Ion milling high resolution in-situ microanalysis device

Abstract

The utility model provides a kind of ion grinding high-resolution in-situ microscopic analysis device, the ion grinding high-resolution in-situ microscopic analysis device includes vacuum chamber;Sample stage for carrying the sample to be measured is set in vacuum chamber;Ion grinding unit, the ion grinding unit includes the ion beam emission end extended into vacuum chamber;High-resolution in-situ microscopic analysis unit, the high-resolution in-situ microscopic analysis unit includes the image acquisition end extended into vacuum chamber;And with the processor of high-resolution in-situ microscopic analysis unit electrical connection;The ion grinding unit is used to emit ion beam to the sample to be measured and is ground, obtains the target cross section of target area;The high-resolution in-situ microscopic analysis unit is used to obtain the two-dimensional image of the target cross section;The processor is used to carry out three-dimensional reconstruction to the two-dimensional image, obtains the three-dimensional imaging of the target area.

Description

Technical Field

[0001] This utility model relates to the field of ion milling technology. More specifically, it relates to a high-resolution in-situ microscopic analysis device for ion milling. Background Technology

[0002] With the rapid development of science and technology, the fine structure of the interface between materials and devices plays a decisive role in their performance. In fields such as the pursuit of high energy in "advanced solid-state laser technology," the development of unique properties in "special functional materials," and the simulation of biological characteristics by "bionic materials," there is an urgent need for large-scale, nanoscale fine structural analysis of materials and devices.

[0003] However, existing instruments and equipment present numerous challenges in three-dimensional nanoprecision analysis. Taking nano-ceramic composite materials and semiconductor chips as examples, traditional structural analysis methods rely on cross-section polishing followed by observation, which has many drawbacks: it easily generates a large number of invalid polished areas, consuming manpower, resources, and time; when transferring samples to the scanning electron microscope chamber for detection, there is a high risk of secondary contamination, and repeated positioning is required, resulting in low analysis efficiency, poor reconstruction resolution, and serious loss of precious resources and samples.

[0004] Three-dimensional reconstruction technology for materials, as an emerging research method, provides scientists with a completely new perspective on the relationship between the microstructure and properties of materials at the nanoscale, microscale, and even macroscale. Through 3D reconstruction, researchers can more intuitively observe the complex internal structures of materials and, based on this, perform quantitative analysis and modeling, thus providing important theoretical support for the design and optimization of materials.

[0005] Three-dimensional reconstruction technology for materials, through high-precision imaging and data processing, visualizes and quantifies the internal structure of materials in three-dimensional space, providing crucial microstructural information for fields such as materials science, geology, and biomedicine. Commonly used three-dimensional reconstruction techniques include sequential slicing, X-ray computed tomography (X-CT), focused ion beam scanning electron microscopy (FIB-SEM), electron tomography (ET), and atom probe tomography (APT). Sequential slicing technology involves cutting samples into thin slices (typically tens of nanometers to several micrometers thick) using a slicer, simultaneously collecting images of each slice, and processing the two-dimensional slice images with software to generate a three-dimensional model, which can intuitively display the internal structure of the sample. The resolution can reach the nanometer level (electron microscopy slices), making it suitable for fields such as biomedicine, materials science, and geology. However, it is complex and time-consuming to operate, and the slicing process may cause sample deformation (such as thermal damage or mechanical stress), affecting the accuracy of the three-dimensional structure; it is only suitable for sliceable solid samples, and it is difficult to process soft or ultra-large samples (such as organs). X-ray CT, with its non-destructive nature and ability to process large samples (micrometer to centimeter scale), is widely used in the study of three-dimensional pore and crack networks in large-volume materials such as rocks and composite materials. However, its ability to distinguish low atomic number elements (such as C, H, and O in biological tissues) or materials with small density differences is poor. Conventional laboratory micro-CT is usually at the micrometer scale (~0.5-5 μm), while synchrotron radiation or nano-CT can reach tens to hundreds of nanometers, but it is still far inferior to electron / ion beam technology. FIB-SEM, through focused ion beam (Ga2) + Ion beam milling involves layer-by-layer milling of the sample (layer thickness 5-100 nm), followed by SEM imaging of each layer cross-section (resolution 1-5 nm). Stacking the two-dimensional layers generates a three-dimensional model. This method is suitable for metals, ceramics, semiconductors, geological samples, and some biological samples. However, the sample can be damaged during milling, and the reconstruction volume is typically limited to tens of micrometers square due to ion beam milling efficiency and SEM field of view. Depth is also limited by ion beam penetration and redeposition, and ion contamination can be introduced. Transmission electron microscopy (ET), on the other hand, involves tilting the sample around a single axis (typically ±60-70°) and acquiring a series of two-dimensional projection images at different tilt angles. The three-dimensional structure is reconstructed using weighted back projection (WBP) or SIRT algorithms, achieving sub-nanometer resolution (0.5-2 nm). It can be combined with EDS for component mapping, but the sample needs to be ultra-thin (approximately 100 nm), and the analysis area is limited to the thin region penetrated by the electron beam. The reconstruction volume is very small (typically <1 μm). 3Furthermore, electron beams can damage sensitive materials. APT (Area-of-Flight Mass Spectrometry) involves preparing the sample into an extremely fine tip (radius of curvature <100nm), applying a high DC voltage (and / or an ultrashort laser pulse) under ultra-high vacuum and low temperature to induce field evaporation. The evaporated ions are captured by a position-sensitive detector, and their elemental / isotopic identity is determined by time-of-flight mass spectrometry. The three-dimensional coordinates of the ions in the original tip are reconstructed by the impact position on the detector. The 3D reconstruction resolution can reach the atomic level, and it can detect elements at extremely low concentrations (ppm level). However, the sample must be prepared into a very fine tip (diameter <100nm), with a high aspect ratio, no defects, and good conductivity. The preparation process is complex, and the success rate is greatly affected by the material, resulting in high testing costs. Therefore, current 3D reconstruction technology still faces challenges in terms of resolution and sample size. For example, APT has atomic-level resolution but the analysis volume is very small (usually diameter <200nm, length <500nm), making it difficult to correlate macroscopic properties; industrial CT has a field of view at the centimeter level but insufficient resolution (usually >10μm). Utility Model Content

[0006] To address the aforementioned issues, this invention provides an ion-milling high-resolution in-situ microscopic analysis device that can achieve uniform thinning of large-scale millimeter-sized samples, reducing processing damage, and also enables localized thinning and precise positioning processing at the nanoscale, thereby achieving cross-scale construction of the three-dimensional structure of the target sample.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides an ion-milling high-resolution in-situ microscopic analysis device, comprising:

[0009] Vacuum chamber;

[0010] A sample stage set inside a vacuum chamber to hold the sample to be tested;

[0011] An ion polishing unit, the ion polishing unit including an ion beam emitting end extending into a vacuum chamber;

[0012] A high-resolution in-situ microscopy analysis unit, the high-resolution in-situ microscopy analysis unit including an image acquisition end extending into a vacuum chamber;

[0013] and a processor electrically connected to the high-resolution in-situ microscopy analysis unit;

[0014] The ion polishing unit is used to emit a wide-beam ion beam to polish the sample to be tested, thereby obtaining a target cross-section of the target region; the high-resolution in-situ microscopic analysis unit is used to acquire a two-dimensional image of the target cross-section; and the processor is used to perform three-dimensional reconstruction of the two-dimensional image to obtain a three-dimensional image of the target region.

[0015] In a preferred embodiment, the ion polishing unit includes an ion gun, with the end of the ion gun facing the sample to be tested being the ion beam emission end; the working medium of the ion gun is an inert gas.

[0016] In a preferred embodiment, the device further includes a rotatable shield mounted on the sample stage for sealing the sample; the shield has through holes for the ion beam to pass through.

[0017] A preferred embodiment is that the high-resolution in-situ microscopic analysis unit includes an electron gun and a sample analysis probe disposed within a vacuum chamber; the end of the electron gun facing the sample is the image acquisition end;

[0018] The sample analysis probe is used to acquire data on the compositional distribution of the target cross section of the sample target area; both the electron gun and the sample analysis probe are electrically connected to the processor.

[0019] In a preferred embodiment, both the ion emission end and the image acquisition end are located above the sample stage, and the sample stage is a five-axis sample stage, which can drive the sample to perform five degrees of freedom of motion.

[0020] The preferred embodiment is that the ion source accelerating voltage of the ion milling unit is 0-40 keV and the maximum beam current is 10 nA.

[0021] In a preferred embodiment, the angle between the ion beam emitted by the ion milling unit and the irradiation axis of the electron beam emitted by the high-resolution in-situ microscopy analysis unit is α, where 0°≤α≤90°.

[0022] The beneficial effects of this utility model are as follows:

[0023] This invention boasts a high degree of functional integration, enabling cutting, cross-sectional processing, and polishing of the target area of ​​a sample using a single device, while also allowing for in-situ high-resolution morphology and composition analysis. By adjusting the relative position of the sample stage and the ion beam, the sample can be bombarded from multiple angles, precisely removing the surface layer and acquiring high-resolution morphological information in situ. Simultaneously, by focusing and adjusting the ion beam energy and dosage, this invention achieves both nanoscale local thinning and precise positioning processing, as well as microscale uniform thinning, reducing processing damage. Furthermore, this invention breaks through the layer-cutting limit of FIB-SEM, enabling sheet grinding with nanometer precision (1nm), avoiding distortion and metal ion contamination issues during image processing, thus achieving cross-scale construction of the three-dimensional structure of the target sample. This invention exhibits excellent surface polishing effects on both soft and hard materials, producing samples with a large field of view and clean windows, instantly acquiring high-resolution morphological information, and performing deep nanoscale grinding with high precision. It constructs the nanometer-precision three-dimensional structure and elemental composition information of the target sample, filling a technological gap and advancing materials research. Attached Figure Description

[0024] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0026] Figure reference numerals: 1. Ion gun, 2. Control system, 3. Vacuum chamber, 4. Sample stage, 5. Field emission electron gun, 6. Processor, 7. Shield, 8. Molecular pump, 9. Mechanical pump, 10. Sample analysis probe, 11. Ion source. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0028] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0029] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0030] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0032] Ion milling (or ion beam polishing) is an advanced processing method that uses a high-energy ion beam to bombard the surface of a material, achieving material thinning or surface polishing through a physical sputtering effect. Parameters such as the ion beam energy, incident angle, and beam current density can be precisely controlled to adapt to the processing needs of different materials. Unlike traditional machining, which can easily damage the internal structure of materials, ion milling preserves structural integrity and original properties through gentle impact. With its precise ion beam focusing and intelligent control system, it can achieve nanoscale high-precision processing and characterization. The processed sample surface is nearly mirror-like, allowing for the non-destructive restoration of the true internal structure, aiding subsequent analysis. The high-energy ion beam provides high processing efficiency and rapid removal of redundancy. It also possesses both planar and cross-sectional processing capabilities, offering strong compatibility and meeting diverse experimental needs.

[0033] However, current domestic ion milling equipment has key shortcomings: it lacks in-situ high-resolution microscopy analysis capabilities, making it unable to perform image processing and 3D modeling. It also lacks an automated control system, making it impossible to achieve full automation of ion milling parameter setting, SEM imaging triggering, and sample transfer to achieve the purpose of 3D reconstruction of samples.

[0034] Currently, performing high-precision detection and analysis of the interfaces and internal structures of key materials such as laser crystals, biomimetic materials, and semiconductor chips presents numerous challenges. Existing detection devices are not only scarce but also have significant functional limitations: they are single-function, have narrow fields of view, and acquire limited information; they are time-consuming, hindering research progress; and they are prone to contamination and sample damage. Crucially, they cannot meet the demands for large-field-of-view, high-precision, in-situ three-dimensional analysis. Furthermore, current three-dimensional reconstruction techniques suffer from issues related to ion beam vertical processing of layer thickness, Ga ion contamination, and sample size.

[0035] To address this, this invention takes a novel approach, integrating ion beam polishing technology into scanning electron microscopy. By combining ion beam, micro / nano control, and high-resolution microscopic analysis techniques, it creates a high-resolution in-situ microscopic analysis system for ion polishing. By adjusting the relative position of the sample stage and the ion beam, the sample can be bombarded from multiple angles, precisely removing the surface layer and acquiring high-resolution morphological information in situ. Simultaneously, by adjusting the focusing system and the ion beam energy and dosage, nanometer-precision layer-by-layer polishing of millimeter-sized samples can be achieved. This enables both large-scale uniform thinning to reduce processing damage and deep nanoscale local thinning and precise positioning processing, constructing the three-dimensional structure of the target sample across scales.

[0036] This system promises to achieve several breakthroughs: it provides excellent surface polishing for both soft and hard materials, enabling the preparation of samples with large fields of view and clean windows, and allowing for the immediate acquisition of high-definition morphological information; it also allows for precise control of ion beam energy and dosage, enabling deep nanoscale grinding, and the construction of nanoscale precision three-dimensional structures and elemental composition information of target samples, filling technological gaps and advancing materials research.

[0037] Specifically, this utility model provides an ion milling high-resolution in-situ microscopic analysis device, combined with Figure 1As shown, the ion-milling high-resolution in-situ microscopy analysis device includes: a vacuum chamber 3 for providing a vacuum operating environment; a sample stage 4 disposed within the vacuum chamber 3 for holding the sample to be tested; an ion milling unit, the ion milling unit including an ion beam emitting end extending into the vacuum chamber; a high-resolution in-situ microscopy analysis unit, the high-resolution in-situ microscopy analysis unit including an image acquisition end extending into the vacuum chamber; and a processor 6 electrically connected to the high-resolution in-situ microscopy analysis unit; the ion milling unit is used to emit a focused ion beam to etch the sample to be tested, and to emit a wide-beam ion beam to mill the sample to be tested, to obtain a target cross-section of the target region; the electron beam emission direction is perpendicular to the target cross-section; the high-resolution in-situ microscopy analysis unit is used to acquire a two-dimensional image of the target cross-section; the processor 6 is used to perform three-dimensional reconstruction of the two-dimensional image to obtain a three-dimensional image of the target region. The processor 6 can specifically be a laptop, a handheld mobile terminal, or a desktop computer, etc. Signal transmission between the processor 6 and the high-resolution in-situ microscopy analysis unit can be achieved via electromagnetic waves.

[0038] Furthermore, the ion polishing unit includes an ion gun 1, with the end of the ion gun 1 facing the sample being tested serving as the ion beam emission end; the working medium of the ion gun 1 is an inert gas. That is, the ion gun 1 is connected to an ion source 11 via a pipeline, and the ion source 11 contains an inert gas. The ion gun 1 can ionize the inert gas (including but not limited to one or more combinations of helium, neon, and argon) to form plasma, and extract ions from the plasma through an electric field. It uses a high-voltage electric field (typically several thousand to hundreds of thousands of volts) to accelerate the ions and focuses them into a directional ion beam through an electromagnetic lens. When emitting a focused ion beam, the beam spot size is in the nanometer range (3-10 nm). When emitting a wide-beam ion beam, the beam spot size can reach the micrometer range (approximately 20 μm). The ion beam emission angle can also be adjusted via an ion beam deflection module. The ion gun 1 of this invention can perform non-contact etching on the sample, thereby avoiding problems such as physical deformation, residual stress, and gallium ion implantation contamination. The accelerating voltage of the ion source 11 of the ion polishing unit is 0–40 keV, and the maximum beam current is 10 nA.

[0039] In one specific embodiment, the device further includes a rotatable shield 7 mounted on the sample stage 4 for sealing the sample; the shield 7 has through holes for the ion beam to pass through. The shield 7 of this invention is a screw-on hemispherical structure that can be completely locked onto the sample, thereby preventing sample surface sputtering contamination of the high-resolution in-situ microscopy unit and vacuum chamber 3 during ion grinding. The shield 7 is connected to the sample stage 4 via a rotating shaft and is equipped with a micromotor. The motor can be controlled by a control system to drive the opening and closing of the shield 7 to prevent sample surface sputtering contamination of the microscopy unit and vacuum chamber 3. After grinding, the shield 7 opens upwards, exposing the sample to the high-resolution in-situ microscopy unit for high-resolution microscopic imaging and compositional and structural analysis. The vacuum chamber 3 is entirely sealed with metal to maintain internal vacuum, and is equipped with a venting valve and a sample changing window. The sample stage 4 is detachably fixed within the vacuum chamber. All the above operations can be controlled by a control system 2, which can specifically be a computer. By repeatedly performing the above steps, customized grinding of samples with nanometer precision can be achieved, and three-dimensional reconstruction can be realized, while keeping the chamber clean and reducing the risk of contamination to subsequent samples.

[0040] In one specific embodiment, the high-resolution in-situ microscopy analysis unit includes an electron gun 5 and a sample analysis probe 10 disposed within a vacuum chamber 3; the end of the electron gun 5 facing the sample is an image acquisition end; the sample analysis probe 10 is used to acquire data on the compositional distribution of the target cross-section of the target region of the sample; both the electron gun 5 and the sample analysis probe 10 are electrically connected to a processor 6. The processor 6 processes the images and compositional distribution data acquired by the high-resolution in-situ microscopy analysis unit. Protecting each sample analysis probe 10 with a sputter-deposited protective film enables real-time reception of secondary ions, secondary electrons, characteristic X-rays, and other signals from the sample during ion beam polishing, thereby obtaining more accurate sample compositional information. The sample analysis probe 10 may specifically include: an energy dispersive spectrometer (EDS), a wave dispersive spectrometer (WDS), an electron backscatter diffraction analyzer (EBSD), or a cathodoluminescence spectrometer (CL). Energy dispersive spectrometer (EDS) is used to acquire energy spectrum information of the sample to be tested, wavelength dispersive spectrometer (WDS) is used to acquire wavelength dispersive spectrometer information of the sample to be tested, electron backscatter diffraction analyzer (EBSD) is used to acquire grain orientation information of the sample to be tested, and cathodoluminescence spectrometer (CL) is used to acquire fluorescence information of the sample to be tested.

[0041] This invention also includes a control system 2, which can adjust the ion beam parameters (such as energy and incident angle) of the ion gun 1 in real time to optimize the ion polishing effect, and optimize the image acquisition effect by adjusting the various parameters of the electron gun 5. This invention also includes a molecular pump 8 and a mechanical pump 9, which can be controlled by the control system 2 to maintain a high vacuum level in the vacuum chamber 3. Simultaneously, the control system 2 can also control the sample stage 4 to adjust the sample position in five degrees of freedom; the sample can be glued to the sample stage 4.

[0042] In one specific embodiment, both the ion emission end and the image acquisition end are located above the sample stage 4. The sample stage 4 is a five-axis sample stage, capable of driving the sample to perform five degrees of freedom of motion. This sample stage 4, through rotational offset and cooperation with the ion beam deflection module, can perform customized grinding on the sample surface. This invention achieves multi-degree-of-freedom adjustment through the cooperation of the five-axis sample stage 4 and the ion beam deflection module, enabling ion grinding operations at any selected location on the sample, improving ion grinding efficiency, and achieving in-situ three-dimensional reconstruction of the sample. The sample stage 4 has a horizontal displacement distance of 0-100mm, a vertical displacement distance of 1.5-30mm, and rotation and offset angles of 0-360°.

[0043] In one specific embodiment, the angle between the ion beam emitted by the ion milling unit and the irradiation axis of the electron beam emitted by the high-resolution in-situ microscopy analysis unit is α, where 0°≤α≤90°. The angle between the ion beam and the electron beam irradiation axis can be adjusted by adjusting the emission angle of the ion beam or the electron beam. The ion gun 1 has an ion beam deflection module that adjusts the ion beam deflection angle through electromagnetic field deflection. Similarly, the electron gun 5 includes an electron beam deflection module that adjusts the electron beam deflection angle through electromagnetic field deflection. Both the ion beam deflection module and the electron beam deflection module are controlled by the control system 2.

[0044] This invention can both etch materials using a gaseous focused ion beam and perform layer-by-layer grinding and peeling of sample surfaces using a parallel wide-beam ion beam, without being limited by the cutting precision of traditional focused ion beam slicing methods and without sputtering contamination issues. This invention has broad material versatility, applicable to almost all material types, including soft materials (such as aluminum, gold, and solder) and brittle materials (such as glass and ceramics) that are difficult to process using traditional methods. This invention also has the capability to process samples across scales, handling both millimeter-scale samples and nanoscale materials. Furthermore, this invention can monitor and control the working environment, such as the working gas and sample temperature, in real time through a control system.

[0045] This invention also provides a method for three-dimensional reconstruction of materials based on the high-resolution in-situ microscopic analysis device for ion milling as described above, comprising the following steps: S1: Fix the sample to be reconstructed in three dimensions on the sample stage in the vacuum chamber, and evacuate the vacuum chamber. S2: Drive the sample stage until the surface to be milled of the sample reaches the preset working height, turn on the high-resolution in-situ microscopic analysis unit, adjust the electron beam focal length, and confirm that the surface to be milled of the sample is at the coaxial height of the electron beam and ion beam. S3: Drive the sample stage so that the surface to be milled of the sample is perpendicular to the ion beam emission direction of the ion milling unit, start the ion milling unit and emit a focused ion beam to etch a groove with a depth not less than the predetermined milling depth at the target area near the surface to be milled of the sample. Place and fix the pre-prepared silicon wafer in the groove, and drive the sample stage so that the surface to be milled of the sample is perpendicular to the electron beam emission direction of the high-resolution in-situ microscopic analysis unit. Step S3 further includes: a rotatable baffle is provided on the sample stage; the sample stage is driven so that the sample surface to be polished is perpendicular to the ion beam emission direction of the ion polishing unit; the baffle is closed and the ion polishing unit is started; a focused ion beam is emitted to etch a marking pattern near the target area of ​​the sample surface to be polished, and a groove with a depth not less than a predetermined polishing depth is etched at the location of the marking pattern using the focused ion beam; the baffle is opened, and a pre-prepared trapezoidal cross-section silicon wafer is placed in the groove, with the lower bottom edge of the silicon wafer adhering to the bottom wall of the groove and parallel to the sample surface to be polished, and the length of the lower bottom edge of the silicon wafer being L; the upper bottom edge of the silicon wafer being parallel to the sample surface to be polished and having a length of L0; the height of the silicon wafer being h; platinum is deposited in the groove to fix the silicon wafer. The height of the silicon wafer needs to be the same as or slightly higher than the groove depth. Platinum is deposited in the groove until it completely covers the silicon wafer. At this time, the platinum will be a certain thickness higher than the sample surface at the groove, so platinum of the same thickness as the sample surface at the groove needs to be deposited in the target area. S4: The ion polishing unit is activated to emit a wide-beam ion beam to perform ion polishing and thinning on the target area of ​​the sample surface to be polished and the embedded silicon wafer area to obtain the target cross section of the target area. S5: The high-resolution in-situ microscopic analysis unit is activated to obtain two-dimensional image information and compositional distribution information of the target cross section and transmits it to the processor. Step S5 further includes: opening the shield, activating the high-resolution in-situ microscopic analysis unit to obtain high-resolution morphology information and compositional distribution of the sample and recording the exposed length of the silicon wafer as L1, and transmitting the above information to the processor for processing; the processor calculates the thinning thickness of the target area of ​​the sample as h1 using formula (1); (1). The exposed length L1 of the silicon wafer refers to the length of the upper base of the new trapezoid formed after the trapezoidal silicon wafer in the groove is ground from top to bottom. S6: Repeat steps S4-S5 until the target area reaches the predetermined grinding depth. The processor integrates the information obtained by the high-resolution in-situ microscopic analysis unit to obtain the three-dimensional reconstruction result of the target area of ​​the sample.

[0046] More specifically, this invention alternates between ion polishing and peeling of the sample surface layers using an ion polishing unit and in-situ analysis using a high-resolution in-situ microscopy unit. Combined with a processor to process the acquired data and a control system, it achieves three-dimensional reconstruction of the material. By calculating the difference in exposed length of the pre-embedded trapezoidal cross-section silicon wafer before and after the two layer-by-layer polishing and peeling operations, the actual peeling thickness of each layer is obtained.

[0047] The following are two specific examples of the three-dimensional reconstruction methods for the above materials.

[0048] Example 1

[0049] 1) Use sample compression to press a 1×1cm sample. 2 The silicon wafer sample was placed on the sample stage, the vacuum chamber was sealed, the chiller was turned on, and the mechanical pump and molecular pump were turned on in sequence to evacuate the vacuum chamber until the vacuum level was below 5 × 10⁻⁶. -4 Pa.

[0050] 2) Start the high-resolution in-situ microscopy analysis unit, adjust the sample stage height to a working distance of about 10 mm, finely adjust the electron beam focal length, determine the actual working distance of the sample stage, and adjust the sample stage height to the coaxial point.

[0051] 3) Adjust the sample stage until the sample surface is perpendicular to the ion beam of the ion polishing unit. Select argon gas as the ion source for the ion polishing unit. Close the baffle above the sample stage, start the ion gun, open the argon gas valve, and adjust the gas flow rate to 0.1 sccm. The internal pressure of the ion gun should be 1 × 10⁻⁶. -3 At an acceleration voltage of 12 keV, ion etching was performed near the area to be thinned, forming a 1 μm x 1 μm rectangular groove with a depth of 1 μm. A pre-prepared trapezoidal silicon wafer (1 μm bottom edge and 0.5 μm top edge) was placed into the groove using a robotic arm, with the bottom edge aligned with the bottom of the groove and the top edge parallel to the sample surface to be polished. A Pt mask was then deposited to cover the silicon wafer and the target area to be polished within the groove.

[0052] 4) Rotate the sample stage until the sample surface is perpendicular to the electron beam of the electron gun to obtain sample surface morphology information.

[0053] 5) Close the shield and perform layer-by-layer ion polishing to remove the sample’s three-dimensional reconstruction area and the area embedded in the silicon wafer. The ion polishing process conditions are: accelerating voltage 10keV, ion beam bombardment area Φ 20μm, ion beam current 0.5nA, bombardment 30s.

[0054] 6) Turn off the ion gun, turn on the shield above the sample stage, turn on the high-resolution in-situ microscopy unit to obtain a photograph of the sample surface, measure the exposed edge length of the silicon wafer as 0.501 μm, and calculate its thinning depth as 2 nm according to formula (1).

[0055] 7) Repeat steps 5)-6) until all areas to be reconstructed in 3D are ground and peeled off. Organize the photos obtained by the high-resolution in-situ microscopic analysis unit, and integrate the data through the processor's 3D reconstruction software to obtain the 3D reconstruction result of the target area.

[0056] Example 2

[0057] 1) Use sample compression to press a 1×1cm sample. 2 The silicon wafer sample was placed on the sample stage, the vacuum chamber was sealed, the chiller was turned on, and the mechanical pump and molecular pump were turned on in sequence to evacuate the vacuum in the chamber to a level below 5 × 10⁻⁶. -4 Pa.

[0058] 2) Start the high-resolution in-situ microscopy analysis unit, adjust the sample stage height to a working distance of about 10 mm, finely adjust the electron beam focal length, determine the actual working distance of the sample stage, and adjust the sample stage height to the coaxial point.

[0059] 3) Adjust the sample stage until the sample surface is perpendicular to the ion beam of the ion polishing unit. Select argon gas as the ion source for the ion polishing unit. Close the baffle above the sample stage, start the ion gun, open the argon gas valve, and adjust the gas flow rate to 0.1 sccm. The internal pressure of the ion gun should be 1 × 10⁻⁶. -3 At an acceleration voltage of 15 keV, ion etching was performed on the area to be thinned. The etched area was a 2 μm * 2 μm rectangular groove with a depth of 2 μm. A pre-prepared trapezoidal silicon wafer (bottom edge length 2 μm, top edge length 1 μm) was placed into the groove using a robotic arm. The bottom edge was attached to the bottom of the groove, and the top edge was parallel to the sample surface to be polished. Then, a Pt mask was deposited to cover the silicon wafer and the target area to be polished within the groove.

[0060] 4) Rotate the sample stage until the thinned surface and the high-resolution in-situ microscopic analysis unit reach the preset angle to obtain the surface morphology information of the sample.

[0061] 5) Close the shield and perform plasma thinning on the sample area to be thinned and the area embedded in the silicon wafer. The ion polishing process conditions are: accelerating voltage 12keV, ion beam bombardment area Φ 10μm, ion beam current 0.8nA, bombardment 30s.

[0062] 6) Turn off the ion gun, turn on the shield, turn on the high-resolution in-situ microscopic analysis unit to obtain high-definition morphological information of the sample, measure the length of the exposed right-angled edge of the silicon wafer as 1.002 μm, and calculate its thinning depth as 4 nm according to formula (1).

[0063] 7) Repeat steps 5)-6) until all areas to be reconstructed in 3D are ground and peeled off. Organize the photos obtained by the high-resolution in-situ microscopic analysis unit, and integrate the data through the processor's 3D reconstruction software to obtain the 3D reconstruction result of the target area.

[0064] In summary, this invention boasts a high degree of functional integration, enabling cutting, cross-sectional processing, and polishing of the target area of ​​a sample using a single device, while also allowing for in-situ high-resolution morphology and composition analysis. By adjusting the relative position of the sample stage and the ion beam, the sample can be bombarded from multiple angles, precisely removing the surface layer and acquiring high-resolution morphological information in situ. Simultaneously, by focusing and adjusting the ion beam energy and dosage, this invention achieves both localized thinning and precise positioning at the nanoscale and uniform thinning at the micrometer scale, reducing processing damage. Furthermore, this invention breaks through the cutting limits of FIB-SEM, enabling sheet grinding with nanometer precision (1 nm), thus achieving cross-scale construction of the three-dimensional structure of the target sample. This invention exhibits excellent surface polishing effects on both soft and hard materials, producing samples with a large field of view and clean windows, instantly acquiring high-resolution morphological information, and performing deep nanoscale grinding with high precision. It constructs the three-dimensional structure and elemental composition information of the target sample with nanometer precision, filling a technological gap and advancing materials research.

[0065] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A high-resolution in-situ microscopic analysis device for ion milling, characterized in that, include: Vacuum chamber; A sample stage set inside a vacuum chamber to hold the sample to be tested; An ion polishing unit, the ion polishing unit including an ion beam emitting end extending into a vacuum chamber; A high-resolution in-situ microscopy analysis unit, the high-resolution in-situ microscopy analysis unit including an image acquisition end extending into a vacuum chamber; and a processor electrically connected to the high-resolution in-situ microscopy analysis unit; The ion polishing unit is used to emit an ion beam to polish the sample to be tested, thereby obtaining the target cross section of the target region; The high-resolution in-situ microscopic analysis unit is used to acquire a two-dimensional image of the target cross section; the processor is used to perform three-dimensional reconstruction of the two-dimensional image to obtain a three-dimensional image of the target region.

2. The ion milling high-resolution in-situ microscopic analysis device according to claim 1, characterized in that, The ion polishing unit includes an ion gun, the end of which faces the sample to be tested is the ion beam emission end; the working medium of the ion gun is an inert gas.

3. The ion milling high-resolution in-situ microscopic analysis device according to claim 1, characterized in that, The device also includes a rotatable shield mounted on the sample stage for sealing the sample; the shield has through holes for the ion beam to pass through.

4. The ion milling high-resolution in-situ microscopic analysis device according to claim 1, characterized in that, The high-resolution in-situ microscopic analysis unit includes an electron gun and a sample analysis probe disposed in a vacuum chamber; the end of the electron gun facing the sample is the image acquisition end; The sample analysis probe is used to acquire data on the compositional distribution of the target cross section in the target region of the sample; both the electron gun and the sample analysis probe are electrically connected to the processor.

5. The ion milling high-resolution in-situ microscopic analysis device according to claim 1, characterized in that, Both the ion emitter and the image acquisition end are located above the sample stage. The sample stage is a five-axis sample stage, which can drive the sample to perform five degrees of freedom of motion.

6. The ion milling high-resolution in-situ microscopic analysis device according to claim 1, characterized in that, The ion source accelerating voltage of the ion milling unit is 0–40 keV, and the maximum beam current is 10 nA.

7. The ion milling high-resolution in-situ microscopic analysis device according to claim 4, characterized in that, The angle between the ion beam emitted by the ion milling unit and the irradiation axis of the electron beam emitted by the high-resolution in-situ microscopy analysis unit is α, where 0°≤α≤90°.

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