WO2021163053A1

WO2021163053A1 - Coating for plasma processing chamber part

Info

Publication number: WO2021163053A1
Application number: PCT/US2021/017249
Authority: WO
Inventors: David Joseph WETZEL; Lin Xu; Hong Shih; Yiwei SONG; Michael Julius KINSLER
Original assignee: Lam Research Corporation
Priority date: 2020-02-13
Filing date: 2021-02-09
Publication date: 2021-08-19
Also published as: TW202147381A

Abstract

A method for providing a coating on an aluminum-containing component body for use in a plasma processing chamber is provided. An anodization layer is formed on the component body. The anodization layer is polished to reduce surface roughness. A rare earth containing layer is deposited on the polished anodization layer by at least one of aerosol deposition, plasma vapor deposition, and atomic layer deposition.

Description

COATING FOR PLASMA PROCESSING CHAMBER PART

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of priority of U.S. Application No.

62/976,063, filed February 13, 2020, which is incorporated herein by reference for all purposes.

BACKGROUND

[0002] The disclosure relates to a method for conditioning a part for a plasma processing chamber. More specifically, the disclosure relates a method for conditioning an aluminum- containing part for use in a plasma processing chamber.

[0003] In forming semiconductor devices plasma processing chambers are used to process the substrates. Some plasma processing chambers have aluminum alloy parts, such as pinnacles. Such aluminum alloy parts may be damaged during plasma processing. A coating may be used to protect the parts. Coatings may be subjected to cracking, flaking, or spalling. [0004] The background description provided here is for the purpose of generally presenting the context of the disclosure. Information described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] To achieve the foregoing and in accordance with the purpose of the present disclosure, a method for providing a coating on an aluminum-containing component body for use in a plasma processing chamber is provided. An anodization layer is formed on the component body. The anodization layer is polished to reduce surface roughness. A rare earth containing layer is deposited on the polished anodization layer by at least one of aerosol deposition, plasma vapor deposition, and atomic layer deposition.

[0006] In another manifestation, a component for use in a plasma processing chamber is provided. The component has a component body. An anodization layer is disposed on the component body with a surface roughness of less than 0.25 Ra mhi. A rare earth containing layer is disposed on the anodization layer.

[0007] These and other features of the present disclosure will be described in more detail below in the detailed description of the disclosure and in conjunction with the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:

[0009] FIG. 1 is a high level flow chart of an embodiment. [0010] FIGS. 2A-D are schematic cross-sectional views of a component body processed according to an embodiment.

[0011] FIG. 3 is a schematic view of a plasma processing chamber that may be used in an embodiment.

[0012] FIGS. 4A-B schematic cross-sectional views of a component body processed according to another embodiment.

[0013] FIGS. 5A-B schematic cross-sectional views of a component body processed according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0014] The present disclosure will now be described in detail with reference to a few preferred embodiments thereof as 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. It will be apparent, however, 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 to not unnecessarily obscure the present disclosure.

[0015] To facilitate understanding, FIG. 1 is a high level flow chart of a process used in an embodiment. A component body is provided (step 104). In this embodiment, the component body is made of an aluminum-containing material. In this example, the aluminum-containing material is an aluminum alloy material, such as A16061. A16061 is an aluminum alloy containing magnesium and silicon as the major alloying elements. FIG. 2A is a schematic cross- sectional view of part of component body 204. In this example, the component body 204 forms a pinnacle.

[0016] An aluminum layer is deposited on at least one surface of the component body

204 (step 108). In this embodiment, electroplating is used to provide the aluminum layer that is 99.9% pure by mass. The aluminum layer is plated by using a non-aqueous electrolyte and soluble ultra-high purity aluminum anodes to electrodeposit pure A1 in a completely enclosed environment. To provide the aluminum layer with sufficiently high purity, a conductive organic- based solution instead of a water-based solution is desired. FIG. 2B is a schematic cross- sectional view of part of the component body 204 after an aluminum layer 208 has been deposited. The drawing is not to scale in order to illustrate various aspects of the embodiment. [0017] An anodization layer is formed (step 112). In this embodiment, the surface of the aluminum layer 208 is anodized with a Type II anodization to form aluminum oxide (AI2O3). Type II anodization uses sulfuric acid at a temperature of between 10° C to 40° C, resulting in the anodization layer with a thickness between about 1.8 microns to 25 microns. In addition, in this embodiment, the anodization layer is not sealed. FIG. 2C is a cross-sectional view of part of the component body after the surface of the aluminum layer 208 has been hard anodized to form an anodization layer 212 made of aluminum oxide. Since the aluminum layer 208 has a high purity, the anodization process may result in the anodization layer 212 having high purity and fewer defects.

[0018] The anodization layer 212 is polished to reduce surface roughness. Mechanical polishing on a turntable with various grits of polishing pads is used to achieve target Ra uniformly. In this embodiment, the polishing reduces the surface roughness to be less than 0.25 Ra mhi. In another embodiment, the surface roughness is polished to less or equal to 0.1 Ra pm. In an embodiment, the polishing uses Scotch-Brite® pads by 3M or diamond pads with a grit in the range of 280 to 3000. In this embodiment a polishing slurry is not used.

[0019] A rare earth containing layer or coating is deposited on the polished anodization layer 212 (step 120). In this embodiment, a yttria coating is deposited by aerosol deposition. Aerosol deposition is achieved by passing a carrier gas through a fluidized bed of solid powder. Driven by a pressure difference, the powder particles are accelerated through a nozzle, forming an aerosol jet at its outlet. The aerosol jet is then directed at the surface of the anodization layer 212, where the aerosol jet impacts the surface with high velocity. The powder particles break up into solid nanosized fragments, forming a coating. Optimization of carrier gas species, gas consumption, standoff distance, and scan speed provides high-quality coatings. FIG. 2D is a schematic cross-sectional view of part of the component body 204 after the rare earth containing layer 216 has been deposited.

[0020] The component body is mounted in a plasma processing chamber (step 124). In this example, the component body is used as a pinnacle. FIG. 3 schematically illustrates an example of a plasma processing chamber system 300 that may be used in an embodiment. The plasma processing chamber system 300 includes a plasma reactor 302 having a plasma processing confinement chamber 304 therein. A plasma power supply 306, tuned by a matching network 308, supplies power to a transformer coupled plasma (TCP) coil 310 located near a dielectric inductive power window 312 to create a plasma 314 in the plasma processing confinement chamber 304 by providing an inductively coupled power. A pinnacle 372 extends from a chamber wall 376 of the plasma processing confinement chamber 304 to the dielectric inductive power window 312 forming a pinnacle ring. The pinnacle 372 is angled with respect to the chamber wall 376 and the dielectric inductive power window 312, such that the interior angle between the pinnacle 372 and the chamber wall 376 and the interior angle between the pinnacle 372 and the dielectric inductive power window 312 are each greater than 90° and less than 180°. The pinnacle 372 provides an angled ring near the top of the plasma processing confinement chamber 304, as shown. The TCP coil (upper power source) 310 may be configured to produce a uniform diffusion profile within the plasma processing confinement chamber 304. For example, the TCP coil 310 may be configured to generate a toroidal power distribution in the plasma 314. The dielectric inductive power window 312 is provided to separate the TCP coil 310 from the plasma processing confinement chamber 304 while allowing energy to pass from the TCP coil 310 to the plasma processing confinement chamber 304. A wafer bias voltage power supply 316 tuned by a matching network 318 provides power to an electrode 320 to set the bias voltage on the substrate 366. The substrate 366 is supported by the electrode 320. A controller 324 controls the plasma power supply 306 and the wafer bias voltage power supply 316.

[0021] The plasma power supply 306 and the wafer bias voltage power supply 316 may be configured to operate at specific radio frequencies such as, for example, 13.56 megahertz (MHz), 27 MHz, 2 MHz, 60 MHz, 400 kilohertz (kHz), 2.54 gigahertz (GHz), or combinations thereof. Plasma power supply 306 and wafer bias voltage power supply 316 may be appropriately sized to supply a range of powers in order to achieve desired process performance. For example, in one embodiment, the plasma power supply 306 may supply the power in a range of 50 to 5000 Watts, and the wafer bias voltage power supply 316 may supply a bias voltage of in a range of 20 to 2000 volts (V). In addition, the TCP coil 310 and/or the electrode 320 may be comprised of two or more sub-coils or sub-electrodes. The sub-coils or sub-electrodes may be powered by a single power supply or powered by multiple power supplies.

[0022] As shown in FIG. 3, the plasma processing chamber system 300 further includes a gas source/gas supply mechanism 330. The gas source 330 is in fluid connection with plasma processing confinement chamber 304 through a gas inlet, such as a gas injector 340. The gas injector 340 may be located in any advantageous location in the plasma processing confinement chamber 304 and may take any form for injecting gas. Preferably, however, the gas inlet may be configured to produce a “tunable” gas injection profile. The tunable gas injection profile allows independent adjustment of the respective flow of the gases to multiple zones in the plasma process confinement chamber 304. More preferably, the gas injector is mounted to the dielectric inductive power window 312. The gas injector may be mounted on, mounted in, or form part of the power window. The process gases and by-products are removed from the plasma process confinement chamber 304 via a pressure control valve 342 and a pump 344. The pressure control valve 342 and pump 344 also serve to maintain a particular pressure within the plasma processing confinement chamber 304. The pressure control valve 342 can maintain a pressure of less than 1 torr during processing. An edge ring 360 is placed around the substrate 366. The gas source/gas supply mechanism 330 is controlled by the controller 324. A Kiyo® by Lam Research Corp.® of Fremont, CA, may be used to practice an embodiment.

[0023] In various embodiments, the component body may be other parts of a plasma processing chamber, such as confinement rings, edge rings, the electrostatic chuck, ground rings, chamber liners, door liners, high flow liners, showerhead, or other components. Other components of other types of plasma processing chambers may be used. For example, plasma exclusion rings on a bevel etch chamber may be coated in an embodiment. In another example, the plasma processing chamber may be a dielectric processing chamber or conductor processing chamber. In some embodiments, one or more, but not all surfaces are coated.

[0024] If the component body of an aluminum alloy is anodized, the alloying metal(s) in the aluminum alloy cause secondary phase impurities thereby creating voids and large pores for the anodization layer. The voids and large pores increase surface roughness. By providing the aluminum layer 208 with high purity over the component body 204, the voids and pores are reduced, resulting in a smoother surface.

[0025] Type II anodization layers have less stress and are thinner layers. As a result, type

II anodization layers have been found to provide a smoother surface with fewer defects and fewer micro cracks in order to better facilitate subsequent aerosol deposition, increasing adhesion. In addition, type II anodization layer is able to withstand higher temperatures. Not sealing the anodization layer 212 has been found to prevent the formation of boehmite to provide higher temperature stability and increased adhesion of the rare earth containing layer 216. However, in other embodiments, a water sealing may be used to provide lower temperature stability. In other embodiments, the forming of the anodization layer 212 may use other types of anodization or plasma electrolytic oxidation.

[0026] In various embodiments, a plasma electrolytic oxidation (PEO) or anodization types I, II, or III may be used to form the anodization layer 212. In another embodiment, instead of depositing an aluminum layer 208 (step 108), the anodization layer 212 may be formed by anodizing a surface of the component body 204.

[0027] In other embodiments, the rare earth containing layer 216 may be deposited by plasma vapor deposition (PVD), or atomic layer deposition (ALD). Aerosol deposition has been found to quickly provide a coat with desired qualities at a relatively low cost. In various embodiments, the rare earth containing layer 216 comprises one or more of yttria, yttrium oxyfluoride, gadolinium oxide, dysprosium oxide, and erbium oxide. Yttria containing layers include layers of yttrium aluminum oxide, such as yttrium aluminum garnet (YAG), yttrium aluminum monoclinic (YAM), and yttrium aluminum perovkskite (YAP). [0028] In some embodiments, the use of the aluminum layer 208 that is at least 99.9% pure by mass causes the anodization layer 212 to be so smooth that polishing is not needed.

Such embodiments may not have a polishing step. Other embodiments may use component bodies of other electrically conductive materials.

[0029] FIG. 4A is a schematic illustration of a cross-sectional view of a component body

404 with an anodization layer 408 formed from the component body 404 (step 112) in another embodiment. In this schematic example, micro-cracks 412 are formed in the anodization layer 408. In addition, pores 416 caused by secondary phase impurities are also formed. In addition, the anodization process causes an uneven anodization layer thickness resulting in a surface roughness 420 of greater than 0.4 Ra mhi. The use of Type II anodization, when the anodization is performed directly on the component body 404, minimizes micro-cracks and surface roughness.

[0030] FIG. 4B is a schematic illustration of a cross-sectional view of the component body 404 and anodization layer 408 after the anodization layer 408 has been polished (step 116). The polishing further reduces the surface roughness to less than 0.25 Ra mhi.

[0031] FIG. 5A is a schematic illustration of a cross-sectional view of a component body

504 with a deposited aluminum layer 506 and an anodization layer 508 formed from the aluminum layer 506 (step 112) in another embodiment. In this schematic example, a micro-crack 512 is formed in the anodization layer 508. Since the aluminum layer 506 does not contain secondary impurities, pores are not formed. In addition, the anodization process causes an uneven anodization layer thickness resulting in a surface roughness 520 of greater than 0.4 Ra mhi. In this example, the surface roughness 520 is greater than the surface roughness 420 of the previous example. The use of Type II anodization, when the anodization is performed directly on the component body 404, reduces surface roughness but increases pores.

[0032] FIG. 5B is a schematic illustration of a cross-sectional view of the component body 504 and anodization layer 508 after the anodization layer 508 has been polished (step 116). The polishing further reduces the surface roughness to less than 0.25 Ra mhi.

[0033] While this disclosure has been described in terms of several preferred embodiments, there are alterations, modifications, permutations, and various substitute equivalents, which fall within the scope of this 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 as including all such alterations, modifications, permutations, and various substitute equivalents as fall within the true spirit and scope of the present disclosure.

Claims

CLAIMS What is claimed is:

1. A method for providing a coating on an aluminum-containing component body for use in a semiconductor processing chamber, comprising: forming an anodization layer on the component body; polishing the anodization layer to reduce surface roughness; and depositing a rare earth containing layer on the polished anodization layer by at least one of aerosol deposition, plasma vapor deposition, and atomic layer deposition.

2. The method, as recited in claim 1, wherein the component body is at least one of a pinnacle, confinement ring, edge ring, electrostatic chuck, ground ring, chamber liner, door liner, high flow liner, and showerhead.

3. The method, as recited in claim 1, wherein the forming the anodization layer comprises using a Type II anodization.

4. The method, as recited in claim 3, wherein the forming the anodization layer does not seal.

5. The method, as recited in claim 1, further comprising depositing an aluminum layer on the component body before forming the anodization layer, wherein the forming the anodization layer comprises anodizing the aluminum layer to form the anodization layer.

6. The method, as recited in claim 5, the aluminum layer is 99.9% pure aluminum by mass.

7. The method, as recited in claim 5, wherein the depositing the aluminum layer is by electroplating.

8. The method, as recited in claim 1, the rare earth containing layer comprises at least one of yttria, yttrium oxyfluoride, yttrium aluminum garnet, and erbium oxide.

9. The method, as recited in claim 1, wherein the anodization layer has a surface roughness to less than 0.25 Ra mhi.

10. A component for use in a semiconductor processing chamber, comprising: a component body; and an anodization layer disposed on the component body with a surface roughness of less than 0.25 Ra mhi; and a rare earth containing layer disposed on the anodization layer.

11. The component, as recited in claim 10, further comprising an aluminum layer disposed between the component body and the anodization layer.

12. The component body, as recited in claim 11, wherein the anodization layer is formed by a Type II anodization of the aluminum layer.

13. The component body, as recited in claim 11, wherein the aluminum layer is anodized to form the anodization layer.

14. The component body, as recited in claim 11, wherein the anodization layer is not sealed.

15. The component, as recited in claim 11, wherein the aluminum layer is 99.9% pure by mass.

16. The component, as recited in claim 10, wherein the component is at least one of an electrode, a showerhead, an edge ring, a pinnacle and a high flow liner for use in the semiconductor processing chamber.

17. The component, as recited in claim 10, wherein the rare earth containing layer is at least one of yttria, yttrium oxyfluoride, yttrium aluminum garnet, and erbium oxide.

18. The component, as recited in claim 10, wherein the anodization layer is polished.

19. The component, as recited in claim 10, wherein the component body is made of an aluminum alloy.