Focused ion beam generation system based on gallium ion filament

Abstract

The invention provides an ion beam generation system based on a gallium ion filament, which comprises an ion source assembly, an emission gun assembly, an ion acceleration assembly, a focusing assembly and a deflection assembly, and is characterized in that the gallium ion filament forms a liquid film through current heating, gallium ions are ionized under a high-voltage electric field, and a primary ion beam is formed; the ion beam is further focused through an accelerating electrode and a multi-pole electrostatic lens in the system, biaxial scanning is achieved through an electrostatic deflection electrode set, and nanoscale beam spot control can be achieved in cooperation with a modular cavity, an anti-interference shielding structure and a vacuum compatible design. The device supports a 10 <-6 > Pa vacuum environment and a gas-assisted process, has the advantages of modular maintenance, high and low voltage signal isolation and the like, and is suitable for micro-nano processing scenes such as semiconductor repair, sample preparation, ion imaging and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano processing equipment, and in particular to a focused ion beam generating system based on a gallium ion filament. Background Art

[0002] Ion beam generation systems are widely used in micro-nanofabrication applications, including material etching, cutting, failure analysis, semiconductor etching, deposition, chip wafer circuit repair, sample preparation, and ion imaging. Their core function is to generate an ion beam from an ionized gas and precisely control the ion emission direction and energy. Traditional ion generators typically consist of an ion generation unit (such as a filament and ion source chamber) and an ion beam control unit (such as an accelerating electrode and deflection structure). Their performance directly affects the stability, focusing accuracy, and energy controllability of the ion beam.

[0003] Deficiencies of existing technology: 1. The ion emission gun has a high degree of structural integration, which is not conducive to module maintenance and electrode precision adjustment; 2. Ion beam path control relies on a limited field deflection mechanism, making high-resolution scanning difficult to achieve; 3. Complex electrode arrangement, large electrical interference and poor stability; 4. The high-voltage interface and vacuum interface are compactly arranged, resulting in insufficient heat dissipation and safety isolation; 5. This invention fills the gap in the domestic focused ion beam field.

[0004] Therefore, the existing technology has deficiencies and needs further improvement. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a focused ion beam generating system based on a gallium ion filament.

[0006] To achieve the above object, the specific solutions of the present invention are as follows: The present invention provides a focused ion beam generating system based on a gallium ion filament, comprising: an ion source component, a launch gun component, an ion acceleration component, a focusing component, and a deflection component; The ion source assembly is mounted on the first base and is electrically connected to the first base via a plurality of ejector pins; The ion source assembly includes a filament, which is located inside the ion source cavity and electrically connected to the ejector pin; the ion source cavity is provided with a first opening for mounting a miter flange; The ion source cavity is installed at the lower end of the first base, and the emission gun assembly is installed at the lower end of the ion source cavity; The launch gun assembly includes a launch gun center axis, a field deflection frame, a field acceleration electrode, a lens, and a beam shaping assembly; The central axis of the emission gun is installed at the lower end of the ion source cavity, the field deflection frame is installed inside the central axis of the emission gun, the field acceleration electrode is installed inside the field deflection frame, the lens is located below the field acceleration electrode and is installed on the beam shaping assembly, and the beam shaping assembly is installed at the lower end of the central axis of the emission gun.

[0007] Furthermore, the filament is mounted on a conductive column; The upper end of the conductive column is electrically connected to the spring, and the spring is electrically connected to the lower end of the ejector pin.

[0008] Furthermore, a ceramic base is provided in the ion source cavity, and the ceramic base is located below the first base; A stainless steel shielding cover is provided on the upper side of the ceramic base, and a second base is provided on the lower side of the ceramic base; The conductive column of the filament is mounted on the second base, an ion source heating module is further provided below the second base, and the filament is located between the ceramic base and the ion source heating module; The ejector pin passes through the stainless steel shielding cover and is connected to the first base.

[0009] Furthermore, the filament is a gallium ion filament.

[0010] Furthermore, four handle knobs are evenly distributed on the outer wall of the ion source cavity, which are used to adjust the center position of the ceramic base, thereby adjusting the center position of the ion source.

[0011] Furthermore, a control rod is provided at the interface between the ion source assembly and the emission gun assembly; The control rod is mounted on the output shaft of the first cylinder, the first cylinder is mounted on the outer wall of the ion source cavity, and the front end of the control rod is located between the filament and the field acceleration electrode.

[0012] Furthermore, three groups of field acceleration electrodes are stacked inside the field deflection skeleton; A BNC connector is installed on the outer wall of the ion source cavity, and the BNC connector is electrically connected to the three sets of field acceleration electrodes.

[0013] Furthermore, a fifth joint is provided between the field acceleration electrode and the lens; A lens cover is provided below the beam shaping assembly; A terminal conical nozzle is also provided on the outside of the lens cover, and the terminal conical nozzle is installed at the lower end of the beam shaping component. The outer wall of the launch gun central axis is also covered with a launch gun outer cover.

[0014] Furthermore, a second flange is provided on the outer wall of the ion source cavity, which is used to control the size of the ion beam by moving the XY motor.

[0015] Furthermore, the first base is made of stainless steel.

[0016] The technical solution of the present invention has the following beneficial effects: 1. Modular design: ion source, emission gun, accelerating electrode, focusing module, deflection system, etc. are all independent modules, which are convenient for maintenance, debugging and expansion; 2. High beam control precision: The multi-stage electrostatic deflection and focusing system work together to achieve nanometer-scale beam spot control, with a maximum ion beam resolution of 7nm; 3. Strong compatibility between vacuum and gas source: the structure supports 10⁻ 6 Pa-level vacuum environment, compatible with auxiliary gas introduction; 4. Advanced electrical isolation design: physical isolation of high and low voltage signals, enhancing system safety and anti-interference capabilities; 5. Strong adaptability: supports a variety of ion sources (such as 69 Ga / 71 Ga), suitable for a variety of FIB application scenarios (imaging, etching, deposition, etc.). BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of the present invention; Figure 2 It is a three-dimensional diagram from another perspective of the present invention; Figure 3 is a cross-sectional view of the present invention; Figure 4 It is an exploded view of the present invention.

[0018] Figure annotation: 1. First base; 2. Ejector pin; 3. Ion source chamber; 4. Filament; 5. Emitting gun center axis; 6. Field deflection frame; 7. Field accelerating electrode; 8. Lens; 9. Beam shaping assembly; 10. Conductive column; 11. Shrapnel; 12. Ceramic base; 13. Stainless steel shield; 14. Second base; 15. Handle knob; 16. Miter flange; 17. Control rod; 18. First cylinder; 19. BNC connector; 20. Fifth connector; 21. Lens cover; 22. Terminal conical nozzle; 23. Emitting gun cover; 24. Ion source heating module; 25. Second flange. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It will be understood that the specific embodiments described herein are merely intended to explain the present invention rather than to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only show portions related to the present invention rather than all of the present invention.

[0020] Combine Figures 1-4As shown, the present invention provides a focused ion beam generating system based on a gallium ion filament, comprising: an ion source assembly, a launch gun assembly, an ion acceleration assembly, a focusing assembly, and a deflection assembly; The ion source assembly is mounted on the first base 1 and is electrically connected to the first base 1 through a plurality of ejector pins 2; The ion source assembly includes a filament 4, which is located inside the ion source cavity 3 and is electrically connected to the ejector pin 2; the ion source cavity 3 is provided with a first opening for mounting a miter flange; The ion source cavity 3 is installed at the lower end of the first base 1, and the emission gun assembly is installed at the lower end of the ion source cavity 3; The launch gun assembly includes: a launch gun central axis 5, a field deflection frame 6, a field acceleration electrode 7, a lens 8, and a beam shaping assembly 9; The emission gun central axis 5 is installed at the lower end of the ion source cavity 3, the field deflection frame 6 is installed inside the emission gun central axis 5, the field acceleration electrode 7 is installed inside the field deflection frame 6, the lens 8 is located below the field acceleration electrode 7 and is installed on the beam shaping component 9, and the beam shaping component 9 is installed at the lower end of the emission gun central axis 5.

[0021] The filament 4 is mounted on the conductive column 10; The upper end of the conductive pillar 10 is electrically connected to the spring 11 , and the spring 11 is electrically connected to the lower end of the ejector pin 2 .

[0022] A ceramic base 12 is further provided in the ion source cavity 3 , and the ceramic base 12 is located below the first base 1 ; A stainless steel shielding cover 13 is provided on the upper side of the ceramic base 12, and a second base 14 is provided on the lower side of the ceramic base 12; The conductive column 10 of the filament 4 is mounted on the second base 14 , and an ion source heating module 24 is further provided below the second base 14 , so that the filament 4 is located between the ceramic base 12 and the ion source heating module 24 ; The ejector pin 2 passes through the stainless steel shielding cover 13 and is connected to the first base 1 .

[0023] The filament 4 is a gallium ion filament.

[0024] Four handle knobs 15 are evenly distributed on the outer wall of the ion source chamber 3 for adjusting the center position of the ceramic base 12 , thereby adjusting the center position of the ion source.

[0025] A control rod 17 is also provided at the joint between the ion source assembly and the emission gun assembly; The control rod 17 is mounted on the output shaft of the first cylinder 18 . The first cylinder 18 is mounted on the outer wall of the ion source chamber 3 . The front end of the control rod 17 is located between the filament 4 and the field acceleration electrode 7 .

[0026] Three groups of field acceleration electrodes 7 are stacked inside the field deflection frame 6; A BNC connector 19 is installed on the outer wall of the ion source chamber 3 , and the BNC connector 19 is electrically connected to the three sets of field acceleration electrodes 7 .

[0027] A fifth connector 20 is further provided between the field acceleration electrode 7 and the lens 8; A lens cover 21 is provided below the beam shaping assembly 9; A terminal conical nozzle 22 is further provided on the outside of the lens cover 21 , and the terminal conical nozzle 22 is mounted on the lower end of the beam shaping assembly 9 . The outer wall of the launch gun central axis 5 is also covered with a launch gun outer cover 23 .

[0028] A second flange opening 25 is also provided on the outer wall of the ion source chamber, which is used to control the size of the ion beam by moving the XY motor.

[0029] The first base 1 is made of stainless steel.

[0030] Working principle: 1. Ion source structure The ion source assembly is located at the top of the entire device and is installed in the ion source chamber (3). It consists of the following parts: Ion source heating module (24): adopts a needle-tip field evaporation structure (adapted to liquid metal Ga source), forms a liquid film through current heating, and realizes ion emission under high voltage electric field; Ion source fixed structure (conductive column 10, spring 11, ceramic base 12): high voltage isolation and electromagnetic shielding are achieved through ceramic insulating parts (12) and metal shielding cover (13); Gas / vacuum interface (16): The miter flange 16 is connected to an external gas or vacuum system to support gas-assisted deposition / etching processes.

[0031] 2. Ion beam acceleration and focusing module After being ejected from the emission needle tip, the ion beam passes through multiple functional electrodes in sequence to achieve acceleration and focusing, including: Field acceleration electrode (7): accelerates primary ions in the range of 10–30 kV; Focusing lens (8): uses a multi-pole electrostatic lens combination to control the beam spot size to the order of several nanometers; Beam shaping component (9): finely controls beam distribution; Terminal cone nozzle (22): Metal precision cone hole structure, providing the last level of mechanical shaping and vacuum isolation.

[0032] 3. Deflection Control and Electrode System The middle part of the device is designed with multiple sets of deflection and shaping control electrodes, the structure includes: Deflection electrode group (5, 20): electrostatic XY deflection mechanism, providing dual-axis beam trajectory adjustment capability; Signal channel interfaces (15, 18, 19): Separate high-voltage control, deflection adjustment, and beam control feedback signals to avoid electrical coupling; Auxiliary shielding shell (23): the inner layer is a metal conductive shell, and the outer layer is a supporting shell, which effectively suppresses electromagnetic interference.

[0033] 4. Structural modules and maintenance optimization The whole machine adopts modular design, and its specific features are as follows: The cavity module (3) and the electrode assemblies (5, 6, 7, 8, 9) can be independently disassembled and assembled, making replacement and upgrading easy; The wiring ports (18, 19) use standardized high-voltage connectors, which can be quickly connected to the control system; The cooling cone structure (21) is used for end heat dissipation to ensure the stability of the ion beam path.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the scope of the invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the protection scope of the present invention.

Claims

1. A focused ion beam generating system based on a gallium ion filament, characterized in that: include: Ion source assembly, launch gun assembly, ion acceleration assembly, focusing assembly, deflection assembly; The ion source assembly is mounted on the first base and is electrically connected to the first base via a plurality of ejector pins; The ion source assembly includes a filament, which is located inside the ion source cavity and electrically connected to the ejector pin; the ion source cavity is provided with a first opening for mounting a miter flange; The ion source cavity is installed at the lower end of the first base, and the emission gun assembly is installed at the lower end of the ion source cavity; The launch gun assembly includes a launch gun center axis, a field deflection frame, a field acceleration electrode, a lens, and a beam shaping assembly; The central axis of the emission gun is installed at the lower end of the ion source cavity, the field deflection frame is installed inside the central axis of the emission gun, the field acceleration electrode is installed inside the field deflection frame, the lens is located below the field acceleration electrode and is installed on the beam shaping assembly, and the beam shaping assembly is installed at the lower end of the central axis of the emission gun.

2. The focused ion beam generating system according to claim 1, wherein: The filament is mounted on a conductive column; The upper end of the conductive column is electrically connected to the spring, and the spring is electrically connected to the lower end of the ejector pin.

3. The focused ion beam generating system according to claim 2, wherein: A ceramic base is also provided in the ion source cavity, and the ceramic base is located below the first base; A stainless steel shielding cover is provided on the upper side of the ceramic base, and a second base is provided on the lower side of the ceramic base; The conductive column of the filament is mounted on the second base, an ion source heating module is further provided below the second base, and the filament is located between the ceramic base and the ion source heating module; The ejector pin passes through the stainless steel shielding cover and is connected to the first base.

4. The focused ion beam generating system according to claim 1, wherein: The filament is a gallium ion filament.

5. The focused ion beam generating system according to claim 3, wherein: Four handle knobs are evenly distributed on the outer wall of the ion source cavity, which are used to adjust the center position of the ceramic base, thereby adjusting the center position of the ion source.

6. The focused ion beam generating system according to claim 1, wherein: A control rod is also provided at the joint between the ion source assembly and the emission gun assembly; The control rod is mounted on the output shaft of the first cylinder, the first cylinder is mounted on the outer wall of the ion source cavity, and the front end of the control rod is located between the filament and the field acceleration electrode.

7. The focused ion beam generating system according to claim 1, wherein: Three groups of field acceleration electrodes are stacked inside the field deflection frame; A BNC connector is installed on the outer wall of the ion source cavity, and the BNC connector is electrically connected to the three sets of field acceleration electrodes.

8. The focused ion beam generating system according to claim 1, wherein: A fifth joint is further provided between the field acceleration electrode and the lens; A lens cover is provided below the beam shaping assembly; A terminal conical nozzle is also provided on the outside of the lens cover, and the terminal conical nozzle is installed at the lower end of the beam shaping component. The outer wall of the launch gun central axis is also covered with a launch gun outer cover.

9. The focused ion beam generating system according to claim 1, wherein: A second flange is also provided on the outer wall of the ion source cavity, which is used to control the size of the ion beam by moving the XY motor.

10. The focused ion beam generating system according to claim 1, wherein: The first base is made of stainless steel.

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