Arc prevention device for ion source chamber

Abstract

This invention discloses an anti-arcting device for an ion source chamber, comprising a detachable and nested inner liner plate and an outer liner plate. Both the inner and outer liner plates are made of conductive materials, and are electrically connected to the ion source chamber, as are the inner and outer liner plates. The inner liner plate surrounds the ion source and has a mesh structure to reduce the arcing frequency caused by the deposition of non-conductive materials. The outer liner plate has a single-plate structure to support deposits and prevent them from depositing on the inner wall of the ion source chamber. This invention features a compact structure, convenient assembly and disassembly, and high reliability. The combined effect of the inner and outer liner plates enhances the anti-arcting effect of the ion source chamber and improves the operational safety of the ion implantation equipment.

Description

Technical Field

[0001] This invention relates to the field of semiconductor ion implantation equipment technology, and specifically to an anti-sparking device for an ion source chamber. Background Technology

[0002] The ion source is one of the most important components of an ion implanter. Its main function is to ionize the material carrying the implanted element and it is the source of the ion implanter's beam. For example... Figure 1 This is a schematic diagram of the most widely used ion source structure, which generally includes an ion source cavity 20 and an ion source 30 mounted on the cavity via an ion source insulating ring 10. A vacuum acquisition device is typically installed on the ion source cavity 20 at the ion source extraction port 201 (specific details not shown). An ion beam extraction device 40 is installed at the opening of the ion source cavity; only the extraction plate is shown in the diagram, the other parts are not shown. The ion source cavity 20 has a beam channel 204. Ions are extracted from the ion source arc chamber 301 via the extraction device 40 to form a beam, which then enters the subsequent components of the ion implanter through the beam channel 204 of the ion source cavity 20.

[0003] To generate the desired ions, compounds or elements carrying the desired ions are typically introduced into the ion source arc chamber 301 in gaseous or solid form. During operation, the material inside the ion source arc chamber 301 diffuses throughout the ion source cavity 20, forming a non-conductive deposition layer on the inner wall 203 of the cavity and on the ion source 30. This non-conductive deposition layer gradually accumulates charge during ion source operation; however, because it is non-conductive, its accumulated potential gradually increases until a discharge breakdown occurs between it and the ion source or extraction mechanism. Discharge breakdown is what is commonly referred to as "arresting" in ion implanters. Arresting causes beam fluctuations, and frequent arcing will prevent the ion implantation process from operating, affecting equipment use.

[0004] To improve equipment usage, such as Figure 2 As shown, most ion implanters add a liner 60 inside the ion source chamber 20, such as... Figure 3 As shown, the inner surface 601 of the liner 60 faces the ion source 30, and except for the necessary opening 602, it basically covers all areas of the inner wall 203 of the cavity. Furthermore, the liner 60 can be directly removed after disassembling some components. By preparing two or more liners 60, the liner 60 can be directly replaced during equipment maintenance, avoiding the need for grinding and cleaning the insulating material on the inner wall of the ion source cavity, thus improving maintenance speed. However, this design does not reduce the arcing frequency caused by the non-conductivity of the deposits, because the material of the liner 60 is generally the same as that of the ion source cavity 20, both being aluminum alloy; the surface of the liner 60 is generally sandblasted, with little difference from the surface of the inner wall 203 of the cavity, therefore it does not reduce the arcing effect of the deposits.

[0005] During the design and use of equipment, technicians will do their best to reduce the rate of deposit formation in order to extend the equipment maintenance interval. However, except for processes that use clean gases such as H2 as source materials, deposits cannot be completely avoided. Therefore, it is also necessary to find ways to reduce the arcing frequency caused by deposits in the ion source cavity. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an anti-arc device for an ion source chamber that is compact in structure, easy to operate, and conducive to improving production capacity, in order to address the shortcomings of the existing technology.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An anti-arcing device for an ion source chamber includes a detachable and nested inner liner and an outer liner, both made of conductive material. The outer liner and the ion source chamber, as well as the inner liner and the outer liner, are electrically connected. The inner liner surrounds the ion source and has a mesh structure to reduce the arcing frequency caused by the deposition of non-conductive materials. The outer liner has a single-plate structure to support deposits and prevent them from settling on the inner wall of the ion source chamber.

[0008] As a further improvement of the present invention, the inner lining plate includes a frame and a grid plate, the frame surrounding the edge of the grid plate, and the frame being riveted to the outer lining plate.

[0009] As a further improvement of the present invention, the distance between adjacent grids in the grid plate is less than 3cm.

[0010] As a further improvement of the present invention, the mesh plate is made of aluminum mesh, carbon steel mesh, or stainless steel mesh.

[0011] As a further improvement of the present invention, the area of ​​the mesh plate near the cathode cap of the ion source is made of molybdenum wire mesh or tungsten wire mesh.

[0012] As a further improvement of the present invention, the mesh in the mesh plate is a rectangular hole or a circular hole.

[0013] As a further improvement of the present invention, the outer liner is made of conductive metal or graphite.

[0014] As a further improvement of the present invention, the outer liner is in direct contact with the ion source cavity, or connected by screws, or electrically connected by conductive wires.

[0015] As a further improvement of the present invention, the resistance between the outer liner and the ion source cavity is less than 100 ohms.

[0016] Compared with the prior art, the advantages of the present invention are as follows: The anti-sparking device for the ion source chamber of the present invention is formed by detachably nesting an inner liner plate and an outer liner plate made of conductive material, thus creating a compact and easy-to-assemble anti-sparking device. Electrical conductivity is achieved between the outer liner plate and the ion source chamber, and between the inner liner plate and the outer liner plate. Moreover, the mesh structure of the inner liner plate surrounds the ion source, reducing the sparking frequency caused by the deposition of non-conductive materials. The outer liner plate bears the deposits, effectively preventing the deposits from settling on the inner wall of the ion source chamber, thus enhancing the anti-sparking effect of the ion source chamber and improving the safety of the ion implantation equipment. Attached Figure Description

[0017] Figure 1 This is one of the schematic diagrams of a partial structure of an existing ion source; Figure 2 This is the second schematic diagram of a partial structure of an existing ion source; Figure 3 This is a structural schematic diagram of the existing inner lining plate; Figure 4 This is a schematic diagram illustrating the structural principle of the anti-sparking device for the ion source chamber in a specific embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the structural principle of the inner lining plate in a specific embodiment of the present invention.

[0018] Legend: 10, Ion source insulating ring; 20, Ion source cavity; 201, Ion source exhaust port; 202, Extraction device mounting port; 203, Inner wall of the cavity; 204, Beam channel; 30, Ion source; 301, Ion source arc chamber; 40, Extraction device; 60, Liner plate; 601, Inner surface; 602, Opening; 70, Inner liner plate; 701, Frame; 702, Mesh plate; 80, Outer liner plate. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0022] Example like Figure 4 and Figure 5 As shown, the anti-arcing device for the ion source chamber of the present invention includes a detachably nested inner liner plate 70 and an outer liner plate 80, both of which are made of conductive materials and possess excellent conductivity. The outer liner plate 80 is electrically conductive to the ion source chamber 20, and the inner liner plate 70 is electrically conductive to the outer liner plate 80. The inner liner plate 70 surrounds the ion source 30. The surfaces of the inner liner plate 70 and the outer liner plate 80 facing the ion source 30 must not have sharp protrusions. The inner liner plate 70 employs a mesh structure, which divides the surface of the inner chamber capable of accumulating charge into multiple small faces. After charge accumulates on these small faces, because the mesh itself is conductive, and its sides and the side near the outer liner plate are not blocked by insulating material, the accumulated charge on the small faces preferentially discharges and conducts through the mesh. This prevents the inner wall 203 of the chamber from conducting with high-potential components such as the ion source, reducing the arcing frequency caused by the deposition of non-conductive materials, thereby preventing discharge. The outer liner 80 adopts a single-plate structure to support deposits and prevent them from depositing on the inner wall 203 of the ion source chamber 20. The combined effect of the inner liner 70 and the outer liner 80 enhances the anti-sparking effect of the ion source chamber and improves the operational safety of the ion implantation equipment.

[0023] like Figure 5 As shown, the inner lining 70 includes a frame 701 and a grid plate 702. The frame 701 surrounds the edge of the grid plate 702, allowing the inner lining 70 to maintain its shape. Furthermore, the corners of the inner lining 70 can also be reinforced, such as by clamping the corners of the inner lining 70 with metal strips.

[0024] In this embodiment, the frame 701 is riveted to the outer liner plate 80, so that the inner liner plate 70 and the outer liner plate 80 are connected to form a whole, and the inner liner plate 70 and the outer liner plate 80 can also be disassembled from each other. On the one hand, when maintaining the ion source cavity 20, the anti-sparking device can be replaced as a whole; on the other hand, the inner liner plate 70 and the outer liner plate 80 are tightly fitted by multi-point riveting, which prevents the mesh plate 702 from bulging and thus reducing the insulation distance between the inner liner plate 70 and the ion source 30 and the extraction device 40.

[0025] In this embodiment, the inner lining plate 70 and the outer lining plate 80 can be easily cleaned by sandblasting or other cleaning operations, so that the inner lining plate 70 and the outer lining plate 80 can be thoroughly cleaned.

[0026] The inner liner 70 can be a single, non-perforated plate with through holes machined into its surface, or it can be a perforated plate. For example, based on a perforated plate, the inner liner 70 can be manufactured by bending or splicing. When using the splicing method, the inner liner 70 can be spliced ​​into a whole before being installed into the ion source cavity 20; alternatively, a modular splicing method can be used, that is, the inner liner 70 can be installed into the ion source cavity 20 in sections. After the inner liner 70 and the outer liner 80 are all installed, they form a protective layer on the inner surface of the ion source cavity 20.

[0027] In this embodiment, the mesh plate 702 is made of aluminum mesh with circular holes, and the distance between adjacent meshes is less than 3 cm. In other embodiments, the mesh plate 702 can also be made of carbon steel mesh or stainless steel mesh, and the mesh can also be set with rectangular holes. The total area of ​​the mesh plate 702 is 10 cm². 2 ~100cm 2 The width of the 701 border does not exceed 5cm. Near the cathode cap of the ion source 30, a protrusion forms due to the filament, and some of the gas supplied to the arc chamber 301 of the ion source leaks out from the gap between the cathode cap and the arc chamber wall. This makes this area the most prone to arcing between the ion source 30 and the inner wall of the ion source, and often results in the inner wall of the ion source being burned. Therefore, in the mesh plate 702, the area near the cathode cap of the ion source uses a refractory metal mesh such as molybdenum wire mesh or tungsten wire mesh to prevent it from being burned by discharge and causing damage to the inner liner plate 70.

[0028] In this embodiment, the outer liner 80 is made of conductive metal or graphite. Furthermore, the outer liner 80 is in direct contact with the ion source cavity 20 and is electrically conductive to it. The resistance between the outer liner 80 and the ion source cavity 20 is less than 100 ohms to facilitate charge dissipation and prevent charge accumulation that could lead to arcing. In other embodiments, the outer liner 80 and the ion source cavity 20 can also be connected by screws or electrically connected via conductive wires.

[0029] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An anti-sparking device for an ion source chamber, characterized in that, The device includes a detachable nested inner liner (70) and an outer liner (80), both of which are made of conductive materials. The outer liner (80) and the ion source cavity (20) are electrically connected, as are the inner liner (70) and the outer liner (80). The inner liner (70) surrounds the outer periphery of the ion source (30) and has a mesh structure to reduce the arcing frequency caused by the deposition of non-conductive materials. The outer liner (80) has a solid plate structure to support the deposits and prevent them from depositing on the inner wall (203) of the ion source cavity (20).

2. The anti-sparking device for the ion source chamber according to claim 1, characterized in that, The inner lining (70) includes a frame (701) and a mesh plate (702), the frame (701) surrounding the edge of the mesh plate (702), and the frame (701) being riveted to the outer lining (80).

3. The anti-sparking device for the ion source chamber according to claim 2, characterized in that, In the grid plate (702), the distance between adjacent grids is less than 3cm.

4. The anti-sparking device for the ion source chamber according to claim 2, characterized in that, The mesh plate (702) is made of aluminum mesh, carbon steel mesh or stainless steel mesh.

5. The anti-sparking device for the ion source chamber according to claim 4, characterized in that, In the mesh plate (702), the area near the cathode cap of the ion source is made of molybdenum wire mesh or tungsten wire mesh.

6. The anti-sparking device for the ion source chamber according to any one of claims 2 to 5, characterized in that, In the mesh plate (702), the mesh is a rectangular hole or a circular hole.

7. The anti-sparking device for the ion source chamber according to any one of claims 1 to 5, characterized in that, The outer liner (80) is made of conductive metal or graphite.

8. The anti-sparking device for the ion source chamber according to claim 7, characterized in that, The outer liner (80) is in direct contact with the ion source cavity (20), or is connected by screws, or is electrically connected by conductive wires.

9. The anti-sparking device for the ion source chamber according to claim 8, characterized in that, The resistance between the outer liner (80) and the ion source cavity (20) is less than 100 ohms.

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