Plasma confinement system and method

Abstract

This invention discloses a plasma confinement system, comprising: inner and outer isolation rings, each grounded via a radio frequency grounding device; a support assembly with a thermal deformation release section; and a confinement ring located between the inner and outer isolation rings, with its bottom connected to the top of the support assembly. Simultaneously, this invention also discloses a plasma processing device and a method for maintaining the structural and functional stability of the plasma confinement system. By employing a dual-sided radio frequency grounding structure and incorporating a thermal deformation release section, this invention solves the technical problems of existing plasma confinement systems generating harmful plasma in non-processing areas and the structural and functional damage of the plasma confinement system due to thermal deformation.

Description

Technical Field

[0001] This invention relates to the field of plasma processing, and more specifically to a plasma confinement system and method. Background Technology

[0002] Capacitively coupled plasma etching equipment is a device that uses a radio frequency (RF) power supply applied to electrodes to generate plasma within a reaction chamber via capacitive coupling for etching. It includes a vacuum reaction chamber containing a base for fixing the substrate and a spray head for introducing reactive gas into the chamber. Typically, the spray head serves as the upper electrode, and the base as the lower electrode, forming a reaction region between them. At least one RF power supply is applied to either the upper or lower electrode through a matching network, generating an RF electric field between them. This field dissociates the reactive gas into plasma, which 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, altering its morphology and thus completing the etching process.

[0003] Plasma is diffusive; although most of the plasma remains within the processing area between the upper and lower electrodes, some plasma may fill the entire reaction chamber, diffusing beyond the processing area and causing corrosion, deposition, or erosion in these areas. This leads to particle contamination inside the reaction chamber, reducing the reusability of the plasma processing device and potentially shortening the service life of the reaction chamber or its components. Furthermore, if the plasma is not confined within a defined working area, charged particles will collide with unprotected areas, resulting in impurities and contamination on the semiconductor substrate surface. Currently, plasma distribution is typically constrained using plasma confinement systems.

[0004] Plasma confinement systems require radio frequency (RF) grounding. In existing technologies, RF grounding is typically performed on one side of the plasma confinement system, near the base or the sidewall of the reaction chamber. This approach has two problems: firstly, a large potential difference can easily be generated on the ungrounded side, leading to the generation of new plasma in the unprocessed area and reducing the confinement effect of the plasma confinement system; secondly, the plasma confinement system generates high temperatures due to plasma bombardment, while the grounded side remains relatively cool. This uneven temperature distribution can cause thermal deformation in some areas of the plasma confinement system. Excessive thermal deformation can damage the structure and function of the plasma confinement system, thus affecting the processing. Summary of the Invention

[0005] The purpose of this invention is to provide a plasma confinement system and method, thereby solving the technical problems of existing plasma confinement systems generating harmful plasma in non-processing areas and damaging the structure and function of the plasma confinement system due to thermal deformation, and achieving reliable radio frequency grounding.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A plasma confinement system for a plasma processing apparatus, the plasma processing apparatus including a reaction chamber, within which a base for supporting a substrate is disposed.

[0008] The plasma confinement system is located between the base and the sidewall of the reaction chamber, and the plasma confinement system includes:

[0009] An inner isolation ring surrounds the outer periphery of the base and is grounded through a radio frequency grounding device;

[0010] An outer isolation ring surrounds the inner circumference of the sidewall of the reaction chamber and is grounded through a radio frequency grounding device;

[0011] The support assembly consists of a set of conductive plates arranged radially along the inner isolation ring, located between the inner isolation ring and the outer isolation ring, and each of the conductive plates is provided with a heat deformation relief part;

[0012] A constraint ring is located between the inner isolation ring and the outer isolation ring, and its bottom is connected to the top of the support assembly;

[0013] The inner isolation ring and the outer isolation ring are electrically connected through the support component and the constraint ring.

[0014] Preferably, both ends of each conductive plate are connected to the inner isolation ring and the outer isolation ring, respectively. The heat deformation release part is a notch provided on the conductive plate and an elastic connector connecting the two ends of the notch. The elastic connector is a structure made of conductive material that can generate deformation.

[0015] Preferably, the notches are all located in the middle of each of the conductive plates.

[0016] Preferably, the width of the notch is 1.5mm-2.0mm.

[0017] Preferably, the elastic connector is an arc-shaped soft metal sheet.

[0018] Preferably, the two ends of the elastic connector are fixed to the conductive plates at both ends of the notch by welding or bolting.

[0019] Preferably, each of the conductive plates is uniformly distributed along the circumference of the inner isolation ring.

[0020] Preferably, each of the conductive plates comprises:

[0021] A plurality of internal connecting conductive plates, one end of each internal connecting conductive plate being connected to the inner isolation ring, and the heat deformation release part being a notch provided between the other end of the internal connecting conductive plate and the outer isolation ring;

[0022] A plurality of external conductive plates are provided, one end of each external conductive plate being connected to the outer isolation ring, and the heat deformation release part being a notch provided between the other end of the external conductive plate and the inner isolation ring.

[0023] Preferably, the inner and outer connecting conductive plates are staggered.

[0024] Preferably, the inner and outer connecting conductive plates are evenly distributed in an alternating manner.

[0025] Preferably, the width of each notch is 1.5mm-2.0mm.

[0026] Preferably, the constraint ring is a set of concentric rings radially distributed along the inner isolation ring.

[0027] Preferably, the radio frequency grounding device is a capacitor.

[0028] Preferably, the capacitor is made of graphite pads.

[0029] A plasma processing apparatus includes a reaction chamber, within which a base for supporting a substrate is disposed. A spray head for introducing reactive gases into the reaction chamber is disposed above the base. A processing area is formed between the spray head and the base, and this processing area is surrounded by the chamber wall of the reaction chamber. The plasma processing apparatus also includes an exhaust area at the lower part of the reaction chamber, which is connected to an external exhaust pump. The apparatus further includes:

[0030] The plasma confinement system described above is disposed between the processing area and the exhaust area, and is located between the base and the sidewall of the reaction chamber.

[0031] A method for maintaining the structural and functional stability of a plasma confinement system, implemented based on the aforementioned plasma processing device, comprises the following steps:

[0032] The substrate to be processed is placed on the top of the base of the plasma processing device. The base is used as the lower electrode and high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma. The plasma is then used to perform plasma etching on the substrate to be processed.

[0033] During plasma etching, the inner and outer isolation rings of the plasma confinement system are grounded through radio frequency grounding devices. The middle region of the plasma confinement system between the inner and outer isolation rings is bombarded by plasma, resulting in a higher temperature than the two ends, which causes thermal deformation of the structure of the plasma confinement system.

[0034] The thermal deformation is released in whole or in part through the thermal deformation release part, thereby maintaining the structural and functional stability of the plasma confinement system.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. By adopting a dual-sided radio frequency grounding structure, the potential difference is eliminated, thereby avoiding the generation of plasma in non-processing areas;

[0037] 2. By setting up a thermal deformation release section, a certain deformation margin can be provided to release thermal deformation caused by uneven temperature distribution, avoid thermal deformation affecting the structure and function of the plasma confinement system, and achieve reliable radio frequency grounding. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A schematic diagram of a plasma processing device equipped with the plasma confinement system of the present invention.

[0040] Figure 2a , 2b These are partial structural front and top views of a portion of an embodiment of the plasma confinement system of the present invention;

[0041] Figure 3a , 3b 3c are front and top views of a portion of the structure of one embodiment of the plasma confinement system of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] In the following description, references to "some embodiments" or "one or more embodiments" describe a subset of all possible embodiments. However, it is understood that "some embodiments" or "one or more embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0044] In the following description, the terms "first, second, third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that shown in the illustrations or description.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0046] Figure 1 A capacitively coupled plasma (CCP) processing device is shown, comprising a vacuum-ejectable reaction chamber 1 enclosed by reaction chamber walls. The reaction chamber 1 is connected to a reaction gas supply device 2. The reaction chamber 1 is equipped with a base 3 for fixing a substrate 4 and a spray head 5 for introducing reaction gas into the reaction chamber. The area between the spray head 5 and the base 3 is the processing area. Typically, the spray head 5 serves as the upper electrode and the base 3 serves as the lower electrode. At least one radio frequency power supply 7 is applied to one of the upper or lower electrodes through a matching network, generating a radio frequency electric field between the upper and lower electrodes. This dissociates the reaction gas in the processing area into plasma. The plasma reaching the upper surface of the substrate 4 can perform etching and other processes on the substrate 4. The bottom of the reaction chamber 1 is an exhaust area, which is connected to an external exhaust pump 8 to extract the process waste gas generated after the etching reaction during the processing from the reaction chamber. Furthermore, a plasma confinement system 6 is provided between the processing area and the exhaust area, and between the outer perimeter of the base 3 and the side wall of the reaction chamber 1, to confine the plasma within the processing area and prevent it from spreading out and corroding the unprotected equipment.

[0047] The plasma confinement system 6 includes an inner isolation ring 61 surrounding the outer periphery of the base 3 and an outer isolation ring 62 surrounding the inner periphery of the sidewall of the reaction chamber 1, which respectively isolate the metal sidewall of the base 3 and the metal inner wall of the reaction chamber 1 from the plasma to protect them from plasma erosion; the plasma confinement system 6 also includes a confinement ring 63 located between the inner isolation ring 61 and the outer isolation ring 62, and a support assembly 64 supporting the confinement ring 63 at the bottom of the confinement ring 63 for confining the plasma in the processing area in the vertical direction, and the inner isolation ring 61 and the outer isolation ring 62 are electrically connected by the support assembly.

[0048] To prevent the radio frequency electric field in the base from propagating below the confinement ring 63, the process exhaust gas in the already neutral exhaust area will be re-ignited, forming secondary plasma and contaminating the inner wall of the reaction chamber 1 and the exhaust pipe in the exhaust area. At the same time, the large amount of charge accumulated by the plasma on the confinement ring 63 during the process also needs to be guided to the grounding channel. The plasma confinement system 6 needs to be grounded by radio frequency through the radio frequency grounding device. This will shield the radio frequency energy above the exhaust area, prevent the generation of secondary plasma, and at the same time guide away the accumulated charge on the confinement ring 63.

[0049] In the prior art, one of the inner isolation ring 61 and the outer isolation ring 62 is usually RF grounded on one side by an RF grounding device. This RF grounding structure has two problems: First, a large potential difference is easily generated on the ungrounded side relative to the ground plane, which generates new plasma at the bottom (exhaust area) of the side close to the plasma confinement system 6, thus failing to achieve the ideal plasma confinement effect; Second, because the plasma confinement system is a structure that directly receives plasma bombardment, it will generate a high temperature, and the temperature on the ungrounded side will be higher than that on the grounded side, resulting in uneven thermal deformation. When the thermal deformation is too large, it will cause the RF grounding structure of the plasma confinement system to be damaged, thus affecting the process.

[0050] Committed to solving the above-mentioned technical problems, combined with Figure 1 , 2a As shown in Figures 2b and 3a-3c, the present invention provides a plasma confinement system 6 for a plasma processing apparatus, which is an annular body located between the base 3 and the sidewall of the reaction chamber 1, comprising:

[0051] An inner isolation ring 61, surrounding the outer periphery of the base 3, is used to isolate the plasma from the outer periphery of the base 3, protecting the metal wall of the base 3 from plasma erosion. It is typically made of a metal material with an anti-corrosion coating. It is connected to a radio frequency grounding device 65. Figure 2a , 3a 3b) Grounding, which refers to radio frequency grounding, the inner isolation ring 61 is not directly conductive to the ground plane; and the bottom end of the radio frequency grounding device 65 is fixed to the reaction chamber 1 or other components;

[0052] An outer isolation ring 62 surrounds the inner circumference of the side wall of the reaction chamber 1 to isolate the plasma from the inner circumference of the side wall of the reaction chamber 1 and protect the metal wall of the reaction chamber 1 from plasma erosion. It is usually made of metal material with an anti-corrosion coating on the surface. It is grounded through a radio frequency grounding device 65. This grounding refers to radio frequency grounding. There is no direct electrical conduction between the outer isolation ring 62 and the grounding ground. The bottom end of the radio frequency grounding device 65 is fixed to the reaction chamber 1 or other components.

[0053] The confinement ring 63 is a set of concentric rings located between the inner isolation ring 61 and the outer isolation ring 62. The gaps between the concentric rings form multiple annular channels. Each channel connects the processing area and the exhaust area. The charge present between the adjacent sidewalls of each channel during the process forms a capacitor, which is used to confine the plasma in the processing area.

[0054] The support assembly 64 is located between the inner isolation ring 61 and the outer isolation ring 62, and its top is connected to the bottom of the constraint ring 63. It is used for the physical and electrical connection between the inner isolation ring 61 and the outer isolation ring 62, and supports the constraint ring 63. The support assembly 64 is a group of conductive plates arranged radially along the inner isolation ring 61. One end of each conductive plate is connected to the inner isolation ring 61, and the other end is connected to the outer isolation ring 62. It is made of conductive material.

[0055] The inner isolation ring 61 and the outer isolation ring 62 are electrically connected via a support component 64. The RF grounding devices 65 at the bottom of the inner and outer isolation rings 61 and 62 typically use large capacitors of tens of nF, with sufficiently low impedance to achieve RF grounding without direct conductivity between the isolation rings and the ground plane. In this embodiment, the large capacitor is a graphite pad with an insulating anodic oxide film on its surface, forming a capacitor structure between its upper and lower ends. The upper end is the first electrode of the capacitor, and the lower end is the second electrode. Therefore, the inner isolation ring 61 and the outer isolation ring 62 are respectively RF grounded to the ground plane, and are also electrically connected to each other. By employing this dual-sided grounding method... The dual-sided radio frequency grounding structure (referring to the inner isolation ring 61 side and the outer isolation ring 62 side respectively) can effectively reduce the potential difference between the bottom of the plasma confinement system 6 and the ground plane, thereby avoiding the generation of new plasma in the exhaust area due to the potential difference, thus solving the first technical problem mentioned above. However, it does not solve the second technical problem well. After using the dual-sided radio frequency grounding structure, on the one hand, the thermal deformation on the inner isolation ring 61 side and the outer isolation ring 62 side is different, causing deformation of each conductive plate. On the other hand, the middle area of ​​each conductive plate, being far from the radio frequency grounding points at both ends, will generate a higher temperature than at the ends, resulting in greater thermal deformation and arching. When each conductive plate deforms, it will change the parallel relationship between the bottom surface of the isolation ring connected to both ends and the ground plane, causing the first and second poles of the radio frequency grounding device 65 to become non-parallel. Because the parallel structure between the two poles has changed, an air layer will be filled in, which will cause the capacitance value of the radio frequency grounding device 65 to decrease rapidly, leading to the functional failure of the plasma confinement system 6.

[0056] To further solve this technical problem, the present invention further provides a heat deformation release part 642 on each of the conductive plates. The heat deformation release part 642 is a structure that can generate its own deformation, which is used to release the heat deformation of the conductive plate through its own deformation, so that the bottom of the isolation ring at both ends and the ground plane, as well as the first pole and the second pole of the radio frequency grounding device 65, always maintain a stable parallel relationship, thereby making the radio frequency grounding device 65 maintain a stable capacitance value.

[0057] Figure 2a , 2b This illustration shows a partial embodiment of the plasma confinement system 6 of the present invention, wherein each conductive plate 641 has its two ends connected to the inner isolation ring 61 and the outer isolation ring 62, respectively. The thermal deformation release part 642 is a notch provided on the conductive plate 641, and an elastic connector connecting the two ends of the notch to the conductive plates 641. The elastic connector is a structure made of conductive material capable of deformation. In some embodiments, the elastic connector is an arc-shaped soft metal sheet, which can deform and release the pressure at both ends when subjected to force. In some embodiments, the elastic connector is connected to the conductive plates at both ends. The connection method of 641 is by screw connection or welding connection; in some embodiments, each conductive plate 641 is evenly distributed around the circumference of the inner isolation ring 61, and its structure and stress are more uniform; in some embodiments, the notches on the conductive plates 641 are uniformly set in the middle of each conductive plate 641, and the stress is more uniform; in some embodiments, the notches on the conductive plates 641 are the gaps between two adjacent concentric rings of the constraint ring 63, and their width is about 1.5-2.0mm, thereby providing sufficient deformation space for the heat deformation release part 642, while taking into account the structure and function of the constraint ring 63. Its working principle is as follows: On the one hand, the two ends of the notches of each conductive plate 641 are connected through the heat deformation release part 642 of the conductive material, which can realize the conductive connection between the inner and outer isolation rings; on the other hand, when each conductive plate 641 generates deformation pressure, the pressure is transmitted through each conductive plate 641 to its respective heat deformation release part 642. The heat deformation release part 642 deforms to release the deformation pressure at both ends, so that the isolation rings connected to both ends of each conductive plate 641 will not be subjected to force and deform. In this way, the bottom of the inner and outer isolation rings and the grounding ground, as well as the first pole and the second pole of the radio frequency grounding device 65, always maintain a stable parallel relationship, thereby maintaining a stable capacitance value of the radio frequency grounding device 65 and realizing reliable radio frequency grounding.

[0058] Figures 3a-3cSome other embodiments of the plasma confinement system 6 of the present invention are shown, wherein the conductive plate includes: a plurality of inner connecting conductive plates 6411, one end of each inner connecting conductive plate 6411 being connected to the inner isolation ring 61, and the thermal deformation release part 642 being a notch provided between the other end of the inner connecting conductive plate 6411 and the outer isolation ring 62; and a plurality of outer connecting conductive plates 6412, one end of each outer connecting conductive plate 6412 being connected to the outer isolation ring 62, and the thermal deformation release part 642 being a notch provided between the other end of the outer connecting conductive plate 6412 and the inner isolation ring 61. Preferably, in some embodiments, the inner connecting conductive plates 6411 and the outer connecting conductive plates 6412 are staggered to uniformly release deformation pressure; more preferably, in some embodiments, the inner connecting conductive plates 6411 and the outer connecting conductive plates 6412 are staggered and uniformly distributed to make the deformation pressure release more uniform and the structure more stable; in some embodiments, the notches on the inner connecting conductive plates 6411 and the outer connecting conductive plates 6412 are gaps between two adjacent concentric rings of the constraint ring 63, with a width of about 1.5-2.0 mm, thereby providing sufficient deformation space for the heat deformation release part 642, while taking into account the structure and function of the constraint ring 63. Its working principle is as follows: On the one hand, since the notches of the inner connecting conductive plate 6411 and the outer connecting conductive plate 6412 are distributed at different ends, and the concentric rings of the constraint ring 63 are electrically connected to each conductive plate, the support component 64 and the constraint ring 63 form a conductive mesh structure. The inner and outer isolation rings are electrically connected through this conductive mesh structure. On the other hand, when each conductive plate generates deformation pressure, the pressure is released through the notches on each conductive plate. Furthermore, the concentric rings of the constraint ring 63 connected to each conductive plate can also deform to release the deformation pressure from the inner connecting conductive plate 6411 and the outer connecting conductive plate 6412. This prevents the inner and outer isolation rings from being stressed and deformed, thereby ensuring that the bottom of the inner and outer isolation rings and the ground plane, as well as the first and second poles of the RF grounding device 65, always maintain a stable parallel relationship. This ensures that the RF grounding device 65 maintains a stable capacitance value and achieves reliable RF grounding.

[0059] At the same time, combined Figure 1As shown, the present invention also provides a plasma processing device, including a reaction chamber 1, a base 3 for supporting a substrate 4 disposed within the reaction chamber 1, and a spray head 5 for introducing reaction gas into the reaction chamber 1 disposed above the base 3; the area between the spray head 5 and the base 3 is a processing area, which is surrounded by the cavity wall of the reaction chamber 1; the plasma processing device has an exhaust area at the lower part of the reaction chamber 1, which is connected to an external exhaust pump 8; the plasma processing device further includes: a plasma confinement system 6 provided in this embodiment, disposed between the processing area and the exhaust area, and located between the base 3 and the side wall of the reaction chamber 1.

[0060] In addition, combined Figure 1 , 2a As shown in Figures 2b and 3a-3c, the present invention also provides a method for maintaining the structural and functional stability of the plasma confinement system 6, implemented based on the plasma processing apparatus of the present invention, the method comprising the following steps:

[0061] The substrate 4 to be processed is placed on the top of the base 3 of the plasma processing device. The base 3 serves as the lower electrode and is subjected to high-frequency radio frequency power through the radio frequency power supply 7 to dissociate the reactive gas in the processing area into plasma. The plasma is then used to perform plasma etching on the substrate 4 to be processed.

[0062] During the plasma etching process, the inner isolation ring 61 and the outer isolation ring 62 of the plasma confinement system 6 are grounded through the radio frequency grounding device 65. The middle region of the plasma confinement system 6 between the inner isolation ring 61 and the outer isolation ring 62 is bombarded by plasma and generates a higher temperature than the two ends, thereby causing thermal deformation of the structure of the plasma confinement system 6.

[0063] The thermal deformation is released in whole or in part through the thermal deformation release part 642, thereby maintaining the structural and functional stability of the plasma confinement system 6.

[0064] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

Claims

1. A plasma confinement system for a plasma processing apparatus, the plasma processing apparatus comprising a reaction chamber, wherein a base for supporting a substrate is disposed within the reaction chamber, characterized in that, The plasma confinement system is located between the base and the sidewall of the reaction chamber, and the plasma confinement system includes: An inner isolation ring surrounds the outer periphery of the base and is grounded through a radio frequency grounding device; An outer isolation ring surrounds the inner circumference of the sidewall of the reaction chamber and is grounded through a radio frequency grounding device; The support assembly consists of a set of conductive plates arranged radially along the inner isolation ring, located between the inner isolation ring and the outer isolation ring, and each of the conductive plates is provided with a heat deformation relief part; A constraint ring is located between the inner isolation ring and the outer isolation ring, and its bottom is connected to the top of the support assembly; The inner isolation ring and the outer isolation ring are electrically connected through the support component and the constraint ring.

2. The plasma confinement system as described in claim 1, characterized in that, Each of the conductive plates has its two ends connected to the inner isolation ring and the outer isolation ring, respectively. The heat deformation release part is a notch provided on the conductive plate and an elastic connector connecting the two ends of the notch to the conductive plates. The elastic connector is a structure made of conductive material that can deform.

3. The plasma confinement system as described in claim 2, characterized in that, The notches are all located in the middle of each of the conductive plates.

4. The plasma confinement system as described in claim 2, characterized in that, The width of the notch is 1.5mm-2.0mm.

5. The plasma confinement system as described in claim 2, characterized in that, The elastic connector is an arc-shaped soft metal sheet.

6. The plasma confinement system as described in claim 2, characterized in that, The two ends of the elastic connector are fixed to the conductive plates at both ends of the notch by welding or bolts.

7. The plasma confinement system as described in claim 2, characterized in that, Each of the conductive plates is uniformly distributed along the circumference of the inner isolation ring.

8. The plasma confinement system as described in claim 1, characterized in that, Each of the aforementioned conductive plates includes: A plurality of internal connecting conductive plates, one end of each internal connecting conductive plate being connected to the inner isolation ring, and the heat deformation release part being a notch provided between the other end of the internal connecting conductive plate and the outer isolation ring; A plurality of external conductive plates are provided, one end of each external conductive plate being connected to the outer isolation ring, and the heat deformation release part being a notch provided between the other end of the external conductive plate and the inner isolation ring.

9. The plasma confinement system as described in claim 8, characterized in that, The internal and external conductive plates are staggered.

10. The plasma confinement system as described in claim 8, characterized in that, The internal and external conductive plates are evenly distributed in an alternating pattern.

11. The plasma confinement system as described in claim 8, characterized in that, The width of each notch is 1.5mm-2.0mm.

12. The plasma confinement system as claimed in claim 1, characterized in that, The constraint ring is a set of concentric rings radially distributed along the inner isolation ring.

13. The plasma confinement system as claimed in claim 1, characterized in that, The radio frequency grounding device is a capacitor.

14. The plasma confinement system as described in claim 13, characterized in that, The capacitor is made of graphite pads.

15. A plasma processing apparatus, comprising a reaction chamber, wherein a base for supporting a substrate is disposed within the reaction chamber, and a spray head for introducing reactive gas into the reaction chamber is disposed above the base; a processing area is formed between the spray head and the base, and the processing area is surrounded by the cavity wall of the reaction chamber; the plasma processing apparatus has an exhaust area at the lower part of the reaction chamber, and the exhaust area is connected to an external exhaust pump; characterized in that, Also includes: The plasma confinement system as described in any one of claims 1-14 is disposed between the processing region and the exhaust region, and located between the base and the sidewall of the reaction chamber.

16. A method for maintaining the structural and functional stability of a plasma confinement system, characterized in that, Based on the plasma processing apparatus as described in claim 15, the method comprises the following steps: The substrate to be processed is placed on the top of the base of the plasma processing device. The base is used as the lower electrode and high-frequency radio frequency power is applied to dissociate the reactive gas in the processing area into plasma. The plasma is then used to perform plasma etching on the substrate to be processed. During plasma etching, the inner and outer isolation rings of the plasma confinement system are grounded through radio frequency grounding devices. The middle region of the plasma confinement system between the inner and outer isolation rings is bombarded by plasma, resulting in a higher temperature than the two ends, which causes thermal deformation of the structure of the plasma confinement system. The thermal deformation is released in whole or in part through the thermal deformation release part, thereby maintaining the structural and functional stability of the plasma confinement system.

Images