Plasma-exposed parts with etch-resistant materials - Patent Application 20070122997

Abstract

As an example, a plasma-exposed component for a plasma processing tool is provided. The plasma-exposed component comprises an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry containing fluorine and / or oxygen. The etch-resistant material comprises one or more of: (a) one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin, or (b) one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

Description

[Background technology]

[0001] Plasma processes are commonly used to remove material from substrates in semiconductor fabrication processes. One example of a plasma process is reactive ion etching (RIE). RIE involves forming a plasma containing a chemically reactive gas. Ions of the reactive gas formed in the plasma react with the substrate in the processing chamber to form volatile products. The volatile products are then removed from the processing chamber in the gas phase. Summary of the Invention

[0002] This Summary is provided to introduce a selection of concepts in a simplified form, which are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

[0003] As an example, a plasma-exposed component for a plasma processing tool is provided. The plasma-exposed component comprises an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry. The etch-resistant material comprises one or more of: (a) one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin, or (b) one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

[0004] In some such examples, the etch-resistant material is configured to form a fluoride upon reaction with a fluorine-containing plasma process gas chemistry, the fluoride having a boiling point of 1000° C. or less.

[0005] In some such examples, alternatively or additionally, the etch-resistant material comprises one or more of an oxide, nitride, or oxynitride of titanium or zirconium.

[0006] In some such examples, alternatively or additionally, the etch-resistant material comprises titanium nitride or zirconium nitride.

[0007] In some such instances, the bulk portion and surfaces of the plasma-exposed component are alternatively or additionally formed from an etch-resistant material.

[0008] In some such examples, the plasma exposed component is alternatively or additionally an electrode, a plasma confinement shroud, or an edge ring.

[0009] As another example, a plasma processing tool is provided that includes a processing chamber and a plasma-exposed component located within the processing chamber. The plasma-exposed component comprises an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry that includes fluorine and / or oxygen. The etch-resistant material comprises one or more of: (a) one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin, or (b) one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

[0010] In some such instances, the tool alternatively or additionally comprises a dielectric plasma etching tool.

[0011] In some such examples, alternatively or additionally, the etch-resistant material is configured to form a fluoride upon reaction with a fluorine-containing plasma process gas chemistry, the fluoride having a boiling point of 1000° C. or less.

[0012] In some such examples, alternatively or additionally, the plasma-exposed component comprises an outer layer supported by the bulk portion, the outer layer comprising an etch-resistant material.

[0013] In some such examples, alternatively or additionally, the bulk portion comprises one or more of silicon, silicon carbide, or silicon oxide.

[0014] In some such instances, alternatively or additionally, the bulk portion and surface of the plasma-exposed component are formed from an etch-resistant material.

[0015] In some such examples, alternatively or additionally, the plasma exposed component is an electrode, a plasma confinement shroud, or an edge ring.

[0016] As another example, a plasma-exposed component for a plasma processing tool is provided. The plasma-exposed component includes a bulk portion and an outer layer supported by the bulk portion. The outer layer includes an etch-resistant material that is different from the material of the bulk portion. The etch-resistant material is configured to etch at a slower rate than silicon or silicon carbide in a selected plasma chemistry.

[0017] In some such instances, alternatively or additionally, the outer layer contacts the bulk portion.

[0018] In some such examples, alternatively or additionally, the etch-resistant material comprises one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin.

[0019] In some such examples, the etch-resistant material alternatively or additionally comprises one or more of an oxide, nitride, or oxynitride of titanium or zirconium.

[0020] In some such examples, alternatively or additionally, the etch-resistant material comprises one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

[0021] In some such examples, alternatively or additionally, the etch-resistant material is configured to form a fluoride upon reaction with a fluorine-containing plasma process gas chemistry, the fluoride having a boiling point of 1000° C. or less.

[0022] In some such examples, alternatively or additionally, the bulk portion comprises one or more of silicon, silicon carbide, or silicon oxide.

[0023] In some such examples, alternatively or additionally, the plasma exposed component is an electrode, a plasma confinement shroud, or an edge ring. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 shows a block diagram of an exemplary plasma processing tool.

[0025] [Figure 2] FIG. 2 illustrates a schematic bottom view of an exemplary plasma confinement shroud including an etch-resistant material.

[0026] [Figure 3] FIG. 3 shows a schematic cross-sectional side view taken along line 3-3 of FIG.

[0027] [Figure 4] FIG. 4 shows a schematic bottom view of an exemplary inner electrode comprising an etch-resistant material.

[0028] [Figure 5] FIG. 5 shows a schematic cross-sectional side view taken along line 5-5 of FIG.

[0029] [Figure 6] FIG. 6 schematically illustrates a bottom view of an exemplary external electrode comprising an etch-resistant material.

[0030] [Figure 7] FIG. 7 shows a schematic cross-sectional side view taken along line 7-7 of FIG.

[0031] [Figure 8] FIG. 8 schematically illustrates a bottom view of an exemplary edge ring comprising an etch-resistant material.

[0032] [Figure 9] FIG. 9 shows a schematic cross-sectional side view of the edge ring taken along line 9-9 of FIG.

[0033] [Figure 10] FIG. 10 illustrates a schematic of an exemplary plasma confinement shroud including a coating of etch-resistant material.

[0034] [Figure 11] FIG. 11 shows a schematic diagram of an exemplary inner electrode including a coating of etch-resistant material.

[0035] [Figure 12] FIG. 12 illustrates a schematic of an exemplary external electrode including a coating of etch-resistant material.

[0036] [Figure 13] FIG. 13 illustrates a schematic of an exemplary edge ring including a coating of etch-resistant material.

[0037] [Figure 14] FIG. 14 illustrates a schematic of an exemplary plasma confinement shroud including a partial coating of an etch-resistant material.

[0038] [Figure 15]FIG. 15 shows a schematic of an exemplary inner electrode that includes a partial coating of an etch-resistant material.

[0039] [Figure 16] FIG. 16 illustrates a schematic of an exemplary external electrode that includes a partial coating of an etch-resistant material.

[0040] [Figure 17] FIG. 17 illustrates a schematic of an exemplary edge ring that includes a partial coating of an etch-resistant material.

[0041] [Figure 18] FIG. 18 shows a flow diagram depicting an exemplary method of using a plasma-exposed component comprising an etch-resistant material. DETAILED DESCRIPTION OF THE INVENTION

[0042] The term "atomic layer deposition" (ALD) may generally refer to a process in which a film is formed on a surface in one or more discrete layers by sequentially conformally adsorbing precursors onto the surface and reacting the adsorbed precursors to form the film layers. One example of an ALD process is plasma-enhanced ALD (PEALD). PEALD utilizes a plasma of reactive gases to promote chemical transformation of adsorbed precursors into a film on the surface.

[0043] The term "bulk portion" may generally refer to the bulk of the mass of a component of a plasma processing tool. The bulk portion of the component may be coated with a coating comprising a different material than the bulk portion.

[0044] The term "chemical vapor deposition" (CVD) may generally refer to a process for forming a film on a surface by sequentially conformally adsorbing precursors onto the surface and reacting the adsorbed precursors to form a film layer. One example of a CVD process is plasma-enhanced CVD (PECVD), which utilizes a plasma of reactive gases to promote chemical transformation of adsorbed precursors into a film on the surface.

[0045] The term "dielectric plasma etch process" may generally refer to a plasma process for etching a dielectric material on a substrate.

[0046] The term "dielectric plasma etch tool" may generally refer to a machine that includes a processing chamber and other hardware configured to perform a plasma process for etching a dielectric material on a substrate within the processing chamber.

[0047] The term "edge ring" may generally refer to a component of a plasma processing tool configured to surround a substrate positioned on a substrate support of the plasma processing tool.

[0048] The term "electrode" may generally refer to a component of a plasma processing tool configured to supply power to a plasma.

[0049] The term "etching," and variations thereof, may generally refer to the removal of material from a structure by exposing the structure to a plasma in a plasma processing tool. Substrates and components of plasma processing tools may be etched by the plasma in the plasma processing tool.

[0050] The term "etchant" may generally refer to a chemical used in a plasma processing gas mixture to remove material from a substrate. Example etchants may include fluorine-containing materials. Examples of fluorine-containing etchants include molecular fluorine (F), nitrogen trifluoride (NF), boron trifluoride (BF), sulfur hexafluoride (SF), and fluorine-containing etchants having the general formula C a H b F c , where a=1-10.

[0051] The term "etch rate ratio" may generally refer to the ratio of the distance etched as a function of time for a first material compared to the distance etched as a function of time for a second material.

[0052] The term "etch-resistant material" may generally refer to a material that has a lower etch rate than silicon or silicon carbide when exposed to plasma process gas chemistries that include fluorine and / or oxygen.

[0053] The term "fluoride" may generally refer to chemical species that include a fluorine anion.

[0054] The term "fluorine and / or oxygen-containing plasma process gas chemistry" may generally refer to a plasma processing environment that includes fluorine-containing and / or oxygen-containing materials for chemical etching.

[0055] The term "nitride(s) of titanium, hafnium, zirconium, or tin" may generally refer to a material that includes one or more titanium, hafnium, zirconium, or tin cations and also includes nitrogen anions.

[0056] The term "outer layer" may generally refer to a coating on a plasma-exposed component that has a different composition than the bulk portion of the plasma-exposed component. At least a portion of the outer layer is exposed to the plasma during plasma processing. In some examples, the outer layer may be coated directly onto the bulk portion of the plasma-exposed component. In other examples, one or more intervening layers may be disposed between the outer layer and the bulk portion of the plasma-exposed component. The outer layer may coat the entire surface of the plasma-exposed component or a portion of the surface of the plasma-exposed component.

[0057] The term "oxide(s) of titanium, hafnium, zirconium, or tin" may generally refer to a material that includes one or more of titanium, hafnium, zirconium, or tin cations and also includes oxygen anions.

[0058] The term "oxynitride(s) of titanium, hafnium, zirconium, or tin" may generally refer to a material that includes one or more titanium, hafnium, zirconium, or tin cations, and also includes nitrogen and oxygen anions.

[0059] The term "made only of" may refer to a component within a plasma processing tool that is generally formed from a specified material, but may contain trace impurities of other materials.

[0060] The term "plasma chemistry" may generally refer to the chemical environment within a processing chamber during a plasma process.

[0061] The term "plasma confinement region" may generally refer to the volume of space within a processing chamber that is at least partially surrounded by plasma-exposed components.

[0062] The term "plasma confinement shroud" may generally refer to a component within a processing chamber that forms the sides of a plasma confinement region.

[0063] The term "plasma-exposed parts" may generally refer to parts within a plasma processing tool that are exposed to plasma during plasma processing.

[0064] The term "plasma-exposed surface" may generally refer to the surface of a plasma-exposed component that is exposed to the plasma during plasma processing.

[0065] The term "plasma processing tool" may generally refer to a machine that includes a processing chamber and other hardware configured to enable a plasma process to be performed within the processing chamber.

[0066] The term "processing chamber" may generally refer to an enclosure in which plasma processing is performed on a substrate. The pressure, temperature, atmospheric composition, and other conditions within the processing chamber may be controllable to perform a plasma process.

[0067] The terms "reactive ion etching" and "RIE" may generally refer to an etching process that uses a plasma to form reactive ionic species to etch a substrate.

[0068] The term "silicon doped with one or more of titanium, hafnium, zirconium, or tin" may generally refer to elemental silicon that includes a concentration of one or more of titanium atoms, hafnium atoms, zirconium atoms, or tin atoms in any suitable oxidation state.

[0069] The term "silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin" may generally refer to silicon carbide that includes a concentration of one or more of titanium atoms, hafnium atoms, zirconium atoms, or tin atoms in any suitable oxidation state.

[0070] The term "substrate" may generally refer to any object that is subjected to a plasma process, for example, in a plasma etching process, material is removed from the substrate.

[0071] Plasma etching processes utilize a plasma to provide energy for removing material from a substrate. For example, in an RIE process, one or more etchants are introduced into the plasma. The plasma forms reactive ions from the etchant(s). The reactive ions react with material on the substrate surface to form volatile products. The volatile products are then removed from the processing chamber in the gas phase.

[0072] In some examples, the etchant may include a fluorine-containing gas. The plasma generates reactive fluorine-containing species, which react with materials such as silicon oxide or silicon nitride to form volatile products such as SiF. However, plasma etching conditions may also etch plasma-exposed components within the processing chamber. For example, a dielectric plasma etching tool may utilize plasma-exposed components containing materials such as silicon or silicon carbide. Silicon and silicon carbide are etched, albeit at a slower rate, by the etchant used to etch the dielectric. Etching may result not only from chemical effects but also from physical effects such as sputtering.

[0073] Over time, material loss from plasma-exposed components can affect the plasma etching process. Therefore, plasma-exposed components are periodically replaced as part of scheduled maintenance. The useful life of a plasma-exposed component affects how often it is replaced. The useful life of a plasma-exposed component also affects the average cleaning interval for the plasma-exposed component. Depending on the total usage time, plasma-exposed components that are replaced more frequently can increase the cost of ownership of a plasma processing tool compared to components that are replaced less frequently. In some scenarios, the life of a silicon or silicon carbide plasma-exposed component can be approximately 2000 radio frequency (RF) hours. Furthermore, plasma-exposed components that etch at relatively fast rates may require more frequent cleaning of the processing chamber. Depending on the usage time of the tool, more frequent cleanings can increase the operating costs of a plasma processing tool compared to components with longer cleaning intervals.

[0074] Thus, examples are disclosed relating to plasma-exposed components including etch-resistant materials that can extend the useful life of the plasma-exposed components. The etch-resistant materials disclosed herein have a lower etch rate than silicon or silicon carbide when exposed to process gases containing fluorine and / or oxygen. In some cases, the etch rate is also referred to as the erosion rate, which indicates the etch distance over time, e.g., micrometers (um) divided by radio frequency hours (RFH), i.e., um / RFH. Plasma-exposed components made of materials with lower etch rates may have a longer useful life. Furthermore, these components may require less frequent cleaning depending on the tool's usage time, resulting in reduced overall tool downtime. In some examples, the etch-resistant material includes one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin. In other examples, the etch-resistant material includes one or more silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin. In some examples, the bulk portion and the surface of the plasma exposed component are formed from an etch-resistant material. In other examples, the plasma exposed component comprises a bulk portion coated with an outer layer comprising an etch-resistant material. Although described herein in the context of a dielectric plasma etch process, the plasma exposed component comprising an etch-resistant material may be used in any suitable plasma process.

[0075] Before describing these examples in more detail, Figure 1 schematically illustrates an exemplary plasma processing tool 100 in the form of a plasma etching tool. The plasma processing tool 100 includes a processing chamber 102. The plasma processing tool 100 further includes a substrate support 104 disposed within the processing chamber 102. During operation, a substrate 110 is disposed on the substrate support 104. The substrate support 104 may include a pedestal, an electrostatic chuck, and / or any other suitable component for supporting the substrate 110.

[0076] The plasma processing tool 100 further comprises an inner electrode 106 and an outer electrode 108. The use of separate components for the inner electrode 106 and the outer electrode 108 instead of a single, large electrode allows the inner electrode 106 and the outer electrode 108 to be replaced at different frequencies. For example, the inner electrode 106 may be replaced more frequently than the outer electrode 108.

[0077] In the illustrated example, the inner electrode 106 and outer electrode 108 are incorporated into a showerhead 112 configured to introduce and distribute process gases, such as fluorine-containing materials for chemical etching, inert gases as diluents, purge gases, and / or sputtering gases. The substrate-facing surface of the showerhead 112 includes a plurality of holes through which the process gases flow.

[0078] A heater 113 is disposed above the inner electrode 106 and the outer electrode 108. The heater 113 is thermally coupled to the inner electrode 106 and the outer electrode 108. The heater 113 is used to control the temperature of the inner electrode 106 and / or the outer electrode 108 during substrate processing.

[0079] The substrate support 104 includes an electrically conductive base plate 114 that functions as a bottom electrode. The base plate 114 supports a ceramic layer 116. In some examples, the ceramic layer 116 may comprise a heater. An exemplary heater comprises a ceramic multi-zone heater plate. A thermal resistance layer 118 is disposed between the ceramic layer 116 and the base plate 114. The base plate 114 includes one or more coolant channels 120 for flowing coolant within the base plate 114. The substrate support 104 further includes an edge ring 122 configured to surround the substrate 110.

[0080] An RF generation system 124 generates and outputs an RF voltage to the inner electrode 106 and the outer electrode 108. In some examples, the RF voltage oscillates around a bias voltage. The base plate 114 can be direct current (DC) grounded, alternating current (AC) grounded, or floating. The RF generation system 124 includes an RF voltage generator 126 configured to generate an RF voltage supplied to the inner electrode 106 and the outer electrode 108 using a matching and distribution network 128. In other examples, the plasma can be generated inductively, remotely, or using any other suitable method. Examples of the RF generation system 124 include a capacitively coupled plasma (CCP) system, a transformer coupled plasma (TCP) system, a CCP cathode system, and a remote microwave plasma generation and delivery system. In other examples, an RF voltage can be delivered to the base plate 114, and the inner electrode 106 and the outer electrode 108 can be DC grounded, AC grounded, or floating.

[0081] The gas delivery system 130 includes gas sources 132A and 132N (collectively, gas sources 132), where N represents any number of gas sources, zero or greater, in addition to the gas source 132A. The gas source 132 supplies one or more precursors and / or mixtures thereof. The gas source 132 may also supply a purge gas. Vaporized precursors may also be used. The gas sources 132 are connected to a manifold 138 by valves 134A and 134N (collectively, valves 134) and mass flow controllers (MFCs) 136A and 136N (collectively, mass flow controllers 136). Examples of gas sources include an etchant source and an inert gas source. The output of the manifold 138 is supplied to the processing chamber 102, such as the showerhead 112. Additionally, the gas delivery system 130 may be capable of controlling the pressure of the processing chamber 102. In some examples, the pressure of the processing chamber 102 is approximately milliTorr. In other examples, the gas supply system 130 may include one gas source 132 , a valve 134 , and / or an MFC 136 .

[0082] The temperature controller 140 is connected to a plurality of thermal control elements (TCEs) 142 disposed on the ceramic layer 116. The temperature controller 140 is used to control the plurality of heating elements 142 to control the temperature of the substrate support 104 and the substrate 110. Additionally, the temperature controller 140 is in communication with a coolant assembly 144 to control the flow of coolant within the coolant channels 120. In some examples, the coolant assembly 144 may include a coolant pump and a reservoir. The temperature controller 140 operates the coolant assembly 144 to selectively flow coolant within the coolant channels 120 to cool the substrate support 104.

[0083] Reactants can be evacuated from the processing chamber 102 using valves 146 and pumps 148. Furthermore, a system controller 150 is configured to control the components of the plasma processing tool 100. A robot 152 transfers substrates onto and removes substrates from the substrate support 104. For example, the robot 152 transports substrates between the substrate support 104 and a load lock 154. Although shown as a separate controller, the temperature controller 140 can be implemented within the system controller 150. Furthermore, a protective seal 156 is provided around the periphery of the thermal resistance layer 118 between the ceramic layer 116 and the base plate 114. In other examples, the protective seal 156 may be omitted.

[0084] The processing chamber 102 further includes a plasma confinement shroud 158. The plasma confinement shroud 158 is disposed around the outer electrode 108 and the edge ring 122. In the illustrated example, the inner electrode 106, the outer electrode 108, the plasma confinement shroud 158, and the edge ring 122 confine the plasma within a plasma confinement region 160. In some examples, the plasma confinement shroud 158 is electrically connected to the outer electrode 108 and the inner electrode 106. The plasma confinement shroud 158 includes one or more slots 162 that provide fluid communication between the plasma confinement region 160 and an environment external to the plasma confinement shroud 158. During operation, one or more of the plasma confinement shroud 158, the inner electrode 106, the outer electrode 108, or the edge ring 122 may be exposed to plasma process gas chemistries including fluorine and / or oxygen. As such, these components are collectively referred to as plasma-exposed components. Alternatively, any other suitable plasma-exposed component may be used to confine the plasma within the plasma confinement region.

[0085] FIG. 1 is exemplary. In other examples, the plasma processing tool may include any other components suitable for performing a plasma process. Other exemplary components may include a remote plasma generation and delivery system. Additionally, in some examples, the plasma processing tool 100 may omit one or more components shown. Although described herein in the context of a plasma etching tool, other plasma processing tools may be used to perform suitable plasma processes. Other examples of plasma processing tools may include PEALD tools and PECVD tools. Such tools may, in some examples, be configured to perform in-situ etching.

[0086] As previously mentioned, fluorine-containing etchants used to perform dielectric etching may also etch / erode plasma-exposed components. Many known plasma-exposed components for plasma processing tools are made of silicon and / or silicon carbide. Silicon and / or silicon carbide will experience material loss over time due to exposure to plasma process gas chemistries. Such plasma-exposed components must be replaced when the material loss reaches a replacement threshold condition. To reduce replacement frequency, examples of the present disclosure introduce plasma-exposed components comprising a material that is more etch-resistant than silicon or silicon carbide.

[0087] Thus, plasma-exposed components according to the present disclosure include an etch-resistant material that is more etch-resistant than silicon or silicon carbide. As previously mentioned, the term "etch-resistant material" as used herein may generally refer to a material that has a lower etch rate than silicon or silicon carbide when exposed to plasma process gas chemistries containing fluorine and / or oxygen. Furthermore, such a configuration may enable the plasma-exposed component to have a longer service life than a plasma-exposed component formed from silicon and / or silicon carbide. Furthermore, the extended service life may reduce the cost of ownership of the plasma processing tool. In some examples, the etch-resistant material may include one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin. In other examples, the etch-resistant material may include one or more silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin. Such materials may have a lower etch rate than silicon or silicon carbide in plasma process gas chemistries containing fluorine and / or oxygen. This potentially extends the useful life of plasma-exposed parts containing etch-resistant materials over parts made solely from silicon or silicon carbide.

[0088] As mentioned above, in some examples, the bulk portion of the plasma-exposed component, including the plasma-exposed surface, comprises an etch-resistant material. FIG. 2 schematically illustrates a bottom view of an exemplary plasma confinement shroud 200 comprising an etch-resistant material. FIG. 3 schematically illustrates a cross-sectional side view of plasma confinement shroud 200 taken along line 3-3 in FIG. 2. Plasma confinement shroud 200 is an example of plasma confinement shroud 158. Additionally, slot 201 is an example of slot 162. As shown, the bulk of plasma confinement shroud 200, including plasma-exposed surface 202 shown in FIG. 3, is formed from an etch-resistant material.

[0089] The plasma confinement shroud 200 and other plasma-exposed components may be fabricated using any suitable method. In some examples, the plasma confinement shroud 200 or other plasma-exposed components may be formed by hot pressing of a powder of an etch-resistant material. Hot pressing involves applying pressure during sintering of a powder including the etch-resistant material. Applying pressure during sintering of the powder of the etch-resistant material may enable the plasma confinement shroud 200 to be formed more quickly than thermal sintering without pressure. In other examples, the plasma confinement shroud 200 may be formed by spark plasma sintering of the etch-resistant material. Spark plasma sintering can be performed on the etch-resistant material in a compressed, dry powder form. In further examples, the plasma confinement shroud 200 or other plasma-exposed components may be formed using other suitable ceramic processing methods, such as calcination of appropriate starting materials, sintering under atmospheric pressure, additive manufacturing, and annealing. In further examples, doped silicon plasma confinement shrouds or other plasma-exposed components may be formed using additive manufacturing.

[0090] As noted above, in other examples, the plasma confinement shroud 200 or other plasma-exposed components may be formed from silicon doped with one or more of titanium, hafnium, zirconium, or tin. The doped silicon plasma confinement shroud may be formed in any suitable manner. In some examples, the dopant may be added during the silicon's production. For example, the silicon may be doped when the silicon ingot is produced. In such examples, the silicon ingot may include a doping rate of about 5 atomic percent or less. In other examples, the silicon ingot may include any other suitable concentration of dopant. The silicon ingot may then be machined to form the plasma confinement shroud 200. In other examples, elemental silicon may be melted. The silicon is then doped in the molten state and poured into a mold. The molded silicon is then cooled to form the plasma confinement shroud 200. In some such examples, annealing may be performed to further reduce internal stress in the silicon form in the plasma confinement shroud 200. In other examples, the plasma confinement shroud or other plasma exposed components may be formed from silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

[0091] Other examples of plasma-exposed components are shown in FIGS. 4-9. More specifically, FIG. 4 schematically illustrates a bottom view of an exemplary internal electrode 400. The internal electrode 400 is an example of the internal electrode 106. FIG. 5 schematically illustrates a cross-sectional side view of the internal electrode 400 taken along line 5-5 in FIG. 4. As shown, the bulk of the internal electrode 400, including the plasma-exposed surface 402, is formed from an etch-resistant material. Next, FIG. 6 schematically illustrates a bottom view of an exemplary external electrode 600, including an etch-resistant material. The external electrode 600 is an example of the external electrode 108. FIG. 7 schematically illustrates a cross-sectional side view of the external electrode 600 taken along line 7-7 in FIG. 6. As shown, the bulk of the external electrode 600, including the plasma-exposed surface 602, is formed from an etch-resistant material. Next, FIG. 8 schematically illustrates a bottom view of an exemplary edge ring 800, including an etch-resistant material. The edge ring 800 is an example of the edge ring 122. Figure 9 schematically illustrates a cross-sectional side view of edge ring 800 taken along line 9-9 of Figure 8. As shown, the bulk of edge ring 800, including plasma-exposed surface 802, is formed from an etch-resistant material.

[0092] In another example, a plasma-exposed component according to the present disclosure may include an outer layer including a plasma-exposed surface formed from an etch-resistant material and a bulk portion made from a different material. The bulk portion supports the outer layer. This configuration may extend the useful life of the plasma-exposed component over a plasma-exposed component made solely from silicon and / or silicon carbide. Furthermore, a plasma-exposed component including a bulk portion and an outer layer may be less expensive than a plasma-exposed component including a bulk portion formed from an etch-resistant material.

[0093] FIG. 10 illustrates an exemplary plasma confinement shroud 1000 comprising a bulk portion 1002 and an outer layer 1004. The plasma confinement shroud 1000 is an example of the plasma confinement shroud 158. In the illustrated example, the outer layer 1004 contacts the bulk portion 1002. In other examples, one or more intervening layers may be disposed between the outer layer 1004 and the bulk portion 1002. In the illustrated example, the outer layer 1004 covers the entire surface of the plasma confinement shroud 1000. In other examples, the outer layer 1004 may cover only a portion of the surface of the plasma confinement shroud 1000. In yet other examples, the outer layer 1004 may vary in thickness spatially across the surface of the plasma confinement shroud 1000.

[0094] The outer layer 1004 includes an etch-resistant material configured to etch at a slower rate than silicon or silicon carbide in plasma process gas chemistries including fluorine and / or oxygen. In some examples, the etch-resistant material may include one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin. In other examples, the etch-resistant material may include one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin. A lower etch rate may enable an extended useful life of the plasma confinement shroud 1000.

[0095] The outer layer 1004 may be deposited on the bulk portion 1002 by any suitable method. Examples include ALD, CVD, sputtering, pulsed laser deposition, thermal spray, plasma spray deposition, or a combination thereof. In another example, a dispersion may be applied to the outer layer 1004 in a solvent. The dispersion may be applied by spin coating, thermal spray coating, doctor blading, dip coating, or other suitable method. The solvent may then be evaporated, and the etch-resistant material may be treated to form the outer layer 1004. For example, after evaporating the solvent, the etch-resistant material may be treated by firing, sintering, and / or annealing.

[0096] Bulk portion 1002 comprises a different material than outer layer 1004. In some examples, bulk portion 1002 may comprise one or more of silicon, silicon carbide, or silicon oxide. In other examples, bulk portion 1002 may comprise graphite, metal, silicon, silicon carbide, or other suitable dielectric ceramic material. Bulk portion 1002 may be formed by machining, die casting, and / or any other suitable method(s).

[0097] As previously mentioned, the plasma confinement shroud 1000 can be electrically coupled to other components within the processing chamber. Therefore, the etch-resistant material may be selected to have electrical conductivity suitable for the plasma etching process being performed. In some instances, an etch-resistant material selected for a desired etch resistance may not have sufficient electrical conductivity. In such instances, the outer layer 1004 may be applied with a sufficiently thin coating, and the material of the bulk portion 1002 may be selected for electrical conductivity. In some instances, a sufficiently thin coating may include a thickness of 400 micrometers or less.

[0098] 11-13 illustrate other exemplary plasma-exposed components having an outer layer including an etch-resistant material supported by a bulk portion including a different material. FIG. 11 schematically illustrates an exemplary inner electrode 1100 having a bulk portion 1102 supporting an outer layer 1104 including an etch-resistant material. The inner electrode 1100 is an example of the inner electrode 106. Next, FIG. 12 schematically illustrates an exemplary outer electrode 1200 having a bulk portion 1202 supporting an outer layer 1204 including an etch-resistant material. The outer electrode 1200 is an example of the outer electrode 108. Next, FIG. 13 schematically illustrates an exemplary edge ring 1300 having a bulk portion 1302 supporting an outer layer 1304 including an etch-resistant material. The edge ring 1300 is an example of the edge ring 122.

[0099] As mentioned above, in some examples, a plasma-exposed component may be partially coated with an etch-resistant material. FIGS. 14-17 illustrate an example plasma-exposed component including a partial coating of an etch-resistant material supported by a bulk portion including a different material. More specifically, FIG. 14 illustrates an example plasma confinement shroud 1400 including a bulk portion 1402 and an outer layer 1404 including a partial coating of an etch-resistant material. The outer layer 1404 covers the plasma-exposed surface of the plasma confinement shroud 1400. The plasma confinement shroud 1400 is an example of the plasma confinement shroud 158. In the illustrated example, the outer layer 1404 contacts the bulk portion 1402. In other examples, one or more intervening layers may be disposed between the outer layer 1404 and the bulk portion 1402. In the illustrated example, the outer layer 1404 has a uniform thickness. In some other examples, the outer layer 1404 may vary in thickness spatially across the plasma-exposed surface of the plasma confinement shroud 1400 .

[0100] FIG. 15 schematically illustrates an exemplary inner electrode 1500 comprising a bulk portion 1502 supporting a partial coating of an outer layer 1504 comprising an etch-resistant material. The inner electrode 1500 is an example of the inner electrode 106. Next, FIG. 16 schematically illustrates an exemplary outer electrode 1600 comprising a bulk portion 1602 supporting a partial coating of an outer layer 1604 comprising an etch-resistant material. The outer electrode 1600 is an example of the outer electrode 108. Next, FIG. 17 schematically illustrates an exemplary edge ring 1300 comprising a bulk portion 1702 supporting a partial coating of an outer layer 1704 comprising an etch-resistant material. The edge ring 1700 is an example of the edge ring 122.

[0101] As previously mentioned, examples of etch-resistant materials include one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, tin, or any suitable combination thereof. In some examples, the etch-resistant material comprises one or more oxides, nitrides, or oxynitrides of titanium or zirconium.

[0102] The etch-resistant material may be selected based on its etch rate relative to silicon in a plasma process gas chemistry containing fluorine and / or oxygen. As a specific example, an internal electrode containing TiN as the etch-resistant material may have an etch rate ratio of 0.8 relative to silicon in a plasma process gas chemistry containing fluorine and / or oxygen. As another example, an internal electrode containing ZrN0 as the etch-resistant material may have an etch rate ratio of 0.8 relative to silicon in a plasma process gas chemistry containing fluorine and / or oxygen. As yet another example, an internal electrode containing ZrN as the etch-resistant material may have an etch rate ratio of 0.9 relative to silicon in a plasma process gas chemistry containing fluorine and / or oxygen. An etch rate ratio of less than 1.0 relative to silicon may extend the useful life of plasma-exposed components compared to components made from silicon. Table 1 lists examples of various etch-resistant materials and their associated calculated etch rates. [Table 1] The etch rate ratio of the plasma-exposed components may vary depending on the bias voltage applied to the plasma-exposed components, the temperature of the plasma-exposed components, the oxygen gas flow, and / or other process parameters. The calculated values ​​shown may not represent erosion at all plasma-exposed locations within the chamber, as process conditions may vary between components. Additionally, the etch rate of a material may vary based on variations in stoichiometry and structure (e.g., grain size and / or crystal structure).

[0103] As previously mentioned, the etch-resistant material of the plasma-exposed component may be selected to form a fluoride upon reaction with a fluorine-containing plasma process gas chemistry. In some examples, the fluoride may be a volatile product and removed from the processing chamber in the gas phase. In some such examples, the fluoride may have a boiling point of 1000°C or less. This configuration may allow the fluoride to be removed from the processing chamber during cleaning performed during or after processing. In contrast, fluorides with boiling points above 1000°C may not be sufficiently volatile to be removed from the processing chamber. Therefore, such fluorides may pose a risk of particle formation. As a specific example, if the etch-resistant material includes ZrN and / or Zr5N5O2, the fluoride formed may include ZrF4. ZrF4 has a boiling point of approximately 910°C.

[0104] In some instances, multiple fluorides may be formed when a reaction occurs between an etch-resistant material and a fluorine-containing plasma process gas chemistry. For example, TiN may form one or more of TiF4, TiF3, TiOF2, and / or TiOF. However, such titanium compounds may further react over time to form TiF4 because fluorine radicals in the etching plasma can oxidize TiF4, TiF3, TiOF2, and / or TiOF to TiF4. TiF4 has a boiling point of approximately 284°C. Therefore, such titanium fluorides may be used as etch-resistant materials for plasma-exposed parts.

[0105] Plasma-exposed components including the etch-resistant materials described herein may be used in any suitable plasma processing tool. FIG. 18 shows a flow diagram of an exemplary method 1800 for using such a plasma-exposed component. Method 1800 may be performed in any suitable plasma processing tool, such as plasma processing tool 100. Other examples include PECVD and PEALD tools. Method 1800 includes, at 1802, placing a substrate in a processing chamber of the plasma processing tool. Method 1800 further includes, at 1804, exposing the plasma-exposed component of the plasma processing tool to a selected plasma chemistry in the processing chamber. The plasma-exposed component includes an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to the selected plasma chemistry. The etch-resistant material may include any suitable material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry including fluorine and / or oxygen. In some examples, the plasma-exposed component may be one or more of an inner electrode, an outer electrode, a plasma confinement shroud, or an edge ring. In other examples, the plasma exposed component may include any other suitable components. In some examples, the bulk and surface of the plasma exposed component may be formed from an etch-resistant material, as shown at 1806. In other examples, the plasma exposed component may include a bulk layer that supports an outer layer that includes an etch-resistant material, as shown at 1808.

[0106] Subsequently, exposing the plasma-exposed component to a selected plasma chemistry, as indicated at 1810, may include exposing the plasma-exposed component to a fluorine-containing plasma process gas chemistry. This results in the formation of fluorides by reacting the etch-resistant material with the fluorine-containing plasma process gas chemistry, as indicated at 1812. In some examples, fluorides have boiling points below 1000°C. This configuration potentially allows the fluorides to be removed from the processing chamber in the gas phase. While the etch-resistant material is etched by the fluorine-containing plasma process gas chemistry, the etch-resistant material etches at a slower rate than silicon or silicon carbide. Therefore, the plasma-exposed component including the etch-resistant material will have a longer service life than a comparable component made from silicon.

[0107] Subsequently, method 1800 includes removing the substrate from the processing chamber at 1814. Method 1800 further includes, at 1816, replacing the plasma exposed component if the plasma exposed component meets the replacement threshold condition. In some examples, the edge ring may meet the replacement threshold condition faster than the inner electrode, followed by the confinement shroud. In some examples, if the replacement threshold condition is not met, method 1800 may return to 1802. In other examples, after the plasma exposed component is replaced, method 1800 may return to 1802.

[0108] It will be understood that the configurations and / or approaches described herein are exemplary in nature and are susceptible to numerous variations, and therefore, these specific embodiments or examples should not be considered in a limiting sense. The particular routines or methods described herein may represent one or more of any number of processing strategies. As such, the various operations illustrated and / or described may be performed in the order illustrated and / or described, in other orders, in parallel, or omitted. Similarly, the order of the processes described above may be changed.

[0109] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, operations, and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. 1. A plasma-exposed component for a plasma processing tool, comprising:

1. A plasma-exposed component comprising an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry comprising fluorine and / or oxygen, said etch-resistant material comprising one or more of: (a) one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin; or (b) silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

2. 10. The component of claim 1, The component, wherein the etch-resistant material is configured to form a fluoride upon reaction with the plasma process gas chemistry containing fluorine, the fluoride having a boiling point of 1000° C. or less.

3. 10. The component of claim 1, The component, wherein the etch-resistant material comprises one or more of the oxides, nitrides, or oxynitrides of titanium or zirconium.

4. 4. The component of claim 3, The component, wherein the etch-resistant material comprises the nitride of titanium or the nitride of zirconium.

5. 10. The component of claim 1, A component, wherein a bulk portion and a surface of the plasma-exposed component are formed from the etch-resistant material.

6. 10. The component of claim 1, The plasma-exposed component is an electrode, a plasma confinement shroud, or an edge ring.

7. 1. A plasma processing tool comprising: a processing chamber; a plasma-exposed component located within the processing chamber; Equipped with 1. A plasma processing tool, wherein the plasma-exposed component comprises an etch-resistant material that has an etch rate lower than silicon or silicon carbide when exposed to a plasma process gas chemistry comprising fluorine and / or oxygen, the etch-resistant material comprising one or more of: (a) one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin; or (b) silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

8. 8. The tool of claim 7, The tool comprises a dielectric plasma etching tool.

9. 8. The tool of claim 7, The tool, wherein the etch-resistant material is configured to form a fluoride upon reaction with the plasma process gas chemistry containing fluorine, the fluoride having a boiling point of 1000° C. or less.

10. 8. The tool of claim 7, The tool, wherein the plasma-exposed component comprises an outer layer supported by a bulk portion, the outer layer comprising the etch-resistant material.

11. 11. The tool of claim 10, The tool, wherein the bulk portion comprises one or more of silicon, silicon carbide, or silicon oxide.

12. 8. The tool of claim 7, A tool, wherein a bulk portion and a surface of the plasma-exposed component are formed from the etch-resistant material.

13. 8. The tool of claim 7, The tool, wherein the plasma exposed component is an electrode, a plasma confinement shroud, or an edge ring.

14. 1. A plasma exposed component for a plasma processing tool, the plasma exposed component comprising: A bulk portion and an outer layer supported by the bulk portion; Equipped with The plasma-exposed component, wherein the outer layer comprises an etch-resistant material that is different from a material of the bulk portion, the etch-resistant material being configured to etch at a slower rate than silicon or silicon carbide in a selected plasma chemistry.

15. 15. The component of claim 14, The outer layer contacts the bulk portion.

16. 15. The component of claim 14, The component, wherein the etch-resistant material comprises one or more oxides, nitrides, or oxynitrides of one or more of titanium, hafnium, zirconium, or tin.

17. 17. The component of claim 16, The component, wherein the etch-resistant material comprises one or more of the oxides, nitrides, or oxynitrides of titanium or zirconium.

18. 15. The component of claim 14, The component, wherein the etch-resistant material comprises one or more of silicon or silicon carbide doped with one or more of titanium, hafnium, zirconium, or tin.

19. 15. The component of claim 14, The component, wherein the etch-resistant material is configured to form a fluoride upon reaction with a fluorine-containing plasma process gas chemistry, the fluoride having a boiling point of 1000°C or less.

20. 15. The component of claim 14, The component, wherein the bulk portion comprises one or more of silicon, silicon carbide, or silicon oxide.

21. 15. The component of claim 14, The plasma-exposed component is an electrode, a plasma confinement shroud, or an edge ring.

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