Gas conveying assembly and plasma generating device
By employing a multi-chamber design and uniformly dispersing gas delivery components, the problems of low processing efficiency and poor process consistency in traditional RPS systems have been solved, achieving efficient and uniform plasma generation and improving production efficiency and process flexibility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN CSL VACUUM SCI & TECH CO LTD
- Filing Date
- 2025-05-07
- Publication Date
- 2026-05-01
AI Technical Summary
Traditional RPS systems have low processing efficiency in large-scale production, making it difficult to meet high throughput requirements. They also lack flexibility in complex or multi-step processes, resulting in poor process consistency and difficulty in ensuring plasma uniformity and stability.
The plasma generation device, which adopts a multi-chamber design, uniformly disperses process gas into multiple plasma generation chambers through a gas delivery component, and uses an electromagnetic field generator to excite plasma, thereby improving processing efficiency and uniformity.
It improves the processing efficiency of process gases, ensures the uniformity and stability of plasma, and enhances process consistency and production efficiency.
Smart Images
Figure CN224192116U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of plasma processing technology, and in particular to a gas delivery component and a plasma generation device. Background Technology
[0002] Remote Plasma Source (RPS) systems are a widely used technology in semiconductor manufacturing, material surface treatment, and thin film deposition. Traditional RPS systems typically generate plasma through a single plasma generation chamber and then deliver it to the target area for processing. However, this single-chamber design has certain limitations: First, the plasma generation capacity of a single plasma generation chamber is limited, resulting in low processing efficiency and difficulty in meeting the high throughput requirements of large-scale production. Second, single-chamber systems lack flexibility when handling complex or multi-step processes, potentially leading to poor process consistency or low production efficiency. Furthermore, with the continuous miniaturization of semiconductor devices and the increasing complexity of processes, the requirements for plasma uniformity, stability, and controllability are becoming increasingly stringent, posing significant challenges to traditional single-chamber RPS systems in these aspects. Utility Model Content
[0003] The main purpose of this invention is to propose a gas delivery component and a plasma generation device, which aims to solve the problem of low efficiency in the traditional RPS system for process gas handling.
[0004] To achieve the above objectives, the gas delivery assembly proposed in this utility model is applied to a plasma generating device, the plasma generating device including a plasma generating body having multiple spaced-apart plasma generating chambers, and the gas delivery assembly including:
[0005] A first connecting plate, the first connecting plate being provided with an air intake channel; and
[0006] The second connecting plate is located on the side of the first connecting plate close to the plasma generating body and is connected to the first connecting plate to form a diffusion chamber. One end of the air intake channel is used to communicate with an external air source, and the other end of the air intake channel is communicated with the diffusion chamber.
[0007] The side of the second connecting plate away from the first connecting plate is used to connect to the plasma generating body. The second connecting plate is provided with a plurality of gas diffusion ports that communicate with the diffusion chambers. Each gas diffusion port is used to communicate with one of the plasma generating chambers.
[0008] In one embodiment, the plasma generating chamber is provided with an air inlet at one end near the second connecting plate, and the second connecting plate is provided with a diffuser for each air inlet of the plasma generating chamber. Each diffuser is provided with a plurality of exhaust holes, and the plurality of exhaust holes form the gas diffuser.
[0009] In one embodiment, a plurality of exhaust holes on each of the diffusion sections corresponding to a plasma generation chamber are evenly distributed within the air inlet area of the plasma generation chamber.
[0010] In one embodiment, the axial direction of the plasma generation chamber is parallel to the axial direction of the exhaust port.
[0011] In one embodiment, each of the diffusion sections is provided with the same number of exhaust holes, so that the process gas entering the diffusion chamber along the air inlet channel is uniformly delivered from the multiple exhaust holes to the multiple plasma generation chambers.
[0012] In one embodiment, the diffusion chamber has a regular shape, the projection of the air inlet channel on the second connecting plate is located at the center of the diffusion chamber, and the second connecting plate is provided with a plurality of gas diffusion ports evenly distributed around the air inlet channel so that the plurality of plasma generation chambers of the plasma generation body are correspondingly connected.
[0013] In one embodiment, the first connecting plate and the second connecting plate are sealed together.
[0014] In one embodiment, the gas delivery assembly further includes a sealing element, which is an annular sealing ring. An installation groove is provided around the diffusion chamber on the first connecting plate or the second connecting plate, and the annular sealing ring is embedded in the installation groove and abuts against the first connecting plate and the second connecting plate.
[0015] In one embodiment, the air inlet of each plasma generation chamber is sealed to the second connecting plate.
[0016] This utility model also proposes a plasma generating device, including a plasma generating body, an electromagnetic field generating device, and a gas delivery assembly as described in any of the foregoing embodiments. The plasma generating body has a plurality of spaced-apart plasma generating chambers. The gas delivery assembly is disposed on the plasma generating body so that each plasma generating chamber is connected to at least one gas diffusion port. The electromagnetic field generating device is disposed on the plasma generating body and is used to generate an alternating magnetic field in each plasma generating chamber to excite the process gas in the plasma generating chamber to generate plasma.
[0017] The plasma generation device of this utility model adopts a multi-chamber design and improves processing efficiency by uniformly dispersing process gas into each chamber through a gas delivery assembly. Specifically, the gas delivery assembly is used in the plasma generation device, which includes a plasma generation body with multiple spaced-apart plasma generation chambers. The gas delivery assembly includes a first connecting plate and a second connecting plate. The first connecting plate has an inlet channel. The second connecting plate is connected to the first connecting plate and encloses it to form a diffusion chamber. One end of the inlet channel is connected to an external gas source, and the other end is connected to the diffusion chamber. The plasma generation body is located on the side of the second connecting plate away from the first connecting plate. The second connecting plate has gas diffusion ports that correspond one-to-one with the multiple plasma generation chambers. The process gas provided by the external gas source enters the diffusion chamber through the inlet channel and is then uniformly dispersed into the multiple plasma generation chambers through the multiple gas diffusion ports to be excited and generate plasma. This structure can improve the processing efficiency of process gas. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0019] Figure 1 A schematic diagram of the assembly structure of the gas delivery component and the plasma generating body in one embodiment of the plasma generating device provided by this utility model;
[0020] Figure 2 A top view of the gas delivery assembly and the plasma generating body in one embodiment of the plasma generating device provided by this utility model;
[0021] Figure 3 for Figure 2 A cross-sectional view along the AA direction;
[0022] Figure 4 for Figure 3 A magnified view of a portion of the image;
[0023] Figure 5 A schematic diagram of the structure of the second connecting plate in one embodiment of the gas delivery assembly provided by this utility model;
[0024] Figure 6 This is a schematic diagram of an embodiment of the plasma generating device provided by this utility model.
[0025] Explanation of icon numbers:
[0026] 100. Plasma generating device; 110. Plasma generating main body; 111. Plasma generating chamber; 112. Connecting plate;
[0027] 200. Plasma excitation assembly;
[0028] 300, Gas delivery assembly; 300a, Diffusion chamber; 310, First connecting plate; 310a, Inlet channel; 320, Second connecting plate; 321, Gas diffuser port; 322, Diffusion section; 323, Exhaust port; 324, Mounting groove; 325, Limiting groove.
[0029] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0031] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0032] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0033] This utility model proposes a gas delivery assembly 300.
[0034] Please see Figure 1 In one embodiment of the present invention, the gas delivery assembly 300 is used in a plasma generating device 100. The plasma generating device 100 includes a plasma generating body 110, which has a plurality of spaced-apart plasma generating chambers 111. Further reference... Figure 2 and Figure 3 The gas delivery assembly 300 includes a first connecting plate 310 and a second connecting plate 320. An air inlet channel 310a is provided through the center of the first connecting plate 310. A recessed area is provided on the side of the second connecting plate 320 away from the plasma generating body 110. The second connecting plate 320 and the first connecting plate 310 are connected and enclose the recessed area to form a diffusion chamber 300a. One end of the air inlet channel 310a is connected to an external gas source, and the other end is connected to the diffusion chamber 300a. The external gas source inputs process gas into the diffusion chamber 300a through the air inlet channel 310a.
[0035] Furthermore, the plasma generating body 110 is located on the side of the second connecting plate 320 away from the first connecting plate 310. A gas diffuser 321, corresponding to and communicating with each of the multiple plasma generating chambers 111, is provided through the recessed area of the second connecting plate 320. The process gas supplied by an external gas source enters the diffuser chamber 300a through the inlet channel 310a, disperses, and is evenly distributed from the multiple gas diffusers 321 into the multiple plasma generating chambers 111, where it is excited to generate plasma. Therefore, by increasing the number of plasma generating chambers 111 and providing corresponding gas delivery components 300, the processing efficiency of the process gas can be effectively improved.
[0036] It should be noted that in this embodiment, both the first connecting plate 310 and the second connecting plate 320 are flanges. The second connecting plate 320 is provided with screw holes. Screws or bolts can be used to pass through the first connecting plate 310 and screw into the screw holes of the second connecting plate 320 to fix the two together. The first connecting plate 310 is also provided with screw holes around the air inlet channel 310a to facilitate the connection of an external gas source device. In some other embodiments of this utility model, the first connecting plate 310 and the second connecting plate 320 are designed to form a diffusion chamber 300a. The specific structure is not limited. In addition to bolts, the connection method can also be welding, threaded connection, clamping device, etc. The process gas can be such as silane SiH4, ammonia NH3, argon Ar, etc., and no specific limitation is made here.
[0037] In one embodiment, the plasma generating chamber 111 is provided with an air inlet at one end near the second connecting plate 320. The second connecting plate 320 is provided with a diffuser 322 corresponding to the air inlet of each plasma generating chamber 111. Each diffuser 322 is provided with a plurality of exhaust holes 323, and the plurality of exhaust holes 323 form a gas diffuser 321.
[0038] like Figures 1 to 3 As shown, in one embodiment of this utility model, the sidewall of the plasma generating chamber 111 is made of ceramic and has a hollow tubular structure, with an air inlet at its upper end. A diffuser 322 is respectively provided on the second connecting plate 320 corresponding to the air inlet of each plasma generating chamber 111. Further reference... Figure 4 and Figure 5 Each diffuser 322 has multiple exhaust holes 323 extending through it. Each exhaust hole 323 is connected at both ends to a diffusion chamber 300a and a plasma generation chamber 111, respectively. The multiple exhaust holes 323 form a gas diffusion port 321. In some other embodiments of this invention, the sidewalls of the plasma generation chamber 111 may also be made of insulating materials such as quartz, which can be selected according to actual needs and is not specifically limited here.
[0039] Understandably, each gas diffuser 321 is provided with multiple exhaust holes 323, which can diffuse the process gas and uniformly enter the plasma generation chamber 111, thereby ensuring that the collision between the atmospheric gas or reactive gas and electrons is more uniform during the plasma generation process, improving the stability and uniformity of the plasma. The gas diffuser 321 can also adjust the concentration and flow rate of the gas in the plasma generation chamber 111 to optimize the chemical reaction and physical properties of the plasma and enhance the process effect.
[0040] In one embodiment, a plurality of exhaust holes 323 on each diffuser 322 corresponding to a plasma generation chamber 111 are evenly distributed within the air inlet area of the plasma generation chamber 111.
[0041] like Figure 5 As shown, in one embodiment of the present invention, the plurality of exhaust holes 323 of each diffuser 322 are uniformly distributed within the air inlet range of the corresponding plasma generation chamber 111. The aperture size of each exhaust hole 323 is the same, so that the process gas entering the plasma generation chamber 111 is uniformly distributed in the plasma generation chamber 111. The diffused gas helps to reduce the excessive accumulation of gas in certain areas of the chamber, thereby avoiding overheating or excessively high concentration in local areas and reducing plasma instability caused by local non-uniformity.
[0042] In one embodiment, the axial direction of the plasma generation chamber 111 is arranged parallel to the axial direction of the exhaust port 323.
[0043] like Figure 1 and Figure 5 As shown, in one embodiment of this utility model, the plasma generating body 110 has a plurality of cylindrical plasma generating chambers 111, and each exhaust port 323 on the second connecting plate 320 is also a cylindrical structure and its axis is arranged parallel to the axis of the plasma generating chamber 111, so that the process gas enters the plasma generating chamber 111 along the axial direction and flows in the same direction. When installed and used, the axial direction of the plasma generating chamber 111 and the exhaust port 323 is perpendicular to the horizontal plane.
[0044] It is understandable that a circular chamber, due to its symmetry, can achieve a more uniform gas distribution, avoiding gas accumulation or uneven distribution within the chamber. The gas can diffuse uniformly along the radial direction of the orifice, which helps to improve the interaction between the gas and the plasma, ensuring the density and uniformity of the plasma. It should be noted that in some other embodiments of this utility model, the cross-sectional shape of the plasma generating chamber 111 and the exhaust port 323 can also be hexagonal, octagonal, elliptical, etc., and can be designed according to actual needs, without specific limitations here.
[0045] In one embodiment, each diffuser 322 is provided with a plurality of exhaust holes 323 of the same number, so that the process gas entering the diffuser chamber 300a along the intake channel 310a is uniformly delivered from the plurality of exhaust holes 323 to the plurality of plasma generation chambers 111.
[0046] like Figure 5 As shown, in one embodiment of this utility model, the multiple exhaust holes 323 of each diffuser 322 form a gas diffusion port 321. The number of gas diffusion ports 321 on the second connecting plate 320 is the same as the number of plasma generation chambers 111. In order to control the flow rate of the process gas entering each plasma generation chamber 111 and to make the gas diffuse evenly, the number and arrangement of exhaust holes 323 provided on each diffuser 322 are also the same, which facilitates precise control of the flow rate of the process gas entering each plasma generation chamber 111, thereby improving the consistency of the process.
[0047] In one embodiment, the diffusion chamber 300a has a regular shape, and the projection of the air inlet channel 310a on the second connecting plate 320 is located at the center of the diffusion chamber 300a. The second connecting plate 320 is provided with a plurality of gas diffusion ports 321 evenly distributed around the air inlet channel 310a, so that the plurality of plasma generation chambers 111 of the plasma generation body 110 are correspondingly connected.
[0048] like Figures 2 to 5 As shown, in one embodiment of this utility model, the diffusion chamber 300a has a regular shape. For details, please refer to [reference needed]. Figure 4 and Figure 5 A regular groove-shaped area is formed by a recess on the side of the second connecting plate 320 near the first connecting plate 310. When the first connecting plate 310 is placed on the second connecting plate 320, the groove of this area is closed to form a diffusion chamber 300a. The projection of the air intake channel 310a of the first connecting plate 310 on the second connecting plate 320 is located at the center of the diffusion chamber 300a. Three gas diffusion ports 321 are evenly distributed in the diffusion chamber 300a and arranged around the air intake channel 310a. The line connecting the three gas diffusion ports 321 forms an isosceles triangle structure. The air intake channel 310a is located at the center of the isosceles triangle, that is, the distance between each gas diffusion port 321 and the air intake channel 310a is equal.
[0049] It is understandable that the regular shape of the diffusion chamber 300a and the central air inlet channel 310a make the process gas entering the diffusion chamber 300a flow more uniformly to each gas diffuser 321, and can control the process gas flow rate entering each plasma generation chamber 111 to be equal. When the gas flow rate is uniform and the distribution is consistent, the plasma density and characteristics in each plasma generation chamber 111 can also be kept consistent. During the entire reaction process, there will be no phenomenon of local plasma being too strong or too weak, avoiding the gas concentration in some chambers being too high or too low, and further improving the uniformity and efficiency of the process reaction.
[0050] In some other embodiments of this utility model, the gas diffuser 321 can be two, four, five or other numbers, and there is no specific limitation. Multiple gas diffusers 321 can be evenly distributed around the circumference of the air intake channel 310a. The number of plasma generation chambers 111 is the same as the number of gas diffusers 321 and they are connected in a one-to-one correspondence.
[0051] In one embodiment, the first connecting plate 310 and the second connecting plate 320 are sealed together.
[0052] like Figure 4 and Figure 5 As shown, in one embodiment of this invention, to prevent process gas leakage in the diffusion chamber 300a and maintain the vacuum environment of the plasma generation chamber 111, the first connecting plate 310 and the second connecting plate 320 are sealed together. The sealing method can be welding, or the use of sealing elements such as gaskets, corrugated gaskets, O-rings, etc., with the sealing elements clamped by the first connecting plate 310 and the second connecting plate 320. Sealing the diffusion chamber 300a ensures that the pressure inside the plasma generation chamber 111 is maintained within the required range. Plasma generation depends on low-pressure conditions, and the vacuum environment can effectively remove unwanted gases and generate charged particles such as electrons and ions, as well as active groups.
[0053] In one embodiment, the gas delivery assembly 300 further includes a sealing element, which is an annular sealing ring. An installation groove 324 is provided around the diffusion chamber 300a on the first connecting plate 310 or the second connecting plate 320. The annular sealing ring is embedded in the installation groove 324 and abuts against the first connecting plate 310 and the second connecting plate 320.
[0054] In one embodiment of this utility model, the gas delivery assembly 300 further includes a sealing element, specifically, an annular sealing ring (not shown), such as... Figure 4 and Figure 5 As shown, a mounting groove 324 is formed around the diffusion chamber 300a on the second connecting plate 320, and the seal is embedded in the mounting groove 324. When the first connecting plate 310 is connected to the second connecting plate 320, it abuts against the seal.
[0055] It is understandable that the structure using an annular sealing ring and the mounting groove 324 is relatively simple, easy to install, and provides a good sealing effect. In some other embodiments of this utility model, the mounting groove 324 is provided on the first connecting plate 310, or the first connecting plate 310 and the second connecting plate 320 are respectively provided with grooves for installing the sealing element. The specific structure can be designed according to the requirements.
[0056] In one embodiment, the air inlet of each plasma generation chamber 111 is sealed to the second connecting plate 320.
[0057] like Figure 3 and Figure 4 As shown, in one embodiment of this utility model, a plurality of limiting grooves 325 are provided on the side of the second connecting plate 320 away from the first connecting plate 310. The hollow ceramic tube forming each plasma generation chamber 111 on the plasma generation body 110 has one end of its air inlet inserted into the limiting groove 325 and sealed by a rubber ring (not shown) to ensure the high vacuum environment required by the plasma generation chamber 111 and prevent gas leakage.
[0058] This utility model also proposes a plasma generating device 100, which includes a plasma generating body 110, an electromagnetic field generating device, and a gas delivery component 300 as described in any of the foregoing embodiments. The specific structure of the gas delivery component 300 is as described in the above embodiments. Since this plasma generating device 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.
[0059] Among them, such as Figure 6As shown, the plasma generating body 110 has multiple plasma generating chambers 111 and a gas delivery assembly 300 is provided above it to deliver process gas to the multiple plasma generating chambers 111. The electromagnetic field generating device includes a plasma excitation assembly 200, which is composed of multiple inductors connected in series or in parallel and wound around the outside of the plasma generating chambers 111. It is connected to an external radio frequency (RF) power supply. When the inductors are energized, they generate an alternating magnetic field, which generates an alternating current to excite the process gas in the plasma generating chambers 111 to dissociate and generate plasma.
[0060] Furthermore, the plasma generating body 110 also includes a connecting plate 112, which is located on the side of the plasma generating chamber 111 away from the gas delivery assembly 300. The connecting plate 112 is used to connect to the reaction body, which has a reaction chamber. The outlet ends of the multiple plasma generating chambers 111 are connected to the reaction chamber. The plasma entering the reaction chamber can be used for processes such as thin film deposition, etching, and cleaning. In addition, a conveying component can be provided between the connecting plate 112 and the reaction body to collect the plasma generated by the multiple plasma generating chambers 111 and deliver it to the reaction chamber. The specific structure will not be described in detail here.
[0061] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A gas delivery assembly, used in a plasma generation device, characterized in that, The plasma generating device includes a plasma generating body, the plasma generating body having multiple spaced-apart plasma generating chambers, and the gas delivery assembly includes: A first connecting plate, the first connecting plate being provided with an air intake channel; and The second connecting plate is located on the side of the first connecting plate close to the plasma generating body and is connected to the first connecting plate to form a diffusion chamber. One end of the air intake channel is used to communicate with an external air source, and the other end of the air intake channel is communicated with the diffusion chamber. The side of the second connecting plate away from the first connecting plate is used to connect to the plasma generating body. The second connecting plate is provided with a plurality of gas diffusion ports that communicate with the diffusion chambers. Each gas diffusion port is used to communicate with one of the plasma generating chambers.
2. The gas delivery assembly of claim 1, wherein, The plasma generating chamber has an air inlet at one end near the second connecting plate. The second connecting plate has a diffuser corresponding to the air inlet of each plasma generating chamber. Each diffuser has multiple exhaust holes, and the multiple exhaust holes form the gas diffuser.
3. The gas delivery assembly as described in claim 2, characterized in that, The plurality of exhaust holes on each of the diffusion sections corresponding to a plasma generation chamber are evenly distributed within the air inlet area of the plasma generation chamber.
4. The gas delivery assembly as described in claim 3, characterized in that, The axial direction of the plasma generation chamber is parallel to the axial direction of the exhaust port.
5. The gas delivery assembly of claim 4, wherein, Each of the diffusion sections is provided with the same number of exhaust holes, so that the process gas entering the diffusion chamber along the air inlet channel is uniformly delivered from the multiple exhaust holes to the multiple plasma generation chambers.
6. The gas delivery assembly of any one of claims 1 to 5, wherein, The diffusion chamber has a regular shape, and the projection of the air inlet channel on the second connecting plate is located at the center of the diffusion chamber. The second connecting plate is provided with a plurality of gas diffusion ports evenly distributed around the air inlet channel, so that the plurality of plasma generation chambers of the plasma generation body are correspondingly connected.
7. The gas delivery assembly of claim 1, wherein, The first connecting plate and the second connecting plate are sealed together.
8. The gas delivery assembly of claim 7, wherein, The gas delivery assembly further includes a sealing element, which is an annular sealing ring. An installation groove is provided around the diffusion chamber on the first connecting plate or the second connecting plate, and the annular sealing ring is embedded in the installation groove and abuts against the first connecting plate and the second connecting plate.
9. The gas delivery assembly as claimed in claim 1, characterized in that, The air inlet of each plasma generation chamber is sealed to the second connecting plate.
10. A plasma generating device, characterized by, The device includes a plasma generating body, an electromagnetic field generating device, and a gas delivery assembly as described in any one of claims 1 to 9. The plasma generating body has a plurality of spaced-apart plasma generating chambers. The gas delivery assembly is disposed on the plasma generating body so that each plasma generating chamber is connected to at least one gas diffusion port. The electromagnetic field generating device is disposed on the plasma generating body and is used to generate an alternating magnetic field in each plasma generating chamber to excite the process gas in the plasma generating chamber to generate plasma.