Non-positioning and extraction-free FIB preparation and TKD characterization integrated method

Abstract

The invention discloses a non-positioning and extraction-free FIB preparation and TKD characterization integrated method, which comprises the following steps: fixing a pretreated sample, putting the sample into a double-beam electron microscope FIB-SEM, and selecting a processing area; carrying out FIB processing, depositing a protective layer in a processing area of the sample, thinning the upper surface and the lower surface of the sample by adopting an ion beam until an electron beam is transparent, and cleaning the sample by adopting the ion beam to reduce an amorphous layer; and finally, TKD characterization is carried out. The problems that in the prior art, a sample prepared through FIB is transferred to a copper net, the FIB-TKD process is tedious in operation, the sample is prone to being damaged, and the working efficiency is low are solved. According to the method, FIB-TKD is combined, so that the extraction time is saved, the steps are simplified, the efficiency is improved, the limitation on the size of a sample is reduced, flaws can be remedied again, and the method is also suitable for blocks, films and particles processed at non-specific positions.

Description

Technical Field

[0001] This invention relates to a method for FIB preparation and TKD characterization, specifically a non-localized, extraction-free method for integrating FIB preparation and TKD characterization. Background Technology

[0002] Focused ion beam (FIB) technology is a precise micro / nano fabrication tool widely used in transmission electron microscopy (TEM) sample preparation. The method for precisely positioning and fabricating TEM samples involves: accurately locating the target area using SEM imaging; using the FIB ion beam to initially cut the selected area; employing a micro / nano robotic arm to extract the sheet onto a copper mesh; then using ion beam-assisted deposition; and finally performing fine thinning and cleaning (the final amorphous layer removal step is performed at low voltage, such as 5kV), ultimately obtaining a high-quality electron transmission region with a thickness of less than 100nm and a suitable area. This method can achieve high-precision sample preparation for specific micro-regions or key areas, significantly improving flexibility, specificity, sample preparation efficiency, and sample quality compared to traditional mechanical preparation methods, making it suitable for subsequent TKD or TEM characterization. In the field of crystallography, transmission electron Kikuchi diffraction (TKD) is a high-resolution analytical technique using a standard EBSD probe. Compared to the spatial resolution of approximately 50nm for conventional EBSD, TKD offers significantly higher lateral resolution. Since the preparation requirements for TKD samples and transmission electron microscopy (TEM) samples are the same, a single sample can be used for both TKD and TEM characterization analyses simultaneously. However, existing FIB preparation and TKD testing methods still have shortcomings: each experiment requires a separate fixture, and FIB-prepared samples must be transferred to the TKD fixture, making direct use impossible; when using the TEM fixture, the TEM samples prepared by FIB are small in size (length of tens of micrometers, thickness <100 nm, placed on a 3 mm copper or molybdenum mesh), making them prone to falling or detaching during transfer; and the usual methods for preparing TEM samples are cumbersome and inefficient. Existing literature 1 (Chinese invention patent application CN202310109572.2) utilizes a sample fixture to adjust the sample position, enabling rapid and efficient preparation of planar TEM samples that meet testing requirements, and also allowing for transmission EBSD (TKD) experiments. However, this literature has certain limitations: extracting and placing the sample on a semi-copper mesh is a common and time-consuming step in TEM sample preparation; if a positioning operation is performed, i.e., extracting the sample from feature points for thinning, it is essential, but if the positioning operation is not required, extraction introduces additional complexity and time consumption; moreover, the component contains a semi-copper mesh clamp, which still uses the method for preparing TEM samples to prepare TKD samples. Because TEM and FIB cannot be used on the same device, and the TEM fixture needs to hold a 3mm sample, FIB preparation of TEM samples requires the use of a semi-copper mesh. The pre-thinned portion is extracted from the sample and soldered onto the semi-copper mesh. However, TKD can be used on the same device as FIB, and TKD samples do not necessarily need to be placed on a semi-copper mesh. Summary of the Invention

[0003] The purpose of this invention is to provide a non-localized, extraction-free method for integrating FIB preparation and TKD characterization, which solves the problems of cumbersome operation, easy damage, and low efficiency in the transfer of FIB-prepared samples to TKD testing in the prior art. It realizes the direct use of FIB preparation and TKD testing, saves time, simplifies the operation process, improves the efficiency of sample preparation and testing, and ensures the quality of the samples.

[0004] To achieve the above objectives, this invention provides a method for integrating non-localized, extraction-free FIB preparation and TKD characterization, the method comprising: Step 1: Fix the sample and place it in a dual-beam electron microscope (FIB-SEM). Use the SEM to select the processing area and use the SEM to emit an electron beam to deposit an electron beam protective layer on the processing area. Step 2: Perform FIB processing, as detailed below: (1) Rotate the angle to keep the ion beam parallel to the surface of the sample to be processed, and use the FIB emission ion beam to deposit the ion beam protection layer on the electron beam protection layer; (2) Use an ion beam for coarse etching in the area above and below the protective layer; use an ion beam for fine etching in the area close to the protective layer; (3) Adjust the angle and use an ion beam to thin the top and bottom of the etched sample in sequence; then use an ion beam to clean the top and bottom of the thinned sample. Step 3: Rotate the electron microscope stage so that the bottom surface of the sample is at a 20° angle to the horizontal plane, insert the electron backscatter diffraction (EBSD) detector, and perform TKD characterization.

[0005] Preferably, in step one, the fixing is achieved by vertically fixing the sample surface to be processed using a clamp. This clamp is a dual-beam electron microscope sample clamp for FIB-TKD combined operation, which can meet the requirements of angle switching, FIB processing, and TKD characterization position, and will not damage the equipment. In step two, the sample is tilted, and after tilting, the angle between the bottom surface of the sample to be processed and the horizontal plane is 34° or 36°.

[0006] More preferably, in step two (1), the processing surface of the sample faces downwards, and the rotation angle is 54°, that is, the angle between the bottom surface of the sample to be processed and the horizontal plane is 36°.

[0007] Preferably, in step one, when the sample is a bulk sample, it is without a substrate; when the sample is a particulate sample, it is with a substrate, and the particulate sample is placed on the edge surface of the substrate.

[0008] Preferably, in step one, when the sample is a sheet-like thin film sample, the sheet-like thin film sample has a substrate and the sheet-like thin film sample is a crystalline material.

[0009] Preferably, the processing area is a region protruding from the substrate at the rear end of the sample by several micrometers to several hundred micrometers. Since the Young's modulus of the thin film and the substrate in the sample differs, they may delaminate upon fracture. Therefore, characterizing the protruding part of the thin film reduces the amount of processing required.

[0010] Preferably, in step one, the electron beam protective layer has a length of 10 μm to 99 μm, a width of 1 μm to 2 μm, and a thickness of 100 nm, and the material of the electron beam protective layer is Pt, W, or C. A deposition region length of tens to hundreds of micrometers is just right; from an efficiency standpoint, a deposition length that is too long is time-consuming, while a length that is too short results in a too small characterization region. From the perspective of TKD (Transmission-Killing Diagnostics), it aims for a resolution of tens of nanometers, so the characterization region is typically at the micrometer level.

[0011] Preferably, in step two (1), the length of the ion beam protective layer is 10μm~99μm, the width is 1μm~2μm and the thickness is 1μm; the voltage of the ion beam is 30 kV and the beam current is 50pA~700pA.

[0012] Preferably, in step two (2), during coarse etching, the accelerating voltage of the ion beam used is 30 kV and the beam current is 30 nA to 65 nA; during fine etching, the accelerating voltage of the ion beam used is 30 kV and the beam current is 3 to 15 nA; after fine etching, the protective layer area forms a 2 μm to 10 μm protrusion relative to the etched areas on both sides.

[0013] Preferably, in step two (3), adjusting the angle means that when thinning the upper part of the etched sample, the angle between the ion beam and the vertical line of the center of the upper surface of the protective layer is adjusted to 1.5°, and when thinning the lower part of the etched sample, the angle between the ion beam and the vertical line of the center of the upper surface of the protective layer is adjusted to -1.5°; during thinning, the accelerating voltage of the ion beam used is 30 kV and the beam current is 50 pA to 3 nA; during cleaning, the accelerating voltage of the ion beam used is 5 kV and the beam current is 10 pA.

[0014] Preferably, in step two (3), the thickness of the thinned sample is less than 100 nm; in step three, the rotation angle is 70°.

[0015] The present invention provides a non-localized, extraction-free method for integrating FIB preparation and TKD characterization, which solves the problems of cumbersome operation, easy damage, and low efficiency in the transfer of FIB-prepared samples to TKD testing in the prior art, and has the following advantages: 1. Existing FIB technology first uses a dedicated clamp for preparing TKD samples for transmission electron microscopy (TEM) to prepare the sample. After removing the sample from the electron microscope, tweezers are used to fix it back onto the TKD sample stage before placing it back into the electron microscope for TKD characterization. However, because the sample is very small, it is difficult to hold and is easily damaged. This invention combines FIB and TKD, eliminating the need for FIB preparation followed by removal and placement onto the TKD sample stage for testing. This saves extraction time, simplifies the process, makes operation easier, and reduces the risk of sample damage.

[0016] 2. Existing FIB technology first uses a dedicated fixture for preparing TKD samples for transmission electron microscopy (TEM) and follows the same TEM sample preparation method. This requires the sample to be thinned to be extracted onto a copper mesh using a robotic arm, and then thinned on the copper mesh. The entire sample preparation process takes approximately 1.5 hours. Then, it is fixed onto the TKD fixture and placed in the TEM for characterization, a process that takes approximately 1 hour. The total time for one sample is approximately 2.5 hours. In contrast, this invention eliminates the need for extraction during sample preparation, taking only 0.5 hours for the entire process. It also eliminates the need to remove the TEM microscope; the sample is directly rotated for characterization, taking approximately 0.5 hours. The total time for one sample is approximately 1 hour, saving approximately 1.5 hours. Therefore, this invention eliminates the need for processing and characterizing specific locations for thin film samples and many bulk materials, even particulate samples. The sample is clamped on the sample stage, and a suitable area is selected for thinning, eliminating the need for extraction and the copper mesh. The entire process saves more than half the time, improving efficiency and reducing limitations on sample size.

[0017] 3. In existing technologies, if the FIB-prepared sample is found to be unsatisfactory when characterized by TKD, the sample must be removed from the TKD sample and prepared again, and the original process must be repeated, which is very time-consuming. However, the integrated FIB-TKD process of this invention (because FIB-TKD is entirely within the electron microscope) allows for remedial treatment by adjusting the angle and then using FIB processing if the TKD characterization effect is unsatisfactory (the fixture can support FIB-TKD, so only angle adjustment and thinning are needed). Directly selecting a region on the original sample for processing and characterization is not only the simplest and most direct method, but it also allows for the processing and characterization of multiple regions, yielding more statistically significant results.

[0018] 4. Existing FIB (Fill-in-the-Brush) techniques for preparing transmission electron microscopy (TEM) samples rely on robotic arms and semi-copper meshes, and are limited by the extraction operation (robotic arms cannot easily extract large volumes of samples onto the semi-copper mesh), making it difficult to obtain large-area thin regions. Typically, the size usable for TKD characterization is only in the micrometer range. In contrast, this invention eliminates the need for an extraction step, directly processing the sample to produce continuous thin regions ranging from tens to hundreds of micrometers for TKD characterization, thereby significantly improving statistical representativeness and the reliability of the results. Attached Figure Description

[0019] Figure 1 This is a flowchart of the integrated FIB preparation and TKD characterization method of Embodiment 1 of the present invention.

[0020] Figure 2 This is a schematic diagram of the FIB processing in Embodiment 1 of the present invention.

[0021] Figure 3 This is a flowchart of the integrated FIB preparation and TKD characterization method of Example 4 of the present invention.

[0022] Figure 4 The image shows the TKD characterization results of the quaternary alloy thin film on the silicon substrate processed in Example 1 of this invention.

[0023] Figure 5 The TKD characterization results are taken from samples taken from the Ag block processed in Example 3 of this invention. Figure 1 .

[0024] Figure 6 The TKD characterization results are taken from samples taken from the Ag block processed in Example 3 of this invention. Figure 2 .

[0025] Figure 7 The TKD characterization results of Ag nanoparticles processed in Example 4 of this invention are shown below. Figure 1 .

[0026] Figure 8 This is a cross-sectional view of the sample holder for a dual-beam electron microscope used in conjunction with FIB-TKD as provided in Embodiment 1 of the present invention.

[0027] Figure 9 This is a schematic diagram of the state when preparing a transmission sample using the dual-beam electron microscope sample holder for FIB-TKD combined with the present invention in Embodiment 1.

[0028] Figure 10 This is a schematic diagram of the TKD characterization state of the dual-beam electron microscope sample holder used for FIB-TKD combined with the present invention provided in Embodiment 1.

[0029] Figure 11 This is 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 use provided in Embodiment 1 of the present invention.

[0030] Notes: 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

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: A non-localized, extraction-free method integrating FIB preparation and TKD characterization, such as Figure 1 The flowchart shown is a process for the integrated FIB preparation and TKD characterization method of Embodiment 1 of the present invention. For sheet-like samples, the method includes: pretreatment: attaching a NiMoAlCrCo thin film (NiMoAlCrCo) with a thickness of approximately 50 nm tightly onto a single-crystal silicon substrate with a thickness of 1 mm to 2 mm. 25.5 Mo 17.4 Al 18.0 Cr 16.2 Co 22.9 The method involves breaking the film off the substrate. This avoids peeling the film off the substrate and allows for finding a slight protrusion at the film location, as the silicon substrate and the metal film are clearly distinguishable to the naked eye.

[0033] Placement: Vertically place the sheet sample into the fixture and secure it, ensuring the film is tilted downwards. Hold the sample in place using the fixture. Then place it into a dual-beam electron microscope (FIB-SEM) (using a Zeiss Crossbeam 350, which has SEM and FIB functions; the electron beam is above the ion beam, and the angle between the electron and ion beams is 54°; the SEM emits an electron beam for imaging and electron beam deposition; the FIB emits an ion beam for ion beam deposition and etching).

[0034] Select the processing area: The thin film and the substrate in the sample are tightly bonded, and the processing area is the region where the thin film is raised above the substrate and protrudes from the substrate by several micrometers to several hundred micrometers.

[0035] like Figure 1 As shown, the thin film and substrate in the sample are tightly bonded, and areas protruding from the substrate by several micrometers to several hundred micrometers can be selected as processing areas. Characterizing the protruding areas of the thin film reduces the amount of processing required. Whether a protrusion is present can be determined by fixing the sample and observing it from different angles using SEM and FIB, or by rotating the sample and observing it using SEM or FIB.

[0036] SEM processing: In the processing area, an electron beam protective layer is deposited using SEM electron beam emission. The electron beam protective layer (material is Pt, W or C, depending on the choice of transmission electron microscope sample preparation and the configuration of the electron microscope itself, which is a conventional choice) is deposited in the above processing area. At this time, the SEM voltage is 1kV, the current is about 4 nA, the length of the deposition area is 10μm~99μm, the width is 1μm~2μm, and the thickness is about 100 nm.

[0037] FIB processing is used, as detailed below: (1) First, the film is tilted by rotating the angle so that the ion beam is parallel to the surface of the sample to be processed. The ion beam is deposited on the electron beam protection layer using the FIB emission ion beam. The voltage of the ion beam is 30 kV, the beam current is 50 pA to 700 pA, the length of the ion beam protection layer is 10 μm to 99 μm, the width is 1 μm to 2 μm, and the target thickness is 1 μm.

[0038] like Figures 1-2 As shown, the thin film and substrate in the sample are tightly bonded. The electron microscope stage is rotated to tilt the thin film downwards. After tilting, the angle between the bottom surface of the thin film to be processed and the horizontal plane is 34° or 36°, and the angle between the front surface of the thin film and the horizontal plane is 54° or 52° (the specific angle depends on the model of the dual-beam electron microscope; the rotation angle of the Thermo Fisher electron microscope stage is 52°, and the rotation angle of the Zeiss electron microscope stage is 54°).

[0039] (2) To prevent the Kikuchi pattern from being obscured by the protrusions above or below during TKD characterization, the protrusions were rapidly etched away using a relatively large ion beam with an accelerating voltage of 30 kV and a beam current of 65 nA (etching was performed in the areas above and below the protective layer, including the single-crystal silicon substrate). In the area near the protective layer (thin film area), fine etching was performed using a medium beam current with an accelerating voltage of 30 kV and a beam current of 15 nA to avoid damaging the protective layer area and affecting subsequent characterization tests. After fine etching, the protective layer area formed protrusions of 2 μm to 10 μm relative to the etched areas on both sides, and the thickness of the thin film area after etching was approximately several hundred nanometers.

[0040] (3) Secondly, the etched film (around the protective layer area) was precisely thinned using a common TEM sample preparation procedure (the common TEM sample preparation procedure, with changes to the FIB parameters, and SEM monitoring, was used to precisely thin the film to highlight the protective layer area for subsequent characterization tests): the beam current was gradually reduced, and the upper and lower surfaces of the etched film were thinned in sequence with a small angle tilt (approximately ±1.5°; when thinning the upper surface of the etched sample, the angle between the ion beam and the vertical line from the center of the upper surface of the protective layer was adjusted to 1.5°; when thinning the lower surface of the etched sample, the angle between the ion beam and the vertical line from the center of the upper surface of the protective layer was adjusted to -1.5°). The accelerating voltage of the FIB was 30 kV, and the beam current selection range was 50 pA to 3 nA. When the electron beam was thinned to transparency, the total thickness of the film was approximately 100 mm. nm. Based on empirical rules, the thickness of the amorphous layer at this point is approximately 30 nm (the surface of the thin film etched by the ion beam will become amorphous, and the thickness of the amorphous layer is positively correlated with the ion beam acceleration voltage). Using a low-voltage ion beam, the thickness of the amorphous layer is further reduced. The acceleration voltage of the FIB is 5 kV and the beam current is 10 pA. Finally, the amorphous layer in the thin region is relatively thin (thickness less than 10 nm).

[0041] TKD characterization: The electron microscope stage is rotated 70° so that the thin film is at a 20° angle to the horizontal plane (this is the most commonly used TKD characterization angle, with the thin film facing down), and an electron backscatter diffraction (EBSD) detector is inserted for EBSD characterization.

[0042] like Figure 4 The image shows the TKD characterization results of the quaternary alloy thin film on the silicon substrate processed in Example 1 of this invention. Figure 4 IPF-Z images of the thin film material show typical polycrystalline characteristics; the grain size distribution spans from tens to hundreds of nanometers, with generally moderate uniformity, indicating a certain preferred orientation. Overall, the film has high crystallinity and clear grain boundaries, but defects such as grain size dispersion and a small number of pores are visible. In summary, the TKD characterization quality is good, and the spatial resolution and contrast of the orientation images are sufficient to support microstructure analysis.

[0043] The structure of the sample clamp described above is as follows: The fixture includes a base 2, a fixed clamping block 3, a movable clamping block 4, and a fastener 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 sample stage 1, allowing angle adjustment using the sample stage 1 itself, eliminating the need to open the sample chamber to adjust the sample fixture angle, thus improving efficiency. The fixed clamping block 3 is fixed to the base 2 and has a first clamping surface 31 on one side. The fixed clamping block 3 can be integrally formed with the base 2 or welded to it. The movable clamping block 4 is detachably connected to the fixed clamping block 3 via the fastener 5. The movable clamping block 4 has a second clamping surface 41 on one side. When the fastener 5 is loosened, a semi-copper mesh 6 is placed between the first clamping surface 31 and the second clamping surface 41. Then, the fastener 5 is tightened, causing the first clamping surface 31 and the second clamping surface 41 to clamp the semi-copper mesh 6. The semi-copper mesh 6 protrudes from the top surface 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.

[0044] 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.

[0045] To facilitate quick docking of the movable clamping block 4 and the fixed clamping block 3, and to ensure accurate clamping of the semi-copper mesh 6, the movable clamping block 4 has a right-angle notch 43 below the first clamping surface 31, and the fixed clamping block 3 has a right-angle boss 33 below the second clamping surface 41. After the right-angle boss 33 is fitted into the right-angle notch 43, the first clamping surface 31 and the second clamping surface 41 are parallel and in contact. 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 placed in contact with the second clamping surface 41. Then, the movable clamping block 4 can be assembled to clamp the semi-copper mesh 6.

[0046] Specifically, 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.

[0047] 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.

[0048] like Figure 8 The diagram shown is a cross-sectional view of the dual-beam electron microscope sample holder for FIB-TKD combined use provided in Embodiment 1 of the present invention. Figure 8 It can be seen that the bottom center of the base 2 is provided with a plug post 21, the electron microscope sample stage 1 is provided with a mounting hole 11, the plug 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 locking the plug post 21, thereby fixing the base 2 on the electron microscope sample stage 1.

[0049] like Figure 11 The diagram shown illustrates specific dimensions of the fixed and movable clamps in the dual-beam electron microscope sample holder for FIB-TKD coupling provided in Embodiment 1 of the present invention. Figure 11 It can be seen that the specific data of the fixed clamp 3 and the movable clamp 4 are known, and the size of the fixed clamp 3 and the movable clamp 4 can also be adjusted according to the model of the objective lens.

[0050] The specific workflow of the above-mentioned sample clamping fixture is as follows: 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.

[0051] 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.

[0052] like Figure 9 The diagram shown illustrates the state of the FIB-TKD coupled dual-beam electron microscope sample holder during FIB preparation of a transmission sample, as provided in Embodiment 1 of this invention. Figure 9 As can be seen, in this step, the electron microscope sample stage 1 will tilt by 52° or 54° (depending on the electron microscope model and settings; the objective lens is an SEM objective lens, as described below). The ion beam is parallel to the test surface for double-sided thinning. The sample test surface is often at an angle of 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 clamp is relatively small, it will not touch the objective lens when tilted.

[0053] Step 3: As Figure 10The diagram shows a state diagram of TKD characterization using the dual-beam electron microscope sample holder for FIB-TKD combined with the present invention, provided in Embodiment 1 of the present invention. Figure 10 As can be seen, the tilting electron microscope stage ranges 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 highly tilted, nor will it obstruct the electron diffraction pattern and affect the TKD characterization effect.

[0054] 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.

[0055] Example 2: A non-localized, extraction-free method for the preparation of FIB and TKD characterization is basically the same as that in Example 1, except that: In the selected processing area, the thin film and the substrate are not tightly bonded, and the thin film protrudes from the substrate by several micrometers to several hundred micrometers.

[0056] In the FIB processing, step (2) is omitted, and step (3) is performed directly after the same operation as step (1) in Example 1. Some thin film samples have a large difference in Young's modulus between the thin film and the substrate or poor bonding, and may delaminate when broken, with the thin film significantly detaching from the substrate. Since the thickness of the detached thin film is usually on the nanometer to micrometer scale and significantly protrudes from the substrate, it is not necessary to use a large ion beam to etch the blocking area.

[0057] Example 3: A non-localized, extraction-free method for the integrated preparation of FIB and TKD characterization is basically the same as in Example 1, except that it is for bulk samples. In the selected processing area, choose a block with a thickness of 1mm to 2mm, or process the block to a thickness of 1mm to 2mm, and use an appropriate fracture method. Locate slightly protruding areas with the naked eye, and under an electron microscope, screen for areas that protrude from the substrate by several micrometers to several hundred micrometers.

[0058] like Figure 5 As shown, the TKD characterization results of samples taken from the Ag block processed in Example 3 of the present invention are presented. Figure 1 .

[0059] like Figure 6 As shown, the TKD characterization results of samples taken from the Ag block processed in Example 3 of the present invention are presented. Figure 2 .

[0060] Depend on Figure 5and 6 As can be seen, Example 3 of the present invention exhibits excellent characterization results, clearly revealing the microstructure of the material at the 1 μm scale. Compared to Figure 7 The powder sample shows that the bulk material exhibits a denser polycrystalline structure with clearly distinguishable grain boundaries and good crystallinity. Overall, it displays typical characteristics of bulk nano-silver sintered materials, with both density and crystallinity being quite ideal.

[0061] Example 4: A non-localized, extraction-free method for the preparation of FIB and TKD characterization is basically the same as in Example 1, such as... Figure 3 The flowchart shown is a process for the integrated FIB preparation and TKD characterization method of Embodiment 4 of the present invention. For particulate samples, the differences lie in the pretreatment and the following steps during sample preparation: A cross-section of a fresh single-crystal silicon wafer is prepared (by breaking or smashing), and a portion of the wafer with sharp edges is selected as the substrate; the particles are added to anhydrous ethanol and ultrasonically dispersed to obtain a dispersion of suitable concentration (too dilute results in too few selectable particles, too thick leads to severe particle aggregation); the dispersion is then dripped onto the sharp edge surface of the substrate using a dropper; the dried particles and substrate are then placed in a dual-beam electron microscope, ensuring that the sharp edges face downwards during FIB processing and characterization. Particles near and protruding from the sharp edges are selected for subsequent steps.

[0062] like Figure 7 The image shows the TKD characterization results of the Ag nanoparticles processed in Example 4 of this invention. Figure 7 As can be seen, the characterization effect of Example 4 of the present invention is excellent, and it can clearly show the microstructure details at the 500nm scale. The sample exhibits a typical porous structure, with silver particles forming an interconnected network morphology. The particle size is mainly distributed in the range of tens to hundreds of nanometers, and there are residual pores between the particles.

[0063] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for integrating non-localized, extraction-free FIB preparation and TKD characterization, characterized in that, The method includes: Step 1: Fix the sample and place it in a dual-beam electron microscope (FIB-SEM). Use the SEM to select the processing area and use the SEM to emit an electron beam to deposit an electron beam protective layer on the processing area. Step 2: Perform FIB processing, as detailed below: (1) Rotate the angle to keep the ion beam parallel to the surface of the sample to be processed, and use the FIB emission ion beam to deposit the ion beam protection layer on the electron beam protection layer; (2) Use an ion beam for coarse etching in the area above and below the protective layer; use an ion beam for fine etching in the area close to the protective layer; (3) Adjust the angle and use an ion beam to thin the top and bottom of the etched sample in sequence; then use an ion beam to clean the top and bottom of the thinned sample. Step 3: Rotate the electron microscope stage so that the bottom surface of the sample is at a 20° angle to the horizontal plane, insert the electron backscatter diffraction (EBSD) detector, and perform TKD characterization.

2. The method according to claim 1, characterized in that, In step one, the fixing is achieved by vertically fixing the sample surface to be processed using a clamp; in step two, the sample is tilted, and the angle between the bottom surface of the sample to be processed and the horizontal plane after tilting is 34° or 36°.

3. The method according to claim 2, characterized in that, In step two (1), the length of the ion beam protective layer is 10μm~99μm, the width is 1μm~2μm and the thickness is 1μm; the voltage of the ion beam is 30 kV and the beam current is 50pA~700pA; the degree of the rotation angle is 54°, that is, the angle between the bottom surface of the sample to be processed and the horizontal plane is 36°.

4. The method according to claim 1, characterized in that, In step one, when the sample is a bulk sample, it is without a substrate; when the sample is a particulate sample, it is with a substrate, and the particulate sample is placed on the edge surface of the substrate.

5. The method according to claim 1, characterized in that, In step one, when the sample is a sheet-like thin film sample, the sheet-like thin film sample has a substrate and is made of crystalline material.

6. The method according to claim 1, characterized in that, The processing area is a region protruding from the substrate at the rear end of the sample, ranging from a few micrometers to several hundred micrometers.

7. The method according to claim 1, characterized in that, In step one, the electron beam protection layer has a length of 10μm~99μm, a width of 1μm~2μm, and a thickness of 100 nm, and the material of the electron beam protection layer is Pt, W, or C.

8. The method according to claim 1, characterized in that, In step 2 (2), during coarse etching, the ion beam used has an accelerating voltage of 30 kV and a beam current of 30 nA to 65 nA; during fine etching, the ion beam used has an accelerating voltage of 30 kV and a beam current of 3 to 15 nA; after fine etching, the protective layer area forms a 2 μm to 10 μm protrusion relative to the etched areas on both sides.

9. The method according to claim 1, characterized in that, In step two (3), adjusting the angle means that when thinning the upper part of the etched sample, the angle between the ion beam and the center vertical line of the upper surface of the protective layer is adjusted to 1.5°, and when thinning the lower part of the etched sample, the angle between the ion beam and the center vertical line of the upper surface of the protective layer is adjusted to -1.5°. During thinning, the accelerating voltage of the ion beam is 30 kV and the beam current is 50 pA to 3 nA. During cleaning, the accelerating voltage of the ion beam is 5 kV and the beam current is 10 pA.

10. The method according to claim 1, characterized in that, In step two (3), the thickness of the thinned sample is less than 100 nm; in step three, the rotation angle is 70°.

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