Coil base plate and plasma processing apparatus

Abstract

A coil base plate and a plasma processing device. The coil base plate comprises: a base plate body having a first surface and a second surface, the first surface of the base plate body being opposite to the second surface of the base plate body; a plurality of protruding structures on the first surface of the base plate body and protruding from the first surface of the base plate body; wherein at least two of the protruding structures are connected to form a coil accommodating groove, the coil accommodating groove being shaped to match a path of a radio frequency coil to surround at least part of the radio frequency coil. The above scheme can suppress the arc effect between the radio frequency coil and the metal heating clothes in the plasma processing device.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, specifically to a coil base plate and plasma processing equipment. Background Technology

[0002] Plasma processing equipment is a key semiconductor device that uses active particles (ions, free radicals) in low-temperature plasma to react with materials physically or chemically, selectively removing materials from the surface of wafers (or other substrates).

[0003] In plasma processing equipment, the radio frequency (RF) coil is a crucial component for generating plasma. Typically, the RF coil is placed on a coil base plate, which in turn rests on a dielectric window. A metal heating garment is formed on the surface of the dielectric window to maintain the equipment at a specific temperature.

[0004] However, due to the complex electromagnetic environment and high-frequency current changes inside the equipment, the RF coil and metal heating garment are highly susceptible to arcing during operation, resulting in sparking. Sparking not only releases a large amount of energy instantaneously, impacting the equipment's electrical system and interfering with normal etching processes, but it can also cause burning and damage to the surface of metal parts, significantly shortening the equipment's lifespan. Utility Model Content

[0005] The problem this invention aims to solve is: how to suppress the electric arc effect between the radio frequency coil and the metal heating garment in a plasma processing device.

[0006] To address the above problems, this utility model provides a coil base plate, which includes:

[0007] The base plate body has a first surface and a second surface, wherein the first surface of the base plate body is opposite to the second surface of the base plate body.

[0008] Several protruding structures are located on the first surface of the base plate body and protrude from the first surface of the base plate body;

[0009] In this configuration, at least two protruding structures are connected to form a coil receiving groove, the shape of which matches the orientation of the radio frequency coil to surround at least a portion of the radio frequency coil.

[0010] In one possible embodiment, the protrusion structure includes: a connecting portion, one end of which is connected to the base plate body; the connecting portion protrudes from a first surface of the base plate body in a first direction.

[0011] In one possible embodiment, the first direction is a direction perpendicular to the first surface of the base plate body.

[0012] In one possible embodiment, the protruding structure further includes: a first curved portion connected to the other end of the connecting portion and protruding in a second direction.

[0013] In one possible embodiment, the second direction is a direction parallel to the first surface of the base plate body.

[0014] In one possible embodiment, the first bend extends into the interior of the coil receiving groove.

[0015] In one possible embodiment, the first bend extends outward into the coil receiving groove.

[0016] In one possible embodiment, the protrusion structure further includes a second curved portion, which is connected to the other end of the first curved portion and protrudes in a third direction.

[0017] In one possible embodiment, the third direction is parallel to the first direction.

[0018] In one possible embodiment, along the protrusion direction of the protrusion structure, the connecting portion includes: a central portion and a first edge portion and a second edge portion on both sides of the central portion; the first edge portion is connected to the base plate body.

[0019] In one possible embodiment, the central portion protrudes outward from or into the coil receiving groove relative to the first edge portion and the second edge portion.

[0020] In one possible embodiment, the thickness of the first edge portion and the second edge portion is less than the thickness of the center portion.

[0021] In one possible embodiment, a groove is formed within the second edge portion.

[0022] In one possible embodiment, the cross-sectional shape of the groove is square, triangular, or circular.

[0023] In one possible embodiment, the base plate body and the protruding structure are made of polyetheretherketone (PEEK).

[0024] This utility model embodiment also provides a plasma processing device, the device including any of the above-described coil base plates, a radio frequency coil located above the coil base plates, and a metal heating garment located below the coil base plates.

[0025] Compared with the prior art, the technical solution of this utility model embodiment has the following advantages:

[0026] By applying the solution of this utility model, since the base plate of the coil base plate has several protruding structures, connecting two protruding structures can form a coil receiving groove. The formation of the coil receiving groove matches the orientation of the RF coil, thereby surrounding at least part of the RF coil. Thus, due to the presence of the protruding structures, the creepage distance between the RF coil surrounded by the coil receiving groove and the underlying metal heating garment is increased. This disables the creepage path between the RF coil on the base plate and the underlying metal heating garment, enhances the voltage withstand capability of the coil base plate, suppresses the arcing effect between the RF coil and the metal heating garment, and extends the service life of the equipment. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a plasma processing device;

[0028] Figure 2 This is a top view of a coil base plate;

[0029] Figure 3 This is a schematic diagram of the structure of a coil base plate in an embodiment of this utility model;

[0030] Figures 4 to 7 These are schematic diagrams of different radial cross-sectional structures of the coil base plate in embodiments of this utility model;

[0031] Figures 8 to 12 These are schematic diagrams showing different structures of the connecting part in the protruding structure in the embodiments of this utility model. Detailed Implementation

[0032] Reference Figure 1 The plasma processing equipment may include: a chamber 10, a radio frequency (RF) system located above the chamber 10, and an air intake system. The RF system may include: a ceramic dielectric window 11, a coil base plate 12, an RF coil 13, a matching network 14, and an RF power supply 15. Wherein:

[0033] A ceramic dielectric window 11 is located at the top of chamber 10 and seals chamber 10. A metal heating garment, typically aluminum foil, is formed on the upper surface to allow the device to operate at specific temperature environments. A coil base plate 12 is located above the ceramic dielectric window 11, and an RF coil 13 is located above the coil base plate 12. The air intake system may include an air intake nozzle 16. The air intake nozzle 16 passes through the central hole of the RF coil 13, the coil base plate 12, and the ceramic dielectric window 11 to enter the intake chamber 10.

[0034] The RF power supply 15, through the matching network 14, applies all its RF power to the RF coil 13. The RF coil 13 then generates an electromagnetic field, ionizing the process gas entering the chamber 10 via the intake nozzle 16, thus producing plasma. The RF coil 13 is the core component in the RF system that enables contactless energy transfer, generating plasma with a density as high as 10⁻⁶ without the need for complex resonance mechanisms. 11 ~10 12 cm −3 The plasma operates based on the phenomenon of electromagnetic induction. An radio frequency coil 13 generates an alternating magnetic field through a high-frequency current (typically 13.56 MHz), inducing a vortex electric field to accelerate electrons, achieving efficient ionization of the reactant gas and thus generating plasma. The generated plasma enters the chamber 10 and acts on the wafer surface of the chamber 10, achieving etching.

[0035] Since the RF coil 13 receives the power output from the RF power supply 15 and generates high voltage, in order to avoid the RF coil 13 from generating an electric arc effect with the metal heating garment above the ceramic dielectric window 11, a coil base plate 12 is provided between the RF coil 13 and the ceramic dielectric window 11 to suppress the electric arc effect.

[0036] However, due to the complex electromagnetic environment and high-frequency current changes inside the equipment, the surface of the radio frequency coil 13 and the metal heating garment in existing plasma processing equipment is still prone to arcing during operation, i.e., sparking is very likely to occur. Sparking not only releases a large amount of energy instantaneously, impacting the electrical system of the equipment and causing the machine to malfunction and interfering with normal etching processes, but it can also lead to ablation and damage to the surface of metal parts, greatly shortening the service life of the equipment.

[0037] The inventors discovered that the coil base plate 12 in existing plasma processing equipment is... Figure 2 In the planar structure shown, when the RF coil 13 covers the coil base plate 12, the creepage distance between it and the metal heating garment below is short, resulting in poor withstand voltage of the coil base plate 12. This makes it very easy for arcing to occur between the RF coil 13 and the metal heating garment below.

[0038] To address this, the present invention provides a coil base plate with several protruding structures formed on the base plate body. Due to the presence of the protruding structures, the creepage distance between the radio frequency coil surrounded by the coil receiving groove and the metal heating garment below is increased. This can disable the creepage channel between the radio frequency coil on the base plate body and the metal heating garment below, enhance the voltage resistance of the coil base plate, and thus suppress the arcing effect between the radio frequency coil and the metal heating garment.

[0039] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0040] Reference Figure 3 This utility model embodiment provides a coil base plate 100, which may include: a base plate body 101 and a plurality of protruding structures. Specifically:

[0041] The base plate body 101 has a first surface and a second surface, and the first surface of the base plate body 101 is opposite to the second surface of the base plate body 101.

[0042] The plurality of protruding structures are located on the first surface of the base plate body 101 and protrude from the first surface of the base plate body 101.

[0043] In this configuration, at least two protruding structures are connected to form a coil receiving groove, the shape of which matches the orientation of the radio frequency coil to surround at least a portion of the radio frequency coil.

[0044] In a specific implementation, the first surface of the base plate body 101 faces the radio frequency coil, and the second surface of the base plate body 101 faces the metal heating garment. Multiple protruding structures are provided on the first surface of the base plate body 101. The radio frequency coil is located within a coil receiving groove formed by connecting two or more protruding structures, and is surrounded by the coil receiving groove. In this case, the protruding structures serve as the sidewalls of the coil receiving groove.

[0045] The creepage distance between the RF coil and the metal heating garment refers to the shortest path along the insulating surface (i.e., the surface of the coil base plate 100) between the RF coil and the metal heating garment. With the raised structure, the creepage distance between the RF coil and the metal heating garment includes not only the path along the surface of the base plate 101 but also the path along the surface of the raised structure. Therefore, by setting the raised structure, the creepage distance between the RF coil and the metal heating garment can be increased. When the creepage distance between the RF coil and the metal heating garment increases, the electric field intensity distribution on the surface of the base plate 101 becomes more uniform, and the breakdown voltage is significantly increased. This suppresses the formation of a discharge channel along the surface of the coil base plate 100, causing the creepage channel between the RF coil and the metal heating garment to fail. This path is no longer a low-impedance path, and RF energy can no longer leak or break down through this path, thus increasing the withstand voltage of the coil base plate 100 and suppressing the arcing effect between the RF coil and the metal heating garment.

[0046] In practice, the number and arrangement of the protrusions can be set according to the direction of the RF coil, so that the shape of the coil receiving slot matches the direction of the RF coil.

[0047] For example, a first protruding structure 1021, a second protruding structure 1022, a third protruding structure 1023, a fourth protruding structure 1024, a fifth protruding structure 1025, a sixth protruding structure 1026, and a seventh protruding structure 1027 can be provided on the edge of the first surface of the base plate body 101. An eighth protruding structure 1028 and a ninth protruding structure 1029 can also be provided in the central area of ​​the first surface of the base plate body 101.

[0048] The first protruding structure 1021, the second protruding structure 1022, and the third protruding structure 1023 can form the first coil receiving slot 1031. The first protruding structure 1021, the fourth protruding structure 1024, and the sixth protruding structure 1026 can form the second coil receiving slot 1032. The fifth protruding structure 1025, the sixth protruding structure 1026, and the seventh protruding structure 1027 can form the third coil receiving slot 1033. Some of the coil receiving slots may be connected or disconnected depending on the orientation of the RF coil. For example, the first coil receiving slot 1031 may be connected to the third coil receiving slot 1033, but not to the second coil receiving slot 1032.

[0049] In practice, the radio frequency coil located in the coil receiving slot can be a planar coil or a three-dimensional coil (e.g., a solenoid coil). The height of the protruding structure in the coil receiving slot where the radio frequency coil is located can be lower than, equal to, or higher than the height of the radio frequency coil.

[0050] In practical implementation, the creepage distance between the radio frequency coil and the metal heating garment can be increased by changing the structure of the protrusion. The protrusion can have various structures, and there is no specific limitation, as long as it protrudes from the first surface of the base plate body 101.

[0051] In one embodiment, the protruding structure may include: a connecting portion, one end of which is connected to the base plate body 101; the connecting portion protrudes from a first surface of the base plate body 101 in a first direction. The first direction can be any direction away from the first surface of the base plate body 101, specifically determined according to the height direction of the surrounding radio frequency coil.

[0052] In one embodiment, the first direction is a direction perpendicular to a first surface of the base plate body 101. For example, Figure 4 This is a schematic diagram of a radial cross-sectional structure of the coil base plate 100 in an embodiment of this utility model. (Refer to...) Figure 4Taking the eighth protrusion structure 1028 and the ninth protrusion structure 1029 as examples, the eighth protrusion structure 1028 may only have a connecting portion 1028a perpendicular to the first surface of the base plate body 101, and the ninth protrusion structure 1029 may only have a connecting portion 1029a perpendicular to the first surface of the base plate body 101. When the first surface of the base plate body 101 is horizontal, the connecting portions 1028a and 1029a protrude vertically relative to the first surface of the base plate body 101. This vertical protrusion can increase the creepage distance between the metal heating garment and the radio frequency coil, thereby improving the withstand voltage of the coil base plate 100 and suppressing the arc effect.

[0053] In another embodiment, in addition to the connecting portion, the protruding structure may further include a first curved portion. The first curved portion is connected to the other end of the connecting portion and protrudes in a second direction. The second direction can be any direction different from the first direction, as long as it does not affect the coil routing.

[0054] In one embodiment, the second direction can be a direction parallel to the first surface of the base plate body 101. The first curved portion can extend either into the interior of the coil receiving groove or outwards from the coil receiving groove.

[0055] For example, Figure 5 and Figure 6 This is a schematic diagram of a radial cross-sectional structure of the coil base plate 100 in an embodiment of this utility model. (Refer to...) Figure 5 and Figure 6 Taking the eighth protruding structure 1028 and the ninth protruding structure 1029 as examples, in addition to the connecting portion 1028a, the eighth protruding structure 1028 may also include a first curved portion 1028b. In addition to the connecting portion 1029a, the ninth protruding structure 1029 may also include a second curved portion 1029b. For example... Figure 5 As shown, the first bent portion 1028b and the second bent portion 1029b can extend outward from the coil receiving groove. Figure 6 As shown, the first curved portion 1028b and the second curved portion 1029b can extend into the interior of the coil receiving groove.

[0056] By setting the first bend, the creepage distance between the metal heating garment and the radio frequency coil can be further increased, thereby further improving the withstand voltage of the coil base plate 100 and making the arc suppression effect better.

[0057] In another embodiment, in addition to the connecting portion and the first bent portion, the protruding structure may further include a second bent portion, which may be connected to the other end of the first bent portion and protrude in a third direction. The third direction may be any direction different from the second direction, as long as it does not affect the coil routing.

[0058] In one embodiment, the third direction is parallel to the first direction, that is, the third direction is perpendicular to the first surface of the base plate body 101. The second curved portion can extend from one end of the first curved portion along the third direction away from the first surface of the base plate body 101, or it can extend from one end of the first curved portion along the third direction towards the first surface of the base plate body 101.

[0059] For example, 7 is a schematic diagram of a radial cross-sectional structure of the coil base plate 100 in an embodiment of this utility model. (Refer to...) Figure 7 Similarly, taking the eighth protruding structure 1028 and the ninth protruding structure 1029 as examples, in addition to the connecting portion 1028a and the first curved portion 1028b, the eighth protruding structure 1028 may also include a second curved portion 1028c. In addition to the connecting portion 1029a and the first curved portion 1029b, the ninth protruding structure 1029 may also include a second curved portion 1029c. For example... Figure 7 As shown, the second curved portion 1029c extends from one end of the first curved portion in a third direction toward the first surface of the base plate body 101.

[0060] By providing a second bend, the creepage distance between the metal heating garment and the radio frequency coil can be further increased, thereby further improving the withstand voltage of the coil base plate 100 and making the arc suppression effect more effective.

[0061] In practical implementation, when the protruding structure is only provided with a connecting part, the creepage distance between the metal heating garment and the radio frequency coil can be increased by changing the structure of the connecting part itself.

[0062] Specifically, along the protrusion direction of the protrusion structure, the connecting portion may include: a central portion and first edge portions and second edge portions on both sides of the central portion; the first edge portions are connected to the base plate body. The radio frequency coil 13 is located inside the first edge portion.

[0063] In one embodiment, the central portion may be configured to protrude outward from or into the coil receiving groove relative to the first edge portion and the second edge portion.

[0064] For example, refer to Figure 8 The central portion 81c can be configured to protrude outward from the coil receiving groove relative to the first edge portion 81a and the second edge portion 81b. In this case, viewed along the protrusion direction of the protrusion structure, the central portion 81c, the first edge portion 81a, and the second edge portion 81b form a wavy shape. This further increases the creepage distance between the metal heating garment and the radio frequency coil, thereby further improving the voltage withstand capability of the coil base plate and resulting in better suppression of the arcing effect.

[0065] In another embodiment, reference is made to Figure 9 Furthermore, the thickness of the first edge portion 81a and the second edge portion 81b can be set to be less than the thickness of the central portion 81c. Further, the thickness can be set to gradually decrease from the central portion 81c to the first edge portion 81a, and gradually decrease from the central portion 81c to the second edge portion 81b, making the cross-section of the entire groove bottom rhomboid. This increases the creepage distance between the metal heating garment and the radio frequency coil while ensuring the strength of the connection.

[0066] In yet another embodiment, reference is made to... Figures 10 to 12 Furthermore, a groove 81d can be formed within the second edge portion 81b. The opening of the groove 81d can be formed on the side of the second edge portion 81b or on the top of the second edge portion 81b. By using the groove, the creepage distance between the metal heating garment and the radio frequency coil is increased, thereby improving the effect of suppressing the arcing effect.

[0067] In specific implementations, the cross-sectional shape of the groove 81d can exist in various ways, and no restrictions are imposed here.

[0068] In some embodiments, the cross-sectional shape of the groove 81d can be set to a regular shape. For example, refer to Figure 10 The cross-sectional shape of groove 81d can be square; refer to Figure 11 The cross-sectional shape of groove 81d can be triangular; refer to Figure 12 The cross-sectional shape of groove 81d can be circular.

[0069] In other embodiments, the cross-sectional shape of the groove 81d may also be set to an irregular shape.

[0070] In practice, in addition to changing the structure of the protrusion itself and the structure of the connection, the arc effect can also be suppressed by changing the material of the coil base plate.

[0071] In the prior art, the material of the coil base plate is polyetherimide (Ultem). Polyetherimide is an amorphous thermoplastic, and its thermal stability and insulation properties are difficult to meet the requirements.

[0072] In one embodiment of this invention, the base plate body and the raised structure can be made of polyetheretherketone (PEEK). PEEK is a semi-crystalline high-performance thermoplastic belonging to the polyaryletherketone (PAEK) family. It has high thermal stability and insulation properties, ensuring long-term insulation under high voltage and high temperature conditions, thereby suppressing arcing in the radio frequency coil.

[0073] In practical implementation, the base plate body 101 can have various structures, for example, referring to... Figure 3The base plate body may also include a reinforcing section 1011, with the central region of the first surface of the base plate body 101 directly connected to the edge of the first surface of the base plate body 101 via the reinforcing section 1011. There may be a hollowed-out area between adjacent reinforcing sections 1011. The radio frequency coil may be placed in the central region of the base plate body 101 or at the edge of the base plate body 101, and surrounded by a coil receiving groove formed by a raised structure. The metal heating garment is located below the base plate body 101. The central region of the first surface of the base plate body 101 may be provided with a through hole 1012 penetrating the base plate body 101, which allows the air intake nozzle to connect to the chamber.

[0074] As can be seen from the above, in the embodiment of this utility model, the coil base plate has a raised structure on the base plate body, which can reduce the creepage path failure between the radio frequency coil on the base plate body and the metal heating garment below, enhance the voltage resistance of the coil base plate, thereby suppressing the arc effect between the radio frequency coil and the metal heating garment and extending the service life of the equipment.

[0075] This utility model embodiment also provides a plasma processing device, which includes the aforementioned coil base plate. In addition, the plasma processing device may further include: a radio frequency coil located above the coil base plate, and a metal heating garment located below the coil base plate.

[0076] In some embodiments, the plasma processing apparatus may further include a radio frequency (RF) system and an intake system. The RF system can provide RF power and load it onto an RF coil, which can generate an electromagnetic field, thereby ionizing the process gas entering the chamber through the intake system to generate plasma.

[0077] It is understandable that plasma processing equipment includes plasma etching equipment, plasma deposition equipment, etc.

[0078] By using the coil base plate in this embodiment of the invention, the arc effect between the radio frequency coil and the metal heating garment can be better suppressed, thus extending the service life of the equipment.

[0079] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A coil base plate, characterized in that, include: The base plate body has a first surface and a second surface, wherein the first surface of the base plate body is opposite to the second surface of the base plate body. Several protruding structures are located on the first surface of the base plate body and protrude from the first surface of the base plate body; In this configuration, at least two protruding structures are connected to form a coil receiving groove, the shape of which matches the orientation of the radio frequency coil to surround at least a portion of the radio frequency coil.

2. The coil base plate as described in claim 1, characterized in that, The protruding structure includes: a connecting part, one end of which is connected to the base plate body; the connecting part protrudes from a first surface of the base plate body in a first direction.

3. The coil base plate as described in claim 2, characterized in that, The first direction is the direction perpendicular to the first surface of the base plate body.

4. The coil base plate as described in claim 2, characterized in that, The protruding structure further includes: a first curved portion, which is connected to the other end of the connecting portion and protrudes in a second direction.

5. The coil base plate as described in claim 4, characterized in that, The second direction is a direction parallel to the first surface of the base plate body.

6. The coil base plate as described in claim 5, characterized in that, The first curved portion extends into the interior of the coil receiving groove.

7. The coil base plate as described in claim 5, characterized in that, The first curved portion extends outward into the coil receiving groove.

8. The coil base plate as described in claim 4 or 5, characterized in that, The protruding structure further includes a second curved portion, which is connected to the other end of the first curved portion and protrudes in a third direction.

9. The coil base plate as described in claim 8, characterized in that, The third direction is parallel to the first direction.

10. The coil base plate as described in claim 2, characterized in that, Along the protrusion direction of the protrusion structure, the connecting portion includes: The central portion and the first and second edge portions on both sides of the central portion; the first edge portions are connected to the base plate body.

11. The coil base plate as described in claim 10, characterized in that, The central portion protrudes outward from or into the coil receiving groove relative to the first and second edge portions.

12. The coil base plate as described in claim 10, characterized in that, The thickness of the first edge portion and the second edge portion is less than the thickness of the center portion.

13. The coil base plate as described in claim 10, characterized in that, A groove is formed in the second edge portion.

14. The coil base plate as described in claim 13, characterized in that, The groove has a square, triangular, or circular cross-sectional shape.

15. The coil base plate as described in claim 1, characterized in that, The base plate and the raised structure are made of polyetheretherketone.

16. A plasma processing device, characterized in that, It includes a coil base plate as described in any one of claims 1 to 15, a radio frequency coil located above the coil base plate, and a metal heating garment located below the coil base plate.

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