FIB-TKD combined double-beam electron microscope sample clamp

Abstract

The utility model relates to the technical field of material test sample preparation, and provides an FIB-TKD combined double-beam electron microscope sample clamp, which comprises a base detachably fixed on an electron microscope sample table capable of automatically adjusting the angle along with the inclination of an electron microscope; the fixed clamping block is fixed on the base, and one side of the fixed clamping block is provided with a first clamping surface; the movable clamping block is detachably connected with the fixed clamping block through a fastener, one side of the movable clamping block is provided with a second clamping face, and the first clamping face and the second clamping face are matched to be used for clamping the half copper mesh; the semi-copper net protrudes out of the top surfaces of the fixed clamping block and the movable clamping block; a first receding face is arranged on the side, away from the first clamping face, of the movable clamping block, and a second receding face is arranged on the side, away from the second clamping face, of the fixed clamping block. The fixture does not touch an objective lens and an EBSD probe during angle adjustment, the fixture does not need to be replaced, direct combination of FIB and TKD is realized, interruption caused by angle adjustment through the fixture and risks caused by secondary lofting are avoided, and the fixture is simple in structure and low in machining difficulty and cost.

Description

Technical Field

[0001] This application belongs to the field of sample preparation technology for materials testing, and more specifically, it relates to a sample holder for a dual-beam electron microscope using FIB-TKD combined. Background Technology

[0002] Focused ion beam (FIB) is an important technique for point-to-point fabrication, cross-sectioning, and transmission electron microscopy (TEM) sample preparation. Transmission Kikuchi diffraction (TKD) is a crystallographic experiment based on a conventional EBSD detector, using an electron beam to conduct experiments on transparent samples (less than 100 nm thick). Compared to the approximately 50 nm spatial resolution of conventional EBSD, TKD offers a lateral spatial resolution better than 10 nm. Furthermore, TKD samples are interchangeable with TEM samples; TEM sample preparation can be performed in a dual-beam electron microscope, followed by characterization using an EBSD mounted within the dual-beam microscope. In the following text, samples used in TKD will be referred to as transmission samples.

[0003] The two techniques have different requirements for the angle of the test surface. In transmission electron microscopy (TEM) sample preparation, the target sample is placed on a semi-copper mesh, and the fixture is typically rotated 52° or 54° (depending on the electron microscope model and settings). The ion beam is parallel to the test surface for double-sided thinning, and the sample test surface is often at an angle of 36° or 38° to the horizontal plane. In TKD characterization, the sample test surface is often at an angle of 20° to the horizontal plane. Therefore, both techniques have high requirements for the sample angle. The distance between the objective lens and the sample must also be considered. In TEM sample preparation, the distance between the sample and the objective lens is approximately 4.5 mm or 5.1 mm (depending on the electron microscope model and settings). In TKD characterization, the distance is typically 4-5 mm. Therefore, during angle changes, a standard sample stage can easily touch the objective lens.

[0004] However, existing FIB processing and TKD testing methods still have the following significant shortcomings:

[0005] 1. Each experiment requires a separate fixture, divided into fixtures for preparing transmission electron microscopy (TEM) samples and fixtures for TKD characterization. In many FIBs, existing standard TEM sample preparation fixtures cannot directly connect FIB and TKD. The prepared TEM samples need to be transferred to the TKD sample fixture before testing, requiring a second sample placement (i.e., after preparing the TEM sample using the TEM sample preparation fixture, the sample is removed from the electron microscope, then placed back into the TKD fixture, and then placed back into the electron microscope for characterization).

[0006] 2. Transmission samples prepared by FIB are usually small in size (a few micrometers in length and less than 100nm in thickness). When the transmission sample is placed on a half copper mesh of about 3 mm, it is easy for it to fall, deform or become contaminated during the sample transfer process of secondary placement.

[0007] 3. During TKD characterization, the EBSD detector will be close to the transmission sample. If the fixture is too large, it may touch the objective lens above or the EBSD detector, resulting in a very high risk.

[0008] 4. During TKD characterization, if there is an obstruction below the sample when the electron beam passes through the transmission sample, it will cast a shadow on the EBSD detector, which will seriously affect the characterization effect.

[0009] 5. There are also readily available combined fixtures, such as the patent with application number CN202320204611.2. However, its disclosed design structure and implementation method are complex, and it requires adjusting the sample fixture to achieve angle changes (which may require opening the sample chamber, increasing the operation time). Utility Model Content

[0010] To address the shortcomings of the prior art, the purpose of this application is to provide a dual-beam electron microscope sample holder for use with FIB-TKD.

[0011] To achieve the above objectives, the technical solution adopted in this application is: to provide a dual-beam electron microscope sample holder for FIB-TKD coupling, comprising:

[0012] The base is detachably fixed to the electron microscope sample stage, which can automatically adjust its angle as the electron microscope tilts.

[0013] A fixing block is fixed on the base and has a first clamping surface on one side;

[0014] The movable clamping block is detachably connected to the fixed clamping block by fasteners. One side of the movable clamping block has a second clamping surface. The first clamping surface and the second clamping surface cooperate to clamp the semi-copper mesh. The semi-copper mesh protrudes from the top surfaces of the fixed clamping block and the movable clamping block.

[0015] The movable clamping block has a first clearance surface on the side away from the first clamping surface, and the fixed clamping block has a second clearance surface on the side away from the second clamping surface.

[0016] In one embodiment, the movable clamping block has a right-angle notch below the first clamping surface, and the fixed clamping block has a right-angle boss below the second clamping surface. After the right-angle boss is assembled into the right-angle notch, the first clamping surface and the second clamping surface are parallel and in contact.

[0017] In one embodiment, the first avoidance surface is an inclined surface or an arc surface.

[0018] In one embodiment, the second avoidance surface is an inclined surface or an arc surface.

[0019] In one embodiment, the fastener is a screw, the fixed clamping block has a threaded hole, and the movable clamping block has a through hole; or, the fixed clamping block has a through hole, and the movable clamping block has a threaded hole; the through hole is a countersunk hole that can accommodate a screw nut.

[0020] In one embodiment, the base has a plug-in post at its bottom center, the electron microscope sample stage has a mounting hole, and the side has a locking screw for abutting the plug-in post.

[0021] The beneficial effects of the dual-beam electron microscope sample holder for FIB-TKD coupling provided in this application are as follows:

[0022] 1. The fixture is mounted on an electron microscope sample stage that can automatically adjust its angle as the electron microscope tilts. It is equipped with a first clearance surface and a second clearance surface, which prevents the objective lens and EBSD probe from being touched during angle adjustment. The fixture does not need to be replaced, and the sample fixture enables direct use of FIB and TKD.

[0023] 2. Using this fixture, transmission samples can be prepared directly, and TKD characterization can be performed without removing the electron microscope. No secondary mounting is required. Since no secondary mounting is required, there are no problems such as sample dropping, deformation or contamination that may occur during sample transfer.

[0024] 3. The design is simplified to reduce processing costs and implementation steps. Therefore, it eliminates the need to adjust the sample clamps to change angles; instead, the electron microscope's own sample stage is used for angle adjustment. This also eliminates the need to open the electron microscope sample chamber to adjust the sample clamp angle, thus improving efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A cross-sectional schematic diagram of the sample holder for a dual-beam electron microscope used in conjunction with FIB-TKD provided in an embodiment of this application;

[0027] Figure 2A schematic diagram of the state of FIB preparation of transmission samples using the dual-beam electron microscope sample holder for FIB-TKD combined with the embodiments of this application;

[0028] Figure 3 A schematic diagram of the TKD characterization state of the dual-beam electron microscope sample holder used for FIB-TKD in the embodiments of this application;

[0029] Figure 4 A schematic diagram showing the specific dimensions of the fixed clamp and the movable clamp in the dual-beam electron microscope sample holder for FIB-TKD combined with the embodiments of this application;

[0030] Figure 5 This is a schematic diagram showing the results of TKD characterization of nano-copper twins using this dual-beam electron microscope sample holder;

[0031] Figure 6 This is a schematic diagram showing the results of TKD characterization of nano-sintered copper using this dual-beam electron microscope sample holder.

[0032] The following are the labeling elements in the figure:

[0033] 1. Electron microscope sample stage; 11. Mounting hole; 12. Locking screw; 2. Base; 21. Insertion post; 3. Fixing clamp; 31. First clamping surface; 32. Second clearance surface; 33. Right-angle boss; 34. Threaded hole; 4. Movable clamp; 41. Second clamping surface; 42. First clearance surface; 43. Right-angle notch; 44. Through hole; 5. Fastener; 6. Semi-copper mesh. Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0038] like Figures 1-4 As shown in the illustration, a dual-beam electron microscope sample holder for FIB-TKD combined use is described below. This dual-beam electron microscope sample holder for FIB-TKD combined use includes: a base 2, a fixed clamping block 3, a movable clamping block 4, and fasteners 5. The base 2 is detachably fixed to an electron microscope sample stage 1, which automatically adjusts its angle according to the tilt of the electron microscope. Existing electron microscope products have an automatically adjustable electron microscope sample stage 1, thus using the electron microscope's own sample stage 1 for angle adjustment eliminates the need to open the electron microscope sample compartment to adjust the sample holder angle, thereby improving efficiency.

[0039] The fixing clamp 3 is fixed on the base 2 and has a first clamping surface 31 on one side; the fixing clamp 3 can be integrally formed with the base 2 or welded to the base 2.

[0040] The movable clamping block 4 is detachably connected to the fixed clamping block 3 via fasteners 5. One side of the movable clamping block 4 has a second clamping surface 41. When the fasteners 5 are loosened, the semi-copper mesh 6 is placed between the first clamping surface 31 and the second clamping surface 41. Then, the fasteners 5 are tightened so that the first clamping surface 31 and the second clamping surface 41 cooperate to clamp the semi-copper mesh 6. The semi-copper mesh 6 protrudes from the top surfaces of the fixed clamping block 3 and the movable clamping block 4, which facilitates the preparation of FIB transmission samples and TKD characterization on the semi-copper mesh 6.

[0041] To enable switching between FIB transmission sample preparation and TKD characterization, a first clearance surface 42 is provided on the side of the movable clamp 4 away from the first clamping surface 31, and a second clearance surface 32 is provided on the side of the fixed clamp 3 away from the second clamping surface 41. The design of the first clearance surface 42 and the second clearance surface 32 ensures that the objective lens and EBSD probe will not be touched during angle adjustment, thus enabling direct use of FIB and TKD without secondary sample preparation.

[0042] In this embodiment, to facilitate the quick docking of the movable clamping block 4 and the fixed clamping block 3 and to ensure the accuracy of the clamping position of the semi-copper mesh 6, the movable clamping block 4 is provided with a right-angle notch 43 below the first clamping surface 31, and the fixed clamping block 3 is provided with a right-angle boss 33 below the second clamping surface 41. After the right-angle boss 33 is assembled into the right-angle notch 43, the first clamping surface 31 and the second clamping surface 41 are parallel and attached. The upper plane of the right-angle boss 33 is perpendicular to the second clamping surface 41, so that the bottom of the semi-copper mesh 6 can be placed on the upper plane of the right-angle boss 33 and attached to the second clamping surface 41. Then, the movable clamping block 4 can be assembled to clamp the semi-copper mesh 6.

[0043] In this embodiment, the first clearance surface 42 is an inclined surface or an arc-shaped surface, and the second clearance surface 32 is an inclined surface or an arc-shaped surface; preferably, both the first clearance surface 42 and the second clearance surface 32 are inclined surfaces, which facilitates processing. During manufacturing, two cuboid blocks are selected. One block is cut with a first clamping surface 31 and a right-angle notch 43 to obtain a movable clamping block 4; the other block is cut with a second clamping surface 41 and a right-angle boss 33 to obtain a fixed clamping block 3. Then, after the fixed clamping block 3 and the movable clamping block 4 are fitted together, a coaxial hole is drilled. Internal threads can be made on the hole in the fixed clamping block 3 or the movable clamping block 4.

[0044] Specifically, the fastener 5 is a screw, the fixed clamping block 3 has a threaded hole 34, and the movable clamping block 4 has a through hole 44; or, the fixed clamping block 3 has a through hole 44, and the movable clamping block 4 has a threaded hole 34; the through hole 44 is a countersunk hole that can accommodate the screw nut, thus preventing the nut from protruding out of the first relief surface 42 and affecting the angle adjustment. The length of the screw can extend beyond the second relief surface.

[0045] like Figure 1 In this embodiment, the base 2 has a plug-in post 21 at the bottom center, and the electron microscope sample stage 1 has a mounting hole 11. The plug-in post 21 is inserted into the mounting hole 11, and the side of the electron microscope sample stage 1 is provided with a locking screw 12 for pressing the plug-in post 21, thereby fixing the base 2 on the electron microscope sample stage 1.

[0046] like Figure 4 As shown, a fixed clamp 3 and a movable clamp 4 are provided for specific data; of course, the size of the fixed clamp 3 and the movable clamp 4 can also be adjusted according to the model of the objective lens.

[0047] In this embodiment, the working process of the fixture is as follows:

[0048] Step 1: First, loosen the fastener 5, loosen the movable clamp 4, and put in the semi-copper mesh 6. At this time, the fixture can be used as a regular transmission electron microscope sample preparation fixture.

[0049] Step 2: Using the usual transmission electron microscopy sample preparation procedure, fix the pre-thinned sample on the semi-copper mesh 6 for thinning until it is transparent to the electron beam.

[0050] like Figure 2 As shown, in this step, the electron microscope sample stage 1 is tilted 52° or 54° (depending on the electron microscope model and settings). The ion beam is parallel to the test surface for double-sided thinning. The sample test surface is often at 36° or 38° to the horizontal plane, and the distance between the sample and the objective lens is approximately 4.5 mm or 5.1 mm (depending on the electron microscope model and settings). Because the fixture is relatively small, it will not touch the objective lens when tilted.

[0051] Step 3: As Figure 3 As shown, the tilting electron microscope stage is from 1 to 70°. At this angle, the sample test surface is at 20° to the horizontal plane, which is a commonly used angle for TKD testing. Then, the sample height is adjusted, the EBSD probe is inserted, and TKD testing is performed. Because the fixture is relatively small, it will not touch the objective lens when tilted at a high angle, nor will it obstruct the electron diffraction pattern and affect the TKD characterization effect.

[0052] like Figure 5 The image shows the results of TKD characterization of nano-copper twins using this dual-beam electron microscope sample holder. In this case, a transmission sample was first prepared using this holder, and then TKD characterization was performed directly according to the angle transformation steps described above, successfully characterizing twin boundaries smaller than 10 nm; as shown... Figure 6 As shown, the TKD characterization of nano-sintered copper using this dual-beam electron microscope sample holder also successfully characterized nano-copper particles of tens of nanometers.

[0053] This fixture allows for the preparation of thin samples via FIB (Film Injection Brush) and direct TKD (Total Knockout) testing simply by adjusting the angle of the electron microscope sample stage 1. This avoids the interruptions caused by adjusting the angle using a fixture, as well as the risks associated with secondary sample placement. Furthermore, this fixture has a simple structure and is relatively easy and cost-effective to manufacture.

[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dual-beam electron microscope sample holder for FIB-TKD combination, characterized by, The utility model relates to a half copper mesh fixing device for electron microscope, including: Base (2) can be detachably fixed on electron microscope sample stage (1) that can be adjusted angle automatically with electron microscope tilting, Fixed clamp block (3) is fixed on the base (2), and one side has first clamping surface (31), Movable clamp block (4) is detachably connected with the fixed clamp block (3) through fastener (5), one side of the movable clamp block (4) has second clamping surface (41), and the first clamping surface (31) and the second clamping surface (41) cooperate for clamping half copper mesh (6), and the half copper mesh (6) protrudes from the top surface of the fixed clamp block (3) and the movable clamp block (4), The side of the movable clamp block (4) away from the first clamping surface (31) is equipped with first avoiding surface (42), and the side of the fixed clamp block (3) away from the second clamping surface (41) is equipped with second avoiding surface (32).

2. The dual-beam FIB-TEM sample holder of claim 1, wherein: The straight angle recess (43) is equipped on the movable clamp block (4) below the first clamping surface (31), and the straight angle boss (33) is equipped on the fixed clamp block (3) below the second clamping surface (41), after the straight angle boss (33) is assembled into the straight angle recess (43), the first clamping surface (31) and the second clamping surface (41) parallelly fit.

3. The dual-beam FIB-TEM sample holder of claim 2, wherein: The first avoiding surface (42) is inclined surface or arc surface.

4. The dual-beam FIB-TEM sample holder of claim 3, wherein: The second avoiding surface (32) is inclined surface or arc surface.

5. The dual-beam FIB-TEM sample holder of claim 1, wherein: The fastener (5) is screw, the fixed clamp block (3) is equipped with threaded hole (34), and the movable clamp block (4) is equipped with through hole (44), or the fixed clamp block (3) is equipped with through hole (44), and the movable clamp block (4) is equipped with threaded hole (34);The through hole (44) is counterbore that can accommodate the nut of screw.

6. The dual-beam FIB-TEM sample holder of any one of claims 1-5, wherein: The bottom center of the base (2) is equipped with the plug-in column (21), the electron microscope sample stage (1) is equipped with the mounting hole (11), and the side is equipped with the locking screw (12) for abutting the plug-in column (21).

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