TEM sample preparation method
By using auxiliary positioning structures and cutting angle deflection technology in TEM sample preparation, the problems of position uncertainty and sample deformation in TEM sample preparation were solved, achieving precise positioning and efficient sample preparation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI INTEGRATED CIRCUIT EQUIPMENT & MATERIALS INDUSTRY INNOVATION CENTER CO LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-30
AI Technical Summary
In TEM sample preparation, existing techniques suffer from problems such as small key hole size leading to uncertain position, requiring frequent scanning and observation, long time consumption, and sample deformation due to prolonged cutting.
Using an auxiliary positioning structure and cutting angle deflection technology, the auxiliary positioning structure is cut on one side of the target structure. The cutting stop position is determined by using the plane formed by the cutting direction and the Z and X directions to form the target angle. Cutting stops when the auxiliary positioning structure is cut open. Different surfaces are cut alternately until the target structure is cut open.
It achieves precise positioning during sample thinning, avoids frequent scanning observations, improves the success rate of TEM sample preparation, reduces sample deformation, and improves preparation efficiency.
Smart Images
Figure CN122306495A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and in particular to a method for preparing TEM samples. Background Technology
[0002] In the semiconductor field, failure analysis of chip structures is often performed by preparing transmission electron microscope (TEM) samples. When preparing TEM samples, the target location must first be located.
[0003] In TEM sample preparation, there is a type of PR ISO structure where sample preparation requires cutting open a single small hole. The current technical solution involves: coarsely cutting and thinning the sample from side A until the hole shadow is observed, then cutting and thinning the sample from side B to its thinnest point before fine cutting, until the hole is cut open.
[0004] This solution has the following problems:
[0005] (1) During the thinning process, the critical size of the hole (CD) is small, and the position of the A-side is uncertain during thinning. Frequent scanning and observation are required, which takes a long time.
[0006] (2) Cutting stops when the hole shadow is observed on surface A. The final cutting stop position on surface B is far from the target structure, which means that fine cutting takes a long time. Moreover, cutting the sample on the same surface for a long time can easily cause the sample to deform and make it impossible to cut the hole. Summary of the Invention
[0007] The purpose of this invention is to provide a method for preparing TEM samples to solve one or more problems in the prior art.
[0008] To address the aforementioned technical problems, this invention provides a method for preparing a TEM sample, comprising:
[0009] A sample to be tested is provided, the sample to be tested having at least two opening structures, each opening structure having a transverse cross section parallel to a plane formed by the orthogonality of the X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure, and the opening structure located in the X direction of the target structure is used as an auxiliary positioning structure;
[0010] The sample to be tested is cut on one side of the target structure until the auxiliary positioning structure is cut open. At this time, the cutting stops at the first cutting surface. The X direction and the Z direction intersect to form a reference surface. The first cutting surface is deflected by a target angle relative to the reference surface in a direction away from the target structure.
[0011] The sample to be tested is cut on the other side of the target structure and stops at a second cutting surface, which is parallel to the first cutting surface.
[0012] Optionally, in the method for preparing the TEM sample, the preparation method further includes:
[0013] The sample to be tested is cut alternately on the first cutting surface and the second cutting surface until the target structure is cut open, and the cutting accuracy when cutting the sample to be tested alternately is greater than the cutting accuracy when cutting the sample to be tested stops at the first cutting surface and the second cutting surface.
[0014] Optionally, in the TEM sample preparation method, when cutting the sample to be tested, the position of the sample to be tested is kept unchanged, and the cutting direction of the cutting device is deflected to the angle between the cutting device and the reference surface, which is the target angle.
[0015] Optionally, in the method for preparing the TEM sample, the target angle ranges from 1° to 1.5°.
[0016] Optionally, in the method for preparing the TEM sample, before cutting the sample to be tested, the method further includes: forming a protective layer on the surface of the sample to be tested, the protective layer at least covering the target structure and the auxiliary positioning structure.
[0017] Optionally, in the method for preparing the TEM sample, the protective layer includes a photoresist layer and an ion beam layer covering the photoresist layer.
[0018] The present invention also provides another method for preparing a TEM sample, comprising:
[0019] A sample to be tested is provided, the sample to be tested having at least three opening structures, each of the opening structures having a transverse cross section parallel to a plane formed by the orthogonal X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure, the opening structure located in the X direction of the target structure is used as a first auxiliary positioning structure, and the other opening structure located in the opposite direction of the X direction of the target structure is used as a second auxiliary positioning structure;
[0020] The sample to be tested is cut along one side of the target structure until the first auxiliary positioning structure is cut open. At this point, the cutting stops at the first cutting surface. The X direction and the Z direction intersect to form a reference surface. The first cutting surface is deflected relative to the reference surface in a direction away from the target structure by a first target angle; and...
[0021] The sample to be tested is cut on the other side of the target structure until the second auxiliary positioning structure is cut open. At this point, the cutting stops at the second cutting surface. The second cutting surface is deflected at a second target angle relative to the reference surface in a direction away from the target structure. The second target angle is opposite to the direction of the first target angle.
[0022] Optionally, in another method for preparing a TEM sample, the preparation method further includes:
[0023] The sample to be tested is cut alternately along the first cutting surface and along the second cutting surface until the target structure is cut open, and the cutting accuracy when cutting the sample to be tested alternately is greater than the cutting accuracy when cutting the sample to be tested stops at the first cutting surface and the second cutting surface.
[0024] Optionally, in another method for preparing a TEM sample, the values of the first target angle and the second target angle range from 1° to 1.5°, and the first target angle and the second target angle may be the same or different.
[0025] In summary, the TEM sample preparation method provided by this invention includes: selecting another opening structure as an auxiliary positioning structure in the X direction of the target opening structure, wherein the depth direction of both the target opening structure and the auxiliary positioning structure is the Z direction; during cutting, the plane formed by the intersection of the cutting direction with the Z and X directions forms a target angle; thus, cutting can be stopped when the auxiliary positioning structure is cut open; at this time, the distance between the cutting stop position and the target opening structure can be determined based on the target angle and the distance between the target structure and the auxiliary positioning structure; therefore, the target opening structure can be accurately located during sample thinning, and the distance from the cutting stop position to the target opening structure can be adjusted according to individual needs, avoiding the need for frequent scanning observations due to the uncertainty of the cutting stop position.
[0026] Furthermore, after coarse cutting, the TEM sample preparation method provided by this invention further includes: alternating fine cutting of the sample under test on different surfaces until the target structure is cut open. This avoids the problem of deformation at the top of the sample under test due to repeated fine cutting on the same surface, which could prevent the hole from being cut open, thereby significantly improving the success rate of TEM sample preparation. Attached Figure Description
[0027] Figure 1 This is a flowchart of the TEM sample preparation method provided in Embodiment 1 of the present invention;
[0028] Figure 2 This is a schematic diagram of the state of cutting to the first cutting surface in an embodiment of the present invention;
[0029] Figure 3 This is a schematic diagram of the cutting position in Embodiment 1 of the present invention;
[0030] Figure 4 This is a flowchart of the TEM sample preparation method provided in Embodiment 2 of the present invention;
[0031] Figure 5 This is a schematic diagram of the cutting position in Embodiment 2 of the present invention;
[0032] The labels in the accompanying drawings are explained as follows:
[0033] 100 - Target structure; 200 - Auxiliary positioning structure;
[0034] 10 - First cutting surface; 20 - Second cutting surface;
[0035] 201 - First auxiliary positioning structure; 202 - Second auxiliary positioning structure. Detailed Implementation
[0036] The core idea of this invention is to provide a method for preparing TEM samples, including: selecting another opening structure as an auxiliary positioning structure for the target opening structure; during cutting, deflecting the sample or the cutting direction; and stopping when the auxiliary positioning structure is cut open. In this way, the distance between the cutting stop position and the target opening structure can be determined according to the deflection angle and the distance between the two opening structures. Thus, the target opening structure can be accurately located when the sample is thinned, and the distance between the cutting stop position and the target opening structure can be adjusted according to individual needs, avoiding the need for frequent scanning observations due to the uncertainty of the cutting stop position.
[0037] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different figures need to show different emphases, and sometimes different proportions are used. It should be understood that relative terms such as "above," "below," "top," "bottom," and "upper" shown in the drawings can be used to describe the relationships between various elements. These relative terms are intended to cover different orientations of elements other than those depicted in the drawings. For example, if the device is inverted relative to the view in the drawings, an element described as "above" another element will now be below that element. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate logical or sequential relationships between the various components, elements, steps, etc.
[0038] Example 1
[0039] Please see Figure 1This invention provides a method for preparing a TEM sample, comprising the following steps:
[0040] S11, Provide a sample to be tested, the sample to be tested having at least two opening structures, each opening structure having a transverse cross section parallel to a plane formed by the orthogonality of the X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure, and the opening structure located in the X direction of the target structure is used as an auxiliary positioning structure;
[0041] S12, the sample to be tested is cut on one side of the target structure until the auxiliary positioning structure is cut open. At this point, the cutting stops at the first cutting surface. The X direction and the Z direction intersect to form a reference surface. The first cutting surface is deflected by a target angle relative to the reference surface in a direction away from the target structure; and...
[0042] S13, the sample to be tested is cut on the other side of the target structure and stops at the second cutting surface, the second cutting surface being parallel to the first cutting surface.
[0043] Using the preparation method provided in this embodiment, with the help of an auxiliary positioning structure and by adjusting the cutting angle, the sample can be accurately positioned to the target structure during thinning. Furthermore, the distance from the cutting stop position to the target structure can be adjusted according to individual needs, avoiding the need for frequent scanning and observation due to the uncertainty of the cutting stop position.
[0044] The following is a further description of each of the above steps.
[0045] First, perform step S11, please refer to [link / reference]. Figure 2 A sample to be tested is provided, the sample to be tested having at least two opening structures, each opening structure having a transverse cross section parallel to a plane formed by the orthogonality of the X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure 100, and the other opening structure located in the X direction of the target structure 100 is used as an auxiliary positioning structure 200. Figure 2 Only the X and Z directions are illustrated in this embodiment. In this embodiment, the X, Y, and Z directions are mutually perpendicular, and the Z direction is perpendicular to the plane formed by the orthogonality of the X and Y directions. In other embodiments, the Z direction may not be perpendicular to the plane formed by the orthogonality of the X and Y directions. That is, the preparation method provided in this embodiment is applicable not only to vertical hole structures where the axis is perpendicular to the transverse section, but also to inclined hole structures where the axis is not perpendicular to the transverse section. Figure 2 The diagram shows the Z-direction perpendicular to the plane formed by the orthogonal X and Y directions.
[0046] In this embodiment, the opening structure is a through hole. Specifically, the sample to be tested is a sample with a through hole layer. Generally, the through hole layer includes multiple through holes arranged in an array, and the through holes have the same or similar size and specifications. One of the through holes in the through hole layer is the target structure 100, and the other through hole in the through hole layer is used as an auxiliary positioning structure 200.
[0047] When a through hole in the X direction of the target structure 100 is used as an auxiliary positioning structure 200, the selected through hole can be an adjacent through hole to the target structure 100 or a non-adjacent through hole. The X direction can be the direction of the row or column of the target structure 100, or other directions. This application does not limit this.
[0048] Preferably, the through-holes located in the same row or column direction as the target structure 100 and adjacent to it are selected as the auxiliary positioning structure 200 to reduce the difficulty of TEM sample preparation.
[0049] In other embodiments, the opening structure may also be a groove. Specifically, the sample to be tested may also be a sample to be tested with multiple grooves, which are arranged sequentially at intervals along the X direction. One of the grooves is the target structure 100, and another groove adjacent to or spaced apart from it is the auxiliary positioning structure 200.
[0050] Similarly, preferably, the groove adjacent to the target structure 100 is selected as the auxiliary positioning structure 200 to reduce the difficulty of TEM sample preparation.
[0051] Next, proceed to step S12, please refer to [link / reference]. Figure 3 and combined Figure 2 The sample to be tested is cut on one side of the target structure until the auxiliary positioning structure 200 is cut open. At this time, the cutting stops on the first cutting surface 10. The X direction and the Z direction intersect to form a reference surface. The first cutting surface 10 is deflected by a target angle θ relative to the reference surface in a direction away from the target structure 100.
[0052] The distance between the target structure 100 and the auxiliary positioning structure 200 is D. Therefore, the distance d between the first cutting surface 10 and the target structure 100 is d = D * tanθ. During actual cutting, this distance d can also be used to determine the cutting stop position.
[0053] Preferably, the target angle θ is in the range of 1° to 1.5°, for example, it can be 1°, 1.2°, 1.5°, etc. Within this range, the target angle θ can ensure that the target structure 100 is not cut when the auxiliary positioning structure 200 is cut, and can make the cutting stop position as close as possible to the target structure 100.
[0054] Next, proceed to step S13. Please continue to see... Figure 3 The sample to be tested is cut again, but the cutting position has changed. Specifically, the sample to be tested is cut on the other side of the target structure 100 and stops at the second cutting surface 20. The second cutting surface 20 is parallel to the first cutting surface 10 and is located on opposite sides of the target structure 100. At this time, the angle of the second cutting surface 20 relative to the reference surface is opposite to the direction of the target angle and equal in magnitude.
[0055] In step S12, after the first cutting surface 10 stops cutting, the position of the target structure 100 can be roughly determined based on the position d between the first cutting surface 10 and the target structure 100. Therefore, when cutting in this step, the approximate cutting stop position of this step can be determined based on the position of the target structure 100.
[0056] This application does not impose any particular limitation on the distance between the second cutting surface 20 and the target structure 100. If the approximate position of the target structure 100 is determined after step S22, it is preferable to make the positions of the second cutting surface 20 and the target structure 100 as close as possible to reduce the difficulty of subsequent finishing processes. Furthermore, it is understood that... Figure 3 As shown, if the cutting is stopped at a distance d from the target structure 100 during this step, the first cutting surface 10 and the second cutting surface 20 are centrally symmetrical about the target structure 100.
[0057] The above two steps of cutting can be performed using a coarse cutting method, meaning that high cutting precision is not required. In addition, after completing the above two coarse cutting steps, the preparation method provided in this embodiment also includes a fine cutting step. Preferably, the fine cutting step includes: alternately cutting the sample to be tested on the first cutting surface 10 and the second cutting surface 20 until the target structure 100 is cut open. The cutting precision when alternately cutting the sample to be tested is greater than the cutting precision when the cutting of the sample to be tested stops at the first cutting surface 19 and the second cutting surface 20.
[0058] Precision cutting of the sample to be tested on different sides can avoid the problem of deformation of the top of the sample due to repeated precision cutting on the same side, which would prevent the hole from being cut open. This can greatly improve the success rate of TEM sample preparation.
[0059] In the above description, although "rough cutting" and "fine cutting" are not restrictive, it should be understood that "rough cutting" and "fine cutting" are relative terms. The thickness reduced by each cut in "rough cutting" is greater than the thickness reduced by each cut in "fine cutting".
[0060] Since the cutting angle of the cutting equipment only requires adjusting the setting parameters, adjusting the cutting angle will not affect the cutting accuracy. However, adjusting the position of the sample to be tested requires manual positioning, which may result in low positioning accuracy. Therefore, during actual cutting, it is preferable to keep the position of the sample to be tested unchanged and deflect the cutting direction of the cutting equipment until the angle between it and the reference surface is the target angle. This avoids unnecessary cutting errors caused by adjusting the sample to be tested.
[0061] Alternatively, before cutting the sample to be tested, the preparation method provided in this embodiment further includes forming a protective layer on the surface of the sample to be tested, the protective layer at least covering the target structure 100 and the auxiliary positioning structure 200. Optionally, the protective layer may also cover the entire surface of the sample to be tested.
[0062] In this embodiment, the protective layer may include a photoresist layer and an ion beam layer covering the photoresist layer. In other embodiments, the protective layer may also be a combination of an electron beam layer and an ion beam layer covering the electron beam layer, and so on.
[0063]
Example 2
[0064] Please see Figure 4 and combined Figure 5 This embodiment provides a method for preparing a TEM sample, including the following steps:
[0065] S21, a sample to be tested is provided, the sample to be tested having at least three opening structures, each of the opening structures having a transverse cross section parallel to a plane formed by the orthogonality of the X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure 100, the opening structure located in the X direction of the target structure 100 is used as a first auxiliary positioning structure 201, and the other opening structure located in the opposite direction of the X direction of the target structure 100 is used as a second auxiliary positioning structure 202;
[0066] S22, the sample to be tested is cut on one side of the target structure 100 until the first auxiliary positioning structure 201 is cut open. At this time, the cutting stops on the first cutting surface 10. The X direction and the Z direction intersect to form a reference surface. The first cutting surface 10 is deflected by a first target angle relative to the reference surface in a direction away from the target structure 100; and,
[0067] S23, the sample to be tested is cut on the other side of the target structure until the second auxiliary positioning structure 202 is cut open. At this time, the cutting stops on the second cutting surface 20. The second cutting surface 20 is deflected by a second target angle relative to the reference surface in a direction away from the target structure. The second target angle is opposite to the direction of the first target angle.
[0068] Similar to Example 1, the preparation method provided in this example uses an auxiliary positioning structure and adjusts the cutting angle. In this way, the sample can be accurately positioned at the target structure 100 during thinning, and the distance from the cutting stop position to the target structure 100 can be adjusted according to individual needs, avoiding the need for frequent scanning and observation due to the uncertainty of the cutting stop position.
[0069] The difference from Embodiment 1 is that in Embodiment 1, one auxiliary positioning structure is used to determine the cutting stop position, while in this embodiment, two auxiliary positioning structures are used to determine the cutting stop position. However, in this embodiment, the cutting positioning principle of step S22 and the cutting positioning principle of step S23 are the same as the cutting positioning principle of step S12 in Embodiment 1.
[0070] In addition, in this embodiment, the values of the first target angle and the second target angle are both in the range of 1° to 1.5°, for example, 1°, 1.2°, 1.5°, etc. When the first target angle and the second target angle are in this range, it can be ensured that when the first auxiliary positioning structure 201 and the second auxiliary positioning structure 202 are cut apart, the target structure 100 is not cut apart, and the cutting stop position can be made as close as possible to the target structure 100.
[0071] The first target angle and the second target angle may be the same or different. For example, the first target angle may be 1° and the second target angle may be 1.5°. When the first target angle and the second target angle are the same, and the distances between the first auxiliary structure 201 and the second auxiliary structure 202 and the target structure 100 are equal, the first cutting surface 10 and the second cutting surface 20 are centrally symmetrical about the target structure 100.
[0072] Compared to the prior art document 1, the technical solution provided in this embodiment can further reduce the difficulty of determining the cutting stop position when forming the second cutting surface 20 and improve the cutting accuracy. However, compared to embodiment one, an auxiliary positioning structure needs to be added to the sample to be tested. In practical applications, the technical solution of embodiment one or embodiment two can be selected according to the requirements or sample conditions.
[0073] In addition, the preparation method provided in this embodiment may also include the same fine cutting step as in Embodiment 1, and the same step as in Embodiment 1 of forming the protective layer before cutting. Please refer to the description of Embodiment 1 for this part, and it will not be repeated here.
[0074] In summary, the TEM sample preparation method provided by the embodiments of the present invention includes: selecting another opening structure as an auxiliary positioning structure in the X direction of the target opening structure, wherein the depth direction of both the target opening structure and the auxiliary positioning structure is the Z direction; during cutting, the plane formed by the intersection of the cutting direction with the Z and X directions forms a target angle; thus, cutting can be stopped when the auxiliary positioning structure is cut open; at this time, the distance between the cutting stop position and the target opening structure can be determined based on the target angle and the distance between the target structure and the auxiliary positioning structure; therefore, the target opening structure position can be accurately located during sample thinning, and the distance from the cutting stop position to the target opening structure can be adjusted according to individual needs, avoiding the need for frequent scanning observations due to the uncertainty of the cutting stop position.
[0075] Furthermore, the TEM sample preparation method provided in this embodiment of the invention further includes: alternately and precisely cutting the sample to be tested on different surfaces until the target structure is cut open. This avoids the problem of deformation at the top of the sample to be tested due to repeated precision cutting on the same surface, which could prevent the hole from being cut open, thereby significantly improving the success rate of TEM sample preparation.
[0076] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to mutually. In addition, different parts between embodiments can also be combined with each other, and this invention does not limit this.
[0077] Furthermore, it should be understood that the above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.
Claims
1. A method for preparing a TEM sample, characterized in that, include: A sample to be tested is provided, the sample to be tested having at least two opening structures, each opening structure having a transverse cross section parallel to a plane formed by the orthogonality of the X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure, and the opening structure located in the X direction of the target structure is used as an auxiliary positioning structure; The sample to be tested is cut on one side of the target structure until the auxiliary positioning structure is cut open. At this time, the cutting stops at the first cutting surface. The X direction and the Z direction intersect to form a reference surface. The first cutting surface is deflected by a target angle relative to the reference surface in a direction away from the target structure. The sample to be tested is cut on the other side of the target structure and stops at a second cutting surface, which is parallel to the first cutting surface.
2. The method for preparing a TEM sample as described in claim 1, characterized in that, The preparation method further includes: The sample to be tested is cut alternately on the first cutting surface and the second cutting surface until the target structure is cut open, and the cutting accuracy when cutting the sample to be tested alternately is greater than the cutting accuracy when cutting the sample to be tested stops at the first cutting surface and the second cutting surface.
3. The method for preparing a TEM sample as described in claim 1, characterized in that, When cutting the sample to be tested, the position of the sample to be tested is kept unchanged, and the cutting direction of the cutting device is deflected to the angle between the cutting device and the reference surface, which is the target angle.
4. The method for preparing a TEM sample as described in claim 1, characterized in that, The target angle ranges from 1° to 1.5°.
5. The method for preparing a TEM sample as described in claim 1, characterized in that, Before cutting the sample to be tested, the preparation method further includes: forming a protective layer on the surface of the sample to be tested, the protective layer at least covering the target structure and the auxiliary positioning structure.
6. The method for preparing a TEM sample as described in claim 1, characterized in that, The protective layer includes a photoresist layer and an ion beam layer covering the photoresist layer.
7. A method for preparing a TEM sample, characterized in that, include: A sample to be tested is provided, the sample to be tested having at least three opening structures, each of the opening structures having a transverse cross section parallel to a plane formed by the orthogonal X and Y directions, and having a depth in the Z direction, wherein one of the opening structures is a target structure, the opening structure located in the X direction of the target structure is used as a first auxiliary positioning structure, and the other opening structure located in the opposite direction of the X direction of the target structure is used as a second auxiliary positioning structure; The sample to be tested is cut along one side of the target structure until the first auxiliary positioning structure is cut open. At this point, the cutting stops at the first cutting surface. The X direction and the Z direction intersect to form a reference surface. The first cutting surface is deflected relative to the reference surface in a direction away from the target structure by a first target angle; and... The sample to be tested is cut on the other side of the target structure until the second auxiliary positioning structure is cut open. At this point, the cutting stops at the second cutting surface. The second cutting surface is deflected at a second target angle relative to the reference surface in a direction away from the target structure. The second target angle is opposite to the direction of the first target angle.
8. The method for preparing a TEM sample as described in claim 7, characterized in that, The preparation method further includes: The sample to be tested is cut alternately along the first cutting surface and along the second cutting surface until the target structure is cut open, and the cutting accuracy when cutting the sample to be tested alternately is greater than the cutting accuracy when cutting the sample to be tested stops at the first cutting surface and the second cutting surface.
9. The method for preparing a TEM sample as described in claim 7, characterized in that, The first target angle and the second target angle are both within the range of 1° to 1.5°, and the first target angle and the second target angle may be the same or different.
10. A TEM sample, characterized in that, The TEM sample was prepared using the preparation method described in any one of claims 1 to 9.