L-shaped direct flight type three-dimensional atom probe ultra-high vacuum system

Abstract

The application provides an L-shaped direct flight type three-dimensional atom probe ultra-high vacuum system, and relates to the technical field of three-dimensional atom probes.The system comprises a sample feeding chamber, a transition chamber and an analysis chamber, and each chamber is connected to an independent vacuum pumping system.A lifting type sample storage bin is arranged in the transition chamber to temporarily store and switch the sample.A first horizontal vacuum magnetic rod and a second vertical vacuum magnetic rod intersect in the transition chamber to form an L-shaped transmission path.The second vacuum magnetic rod vertically sends the sample stage upward into the analysis chamber, so that the sample needle tip directly aims at the center of the local electrode.A high vacuum isolation valve with a gas locking device is arranged between the transition chamber and the analysis chamber.The application can eliminate the complicated mechanical alignment and calibration steps, greatly improve the sample switching and pumping efficiency, and has a quick isolation protection mechanism, thereby significantly improving the safety and reliability of the system.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional atomic probe technology, and more specifically, to an L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system. Background Technology

[0002] Atomic probe tomography (APT) is a cutting-edge characterization technique capable of analyzing the three-dimensional spatial composition of materials at the sub-nanometer scale. Based on the principles of electric field evaporation and time-of-flight mass spectrometry, this technique applies a high-voltage pulse or laser pulse to an extremely sharp needle-like sample, causing atoms on the sample surface to evaporate one by one and be collected by a detector, thereby reconstructing the three-dimensional atomic-level distribution information within the material. Due to its extremely high spatial resolution and all-element detection capability, 3D atomic probes play an irreplaceable foundational role in cutting-edge scientific research fields such as advanced alloy development, semiconductor device failure analysis, natural mineral evolution, and nanomaterial characterization.

[0003] To ensure high-precision analysis using a 3D atom probe microanalyzer, its analytical chamber must be maintained in an extremely high vacuum environment. This ultra-high vacuum environment not only effectively ensures that ions evaporated by the electric field do not collide with residual gas molecules and be deflected during their journey to the detector, but also significantly suppresses the adsorption of residual gas molecules on the extremely low-temperature sample tip surface. If the vacuum level is insufficient during analysis, these adsorbed impurity molecules will evaporate simultaneously, introducing severe background noise into the mass spectrum and even interfering with the peak identification of target elements. Furthermore, a poor vacuum level can easily lead to surface oxidation of the sample tip or micro-arc breakdown discharge when a high-voltage electric field is applied, directly causing tip breakage and resulting in the complete failure of a single experiment. Therefore, constructing a stable, reliable, and extremely low-gas-load ultra-high vacuum system is a fundamental prerequisite for the successful operation of a 3D atom probe microanalyzer.

[0004] Currently, mainstream three-dimensional atomic probe ultra-high vacuum systems typically employ multi-chamber cascaded vacuum systems, generally consisting of three chambers: a sample delivery chamber, a transition chamber, and an analysis chamber. However, this traditional linear series layout has revealed numerous design flaws and technical bottlenecks in practical applications. The traditional linear series layout results in an extremely long overall axial dimension of the system, not only occupying a large area and placing extremely high demands on laboratory space layout, but also making the sample transport path very long. Due to the extremely small central aperture of the local electrodes of the atomic probe, even slight mechanical vibrations or accumulated manufacturing errors during long-path transport can cause the sample delivery rod to fail to accurately deliver the sample into the analysis chamber in one go. Operators often need to rely on extremely cumbersome optical microscopic observation and multi-dimensional fine-tuning mechanisms for repeated calibration to barely align the sample tip with the central area of ​​the local electrode. This not only heavily relies on the operator's technical experience but also significantly reduces the daily testing throughput and lifespan of the equipment.

[0005] Existing vacuum systems also face significant challenges in sample change efficiency and system maintenance. Current transition chambers generally lack multi-station sample storage and scheduling capabilities. Each time a new sample is replaced or an old sample is removed, a complete cycle must be performed: fully retracting the sample feed rod, venting the sample feed chamber, loading the new sample, and re-evacuating to a high vacuum. This frequent venting and evacuation not only consumes a significant amount of time per sample change but also easily leads to periodic minor fluctuations in the vacuum environment of the analysis chamber itself, severely affecting the stability and repeatability of long-term analytical results. Furthermore, to accommodate traditional linear sample feed mechanisms, the inner surfaces of the sample feed chamber and transition chamber in existing systems have material venting loads, further extending the time required to re-evacuate to the target vacuum level after each venting, significantly slowing down the experimental operation.

[0006] Regarding system safety, if an accidental leak occurs in the transition chamber or sample inlet, due to human error, or a sudden mechanical failure of the pump unit causing a sharp increase in vacuum, and if the connection between the analysis chamber and the outside cannot be severed within a very short time, contaminated gases from the outside will rapidly enter the analysis chamber, severely polluting its pristine ultra-high vacuum analytical environment. Once the analysis chamber is contaminated, continuous high-temperature baking and degassing of the entire chamber are usually required, which will result in incalculable economic and time losses for scientific research and testing. A completely new vacuum system architecture is urgently needed to overcome the aforementioned technical barriers in terms of spatial layout, alignment efficiency, sample changeover rhythm, and safety protection. Summary of the Invention

[0007] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.

[0008] Therefore, the present invention provides an L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system.

[0009] The present invention provides an L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system, comprising a sample delivery chamber, a transition chamber, and an analysis chamber, wherein each of the sample delivery chamber, the transition chamber, and the analysis chamber is connected to an independent vacuum pumping system; One end of the transition chamber is connected to the sample delivery chamber via a first ultra-high vacuum isolation valve, and the top of the transition chamber is connected to the bottom of the analysis chamber via a second ultra-high vacuum isolation valve. The transition chamber is equipped with a liftable sample storage compartment for storing and avoiding samples. The system also includes a horizontally arranged first vacuum magnetic rod and a vertically arranged second vacuum magnetic rod; the transmission axis of the first vacuum magnetic rod and the transmission axis of the second vacuum magnetic rod are arranged perpendicular to each other and intersect in the transition chamber to form an L-shaped sample transmission path; The first vacuum magnetic rod is configured to transport the sample stage carrying the sample from the sample delivery chamber to the transition chamber in a horizontal direction when the first ultra-high vacuum isolation valve is opened; The analysis chamber is horizontally equipped with a local electrode and a delay line detector. The vertical transmission axis of the second vacuum magnetic rod intersects perpendicularly with the central horizontal axis of the local electrode. The second vacuum magnetic rod is configured to vertically transport the sample stage located in the transition chamber to the analysis chamber when the second ultra-high vacuum isolation valve is opened, so that the sample needle tip on the sample stage is directly aligned with the central region of the local electrode.

[0010] The L-shaped direct-flying three-dimensional atom probe ultra-high vacuum system according to the above-described technical solution of the present invention may also have the following additional technical features: In the above technical solution, the lifting sample storage chamber in the transition chamber has multiple sample storage positions for accommodating sample stages; the lifting sample storage chamber is configured to perform vertical lifting displacement in the transition chamber, so as to move any one of the sample storage positions to the intersection of the horizontal transmission axis of the first vacuum magnetic rod and the vertical transmission axis of the second vacuum magnetic rod. During the sample replacement stage, the lifting sample storage chamber switches between different sample storage positions through lifting and lowering movements to receive a new sample stage sent in by the first vacuum magnetic rod, or to move the sample storage position containing the selected sample stage to the vertical conveying axis so that the sample stage is locked by the second vacuum magnetic rod and sent into the analysis chamber in the vertical direction.

[0011] In the above technical solution, the analysis chamber is also equipped with an ultra-low temperature cooling device, which is equipped with a cold head copper conductor. The cold head copper conductor is connected to the sample stage at a preset locking position in the analysis chamber, so as to cool the sample stage after the sample stage is sent in by the second vacuum magnetic rod and the sample needle tip is directly aligned with the center area of ​​the local electrode, so that the analysis chamber is in an ultra-low temperature and ultra-high vacuum state.

[0012] In the above technical solution, the second ultra-high vacuum isolation valve is an ultra-high vacuum isolation valve equipped with an air-locking device; the system also includes a controller that is signal-connected to the ultra-high vacuum isolation valve equipped with the air-locking device, so as to jointly protect the vacuum environment in the analysis chamber from interference by the sample change operation in the transition chamber.

[0013] In the above technical solution, the controller is configured to monitor the vacuum level inside the analysis chamber in real time in ultra-high vacuum mode, and acquire a control signal when the vacuum level inside the analysis chamber rises and exceeds a preset safety threshold. Then, the controller automatically triggers the air-locking device of the ultra-high vacuum isolation valve equipped with an air-locking device to close, so as to prevent the vacuum level inside the analysis chamber from continuing to deteriorate.

[0014] In the above technical solution, the ultra-high vacuum isolation valve with an air-locking device is a vacuum proportional valve with a reverse-locking function.

[0015] In the above technical solution, the independent vacuum pumping system of the analysis chamber includes a titanium sublimation composite ion pump, a first cold trap, a first solenoid valve, and a first mechanical pump; the inlet of the titanium sublimation composite ion pump is connected to the analysis chamber through a third ultra-high vacuum valve, and the outlet of the titanium sublimation composite ion pump is connected to the first mechanical pump in sequence through the first cold trap and the first solenoid valve.

[0016] In the above technical solution, the independent vacuum pumping system connected to the transition chamber includes a first molecular pump, a second cold trap, a second solenoid valve, and a second mechanical pump; the inlet of the first molecular pump is connected to the bottom of the transition chamber through a fourth ultra-high vacuum valve, and the outlet of the first molecular pump is connected to the second mechanical pump in sequence through the second cold trap and the second solenoid valve.

[0017] In the above technical solution, the independent vacuum pumping system connected to the sample delivery chamber includes a second molecular pump, a third cold trap, a third solenoid valve, and a third mechanical pump; the inlet of the second molecular pump is connected to the sample delivery chamber through a fifth ultra-high vacuum valve, and the outlet of the second molecular pump is connected to the third mechanical pump in sequence through the third cold trap and the third solenoid valve. Furthermore, a third vacuum magnetic rod is connected to one side of the sample delivery chamber to cooperate with the operation of the first vacuum magnetic rod.

[0018] In the above technical solution, the connecting pipe assemblies between the analysis chamber, the transition chamber, and the sample delivery chamber and their respective independent vacuum pumping systems are all seamless stainless steel corrugated pipes with a circular cross-section; in the analysis mode, the analysis chamber is filled with helium, neon, or argon gas with a purity of 99.999%.

[0019] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are: This invention pioneers an L-shaped sample transport path where the transition chamber and analysis chamber intersect perpendicularly, effectively overcoming the drawbacks of traditional three-dimensional atomic probe direct-flying systems, such as excessively long axial dimensions and large footprint. A horizontally positioned first vacuum magnetic rod and a vertically positioned second vacuum magnetic rod are spatially aligned within the transition chamber, precisely positioned on the central horizontal axis of the local electrode. This structure greatly simplifies the tedious and repetitive fine-tuning and calibration steps required in traditional equipment, significantly shortening sample introduction time, reducing the operational threshold and the risk of mechanical collisions during sample introduction, and significantly improving the equipment's operating efficiency and overall reliability.

[0020] This invention innovatively integrates a vertically lifting sample storage chamber within the transition chamber. Under continuous testing requirements, the lifting sample storage chamber allows for switching and temporary storage between multiple old and new sample stages, thus avoiding the cumbersome cycle of thoroughly venting and re-evacuating the sample delivery chamber every time a sample is changed. This design significantly improves sample replacement efficiency while preventing periodic fluctuations in the ultra-high vacuum environment of the analysis chamber caused by frequent venting and re-evacuation, effectively ensuring the stability and repeatability of analytical results under long-term continuous testing conditions.

[0021] This invention constructs a highly intelligent vacuum safety protection mechanism, specifically configuring an ultra-high vacuum isolation valve with a gas-locking device and a matching controller between the analysis chamber and the transition chamber. In ultra-high vacuum test mode, once the system detects an abnormal increase in the vacuum level of the analysis chamber, the controller will receive a signal and instantly trigger the gas-locking device of the isolation valve to close. This mechanism can immediately and tightly protect the ultra-high vacuum environment of the analysis chamber in the event of a sudden leak or sample change operation, avoiding high maintenance costs and lengthy re-degassing time caused by severe chamber contamination, and greatly improving the system's fault tolerance.

[0022] This invention provides independent vacuum pumping systems for the sample delivery chamber, transition chamber, and analysis chamber, connected by seamless stainless steel corrugated pipes with a circular cross-section. This independent pump design, combined with a compact chamber volume, significantly reduces the overall internal wall gas load and shortens the pumping time. Ultimately, the analysis chamber of this invention can maintain excellent ultra-low temperature and ultra-high vacuum conditions, and the system operating pressure can reach 10... -9 The Pa level is required, and the overall leakage rate is less than 5×10. - 10 Pa·L / s provides an excellent and pure physical environment for suppressing background noise and preventing tip oxidation or arc breakdown for three-dimensional atomic probes.

[0023] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of an L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to an embodiment of the present invention.

[0025] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 1. First vacuum magnetic rod; 2. First displacement stage; 3. Sample delivery chamber; 4. Third vacuum magnetic rod; 5. Fifth ultra-high vacuum valve; 6. Second molecular pump; 7. Third cold trap; 8. Third solenoid valve; 9. Third mechanical pump; 10. First ultra-high vacuum isolation valve; 11. Transition chamber; 12. Second displacement stage; 13. Second vacuum magnetic rod; 14. Fourth ultra-high vacuum valve; 15. First molecular pump; 16. Second cold trap; 17. Second solenoid valve; 18. Second mechanical pump; 19. Second ultra-high vacuum isolation valve; 20. Analysis chamber; 21. Sample stage; 22. Local electrode; 23. Delay line detector; 24. Cold head copper conductor; 25. Ultra-low temperature cooling device; 26. Third ultra-high vacuum valve; 27. Titanium sublimation composite ion pump; 28. First cold trap; 29. ​​First solenoid valve; 30. First mechanical pump. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0028] The following reference Figure 1 This describes an L-shaped direct-flying three-dimensional atom probe ultra-high vacuum system provided according to some embodiments of the present invention.

[0029] Some embodiments of this application provide an L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system.

[0030] like Figure 1As shown, the first embodiment of this invention proposes an L-shaped direct-flight three-dimensional atomic probe ultra-high vacuum system, which mainly consists of three chambers: a sample delivery chamber 3, a transition chamber 11, and an analysis chamber 20. To ensure that each chamber can independently maintain the required working vacuum level, the sample delivery chamber 3, transition chamber 11, and analysis chamber 20 are each connected to an independent vacuum pumping system. Regarding the connection and isolation control between the chambers, one end of the transition chamber 11 is connected to the sample delivery chamber 3 via a first ultra-high vacuum isolation valve 10. Switching the first ultra-high vacuum isolation valve 10 can vacuum isolate the sample delivery chamber 3 from the transition chamber 11 or open a passage between them. The top of the transition chamber 11 is connected to the bottom of the analysis chamber 20 via a second ultra-high vacuum isolation valve 19. The second ultra-high vacuum isolation valve 19 vacuum isolates the analysis chamber 20 from the transition chamber 11, thereby ensuring that the extremely pure vacuum environment inside the analysis chamber 20 is not disturbed by sample introduction and changeover operations. Meanwhile, the transition chamber 11 is specially equipped with a liftable sample storage compartment for storing and avoiding samples, so as to achieve temporary storage and scheduling of samples from multiple workstations without disrupting the vacuum of the main system.

[0031] To completely overcome the spatial limitations of traditional linear series layouts, the system in this embodiment also includes a horizontally positioned first vacuum magnetic rod 1 and a vertically positioned second vacuum magnetic rod 13. The transmission axis of the first vacuum magnetic rod 1 extends horizontally, while the transmission axis of the second vacuum magnetic rod 13 extends vertically. The transmission axes of the first vacuum magnetic rod 1 and the second vacuum magnetic rod 13 are perpendicular to each other and precisely intersect at the internal center of the transition chamber 11, thus forming a compact and efficient L-shaped sample transfer path within the system. The first vacuum magnetic rod 1 is configured to extend and move horizontally when the first ultra-high vacuum isolation valve 10 is opened, directly transferring the sample stage 21 carrying the needle tip sample from the sample delivery chamber 3 to the transition chamber 11. After transferring the sample stage 21 to the preset station in the transition chamber 11, the connection is disconnected and the rod is horizontally reset, after which the first ultra-high vacuum isolation valve 10 can be closed.

[0032] In one specific embodiment, a local electrode 22 and a delay line detector 23 are horizontally arranged within the analysis chamber 20, with the local electrode 22 and delay line detector 23 aligned in a straight line to form a horizontal mass spectrometry axis for field evaporation ion flight. The vertical transport axis of the second vacuum magnetic rod 13 intersects the central horizontal axis of the local electrode 22 perpendicularly. The second vacuum magnetic rod 13 is configured to extend vertically upwards when the second ultra-high vacuum isolation valve 19 is opened, thereby transporting the sample stage 21, located at the intersection in the transition chamber 11, upwards into the analysis chamber 20. Since the relative spatial position of the intersection of the vertical trajectory of the second vacuum magnetic rod 13 and the horizontal axis is pre-fixed mechanically, during sample injection, as the second vacuum magnetic rod 13 rises vertically, the sample tip on the sample stage 21 can be precisely aligned with the central hole region of the local electrode 22. This direct-flight alignment and transport design eliminates the cumbersome mechanical position calibration steps required for traditional long-path straight-line transport, significantly reducing the difficulty of position calibration and greatly improving the overall throughput of the equipment.

[0033] In some embodiments, combined with Figure 1As shown, the lifting sample storage chamber within the transition chamber 11 constitutes the core mechanism for achieving rapid and efficient sample changing in this system. This lifting sample storage chamber has multiple independently partitioned sample storage positions for accommodating the sample stage 21, and its overall configuration allows for precise vertical lifting and lowering within the transition chamber 11. Due to this lifting action, the system can accurately move and position any sample storage position within the chamber to the spatial intersection of the horizontal conveying axis of the first vacuum magnetic rod 1 and the vertical conveying axis of the second vacuum magnetic rod 13. During the sample changing phase, the operator does not need to vent the entire chamber; the lifting sample storage chamber, through its vertical lifting action, can flexibly switch the positions of different sample storage positions at the intersection. When external sample introduction is required, the first ultra-high vacuum isolation valve 10 is opened. Driven by the first displacement stage 2, the first vacuum magnetic rod 1 horizontally pushes the sample stage 21 carrying the new sample into the currently aligned empty sample storage position in the transition chamber 11, completing the reception of the new sample stage. Subsequently, the first vacuum magnetic rod 1 disconnects and resets, and the first ultra-high vacuum isolation valve 10 closes. When a sample needs to be sent to the analysis chamber 20 for testing, the lifting sample storage chamber moves the specific sample storage position containing the selected sample stage to the vertical conveying axis through further lifting displacement, precisely aligning it with the second vacuum magnetic rod 13. At this time, the second ultra-high vacuum isolation valve 19 is opened, and the second vacuum magnetic rod 13, located below, locks the selected sample stage 21 upwards with the cooperation of the second displacement stage 12, and continues to vertically send it into the analysis chamber 20. This design, which utilizes a lifting structure within the transition chamber 11 to achieve multi-position storage and mechanical avoidance, greatly simplifies the entire sample changing process and effectively shortens the evacuation waiting time for each sample change.

[0034] In one specific embodiment, to meet the testing requirements of the three-dimensional atomic probe for field evaporation of the tip sample in an extremely low temperature environment, the analysis chamber 20 is also specially equipped with an ultra-low temperature cooling device 25, and the cold end of the ultra-low temperature cooling device 25 is connected to a high thermal conductivity cold head copper conductor 24. The spatial position of the cold head copper conductor 24 corresponds to the preset locking position of the sample stage 21 in the analysis chamber 20. When the sample stage 21 is fed into the analysis chamber 20 from the transition chamber 11 upward along the vertical conveying axis by the second vacuum magnetic rod 13, and the sample tip on the sample stage 21 is directly and accurately aligned with the center area of ​​the local electrode 22 and locked, the second vacuum magnetic rod 13 is disconnected and returns to the transition chamber 11, and the second ultra-high vacuum isolation valve 19 is closed at the same time. At this time, the cold head copper conductor 24 and the sample stage 21 locked in the test position achieve reliable contact or thermal conduction connection, and the ultra-low temperature cooling device 25 begins to efficiently cool the sample stage 21 and the tip sample on top. Through the continuous heat conduction of the cold-head copper conductor 24, the temperature of the sample stage 21 and the sample tip on it can be steadily reduced to below 80K, thereby keeping the entire interior of the analysis chamber 20 in an ultra-low temperature and ultra-high vacuum mode. This ultra-low temperature environment effectively suppresses the adsorption noise of residual hydrogen on the low-temperature tip and prevents reactive gases from causing tip oxidation or arc breakdown under field evaporation high pressure, thus providing solid temperature and physical environment support for the delay line detector 23 to capture high-quality field evaporation ion data.

[0035] In some embodiments, to cope with sudden vacuum deterioration and protect the extremely expensive ultra-high vacuum analysis chamber, this system incorporates a highly intelligent vacuum safety protection mechanism. For example... Figure 1 As shown, the second ultra-high vacuum isolation valve 19, located between the transition chamber 11 and the analysis chamber 20, is an ultra-high vacuum isolation valve equipped with a gas-locking device. During the normal sample preparation phase, this ultra-high vacuum isolation valve 19 with a gas-locking device is used to strictly isolate the analysis chamber 20 from the transition chamber 11 under vacuum. More importantly, when the system's analysis chamber 20 is in ultra-high vacuum test mode, if a leakage in the transition chamber or a sample injection misoperation causes an abnormal increase in the vacuum level of the analysis chamber 20, the valve will automatically trigger the closure of its internal gas-locking device, thereby instantly cutting off the channel for external gas inflow and protecting the ultra-high vacuum environment of the analysis chamber 20 from damage.

[0036] In one specific embodiment, the rapid response of this vacuum safety protection mechanism is achieved through coordinated action by a controller. The system also includes a controller that is signal-connected to the ultra-high vacuum isolation valve 19 equipped with a gas-locking device. In ultra-high vacuum mode, the controller is configured to monitor the vacuum level within the analysis chamber 20 in real time. When the system detects that the vacuum level in the analysis chamber 20 continues to deteriorate and exceeds a preset safety threshold, for example, the vacuum level rises to 10...-7 Pa or 10 -8 When the pressure reaches a certain level (Pa), the system can immediately issue an alarm, and the controller will immediately receive a control signal. The controller uses this control signal to automatically and in real time control the ultra-high vacuum isolation valve 19 equipped with a gas-locking device, causing the gas-locking device to open and close instantly for protection, in order to prevent the vacuum level in the analysis chamber 20 from continuing to rise and deteriorate.

[0037] In a further embodiment, to ensure that the isolation valve can withstand the pressure difference that may occur on both sides after emergency triggering and closing without leakage or accidental opening, the ultra-high vacuum isolation valve 19 with a gas-locking device is specifically adopted as a vacuum proportional valve with a back-locking function. This vacuum proportional valve with a back-locking function can not only control the opening and closing state of the valve during normal sample changing, but also provide a reliable hard seal guarantee through the back-locking mechanical structure in emergency gas-locking state, thereby strictly and independently protecting the ultra-high vacuum environment of the analysis chamber 20 and improving the safety and reliability of the overall vacuum layout of the system.

[0038] In some embodiments, to ensure the overall vacuum level of the system, the sample delivery chamber 3, the transition chamber 11, and the analysis chamber 20 are each equipped with an independent vacuum pumping system. For example... Figure 1 As shown, for the most demanding analytical chamber 20, its connected independent vacuum pumping system mainly includes a titanium sublimation composite ion pump 27, a first cold trap 28, a first solenoid valve 29, and a first mechanical pump 30. The inlet of the titanium sublimation composite ion pump 27 is connected to the bottom of the analytical chamber 20 via a third ultra-high vacuum valve 26, and the outlet of the titanium sublimation composite ion pump 27 is connected to the first mechanical pump 30, which serves as a backing pump, via the first cold trap 28 and the first solenoid valve 29. In ultra-high vacuum mode, the first solenoid valve 29 is open to cooperate with the titanium sublimation composite ion pump 27 to maintain the internal temperature of the analytical chamber 20 at 10°C. -9 Ultimate vacuum at the Pa level.

[0039] In one specific embodiment, the independent vacuum pumping system connected to the transition chamber 11 includes a first molecular pump 15, a second cold trap 16, a second solenoid valve 17, and a second mechanical pump 18. The inlet of the first molecular pump 15 is connected to the bottom of the transition chamber 11 via a fourth ultra-high vacuum valve 14, and the outlet of the first molecular pump 15 is connected to the preceding second mechanical pump 18 via the second cold trap 16 and the second solenoid valve 17. When in ultra-high vacuum mode, by opening the fourth ultra-high vacuum valve 14, the second cold trap 16, and the second solenoid valve 17, the vacuum level in the transition chamber 11 can be maintained at less than 1 × 10⁻⁶. -8 Pa is a high vacuum state.

[0040] Furthermore, the independent vacuum pumping system connected to the sample delivery chamber 3 includes a second molecular pump 6, a third cold trap 7, a third solenoid valve 8, and a third mechanical pump 9. The inlet of the second molecular pump 6 is connected to the sample delivery chamber 3 through a fifth ultra-high vacuum valve 5, and the outlet of the second molecular pump 6 is connected to the third mechanical pump 9 sequentially through the third cold trap 7 and the third solenoid valve 8. To facilitate sample handling within the sample delivery chamber 3, a third vacuum magnetic rod 4 is also connected to one side of the sample delivery chamber 3 to assist in the operation of the first vacuum magnetic rod 1.

[0041] In one specific embodiment, the linear displacement axis of the third vacuum magnetic rod 4, located on one side of the sample delivery chamber 3, is perpendicularly orthogonal to the horizontal transmission axis of the first vacuum magnetic rod 1. During the initial sample loading stage, when a new sample stage from the external atmospheric environment is loaded into the sample delivery chamber 3, the third vacuum magnetic rod 4 is configured to extend along its own displacement axis toward the center of the sample delivery chamber 3 to laterally receive the new sample stage placed from the outside. After the sample delivery chamber 3 is sealed and its independent vacuum pumping system completes the high-vacuum operation, the third vacuum magnetic rod 4 and the first vacuum magnetic rod 1 collaboratively connect within the sample delivery chamber 3, securely transferring and locking the temporarily received sample stage to the front end of the first vacuum magnetic rod 1. After confirming the sample stage handover and locking is complete, the third vacuum magnetic rod 4 retracts to its initial clearance position on the side of the chamber, thus smoothly completing the transition of the sample stage from the outside to the inside of the vacuum system and clearing motion interference for the subsequent horizontal transmission of the first vacuum magnetic rod 1 to the transition chamber 11.

[0042] In some embodiments, to further reduce the gas load on the inner wall of the system and improve the overall sealing reliability of the pipeline connections, the connecting pipe assemblies between the analysis chamber 20 and its corresponding vacuum pumping system are all made of seamless stainless steel corrugated pipes with a circular cross-section. Correspondingly, the connecting pipe assemblies between the transition chamber 11 and the sample delivery chamber 3 and their respective independent vacuum pumping systems are also made of seamless stainless steel corrugated pipes with a circular cross-section. When actually performing sample analysis and entering the analysis mode, the working gas filled in the analysis chamber 20 is ultra-high purity helium, neon, or argon, with a purity of 99.999%.

[0043] In one specific embodiment, to ensure that the vacuum levels of each chamber meet the testing requirements and are independent of each other, the system sets specific valve control and operating modes for different chambers. Specifically, the sample delivery chamber 3 has a high vacuum mode. In this mode, the first ultra-high vacuum isolation valve 10 is closed, and the fifth ultra-high vacuum valve 5, along with the corresponding third cold trap 7 and third solenoid valve 8, are opened, making the vacuum level in the sample delivery chamber 3 less than 1×10⁻⁶. -8Pa. The transition chamber 11 has an ultra-high vacuum mode. In this mode, the first ultra-high vacuum isolation valve 10 and the second ultra-high vacuum isolation valve 19 are closed, and the fourth ultra-high vacuum valve 14 and the corresponding second cold trap 16 and second solenoid valve 17 are opened, so that the vacuum degree in the transition chamber 11 is also maintained at less than 1 × 10 Pa. -8 The analysis chamber 20 has ultra-low temperature and ultra-high vacuum modes. In this mode, the second ultra-high vacuum isolation valve 19 is closed, the ultra-low temperature cooling device 25 is turned on, and the third ultra-high vacuum valve 26, along with the corresponding first cold trap 28 and first solenoid valve 29, are opened. Through the coordinated operation of the system, the ultimate vacuum level in the analysis chamber 20 can reach 10 Pa. -9 The Pa level is maintained, and the temperature is controlled below 80K.

[0044] To further illustrate the overall collaborative working process of the three-dimensional atomic probe ultra-high vacuum system of the present invention, this embodiment also provides a sample introduction operation method based on any of the above embodiments of the three-dimensional atomic probe ultra-high vacuum system. First, the sample tip to be tested is placed and fixed on the sample stage 21, aligning the sample stage 21 with the first vacuum magnetic rod 1 located in the sample delivery chamber 3. After the sample delivery chamber 3 is initially evacuated and reaches a high vacuum mode, the first ultra-high vacuum isolation valve 10 between the sample delivery chamber 3 and the transition chamber 11 is opened. The sample stage 21 is then transferred to the sample storage position in the transition chamber 11 by the horizontal movement of the first vacuum magnetic rod 1. Subsequently, the connection between the first vacuum magnetic rod 1 and the bottom of the sample stage 21 is disconnected, the first vacuum magnetic rod 1 horizontally retracts, and the first ultra-high vacuum isolation valve 10 is closed. Next, in conjunction with the movement of the lifting sample storage chamber, the sample stage 21 in the transition chamber 11 is aligned with and locked to the second vacuum magnetic rod 13 below, and then the second vacuum magnetic rod 13 vertically transfers the sample stage 21 into the analysis chamber 20. Since the position of the second vacuum magnetic rod 13 on the horizontal plane is fixed by the mechanical structure, it can directly align the sample needle tip on the sample stage to the center region of the local electrode 22 during the vertical ascent. After the final alignment and confirmation are completed, the second vacuum magnetic rod 13 is disconnected from the sample stage 21 and returns downward to the transition chamber 11. Finally, the second ultra-high vacuum isolation valve 19 is closed, the cryogenic cooling device 25 is activated, and the vacuum system of the analysis chamber is turned on, so that the system officially enters the ultra-high vacuum testing and analysis state.

[0045] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. An L-shaped, direct-flying three-dimensional atomic probe ultra-high vacuum system, characterized in that, It includes a sample delivery chamber, a transition chamber, and an analysis chamber, each of which is connected to an independent vacuum pumping system; One end of the transition chamber is connected to the sample delivery chamber via a first ultra-high vacuum isolation valve, and the top of the transition chamber is connected to the bottom of the analysis chamber via a second ultra-high vacuum isolation valve. The transition chamber is equipped with a liftable sample storage compartment for storing and avoiding samples. The system also includes a horizontally arranged first vacuum magnetic rod and a vertically arranged second vacuum magnetic rod; the transmission axis of the first vacuum magnetic rod and the transmission axis of the second vacuum magnetic rod are arranged perpendicular to each other and intersect in the transition chamber to form an L-shaped sample transmission path; The first vacuum magnetic rod is configured to transport the sample stage carrying the sample from the sample delivery chamber to the transition chamber in a horizontal direction when the first ultra-high vacuum isolation valve is opened; The analysis chamber is horizontally equipped with a local electrode and a delay line detector. The vertical transmission axis of the second vacuum magnetic rod intersects perpendicularly with the central horizontal axis of the local electrode. The second vacuum magnetic rod is configured to vertically transport the sample stage located in the transition chamber to the analysis chamber when the second ultra-high vacuum isolation valve is opened, so that the sample needle tip on the sample stage is directly aligned with the central region of the local electrode.

2. The L-shaped direct-flying three-dimensional atom probe ultra-high vacuum system according to claim 1, characterized in that, The lifting sample storage chamber in the transition chamber has multiple sample storage positions for accommodating sample stages; the lifting sample storage chamber is configured to move vertically up and down in the transition chamber, so as to move any one of the sample storage positions to the intersection of the horizontal transmission axis of the first vacuum magnetic rod and the vertical transmission axis of the second vacuum magnetic rod. During the sample replacement stage, the lifting sample storage chamber switches between different sample storage positions through lifting and lowering movements to receive a new sample stage sent in by the first vacuum magnetic rod, or to move the sample storage position containing the selected sample stage to the vertical conveying axis so that the sample stage is locked by the second vacuum magnetic rod and sent into the analysis chamber in the vertical direction.

3. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The analysis chamber is also equipped with an ultra-low temperature cooling device, which has a cold head copper conductor. The cold head copper conductor is connected to the sample stage at a preset locking position in the analysis chamber, so as to cool the sample stage after the sample stage is sent in by the second vacuum magnetic rod and the sample needle tip is directly aligned with the center area of ​​the local electrode, so that the analysis chamber is in an ultra-low temperature and ultra-high vacuum state.

4. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The second ultra-high vacuum isolation valve is an ultra-high vacuum isolation valve equipped with an air-locking device; the system also includes a controller that is signal-connected to the ultra-high vacuum isolation valve equipped with the air-locking device, so as to jointly protect the vacuum environment in the analysis chamber from interference by the sample change operation in the transition chamber.

5. The L-shaped direct-flying three-dimensional atom probe ultra-high vacuum system according to claim 4, characterized in that, The controller is configured to monitor the vacuum level inside the analysis chamber in real time in ultra-high vacuum mode, and to acquire a control signal when the vacuum level inside the analysis chamber rises and exceeds a preset safety threshold. Then, the controller automatically triggers the air-locking device of the ultra-high vacuum isolation valve equipped with an air-locking device to close, so as to prevent the vacuum level inside the analysis chamber from deteriorating further.

6. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 4, characterized in that, The ultra-high vacuum isolation valve equipped with an airlock device is a vacuum proportional valve with a reverse-lock function.

7. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The independent vacuum pumping system of the analysis chamber includes a titanium sublimation composite ion pump, a first cold trap, a first solenoid valve, and a first mechanical pump. The inlet of the titanium sublimation composite ion pump is connected to the analysis chamber through a third ultra-high vacuum valve, and the outlet of the titanium sublimation composite ion pump is connected to the first mechanical pump in sequence through the first cold trap and the first solenoid valve.

8. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The independent vacuum pumping system connected to the transition chamber includes a first molecular pump, a second cold trap, a second solenoid valve, and a second mechanical pump. The inlet of the first molecular pump is connected to the bottom of the transition chamber through a fourth ultra-high vacuum valve, and the outlet of the first molecular pump is connected to the second mechanical pump in sequence through the second cold trap and the second solenoid valve.

9. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The independent vacuum pumping system connected to the sample delivery chamber includes a second molecular pump, a third cold trap, a third solenoid valve, and a third mechanical pump. The inlet of the second molecular pump is connected to the sample delivery chamber through a fifth ultra-high vacuum valve, and the outlet of the second molecular pump is connected to the third mechanical pump in sequence through the third cold trap and the third solenoid valve. A third vacuum magnetic rod is also connected to one side of the sample delivery chamber to cooperate with the operation of the first vacuum magnetic rod.

10. The L-shaped direct-flying three-dimensional atomic probe ultra-high vacuum system according to claim 1, characterized in that, The connecting pipe assemblies between the analysis chamber, transition chamber, and sample delivery chamber and their respective independent vacuum pumping systems are all seamless stainless steel corrugated pipes with a circular cross-section; in analysis mode, the analysis chamber is filled with helium, neon, or argon gas with a purity of 99.999%.

Images