Coated chamber component, method for reducing particles, and method for coating chamber component

Abstract

The embodiments disclosed herein pertain to an article, a coated chamber component, and a method for coating a chamber component with a protective coating comprising at least one metal fluoride of the formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw6, wherein at least one of M1, M2, or M3 is magnesium or lanthanum. The protective coating can be deposited by atomic layer deposition, chemical vapor deposition, electron beam ion-assisted deposition, or physical vapor deposition.

Description

[Technical Field]

[0001] The embodiments of this disclosure relate to articles, coated chamber components, methods of coating chamber components, methods of reducing or eliminating particles, methods of reducing deposition rate drift or etching rate drift, and methods of improving thin film uniformity or etching uniformity in semiconductor processing chambers. [Previous Technology]

[0002] Various semiconductor manufacturing processes utilize mixtures of high temperatures, high-energy plasmas (such as remote and direct fluorine plasmas, such as NF3, CF4, and the like), corrosive gases, and high stress, and combinations thereof. These extreme conditions can cause reactions between component materials within the chamber and the plasma or corrosive gases, resulting in high vapor pressure gases (e.g., AlFx). These gases may readily sublimate and deposit on other components within the chamber. During subsequent process steps, the deposited material may be released as particles from other components and fall onto the wafer, leading to defects. Other problems caused by these reactions include deposition rate drift, etch rate drift, impaired film uniformity, and impaired etch uniformity. It is advantageous to reduce these defects by applying a low-volatility coating over the reactive material to limit the sublimation and / or deposition of reactants on components within the chamber. [Summary of the Invention]

[0003] This embodiment describes a semiconductor chamber component including a substrate and a protective coating deposited on an unroughened surface of the substrate. In embodiments, the protective coating includes at least one metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. In embodiments where the metal fluoride has the formula M1xFw, x is 1, and w ranges from 1 to 3. In embodiments where the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments where the metal fluoride has the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments, at least one of M1, M2, or M3 includes magnesium or lanthanum.

[0004] This embodiment describes a method for reducing particles in a semiconductor processing chamber during processing. The method includes depositing a protective coating on an unroughened surface of a substrate by atomic layer deposition (ALD), chemical vapor deposition (CVD), electron beam ion assisted deposition (EB-IAD), or physical vapor deposition (PVD). In embodiments, the protective coating includes at least one metal fluoride having the formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. In embodiments where the metal fluoride has the formula M1xFw, x is 1, and w ranges from 1 to 3. In embodiments where the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments of metal fluorides having the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments, at least one of M1, M2, or M3 comprises magnesium or lanthanum.

[0005] This embodiment describes a method for coating the surface of a substrate using atomic layer deposition (ALD). In an embodiment, the method includes depositing a first adsorbed layer on the surface of the substrate by pulsedly introducing one or more metal precursors, M1, M2, M3, or combinations thereof, into an ALD processing chamber. In an embodiment, the method further includes introducing a fluorine component into the ALD processing chamber to form at least one metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. In an embodiment where the metal fluoride has the formula M1xFw, x is 1, and w ranges from 1 to 3. In an embodiment where the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments of metal fluorides having the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3. In embodiments, at least one of M1, M2, or M3 comprises magnesium or lanthanum.

Implementation Method

[0027] The embodiments described herein cover articles, coated chamber components, methods of coating chamber components, methods of reducing or eliminating particles from semiconductor processing chambers, methods of reducing deposition rate drift or etching rate drift in semiconductor processing chambers, and methods of improving film uniformity or etching uniformity on wafers processed in semiconductor processing chambers.

[0028] In an embodiment, the coated semiconductor chamber component includes a substrate and a protective coating deposited on the surface of the substrate. Exemplary substrates having surfaces suitable for coating with the protective coating described herein include, but are not limited to, semiconductor chamber components positioned in the upper portion of a processing chamber (e.g., nozzles, panels, pads, electrostatic chucks, edge rings, barrier plates) and in the lower portion of a processing chamber (e.g., sleeves, lower pads, bellows, gaskets). Certain semiconductor process chamber components suitable for coating with the protective coating described herein may have portions with high aspect ratios, and the surfaces of these high aspect ratio portions may be coated with the protective coating described herein.

[0029] The protective coating described herein comprises at least one metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw, wherein: a) when the metal fluoride has the formula M1xFw, x is 1, and w ranges from 1 to 3; b) when the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3; and c) when the metal fluoride has the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3. At least one of M1, M2, or M3 is magnesium or lanthanum. M1, M2, and M3 each represent different metals, such as, and not limited to, magnesium, yttrium, aluminum, or lanthanum. Without being construed as limiting, magnesium-containing metal fluorides and lanthanum-containing metal fluorides are suitable candidates for protective coatings because the reaction products of magnesium-containing or lanthanum-containing fluorides with fluorinated plasma have a lower vapor pressure than the reaction products of the substrate material with fluorinated plasma.

[0030] The exemplary protective coatings as defined above may include at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw or YxMgyLazFw.

[0031] In some embodiments, the metal fluoride protective coating described herein may also be a "low-volatility coating." As used herein, the term "low-volatility coating" means a coating that, when exposed to high-temperature plasma, will react with the plasma to form a low vapor pressure compound or a metal compound (e.g., a metal fluoride). In embodiments, the vapor pressure of the low vapor pressure metal compound will be at least an order of magnitude lower than the vapor pressure of the gas formed when the plasma reacts with the material of an uncoated chamber component under the same conditions (e.g., under the same conditions and using the same measurement methods).

[0032] Exemplary materials for the substrate include metals or ceramics, such as, but not limited to, aluminum alloys, AlN, Al2O3, stainless steel, nickel, nickel-chromium alloys and the like.

[0033] In one example, the substrate may include an aluminum-based component (such as aluminum, aluminum alloy, or Al2O3). When the aluminum-based component is exposed to a fluorinated plasma at a temperature between 400°C and 1000°C, the aluminum in the aluminum-based component can react with fluorine to form AlFx substances, which are highly volatile due to their high vapor pressure at the illustrated temperature range. Coating the aluminum-based component with a protective coating including, for example, MgxFw reduces the number of particles generated by the reaction between the magnesium component in the MgxFw coating and the fluorinated plasma to form reaction products, which have a lower vapor pressure than AlFx at the illustrated temperature range and are less likely to sublimate and deposit elsewhere in the processing chamber.

[0034] Various coating architectures are considered for the protective coating described herein. In one embodiment, the protective coating may be deposited directly on the bare surface of the substrate. In another embodiment, an adhesive layer may be deposited on the surface of the substrate, and a metal fluoride-containing protective coating may be deposited on the adhesive layer. The adhesive layer may be configured to improve the adhesion strength between the substrate surface and the metal fluoride-containing protective coating. The adhesive layer may also be configured to, for example, relieve stress by having a CTE value between the coefficient of thermal expansion (CTE) of the protective coating and the CTE of the substrate to mitigate any potential mismatch in CTE between the substrate and the protective coating. The adhesive layer may also be configured as a diffusion barrier layer that prevents fluorine-containing substances (such as fluorine radicals) from the processing environment in the semiconductor processing chamber or from the fluorine-containing protective coating all the way to the underlying substrate. In some embodiments, the adhesive layer may be amorphous, such as amorphous alumina or amorphous yttrium aluminum garnet (YAG).

[0035] Another suitable coating architecture for a fluorine-containing protective coating may be a continuously growing crystalline phase with a rough surface. In some embodiments, the protective coating is designed to have a certain roughness on the top surface of the coating so that if any particles are generated during processing, these particles will primarily adhere to the coating of the semiconductor chamber component, rather than to the wafer being processed. One way to roughen the top surface of the coating is by sandblasting the coating. Although sandblasting is commonly used, it is less advantageous because particles generated during sandblasting at high processing temperatures may detach and contaminate the wafer being processed inside the chamber. In this disclosure, the crystalline nature of Mg-based metal fluorides and / or La-based metal fluorides can be utilized to continuously grow crystalline Mg-based metal fluorides and / or crystalline La-based metal fluorides while simultaneously controlling the nanoscale surface configuration to achieve the target roughness. In other words, in this disclosure, the nano- or micron-scale roughness of the top surface of the metal fluoride-containing protective coating can be tuned by controlling the deposition of the crystalline phase of the metal fluoride forming the protective coating. The resulting nano- or micron-scale roughness of the top surface of the metal fluoride-containing protective coating may be suitable for promoting the adhesion of particles that may be generated during processing within a semiconductor processing chamber. In some embodiments, the roughness of the top surface of the protective coating ranges from about 0.1 microinch to 200 microinches, from about 0.5 microinches to about 50 microinches, from about 2 microinches to about 30 microinches, from about 5 microinches to about 20 microinches, from about 75 microinches to about 150 microinches, or from about 30 microinches to about 100 microinches, or any subrange or single value thereof.

[0036] Another suitable coating architecture for a fluorine-containing protective coating is a multilayer structure, such as a layered structure. The multilayer structure may include, for example, alternating layers of amorphous and crystalline layers. In one exemplary embodiment, the layered structure may include alternating layers of amorphous Al2O3 and crystalline MgF2.

[0037] Depending on the coating architecture, target thickness, porosity, uniformity, conformability, composition, application, etc., a variety of deposition techniques can be used to coat the substrate surface. Appropriate deposition techniques include atomic layer deposition (ALD), chemical vapor deposition (CVD), electron beam ion-assisted deposition (EB-IAD), or physical vapor deposition (PVD).

[0038] ALD and CVD technologies are non-line-of-sight deposition technologies and are suitable for depositing thin protective coatings. Thinner protective coatings are suitable for applications where the protective coating should maintain the properties of the underlying component (such as thermal properties) substantially unaffected (e.g., within about + / -10%). For example, thinner coatings may be suitable for heaters to provide fluorine protection without substantially affecting the thermal properties of the underlying heater (such as thermal conductivity, heat capacity, or temperature). PVD and EB-IAD are line-of-sight technologies and may be more suitable for applications where thicker coatings than those deposited by ALD or CVD are acceptable.

[0039] In one embodiment, ALD is advantageously used to deposit the protective coating described herein due to the high density, low porosity (0%), high uniformity, high conformability, ability to coat high aspect ratio surfaces and complex three-dimensional features, low defect rate, and high toughness associated with ALD technology. Unlike ALD, methods such as thermal spraying, sputtering, plasma spraying, or evaporation techniques are generally unable to deposit conformally consistent, uniform coatings onto complex configuration features of components with low defect density and ALD coatings. With ALD technology, protective coatings containing crystalline metal fluorides can be deposited in a controlled manner to achieve target micron or nanometer roughness to promote particle adhesion. ALD technology can also achieve a multilayered architecture of alternating amorphous and crystalline layers. The coating deposited by ALD has a uniform thickness. When comparing the thickness of the coating at one location with the thickness of the coating at another location, or when quantifying the standard deviation of multiple thickness values ​​obtained from protective coatings at multiple locations, the thickness has a thickness variation of less than ±20%, or less than ±10%, or less than ±5%, or even lower.

[0040] ALD allows for self-limiting material deposition controlled by chemical reactions with the surface of the workpiece. Besides providing conformal and uniform processes, ALD can also form very thin films. A typical reaction cycle in an ALD process begins by injecting one or more precursors into an ALD chamber and adsorbing them onto the surface of the substrate (including the surface of the borehole walls within the substrate). In this disclosure, the precursors may be one or more of metal precursors, such as M1, M2, M3, or combinations thereof. Then, excess (amounts) of the precursors are flushed out of the ALD chamber before introducing one or more reactants and subsequently flushing them out. In this disclosure, the reactants may be fluorinated reactants in one embodiment or oxygenated reactants that will subsequently undergo fluorination in another embodiment. For ALD, the final thickness of the material depends on the number of reaction cycles run, as each reaction cycle will grow a layer of a certain thickness, which may be one atomic layer or less.

[0041] ALD technology can deposit thin layers of material at relatively low temperatures (e.g., from about 25°C to about 350°C) without damaging or deforming any material of the chamber component. Furthermore, ALD technology can deposit material layers within complex features of the component (e.g., features with high aspect ratios). Additionally, ALD technology generally produces relatively thin (i.e., 1 µm or less) non-porous (i.e., pinhole-free) coatings, which eliminates crack formation during deposition.

[0042] As described with respect to ALD technology, in some embodiments, a protective coating containing a metal fluoride is formed by fluorinating a metal oxide material (e.g., M1xM2yM3zOa) (among other steps). Thus, in some embodiments, the protective coating may contain a certain amount of oxygen atoms, such as up to 40 atomic% oxygen. In some embodiments, the amount of oxygen may be reduced to single-digit atomic% (e.g., less than 10 atomic%) or may be completely eliminated (e.g., 0 atomic% oxygen).

[0043] The atomic percentages of various components (i.e., M1, M2, M3, F, and, where applicable, O) of the metal fluoride protective coating can be adjusted based on the intended application and properties of the protective coating. For example, the components can be adjusted to control and / or achieve a target vapor pressure of the coating. Thus, in some embodiments, this disclosure relates to a method for adjusting / controlling the vapor pressure of a protective coating. In another example, the components can be adjusted to modify / blend / enhance the fluorine resistance of the protective coating. Thus, in some embodiments, this disclosure relates to a method for modifying / adjusting / enhancing the fluorine resistance of a protective coating. In yet another example, the composition of the coating can be adjusted to control the phase (e.g., amorphous or crystalline) and structure of the protective coating. Thus, in some embodiments, this disclosure relates to a method for controlling the phase and / or structure of a protective coating.

[0044] For thicker protective coatings (e.g., at the micrometer level), techniques such as EB-IAD and PVD can be advantageously utilized. Similar to ALD, these techniques can be used to deposit protective coatings on an adhesive layer, continuous single protective layers, and protective coatings with multi-layer structures. EB-IAD can be a favorable alternative to deposition techniques such as plasma spraying. Plasma spraying relies on sandblasting to increase the surface roughness of the underlying substrate and promote coating adhesion to the substrate surface. Sandblasting used to roughen the underlying substrate results in the underlying substrate being covered with microcracks. In contrast, sandblasting is not part of the EB-IAD deposition process. Therefore, substrates coated by EB-IAD are not roughened and do not have microcracks like substrates coated by plasma spraying.

[0045] Compared to common reaction products between a substrate and a fluorinated substance (e.g., AlFx), the metal fluoride protective coating described herein (which includes at least a Mg or La component) exhibits a lower evaporation rate (lower vapor pressure). Furthermore, because the metal fluoride protective coating is fluorinated, it is expected to exhibit higher fluorine resistance (i.e., forming a better barrier to fluorine diffusion) compared to the underlying substrate or the same metal in oxide form. It is also expected to exhibit higher fluorine resistance than the natural oxide layer of the underlying substrate material.

[0046] Figure 1 is a cross-sectional view of a semiconductor processing chamber 100 according to an embodiment, having one or more chamber components coated with a protective coating. The processing chamber 100 can be used in processes in which a corrosive plasma environment with plasma processing conditions is provided. For example, the processing chamber 100 can be a chamber for a plasma etching machine or plasma etching reactor, a plasma cleaner, a plasma-enhanced CVD or ALD reactor, etc. Examples of chamber components that may include a protective coating are chamber components that are at risk of exposure to fluorinated chemicals and corrosive environments during processing. These chamber components can be in the upper or lower portion of the chamber and are, for example, heaters, electrostatic chucks, panels, nozzles, gaskets, baffles, gas boxes, edge rings, bellows, and the like. The protective coating (described in more detail below) can be applied by ALD, CVD, PVD, or EB-IAD.

[0047] In one embodiment, the processing chamber includes a chamber body 102 and a nozzle 130 that encloses the internal space 106. The nozzle 130 may include a nozzle base and a nozzle gas distribution plate. Alternatively, in some embodiments, the nozzle 130 may be replaced by a cover and a nozzle, or in other embodiments, the nozzle 130 may be replaced by a plurality of disc nozzle compartments and a plasma generation unit. The chamber body 102 may be made of aluminum, stainless steel, or other suitable materials such as titanium (Ti). The chamber body 102 generally includes sidewalls 108 and a bottom 110. A liner 116 may be disposed adjacent to the sidewalls 108 to protect the chamber body 102.

[0048] The exhaust port 126 may be defined in the chamber body 102 and may be coupled to the internal space 106 to the pump system 128. The pump system 128 may include one or more pumps and throttle valves for venting and regulating the pressure of the internal space 106 of the processing chamber 100.

[0049] The nozzle 130 may be supported on the sidewall 108 of the chamber body 102. The nozzle 130 (or cover) may be opened to allow access to the interior space 106 of the processing chamber 100 and may provide a seal to the processing chamber 100 when closed. A gas control plate 158 may be coupled to the processing chamber 100 to supply processing and / or cleaning gases to the interior space 106 via the nozzle 130 or cover and nozzle. The nozzle 130 may be used in processing chambers used for dielectric etching (etching of dielectric materials). The nozzle 130 may include a gas distribution plate (GDP) and may have a plurality of gas outlets 132 extending through the GDP. The nozzle 130 may include a GDP bonded to an aluminum substrate or anodized aluminum substrate. The GDP may be made of Si or SiC, or may be ceramic, such as Y2O3, Al2O3, Y3Al5O12 (YAG), etc.

[0050] For a processing chamber used for conductor etching (etching of conductive materials), a cover may be used instead of a nozzle. The cover may include a central nozzle adapted to a central hole in the cover. The cover may be a ceramic such as Al2O3, Y2O3, or YAG, or a ceramic compound comprising a solid solution of Y4Al2O9 and Y2O3-ZrO2. The nozzle may also be a ceramic such as Y2O3 or YAG, or a ceramic compound comprising a solid solution of Y4Al2O9 and Y2O3-ZrO2.

[0051] Examples of processing gases that can be used to process the substrate in the processing chamber 100 include halogen-containing gases such as C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, and SiF4 (and others), as well as other gases such as O2 or N2O. Examples of carrier gases include N2, He, Ar, and other gases that are inert to the processing gas (e.g., non-reactive gases).

[0052] The heater assembly 148 is disposed within the interior space 106 of the processing chamber 100, below the nozzle 130 or cap. The heater assembly 148 includes a support 150 that holds the substrate 144 during processing. The support 150 is attached to the end of a shaft 152, which is coupled to the chamber body 102 via a flange. The support 150, shaft 152, and flange may be made of a heater material containing AlN (e.g., AlN ceramic). The support 150 may further include a mesa (e.g., a recess or protrusion). The support may additionally include wires, such as tungsten wires (not shown), embedded within the heater material of the support 150. In one embodiment, the support 150 may include a metal heater and a sensor layer sandwiched between AlN ceramic layers. This assembly may be sintered in a high-temperature furnace to produce an integral assembly. These layers may include heater circuitry, sensor elements, a ground plane, an RF grid, and a combination of metallic and ceramic flow channels.

[0053] The protective coating according to the embodiments described herein may be deposited on at least a portion of the surface of any of the chamber components described herein (and others that may not be shown in Figure 1), which may be exposed to the processing chemicals used within the processing chamber. Exemplary chamber components to which the protective coating described herein may be applied include, but are not limited to, electrostatic chucks, nozzles, gas distribution plates, nozzles (e.g., 130), electrostatic chuck components, chamber walls (e.g., 108), gaskets (e.g., 116), gasket sleeves, gas lines, chamber covers, nozzles, single rings, processing sleeve rings, edge rings, bases, protective covers, plasma shields, flow equalizers, cooling bases, chamber viewing ports, bellows, any part of the heater assembly (including support 150, shaft 152, flanges), panels, barrier plates, etc.

[0054] Figures 2A through 2C depict cross-sectional views of an article 210 having a protective coating deposited thereon according to various embodiments covered herein. The article 210 may be made of ceramic (e.g., oxide-based ceramic, nitride-based ceramic, or carbide-based ceramic), metal, or metal alloy. Examples of oxide-based ceramics include SiO2 (quartz), Al2O3, Y2O3, etc. Examples of carbide-based ceramics include SiC, Si-SiC, etc. Examples of nitride-based ceramics include AlN, SiN, etc. In some embodiments, the article 210 may be made of aluminum, anodized aluminum, aluminum alloys (e.g., Al 6061), or anodized aluminum alloys. In some embodiments, the article 210 may be made of stainless steel, nickel, nickel-chromium alloys, titanium, and the like. Throughout this document, the terms "substrate," "article," and "chamber component" are used interchangeably.

[0055] As depicted in Figures 2A to 2D, at least a portion of the surface of article 210 may be coated with a protective coating (e.g., 220, 230, and 240), the protective coating comprising at least one metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. In an embodiment, when the metal fluoride formula is M1xFw, x is 1, and w ranges from 1 to 3. In an embodiment, when the metal fluoride formula is M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3. In an embodiment, when the metal fluoride formula is M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3. The values ​​of x, y, z, and w can be integers or fractions. The range of x, y, z, and w includes endpoint values ​​(i.e., x, y, and z include 0.1 and 1, and w includes 1 and 3). The range of x, y, z, and w also includes each individual value falling within the specified range and any subrange falling within the specified range, whether integer or fractional. For example, x, y, and z can independently (but are not limited to) be about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, or about 1. Similarly, w can be about 1, about 2, or about 3, but is not limited to integers (because fractions are also possible).

[0056] In the metal fluoride formula, M1, M2, and M3 each represent a different metal. Exemplary suitable metals for M1, M2, and M3 include, but are not limited to, magnesium, yttrium, lanthanum, or aluminum. In some embodiments, suitable metals for M1, M2, and M3 include magnesium, yttrium, and lanthanum. At least one of M1, M2, and M3 is magnesium or lanthanum. Exemplary protective coatings as defined above may include at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw. Without being construed as limiting, magnesium-containing metal fluorides and lanthanum-containing metal fluorides are believed to be suitable candidates for protective coatings because the reaction products of magnesium-containing fluorides or lanthanum-containing fluorides with fluorinated chemicals (such as fluorinated plasmas) have a lower vapor pressure than the reaction products of the substrate material with fluorinated plasmas (e.g., the reaction products of aluminum and fluorine). For example, the vapor pressure of AlF3 ranges from about 0.001 Torr to about 1000 Torr at temperatures ranging from about 750°C to about 1250°C. In contrast, the vapor pressure of MgF2 ranges from about 0.001 Torr to about 0.1 Torr in the temperature range of 1000°C to about 1250°C, and only reaches 1000 Torr at temperatures up to about 2250°C. Similarly, LaF3 has a vapor pressure of about 10⁻⁵ to about 10⁻³ in the temperature range of about 920°C to about 1120°C, which is much lower than that of AlF3. For components that will be exposed to high temperatures (e.g., above 650°C), the aluminum content in the protective coating can be minimized to reduce the formation of reaction products between aluminum and fluorine, which may easily sublimate. For components that are unlikely to be exposed to temperatures above 650°C during processing, some aluminum may be incorporated into a protective coating, but if incorporated, it is preferable to combine it with at least one other metal (such as Mg and / or La).

[0057] In other words, aluminum in articles made of aluminum or aluminum alloys exposed to processing gases (such as fluorinated processing gases or plasma) can react with fluorine in the processing gases at processing temperatures such as 400°C to 1000°C to form AlFx substances, which are highly volatile due to their high vapor pressure within the illustrated temperature range. It is believed that coating aluminum-based articles with a protective coating including metal fluorides as described herein will reduce the number of particles generated for several reasons. Because the protective coating is fluorinated, it is believed that fluorine from the processing environment is unlikely to corrode the protective coating. In addition, the protective coating and its reaction products with fluorine from the processing environment (if present) are believed to have a lower vapor pressure than the vapor pressure of the underlying material and the possible reaction products of fluorine (e.g., AlFx substances). Therefore, if any component of the protective coating reacts with fluorine in the processing environment, the products of such reaction are unlikely to sublimate and deposit elsewhere in the chamber.

[0058] Various coating architectures are considered for the protective coating described herein. In one embodiment, the protective coating may be deposited directly on the bare surface of the article. When the protective coating is deposited directly on the bare surface of the article, the boundary between the bare surface of the article and the protective coating may be discrete or may not be discrete (e.g., the protective coating and the bare surface of the article may interact / diffly / become a whole).

[0059] In another embodiment, as depicted in Figure 2A, the adhesive layer 205 may be deposited directly onto the surface of the substrate, and the metal fluoride-containing protective coating 220 may be deposited on the adhesive layer. The adhesive layer 205 may be configured to improve the adhesion strength between the surface of the article 210 and the metal fluoride-containing protective coating 220. The adhesive layer 205 may also be configured to, for example, relieve stress by having a CTE value between the coefficient of thermal expansion (CTE) of the protective coating and the CTE of the substrate to mitigate any potential mismatch in CTE between the article and the protective coating. For example, the surface of the coated article (e.g., a process chamber component) can be a metallic body (e.g., aluminum or an aluminum alloy such as Al 6061) or a ceramic body (e.g., Al2O3, AlN, SiC, etc.) having a CTE of approximately 22–25 ppm / K for aluminum or approximately 13 ppm / K for stainless steel. The adhesive layer can be amorphous Al2C3, and the metal fluoride coating can be at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw, having a CTE closer to that of the adhesive layer than that of the article. In this embodiment, the buffer layer mitigates the CTE difference between the protective coating and the process chamber component, thereby reducing the coating's susceptibility to cracking during thermal cycling, which may be caused by poor CTE matching.

[0060] The adhesive layer 205 may also be configured as a diffusion barrier layer, preventing fluorinated substances (such as fluorine radicals) from the processing environment within the semiconductor processing chamber or from the fluorinated protective coating all the way to the underlying article (e.g., via grain boundaries in the protective coating). In some embodiments, the adhesive layer 205 may be amorphous, such as amorphous alumina or amorphous yttrium aluminum garnet (YAG). The boundaries between the adhesive layer 205 and the underlying article 210 and / or between the adhesive layer 205 and the protective coating 220 deposited thereon may be discrete or non-discrete (e.g., the protective coating and the adhesive layer and / or the article and the adhesive layer may be intermixed / interdiffused / integrated).

[0061] The thickness of the adhesive layer described herein may range from about 5 nm to about 3000 nm, from about 10 nm to about 1000 nm, from about 15 nm to about 750 nm, from about 20 nm to about 500 nm, from about 25 nm to about 250 nm, from about 30 nm to about 100 nm, about 50 nm, or any sub-range or single value of thickness therein. The thickness and properties of the adhesive layer and any other layer of the protective coating described herein depend on the deposition method used to deposit said layers. These properties may be adjusted and modified according to the intended application of the coated article. For example, a protective coating deposited by ALD may have a thinner overall thickness and may be deposited on a thin adhesive layer with a thickness of about 30 nm to about 100 nm. As described in more detail in the examples, Figure 9A depicts an exemplary protective coating deposited by ALD on a thin adhesive layer. In comparison, protective coatings deposited using line-of-sight techniques (such as PVD and EB-IAD) can have a thicker overall thickness and can be deposited on a thicker adhesive layer with a thickness of approximately 250 nm to approximately 1000 nm. As described in more detail in the examples, Figure 13 depicts an exemplary protective coating deposited on a thick adhesive layer using EB-IAD.

[0062] Another suitable coating architecture for the fluorine-containing protective coating may be a continuously growing crystalline phase with a rough surface, as depicted in Figure 2B. The protective coating 230 of the continuously growing crystalline phase type may also be deposited on an adhesive layer (such as layer 205) or directly onto the bare surface of the underlying article 210. In some embodiments, the protective coating (e.g., 230) is designed to have a certain roughness on the top surface of the coating so that if any particles are generated during processing, the particles adhere primarily to the coating of the semiconductor chamber component rather than to the wafer being processed. One way to roughen the top surface of the coating is by sandblasting the coating. While sandblasting is commonly used, it is less advantageous because particles generated during sandblasting at high processing temperatures may detach and contaminate the wafer being processed inside the chamber.

[0063] In this disclosure, the crystalline nature of Mg-based metal fluorides and / or La-based metal fluorides can be utilized to continuously grow crystalline Mg-based metal fluorides and / or crystalline La-based metal fluorides, while simultaneously controlling the nanoscale surface configuration to achieve the target roughness. In other words, in this disclosure, the nanoscale or microscale roughness of the top surface of the metal fluoride-containing protective coating 230 can be adjusted by controlling the deposition of the crystalline phase of the metal fluoride forming the protective coating. The resulting nanoscale or microscale roughness of the top surface of the metal fluoride-containing protective coating may be suitable for promoting the adhesion of particles that may be generated during processing within the semiconductor processing chamber. In this way, if any particles are generated within the processing chamber during processing, these particles will adhere to the chamber components rather than contaminate the wafer being processed. As described in more detail in the examples, Figures 9A, 9C1, 9C2 and 9C3 illustrate a protective coating deposited by ALD, which has nano-roughness on the top surface of the protective coating.

[0064] In some embodiments, the roughness of the protective coating 230 ranges from about 0.1 microinch to 200 microinch, from about 0.5 microinch to about 50 microinch, from about 2 microinch to about 30 microinch, from about 5 microinch to about 20 microinch, from about 75 microinch to about 150 microinch, or from about 30 microinch to about 100 microinch, or any subrange or single value thereof.

[0065] In some embodiments, the microhardness of the protective coating 230 is greater than about 5 mN, greater than about 6 mN, greater than about 7 mN, greater than about 8 mN, greater than about 9 mN, greater than about 10 mN, greater than about 11 mN, or greater than about 12 mN. In some embodiments, the microhardness of the protective coating 230 is at least twice the microhardness of stainless steel and / or at least four times the microhardness of alumina. The above microhardness values ​​represent the force applied to the protective coating to observe the first failure (or first crack formation) of the protective coating.

[0066] Another suitable coating architecture for the fluorine-containing protective coating is a multilayer structure, such as a layered structure. This multilayer structure may include, for example, a plurality of alternating layers of amorphous and crystalline layers (such as 240A, 240B, 240C, and 240D in Figure 2C). In some embodiments, as previously described with respect to Figures 2A and 2B, the multilayer protective coating may be formed on the adhesive layer 205. In other embodiments, the multilayer protective coating may be deposited directly onto the surface of the article 210.

[0067] The multilayer structure may include two layers of different compositions. In some embodiments, the multilayer structure may include three or more layers of different compositions. The multilayer structure may be deposited by repeating a supercycle of any of the deposition techniques described herein. A supercycle may represent depositing a first layer, followed by depositing a second layer, followed by depositing a subsequent layer (if present). This supercycle may be repeated multiple times until the target thickness of the protective coating is achieved.

[0068] In some embodiments, the boundaries between the various layers in the multilayer protective coating may be discrete, and / or the boundary between the multilayer protective coating and the adhesive layer 205 (if present) may be discrete, and / or the boundary between the multilayer protective coating and the surface of the article 210 may be discrete, and / or the boundary between the adhesive layer 205 (if present) and the surface of the article 210 may be discrete. In some embodiments, one or more of these boundaries may not be discrete (i.e., adjacent layers may interact, mix / diffuse / become a whole).

[0069] In one exemplary embodiment, the multilayer structure of the protective coating may include alternating layers of amorphous Al2O3 and crystalline MgF2. For example, 240A may be an amorphous alumina layer, 240B may be crystalline MgF2, 240C may be amorphous alumina, 240D may be crystalline MgF2, and so on. As explained in further detail in the examples, Figures 10A1 to 10A3 and 11A1 to 11A3 depict exemplary multilayer protective coatings with alternating layers of MgF2 and alumina.

[0070] The protective coating may comprise any number of alternating layers, such as about 2 to about 250 layers, about 3 to about 200 layers, about 4 to about 150 layers, about 5 to about 100 layers, about 6 to about 50 layers, or about 7 to about 25 layers, or any subrange or single value thereof. As described further in detail below, when depositing a multilayer protective coating by ALD, the number of alternating layers may be adjusted based on the number of ALD cycles performed to deposit each layer. The thickness of each layer may also be adjusted. For example, a protective coating comprising a plurality of alternating layers of MgxFw and alumina may have a ratio of the thickness of each MgxFw layer to the thickness of each alumina layer, the ratio ranging from about 10:1 to about 10:1, from about 8:1 to about 1:8, from about 5:1 to about 1:5, from about 3:1 to about 1:3, from about 10:1 to about 1:1, from about 8:1 to about 1:1, from about 5:1 to about 1:1, or from about 3:1 to about 1:1, or any subrange or single value therein. While this example relates to alternating layers of MgxFw and alumina, it should not be construed as limiting. Similar thickness ratios can be applied to other alternating layer arrangements in multilayer protective coatings.

[0071] In some embodiments, thin amorphous layers may be introduced between the thicker crystalline layers in the protective coating to control the overall phase of the protective coating. For example, the protective coating may be adjusted to be more amorphous.

[0072] In some embodiments, the structure and composition of the protective coating may be adjusted to harmonize the fluorine resistance of the protective coating and / or mitigate grain boundary erosion caused by fluorine in the processing chamber.

[0073] In some embodiments, a multilayer protective coating (such as one depicted in Figure 2C, or any of the other protective coatings described herein (such as those depicted in Figures 2A and 2B)) may undergo a post-coating treatment. Non-limiting exemplary post-coating treatments include annealing the protective coating by, for example, subjecting it to a temperature ranging from about 400°C to about 2500°C, from about 450°C to about 2000°C, or from about 500°C to about 1800°C, or any single value or subrange thereof, for a duration of about 2 hours to about 24 hours, about 4 hours to about 15 hours, or about 6 hours to about 12 hours, or any single value or subrange thereof. The annealing temperature and duration may be selected based on the materials of the article, surface, and protective coating to maintain their integrity and prevent any or all of these components from deforming, decomposing, or melting. In some embodiments, the post-processing protective coating can form a homogeneous protective coating 240 with a uniform composition throughout the coating, as shown in Figure 2D. Alternatively, the composition of the protective coating can be adjusted using post-processing to create a compositional gradient within the coating.

[0074] The composition of various protective coatings can be adjusted to achieve target coating properties based on the intended application of the coated article. For example, the M1xFw coating may include an M1 concentration between about 5 atomic% and 100 atomic%, between about 10 atomic% and 95 atomic%, between about 20 atomic% and 90 atomic%, between about 20 atomic% and 80 atomic%, about 10 atomic%, about 20 atomic%, about 30 atomic%, about 40 atomic%, about 50 atomic%, about 60 atomic%, about 70 atomic%, about 80 atomic%, about 90 atomic%, or any other value and / or number within these ranges, wherein the concentration is measured based on the total amount of metal in the metal fluoride protective coating. When the concentration is measured as a whole based on the metal fluoride protective coating, the M1 concentration can be as high as about 40 atomic%, up to about 35 atomic%, up to about 30 atomic%, up to about 25 atomic%, up to about 20 atomic%, up to about 15 atomic%, up to about 10 atomic%, up to about 5 atomic%, between about 20 atomic% and about 45 atomic%, or any other range and / or figure within these ranges.

[0075] When the metal fluoride protective coating has the formula M1xM2yFw, the concentration of the metal can be about 20 to 80 atomic% of M1 and 20 to 80 atomic% of M2, about 30 to 70 atomic% of M1 and 30 to 70 atomic% of M2, about 40 to 60 atomic% of M1 and 40 to 60 atomic% of M2, about 50 to 80 atomic% of M1 and 20 to 50 atomic% of M2, or about 60 to 70 atomic% of M1 and 30 to 40 atomic% of M2, wherein the concentrations of M1 and M2 are measured based on the total amount of metal (M1+M2) in the metal fluoride protective coating. When the concentration is measured as a whole based on the metal fluoride protective coating, M1+M2 may together have a concentration of up to about 40 atomic%, up to about 35 atomic%, up to about 30 atomic%, up to about 25 atomic%, up to about 20 atomic%, up to about 15 atomic%, up to about 10 atomic%, up to about 5 atomic%, or any other range and / or number between about 20 atomic% and about 45 atomic%, or within these ranges.

[0076] When the metal fluoride protective coating has the formula M1xM2yM3zFw, the concentration of the metal can be about 5 to 80 atomic% of M1 and 5 to 80 atomic% of M2 and 5 to 80 atomic% of M3, about 10 to 70 atomic% of M1 and 10 to 70 atomic% of M2 and 10 to 70 atomic% of M3, or about 1 to 90 atomic% of M1 and 1 to 90 atomic% of M2 and 1 to 90 atomic% of M3, wherein the concentrations of M1, M2 and M3 are based on the total amount of metal (M1+M2+M3) in the metal fluoride protective coating. When the concentration is measured as a whole based on the metal fluoride protective coating, M1+M2+M3 may collectively have a concentration of up to about 40 atomic%, up to about 35 atomic%, up to about 30 atomic%, up to about 25 atomic%, up to about 20 atomic%, up to about 15 atomic%, up to about 10 atomic%, up to about 5 atomic%, in any other range and / or number between about 20 atomic% and about 45 atomic%, or within these ranges.

[0077] The fluorine concentration in the metal fluoride protective coating described herein may be higher than 0 atomic% up to about 95 atomic%, from about 5 atomic% to about 90 atomic%, from about 10 atomic% to about 85 atomic%, from about 20 atomic% to about 80 atomic%, from about 40 atomic% to about 75 atomic, or from about 50 atomic% to about 70 atomic, or any other range and / or figure within these ranges.

[0078] The resistance of the protective coating to plasma can be measured by the "etch rate (ER)," which spans the operation of the coated component and the duration of exposure to plasma (such as halogen or specifically fluorine plasma). The etch rate can be measured in micrometers per hour (µm / hr) or angstroms per hour (Å / hr). Measurements can be taken after different processing times. For example, measurements can be taken before processing, or at approximately 50 processing hours, or at approximately 150 processing hours, or at approximately 200 processing hours, etc. In one example, according to an embodiment, MgF2 protective coatings deposited by EB-IAD and MgF2 deposited by ALD were exposed to fluorine chemicals at 650°C for approximately 56 hours without showing measurable coating loss. Variations in the composition of the protective coating deposited on the chamber component can result in several different plasma resistance or erosion rate values. Furthermore, a protective coating with a single component exposed to various plasmas may have a variety of different plasma resistance or erosion rate values. For example, an anti-plasma material may have a first plasma resistance or erosion rate associated with a first type of plasma and a second plasma resistance or erosion rate associated with a second type of plasma.

[0079] Figure 3 illustrates a method 300 for reducing particles during processing in a semiconductor processing chamber according to an embodiment. In method 300, an article (305) is provided, at least a portion of one surface of which is exposed to an aggressive chemical (e.g., halogenated or fluorine-based chemical) typically found in processing chambers. The portion of the article exposed to the aggressive chemical may be coated with a protective coating as described herein. In some embodiments, the coated surface is not roughened, and the article is substantially free of microcracks.

[0080] In some embodiments, method 300 further includes depositing an adhesive and fluorine diffusion barrier layer (310), such as the adhesive layer 205 described above. The adhesive layer (if present) may be deposited using the same process as the protective coating or using a different deposition process than the protective coating. In some embodiments, the adhesive layer may be deposited using one of the following: atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), or electron beam ion-assisted deposition (EB-IAD).

[0081] In some embodiments, method 300 further includes depositing a protective coating on the surface of the article to be coated (or on the adhesive layer (if present)) by one of the following: atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), or electron beam ion-assisted deposition (EB-IAD) (315). The deposition method of the protective coating may be selected depending on the coating architecture, target thickness, porosity, uniformity, conformability, composition, application, etc.

[0082] In some embodiments, method 300 further includes subjecting the protective coating to a post-deposition treatment (320). A non-limiting example of such a post-deposition treatment includes annealing.

[0083] While a variety of deposition techniques can be used to deposit protective coatings (and adhesive layers, if present), ALD is an advantageous deposition technique in some embodiments. ALD can be advantageously used to deposit certain protective coatings described herein due to the high density, low porosity (0%), high uniformity, high conformability, ability to coat surfaces with high aspect ratios and complex three-dimensional features, low defect rate, and high toughness associated with ALD technology.

[0084] Unlike ALD, methods such as thermal spraying, sputtering, plasma spraying, or evaporation techniques are generally unable to deposit conformal, uniform coatings onto the complex configuration features of parts with low defect density having ALD coatings. In addition, compared to techniques such as plasma spraying (which involves pretreatment by roughening the surface to be coated), ALD coatings can be deposited on unroughened surfaces.

[0085] By means of ALD technology, a protective coating containing crystalline metal fluoride can be continuously deposited in a controlled manner to obtain a target micron roughness or nanon roughness in order to promote particle adhesion, as depicted in Figure 2B.

[0086] By means of ALD technology, a multilayered structure of alternating amorphous and crystalline layers can also be realized, as depicted in Figure 2C.

[0087] The coating deposited by ALD has a uniform thickness, and when comparing the thickness of the coating at one location with the thickness of the coating at another location, or when quantifying the standard deviation of multiple thickness values ​​obtained from protective coatings at multiple locations, the thickness has a thickness variation of less than ±20%, or less than ±10%, or less than ±5%, or even lower.

[0088] ALD allows for the deposition of self-limiting materials controlled by chemical reactions with the surface of the product. In addition to providing a conformal and uniform process, ALD can also form very thin films compared to other deposition technologies.

[0089] Figure 4A depicts an example of an ALD process 500 that can be used to deposit the protective coating described herein. In process 400, an adhesive layer 205 is deposited on the surface of article 210. Subsequently, the article (which has an optional adhesive layer) is coated with a protective coating. The cycle depicted in process 400 begins by injecting one or more precursors 490A and 490B into an ALD chamber and adsorbing them onto the surface of a substrate (including the surface of the hole walls within the substrate). In the depicted process 400, precursors 490A and 490B adsorb onto the surface of adhesive layer 205. In this disclosure, precursors 490A and 490B may be one or more of M1, M2, M3, or combinations thereof, metallic precursors.

[0090] When the metal fluoride has the formula M1xFw, a single metal precursor 490A of metal M1 may be introduced into the ALD chamber, or two or more metal precursors of metal M1 may be introduced into the ALD chamber. When the metal fluoride has the formula M1xM2yFw, a single metal precursor 490A of metal M1 and a single metal precursor 490B of metal M2 may be introduced into the ALD chamber, or two or more metal precursors of each of metal M1 and / or metal M2 may be introduced into the ALD chamber. When the metal fluoride has the formula M1xM2yM3zFw, a single metal precursor 490A of metal M1, a single metal precursor 490B of metal M2, and a single metal precursor (not shown) of metal M3 may be introduced into the ALD chamber, or two or more metal precursors of each of metal M1 and / or metal M2 and / or metal M3 may be introduced into the ALD chamber.

[0091] When two or more metal precursors are introduced into the ALD chamber, they may be introduced simultaneously (e.g., co-feeding) or one after another (co-deposition). Whether co-feeding or co-deposition, the one or more precursors form an adsorbed layer 440A (also referred to as the pre-reaction). Then, before introducing one or more reactants 492 into the ALD chamber and subsequently flushing them out, excess (amounts) of the precursor(s) are flushed out of the ALD chamber. In this disclosure, the reactants may be fluorinated reactants in one embodiment or oxygenated reactants that will subsequently undergo fluorination (e.g., in-situ fluorination) in another embodiment. If reactant 492 is a fluorinated reactant, it reacts with the adsorbed layer 440A to form a first layer 230A having the formula M1xFw, M1xM2yFw, or M1xM2yM3zFw. If reactant 492 is an oxygen-containing reactant, it reacts with adsorbed layer 440A to form a first layer having the formula M1xOa, M1xM2yOa, or M1xM2yM3zOa. This first layer may be fluorinated (e.g., in-situ fluorination) after or during the ALD cycle to form a first layer 230A having the formula M1xFw, M1xM2yFw, or M1xM2yM3zFw. Similar to metal precursors, when more than one reactant is introduced during ALD, it may be introduced simultaneously (e.g., co-feeding) or one after another (co-deposition).

[0092] "Co-deposition" represents atomic layer deposition in which metal precursors, or O-containing reactants, or F-containing reactants are sequentially co-injected (i.e., one metal precursor is injected, followed by another metal precursor, and reactants are introduced only after a mixture of different metal precursors has been deposited to react with the precursors). The concentration of each component in co-deposition may be related to the injection rate of each component.

[0093] "Co-feeding" represents atomic layer deposition in which a metal precursor, an O-containing reactant, or an F-containing reactant is simultaneously co-injected (i.e., a metal precursor is fed simultaneously with a second metal precursor, and the reactant is introduced to react with the precursor only after the mixture of different metal precursors has been deposited). The concentration of each component in co-feeding may be related to the injection rate of each component.

[0094] A supercycle, referred to as process 400, may be performed by injecting one or more metal precursors, M1, M2, M3, or combinations thereof, into the ALD chamber, purging excess metal precursors from the ALD chamber, injecting one or more fluorine- or oxygen-containing reactants into the ALD chamber, and purging excess reactants from the ALD chamber. This supercycle may be repeated n times to form a protective coating 230 (e.g., an uninterrupted continuous protective coating) having a target thickness and other target properties (such as, but not limited to, a target micrometer roughness or nanometer roughness). n is an integer and may represent a finite number of ALD supercycles selected based on the target thickness of the protective coating.

[0095] Figure 4B depicts another example of an ALD process 410, which may be referred to herein as sequential ALD deposition. This process, including a supercycle, can be used to form a multilayered protective coating (such as the protective coating depicted in Figure 2C), in which: a first layer 240A can be deposited as described above with respect to process 400 until a first target thickness of the first layer 240A is achieved; then a second layer 240B (which is different in composition from the first layer 240A) can be deposited as described above with respect to process 400 until a second target thickness of the second layer 240B is achieved; followed by similar deposition of additional layers of different compositions. This supercycle can be repeated w times to achieve a multilayered protective coating of a target thickness (such as the thickness depicted in Figure 2C).

[0096] In process 410, a first layer 240A is formed by injecting one or more precursors (480) of metals M1, M2, M3 or combinations thereof into an ALD deposition chamber to react with an adhesive layer 205 (which may be optional) to deposit a first adsorption layer 422. Subsequently, the ALD deposition chamber is purged to flush out excess (a number of) precursors 480. Then, one or more fluorine-containing or oxygen-containing reactants 482 are introduced into the ALD chamber to react with the first adsorption layer 422 to ultimately form a metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. The cycle for forming the first layer 240A may be repeated m times until a first target thickness of the first layer 240A is achieved. m is an integer and may represent a finite number of ALD cycles selected based on the first target thickness of the first layer in the protective coating.

[0097] The thickness of the first target may be from about 1 nm to 3000 nm, from about 5 nm to about 2000 nm, from about 10 nm to about 1000 nm, from about 15 nm to about 750 nm, from about 20 nm to about 500 nm, from about 25 nm to about 400 nm, from about 35 nm to about 300 nm, or from about 50 nm to about 250 nm, or any subrange or single value therein.

[0098] In process 410, a second layer 240B is formed by injecting one or more precursors (484) of metals M1, M2, M3 or combinations thereof into an ALD deposition chamber to react with the first layer 240A to deposit a second adsorbed layer 426. Subsequently, the ALD deposition chamber is purged to flush out excess (amounts) of precursors 484. Then, one or more fluorine-containing or oxygen-containing reactants 486 are introduced into the ALD chamber to react with the second adsorbed layer 426 to ultimately form a metal fluoride having a composition selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw. The cycle for forming the second layer 240B (which differs in composition from the first layer 240A) can be repeated p times until a second target thickness of the second layer 240B is achieved. p is an integer and can represent a finite number of ALD cycles selected based on the second target thickness of the second layer in the protective coating.

[0099] The thickness of the second target may be from about 1 nm to 3000 nm, from about 5 nm to about 2000 nm, from about 10 nm to about 1000 nm, from about 15 nm to about 750 nm, from about 20 nm to about 500 nm, from about 25 nm to about 400 nm, from about 35 nm to about 300 nm, or from about 50 nm to 250 nm, or any subrange or single value therein.

[0100] For ALD, the final thickness of the material depends on the number of reaction cycles performed, as each reaction cycle grows a layer of a certain thickness, which can be an atomic layer or a small portion of an atomic layer. These supercycles can be repeated k times until a multilayer protective coating with a target number of layers (e.g., 240A, 240B, 240C, 240D, etc.) and a target thickness is achieved. k can represent a finite number of ALD supercycles, which is selected based on the target thickness of the entire protective coating and the number of alternating layers of the first and second layers in the multilayer protective coating. Multilayer protective coatings can also be referred to as "stacks of multiple layers" or "nano-laminated coatings" or similar variations.

[0101] The total thickness of the protective coating deposited by ALD can range from about 5 nm to about 3 μm, from about 10 nm to about 2 μm, from about 20 nm to about 1 μm, from about 30 nm to about 750 nm, from about 40 nm to about 500 nm, or from about 50 nm to about 250 nm, or any single value or subrange therein.

[0102] ALD technology deposits thin layers of material at relatively low temperatures (e.g., from about 25°C to about 350°C) without damaging or deforming any material in the chamber components. The optimal temperature range for a particular ALD process is referred to as the "ALD temperature window". Temperatures below the ALD temperature window may result in undesirable growth rates and non-ALD type deposition. Temperatures above the ALD temperature window may result in reactions via chemical vapor deposition (CVD). The ALD temperature window can range from about 25°C to about 350°C. In some embodiments, the ALD temperature window ranges from about 25°C to about 200°C, or from about 25°C to about 150°C, or from about 100°C to about 120°C, or from about 25°C to 125°C, or from about 250°C to about 350°C.

[0103] Additionally, ALD technology can also deposit material layers within complex features of a component (e.g., features with high aspect ratios). In some embodiments, the surface coated with the protective coating described herein has at least a portion of a high aspect ratio (e.g., ranging from any one of about 2:1, about 5:1, or about 10:1 to about 50:1, about 100:1, about 200:1, or about 300:1), and that portion of the high aspect ratio is conformally and uniformly coated with the protective coating according to embodiments. The term "uniform" means a protective coating that has a thickness variation of less than about + / -20%, less than about + / -10%, less than about + / -5%, or lower when comparing the standard deviation of the average thickness of the coating or comparing the thickness of the coating at one location with the thickness of the coating at another location.

[0104] In addition, ALD technology generally produces relatively thin (i.e., 1 μm or less) coatings that are very dense and have extremely low porosity of less than about 1.5%, less than about 1%, less than about 0.5%, or about 0% (e.g., no porosity, i.e., no pinholes)), which eliminates crack formation during deposition. As used herein, the term "no porosity" means that, as measured by transmission electron microscopy (TEM), there are no pores, pinholes, or voids along the entire depth of the coating.

[0105] As described regarding ALD technology, in some embodiments, a protective coating containing a metal fluoride is formed by fluorinating a metal oxide material (e.g., M1xM2yM3zOa) (among other steps). Thus, in some embodiments, the protective coating may contain a certain amount of oxygen atoms, such as up to 40 atomic% oxygen. In some embodiments, the amount of oxygen may be reduced to single-digit atomic% (e.g., less than 10 atomic%) or may be completely eliminated (e.g., 0 atomic% oxygen). In some embodiments, the amount of oxygen in the protective coating may range from any one of 0 atomic%, about 2 atomic%, about 4 atomic%, about 6 atomic%, about 8 atomic%, about 10 atomic%, or about 15 atomic% to any one of about 20 atomic%, about 25 atomic%, about 30 atomic%, about 35 atomic%, or about 40 atomic%. Similar oxygen concentrations can be achieved in protective coatings deposited by other techniques (e.g., CVD, EB-IAD, and PVD), and such oxygen concentrations are not limited to protective coatings deposited solely by ALD.

[0106] The atomic percentages of various components (i.e., M1, M2, M3, F, and, where applicable, O) of a metal fluoride protective coating can be adjusted based on the intended application and properties of the protective coating. For example, the components can be adjusted to control and / or achieve a target vapor pressure of the coating. Thus, in some embodiments, this disclosure relates to a method for adjusting / controlling the vapor pressure of a protective coating. In another example, the components can be adjusted to modify / blend / enhance the fluorine resistance of the protective coating. Thus, in some embodiments, this disclosure relates to a method for modifying / adjusting / enhancing the fluorine resistance of a protective coating. In yet another example, the composition of the coating can be adjusted to control the phase (e.g., amorphous or crystalline) and structure of the protective coating. Thus, in some embodiments, this disclosure relates to a method for controlling the phase and / or structure of a protective coating.

[0107] By means of ALD, the composition and properties, vapor pressure, fluorine resistance, structure, etc. of the protective coating can be adjusted by selecting metal precursors, reactants, and the number of cycles (n, m, k, p).

[0108] The precursors that can be used in the ALD process described herein depend on the specific metal fluoride layer that is being formed.

[0109] For example, suitable Mg precursors include, but are not limited to, the following categories of ligands, namely, Cp (cyclopentadienyl), thd (tetraheptanedione), and amd (amidine) having various R-subgroups (Et, Me, Bu, Pr, etc.).

[0110] For example, suitable La precursors include, but are not limited to, lanthanum methylsilyl amide, La[N(SiMe3)2]3, and the following ligand classes: thd, Cp compounds, amidines and heterojunction precursors (such as, Cp-amd).

[0111] For example, suitable Y precursors include, but are not limited to, tris(N,N-bis(trimethylsilyl)amide)yttrium(III), tris(2,2,6,6-tetramethyl-3,5-heptadecane)yttrium(III) or yttrium(III)butanol, yttrium cyclopentadienyl compounds (e.g., tris(cyclopentadienyl)yttrium(Cp3Y), tris(methylcyclopentadienyl)yttrium((CpMe)3Y), tris(butylcyclopentadienyl)yttrium, tris(cyclopentadienyl)yttrium, tris(ethylcyclopentadienyl)yttrium), or combinations thereof. Other yttrium-containing precursors that may be used include yttrium-containing acetamyl compounds (e.g., tris(N,N'-di-isopropylformamidinium)yttrium or tris(bis(trimethylsilyl)acetamyl)lanthanum) and yttrium-containing β-diketone compounds.

[0112] For example, suitable Al precursors include, but are not limited to, aluminum diethylethoxide, tris(ethylmethylamino)aluminum, aluminum dibutoxide, aluminum tribromide, aluminum trichloride, triethylaluminum, triisobutylaluminum, trimethylaluminum, tris(diethylamino)aluminum, or combinations thereof.

[0113] The oxygen reactant that can be used by the ALD system to form a metal oxide layer (before the layer is fluorinated to form the metal fluoride described herein) can be oxygen, water vapor, ozone, oxygen, oxygen radicals, alcohol, another oxygen source, or a combination thereof.

[0114] The fluoride reactant used by the ALD system to form the metal fluoride layer may be, for example, a fluoride (e.g., TiF4, HF, Hhfac, tetrafluoropropanol, hexafluoropropanol, hexafluoroacetyl ketone, NF3, HF-pyridine), another fluorine source, or a combination thereof.

[0115] Referring back to Figure 4B, in some embodiments, the multilayer protective coating deposited by ALD may undergo post-deposition treatment (such as annealing) to form, for example, a homogeneous protective coating 240.

[0116] Another deposition technique that can be used to deposit the protective coating described herein is chemical vapor deposition (CVD). Figure 5 depicts an exemplary chemical vapor deposition (CVD) system that can be used for coating articles according to an embodiment.

[0117] The system includes a chemical vapor precursor supply system 505 and a CVD reactor 510. The function of the chemical vapor precursor supply system 505 is to generate a gaseous precursor 520 (such as a gaseous precursor of metals M1, M2, M3 or combinations thereof) from a starting material 515 (which may be in solid, liquid or gaseous form). The vapor is then conveyed to the CVD reactor 510 and deposited as a thin film 545 (e.g., a metal fluoride having the form selected from the group consisting of M1xFw, M1xM2yFw and M1xM2yM3zFw) positioned on a product holder 535.

[0118] The CVD reactor 510 uses a heater 540 to heat the article 530 to the deposition temperature. In some embodiments, the heater may heat the walls of the CVD reactor (also referred to as a "hot-wall reactor"), and the reactor walls may transfer heat to the article. In other embodiments, the article may be heated separately while the walls of the CVD reactor remain cold (also referred to as a "cold-wall reactor"). It should be understood that the CVD system configuration should not be construed as limiting. A variety of devices can be used in a CVD system, and devices are selected to obtain optimal processing conditions that result in coatings with uniform thickness, surface morphology, structure, and composition.

[0119] Various CVD processes include the following process steps: (1) generating active gaseous reactant substances (also known as "reactants") from starting materials; (2) transporting the precursors to a reaction chamber (also known as a "reactor"); (3) adsorbing the precursors onto a heated article; (4) participating in a chemical reaction between the precursors and the article at the gas-solid interface to form deposits and gaseous byproducts; and (5) removing the gaseous byproducts and unreacted gaseous precursors from the reaction chamber.

[0120] Suitable CVD precursors can be stable at room temperature, have low vaporization temperatures, produce vapors stable at low temperatures, have suitable deposition rates (low deposition rates for thin film coatings and high deposition rates for thick film coatings), be relatively low in toxicity, cost-effective, and relatively pure. For some CVD reactions, such as thermal decomposition (also known as "pyrolysis") or disproportionation reactions, a single chemical precursor may be sufficient to complete the deposition. For other CVD reactions, in addition to chemical precursors, other reagents or reactants (such as oxygen- or fluorine-containing reactants) may be used to complete the deposition to form metal fluoride protective coatings such as those described herein.

[0121] CVD offers numerous advantages, including its ability to deposit very dense and pure coatings and to produce uniform films with good reproducibility and adhesion at reasonably high deposition rates. In embodiments, layers deposited using CVD can have porosity below 1% and below 0.1% (e.g., approximately 0%). Therefore, it can be used to uniformly coat components with complex shapes and deposit conformal films with good conformal coverage (e.g., a generally uniform thickness). CVD can also be used to deposit films composed of multiple components, for example, by feeding multiple chemical precursors (e.g., precursors of two or more of M1, M2, and M3) into a mixing chamber at a predetermined ratio, and then supplying the mixture to a CVD reactor system. In some embodiments, CVD deposition rates are higher than ALD while still providing many of the aforementioned advantages associated with ALD deposition. The higher deposition rates of CVD can also correspond to higher throughput and reduced protective coating costs. Therefore, in some embodiments, CVD may be chosen as the deposition technique at least in part due to its high deposition rate, high throughput and lower cost.

[0122] In some embodiments, any of the protective coatings described herein are deposited via CVD using a CVD system (such as the CVD system described in Figure 5) or a similar system. In some embodiments, the protective coating may include a metal fluoride coating, including at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw. In some embodiments, the protective coating may have any of the coating architectures described above (such as a multilayer architecture, a continuous uninterrupted coating, and a coating deposited on an adhesive layer 205 positioned between the coating 545 and the surface of the article 530).

[0123] For thicker protective coatings (e.g., at the micrometer level), techniques such as EB-IAD and PVD can be advantageously used to deposit the protective coatings described herein. Similar to ALD, these techniques can be used to deposit protective coatings on an adhesive layer, continuous single protective layers, and protective coatings with multi-layer structures.

[0124] Figure 6 depicts an exemplary physical vapor deposition (PVD) system for use in coating articles according to an embodiment. Various PVD processes share three basic steps: (1) evaporating material from a solid source with the aid of high temperature or gaseous plasma; (2) conveying the evaporated material to the surface of the article in a vacuum; and (3) condensing the evaporated material onto the article to produce a thin film layer. An illustrative PVD reactor is depicted in Figure 6 and discussed in more detail below.

[0125] In Figure 6, the PVD reactor chamber 600 includes a plate 610 adjacent to the article 620 and a plate 615 adjacent to the target 630. Air can be removed from the reactor chamber 600 to create a vacuum. Argon gas can then be introduced into the reactor chamber, a voltage can be applied to the plates (610 and 615), and a plasma comprising electrons and positive argon ions 640 can be generated. The positive argon ions 640 can be attracted to the negative plate 615, where they can bombard the target 630 and release atoms 635 from the target. The released atoms 635 can be transported and deposited as a protective coating 645 onto an optional adhesive layer 625, which is deposited on the surface of the article 620.

[0126] Any of the protective coatings described herein can be deposited via PVD using a PVD reactor such as that depicted in Figure 6 or with a similar operating principle. In some embodiments, the protective coating deposited by PVD may include a metal fluoride coating, including at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw. In some embodiments, the protective coating deposited by PVD may have any of the coating architectures described above (such as a multilayer architecture, a continuous uninterrupted coating, and a coating deposited on an adhesive layer 625 positioned between the coating 645 and the surface of the article 630).

[0127] Suitable targets for depositing the metal fluoride protective coatings described herein include Mg metal, La metal, Y, Al, sintered fluorinated objects, or metal targets via a reactive F source.

[0128] In some embodiments, PVD technology provides a relatively higher deposition rate than certain other deposition technologies (e.g., ALD). In some embodiments, PVD also provides additional process knobs to control the coating stress state, which can provide additional benefits. For example, increased coating hardness can be achieved through a higher compressive stress state of the coating, which can help enhance the sputtering resistance of coatings deposited by PVD compared to coatings deposited by certain other technologies.

[0129] In some embodiments, EB-IAD can be an advantageous alternative to deposition techniques such as plasma spraying. Plasma spraying relies on sandblasting to increase the surface roughness of the underlying substrate and promote coating adhesion to the substrate surface. Sandblasting used to roughen the underlying substrate results in the underlying substrate being covered with microcracks. In contrast, sandblasting is not part of the EB-IAD deposition process. Therefore, substrates coated by EB-IAD are not roughened and do not have microcracks like substrates coated by plasma spraying.

[0130] Figure 7A depicts a deposition mechanism applicable to various deposition techniques utilizing high-energy particles, such as ion-assisted deposition (IAD). Exemplary IAD methods include deposition processes incorporating ion bombardment, such as evaporation (e.g., activated reactive evaporation (ARE)) and sputtering in the presence of ion bombardment to form a plasma-resistant protective coating as described herein.

[0131] One specific type of IAD performed in the embodiments is electron beam IAD (e-beam IAD). Any of the IAD methods can be performed in the presence of reactive gaseous substances (such as O2, N2, halogens (e.g., fluorine), argon, etc.). The reactive substances can burn off surface organic contaminants before and / or during deposition. In some embodiments, IAD deposition is performed in the presence of fluorine to deposit a metal fluoride protective coating.

[0132] As shown in Figure 7A, a protective coating 715 (similar to the protective coating in the previous figure) is formed on the article 710 (such as a chamber component) or on an adhesive layer positioned between the surface of the article 710 and the protective coating 715. In Figures 7A and 7B, the protective coating 715 is formed by the accumulation of a deposited material 702 in the presence of high-energy particles 703 (such as ions). The deposited material 702 may include atoms, ions, free radicals, etc. The high-energy particles 702 may impact and compact the protective coating 715 during its formation.

[0133] In one embodiment, EB-IAD is used to form a plasma-resistant protective coating 715. Figure 7B depicts a schematic diagram of an IAD deposition apparatus. As shown, a material source 750 provides a flux of deposited material 702, while a high-energy particle source 755 provides a flux of high-energy particles 703, both of which impact the article 710 throughout the IAD process. The high-energy particle source 755 may be an oxygen or fluorine or other ion source. The high-energy particle source 755 may also provide other types of high-energy particles from a particle generation source (e.g., from plasma, reactive gases, or from the material source providing the deposited material), such as free radicals, neutrons, atomic, and nano-sized particles.

[0134] The material source (e.g., target or plugging material) 752 used to provide the deposition material 702 may be a metal corresponding to the same metal constituting the protective metal fluoride coating 715. This material source may be or include Mg or other materials used to form the protective coating. The material source may be in the form of a sintered body, pellets, granules, or powder. In some embodiments, multiple material sources are used, such as a first material source of Mg target and a second material source of bulk sintered Al2O3 target. Other target materials may also be used, such as powders, calcined powders, preformed materials (e.g., formed by green pressing or hot pressing) or machined bodies (e.g., molten materials). During deposition, all different types of material sources 750 melt into a molten material source. However, different types of starting materials require different amounts of time to melt. Therefore, EB-IAD deposition can be optimized to deposit a metal fluoride protective coating with target composition and properties.

[0135] The IAD may utilize one or more plasmas or beams (e.g., electron beams) to provide the material and high-energy ion source. Reactive materials may also be provided during the deposition of the anti-plasma coating. In one embodiment, the high-energy particles 703 include at least one of a non-reactive material (e.g., Ar) or a reactive material (e.g., O). In other embodiments, reactive materials such as CO and halogens (Cl, F, Br, etc., especially F) may also be introduced during the formation of the protective coating.

[0136] Through the IAD process, high-energy particles 703 can be controlled independently of other deposition parameters by a high-energy ion (or other particle) source 755. The composition, structure, crystal orientation, grain size, and amorphous or crystalline nature of the protective coating can be manipulated based on the energy (e.g., velocity), density, and incident angle of the energy ion flux. In some embodiments, the deposition rate ranges from about 0.1 Å / s to about 2 Å / s, from about 0.3 Å / s to about 1.5 Å / s, or from about 0.5 Å / s to about 1 Å / s. Without being construed as limiting, it is believed that higher deposition rates and / or higher ion assistance (also referred to herein as "high IAD") contribute to a more uniform, denser, and more compact structure in the protective coating.

[0137] Adjustable additional parameters include the temperature of the article during deposition and the duration of deposition. In one embodiment, the IAD chamber includes a heat lamp for heating. In an alternative embodiment, the IAD chamber and the article being coated are not heated. If the chamber is not heated, its temperature will naturally rise due to the IAD process. Higher temperatures during deposition can increase the density of the protective coating and may also increase the mechanical stress of the protective coating. Active cooling can be added to the chamber to maintain a low temperature during coating. In some embodiments, the metal fluoride protective coating described herein is deposited by EB-IAD at temperatures ranging from about 50°C to about 400°C or from about 150°C to about 300°C.

[0138] Other parameters that can be adjusted for EB-IAD are the working distance and the incident angle. The working distance is the distance between the material source 752 and the product 710. Reducing the working distance will increase the deposition rate and increase the effectiveness of ion energy. However, reducing the working distance below a certain point may reduce the uniformity of the protective layer. The incident angle is the angle at which the deposited material 702 impacts the product 710.

[0139] IAD coatings can be applied to a wide range of surface conditions, with roughness from about 0.1 microinch (μm) to about 180 μm. However, smoother surfaces will result in more uniform coating coverage. In addition, EB-IAD can be used on surfaces without pretreatment, and therefore EB-IAD can be used on unroughened surfaces.

[0140] In some embodiments, the EB-IAD coating may be amorphous. Compared to crystalline coatings, amorphous coatings are more conformal and reduce epitaxial cracks caused by lattice mismatch. In other embodiments, the EB-IAD protective coating described herein is crystalline.

[0141] Multiple electron beam guns can be used to co-deposit multiple targets to form thicker coatings and layered structures. For example, two targets of the same material type can be used simultaneously. Each target can be bombarded by different electron beam guns. This can increase the deposition rate and thickness of the protective layer. In another example, the two targets can be different ceramic materials. For example, one target of Mg and another target of Y can be used. A first electron beam gun can bombard the first target to deposit a first protective layer, and a second electron beam gun can subsequently bombard the second target to form a second protective layer having a different material composition than the first protective layer.

[0142] In the embodiments, a single target material (also known as an embolization material) and a single electron beam gun can be used to obtain the anti-plasma protective coating described herein.

[0143] In one embodiment, multiple chamber components can be processed in parallel within the IAD chamber. Each chamber component can be supported by a different fixture. Alternatively, a single fixture can be configured to hold multiple chamber components. During deposition, the fixture can move the supported chamber components.

[0144] In one embodiment, the fixture for holding the chamber component may be designed from a metal component, such as cold-rolled steel, or from a ceramic component (such as Al2O3, Y2O3, etc.). The fixture may be used to support the chamber component above or below the material source and electron beam gun. The fixture may have the ability to hold the chamber component for safer and easier handling during coating. Furthermore, the fixture may have features for orienting or aligning the chamber component. In one embodiment, the fixture may be repositioned and / or rotated about one or more axes to change the orientation of the supported chamber component relative to the source material. The fixture may also be repositioned to change the working distance and / or angle of incidence before and / or during deposition. The fixture may have cooling or heating channels to control the temperature of the chamber component during coating. Because IAD is a line-of-sight process, the ability to reposition and rotate the chamber component enables maximum coating coverage of 3D surfaces (such as holes).

[0145] Metal fluoride protective coatings deposited by EB-IAD can be thicker than those deposited by ALD or CVD. For example, these coatings can have a thickness ranging from about 50 nm to about 10 μm, from about 100 nm to about 8 μm, from about 250 nm to about 5 μm, from about 500 nm to about 3 μm, or from about 750 nm to about 2 μm, or any subrange or single value thereof.

[0146] The microstructure and / or porosity of the protective coating deposited by EB-IAD depends on the configuration of the underlying substrate. In some embodiments, the porosity of the metal fluoride protective coating deposited by EB-IAD ranges from 0% to 35%, up to 30%, up to 25%, up to 20%, up to 15%, up to 10%, up to 5%, or up to 1%, or any subrange or individual value therein. Illustrative Examples

[0147] The following examples are provided to aid in understanding this disclosure and should not be construed as specifically limiting the content described and claimed herein. These variations of this disclosure are considered to be within the scope of this disclosure incorporated herein, including substitutions for all known or subsequently developed equivalents, which will be within the capabilities of those skilled in the art and involve minor changes in formulation or experimental design. Example 1 - Atomic Layer Deposition (ALD) of M1xFw Protective Coating

[0148] This document illustrates a protective coating of formula M1xFw, where M1 is Mg. This protective coating is deposited by ALD, for example, by the process depicted in Figure 4A or Figure 4B. In this example, a magnesium precursor is used in combination with an oxygen reactant to form a protective coating of formula M1xOa, where M1 is Mg. Subsequently, the protective coating is fluorinated (e.g., by subjecting it to a fluorinated substance) to form M1xFw. In this example, the protective coating is deposited directly on the surface of the article (in this case, on the natural oxide of the article's surface) rather than on a separately deposited adhesive layer.

[0149] Figure 8A depicts a cross-sectional view of an article coated with the above-described protective coating deposited by ALD according to the embodiment, as viewed by scanning electron microscopy (SEM) at a scale of 100 nm. From the SEM image, it was observed that the thickness of the protective coating is approximately 290 nm. It was further observed that the protective coating is crystalline.

[0150] Figure 8B depicts the energy-dispersive X-ray spectroscopy (EDS) line scan of the protective coating observed in Figure 8A. From part A of Figure 8B, it was observed that the coating includes oxygen at a concentration of approximately 35 atomic percent (line 810). Therefore, the protective coating can also be referred to as Mg-OF. The fluorine concentration in the protective coating is approximately 25 atomic percent (line 820), and the magnesium concentration in the protective coating is approximately 30 atomic percent (line 830). Example 2 - Continuous, uninterrupted protective coating deposited by ALD

[0151] This document illustrates a protective coating of formula M1xFw, where M1 is Mg. This protective coating is deposited continuously by ALD, for example, by the process depicted in Figure 4A or Figure 4B. In this example, a magnesium precursor is used in combination with a fluorine reactant to form a protective coating of formula M1xFw, where M1 is Mg. The protective coating is continuously deposited to form crystalline MgxFw, which has a uniform composition and thickness throughout the coating (except for the coating surface), wherein nano-roughness is formed to improve the adhesion of the protective coating to any particles that may form during processing, so that these particles will not contaminate the processed wafer. In this example, the protective coating is deposited on an adhesion layer positioned on the surface of the product.

[0152] Figure 9A depicts a cross-sectional view of an AlN article 910 according to an embodiment (corresponding to part C in Figure 9B), the AlN article 910 being coated with an amorphous alumina adhesive layer 920 deposited by ALD (corresponding to part B in Figure 9B) and a MgxFw protective coating 930 (corresponding to part C in Figure 9B), as examined by transmission electron microscopy (SEM) at a scale of 200 nm.

[0153] Figure 9B depicts the EDS line scan of the protective coating observed in Figure 9A. From part A of Figure 9B, it is observed that the MgxFw protective coating includes a low oxygen content of less than 5 atomic percent (line 940). The fluorine concentration in the protective coating (part A) is about 70 atomic percent (line 950) and the magnesium concentration in the protective coating (part B) is about 25 atomic percent (line 960).

[0154] As observed in part B of Figure 9B, the amorphous alumina adhesive layer comprises approximately 70 atomic percent oxygen and approximately 25 atomic percent aluminum. The boundary between the protective coating 930 and the adhesive layer 920 appears to be discrete rather than cross-diffused.

[0155] As observed in part C of Figure 9C, the coated article is made of AlN and includes N at a concentration of about 65 atomic% to about 70 atomic% and aluminum at a concentration of about 30 atomic%. The boundary between the adhesive layer 920 and the article 910 appears to be discrete rather than cross-diffused.

[0156] The amorphous alumina adhesive layer has a thickness of approximately 60 nm. The dense crystalline MgxFw protective coating has a thickness of approximately 320 nm. When comparing Figures 9C1 to 9C3, it can be further observed that the composition of the protective coating is uniform throughout the coating thickness, except for the surface of the protective coating (approximately 50 nm thick, or about 15% of the top of the coating), where the protective coating exhibits nano-roughness.

[0157] Figures 9C1, 9C2 and 9C3 depict cross-sectional views of the protective coating observed in Figure 9A, as viewed by scanning electron microscopy (SEM) at a scale of 100 nm, showing the thickness and compositional uniformity of the entire coating except for the coating surface where nano-roughness is observed.

[0158] Specifically, in Figure 9C1, a SEM image of portion 910C1 of article 910 is depicted at a scale of 100 nm. Portion 920C1 of portion 910C1 is coated with adhesive layer 920. Portion 920C1 has a thickness of approximately 66 nm. Portion 930C1 of portion 920C1 is coated with protective coating 930. Portion 930C1 has a thickness of approximately 340 nm.

[0159] In Figure 9C2, a SEM image of portion 910C2 of article 910 is depicted at a scale of 100 nm. Portion 920C2 is coated with adhesive layer 920. Portion 920C2 has a thickness of approximately 69 nm. Portion 930C2 is coated with protective coating 930. Portion 930C2 has a thickness of approximately 315 nm.

[0160] In Figure 9C3, a SEM image of portion 910C3 of article 910 is depicted at a scale of 100 nm. Portion 920C3 is coated with adhesive layer 920. Portion 920C3 has a thickness of approximately 57 nm. Portion 930C3 is coated with protective coating 930. Portion 930C3 has a thickness of approximately 316 nm.

[0161] It can be seen that the thickness variation of the adhesive layer between some of 920C1, 920C2 and 920C3 is less than about + / -25%, less than about + / -20% or less than about + / -15%. It can also be seen that the thickness variation of the protective coating between some of 930C1, 930C2 and 930C3 is less than about + / -25%, less than about + / -20%, less than about + / -15% or less than about + / -10%.

[0162] In reality, unlike the protective coating surface that achieves the target nano-roughness (according to the embodiment described with respect to Figure 2B), the protective coating 930 exhibits uniform thickness and uniform composition. Example 3 - First multilayer protective coating deposited by ALD

[0163] This document illustrates a protective coating with a multilayered coating structure having alternating thin layers of crystalline MgxFw and amorphous alumina. This protective coating is deposited continuously by ALD. In this example, the protective coating is deposited on an amorphous alumina adhesive layer positioned on the surface of the product.

[0164] Figures 10A1, 10A2 and 10A3 depict cross-sectional views of an article coated with a multilayer protective coating deposited by ALD according to the embodiment, as viewed by SEM at a scale of 200 nm (Figure 10A1), 100 nm (Figure 10A2) and 20 nm (Figure 10A3).

[0165] As can be seen from Figures 10A1 and 10A2, the protective coating comprises nine crystalline MgxFw layers and nine amorphous alumina layers. As can be seen from Figure 10A3, the crystalline MgxFw deposits have a uniform thickness of approximately 15 nm, and the amorphous alumina layers (excluding the first amorphous alumina adhesive layer) have a uniform thickness of approximately 30 nm. The first amorphous alumina adhesive layer has a thickness of approximately 50 nm.

[0166] These figures also illustrate that the boundaries between the surface of the coated article and the adhesive layer, between the adhesive layer and the protective coating, and between the various layers in the multilayer protective coating are discrete and not cross-diffusion / cross-mixing.

[0167] Figure 10B depicts the EDS line scan of the protective coatings observed in Figures 10A1, 10A2, and 10A3. Part A of the EDS line scan illustrates the multilayer protective coating, part B illustrates the adhesive layer, and part C illustrates the coated article.

[0168] In part A, the oscillating lines of magnesium (1010), fluorine (1020), oxygen (1030), and aluminum (1040) reflect the various layers in the multilayered protective coating. The MgxFw layer has a magnesium concentration of approximately 30 atomic% and a fluorine concentration of approximately 60 atomic% and an oxygen concentration of approximately 10 atomic% respectively. The amorphous alumina layer has an aluminum concentration of approximately 25 atomic% and an oxygen concentration of approximately 65 atomic% respectively. The total protective coating thickness is approximately 430 nm.

[0169] In section B, the amorphous alumina adhesive layer is shown to have an aluminum concentration of about 30 atomic% and an oxygen concentration of about 70 atomic% . In section C, the AlN article is shown to have a nitrogen concentration of about 70 atomic% and an al concentration of about 30 atomic% . Example 4 - Second multilayer protective coating deposited by ALD

[0170] This document illustrates a protective coating with a multilayered coating structure having alternating thin layers of crystalline MgxFw and amorphous alumina. This protective coating is deposited continuously by ALD. In this example, the protective coating is deposited on an amorphous alumina adhesive layer positioned on the surface of the product.

[0171] Figures 11A1, 11A2 and 11A3 depict cross-sectional views of an article coated with another multilayer protective coating deposited by ALD according to the embodiment, as viewed by SEM at a scale of 200 nm (Figure 11A1), 100 nm (Figure 11A2) and 20 nm (Figure 11A3).

[0172] As can be seen from Figures 11A1 and 11A2, the protective coating comprises six alternating crystalline MgxFw layers and six amorphous alumina layers. As can be seen from Figure 11A3, the crystalline MgxFw layers have a uniform thickness of approximately 60 nm, and the amorphous alumina layers (excluding the first amorphous alumina adhesive layer) have a uniform thickness of approximately 15 nm. The first amorphous alumina adhesive layer has a thickness of approximately 50 nm.

[0173] These figures also illustrate that the boundaries between the surface of the coated article and the adhesive layer, between the adhesive layer and the protective coating, and between the various layers in the multilayer protective coating are discrete and not cross-diffusion / cross-mixing.

[0174] Figure 11B depicts the EDS line scan of the protective coatings observed in Figures 11A1, 11A2, and 11A3. Part A of the EDS line scan illustrates the multilayer protective coating, part B illustrates the adhesive layer, and part C illustrates the coated article.

[0175] In part A, the oscillating lines of magnesium (1110), fluorine (1120), oxygen (1130), and aluminum (1140) reflect the various alternating layers in the multilayered protective coating. The MgxFw layer has a magnesium concentration of about 30 atomic% and a fluorine concentration of about 60–65 atomic% and an oxygen concentration of about 5–10 atomic% respectively. The amorphous alumina layer has an aluminum concentration of about 25 atomic% and an oxygen concentration of about 65 atomic% respectively. The total protective coating thickness is about 490 nm.

[0176] In section B, the amorphous alumina adhesive layer is shown to have an aluminum concentration of about 30 atomic% and an oxygen concentration of about 70 atomic% . In section C, the AlN product is shown to have a nitrogen concentration of about 65-70 atomic% and an al concentration of about 30-35 atomic% . Example 5 - MgxFw protective coating deposited by electron beam ion-assisted deposition (EB-IAD)

[0177] Figures 12A1 and 12A2 depict cross-sectional views of a product coated with a protective coating of 427–438 nm thickness deposited by EB-IAD at a high deposition rate of 1 Å / s and high ion-assisted deposition, as examined by SEM at a scale of 50 nm and approximately 0.2 μm, respectively.

[0178] Figures 12B1 and 12B2 depict cross-sectional views of a product coated with a protective coating of 428–434 nm thickness deposited by EB-IAD at a high deposition rate of 1 Å / s and low ion-assisted deposition, as examined by SEM at a scale of 50 nm and approximately 0.2 μm, respectively.

[0179] Figures 12C1 and 12C2 depict cross-sectional views of a product coated with a protective coating of 493–529 nm thickness deposited by EB-IAD at a high deposition rate of 1 Å / s and without ion-assisted deposition, as examined by SEM at a scale of 50 nm and approximately 0.2 μm, respectively.

[0180] Figures 12D1 and 12D2 depict cross-sectional views of a product coated with a protective coating of 455–488 nm thickness deposited by EB-IAD at a low deposition rate of 0.5 Å / s and without ion-assisted deposition, as examined by SEM at a scale of 50 nm and approximately 0.2 μm, respectively.

[0181] Figures 12A1 to 12D2 illustrate that lower IAD provides more rows of protective coating structures, while high IAD and high deposition rate show the most uniform, dense, and compact protective coating structures, which may be preferred in some embodiments. Example 6 - Protective coating deposited on an adhesive layer by means of EB-IAD

[0182] Figure 13 depicts a cross-sectional view of an article coated with an amorphous yttrium aluminum garnet (YAG) adhesive layer and a crystalline MgxFw protective coating deposited by EB-IAD according to an embodiment, as viewed by SEM at a scale of 0.2 μm. This example illustrates that EB-IAD can be appropriately used to form a multilayer protective coating of uniform thickness and composition. Example 7 - Chemical resistance of the protective layer deposited by EB-IAD in the NF3 cleaning test.

[0183] EB-IAD is used to deposit a crystalline MgxFw protective coating on the front and back sides of a wafer. The coated wafer is then subjected to a rigorous cleaning test, in which the front side of the wafer is exposed to NF3 cleaning at 550°C. After the test, the elemental composition of the center of the front side of the wafer (exposed to NF3 at 550°C) is compared with the elemental composition of the center of the back side of the wafer (not exposed to NF3 at 550°C).

[0184] Figure 14 illustrates a consistent fluorine concentration of approximately 65–70 atomic percent on both sides (1410 on the front side, 1420 on the back side), a consistent magnesium concentration of approximately 25–30 atomic percent on both sides (1430 on the front side, 1440 on the back side), and a consistent oxygen concentration of approximately 6–8 atomic percent on both sides (1450 on the front side, 1460 on the back side). The similar composition between the front and back sides of the coated wafer indicates that the coating composition is stable after NF3 cleaning at 550°C.

[0185] The preceding description has set forth numerous specific details, such as examples of specific systems, components, methods, etc., to provide a good understanding of several embodiments of this disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of this disclosure can be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or have been presented in the form of simple block diagrams to avoid unnecessarily obscuring this disclosure. Therefore, the specific details described are merely illustrative. Specific implementations may differ from these exemplary details and are still contemplated within the scope of this disclosure.

[0186] As used herein, unless the context clearly indicates otherwise, the singular forms “a”, “an” and “the” include plural references. Thus, for example, a reference to “precursor” includes a single precursor and a mixture of two or more precursors; and a reference to “reactant” includes a single reactant and a mixture of two or more reactants, and so on.

[0187] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily all represent the same embodiment. Additionally, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." When the terms "about" or "approximately" are used herein, this is intended to mean that the presented nominal values ​​are exactly within ±10%, such that "about 10" would include values ​​from 9 to 11.

[0188] Unless otherwise stated herein, the enumeration of value ranges herein is intended only as a shorthand method to represent each individual value within that range, and each individual value is incorporated into this specification as if it were described separately herein. All methods described herein may be performed in any suitable order unless otherwise stated herein or clearly contradicted by the context. Unless otherwise required, the use of any and all examples or illustrative language (e.g., "such as") provided herein is intended only to illustrate certain materials and methods and does not constitute a limitation on scope. No language in this specification should be construed as indicating that any unrequired element is essential to the practice of the disclosed materials and methods.

[0189] Although the operations of the methods are shown and described in a particular order herein, the order of operations of each method may be changed so that certain operations can be performed in reverse order, or that certain operations can be performed at least partially concurrently with other operations. In another embodiment, instructions or sub-operations of different operations may be performed intermittently and / or alternately.

[0190] It should be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will become apparent to those skilled in the art after reading and understanding the above description. Therefore, the scope of this disclosure should be determined by referring to the entire scope of the appended claims together with the equivalents granted by the claims of this application. [Simplified Explanation of the Diagram]

[0006] The present disclosure is illustrated by way of example rather than by way of limitation in the accompanying drawings, and in the accompanying drawings, the same element symbols indicate similar elements. It should be noted that different references to "a" or "an" embodiment in the present disclosure do not necessarily represent the same embodiment, and such references mean at least one.

[0007] Figure 1 depicts a cross-sectional view of the treatment chamber.

[0008] Figures 2A to 2D are cross-sectional views of articles coated with various protective coatings according to the embodiments.

[0009] Figure 3 depicts a method for reducing particles during processing in a semiconductor processing chamber according to an embodiment.

[0010] Figure 4A depicts a co-feeding or co-deposition mechanism according to an embodiment of an atomic layer deposition (ALD) technique applicable to coated articles.

[0011] Figure 4B depicts a sequential deposition mechanism of ALD technology applicable to coated articles according to an embodiment.

[0012] Figure 5 depicts an exemplary chemical vapor deposition (CVD) system that can be used for coating articles according to an embodiment.

[0013] Figure 6 depicts an exemplary physical vapor deposition (PVD) system that can be used for coating articles according to an embodiment.

[0014] Figures 7A to 7B depict an exemplary electron beam ion-assisted deposition (EB-IAD) mechanism that can be used in coated articles according to an embodiment.

[0015] Figure 8A depicts a cross-sectional view of an article coated with a protective coating deposited by ALD according to an embodiment, as viewed by a scanning electron microscope (SEM) at a scale of 100 nm.

[0016] Figure 8B depicts the energy dispersive x-ray spectroscopy (EDS) line scan of the protective coating observed in Figure 8A.

[0017] Figure 9A depicts a cross-sectional view of an article coated with an adhesive layer and a protective coating deposited by ALD according to an embodiment, as viewed by scanning electron microscopy (SEM) at a scale of 200 nm.

[0018] Figure 9B depicts the EDS line scan of the protective coating observed in Figure 9A.

[0019] Figures 9C1, 9C2 and 9C3 depict cross-sectional views of the protective coating observed in Figure 9A, as viewed by scanning electron microscopy (SEM) at a scale of 100 nm, showing the thickness and compositional uniformity of the entire coating except for the coating surface where nano-roughness is observed.

[0020] Figures 10A1, 10A2 and 10A3 depict cross-sectional views of an article coated with a multilayer protective coating deposited by ALD according to the embodiment, as viewed by SEM at a scale of 200 nm (Figure 10A1), 100 nm (Figure 10A2) and 20 nm (Figure 10A3).

[0021] Figure 10B depicts the EDS line scan of the protective coating observed in Figures 10A1, 10A2 and 10A3.

[0022] Figures 11A1, 11A2 and 11A3 depict cross-sectional views of an article coated with another multilayer protective coating deposited by ALD according to the embodiment, as viewed by SEM at a scale of 200 nm (Figure 11A1), 100 nm (Figure 11A2) and 20 nm (Figure 11A3).

[0023] Figure 11B depicts the EDS line scan of the protective coating observed in Figures 11A1, 11A2 and 11A3.

[0024] Figures 12A1 to 12D2 depict cross-sectional views of articles coated with protective coatings deposited by EB-IAD under different electron beam ion-assisted deposition (EB-IAD) deposition parameters according to the embodiments, as viewed by SEM at different scales.

[0025] Figure 13 depicts a cross-sectional view of an article coated with an adhesive layer and a protective coating deposited by EB-IAD according to an embodiment, as viewed by SEM at a scale of 0.2 μm.

[0026] Figure 14 depicts an EDS line scan of a protective coating deposited on the front side of a wafer relative to the back side of the wafer after the wafer has undergone a rigorous cleaning test, according to an embodiment. The figure illustrates the chemical stability of the coating composition. [Biomaterial Storage]

[0192] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A semiconductor chamber component, comprising: One substrate; A protective coating is deposited on an unroughened surface of the substrate. The protective coating comprises a plurality of alternating stacks of one of a first metal fluoride layer and one of a second metal fluoride layer with different compositions. The thickness ratio of the first metal fluoride layer to the second metal fluoride layer is between about 10:1 and about 3:

1. The protective coating contains more than 2 atomic% to about 25 atomic% oxygen. The first and second metal fluoride layers with different compositions each contain at least one metal fluoride having a formula selected from the group consisting of M1xFw, M1xM2yFw, and M1xM2yM3zFw, wherein: a) when the metal fluoride has the formula M1xFw, x is 1, and w ranges from 1 to 3; b) when the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3; and c) When the metal fluoride has the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3; wherein at least one of M1, M2, or M3 includes magnesium or lanthanum.

2. The semiconductor chamber component as claimed in claim 1, wherein the protective coating comprises at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw.

3. The semiconductor chamber component as claimed in claim 1, further comprising an adhesion and fluorine diffusion barrier layer deposited between the surface of the substrate and the protective coating.

4. The semiconductor chamber component as claimed in claim 1, wherein the protective coating is crystalline.

5. The semiconductor chamber component as claimed in claim 4, wherein one of the top surfaces of the protective coating has a nanometer roughness ranging from about 0.1 microinch to about 200 microinch.

6. The semiconductor chamber component as claimed in claim 1, wherein the protective coating has a multilayered structure of alternating amorphous and crystalline layers.

7. The semiconductor chamber component as claimed in claim 1, wherein the substrate comprises aluminum alloy, AlN, Al2O3, Ni, stainless steel, or nickel-chromium alloy.

8. The semiconductor chamber component as claimed in claim 1, wherein the substrate is a heater, an electrostatic chuck, a panel, a nozzle, a gasket, a barrier plate, a gas box, an edge ring, or a bellows.

9. The semiconductor chamber component as claimed in claim 1, wherein the protective coating comprises more than 2 atomic% up to about 20 atomic% oxygen.

10. A method for reducing particles in a semiconductor processing chamber during processing, comprising the steps of: depositing a protective coating on an unroughened surface of a substrate by atomic layer deposition (ALD), chemical vapor deposition (CVD), electron beam ion-assisted deposition (EB-IAD), or physical vapor deposition (PVD), wherein the protective coating comprises a plurality of alternating stacks of one of first metal fluoride layers and one of second metal fluoride layers with different compositions, the thickness ratio of the first metal fluoride layer and one of the second metal fluoride layers being between about 10:1 and about 3:1, wherein the protective coating contains more than 2 atomic% to about 25 atomic% oxygen, the first metal fluoride layers and the second metal fluoride layers with different compositions comprising at least one metal fluoride having the formula M1xFw, M1xM2yFw, or M1xM2yM3zFw, wherein: a) When the metal fluoride has the formula M1xFw, x is 1 and w ranges from 1 to 3; b) When the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3; and c) When the metal fluoride has the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3; wherein at least one of M1, M2, or M3 includes magnesium or lanthanum.

11. The method as described in claim 10, wherein the protective coating comprises at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw.

12. The method of claim 10 further includes the step of depositing an adhesion and fluorine diffusion barrier layer between the surface of the substrate and the protective coating.

13. The method of claim 10, comprising the steps of: continuously depositing the protective coating by means of an ALD to obtain a target thickness, wherein the protective coating is crystalline, and wherein the deposition step adjusts the roughness of one top surface of the protective coating to a range from about 0.1 microinch to about 200 microinch.

14. The method as claimed in claim 10, comprising the step of: obtaining a multilayered structure by depositing alternating amorphous and crystalline layers by ALD, wherein each layer is homogeneous and conformally oriented.

15. The method as described in claim 10, wherein the substrate comprises aluminum alloy, AlN, Al2O3, Ni, stainless steel, or nickel-chromium alloy.

16. The method as described in claim 10, wherein the substrate is a heater, an electrostatic chuck, a panel, a nozzle, a gasket, a barrier plate, an air box, an edge ring, or a bellows.

17. A method for coating a surface of a substrate using atomic layer deposition (ALD), comprising the steps of: depositing a first adsorbent layer on the surface of the substrate by pulsedly introducing one or more metal precursors of M1, M2, M3 or a combination thereof into an ALD processing chamber; introducing a fluorine component into the ALD processing chamber to form a protective coating comprising a plurality of alternating stacks of one of first metal fluoride layers and one of second metal fluoride layers with different compositions, the thickness ratio of one of the first metal fluoride layers and one of the second metal fluoride layers being between about 10:1 and about 3:1; wherein the protective coating comprises more than 2 atomic% to about 25 atomic% oxygen; the first metal fluoride layers and the second metal fluoride layers with different compositions comprising at least one metal fluoride having a composition selected from the group consisting of M1xFw, M1xM2yFw and M1xM2yM3zFw, wherein: a) When the metal fluoride has the formula M1xFw, x is 1 and w ranges from 1 to 3; b) When the metal fluoride has the formula M1xM2yFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, and w ranges from 1 to 3; and c) When the metal fluoride has the formula M1xM2yM3zFw, x ranges from 0.1 to 1, y ranges from 0.1 to 1, z ranges from 0.1 to 1, and w ranges from 1 to 3; wherein at least one of M1, M2, or M3 includes magnesium or lanthanum.

18. The method as described in claim 17, wherein the introduced step includes the step of directly fluorinating the first adsorbed layer by pulsed introduction of a fluorine-containing reactant into the atomic layer deposition chamber.

19. The method as claimed in claim 17, wherein the step of introduction includes the following steps: pulse-introducing an oxygen-containing reactant into the atomic layer deposition chamber, and then exposing the first adsorbed layer of the oxygen reaction to a fluorine-containing substance to fluorinate the first adsorbed layer of the oxygen reaction and convert it into at least one metal fluoride having the formula M1xM2yM3zFw.

20. The method as described in claim 17, wherein the protective coating comprises at least one of MgxFw, LaxFw, YxMgyFw, YxLayFw, LaxMgyFw, or YxMgyLazFw.

Images