Plasma etching equipment

Abstract

This invention provides a plasma etching apparatus, comprising: a reaction chamber with a wafer transfer port on its side wall; a gas spray head for supplying process gas into the reaction chamber; a base located within the reaction chamber and opposite to the gas spray head for supporting a substrate; a plasma confinement ring including an exhaust portion and an extension portion, the exhaust portion being arranged around the periphery of the base between the base and the side wall of the reaction chamber, the extension portion extending upward along the end of the exhaust portion away from the base and electrically connected to the top wall of the reaction chamber, the extension portion having an opening opposite to the wafer transfer port for the substrate to enter and exit; and a movable door for closing or opening the opening. This invention addresses the problem in the prior art where polymer deposition and detachment on the surface of the movable ring affects the uniformity and consistency of etching.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor equipment technology, and in particular to a plasma etching device. Background Technology

[0002] In semiconductor manufacturing, plasma etching is a key technology used to form precise patterns on a substrate. The plasma etching process is typically performed in a plasma etching apparatus, which includes a reaction chamber and opposing upper and lower electrodes. Plasma is generated by applying radio frequency power between the upper and / or lower electrodes.

[0003] To facilitate substrate transfer, a transfer port is typically installed on the side wall of the reaction chamber. However, the presence of this port results in poor plasma uniformity within the chamber. To address this issue, a movable ring is usually installed within the reaction chamber. When substrate transfer is required, the ring is raised, exposing the transfer port, through which the substrate is transferred. When further processing is needed within the reaction chamber, the ring is lowered to the processing position, at which point it covers the transfer port, thus improving the uniformity of plasma distribution above the substrate.

[0004] However, the moving ring is typically made of insulating material, which prevents effective coupling of radio frequency power to it. This results in less ion bombardment on its surface and a lower moving ring temperature, causing polymers to preferentially deposit on the moving ring surface in some processes that generate large amounts of polymer. These deposited polymers may detach during the process, altering the plasma state and affecting the uniformity and consistency of etching. Furthermore, the detached polymer may contaminate the substrate and even trigger chamber arcing, leading to damage to the substrate and equipment.

[0005] The statements herein provide only background information relating to this invention and do not necessarily constitute prior art. Utility Model Content

[0006] The purpose of this invention is to provide a plasma etching device to solve the problem of polymer deposition and detachment on the surface of a moving ring, which affects the uniformity and consistency of etching.

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0008] A plasma etching apparatus, comprising:

[0009] A reaction chamber, wherein a transfer port is provided on the side wall of the reaction chamber;

[0010] A gas spray head is used to deliver process gas into the reaction chamber;

[0011] The base, located inside the reaction chamber and positioned opposite the gas spray head, is used to support the substrate.

[0012] A plasma confinement ring includes an exhaust section and an extension section. The exhaust section is disposed around the periphery of the base between the sidewall of the reaction chamber and the periphery of the base. The extension section extends upward along the end of the exhaust section away from the base and is electrically connected to the top wall of the reaction chamber. The extension section has an opening opposite to the transfer port for the substrate to enter and exit.

[0013] A movable door for closing or opening the opening.

[0014] Optionally, the plasma confinement ring further includes a connecting portion extending radially inward from the top end of the extension portion along the base, the connecting portion being connected to the top wall of the reaction chamber by a fastener.

[0015] Optionally, it further includes: a first groove recessed on the lower surface of the top wall of the reaction chamber, and / or a second groove recessed on the upper surface of the connecting portion; the first groove and / or the second groove are used to accommodate a first radio frequency gasket, the first radio frequency gasket being used to realize the electrical connection between the connecting portion and the top wall of the reaction chamber.

[0016] Optionally, the plasma confinement ring is made of a conductive material.

[0017] Optionally, the plasma confinement ring is made of at least one of metal, silicon, or silicon carbide.

[0018] Optionally, the plasma confinement ring is made of metal and has a plasma corrosion resistant coating on its surface.

[0019] Optionally, the movable door is disposed between the plasma confinement ring and the side wall of the reaction chamber; it also includes: a driving device connected to the movable door for driving the movable door to move, so as to close or open the opening.

[0020] Optionally, the sliding door is made of insulating material.

[0021] Optionally, the sliding door is made of quartz or ceramic.

[0022] Optionally, the movable door is made of a conductive material.

[0023] Optionally, a third groove is provided around the opening, recessed into the outer side wall of the extension, and a second radio frequency gasket is provided in the third groove. When the movable door moves to close the opening, the movable door is electrically connected to the side wall of the extension through the second radio frequency gasket to ground.

[0024] Optionally, the movable door further has a first protrusion facing the opening. When the movable door moves to close the opening, the first protrusion is located inside the opening and fills the opening.

[0025] Optionally, the movable door further has a second protrusion facing the opening, and the opening is further provided with a fourth groove recessed on its lower surface. The fourth groove accommodates a third radio frequency gasket. When the movable door moves to close the opening, the second protrusion is located inside the opening and fills the opening. The second protrusion is electrically connected to the plasma confinement ring via the third radio frequency gasket to ground.

[0026] Optionally, the exhaust section is further provided with a step at the end away from the base, and the step is further provided with a fifth groove recessed on its upper surface. The fifth groove contains a fourth radio frequency gasket. When the movable door moves to close the opening, the step supports the movable door, and the movable door is electrically connected to the plasma confinement ring through the fourth radio frequency gasket to ground.

[0027] Optionally, the exhaust section has a receiving groove recessed on its upper surface at one end away from the base, and the receiving groove has a sixth groove recessed on its bottom surface. The sixth groove contains a fifth radio frequency gasket. When the movable door moves to close the opening, the movable door is located in the receiving groove, and the movable door is electrically connected to the plasma confinement ring through the fifth radio frequency gasket to ground.

[0028] Compared with the prior art, the technical solution of this utility model has at least the following advantages:

[0029] In this invention's plasma etching apparatus, the plasma confinement ring includes an exhaust section and an extension section. The exhaust section is used to discharge gas from the reaction region and extinguish the plasma, while the extension section is used to confine the plasma above the substrate, ensuring uniform plasma distribution in the reaction region. Since the plasma confinement ring is made of a conductive material, and the extension section is electrically connected to the top wall of the reaction chamber, the extension section is bombarded by ions, making it less prone to polymer deposition on its surface. Simultaneously, because the entire plasma confinement ring cannot move vertically, an opening is provided in the extension section to facilitate wafer transfer, corresponding to the wafer transfer port on the side wall of the reaction chamber. Furthermore, to prevent plasma leakage from the opening, a movable door is provided outside the opening. When wafer transfer is required, the movable door opens the opening. During the etching process, the movable door closes the opening. This invention eliminates the movable ring, modifying the existing plasma confinement ring to possess the function of a movable ring without affecting wafer transfer. This solves the problems of polymer deposition and detachment on the surface of existing movable rings, affecting the uniformity and consistency of etching, and causing damage to the substrate and equipment. Attached Figure Description

[0030] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings in the following description are one embodiment of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0031] Figure 1 This is a schematic diagram of the structure of a plasma etching device;

[0032] Figure 2 This is a schematic diagram of the structure of a plasma etching device according to the present invention;

[0033] Figure 3 This is a schematic diagram of another plasma etching device according to the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of another plasma etching device according to the present invention;

[0035] Figure 5 This is a schematic diagram of another plasma etching device according to the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of another plasma etching device according to the present invention;

[0037] Figure 7 This is a schematic diagram of another plasma etching device according to the present invention. Detailed Implementation

[0038] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the proposed solution of this utility model. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of this utility model. Please refer to the drawings to make the objectives, features, and advantages of this utility model more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model.

[0039] Figure 1 This is a structural diagram of a plasma etching apparatus, including a reaction chamber 100. The reaction chamber 100 includes a generally cylindrical sidewall 110 made of metallic material, with a wafer transfer port (not shown) on the sidewall for receiving and exiting a substrate W. A gas spray head 120 and a base 130 opposite to the gas spray head 120 are disposed within the reaction chamber 100. The gas spray head 120 is connected to a gas supply device (not shown) for supplying process gas to the reaction chamber 100 and also serves as the upper electrode of the reaction chamber 100. The base 130 supports the substrate W and also serves as the lower electrode of the reaction chamber 100. A reaction region is formed between the upper electrode and the lower electrode. At least one radio frequency (RF) power supply (not shown) is applied to one of the upper or lower electrodes through a matching network, generating an RF electric field between the upper and lower electrodes to dissociate the process gas into plasma. The plasma contains a large number of active particles such as electrons, ions, excited-state atoms, molecules, and free radicals. These active particles can undergo various physical and chemical reactions with the surface of the substrate W to be processed, causing a change in the morphology of the substrate W surface, thus completing the etching process. An exhaust port 140 is also provided below the reaction chamber 100, connected to an exhaust pump (not shown), for discharging reaction byproducts from the reaction chamber 100 and maintaining a vacuum environment in the reaction chamber 100.

[0040] To reduce the influence of the wafer transfer port and improve the uniformity of plasma distribution within the reaction chamber 100, a moving ring 150 is also provided within the reaction chamber 100. This moving ring surrounds the outside of the gas spray head 120 and can move up and down. During wafer transfer, the moving ring 150 is in a raised state to allow the robotic arm to smoothly transfer the wafer through the transfer port; during etching, the moving ring 150 is in a lowered state. Figure 1The diagram shows the moving ring 150 in a descending state. Because the moving ring 150 is made of an insulating material, such as quartz or ceramic, radio frequency power cannot couple to it, resulting in weak ion bombardment on its surface. Furthermore, the temperature of the moving ring 150 is much lower than other components in the reaction region, leading to the deposition of a large amount of polymer on its surface. If this polymer detaches during the process, it will alter the plasma state; moreover, the detached polymer can contaminate the substrate W and even cause arc discharge within the chamber, rendering the substrate or even the equipment unusable.

[0041] To address the aforementioned issues, this invention provides a plasma etching apparatus. By eliminating the moving ring and extending a conductive plasma confinement ring upwards to make electrical contact with the top wall of the reaction chamber, the plasma confinement ring acts as the moving ring, confining the plasma within the reaction area and improving the uniformity of plasma distribution within the reaction chamber. Simultaneously, because the plasma confinement ring is made of a conductive material, it is less prone to polymer deposition on its surface when bombarded by ions. This solves the problem of polymer shedding affecting the uniformity and consistency of etching, as well as causing damage to the substrate and the apparatus.

[0042] like Figure 2 As shown, a plasma etching apparatus according to an embodiment of the present invention includes: a reaction chamber 200, wherein a wafer transfer port is provided on the side wall 210 of the reaction chamber 200; a gas spray head 220 for supplying process gas into the reaction chamber 200; a base 230 located inside the reaction chamber 200 and disposed opposite to the gas spray head 220 for supporting a substrate W; a plasma confinement ring 240 including an exhaust portion 241 and an extension portion 242, wherein the exhaust portion 241 is disposed around the periphery of the base 230 and between the side wall 210 of the reaction chamber 200, the extension portion 242 extends upward along the end of the exhaust portion 241 away from the base 230 and is electrically connected to the top wall of the reaction chamber 200, and the extension portion 242 is provided with an opening 2421 opposite to the wafer transfer port for the substrate W to enter and exit; and a movable door 250 for closing or opening the opening 2421.

[0043] The plasma confinement ring 240 of this embodiment includes an exhaust section 241 and an extension section 242. The exhaust section 241 functions the same as existing plasma confinement rings, allowing gas to exit the reaction region and extinguishing charged particles in the gas. The extension section 242 functions as an existing moving ring, confining the plasma above the substrate and reducing the problem of uneven plasma distribution caused by the wafer transfer port. Since the entire plasma confinement ring 240 cannot move vertically, an opening 2421 is provided in the extension section 242 to facilitate wafer transfer, corresponding to the wafer transfer port of the reaction chamber sidewall 210. Furthermore, to prevent plasma leakage from the opening 2421, a moving door 250 is provided outside the opening 2421. When wafer transfer is needed, the moving door 250 opens the opening 2421; during the etching process, the moving door 250 closes the opening 2421.

[0044] In this embodiment, the plasma confinement ring 240 is made of a conductive material, thereby extinguishing the plasma within the gas as it passes through the exhaust section 241, and ensuring that the plasma in the reaction region bombards the surface of the extension section 242, preventing polymer deposition on that surface. For example, the plasma confinement ring 240 can be made of metal, silicon, or silicon carbide. It should be noted that using a conductive material for the plasma confinement ring 240 is prior art; for example, patent application CN112687510A discloses a confinement ring made of aluminum, and patent application CN118280800A discloses a confinement ring made of silicon or silicon carbide. Furthermore, the surface of the plasma confinement ring 240 can be coated with a plasma-resistant coating, such as Y₂O₃ or Al₂O₃. Of course, if the plasma confinement ring 240 is made of silicon, silicon carbide, or similar materials, since there is no metal contamination, a coating may not be necessary.

[0045] like Figure 2As shown, the plasma confinement ring 240 further includes a connecting portion 243, which extends radially inward from the top end of the extension portion 242 along the base 230. The connecting portion 243 is connected to the top wall of the reaction chamber 200 by a fastener 244 (e.g., a bolt), thereby allowing the extension portion 242 to be in close contact with the top of the reaction chamber 200 through the connecting portion 243 and the fastener 244. Furthermore, a first groove recessed on the lower surface of the top wall of the reaction chamber 200 can be provided, containing a first radio frequency (RF) gasket 245. The first RF gasket provides a stable electrical connection between the connecting portion 243 and the top wall of the reaction chamber 200. Additionally, a second groove recessed on the upper surface of the connecting portion 243 can be provided, with the first RF gasket 245 accommodated within the second groove. Alternatively, both the first and second grooves can be provided simultaneously, with the first and second grooves facing each other, and the first RF gasket 245 accommodated within the groove formed by the mating of the first and second grooves.

[0046] like Figure 2 As shown, the movable door 250 is connected to a drive device 251, which drives the movable door 250 to move, thereby closing or opening the opening 2421. The drive device 251 can drive the movable door 250 to move up and down or laterally to close or open the opening 2421. The drive device 251 can be electric, pneumatic, or hydraulic; this embodiment does not limit its use.

[0047] In this embodiment, the movable door 250 is made of an insulating material, such as quartz or ceramic. When the movable door 250 closes the opening 2421, it can prevent plasma from leaking out of the opening 2421.

[0048] In other embodiments, the movable door (e.g.) Figures 3-7 The numbers 350, 450, 550, 650, and 750 shown can also be made of conductive material, when the movable door closes the opening (e.g. Figures 3-7 When labeled 3421, 4421, 5421, 6421, and 7421, it can not only prevent plasma from leaking out of the opening, but also prevent radio frequency signals from leaking out through the opening, thus avoiding the generation of plasma by ionization in the non-reactive space within the reaction chamber. It should be noted that the movable door can be made of insulating or conductive materials, as is existing technology. For example, patent application CN104051210A discloses the use of an insulating lifting ring to block the door opening, or a conductive metal baffle to block the door opening.

[0049] The following is a detailed description of an embodiment where the sliding door is made of a conductive material.

[0050] exist Figure 3 In the illustrated embodiment, a third groove is provided around the opening 3421, recessed into the outer wall of the extension 342. A second radio frequency washer 346 is provided within the third groove. When the movable door 350 moves to close the opening 3421, the movable door 3421 is electrically connected to the side wall of the extension 342 through the second radio frequency washer 346 to ground. This ensures good electrical contact between the movable door 350 and the extension 342, preventing arcing between them due to a pressure difference. It should be noted that the driving device 351 can apply a force to the movable door 350 towards the extension 342 to press the movable door 350 against the second radio frequency washer 346, thereby ensuring good electrical contact between the movable door 350 and the extension 342.

[0051] Furthermore, such as Figure 4 As shown, in Figure 3 Based on the illustrated embodiment, the movable door 450 further includes a first protrusion 452 facing the opening 4421. When the movable door 450 moves to close the opening 4421, the first protrusion 452 is located within the opening 4421 and fills it. By adding the first protrusion 452 to the movable door 450, when the movable door 450 closes the opening 4421, the first protrusion 452 blocks the entire opening 4421, ensuring that the conduction paths of radio frequency signals and airflow at the opening 4421 are consistent with the conduction paths at other locations of the plasma confinement ring 440, thereby guaranteeing a normal radio frequency electric field distribution and etching effect. It should be noted that in this embodiment, the driving device 451 needs to first drive the movable door 450 radially outward along the base 430 until the first protrusion 452 leaves the opening 4421, and then move upward to open the opening 4421.

[0052] exist Figure 5In the illustrated embodiment, the movable door 550 has a second protrusion 553 facing the opening 5421. The opening 5421 also has a fourth groove recessed on its lower surface, which accommodates a third radio frequency washer 547. When the movable door 550 moves to close the opening 5421, the second protrusion 553 is located within the opening 5421 and fills it. The second protrusion 553 is electrically connected to the plasma confinement ring 540 via the third radio frequency washer 547 for grounding. The effect of the second protrusion 553 is the same as that of the first protrusion 452. Furthermore, in this embodiment, the fourth groove and the third radio frequency washer 547 are provided within the opening 5421, so after the driving device 551 moves the movable door 550 to close the opening 5421, it is not necessary to... Figure 3 As shown in the embodiment, when a force is applied to the movable door 350 toward the extension 342, the second protrusion 553 can be pressed against the third radio frequency washer 547 by the movable door 550 under the action of gravity, thereby ensuring good electrical contact between the movable door 550 and the plasma confinement ring 540.

[0053] exist Figure 6 In the illustrated embodiment, the exhaust portion 641 has a step 648 at its end away from the base 630. The step 648 protrudes relative to the extension 642, and the exterior of the extension 642 and the step 648 are used to accommodate the movable door 650. The step 648 also has a fifth groove recessed into its upper surface, which accommodates a fourth radio frequency washer 649. When the movable door 650 moves to close the opening 6421, the step 648 supports the movable door 650, and the movable door 650 is electrically connected to the plasma confinement ring 640 via the fourth radio frequency washer 649 for grounding. Figure 3 Compared to the illustrated embodiment, this embodiment provides a step 648 on the outer side of the exhaust section 641, and a fourth groove and a fourth radio frequency washer 649 on the step 648. Therefore, the driving device 651 moves the movable door 650 to close the opening 6421, eliminating the need for... Figure 3 As shown in the embodiment, a force is applied to the movable door 350 toward the extension 342. Under the action of gravity or a downward force, the movable door 650 can press the fourth radio frequency gasket 649, thereby ensuring good electrical contact between the movable door 649 and the plasma confinement ring 640.

[0054] exist Figure 7In the illustrated embodiment, the exhaust section 741 has a receiving groove 748 recessed on its upper surface at one end away from the base 730. The receiving groove 748 has a sixth recessed groove on its bottom surface. The sixth recessed groove accommodates a fifth radio frequency washer 749. When the movable door 750 moves to close the opening 7421, the movable door 750 is located within the receiving groove 748, and the movable door 750 is electrically connected to the plasma confinement ring 740 via the fifth radio frequency washer 749 for grounding. Figure 6 Compared to the illustrated embodiment, in this embodiment, a receiving groove 748 is formed on the outer side of the exhaust section 741, the movable door 750 moves to be located within the receiving groove 748 to close the opening 7421, the bottom of the receiving groove 748 supports the movable door 750, and the outer wall of the receiving groove 748 can provide radial constraint on the movable door 750.

[0055] In summary, the plasma confinement ring of this invention includes an exhaust section and an extension section. The exhaust section is used to discharge gas from the reaction region and extinguish the plasma in the gas. The extension section is used to confine the plasma above the substrate, ensuring uniform plasma distribution in the reaction region. Since the plasma confinement ring is made of a conductive material and the extension section is electrically connected to the top wall of the reaction chamber, the extension section is bombarded by ions, making it less prone to polymer deposition on its surface. Simultaneously, since the entire plasma confinement ring cannot move vertically, an opening is provided in the extension section to facilitate wafer transfer, corresponding to the wafer transfer port on the side wall of the reaction chamber. Furthermore, to prevent plasma leakage from the opening, a movable door is provided outside the opening. When wafer transfer is needed, the movable door opens the opening; during the etching process, the movable door closes the opening. This invention eliminates the movable ring, modifying the existing plasma confinement ring to possess the function of a movable ring without affecting wafer transfer. This solves the problems of polymer deposition and detachment on the surface of existing movable rings, affecting the uniformity and consistency of etching, and causing damage to the substrate and equipment.

[0056] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] In the description of this utility model, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not 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 utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0058] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0060] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A plasma etching apparatus, characterized in that, include: A reaction chamber, wherein a transfer port is provided on the side wall of the reaction chamber; A gas spray head is used to deliver process gas into the reaction chamber; The base, located inside the reaction chamber and positioned opposite the gas spray head, is used to support the substrate. A plasma confinement ring includes an exhaust section and an extension section. The exhaust section is disposed around the periphery of the base between the sidewall of the reaction chamber and the periphery of the base. The extension section extends upward along the end of the exhaust section away from the base and is electrically connected to the top wall of the reaction chamber. The extension section has an opening opposite to the transfer port for the substrate to enter and exit. A movable door for closing or opening the opening.

2. The plasma etching apparatus as described in claim 1, characterized in that, The plasma confinement ring further includes a connecting portion that extends radially inward from the top end of the extension portion along the base, and the connecting portion is connected to the top wall of the reaction chamber by a fastener.

3. The plasma etching apparatus as described in claim 2, characterized in that, Also includes: A first groove is provided recessed on the lower surface of the top wall of the reaction chamber, and / or a second groove is provided recessed on the upper surface of the connecting part; the first groove and / or the second groove are used to accommodate a first radio frequency gasket, which is used to realize the electrical connection between the connecting part and the top wall of the reaction chamber.

4. The plasma etching apparatus as described in claim 1, characterized in that, The plasma confinement ring is made of a conductive material.

5. The plasma etching apparatus as described in claim 4, characterized in that, The plasma confinement ring is made of at least one of metal, silicon, or silicon carbide.

6. The plasma etching apparatus as described in claim 5, characterized in that, The plasma confinement ring is made of metal and has a plasma corrosion resistant coating on its surface.

7. The plasma etching apparatus as described in claim 1, characterized in that, The movable door is located between the plasma confinement ring and the side wall of the reaction chamber; it also includes a driving device connected to the movable door for driving the movable door to move in order to close or open the opening.

8. The plasma etching apparatus as described in claim 1, characterized in that, The sliding door is made of insulating material.

9. The plasma etching apparatus as described in claim 8, characterized in that, The sliding door is made of quartz or ceramic.

10. The plasma etching apparatus as described in claim 1, characterized in that, The movable door is made of conductive material.

11. The plasma etching apparatus as described in claim 10, characterized in that, A third groove is provided around the opening, recessed into the outer wall of the extension. A second radio frequency gasket is provided in the third groove. When the movable door moves to close the opening, the movable door is electrically connected to the side wall of the extension through the second radio frequency gasket to ground.

12. The plasma etching apparatus as described in claim 11, characterized in that, The movable door also has a first protrusion facing the opening. When the movable door moves to close the opening, the first protrusion is located inside the opening and fills the opening.

13. The plasma etching apparatus as described in claim 10, characterized in that, The movable door also has a second protrusion facing the opening. The opening is further provided with a fourth groove recessed on its lower surface. The fourth groove accommodates a third radio frequency gasket. When the movable door moves to close the opening, the second protrusion is located inside the opening and fills the opening. The second protrusion is electrically connected to the plasma confinement ring via the third radio frequency gasket to ground.

14. The plasma etching apparatus as described in claim 10, characterized in that, The exhaust section is provided with a step at the end away from the base. The step is also provided with a fifth groove recessed on its upper surface. The fifth groove contains a fourth radio frequency gasket. When the movable door moves to close the opening, the step supports the movable door, and the movable door is electrically connected to the plasma confinement ring through the fourth radio frequency gasket to ground.

15. The plasma etching apparatus as described in claim 10, characterized in that, The exhaust section has a receiving groove recessed on its upper surface at one end away from the base. The receiving groove has a sixth groove recessed on its bottom surface. The sixth groove contains a fifth radio frequency gasket. When the moving door moves to close the opening, the moving door is located in the receiving groove, and the moving door is electrically connected to the plasma confinement ring through the fifth radio frequency gasket to ground.

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