Sealant coating for plasma processing chamber components - Patents.com

Abstract

A component for use in a plasma processing chamber is provided. A metal-containing component body is provided. A sealant coating is on a surface of the metal-containing component body and includes at least one of a silicone sealant, an organic sealant, and an epoxy sealant. The sealant coating is uncoated and is directly exposed to plasma in the plasma processing chamber.

Description

[Background technology]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority to U.S. Application No. 62 / 860,540, filed June 12, 2019, which is incorporated by reference herein for all purposes.

[0002] The present disclosure relates to the manufacture of semiconductor devices, and more particularly to plasma chamber components used in the manufacture of semiconductor devices.

[0003] During semiconductor wafer processing, plasma processing chambers are used to process semiconductor devices, and components of the plasma processing chamber are exposed to the plasma and can become degraded. Summary of the Invention

[0004] To achieve the foregoing and in accordance with the objectives of the present disclosure, a component for use in a plasma processing chamber is provided. A metal-containing component body is provided. A sealant coating is provided on a surface of the metal-containing component body, the sealant coating comprising at least one of a silicone sealant, an organic sealant, and an epoxy sealant. The sealant coating is uncoated and is directly exposed to the plasma in the plasma processing chamber.

[0005] In another embodiment, a method for forming a plasma processing chamber component is provided: A metal-containing component body is provided: A sealant is applied onto a surface of the metal-containing component body.

[0006] These and other features of the present disclosure are described in more detail below in the detailed description of the present disclosure taken in conjunction with the following figures. [Brief description of the drawings]

[0007] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to like elements and in which:

[0008] [Figure 1] 1 is a high level flow chart of an embodiment.

[0009] [Figure 2A] 1 is a schematic diagram of a portion of a component processed according to an embodiment; [Figure 2B] 1 is a schematic diagram of a portion of a component processed according to an embodiment; [Figure 2C] 1 is a schematic diagram of a portion of a component processed according to an embodiment;

[0010] [Diagram 3] 1 is a schematic diagram of a plasma reactor that may be used in embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present disclosure will now be described in detail with reference to several preferred embodiments thereof, as illustrated in the accompanying drawings. In the following description, several specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process steps and / or structures have not been described in detail in order not to unnecessarily obscure the present disclosure.

[0012] Materials that provide resistance to arcing are typically metal oxides. Metal oxides are typically brittle and prone to cracking, and have a relatively low coefficient of thermal expansion (CTE). Cracking induced by cycling over a wide range of temperatures will result in dielectric breakdown and cause the component to fail.

[0013] Current protective coatings on electrostatic chuck (ESC) base plates include anodization, ceramic paint coatings, or paint coatings over anodization. Some products use an aluminum nitride coating grown directly on the surface of the aluminum base plate. Data shows that when anodization is on aluminum flat surfaces, it collapses at about 2 kilovolts (kV) for a 0.002 inch (0.00508 centimeter) thick coating, and 600 volts (V) at the corner radius. Paint coatings applied perpendicular to the surface will withstand up to 10 kV on flat surfaces, but only about 4-5 kV at the corner radius. Attempts to further improve collapse by making the coating thicker cause existing technology to reach its limits at these values, as the mismatch between the CTE of the substrate and the CTE of the coating material causes cracking in response to thermal cycling.

[0014] The metal parts of the ESC may be exposed to greater voltages than the chamber body, and therefore it may be desirable to protect the metal parts of the ESC from chemical degradation and dielectric breakdown.

[0015] For ease of understanding, Figure 1 is a high level flow chart of the process used in the embodiments. A metal-containing component body is provided (step 104). Figure 2A is a simplified cross-sectional view of a portion of a metal-containing component body 204 of a component 200. In this example, the component 200 is an electrostatic chuck (ESC). In this embodiment, the metal-containing component body 204 is aluminum. The component body 204 has a surface 206. In this embodiment, the surface 206 is a plasma-facing surface, or a surface exposed to radicals formed by the plasma, or a surface exposed to a static charge during plasma processing.

[0016] A ceramic coating is deposited on the surface 206 of the metal-containing component body 204 (step 108). Figure 2B is a simplified cross-sectional view of the metal-containing component body 204 after the ceramic coating 208 has been deposited on the surface 206 of the metal-containing component body 204. In this embodiment, the ceramic coating 208 is alumina deposited by plasma spraying. In this embodiment, the plasma spraying produces holes 210 in the ceramic coating 208.

[0017] Plasma spraying is a type of thermal spraying in which a torch is formed by applying an electric potential between two electrodes, causing the ionization of an accelerating gas (plasma). This type of torch can easily reach temperatures of several thousand degrees Celsius and melt high melting point materials such as ceramics. Particles of the desired material are injected into a nozzle, melted, and accelerated toward a substrate so that the molten or plasticized material coats the surface of the component and cools to form a solid conformal coating. Plasma spraying is preferably used to deposit the ceramic coating 208. These processes differ from deposition processes that use evaporated material rather than molten material. In this embodiment, the ceramic coating 208 has a thickness of 30 μm to 750 μm. In another embodiment, the ceramic coating 208 has a thickness of 300 μm to 600 μm. In another embodiment, the ceramic coating 208 is a plasma electrolytic oxidation ceramic coating having a thickness of 30 μm to 200 μm. An example recipe for plasma spraying the ceramic coating 208 is as follows: A carrier gas is forced into the arc cavity and forced out through a nozzle. In the cavity, the cathode and anode contain a portion of the arc cavity. The cathode and anode are maintained at a high DC bias voltage until the carrier gas ionizes and forms a plasma. The hot ionized gas is then forced out through a nozzle, forming a torch. Flowing ceramic particles, tens of micrometers in size, are injected into the chamber near the nozzle. These particles are heated by the hot ionized gas in the plasma torch so that they exceed the melting temperature of the ceramic. The nozzle of the plasma and molten ceramic are then directed at the substrate. The particles impact the substrate, flattening and cooling to form a ceramic coating.

[0018] A sealant coating is applied to the ceramic coating 208 (step 112). In this example, the sealant is Loctite® PC7319™ (also known as Loctite® Nordbak® Chemical Resistant Coating™) manufactured by Henkel Corporation of Westlake, Ohio. Loctite PC7319 is an epoxy. Loctite PC7319 provides a breakdown voltage greater than 2000 volts. Generally, the sealant is an organic sealant that includes at least one of fluorinated polymers, perfluoropolymers, silicones, epoxy sealants, and parylene. The sealant may be applied by brushing, spraying, or dipping. In this embodiment, the sealant is applied by an impregnation method. The sealant is poured, dipped, or rubbed onto the ceramic coating 208 so that the sealant penetrates the holes 210 in the ceramic coating 208. The sealant is then cured (step 116). Curing of the sealant may be achieved by drying, heating, or polymerizing the sealant to form a sealant coating.

[0019] 2C is a simplified cross-sectional view of the metal-containing component body 204 after a sealant coating 212 has been formed on the ceramic coating 208 on the surface of the metal-containing component body 204. In this embodiment, the sealant fills the holes but does not form a continuous surface over the ceramic coating 208. In some embodiments, a top surface layer less than 50 microns thick is formed.

[0020] The component is mounted in a plasma processing chamber, step 120. The plasma processing chamber is used to process a substrate, step 124. A plasma is generated in the chamber to process the substrate, such as etching the substrate, and the unprotected sealant coating 212 is exposed to the plasma.

[0021] 3 is a schematic diagram of a plasma processing chamber 300 with installed components. The plasma processing chamber 300 comprises a confinement ring 302, an upper electrode 304, a lower electrode 308 in the form of an electrostatic chuck (ESC), a gas source 310, a liner 362, and an exhaust pump 320. In this example, the components are ESCs. In the plasma processing chamber 300, a wafer 366 is placed on the lower electrode 308. The lower electrode 308 incorporates a substrate chucking mechanism (e.g., electrostatic clamp, mechanical clamp, etc.) suitable for holding the wafer 366. The reactor top 328 incorporates an upper electrode 304 disposed directly opposite the lower electrode 308. The upper electrode 304, the lower electrode 308, and the confinement ring 302 define a confined plasma volume 340.

[0022] Gas is supplied to the confined plasma volume 340 from a gas source 310 through a gas inlet 343 and is exhausted from the confined plasma volume 340 by an exhaust pump 320 through the confinement rings 302 and an exhaust port. The exhaust pump 320 serves to exhaust the gas and also to regulate the pressure. A radio frequency (RF) source 348 is electrically connected to the lower electrode 308.

[0023] The chamber walls 352 surround the liner 362, the confinement rings 302, the upper electrode 304, and the lower electrode 308. The liner 362 helps to prevent gas or plasma passing through the confinement rings 302 from contacting the chamber walls 352. Different combinations of RF power connections to the electrodes are possible. In a preferred embodiment, 27 MHz, 60 MHz, and 2 MHz power sources constitute the RF source 348 that connects to the lower electrode 308, and the upper electrode 304 is grounded. A controller 335 is controllably connected to the RF source 348, the exhaust pump 320, and the gas source 310. The plasma processing chamber 300 may be a CCP (capacitively coupled plasma) reactor or an ICP (inductively coupled plasma) reactor, or may use other sources such as surface waves, microwaves, or electron cyclotron resonance (ECR) may be used.

[0024] The resulting coating is resistant to chemical degradation and arcing, and as a result, plasma processing chambers equipped with such components will have fewer defects, reducing the failure rate of such systems and increasing the time between replacement of various parts.

[0025] In other embodiments, the sealant may be an organic coating including at least one of fluorinated polymers, perfluoropolymers, silicones, epoxies, and parylenes. In an embodiment, the sealant is Xylan® 1620 manufactured by Micro Surface Corporation of Morris, Illinois. Xylan 1620 provides a fluoropolymer coating with a coefficient of friction as low as 0.02. In another embodiment, the sealant is PCT S-Sealer, previously manufactured by Protective Coating Technology of Haifa Bay, Israel. PCT S-Sealer is an organic ceramic self-leveling sealer. PCT S-Sealer has a coefficient of friction of 0.12. PCT S-Sealer has been found to provide a breakdown voltage greater than 5000 volts. In another embodiment, the sealant is Dichtor WF49 manufactured by Diamant of Germany. Dichtor WF49 has been found to provide a breakdown voltage greater than 2000 volts. In another embodiment, the sealant is parylene. Parylene is made of poly(p-xylylene) polymer. Parylene is deposited using a heat process in which gases are decomposed and then condensed on the ceramic coating 208. In various embodiments, the sealant may be used at temperatures ranging from about -60°C to 300°C.

[0026] In various embodiments, the component may be other parts of a plasma processing chamber, such as a confinement ring, edge ring, ground ring, chamber liner, door liner, or other parts. The plasma processing chamber may be a dielectric processing chamber or a conductive processing chamber. In some embodiments, one or more, but not all, surfaces are coated. The plasma processing chamber may be used for etching, deposition, or other substrate processing. In the above embodiment, the substrate support was provided by an ESC, but in other embodiments, the coating may be used on other substrate supports, such as a pedestal or substrate support without electrostatic chucking.

[0027] In other embodiments, the sealant coating 212 is deposited directly on the metal-containing component body 204 without the ceramic coating 208. In various embodiments, the metal-containing component body 204 can be aluminum or aluminum-based with silicon carbide particles (AlSiC). The aluminum component body 204 includes an aluminum-based alloy, such as aluminum 6061. The metal-containing component body 204 can further include a filler, such as a filler comprised of boron carbide or boron nitride.

[0028] While the present disclosure has been described in terms of several preferred embodiments, there are changes, permutations, modifications, and various substitute equivalents that fall within the scope of the present disclosure. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present disclosure. It is therefore intended that the following appended claims be interpreted to include all such changes, permutations, and various substitute equivalents that fall within the true spirit and scope of the present disclosure. The present disclosure may be realized in the following forms. [Form 1] 1. A component for use in a plasma processing chamber, comprising: A metal-containing component body; a sealant coating on a surface of the metal-containing component body, the sealant coating comprising at least one of a silicone-based sealant, an organic sealant, and an epoxy sealant, the sealant coating being uncoated and directly exposed to plasma in the plasma processing chamber; A component comprising: [Form 2] The component according to aspect 1, The component, wherein the sealant coating is an organic coating of at least one of a fluorinated polymer, a perfluoropolymer, a silicone, an epoxy, and a poly(p-xylylene) polymer. [Form 3] The component according to aspect 1, The component, wherein the sealant coating is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dictol WF49. [Form 4] The component according to aspect 1, The metal-containing component body forms a substrate support. [Form 5] The component according to aspect 1, further comprising: 13. A component comprising a ceramic coating on a surface of the metal-containing component body, the sealant coating being impregnated into the ceramic coating. [Form 6] The component according to aspect 5, The component, wherein the sealant coating is an organic coating of at least one of a fluorinated polymer, a perfluoropolymer, and a poly(p-xylylene) polymer. [Form 7] The component according to aspect 5, The component, wherein the sealant coating is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dictol WF49. [Form 8] The component according to aspect 5, The metal-containing component body forms a substrate support. [Form 9] 1. A method for forming a plasma processing chamber component, comprising: providing a metal-containing part body; applying a sealant onto a surface of the metal-containing component body; A method comprising: [Form 10] 10. The method of claim 9, further comprising: The method, wherein the sealant is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dictol WF49. [Form 11] 10. The method of claim 9, further comprising: The sealant is parylene, and the step of applying the parylene comprises: evaporating the parylene; condensing the parylene on the metal-containing component body; A method comprising: [Form 12] 10. The method of claim 9, further comprising: The method, wherein the sealant is an organic sealant, at least one of a fluorinated polymer, a perfluoropolymer, a silicone, an epoxy, and a poly(p-xylylene) polymer. [Form 13] 10. The method of aspect 9, further comprising: placing the metal-containing component body in a plasma processing chamber; plasma processing a substrate in the plasma processing chamber, the sealant being exposed to plasma during the plasma processing; A method comprising: [Form 14] 10. The method of claim 9, further comprising: The method of claim 1, wherein the metal-containing component body forms a substrate support. [Form 15] 10. The method of aspect 9, further comprising: depositing a ceramic coating on a surface of the metal-containing component body, wherein the sealant is impregnated into the ceramic coating. [Form 16] 16. The method of claim 15, further comprising: The method, wherein the sealant is at least one of a fluorinated polymer, a perfluoropolymer, and a poly(p-xylylene) polymer. [Form 17] 16. The method of claim 15, further comprising: The method, wherein the sealant is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dictol WF49. [Form 18] 16. The method of claim 15, further comprising: The method of claim 1, wherein the metal-containing component body forms a substrate support. [Form 19] 10. The method of aspect 9, further comprising: allowing the sealant to cure.

Claims

1. 1. A component for use in a plasma processing chamber, comprising: A metal-containing component body; a sealant coating on a surface of the metal-containing component body, the sealant coating comprising at least one of a silicone-based sealant, an organic sealant, and an epoxy sealant, the sealant coating being uncoated and directly exposed to plasma in the plasma processing chamber; Equipped with The metal-containing component body forms a substrate support.

2. Component according to claim 1, The component, wherein the sealant coating is an organic coating of at least one of a fluorinated polymer, a perfluoropolymer, a silicone, an epoxy, and a poly(p-xylylene) polymer.

3. Component according to claim 1, The component, wherein the sealant coating is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dihytor WF49.

4. 10. The component of claim 1, further comprising:

13. A component comprising a ceramic coating on a surface of the metal-containing component body, the sealant coating being impregnated into the ceramic coating.

5. Component according to claim 4, The component, wherein the sealant coating is an organic coating of at least one of a fluorinated polymer, a perfluoropolymer, and a poly(p-xylylene) polymer.

6. Component according to claim 4, The component, wherein the sealant coating is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dihytor WF49.

7. 1. A method for forming a plasma processing chamber component, comprising: providing a metal-containing part body; applying a sealant onto a surface of the metal-containing component body; Including, the sealant comprises at least one of a silicone-based sealant, an organic sealant, and an epoxy sealant; the metal-containing component body forms a substrate support; method.

8. 8. The method of claim 7, The method, wherein the sealant is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dihytor WF49.

9. 8. The method of claim 7, The sealant is parylene, and the step of applying the parylene comprises: evaporating the parylene; condensing the parylene on the metal-containing component body; A method comprising:

10. 8. The method of claim 7, The method, wherein the sealant is an organic sealant, at least one of a fluorinated polymer, a perfluoropolymer, a silicone, an epoxy, and a poly(p-xylylene) polymer.

11. 8. The method of claim 7 further comprising: placing the metal-containing component body in a plasma processing chamber; plasma processing a substrate in the plasma processing chamber, the sealant being exposed to plasma during the plasma processing; A method comprising:

12. 8. The method of claim 7 further comprising: depositing a ceramic coating on a surface of the metal-containing component body, wherein the sealant is impregnated into the ceramic coating.

13. 13. The method of claim 12, The method, wherein the sealant is at least one of a fluorinated polymer, a perfluoropolymer, and a poly(p-xylylene) polymer.

14. 13. The method of claim 12, The method, wherein the sealant is at least one of Parylene, PCT S-Sealer, Loctite PC7319, Xylan 2630, and Dihytor WF49.

15. 8. The method of claim 7 further comprising: allowing the sealant to cure.

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