Vertical fastener assembly for fastening upper electrode of plasma chamber

Abstract

To provide a vertical fastener assembly for fastening an upper electrode of a plasma chamber.SOLUTION: A vertical fastener assembly for fastening an upper electrode of a plasma chamber includes a vertical shaft 11 that extends vertically and is connected to the upper plate, a rotation unit 12 that is connected to the upper side of the vertical shaft 11 and raises and lowers the vertical shaft 11, a tension relief pin 13 that is connected to the upper electrode and is detachably connected to the vertical shaft 11, an elastic unit 14 that is connected to a lower portion of the tension relief pin 13, and a pin housing 15 that is connected to the upper portion of the tension relief pin 13.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This research was conducted with funding from the Korean government (Ministry of Trade, Industry and Energy) and support from the World Class Plus Project Foundation (P0021943, Development of oxide film dry etching equipment for next-generation 300mm high aspect ratio process).

[0002] The present invention relates to a vertical fastener assembly for fastening an upper electrode of a plasma chamber, and more particularly to a vertical fastener assembly for fastening an upper electrode of a plasma chamber vertically to an upper plate of the plasma chamber and an upper electrode. [Background technology]

[0003] If a plasma chamber upper electrode is fastened by directly forming a thread, the fastening force of the bolt can damage the threads of the bolt fastening portion. Furthermore, due to the chamber's characteristics of large temperature fluctuations, loosening of the threads can create a gap between the upper electrode and the plate, reducing the performance of the etching process and increasing the risk of it falling. Therefore, a fastener assembly is needed that fastens the plasma chamber upper electrode with a simplified structure, allowing for easy maintenance, ensuring uniform lifting to ensure the performance of the etching process, and absorbing thermal stress caused by temperature changes and preventing it from falling. Regarding fastening an upper electrode in a vacuum plasma chamber, International Publication No. WO 2009 / 114175 discloses a technology for fastening an electrode using a cam fastening method that utilizes an asymmetric cutout area in a cylindrical body. Furthermore, Korean Patent Publication No. 10-2016-0007409 discloses a technology for finely adjusting the lifting force using a sliding member. These known technologies have the disadvantage that the connecting members are configured to be clamped in a radial direction or by extending radially, making vertical fastening impossible. Furthermore, in a vacuum plasma chamber where rapid temperature changes occur, loosening or deformation of the fastening members due to thermal stress can not only degrade the performance of the etching process but also pose a risk of the chamber falling. Furthermore, in a vacuum plasma chamber, various processes are performed inside the chamber, and byproducts from these processes can flow between the various structures and cause problems such as byproduct entrapment, which can adversely affect the process. Therefore, frequent cleaning and replacement are very important factors. However, the known technologies have the disadvantage that they are unable to solve these problems due to their complex structure, making maintenance difficult.

[0004] The present invention is intended to solve the problems of the prior art and has the following objects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. WO2009 / 114175 (Lam Research Corporation, published September 17, 2009) Cam-fixed electrode clamp [Patent Document 2] Korean Patent Publication No. 10-2016-0007409 (Tokyo Electron Limited, published January 20, 2016) Plasma Processing Apparatus and Upper Electrode Assembly Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a vertical fastener assembly for fastening an upper electrode of a plasma chamber, which fastens the upper plate and the upper electrode of the plasma chamber in a vertical direction and can accommodate various deformations. [Means for solving the problem]

[0007] According to a suitable embodiment of the present invention, a vertical fastener assembly for fastening an upper electrode of a plasma chamber includes a vertical shaft extending vertically and coupled to an upper plate; a rotation unit coupled to the upper side of the vertical shaft and raising and lowering the vertical shaft; a tension relief pin coupled to the upper electrode and detachably coupled to the vertical shaft; an elastic unit coupled to a lower portion of the tension relief pin; and a pin housing coupled to an upper portion of the tension relief pin.

[0008] According to another suitable embodiment of the present invention, the vertical shaft includes a cylindrical fastening portion and a fastening hole formed perpendicular to the extension direction of the fastening portion, and a fastening tap formed in the upper portion of the strain relief pin is detachably coupled to the fastening portion.

[0009] According to yet another suitable embodiment of the present invention, the elastic unit is coupled to the tension relief pin in a manner that the tension relief pin passes through the elastic unit while being coiled.

[0010] According to yet another suitable embodiment of the present invention, the vertical shaft includes a central block; and an insert fastening portion extending above the central block and coupled to the rotation unit; and a rotation limiting portion is formed in the central block.

[0011] According to yet another suitable embodiment of the invention, the raising and lowering of the strain relief pin is guided by an elastic unit.

[0012] According to yet another suitable embodiment of the invention, rotation of the rotation unit changes the direction of the vertical axis or raises or lowers the vertical axis.

[0013] According to yet another preferred embodiment of the present invention, the device further includes a separation prevention ring coupled to an upper side of the rotation unit to prevent separation of the rotation unit. [Effects of the Invention]

[0014] The vertical fastener assembly for fastening an upper electrode of a plasma chamber according to the present invention is positioned between the upper electrode and the upper plate and may be configured in multiple units depending on the size of the upper electrode and the plate and the need. The vertical fastener assembly according to the present invention simplifies the structure by configuring the connecting member vertically, making maintenance easier. Furthermore, the vertical fastener assembly can maintain a fastened state with a stable and uniform force in a vacuum plasma chamber where sudden temperature changes occur. The vertical fastener assembly according to the present invention can be used to fasten the upper plate and upper electrode of a plasma chamber for various processes, and the present invention is not limited thereto. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a view showing an embodiment of a vertical fastener assembly for fastening an upper electrode of a plasma chamber according to the present invention; [Figure 2] 1 is a view showing an embodiment in which an upper plate and an upper electrode are fastened by a vertical fastener assembly according to the present invention; [Figure 3]4A and 4B are views illustrating an embodiment of a process in which an upper plate and an upper electrode are fastened together by a vertical fastener assembly according to the present invention; [Figure 4] 1 is a view showing an embodiment of an upper fastener forming a vertical fastener assembly according to the present invention. [Figure 5] 10 is a view showing another embodiment of a vertical fastener assembly according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the embodiments are for a clear understanding of the present invention and the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, and therefore, unless necessary for understanding the invention, repeated description will not be provided. Known components will be briefly described or omitted, but should not be understood as being excluded from the embodiments of the present invention.

[0017] FIG. 1 illustrates an embodiment of a vertical fastener assembly for fastening an upper electrode of a plasma chamber according to the present invention.

[0018] Referring to FIG. 1, the vertical fastener assembly for fastening the upper electrode of a plasma chamber includes a vertical shaft 11 that extends vertically and is connected to the upper plate; a rotation unit 12 that is connected to the upper side of the vertical shaft 11 and raises and lowers the vertical shaft 11; a tension relief pin 13 that is connected to the upper electrode and is detachably connected to the vertical shaft 11; an elastic unit 14 that is connected to the lower portion of the tension relief pin 13; and a pin housing 15 that is connected to the upper portion of the tension relief pin 13.

[0019] The vertical fastener assembly includes an upper fastener fastened to the upper plate and a lower fastener fastened to an upper electrode coupled to the underside of the upper plate. The upper electrode can be coupled to the upper plate by fastening the lower fastener to the upper fastener. The upper fastener includes a vertical shaft 11 extending vertically and coupled to the upper plate; and a rotation unit 12 coupled to the upper side of the vertical shaft 11 to raise and lower the vertical shaft 11. The lower fastener includes a tension relief pin 13 coupled to the upper electrode and detachably coupled to the vertical shaft 11; an elastic unit 14 coupled to the lower portion of the tension relief pin 13; and a pin housing 15 coupled to the upper portion of the tension relief pin 13. The vertical shaft 11 includes a center block 111; a cylindrical fastening portion 112 extending downward from the center block 111; a fastening hole 113 formed perpendicular to the extension direction of the fastening portion 112; and an insert fastening portion 114 extending upward from the center block 111. The vertical shaft 11 is connected to the upper plate by penetrating the edge of the upper plate and is raised and lowered by the rotation unit 12. The center block 111 may have a shape in which opposing portions of a circular plate having a certain thickness are cut away. Thus, the center block 111 may be composed of two opposing arc-shaped portions and two parallel linear portions. The two opposing linear portions may form a rotation limiting portion. A cylindrical connecting joint is formed on the upper side of the center block 111, and a cylindrical insert fastening portion 114 extends above the connecting joint. The insert fastening portion 114 is inserted into and connected to the rotation unit 12, thereby connecting the vertical shaft 11 to the rotation unit 12. A cylindrical fastening portion 112 may be formed on the lower side of the center block 111, and a fastening hole 113 may be formed in the lower portion of the fastening portion 112 perpendicular to the extension direction of the fastening portion 112. The fastening hole 113 is cylindrical, and an insertion gap 113a may be formed in the lower portion of the fastening hole 113. The fastening hole 113 is formed in a structure that penetrates the lower part of the fastening portion 112 and has a shape with both sides open, and the insertion gap 113a can be formed in a structure that cuts the lower end of the fastening portion 112 to a certain width along the radial direction.As a result, the lower portion of the fastening hole 113 and the upper portion of the insertion gap 113a are connected to form a passage connecting the lower portion of the fastening portion 112 to the outside. The rotation unit 12 may include a cylindrical rotation body 121; a hollow cylindrical fastening cylinder 122 below the rotation body 121 into which the insert fastening portion 114 is inserted; and a fastening tap 123 extending above the rotation body 121. The fastening tap 123 may have various structures that can be rotated by various rotary tools, and the rotation unit 12 rotates as the fastening tap 123 rotates, thereby raising and lowering the vertical shaft 11. The rotation unit 12 or the vertical shaft 11 connected thereto may be raised and lowered in various ways, and the present invention is not limited thereto.

[0020] The tension relief pin 13 may include a cylindrical lower body 131; a cylindrical fixing member 132 having a smaller diameter than the lower body 131 and extending upward from an upper end of the lower body 131; a joint member 134 extending from the fixing member 132 with a relatively smaller diameter; and a cylindrical fastening tap 133 extending from the joint member 134 and sized to be received within the fastening hole 113. A coil spring-shaped elastic unit 14 is connected to the fixing member 132, and the tension relief pin 13 may be connected to the pin housing 15 by passing through the pin housing 15. The pin housing 15 may include a cylindrical housing body 151; a polygonal nut-shaped fixed coupling block 152 coupled to the upper side of the housing body 151; and a guide block 153 extending from the lower side of the housing body 151. The tension relief pin 13 may be coupled in such a way that, with the elastic unit 14 coupled to the tension relief pin 13, the tension relief pin 13 is received in a coupling hole formed along the length of the pin housing 15. An upper portion of the fixing member 132, the joint member 134, and the fastening tap 133 protrude upward from the pin housing 15. When the lower fastener is coupled to the upper fastener, the joint member 134 may be positioned in the insertion gap 113a, and the fastening tap 133 may be positioned inside the fastening hole 113. As a result, the upper electrode may be detachably coupled to the upper plate.

[0021] FIG. 2 illustrates an embodiment of the top plate and top electrode fastened together by a vertical fastener assembly according to the present invention.

[0022] Referring to FIG. 2, the upper plate 21 has a circular band shape extending in a circular direction with a certain width. A plurality of fastening holes are formed along the edge of the upper plate 21, and upper fasteners 23_1 to 23_L can be coupled to the respective fastening holes. The upper electrode 22 coupled to the underside of the upper plate 21 may have a shape similar to the upper plate 21, for example, a circular band shape. A plurality of fastening holes are formed along the edge of the upper electrode 22, and lower fasteners 24_1 to 24_L can be coupled to the respective fastening holes. The number of fastening holes may be the same as the number of fastening holes, and the fastening holes may be formed at positions corresponding to the fastening holes. The upper electrode 22 can be coupled to the upper plate 21 by coupling each of the lower fasteners 24_1 to 24_L to the respective upper fasteners 23_1 to 23_L. As shown in the middle and right sides of FIG. 2, the lower fasteners may be coupled to the upper fasteners within the coupling grooves 26. The coupling groove 26 may be formed at a portion of the upper plate 21 where it contacts the upper electrode and may extend circumferentially of the upper plate 21. The vertical shaft 11 and the rotation unit 12 coupled to the upper side of the vertical shaft 11 are fastened to each other in a structure penetrating the upper plate 21 from top to bottom. The tension relief pin 13 may extend upward from the upper electrode 22 and protrude into the upper plate 21 to be coupled to the vertical shaft 11, and the pin housing 15 may be located at the interface between the upper plate 21 and the upper electrode 22. With the upper and lower fasteners already fastened to the upper plate 21 and the upper electrode 22, the tension relief pin 13 may be coupled to the vertical shaft 11, thereby coupling the upper plate 21 and the upper electrode 22 to each other. With the upper plate 21 and the upper electrode 22 coupled in this manner, deformation due to heat or impact is absorbed by the elastic unit 14. Furthermore, since the fastener assemblies are coupled to each other vertically, ease of assembly and maintenance is improved.

[0023] FIG. 3 illustrates an embodiment of a process in which the upper plate and the upper electrode are fastened together by the vertical fastener assembly according to the present invention.

[0024] Referring to FIG. 3, an upper fastener including a vertical shaft 11 and a rotary unit 12 coupled to the upper side of the vertical shaft 11 to raise and lower the vertical shaft 11 may be coupled to an upper plate 21. A coupling groove 26 is formed in the upper plate 21, and the coupling groove 26 is formed in the lower portion of the upper plate 21 and extends in the circumferential direction. A lower fastener having a structure in which a tension relief pin 13 is housed in a pin housing 15 and an elastic unit 14 is coupled to the upper electrode 22 by penetrating the upper electrode 22 from bottom to top. The tension relief pin 13 protrudes upward from the upper electrode 22, and the upper portion of the pin housing 15 protrudes upward from the upper electrode 22. The lower surface of the upper plate 21 and the upper surface of the upper electrode 22 are in contact with each other, based on the fastening position of the upper fastener and the lower fastener. When the upper plate 21 and the upper electrode 22 are in contact with each other, the upper portion of the tension relief pin 13 may be positioned in the coupling groove 26. In addition, the vertical shaft 11 and the tension relief pin 13 may be positioned concentrically. In this state, as the upper electrode 22 rotates about its center, the fastening taps of the tension relief pins 13 are received in the fastening holes of the vertical shaft 11, and the upper and lower fasteners are coupled to each other. When the rotation unit 12 rotates in this coupled state, the vertical shaft 11 moves upward, applying pressure to the tension relief pins 13. As a result, the elastic unit 14 is compressed, lifting the upper electrode 22 and closely contacting the upper plate 21. The multiple upper fasteners coupled to the upper plate 21 and the multiple lower fasteners coupled to the upper electrode 22 are coupled to each other using the above-described method, and each upper fastener and each lower fastener are attached with the same torque, maintaining the fastening with a uniform force and improving coupling stability.

[0025] FIG. 4 illustrates an embodiment of an upper fastener forming a vertical fastener assembly according to the present invention.

[0026] Referring to FIG. 4, rotation-limiting portions 111a and 111b may be formed at opposing positions on a center block 111 of the vertical shaft 11. The center block 111 may include a circularly extending peripheral portion and a linearly extending peripheral portion having a uniform thickness, and the two linearly extending peripheral portions facing each other may be the rotation-limiting portions 111a and 111b. Thus, the center block 111 may include rotation-limiting portions 111a and 111b extending parallel to each other and an arc-shaped peripheral portion connecting the rotation-limiting portions 111a and 111b. A cylindrical fastening cylinder 122 having a smaller diameter than the rotating body 121 may be formed below a cylindrical rotating body 121, and a fastening tap 123 may be formed on the upper surface of the rotating body 121. An insert fastening portion 114 may be inserted into and coupled to the inside of the fastening cylinder 122, and the center block having the rotation-limiting portions 111a and 111b may be located below the insert fastening portion 114. The rotation of the rotation unit 12 raises and lowers the vertical shaft 11, which raises and lowers the central block 111. When the central block 111 moves to a predetermined position, the rotation of the central block 111 is restricted by the shape of the rotation restriction units 111a and 111b, thereby fixing the upper fastener or the vertical shaft 11 in place and maintaining a stable fastening state. The rotation restriction units 111a and 111b may be formed in various structures capable of preventing the rotation of the central block 111, and are not limited thereto.

[0027] FIG. 5 illustrates another embodiment of a vertical fastener assembly according to the present invention.

[0028] Referring to FIG. 5 , the rotation unit 12 further includes a separation prevention ring 51 coupled to the upper side thereof to prevent separation of the rotation unit 12. The upper fastener may have a shape penetrating from the upper surface to the lower surface of the upper plate, and the upper fastener must be stably fixed to the upper plate. For example, various tightening rings or elastic means may be used to prevent the fastened state from being released due to external vibration, impact, or thermal change. Also, an appropriate type of fixing means may be applied to prevent separation of the fastening means. Specifically, to prevent separation of the rotation unit 12, a separation prevention ring unit 51 may be coupled to the upper portion of the rotation unit 12. The separation prevention ring unit 51 may include a ring body 511 that accommodates the vertical shaft 11 and the rotation unit 12; a receiving body 512 that extends cylindrically below the ring body 511; and fixing blades 513a and 513b that extend on both sides of the ring body 511. The receiving body 512 is cylindrical with a smaller diameter than the ring body 511, and a stepped surface may be formed at the boundary between the ring body 511 and the receiving body 512. In addition, the fixed blades 513a and 513b are cylindrical, and a stepped surface may be formed inside each of the fixed blades 513a and 513b. The rotation unit 12 and a portion of the vertical shaft 11 are received inside the ring body 511 and the receiving body 512, and each of the fixed blades 513a and 513b is fixed to the upper plate to prevent the upper fastener from coming off. Various types of C-rings or O-rings may be applied to the upper fastener or lower fastener, and the present invention is not limited thereto.

[0029] Although the present invention has been described in detail above with reference to the embodiments presented, those skilled in the art may make various modifications and alterations without departing from the technical spirit of the present invention by referring to the embodiments presented. The present invention is not limited by such modifications and alterations, but is limited only by the scope of the claims. [Explanation of symbols]

[0030] 11: Vertical axis 12: Rotating unit 13: Tension relief pin 14: Elastic unit 15: Pin housing 51: Anti-detachment ring 111a, 111b: rotation limiting portion 112: Fastening part 113: Concluding hole 114: Insertion fastening part 133: Fastening tap

Claims

1. a vertical shaft 11 extending vertically and connected to the upper plate; a rotation unit 12 coupled to the upper side of the vertical shaft 11 to raise and lower the vertical shaft 11; a strain relief pin 13 detachably coupled to the vertical shaft 11 while being coupled to the upper electrode; an elastic unit 14 coupled to the lower portion of the tension relief pin 13; a pin housing 15 coupled to the upper portion of the strain relief pin 13; A vertical fastener assembly for fastening an upper electrode of a plasma chamber, comprising:

2. The vertical shaft 11 includes a cylindrical fastening portion 112 and a fastening hole 113 formed perpendicular to the extension direction of the fastening portion 112.

2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber as claimed in claim 1, wherein a fastening tap formed on an upper portion of the tension relief pin is detachably coupled to the fastening portion.

3. 2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber according to claim 1, wherein the elastic unit is coupled to the tension relief pin in a coiled form through which the tension relief pin passes.

4. The vertical axis 11 includes a central block 111 and an insert fastening portion 114 extending above the central block 111 and coupled to the rotation unit 12; 2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber as claimed in claim 1, wherein rotation limiting portions 111a and 111b are formed on the central block 111.

5. 2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber as claimed in claim 1, wherein the elastic unit (14) guides the tension relief pin (13) to move up and down.

6. 2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber according to claim 1, wherein the direction of the vertical shaft is changed or the vertical shaft is raised and lowered by the rotation of the rotation unit.

7. 2. The vertical fastener assembly for fastening an upper electrode of a plasma chamber according to claim 1, further comprising a separation prevention ring (51) coupled to an upper side of the rotation unit (12) to prevent the rotation unit (12) from separating.

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