TW202102720A - Surface coating for aluminum plasma processing chamber components - Google Patents

Abstract

A component adapted for use in a plasma processing chamber is provided. An aluminum body with a surface is provided. An aluminum oxide coating is over a first region of the surface. An yttrium containing aerosol deposition coating is on a second region of the surface. An yttrium containing thermal spray coating is on the aluminum oxide coating and on the surface at a third region of the surface between the first region and the second region.

Description

Surface coating for aluminum plasma processing chamber components

This disclosure generally relates to the manufacture of semiconductor devices. More specifically, the present disclosure relates to plasma chamber components used in the manufacture of semiconductor devices. [Cross-reference of related applications]

This application claims the priority of U.S. Patent Application No. 62/812,437 filed on March 1, 2019, all of which are incorporated herein by reference.

During the processing of semiconductor wafers, plasma processing chambers are used to process semiconductor devices. The aluminum components in the plasma processing chamber undergo plasma. The plasma may degrade the element.

In order to achieve the foregoing and meet the objectives of the present disclosure, a device suitable for use in a plasma processing chamber is provided. Provide an aluminum body with a surface. The aluminum oxide coating is located on the first area of the surface. The yttrium-containing aerosol deposited coating is located on the second area of the surface. The yttrium-containing thermal spray coating is located on the aluminum oxide coating and at the third area of the surface on the surface, and the third area is between the first area and the second area.

In another manifestation, a coating method for the components of the plasma processing chamber is provided. Anodize the first area on the surface of the element. The yttrium-containing aerosol deposition coating is deposited as aerosol on the second area of the surface of the element. The yttrium-containing thermal spray coating is thermally sprayed on the first area of the surface of the element and a third area of the surface on the surface, the third area being between the first area and the second area of the element Between the two regions.

These and other features of the present disclosure will be described in more detail in the embodiments of the present disclosure in conjunction with the following drawings.

The present disclosure will now be described in more detail with reference to several preferred embodiments of the present disclosure as shown in the accompanying drawings. In the following description, many specific details are explained in order to provide a thorough understanding of this disclosure. However, it is obvious to those with ordinary knowledge in the field that the present disclosure can be implemented without some or all of these specific details. In other cases, the conventional processing steps and/or structures are not described in detail, so as not to unnecessarily obscure the disclosure.

For plasma processing chamber components, since it is relatively easy to reduce the surface roughness, bare aluminum (Al) is a common component material used to set coating components. Due to the better resistance of anodizing to plasma erosion, the remaining uncoated surface of the element can be anodized. On the aerosol deposition coating element, the transition area between the aerosol deposition area and the aluminum oxide coating has an exposed surface of bare aluminum. Since aerosol deposition is difficult to adhere to the aluminum oxide coating, and since the exposed surface of bare aluminum should be minimized, it is very important to accurately and accurately terminate at the end of the bare aluminum component. The transition/termination area between bare Al and the uncoated aluminum oxide coating presents some challenges for the use of the chamber.

For ease of understanding, FIG. 1 is a high-level flowchart of the processing used in the embodiment. In step 104, the component is shielded. FIG. 2A is a schematic cross-sectional view of the device body 204 with the bare surface mask 208. In this example, the element body 204 is part of a pinnacle. The element body 204 is aluminum. Therefore, this element has an aluminum body in this system. In this example, the aluminum system is at least 90% pure aluminum by weight. For example, the aluminum system is made of Al 6061. Generally speaking, the aluminum system is pure aluminum or aluminum alloy. Generally, the aluminum alloy is at least 90% pure aluminum by weight. The flat surface of the element body 204 (which will be exposed to the plasma in the plasma processing chamber) is shielded by a bare surface mask 208.

In step 108, the exposed or unshielded part of the element is anodized to form an aluminum oxide (Al ₂ O ₃ ) coating. In various embodiments, type II or type III anodizing can be used. 2B is a schematic cross-sectional view of the device body 204, which has a bare surface mask 208 and an aluminum oxide coating 212 on an exposed portion of the device body 204. The aluminum oxide coating 212 is located on the first area of the surface of the element body 204. The aluminum oxide coating 212 has a thickness not shown to scale for ease of understanding.

In step 112, the bare surface mask 208 is removed. 2C is a schematic cross-sectional view of the device body 204 after the bare surface mask 208 is removed. The surface part of the element body 204 that is not anodized can be polished to make the surface smoother. In step 116, an anodized surface mask 216 is used to mask the aluminum oxide coating 212 and part of the exposed surface.

In step 120, an aerosol deposition layer is deposited on the exposed surface of the element body 204. Aerosol deposition is achieved by passing a carrier gas through a fluid bed of solid ceramic particles. Driven by the pressure difference, the solid ceramic particles will accelerate through the nozzle to form an aerosol jet at the outlet. Next, the aerosol jet is directed to the exposed surface of the element body 204, wherein the aerosol jet impacts the surface at a high speed. The solid ceramic particles are broken into nano-sized solid fragments to form a coating. The optimization of carrier gas type, gas consumption, target distance, and scanning speed will provide high-quality coatings. In this embodiment, the aerosol deposition layer is a yttrium-containing coating, for example, a coating including yttrium oxide (Y ₂ O ₃ ). In other embodiments, the yttrium-containing aerosol deposition coating includes yttrium oxyfluoride (YOF), yttrium alumina, yttria stabilized zirconia (YSZ), or yttrium (III) fluoride (YF ₃ ) At least one of them. Yttrium alumina usually describes many materials, such as yttrium aluminum garnet (Y ₃ Al ₅ O ₁₂ (YAG)), yttrium aluminum monoclinic (Y ₄ Al ₂ O ₉ (YAM)), or yttrium aluminum perovskite ( YAlO ₃ (YAP)). 2D is a schematic cross-sectional view of the device body 204 after the yttrium-containing aerosol deposition coating 220 has been deposited. The yttrium-containing aerosol deposition coating 220 is located on the second area of the surface of the element body 204.

In step 124, the anodized surface mask 216 is removed. 2E is a schematic cross-sectional view of the device body 204 after the anodized surface mask 216 has been removed. The exposed surface area 228 of the element body 204 is retained. The anodized surface mask 216 covers the exposed surface area 228 to prevent the aerosol deposition coating 220 containing yttrium from being deposited on the aluminum oxide coating 212. The yttrium-containing aerosol deposited coating 220 has poor adhesion to the aluminum oxide coating 212. When used in a plasma processing chamber, the poor adhesion will cause defects and pollution. Since some tolerances are required during the masking process to avoid the deposition of the yttrium-containing aerosol deposition coating 220 on the aluminum oxide coating 212, the anodized surface mask 216 covers the exposed surface area 228.

In step 128, the yttrium-containing aerosol deposited coating 220 is masked. 2F is a schematic cross-sectional view of the device body 204 after the aerosol deposition layer mask 232 has been formed.

In step 132, the thermal spray deposition system is deposited on the bare surface area 228 and the aluminum oxide coating 212. In one example, plasma spraying is used to deposit the thermal sprayed deposition layer. Plasma spraying is a type of thermal spraying in which a torch is formed by applying a potential between two electrodes to cause the ionization of accelerated gas (plasma). This type of torch can easily reach a temperature of several thousand degrees Celsius and liquefy high-melting materials such as ceramics. The molten particles of the desired material are injected into the jet and then accelerated toward the component, so that the molten or plasticized material is coated on the surface of the component, and then cooled to form a solid, conformal coating. The carrier gas system is pushed through the arc chamber and exits through the nozzle. In the cavity, the cathode and the anode include a part of the arc cavity and are maintained at a large direct current (DC) bias until the carrier gas begins to ionize to form plasma. Then, the hot ionized gas is pushed out through the nozzle to form a torch. The fluidized ceramic particles with a size of tens of microns are injected into the cavity near the nozzle. These particles are heated by the hot ionized gas in the plasma torch, causing it to exceed the melting temperature of the ceramic. Then, the plasma jet and the molten ceramic are aimed at the component body 204. The particles will impact the element body 204, planarize, and cool to form a ceramic coating. In this example, the thermal spray deposition is a thermal spray coating containing yttrium, such as a coating including yttrium oxide. In other examples, the yttrium-containing thermal spray coating includes at least one of _{YOF, yttrium alumina, YSZ, or YF 3.} 2G is a schematic cross-sectional view of the device body 204 after the thermal spray coating 236 containing yttrium has been deposited.

In step 136, the aerosol deposition layer mask 232 is removed. 2H is a schematic cross-sectional view of the device body 204 after the aerosol deposition layer mask 232 has been removed. The thermal spray coating 236 containing yttrium is located on the third area on the surface of the element body 204 and on the first area on the surface of the element body 204. In this embodiment, the first area, the second area, and the third area are mutually exclusive and do not overlap with each other.

The element is suitable for use in a plasma processing chamber. In step 140, the component body 204 is installed in the plasma processing chamber. In step 144, the plasma processing chamber is used for processing the substrate. Plasma is generated in the plasma processing chamber to process the substrate (for example, to etch the substrate), and the yttrium-containing aerosol deposition coating 220 is exposed to the plasma. The yttrium-containing aerosol deposition coating 220 protects the device body 204 from plasma damage.

In some embodiments, during the thermal spraying of the yttrium-containing thermal sprayed layer 236, the yttrium-containing aerosol deposited coating 220 is not shielded. Therefore, in such an embodiment, the yttrium-containing thermal spray coating 236 is also deposited on the yttrium-containing aerosol deposition coating 220 to provide additional protection. In some embodiments, the yttrium-containing thermal sprayed layer 236 has a thickness between 150 and 200 microns.

In various embodiments, for aerosol deposition, it is preferable that the spray direction of aerosol deposition is perpendicular to the application surface. When the spraying direction is not perpendicular to the application surface, the adhesion of the particles will decrease. Therefore, aerosol deposits on corners or curved surfaces will be reduced. For this reason, the corner or curved surface of the element body 204 is protected by the thermal spray coating 236 containing yttrium and the aluminum oxide coating 212 instead of the coating 220 deposited by aerosol containing yttrium. The exposed surface area 228 between the aluminum oxide coating 212 and the yttrium-containing aerosol deposited coating 220 is protected by the yttrium-containing thermal spray coating 236. This embodiment avoids any overspraying of the yttrium-containing aerosol deposition coating 220 on the aluminum oxide coating 212. Thus, the device body 204 is provided with a surface that is protected from plasma processing. This embodiment also minimizes defects and contamination.

In various embodiments, in order to improve aerosol deposition, the surface covered by aerosol deposition should be relatively flat. In the case where the spray direction of aerosol deposition is not perpendicular to the surface, it is usually challenging for the surface of the aerosol deposition coating. Therefore, it is preferable that the surface to be covered by the aerosol deposition is relatively flat without curvature or curvature. In addition, the surface covered by the aerosol deposition should be smooth. For example, the surface covered by aerosol deposition should have a roughness of less than 5 Ra (microinches). In other embodiments, the surface covered by aerosol deposition has a roughness of less than 15 Ra. In many embodiments, the anodized surface is curved or curved.

FIG. 3 schematically illustrates an example of the plasma processing chamber 300 used in the embodiment. The plasma processing chamber 300 includes a plasma reactor 302 having a plasma processing confinement chamber 304 in the plasma reactor 302. The plasma power supply 306 adjusted by the matching network 308 provides power to the transformer coupled plasma (TCP) coil 310 located near the power window 312 to generate inductively coupled power in the plasma processing limit chamber 304 Plasma 314. The peak 372 extends from the chamber wall 376 of the plasma processing restriction chamber 304 to the power window 312 to form a peak ring. Peaks 372 and 376 with respect to the chamber wall power window 312 at an angle, such that the peak internal angle portion 312 and the angle between the peaks 372 and 376 between the power window and chamber walls 372 are each greater than and less than 90 ^o 180 ^o . As shown, the peak 372 provides an angled ring near the top of the plasma processing confinement chamber 304. The TCP coil (upper power supply) 310 can be configured to produce a uniform diffusion profile in the plasma processing confinement chamber 304. For example, the TCP coil 310 may be configured to produce a circular power distribution in the plasma 314. The power window 312 is provided to separate the TCP coil 310 from the plasma treatment confinement chamber 304 while allowing energy to be transferred from the TCP coil 310 to the plasma treatment confinement chamber 304. The wafer bias power supply 316 adjusted by the matching network 318 will supply power to the electrode 320 to set the bias voltage on the substrate 366. The substrate 366 is supported by the electrode 320. The controller 324 sets values for the plasma power supply 306 and the wafer bias power supply 316.

Plasma power supply 306 and wafer bias power supply 316 can be configured to operate at specific radio frequencies, such as 13.56 megahertz (MHz), 27 MHz, 2MHz, 60 MHz, 400 kilohertz (KHz), 2.54 gigahertz (GHz) ), or a combination thereof. The plasma power supply 306 and the wafer bias power supply 316 can be appropriately sized to supply a range of power to achieve the desired processing performance. For example, in one embodiment, the plasma power supply 306 can supply power in the range of 50 to 5000 watts, and the wafer bias power supply 316 can supply the bias voltage in the range of 20 to 2000 volts (V). In addition, the TCP coil 310 and/or the electrode 320 may include two or more sub-coils or sub-electrodes. The TCP coil 310 and/or the electrode 320 can be powered by a single power source or can be powered by multiple power sources.

As shown in FIG. 3, the plasma processing chamber 300 further includes a gas source/gas supply mechanism 330. The gas source 330 is fluidly connected to the plasma processing confinement chamber 304 through the gas inlet of the gas injector 340, for example. The gas injector 340 may be located at any advantageous position in the plasma processing confinement chamber 304, and may be formed in any form for injecting gas. However, the gas inlet can be better configured to create an "adjustable" gas injection profile. The adjustable gas injection profile allows the individual gas flow to multiple regions in the plasma processing restriction chamber 304 to be independently adjusted. More preferably, the gas injector is installed to the power window 312. In such examples, the gas injector may be installed on the power window, installed in the power window, or form part of the power window. The processing gas and by-products are removed from the plasma processing restriction chamber 304 through the pressure control valve 342 and the pump 344. The pressure control valve 342 and the pump 344 are also used to maintain a specific pressure in the plasma processing restriction chamber 304. The pressure control valve 342 can maintain a pressure of less than 1 Torr during the treatment. The edge ring 360 is placed around the substrate 366. The gas source/gas supply mechanism 330 is controlled by the controller 324. Kiyo manufactured by Lam Research Corp. of Fremont, CA can be used to implement the examples.

In various embodiments, the element may be other components of the plasma processing chamber, such as a confinement ring, an edge ring, an electrostatic chuck, a ground ring, a chamber liner, a door liner, or other elements. Other types of other components of the plasma processing chamber can be used. For example, in one embodiment, the plasma rejection ring located on the edge etching chamber may be coated. In another example, the plasma processing chamber may be a dielectric processing chamber or a conductor processing chamber. In some embodiments, one or more, but not all surfaces are coated.

Although the present disclosure has been described based on several preferred embodiments, there are changes, substitutions, modifications, and various alternative equivalents that fall within the scope of the present disclosure. It should also be noted that there are many alternative methods for implementing the methods and devices of this disclosure. Therefore, it is intended to interpret the scope of the following attached patent application as including all such changes, substitutions, and various substitute equivalents that fall within the true spirit and scope of this disclosure.

104,108,112,116,120,124,128,132,136,140,144: steps 204: component body 208: bare surface mask 212: Aluminum oxide coating 216: Anodized surface mask 220: aerosol deposition coating containing yttrium 228: exposed surface area 232: Aerosol deposition layer mask 236: Thermal spray coating containing yttrium 300: Plasma processing chamber 302: Plasma reactor 304: Plasma processing limit chamber 306: Plasma Power 308: matching network 310: Transformer-coupled plasma (TCP) coil 312: power window 314: Plasma 316: Wafer bias power supply 318: matching network 320: Electrode 324: Controller 330: gas source 340: Gas injector 342: Pressure Control Valve 344: Pump 360: edge ring 366: Substrate 372: The Peak 376: Chamber Wall

In the accompanying drawings, the present disclosure is illustrated by way of example rather than limitation, wherein the same component symbols refer to similar components, and among them:

Fig. 1 is a high-level flow chart of the embodiment.

2A-2H are schematic cross-sectional views of components processed according to the embodiment.

Fig. 3 is a schematic diagram of a plasma processing chamber that can be used in the embodiment.

204: component body

212: Aluminum oxide coating

220: aerosol deposition coating containing yttrium

236: Thermal spray coating containing yttrium

Claims (20)

A component suitable for use in a plasma processing chamber, the component includes: An aluminum body with a surface; An aluminum oxide coating on a first area of the surface; An aerosol-deposited coating containing yttrium on a second area of the surface; and A thermal spray coating containing yttrium is located on the aluminum oxide coating and at a third area of the surface on the surface, the third area being between the first area and the second area. The component suitable for use in a plasma processing chamber as described in claim 1, wherein the yttrium-containing thermal spray coating is located on the yttrium-containing aerosol deposition coating. The component suitable for use in a plasma processing chamber as described in claim 1, wherein the yttrium-containing aerosol deposition coating and the yttrium-containing thermal spray coating include yttrium oxide, yttrium fluoride, yttrium alumina, and yttrium oxide One or more of stabilized zirconia and yttrium(III) fluoride. The component suitable for use in a plasma processing chamber as described in claim 1, wherein the second area of the surface has a roughness of less than 5 Ra (microinches). The element suitable for use in a plasma processing chamber as described in claim 1, wherein a portion of the first area of the surface is curved or curved. The element suitable for use in a plasma processing chamber as described in claim 1, wherein the second area of the surface is flat. The element suitable for use in a plasma processing chamber as described in claim 1, wherein the element is at least one of a restriction ring, an edge ring, an electrostatic chuck, a ground ring, a chamber liner, or a door liner. The component suitable for use in a plasma processing chamber according to claim 1, wherein the yttrium-containing aerosol deposition coating and the yttrium-containing thermal spray coating include yttrium oxide. The component suitable for use in a plasma processing chamber as described in claim 1, wherein the aluminum system is at least 90% pure aluminum by weight. A method for coating components of a plasma processing chamber, wherein the method includes: Anodize a first area on a surface of the element; Depositing an aerosol deposition coating containing yttrium on a second area of the surface of the element as aerosol; and A thermal spray coating containing yttrium is thermally sprayed on the first area of the surface of the element and on the surface at a third area of the surface, the third area being between the first area And the second area. The method for coating a component of a plasma processing chamber according to claim 10, further comprising, after anodizing the first region of the surface of the component, performing the second region of the surface of the component Grind. The coating method for the components of the plasma processing chamber as described in claim 11 further includes: Masking the second area of the surface of the element before the first area of the surface of the element is anodized; After the first area of the surface of the element is anodized, the second area of the surface of the element is removed and shielded; Before the yttrium-containing aerosol deposition coating is deposited as aerosol on the second area of the surface of the element, masking the first area and the third area of the surface of the element; and After the yttrium-containing aerosol deposition coating is deposited as aerosol on the second area of the surface of the element, the first area and the third area of the surface of the element are removed and shielded. The method for coating a component of a plasma processing chamber according to claim 12, further comprising, after removing and shielding the second region of the surface of the component, performing the second region of the surface of the component Grind. The method for coating a component of a plasma processing chamber according to claim 12, wherein the component is at least one of a restriction ring, an edge ring, an electrostatic chuck, a ground ring, a chamber liner, or a door liner. The method for coating a component of a plasma processing chamber according to claim 10, wherein part of the yttrium-containing thermal spray coating is located on the yttrium-containing aerosol deposition coating. The method for coating components of a plasma processing chamber according to claim 10, wherein the yttrium-containing aerosol deposition coating and the yttrium-containing thermal spray coating include yttrium oxide, yttrium fluoride, yttrium alumina, and yttrium oxide One or more of yttrium stabilized zirconia and yttrium(III) fluoride. The method for coating a component of a plasma processing chamber according to claim 10, further comprising, after anodizing the first region of the surface of the component, performing the second region of the surface of the component Grind to have a roughness of less than 5 Ra (microinches). The method for coating a component of a plasma processing chamber according to claim 10, wherein a portion of the first region of the surface is curved or curved. The method for coating a component of a plasma processing chamber according to claim 10, wherein the second area of the surface is flat. The method for coating a component of a plasma processing chamber according to claim 10, wherein the yttrium-containing aerosol deposition coating and the yttrium-containing thermal spray coating include yttrium oxide.

Images