An enhanced inductively coupled radio frequency plasma discharge device

Abstract

This invention relates to an enhanced inductively coupled radio frequency plasma discharge device. In this device, a feed post is mounted on the upper flange cover plate. A copper coil passes through the feed post and is fitted with a conical sealing ring and an insulating gasket. The lower end of the copper coil is placed inside a double-layered glass tube, which is pressed against the lower flange cover plate via a flange sealing groove. A PEEK rod is located outside the double-layered glass tube; its lower half passes through a magnet bracket base and is fixed to the lower flange cover plate, while its upper half passes through a through-hole in the upper flange cover plate and is fixed with a nut. The magnet is fixed to the base plate via the L-shaped magnet bracket, the magnet bracket base, and the lower flange cover plate. This invention provides a reference for solving a series of practical engineering problems related to effective radio frequency feed in a vacuum environment, effective heat removal from the discharge chamber, and simple and effective installation of an external multipole magnet. Furthermore, this device features a simple overall structure, modular layout, convenient installation, and easy operation.

Description

Technical Field

[0001] This invention relates to the field of plasma discharge devices, and more particularly to an enhanced inductively coupled radio frequency plasma discharge device. Background Technology

[0002] Inductively coupled plasma (ICP) is characterized by its relatively simple physical properties and ease of generating uniform, high-density plasma, making it applicable in semiconductor manufacturing, materials modification, and biomedicine. In recent years, with the increasing demands for ICP sources, higher requirements have been placed on the density and uniformity of the generated plasma. This has led to the development of two main types: those with built-in coils and those with externally added multipole magnetic fields. The built-in coil type, where the coil is directly placed inside the discharge chamber, achieves a higher electron density and better particle uniformity at the same power compared to ordinary externally coiled ICP sources. The externally added magnetic field type, by constraining the plasma's trajectory and focusing the plasma beam, also increases plasma density and enhances plasma uniformity.

[0003] While the enhanced inductively coupled discharge method described above can improve plasma density and uniformity, several questions arise: How to rationally place the built-in coil while maintaining a vacuum? How to effectively feed the radio frequency (RF) signal? How to effectively cool the ion source chamber to ensure airtightness? How to place and install the permanent magnets to effectively confine the plasma? To address these issues, this invention designs an enhanced inductively coupled discharge device. This device can prevent coil short circuits while simultaneously feeding RF vacuum, remove heat generated during discharge to ensure chamber airtightness, and provide a simple and effective way to install and fix multiple magnets. Summary of the Invention

[0004] The purpose of this invention is to provide an enhanced inductively coupled radio frequency plasma discharge device that solves a series of practical engineering problems, such as effective radio frequency feeding in a vacuum environment, effective heat removal from the discharge chamber, and simple and effective installation of an external multipole magnet. The device features a simple overall structure, modular layout, convenient installation, and easy operation.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] An enhanced inductively coupled radio frequency plasma discharge device is characterized in that the device includes an upper flange cover plate, a lower flange cover plate, a feed support column, a conical sealing ring, an insulating washer, a concave nut, a T-shaped ceramic tube, a double-layer glass cylinder, an L-shaped magnet support, and a magnet support base.

[0007] The feed post is set on the upper cover plate of the flange. After the copper coil passes through the feed post, a conical sealing ring and an insulating washer are fitted on it. A concave nut is used to engage with the external thread at the upper end of the feed post to secure the copper coil. The lower end of the copper coil is placed inside a double-layer glass tube. The double-layer glass tube is pressed onto the lower cover plate of the flange after being engaged with the flange sealing groove.

[0008] The PEEK rod is located outside the double-layer glass cylinder. The lower half of the PEEK rod passes through the magnet bracket base and is fixed to the lower flange cover plate. The upper half passes through the through hole of the upper flange cover plate and is fixed with a nut, thereby fastening the upper flange cover plate to the double-layer glass cylinder and the lower flange cover plate together.

[0009] The magnet is fixed to the base plate via the L-shaped magnet bracket, the magnet bracket base, and the flange cover plate.

[0010] Furthermore, the copper coil is made of oxygen-free copper or pure copper, and it is wound into a single-turn circular or multi-turn spiral shape.

[0011] When the copper coil is wound with oxygen-free copper tubing, water pipes are connected to both ends of the copper coil and connected to a cooling machine. A cooling cycle is formed by adding water, fluorinated liquid or deionized water as a cooling medium to the copper coil, thereby removing the heat generated during the discharge process.

[0012] Furthermore, the flange cover plate is made of SUS316 or SUS304 material, a cooling water channel is provided under the flange sealing groove, and three through holes are opened in the middle of the flange cover plate, two of which are welded to feed supports and the other is welded to a gas pipe.

[0013] Furthermore, the feed post is made of SUS316 or SUS304 material, and the upper end is machined with external threads for engaging with the concave nut; the feed post has a boss inside for placing the T-shaped ceramic tube, and the inner side of the port has a conical structure for engaging with the conical sealing ring.

[0014] Furthermore, the gas pipe is a seamless SUS316 pipe, one end of which is welded to the flange cover plate, and the other end is connected to a gas cylinder, which provides the gas used for discharge.

[0015] Furthermore, the concave nut is a cube of 20×20×15mm with a 10mm deep thread inside.

[0016] Furthermore, the T-shaped ceramic tube is made of silicon nitride / alumina material, with its upper end placed on the boss portion of the feed post and its lower end extending far beyond the lower surface of the flange cover plate. This serves to isolate the copper coil from contact with the feed post and the flange cover plate.

[0017] Furthermore, the conical sealing ring is made of polytetrafluoroethylene, PEEK, or rubber, and its conical surface contacts and fits with the conical surface of the feed post. This converts the downward pressure generated by the threaded connection between the concave nut and the feed post into a positive pressure perpendicular to the conical surface and a frictional force parallel to the conical surface. The positive pressure compresses the conical sealing ring and then compresses the copper coil, making the sealing ring and the copper coil fit tightly together, and together with the frictional force, fixes the copper coil in place.

[0018] Furthermore, the insulating washer is made of polytetrafluoroethylene or PEEK, with its upper end face contacting the concave nut and its lower end face contacting the tapered sealing ring, transmitting the downward pressure generated by the threaded connection between the concave nut and the feed post.

[0019] Furthermore, the double-layered glass tube consists of two glass tubes of different sizes nested together, with their end faces sintered together; the gap between the double-layered glass tubes is only connected to the outside through two cylindrical glass tubes set on its side; the cylindrical glass tubes are connected to water pipes by clamps and then to a cooling machine; water cooling medium or inert gas is introduced into the cylindrical glass tubes to cool the double-layered glass tubes, wherein the cooling water circulation mode is bottom inlet and top outlet.

[0020] Furthermore, the PEEK rod has threaded holes at both ends. One end is threaded to the lower cover plate of the flange, and the other end passes through the upper cover plate of the flange and is secured with a nut.

[0021] Furthermore, the flange lower cover plate is made of SUS316 or SUS304 material, and its end face has evenly distributed threaded holes and evenly distributed threaded through holes, the threaded holes being connected to the PEEK rod.

[0022] Furthermore, the magnet is made of neodymium iron boron or samarium cobalt, and the core can provide a magnetic field of 1.1T.

[0023] Furthermore, the L-shaped magnet bracket includes two end faces. One end face has a rectangular groove with a threaded hole on the side. The size of the rectangular groove is the same as that of the magnet. The magnet can be fixed in the rectangular groove by screws through the threaded hole. The other end face has a U-shaped groove, which is used to fit bolts to fix the L-shaped magnet bracket.

[0024] Furthermore, the magnet bracket base is evenly distributed with 2-3mm deep grooves, the width of which matches the size of the L-shaped magnet bracket. This is used to restrict the rotation of the L-shaped magnet bracket on the plane, thereby ensuring that the magnets evenly distributed in a circle can be centered. Threaded holes are opened in the grooves for bolts to be used to fasten the L-shaped magnet bracket.

[0025] In summary, the beneficial effects of this invention are:

[0026] 1. Ensure the interior of the chamber is 10 -4Under vacuum requirements in the Pa range, the copper coil can be placed inside the cavity and can be effectively fed into the radio frequency from both ends of the copper coil without forming a short circuit with other structures in the cavity.

[0027] 2. The reasonable arrangement of several cooling methods, including cooling medium cooling through the upper (lower) flange cover plate, air (water) cooling through the double-layer glass cylinder, and deionized water cooling inside the copper coil, effectively removes the heat generated during the discharge process, prevents the sealing ring from deforming due to high temperature, and ensures the airtightness of the entire device.

[0028] 3. The bar magnet's rotation on that plane is restricted after it mates with the slot on the surface of the magnet support base via the L-shaped magnet bracket. Furthermore, because the magnet support base, the upper (lower) flange cover, and the double-layered glass cylinder are all concentrically assembled, the multipolar magnetic field is ensured to be evenly distributed around the circumference of the entire device. Bolts are used for fastening, which is convenient and quick. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall enhanced inductive coupling device.

[0030] Figure 2 This is a schematic diagram of the radio frequency feed module.

[0031] Figure 3 This is a schematic diagram of the cooling module structure.

[0032] Figure 4 This is a schematic diagram of the permanent magnet mounting module structure.

[0033] In the diagram: 1-Cavity; 2-Exhaust port; 3-Base plate; 4-L-shaped magnet bracket; 5-PEEK rod; 6-Flange top cover plate; 7-PEEK fastening nut; 8-Copper coil; 9-Gas pipe; 10-Concave nut; 11-Double-layer glass cylinder; 12-Magnet bracket base; 13-Flange bottom cover plate; 14-Cavity connection fastening bolt; 41-Bar magnet; 42-Magnet bracket fastening bolt; 61-Flange top cover plate cooling water channel; 101-Insulating gasket; 102-Conical sealing ring; 103-Feeding support column; 104-T-shaped ceramic tube; 111-Cooling water interface; 131-Flange bottom cover plate cooling water channel; 132-Water tank cover plate; 133-Sealing ring. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] This invention comprises three main modules: radio frequency (RF) feed, chamber cooling, and permanent magnet placement. These modules are connected by threads, allowing for quick and easy assembly and disassembly. This invention enables RF feed of the internal coil while maintaining the overall airtightness of the device. It also cools the chamber to remove heat generated during discharge, ensuring airtightness, and provides a simple and effective way to install and secure multiple magnets. The following detailed description of the invention, in conjunction with the embodiments shown in the accompanying drawings, further illustrates this invention:

[0036] like Figure 1-4 As shown, the radio frequency feed module of the present invention includes: a flange cover plate 6, a feed support 103, a conical sealing ring 102, an insulating washer 101, a T-shaped ceramic tube 104, a concave nut 10, and an air tube 9.

[0037] The chamber cooling module of this invention includes: a double-layer glass cylinder 11, an upper flange cover plate 6, a lower flange cover plate 13, water pipes, and clamps;

[0038] The permanent magnet mounting module of the present invention includes: an L-shaped magnet bracket 4 and a magnet bracket base 12.

[0039] like Figure 2 As shown, after the copper coil 8 passes through the feed post 103 welded to the flange cover plate 6, it is sequentially fitted with a T-shaped ceramic tube 104, a conical sealing ring 102, and an insulating washer 101. It is then tightened by the concave nut 10 engaging with the threaded upper end of the feed post 103. The engagement of the concave nut 10 with the feed post 103 generates downward pressure, which is transmitted to the conical sealing ring 102 via the insulating washer 101. The conical surface of the sealing ring, under pressure, generates a positive pressure that compresses inwards and a frictional force parallel to the conical surface. This positive pressure ensures a tight seal between the conical sealing ring 102 and the copper coil 8 passing through it, preventing external gas from communicating with the chamber 1 through the gap between them. Furthermore, the conical structure of the conical sealing ring 102 and the feed post 103 restricts the vertical displacement of the copper coil 8, preventing it from falling due to gravity. Meanwhile, the T-shaped ceramic tube 104, which cooperates with the feed post 103 through a T-shaped structure, isolates the copper coil 8 from the surrounding metal body, preventing short circuits after RF feeding. The copper coil 8 has an outer diameter of φ6mm and is wound into a 4.5-turn spiral coil with an inner diameter of φ41mm and an outer diameter of φ47mm. Deionized water is circulated inside to form a deionized water cooling cycle, removing the heat generated during the discharge process.

[0040] like Figure 4As shown, after stacking the magnet bracket base 12 on top of the flange lower cover plate 13, the L-shaped magnet bracket 4 is fastened to the magnet bracket base 12 and the flange lower cover plate 13 on the base plate 3 using M8 magnet bracket fastening bolts 42. The end face of the L-shaped magnet bracket 4 has a 17*7*110mm groove, and M3 threaded through holes are opened on both sides of the groove. The bar magnet 41 is fastened to the L-shaped magnet bracket 4 using M3 screws. The upper surface of the magnet bracket base 12 has a groove with a depth of 2mm and a width of 20mm, which restricts the rotation of the L-shaped magnet bracket 4 on its upper surface, ensuring that the six evenly distributed L-shaped magnet brackets 4 and bar magnets 41 can form a concentric structure and constitute a multi-pole magnetic field.

[0041] like Figure 3 As shown. PEEK rods 5, with M6 specifications at both ends, are threaded through the magnet bracket base 12 and fastened to the flange lower cover plate 13. The flange upper cover plate 6, with the copper coil 8 fixed in place, is then concentrically fitted with the double-layered glass cylinder 11 via a cooling groove, and pressed onto the cooling groove of the flange lower cover plate 13. Both the flange upper cover plate 6 and the flange lower cover plate 13 have water channel grooves 6mm wide and 10mm deep. A water channel cover plate 132 is welded above the groove opening. Two flange lower cover plate cooling water channels 131 with a diameter of φ6mm are opened on the side of the water channel grooves. Cooling water enters the water channel groove through one of the cooling water channels, providing cooling for the sealing ring 133 above the water channel cover plate 132, and then flows back to the water chiller through the other cooling water channel. The inner glass of the double-layered glass tube 11 is quartz glass with an inner diameter of φ90mm and an outer diameter of φ96mm, while the outer glass has an inner diameter of φ102mm and an outer diameter of φ106mm. Cooling water circulation is formed between the two glass tubes through the two cooling water inlets 111 on the side and the middle layer of the two glass tubes, which removes the heat from the glass tubes during discharge.

[0042] The feed support is made of SUS316 (304) seamless tube with an outer diameter of φ16~18mm. The upper end has a 5~6° tapered opening and the upper end is threaded. The feed support has a boss structure inside for placing T-shaped ceramic tubes, and the lower end is sealed and welded to the flange cover plate 6.

[0043] The flange cover plate is made of SUS316 (304) material, with a diameter of φ180~200mm and a thickness of 10~20mm. It has one φ6mm gas pipe through hole and two φ16~18mm through holes for welding the feed support, with a spacing of 47mm between the two through holes. An internal cooling water channel is located below the flange sealing groove. This channel circulates deionized water, fluorinated liquid, and water as cooling media through water pipes and a cooling machine to remove heat from the flange cover plate and sealing ring.

[0044] The T-shaped ceramic tube 104 is made of silicon nitride / alumina material, with an outer diameter of φ8-9mm and a length of 50-120mm, protruding 40-100mm from the lower end face of the flange cover plate. Placed in the feed support, it isolates the copper coil from the feed support, flange cover plate, and other metal structures, preventing short circuits after RF feeding.

[0045] The conical sealing ring 102 is made of polytetrafluoroethylene, PEEK or rubber material, with a φ6mm through hole in the middle, the angle between the edge and the upper and lower ends is 5 to 6°, and the height is 10 to 15mm.

[0046] The insulating washer 101 is made of polytetrafluoroethylene or PEEK material, with an outer diameter of φ10~13mm and a φ6mm through hole in the middle. One end of the insulating washer contacts a concave nut, and the other end contacts a conical sealing ring.

[0047] The copper coil 8 is secured by having the conical surface of the conical sealing ring 102 contact the conical surface of the feed post 103, with the copper coil passing through its internal through-hole. When the concave nut 10 engages with the feed post 103 via its threads, it generates downward pressure, which compresses the insulating washer and the conical sealing ring. The compression of the sealing ring's conical surface generates a normal force perpendicular to the conical surface and a frictional force parallel to it. This normal force is converted into a force that compresses inward, thus compressing the copper coil passing through the conical sealing ring. The combination of the conical structure and the frictional force restricts the movement of the copper coil. In other words, the copper coil is fixed in place by the frictional force and the compressive force.

[0048] The double-layered glass tube 11 is made of quartz glass. The inner glass tube has an inner diameter of φ90mm, an outer diameter of φ94-100mm, and a height of 180-220mm. The outer glass tube has an inner diameter of φ102-110mm, an outer diameter of φ108-120mm, and a height of 150-190mm. The two glass layers are fused together concentrically. The outer glass tube has 55-100mm long air nozzles on both sides, with an outer diameter of φ8-12mm, which can be connected to φ12-16mm air pipes using clamps. The medium between the two glass tubes can be cooled by passing deionized water or inert gas.

[0049] The flange lower cover plate 13 is made of SUS316 (304) material, with a diameter of φ180~200mm and a thickness of 10~20mm. It has 6 M6 threaded holes and 6 M8 threaded through holes evenly distributed on it. Cooling water channels are opened inside, located below the flange sealing groove. The cooling water channels can circulate deionized water, fluorinated liquid, water and other cooling media through water pipes and a cooling machine to remove heat from the flange lower cover plate and sealing ring.

[0050] The magnet support base 12 is made of polytetrafluoroethylene and is an overall ring with an inner diameter of φ120-140mm, an outer diameter of φ180-200mm, and a thickness of 10-20mm. It has 6 M6 threaded through holes and 6 M8 threaded through holes evenly distributed on it, and the upper surface is evenly distributed with positioning grooves that are 20-25mm wide and 2-3mm deep.

[0051] The PEEK rod 5 is made of PEEK material and is a cylinder with a height of 220-300mm. Both ends are machined with M6 threads with a length of 60-90mm.

[0052] The L-shaped magnet bracket 4 is made of polytetrafluoroethylene. The L-shaped side end face has a 17×7×110mm slot for placing bar magnets. M3 threaded through holes are opened on both sides of the slot for fixing the bar magnets. The lower section of the L-shape has a 9mm through groove for fixing to the magnet bracket base with bolts.

[0053] The bar magnet 41 is made of neodymium iron boron or samarium cobalt, with dimensions of 17×7×100mm, a magnetized surface of 17×100mm, and a core magnetic field of 1.0 to 1.2T.

[0054] The base plate 3 is a transition device connecting the enhanced inductively coupled plasma discharge device and the chamber. Depending on the application of the device, the chamber can hold etched parts, electrodes, metal targets, etc.

[0055] like Figure 1 As shown. After the upper flange cover 6 is concentrically fitted with the double-layer glass cylinder 11 and the lower flange cover 13, the upper part of the PEEK rod 5 on the lower flange cover 13 passes through the through hole of the upper flange cover 6, and is tightened and fixed using the PEEK fastening nut 7. The RF feed module, cooling module, and permanent magnet mounting module are then fastened to the base plate 3, and the base plate 3 and the chamber 1 are threaded together by the chamber connecting fastening bolt 14. At this point, the entire device forms a sealed structure, and the chamber is evacuated to the -4 Pa level through the evacuation port 2. During discharge, the discharge gas can be introduced into the device through the gas pipe 9 welded to the upper flange cover 6.

[0056] The parts of this invention not described in detail are well-known in the art. The embodiments described above are merely preferred embodiments of the present invention, and do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Various modifications and improvements to the technical solutions of this invention made by those skilled in the art without departing from the spirit of the invention should fall within the protection scope defined by the claims of this invention.

Claims

1. An enhanced inductively coupled radio frequency plasma discharge device, characterized in that, The device includes an upper flange cover plate, a lower flange cover plate, a feed support column, a conical sealing ring, an insulating washer, a concave nut, a T-shaped ceramic tube, a double-layer glass cylinder, an L-shaped magnet bracket, a magnet bracket base, and a PEEK rod. The feed post is set on the upper cover plate of the flange. After the copper coil passes through the feed post, a conical sealing ring and an insulating washer are fitted on it. A concave nut is used to engage with the external thread at the upper end of the feed post to secure the copper coil. The lower end of the copper coil is placed inside a double-layer glass tube. The double-layer glass tube is pressed onto the lower cover plate of the flange after being engaged with the flange sealing groove. The PEEK rod is located outside the double-layer glass cylinder. The lower half of the PEEK rod passes through the magnet bracket base and is fixed to the lower flange cover plate. The upper half passes through the through hole of the upper flange cover plate and is fixed with a nut, thereby fastening the upper flange cover plate to the double-layer glass cylinder and the lower flange cover plate together. The magnet is fixed to the base plate via the L-shaped magnet bracket, the magnet bracket base, and the flange cover plate.

2. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The copper coil is made of oxygen-free copper or pure copper material, and it is wound into a single-turn circular or multi-turn spiral shape. When the copper coil is wound with oxygen-free copper tubes, water pipes are connected to both ends of the copper coil and connected to a cooling machine. A cooling cycle is formed by adding water, fluorinated liquid or deionized water as a cooling medium to the copper coil.

3. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The flange cover plate is made of SUS316 or SUS304 material. A cooling water channel is provided under the flange sealing groove, and a cover plate is welded on the cooling water channel. The flange cover plate has three through holes in the middle, two of which are welded with feed supports, and the other is welded with a gas pipe.

4. The enhanced inductively coupled radio frequency plasma discharge device according to claim 3, characterized in that, The feed post is made of SUS316 or SUS304 material, and the upper end is machined with external threads for mating with the concave nut; the feed post has a boss inside for placing a T-shaped ceramic tube, and the inner side of the port has a conical structure for mating with a conical sealing ring.

5. The enhanced inductively coupled radio frequency plasma discharge device according to claim 3, characterized in that, The gas pipe is a seamless SUS316 pipe, one end of which is welded to the flange cover plate, and the other end is connected to a gas cylinder, which provides the gas used for discharge.

6. The enhanced inductively coupled radio frequency plasma discharge device according to claim 4, characterized in that, The concave nut is a cube of 20×20×15mm with a 10mm deep thread inside.

7. The enhanced inductively coupled radio frequency plasma discharge device according to claim 4, characterized in that, The T-shaped ceramic tube is made of silicon nitride / alumina. Its upper end is placed on the boss part of the feed post, and its lower end extends far beyond the lower surface of the flange cover plate, which is used to isolate the copper coil from contact with the feed post and the flange cover plate.

8. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The conical sealing ring is made of polytetrafluoroethylene, PEEK, or rubber. Its conical surface contacts and fits with the conical surface of the feed post, converting the downward pressure generated by the threaded connection between the concave nut and the feed post into a positive pressure perpendicular to the conical surface and a frictional force parallel to the conical surface. The positive pressure squeezes the conical sealing ring and then squeezes the copper coil, making the sealing ring and the copper coil fit tightly together, and together with the frictional force, fixes the copper coil in place.

9. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The insulating washer is made of polytetrafluoroethylene or PEEK, with its upper end face contacting the concave nut and its lower end face contacting the tapered sealing ring, transmitting the downward pressure generated by the threaded connection between the concave nut and the feed post.

10. An enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The double-layered glass tube consists of two glass tubes of different sizes nested together, with their end faces sintered together. The gap between the double-layered glass tubes is only connected to the outside through two cylindrical glass tubes set on its side. The cylindrical glass tubes are connected to water pipes by clamps and then to a cooling machine. Water cooling medium or inert gas is introduced into the cylindrical glass tubes to cool the double-layered glass tubes. The cooling water circulation method is bottom inlet and top outlet.

11. An enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The PEEK rod has threaded holes at both ends. One end is threaded to the lower cover plate of the flange, and the other end passes through the upper cover plate of the flange and is tightened with a nut.

12. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The flange lower cover plate is made of SUS316 or SUS304 material, and its end face has evenly distributed threaded holes and evenly distributed threaded through holes, the threaded holes being connected to the PEEK rod.

13. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The magnet is made of neodymium iron boron or samarium cobalt, and its core can provide a magnetic field of 1.1T.

14. The enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The L-shaped magnet bracket includes two end faces. One end face has a rectangular groove with a threaded hole on the side. The size of the rectangular groove is the same as that of the magnet. The magnet can be fixed in the rectangular groove by screws through the threaded hole. The other end face has a U-shaped groove, which is used to fit bolts to fix the L-shaped magnet bracket.

15. An enhanced inductively coupled radio frequency plasma discharge device according to claim 1, characterized in that, The base of the magnet bracket has evenly distributed grooves with a depth of 2-3mm. The width of the grooves is exactly matched with the size of the L-shaped magnet bracket. This is used to restrict the rotation of the L-shaped magnet bracket on the plane, thereby ensuring that the magnets evenly distributed in a circle can be centered. The grooves have threaded holes for bolts to be used to fasten the L-shaped magnet bracket.

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