An analysis method and system for realizing micro-area XRF in a dual-beam electron microscope

Abstract

The application relates to the field of focused ion beam (FIB) and scanning electron microscope (SEM) technology, and particularly discloses a method and system for realizing micro-area XRF analysis in a dual-beam electron microscope, which comprises the following steps: using a focused ion beam to perform subtractive machining on a target material to form an X-ray excitation probe; accurately positioning the X-ray excitation probe to an analysis position, and adjusting the position of the X-ray excitation probe and the sample to be measured to ensure that the X-ray excitation probe does not contact the sample to be measured; using a scanning electron microscope to emit an electron beam in a point mode and act on the X-ray excitation probe to excite the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and to excite the sample to be measured to generate fluorescent X-rays; using an energy spectrometer detector to receive and analyze the fluorescent X-ray signals generated by the sample to be measured; and the application realizes non-contact micro-area element composition analysis by preparing an X-ray excitation probe through a focused ion beam and exciting the X-ray excitation probe to generate X-rays and excite the sample to be measured to generate fluorescence.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of focused ion beam (FIB) and scanning electron microscope (SEM), and more particularly, to a method and system for realizing micro-area XRF analysis in dual-beam electron microscope. BACKGROUND

[0002] In the field of scanning electron microscope (SEM), as early as in the 1970s and 1980s, it was proposed to add a metal foil as a target in the SEM, and to use the electron beam of the electron microscope to excite the target to generate X-rays, which are used as an X-ray source. This innovative technology not only successfully applied for a patent, but also launched related products. This practice fully proves that it is feasible to use thin materials as an X-ray source in the SEM and use an energy dispersive spectrometer (EDS) as a detector to realize X-ray fluorescence (XRF) function. However, to achieve this goal, the electron microscope needs to be modified or additional components need to be added.

[0003] In 2014, Stahlhut also used a foil as a target in the SEM, used the electron beam of the electron microscope to excite X-rays as an X-ray source, and applied it to the field of computed tomography (CT). In recent years, dual-beam electron microscopes (FIB-SEM) have been increasingly widely used. It skillfully combines the micro-nano processing capability of focused ion beam (FIB) and the topography observation and element characterization capability of SEM, showing strong comprehensive performance.

[0004] In the study of dual-beam electron microscopes, some studies use electron beam irradiation of a needle tip to obtain X-rays, and then carry out CT characterization work. In these research papers, FIB mainly undertakes the task of processing the sample to be tested. In addition, the invention patent EP18182591 mentions that a sheet-shaped target can be processed using FIB and applied to CT analysis in SEM, but does not provide specific processing methods, and the target is fixed on a specific target stage (810 in the patent).

[0005] In the field of commercial equipment, Bruker QUANTAX micro-XRF successfully realizes XRF function in SEM by adding a dedicated X-ray light source and cooperating with an EDS detector.

[0006] The existing technology has the following limitations:

[0007] 1) Limited application of functions: After a comprehensive search of related literature and patents, it was found that there is currently no technical solution for using FIB to prepare an X-ray source excitation target in a dual-beam electron microscope and using the energy dispersive spectrometer of the electron microscope for XRF analysis. The existing related researches are mostly limited to realizing CT function in dual-beam electron microscopes, and lack of application expansion in XRF analysis function.

[0008] 2) Device configuration limitations: The existing implementation of XRF function is to add a dedicated accessory, such as the Brook QUANTAX micro-XRF, which adds a dedicated X-ray light source; even if the CT function is implemented based on a specific technical route, there is no integrated solution, such as being unable to complete the preparation of the target material, the generation of X-rays, and the collection of signals on one device, resulting in the need for additional equipment or accessories to support the implementation of different functions, increasing the cost and complexity of using the device.

[0009] 3) Target material usage limitations: When performing XRF analysis, due to the differences in absorption edges of different elements, selecting the appropriate target material can maximize the excitation efficiency. However, the existing technology cannot conveniently replace the target material, and cannot flexibly adjust the target material according to different analysis requirements, limiting the accuracy and applicability of XRF analysis. SUMMARY

[0010] The purpose of the present application is to provide an analysis method and system for realizing micro-XRF in a dual-beam electron microscope, which prepares an X-ray excitation probe using a focused ion beam and uses an electron beam to excite X-rays, indirectly exciting the fluorescence of the sample to be measured, and realizing non-contact micro-area element composition analysis.

[0011] To achieve the above purpose, the present application provides the following technical solutions:

[0012] An analysis method for realizing micro-XRF in a dual-beam electron microscope, comprising the following steps:

[0013] Using a focused ion beam to perform subtractive machining on a target material to form an X-ray excitation probe for exciting X-rays;

[0014] Precisely positioning the machined X-ray excitation probe to the analysis position, and adjusting the relative position of the machined X-ray excitation probe and the sample to be measured to ensure that the X-ray excitation probe and the sample to be measured maintain a safe distance and do not come into contact;

[0015] Starting the scanning electron microscope in the dual-beam electron microscope to emit an electron beam in point mode and act on the X-ray excitation probe, exciting the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and further exciting the sample to be measured to generate fluorescent X-rays;

[0016] Using an energy spectrometer detector to receive and analyze the fluorescent X-ray signals generated by the sample to be measured to realize micro-area composition analysis of the sample to be measured.

[0017] Further, the method for obtaining the X-ray excitation probe comprises:

[0018] a) using a focused ion beam to cut a wedge-shaped groove with a wide upper part and a narrow lower part on both upper and lower sides and the left side of the target material on the bulk target material base material, and performing U-shaped cutting at the bottom of the groove, so that the target material has only one end connected with the target material base material; the process of performing the U-shaped cutting further includes: cutting from both sides of the bottom of the groove to the middle and leaving a width of 1-2 microns in the middle as a hinge connection between the target material and the target material base material;

[0019] b) under the real-time monitoring of an electron beam, precisely positioning the needle tip of a manipulator to the edge of the target material, and using ion beam-induced deposition technology to form a firm welding point at the edge of the target material;

[0020] c) using a low-beam ion beam to cut off the hinge connection between the target material and the target material base material, so that the target material is completely separated from the target material base material, and the target material is obtained;

[0021] d) using a focused ion beam to thin the target material, and controlling the thickness of the target material by etching the upper or lower surface of the target material, so as to obtain an X-ray excitation probe.

[0022] Further, the extraction process of the target material includes: cutting and extracting a micron-level thin sheet target material from the bulk target base material by using a FIB, and fixing by the needle tip of a manipulator.

[0023] Further, the target material is an independently processed target sheet, which is extracted and fixed to an electron beam excitation position by the needle tip of a manipulator, and the target material includes at least one of cobalt, chromium, titanium, copper, molybdenum or tungsten.

[0024] Further, the thickness of the target material can be adjusted according to the absorption edge characteristics of the sample to be measured, so as to optimize the excitation efficiency of the characteristic X-rays and continuous X-rays on the sample to be measured.

[0025] Further, the thickness of the target sheet is 1-20 microns.

[0026] Further, the processing mode of the target material further includes: forming an X-ray excitation probe of a thin film target material by using a focused ion beam to process the needle tip of a manipulator.

[0027] The application also provides a system for performing an analysis method for realizing micro-area XRF in a dual-beam electron microscope, comprising:

[0028] a focused ion beam system for subtractive processing of a target material to form an X-ray excitation probe for exciting X-rays;

[0029] a scanning electron microscope system for monitoring the working process in the scanning electron microscope in the dual-beam electron microscope, and emitting an electron beam in a point mode to act on the X-ray excitation probe to excite the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and further excite the sample to be measured to generate fluorescent X-rays.

[0030] A robotic arm is used to carry and hold target materials.

[0031] The energy dispersive X-ray detector is used to receive and analyze the fluorescence X-ray signals generated by the sample to achieve micro-area composition analysis of the sample.

[0032] According to specific embodiments provided by the present invention, the present invention has the following technical effects compared to the prior art:

[0033] This invention allows for flexible adjustment of the target material according to different analytical needs. A micrometer-sized X-ray excitation probe is prepared using a focused ion beam and precisely positioned at the electron beam focal point. The electron beam excites the X-ray probe to generate X-rays, which in turn indirectly excite the sample to produce fluorescent X-rays. Finally, an energy dispersive X-ray spectrometer (EDS) detector is used to perform micro-area elemental analysis. Its technical advantages include: significantly improving the spatial resolution of the analysis, achieving micro- and nano-scale micro-area characterization, and avoiding direct damage to the sample by the electron beam through non-contact indirect excitation, while ensuring the sensitivity and accuracy of detection. This provides a non-destructive testing method for elemental analysis at the micro- and nano-scale. In this integrated solution, a single dual-beam electron microscope performs three key functions: first, an ion beam is used to fabricate the X-ray source target; second, an electron beam bombards the target to generate X-rays to excite the sample; and finally, an EDS detector collects and analyzes the fluorescent X-ray signals emitted by the sample. This integrates the three steps—target preparation, X-ray generation, and signal detection—that originally required separate equipment into a single machine, saving laboratory space and equipment investment. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] The following description, in conjunction with the accompanying drawings, further illustrates the analytical method and system for realizing micro-area XRF within a dual-beam electron microscope according to the present invention;

[0036] Figure 1 This is a schematic diagram of the overall process of a method for realizing micro-area XRF analysis in a dual-beam electron microscope according to the present invention;

[0037] Figure 2This is a schematic diagram of the in-situ XRF micro-area analysis method of FIB-SEM based on X-ray excitation probe in Embodiment 1 of the present invention, in which the tip of the robotic arm is used as the target material; wherein (a) is a schematic diagram of the robotic arm tip being inserted into the focused ion beam (FIB) processing area; (b) is a schematic diagram of the focused ion beam processing the robotic arm tip; and (c) is a schematic diagram of the processed robotic arm tip being precisely positioned near the sample to be tested as an X-ray excitation probe.

[0038] Figure 3 This is a schematic diagram of placing the target material under the SEM objective lens in Embodiment 2 of the present invention; wherein (a) is a schematic diagram of the initial placement state of the bulk target material in the electron microscope; (b) is a schematic diagram of the target material being cut and processed by the focused ion beam; (c) is a schematic diagram of the probe being extracted by the robotic arm after processing; and (d) is a schematic diagram of receiving and analyzing the fluorescence X-ray signal generated by the sample under test using the energy dispersive X-ray detector of the scanning electron microscope.

[0039] Figure 4 Comparison of continuous X-rays generated by the XRF analysis method of the X-ray excitation probe of this invention and the conventional energy dispersive spectroscopy method. The electron microscope parameters in the figure are consistent, and the same energy dispersive spectroscopy was used to test the same location of the same material. Among them, (a) is the spectrum obtained by testing using the conventional EDS method, with a high background; (b) is the spectrum obtained by using the method of this invention, with a low background; and (c) shows that trace amounts of Mg can be detected using this method, but cannot be detected by conventional EDS. Detailed Implementation

[0040] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0042] Example 1

[0043] like Figure 1 As shown in the figure, the present invention provides a method for realizing micro-region XRF analysis within a dual-beam electron microscope, comprising the following steps:

[0044] A focused ion beam is used to subtractively process the tip of a robotic arm, forming a thin-film target at the tip to create an X-ray excitation probe. The processed X-ray excitation probe is precisely positioned at the analysis location, and its relative position to the sample is adjusted to ensure a safe distance and prevent contact. An electron beam is emitted using a scanning electron microscope, which then acts on the X-ray excitation probe, exciting it to produce characteristic and continuous X-rays, which in turn excite the sample to produce fluorescent X-rays.

[0045] It should be noted that: such as Figure 2 As shown in (a), the tip of the robotic arm is inserted into the processing position of the FIB. It should be noted that the robotic arm is a standard component in scanning electron microscopy (SEM), primarily used to extract samples during transmission electron microscopy (TEM) sample preparation. The robotic arm is typically made of tungsten and shaped like a needle with a circular cross-section. The curvature at the very tip is several hundred nanometers (however, it is a consumable and may disappear during subsequent processing), while the size of most of the area ranges from micrometers to tens of micrometers. In this invention, the tip is processed into a thin film to better excite X-rays.

[0046] The operation of processing the tip of the robotic arm into a thin film is as follows: (e.g.) Figure 2 As shown in (b), the upper and lower surfaces of the tip of a robotic arm can be processed using an ion beam to make it thinner, with a thickness in the micrometer range. Depending on the actual needs, it can be processed to a thickness of 1 micrometer or even 10 to 20 micrometers. A micrometer-level tip is selected, and its upper and lower surfaces are processed to make it a target material for an X-ray source.

[0047] like Figure 2As shown in (c), the needle tip is appropriately raised, and then the sample to be tested is placed in and positioned at the analysis location. Specifically, the analysis location refers to the position where the sample needs to be placed at a specific working distance to meet the requirements of sufficient X-ray detection in energy dispersive X-ray spectrometer (EDS) analysis. The working distance (WD) is the distance from the sample surface to the lower end face of the objective lens pole piece, usually measured in millimeters. In EDS analysis, the working distance of the sample to be tested needs to be fixed at a specific value (usually 4-15 mm). This is because the EDS probe is mounted at a fixed angle on the side of the sample chamber, and the working distance directly determines the geometric path and collection efficiency of X-rays from the sample to the probe. A fixed working distance ensures consistent geometric conditions for X-ray signal collection, avoiding signal intensity fluctuations and changes in the relative intensity of different elements due to distance variations. It also ensures the accuracy of quantitative analysis and data reproducibility, as the standardized calibration of the EDS is based on a specific working distance. The term "appropriate" here means ensuring that the needle tip does not touch the sample when it is at the specific working distance, depending on the actual situation. The specific value depends on the operator's adjustments.

[0048] In this embodiment, the FIB processing position and the energy dispersive spectrometer (EDS) characterization position in the scanning electron microscope (SEM) are approximately at the same height (as explained above: in a scanning electron microscope, the point where the ion beam and electron beam coincide on the surface of the sample is called the "coincident point," which corresponds to a specific working distance (typically 4-7 mm), determined by the instrument's optical design and the geometric intersection angle of the two beams. The EDS probe is also precisely mounted at this coincident point. The advantage of this design is that when the sample is placed at the coincident point, seamless switching between precise ion beam processing and high-resolution electron beam imaging can be achieved, while ensuring optimal X-ray collection efficiency and geometric conditions for EDS analysis. This allows for simultaneous ion beam cutting, electron beam observation, and component analysis at the same location, significantly improving analytical efficiency and data correlation). To prevent the probe tip from touching the sample, the tip must be appropriately raised.

[0049] At this point, the electron beam is activated. When the electron beam acts on the target material, it excites X-rays. These X-rays then excite X-rays from the sample being tested, and the energy dispersive spectrometer (EDS) receives these signals. Specifically, the electron beam acts on the target material, causing the inner-shell electrons of the target atoms to be excited and leave their orbits, creating vacancies within the atoms. Subsequently, when outer-shell electrons fill these vacancies, they release characteristic X-rays with specific energies, accompanied by continuous X-rays. These high-energy X-rays may further excite atoms in the sample below the target material, producing secondary X-rays, namely fluorescent X-rays. The EDS probe receives these X-ray signals from the sample and, by analyzing their energy characteristics and quantity, identifies the elements contained in the sample and their content. While conventional EDS directly excites the X-rays from the sample with the electron beam, the method in this invention first excites the target material with X-rays, and the X-rays emitted by the target material then excite the fluorescent X-rays from the sample, thus realizing the XRF analysis method.

[0050] The main differences between XRF (X-ray fluorescence spectrometer) and EDS (energy-dispersive X-ray spectroscopy) are as follows:

[0051] 1) Different excitation sources: XRF uses X-rays generated by an X-ray tube to excite the sample, while energy dispersive spectroscopy uses an electron beam to excite the sample. However, the X-rays generated by the X-ray tube are also generated in a vacuum tube, and the X-rays of the target are excited by electrons bombarding the target.

[0052] 2) Different analytical scales: XRF is suitable for large-area sample analysis (millimeters to centimeters), while energy dispersive spectrometers are specifically designed for micro-area analysis (nanometers to micrometers).

[0053] 3) Different sample preparation methods: XRF can directly analyze block samples and can be performed in air, while energy dispersive spectroscopy needs to be performed in an electron microscope, requiring the sample to meet the requirements for electron microscope sample preparation.

[0054] 4) Different detection limits and precision: XRF has a lower detection limit and higher quantitative precision, making it particularly suitable for trace element analysis, while energy dispersive spectrometers, although relatively less precise, have extremely high spatial resolution.

[0055] 5) Different levels of equipment integration: XRF is an independent analytical instrument (self-integrated X-ray source), while energy dispersive spectrometer must be used in conjunction with electron microscope (electron microscope provides electron beam).

[0056] Therefore, XRF is more suitable for rapid quantitative analysis of larger samples, while energy dispersive spectroscopy is more suitable for micro-area composition analysis that requires high spatial resolution.

[0057] This embodiment utilizes the energy dispersive spectroscopy (EDS) detector of a scanning electron microscope to receive and analyze the fluorescence X-ray signals generated by the sample, thereby achieving micro-area elemental composition analysis. In this embodiment, thin films of varying thicknesses can also be fabricated on the probe tip to facilitate XRF selection and analysis. Specifically, if the probe tip can rotate, the angle between the thin film and the horizontal plane can also be adjusted.

[0058] In existing technologies, the current applied to the X-ray tube of an XRF system to excite X-rays is typically in the range of microamps to milliamps; however, the current applied to the sample in an electron microscope is typically in the range of picoamps to microamps, which is relatively small. In this embodiment, the electron microscope beam current should be set to a larger value, in the range of tens of nanoamps to microamps, to increase the intensity of the X-rays.

[0059] Example 2

[0060] This invention also provides another method for realizing micro-area XRF analysis within a dual-beam electron microscope, comprising the following steps:

[0061] A focused ion beam is used to perform subtractive processing on a target material to form an X-ray excitation probe for exciting X-rays.

[0062] The processed X-ray excitation probe is precisely positioned at the analysis location, and the relative position of the processed X-ray excitation probe and the sample to be tested is adjusted to ensure that the X-ray excitation probe and the sample to be tested maintain a safe distance and do not come into contact.

[0063] The scanning electron microscope in the dual-beam electron microscope is activated to emit an electron beam in point mode and act on the X-ray excitation probe, which excites the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and then excites the sample to generate fluorescent X-rays.

[0064] The fluorescence X-ray signal generated by the sample is received and analyzed by an energy dispersive spectrometer detector to achieve micro-area composition analysis of the sample.

[0065] The methods for obtaining the target material include:

[0066] a) Drawing on the method of FIB processing transmission electron microscopy samples, a wedge-shaped groove, wider at the top and narrower at the bottom, is cut on the upper and lower sides and left side of the target material using a focused ion beam. A U-shaped cut is then made at the bottom of the groove, so that only one end of the target material is connected to the target material. The U-shaped cutting process also includes cutting from both sides of the bottom of the groove towards the middle, leaving a width of 1-2 micrometers in the middle as a hinge connection between the target material and the target material.

[0067] b) Under real-time electron beam monitoring, the tip of the robotic arm is precisely positioned to the edge of the target material, and a strong welding point is formed at the edge of the target material using ion beam induced deposition technology;

[0068] c) A low-current ion beam is used to precisely sever the hinge connection between the target material and the target substrate, so that the target material is completely separated from the target substrate and successfully extracted by the tip of the robotic arm, completing the entire in-situ transfer process.

[0069] d) Thinning of the target material using a focused ion beam, controlling the target thickness by etching the upper or lower surface of the target. The target material is an independently processed target sheet, extracted and fixed to the electron beam excitation position by the tip of a robotic arm. The independent target material includes at least one of cobalt, chromium, titanium, copper, molybdenum, or tungsten.

[0070] The thickness of the target material can be adjusted according to the absorption edge characteristics of the sample to optimize the excitation efficiency of characteristic X-rays and continuous X-rays on the sample.

[0071] The thickness of the thin-film target is 1-20 micrometers.

[0072] The specific details of this embodiment are as follows:

[0073] 1. For example Figure 3 As shown in (a), the original target material block is first loaded. Commonly used XRF source target materials such as cobalt (Co), chromium (Cr), titanium (Ti), copper (Cu), molybdenum (Mo) and tungsten (W) can be selected as materials.

[0074] 2. Next, as Figure 3 As shown in (b), the target material is excavated. This can be achieved using common transmission electron microscopy (TEM) techniques, including trenching, undercutting, ion beam-induced deposition, and in-situ extraction. It is particularly important to note that to reduce interference from backscattered electrons and stray X-rays in subsequent analysis, a box-shaped region with a lower center and higher edges can be fabricated. This way, the higher, wall-like surrounding area can partially block backscattered electrons generated by the target material and X-rays that do not reach the sample. The target material thickness is in the micrometer range; depending on actual needs, it can be processed to a thickness of 1 micrometer or even 10-20 micrometers. For blocky target materials, in the roughing stage, a high-current ion beam (30kV, 30-100nA) is first used to cut trapezoidal grooves on both sides, using an ion beam incident angle of 52° / 54° (depending on the brand of the dual-beam TEM) to form a wedge-shaped structure that is wider at the top and narrower at the bottom. The groove width is 15-20 micrometers, and the depth is 2-20 micrometers.

[0075] A U-shaped cut is then made at the bottom of the slice, cutting from both sides towards the center, but intentionally leaving about 1-2 micrometers of width in the middle as a "hinge" connection. This design prevents the slice from accidentally detaching and provides a control point for subsequent extraction operations. The entire cutting process requires precise control of depth and angle to ensure that the slice maintains its connection while possessing uniform thickness.

[0076] 3. In the in-situ extraction stage, under electron beam monitoring, a tungsten needle is precisely positioned to contact the edge or thicker portion of the sheet, avoiding the area of ​​interest. Then, ion beam-induced deposition technology is used to deposit platinum or tungsten in situ at the contact point, forming a strong weld point of 1-2 micrometers. The entire platinum deposition process uses an ion beam current of 30kV, ranging from tens to hundreds of pA. After welding is completed and the connection strength is confirmed, a smaller current ion beam (a few nA to tens of nA) is used to precisely sever the previously retained "hinge" connection. At this point, the sheet is completely detached from the substrate and supported by the tip of a robotic arm. The entire process requires alternating monitoring with electron and ion beams to ensure operational precision and sheet integrity.

[0077] 4. Thin the target material to control its thickness.

[0078] In this embodiment, to find a simpler alternative, foil with the target material composition can be used, such as copper foil ranging from a few micrometers to tens of micrometers. The simplified process is as follows: In the roughing stage, a high-current ion beam (30kV, 30-100nA) is first used to cut along three sides at an ion beam incident angle of 52° / 54°, intentionally leaving only about 1-2 micrometers of width in the middle of the fourth side as a "hinge" connection. Simply put, it's like cutting a rectangle from paper; three sides are cut off, leaving a small portion of the fourth side so it doesn't fall off completely. Then, the in-situ extraction steps described above are followed. This method eliminates the step of cutting at the bottom of the sheet, and the processed top and bottom surfaces are flatter. However, some target materials, such as tungsten, are difficult to provide in foil form.

[0079] 5. For example Figure 3 As shown in (c), the excavated target material is fixed on the probe of the robotic arm. This process can also be achieved using the techniques commonly used in transmission electron microscopy.

[0080] 6. For example Figure 3 As shown in (d), the X-ray excitation probe is appropriately raised, and then the sample to be tested is placed in the analytical position. At this time, the electron beam is turned on, and the electron beam acts on the X-ray excitation probe to excite X-rays. These X-rays then excite X-rays in the sample to be tested, and the energy dispersive spectrometer can receive these signals.

[0081] like Figure 4 As shown, for a certain type of steel, if the conventional EDS method is used, the continuous X-rays generated by the electron beam will produce a high background, resulting in a poor detection limit and the inability to identify trace amounts of magnesium. This is because the detection limit of conventional EDS is usually a few parts per thousand, while magnesium in steel is usually present in amounts less than a few parts per ten thousand.

[0082] Example 3

[0083] The present invention also provides a system for performing the analysis method of realizing micro-region XRF in a dual-beam electron microscope as described in Example 2, comprising:

[0084] A focused ion beam system is used to perform subtractive processing on a target material to form an X-ray excitation probe for exciting X-rays.

[0085] The scanning electron microscope system is used to monitor the working process inside the scanning electron microscope in a dual-beam electron microscope. It emits an electron beam in point mode to act on the X-ray excitation probe, which excites the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and then excites the sample to generate fluorescent X-rays.

[0086] A robotic arm is used to carry and hold target materials.

[0087] The energy dispersive X-ray detector is used to receive and analyze the fluorescence X-ray signals generated by the sample to achieve micro-area composition analysis of the sample.

[0088] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for micro-area XRF analysis within a dual-beam electron microscope, characterized in that, Includes the following steps: A focused ion beam is used to perform subtractive processing on a target material to form an X-ray excitation probe for exciting X-rays. The method for obtaining the X-ray excitation probe includes: a) Using a focused ion beam, wedge-shaped grooves, wider at the top and narrower at the bottom, are cut on the upper and lower sides and left side of the target material on the block-shaped target material base. A U-shaped cut is made at the bottom of the groove so that only one end of the target material is connected to the target material base. The process of making the U-shaped cut also includes cutting from both sides of the bottom of the groove towards the middle while retaining a width of 1-2 micrometers in the middle as a hinge connection between the target material and the target material base. b) Under real-time monitoring of the electron beam, the tip of the robotic arm is precisely positioned to the edge of the target material, and a strong welding point is formed at the edge of the target material using ion beam induced deposition technology; c) Use a low-current ion beam to sever the hinge connection between the target material and the target substrate, so that the target material is completely separated from the target substrate, and the target material is obtained. d) Using a focused ion beam to thin the target material, and controlling the thickness of the target material by etching the upper or lower surface of the target material, an X-ray excitation probe is obtained; The processed X-ray excitation probe is precisely positioned at the analysis location, and the relative position of the processed X-ray excitation probe and the sample to be tested is adjusted to ensure that the X-ray excitation probe and the sample to be tested maintain a safe distance and do not come into contact. The scanning electron microscope in the dual-beam electron microscope is activated to emit an electron beam in point mode and act on the X-ray excitation probe, which excites the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and then excites the sample to generate fluorescent X-rays. The fluorescence X-ray signal generated by the sample is received and analyzed by an energy dispersive spectrometer detector to achieve micro-area composition analysis of the sample.

2. The method for realizing micro-region XRF analysis within a dual-beam electron microscope according to claim 1, characterized in that, The extraction process of the target material includes: using FIB to cut and extract micron-sized thin target material from the blocky target material matrix, and fixing it with the needle tip of a robotic arm.

3. The method for realizing micro-region XRF analysis within a dual-beam electron microscope according to claim 1, characterized in that, The target material is an independently processed target sheet, which is extracted and fixed to the electron beam excitation position by the tip of a robotic arm. The target material includes at least one of cobalt, chromium, titanium, copper, molybdenum or tungsten.

4. The method for realizing micro-region XRF analysis within a dual-beam electron microscope according to claim 1, characterized in that, The thickness of the target material can be adjusted according to the absorption edge characteristics of the sample to optimize the excitation efficiency of characteristic X-rays and continuous X-rays on the sample.

5. The method for realizing micro-region XRF analysis within a dual-beam electron microscope according to claim 3, characterized in that, The thickness of the target sheet is 1-20 micrometers.

6. An analysis system for realizing micro-region XRF within a dual-beam electron microscope, used to perform the analysis method for realizing micro-region XRF within a dual-beam electron microscope as described in any one of claims 1-5, characterized in that, include: A focused ion beam system is used to perform subtractive processing on target materials to form an X-ray excitation probe for exciting X-rays. The scanning electron microscope system is used to monitor the working process inside the scanning electron microscope in a dual-beam electron microscope. It emits an electron beam in point mode to act on the X-ray excitation probe, which excites the X-ray excitation probe to generate characteristic X-rays and continuous X-rays, and then excites the sample to generate fluorescent X-rays. A robotic arm is used to carry and hold target materials. The energy dispersive X-ray detector is used to receive and analyze the fluorescence X-ray signals generated by the sample to achieve micro-area composition analysis of the sample.

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