High-energy ion source

Abstract

This invention provides a high-energy ion source. This invention relates to the field of ultra-high vacuum equipment development. The high-energy ion source mainly consists of an ion focusing mechanism, an ion generation and guiding mechanism, an electron emission mechanism, an argon gas entry mechanism, and an angle-adjustable mechanism. This core structure generates argon ions and completes their acceleration and focusing. The ion generation and guiding mechanism of this invention is composed of an extraction and top-covering grid. This guiding aperture is at a negative voltage relative to the argon ions, and the voltage value is adjustable between several hundred and several thousand volts. The ion guiding aperture can not only accelerate argon ions but also constrain the direction of the ion beam. The ion focusing mechanism of this invention uses three mutually insulated electrostatic lenses, and the ion beam is adjusted by adjusting the variable resistance of the middle lens for further constraint. The angle-adjustable mechanism of this invention also ensures that the gas inlet pipe and the gas inlet are coaxially aligned to form cluster atoms. This invention can effectively constrain the direction of the ion beam.

Description

Technical Field

[0001] This invention relates to apparatus for generating, emitting, and focusing argon ions, and more particularly to a high-energy ion source. Background Technology

[0002] Because the atoms on a solid surface lose the periodicity of their bulk atomic arrangement, they exhibit a range of different physical and chemical properties. Surface science research primarily encompasses surface states, surface diffusion, surface reconstruction, surface phonons, surface plasmons, electron emission and tunneling effects, spin electrons, self-assembly, and nanostructures. Obtaining and controlling the precise construction of surface atoms is fundamental to surface science and a prerequisite for nanotechnology. Typical surface treatment methods include dissociation, annealing, and ion sputtering, with annealing and ion sputtering being almost standard features in surface analysis instruments. Annealing is relatively simple, requiring only precise temperature control. Ion sputtering requires an ion gun, which ionizes massive, inert argon (Ar) atoms, accelerates them to thousands of electron volts, and focuses them onto the sample surface for surface cleaning, etching, or depth analysis. It is a crucial component of surface analysis and nanotechnology devices; however, existing ion equipment suffers from low ion beam focusing, resulting in unsatisfactory experimental results. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a high-energy ion source that is simple in structure, has a long service life, adjustable beam direction, withstands high-temperature baking, and is easy to use. The technical means employed in this invention are as follows:

[0004] A high-energy ion source includes an ion focusing mechanism, an ion generating and guiding mechanism, an electron emission mechanism, and an argon gas entry mechanism. The output end of the argon gas entry mechanism is connected to a preparation chamber, and the argon gas entry mechanism is used to introduce argon gas into the preparation chamber in a pulsed manner. The top of the preparation chamber is connected to the electron emission mechanism through a second air inlet. The electron emission mechanism includes an ion generating grid and a filament for releasing thermionic electrons when energized. The electron emission mechanism is used to confine electrons inside the ion generating grid by the potential difference between the filament and the ion generating grid. The ion generating and guiding mechanism includes a lead-out electrode disposed at the output end of the electron emission mechanism, which is at a negative voltage relative to argon ions. The output end of the ion generating and guiding mechanism is connected to an ion focusing mechanism, and the ion focusing mechanism includes a focusing lens, which is used to further constrain the ion beam passing through the electron emission mechanism and the ion generating and guiding mechanism.

[0005] Furthermore, the filament comprises a tantalum wire with a diameter of 0.125 mm, which is under negative high voltage and connected to the filament rod at both ends.

[0006] Furthermore, there are two filaments that share a common electrode.

[0007] Furthermore, the ion generating mesh is a stainless steel grid formed into a cylindrical shape, and the ion generating mesh is at a positive potential relative to the filament, with the voltage value adjustable between several hundred and several thousand volts.

[0008] Furthermore, flanges are installed at both the input and output ends of the electronic emission mechanism, the second air inlet is connected to the flange, and an outer cover is fitted onto the outside of the flange.

[0009] Furthermore, the grid covering the ion guiding hole at the front end of the lead-out electrode is adjacent to the focusing lens.

[0010] Furthermore, the focusing lens comprises a first cylindrical electrode, a second cylindrical electrode, and a third cylindrical electrode. An insulating sheet is provided between adjacent cylindrical electrodes, and an insulating outer cover is provided on the outside of the focusing lens. The second cylindrical electrode is under positive voltage, and its resistance can be adjusted by changing the voltage to regulate the ion beam. The first and third cylindrical electrodes are grounded and at zero potential.

[0011] Furthermore, it also includes an angle-adjustable mechanism, which is used to adjust the first air inlet and the second air inlet to be coaxial.

[0012] Furthermore, the high-energy ion source is made of 304 stainless steel and polytetrafluoroethylene.

[0013] The present invention has the following advantages:

[0014] 1. The lead-out electrode is a grid covering the ion guiding hole at the front end of the outer casing. It is under negative voltage relative to the argon ions. The argon ions are attracted by the focusing lens and fly out of the lead-out electrode. Some are captured by the lead-out electrode, and most of them pass through the lead-out electrode and are ejected. The lead-out electrode can not only accelerate the argon ions, but also constrain the direction of the ion beam.

[0015] 2. The electrostatic focusing lens consists of three mutually insulated cylindrical electrodes (made of stainless steel). The middle electrode is at a positive voltage, while the electrodes on both sides are grounded and at zero potential. The voltage of the middle electrode is adjusted by a variable resistor to further confine the ion beam.

[0016] 3. The advantage of argon gas introduction is that it can cause atoms to form clusters, and after ionization, it generates a cluster ion source, which is beneficial to achieving a better surface smoothing effect.

[0017] 4. The ion energy of this invention can reach up to 20kV and the beam current intensity can reach 50mA.

[0018] 5. Because the high-energy ion source of this invention is made of SUS304 and polytetrafluoroethylene, it can withstand high-temperature baking at 220°C. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the internal structure of the high-energy ion source of the present invention.

[0021] Figure 2 This is a schematic diagram of the external structure of the high-energy ion source of the present invention.

[0022] Figure 3 This is a top view of the present invention.

[0023] Figure 4 for Figure 3 AA sectional view.

[0024] Figure 5 This is a schematic diagram of the emission and acceleration of hot electrons.

[0025] Figure 6 This is a schematic diagram of an electrostatic focusing lens.

[0026] In the diagram: 1. Ion focusing mechanism; 2. Ion generation and guiding mechanism; 3. Electron emission mechanism; 4. Argon gas entry mechanism; 5. Angle adjustment mechanism; 6. First cylindrical electrode; 7. First insulating sheet; 8. Second cylindrical electrode; 9. Insulating outer cover; 10. Second insulating sheet; 11. Third cylindrical electrode; 12. Third insulating sheet; 13. Lead-out electrode; 14. Ion generating mesh; 15. Filament; 16. Flange; 17. Outer cover; 18. Filament rod; 19. Chamber outer cover; 20. Second air inlet; 21. Support rod; 22. Insulating base; 23. Preparation chamber; 24. First air inlet; 25. Electrode flange. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figures 1-4As shown in the figure, this embodiment of the invention discloses a high-energy ion source, including an ion focusing mechanism 1, an ion generating and guiding mechanism 2, an electron emission mechanism 3, and an argon gas entry mechanism 4. The output end of the argon gas entry mechanism is connected to a preparation chamber 23. The argon gas entry mechanism is used to introduce argon gas into the preparation chamber in a pulsed manner through a first inlet 24. The gas expands and cools to form cluster atoms, finally forming a cluster ion source. The upper part of the preparation chamber is connected to the electron emission mechanism through a second inlet 20. The electron emission mechanism includes an ion generating grid 14 and a filament 15 for releasing thermionic electrons by energizing it. The electron emission mechanism is used to bind electrons inside the ion generating grid by the potential difference between the filament and the ion generating grid. The ion generating and guiding mechanism includes a lead-out electrode 13 disposed at the output end of the electron emission mechanism, which is at a negative voltage relative to argon ions. The output end of the ion generating and guiding mechanism is connected to the ion focusing mechanism. The ion focusing mechanism includes a focusing lens, which is used to further constrain the ion beam passing through the electron emission mechanism and the ion generating and guiding mechanism.

[0029] The filament consists of a tantalum wire with a diameter of 0.125 mm, which is under negative high voltage and connected to the filament rod 18 at both ends.

[0030] There are two filaments that share a common electrode. The electrode is led out through electrode flanges 25 on both sides so that the other spare filament can be used without breaking the vacuum environment in the event of a short circuit in one filament.

[0031] The ion generating mesh is a stainless steel grid formed into a cylindrical shape. The ion generating mesh is at a positive potential relative to the filament, and the voltage value is adjustable between several hundred and several thousand volts.

[0032] An outer cover 17 is fitted around the outside of the electronic transmitting mechanism. The input end of the electronic transmitting mechanism is mounted on the insulating base 22 via a support rod 21. An outer cover 19 is fitted around the entire structure. This chamber is connected to the preparation chamber. Flanges 16 are installed on the upper and lower sides of the chamber. The second air inlet is connected to the lower flange. An outer cover is fitted around the outside of the flange.

[0033] The extractor is a grid covering the ion guiding hole at the front end of the outer casing, adjacent to the focusing lens. Argon ions are attracted by the focusing lens C and fly out of the extractor; some are captured by the extractor, and most pass through the extractor and are ejected. The extractor can not only accelerate argon ions but also constrain the direction of the ion beam.

[0034] The focusing lens comprises a first cylindrical electrode 6, a second cylindrical electrode 8, and a third cylindrical electrode 11. An insulating sheet is provided between adjacent cylindrical electrodes, specifically a first insulating sheet 7, a second insulating sheet 10, and a third insulating sheet 12. An insulating cover 9 is provided on the outside of the focusing lens. The second cylindrical electrode is under a positive voltage, and its resistance can be adjusted by changing the voltage to regulate the ion beam. The first and third cylindrical electrodes are grounded and at zero potential.

[0035] It also includes an angle-adjustable mechanism 5, which is used to adjust the first air inlet and the second air inlet to be coaxial. Specifically, an XY worktable can be used, which can be adjusted by two angle knobs.

[0036] The non-insulating parts of the high-energy ion source are made of SUS304 stainless steel, while the insulating parts are made of polytetrafluoroethylene.

[0037] like Figure 5 The diagram shows the emission and acceleration of hot electrons. Electrons of a certain energy collide with argon atoms, ionizing them. The process by which electrons ionize gas molecules is as follows:

[0038] M+e-→M++2e-(1)

[0039] Where M is an ionized neutral gas molecule, e - It is an electron, M + It is an ion.

[0040] Thermionic electrons are released by heating a resistance wire, and a relatively high-voltage anode grid is placed near the resistance wire. If the potential difference between the anode grid and the resistance wire is U, the electrons are accelerated and gain kinetic energy eU. Most of the electrons are trapped in the anode grid. Inert gas argon (Ar) is introduced from a direction perpendicular to the acceleration motion of the thermionic electrons. The accelerated electrons cause a drastic change in the electric field around the neutral argon atoms, causing them to lose an electron and be ionized according to the process of equation (1).

[0041] The ion beam is focused using an electrostatic focusing lens, the basic principle of which is as follows: Figure 6 As shown. Argon ions entering the lens from point A are decelerated before reaching the intermediate electrode, accelerated to their initial energy after passing through the intermediate electrode, and finally exit the focusing lens. Ions originating from A experience an outward force at point B and an inward force at point C. Therefore, the ion beam diverges at point B and focuses at point C. Although the forces at points B and C are the same, the axial velocity of the argon ions decreases near point C, resulting in a greater focusing effect than a diverging effect. After passing through the intermediate electrode, the argon ions focus at point D and diverge at point E. Overall, the ion beam is focused.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-energy ion source, characterized in that, The device includes an ion focusing mechanism, an ion generating and guiding mechanism, an electron emission mechanism, and an argon gas entry mechanism. The output end of the argon gas entry mechanism is connected to a preparation chamber, and the argon gas entry mechanism is used to introduce argon gas into the preparation chamber in a pulsed manner. The top of the preparation chamber is connected to the electron emission mechanism through a second air inlet. The electron emission mechanism includes an ion generating grid and a filament for releasing thermionic electrons when energized. The electron emission mechanism is used to confine electrons inside the ion generating grid by the potential difference between the filament and the ion generating grid. The ion generating and guiding mechanism includes a lead-out electrode disposed at the output end of the electron emission mechanism, which is at a negative voltage relative to argon ions. The output end of the ion generating and guiding mechanism is connected to an ion focusing mechanism, and the ion focusing mechanism includes a focusing lens, which is used to further constrain the ion beam passing through the electron emission mechanism and the ion generating and guiding mechanism. It also includes an angle adjustment mechanism, which is used to adjust the first air inlet and the second air inlet to be coaxial, specifically an XY worktable, which is adjusted by two angle knobs; The filament comprises a tantalum wire with a diameter of 0.125 mm, which is under negative high voltage and connected to the filament rod at both ends; The argon gas inlet mechanism is used to introduce argon gas into the preparation chamber through the first inlet in a pulse manner. The gas expands and cools to form cluster atoms, and finally forms a cluster ion source. The ion energy reaches a maximum of 20 kV, and the beam current intensity reaches 50 mA. Flanges are installed at both the input and output ends of the electronic emission mechanism. The second air inlet is connected to the flange, and an outer cover is fitted over the outside of the flange. The input end of the electronic emission mechanism is mounted on an insulating base via a support rod. An outer cover is fitted over the entire structure. This chamber is connected to the preparation chamber. Flanges are installed at both the top and bottom of the chamber. The second air inlet is connected to the lower flange, and an outer cover is fitted over the outside of the flange.

2. The high-energy ion source according to claim 1, characterized in that, There are two filaments that share a common electrode.

3. The high-energy ion source according to claim 1, characterized in that, The ion generating mesh is a stainless steel grid formed into a cylindrical shape. The ion generating mesh is at a positive potential relative to the filament, and the voltage value is adjustable between several hundred and several thousand volts.

4. The high-energy ion source according to claim 1, characterized in that, The grid covering the ion guide hole at the front end of the lead-out electrode is adjacent to the focusing lens.

5. The high-energy ion source according to claim 1 or 4, characterized in that, The focusing lens comprises a first cylindrical electrode, a second cylindrical electrode, and a third cylindrical electrode. An insulating sheet is provided between adjacent cylindrical electrodes, and an insulating outer cover is provided on the outside of the focusing lens. The second cylindrical electrode is under positive voltage, and its resistance can be adjusted by changing the voltage to regulate the ion beam. The first and third cylindrical electrodes are grounded and at zero potential.

6. The high-energy ion source according to claim 1, characterized in that, The high-energy ion source is made of 304 stainless steel and polytetrafluoroethylene.

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