Electron lens assembly and electron microscope

Abstract

The utility model relates to the technical field of electron microscopes, in particular to an electron lens assembly and an electron microscope. The electronic lens assembly comprises a cooling device, a condenser assembly and an objective lens, a liquid cooling pipe is arranged on the cooling equipment and comprises an input section, a cooling section and an output section which are connected in sequence; the input section of the liquid cooling pipe is connected with the output end of the cooling device, at least part of the cooling section is located in the condenser assembly and the objective lens, and the output section is connected with the input end of the cooling device. According to the electronic lens assembly, the condenser assembly and the objective lens are cooled through the liquid cooling pipe at the same time, Joule heat generated by coils of all stages of an electron microscope can be taken away by a cooling medium, uniform heat dissipation of the coils of all stages can be kept, the influence of uneven heat dissipation on an optical axis is reduced, and the service life of the electron microscope is prolonged. Therefore, the requirement of high-quality imaging of a high-resolution electron microscope can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of electron microscopes, in particular to an electron lens assembly and an electron microscope. Background Art

[0002] As integrated circuit process nodes continue to shrink, especially at the 14nm level and below, optical inspection technology has been unable to meet the requirements of efficient identification of subtle defects. Therefore, electron beam inspection equipment, especially scanning electron microscopes (SEMs), has become a key tool for detecting semiconductor wafer defects.

[0003] The working principle of SEM is based on the precise focusing and scanning of the electron beam. This process relies on the precise operation of the electron lens assembly, in which the coil of the electron lens generates a magnetic field through current excitation to focus the electron beam. However, the coil will generate significant Joule heat under long-term high current excitation. If the heat cannot be effectively dissipated, it will not only affect the uniformity of the magnetic field, but also cause image drift, thus affecting the imaging quality.

[0004] In order to solve the heat dissipation problem of the scanning electron microscope, the existing solution is to add a cooling device to the objective lens to cool the objective lens coil; however, when performing electron microscope applications that require high-resolution observation, it is usually necessary to image the sample very accurately, which often involves the use of a smaller electron beam spot. Therefore, it is necessary to apply strong excitation to the condenser to ensure that the electron beam spot is smaller to meet the high-resolution requirements; at this time, if the condenser is strongly excited for a long time and only the objective lens is cooled, the scanning electron microscope coil will dissipate uneven heat, resulting in uneven distribution of the magnetic field passing through the condenser, causing the main optical axis to drift, and seriously affecting imaging. Utility Model Content

[0005] In order to solve the technical problem that the imaging quality of the existing electron microscope is easily affected by uneven heat dissipation when performing high-resolution imaging, the utility model provides an electron lens assembly and an electron microscope.

[0006] The utility model solves the technical problem by providing an electronic lens assembly, comprising a cooling device and a condenser assembly and an objective lens arranged in sequence; the cooling device is provided with a liquid cooling tube, and the liquid cooling tube comprises an input section, a cooling section and an output section connected in sequence; the input section of the liquid cooling tube is connected to the output end of the cooling device, at least part of the cooling section is located in the condenser assembly and the objective lens, and the output section is connected to the input end of the cooling device.

[0007] Preferably, it further comprises a thermal sensor and a control module, wherein the thermal sensor is electrically connected to the control module, and the control module is electrically connected to the cooling device, and the thermal sensors are respectively arranged in the condenser lens assembly and the objective lens.

[0008] Preferably, a flow regulating valve is provided at the output end of the cooling device, and the control module is electrically connected to the flow regulating valve.

[0009] Preferably, the thermal sensor is a thermocouple, and the thermocouple comprises a measuring end and a reference end which are electrically connected, the measuring end is arranged in the condenser lens assembly and the objective lens, and the reference end is electrically connected to the control module.

[0010] Preferably, the condenser assembly comprises at least one condenser, the condenser and the objective lens both comprise an electromagnetic coil, and the measuring end is disposed in the electromagnetic coil.

[0011] Preferably, the measuring end comprises a hot electrode wire, and the electromagnetic coil is obtained by winding a conductive wire together with the hot electrode wire.

[0012] Preferably, the condenser includes a first condenser and a second condenser, and the first condenser, the second condenser and the objective lens are arranged in sequence and coaxially; the first condenser, the second condenser and the objective lens all include a shell, the electromagnetic coil is arranged in the shell, there is a gap between the electromagnetic coil and the inner wall of the shell, the corresponding area of ​​the liquid cooling tube is located in the gap, and the shell is provided with an inlet and outlet connecting the gap with the outside.

[0013] Preferably, the gap is located between the electromagnetic coil and the top of the shell, and the inlet and outlet are arranged on the circumferential outer side wall of the shell.

[0014] Preferably, the cooling section includes a secondary cooling section and a connecting section respectively arranged corresponding to each electromagnetic coil, the cooling section is arranged in the gap, and the input end and the output end of the cooling section are exposed through the inlet and outlet; along the flow direction of the coolant, the output end of one secondary cooling section is connected to the input end of the next secondary cooling section through the connecting section; the arrangement positions of the input end and the output section of two adjacent secondary cooling sections are opposite.

[0015] Another solution of the utility model to solve the technical problem is to provide an electron microscope, including the electron lens assembly as described above.

[0016] Compared with the prior art, the utility model provides an electron lens assembly and an electron microscope, which have the following advantages:

[0017] 1. The electronic lens assembly provided by the embodiment of the utility model realizes active cooling of key optical components by integrating cooling equipment, condenser assembly and objective lens, effectively suppresses the degradation of equipment performance in high temperature environment, and improves the stability and working efficiency of the electron microscope. Specifically, the scheme provides heat dissipation function by setting cooling equipment and liquid cooling pipe; the input section, cooling section and output section of the liquid cooling pipe are connected in sequence, and form a closed loop with the cooling equipment to ensure the continuous circulation of the coolant, so as to efficiently take away the heat generated by the condenser assembly and the objective lens; the liquid cooling pipe dissipates heat for the condenser assembly and the objective lens at the same time, ensuring that the Joule heat generated by the coils of each level of the electron microscope can be taken away by the cooling medium, which is conducive to maintaining uniform heat dissipation of the coils at each level, reducing the influence of uneven heat dissipation on the optical axis, so as to meet the requirements of high-resolution electron microscope high-quality imaging; the cooling section is located in part of the lens assembly, directly in contact with or adjacent to the heat source, which can significantly improve the heat exchange efficiency, reduce heat accumulation, and further improve the heat dissipation capacity of the electronic lens assembly.

[0018] 2. The electronic lens assembly of the utility model embodiment adds a thermal sensor and a control module to the basic cooling mechanism, forming an intelligent temperature control system, so that the lens assembly can dynamically adjust the cooling strategy according to the actual temperature; specifically, the thermal sensor is set in the condenser assembly and the objective lens, which can ensure direct monitoring of the hottest point and improve the accuracy of temperature measurement; by electrically connecting the integrated thermal sensor and the control module, real-time monitoring of temperature data is achieved, and the response speed and control accuracy of the system are improved; the combination of the two can respond to local overheating in a timely manner, improve cooling efficiency, and further ensure the long-term stable operation of the equipment.

[0019] 3. The electronic lens assembly of the utility model embodiment introduces a flow regulating valve, which enhances the adaptability of the cooling system, allows dynamic adjustment of the coolant flow as needed, and improves energy efficiency and cooling efficiency; the electrical connection between the control module and the flow regulating valve enables the system to automatically respond to the signal of the thermal sensor and instantly adjust the coolant flow, ensuring the accuracy of temperature control.

[0020] 4. The electronic lens assembly of the embodiment of the utility model adopts a thermocouple as a thermal sensor, which enhances the reliability and accuracy of temperature measurement and enables the entire system to control the temperature more accurately. Specifically, the separation design of the measuring end and the reference end of the thermocouple, combined with the precise arrangement of the measuring end in the condenser assembly and the objective lens, ensures the accurate transmission of temperature information to the control module, thereby achieving high-precision temperature monitoring.

[0021] 5. The electronic lens assembly of the embodiment of the utility model sets the measuring end inside the electromagnetic coil, which ensures the accurate monitoring of the heating area of ​​the electromagnetic coil, which is directly related to the stability of the lens magnetic field and the imaging quality.

[0022] 6. The electronic lens group of the utility model embodiment realizes the integration of temperature monitoring and electromagnetic driving functions by winding the thermocouple wire and the conductive wire together into an electromagnetic coil, which saves space and improves the accuracy of thermal management; specifically, this design enables the measuring end of the thermocouple to directly sense the temperature change inside the electromagnetic coil without the need for additional installation space, thereby improving the immediacy and accuracy of temperature detection; at the same time, the thermal effect of the thermocouple measuring end is tightly coupled with the electromagnetic coil, ensuring the directness and rapidity of temperature feedback, facilitating rapid response and adjustment of cooling strategies, and avoiding control errors caused by heat transfer delays.

[0023] 7. The electronic lens group of the embodiment of the utility model realizes an optimized combination of thermal management and optical path by arranging the first condenser, the second condenser and the objective lens in the shell, and retaining a gap between the shell and the electromagnetic coil for arranging the liquid cooling tube, thereby effectively improving the cooling efficiency and optical performance; specifically, the coaxial arrangement of the lens ensures the continuity and focusing effect of the optical path, and the shell design provides mechanical support and thermal isolation for each component, reducing the influence of the external environment on the optical performance; the liquid cooling tube is arranged in the gap between the electromagnetic coil and the shell, which not only reduces the interference to the optical path, but also directly acts on the hottest electromagnetic coil area, realizing efficient local cooling and maintaining the thermal stability of the lens assembly.

[0024] 8. The electronic lens assembly of the embodiment of the utility model ensures smooth entry and exit of the coolant by arranging the inlet and outlet on the circumferential outer wall of the shell, optimizes the maintainability and operability of the liquid cooling system, and reduces the impact of the liquid cooling system on the optical path; specifically, the inlet and outlet are located in the gap between the top of the shell and the top of the electromagnetic coil. This design facilitates the circulation of the coolant, while avoiding obstruction of the condenser and the objective lens, maintaining the purity of the optical path; the inlet and outlet design of the outer wall makes it easier to replace or check the coolant, simplifies the cleaning and maintenance process of the cooling system, and reduces maintenance costs.

[0025] 9. The electronic lens assembly of the utility model embodiment ensures the uniform distribution and efficient flow of the cooling liquid among multiple electromagnetic coils through the layout of the secondary cooling section and the connecting section, improves the heat exchange efficiency, and ensures the uniform cooling of the electronic lens assembly; specifically, along the flow direction of the cooling liquid, the secondary cooling sections are connected in sequence to ensure the continuous transfer of heat, avoid local overheating, and make the temperature of the entire lens assembly more uniform; the reverse arrangement of the input end and the output section of adjacent secondary cooling sections facilitates the installation of the connecting section, and effectively optimizes the line layout of the liquid cooling pipe.

[0026] 10. The embodiment of the utility model also provides an electron microscope, including the electron lens assembly as described above; it has the same beneficial effects as the above-mentioned electron lens assembly, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of an existing electron lens assembly.

[0028] Figure 2 This is a schematic diagram of the structure of the electronic lens assembly provided by the embodiment of the utility model. Figure 1 .

[0029] Figure 3 This is a schematic diagram of the heat dissipation of the electronic lens assembly provided by the embodiment of the utility model Figure 1 .

[0030] Figure 4 This is a schematic diagram of the heat dissipation of the electronic lens assembly provided by the embodiment of the utility model Figure 2 .

[0031] Figure 5 The first condenser of the electronic lens assembly provided by the embodiment of the utility model is schematically shown in FIG. Figure 1 .

[0032] Figure 6 The first condenser of the electronic lens assembly provided by the embodiment of the utility model is schematically shown in FIG. Figure 2 .

[0033] Figure 7 This is a schematic diagram of the structure of the electronic lens assembly provided by the embodiment of the utility model. Figure 2 .

[0034] Figure 8 It is a schematic diagram of the arrangement of liquid cooling pipes outside the housing of the electronic lens assembly provided in an embodiment of the utility model.

[0035] Fig. 9 It is a block diagram of an electron microscope provided by an embodiment of the utility model.

[0036] Description of the accompanying drawings:

[0037] 1001, electron source; 1002, suppression electrode; 1003, extraction electrode; 1004, condenser lens 1; 1005, condenser lens 2; 1006, objective lens; 1007, cooling tube; 1008, coil; 1009, deflector; 1010, electron beam channel;

[0038] 100. Electron microscope; 10. Electron lens assembly;

[0039] 1. condenser assembly; 11. first condenser; 111. first housing; 1111. accommodating cavity; 1112. gap; 1113. inlet and outlet; 112. first coil; 1121. wire;

[0040] 12. second condenser; 121. second housing; 122. second coil;

[0041] 2. Objective lens; 21. Third shell; 22. Third coil; 31. Input section; 32. Cooling section; 321. Secondary cooling section; 322. Connecting section; 33. Output section; 4. Cooling device; 41. Flow regulating valve; 5. Thermal sensor; 51. Thermal electrode; 6. Control module. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0043] It should be noted that the terms "first" and "second" and the like in the specification and claims of the present invention are used to distinguish different objects rather than to describe a specific order.

[0044] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0045] In the present invention, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0046] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this utility model can be understood according to specific circumstances.

[0047] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0048] To facilitate understanding of this solution, a preliminary explanation of the existing technical solution is given here. Figure 1 , Figure 1 The present invention is a schematic diagram of a lens assembly of an existing scanning electron microscope; as shown in the figure, the lens assembly includes a condenser lens 1004, a condenser lens 1005 and an objective lens 1006 which are arranged in sequence from top to bottom; a coil 1008 is arranged inside each of the condenser lens 1004, the condenser lens 1005 and the objective lens 1006; at the same time, an electron beam channel 1010 is arranged at the central axis of the condenser lens 1004, the condenser lens 1005 and the objective lens 1006; an electron source 1001 is arranged at the entrance of the electron beam channel, and a suppressor electrode 1002 and an extraction electrode 1003 are arranged corresponding to the electron source 1001; a deflector 1009 is also arranged at the end of the electron beam channel 1010;

[0049] During operation, the electron source 1001 excites an electron beam under high voltage, the suppressor 1002 suppresses stray electrons, and the extractor 1003 extracts the electron beam to enter the electron beam channel 1010. The electron beam is transmitted downward along the electron beam channel 1010. When the electron beam passes through the condenser 1004, the current in the coil 1008 of the condenser 1004 generates a magnetic field, which performs preliminary focusing on the electron beam and adjusts the direction and intensity of the electron beam to make it more convergent. This process is similar to the function of a lens in an optical microscope, but here it is achieved by electromagnetic rather than optical means. The deflector 1009 at the end of the electron beam channel 1010 is responsible for controlling the scanning trajectory of the electron beam on the sample surface. By quickly and accurately adjusting the direction of the electron beam, the electron beam moves on the sample surface in a predetermined pattern, scanning point by point or line by line to construct a complete sample image.

[0050] A cooling tube 1007 is also provided in the objective lens 1006 for cooling the coil 1008 in the objective lens 1006 during operation. However, when electron microscope applications that require high-resolution observation are performed, it is usually necessary to image the sample very accurately, which often involves the use of a smaller electron beam spot. Therefore, it is necessary to apply strong excitation to the condenser to ensure that the electron beam spot is smaller to meet the high-resolution requirement. At this time, if the condenser is strongly excited for a long time and only the objective lens 1006 is cooled, the scanning electron microscope coil 1008 will dissipate heat unevenly, thereby causing uneven distribution of the magnetic field passing through the condenser, causing the main optical axis to drift, and seriously affecting the imaging.

[0051] Please combine Figure 2 and Figure 3 In order to solve the above problems, the first embodiment of the utility model provides an electronic lens assembly, which includes a cooling device and a condenser lens assembly and an objective lens arranged in sequence; a liquid cooling tube is provided on the cooling device, and the liquid cooling tube includes an input section, a cooling section and an output section connected in sequence; the input section of the liquid cooling tube is connected to the output end of the cooling device, at least a part of the cooling section is located in the condenser lens assembly and the objective lens, and the output section is connected to the input end of the cooling device.

[0052] It can be understood that the electron lens assembly provided in this embodiment realizes active cooling of key optical components by integrating cooling equipment, condenser assembly and objective lens, effectively suppresses the degradation of equipment performance in high temperature environment, and improves the stability and working efficiency of the electron microscope.

[0053] Please combine Figure 2 and Figure 3 In order to solve the above problems, the first embodiment of the utility model provides an electronic lens assembly 10, which includes a cooling device 4 and a condenser lens assembly 1 and an objective lens 2 arranged in sequence; a liquid cooling pipe is provided on the cooling device 4, and the liquid cooling pipe includes an input section 31, a cooling section 32 and an output section 33 connected in sequence; the input section 31 of the liquid cooling pipe is connected to the output end of the cooling device 4, at least a part of the cooling section 32 is located in the condenser lens assembly 1 and the objective lens 2, and the output section 33 is connected to the input end of the cooling device 4.

[0054] It can be understood that the electron lens assembly 10 provided in this embodiment realizes active cooling of key optical components by integrating the cooling device 4, the condenser assembly 1 and the objective lens 2, effectively suppresses the degradation of equipment performance in a high temperature environment, and improves the stability and working efficiency of the electron microscope 100.

[0055] For details, please continue to refer to Figure 2 and Figure 3 , Figure 2 It is a schematic diagram of the electronic lens assembly 10 in the embodiment of the utility model; Figure 3 This is a schematic diagram of heat dissipation in an embodiment of the utility model. Figure 3 The arrows in the figure indicate the flow direction of the coolant during heat dissipation; the present solution provides heat dissipation function by setting up a cooling device 4 and a liquid cooling pipe; the input section 31, the cooling section 32, and the output section 33 of the liquid cooling pipe are connected in sequence and form a closed loop with the cooling device 4, thereby ensuring the continuous circulation of the coolant, thereby efficiently taking away the heat generated by the condenser lens assembly 1 and the objective lens 2; the liquid cooling pipe simultaneously dissipates heat for the condenser lens assembly 1 and the objective lens 2, thereby ensuring that the Joule heat generated by the coils at all levels of the electron microscope 100 can be taken away by the cooling medium, which is conducive to maintaining uniform heat dissipation of the coils at all levels and reducing the influence of uneven heat dissipation on the optical axis, thereby meeting the requirements of high-resolution electron microscope 100 for high-quality imaging; a part of the cooling section 32 is located inside the lens assembly, directly in contact with or adjacent to the heat source, which can significantly improve the heat exchange efficiency, reduce heat accumulation, and further improve the heat dissipation capacity of the present electronic lens assembly 10.

[0056] It can be understood that the cooling device 4 is used to drive the coolant in the liquid cooling tube to circulate, thereby providing a stable heat dissipation capacity; optionally, the coolant can be water, deionized water, ethylene glycol aqueous solution, carbon fluoride refrigerant and liquid cooling oil, etc.; in this embodiment, the type of coolant is not limited, and the change of the coolant type does not affect the implementation of this solution.

[0057] For further information, see Figure 4 The output end of the cooling device 4 is provided with a flow regulating valve 41. It can be understood that the electronic lens assembly 10 of this embodiment introduces the flow regulating valve 41, which enhances the adaptability of the cooling system, allows the coolant flow to be dynamically adjusted as needed, and improves energy efficiency and cooling efficiency.

[0058] Further, it continues to refer to Figure 4 The electronic lens assembly 10 also includes a thermal sensor 5 and a control module 6. The thermal sensor 5 is electrically connected to the control module 6. The control module 6 is electrically connected to the cooling device 4. The thermal sensors 5 are respectively provided in the condenser assembly 1 and the objective lens 2.

[0059] It can be understood that the electronic lens assembly 10 of this embodiment adds a thermal sensor 5 and a control module 6 to the basic cooling mechanism, forming an intelligent temperature control system, so that the lens assembly can dynamically adjust the cooling strategy according to the actual temperature; specifically, the thermal sensor 5 is set in the focusing lens assembly 1 and the objective lens 2, which can ensure direct monitoring of the hottest point and improve the accuracy of temperature measurement; by electrically connecting the integrated thermal sensor 5 and the control module 6, real-time monitoring of temperature data is achieved, and the response speed and control accuracy of the system are improved; the combination of the two can respond to local overheating in a timely manner, improve cooling efficiency, and further ensure the long-term stable operation of the equipment.

[0060] As an implementation method, the control module 6 uses a PID temperature control module; the PID temperature control module is an automatic control device used to accurately adjust and maintain the temperature of a system or device near a set value. PID stands for proportional, integral and derivative control algorithm, which is a control strategy widely used in control theory, and is particularly suitable for occasions that require fine temperature control, such as electronic equipment, chemical reactors, environmental control systems, etc.

[0061] The working principle of the PID module is as follows:

[0062] Proportional (P) control: The P control part produces an output proportional to the current error (the difference between the set temperature and the actual temperature). The larger the error, the stronger the corrective effect of the output. P control can respond to errors quickly, but there may be steady-state errors, that is, the system cannot completely eliminate the error.

[0063] Integral (I) control: The I control portion accumulates error over time, and if the error persists, the integral action gradually increases the output until the error is eliminated. This portion helps eliminate steady-state errors, but excessive integration can cause the system to overshoot or oscillate.

[0064] Derivative (D) control: The D control part predicts the future error change trend and makes adjustments based on the current error change rate. It can respond in advance and reduce overshoot, but is sensitive to noise.

[0065] Combining these three parts, the PID controller can provide fast response, no steady-state error and strong anti-disturbance temperature control. The PID module continuously compares the set temperature with the actual temperature and calculates a control signal to adjust the operation of the heating or cooling device 4 to achieve and maintain the desired temperature set point. The control algorithm can be implemented in hardware or in software programming in a microprocessor or controller, such as in an industrial automation system, PLC, DCS system or a dedicated temperature controller.

[0066] For further information, please refer to Figure 4 , the control module 6 is electrically connected to the flow regulating valve 41 .

[0067] It can be understood that the electrical connection between the control module 6 and the flow regulating valve 41 enables the system to automatically respond to the signal of the thermal sensor 5 and adjust the coolant flow in real time, thereby ensuring the accuracy of temperature control.

[0068] As a feasible implementation, the thermal sensor 5 is a thermocouple, which includes a measuring end and a reference end that are electrically connected. The measuring end is disposed in the condenser lens assembly 1 and the objective lens 2 , and the reference end is electrically connected to the control module 6 .

[0069] It can be understood that the electronic lens assembly 10 of this embodiment uses a thermocouple as a thermal sensor 5, which enhances the reliability and accuracy of temperature measurement, allowing the entire system to control temperature more accurately; specifically, the separate design of the measuring end and the reference end of the thermocouple, combined with the precise arrangement of the measuring end in the condenser assembly 1 and the objective lens 2, ensures the accurate transmission of temperature information to the control module 6, thereby achieving high-precision temperature monitoring.

[0070] Furthermore, please combine Figure 5 and Figure 6 The measuring end includes a hot electrode 51 wire, and the electromagnetic coil is obtained by winding the wire 1121 and the hot electrode 51 wire together.

[0071] It can be understood that the electronic lens group of this embodiment will realize the integration of temperature monitoring and electromagnetic driving functions by winding the thermocouple wire 51 and the conductive wire 1121 together into an electromagnetic coil, which not only saves space but also improves the accuracy of thermal management; specifically, this design enables the measuring end of the thermocouple to directly sense the temperature changes inside the electromagnetic coil without the need for additional installation space, thereby improving the immediacy and accuracy of temperature detection; at the same time, the thermal effect of the thermocouple measuring end is tightly coupled with the electromagnetic coil, ensuring the directness and rapidity of temperature feedback, facilitating rapid response and adjustment of cooling strategies, and avoiding control errors caused by heat transfer delays.

[0072] Specifically, Figure 5 and Figure 6 Two different winding methods of the conductor 1121 and the hot electrode 51 are shown respectively, wherein Figure 5 The winding method shown in the figure is that a wire 1121 and a hot electrode 51 wire are wound simultaneously; Figure 6 The winding method shown is that four wires 1121 are wound together with one thermode 51 wire, and the thermode 51 wire is located between the corresponding four wires 1121.

[0073] Furthermore, the condenser lens assembly 1 includes at least one condenser lens, and both the condenser lens and the objective lens 2 include an electromagnetic coil, and the measuring end is disposed in the electromagnetic coil.

[0074] It can be understood that the electronic lens assembly of this embodiment has the measuring end disposed inside the electromagnetic coil, which ensures accurate monitoring of the heating area of ​​the electromagnetic coil, and is directly related to the stability of the lens magnetic field and the imaging quality.

[0075] It should be noted that in the electron microscope 100, these "condensers" are not actually glass lenses, but electromagnetic lenses that manipulate and focus the electron beam through electromagnetic fields. Traditionally, the name condenser comes from the function of similar components in optical instruments, and the word focusing is used to describe the process of concentrating and intensifying light, making it more concentrated and brighter in a specific area. In the context of the electron microscope 100, the function of the condenser is similar to that of an optical lens, which is to concentrate the flow of energy (in this case, the flow of electrons), so the term focusing is used.

[0076] For further information, see Figure 7 The condenser includes a first condenser 11 and a second condenser 12, and the first condenser 11, the second condenser 12 and the objective lens 2 are arranged in sequence and coaxially; the first condenser 11, the second condenser 12 and the objective lens 2 all include a shell, the electromagnetic coil is arranged in the shell, and there is a gap 1112 between the electromagnetic coil and the inner wall of the shell, the corresponding area of ​​the liquid cooling tube is located in the gap 1112, and the shell is provided with an inlet and outlet 1113 connecting the gap 1112 with the outside.

[0077] It can be understood that the electronic lens group of this embodiment achieves an optimized combination of thermal management and optical path by arranging the first condenser 11, the second condenser 12 and the objective lens 2 in the shell, and retaining a gap 1112 between the shell and the electromagnetic coil for arranging the liquid cooling tube, thereby effectively improving the cooling efficiency and optical performance; specifically, the coaxial arrangement of the lens ensures the continuity and focusing effect of the optical path, and the shell design provides mechanical support and thermal isolation for each component, reducing the influence of the external environment on the optical performance; the liquid cooling tube is arranged in the gap 1112 between the electromagnetic coil and the shell, which not only reduces the interference with the optical path, but also directly acts on the hottest electromagnetic coil area, achieving efficient local cooling and maintaining the thermal stability of the lens assembly.

[0078] Specifically, the first condenser 11 includes a first shell 111 and a first coil 112 disposed in the first shell 111; the second condenser 12 includes a second shell 121 and a second coil 122 disposed in the second shell 121; the objective lens 2 includes a third shell 21 and a third coil 22 disposed in the third shell 21.

[0079] For details, please refer to Figure 5 Taking the first condenser 11 as an example, the first shell 111 defines a accommodating cavity 1111, and the electromagnetic coil obtained by winding the wire 1121 and the hot electrode 51 wire together is arranged in the accommodating cavity 1111; a gap 1112 is defined between the electromagnetic coil and the top of the inner surface of the accommodating cavity 1111.

[0080] Furthermore, the gap 1112 is located between the electromagnetic coil and the top of the shell, and the inlet and outlet 1113 are provided on the circumferential outer side wall of the shell.

[0081] It can be understood that the electronic lens assembly 10 of this embodiment ensures smooth entry and exit of the coolant by setting the inlet and outlet 1113 on the circumferential outer wall of the shell, optimizes the maintainability and operability of the liquid cooling system, and reduces the impact of the liquid cooling system on the optical path; specifically, the inlet and outlet 1113 are located in the gap 1112 between the top of the shell and the top of the electromagnetic coil. This design facilitates the circulation of the coolant while avoiding obstruction of the condenser and the objective lens 2, thereby maintaining the purity of the optical path; the design of the inlet and outlet 1113 on the outer wall makes it easier to replace or check the coolant, simplifies the cleaning and maintenance process of the cooling system, and reduces maintenance costs.

[0082] Furthermore, please combine Figure 4 and Figure 8 The cooling section 32 includes a secondary cooling section 321 and a connecting section 322 respectively arranged corresponding to each electromagnetic coil. The cooling section 32 is arranged in the gap 1112, and the input end and the output end of the cooling section 32 are exposed through the inlet and outlet 1113; along the flow direction of the coolant, the output end of a secondary cooling section 321 is connected to the input end of the next secondary cooling section 321 through the connecting section 322; the arrangement positions of the input ends and the output sections 33 of two adjacent secondary cooling sections 321 are opposite.

[0083] It can be understood that the electronic lens assembly 10 of this embodiment ensures the uniform distribution and efficient flow of the cooling liquid among multiple electromagnetic coils through the layout of the secondary cooling section 321 and the connecting section 322, improves the heat exchange efficiency, and ensures the uniform cooling of the electronic lens assembly 10; specifically, along the flow direction of the cooling liquid, the secondary cooling sections 321 are connected in sequence to ensure the continuous transfer of heat, avoid local overheating, and make the temperature of the entire lens assembly more uniform; the reverse arrangement of the input end and the output section 33 of adjacent secondary cooling sections 321 facilitates the installation of the connecting section 322, and effectively optimizes the line layout of the liquid cooling pipe.

[0084] See also Fig. 9 The second embodiment of the present invention further provides an electron microscope 100, comprising the electron lens assembly 10 as described above. It can be understood that the electron microscope 100 has the same beneficial effects as the above-mentioned electron lens assembly 10, which will not be described in detail here.

[0085] Compared with the prior art, the utility model provides an electron lens assembly and an electron microscope, which have the following advantages:

[0086] 1. The electronic lens assembly provided by the embodiment of the utility model realizes active cooling of key optical components by integrating cooling equipment, condenser assembly and objective lens, effectively suppresses the degradation of equipment performance in high temperature environment, and improves the stability and working efficiency of the electron microscope. Specifically, the scheme provides heat dissipation function by setting cooling equipment and liquid cooling pipe; the input section, cooling section and output section of the liquid cooling pipe are connected in sequence, and form a closed loop with the cooling equipment to ensure the continuous circulation of the coolant, so as to efficiently take away the heat generated by the condenser assembly and the objective lens; the liquid cooling pipe dissipates heat for the condenser assembly and the objective lens at the same time, ensuring that the Joule heat generated by the coils of each level of the electron microscope can be taken away by the cooling medium, which is conducive to maintaining uniform heat dissipation of the coils at each level, reducing the influence of uneven heat dissipation on the optical axis, so as to meet the requirements of high-resolution electron microscope high-quality imaging; the cooling section is located in part of the lens assembly, directly in contact with or adjacent to the heat source, which can significantly improve the heat exchange efficiency, reduce heat accumulation, and further improve the heat dissipation capacity of the electronic lens assembly.

[0087] 2. The electronic lens assembly of the utility model embodiment adds a thermal sensor and a control module to the basic cooling mechanism, forming an intelligent temperature control system, so that the lens assembly can dynamically adjust the cooling strategy according to the actual temperature; specifically, the thermal sensor is set in the condenser assembly and the objective lens, which can ensure direct monitoring of the hottest point and improve the accuracy of temperature measurement; by electrically connecting the integrated thermal sensor and the control module, real-time monitoring of temperature data is achieved, and the response speed and control accuracy of the system are improved; the combination of the two can respond to local overheating in a timely manner, improve cooling efficiency, and further ensure the long-term stable operation of the equipment.

[0088] 3. The electronic lens assembly of the utility model embodiment introduces a flow regulating valve, which enhances the adaptability of the cooling system, allows dynamic adjustment of the coolant flow as needed, and improves energy efficiency and cooling efficiency; the electrical connection between the control module and the flow regulating valve enables the system to automatically respond to the signal of the thermal sensor and instantly adjust the coolant flow, ensuring the accuracy of temperature control.

[0089] 4. The electronic lens assembly of the embodiment of the utility model adopts a thermocouple as a thermal sensor, which enhances the reliability and accuracy of temperature measurement and enables the entire system to control the temperature more accurately. Specifically, the separation design of the measuring end and the reference end of the thermocouple, combined with the precise arrangement of the measuring end in the condenser assembly and the objective lens, ensures the accurate transmission of temperature information to the control module, thereby achieving high-precision temperature monitoring.

[0090] 5. The electronic lens assembly of the embodiment of the utility model sets the measuring end inside the electromagnetic coil, which ensures the accurate monitoring of the heating area of ​​the electromagnetic coil, which is directly related to the stability of the lens magnetic field and the imaging quality.

[0091] 6. The electronic lens group of the utility model embodiment realizes the integration of temperature monitoring and electromagnetic driving functions by winding the thermocouple wire and the conductive wire together into an electromagnetic coil, which saves space and improves the accuracy of thermal management; specifically, this design enables the measuring end of the thermocouple to directly sense the temperature change inside the electromagnetic coil without the need for additional installation space, thereby improving the immediacy and accuracy of temperature detection; at the same time, the thermal effect of the thermocouple measuring end is tightly coupled with the electromagnetic coil, ensuring the directness and rapidity of temperature feedback, facilitating rapid response and adjustment of cooling strategies, and avoiding control errors caused by heat transfer delays.

[0092] 7. The electronic lens group of the embodiment of the utility model realizes an optimized combination of thermal management and optical path by arranging the first condenser, the second condenser and the objective lens in the shell, and retaining a gap between the shell and the electromagnetic coil for arranging the liquid cooling tube, thereby effectively improving the cooling efficiency and optical performance; specifically, the coaxial arrangement of the lens ensures the continuity and focusing effect of the optical path, and the shell design provides mechanical support and thermal isolation for each component, reducing the influence of the external environment on the optical performance; the liquid cooling tube is arranged in the gap between the electromagnetic coil and the shell, which not only reduces the interference to the optical path, but also directly acts on the hottest electromagnetic coil area, realizing efficient local cooling and maintaining the thermal stability of the lens assembly.

[0093] 8. The electronic lens assembly of the embodiment of the utility model ensures smooth entry and exit of the coolant by arranging the inlet and outlet on the circumferential outer wall of the shell, optimizes the maintainability and operability of the liquid cooling system, and reduces the impact of the liquid cooling system on the optical path; specifically, the inlet and outlet are located in the gap between the top of the shell and the top of the electromagnetic coil. This design facilitates the circulation of the coolant, while avoiding obstruction of the condenser and the objective lens, maintaining the purity of the optical path; the inlet and outlet design of the outer wall makes it easier to replace or check the coolant, simplifies the cleaning and maintenance process of the cooling system, and reduces maintenance costs.

[0094] 9. The electronic lens assembly of the utility model embodiment ensures the uniform distribution and efficient flow of the cooling liquid among multiple electromagnetic coils through the layout of the secondary cooling section and the connecting section, improves the heat exchange efficiency, and ensures the uniform cooling of the electronic lens assembly; specifically, along the flow direction of the cooling liquid, the secondary cooling sections are connected in sequence to ensure the continuous transfer of heat, avoid local overheating, and make the temperature of the entire lens assembly more uniform; the reverse arrangement of the input end and the output section of adjacent secondary cooling sections facilitates the installation of the connecting section, and effectively optimizes the line layout of the liquid cooling pipe.

[0095] 10. The embodiment of the utility model also provides an electron microscope, including the electron lens assembly as described above; it has the same beneficial effects as the above-mentioned electron lens assembly, which will not be described in detail here.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An electronic lens assembly, characterized in that: It includes a cooling device and a condenser lens assembly and an objective lens arranged in sequence; The cooling device is provided with a liquid cooling tube, which includes an input section, a cooling section and an output section which are connected in sequence; the input section of the liquid cooling tube is connected to the output end of the cooling device, at least part of the cooling section is located in the condenser assembly and the objective lens, and the output section is connected to the input end of the cooling device.

2. The electronic lens assembly according to claim 1, wherein: It also includes a thermal sensor and a control module. The thermal sensor is electrically connected to the control module, and the control module is electrically connected to the cooling device. The thermal sensors are respectively arranged in the condenser lens assembly and the objective lens.

3. The electronic lens assembly according to claim 2, wherein: The output end of the cooling device is provided with a flow regulating valve, and the control module is electrically connected to the flow regulating valve.

4. The electronic lens assembly according to claim 2, wherein: The thermal sensor is a thermocouple, and the thermocouple includes a measuring end and a reference end which are electrically connected. The measuring end is arranged in the condenser lens assembly and the objective lens, and the reference end is electrically connected to the control module.

5. The electronic lens assembly according to claim 4, characterized in that: The condenser lens assembly comprises at least one condenser lens. Both the condenser lens and the objective lens comprise an electromagnetic coil. The measuring end is arranged in the electromagnetic coil.

6. The electron lens assembly according to claim 5, characterized in that: The measuring end includes a hot electrode wire, and the electromagnetic coil is obtained by winding a conductive wire together with the hot electrode wire.

7. The electron lens assembly according to claim 5, characterized in that: The condenser includes a first condenser and a second condenser, and the first condenser, the second condenser and the objective lens are arranged in sequence and coaxially; the first condenser, the second condenser and the objective lens all include a shell, the electromagnetic coil is arranged in the shell, there is a gap between the electromagnetic coil and the inner wall of the shell, the corresponding area of ​​the liquid cooling tube is located in the gap, and the shell is provided with an inlet and outlet connecting the gap with the outside.

8. The electron lens assembly according to claim 7, wherein: The gap is located between the electromagnetic coil and the top of the shell, and the inlet and outlet are arranged on the circumferential outer side wall of the shell.

9. The electron lens assembly according to claim 8, characterized in that: The cooling section includes a secondary cooling section and a connecting section respectively arranged corresponding to each electromagnetic coil, the cooling section is arranged in the gap, and the input end and the output end of the cooling section are exposed through the inlet and outlet; along the flow direction of the coolant, the output end of one secondary cooling section is connected to the input end of the next secondary cooling section through the connecting section; the arrangement positions of the input ends and the output sections of two adjacent secondary cooling sections are opposite.

10. An electron microscope, characterized in that: Comprising the electronic lens assembly as described in any one of claims 1 to 9.

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