Plasma treatment equipment

Abstract

A plasma processing device comprises: a reaction chamber; a gas shower head, arranged at the top of the reaction chamber; a lower electrode assembly, arranged at the bottom of the reaction chamber, the lower electrode assembly being arranged opposite to the gas shower head; a conductive moving ring, arranged at the periphery of the gas shower head and movable up and down; a grounded plasma confinement ring, arranged at the periphery of the lower electrode assembly; a conductive gasket, arranged between the plasma confinement ring and the moving ring, when the moving ring moves downward to a process position, the moving ring is electrically connected to the plasma confinement ring and grounded through the conductive gasket. The plasma processing device is conducive to reducing the deposition of polymer on the surface of the moving ring.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a plasma processing device. Background Art

[0002] In a plasma processing device, in order to transfer a substrate in or out, a film transfer port is usually set on the side wall of the reaction chamber. However, the existence of the film transfer port makes the plasma distribution uniformity in the reaction chamber poor. In order to solve this problem, a moving ring is usually set in the reaction chamber, and the moving ring can move up and down. When the film needs to be transferred, the moving ring is raised to expose the film transfer port, and the substrate is transferred through the film transfer port; when the reaction chamber needs process treatment, the moving ring is lowered to the process position. At this time, the moving ring covers the film transfer port to improve the uniformity of plasma distribution above the substrate.

[0003] Usually, the temperature of the moving ring is much lower than that of other components. In some processes that will produce a large amount of polymers, the polymers will preferentially deposit on the surface with low temperature. When these polymers accumulate to a certain amount, they will fall and form particle contaminants. These particle contaminants are not conducive to improving the yield of the substrate. Summary of the invention

[0004] The object of the present invention is to provide a plasma processing device which can reduce the deposition of polymer on the surface of a moving ring and reduce particle pollutants.

[0005] To achieve the above-mentioned purpose, the present invention provides a plasma processing device, comprising: a reaction chamber; a gas shower head, arranged at the top of the reaction chamber; a lower electrode assembly, arranged at the bottom of the reaction chamber, the lower electrode assembly and the gas shower head being arranged opposite to each other; a conductive moving ring, arranged at the periphery of the gas shower head and movable up and down; a grounded plasma confinement ring, arranged at the periphery of the lower electrode assembly; and a conductive gasket, arranged between the plasma confinement ring and the moving ring, wherein when the moving ring moves downward to a process position, the moving ring is electrically connected to the plasma confinement ring and grounded through the conductive gasket.

[0006] Optionally, the conductive gasket is at least one of a metal material or a semiconductor material.

[0007] Optionally, when the conductive gasket is made of metal material, the material of the conductive gasket includes at least one of copper, beryllium copper or nickel.

[0008] Optionally, it further includes: a metal layer disposed on the surface of the conductive gasket; the material of the metal layer includes: at least one of silver, gold and nickel.

[0009] Optionally, the conductive gasket includes: an inner component and a conductive layer wrapped around the surface of the inner component.

[0010] Optionally, the material of the inner component is a rubber material; the material of the conductive layer includes: at least one of copper, beryllium copper or nickel.

[0011] Optionally, the conductive gasket is arranged at a position where the plasma confinement ring is opposite to the moving ring.

[0012] Optionally, the conductive gasket is arranged on the upper surface of the plasma confinement ring.

[0013] Optionally, the plasma confinement ring is provided with a first groove sunken in the upper surface thereof, and the first groove is used for placing the conductive gasket.

[0014] Optionally, the plasma confinement ring includes: a confinement ring body and a second corrosion-resistant coating located on the surface of the confinement ring body; the confinement ring body is made of metal material, the confinement ring body is provided with the first groove recessed in its upper surface, the side walls and bottom walls of the first groove are not provided with the second corrosion-resistant coating, and the surface of the confinement ring body around the first groove is provided with the second corrosion-resistant coating.

[0015] Optionally, the material of the plasma confinement ring includes: silicon or silicon carbide.

[0016] Optionally, the lower surface of the movable ring is a plane; or, the movable ring is provided with a second groove sunken in the lower surface thereof, the second groove is arranged opposite to the first groove, and the second groove is used to accommodate the top of the conductive gasket.

[0017] Optionally, when the movable ring moves downward to the process position, the gas shower head, the lower electrode assembly and the movable ring form a plasma environment; further comprising: a sealing ring, arranged on the inner side of the conductive gasket, for blocking the plasma and reducing the corrosion of the conductive gasket by the plasma.

[0018] Optionally, the top of the plasma confinement ring is further provided with a third groove sunken into its upper surface, and the third groove is used to accommodate the sealing ring.

[0019] Optionally, the conductive gasket is arranged on the lower surface of the movable ring; the movable ring is provided with a fourth groove sunken in the lower surface thereof, and the fourth groove is used for placing the conductive gasket.

[0020] Optionally, the material of the moving ring includes: silicon or silicon carbide.

[0021] Optionally, the movable ring includes a movable ring body and a first corrosion-resistant coating; the material of the movable ring body is a conductive material; the movable ring body is provided with a fourth groove recessed in its lower surface, the side wall and the bottom wall of the fourth groove are not provided with the first corrosion-resistant coating, and the surface of the constraint ring body around the fourth groove is provided with the first corrosion-resistant coating.

[0022] Optionally, it also includes: a middle grounding ring, which is arranged below the plasma confinement ring, the middle grounding ring is grounded, and the plasma confinement ring is electrically connected to the middle grounding ring for grounding.

[0023] Optionally, it further comprises: an upper grounding ring, which is arranged at the periphery of the gas shower head and located between the gas shower head and the moving ring, and the upper grounding ring is grounded; and the chamber wall of the reaction chamber is grounded.

[0024] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0025] In the plasma processing device provided by the present invention, the moving ring is electrically connected to the plasma confinement ring through the conductive gasket to be grounded only when the moving ring is lowered to the process position. Otherwise, the moving ring is not grounded, so that there is no need to set up additional metal connectors to achieve the grounding of the moving ring, and the moving ring is not affected by the metal connectors during the up and down movement. When the moving ring is lowered to the process position, the moving ring is grounded, so that the plasma bombards the moving ring more severely, and the temperature of the moving ring is higher, so it is not easy to deposit and form polymers on the surface of the moving ring, so it is beneficial to reduce particle pollution.

[0026] Furthermore, the upper grounding ring, the plasma confinement ring, and the chamber wall of the reaction chamber are all grounded, and the moving ring is also grounded. Therefore, there is no potential difference between the moving ring and surrounding components, and therefore, arc discharge is not likely to occur between the moving ring and surrounding components. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a plasma processing device of the present invention;

[0028] Figure 2 yes Figure 1 A top view of the plasma confinement ring and the conductive gasket;

[0029] Figure 3 yes Figure 1 A partial enlarged view of the middle area A;

[0030] Figure 4 yes Figure 1 Another partial magnified view of the middle area A;

[0031] Figure 5 It is a structural schematic diagram of a conductive gasket of the present invention;

[0032] Figure 6 is a schematic structural diagram of another plasma processing device of the present invention;

[0033] Figure 7 yes Figure 6 Top view of the plasma confinement ring and conductive gasket. DETAILED DESCRIPTION

[0034] The following will be combined with the attached embodiment of the present invention Figure 1 ~Attached Figure 7 , the technical solutions, structural features, objectives achieved and effects in the embodiments of the present invention are described in detail.

[0035] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0036] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0037] As described in the background art, in the existing plasma processing apparatus, polymers are easily deposited on the surface of the moving ring.

[0038] To solve this technical problem, the present invention provides a plasma processing device, wherein a conductive gasket is provided between the plasma confinement ring and the moving ring. When the moving ring descends to the process position, the moving ring is electrically connected to the plasma confinement ring through the conductive gasket, and the plasma confinement ring is grounded. Therefore, the moving ring is grounded when in the process position, thereby enhancing the bombardment of the plasma on the surface of the moving ring, which is beneficial to increasing the temperature of the moving ring, thereby reducing the deposition of polymers on the surface of the moving ring.

[0039] Figure 1 The figure is a schematic structural diagram of a plasma processing device according to the present invention.

[0040] In this embodiment, the plasma processing device 100 is a capacitively coupled plasma etching device, which is a device that generates plasma in a reaction chamber by capacitive coupling by a radio frequency power source applied to an electrode plate and is used for etching. It includes a reaction chamber 101, and the reaction chamber 101 includes a roughly cylindrical reaction chamber side wall made of metal material, and a film conveying port (not shown in the figure) is arranged on the reaction chamber side wall for accommodating the entry and exit of substrates. A gas shower head 102 and a lower electrode assembly 103 arranged opposite to the gas shower head 102 are arranged in the reaction chamber 101. The gas shower head 102 is used to transport reaction gas into the reaction chamber 101, and at the same time serves as the upper electrode of the reaction chamber, and a reaction area is formed between the upper electrode and the lower electrode assembly. At least one radio frequency power source (not shown in the figure) is applied to one of the upper electrode or lower electrode assembly through a matching network, generating a radio frequency electric field between the upper electrode and the lower electrode assembly to dissociate the reaction gas into plasma, which contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above-mentioned active particles can undergo various physical and chemical reactions with the surface of the substrate to be processed, so that the morphology of the surface of the substrate W changes, that is, the etching process is completed. An exhaust port 140 is also provided below the reaction chamber 101 to discharge the reaction by-products out of the reaction chamber and maintain the vacuum environment of the reaction chamber.

[0041] The lower electrode assembly 103 includes an electrostatic electrode (not shown in the figure) for generating an electrostatic suction force to support and fix the substrate W during the process. A heating device (not shown in the figure) is arranged below the electrostatic chuck to control the temperature of the substrate during the process. A focusing ring (not shown in the figure) is arranged around the base, and the focusing ring is used to adjust the electric field or temperature distribution around the substrate to improve the uniformity of substrate processing. A plasma confinement ring 105 is arranged around the periphery of the lower electrode assembly 103, and an exhaust channel is arranged on the plasma confinement ring 105. By reasonably setting the depth and width ratio of the exhaust channel, the plasma is confined in the plasma region P between the upper electrode and the lower electrode assembly 103 while the reaction gas is discharged, so as to avoid leakage of plasma to undesirable areas and damage to components in undesirable areas.

[0042] In order to reduce the adverse effects of the film transfer port, the plasma processing device 100 further includes: a moving ring 104, the moving ring 104 is connected to a driving device (not shown in the figure), and the driving device is used to drive the moving ring 104 to move up and down. When it is necessary to transfer a film, the moving ring 104 is lifted to expose the film transfer port, and the substrate W is transferred in or out through the film transfer port; when it is necessary to process the surface of the substrate W on the surface of the lower electrode assembly 103, the moving ring 104 is lowered to cover the film transfer port, so that the difference in the circumferential distribution of the plasma on the substrate W is small, which is conducive to improving the uniformity of the surface treatment of the substrate W.

[0043] In this embodiment, the moving ring 104 is made of a conductive material. Specifically, the material of the moving ring 104 includes: at least one of silicon or silicon carbide. Selecting silicon or silicon carbide as the material of the moving ring 104 not only makes the moving ring 104 have good electrical conductivity and a good electrical connection between the moving ring 104 and the plasma confinement ring 105, but also makes the moving ring 104 have good corrosion resistance and no metal pollution. Therefore, there is no need to form an additional corrosion-resistant coating on the surface of the moving ring 104.

[0044] In another embodiment, the moving ring 104 includes a moving ring body and a first corrosion-resistant coating, wherein the material of the moving ring body is a conductive material, and in order to prevent the corrosion of the moving ring body by plasma, except for a portion of the lower surface of the moving ring body opposite to the plasma confinement ring 103 which is not coated with the first corrosion-resistant coating, the other surfaces of the moving ring are coated with the first corrosion-resistant coating, and the portion of the moving ring body not coated with the corrosion-resistant coating is used for subsequent electrical connection with a conductive gasket.

[0045] In this embodiment, the structural schematic diagram of the plasma confinement ring 105 is as follows: Figure 2As shown, the plasma confinement ring 105 includes a plurality of concentrically arranged annular members 1051 and a gas channel 1052 formed between adjacent annular members 1051, wherein the annular member 1051 includes: a confinement ring body and a second corrosion-resistant coating located on the surface of the confinement ring body. The material of the confinement ring body is a conductive material, for example, the confinement ring body is made of metal, and the conductive gasket 106 is disposed on the upper surface of the confinement ring body opposite to the moving ring 104. In order to prevent metal contamination, the second corrosion-resistant coating is disposed on the surface of the confinement ring body around the conductive gasket 106, so that when the moving ring 104 is lowered to the process position, the moving ring abuts against the conductive gasket 106 and is electrically connected to the conductive gasket 106. Since the conductive gasket 106 is electrically connected to the plasma confinement ring 105 and the plasma confinement ring 105 is grounded, the moving ring 104 is also grounded.

[0046] In another embodiment, the material of the plasma confinement ring includes: silicon or silicon carbide. When silicon or silicon carbide is selected as the material of the plasma confinement ring, since there is no metal contamination, there is no need to additionally form a second corrosion-resistant coating.

[0047] In this embodiment, the plasma processing device 100 further includes: an upper grounding ring 107, which is arranged at the periphery of the gas shower head 102 and is located between the gas shower head 102 and the moving ring 104. The upper grounding ring 107 is grounded, the chamber wall of the reaction chamber 101 is grounded, the plasma confinement ring 105 is grounded, and the moving ring 104 is also grounded, so that there is no potential difference between the moving ring 104 and the surrounding parts, so that the moving ring 104 is not easy to have arc discharge with adjacent parts. In addition, the moving ring 104 is grounded, so that the plasma has a strong bombardment ability on the surface of the moving ring 104, so that the temperature of the surface of the moving ring 104 is high, so it is not easy to deposit polymer on the surface of the moving ring 104.

[0048] Furthermore, in this embodiment, when the moving ring 104 is at the film conveying position, the moving ring 104 is separated from the conductive gasket 106. At this time, the moving ring 104 is not grounded. Only when the moving ring 104 is lowered to the process position, the moving ring 104 is pressed on the plasma confinement ring 105. The moving ring 104 is electrically connected to the plasma confinement ring 105 through the conductive gasket 106. Since the plasma confinement ring 105 is grounded, the moving ring 104 is grounded when it is at the process position. In order to ground the moving ring 104, a common practice is to electrically connect the moving ring 104 through a metal connector. Whether the moving ring 104 is at the film conveying position or the process position, or even during the movement, the moving ring 104 is grounded through the metal connector. However, during the up and down movement of the moving ring 104, the metal connector is driven to move, so that the grounding stability of the moving ring 104 is poor. In this embodiment, the moving ring 104 does not need to be grounded all the time, but is grounded only during the process, and is not grounded during the up and down movement, so that the up and down movement of the moving ring 104 is not restricted by the metal connector, and there is no situation where the grounding of the moving ring 104 is unstable during the movement. In addition, the moving ring 104 presses downward on the plasma confinement ring 105, so that there is sufficient contact area and pressure between the moving ring 104 and the conductive gasket 106, so that there is a stable grounding effect between the moving ring 104 and the plasma confinement ring 105. In addition, the structure of this embodiment is relatively simple, and the modification of the existing device is small, and it is more compatible with the existing plasma processing device.

[0049] The positional relationship between the plasma confinement ring 105, the moving ring 104 and the conductive gasket 106 is described in detail as follows:

[0050] In one embodiment, if Figure 3 As shown, the plasma confinement ring 105 has a first groove 1053 recessed in its upper surface, the conductive gasket 106 is disposed in the first groove 1053, and the lower surface of the moving ring 104 is a plane. When the moving ring 104 descends to the process position, it does not need to be aligned, and the moving ring 104 only needs to be pressed onto the conductive gasket 106, thereby achieving stable grounding of the moving ring 104 through the conductive gasket 106.

[0051] In another embodiment, if Figure 4 As shown, except for Figure 3The same thing is that the plasma confinement ring 105 has a first groove 1053 recessed in its upper surface, and the bottom of the conductive gasket 106 is arranged in the first groove 1053. The difference is that the moving ring 104 has a second groove 1041 recessed in its lower surface, and the second groove 1041 is arranged opposite to the first groove 1053, so that when the moving ring 104 descends to the process position, the top of the conductive gasket 106 can just be placed in the second groove 1041, thereby realizing the grounding of the moving ring 104.

[0052] The conductive gasket 106 is made of at least one of a metal material and a semiconductor material. The conductive gasket 106 is used to electrically connect the moving ring 104 and the plasma confinement ring 105 .

[0053] In one embodiment, the conductive gasket 106 is made of metal material, and the material of the conductive gasket includes at least one of copper, beryllium copper or nickel.

[0054] In another embodiment, the conductive gasket 106 is made of metal material, and the material of the conductive gasket includes: at least one of copper, beryllium copper or nickel, and also includes: a metal layer arranged on the surface of the conductive gasket; the material of the metal layer includes: at least one of silver or gold.

[0055] In yet another embodiment, Figure 5 As shown, the conductive gasket 106 includes: an inner part 1061 and a conductive layer 1062 wrapped on the surface of the inner part 1061. The material of the inner part 1061 is an elastic material, such as a rubber material. The material of the conductive layer includes: at least one of copper, beryllium copper, gold, silver, stainless steel or nickel. The surface of the conductive layer may also include a metal plating layer, or may not include a metal plating layer. The material of the metal plating layer includes: at least one of silver, gold and nickel. The conductive gasket 106 of this design, because the conductive gasket 106 includes the inner part 1061 of rubber material, makes the conductive gasket 106 have good elasticity, so that when the moving ring 104 descends to the conductive gasket 106, it can squeeze the conductive gasket 106, so that the conductive gasket 106 has a good grounding effect with the moving ring 104 and the plasma confinement ring 105.

[0056] In this embodiment, the conductive gasket 106 is a ring-shaped structure. The advantage of such a design is that the entire interface between the moving ring 104 and the plasma confinement ring 105 is radio frequency grounded, so that the moving ring 104 has better electrical grounding.

[0057] In other embodiments, the conductive gasket 106 may also be an arc-shaped structure.

[0058] Figure 6It is a structural schematic diagram of another plasma processing device of the present invention; Figure 7 for Figure 6 A top view of a plasma confinement ring and conductive spacers in an embodiment.

[0059] In this embodiment, the moving ring 204, the plasma confinement ring 205 and the conductive gasket 206 in the plasma processing device 200 are Figure 1 The materials, positions and functions in the embodiments are the same and will not be described in detail here.

[0060] Figure 6 Example and Figure 1 The embodiment is similar, except that it further comprises a sealing ring 208 disposed on the inner side of the conductive gasket 206 for blocking plasma and reducing the corrosion of the conductive gasket 206 by the plasma.

[0061] In this embodiment, the material of the sealing ring 208 includes: rubber.

[0062] The top of the plasma confinement ring 205 is further provided with a third groove sunken in the upper surface thereof, and the third groove is used to accommodate the sealing ring 208 .

[0063] The above embodiments are all described by taking the conductive gasket 206 disposed on the upper surface of the plasma confinement ring 205 as an example. In fact, the conductive gasket 206 can also be disposed on the lower surface of the moving ring 204. Specifically, the moving ring 204 is provided with a fourth groove sunken in its lower surface, and the fourth groove is used to place the conductive gasket.

[0064] In one embodiment, the material of the moving ring includes: silicon or silicon carbide.

[0065] In another embodiment, the moving ring includes a moving ring body and a first corrosion-resistant coating; the material of the moving ring body is a conductive material; the fourth groove is arranged on the lower surface of the moving ring body, the side wall and the bottom wall of the fourth groove are not provided with the first corrosion-resistant coating, and the surface of the constraint ring body around the fourth groove is provided with the first corrosion-resistant coating.

[0066] The principle of setting the conductive gasket on the lower surface of the moving ring is the same as the principle of setting the conductive gasket on the upper surface of the plasma confinement ring. Only when the moving ring is lowered to the process position, the moving ring is electrically connected to the plasma confinement ring through the conductive gasket to be grounded. Otherwise, the moving ring is not grounded, so that the moving ring is not affected by the metal connector during the up and down movement. When the moving ring is lowered to the process position, the moving ring is grounded, so that the plasma bombards the moving ring more severely, so that the temperature of the moving ring is higher, so it is not easy to deposit and form polymers on the surface of the moving ring, so it is beneficial to reduce particle pollution.

[0067] Furthermore, the upper grounding ring, the plasma confinement ring, and the chamber wall of the reaction chamber are all grounded, and the moving ring is also grounded. Therefore, there is no potential difference between the moving ring and surrounding components, and therefore, arc discharge is not likely to occur between the moving ring and surrounding components.

[0068] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A plasma processing device, characterized in that: include: Reaction chamber; A gas shower head is arranged at the top of the reaction chamber; A lower electrode assembly is disposed at the bottom of the reaction chamber, and the lower electrode assembly is disposed opposite to the gas shower head; A conductive moving ring is arranged on the periphery of the gas shower head and can move up and down; A grounded plasma confinement ring is disposed at the periphery of the lower electrode assembly; The conductive gasket is arranged between the plasma confinement ring and the moving ring. When the moving ring moves downward to the process position, the moving ring is electrically connected to the plasma confinement ring through the conductive gasket to be grounded.

2. The plasma processing device according to claim 1, characterized in that: The conductive pad is made of at least one of a metal material and a semiconductor material.

3. The plasma processing device according to claim 2, characterized in that: When the conductive gasket is made of metal material, the material of the conductive gasket includes at least one of copper, beryllium copper or nickel.

4. The plasma processing device according to claim 3, characterized in that: Also includes: A metal layer disposed on the surface of the conductive pad; The material of the metal layer includes at least one of silver, gold and nickel.

5. The plasma processing apparatus according to claim 1, wherein: The conductive gasket comprises an inner component and a conductive layer wrapped on the surface of the inner component.

6. The plasma processing apparatus according to claim 5, wherein: The material of the inner component is rubber material; the material of the conductive layer includes: at least one of copper, beryllium copper or nickel.

7. The plasma processing apparatus according to claim 1, wherein: The conductive gasket is arranged at a position where the plasma confinement ring is opposite to the moving ring.

8. The plasma processing apparatus according to claim 1, wherein: The conductive gasket is arranged on the upper surface of the plasma confinement ring.

9. The plasma processing apparatus according to claim 8, wherein: The plasma confinement ring is provided with a first groove sunken in the upper surface thereof, and the first groove is used for placing the conductive gasket.

10. The plasma processing apparatus according to claim 9, wherein: The plasma confinement ring comprises: a confinement ring body and a second corrosion-resistant coating located on the surface of the confinement ring body; the confinement ring body is made of metal material, the confinement ring body is provided with the first groove recessed in its upper surface, the side wall and the bottom wall of the first groove are not provided with the second corrosion-resistant coating, and the surface of the confinement ring body around the first groove is provided with the second corrosion-resistant coating.

11. The plasma processing apparatus according to claim 9, wherein: The material of the plasma confinement ring includes silicon or silicon carbide.

12. The plasma processing apparatus according to claim 9, wherein: The lower surface of the moving ring is a plane; or, the moving ring is provided with a second groove sunken in the lower surface thereof, the second groove is arranged opposite to the first groove, and the second groove is used to accommodate the top of the conductive gasket.

13. The plasma processing apparatus according to claim 1, wherein: When the moving ring moves downward to the process position, the gas shower head, the lower electrode assembly and the moving ring form a plasma environment; and further comprising: a sealing ring, arranged on the inner side of the conductive gasket, for blocking the plasma and reducing the corrosion of the conductive gasket by the plasma.

14. The plasma processing apparatus according to claim 13, wherein: The top of the plasma confinement ring is also provided with a third groove sunken in the upper surface thereof, and the third groove is used to accommodate the sealing ring.

15. The plasma processing apparatus according to claim 1, wherein: The conductive gasket is arranged on the lower surface of the moving ring; the moving ring is provided with a fourth groove sunken in the lower surface thereof, and the fourth groove is used for placing the conductive gasket.

16. The plasma processing apparatus according to claim 15, wherein: The material of the moving ring includes: silicon or silicon carbide.

17. The plasma processing apparatus according to claim 15, wherein: The movable ring includes a movable ring body and a first corrosion-resistant coating; the material of the movable ring body is a conductive material; the movable ring body is provided with a fourth groove recessed in its lower surface, the side wall and the bottom wall of the fourth groove are not provided with the first corrosion-resistant coating, and the surface of the constraint ring body around the fourth groove is provided with the first corrosion-resistant coating.

18. The plasma processing apparatus according to claim 1, wherein: Also includes: The middle grounding ring is arranged below the plasma confinement ring, the middle grounding ring is grounded, and the plasma confinement ring is electrically connected to the middle grounding ring for grounding.

19. The plasma processing apparatus according to claim 1, wherein: Also includes: An upper grounding ring is arranged at the periphery of the gas shower head and between the gas shower head and the moving ring. The upper grounding ring is grounded; and the chamber wall of the reaction chamber is grounded.

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