SEM secondary electron detector

Abstract

The present invention discloses a scanning electron microscope secondary electron detector, which comprises: a cylinder assembly, a grid assembly, a high-voltage cylinder, a light guide column, a scintillator, a housing, a photomultiplier and a power supply, wherein the high-voltage cylinder comprises an upper high-voltage cylinder section and a lower high-voltage cylinder section connected in the axial direction of the cylinder assembly. According to the scanning electron microscope secondary electron detector of the present invention, by setting the radial dimension of the outer peripheral wall of the lower high-voltage cylinder section to gradually decrease in the direction from the upper high-voltage cylinder section to the lower high-voltage cylinder section, the high-voltage cylinder can avoid the occurrence of high-voltage discharge phenomenon to the greatest extent when transmitting high voltage, thereby avoiding the influence of high-voltage discharge phenomenon on the detection efficiency and imaging effect of the scanning electron microscope secondary electron detector to the greatest extent.

Description

Technical Field

[0001] The invention relates to the field of scanning electron microscopes, and in particular to a secondary electron detector for a scanning electron microscope. Background Art

[0002] SEM (Scanning Electron Microscope) is a large precision instrument used for high-resolution micro-area morphology analysis. It is widely used in materials, life sciences and other fields. The SEM sample measurement action is that a high-energy electron beam hits a test sample fixed on the surface of a standard sample holder. The extranuclear electrons of the sample atoms that are bombarded by the high-energy electron beam and leave the sample surface are called secondary electrons. Since secondary electrons are very sensitive to the surface morphology of the sample and can effectively display the surface morphology of the sample, the main imaging method of SEM is secondary electron imaging.

[0003] Among them, in SEM applications, the secondary electron detector of the scanning electron microscope is used to collect and analyze secondary electrons, and in the secondary electron detector of the scanning electron microscope, the high-voltage cylinder that provides high voltage for the scintillator is an indispensable component. In the existing secondary electron detector of the scanning electron microscope, when the high voltage is transmitted through the high-voltage cylinder, high-voltage discharge is prone to occur, thereby affecting the detection efficiency and imaging effect of the secondary electron detector of the scanning electron microscope. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a secondary electron detector for a scanning electron microscope, which has higher detection efficiency and clearer imaging effect.

[0005] According to an embodiment of the present invention, a secondary electron detector for a scanning electron microscope comprises: a cylinder assembly, a first accommodating space is formed in the cylinder assembly, and both axial ends of the first accommodating space are open; a grid assembly, the grid assembly is arranged at one axial end of the cylinder assembly; a high-voltage cylinder, the high-voltage cylinder is arranged in the first accommodating space, the high-voltage cylinder comprises an upper high-voltage cylinder section and a lower high-voltage cylinder section connected in the axial direction of the cylinder assembly, the lower high-voltage cylinder section is located on a side of the upper high-voltage cylinder section close to the grid assembly, and the radial dimension of the outer peripheral wall of the lower high-voltage cylinder section gradually decreases in the direction from the upper high-voltage cylinder section to the lower high-voltage cylinder section; a light guide column, the light guide column is arranged in the upper high-voltage cylinder section and the lower high-voltage cylinder section. The lower high-voltage cylinder section; a scintillator, the scintillator is arranged in the lower high-voltage cylinder section and is located on the side of the light guide column facing the grid assembly and stops with the light guide column; a shell, the shell has a second accommodating space, one end of the shell is connected to the end of the cylinder assembly away from the grid assembly, and the first accommodating space is connected to the second accommodating space; a photomultiplier tube, the photomultiplier tube is arranged in the second accommodating space, and the end of the light guide column away from the scintillator extends into the second accommodating space and stops with the photomultiplier tube; a power supply, the power supply is arranged in the second accommodating space and is located on the side of the photomultiplier tube away from the light guide column and connected to the photomultiplier tube.

[0006] According to the scanning electron microscope secondary electron detector of the embodiment of the present invention, a high-voltage cylinder is provided including an upper high-voltage cylinder section and a lower high-voltage cylinder section connected in the axial direction of the cylinder assembly, and the radial dimension of the outer peripheral wall of the lower high-voltage cylinder section gradually decreases in the direction from the upper high-voltage cylinder section to the lower high-voltage cylinder section, so that when the high-voltage cylinder transmits high voltage, the occurrence of high-voltage discharge phenomenon is avoided to the greatest extent, thereby avoiding the influence of high-voltage discharge phenomenon on the detection efficiency and imaging effect of the scanning electron microscope secondary electron detector to the greatest extent.

[0007] According to some embodiments of the present invention, the upper high-pressure cylinder section and the lower high-pressure cylinder section are an integral part; or, the upper high-pressure cylinder section and the lower high-pressure cylinder section are separate parts connected to each other.

[0008] According to some embodiments of the present invention, an end of the lower high-pressure cylinder section away from the upper high-pressure cylinder section is provided with a stop portion extending toward the center line direction of the lower high-pressure cylinder section, and the scintillator abuts against the surface of the stop portion facing the upper high-pressure cylinder section.

[0009] According to some embodiments of the present invention, a first sealing ring is provided between the upper high-pressure cylinder section and the light guide column.

[0010] According to some embodiments of the present invention, an exhaust hole is provided on the peripheral wall of the lower high-pressure cylinder section.

[0011] According to some embodiments of the present invention, the cylinder assembly includes: a shielding cylinder, the grid assembly is connected to one axial end of the shielding cylinder; a first flange, one axial end of the first flange is connected to one end of the shielding cylinder away from the grid assembly, the first flange and the shielding cylinder define the first accommodating space, and the outer shell is connected to the first flange; the first flange is sleeved on the outside of the upper high-pressure cylinder section, and a second sealing ring is provided between the first flange and the upper high-pressure cylinder section.

[0012] According to some embodiments of the present invention, it also includes: a second flange, which is connected to the first flange and located radially outside the first flange, and the end of the shielding tube away from the grid assembly is located between the first flange and the second flange; a third sealing ring is provided between the first flange and the second flange.

[0013] According to some embodiments of the present invention, the scanning electron microscope secondary electron detector also includes: a third flange, which is sleeved on the outside of the barrel assembly and the outer shell; a fourth sealing ring is provided between the third flange and the barrel assembly, and a fifth sealing ring is provided on the side surface of the third flange facing the grid assembly.

[0014] According to some embodiments of the present invention, the third flange has a through hole that penetrates the third flange in the thickness direction of the third flange, and the scanning electron microscope secondary electron detector also includes a first power supply component, the first power supply component includes a connecting plate and connecting columns arranged on both sides of the connecting plate in the thickness direction, the connecting plate is connected to the third flange, the connecting column on one side of the connecting plate is passed through the through hole, and a sealing gasket is provided between the connecting plate and the third flange.

[0015] According to some embodiments of the present invention, it also includes: a pressure cover, which is sleeved on the light guide column, the first flange includes a first mating section and a second mating section, the first mating section is sleeved on the upper high-pressure cylinder section, and the second mating section is sleeved on the pressure cover; a mating groove is provided on the cross-section of the first mating section facing the second mating section, and a part of the pressure cover is located in the mating groove.

[0016] According to some embodiments of the present invention, one end of the outer shell is sleeved on the outside of the barrel assembly, and the scanning electron microscope secondary electron detector also includes: a second power supply assembly for supplying power to the high-voltage barrel, the second power supply assembly including a resistor, a connector and a spring, the resistor is passed through the outer shell and the barrel assembly, the connector is connected to the resistor, the spring is arranged between the resistor and the high-voltage barrel to connect the resistor and the high-voltage barrel; an insulating sleeve, the insulating sleeve is arranged between the resistor and the outer shell and between the resistor and the barrel assembly.

[0017] According to some embodiments of the present invention, a metal plate is provided at one end of the spring away from the resistor, and the metal plate abuts against the high-voltage cylinder.

[0018] According to some embodiments of the present invention, the grid assembly includes: a metal bracket formed in a ring shape and arranged on the cylinder assembly; an insulating ring is arranged between the metal bracket and the cylinder assembly; and a grid, which is arranged on the metal bracket.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 is a stereogram of a secondary electron detector of a scanning electron microscope according to an embodiment of the present invention;

[0022] Figure 2 is a cross-sectional view of a secondary electron detector of a scanning electron microscope according to an embodiment of the present invention;

[0023] Figure 3 yes Figure 2 The enlarged view of point A in the middle;

[0024] Figure 4 It is a stereoscopic view from another angle of the secondary electron detector of a scanning electron microscope according to an embodiment of the present invention, in which the barrel assembly, the grid assembly and the outer shell are hidden.

[0025] Reference numerals:

[0026] 100. Secondary electron detector for scanning electron microscope;

[0027] 1. Cylinder assembly; 11. Shielding cylinder; 111. First accommodating space; 12. First flange; 121. Second sealing ring; 122. First matching section; 1221. Matching groove; 123. Second matching section; 13. Second flange; 131. Third sealing ring; 132. Vertical section; 133. Extended section; 14. Third flange; 141. Fourth sealing ring; 142. Fifth sealing ring; 15. Gland;

[0028] 2. Grid assembly; 21. Metal bracket; 22. Insulation ring; 23. Grid;

[0029] 3. High-pressure cylinder; 31. Upper high-pressure cylinder section; 32. Lower high-pressure cylinder section; 321. Stopper; 322. Exhaust hole; 33. First sealing ring;

[0030] 4. Light guide column;

[0031] 5. Scintillator;

[0032] 6. housing; 61. second accommodation space; 62. housing; 63. end cover; 631. electrical signal connector;

[0033] 7. Photomultiplier tube; 71. Convex connector;

[0034] 8. Power supply; 81. Groove;

[0035] 91. first power supply assembly; 911. connection plate; 912. connection column;

[0036] 92. Second power supply assembly; 921. Resistor; 922. Connector; 923. Spring; 9231. Metal plate; 924. Insulating sleeve. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Reference below Figure 1-Figure 4 A secondary electron detector 100 for a scanning electron microscope according to an embodiment of the present invention is described.

[0041] like Figure 1-Figure 4 As shown, the secondary electron detector 100 of a scanning electron microscope according to an embodiment of the present invention includes a cylinder assembly 1, a grid assembly 2, a high-voltage cylinder 3, a light guide column 4, a scintillator 5, a housing 6, a photomultiplier tube 7 and a power supply 8.

[0042] Specifically, Figure 2 As shown, a first accommodation space 111 is formed in the cylinder assembly 1, and both axial ends of the first accommodation space 111 are open, so that the first accommodation space 111 is through. The grid assembly 2 is arranged at one axial end of the cylinder assembly 1, and the high-voltage cylinder 3 is arranged in the first accommodation space 111. The high-voltage cylinder 3 includes an upper high-voltage cylinder section 31 and a lower high-voltage cylinder section 32 connected in the axial direction of the cylinder assembly 1. The lower high-voltage cylinder section 32 is located on the side of the upper high-voltage cylinder section 31 close to the grid assembly 2. The radial dimension of the outer peripheral wall of the lower high-voltage cylinder section 32 gradually decreases in the direction from the upper high-voltage cylinder section 31 to the lower high-voltage cylinder section 32. Through such an arrangement, the high-voltage cylinder 3 can avoid the occurrence of high-voltage discharge to the greatest extent when transmitting high voltage. Among them, the radial dimension of the outer peripheral wall of the lower high-voltage cylinder section 32 is: the center of the lower high-voltage cylinder section 32 is the center, the direction of the line connecting the center and the outer edge of the outer peripheral wall of the lower high-voltage cylinder section 32 is the radial direction, and the dimension in the radial direction is the radial dimension.

[0043] Furthermore, the radial dimension of the outer peripheral wall of the upper high-pressure cylinder section 31 remains unchanged in the direction from the upper high-pressure cylinder section 31 to the lower high-pressure cylinder section 32. Among them, the radial dimension of the outer peripheral wall of the upper high-pressure cylinder section 31 is: the center of the upper high-pressure cylinder section 31 is the center, the direction of the line connecting the center and the outer edge of the outer peripheral wall of the upper high-pressure cylinder section 31 is the radial direction, and the dimension in the radial direction is the radial dimension. Such a setting can make it easier to assemble the upper high-pressure cylinder section 31 into the first accommodating space 111 when assembling the secondary electron detector 100 of the scanning electron microscope.

[0044] Optionally, the outer contour of the cross section of the upper high-pressure cylinder section 31 is circular, and the outer contour of the cross section of the lower high-pressure cylinder section 32 is circular, that is, the outer contour of the upper high-pressure cylinder section 31 is cylindrical with a constant cross-sectional size, and the outer contour of the lower high-pressure cylinder section 32 is a truncated cone with a cross-sectional size that gradually decreases in the direction from the upper high-pressure cylinder section 31 to the lower high-pressure cylinder section 32.

[0045] Furthermore, the outer peripheral walls of the upper high-voltage cylinder section 31 and the lower high-voltage cylinder section 32 are finely polished during processing and manufacturing, so as to further reduce the occurrence of high-voltage discharge.

[0046] like Figure 2 As shown, the light guide column 4 is arranged in the upper high-voltage cylinder section 31 and the lower high-voltage cylinder section 32, and the scintillator 5 is arranged in the lower high-voltage cylinder section 32 and is located on the side of the light guide column 4 facing the grid assembly 2, and stops with the light guide column 4. It can be understood that the scanning electron microscope secondary electron detector 100 supplies high voltage electricity to the scintillator 5 through the high-voltage cylinder 3, so that the scintillator 5 converts the electrons absorbed by the grid assembly 2 into light signals, and the light signals are then transmitted through the light guide column 4. By setting the radial size of the outer peripheral wall of the lower high-voltage cylinder section 32 to gradually decrease in the direction from the upper high-voltage cylinder section 31 to the lower high-voltage cylinder section 32, the influence of the high-voltage discharge phenomenon on the detection efficiency and imaging effect when using the scanning electron microscope secondary electron detector 100 can be avoided to the greatest extent.

[0047] The outer shell 6 has a second accommodating space 61, one end of the outer shell 6 is connected to the end of the barrel assembly 1 away from the grid assembly 2, the first accommodating space 111 is communicated with the second accommodating space 61, the photomultiplier tube 7 is arranged in the second accommodating space 61, and the end of the light guide column 4 away from the scintillator 5 extends into the second accommodating space 61 and stops at the photomultiplier tube 7, so that the light signal transmitted through the light guide column 4 can be transmitted to the photomultiplier tube 7, and the light signal is converted into an electrical signal by the photomultiplier tube 7 and then output to the outside for imaging.

[0048] The power supply 8 is arranged in the second accommodation space 61 and is located on the side of the photomultiplier tube 7 away from the light guide column 4 and is connected to the photomultiplier tube 7. The power supply 8 provides voltage to the photomultiplier tube 7, and the photomultiplier tube 7 amplifies and filters the electrical signal. Further, a convex electric head 71 can be provided on the side of the photomultiplier tube 7 away from the light guide column 4, and a groove 81 that cooperates with the convex electric head 71 is provided on the side of the battery close to the photomultiplier tube 7. The power supply 8 provides voltage to the photomultiplier tube 7 through the cooperation between the convex electric head 71 and the groove 81.

[0049] Alternatively, if Figure 2As shown, the housing 6 includes a shell 62 and an end cap 63. The shell 62 is formed in a cylindrical shape. One end of the shell 62 is connected to the end of the barrel assembly 1 away from the grid assembly 2. The photomultiplier tube 7 and the power supply 8 are arranged in the shell 62. The end cap 63 is arranged at the end of the shell 62 away from the barrel assembly 1. The end cap 63 is used to block the open mouth of the end of the shell 62 away from the barrel assembly 1, thereby facilitating the installation and assembly of the photomultiplier tube 7 and the power supply 8. At the same time, an electric signal connector 631 is provided on the end cap 63, and the electric signal converted by the photomultiplier tube 7 is output to an external device through the electric signal connector 631. The yield of secondary electrons can be analyzed by the strength of the detected electric signal, thereby measuring the morphology of the sample surface.

[0050] According to the scanning electron microscope secondary electron detector 100 of the embodiment of the present invention, the high-voltage cylinder 3 includes an upper high-voltage cylinder section 31 and a lower high-voltage cylinder section 32 connected in the axial direction of the cylinder assembly 1, and the radial dimension of the outer peripheral wall of the lower high-voltage cylinder section 32 gradually decreases in the direction from the upper high-voltage cylinder section 31 to the lower high-voltage cylinder section 32, so that when the high-voltage cylinder 3 transmits high voltage, the occurrence of high-voltage discharge phenomenon is avoided to the greatest extent, thereby avoiding the influence of high-voltage discharge phenomenon on the detection efficiency and imaging effect of the scanning electron microscope secondary electron detector 100 to the greatest extent.

[0051] In some embodiments of the present invention, the inner circumferential wall of the upper high-pressure cylinder section 31 is flush with the inner circumferential wall of the lower high-pressure cylinder section 32, the radial dimension of the inner circumferential wall of the upper high-pressure cylinder section 31 is the same as the radial dimension of the inner circumferential wall of the lower high-pressure cylinder section 32, and the radial dimension of the inner circumferential wall of the upper high-pressure cylinder section 31 and the radial dimension of the inner circumferential wall of the lower high-pressure cylinder section 32 are substantially the same as the radial dimension of the outer circumferential wall of the light guide column 4, thereby fixing the light guide column 4 and further ensuring the reliability of the scanning electron microscope secondary electron detector 100 during operation.

[0052] In some embodiments of the present invention, the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 are an integral part or the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 are separate parts connected to each other. It is understandable that the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 can form the high-pressure cylinder body 3 as an integral part, thereby improving the stability and reliability of the overall structure of the high-pressure cylinder body 3. It should be noted that the integral part can be an integrally molded part or a secondary injection molded part, etc.; the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 can also be separate parts, which are assembled and connected to form the high-pressure cylinder body 3, so that the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 can be separately processed to meet the radial dimensions of their respective outer peripheral walls. At the same time, the design of the separate parts facilitates the assembly of the secondary electron detector 100 of the scanning electron microscope. It should be noted that the specific method of assembling and connecting the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 is not limited. It can be a non-detachable assembly connection, such as riveting, welding, etc.; it can also be a detachable assembly connection, such as threaded connection, snap connection, magnetic connection, etc., so that the upper high-pressure cylinder section 31 or the lower high-pressure cylinder section 32 can be disassembled as needed for cleaning, replacement, maintenance and other operations.

[0053] For example, in some specific embodiments, an external thread is provided on the outer circumferential wall of the upper high-pressure cylinder section 31 near the lower high-pressure cylinder section 32, and an internal thread matching the external thread is provided on the inner circumferential wall of the upper and lower high-pressure cylinder sections 32 near the upper high-pressure cylinder section 31, and the connection between the upper high-pressure cylinder section 31 and the lower high-pressure cylinder section 32 is achieved through the cooperation of the internal thread and the external thread.

[0054] In some embodiments of the present invention, Figure 2-Figure 4 As shown, a stopper 321 extending in the direction of the center line of the lower high-voltage cylinder section 32 is provided at one end of the lower high-voltage cylinder section 32 away from the upper high-voltage cylinder section 31, and the scintillator 5 abuts against the surface of the stopper 321 facing the upper high-voltage cylinder section 31. The stopper 321 is provided to limit the scintillator 5 in the axial direction of the cylinder assembly 1, so that the scintillator 5 abuts against the light guide column 4, thereby achieving the fixation of the scintillator 5, further ensuring the reliability of the secondary electron detector 100 of the scanning electron microscope during operation, and then allowing the optical signal converted by the scintillator 5 to be transmitted through the light guide column 4.

[0055] It can be understood that by providing a stopper 321 on the lower high-voltage cylinder section 32 that abuts against the scintillator 5, the high-voltage cylinder 3 is in direct contact with the scintillator 5, so that the high voltage transmitted through the high-voltage cylinder 3 can be directly transmitted to the scintillator 5, and there is no need to provide a high-voltage wire connecting the high-voltage cylinder 3 and the scintillator 5 in the scanning electron microscope secondary electron detector 100, thereby reducing the assembly steps, saving costs, and reducing the volume of the scanning electron microscope secondary electron detector 100. At the same time, compared with the prior art method of transmitting high voltage to the scintillator through high-voltage wires, the scanning electron microscope secondary electron detector 100 of the present invention can avoid the interference of high-voltage wires on electrical signals when transmitting high voltage, thereby further ensuring the clarity of secondary electron imaging.

[0056] In addition, the outer wall of the scintillator 5 can contact the inner wall of the lower high-voltage cylinder section 32 , thereby achieving electrical connection between the lower high-voltage cylinder section 32 and the scintillator 5 , so that the high-voltage cylinder 3 can supply power to the scintillator 5 .

[0057] In some embodiments of the present invention, Figure 3 As shown, a first sealing ring 33 is provided between the upper high-voltage cylinder section 31 and the light guide column 4. One end of the light guide column 4 abuts against the scintillator 5, and the other end abuts against the photomultiplier tube 7. By providing the first sealing ring 33 between the upper high-voltage cylinder section 31 and the light guide column 4, a certain friction force exists between the upper high-voltage cylinder section 31 and the light guide column 4, thereby achieving the fixation of the light guide column 4.

[0058] When the scanning electron microscope secondary electron detector 100 is working, the lower high-voltage cylinder section 32, part of the light guide column 4, the scintillator 5 and the grid assembly 2 need to be in a vacuum environment. Therefore, the first sealing ring 33 is also used to seal the gap between the upper high-voltage cylinder section 31 and the light guide column 4, so that the outside air cannot enter the vacuum environment through the gap between the upper high-voltage cylinder section 31 and the light guide column 4.

[0059] In some embodiments of the present invention, Figure 4 As shown, an exhaust hole 322 is provided on the peripheral wall of the lower high-pressure cylinder section 32. Such a setting ensures that all the gas in the lower high-pressure cylinder section 32 is exhausted when the SEM secondary electron detector 100 is vacuum-evacuated, thereby ensuring that the SEM secondary electron detector 100 is in a vacuum environment when working.

[0060] Figure 4Three exhaust holes 322 are shown for the purpose of illustration, but after reading the following technical solution, ordinary technicians can obviously understand that the technical solution of setting one, two, four or more exhaust holes 322 in this solution also falls within the protection scope of the present invention. Of course, multiple exhaust holes 322 can also be evenly or unevenly set around the peripheral wall of the lower high-pressure cylinder. It should be noted that the shape of the exhaust hole 322 is not limited here, and can be a waist-shaped hole, a circular hole, an elliptical hole, a rectangular hole, a square hole or other special-shaped holes.

[0061] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the cylinder assembly 1 includes a shielding cylinder 11 and a first flange 12. Among them, one axial end of the shielding cylinder 11 is connected to the grid assembly 2, and one axial end of the first flange 12 is connected to the end of the shielding cylinder 11 away from the grid assembly 2. The first flange 12 and the shielding cylinder 11 define a first accommodating space 111. It can be understood that the high-voltage cylinder 3 is arranged in the first flange 12 and the shielding cylinder 11, and the shielding cylinder 11 can shield noise, thereby reducing the noise pollution of the electrical signal and making the secondary electron imaging clearer.

[0062] The shell 6 is connected to the first flange 12 to realize the communication between the first accommodating space 111 and the second accommodating space 61. Optionally, the shell 6 is connected to the first flange 12 by bolts. The first flange 12 is sleeved outside the upper high-pressure cylinder section 31, and a second sealing ring 121 is provided between the first flange 12 and the upper high-pressure cylinder section 31. The second sealing ring 121 is used to seal the gap between the upper high-pressure cylinder section 31 and the first flange 12, so that the outside air cannot enter the vacuum environment through the gap between the upper high-pressure cylinder section 31 and the first flange 12.

[0063] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the cylinder assembly 1 also includes a second flange 13. The second flange 13 is connected to the first flange 12 and is located radially outside the first flange 12, and the end of the shielding cylinder 11 away from the grid assembly 2 is located between the first flange 12 and the second flange 13. By setting the second flange 13, the shielding cylinder 11 can be better fixed, thereby ensuring the stability of the overall structure of the scanning electron microscope secondary electron detector 100. Optionally, the second flange 13 is fastened to the first flange 12 by bolts. A third sealing ring 131 is provided between the first flange 12 and the second flange 13. The third sealing ring 131 is used to seal the gap between the first flange 12 and the second flange 13, so that outside air cannot enter the vacuum environment through the gap between the first flange 12 and the second flange 13.

[0064] In some embodiments of the present invention, Figure 2 and Figure 3As shown, the scanning electron microscope secondary electron detector 100 also includes a third flange 14, and the third flange 14 is sleeved outside the barrel assembly 1 and the outer shell 6. A fourth sealing ring 141 is provided between the third flange 14 and the barrel assembly 1, and a fifth sealing ring 142 is provided on the side surface of the third flange 14 facing the grid assembly 2. It can be understood that when the scanning electron microscope secondary electron detector 100 is assembled to the assembly hole reserved in the test object detection space, the part of the third flange 14 facing the grid assembly 2 is located inside the detection space, the fourth sealing ring 141 is used to seal the gap between the third flange 14 and the barrel assembly 1, and the fifth sealing ring 142 is used to seal the gap between the third flange 14 and the SEM, so that the outside air cannot enter the vacuum environment through the gap between the third flange 14 and the barrel assembly 1 and the gap between the third flange 14 and the SEM.

[0065] In some embodiments of the present invention, Figure 1 As shown, the third flange 14 has a through hole that penetrates the third flange 14 in the thickness direction of the third flange 14, and the scanning electron microscope secondary electron detector 100 also includes a first power supply component 91, the first power supply component 91 includes a connecting plate 911 and connecting columns 912 arranged on both sides of the connecting plate 911 in the thickness direction, the connecting plate 911 is connected to the third flange 14, and the connecting column 912 on one side of the connecting plate 911 is penetrated through the through hole. It can be understood that the first power supply component 91 is arranged on the third flange 14 and supplies power to the grid component 2 through a wire (not shown in the figure) that penetrates the cylinder component 1. A sealing gasket is provided between the connecting plate 911 and the third flange 14, and the setting of the sealing gasket can seal the gap between the connecting plate 911 and the third flange 14, so that when the scanning electron microscope secondary electron detector 100 is working, the outside air cannot enter the vacuum environment through the through hole.

[0066] In some embodiments of the present invention, Figure 2 and Figure 3As shown, the cylinder assembly 1 also includes a gland 15. The gland 15 is sleeved on the light guide column 4, and the first flange 12 includes a first matching section 122 and a second matching section 123. The first matching section 122 is sleeved on the upper high-voltage cylinder section 31, and the second matching section 123 is sleeved on the gland 15. A matching groove 1221 is provided on the cross section of the first matching section 122 facing the second matching section 123, and part of the gland 15 is located in the matching groove 1221. The arrangement of the gland 15 can further ensure that the SEM secondary electron detector 100 in the detection space is in a vacuum sealed environment, while isolating the interference of the external light source to the SEM secondary electron detector 100. In addition, by arranging the matching groove 1221 that matches the gland 15 on the first flange 12, the creeping distance of electrons on the surface of the gland 15 and the first flange 12 is increased, so that the high voltage performance transmitted to the high-voltage cylinder 3 is better, and the signal interference caused by vacuum discharge is further prevented. Preferably, the gland 15 and the first flange 12 are made of polyetheretherketone material. It should be noted that the number of the matching grooves 1221 is not limited here.

[0067] Of course, a protrusion may be provided on the second matching section 123 , and a groove matching the protrusion may be provided on the gland 15 to achieve connection between the gland 15 and the first flange 12 , while increasing the creeping distance of electrons on the surfaces of the gland 15 and the first flange 12 .

[0068] Furthermore, the radial dimension of the outer contour of the second mating segment 123 is greater than the radial dimension of the outer contour of the first mating segment 122, the housing 6 is connected to the second mating segment 123, and the second flange 13 is sleeved outside the first mating segment 122. Such a configuration allows the radial dimension of the outer contour of the second flange 13 to be smaller than the radial dimension of the outer contour of the housing 6 when the second flange 13 is sleeved outside the first mating segment 122 and connected to the first flange 12, so that the housing 6 can cover the first flange 12 and the second flange 13, thereby protecting the first flange 12 and the second flange 13 and enhancing the stability of the overall structure of the secondary electron detector 100 of the scanning electron microscope.

[0069] Furthermore, the second flange 13 includes a vertical section 132 and an extension section 133, the vertical section 132 is sleeved outside the first matching section 122, the end of the shielding tube 11 away from the grid assembly 2 is arranged between the vertical section 132 and the first matching section 122, and the extension section 133 is connected to the end of the vertical section 132 away from the grid assembly 2 and is matched with the surface of the second matching section 123 facing the grid assembly 2. Such a setting can further fix the shielding tube 11 to prevent the shielding tube 11 from shifting when the secondary electron detector 100 of the scanning electron microscope is vacuum-evacuated.

[0070] In some embodiments of the present invention, Figure 2 and Figure 3As shown, one end of the housing 6 is sleeved outside the cylinder assembly 1, and the scanning electron microscope secondary electron detector 100 also includes an insulating sleeve 924 and a second power supply assembly 92 for supplying power to the high-voltage cylinder 3, and the second power supply assembly 92 includes a resistor 921, a connector 922 and a spring 923. Among them, the resistor 921 is inserted into the housing 6 and the cylinder assembly 1, the connector 922 is connected to the resistor 921, and the spring 923 is arranged between the resistor 921 and the high-voltage cylinder 3 to connect the resistor 921 and the high-voltage cylinder 3. It can be understood that the high voltage transmitted by the connector 922 is transmitted to the high-voltage cylinder 3 through the resistor 921 and the spring 923. The setting of the spring 923 allows a certain elastic error when the resistor 921 and the high-voltage cylinder 3 are assembled, so as to avoid poor contact caused by the resistor 921 and the high-voltage cylinder 3 being too far apart when the scanning electron microscope secondary electron detector 100 is assembled, or the resistor 921 squeezes the high-voltage cylinder 3 too much to cause damage.

[0071] The insulating sleeve 924 is arranged between the resistor 921 and the housing 6 and between the resistor 921 and the barrel assembly 1. Such an arrangement can effectively prevent the high voltage transmitted by the resistor 921 from contacting the air and causing gas breakdown, and at the same time prevent the high voltage on the housing 6 from causing electric shock.

[0072] In some embodiments of the present invention, Figure 3 As shown, a metal plate 9231 is provided at one end of the spring 923 away from the resistor 921, and the metal plate 9231 abuts against the high-voltage cylinder 3. It can be understood that the high voltage electricity transmitted by the resistor 921 is transmitted to the high-voltage cylinder 3 through the metal plate 9231, and the provision of the metal plate 9231 increases the contact area between the spring 923 and the high-voltage cylinder 3, thereby improving the transmission efficiency of the high voltage electricity.

[0073] In some embodiments of the present invention, Figure 1 As shown, the grid assembly 2 includes a metal bracket 21 and a grid 23. The grid 23 is arranged on the metal bracket 21. The metal bracket 21 is formed into a ring shape, so that the end of the grid 23 away from the test product is in a ring shape, thereby improving the efficiency of the grid assembly 2 in absorbing secondary electrons. The metal bracket 21 is arranged on the barrel assembly 1, and an insulating ring 22 is arranged between the metal bracket 21 and the barrel assembly 1. The setting of the insulating ring 22 can effectively insulate the metal bracket 21 from the barrel assembly 1.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0075] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A secondary electron detector for a scanning electron microscope, characterized in that: include: A barrel assembly, wherein a first accommodation space is formed in the barrel assembly, and both axial ends of the first accommodation space are open; A grid assembly, wherein the grid assembly is arranged at one axial end of the cylinder assembly; a high-pressure cylinder, the high-pressure cylinder being arranged in the first accommodation space, the high-pressure cylinder comprising an upper high-pressure cylinder section and a lower high-pressure cylinder section connected in the axial direction of the cylinder assembly, the lower high-pressure cylinder section being located on a side of the upper high-pressure cylinder section close to the grid assembly, and the radial dimension of the outer peripheral wall of the lower high-pressure cylinder section gradually decreasing in the direction from the upper high-pressure cylinder section to the lower high-pressure cylinder section; A light guide column, wherein the light guide column is arranged in the upper high-pressure cylinder section and the lower high-pressure cylinder section; A scintillator, the scintillator is arranged in the lower high-voltage cylinder section and is located on a side of the light guide column facing the grid assembly and abuts against the light guide column; A shell having a second accommodating space, one end of the shell being connected to an end of the cylinder assembly away from the grid assembly, and the first accommodating space and the second accommodating space being in communication; A photomultiplier tube, wherein the photomultiplier tube is disposed in the second accommodation space, and an end of the light guide column away from the scintillator extends into the second accommodation space and abuts against the photomultiplier tube; A power source is disposed in the second accommodation space and is located on a side of the photomultiplier tube away from the light guide column and is connected to the photomultiplier tube.

2. The secondary electron detector of a scanning electron microscope according to claim 1, characterized in that: The upper high-pressure cylinder section and the lower high-pressure cylinder section are an integral part; Alternatively, the upper high-pressure cylinder section and the lower high-pressure cylinder section are separate parts connected to each other.

3. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: An end of the lower high-pressure cylinder section away from the upper high-pressure cylinder section is provided with a stopper extending toward the center line direction of the lower high-pressure cylinder section, and the scintillator abuts against a surface of the stopper facing the upper high-pressure cylinder section.

4. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: A first sealing ring is provided between the upper high-pressure cylinder section and the light guide column.

5. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: An exhaust hole is arranged on the peripheral wall of the lower high-pressure cylinder section.

6. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: The barrel assembly comprises: A shielding cylinder, wherein the grid assembly is connected to one axial end of the shielding cylinder; A first flange, one axial end of the first flange is connected to an end of the shielding cylinder away from the grid assembly, the first flange and the shielding cylinder define the first accommodating space, the outer shell is connected to the first flange, the first flange is sleeved outside the upper high-pressure cylinder section, and a second sealing ring is provided between the first flange and the upper high-pressure cylinder section.

7. The secondary electron detector for a scanning electron microscope according to claim 6, characterized in that: Also includes: The second flange is connected to the first flange and is located radially outside the first flange. The end of the shielding tube away from the grid assembly is located between the first flange and the second flange. A third sealing ring is provided between the first flange and the second flange.

8. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: The scanning electron microscope secondary electron detector also includes: The third flange is sleeved outside the cylinder assembly and the shell, a fourth sealing ring is arranged between the third flange and the cylinder assembly, and a fifth sealing ring is arranged on the surface of the third flange on one side facing the grid assembly.

9. The secondary electron detector for a scanning electron microscope according to claim 8, characterized in that: The third flange has a through hole that penetrates the third flange in the thickness direction of the third flange. The scanning electron microscope secondary electron detector also includes a first power supply component, which includes a connecting plate and connecting columns arranged on both sides of the connecting plate in the thickness direction. The connecting plate is connected to the third flange, and the connecting column on one side of the connecting plate is passed through the through hole. A sealing gasket is provided between the connecting plate and the third flange.

10. The secondary electron detector for a scanning electron microscope according to claim 6, characterized in that: Also includes: A pressure cover is sleeved on the light guide column, the first flange includes a first mating section and a second mating section, the first mating section is sleeved on the upper high-pressure cylinder section, the second mating section is sleeved on the pressure cover, a mating groove is provided on the cross-section of the first mating section facing the second mating section, and a portion of the pressure cover is located in the mating groove.

11. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: One end of the shell is sleeved outside the barrel assembly, and the secondary electron detector of the scanning electron microscope also includes: A second power supply assembly for supplying power to the high-voltage cylinder, the second power supply assembly comprising a resistor, a connector and a spring, the resistor being inserted through the housing and the cylinder assembly, the connector being connected to the resistor, and the spring being provided between the resistor and the high-voltage cylinder to connect the resistor and the high-voltage cylinder; An insulating sleeve is arranged between the resistor and the shell and between the resistor and the barrel assembly.

12. The secondary electron detector for a scanning electron microscope according to claim 11, characterized in that: A metal plate is provided at one end of the spring away from the resistor, and the metal plate abuts against the high-voltage cylinder.

13. The secondary electron detector for a scanning electron microscope according to claim 1, characterized in that: The grid assembly comprises: A metal bracket, the metal bracket is formed in a ring shape, the metal bracket is arranged on the barrel assembly, and an insulating ring is arranged between the metal bracket and the barrel assembly; A grid is arranged on the metal support.

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