Plasma etching device
By setting up a pressure regulating structure and a lifting function of the suspension ring in the plasma etching device, the problem of uneven plasma distribution is solved, and the uniformity of the etching rate and the improvement of wafer quality are achieved.
Patent Information
- Application Number
- CN202422815597.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-11-18
AI Technical Summary
In existing asymmetric plasma etching devices, the plasma is unevenly distributed in the cavity, resulting in differences in etching rates in different areas of the wafer, affecting the quality and yield of the wafer.
A pressure regulating structure is adopted, including at least two suspension rings arranged in sequence along a first direction, with different spacings between the first and second parts of the suspension rings to adjust the airflow and pressure distribution inside the cavity. The uniformity of the plasma in the plasma etching device is achieved through the lifting function of the suspension rings and the cooperation of the moving components.
The uniformity of plasma distribution in the plasma etching device is improved, the uniformity of the etching rate is increased, the regional differences in the thickness of the film layer on the wafer surface are reduced, and the quality and yield of the wafer are improved.
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Figure CN223390493U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor process manufacturing technology, and in particular to a plasma etching device. Background Art
[0002] Inductively coupled plasma (ICP) is a plasma technology used for etching and deposition, which usually generates high-density plasma through an induction coil through a high-frequency current.
[0003] The chamber for ICP etching includes an asymmetric plasma etching device. The uneven distribution of plasma in the existing asymmetric plasma etching device in the chamber will cause differences in etching rates in different areas of the wafer, thereby affecting the quality and yield of the wafer. Utility Model Content
[0004] An embodiment of the present application provides a plasma etching device, aiming to improve the uniformity of plasma distribution in the plasma etching device.
[0005] The embodiments of this application adopt the following technical solutions:
[0006] In a first aspect, a plasma etching device is provided. The plasma etching device includes a carrier platform and a pressure regulating structure. The carrier platform is used to support a wafer. The pressure regulating structure includes at least two suspension rings arranged in sequence along a first direction, and at least two suspension rings are arranged opposite each other in the first direction. The suspension rings are arranged above the carrier platform and include a first portion and a second portion. The spacing between the first portions of two adjacent suspension rings is smaller than the spacing between the second portions of two adjacent suspension rings. The first direction is a direction perpendicular to the wafer surface.
[0007] The arrangement of a pressure regulating structure in a plasma etching device provided in an embodiment of the present application can improve the plasma distribution within the chamber. Due to the spacing between the molecular pump's gas inlet and the central axis of the carrier platform in the structure of an asymmetric plasma etching device, the gas on the wafer side closer to the molecular pump can be pumped out more quickly by the molecular pump, while the gas on the wafer side farther from the molecular pump is pumped out more slowly by the molecular pump. However, the arrangement of at least two suspension rings with different spacings based on the distance from the molecular pump in the pressure regulating structure can mitigate this effect. The spacing between the first portions of two adjacent suspension rings is smaller than the spacing between the second portions of two adjacent suspension rings, meaning that the gap between the second portions of two adjacent suspension rings closer to the molecular pump is smaller, while the gap between the first portions of two adjacent suspension rings farther from the molecular pump is larger. Therefore, the pressure regulating structure, on the one hand, limits the rapid outflow of gas near the molecular pump side, increasing the local pressure in that area, and on the other hand, increases the gas flow rate away from the molecular pump side, thereby ensuring uniform distribution of plasma within the plasma etching device.
[0008] As a possible implementation, at least two suspension rings are arranged in parallel, and the thickness of the first portion of the suspension ring is greater than the thickness of the second portion.
[0009] As a possible implementation manner, at least two suspension rings can be raised and lowered relative to the supporting platform along a first direction.
[0010] As a possible implementation, the pressure regulating structure further includes at least one moving component connected to the at least two suspension rings, and the moving component is configured to drive the at least two suspension rings to rise and fall relative to the supporting platform along the first direction.
[0011] As a possible implementation, the plasma etching apparatus further includes a coil. The coil is disposed above the carrier platform and on a side of the at least two suspension rings away from the carrier platform. The at least two suspension rings include a first suspension ring closest to the coil and a second suspension ring closest to the carrier platform. The moving assembly is configured to: drive the at least two suspension rings downward in a first direction relative to the carrier platform until the second suspension ring is flush with the upper surface of the wafer supported on the carrier platform; and / or drive the at least two suspension rings upward in the first direction relative to the carrier platform until the lower surface of the first suspension ring is flush with the lower surface of the coil.
[0012] As a possible implementation, the moving assembly includes a motor and a guide column, the motor is connected to one end of the guide column, the suspension ring has at least one connecting portion, and the guide column is connected to the connecting portions of at least two suspension rings.
[0013] As a possible implementation manner, the thickness of the first portion of the first suspension ring is equal to the thickness of the second portion, and the thickness of the first portion of the second suspension ring is greater than the thickness of the second portion.
[0014] As a possible implementation manner, the projection profile of the suspension ring on the plane where the surface of the supporting platform is located includes a circular ring shape.
[0015] As a possible implementation manner, the orthographic projections of the at least two suspension rings on the plane where the surface of the supporting platform is located surround the supporting platform.
[0016] As a possible implementation, the plasma etching device further includes a molecular pump, with a gap between the molecular pump's air inlet and the central axis of the carrier platform, and the first portion of the suspension ring is closer to the molecular pump's air inlet than the second portion. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] To more clearly illustrate the technical solutions of this application, the following briefly introduces the drawings required for use in some embodiments of this application. Obviously, the drawings described below are only drawings of some embodiments of this application, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of this application.
[0018] Figure 1 A schematic diagram of an inductively coupled plasma etching chamber provided for some embodiments of the present application;
[0019] Figure 2 An exploded view of a plasma etching device provided in some embodiments of the present application;
[0020] Figure 3 A partial schematic diagram of a plasma etching device provided for some embodiments of the present application;
[0021] Figure 4 A schematic diagram of film thickness in various regions on a wafer provided for some embodiments of the present application;
[0022] Figure 5 A schematic diagram of another plasma etching device provided for some embodiments of the present application;
[0023] Figure 6 A schematic diagram of a pressure regulating structure provided in some embodiments of the present application;
[0024] Figure 7 A schematic diagram of another pressure regulating structure provided for some embodiments of the present application;
[0025] Figure 8 A schematic projection diagram of a suspension ring and a supporting platform provided for some embodiments of the present application. DETAILED DESCRIPTION
[0026] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.
[0027] In the description of this application, it should be understood that, unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" are intended to indicate that the specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.
[0028] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.
[0029] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.
[0030] Plasma etching is a core technology in semiconductor manufacturing, widely used in the fabrication of high-precision micro- and nanostructures. Inductively coupled plasma (ICP) etching, due to its ability to generate high-density plasma over a wide pressure range, is widely used in deep silicon etching, high-aspect ratio structure fabrication, and metal layer etching.
[0031] For example, Figure 1As shown. The inductively coupled plasma etching chamber 100 includes a coil 3 arranged at the top of the chamber. The coil 3 is usually cylindrical or spiral, and a 13.56MHz radio frequency current is passed through it for inductive coupling to generate high-density plasma. A supporting structure 1 is also provided inside the inductively coupled plasma etching chamber 100. Exemplarily, the supporting structure 1 is an electrostatic chuck located at the bottom of the chamber for supporting the wafer 2. The electrostatic chuck can adsorb and fix the wafer 2 and provide the bias voltage required during the etching process. The supporting structure 1 usually controls the energy of ions bombarding the surface of the wafer 2 through radio frequency bias.
[0032] The chamber for ICP etching includes an asymmetric plasma etching device, for example, Figure 2 shown. Figure 2 An exploded view of a plasma etching device is shown. From top to bottom are the plasma blocking screen 11, the screw cover 12, the cathode liner 13, the upper liner 14, the lower liner 15 and the chamber body 16. The chamber body 16 serves as an overall structural frame, which is used to form a vacuum environment and accommodate the various components required for the etching reaction. The upper liner 14 is located above the interior of the cavity and is used to protect the inner wall of the cavity and prevent direct erosion of the cavity by the plasma. The lower liner 15 is arranged at the bottom of the cavity and is usually connected to the supporting structure of the wafer to provide support and protection for the fixation of the wafer and the etching reaction. The cathode liner 13 surrounds the supporting structure of the wafer and is used to assist in improving the distribution of plasma inside the cavity.
[0033] Before the ICP coil generates a high-density plasma through inductive coupling, a molecular pump is required to evacuate the interior of the chamber to a vacuum environment. During the process of the ICP coil exciting the plasma, the molecular pump needs to maintain the low-pressure environment inside the chamber and remove the reaction byproducts produced during the etching process.
[0034] For example, Figure 3 As shown, Figure 3 A partial schematic diagram of a plasma etching device provided in some embodiments of the present application. The plasma blocking screen 11 is located between the supporting structure 1 and the limiting ring 17 for fixing the wafer. The molecular pump 18 is arranged on one side of the supporting structure 1. Figure 2 It can be seen that two inner cavities are formed between the upper liner 14, the lower liner 15, and the chamber body 16, and that the molecular pump 18 and the support structure 1 are not located in the same inner cavity. In other words, in the asymmetric plasma etching apparatus, the position of the molecular pump 18 and the wafer are not symmetrically arranged about the support structure, and the molecular pump 18 is set off the central axis of the chamber body 16.
[0035] This bias setting of the molecular pump 18 directly leads to the asymmetry of the gas flow path and pressure distribution inside the plasma etching device. Specifically, the pumping action of the molecular pump 18 causes the gas flow rate on the side of the cavity close to the molecular pump to be faster and the pressure to be lower, while the gas flow rate on the side away from the molecular pump is slower and the pressure to be higher. This asymmetric pressure distribution will lead to uneven distribution of plasma density and reaction gas inside the etching cavity, which directly affects the etching rate of the wafer. For example, due to the uneven distribution of gas pressure, the plasma density presents an asymmetric distribution in the cavity, on the side close to the molecular pump 18. The plasma density is higher and the ion bombardment is stronger, while on the side away from the molecular pump 18, the plasma density is lower and the etching rate is slower.
[0036] This asymmetric plasma distribution will lead to poor wafer etching uniformity and regional differences in film thickness. For example, Figure 4 shown. Figure 4 The numbers in the figure represent the thickness of the film in each area on the wafer. Figure 4 It can be seen that due to the asymmetry of the gas flow path and pressure distribution inside the plasma etching device, the film thickness distribution of wafer 2 is extremely uneven. Compared with the edge area of wafer 2, the film thickness in the center area of wafer 2 is smaller, which means more etching. From the center of wafer 2 to the boundary, the film thickness on wafer 2 is larger, which means less etching, seriously affecting the quality and yield of the wafer.
[0037] In view of this, an embodiment of the present application provides a plasma etching device. For example, Figure 5 As shown, the plasma etching device 50 includes a carrier 4 and a pressure regulating structure 5. The carrier 4 is used to support the wafer 2. The pressure regulating structure 5 includes at least two suspension rings 51 arranged in sequence along a first direction (the direction indicated by the double arrows in the figure), and the at least two suspension rings 51 are arranged opposite to each other in the first direction. Figure 6 , Figure 6 This is a schematic diagram of a pressure regulating structure provided in an embodiment of the present application. Figure 6 The suspension ring 51 is disposed above the carrier platform and includes a first portion 511 and a second portion 512. The spacing L1 between the first portions 511 of two adjacent suspension rings 51 is smaller than the spacing L2 between the second portions 512 of two adjacent suspension rings 51. The first direction is perpendicular to the surface of the wafer 2.
[0038] As a possible implementation, combining Figure 5 and Figure 6The plasma etching device 50 further includes a molecular pump 18 , and there is a gap between the air inlet of the molecular pump 18 and the central axis of the carrier platform 4 , and the first portion 511 of the suspension ring 51 is closer to the air inlet of the molecular pump relative to the second portion 512 of the suspension ring.
[0039] Due to the offset position of the molecular pump 18 in the plasma etching device, the gas flow rate is high and the pressure is low on the side close to the molecular pump 18, while the gas flow rate is slow and the pressure is high on the side away from the molecular pump 18, resulting in uneven pressure distribution. The at least two suspension rings 51 in the newly added pressure regulation structure 5 in the embodiment of the present application adjust the airflow and pressure distribution within the chamber by varying the spacing between adjacent suspension rings 51.
[0040] The first portion of the suspension ring 51 is close to the molecular pump 18, while the second portion is far from the molecular pump 18. Furthermore, the distance between the first portions 511 of two adjacent suspension rings 51 is small, narrowing the gas passageway in this area. This creates resistance to gas flow and thus limits the gas flow rate near the molecular pump 18. According to Bernoulli's equation (applicable to approximate fluid behavior in low-pressure chambers), when the flow rate decreases, the pressure increases. Therefore, the small distance between the first portions 511 of two adjacent suspension rings 51 can also increase the local pressure near the molecular pump 18.
[0041] The distance between the second portions 512 of two adjacent suspension rings 51 is large, and the gas passageway through this area is larger than the gas passageway between the first portions 511 of two adjacent suspension rings 51, resulting in less resistance to the gas. This can relatively accelerate the flow of gas away from the molecular pump 18. Similarly, according to Bernoulli's equation, as the flow rate increases, the local pressure on the side away from the molecular pump 18 decreases.
[0042] The small spacing near the molecular pump 18 effectively reduces the short-circuit effect of the gas (referring to a complex gas flow system, such as a plasma chamber, in which the reaction gas fails to fully diffuse or evenly distribute in the chamber due to an unreasonable flow path design or an excessively large local pressure difference, and is directly pumped out of the system). This prevents the gas near the molecular pump 18 from being evacuated too quickly, while accelerating the renewal efficiency of the gas away from the molecular pump 18 and improving the efficiency of by-product discharge. By increasing the pressure on the molecular pump 18 side through the small spacing near the molecular pump 18 side, the pressure difference within the plasma etching device 50 is reduced, and ultimately a balanced gas distribution within the chamber is achieved, significantly improving the problem of inconsistent wafer etching rates caused by uneven pressure.
[0043] As a possible implementation, refer to Figure 6At least two suspension rings 51 are arranged in parallel, and the thickness of the first portion 511 of the suspension ring 51 is greater than the thickness of the second portion 512. The parallel arrangement of at least two suspension rings 51 means that the spacing between the first portions 511 of two adjacent suspension rings 51 is equal at all locations, and the spacing between the second portions 512 of two adjacent suspension rings 51 is equal at all locations. The parallel arrangement ensures that the airflow forms a stratified flow between the suspension rings 51, avoiding gas turbulence that may be caused by the uneven thickness of the suspension rings 51. In addition, the parallel arrangement of the suspension rings 51 makes the distribution of the plasma easier to predict and control, thereby achieving more precise control of the etching rate of the wafer 2.
[0044] The first portion 511 of the suspension ring 51 is thicker, providing a stronger physical barrier and limiting the rapid flow of gas on that side. The second portion 512 of the suspension ring 51 is thinner, creating less flow resistance and accelerating the rapid flow of gas on that side, preventing byproduct accumulation in that area. The gap between the thickness differences of the suspension ring 51 helps establish a reasonable pressure gradient within the asymmetric plasma chamber 50, thereby improving the uneven etching rate of the wafer.
[0045] In some embodiments, the thickness of the first portion of the first suspension ring is equal to the thickness of the second portion, and the thickness of the first portion of the second suspension ring is greater than the thickness of the second portion. Figure 7 As shown, Figure 7 The illustrated pressure regulation structure includes five opposing suspension rings 51. The first and second portions of the suspension ring 51 furthest from the wafer 2, i.e., the first suspension ring 51A closest to the coil 3, have the same thickness. The first portion 511 of the second suspension ring 51B closest to the carrier 4 is thicker than the second portion 512. As a possible implementation, the first portion 511 of the suspension ring 51 located between the first suspension ring 51A and the second suspension ring 51B is thicker than the second portion 512. In this case, the distance between the first portions 511 of two adjacent suspension rings 51 and the distance between the second portions 512 of two adjacent suspension rings 51 are not equal. This can also achieve the effect of limiting the gas flow rate near the molecular pump 18 and accelerating the gas flow rate away from the molecular pump 18. Furthermore, a reasonable pressure gradient can be established within the asymmetric plasma chamber 50, thereby improving the uneven wafer etching rate.
[0046] In some embodiments, as Figure 5 As shown, at least two suspension rings 51 can rise and fall relative to the supporting platform 4 along the first direction, which means that the suspension ring 51 can rise along the first direction and continuously approach the coil 3, or the suspension ring 51 can fall along the first direction and continuously approach the wafer 2.
[0047] The suspension ring 51 has a lifting function, which means that its vertical position relative to the support platform 4 can be adjusted as needed within the plasma etching device 50. This allows the affected airflow and gas pressure to be adjusted throughout the entire plasma etching device 50, rather than being confined to a fixed position. This changes the gas flow path within the plasma etching device 50, making the gas flow rate and pressure distribution within the entire cavity more uniform and controllable. By adjusting the position of the suspension ring 51 by lifting and lowering, it can meet the needs of wafers 2 of different sizes. According to different etching depths or other process requirements, adjusting the height and rate of lifting can change the gas flow rate and gas pressure within the plasma etching device 50, greatly improving compatibility.
[0048] As a possible implementation, Figure 5 As shown, the pressure regulating structure 5 further includes at least one moving component 52 , which is connected to at least two suspension rings 51 . The moving component 52 is configured to drive the at least two suspension rings 51 to rise and fall relative to the supporting platform 4 along a first direction.
[0049] In some embodiments, as Figure 5 As shown, the plasma etching apparatus 50 further includes a coil 3. The coil 3 is disposed above the carrier platform 4 and on a side of at least two suspension rings 51 away from the carrier platform 4. The at least two suspension rings 51 include a first suspension ring 51A closest to the coil 3 and a second suspension ring 51B closest to the carrier platform 4. The moving assembly 52 is configured to drive the at least two suspension rings 51 to descend relative to the carrier platform 4 in a first direction until the second suspension ring 51B is flush with the upper surface of the wafer 2 supported on the carrier platform 4.
[0050] Alternatively, the moving assembly 52 is configured to drive the at least two suspension rings 51 to rise relative to the supporting platform 4 along the first direction until the first suspension ring 51A and the lower surface of the coil 3 are located at the same horizontal plane.
[0051] Coil 3 provides inductively coupled high-frequency energy to generate a high-density plasma. The moving assembly 52 is the core that enables the suspension ring 51 to be raised and lowered. The moving assembly 52 can raise the first suspension ring 51A of the at least two suspension rings 51 to be flush with the lower surface of coil 3, bringing the suspension ring 51 into close proximity with coil 3 and thereby changing the gas flow rate and uniformity at the top of the plasma etching apparatus 50. The moving assembly 52 can lower the second suspension ring 51B of the at least two suspension rings 51 to be flush with the upper surface of wafer 2, thereby changing the gas flow rate and uniformity at the bottom of the plasma etching apparatus 50. Because the suspension ring 51 can reach the top, bottom, or any position in between, the uniformity of the plasma within the plasma etching apparatus 50 can be adjusted, resulting in a more uniform distribution of plasma within the plasma etching apparatus 50 and reducing the problem of uneven etching of wafer 2.
[0052] Specifically, such as Figure 6 As shown, the moving assembly 52 includes a motor 521 and a guide post 522. The motor 521 is connected to one end of the guide post 522. The suspension ring 51 has at least one connecting portion 513. The guide post 522 is connected to the connecting portions 513 of at least two suspension rings 51. In the case where the pressure regulation structure includes multiple moving assemblies, the suspension ring 51 has multiple connecting portions 513, and the guide post 522 of each connecting assembly is connected to a corresponding connecting portion 513 of at least two suspension rings 51.
[0053] For example, Figure 6 As shown, Figure 6 The apparatus includes two moving components and four suspension rings 51 , each of the four suspension rings 51 includes two connecting parts 513 , one connecting part 513 of each suspension ring 51 is connected to one moving component, and the other connecting part 513 of each suspension ring 51 is connected to another moving component.
[0054] As a possible implementation, Figure 5 As shown, the projection of the suspension ring 51 on the plane of the support platform 4 includes a circular ring shape. For example, since the suspension ring 51 is circular and inherently symmetrical, the concentrically arranged circular suspension rings 51 can uniformly restrict the spatial distribution of the plasma, further preventing uneven pressure distribution from causing different etching rates on the wafer surface.
[0055] It should be understood that the present application does not limit the shape of the suspension ring itself, and the suspension ring can also be square, rectangular, triangular, star-shaped, etc.
[0056] As a possible implementation, at least two suspension rings surround the carrier platform with their orthographic projections on the bottom of the plasma etching device. Figure 8 As shown, Figure 8 The figure shows the projections of the suspension ring 51 and the carrier platform 4 on the bottom of the plasma etching device. Figure 8 It can be seen that the projection of the suspension ring 51 on the cavity bottom of the plasma etching device is L4, the projection of the supporting platform 4 on the cavity bottom of the plasma etching device is L3, and the length of L4 is greater than L3.
[0057] At least two suspension rings 51, projected orthographically on the bottom of the plasma etching chamber, surround the carrier 4, ensuring that the gas flow path around the carrier 4 is influenced by the suspension rings 51. Since the wafer 2 is supported on the carrier 4, the gas flow path and pressure distribution around the wafer 2 are uniformly controlled by the suspension rings 51. The surrounding design of the suspension rings 51 avoids short-circuiting of the gas flow, ensuring that the gas flow rate at different locations on the carrier 4 is consistent, thereby alleviating the problem of significant differences in the etching area of the wafer 2.
[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.
Claims
1. A plasma etching device, characterized in that: include: A carrier table for carrying wafers; The pressure regulating structure includes at least two suspension rings arranged in sequence along a first direction, and the at least two suspension rings are arranged opposite each other in the first direction, the suspension rings are arranged above the supporting platform, and the suspension rings include a first portion and a second portion; the spacing between the first portions of two adjacent suspension rings is smaller than the spacing between the second portions of two adjacent suspension rings; The first direction is a direction perpendicular to the surface of the wafer.
2. The plasma etching device according to claim 1, wherein: The at least two suspension rings are arranged in parallel, and the thickness of the first portion of the suspension ring is greater than the thickness of the second portion.
3. The plasma etching device according to claim 1, wherein: The at least two suspension rings can be lifted and lowered relative to the supporting platform along the first direction.
4. The plasma etching device according to claim 3, characterized in that: The pressure regulating structure further includes at least one moving component, which is connected to the at least two suspension rings. The moving component is configured to drive the at least two suspension rings to move up and down relative to the supporting platform along a first direction.
5. The plasma etching device according to claim 4, characterized in that: The plasma etching device further includes a coil; The coil is arranged above the supporting platform and located on a side of the at least two suspension rings away from the supporting platform; The at least two suspension rings include a first suspension ring closest to the coil and a second suspension ring closest to the supporting platform; The moving component is configured to: drive the at least two suspension rings to descend along the first direction relative to the supporting platform until the second suspension ring and the upper surface of the wafer are located at the same horizontal plane; and\or, drive the at least two suspension rings to rise along the first direction relative to the supporting platform until the first suspension ring and the lower surface of the coil are located at the same horizontal plane.
6. The plasma etching device according to claim 4 or 5, characterized in that: The moving assembly includes a motor and a guide column, the motor is connected to one end of the guide column, the suspension ring has at least one connecting portion, and the guide column is connected to the connecting portions of the at least two suspension rings.
7. The plasma etching device according to claim 5, characterized in that: The thickness of the first portion of the first suspension ring is equal to the thickness of the second portion, and the thickness of the first portion of the second suspension ring is greater than the thickness of the second portion.
8. The plasma etching device according to any one of claims 1 to 5, characterized in that: The projection outline of the suspension ring on the plane where the surface of the supporting platform is located includes a circular ring.
9. The plasma etching device according to any one of claims 1 to 5, characterized in that: The orthographic projections of the at least two suspension rings on the plane where the surface of the supporting platform is located surround the supporting platform.
10. The plasma etching device according to any one of claims 1 to 5, characterized in that: The plasma etching device further includes a molecular pump, an air inlet of the molecular pump is spaced from the central axis of the carrier platform, and the first portion of the suspension ring is closer to the air inlet of the molecular pump than the second portion of the suspension ring.