Plasma processing device, lower electrode assembly and forming method thereof

Abstract

A plasma processing device, a lower electrode assembly and a method for forming the same, wherein the lower electrode assembly comprises: a base for carrying a substrate to be processed; a focusing ring surrounding the periphery of the base; a coupling ring arranged below the focusing ring; a conductive layer arranged inside the coupling ring; and a wire for electrically connecting the conductive layer and the base to make the base and the conductive layer have the same potential. The lower electrode assembly is not prone to arc discharge.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a plasma processing device, a lower electrode assembly and a forming method thereof. Background Art

[0002] The plasma processing device comprises: a vacuum reaction chamber; a lower electrode assembly, and a base located in the vacuum reaction chamber, wherein the lower electrode assembly is used to carry the substrate to be processed. The working principle of the plasma processing device is to introduce a reaction gas containing an appropriate etchant source gas into the vacuum reaction chamber, and then input radio frequency energy into the vacuum reaction chamber to activate the reaction gas, so as to excite and maintain plasma, and the plasma is used to process the substrate to be processed.

[0003] As the integration level of semiconductor devices continues to increase, the etching size becomes smaller and smaller, and the corresponding requirement for applied power is higher, which will make the existing lower electrode assembly prone to arc discharge. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a plasma processing device, a lower electrode assembly and a forming method thereof, so as to prevent arc discharge from occurring between a base and a coupling ring in the lower electrode assembly.

[0005] In order to solve the above technical problems, the present invention provides a lower electrode assembly, including: a base, used to support a substrate to be processed; a focusing ring, surrounding the periphery of the base; a coupling ring, arranged below the focusing ring; a conductive layer, arranged in the coupling ring; a wire, used to electrically connect the conductive layer and the base to make the base and the conductive layer have the same potential.

[0006] Optionally, the base includes a platform portion and a step portion located outside the platform portion.

[0007] Optionally, the coupling ring includes a first coupling portion and a second coupling portion, the first coupling portion is opposite to a side wall of the platform portion, and the second coupling portion is opposite to a surface of the step portion.

[0008] Optionally, the conductive layer is disposed in at least one of the first coupling portion and the second coupling portion, and the conductive layer is wrapped by the first coupling portion or the second coupling portion.

[0009] Optionally, the conductive layer is made of metal, semiconductor material or carbon fiber.

[0010] Optionally, the material of the conductive layer is the same as that of the coupling ring, and the conductive layer contains doped ions, and the doped ions have different ion valence states from that of the coupling ring material.

[0011] Optionally, the doping ions are at least one of metal ions and inorganic ions; the metal ions include nickel ions or magnesium ions; the inorganic ions include carbon ions, nitrogen ions or silicon ions.

[0012] Optionally, when the material of the conductive layer is carbon fiber, the conductive layer is clamped in the coupling ring, and the coupling ring exposes the end of the conductive layer.

[0013] Optionally, the distance from the top surface of the conductive layer to the top surface of the coupling ring is greater than 100 microns and less than the thickness of the coupling ring.

[0014] Correspondingly, the present invention also provides a plasma processing device, comprising: a reaction chamber; and the above-mentioned lower electrode assembly, located in the reaction chamber.

[0015] Optionally, the plasma processing device is a capacitively coupled plasma processing device, and further includes: a mounting substrate located at the top of the reaction chamber; a gas shower head located below the mounting substrate and arranged opposite to the lower electrode assembly; a radio frequency power source electrically connected to the gas shower head or the base; and a bias radio frequency power source electrically connected to the base.

[0016] Optionally, the plasma processing device is an inductively coupled plasma processing device, and further includes: an insulating window located at the top of the reaction chamber; an inductive coil located above the insulating window; a radio frequency power source electrically connected to the inductive coil; and a bias radio frequency power source electrically connected to the base.

[0017] Optionally, the power range of the RF power source is greater than 4000 watts; the power of the bias RF power source is greater than 30000 watts.

[0018] Correspondingly, the present invention also provides a method for forming a lower electrode assembly, comprising: providing a base, the base being used to support a substrate to be processed, a focusing ring being arranged on the periphery of the base, and a coupling ring being arranged below the focusing ring; a conductive layer being arranged inside the coupling ring, the conductive layer being electrically connected to the base via a wire so that the base and the conductive layer have the same potential.

[0019] Optionally, the method for forming the conductive layer and the coupling ring includes: providing a first coupling member, the first coupling member including a surface to be processed; setting a mask layer on the periphery of the surface to be processed; forming a conductive layer on the surface to be processed using the mask layer as a mask; after forming the conductive layer, removing the mask layer; after removing the mask layer, forming a second coupling member on the periphery of the surface to be processed and the surface of the conductive layer; the second coupling member and the first coupling member constitute the coupling ring.

[0020] Optionally, the conductive layer is formed by an electrochemical process, which includes: applying silver paste to the surface to be treated and baking to form a silver layer; the silver layer is used as an electrode to form the conductive layer by electroplating.

[0021] Optionally, the conductive layer is formed by a sputtering process.

[0022] Optionally, the formation process of the conductive layer is a process, and the doping ions injected by the ion implantation process are different from the ions of the coupling ring material; the doping ions injected by the ion implantation process are different from the ions of the coupling ring material.

[0023] Optionally, the material of the conductive layer is carbon fiber; the method of the conductive layer and the coupling ring includes: providing a first coupling member, the first coupling member includes a surface to be processed; forming a conductive layer on the surface to be processed; and forming a second coupling member on the surface of the conductive layer.

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

[0025] In the plasma processing device provided by the technical solution of the present invention, in order to allow thermal expansion and contraction between the coupling ring and the base, there is a gap between the coupling ring and the base. Although there is a gap between the coupling ring and the base, a conductive layer is provided in the coupling ring, and the conductive layer is electrically connected to the base through a wire, so that the potential of the base is equal to the potential of the conductive layer. Then, the potential difference between the base and the coupling ring is transferred to the potential difference between the conductive layer and the coupling ring above the conductive layer. Since there is no gap in the coupling ring above the conductive layer and the breakdown resistance is good, it is not easy for discharge to occur between the conductive layer and the coupling ring above the conductive layer. Although there is a gap between the coupling ring below the conductive layer and the base, because the two are at the same potential, arc discharge is not easy to occur between the coupling ring and the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a plasma processing device of the present invention;

[0027] Figure 2 is a schematic structural diagram of another plasma processing device of the present invention;

[0028] Figure 3 yes Figure 1 A partial enlarged view of the middle area A;

[0029] Figure 4 is a process flow chart of a method for forming a lower electrode assembly of the present invention;

[0030] Figures 5 to 7 It is a structural schematic diagram of each step of forming a lower electrode assembly of the present invention;

[0031] Figure 8 It is a schematic diagram of another structure of forming a lower electrode assembly according to the present invention;

[0032] Figures 9 to 11 It is a structural schematic diagram of the steps of forming a lower electrode assembly according to another embodiment of the present invention. DETAILED DESCRIPTION

[0033] As described in the background technology, arc discharge is prone to occur between the existing coupling ring and the base. In order to solve the technical problem, the technical solution of the present invention provides a plasma processing device, a lower electrode assembly and a method for forming the same. The plasma processing device can reduce the arc discharge between the coupling ring and the base.

[0034] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] Figure 1 It is a structural schematic diagram of a plasma processing device of the present invention.

[0036] Please refer to Figure 1 The plasma processing device 1 includes: a reaction chamber 100; a base 101, located in the reaction chamber 100; an electrostatic chuck 102, located above the base 101, for adsorbing a substrate W to be processed; an insulating window 107, located at the top of the reaction chamber 100; and an inductor 108, located above the insulating window 107.

[0037] In this embodiment, the plasma processing device 1 is an inductively coupled plasma reaction device (ICP), and the plasma processing device 1 further includes: a radio frequency power source 109, which applies a radio frequency voltage to the inductor 108 through a radio frequency matching network; and a bias radio frequency power source 110, which is electrically connected to the base 101. A gas injection port (not shown in the figure) is provided at one end of the side wall of the reaction chamber 100 close to the insulating window 107. In other embodiments, a gas injection port can also be provided in the central area of ​​the insulating window 107. The gas injection port is used to inject the reaction gas into the reaction chamber 100. The radio frequency power of the radio frequency power source 109 drives the inductor 108 to generate a strong high-frequency alternating magnetic field, so that the low-pressure reaction gas in the reaction chamber 100 is ionized to generate plasma. Plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above active particles can undergo various physical and chemical reactions with the surface of the substrate W to be processed, so that the morphology of the surface of the substrate W to be processed changes, that is, the etching process is completed. The bias RF power source 110 applies a bias RF voltage to the base through a RF matching network to control the bombardment direction of charged particles in the plasma.

[0038] In addition, the plasma processing device 1 further includes: an equipment plate 105, surrounding the base 101, the equipment plate 105 includes a bottom plate and extension plates extending upward from both ends of the bottom plate, the bottom plate is located below the base 101, and the extension plate is located below the coupling ring 104. The extension plate has a temperature control channel in it, which is used to control the temperature of the focus ring 103.

[0039] Figure 2 It is a schematic structural diagram of another plasma processing device of the present invention.

[0040] Please refer to Figure 2 The plasma processing device 2 includes: a reaction chamber 200; a base 201, located at the bottom of the reaction chamber 200; an electrostatic chuck 202, located above the base 201, used to adsorb the substrate W to be processed; a mounting substrate 206, located at the top of the reaction chamber 200; a gas shower head 207, located below the mounting substrate 206 and arranged opposite to the base 201; a gas source 205, connected to the gas shower head 207, used to transport reaction gas into the reaction chamber 200.

[0041] In this embodiment, the plasma processing device 2 is a capacitively coupled plasma reaction device (CCP), wherein the gas shower head 207 is used as an upper electrode, the base 201 is used as a lower electrode, and a reaction region is formed between the upper electrode and the lower electrode. In addition, the plasma processing device 2 further includes: a radio frequency power source electrically connected to the gas shower head 207 or the base 201; and a bias radio frequency power source electrically connected to the base 201. Here, the radio frequency power source and the bias radio frequency power source are both connected to the base 201 as an example for description.

[0042] The RF power source is applied to one of the upper electrode or the lower electrode through a matching network, and a RF electric field is generated between the upper electrode and the lower electrode to dissociate the reaction gas into plasma. The plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above active particles can undergo various physical and chemical reactions with the surface of the substrate W to be processed, so that the morphology of the surface of the substrate W to be processed changes, that is, the etching process is completed. An exhaust pump (not shown in the figure) is also provided below the vacuum reaction chamber 100 to discharge the reaction by-products from the reaction chamber 100 to maintain the vacuum environment of the reaction chamber 100.

[0043] The density distribution of the plasma in the plasma processing device is proportional to the etching rate of the substrate W to be processed. The higher the density of the plasma, the higher the etching rate, and the lower the density of the plasma, the lower the etching rate. Due to the effect of the plasma gas flow, the plasma density in the central area of ​​the substrate to be processed decreases, and the plasma density in the edge part of the substrate to be processed increases, resulting in a decrease in the etching rate in the central area of ​​the surface of the substrate to be processed and an increase in the etching rate in the edge part, resulting in an uneven etching rate of the substrate to be processed.

[0044] To solve the above problems, Figure 1 Taking an example for schematic illustration, a focusing ring 103 is arranged on the periphery of the substrate W to be processed, which is equivalent to expanding the radius of the substrate W to be processed outward, so that plasma with the same conditions as those above the substrate W to be processed is generated above the focusing ring 103, and the plasma distribution edge above the substrate W to be processed is effectively extended to the outer wall of the focusing ring 103, thereby increasing the distribution range of the plasma, broadening the density distribution curve of the plasma on the surface of the substrate W to be processed, and making the density distribution of the plasma on the substrate W to be processed tend to be flat, so that the plasma density distribution on the substrate W to be processed is more uniform, which is beneficial to ensure the uniformity of the etching process in the edge area and the center area.

[0045] The coupling ring 104 is provided between the focus ring 103 and the base 101 to fill the gap between the focus ring 103 and the base 101 and prevent arc discharge from occurring between the focus ring 103 and the base 101 .

[0046] In addition, as the integration of semiconductor devices continues to increase, the etching size of semiconductor devices is getting smaller and smaller, which requires that the power of the applied RF power source and the power of the bias power source are higher. The power of the applied RF power source and the power of the bias power source are relatively high. Specifically, the power range of the RF power source is greater than 4000 watts; the power of the bias RF power source is greater than 30000 watts, which makes it easy for arc discharge to occur between the base 101 and the coupling ring 104. The present invention sets a conductive layer 106 in the coupling ring 104, and the conductive layer 106 is electrically connected to the base 101 to reduce the arc discharge between the coupling ring 104 and the base 101, as described in detail as follows:

[0047] Figure 3 yes Figure 1 A partial enlarged view of area A in the middle.

[0048] Please refer to Figure 1 and Figure 3 , the base 101 (see Figure 1 ) includes a platform portion 101b and a Figure 3 ) The outer step portion 101a (see Figure 3), the coupling ring 104 includes a first coupling portion and a second coupling portion, the first coupling portion is opposite to the side wall of the platform portion 101b, and the second coupling portion is opposite to the surface of the step portion 101a.

[0049] The base 101 is made of aluminum alloy, and the coupling ring 104 is made of dielectric material, such as ceramic or quartz, specifically aluminum oxide or yttrium oxide. On the one hand, in order to allow thermal expansion and contraction of the coupling ring 104 and the base 101, there is a gap between the coupling ring 104 and the base 101; on the other hand, it is difficult to achieve absolute tight fit between the coupling ring 104 and the base 101, so there is a gap between the coupling ring 104 and the base 101.

[0050] In addition, the potential of the base 101 is different from the potential of the coupling ring 104. Although the potentials of the base 101 and the coupling ring 104 are different, the coupling ring 104 is provided with a conductive layer 106 (see Figure 1 ), and the conductive layer 106 is electrically connected to the base 101 through the wire 150, so that the potential of the conductive layer 106 is equal to the potential of the base 101, then the potential difference between the base 101 and the coupling ring 104 is transferred to the potential difference between the conductive layer 106 and the top of the coupling ring 104 above the conductive layer 106. Since the conductive layer 106 is located in the coupling ring 104, although there is a potential difference between the conductive layer 106 and the top of the coupling ring 104, there is no gap in the coupling ring 104 above the conductive layer 106 and the breakdown resistance is good, so it is not easy for arc discharge to occur between the conductive layer 106 and the coupling ring 104. In addition, although there is a gap between the base 101 and the conductive layer 106, the potential difference between the base 101 and the conductive layer 106 is equal, so it is not easy for arc discharge to occur between the base 101 and the conductive layer 106.

[0051] In this embodiment, the base 101 (see Figure 1 ) includes a platform portion 101b and a Figure 3 ) The outer step portion 101a (see Figure 3 ), the coupling ring 104 includes a first coupling portion and a second coupling portion, the first coupling portion is opposite to the side wall of the platform portion 101b, the second coupling portion is opposite to the surface of the step portion 101a, the first coupling portion is provided with a first conductive layer 106b, the second coupling portion is provided in the second conductive layer 106a, and the conductive layer 106 includes a first conductive layer 106b and a second conductive layer 106a. The ends of the first conductive layer 106b and the second conductive layer 106a may be connected or separated from each other.

[0052] In other embodiments, the first conductive layer is disposed only in the first coupling portion, or the second conductive layer is disposed only in the second coupling portion.

[0053] In other embodiments, the base is a plate structure, the base has no steps, the coupling ring is located below the focusing ring, and the coupling ring is disposed inside the conductive layer.

[0054] In one embodiment, the conductive layer 106 is made of metal, such as copper or nickel. The advantage of using metal as the conductive layer 106 is that since both the conductive layer 106 and the subsequent wires are made of metal, it is easier to weld the two.

[0055] In another embodiment, the conductive layer 106 is made of carbon fiber, semiconductor material, or graphite layer.

[0056] In another embodiment, the material of the conductive layer is the same as that of the coupling ring, but the doped ions in the conductive layer have different valences from those in the coupling ring material, and the doped ions include at least one of metal ions and inorganic ions, the metal ions include nickel ions or magnesium ions; the inorganic ions include carbon ions, nitrogen ions or silicon ions. Since the valence of the doped ions is different from that of the coupling ring material, the doped ions make the coupling ring position where they are located have better conductivity and can be used as the conductive layer.

[0057] The distance from the top surface of the conductive layer 106 to the top surface of the coupling ring 104 is greater than 100 microns and less than the thickness of the coupling ring 104, so that the conductive layer 106 can not only be wrapped by the coupling ring 104, but also the thickness of the coupling ring 104 covered above the conductive layer 106 is not too thin, ensuring that the top of the coupling ring 104 is not easily penetrated.

[0058] The following is a detailed description of the method for forming the lower electrode assembly:

[0059] Figure 4 It is a process flow chart of the method for forming the lower electrode assembly of the present invention.

[0060] Please refer to Figure 4 Step S1: providing a base, the base is used to support the substrate to be processed, a focusing ring is arranged on the periphery of the base, and a coupling ring is arranged under the focusing ring; Step S2: arranging a conductive layer in the coupling ring, the conductive layer is electrically connected to the base through a wire.

[0061] How to form the conductive layer is described in detail as follows:

[0062] Figures 5 to 7 It is a structural schematic diagram of each step of forming the lower electrode assembly of the present invention.

[0063] Please refer to Figure 5 , providing a first coupling member 300, wherein the first coupling member 300 includes a surface B to be processed; and a mask layer 301 is arranged around the surface B to be processed.

[0064] The material of the first coupling member 300 is a dielectric material, such as ceramic or quartz, specifically aluminum oxide or yttrium oxide. The first coupling member 300 and the subsequent second coupling member form the coupling ring.

[0065] The mask layer 301 has a mask opening therein, and the mask opening exposes the central area of ​​the surface to be processed B, and the mask opening is used to define the position of the subsequent conductive layer. The mask layer 301 is located at the periphery of the surface to be processed B, so that the conductive layer formed subsequently does not cover the periphery of the first coupling member 300 but is located at the central area, so that the conductive layer can be completely surrounded and not exposed, which is conducive to preventing metal contamination.

[0066] Please refer to Figure 6 , using the mask layer 301 as a mask, the conductive layer 302 is formed.

[0067] In one embodiment, the formation process of the conductive layer 302 is an electrochemical process, and the electrochemical process includes: brushing silver paste on the surface to be processed and baking to form a silver layer; the silver layer is used as an electrode to form the conductive layer by electroplating.

[0068] In another embodiment, the conductive layer 302 is formed by a sputtering process, and the conductive layer 302 is formed in the central area of ​​the surface B to be processed by the sputtering process.

[0069] Please refer to Figure 7 After forming the conductive layer 302 , the mask layer 301 is removed; after removing the mask layer 301 , the second coupling member 303 is formed on the periphery of the surface B to be processed and on the surface of the conductive layer 302 , and the second coupling member 303 surrounds the conductive layer 302 .

[0070] The mask layer 301 is removed to expose the peripheral area of ​​the surface B to be processed and the side wall of the conductive layer 302. The second coupling member 303 formed subsequently surrounds the conductive layer 302, so that the conductive layer 302 is completely surrounded by the first coupling member 300 and the second coupling member 303, which is beneficial to prevent metal contamination.

[0071] Figure 8 It is a schematic diagram of another structure of forming a lower electrode assembly according to the present invention.

[0072] Similar to the above embodiment, a first coupling member 400 is provided. The first coupling member 400 includes a surface to be processed. A mask layer 401 is formed on the periphery of the surface to be processed.

[0073] Please refer to Figure 8 , using the mask layer 401 as a mask, an ion implantation process is used to form a conductive layer 402 in a portion of the first coupling element 400 .

[0074] Using the mask layer 401 as a mask, doping ions are implanted into the first coupling element 400. The doping ions include at least one of metal ions and inorganic ions, wherein the metal ions include nickel ions or magnesium ions, and the inorganic ions include carbon ions, nitrogen ions or silicon ions.

[0075] The implantation depth can be adjusted by controlling the energy of the implanted doping ions, thereby determining the thickness of the formed conductive layer 402. The advantage of forming the conductive layer 402 by ion implantation is that there is no interface between the conductive layer 402 formed by ion implantation and the first coupling member 400, and no delamination occurs.

[0076] After forming the conductive layer 402, the method further includes: removing the mask layer 401; after removing the mask layer 401, forming a second coupling member in the peripheral area of ​​the conductive layer 402 and the first coupling member 400, wherein the second coupling member surrounds the conductive layer 402. The second coupling member surrounds the conductive layer 402, so that the conductive layer 402 is completely surrounded by the first coupling member 400 and the second coupling member, which is beneficial to preventing metal contamination.

[0077] Figures 9 to 11 It is a structural schematic diagram of the steps of forming a lower electrode assembly according to another embodiment of the present invention.

[0078] Please refer to Fig. 9 , providing a first coupling member 500, wherein the first coupling member 500 includes a surface C to be processed.

[0079] Please refer to Fig.10 , forming a conductive layer 501 on the surface C to be processed.

[0080] In this embodiment, the material of the conductive layer 501 is carbon fiber. Since carbon fiber will not cause metal contamination when exposed to a plasma environment, there is no need for an additional mask layer to allow the subsequent second coupling member to surround the conductive layer 501. This is beneficial for simplifying the process steps and reducing process costs.

[0081] Please refer to Fig.11 , a second coupling element 502 is formed on the surface of the conductive layer 501 .

[0082] In summary, a conductive layer is arranged in the coupling ring, and the conductive layer is electrically connected to the base through a wire, so that the potential of the base is equal to the potential of the conductive layer, then the potential difference between the base and the coupling ring is transferred to the potential difference between the conductive layer and the coupling ring above the conductive layer. Since there is no gap in the coupling ring above the conductive layer and the breakdown resistance is good, no discharge will occur between the conductive layer and the coupling ring above the conductive layer, and since the coupling ring below the conductive layer and the base are at the same potential, arc discharge is not likely to occur between the coupling ring and the base.

[0083] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A lower electrode assembly, characterized in that: include: A base, used for carrying a substrate to be processed, the base comprising a platform portion and a step portion located outside the platform portion; A focusing ring surrounding the periphery of the base; A coupling ring is disposed below the focusing ring, the coupling ring comprising a first coupling portion and a second coupling portion, the first coupling portion is opposite to the side wall of the platform portion, and the second coupling portion is opposite to the surface of the step portion; A conductive layer is disposed in the coupling ring, wherein the distance from the top surface of the conductive layer to the top surface of the coupling ring is greater than 100 microns, and the distance from the top surface of the conductive layer to the top surface of the coupling ring is less than the thickness of the coupling ring; The conductive wire is used to electrically connect the conductive layer and the base so that the base and the conductive layer have the same potential.

2. The lower electrode assembly according to claim 1, characterized in that The conductive layer is disposed in at least one of the first coupling portion and the second coupling portion, and the conductive layer is wrapped by the first coupling portion or the second coupling portion.

3. The lower electrode assembly according to claim 2, characterized in that: The conductive layer is made of metal, semiconductor material or carbon fiber.

4. The lower electrode assembly according to claim 2, characterized in that: The material of the conductive layer is the same as that of the coupling ring, and the conductive layer contains doped ions, and the doped ions have different ion valence states from that of the coupling ring material.

5. The lower electrode assembly according to claim 4, characterized in that The doping ions are at least one of metal ions and inorganic ions; the metal ions include nickel ions or magnesium ions; the inorganic ions include carbon ions, nitrogen ions or silicon ions.

6. The lower electrode assembly according to claim 1, characterized in that When the material of the conductive layer is carbon fiber, the conductive layer is sandwiched in the coupling ring, and the coupling ring exposes the end of the conductive layer.

7. A plasma processing device, characterized in that: include: Reaction chamber; The lower electrode assembly according to any one of claims 1 to 6 is located in the reaction chamber.

8. The plasma processing apparatus according to claim 7, wherein: The plasma processing device is a capacitively coupled plasma processing device, and further includes: a mounting substrate, located at the top of the reaction chamber; a gas shower head, located below the mounting substrate and arranged opposite to the lower electrode assembly; a radio frequency power source, electrically connected to the gas shower head or the base; a bias radio frequency power source, electrically connected to the base; the power range of the radio frequency power source is greater than 4000 watts; the power of the bias radio frequency power source is greater than 30,000 watts.

9. The plasma processing apparatus according to claim 7, wherein: The plasma processing device is an inductively coupled plasma processing device, and further includes: an insulating window located at the top of the reaction chamber; an inductive coil located above the insulating window; a radio frequency power source electrically connected to the inductive coil; a bias radio frequency power source electrically connected to the base; the power range of the radio frequency power source is greater than 4000 watts; the power of the bias radio frequency power source is greater than 30,000 watts.

10. A method for forming a lower electrode assembly according to any one of claims 1 to 6, characterized in that: include: Providing a base, the base is used to carry the substrate to be processed, a focusing ring is arranged on the periphery of the base, and a coupling ring is arranged below the focusing ring; A conductive layer is arranged in the coupling ring, and the conductive layer is electrically connected to the base through a wire, so that the base and the conductive layer have the same potential.

11. The method for forming a lower electrode assembly according to claim 10, wherein: The method for forming the conductive layer and the coupling ring includes: providing a first coupling member, the first coupling member includes a surface to be processed; setting a mask layer on the periphery of the surface to be processed; using the mask layer as a mask, forming a conductive layer on the surface to be processed; after forming the conductive layer, removing the mask layer; after removing the mask layer, forming a second coupling member on the periphery of the surface to be processed and the surface of the conductive layer; the second coupling member and the first coupling member constitute the coupling ring.

12. The method for forming the lower electrode assembly according to claim 11, wherein: The conductive layer is formed by an electrochemical process, which includes: brushing silver paste on the surface to be processed and baking to form a silver layer; the silver layer is used as an electrode to form the conductive layer by electroplating.

13. The method for forming a lower electrode assembly according to claim 11, wherein: The conductive layer is formed by a sputtering process.

14. The method for forming a lower electrode assembly according to claim 11, wherein: The formation process of the conductive layer is an ion implantation process; the doping ions implanted by the ion implantation process are different from the ions of the coupling ring material.

15. The method for forming a lower electrode assembly according to claim 10, wherein: The conductive layer is made of carbon fiber. The method of the conductive layer and the coupling ring comprises: providing a first coupling member, the first coupling member comprising a surface to be processed; forming a conductive layer on the surface to be processed; and forming a second coupling member on the surface of the conductive layer.

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