An electron microscope imaging method

Abstract

An embodiment of the present specification provides an electron microscope imaging method, the method comprising: placing a sample holder carrying at least two samples at an imaging position of the electron microscope, the at least two samples comprising a first sample and at least one second sample; adjusting imaging parameters of the electron microscope based on the first sample; and performing imaging operations on the at least one second sample based on the imaging parameters.

Description

Technical Field

[0001] The present invention relates to the field of electronic imaging technology, and in particular to an electron microscope imaging method. Background Art

[0002] With the development of electron microscopy technology, more and more types of samples can be observed and imaged at high magnification and high resolution through electron microscopes (for example, spherical aberration corrected transmission electron microscopes), providing more references for in-depth research on the composition and structure of various substances. However, electron microscopes have very high requirements for imaging states. Once the imaging parameters are not properly debugged, the imaging effect is directly affected. It is usually necessary to debug the imaging state through standard samples. After the debugging is completed, the standard samples are taken out and placed in the sample to be imaged for observation and imaging. However, the imaging state of the electron microscope is often unstable. In the process of taking and placing samples, the debugged imaging parameters are easy to change, affecting the imaging effect. In addition, a good imaging state cannot be maintained for a long time, and changes in the imaging state may also occur during the imaging process. At this time, the standard sample needs to be re-inserted for debugging, which affects the imaging efficiency and imaging effect. Therefore, it is necessary to provide an electron microscope imaging method to improve imaging efficiency and imaging effect. Summary of the invention

[0003] An embodiment of the present specification provides an electron microscope imaging method, the method comprising: placing a sample holder carrying at least two samples at an imaging position of the electron microscope, the at least two samples comprising a first sample and at least one second sample; adjusting imaging parameters of the electron microscope based on the first sample; and performing imaging operations on the at least one second sample based on the imaging parameters.

[0004] In some embodiments, the first sample is a standard sample.

[0005] In some embodiments, the distance between the first sample and the adjacent second sample is less than a first distance threshold.

[0006] In some embodiments, a distance between adjacent second samples in the at least one second sample is less than a second distance threshold.

[0007] In some embodiments, the at least two samples are evenly distributed on the sample holder.

[0008] In some embodiments, the at least one second sample is different in type or sample parameter.

[0009] In some embodiments, the imaging parameters include at least one of spherical aberration, coma, astigmatism, distortion or chromatic aberration.

[0010] In some embodiments, performing the imaging operation on the at least one second sample based on the imaging parameters includes: setting imaging conditions corresponding to the at least one second sample respectively; and performing the imaging operation on the at least one second sample in sequence based on the imaging conditions.

[0011] In some embodiments, the imaging conditions include at least one of the current size, heating temperature, convergence angle, collection angle, acquisition time, imaging magnification or imaging resolution of the electron beam.

[0012] In some embodiments, the method further includes: determining at least one target image corresponding to each of the at least one second sample based on the imaging operation result; and dynamically displaying the at least one target image.

[0013] In the embodiment of the present specification, a sample holder carrying at least two samples (including a first sample and at least one second sample) is placed in the imaging position of the electron microscope, the imaging parameters of the electron microscope are adjusted based on the first sample (for example, the standard sample), and then the imaging operation is performed on at least one second sample (for example, the sample to be imaged) based on the adjusted imaging parameters. The standard sample and the sample to be imaged are placed in the electron microscope at the same time, and the imaging parameters are adjusted based on the standard sample. After the adjustment, only a slight adjustment is made to the sample holder (for example, the sample holder is slightly moved), and the imaging operation of the sample to be imaged can be realized, and there is no need to take out the standard sample and then put it in the sample to be imaged, which not only improves the imaging efficiency, but also avoids the disturbance of the imaging parameters during the sample replacement process, and improves the imaging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0015] Figure 1 is a flow chart of an exemplary electron microscope imaging method according to some embodiments of the present specification.

[0016] Figure 2 is a schematic diagram of an exemplary electron microscope sample holder and sample holder according to some embodiments of the present specification.

[0017] Figures 3A-3C is a schematic diagram of exemplary sample distribution according to some embodiments of the present specification.

[0018] Figure 4A and Figure 4B is a spherical aberration corrected transmission electron microscope image of the antimony two-dimensional material shown in some embodiments of the present specification. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0020] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0021] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0022] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0023] Figure 1 is a flowchart of an exemplary electron microscope imaging method according to some embodiments of the present specification. In some embodiments, process 100 can be automatically executed by a control system. For example, process 100 can be implemented by a control instruction, and the control system controls each component to complete each operation of process 100 based on the control instruction. In some embodiments, process 100 can be semi-automatically executed. For example, one or more operations of process 100 can be manually performed by an operator. In some embodiments, when completing process 100, one or more additional operations not described above can be added, and / or one or more operations discussed herein can be deleted. In addition, Figure 1 The order of operations shown in is not limiting. Figure 1 As shown, process 100 may include the following steps.

[0024] In step 110 , a sample holder carrying at least two samples is placed at an imaging position of an electron microscope.

[0025] In some embodiments, the electron microscope may include a transmission electron microscope, a spherical aberration corrected transmission electron microscope, a chromatic aberration corrected transmission electron microscope, a scanning electron microscope, the like, or any combination thereof.

[0026] In some embodiments, a sample holder (e.g., Figure 2 The sample holder 20 shown is placed on a sample rod (e.g. Figure 2 The front end of the transmission electron microscope sample holder 10 shown (eg, Figure 2 11) as shown, and place the sample holder in the imaging position within the electron microscope.

[0027] In some embodiments, the sample holder may include a copper mesh, a gold mesh, a nickel mesh, a molybdenum mesh, etc. or any combination thereof.

[0028] In some embodiments, the at least two samples may include a first sample and at least one second sample.

[0029] In some embodiments, the first sample may be a standard sample. In some embodiments, the standard sample may include a cross grating gold standard, a strontium titanate standard, etc. In some embodiments, the first sample may be used to adjust or debug an imaging state or imaging parameter of an electron microscope.

[0030] In some embodiments, the second sample may be a sample to be imaged, such as antimony two-dimensional material, molybdenum disulfide, platinum-nickel alloy, bismuth ferrite, etc., which may be determined according to actual needs.

[0031] In some embodiments, the type or sample parameters of at least one second sample may be different from each other or at least partially different. In some embodiments, the type of sample may reflect the morphology, material, constituent elements, etc. of the sample. In some embodiments, the sample parameters may reflect the properties, size, preparation or synthesis conditions, etc. of the sample. For example, at least one second sample may include a nanowire sample, a nanosheet sample, a nanotube sample, etc. For another example, at least one second sample may include copper, platinum, molybdenum, etc. For another example, at least one second sample may include multiple samples with different synthesis times. For another example, at least one second sample may include multiple samples prepared at different heating temperatures.

[0032] In some embodiments, the type or sample parameters of the at least one second sample may be different. For example, the at least one second sample may be a plurality of samples having the same material and / or substantially the same thickness.

[0033] In some embodiments, at least two samples can be evenly distributed on the sample holder. For more information about at least two samples, see Figures 3A-3C , I will not go into details here.

[0034] At step 120 , imaging parameters of the electron microscope are adjusted based on the first sample.

[0035] In some embodiments, the imaging parameters of the electron microscope may include imaging parameters including spherical aberration, coma, astigmatism, distortion, chromatic aberration, etc. or any combination thereof.

[0036] In some embodiments, the imaging parameters can be adjusted by an automatic debugging system of the electron microscope. In some embodiments, the imaging parameters can be adjusted manually.

[0037] At step 130, an imaging operation is performed on at least one second sample based on the imaging parameters.

[0038] In some embodiments, after adjusting the imaging parameters based on a first sample (eg, a standard sample), the sample holder may be slightly moved, and then an imaging operation may be performed on a second sample.

[0039] In some embodiments, the sample holder 20 may be moved by moving the sample holder 10. For example, the sample holder 10 may be rotated or translated to move the sample holder 20.

[0040] In some embodiments, imaging conditions corresponding to at least one second sample may be set, and imaging operations may be performed on the at least one second sample in sequence based on the corresponding imaging conditions.

[0041] In some embodiments, the imaging conditions may include the current size of the electron beam, the heating temperature, the convergence angle, the collection angle, the acquisition time, the imaging magnification, the imaging resolution, etc. or any combination thereof.

[0042] As an example, assuming that there are five second samples of the same type and / or sample parameters, the electron beam current sizes corresponding to the five second samples can be set (for example, A1, A2, A3, A4 and A5, respectively), and then the five second samples are imaged with the corresponding electron beam current sizes in sequence. Accordingly, images corresponding to the five electron beam current sizes can be obtained. Furthermore, the influence of the electron beam current size on the sample can be studied by analyzing the image information.

[0043] As another example, still assuming that there are 5 second samples of the same type and / or sample parameters, the heating temperatures corresponding to the 5 second samples can be set (for example, T1, T2, T3, T4 and T5, respectively), and then the 5 second samples are heated at the corresponding heating temperatures in turn while performing imaging operations. Accordingly, images corresponding to the 5 heating temperatures can be obtained. Then, the effect of the heating temperature on the sample can be studied by analyzing the image information. It should be noted that in a transmission electron microscope, different positions of the sample heating stage can achieve different heating temperatures (for example, high edge heating temperature and low center heating temperature), and the sample heating stage can move synchronously with the sample holder, so heating and imaging can be achieved simultaneously.

[0044] As another example, assuming that there are 5 second samples of different types and / or sample parameters, the imaging operation can be performed on the 5 second samples in sequence with the same electron beam current. Accordingly, images corresponding to the 5 samples of different types and / or sample parameters can be obtained. Furthermore, by analyzing the image information, the influence of a specific electron beam current on different samples can be studied.

[0045] In some embodiments, after performing an imaging operation on at least one second sample, at least one target image corresponding to the at least one second sample can be determined based on the imaging operation result (for example, the images corresponding to the five electron beam current sizes described above). Further, at least one target image can be dynamically displayed. For example, five target images can be dynamically displayed in order from small to large according to the size of the electron beam current.

[0046] In some embodiments, at least one target image can be displayed by a display device (e.g., a display screen) of the electron microscope. In some embodiments, at least one target image can be displayed by any display device, and this specification does not limit this.

[0047] By dynamically displaying at least one target image, the effects of different imaging conditions on the sample can be clearly seen dynamically, facilitating subsequent further analysis or research.

[0048] It should be noted that the above description of the process 100 is only for example and illustration, and does not limit the scope of application of the present application. For those skilled in the art, various modifications and changes can be made to the process 100 under the guidance of the present application. However, these modifications and changes are still within the scope of the present application.

[0049] Figures 3A-3C is a schematic diagram of exemplary sample distribution according to some embodiments of the present specification.

[0050] like Figure 3AAs shown, the at least two samples include a first sample 1 and a second sample 2, which are respectively distributed on both sides of the sample holder.

[0051] like Figure 3B As shown, the at least two samples include a first sample 1 and second samples 2-1, 2-2 and 2-3, and the four samples are evenly distributed along the circumferential direction of the sample holder.

[0052] like Figure 3C As shown, the at least two samples include a first sample 1 and second samples 2-1, 2-2, 2-3, 2-4, 2-5, 2-6 and 2-7, and the eight samples are evenly distributed along the circumferential direction of the sample holder.

[0053] It should be noted that the above distribution forms are only examples and do not constitute a limitation. The at least two samples may also be distributed on the sample holder in other forms.

[0054] In some embodiments, combined with the above, after completing the debugging of imaging parameters based on the first sample, it is necessary to move the sample holder to perform the imaging operation of the second sample. In order to minimize the movement of the sample holder and thus minimize the disturbance to the imaging state or imaging parameters, the distance between the first sample and the adjacent second sample must be less than the first distance threshold.

[0055] In some embodiments, the first distance threshold may be 0.6 mm-0.1 mm. In some embodiments, the first distance threshold may be 0.55 mm-0.15 mm. In some embodiments, the first distance threshold may be 0.5 mm-0.2 mm. In some embodiments, the first distance threshold may be 0.45 mm-0.25 mm. In some embodiments, the first distance threshold may be 0.4 mm-0.3 mm. In some embodiments, the first distance threshold may be 0.35 mm.

[0056] In some embodiments, combined with the above, when imaging operations are required for multiple second samples, the sample holder needs to be moved accordingly. In order to minimize the movement of the sample holder, thereby minimizing the disturbance to the imaging state or imaging parameters, the spacing between adjacent second samples needs to be less than the second distance threshold.

[0057] In some embodiments, the second distance threshold may be 0.6 mm-0.1 mm. In some embodiments, the second distance threshold may be 0.55 mm-0.15 mm. In some embodiments, the second distance threshold may be 0.5 mm-0.2 mm. In some embodiments, the second distance threshold may be 0.45 mm-0.25 mm. In some embodiments, the second distance threshold may be 0.4 mm-0.3 mm. In some embodiments, the second distance threshold may be 0.35 mm.

[0058] In some embodiments, the first distance threshold and the second distance threshold may be the same or different.

[0059] Example 1

[0060] Figure 4A and Figure 4B is a spherical aberration corrected transmission electron microscope image of the antimony two-dimensional material shown in some embodiments of the present specification.

[0061] In order to verify and illustrate the improvement of imaging effect by the imaging method described in the embodiment of this specification, comparative experiments (referred to as Experiment 1 and Experiment 2) were conducted. Antimony two-dimensional material transmission electron microscope samples were prepared under the same preparation conditions and used for Experiment 1 and Experiment 2. The specific description is as follows:

[0062] Experiment 1: First adjust the imaging parameters based on the standard sample, then take out the standard sample, and then put the sample to be imaged (antimony two-dimensional material sample) into the electron microscope for imaging operation. The imaging results are as follows Figure 4A shown.

[0063] Experiment 2: Place the standard sample and the sample to be imaged (antimony 2D material sample) on the sample holder at the same time and place them at the imaging position of the electron microscope. First, adjust the imaging parameters based on the standard sample, then slightly move the sample holder and perform imaging operations on the sample to be imaged. The imaging results are shown in Figure 2. Figure 4B shown.

[0064] from Figure 4A and Figure 4B It can be seen from the comparison that the imaging effect of Experiment 2 is significantly better than that of Experiment 1.

[0065] The beneficial effects that may be brought by the embodiments of the present application include but are not limited to: 1) Put the standard sample and the sample to be imaged into the electron microscope at the same time, and debug the imaging parameters based on the standard sample. After debugging, only a slight adjustment is made to the sample holder (for example, the sample holder is slightly moved), and the imaging operation of the sample to be imaged can be realized. There is no need to take out the standard sample and then put it into the sample to be imaged. This not only improves the imaging efficiency, but also avoids the disturbance of the imaging parameters during the sample replacement process, thereby improving the imaging effect. 2) The distance between adjacent samples is less than the distance threshold, so that the movement of the sample holder can be as small as possible, thereby minimizing the disturbance of the imaging state or imaging parameters and improving the imaging effect. 3) Based on different imaging conditions, imaging operations are performed on multiple samples separately. There is no need to go through multiple debugging and multiple sample replacements to realize the imaging of samples of the same type and / or sample parameters under different imaging conditions and / or the imaging of samples of different types and / or sample parameters under the same imaging conditions in a single imaging. While improving the imaging efficiency, it can also reduce unnecessary errors introduced in the debugging and sample replacement process, and improve the accuracy of subsequent analysis and research.

[0066] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0067] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0068] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0069] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this specification, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0070] Similarly, it should be noted that in order to simplify the description disclosed in this specification and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this specification, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this specification are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0071] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0072] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, documents, etc., cited in this specification are hereby incorporated by reference in their entirety. Except for application history documents that are inconsistent with or conflicting with the contents of this specification, documents that limit the broadest scope of the claims of this specification (currently or later attached to this specification) are also excluded. It should be noted that if the descriptions, definitions, and / or use of terms in the materials attached to this specification are inconsistent or conflicting with the contents described in this specification, the descriptions, definitions, and / or use of terms in this specification shall prevail.

[0073] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A transmission electron microscope imaging method, characterized in that: The method comprises: A sample holder carrying at least two samples is placed at an imaging position of a transmission electron microscope, wherein the at least two samples include a first sample and at least one second sample, wherein: The first sample is a standard sample, and the distance between the first sample and an adjacent second sample is less than a first distance threshold, and the first distance threshold is 0.35 mm; The distance between adjacent second samples in the at least one second sample is less than a second distance threshold, and the second distance threshold is 0.35 mm; The type and sample parameters of the at least one second sample are the same, and the at least two samples are evenly distributed on the sample holder; adjusting imaging parameters of the transmission electron microscope based on the first sample; Based on the imaging parameters, setting imaging conditions corresponding to the at least one second sample respectively, the imaging conditions including a heating temperature for heating treatment; sequentially performing heating treatment on the at least one second sample at corresponding heating temperatures while performing imaging operation; determining at least one target image of the at least one second sample at a corresponding heating temperature based on the imaging operation result; The at least one target image is dynamically displayed to show the effect of heating temperature on samples of the same type and sample parameters.

2. The method according to claim 1, characterized in that The imaging parameters include at least one of spherical aberration, coma, astigmatism, distortion or chromatic aberration.

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