Plasma device

Abstract

This disclosure provides a plasma device, relating to the field of semiconductor equipment technology. The plasma device includes: a dielectric cylinder; a first cover plate, which, together with the dielectric cylinder, forms a plasma generation space; a housing located below the dielectric cylinder; a second cover plate connected to the lower part of the dielectric cylinder and covering the upper part of the housing, forming a workpiece processing space together with the housing; and a grid located between the plasma generation space and the workpiece processing space. At least one of the second cover plate and the grid is provided with multiple accelerating gas channels, and at least two of the accelerating gas channels are spaced apart circumferentially along the plasma device. The accelerating gas provided by the accelerating gas channels is used to accelerate free radicals entering the workpiece processing space from the plasma generation space. Accelerating gas control valves are respectively provided in the accelerating gas inlet pipes connected to the at least two accelerating gas channels spaced apart circumferentially along the plasma device.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor equipment technology, and more particularly to a plasma device. Background Technology

[0002] Plasma equipment based on remote plasma technology is a crucial process tool in semiconductor chip manufacturing. Remote plasma technology generates plasma at a distance from the wafer. As the plasma passes through a grid, the grid eliminates most of the ions in the plasma, reducing ion bombardment of the wafer. The neutralized free radicals in the plasma then continue their journey to the wafer surface to undergo chemical reactions, completing the wafer surface treatment. Currently, improving the uniformity of wafer surface treatment remains a key research topic. Summary of the Invention

[0003] This disclosure provides a plasma device.

[0004] As one aspect of this disclosure, an embodiment provides a plasma device, comprising: a dielectric cylinder; a first cover plate covering the upper part of the dielectric cylinder, forming a plasma generation space together with the dielectric cylinder; a coil disposed on the outside of the dielectric cylinder for exciting process gas in the plasma generation space into plasma; a housing located below the dielectric cylinder; a second cover plate connected to the lower part of the dielectric cylinder and covering the upper part of the housing, forming a workpiece processing space together with the housing; and a grid located between the plasma generation space and the workpiece processing space; wherein at least one of the second cover plate and the grid is provided with a plurality of accelerating gas channels, and at least two of the accelerating gas channels are distributed circumferentially around the plasma device, the accelerating gas provided by the accelerating gas channels is used to accelerate free radicals entering the workpiece processing space from the plasma generation space; wherein accelerating gas control valves are respectively provided in the accelerating gas inlet pipes connected to the at least two accelerating gas channels distributed circumferentially around the plasma device.

[0005] In one embodiment, the axial direction of the outlet of the accelerating gas channel is parallel to the radial direction of the plasma device.

[0006] In one embodiment, the second cover plate is provided with a plurality of accelerating gas channels; the air inlets of the accelerating gas channels provided in the second cover plate are located on the upper surface of the second cover plate; and the air outlets of the accelerating gas channels provided in the second cover plate are located near the lower surface of the second cover plate.

[0007] In one embodiment, the medium cylinder is provided with a clearance hole, which corresponds to the outlet of the accelerating gas channel provided on the second cover plate; the clearance hole and the outlet of the accelerating gas channel provided on the second cover plate are coaxially arranged; the diameter of the clearance hole is larger than the diameter of the outlet of the accelerating gas channel provided on the second cover plate.

[0008] In one embodiment, the lower end face of the medium cylinder is located above the lower end face of the second cover plate, and the outlet of the accelerating gas channel provided on the second cover plate is located below the lower end face of the medium cylinder; the distance between the lower end face of the medium cylinder and the lower end face of the second cover plate is greater than the aperture of the outlet of the accelerating gas channel provided on the second cover plate.

[0009] In one embodiment, the grid includes a first grid plate and a second grid plate distributed along the axial direction of the plasma device, the first grid plate being located above the second grid plate; one of the first grid plate and the second grid plate is provided with a connecting ring extending toward the other, and the connecting ring is located near the edge of the first grid plate; the grid is provided with a plurality of accelerating gas channels, at least a portion of the accelerating gas channels being located on the connecting ring.

[0010] In one embodiment, the air inlet of the accelerating gas channel provided by the grille is located on the upper surface of the first grid plate; the air outlet of the accelerating gas channel provided by the grille is located on the connecting ring.

[0011] In one embodiment, the outlet of the accelerating gas channel provided by the second cover plate is closer to the central axis of the plasma device than the outlet of the accelerating gas channel provided by the grille; the outlet of the accelerating gas channel provided by the second cover plate is located above the outlet of the accelerating gas channel provided by the grille.

[0012] In one embodiment, the outlet of the acceleration gas channel provided by the second cover plate is provided with a first guide pipe; the outlet of the acceleration gas channel provided by the grille is provided with a second guide pipe.

[0013] In one embodiment, the second cover plate and the grille are respectively provided with multiple accelerating gas channels; the accelerating gas inlet pipeline includes branch pipelines and a main pipeline, the main pipeline is connected to an accelerating gas supply device, the main pipeline is connected to at least two of the branch pipelines, one of the branch pipelines is connected to the inlet of one of the accelerating gas channels on the second cover plate, and the other branch pipeline is connected to the inlet of the corresponding accelerating gas channel on the grille; at least two of the main pipelines are respectively provided with accelerating gas control valves, or at least two of the branch pipelines are respectively provided with accelerating gas control valves.

[0014] The embodiments disclosed herein can adjust the velocity of free radicals by controlling the accelerating gas, thereby adjusting the concentration of free radicals reaching different regions of the workpiece surface and ensuring the uniformity of free radicals reaching the workpiece surface.

[0015] The above overview is for illustrative purposes only and is not intended to be limiting in any way. Further aspects, embodiments, and features of this disclosure will become readily apparent from the accompanying drawings and the following detailed description, in addition to the illustrative aspects, embodiments, and features described above. Attached Figure Description

[0016] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this disclosure and should not be construed as limiting the scope of this disclosure.

[0017] Figure 1 A schematic diagram of the structure of a plasma device according to an embodiment of the present disclosure is shown; Figure 2 A schematic diagram of the structure of the second cover plate according to an embodiment of the present disclosure is shown. Figure 1 ; Figure 3 A schematic diagram of the structure of the second cover plate according to an embodiment of the present disclosure is shown. Figure 2 ; Figure 4 A schematic diagram of the structure of a grille according to an embodiment of the present disclosure is shown. Figure 1 ; Figure 5 A schematic diagram of the structure of a grille according to an embodiment of the present disclosure is shown. Figure 2 .

[0018] Explanation of reference numerals in the attached drawings: 10-First cover plate; 20-Dielectric cylinder; 21-Plasma generation space; 30-Coil; 40-Second cover plate; 41-Accelerating gas channel; 411-Inlet; 412-Outlet; 50-Box; 51-Workpiece processing space; 60-Grid; 611-First grid plate; 6111-Connecting ring; 612-Second grid plate; 70-Workpiece; 80-Accelerating gas inlet pipeline; 81-Main pipeline; 82-Branch pipeline. Detailed Implementation

[0019] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0020] Please refer to Figures 1 to 5 This embodiment provides a plasma device, including: a dielectric cylinder 20; a first cover plate 10, which covers the upper part of the dielectric cylinder 20 and together with the dielectric cylinder 20 forms a plasma generation space 21; a coil 30, which is disposed on the outside of the dielectric cylinder 20 and is used to excite the process gas in the plasma generation space 21 into plasma; a housing 50, which is located below the dielectric cylinder 20; a second cover plate 40, which is connected to the lower part of the dielectric cylinder 20 and covers the upper part of the housing 50, together with the housing 50 forming a workpiece processing space 51; and a grid 60, which is located between the plasma generation space 21 and the workpiece processing space 51.

[0021] The second cover plate 40 and the grille 60 are provided with a plurality of accelerating gas channels 41, and at least two of the accelerating gas channels 41 are distributed circumferentially along the plasma device. The accelerating gas provided by the accelerating gas channels 41 is used to accelerate the free radicals entering the workpiece processing space 51 from the plasma generation space 21. The accelerating gas inlet pipes 80 connected to the at least two accelerating gas channels 41 distributed circumferentially along the plasma device are respectively provided with accelerating gas control valves.

[0022] The plasma equipment adopts a vertical layout, which includes a plasma generation area and a workpiece 70 processing area from top to bottom.

[0023] The dielectric cylinder 20 can be made of high-purity quartz, possessing excellent insulation, high-temperature resistance, and chemical stability, making it suitable for high-frequency electromagnetic field environments. The dielectric cylinder 20 can be cylindrical. The cylinder surface is smooth to reduce gas turbulence and contaminant accumulation. The dielectric cylinder 20 serves as the sidewall of the plasma generation space 21, isolating the coil 30 from the internal process gas while allowing electromagnetic field penetration to excite the process gas and generate plasma.

[0024] The first cover plate 10 is a circular plate, which covers the upper end of the dielectric cylinder 20 to form the plasma generation space 21. A sealing ring is provided between the first cover plate 10 and the dielectric cylinder 20 to ensure the airtightness of the plasma generation space 21. The first cover plate 10 can be made of metal to facilitate the formation of cooling channels within it. A protective layer can be provided on the lower surface of the first cover plate 10 facing the plasma generation space 21 to prevent it from being corroded by process gases or plasma.

[0025] The first cover plate 10 has a process gas inlet at its center, which is connected to a process gas supply device for introducing process gases, such as a mixture of argon, oxygen, or nitrogen. A flow meter and regulating valve can be installed at the process gas inlet to precisely control the flow rate of the process gas.

[0026] Coil 30 can be made of copper and is wound in a spiral shape around the outer wall of dielectric cylinder 20. Both ends of coil 30 are connected to an RF power supply. When coil 30 is energized, it generates an alternating electromagnetic field that penetrates the wall of dielectric cylinder 20, ionizing the process gas in plasma generation space 21 into plasma.

[0027] A Faraday cage may be installed between the coil 30 and the dielectric cylinder 20. The Faraday cage, made of a conductive material such as stainless steel or aluminum, is a cylindrical cover with multiple axially extending gaps. These axial gaps are uniformly distributed along the circumference of the dielectric cylinder 20. The primary function of the Faraday cage is to shield against electromagnetic interference.

[0028] The housing 50 is connected to the second cover plate 40, forming a relatively enclosed workpiece processing space 51 to ensure that the processing is not affected by external contamination. The housing 50 has side walls and a bottom wall connected to the bottom of the side walls. One side wall of the housing 50 may be provided with an observation window. An exhaust port may also be provided on either the side wall or the bottom wall of the housing 50, and the exhaust port is connected to a vacuum pump. A support device for placing the workpiece 70 may also be provided inside the housing 50.

[0029] The second cover plate 40 is installed on the top of the housing 50. The second cover plate 40 is also connected to the bottom of the medium cylinder 20. A sealing ring is provided between the second cover plate 40 and the medium cylinder 20, and a sealing ring is also provided between the second cover plate 40 and the housing 50.

[0030] The second cover plate 40 and the housing 50 can be made of lightweight and corrosion-resistant aluminum alloy to achieve high mechanical strength. However, the materials of the first cover plate 10, the second cover plate 40, and the housing 50 are not limited to these; they can be selected according to actual needs. Additionally, a cooling channel can be provided inside the second cover plate 40.

[0031] The grid 60 is a mesh plate. The grid 60 has a plurality of evenly distributed through holes. The grid 60 is typically fixed at the connection between the plasma generation space 21 and the workpiece processing space 51. For example, the grid 60 is connected to the lower surface of the second cover plate 40. The opening area of ​​the grid 60 needs to cover the central hole of the second cover plate 40. The grid 60 is used to allow free radicals and small molecules to pass through while blocking large particles or high-energy ions in the plasma.

[0032] The accelerating gas channel 41 can be located at the connection between the plasma generation space 21 and the workpiece processing space 51, and is used to accelerate free radicals in the plasma from the plasma generation space 21. The accelerating gas channel 41 can be located on the second cover plate 40 or on the grid 60.

[0033] For example, at least two accelerating gas channels 41 are distributed circumferentially along the plasma device to ensure that the accelerating gas covers the entire periphery of the workpiece processing space 51 and avoids uneven processing.

[0034] Independent acceleration gas control valves are installed in the acceleration gas inlet pipes 80 connected to at least two acceleration gas channels 41. Optionally, an electric mass flow controller (MFC) can be used as the acceleration gas control valve to precisely adjust the flow rate of the acceleration gas, achieve differentiated control of gas flow in different areas, optimize the distribution and intensity of the acceleration gas, adapt to different workpiece shapes or processing requirements, and achieve homogenization or local enhancement of free radical concentration within the workpiece processing space 51, thereby enhancing process flexibility and uniformity.

[0035] For example, eight acceleration gas channels 41 are opened at intervals in the circumferential direction of the second cover plate 40, and independent acceleration gas control valves are installed in the acceleration gas inlet pipes 80 connected to the eight acceleration gas channels 41.

[0036] For example, eight acceleration gas channels 41 are spaced apart in the circumferential direction of the grille 60. Each of the eight acceleration gas channels 41 is connected to an acceleration gas intake pipe 80, and an independent acceleration gas control valve is installed in each of them.

[0037] For example, multiple accelerating gas channels 41 are provided on the second cover plate 40 and the grille 60 along the circumferential direction. The accelerating gas channels 41 located on the second cover plate 40 and the accelerating gas channels 41 located on the grille 60 can be staggered or correspondingly arranged.

[0038] The workflow of the plasma equipment provided in this embodiment is as follows: The workpiece 70 is placed on the support device inside the housing 50, and the housing 50 is closed and sealed. The vacuum pump is started, and the workpiece processing space 51 is evacuated to the basic pressure through the evacuation port. Process gas is introduced into the plasma generation space 21 through the process gas inlet. The radio frequency power supply is turned on, and the coil 30 excites the process gas to generate plasma, producing a large number of free radicals. The free radicals enter the workpiece processing space 51 through the grid 60, and simultaneously, accelerating gas is injected through the accelerating gas channel 41. This accelerates the free radicals flowing from the plasma generation space 21 to the workpiece processing space 51, mixing them and applying kinetic energy to adjust their velocity. After reaching the surface of the workpiece 70, the free radicals undergo a physical or chemical reaction with it. The processing time can be set according to process requirements (e.g., 2-10 minutes). During the process, the processing status is monitored through the observation window, and the accelerating gas valve is adjusted as necessary to optimize uniformity. After processing, the radio frequency power supply and gas supply are turned off, inert gas is introduced for rinsing, and the workpiece 70 is removed after restoring normal pressure.

[0039] The plasma device provided in this embodiment has multiple accelerating gas channels 41 provided in at least one of the second cover plate 40 and the grid 60, and at least two of the accelerating gas channels 41 are distributed circumferentially along the plasma device. The accelerating gas provided by the accelerating gas channels 41 is used to accelerate the free radicals entering the workpiece processing space 51 from the plasma generation space 21. The accelerating gas inlet pipes 80 connected to the at least two accelerating gas channels 41 distributed circumferentially along the plasma device are respectively provided with accelerating gas control valves. In this way, the speed of the free radicals can be adjusted by controlling the accelerating gas, and the concentration of free radicals reaching different areas of the workpiece 70 surface can be adjusted, thereby ensuring the uniformity of the free radicals reaching the workpiece 70 surface and improving the uniformity of the workpiece 70 processing effect.

[0040] In some embodiments, the axial direction of the outlet 412 of the accelerating gas channel 41 is parallel to the radial direction of the plasma device. Exemplarily, at least a portion of the accelerating gas channel 41 extends radially inward along the second cover plate 40 (or grille 60) until it penetrates the inner edge of the second cover plate 40 (or grille 60). The end of the accelerating gas channel 41 from which gas is discharged forms an outlet 412. The central axis of each outlet 412 is horizontal and parallel to the radial direction of the second cover plate 40 (or grille 60).

[0041] In this embodiment, the free radicals diffusing downwards from the plasma generation space 21 have a downward velocity component. The radially injected accelerating gas can cross-mix with the downward-drifting free radicals. Through momentum transfer, the accelerating gas can more effectively provide the free radicals with a horizontal acceleration pointing towards the central axis of the plasma device, thereby pushing more free radicals in the direction towards the central axis of the plasma device, thus adjusting the horizontal velocity of the free radicals. Since the outlet 412 is axially parallel to the radial direction, when the accelerating gas flow rate at different locations is independently adjusted by the accelerating gas control valve, the free radical concentration in the corresponding area on the surface of the workpiece 70 can be directly changed. This allows more free radicals to become active in areas with low free radical concentration on the surface of the workpiece 70, improving the uniformity of the processing effect of the workpiece 70.

[0042] In some embodiments, a plurality of accelerating gas channels 41 are evenly distributed along the circumference of the plasma device, thereby forming a symmetrical air intake pattern in the circumference of the plasma device.

[0043] In some examples, the second cover plate 40 is provided with eight accelerating gas channels 41, which are evenly arranged along the circumference of the second cover plate 40. The angle between the center lines of two adjacent accelerating gas channels 41 at the center of the plasma device is 45 degrees.

[0044] In other examples, the grid 60 is provided with eight accelerating gas channels 41, which are evenly arranged along the circumference of the grid 60. The angle between the center lines of two adjacent accelerating gas channels 41 at the center of the plasma device is 45 degrees.

[0045] In some other examples, the second cover plate 40 is provided with eight circumferentially distributed acceleration gas channels 41, and the grille 60 is provided with eight circumferentially distributed acceleration gas channels 41.

[0046] In some embodiments, the second cover plate 40 is provided with a plurality of accelerating gas channels 41. The air inlet 411 of the accelerating gas channel 41 provided in the second cover plate 40 is located on the upper surface of the second cover plate 40; the air outlet 412 of the accelerating gas channel 41 provided in the second cover plate 40 is located near the lower surface of the second cover plate 40.

[0047] Each air inlet 411 is connected to the acceleration gas intake pipe 80 via a quick-connect fitting and is sealed to ensure airtightness at the connection point with the pipe.

[0048] For example, the accelerating gas passage 41 of the second cover plate 40 includes a vertical section and a horizontal section. The vertical section starts from the air inlet 411 on the upper surface and extends downward through most of the thickness of the second cover plate 40; the horizontal section starts from the lower end of the vertical section, extends inward, and passes through the second cover plate 40. The vertical section and the horizontal section are connected by a smooth arc segment.

[0049] In this embodiment, when the temperature of the introduced accelerating gas is room temperature or lower, it can effectively remove some of the heat from the second cover plate 40, thus assisting in cooling the second cover plate 40. Moreover, through the above arrangement, the accelerating gas channel 41 provided in the second cover plate 40 can provide a longer gas flow path, thereby improving the cooling effect.

[0050] In some examples, the medium cylinder 20 is provided with a clearance hole, which corresponds to the outlet 412 of the acceleration gas channel 41 provided on the second cover plate 40.

[0051] On the lower side wall of the medium cylinder 20, a clearance hole is provided corresponding to the outlet 412 of the accelerating gas channel 41 on each of the second cover plates 40. The clearance hole is a straight hole with its axis parallel to the radial direction of the plasma device. The clearance hole can be coaxially arranged with the corresponding outlet 412 on the second cover plate 40.

[0052] In the working environment, the accelerating gas enters from the upper surface of the second cover plate 40, is ejected along the radially parallel outlet 412, and immediately passes through the clearance hole on the side wall of the medium cylinder 20, and is sprayed in the direction toward the central axis of the plasma device.

[0053] The diameter of the clearance hole can be 2 to 5 times the diameter of the outlet 412 of the acceleration gas channel 41 provided on the second cover plate 40. For example, the diameter of the clearance hole can be 2, 2.5, 3, 3.5, 4, 4.5, or 5 times the diameter of the outlet 412 of the acceleration gas channel 41 provided on the second cover plate 40.

[0054] In this embodiment, by providing clearance holes on the medium cylinder 20, it is ensured that the accelerating gas flowing out from the internal channel of the second cover plate 40, which has a specific radial direction, can be sprayed without deflection or obstruction along the direction toward the central axis of the plasma device, avoiding scattering, turbulence, or backflow caused by the gas impacting the wall of the medium cylinder 20 at the outlet. The diameter of the clearance hole is larger than that of the outlet 412, which allows for manufacturing errors, assembly errors, and thermal deformation, reducing or even preventing the accelerating gas ejected from the outlet 412 from scraping against the wall of the clearance hole.

[0055] In other embodiments, the lower end face of the medium cylinder 20 is located above the lower end face of the second cover plate 40, and the outlet 412 of the accelerating gas channel 41 provided on the second cover plate 40 is located below the lower end face of the medium cylinder 20. The distance between the lower end face of the medium cylinder 20 and the lower end face of the second cover plate 40 is greater than the aperture of the outlet 412 of the accelerating gas channel 41 provided on the second cover plate 40. For example, the radial center plane of the gap between the lower end face of the medium cylinder 20 and the lower end face of the second cover plate 40 passes through the outlet 412 of the accelerating gas channel 41 provided on the second cover plate 40.

[0056] By providing clearance holes on the medium cylinder 20, it is ensured that the accelerated gas flowing out from the internal channel of the second cover plate 40 with a specific radial direction can be sprayed without deflection or obstruction along the direction toward the central axis of the plasma device, thus avoiding scattering, turbulence or backflow caused by the gas hitting the wall of the medium cylinder 20 at the outlet.

[0057] In some examples, the outlet 412 of the acceleration gas channel 41 provided by the second cover plate 40 is provided with a first guide pipe, at least a portion of which extends into the clearance hole or into the gap between the lower end face of the medium cylinder 20 and the lower end face of the second cover plate 40.

[0058] The first guide tube is a slender tubular component. The first guide tube is a straight, round tube. The first guide tube is made of a chemically stable material resistant to plasma corrosion, such as a high-purity alumina ceramic tube, a quartz tube, or an anodized aluminum alloy tube.

[0059] The first guide tube is fixedly installed at the outlet 412 of the gas passage 41 of the second cover plate 40. Specifically, it can be achieved by pressing in with an interference fit, or by designing a small socket step at the outlet 412 and bonding it with high-temperature ceramic adhesive.

[0060] The grille 60 has an opening area with several through holes. The outlet end of the first guide pipe is located at the periphery of the opening area.

[0061] In this embodiment, the first guide tube provides a confined channel for the accelerating gas, delaying the free diffusion of the accelerating gas and ensuring that the accelerating gas is injected in a highly concentrated state parallel to the radial direction.

[0062] In some embodiments, the grid 60 includes a first grid plate 611 and a second grid plate 612 distributed along the axial direction of the plasma device, with the first grid plate 611 located above the second grid plate 612. One of the first grid plate 611 and the second grid plate 612 is provided with a connecting ring 6111 extending toward the other, and the connecting ring 6111 is disposed near the edge of the first grid plate 611.

[0063] The perforated areas of both the first grid plate 611 and the second grid plate 612 have through holes that allow free radicals to pass through. The size, shape, or distribution of the through holes on the two grid plates may be the same or different.

[0064] The first mesh plate 611 is provided with a downwardly extending connecting ring 6111, which is located on the periphery of the opening area, for example, the connecting ring 6111 is located near the outer edge of the first mesh plate 611. Alternatively, the second mesh plate 612 is provided with an upwardly extending connecting ring 6111, which is located on the periphery of the opening area, for example, the connecting ring 6111 is located near the outer edge of the second mesh plate 612.

[0065] The grille 60 is provided with a plurality of accelerating gas passages 41. At least a portion of the accelerating gas passages 41 are located on the connecting ring 6111 to ensure that the outlets 412 of the accelerating gas passages 41 provided by the grille 60 are parallel to the radial direction.

[0066] In some examples, the inlet 411 of the accelerating gas passage 41 of the grille 60 is located on the upper surface of the first mesh plate 611. The outlet 412 of the accelerating gas passage 41 of the grille 60 is located on the connecting ring 6111. In this way, the accelerating gas passage 41 of the grille 60 can also provide a longer flow path for accelerating gases at room temperature or low temperature.

[0067] In some examples, the outlet 412 of the accelerating gas channel 41 provided on the second cover plate 40 is closer to the central axis of the plasma device than the outlet 412 of the accelerating gas channel 41 provided on the grille 60. The outlet 412 of the accelerating gas channel 41 provided on the second cover plate 40 is located above the outlet 412 of the accelerating gas channel 41 provided on the grille 60.

[0068] The accelerating gas ejected from the second cover plate 40 can directly and efficiently act on the downward-moving free radicals. This accelerating gas initially guides the free radicals to move in the direction toward the central axis of the plasma device.

[0069] The accelerating gas ejected from the grid 60 plays a certain role in rectifying and encapsulating the fluid flowing from the first grid plate 611 to the second grid plate 612, which helps to optimize the convergence flow field of free radicals, reduce radial diffusion loss, and further guide the free radical flow to move towards the central axis of the plasma device.

[0070] In some embodiments, the outlet 412 of the acceleration gas passage 41 provided in the grille 60 is provided with a second guide pipe.

[0071] The second guide tube is a slender tubular component. It is a straight, round tube. The second guide tube is made of a chemically stable material resistant to plasma corrosion, such as a high-purity alumina ceramic tube, a quartz tube, or an anodized aluminum alloy tube.

[0072] The second guide tube is fixedly installed at the outlet 412 of the acceleration gas channel 41 of the grille 60. Specifically, it can be achieved by pressing it in with an interference fit, or by designing a small socket step at the outlet 412 and bonding it with high-temperature ceramic adhesive. The outlet end of the second guide tube is located at the periphery of the opening area.

[0073] In this embodiment, the second guide tube provides a confined channel for the accelerating gas, delaying the free diffusion of the accelerating gas and ensuring that the accelerating gas is injected in a highly concentrated state parallel to the radial direction.

[0074] In some embodiments, the second cover plate 40 and the grille 60 are each provided with a plurality of accelerating gas channels 41. In the axial direction, the accelerating gas channels 41 of the second cover plate 40 correspond to the accelerating gas channels 41 of the grille 60. That is, on a preset horizontal plane, the orthographic projection of the accelerating gas channels 41 of the second cover plate 40 coincides with the orthographic projection of the accelerating gas channels 41 of the grille 60.

[0075] To simplify the gas path structure, the acceleration gas intake pipe 80 includes branch pipes 82 and a main pipe 81. The main pipe 81 is connected to the acceleration gas supply device. The main pipe 81 is connected to at least two branch pipes 82. One branch pipe 82 is connected to the air inlet 411 of one of the acceleration gas channels 41 on the second cover plate 40, and the other branch pipe 82 is connected to the air inlet 411 of the corresponding acceleration gas channel 41 on the grille 60.

[0076] For example, taking the second cover plate 40 and the grille 60 as having eight accelerating gas channels 41 respectively, the accelerating gas supply device can be connected to eight main pipelines 81. Each of the eight main pipelines 81 is connected to two branch pipelines 82, and the two branch pipelines 82 are respectively connected to two corresponding accelerating gas channels 41 along the axial direction. The accelerating gas control valve can be installed on each main pipeline 81 to individually control the concentration of free radicals in different areas of the workpiece 70 surface while also considering cost. Of course, in other examples, the accelerating gas control valve can be installed on each branch pipeline 82.

[0077] The accelerating gas supply device and the process gas supply device can be the same device or different devices.

[0078] Other configurations of the plasma device in the above embodiments can be derived from various technical solutions now and in the future known to those skilled in the art, and will not be described in detail here.

[0079] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0080] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means two or more, unless otherwise explicitly specified.

[0081] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0082] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0083] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements have been described above. Of course, these are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0084] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this disclosure, and these should all be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A plasma device, characterized in that, include: Medium cylinder; The first cover plate is installed on the upper part of the dielectric cylinder, and together with the dielectric cylinder, they form a plasma generation space; A coil, disposed on the outside of the dielectric cylinder, is used to excite the process gas in the plasma generation space into plasma; The housing is located below the medium cylinder; The second cover plate is connected to the lower part of the medium cylinder and covers the upper part of the box body, together with the box body forming a workpiece processing space; A grid is located between the plasma generation space and the workpiece processing space; The second cover plate and the grid are provided with a plurality of accelerating gas channels, and at least two of the accelerating gas channels are distributed at circumferential intervals along the plasma device. The accelerating gas provided by the accelerating gas channels is used to accelerate free radicals entering the workpiece processing space from the plasma generation space. At least two of the accelerating gas channels, which are circumferentially spaced along the plasma device, are connected to accelerating gas inlet pipes, each equipped with an accelerating gas control valve.

2. The plasma device according to claim 1, characterized in that, The axial direction of the outlet of the accelerating gas channel is parallel to the radial direction of the plasma device.

3. The plasma device according to claim 1, characterized in that, The second cover plate is provided with multiple accelerating gas channels; The air inlet of the acceleration gas channel provided in the second cover plate is located on the upper surface of the second cover plate; The outlet of the acceleration gas channel provided in the second cover plate is located near the lower surface of the second cover plate.

4. The plasma device according to claim 3, characterized in that, The medium cylinder is provided with a clearance hole, which corresponds to the outlet of the acceleration gas channel provided on the second cover plate; The clearance hole is coaxially arranged with the outlet of the acceleration gas channel provided on the second cover plate; The diameter of the clearance hole is larger than the diameter of the outlet of the acceleration gas channel provided on the second cover plate.

5. The plasma device according to claim 3, characterized in that, The lower end face of the medium cylinder is located above the lower end face of the second cover plate, and the outlet of the accelerating gas channel provided on the second cover plate is located below the lower end face of the medium cylinder. The distance between the lower end face of the medium cylinder and the lower end face of the second cover plate is greater than the diameter of the outlet of the acceleration gas channel provided on the second cover plate.

6. The plasma device according to claim 3, characterized in that, The grid includes a first grid plate and a second grid plate distributed along the axial direction of the plasma device, with the first grid plate located above the second grid plate; One of the first grid plate and the second grid plate is provided with a connecting ring extending toward the other, and the connecting ring is located close to the edge of the first grid plate; The grille is provided with multiple accelerating gas channels, at least a portion of which are located on the connecting ring.

7. The plasma device according to claim 6, characterized in that, The air inlet of the acceleration gas channel provided by the grille is located on the upper surface of the first grid plate; The outlet of the acceleration gas channel of the grille is located on the connecting ring.

8. The plasma device according to claim 7, characterized in that, The outlet of the accelerating gas channel provided on the second cover plate is closer to the central axis of the plasma device than the outlet of the accelerating gas channel provided on the grille. The outlet of the acceleration gas channel provided on the second cover plate is located above the outlet of the acceleration gas channel provided on the grille.

9. The plasma device according to claim 7, characterized in that, The outlet of the acceleration gas channel provided in the second cover plate is provided with a first guide pipe; The outlet of the acceleration gas channel of the grille is equipped with a second guide pipe.

10. The plasma device according to claim 1, characterized in that, The second cover plate and the grille are each provided with multiple acceleration gas channels; The accelerating gas intake pipeline includes branch pipelines and a main pipeline. The main pipeline is connected to the accelerating gas supply device. The main pipeline is connected to at least two branch pipelines. One branch pipeline is connected to the air inlet of one of the accelerating gas channels on the second cover plate, and the other branch pipeline is connected to the air inlet of the corresponding accelerating gas channel on the grille. At least two of the main pipelines are each equipped with the accelerating gas control valve, or at least two of the branch pipelines are each equipped with the accelerating gas control valve.

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