Electrode assembly and semiconductor pre-cleaning equipment

Abstract

The invention provides an electrode assembly. The electrode assembly comprises a first electrode and a second electrode which are stacked in the vertical direction. The first electrode is located above the second electrode, and a cavity is formed between the first electrode and the second electrode; the first electrode is provided with an air inlet part and an expansion part, the air inlet part is provided with an air inlet, and the air inlet is communicated with the cavity; the expansion part is provided with an upper part and a lower part opposite to the upper part, the upper part of the expansion part is connected with the air inlet part, and the lower part is provided with a lower surface opposite to the second electrode; the expansion part is further provided with an inner wall and an outer wall, the inner wall forms the side wall of the cavity, one end of the outer wall is connected with the air inlet part, and the other end of the outer wall is connected with the lower surface of the expansion part; and a dielectric part is arranged on the lower surface of the extension part and is positioned in a connecting area of the lower surface of the extension part and the outer wall. The electrode assembly provided by the invention can reduce the local high electric field area and improve the electric field intensity uniformity.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to an electrode assembly and semiconductor pre-cleaning equipment. Background Art

[0002] In recent years, remote plasma technology has been widely used in the wafer surface cleaning process in the semiconductor manufacturing process. This process can remove impurities such as silicon dioxide or silicon nitride on the silicon surface with high selectivity.

[0003] In the remote plasma process, plasma is generated in a remote plasma source (RPS), in which plasma and free radicals are generated by exciting process gases in the plasma generation chamber, and only free radicals are transported to the process chamber through the shower plate of the lower electrode. This method can reduce the physical damage to the wafer caused by ion bombardment in the process chamber, and the free radicals generated by the plasma will chemically react with the oxide layer substances to be removed from the surface of the wafer to generate volatile compounds, which are finally decomposed and volatilized by heating. It is a pre-cleaning method with less damage and high cleaning efficiency. In order to stably supply free radicals to the process chamber during the pre-cleaning process, the design of the remote plasma source is crucial.

[0004] Hollow cathode discharge (HCD) is a special discharge process that is commonly used in plasma reactors. When a high voltage electric field is applied to the hollow cathode, electrons are emitted from the surface of the hollow cathode. These electrons collide with gas molecules, causing the ionization of the gas molecules and producing free electrons and cations. The electrons and cations form a discharge region inside the hollow cathode and continue to collide in this region, producing more electrons and cations, thereby expanding the discharge region. In the discharge region, gas molecules react chemically with the free electrons and cations to generate free radicals.

[0005] When a high voltage electric field acts on the hollow cathode, a local high electric field intensity problem will occur in the cavity area near the ceramic separator at the bottom of the hollow electrode. Summary of the invention

[0006] The object of the present invention is to provide an electrode assembly and semiconductor pre-cleaning equipment to reduce local high electric field areas and improve the uniformity of electric field strength.

[0007] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0008] An electrode assembly, comprising a first electrode and a second electrode stacked in a vertical direction; the first electrode is located above the second electrode, and a cavity is provided between the first electrode and the second electrode;

[0009] The first electrode is provided with an air inlet portion and an expansion portion, the air inlet portion is provided with an air inlet, and the air inlet is communicated with the cavity;

[0010] The extension portion is provided with an upper portion and a lower portion opposite to the upper portion, the upper portion of the extension portion is connected to the air inlet portion, and the lower portion has a lower surface opposite to the second electrode; the extension portion is also provided with an inner wall and an outer wall, the inner wall constitutes a side wall of the cavity, one end of the outer wall is connected to the air inlet portion, and the other end of the outer wall is connected to the lower surface of the extension portion;

[0011] A dielectric portion is disposed on the lower surface of the extension portion, and the dielectric portion is located in a connection area between the lower surface of the extension portion and the outer wall.

[0012] Optionally, the motor assembly further includes an isolating member, which is located between the first electrode and the second electrode, and electrically isolates the first electrode from the second electrode; the isolating member is provided with a first side wall opposite to the outer wall of the extended portion of the first electrode, and an isolating layer is provided on the surface of the first side wall.

[0013] Optionally, a separation gap is provided between the first side wall of the isolation member and the outer wall of the extended portion of the first electrode, and the dielectric portion is also provided on the outer wall of the extended portion of the first electrode.

[0014] Optionally, the dielectric portion is filled in the separation gap.

[0015] Optionally, the first side wall of the isolation member contacts the outer wall of the extended portion of the first electrode; the dielectric portion is arranged at the junction area between the lower surface of the extended portion of the first electrode and the first side wall of the isolation member, the connection surface between the dielectric portion and the first side wall is the first connection surface, and the connection surface between the dielectric portion and the lower surface of the first electrode is the second connection surface.

[0016] Optionally, the dielectric portion forms a first contact width D at the first connection surface, and the dielectric portion forms a second contact width d at the second connection surface, and D≥d.

[0017] Optionally, the second electrode is provided with a third surface opposite to the first electrode, the lower surface of the first electrode extension portion forms an electrode distance L with the third surface of the second electrode, and the first contact width D is smaller than the electrode distance L.

[0018] Optionally, the cross-section of the dielectric portion is fan-shaped or triangular.

[0019] Optionally, a connection between the outer wall and the lower surface of the first electrode extension portion is arranged as an arc-shaped chamfer, and the dielectric portion is arranged at the arc-shaped chamfer.

[0020] Optionally, the dielectric part is a dielectric material with a dielectric constant of 4-6.

[0021] Optionally, the thickness of the dielectric part is greater than or equal to 0.2 mm.

[0022] Optionally, the isolation layer is made of a dielectric material with a dielectric constant of 2 to 8, and the isolation layer has a thickness greater than 0.1 mm.

[0023] Optionally, the air inlet portion and the extension portion of the first electrode are integrally formed, the extension portion is a ring-shaped member, the inner wall of the extension portion gradually increases in diameter from the air inlet to a direction away from the air inlet, and the outer wall of the extension portion remains unchanged in diameter.

[0024] A semiconductor pre-cleaning device comprises: an electrode assembly; and a process chamber, wherein the process chamber is arranged below the electrode assembly.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) By providing a dielectric portion on the lower surface of the first electrode extension and the outer wall of the extension, the dielectric constant of the dielectric portion is located between the plasma in the cavity and the isolation member. By introducing the dielectric portion, the electric field distribution is uniformed and the local electric field strength is reduced. By providing the dielectric portion in the connection area between the lower surface of the extension and the outer wall, the influence on the electric field environment in other areas of the cavity is reduced.

[0027] (2) By providing an isolation layer on the first side wall of the isolation element, the interface characteristics between the isolation element and the plasma in the cavity are improved, the surface structure of the isolation element is optimized, the flatness of the surface of the isolation element is improved, and the uniformity of the electric field distribution is thereby improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the description. Obviously, the drawings described below are an embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0029] Figure 1 It is a structural schematic diagram of semiconductor pre-cleaning equipment;

[0030] Figure 2 is a schematic structural diagram of a first electrode;

[0031] Figure 3A It is a schematic diagram of the structure of A in one embodiment of the present invention;

[0032] Figure 3B This is a simulation result diagram of A in one embodiment of the present invention;

[0033] Figure 4A It is a structural schematic diagram of another embodiment A of the present invention;

[0034] Figure 4B This is a simulation result diagram of another embodiment A of the present invention;

[0035] Figure 5A It is a structural schematic diagram of another embodiment A of the present invention;

[0036] Figure 5B This is a simulation result diagram of another embodiment A of the present invention;

[0037] Figure 6 It is a structural schematic diagram of another embodiment A of the present invention. DETAILED DESCRIPTION

[0038] The scheme proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the accompanying drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0039] Semiconductor equipment generally includes a wafer front-end module (EFEM), a load lock chamber (Load Lock), a wafer transfer chamber (TM), and a process chamber (PM) connected in sequence. The wafer front-end module transports the wafer to the load lock chamber and performs a negative pressure pumping process. Then, under the action of the manipulator in the wafer transfer chamber, the wafer in the load lock chamber is moved to the wafer transfer chamber, and then transferred to the process chamber for the corresponding process. According to different semiconductor processes, it can be divided into pre-cleaning, epitaxy, etching, ion implantation and other processes, and different processes correspond to different process chambers.

[0040] Figure 1 A schematic diagram of the structure of the semiconductor pre-cleaning device 100 provided by the present invention is shown in FIG. Figure 1As shown, the semiconductor pre-cleaning equipment 100 includes an electrode assembly, a distribution assembly, a process chamber and a support assembly. The electrode assembly is arranged at the upper end of the process chamber. The motor assembly includes a first electrode 10, a second electrode 11 and an isolation member 12 stacked in a vertical direction; the first electrode 10 is located above the second electrode 11, and a cavity 104 for confining plasma is provided between the first electrode 10 and the second electrode 11; there is a certain electrode distance L between the first electrode 10 and the second electrode 11. The first electrode 10 is connected to a power supply, and further, the power supply is a radio frequency power supply; the second electrode is grounded, so that a capacitor is formed between the first electrode 10 and the second electrode 11.

[0041] The first electrode 10 includes an air inlet 101 and an extension 102, and the extension 102 is arranged below the air inlet 101. The air inlet is provided with one or more air inlets 103, and the air inlet 103 is connected with the cavity 104. The reaction gas enters the cavity 104 through the air inlet 103, and the reaction gas entering the cavity 104 is excited to generate plasma. The air inlet includes a first surface 106 opposite to the second electrode and a second surface 107 opposite to the first surface. The air inlet 103 penetrates the first surface 106 and the second surface 107 of the air inlet. Further, the air inlet 103 is symmetrically distributed along the symmetric center line of the cavity 104. Further, the air inlet 101 is also provided with a side surface connecting the first surface and the second surface, the air inlet pipeline is arranged parallel to the second surface, the air inlet end of the air inlet pipeline is located on the side of the air inlet, and the air outlet end of the air inlet pipeline, that is, the air inlet 103, is symmetrically distributed along the symmetric center line of the cavity. Optionally, the air inlet portion is disc-shaped.

[0042] In some embodiments, Figure 1 and 2 As shown, the extension part is a ring-shaped part, and the extension part is provided with an upper part and a lower part opposite to the upper part. The upper part of the extension part is connected to the first surface 106 of the air inlet part, and the lower part has a lower surface 205 opposite to the lower electrode, as well as an inner wall 206 and an outer wall 204. The inner wall constitutes the side wall of the cavity 104, and the diameter of the inner wall of the extension part gradually increases from the air inlet 103 to the direction away from the air inlet, and the inner wall of the extension part is like an inverted cone or a funnel. Further, the diameter of the inner wall of the extension part from the air inlet 103 to the direction away from the air inlet remains unchanged, that is, the inner wall of the extension part is cylindrical. One end of the outer wall 204 is connected to the first surface 106 of the air inlet part, and the other end of the outer wall is connected to the lower surface 205 of the extension part, and the diameter of the outer wall of the extension part remains unchanged. The outer wall diameter of the extension part remains unchanged, that is, when the extension part is at a certain distance from the isolating part, the distance between the outer wall of the extension part and the isolating part remains unchanged, so as to avoid sparking due to excessive local electric field caused by the reduced distance.

[0043] In some embodiments, Figure 1 As shown, the isolating member 12 is disposed between the first electrode 10 and the second electrode 11. The isolating member 12 realizes electrical isolation between the first electrode and the second electrode. The isolating member 12 is a ring-shaped member. The isolating member is disposed around or substantially around the extension portion 102 of the first electrode. The height of the isolating member is greater than the height of the extension portion (i.e., the distance from the first surface to the lower surface of the extension portion). The isolating member 12 can be made of alumina ceramic or any other insulating material. The dielectric constant of the alumina ceramic is between 9 and 10.

[0044] In some embodiments, the second electrode 11 is provided with a third surface 112 opposite to the first electrode 10, and the lower surface 205 of the first electrode extension portion and the third surface 112 of the second electrode form an electrode distance L. By adjusting the electrode distance L, the uniformity of the plasma distribution between the first electrode 10 and the second electrode 11 can be improved. Further, the second electrode includes a plurality of gas passages 111, and the plurality of gas passages 111 are formed below the cavity to allow the plasma in the cavity to flow through the gas passages 111 and enter the process chamber 14. A distribution component (not shown) is also provided below the gas passage of the second electrode. Further, the distribution component is a circular gas distribution plate, and the gas distribution plate is provided with openings. The openings can prevent the free radicals flowing out of the gas passage from directly impacting the surface of the wafer 15 by slowing down the gas flow speed and guiding the gas flow to be evenly distributed.

[0045] In some embodiments, the support assembly 18 is located inside the process chamber and is used to support the wafer 5 during the process. During the process, the support assembly can be used to lift the wafer to be close to the gas distribution plate so that free radicals can act on the surface of the wafer.

[0046] In some embodiments, the process chamber 14 is further provided with a sleeve (not shown), which is arranged on the inner surface of the side wall of the process chamber and around the support assembly 18, and is used to evenly distribute the process gas on the wafer surface and discharge the remaining process gas from the process chamber 14 after the process is completed.

[0047] In some embodiments, Figure 3A and Figure 5A As shown, a dielectric portion is provided on the lower surface of the extension portion, and the dielectric portion is located in a connection area 207 between the lower surface of the extension portion and the outer wall.

[0048] When the radio frequency power source acts on the first electrode 10, the cavity region near the end 207 of the first electrode will have a high electric field strength, and the electric field strength in this region is significantly higher than the electric field strength at other positions in the cavity. In order to improve the uniformity of the electric field strength, a dielectric portion is provided at the end 207 of the first electrode, and the dielectric portion is a dielectric material with a dielectric constant between 4 and 6, and the dielectric constant of the dielectric portion is between the plasma inside the cavity and the ceramic isolation member. The dielectric portion can be one or a mixture of epoxy resin, polyimide, polycarbonate, titanate, aluminum oxide or silicon carbide. The dielectric portion can be provided in the connection region 207 of the lower surface and the outer wall of the extension portion by spraying, coating, electroplating, etc. The specific method is determined according to the characteristics of the dielectric portion material and is not limited thereto. The dielectric portion has the ability to shield the electric field. By providing the dielectric portion at the end 207 of the first electrode, the electric field distribution can be changed to reduce the risk of direct discharge between the electrodes. Disposing the dielectric portion at the end 207 of the first electrode, i.e., the connection area 207 between the lower surface of the extension portion and the outer wall, can reduce the local electric field strength of the cavity near the end of the first electrode, but will not affect the electric field environment in other areas, especially the electric field environment above the gas channel of the second electrode.

[0049] In some embodiments, Figure 6 As shown, the isolating member is provided with a first side wall opposite to the outer wall of the extension portion of the first electrode, and an isolating layer 121 is provided on the surface of the first side wall. The isolating layer is a dielectric material with a dielectric constant of 2 to 8, and the thickness of the isolating layer is greater than 0.1 mm. Providing the isolating layer 121 on the surface of the first side wall of the isolating member can improve the interface characteristics between the isolating member and the gas inside the cavity, and avoid uneven distribution of electric field strength due to uneven surface of the isolating member itself or material reasons.

[0050] In some embodiments, a separation gap is provided between the first side wall of the isolating member and the outer wall of the extension portion of the first electrode, and the outer wall of the extension portion of the first electrode is also provided with the dielectric portion. Further, the dielectric portion is provided at the outer wall of the extension portion near the lower surface. When a separation gap is provided between the first side wall of the isolating member and the first electrode, due to the voltage difference between the first electrode and the isolating member, the electric field in the separation gap will be very strong. By providing the dielectric portion on the outer wall of the extension portion of the first electrode, the electric field distribution can be smoothed and the local high electric field area can be reduced.

[0051] In some embodiments, the dielectric portion is filled in the separation gap. The gas gap between the first electrode and the isolation member is filled with the dielectric portion, and the dielectric portion, as an electric field uniformizing material, can significantly reduce the local electric field strength.

[0052] In some embodiments, Figure 3AAs shown, the first side wall of the isolation member contacts the outer wall of the extension of the first electrode; a dielectric portion 16 is provided at the junction area between the lower surface of the extension of the first electrode and the first side wall of the isolation member, the connection surface between the dielectric portion and the first side wall is a first connection surface 161, and the connection surface between the dielectric portion and the lower surface is a second connection surface 162. The dielectric portion forms a first contact width D at the first connection surface, and the dielectric portion forms a second contact width d at the second connection surface, wherein D≥d. The thickness of the dielectric portion, i.e., the second contact width, is greater than or equal to 0.2 mm.

[0053] By providing a dielectric portion at the junction area between the lower surface of the first electrode extension and the first side wall of the isolation member, not only the local electric field strength is reduced by the dielectric portion, but also the distance between the first electrode and the isolation member is increased, thereby reducing the local electric field strength. Figure 4A and Figure 4B As shown, after the end 207 of the first electrode is chamfered, the local electric field strength is 32201.1 V / m; Figure 3A and Figure 3B As shown, the first electrode is not chamfered, and a dielectric portion is only set in the junction area 207 between the lower surface of the first electrode extension portion and the first side wall of the isolation member. The dielectric portion is a dielectric material with a dielectric constant of 4. By setting the electric field strength at the same position of the dielectric portion to only 3113.8 V / m, the local electric field strength is greatly reduced, making the electric field more uniform.

[0054] In some embodiments, the second electrode has a third surface opposite to the first electrode, the lower surface of the first electrode extension portion and the third surface of the second electrode form an electrode distance L, and the first contact width D is smaller than the electrode distance L.

[0055] In some embodiments, the cross-section of the dielectric portion is a sector or a triangle. The connection surface between the dielectric portion and the first side wall of the isolation member is the first connection surface, and the connection surface between the dielectric portion and the lower surface of the first electrode is the second connection surface. If one side of the first connection surface is connected to one side of the second connection surface, and the other side of the first connection surface is connected to the other side of the second connection surface through a curved surface, the cross-section of the dielectric portion is a sector; if the other side of the first connection surface is connected to the other side of the second connection surface through a plane, the cross-section of the dielectric portion is a triangle. The other side of the first connection surface can also be connected to the other side of the second connection surface in other ways, and is not limited to this.

[0056] In some embodiments, the connection between the outer wall and the lower surface of the first electrode extension portion is configured as an arc chamfer, and the dielectric portion is configured at the arc chamfer. Figure 5AAs shown, the dielectric part can be arranged along an arc chamfer shape, and the thickness of the dielectric part refers to the shortest distance from the outer edge of the chamfer to the outer edge of the dielectric part, and the thickness of the dielectric part is greater than or equal to 0.2 mm. Further, the dielectric part forms a first contact width D on the first connection surface, and the dielectric part forms a second contact width d on the second connection surface, and D≥d.

[0057] like Figure 4A and Figure 4B As shown, when a high voltage electric field is applied to the first electrode, in order to prevent the accumulation of charges at sharp points and cause arc discharge, a smooth chamfer is performed on the end 207 of the first electrode. However, since the electric field is also very strong in the area with a small radius of curvature, only performing an arc chamfer on the first electrode, that is, increasing the radius of curvature, cannot effectively improve the problem of local high electric field strength. Figure 5A and 5B As shown in the figure, a dielectric part is provided in the arc chamfered area, and the dielectric part is a dielectric material with a dielectric constant of 6. Under the same conditions, the electric field strength at the chamfer in the chamber is simulated to be 32201.1 V / m. After the dielectric part is provided at the chamfer, the electric field strength at the same position is 10274.4 V / m, which is reduced to 1 / 3 of the original electric field strength, significantly improving the situation of excessive local electric field.

[0058] In some embodiments, the air inlet of the first electrode further includes a first surface opposite to the second electrode; the isolating member includes an upper mounting surface and a lower mounting surface opposite to the upper mounting surface; the first surface of the first electrode is connected to the upper mounting surface of the isolating member, and the third surface of the second electrode is connected to the lower mounting surface of the isolating member. A sealing member is also provided between the first electrode and the upper mounting surface of the isolating member, and the sealing member is an annular sealing ring; a sealing member is also provided between the third surface of the second electrode and the lower mounting surface of the isolating member, and the sealing member is an annular sealing ring.

[0059] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. In addition, the term "connection" herein means that A and B are directly connected, or that A and B are indirectly connected, such as A and B are connected through C, or even through more components such as C and D, and A and B can be connected in one piece, or in separate pieces, or removable, or fixed. The term "optional" herein means that the technical feature can be combined or not combined with any feature in the text.

[0060] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. An electrode assembly, characterized in that: The electrode assembly comprises a first electrode and a second electrode stacked in a vertical direction; the first electrode is located above the second electrode, and a cavity is provided between the first electrode and the second electrode; The first electrode is provided with an air inlet portion and an expansion portion, the air inlet portion is provided with an air inlet, and the air inlet is communicated with the cavity; The extension portion is provided with an upper portion and a lower portion opposite to the upper portion, the upper portion of the extension portion is connected to the air inlet portion, and the lower portion has a lower surface opposite to the second electrode; the extension portion is also provided with an inner wall and an outer wall, the inner wall constitutes a side wall of the cavity, one end of the outer wall is connected to the air inlet portion, and the other end of the outer wall is connected to the lower surface of the extension portion; A dielectric portion is disposed on the lower surface of the extension portion, and the dielectric portion is located in a connection area between the lower surface of the extension portion and the outer wall.

2. An electrode assembly according to claim 1, characterized in that: It also includes an isolating member, which is arranged between the first electrode and the second electrode, and electrically isolates the first electrode from the second electrode; the isolating member is provided with a first side wall opposite to the outer wall of the extended portion of the first electrode, and an isolating layer is provided on the surface of the first side wall.

3. An electrode assembly according to claim 2, characterized in that: A separation gap is provided between the first side wall of the isolation member and the outer wall of the extended portion of the first electrode, and the dielectric portion is also provided on the outer wall of the extended portion of the first electrode.

4. An electrode assembly according to claim 3, characterized in that: The dielectric portion is filled in the separation gap.

5. The electrode assembly according to claim 2, characterized in that: The first side wall of the isolation member contacts the outer wall of the extended portion of the first electrode; the dielectric portion is arranged at the junction area between the lower surface of the extended portion of the first electrode and the first side wall of the isolation member, the connection surface between the dielectric portion and the first side wall of the isolation member is the first connection surface, and the connection surface between the dielectric portion and the lower surface of the first electrode is the second connection surface.

6. An electrode assembly according to claim 5, characterized in that: The dielectric portion forms a first contact width D at the first connection surface, and the dielectric portion forms a second contact width d at the second connection surface, wherein D≥d.

7. An electrode assembly according to claim 6, characterized in that: The second electrode is provided with a third surface opposite to the first electrode, the lower surface of the first electrode extension portion forms an electrode distance L with the third surface of the second electrode, and the first contact width D is smaller than the electrode distance L.

8. An electrode assembly according to claim 7, characterized in that: The cross section of the dielectric portion is fan-shaped or triangular.

9. The electrode assembly according to claim 5, characterized in that: The connection between the outer wall and the lower surface of the first electrode extension portion is arranged at an arc chamfer, and the dielectric portion is arranged at the arc chamfer.

10. The electrode assembly according to claim 1, characterized in that: The dielectric part is a dielectric material with a dielectric constant of 4-6.

11. An electrode assembly according to claim 10, characterized in that: The thickness of the dielectric portion is greater than or equal to 0.2 mm.

12. The motor assembly according to claim 2, characterized in that: The isolation layer is made of a dielectric material with a dielectric constant of 2 to 8, and the thickness of the isolation layer is greater than 0.1 mm.

13. The electrode assembly according to claim 1, characterized in that: The air inlet and the extension part of the first electrode are integrally formed, the extension part is a ring-shaped part, the inner wall of the extension part gradually increases in diameter from the air inlet to the direction away from the air inlet, and the outer wall of the extension part remains unchanged in diameter.

14. A semiconductor pre-cleaning device, characterized in that: include: The electrode assembly according to any one of claims 1 to 13; A process chamber is disposed below the electrode assembly.

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