A high-energy large-beam diode ion gun device

Abstract

The application provides a high-energy large-beam diode ion gun device, which comprises a gas-tight assembly for providing inert gas and comprising a housing and a gas source connector, the gas source connector being sealingly mounted in the housing; a high-voltage supply assembly for providing a high-voltage power supply and comprising a high-voltage cable, a first insulating block, a second insulating block and a wiring housing; and an ion beam generating assembly for generating an ion beam and comprising an anode, a cathode and an accelerating cathode located on the same axis. The application is characterized in that a gap is provided between the anode and the insulating sleeve, and the gas guide hole and the anode blind hole are connected, so that the inert gas introduced from the gas source connector is introduced from the center of the anode to the ionization space between the cathode and the anode, the inert gas is ionized in the ionization space and completes the primary acceleration, and the high-energy large-beam ion beam is obtained after the secondary acceleration between the cathode and the accelerating cathode.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ion gun, and particularly relates to a high-energy and large-beam two-electrode ion gun device. BACKGROUND

[0002] The development of material science cannot be separated from advanced material sample preparation and analysis means, and an ion thinning instrument is a kind of instrument for mechanically impacting a material surface by using a high-energy ion beam to thin a solid sample to a thickness of less than 200 nanometers, so that the microstructure of the material inside and the composition of the material are observed under a transmission electron microscope (TEM), and thus new materials are researched and developed. Surface treatment is a prerequisite for surface science and nanotechnology. Compared with traditional annealing, electrolysis, chemical response and other surface treatment methods, high-energy ion beam micro-nano machining technology is the mainstream and frontier of sample preparation technology for surface or interface research.

[0003] An ion gun is a key component of the ion thinning instrument, and mainly functions to ionize neutral molecules or atoms, and after acceleration and focusing, the neutral molecules or atoms are impacted on a material surface, hundreds to thousands of electron volts of energy of the ion jet is sprayed to the sample surface to strip the sample surface layer atoms, so that the purpose of ion beam micro-nano machining is achieved. The neutral molecule or atom source is mostly inert gas, especially argon, which has a large mass, low cost, and cannot chemically react with other substances on the surface, so that a flat, clean and non-contact stress actual surface can be obtained, and the machining precision can reach the atomic level.

[0004] At present, commercially available ion guns for surface micro-nano machining in China are all dependent on imports. Laboratory available ion guns include two-electrode ion guns, three-electrode ion guns, hollow cathode guns, Kaufman guns and magnetic control sputtering guns, etc. The traditional two-electrode ion gun has low ionization rate, small beam flow and low energy, and long processing time, which cannot meet the current demand for high-efficiency sample preparation experiments. The three-electrode ion gun has high ionization rate through grid oscillation or axial magnetic field, but has small beam density, complex structure and high-voltage power supply control, which limits its use to superfine surface processing. Other types of ion guns also have their own advantages but are limited by special application occasions. Therefore, it is necessary to develop an ion gun with high energy and large beam flow. SUMMARY

[0005] The application provides a two-electrode ion gun device with high energy and large beam flow.

[0006] In order to solve the above problems, the technical scheme adopted by the application is as follows:

[0007] A high-energy large-current diode ion gun device, comprising:

[0008] A gas-tight assembly for providing inert gas and comprising a housing and a gas source connector, the gas source connector being sealingly mounted in the housing;

[0009] A high-voltage supply assembly for providing a high-voltage power supply and comprising a high-voltage cable, a first insulating block, a second insulating block and a wiring housing, the wiring housing being mounted on the tail of the housing and the high-voltage cable being embedded in the wiring housing;

[0010] An ion beam generating assembly for generating an ion beam and comprising an anode, a cathode and an accelerating cathode located on the same axis, wherein the anode is further sleeved with an insulating sleeve and has an anode blind hole inside, the cathode and the accelerating cathode are respectively provided with a first ion hole and a second ion hole, and the anode blind hole, the first ion hole and the second ion hole form an ion beam channel.

[0011] Preferably, the housing is sleeved outside the insulating sleeve with a gap therebetween, and the flow path of the inert gas input by the gas source connector in the gap is the first channel.

[0012] Preferably, the anode comprises a large cylindrical part and a small cylindrical part, the small cylindrical part passes through a through hole provided on the insulating sleeve and is electrically connected with the core of the high-voltage cable. Further, the large cylindrical part of the anode is provided with a gas guide hole perpendicular to the anode blind hole. Further, there is a gap between the insulating sleeve and the anode, which communicates with the gas guide hole and the anode blind hole.

[0013] Preferably, the cathode is in the form of a disc, the first ion hole is provided in the center of the cathode, the first ion hole is a conical counterbore, a cathode circular hole is provided on the side of the cathode facing the anode, and a conical surface is provided on the other side. Further, there is a certain distance between the cathode and the side end surface of the anode blind hole of the anode to form an ionization space; further, the distance between the cathode and the side end surface of the anode blind hole of the anode is 2-4 mm, a confinement magnet is vertically provided on the cavity between the cathode and the anode blind hole, and the confinement magnet is sleeved outside the insulating sleeve. Preferably, the distance between the cathode and the side end surface of the anode blind hole of the anode is 4 mm. Further, an accelerating insulating sheet is provided between the cathode and the accelerating cathode, the accelerating insulating sheet is provided with a third ion hole, and the anode blind hole, the first ion hole, the second ion hole and the third ion hole are located on the central axis of the anode.

[0014] Preferably, the tail of the housing is further spin-welded with a sealing nut, and the wiring housing is mounted on the sealing nut. Further, the first insulating block is located between the insulating sleeve and the high-voltage cable, and the second insulating block is located between the first insulating block and the wiring housing.

[0015] The application has the following beneficial effects:

[0016] 1、 The application adopts cold cathode ionization, does not need to provide a heating power supply, and the accelerating cathode and the cathode are at the same potential, so that the structure is compact and small, the requirements for the high-voltage power supply and the overall structure complexity are reduced, energy is saved, stability is high, the cost performance is high, and the service life is long.

[0017] 2、 The application is provided with a gap between the anode and the insulating sleeve, and is also provided with an anode blind hole and a gas guide hole, so that the inert gas can be introduced from the center of the anode to the ionization space between the cathode and the anode as much as possible, the inert gas is ionized near the axis to become near-axis ions, and the near-axis ions have a greater probability of being emitted from the accelerating cathode after acceleration, so that a larger ion beam is obtained.

[0018] 3、 The application is provided with a constraint magnet outside the insulating sleeve, so that an axial constraint magnetic field is generated in the discharge area of the anode and the cathode, the collision probability of electrons and inert gas is increased to generate more inert gas ions, the ionization probability of the inert gas is high, and the ion beam flow is further increased.

[0019] 4、 The inert gas is ionized and initially accelerated in the cavity between the cathode and the anode, and is secondarily accelerated between the cathode and the accelerating cathode, so that the emitted ions obtain energy close to the limit under a certain voltage, and a high-energy ion beam is obtained after emission.

[0020] 5、 The ion gun device provided by the application can generate a high-energy and large-beam ion beam, improves the processing efficiency when preparing a sample, reduces the processing time, has a simple structure, a simple high-voltage power supply control, and is convenient for production and wide application. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The application provides a structure schematic diagram of a two-pole ion gun device;

[0022] Figure 2 The application provides an explosion schematic diagram of a two-pole ion gun device;

[0023] Figure 3 The application provides a quarter sectional view of a two-pole ion gun device;

[0024] Figure 4 The application provides a sectional view of a two-pole ion gun device;

[0025] Figure 5 The application provides a sectional view of a two-pole ion gun device; Figure 4

[0026] Figure 6 The application provides a sectional view of a two-pole ion gun device;

[0027] Figure 7 ​This is a schematic diagram of the insulating sleeve.

[0028] Figure 8 A schematic diagram of the anode structure provided by the present invention;

[0029] Figure 9 Schematic diagram of the cathode provided by the present invention Figure 1 ;

[0030] Figure 10 Schematic diagram of the cathode provided by the present invention Figure 2 ;

[0031] In the diagram: 1-Anode, 101-Anode blind hole, 102-Large cylindrical part, 103-Small cylindrical part, 104-Gas vent, 105-Internal threaded hole; 2-Cathode, 201-Cathode circular hole, 202-Conical surface; 3-Insulating sleeve, 301-Large diameter end, 302-Small diameter end; 4-Constraint magnet, 5-Sealing ring, 6-Anode nut, 7-Accelerating insulating sheet, 8-Accelerating cathode, 9-Shell, 10-Gas source connector, 11-First ion hole, 12-Second ion hole, 13-Third ion hole, 14-Sealing gasket, 15-Sealing nut, 16-High voltage cable, 1601-Wire core, 17-Cable screw, 18-First insulating block, 19-Second insulating block, 20-Connecting housing, 21-Bolt, 22-First channel, 23-Second channel. Detailed Implementation

[0032] To describe the present invention more specifically, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. These descriptions are merely illustrative of how the present invention is implemented and do not limit the specific scope of the present invention. The scope of the present invention is defined in the claims.

[0033] like Figures 1 to 4 As shown, this embodiment provides a high-energy, high-current diode-type ion gun device, which includes:

[0034] An airtight assembly is used to provide inert gas and enable the ionization process of the inert gas to occur in a vacuum-sealed environment. The airtight assembly includes a housing 9 and a gas source connector 10, which is sealed and installed inside the housing. Specifically, the housing is a hollow cylindrical structure with threads on the outer walls of both the head and tail, and grooves for securing sealing rings on the inner walls of both the head and tail. A sealing gasket 14 is provided at the tail of the housing, and the threads are sealed by a sealing nut 15. The housing material is selected as a good conductor of electricity (in this embodiment, the housing is made of stainless steel). The gas source connector is vertically embedded in the housing, and the outlet of the gas source connector is connected to the cavity inside the housing so that the inert gas connected to the gas source connector can enter the housing. A sealing ring is provided at the embedding and installation point of the gas source connector and the housing for sealing.

[0035] A high-voltage supply assembly for providing direct current high voltage and comprising a high-voltage cable 16, a first insulating block 18, a second insulating block 19 and a wiring housing 20, the high-voltage cable being embedded in the housing through the wiring housing and the high-voltage cable being insulated from the wiring housing by the second insulating block; in particular, the wiring housing is an open circular groove structure and is fixed to the sealing nut by bolts, the high-voltage cable is vertically embedded on the same side of the wiring housing as the gas source connector, the high-voltage cable is insulated from the wiring housing by the second insulating block, and the first insulating block is located between the insulating sleeve and the high-voltage cable for insulation.

[0036] An ion beam generating assembly for generating an ion beam and comprising an anode, a cathode and an accelerating cathode located on the same axis, wherein the anode is provided with an anode blind hole, the cathode and the accelerating cathode are respectively provided with a first ion hole 11 and a second ion hole 12, and the anode blind hole, the first ion hole and the second ion hole form an ion beam channel; in particular, the anode is further sleeved with an insulating sleeve 3, the housing is sleeved outside the insulating sleeve, and a sealing ring 5 is further arranged between the insulating sleeve and the housing, as shown in Figure 7 , the insulating sleeve is a cylindrical member with a central countersunk through hole and is made of insulating material, the insulating sleeve is divided into a large-diameter end 301 and a small-diameter end 302, the small-diameter end is close to the cathode and is externally sleeved with a constraint magnet 4, the constraint magnet is a hollow cylindrical neodymium iron boron permanent magnet located at a high-voltage discharge distance to provide a magnetic field to constrain the movement of ions, the constraint magnet exerts an axial magnetic field on the anode and the cathode to increase the collision probability of electrons and inert gas to generate more inert gas ions.

[0037] As shown in Figure 8 , the anode 1 is a cylindrical structure made of a good electrical conductor (in this embodiment, the anode is made of molybdenum with a high melting point and difficult to sputter), which is located in the counterbore of the insulating sleeve, and the anode is divided into a large cylindrical part 102 and a small cylindrical part 103, as shown in Figure 6 , wherein the small cylindrical part passes through the through hole of the insulating sleeve and is in contact with the core 1601 of the high-voltage cable, the small cylindrical part is fixed to the insulating sleeve by an anode nut 6, a sealing ring is arranged at the through hole of the insulating sleeve to improve the sealing performance, a first insulating block is arranged between the small cylindrical part and the high-voltage cable, the anode nut is arranged in the first insulating block, the small cylindrical part is provided with an internal threaded hole, the core of the high-voltage cable is fixed in the internal threaded hole by a cable screw 17, the cable screw is arranged in a second insulating block, the first insulating block and the second insulating block are made of insulating material (in this embodiment, polytetrafluoroethylene material) and are fixed by a bolt 21; the large cylindrical part of the anode is provided with an anode blind hole 101 with a tapered bottom, and a gas guiding hole 104 is arranged on the outer wall perpendicular to the anode blind hole;

[0038] As shown in Figure 9 andFigure 10 As shown, the cathode 2 is a stepped disc structure as a whole, the small-diameter side of which faces the anode and the outer edge of which is provided with a cathode circular hole 201, the large-diameter side of which is provided with a conical surface 202, and the center of which is provided with a first ion hole, which is a conical hole with the large end facing the anode, facilitating more ion emission. The cathode is made of a good electrical conductor (molybdenum is selected for the cathode in this embodiment). The cathode is buckled on the shell near the anode through the accelerating cathode 8, and a sealing ring is arranged at the contact position between the step of the cathode and the shell. An accelerating insulating sheet 7 (alumina ceramic is selected for the accelerating insulating sheet in this embodiment) is arranged between the cathode and the accelerating cathode, and is clamped in the accelerating cathode. The accelerating cathode and the accelerating insulating sheet are respectively provided with a second ion hole and a third ion hole 13 in the center. The second ion hole is a conical hole with the large-diameter side facing the accelerating insulating sheet. The cold cathode design is adopted in this embodiment, which does not need to provide a heating power supply, has low requirements on vacuum conditions, is energy-saving and stable, has high maintainability, and has a diode-type design of the cathode and the accelerating cathode at the same potential, thereby reducing the requirements on the high-voltage power supply and the complexity of the overall structure.

[0039] The shell, the anode, the cathode, and the accelerating cathode in this embodiment are made of an electrically conductive material, and the first insulating block, the second insulating block, the insulating sleeve, and the accelerating insulating sheet are made of an insulating material. The first insulating block is arranged between the high-voltage cable and the anode to insulate and isolate them from other components. The second insulating block is arranged between the high-voltage cable and the high-voltage cable to insulate and isolate them. The high-voltage cable is externally connected to a high-voltage stable power supply. The anode is in electrical communication with the core and is connected to the positive electrode of the high-voltage direct current power supply. The cathode, the accelerating cathode, and the shell are in electrical communication and are connected to the ground. The accelerating cathode and the cathode are at the same potential.

[0040] A gap is left between the outer wall of the insulating sleeve and the inner wall of the shell. The tail end of the gap is in communication with the gas source connector, and the head end is in communication with the top of the cathode circular hole of the cathode. The bottom of the cathode circular hole is in communication with the ion beam cavity (the ion beam cavity refers to the space in which the inert gas can flow in the insulating sleeve). The gas source connector is connected to the inert gas. After passing through the gap, the inert gas flows into the ion beam cavity through the cathode circular hole. The flow path of the inert gas in the first channel is as shown by the arrow in Figure 5 ;

[0041] The gap is arranged between the outer wall of the anode and the inner wall of the insulation sleeve, the high-voltage discharge distance between the cathode and the anode is 4mm, the distance between the accelerating cathode and the small end of the cathode conical hole is 4mm, which is the distance of secondary acceleration of the ion beam; the anode blind hole, the first ion hole, the third ion hole and the second ion hole are coaxially arranged and form an ion beam emission channel; when the gas source connector is connected to the inert gas, the inert gas flows into the ion beam cavity through the first channel, part of the inert gas directly enters the cavity between the anode and the cathode, and the other part of the inert gas sequentially passes through the gap between the insulation sleeve and the anode, the gas guide hole and the anode blind hole, and then returns to the space between the anode and the cathode from the anode blind hole, the flow path of the above-mentioned other part of the inert gas is the second channel 23, the inert gas flow path in the second channel is shown by arrows in the figure, and the second channel makes the inert gas be ionized near the anode axis, and the near-axis ions have a greater probability of being emitted from the accelerating cathode after acceleration, so that a larger ion beam current is obtained. Figure 5

[0042] Working principle: under the vacuum state, after the inert gas is connected, the high-voltage power supply is turned on, the direct-current high voltage is connected between the anode and the cathode, the cathode field emission electron is caused, the inert gas is ionized to form plasma in the process of acceleration movement to the anode; at the same time, the constraint magnet applies an axial magnetic field between the anode and the cathode, and under the joint action of the electric field, the cathode electron escapes and spirally accelerates around the anode axis, increases the electron movement path, and increases the ionization rate of the inert gas; the inert gas is ionized between the cathode and the anode and is primarily accelerated by the cathode, is emitted from the first ion hole, is accelerated again after the accelerating cathode, obtains the limit speed matched with the voltage of the cathode and the anode, is emitted from the second ion hole to form the final high-energy large beam current ion beam, the inert gas is ionized near the anode axis, the near-axis ions have a greater probability of being emitted from the accelerating cathode after acceleration, a large beam current ion beam is obtained, the cathode primary acceleration and the accelerating cathode secondary acceleration obtain the energy close to the limit under a certain voltage, and the high-energy ion beam is obtained.

[0043] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the range defined by the claims.​

Claims

1. A high energy, high current diode ion gun apparatus, characterized by: The diode ion gun device comprises: an airtight assembly for providing inert gas and comprising a housing and a gas source connector, the gas source connector being sealingly mounted in the housing; a high-voltage supply assembly for providing a high-voltage power supply and comprising a high-voltage cable, a first insulating block, a second insulating block and a wiring housing, the wiring housing being mounted at the tail of the housing and the high-voltage cable being embedded in the wiring housing; an ion beam generating assembly for generating an ion beam and comprising an anode, a cathode and an accelerating cathode located on the same axis, wherein the anode is further sleeved with an insulating sleeve and the end surface of the anode is provided with an anode blind hole, the cathode and the accelerating cathode are respectively provided with a first ion hole and a second ion hole, and the anode blind hole, the first ion hole and the second ion hole form an ion beam channel; the anode comprises a large cylindrical part and a small cylindrical part, the small cylindrical part passes through a through hole provided on the insulating sleeve and is electrically connected with the core of the high-voltage cable; the large cylindrical part is provided with a gas guiding hole perpendicular to the anode blind hole; a gap is provided between the insulating sleeve and the anode, and the gap is communicated with the gas guiding hole and the anode blind hole.

2. The diode ion gun apparatus of claim 1, wherein: The housing is sleeved outside the insulating sleeve and a gap is provided between the housing and the insulating sleeve, and the inert gas input by the gas source connector flows in the first channel in the gap.

3. The diode-type ion gun apparatus according to claim 1, characterized by: A confinement magnet is vertically arranged on the cavity between the cathode and the anode blind hole, and the confinement magnet is sleeved outside the insulating sleeve.

4. The diode-type ion gun apparatus according to claim 1, characterized by: The cathode is in a whole disc structure, the first ion hole is arranged at the center of the cathode, the first ion hole is a conical counterbore, a cathode circular hole is arranged on the side of the cathode facing the anode, and a conical surface is arranged on the other side.

5. A diode ion gun apparatus as claimed in claim 4, wherein: An accelerating insulating sheet is arranged between the cathode and the accelerating cathode, the accelerating insulating sheet is provided with a third ion hole, and the anode blind hole, the first ion hole, the second ion hole and the third ion hole are located on the central axis of the anode.

6. The diode-type ion gun apparatus according to claim 1, wherein: A sealing nut is further spin-welded at the tail of the housing, and the wiring housing is mounted on the sealing nut.

7. A diode ion gun apparatus as claimed in claim 6, wherein: The first insulating block is located between the insulating sleeve and the high-voltage cable, and the second insulating block is located between the first insulating block and the wiring housing.

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