JP2022553646A - Inorganic coating of plasma chamber components - Google Patents

Abstract

A component for use in a plasma processing chamber is provided. The component body is made of an electrically conductive material. A first ceramic coating of a first ceramic material is on the surface of the component body, the first ceramic coating having a first side adjacent to the component body and a second side remote from the component body. and the first ceramic material is a dielectric material. A second ceramic coating of a second ceramic material on a second side of the first ceramic coating with a gap between the first ceramic coating and the second ceramic coating, the gap comprising a polymer material or gas, and the second ceramic material is a dielectric material. [Selection drawing] Fig. 2D

Description

<Cross reference to related applications>
This application claims the benefit of priority from U.S. Patent Application No. 62/913,619, filed October 10, 2019, which application is incorporated herein by reference for all purposes. .

The present disclosure relates to the manufacture of semiconductor devices. More specifically, the present disclosure relates to coating chamber surfaces used in the manufacture of semiconductor devices.

The background discussion provided herein is for the purpose of generally presenting the content of the present disclosure. All statements made in this background section, and any aspects that may be present in the statements made, are not admitted as prior art with respect to this application, whether express or implied.

In processing semiconductor wafers, plasma processing chambers are used to process semiconductor devices. A coating is used to protect the chamber surfaces.

In the formation of semiconductor devices, plasma processing chambers are used to process substrates. Some plasma processing chambers have aluminum alloy components, such as liners within the plasma processing chamber. Such components may be aluminum to provide electrical and thermal properties useful for plasma maintenance. Aluminum also allows weight and cost savings. Such aluminum parts may be corroded by the plasma used during plasma processing. A coating may be used to protect the aluminum components.

Ceramic coatings are formed over plasma processing chamber components to protect against plasma corrosion. Such coatings are subject to stress due to thermal expansion mismatch and fluorination due to exposure to fluorine plasma, which can result in component failure or contaminant generation from the component. Generally, the coefficient of thermal expansion (CTE) of an aluminum ESC body is higher than that of a ceramic protective coating. CTE differences between the ESC body and the protective coating may cause the protective coating to crack.

To solve the aforementioned problems, and in accordance with the objectives of the present disclosure, a component is provided for use in a plasma processing chamber. The component body is made of an electrically conductive material. A first ceramic coating of a first ceramic material is on the surface of the component body, the first ceramic coating defining a first side adjacent to the component body and a second side remote from the component body. and the first ceramic material is a dielectric material. A second ceramic coating of a second ceramic material is on the second side of the first ceramic coating with a gap between the first ceramic coating and the second ceramic coating, the gap being the polymeric material. or gas, and the second ceramic material is a dielectric material.

In another aspect, a method of coating a component body for use in a plasma processing chamber is provided. A first ceramic coating is formed on a surface of the component body, the first ceramic coating having a first side adjacent to the component body and a second side remote from the component body, the component body of a dielectric material and the first ceramic coating is of a dielectric material. A polymer layer is formed on a second side of the first ceramic coating, the polymer layer having a first side adjacent to the second side of the first ceramic coating and a second side remote from the first ceramic coating. has an aspect of A second ceramic coating is formed on the second side of the polymer layer, the second ceramic coating comprising a dielectric material.

In another aspect, a method of coating a component body for use in a plasma processing chamber is provided. A ceramic coating is formed on the surface of the component body, the component body being of an electrically conductive material and the ceramic coating being of a dielectric material. The ion exchange process forms a compressive layer in the ceramic coating.

In another aspect, a component is provided for use in a plasma processing chamber. The component body is made of an electrically conductive material. There is a diamond-like carbon coating on the surface of the component. On top of the diamond-like carbon coating is a ceramic coating.

In another aspect, a method of coating a component body for use in a plasma processing chamber is provided. A diamond-like carbon coating is formed on the surface of the component body, and the component body is made of a conductive material. A ceramic coating is deposited over the diamond-like carbon coating.

In another aspect, a method of coating a component body for use in a plasma processing chamber is provided. A metal oxide coating is deposited on the component body by performing at least one of metal oxide chemical vapor deposition or plasma enhanced vapor deposition at a temperature less than 300°C.

These and other features of the present disclosure are described in greater detail in conjunction with the detailed description of the disclosure below and the following drawings.

The present disclosure is illustrated in the following accompanying drawings, which are presented for purposes of illustration and not limitation. Similar reference numbers in the figures refer to similar elements.

FIG. 1 is a high-level flow chart of an embodiment.

FIG. 2A is a schematic illustration of a substrate processed according to the embodiment shown in FIG. FIG. 2B is a schematic illustration of a substrate processed according to the embodiment shown in FIG. FIG. 2C is a schematic illustration of a substrate processed according to the embodiment shown in FIG. FIG. 2D is a schematic illustration of a substrate processed according to the embodiment shown in FIG.

FIG. 3 is a schematic diagram of a plasma processing system that may be used in embodiments.

FIG. 4 is a high level flowchart of another embodiment.

FIG. 5A is a schematic illustration of a substrate processed by the embodiment shown in FIG. FIG. 5B is a schematic illustration of a substrate processed according to the embodiment shown in FIG.

FIG. 6 is a high level flowchart of another embodiment.

FIG. 7A is a schematic illustration of a substrate processed according to the embodiment shown in FIG. FIG. 7B is a schematic illustration of a substrate processed according to the embodiment shown in FIG.

FIG. 8 is a high level flowchart of another embodiment.

FIG. 9 is a schematic illustration of a substrate processed according to the embodiment shown in FIG.

The present disclosure will be described in detail with reference to some preferred embodiments illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those 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 so as not to unnecessarily obscure the present disclosure.

In an electrostatic chuck (ESC) in a plasma processing chamber, plasma conditions cause erosion of the ESC. A protective coating can be applied to the surface of the ESC. Aluminum ESC bodies typically have a higher coefficient of thermal expansion (CTE) than ceramic protective coatings. CTE differences between the ESC body and the protective coating may cause the protective coating to crack.

Several embodiments are provided for providing improved protective coatings. To facilitate understanding of the embodiments, FIG. 1 shows a high-level flow chart of the process used in the component body coating embodiments. A component body is installed (step 104). In this example, the component body is made of a conductive material, such as aluminum with an anodized surface. A first ceramic coating of ceramic material is applied to the surface of the component body (step 108). FIG. 2A is a partial schematic cross-sectional view of a component body 204 having a first ceramic coating 208 on its surface. In this embodiment, the first ceramic coating 208 is deposited by thermal spray deposition. In other embodiments, the first ceramic coating can be deposited by plasma vapor deposition (PVD), chemical vapor deposition (CVD) or aerosol deposition. In this embodiment, the ceramic material is yttria. A component body 204 is on a first side of a first ceramic coating 208 .

Thermal spraying is a generic term used to describe various coating processes such as plasma spraying, arc spraying, flame/combustion spraying and suspension spraying. All thermal spraying uses energy to heat a solid into a molten or plasticized state. The molten or plasticized material is accelerated toward the substrate and then cooled to coat the surface of the substrate. These processes differ from vapor deposition processes that use vaporized material instead of molten material. In this embodiment, the ceramic coating has a thickness of 25-500 microns. The first ceramic coating has a porosity ranging from 0.5% to 20%. As used herein and in the claims, porosity is measured according to standard test method ASTM E2109-01 (2014).

A polymer layer of polymer material is deposited over the first ceramic coating 208 . The polymer is deposited by at least one of atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma vapor deposition (PVD), plasma enhanced vapor deposition (PEVD), spin-on processes, or other polymer deposition methods. can be deposited. FIG. 2B is a partial schematic cross-sectional view of component body 204 having first ceramic coating 208 after polymer layer 212 has been deposited. In this embodiment, polymer layer 212 is formed from parylene. In this embodiment, polymer layer 212 has a thickness of 25-500 microns.

A second ceramic coating of ceramic material is deposited over polymer layer 212 (step 116). In this embodiment, the second ceramic coating is deposited by chemical vapor deposition (CVD). In other embodiments, the second ceramic coating can be deposited by plasma vapor deposition (PVD) or aerosol deposition. In this embodiment, the ceramic material is yttria. In this embodiment, the thickness of the second ceramic coating is 25-500 microns. The second ceramic coating has a porosity of less than 0.5%.

FIG. 2C is a partial schematic cross-sectional view of component body 204 after depositing second ceramic coating 216 (step 116). In this example, a second ceramic coating 216 surrounds polymer layer 212 and extends to first ceramic coating 208 .

Polymer layer 212 is removed (step 120). In this embodiment, a combustion gas containing oxygen is provided. Combustion gases are converted to plasma. The plasma burns away and removes the polymer layer 212, leaving voids. FIG. 2D is a partial schematic cross-sectional view of component body 204 with gap 220 left after polymer layer 212 is burned (step 120). In other embodiments, polymer layer 212 melts.

The component is mounted as part of a plasma processing chamber (step 124). In this embodiment, the component is an electrostatic chuck (ESC). FIG. 3 is a schematic diagram of a plasma processing chamber 300 for plasma processing a substrate, in which components may be installed in embodiments. In one or more embodiments, plasma processing chamber 300 includes gas distribution plate 306 with gas inlets and ESC component 316 within plasma processing chamber 304 surrounded by chamber wall 350 . A substrate 307 is placed on top of the ESC component 316 in the plasma processing chamber 304 . ESC component 316 may provide bias from ESC power supply 348 . Gas source 310 is connected to plasma processing chamber 304 through gas distribution plate 306 . An ESC temperature controller 351 is connected to the ESC component 316 and provides temperature control of the ESC component 316 . A radio frequency (RF) power supply 330 provides RF power to the ESC component 316 and the upper electrode. In this embodiment, the top electrode is gas distribution plate 306 . In a preferred embodiment, 400 kilohertz (kHz), 13.56 megahertz (MHz), 1 MHz, 2 MHz, 60 MHz and/or optionally 27 MHz power supplies comprise RF power supply 330 and ESC power supply 348 . A controller 335 is controllably connected to RF power supply 330 , ESC power supply 348 , exhaust pump 320 and gas source 310 . High flow liner 360 is the liner in plasma processing chamber 304 and is a structure having grooves 362 to confine gas from the gas source. Groove 362 maintains a controlled gas flow rate to pass gas from gas source 310 to exhaust pump 320 . One example of such a plasma processing chamber is the Flex(R) etch system manufactured by Lam Research Corporation (Fremont, Calif.). In various embodiments, the processing chamber may be a CCP (capacitively coupled plasma) reactor or an ICP (inductively coupled plasma) reactor.

Plasma processing chamber 304 plasma processes substrate 307 with ESC component 316 (step 128). The plasma treatment may be one or more of etching, deposition, passivation or another plasma treatment. Plasma treatment may be performed in combination with non-plasma treatment. Such processing may expose the ESC component 316 to a halogen- and/or oxygen-containing plasma.

Various components of the plasma processing chamber 304 use a conductive metal matrix coated with a dielectric material such as aluminum oxide or yttrium oxide deposited by a thermal spray or plasma atomization process. Such components include the ESC's Pinnacle® and liner, gas distribution plate 306, and the like.

A defect-free dielectric coating is critical to maintaining both electrical standoff and chemical resistance. The thicker the dielectric ceramic coating, the more prone it is to crack. As dielectric ceramic coatings become thinner, they may not provide sufficient insulation to prevent damage caused by the voltages that plasma processing chamber 304 uses. By using two thin ceramic coatings, first ceramic coating 208 and second ceramic coating 216, cracking can be reduced compared to thicker ceramic coatings. In addition, gap 220 provides first ceramic coating 208 and second ceramic coating 216 with higher dielectric strength, increasing standoff voltage and reducing electrical damage.

In other embodiments, walls, plugs, or pillars can be used to separate the first ceramic coating 208 and the second ceramic coating 216 after the polymer layer 212 is removed. In other embodiments, other methods can be used to create the gap 220 by placing supports. For example, the ring may be placed over the first ceramic coating before the polymer layer fills the ring with polymer. Gap 220 may be filled with air to act as an air gap.

In other embodiments, polymer layer 212 does not burn out. Polymer layer 212 has a higher dielectric strength than first ceramic coating 208 and second ceramic coating 216 . However, the polymer layer 212 is rapidly corroded by the plasma. As such, a second ceramic coating 216 covers the polymer layer and protects it from the plasma. Such embodiments may provide improved standoff voltage and improved thermal insulation.

In various embodiments, the first ceramic coating 208 and the second ceramic coating 216 are made of alumina, yttria, zirconia, stabilized zirconia, yttrium aluminum mixtures (such as yttrium aluminum garnet) or magnesium aluminum oxide _{( MgAl2O4} ). ) may be formed from spinel. In other embodiments, first ceramic coating 208 and second ceramic coating 216 may be formed from rare earth materials such as erbium oxide, dysprosium oxide, cerium oxide, gadolinium oxide, and ytterbium oxide. In some embodiments, first ceramic coating 208 is of the same material as second ceramic coating 216 . If the first ceramic coating 208 and the second ceramic coating 216 consist of the same material, the first ceramic coating 208 and the second ceramic coating have the same CTE.

FIG. 4 is a high level flowchart of another embodiment. A component body is installed (step 404). The component body is made from an electrically conductive material. A ceramic coating is deposited on the surface of the component body (step 408). FIG. 5A is a schematic cross-sectional view of component body 504 after ceramic coating 508 has been deposited on the surface of component body 504 (step 408). In this embodiment, the component body is aluminum with an anodized surface. In this example, a thermal spray process is used to deposit a ceramic coating of alumina.

The ion exchange process forms a compressive layer in the ceramic coating 508 (step 412). In this example, ion exchange is accomplished by subjecting the ceramic coating 508 to vacuum ion bombardment. Ion bombardment may be performed by biasing the plasma of ions. The bias accelerates the ions and implants them into the ceramic coating 508 . FIG. 5B is a schematic cross-sectional view of component body 504 after compressive layer 512 has been formed in ceramic coating 508 (step 412). Ions take up more space, causing compression. The component is installed as part of plasma processing chamber 300 (step 416). The component is used in plasma processing chamber 300 (step 420). It has been found that the ceramic coating 508 hardens with the compressive layer 512 and can be more resistant to stress-induced cracking during handling and temperature cycling. Compressive layer 512 thus helps prevent cracking caused by high temperatures.

In other embodiments, a bath may be used to perform ion exchange. Bath temperatures above a certain temperature may be used to facilitate ion exchange. The ion exchange bath may be a molten salt bath at a temperature below the melting point of ceramic coating 508 . Alkaline ions in the ceramic coating 508 may be exchanged for larger amounts of ions from the bath causing compressive stress. In other embodiments, a diffusion process may be used to form compressive layer 512 .

FIG. 6 is a high level flowchart of another embodiment. A component body is installed (step 604). In this embodiment, the component body is made of a conductive material such as aluminum. A diamond-like coating is formed on the surface of the component body (step 608). In one example of a process for depositing a diamond-like coating, a combination of heat and pressure is used to compress the sp ² -bonded carbon sufficiently to create sp ³ carbon bonds. In this embodiment, the diamond-like coating is an amorphous carbon material and exhibits some properties of diamond. The term diamond-like carbon is known in the art. FIG. 7A is a schematic partial cross-sectional view of component body 704 after a diamond-like carbon layer 708 has been deposited on the surface of component body 704 .

A ceramic coating is formed over the diamond-like carbon layer 708 (step 612). In embodiments, the ceramic coating is formed by atomic layer deposition or chemical vapor deposition. FIG. 7B is a schematic cross-sectional view of component body 704 after ceramic coating 712 has been formed over diamond-like carbon layer 708 . The component is mounted in plasma processing chamber 300 (step 616). The component is used in a plasma processing chamber (step 624).

Diamond-like carbon layer 708 has high dielectric strength and high physical strength. However, diamond-like carbon layer 708 is corroded by plasma containing oxygen or halogen. Therefore, a ceramic coating 712 is provided to protect the diamond-like carbon layer 708 from attack by oxygen- or halogen-containing plasmas. Ceramic coating 712 may be thin. A more non-porous ceramic coating 712 is desirable. Ceramic coatings formed by atomic layer deposition or chemical vapor deposition have such properties. In this embodiment, the thickness of the second ceramic coating is between 100 nanometers and 500 microns. The second ceramic coating has a porosity of less than 0.5%.

FIG. 8 is a high level flowchart of another embodiment. A component body is installed (step 804). In this example, the component body is aluminum. A metal oxide coating is deposited on the surface of the component body (step 808). In this example, the metal oxide coating is aluminum oxide _{( Al2O3} ). Instead of oxidizing the component body, the metal oxide is deposited by metal oxide chemical vapor deposition (MOCVD) or plasma enhanced vapor deposition (PECVD) at low temperature. In this embodiment, metal oxide formation is performed at a temperature of less than 300°C. In other embodiments, metal oxide formation is performed at a temperature below 200°C. In other embodiments, metal oxide formation is performed at a temperature below 100°C. FIG. 9 is a schematic cross-sectional view of component body 904 having metal oxide coating 908 . The components are mounted in plasma processing chamber 300 (step 812). The component is used in plasma processing chamber 300 (step 816).

Although this disclosure has been described in terms of several preferred embodiments, there are alterations, substitutions, modifications and various alternative equivalents that fall within the scope of this disclosure. Also note that there are many alternative ways to implement the disclosed method and apparatus. It is therefore intended that the following appended claims be construed to include such modifications, replacements and various alternative equivalents that fall within the true spirit and scope of this disclosure.

Claims (18)

A component for use in a plasma processing chamber comprising:
a component body made of a conductive material;
A first ceramic coating of a first ceramic material on a surface of the component body, the first ceramic material having a first side adjacent to the component body and spaced from the component body. a first ceramic coating having a second side, wherein the first ceramic material is a dielectric material;
a second ceramic coating of a second ceramic material on the second side of the first ceramic coating, wherein there is a gap between the first ceramic coating and the second ceramic coating; a second ceramic coating, wherein the gap is filled with at least one of a polymeric material or a gas, and wherein the second ceramic material is a dielectric material. A component according to claim 1, comprising:
The first ceramic coating and the second ceramic coating include alumina, yttria, zirconia, stabilized zirconia, yttrium-aluminum mixture, erbium oxide, dysprosium oxide, cerium oxide, gadolinium oxide, magnesium oxide aluminum spinel, and ytterbium oxide. A component comprising at least one of A component according to claim 1, comprising:
further comprising at least one support between the first ceramic coating and the second ceramic coating to maintain the gap between the first ceramic coating and the second ceramic coating; component. A component according to claim 1, comprising:
The component, wherein the first ceramic material is the same as the second ceramic material. A method of coating a component body for use in a plasma processing chamber, comprising:
forming a first ceramic coating on a surface of the component body, the first ceramic coating defining a first side adjacent to the component body and a second side remote from the component body; wherein the component body is a conductive material and the first ceramic coating is a dielectric material;
a polymer layer having a first side adjacent to the second side of the first ceramic coating and a second side remote from the first ceramic coating; forming on the sides;
forming a second ceramic coating of a dielectric material on the second side of the polymer layer. 6. The method of claim 5, wherein
The method further comprising removing the polymer layer after forming the second ceramic coating. 6. The method of claim 5, wherein
The first ceramic coating consists of a first ceramic material, the second ceramic coating consists of a second ceramic material, and the first ceramic material is the same as the second ceramic material. . A method of coating a component body for use in a plasma processing chamber, comprising:
forming a ceramic coating of a dielectric material on the surface of the component body of an electrically conductive material;
forming a compressive layer in said ceramic coating by an ion exchange process. 9. The method of claim 8, wherein
The method, wherein said forming of said compressive layer comprises subjecting said ceramic coating to vacuum ion bombardment. 9. The method of claim 8, wherein
said forming of said compressive layer comprises immersing said ceramic coating in a bath at a temperature sufficient to cause ion exchange or a diffusion step to implant ions into said ceramic coating; Method. A component made by the method of claim 8 . A component for use in a plasma processing chamber comprising:
a component body comprising an electrically conductive material;
a diamond-like carbon coating on the surface of the component body;
A component comprising: a ceramic coating over the diamond-like carbon coating; 13. The component of claim 12, comprising:
The component, wherein the ceramic coating is a dielectric coating formed by at least one of atomic layer deposition or chemical vapor deposition. A method of coating a component body for use in a plasma processing chamber, comprising:
forming a diamond-like carbon coating on a surface of the component body containing a conductive material;
depositing a ceramic coating over the diamond-like carbon coating. 15. The method of claim 14, wherein
The method, wherein said depositing said ceramic coating comprises at least one of atomic layer deposition or chemical vapor deposition. A method of coating a component body for use in a plasma processing chamber, comprising:
A method comprising depositing a metal oxide coating on said component body by performing at least one of metal oxide chemical vapor deposition or plasma enhanced vapor deposition at a temperature of less than 300°C. 17. The method of claim 16, wherein
The method of claim 1, wherein the component body comprises aluminum and is electrically conductive. A component made by the method of claim 16.

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