A method for non-localized, extraction-free preparation of FIB and TKD characterization

Abstract

This invention discloses a non-targeted, extraction-free method integrating FIB preparation and TKD characterization. The method includes: fixing the pretreated sample and placing it in a dual-beam electron microscope (FIB-SEM) to select a processing area; performing FIB processing, first depositing a protective layer in the processing area of ​​the sample, then using an ion beam to thin the top and bottom of the sample until it is transparent to the electron beam, followed by ion beam cleaning to reduce the amorphous layer; and finally performing TKD characterization. This invention solves the problems of existing technologies where sample transfer from FIB preparation to a copper mesh is cumbersome, prone to sample damage, and inefficient in the FIB-TKD process. This invention combines FIB and TKD, saving extraction time, simplifying the steps, improving efficiency, reducing limitations on sample size, allowing for remediation of defects, and is applicable to bulk materials, thin films, and particles processed in non-targeted locations.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for FIB preparation and TKD characterization, in particular to a non-localization and extraction-free integrated method for FIB preparation and TKD characterization. BACKGROUND

[0002] Focused ion beam (FIB) technology is a precise micro-nano processing tool and is widely used in transmission electron microscope (TEM) sample preparation. The method for positioning and processing TEM samples is as follows: the target area is accurately locked by SEM imaging, the selected area is preliminarily cut by using the FIB ion beam, the thin sheet is extracted to the half copper mesh by using the micro-nano mechanical hand, the ion beam assisted deposition is performed, and finally the fine thinning and cleaning (the last step of removing the amorphous layer is performed at a low voltage, such as 5kV) are performed, so that a high-quality electron transmission area with a thickness of less than 100nm and a suitable area is obtained. This method can realize high-precision sample preparation for specific micro areas or key areas, and compared with the traditional mechanical preparation method, the flexibility, pertinence, sample preparation efficiency and sample quality are greatly improved, and the method is suitable for subsequent TKD or TEM characterization. In the field of crystallographic analysis, transmission electron kikuchi diffraction (TKD) technology is a high-resolution analysis method using a general EBSD probe. Compared with the spatial resolution of about 50nm of the conventional EBSD, the lateral resolution of TKD is higher. Since the TKD sample has the same preparation requirements as the transmission electron microscope sample, a single sample can be used for TKD and TEM characterization analysis. However, the existing FIB preparation and TKD test method still has the following problems: a separate clamp is needed for each experiment, the FIB-prepared sample must be transferred to the TKD clamp, and the FIB-prepared transmission electron microscope sample cannot be directly used; the TEM clamp is used, the size of the transmission electron microscope sample prepared by the FIB is small (length of several microns, thickness of <100nm, placed on a 3mm copper mesh or molybdenum mesh), and the sample is easy to fall off or fall off during the transfer process; and the method for preparing the transmission sample is usually complicated and low in efficiency. The existing document 1 (Chinese invention patent application with application number CN202310109572.2) adjusts the position of the sample by using a sample clamp, so that a planar transmission electron microscope sample meeting the test requirements can be quickly and efficiently prepared, and a transmission EBSD (TKD) experiment can also be completed. However, the document has the following limitations: the extraction and placement of the sample on the half copper mesh is a common step in TEM sample preparation, which is time-consuming; if the positioning operation is performed, that is, the sample is extracted from the feature point for thinning, it is necessary, but if the positioning operation is not needed, the extraction will bring additional complexity and time consumption; and the half copper mesh clamping piece is used in the component, which still uses the method for preparing the TEM sample to prepare the TKD sample. Because the TEM and the FIB cannot be used in the same device, and the TEM clamp needs to clamp a sample with a size of 3mm, the FIB-prepared TEM sample needs to be welded to the half copper mesh by the extraction method, but the TKD can be used in the same device with the FIB, and the TKD sample does not need to be placed on the half copper mesh. SUMMARY

[0003] The application aims to provide a non-positioning and extraction-free FIB preparation and TKD characterization integrated method, solve the problems of complicated operation, easy damage and low efficiency when the sample prepared by FIB is transferred to TKD test in the prior art, realize the direct combination of FIB preparation and TKD test, save time, simplify the operation process, improve the efficiency of sample preparation and test, and ensure the quality of the sample.

[0004] In order to achieve the above-mentioned purpose, the application provides a non-positioning and extraction-free FIB preparation and TKD characterization integrated method, which comprises the following steps:

[0005] Step one, fixing the sample and placing it into a dual-beam electron microscope FIB-SEM, using SEM to select a processing area, and using SEM to emit an electron beam to deposit an electron beam protective layer on the processing area;

[0006] Step two, FIB processing, specifically as follows:

[0007] (1) rotating the angle to keep the ion beam parallel to the surface to be processed of the sample, and using FIB to emit an ion beam to deposit an ion beam protective layer on the electron beam protective layer;

[0008] (2) using the ion beam current to perform coarse etching on the area above and below the protective layer, and using the ion beam current to perform fine etching on the area close to the protective layer;

[0009] (3) adjusting the angle, using the ion beam current to sequentially thin the upper surface and the lower surface of the etched sample, and then using the ion beam current to clean the upper surface and the lower surface of the thinned sample;

[0010] Step three, rotating the angle of the electron microscope sample stage to make the lower bottom surface of the sample form an angle of 20° with the horizontal plane, inserting an electron backscattering diffraction EBSD probe, and performing TKD characterization.

[0011] Preferably, in step one, the fixing is to vertically fix the surface to be processed of the sample by a clamp. The clamp is a dual-beam electron microscope sample clamp for FIB-TKD combination, which can meet the above requirements of angle switching, FIB processing and TKD characterization position, and will not damage the equipment. In step two, the sample is tilted, and the angle between the lower bottom surface to be processed of the sample and the horizontal plane is 34° or 36° after tilting.

[0012] More preferably, in (1) of step two, the processing surface of the sample faces downward, and the degree of the rotating angle is 54°, that is, the angle between the lower bottom surface to be processed of the sample and the horizontal plane is 36°.

[0013] Preferably, in step one, when the sample is a bulk sample, no substrate is used; when the sample is a granular sample, a substrate is used, and the granular sample is arranged on the edge surface of the substrate.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Preferably, in step two (3), the thickness of the thinned sample is less than 100 nm; in step three, the rotation angle is 70°.

[0021] 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:

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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

[0026] Figure 1 This is a flowchart of the integrated FIB preparation and TKD characterization method of Embodiment 1 of the present invention.

[0027] Figure 2 This is a schematic diagram of the FIB processing in Embodiment 1 of the present invention.

[0028] Figure 3 This is a flowchart of the integrated FIB preparation and TKD characterization method of Example 4 of the present invention.

[0029] 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.

[0030] Figure 5 The TKD characterization results are taken from samples taken from the Ag block processed in Example 3 of this invention. Figure 1 .

[0031] Figure 6 The TKD characterization results are taken from samples taken from the Ag block processed in Example 3 of this invention. Figure 2 .

[0032] Figure 7 The TKD characterization results of Ag nanoparticles processed in Example 4 of this invention are shown below. Figure 1 .

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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

[0038] 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.

[0039] Example 1:

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] FIB processing is used, as detailed below:

[0046] (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.

[0047] 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°).

[0048] (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.

[0049] (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).

[0050] 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.

[0051] 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.

[0052] The structure of the sample clamp described above is as follows:

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The specific workflow of the above-mentioned sample clamping fixture is as follows:

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] Example 2:

[0067] 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:

[0068] 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.

[0069] 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.

[0070] Example 3:

[0071] 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.

[0072] 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.

[0073] 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 .

[0074] 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 .

[0075] Depend on Figure 5 and 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 crystal quality being quite ideal.

[0076] Example 4:

[0077] 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.

[0078] 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.

[0079] 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 of non-localized, extract-free FIB preparation and TKD characterization integration, characterized in that, The method comprises: Step one, fixing the sample and placing it into a dual-beam electron microscope FIB-SEM, using SEM to select a processing area, and using SEM to emit an electron beam to deposit an electron beam protection layer on the processing area; Step two, FIB processing, specifically as follows: (1) rotating the angle to keep the ion beam parallel to the surface of the sample to be processed, and using FIB to emit an ion beam to deposit an ion beam protection layer on the electron beam protection layer; (2) using an ion beam current to perform coarse etching on the area above and below the protection layer, and using an ion beam current to perform fine etching on the area close to the protection layer; After fine etching, the protection layer area forms a 2-10 mu m protrusion relative to the etched areas on both sides; (3) adjusting the angle, and using an ion beam current to sequentially thin the upper and lower surfaces of the etched sample, and then using an ion beam current to clean the upper and lower surfaces of the thinned sample; Step three, rotating the angle of the electron microscope sample stage so that the lower bottom surface of the sample forms a 20° angle with the horizontal plane, inserting an electron backscattering diffraction EBSD probe, and performing TKD characterization; In step two, the sample is tilted, and the included angle between the lower bottom surface of the sample to be processed and the horizontal plane after tilting is 34° or 36°; In step two (3), the thickness of the thinned sample is less than 100 nm.

2. The method of claim 1, wherein, In step one, the sample to be processed is vertically fixed by a clamp.

3. The method of claim 2, wherein, In step two (1), the length of the ion beam protection layer is 10-99 mu m, the width is 1-2 mu m, and the thickness is 1 mu m; the voltage of the ion beam is 30 kV, the beam current is 50-700 pA; the degree of the rotation angle is 54°, that is, the included angle between the lower bottom surface of the sample to be processed and the horizontal plane is 36°.

4. The method of claim 1, wherein, In step one, when the sample is a bulk sample, it does not have a substrate; when the sample is a granular sample, it has a substrate, and the granular sample is arranged on the edge surface of the substrate.

5. The method of claim 1, wherein, In step one, when the sample is a sheet-shaped thin film sample, the sheet-shaped thin film sample has a substrate, and the sheet-shaped thin film sample is a crystalline material.

6. The method of claim 5, wherein, The processing area is the area of several microns to several hundred microns protruding from the substrate at the back end of the sample.

7. The method of claim 1, wherein, In step one, the length of the electron beam protection layer is 10-99 mu m, the width is 1-2 mu m, and the thickness is 100 nm; the material of the electron beam protection layer is Pt, W or C.

8. The method of claim 1, wherein, In step two (2), during coarse etching, the acceleration voltage of the ion beam current used is 30 kV, and the beam current is 30-65 nA; during fine etching, the acceleration voltage of the ion beam current used is 30 kV, and the beam current is 3-15 nA.

9. The method of claim 1, wherein, In step two (3), adjusting the angle means that when thinning the upper surface of the etched sample, the included angle between the ion beam and the vertical line of the center of the upper surface of the protection layer is adjusted to 1.5°, and when thinning the lower surface of the etched sample, the included angle between the ion beam and the vertical line of the center of the upper surface of the protection layer is adjusted to -1.5°; during thinning, the acceleration voltage of the ion beam current used is 30 kV, and the beam current is 50-3 nA; during cleaning, the acceleration voltage of the ion beam current used is 5 kV, and the beam current is 10 pA.

10. The method of claim 1, wherein, In step three, the rotation angle is 70°.

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