due to the structure increases in proportion to the thickness, which still interferes with the measurement of the potential that we want to measure. Therefore, the structural changes we are concerned with here are structural changes that alter the phase change due to the structure, such as changes in the composition, thickness, and density of the sample.

[0028] As explained above, the influence of phase changes originating from the sample structure on potential measurements is discussed, but a similar problem occurs in magnetic field measurements. Since the phase changes due to the magnetic field are superimposed on the phase changes originating from the structure, if there are phase changes due to the structure in the observation area, magnetic field information cannot be obtained directly from the measurement results.

[0029] As described above, with conventional methods, it has been difficult to accurately measure the phase change originating from the potential or the phase change originating from the magnetic field in measurement targets where the phase originating from the structure (structural phase) changes due to changes in the sample structure.

[0030] Therefore, in an embodiment of the present invention, a microscopy method is provided that allows for accurate measurement of the electromagnetic field of a sample even when the structure of the sample changes, when observing the electromagnetic field of the sample using a scanning transmission electron microscope.

[0031] Here, with reference to Figure 19, an example of an information processing system according to an embodiment of the present invention will be described.

[0032] Figure 19 shows the interference optical system used when measuring the phase of a sample by electron holography.

[0033] In this embodiment, the electron beam phase measurement and the ADF measurement for analyzing the phase originating from the structure, as shown in Figure 19, are performed under different optical conditions. The phase measurement and ADF measurement may also be performed using separate devices.

[0034] The electron wave (electron beam) 2 emitted from the electron source 1 travels as shown in the figure. The current density is adjusted by the first irradiation electron lens 3 and the second irradiation electron lens 80, and the sample 5 is placed on one side of the optical axis between the second irradiation electron lens 80 and the objective lens 4, and the sample 5 is irradiated with the electron beam.

[0035] The image obtained by the action of the objective lens is magnified by the magnifying lens 7, and the electron wave 81 that passes through the first region (sample) on the sample surface 9 and the electron wave 82 that passes through the second region on the object surface are bent inward by the electron beam biprism 15 of the imaging system, superimposed and interfere on the observation surface 8, and interference fringes (hereinafter also called holograms) are detected.

[0036] The resulting hologram is reconstructed to determine the changes in electron waves caused by sample 5. The electron wave 81 that passed through the first region, reflecting the information of sample 5, is the object wave 81, and the electron wave 82 that passed through the second region is the reference wave 82.

[0037] The electron beam biprism 15 has the function of deflecting electron waves passing on either side of the electrode filament inward or outward with respect to the optical axis by an electric field generated between the filament electrode and the parallel plate, which is created by applying a potential to the electrode filament.

[0038] The electron beam measurement by the electron source 1 and camera 10 is controlled by a control system 38 connected to a control personal computer (control PC) 34. The control PC 34 has a typical computer configuration, including interconnected processing units such as a central processing unit (CPU), memory, and input / output interface units. The control PC 34 is connected to a monitor 35.

[0039] As described above, in Figure 5, the phase change due to the potential distribution that we originally wanted to measure is affected by the phase change originating from the structure at the interface, which alters the total phase change.

[0040] Therefore, in the embodiment of the present invention, the phase change due to the potential distribution to be measured is obtained by performing a calculation that subtracts the phase change due to the structure from the total phase change. This calculation is performed by the control PC34 which constitutes the information processing system shown in Figure 19.

[0041] Furthermore, in Figure 6, the derivative of the phase change due to the potential distribution that we originally wanted to measure is affected by the derivative of the total phase change actually measured by DPC, which is influenced by the derivative of the phase change due to the structure, which differs depending on the average internal potential of the material.

[0042] Therefore, in the embodiment of the present invention, by performing a calculation to remove the derivative of the phase change due to the structure, which differs depending on the material, from the derivative of the total phase change measured by the DPC, the derivative of the phase change due to the potential distribution that is originally intended to be measured is obtained. This calculation is performed by the control PC34 which constitutes the information processing system shown in Figure 19.

[0043] As described above, the information processing system of the embodiment of the present invention includes an input unit that receives the structural distribution of the sample 5 and the first phase distribution of the electron beam 2 that has passed through the sample 5 (the total phase change in Figure 5), a processing unit that calculates a second phase distribution (the phase change originating from the structure in Figure 6) based on the structural distribution and calculates the electromagnetic field component of the sample 5 (the phase change due to the potential distribution to be measured in Figure 5) based on the first and second phase distributions, and an output unit that outputs the magnetic field component.

[0044] Here, the processing unit consists of the central processing unit (CPU) of the control PC34, and the input and output units consist of the input / output interface unit of the control PC34.

[0045] Furthermore, the information processing system of the embodiment of the present invention is applicable to the structural distribution of a sample and to X-rays, light, or neutron beams other than electron beams that have passed through the sample.

[0046] Furthermore, the processing unit calculates the phase change due to the average internal potential of the sample 5, which originates from the structural distribution, as the second phase distribution, and calculates the third phase distribution, which is the phase change due to the potential distribution of the sample 5, as the electromagnetic field component. Then, the processing unit calculates the third phase distribution by subtracting the second phase distribution from the first phase distribution.

[0047] Furthermore, the processing unit calculates the first derivative of the first phase distribution (the derivative of the total phase change actually measured by the DPC in Figure 6) and the second derivative of the second phase distribution (the derivative of the phase change due to the structure based on the average internal potential in Figure 6). Based on the first and second derivatives, it calculates the third derivative of the third phase distribution (the derivative of the phase change due to the potential distribution that is originally to be measured in Figure 6), and calculates the electromagnetic field component of the sample based on the third derivative. Specifically, the third derivative is calculated by dividing the first derivative by the second derivative.

[0048] According to embodiments of the present invention, in an information processing system, the electromagnetic field of the object to be measured can be measured with high accuracy even when the structure of the sample changes.

[0049] The following describes an example using drawings. [Examples]

[0050] Embodiment 1 of the electron microscope of the present invention will be described with reference to Figure 7. Figure 7 is a diagram showing one configuration of Embodiment 1, which combines an electron microscope and a phase analysis system in differential phase difference measurement using a scanning transmission electron microscope. The principle configuration described below can also be applied to electron microscopes and phase analysis systems of other embodiments.

[0051] In Figure 7, electron source 1 is located at the upstream end of the direction of electron wave (electron beam) 2 flow. Voltages are applied to the first extraction electrode, second extraction electrode, and accelerating electrode, and the electron wave emitted from electron source 1 is accelerated and focused to the first electron source 11. In this specification, the first extraction electrode, second extraction electrode, and accelerating electrode are collectively defined as the accelerating tube 73. By controlling the applied voltage, the wavelength of electron beam 2 changes, and its trajectory also changes. Therefore, the first electron source 11 in electron optics is depicted again in the figure.

[0052] In this configuration, although an aperture is not shown between the accelerating tube 73 and the sample 6 in Figure 7, the use of an aperture to adjust the electron wave irradiation area to the sample 5 is the same as in a general microscope, so it is omitted from the illustration here. Also, although only one irradiation electron lens 3 is shown, the use of two or more irradiation electron lenses to adjust the electron beam irradiation conditions to the sample 6 is also the same as in a general microscope, so it is omitted from the illustration here.

[0053] The electron beam is focused by the objective lens 4 and irradiated onto the sample. The electron beam 2 is scanned in the in-plane direction at the sample position by the scanning coil 32. The electron beam that has passed through the sample 6 is magnified or reduced by the ADF projection lens 6 and the magnifying lens 7, and the electron beam 2 is detected by the camera 10 installed on the observation surface 8. Differential phase contrast (DPC) information is obtained from the change in electron position 12. On the other hand, scattered electrons 40 scattered by the sample 5 are magnified or reduced by the ADF projection lens 6 and detected by the annular detector 41.

[0054] Figure 8 shows a schematic diagram of the ADF intensity profile obtained for the model sample shown in Figure 3.

[0055] The ADF intensity is given as the sum of the ADF intensity profiles of material M1 and material M2. The image intensity I of the ADF is given by the following equation 2.

[0056] I ∝ Z 2 (Formula 2) Here, Z is the atomic number of the sample. Since the contrast of the ADF image is proportional to the square of Z, 2 This is sometimes called contrast or Z contrast. Depending on the sample and measurement conditions, it may not be perfectly proportional to the square of Z.

[0057] Next, Figure 9 shows the Z signal calculated from the ADF intensity using (Equation 2). The Z signals originating from M1 and M2 are obtained as a sum.

[0058] Furthermore, by utilizing Figure 10, which shows the relationship between the Z signal and phase change, it is possible to obtain the structure-derived phase change (Figure 11) from the Z signal. While there are methods to calculate the relationship between the Z signal and phase change using theoretical simulations, considering that it may vary slightly depending on experimental conditions, it is considered more useful to experimentally determine the relationship using standard samples.

[0059] Figure 12 shows the results of differentiating the structure-derived phase change obtained through stepwise calculations based on the ADF strength.

[0060] Finally, as shown in Figure 13, by subtracting the differential value of the phase change due to the structure, calculated from the structural information, from the measurement result (derivative of the total phase) obtained by the DPC method, the differential value of the phase change due to the potential distribution that we originally wanted to measure can be obtained. Once the differential value is obtained, the phase distribution can be obtained by integrating that value.

[0061] Up to this point, we have explained using a one-dimensional profile, but by performing the same analysis in the x and y directions, we can obtain a two-dimensional image of the differential value of the phase change due to the potential distribution.

[0062] This type of analysis can be performed even when the measurement target is a magnetic field distribution. By removing the differential value of the phase change originating from the sample structure, which can be calculated based on the ADF intensity, from the DPC measurement results, the differential value of the phase change originating from the magnetic field can be obtained. Similar to electric potential, the distribution of the magnetic field phase can be obtained by integrating the phase differential value.

[0063] To explain the measurement system, Figure 7 will be used to describe the electron beam deflection.

[0064] The electron beam 2 is scanned using the scanning coil 32 to scan the electron beam on the sample surface. However, it is necessary to adjust the camera 10 so that the position of the electron beam 2 does not change when there is no differential phase difference (electron beam deflection) due to the sample 5. If this adjustment is not achieved, the electron beam position at the camera 10 will change due to the action of the scanning coil 32, resulting in a differential phase difference image of artifacts that are not information from the sample 5. Therefore, by linking the operation of the reversal coil 33 with the scanning coil 32, it is possible to achieve a state in which the position of the electron beam at the camera 10 does not change even when the electron beam 2 is scanned on the sample surface using the scanning coil 32.

[0065] Specifically, without the sample 5 present, the scanning coil 32 is moved by a fixed amount, and the current flowing through the deflection coil 33 is calibrated so that the position of the electron beam 2 in the camera 10 does not change during this movement. This allows the ratio of the control current of the scanning coil 32 to that of the deflection coil 33 for proper deflection to be determined, and by coordinating the scanning coil 32 and the deflection coil 33 according to this control current ratio and scanning the electron beam, high-precision measurements can be achieved.

[0066] In the electron microscope shown in Figure 7, the applied voltage to each electron source 1 and accelerating tube 73, the excitation state of the sample fine-movement mechanism 36 and electron lens, the control of the current flowing through the scanning coil 32 and recoil coil 33, and the measurement of the electron beam by the camera 10 are all controlled by a control system 38 connected to a control personal computer (PC) 34.

[0067] In actual electron microscopes, in addition to what is shown in this schematic diagram, there are also deflection systems that change the direction of electron beam propagation and aperture mechanisms that limit the area through which the electron beam passes. These elements are also controlled by a control system 38 connected to a control PC 34. However, these devices are not directly related to the electron microscope disclosed herein and are therefore omitted from this diagram.

[0068] The control PC 34 has a standard computer configuration, including interconnected processing units such as a Central Processing Unit (CPU), memory, and an input / output interface. In this specification, these control PC 34 and control system 38, which control the device, may be collectively referred to as the device's control unit. The control PC 34 is connected to the monitor 35.

[0069] Furthermore, as shown in this schematic diagram, the electron-optical elements are assembled in the electron microscope body 74, which is a vacuum chamber, and are continuously evacuated by a vacuum pump. Vacuum systems other than those near the sample chamber are not directly related to the electron microscope of the present invention, so they are not shown or described.

[0070] Figure 14 shows the data analysis flow.

[0071] First, read the DPC data and ADF data (step 141). At this time, the data can be acquired simultaneously, or they can be acquired at different times or by different devices.

[0072] Next, the calculation parameters (relationship between ADF intensity and structural phase) are read, and the structural phase distribution is calculated from the ADF intensity (step 142). Then, the structural phase derivative is calculated from the structural phase distribution (step 143).

[0073] Next, the structural phase derivative is divided by the DPC result (step 144). This gives the derivative of the phase change due to the electromagnetic field distribution (step 145). The phase image is obtained by integrating the derivative of the phase.

[0074] Figure 15 shows an example of a schematic diagram of a GUI for performing data analysis.

[0075] The software includes buttons for selecting DPC data and structural data (ADF intensity data), for selecting structural phase calculation parameters, for executing calculations to calculate the structural phase derivative, for executing a process to remove the structural phase derivative from the DPC data, for displaying or saving the derivative of the phase change due to the structural distribution, and for displaying or saving the derivative of the phase change due to the electromagnetic field distribution.

[0076] Regarding the save button, the ability to set the save location and file name is a standard feature, so we will omit further explanation here.

[0077] According to the phase analysis system and electron microscope configuration of this embodiment 1, in a measurement target where the phase originating from the structure (structural phase) changes due to changes in the sample structure, it becomes possible to accurately obtain the phase change originating from the potential or the phase change originating from the magnetic field that you wish to measure.

[0078] The problem of being unable to accurately measure the phase due to electromagnetic fields due to phase changes originating from the structure is also a problem in measurement methods using electron holography, synchrotron radiation, and neutron beams. By utilizing the present invention, it becomes possible to remove the phase changes originating from the structure from structural information acquired simultaneously or by a separate device. As this combination is an easily inferred application method, further detailed explanation will be omitted.

[0079] This will enable high-precision measurement of potential distributions in semiconductor devices composed of multiple materials, for example. Furthermore, even in high-resolution observations, it will be possible to separate structural information from electromagnetic field information by simulating or experimentally determining the relationship between ADF intensity and phase change. This is expected to lead to applications such as direct observation of potential distributions originating from interatomic bonds at atomic level resolution, and direct observation of magnetic moments at atomic resolution.

[0080] These atomic-level electromagnetic field measurements are attracting considerable attention these days and are expected to contribute to the innovation of various energy conversion materials, fuel cells, lithium-ion batteries, artificial photosynthesis catalysts, and other materials aimed at achieving carbon neutrality, as well as to the elucidation of degradation mechanisms for optimizing their control. [Examples]

[0081] Figure 16 is a schematic diagram of the phase analysis system of Example 2 combined with an electron microscope with adjustable measurement conditions. Since the configuration of this example is similar to that of Example 1, the description of the same parts as in Example 1 will be omitted, and only the differences in the apparatus configuration will be described.

[0082] The system includes a first ADF projection lens 6a and a second ADF projection lens 6b between the sample 5 and the annular detector 41, and a first magnifying lens 7a and a second magnifying lens 7b between the annular detector 41 and the camera 8.

[0083] By adjusting the action of the first magnifying lens 7a and the second magnifying lens 7b, the camera length projected onto the camera 10 can be increased while maintaining the angular range of electrons scattered from the sample 5 detected by the annular detector 41 under the measurement conditions shown in Figure 16A. This reduces the angle of the irradiated electron beam and improves the phase sensitivity to the electromagnetic field (see Figure 16B).

[0084] Furthermore, by adjusting the actions of the ADF projection lens 6a and the second ADF projection lens 6b, and the first magnifying lens 7a and the second magnifying lens 7b, it is possible to change the angular range of electrons scattered from the sample detected by the annular detector 41 while maintaining the camera length projected onto the camera 10 (see Figure 16C).

[0085] By combining these functions, the angular range of electrons scattered from the sample 5 detected by the annular detector 41 and the camera length projected onto the camera 10 can be freely adjusted, making it possible to optimize the measurement conditions to suit the object being measured.

[0086] The essence of this second embodiment is the combination of a phase analysis system with an electron microscope whose measurement conditions can be changed, and is not limited to the configuration shown in Figure 7, including the number of ADF projection lenses and magnifying lenses. [Examples]

[0087] Figure 17 is a schematic diagram showing the phase analysis system of Example 3, which combines an energy-dispersive X-ray spectrometer (EDX) with an electron microscope.

[0088] This third embodiment is a phase analysis system that takes advantage of the characteristic of focusing the electron beam 2 onto the sample 5 and combines it with various measurements and elemental analyses. By including an energy-dispersive X-ray spectrometer 42, elemental analysis of the sample 5 becomes possible.

[0089] By separately simulating or experimentally determining the relationship between EDX intensity and phase change, it is possible to calculate the phase change originating from the electron beam structure from the structural information obtained from the EDX data. Other processing steps are similar to those in Example 1, so they are omitted from this explanation.

[0090] Figure 18 shows a schematic diagram illustrating the data analysis flow that utilizes EDX data as structural information. The essential part is the replacement of the ADF intensity in Example 1 with the EDX result.

[0091] First, read the DPC data and EDX data (step 181). At this time, the data can be acquired simultaneously, or it can be acquired at different times or by different devices.

[0092] Next, the calculation parameters (relationship between EDX intensity and structural phase) are read, and the structural phase distribution is calculated from the EDX result (EDX intensity) (step 182). Then, the structural phase derivative is calculated from the structural phase distribution (step 183).

[0093] Next, the structural phase derivative is divided by the DPC result (step 184). This gives the derivative of the phase change due to the electromagnetic field distribution (step 185). The phase image is obtained by integrating the derivative of the phase.

[0094] According to the phase analysis system and electron microscope configuration of this embodiment 3, in a measurement target where the phase originating from the structure (structural phase) changes due to changes in the sample structure, it becomes possible to accurately obtain the phase change originating from the potential or the phase change originating from the magnetic field that you wish to measure.

[0095] In addition, measurements combining optical properties using a cathodoluminescence detector, which are not shown in Figure 17, can also be inferred. Simultaneous acquisition of these various analytical results and phase differential images is extremely useful for a more detailed understanding of the sample.

[0096] The essence of this embodiment is a phase analysis system combined with an electron microscope having an energy-dispersive X-ray spectrometer (EDX) 42, and is not limited to the configuration shown in Figure 17. It is also possible to perform measurements by combining the energy-dispersive X-ray spectrometer (EDX) 42 with an annular detector 41.

[0097] In the above embodiment, an electron beam is focused onto a sample, irradiated, and scanned. A DPC image is obtained by detecting the differential phase of the electron beam, which has been altered by the sample's electromagnetic field. This DPC image, along with structural information acquired simultaneously or at a different time using a different device, is used to calculate the structural phase from the structural information and remove the influence of the structure from the DPC data. This provides an analysis system that can obtain the distribution information of the electromagnetic field to be measured.

[0098] According to the above embodiment, in a measurement target where the phase originating from the structure (structural phase) changes due to a change in the sample structure, it is possible to obtain the phase change originating from the potential or the phase change originating from the magnetic field that you want to measure.

[0099] The phase analysis system of the present invention described above has been put into practical use as a high-precision electromagnetic field measurement system. By implementing the present invention in a novel system, it will be possible to observe electromagnetic fields in devices with complex structures and observe electromagnetic fields at the atomic level with higher sensitivity.

[0100] The new observation capabilities enabled by the novel system utilizing this invention are expected to contribute to the development of high-performance, highly durable fuel cells and CO2 fuel catalysts, which are necessary for realizing a carbon-neutral society that is required globally in the future, for example, by elucidating the mechanism of catalysts. [Explanation of Symbols]

[0101] 1 electron source 2 Electron waves 3. Electron-irradiated lens 4. Objective lens 5 samples 6 ADF projection lenses 6a First ADF projection lens 6b Second ADF projection lens 7 Magnifying lens 7a First magnifying lens 7b Second magnifying lens 8 Observation surface 9. Sample surface 10 Cameras 11 First electron source 12 Changes in the position of the electron beam 15 Electron beam biprism 32 scanning coils 33 Reversal coil 34 Control PC 35 monitors 38 Control Systems 36 Sample micro-movement mechanism 40 Scattered electrons 41 Circular detector 42 Energy-dispersive X-ray spectrometer 73 Accelerator tube 74 Electron microscope main unit 101 Substance 1 102 Substance 2 80 Second irradiated electron lens 81 Electron wave (object wave) that passed through the first region (sample) 82. Electron wave (reference wave) that has passed through a second region on the surface of an object.

Claims

1. An input unit into which the structural distribution of the sample and the first phase distribution of the electron beam, X-ray, light, or neutron beam that has passed through the sample are input, A processing unit that calculates a second phase distribution based on the structural distribution and calculates the electromagnetic field component of the sample based on the first phase distribution and the second phase distribution, An output unit that outputs the aforementioned electromagnetic field component, It has, The aforementioned processing unit, As the second phase distribution, the phase change due to the average internal potential of the sample derived from the structural distribution is calculated, As the electromagnetic field component, a third phase distribution, which is the phase change due to the potential distribution of the sample, is calculated. The aforementioned processing unit, The third phase distribution is calculated by subtracting the second phase distribution from the first phase distribution. The structural distribution of the aforementioned sample is An information processing system characterized by including a distribution relating to the composition, thickness, or density of the aforementioned sample.

2. The aforementioned processing unit, The first derivative of the first phase distribution and the second derivative of the second phase distribution are calculated, Based on the first derivative and the second derivative, the third derivative of the third phase distribution is calculated. The information processing system according to claim 1, characterized in that it calculates the electromagnetic field component of the sample based on the third derivative value.

3. A phase analysis system comprising an electron microscope and a control device for controlling the electron microscope, The aforementioned electron microscope, An electron source that irradiates the sample with an electron beam, A ring-shaped detector that detects scattered electrons scattered by the aforementioned sample and outputs ADF data, The detector includes an electron beam that has passed through the sample and outputs DPC data, The control device is Based on the ADF data, the structural phase distribution of the sample is calculated. Based on the aforementioned structural phase distribution, the structural phase derivative is calculated, The differential value of the electromagnetic field phase distribution is calculated by dividing the structural phase differential value by the DPC data. The structural phase distribution of the sample is A phase analysis system characterized by including a distribution relating to the composition, thickness, or density of the aforementioned sample.

4. The control device is The phase analysis system according to claim 3, characterized in that it generates a phase image or a differential phase difference image based on the differential value of the electromagnetic field phase distribution.

5. The phase analysis system according to claim 3, characterized in that the detection conditions of the electron beam by the detector and the annular detector can be changed.

6. The phase analysis system according to claim 3, characterized in that the structural phase distribution of the sample is obtained using the signal obtained by the annular detector.

7. The device further comprises a display screen, The aforementioned display device is A selection button for selecting the DPC data and the ADF data, A calculation execution button for performing the calculation of the structural phase derivative value, A removal execution button for performing the removal of the aforementioned structural phase differential value, Display buttons for displaying the structural phase derivative value and the electromagnetic field phase distribution derivative value are displayed on the display screen, respectively. The control device is The phase analysis system according to claim 3, characterized in that it calculates the structural phase distribution, the structural phase derivative, and the derivative of the electromagnetic field phase distribution, respectively, in response to the operation of the selection button, the calculation execution button, the removal execution button, and the display button.

8. A phase analysis system comprising an electron microscope and a control device for controlling the electron microscope, The aforementioned electron microscope, An electron source that irradiates the sample with an electron beam, An energy-dispersive X-ray spectrometer that outputs EDX data, The detector includes an electron beam that has passed through the sample and outputs DPC data, The control device is Based on the EDX data, the structural phase distribution of the sample is calculated. Based on the aforementioned structural phase distribution, the structural phase derivative is calculated, The derivative of the potential distribution is calculated by dividing the structural phase derivative from the DPC data. The structural phase distribution of the sample is A phase analysis system characterized by including a distribution relating to the composition, thickness, or density of the aforementioned sample.

9. The control device is The phase analysis system according to claim 8, characterized in that it generates a phase image or a differential phase difference image based on the differential value of the potential distribution.

10. The phase analysis system according to claim 8, characterized in that the structural phase distribution of the sample is obtained using the signal obtained by the energy-dispersive X-ray spectroscopy.

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