Diffusion bonding of pure metals

Abstract

The method includes applying a bonding layer of a first chemical composition to a first surface of a first metal body, the metal body being of a second chemical composition. The method further includes placing a second metal body of a second chemical composition against the first metal body such that the bonding layer is between the first surface of the first metal body and the second surface of the second metal body. The metal bodies are resistant to diffusion bonding. The bonding layer promotes diffusion bonding of the metal bodies. The method further includes heating the first metal body and the second metal body. The method further includes applying pressure to press the second metal body against the first metal body. The method further includes creating a diffusion bond between the metal bodies in response to heating and applying pressure for a period of time.

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure relate to forming articles using diffusion bonding. More specifically, embodiments of the present disclosure relate to forming articles from pure metal bodies using diffusion bonding. [Background technology]

[0002]

[0002] In manufacturing and processing systems (e.g., processing chambers), conditions proximate to a workpiece (e.g., substrate, semiconductor wafer, etc.) determine the outcome of the process. The conditions are controlled by components of the processing system. In some applications, substrates may be processed in harsh environments, such as high temperatures, corrosive environments (e.g., plasma environments, fluorine gas environments), and high voltages. The process may be sensitive to the materials selected to construct the processing equipment components. For example, aluminum may not be suitable for high temperature environments. In some cases, small amounts of contaminants (e.g., alloying agents) contained in the component materials may leach into the substrate, causing unexpected or unacceptable performance.

[0003]

[0003] In some cases, components may have complex geometries. Complex geometries, especially components with complex internal geometries, may be inconvenient, difficult or impossible to machine. Diffusion bonding is one method of constructing components with complex internal geometries. Diffusion bonding utilizes a concentration gradient (e.g., of two different metals) to facilitate the exchange of atoms between two metal bodies and bond them into one solid object or article. Diffusion bonding is not usually suitable for joining two pure metal bodies composed of the same metal. Summary of the Invention

[0004]

[0004] The following is a brief summary of the present disclosure to provide a basic understanding of some aspects of the present disclosure. This summary is not an exhaustive overview of the present disclosure. It is not intended to identify key or critical elements of the present disclosure, nor is it intended to define the scope of any particular implementation of the present disclosure or the scope of the claims. The sole purpose of this summary is to present some concepts of the present disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0005] In an aspect of the disclosure, a disclosed method includes applying a bonding layer of a first chemical composition to a first surface of a first metal body. The metal body is of a second chemical composition. The second chemical composition is different from the first chemical composition. The method further includes disposing a second metal body of the second chemical composition against the first metal body such that the bonding layer is between the first surface of the first metal body and the second surface of the second metal body. The first metal body and the second metal body are resistant to diffusion bonding. The bonding layer promotes diffusion bonding of the second metal body to the first metal body. The method further includes heating the first metal body and the second metal body. The method further includes applying pressure to press the second metal body against the first metal body. The method further includes creating a diffusion bond between the second metal body and the first metal body in response to heating and applying pressure for a period of time.

[0006]

[0006] In another aspect of the disclosure, a chamber component for a processing chamber is disclosed. The chamber component includes a first substantially pure metal body. The first metal body is configured with a first chemical composition. The chamber component further includes a second substantially pure metal body. The second metal body is configured with a first chemical composition. The first chemical composition is resistant to diffusion bonding. The chamber component further includes a diffusion bond between a first surface of the first metal body and a second surface of the second metal body, the diffusion bond including a spatial gradient between the first chemical composition and the second chemical composition of the bonding layer from the first metal body through the bonding layer to the second metal body.

[0007] In another aspect of the disclosure, a processing chamber is disclosed. The processing chamber includes a showerhead. The showerhead includes a first substantially pure metal body of a first chemical composition. The showerhead includes a second substantially pure metal body of the first chemical composition. The first chemical composition is resistant to diffusion bonding. The showerhead further includes a diffusion bond between a first surface of the first metal body and a second surface of the second metal body. The diffusion bond is configured with a spatial gradient of the first chemical composition and the second chemical composition of the bonding layer, the spatial gradient extending from the first metal body through the bonding layer to the second metal body.

[0008]

[0008] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals indicate like elements. It should be noted that references to "an" or "one" embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. [Brief description of the drawings]

[0009] [Figure 1]

[0009] FIG. 1 is a cross-sectional view of a processing chamber having one or more chamber components that may be fabricated from a substantially pure metal by diffusion bonding in accordance with some embodiments. [Diagram 2]

[0010] 1 illustrates a diffusion bonding system, including a cross-sectional view of a diffusion bonding chamber according to some embodiments. [Diagram 3]

[0011] 1 illustrates an exemplary architecture of a deposition system for performing aerosol deposition according to some embodiments. [Figure 4A-4B]

[0012] 1 illustrates an arrangement and apparatus for performing a deposition technique utilizing energetic particles, according to some embodiments. [Diagram 5]

[0013] FIG. 1 shows a schematic diagram of a plasma spray deposition apparatus used in a thermal spray deposition technique according to some embodiments. [Figure 6]

[0014] 1 shows a schematic diagram of an electroplating system for applying a bond layer coating according to some embodiments. [Figure 7]

[0015] FIG. 1 is a flow diagram of a method for producing a diffusion bonded article comprised of a substantially pure metal according to some embodiments. [Figure 8A-8B]

[0016] 1 illustrates a cross-sectional view of an exemplary article formed from a substantially pure metal body using diffusion bonding according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010]

[0017] Described herein is technology related to improved methods of manufacturing components for processing chambers. In particular, improved methods are disclosed for manufacturing pure metal components of processing chambers (such as those that may be used as components of processing equipment for semiconductor processing) by diffusion bonding. The processing equipment components may include internal structures such as channels, openings, etc. The properties of the components (e.g., dimensions including internal dimensions) affect the conditions proximate to the product produced by the processing equipment. The conditions proximate to the workpiece determine the properties of the final product. For example, a processing chamber can be used to process substrates such as semiconductor wafers. The properties of the processing chamber components affect the processing conditions to which the substrate is subjected. The proximate conditions determine the performance of the product (e.g., whether the final product exhibits targeted property values).

[0011]

[0018] In some embodiments, a target processing component (e.g., a target geometry) may be inconvenient or impossible to machine from a solid stock material, such as a component with complex internal features. Some conventional systems may make compromises to achieve feasibility of the design, such as designing a component with a machinable feature or using multiple pieces that are clamped, glued, or otherwise joined.

[0012]

[0019] Some manufacturing processes are sensitive to contaminants. For such manufacturing processes, the materials from which the components are constructed may be selected to avoid materials that may contaminate the target product. For example, some materials may leak from processing components and adversely affect the performance of semiconductor wafers. Multi-piece components bonded by bonding agents may be subject to this sensitivity to contaminants, as many bonding agents contain materials that may contaminate the manufacturing process.

[0013]

[0020] Diffusion bonding is a joining technique that works by the principle of solid-state diffusion. Under some conditions, the atoms of two solid metal surfaces intermingle over time. Diffusion bonding can be performed by applying high pressure to two metal bodies in a high temperature environment. The atoms of the two metal bodies are gradually exchanged until the interface between the two articles disappears and one article is formed.

[0014]

[0021] Diffusion bonding occurs due to the global (e.g. two dissimilar metals) or local (e.g. two different local environments) concentration of materials. Dissimilar metals are often good candidates for diffusion bonding. Alloys can also be joined by diffusion bonding due to the fact that they contain multiple constituent materials. However, in some applications, the target components are meant to be composed of pure metals without contaminants. In such applications, the metallic bodies are resistant to diffusion bonding, making diffusion bonding impractical.

[0015]

[0022] Aspects of the present disclosure address at least some of these deficiencies of conventional methods. Disclosed herein are chamber components and techniques for manufacturing pure metal chamber components by diffusion bonding. The embodiments allow for manufacturing metal bodies of a single pure metal composition and / or complex internal structure. These metal bodies are free of contaminants. In some embodiments, a thin layer of a second material is disposed between the pure metal bodies, the second material being different from the material of the pure metal bodies. A diffusion bonding procedure is then performed. A concentration gradient between the pure material and the second material facilitates the exchange of atoms between the materials. A diffusion bonded article does not have a distinct bonding layer, unlike a braised or otherwise bonded article. Instead, a diffusion bonded article exhibits a concentration gradient from the pure metal to the area where the second material has diffused into the pure metal, creating a mixed material (e.g., an alloy) in the area between the two metal bodies, which can then be converted back to a pure metal.

[0016]

[0023] In some embodiments of the present disclosure, a method includes forming a first substantially pure metal body. The first substantially pure metal body includes a first chemical composition. The method further includes forming a second substantially pure metal body including the first chemical composition. The method further includes applying a bonding layer to a first surface of the first metal body including a second chemical composition different from the first chemical composition. The method further includes positioning the metal bodies such that the bonding layer is between the first surface of the first metal body and the second surface of the second metal body. The method further includes creating a diffusion bond between the first metal body and the second metal body by applying a pressure and temperature for a period of time to bond the first metal body and the second metal body.

[0017]

[0024] In another aspect of the disclosure, a chamber component for a processing chamber is disclosed. The chamber component includes a first substantially pure metal body having a first chemical composition. The chamber component further includes a second substantially pure metal body having the first chemical composition. The chamber component further includes a diffusion bond between a first surface of the first metal body and a second surface of the second metal body. The diffusion bond includes a spatial gradient of the first chemical composition and the second chemical composition of the bonding layer, the spatial gradient being from the first metal body through the bonding layer to the second metal body. The second chemical composition may be different from the first chemical composition. For example, the first chemical composition may be a pure metal and the second chemical composition may be an alloy of the pure metal. The chemical composition of the chamber component includes a spatial gradient from the first metal body through the bonding layer to the second metal body.

[0018]

[0025] In another aspect of the disclosure, a processing chamber is disclosed. The processing chamber includes a showerhead. The showerhead includes a first substantially pure metal body of a first chemical composition. The showerhead includes a second substantially pure metal body of the first chemical composition. The first chemical composition is resistant to diffusion bonding. The showerhead further includes a diffusion bond between a first surface of the first metal body and a second surface of the second metal body. The diffusion bond is configured with a spatial gradient between the first chemical composition and the second chemical composition from the first metal body through a bonding layer to the second metal body.

[0019]

[0026] FIG. 1 is a cross-sectional view of a processing chamber 100 having one or more chamber components that may be fabricated from a substantially pure metal by diffusion bonding according to some embodiments. The processing chamber 100 may include components with complex internal structures (e.g., internal structures that cannot be machined from a solid block), such as a showerhead. The processing chamber 100 may be used for processes in which a plasma corrosive environment having plasma processing conditions is provided. For example, the processing chamber 100 may be a chamber for a plasma etching apparatus or plasma etching reactor, a plasma cleaner, etc. The processing chamber 100 may be used for contamination sensitive processes, such as semiconductor wafer processing. Examples of chamber components that may be part of the processing chamber 100 include a substrate support assembly 104, an electrostatic chuck (ESC), a ring (e.g., a process kit ring or a single ring), a chamber wall, a base, a gas distribution plate, a showerhead 106, a nozzle, a lid, a liner, a liner kit, a shield, a plasma screen, a flow equalizer, a cooling base, a chamber viewport, a chamber lid, etc.

[0020]

[0027] In one embodiment, the processing chamber 100 includes a chamber body 108 and a showerhead 106 that surround an interior space 110. The showerhead may include a showerhead base and a showerhead gas distribution plate. Alternatively, in some embodiments, the showerhead 106 may be replaced by a lid and a nozzle. The chamber body 108 may be fabricated from aluminum, stainless steel, nickel, or other suitable materials. The chamber body 108 generally includes a sidewall 112 and a bottom 114. Any of the showerhead 106 (or the lid and / or nozzle), the sidewall 112, and / or the bottom 114 may include an arc and / or plasma resistant coating layer.

[0021]

[0028] An exhaust port 116 is defined in the chamber body 108 and connects the interior volume 110 to a pumping system 118. The pumping system 118 may include one or more pumps and a throttle valve that are utilized to evacuate the interior volume 110 of the processing chamber 100 and to regulate the pressure in the interior volume 106.

[0022]

[0029] The showerhead 106 may be supported on a sidewall 112 of the chamber body 108. The showerhead 106 (or lid) may be open to allow access to the interior volume 110 of the processing chamber 100 or may be closed to provide a seal for the processing chamber 100. A gas panel 120 may be coupled to the processing chamber 100 to supply process gases and / or cleaning gases to the interior volume 110 through the showerhead 106 or the lid and nozzles. The showerhead 106 is used in processing chambers used for dielectric etching (etching dielectric materials). The showerhead 106 includes a gas distribution plate (GDP) with multiple gas supply holes throughout the GDP. The showerhead 106 is an example of a component that can be fabricated using the diffusion bonding techniques described in this disclosure. The showerhead 106 may include complex internal structures. The showerhead 106 may be composed of a substantially pure metal. In some embodiments, "substantially pure" refers to a metal having a purity of at least 99.9%. In some embodiments, materials used to fabricate components using diffusion bonding (e.g., the showerhead 106) may have a purity of at least 99.99%. In some embodiments, materials used to fabricate components using diffusion bonding may have a purity of at least 99.999%. In some embodiments, the showerhead 106 may be composed of a substantially pure metal.

[0023]

[0030] For processing chambers used for conductor etching (etching conductive materials), a lid may be used rather than a showerhead. The lid may include a central nozzle that fits into a central hole in the lid. The lid may be a ceramic, such as Al2O3, Y2O3, YAG, or a ceramic compound including a solid solution of Y4Al2O9 and Y2O3-ZrO2. The nozzle may also be a ceramic, such as Y2O3, YAG, or a ceramic compound including a solid solution of Y4Al2O9 and Y2O3-ZrO2. The lid, showerhead base, GDP, and / or nozzle may be coated with an arc layer and / or a plasma resistant coating layer.

[0024]

[0031] Examples of process gases that may be used to process a substrate in the processing chamber 100 include halogen-containing gases (e.g., C2F6, SF6, SiCl4, HBr, NF3, CF4, CHF3, CH2F3, F, NF3, Cl2, CCl4, BCl3, SiF4, among others) and other gases such as O2 or N2O. Examples of carrier gases include N2, He, Ar, and other gases that are inert (e.g., non-reactive gases) with respect to the process gases. A substrate support assembly 104 is disposed in the interior space 1110 of the processing chamber 100 under the showerhead 106 or lid. The substrate support assembly 104 holds the substrate 102 during processing. A ring (e.g., a single ring) may cover a portion of the support assembly 104 (e.g., a susceptor 122) to protect the covered portion from exposure to the plasma during processing. In an embodiment, the ring is silicon or quartz. The substrate support assembly 104 may include a pedestal 124 and a susceptor 122.

[0025]

[0032] 2 illustrates a diffusion bonding system, including a cross-sectional view of a diffusion bonding chamber 202, according to some embodiments. The diffusion bonding system 200 can be configured to perform diffusion bonding of two metallic bodies comprised of a substantially pure metal, such as substantially pure (e.g., 99.9% or greater purity) nickel.

[0026]

[0033] The diffusion bonding system 200 includes a diffusion bonding chamber 202 having an interior 204 surrounded by walls and a bottom. In some embodiments, the interior 204 may be an enclosed chamber capable of maintaining low or high pressure conditions or capable of processing articles under an inert gas environment and may be connected to a suitable gas flow source. In some embodiments, the diffusion bonding chamber 202 includes a furnace 206 that may surround the diffusion bonding chamber 202, for example, in a cylindrical shape. The furnace 206 may be programmable and include one or more temperature sensors disposed within the hot press chamber 202 to provide feedback that is utilized to maintain a target temperature. The gas flow system may also be programmable and the diffusion bonding chamber 202 may include one or more pressure sensors. The furnace 206 may also be ramped to a target temperature at a target rate. In some embodiments, the furnace 206 is operably coupled to a computing device. The computing device may execute one or more stored recipes (which may be predefined or operator defined) that control the conditions of the furnace 206, the gas flow system, and the like. The diffusion bonding chamber 202 can maintain an elevated temperature while performing the diffusion bonding of the metal bodies 212A-B. In some embodiments, the temperature is between 50% and 90% of the absolute melting temperature of the materials comprising the first and second metal bodies. In some embodiments, the temperature is between 60% and 80% of the absolute melting temperature of the materials comprising the first and second metal bodies. In some embodiments, the temperature is about 70% of the absolute melting temperature of the materials comprising the first and second metal bodies. In some embodiments, nickel can be diffusion bonded between 1000°F and 2300°F, between 1400°F and 2000°F, at about 1700°F, or at any subrange of these values. As used herein, "about" indicates a range around the indicated value, for example, ±10% of that value.

[0027]

[0034] The diffusion bonding chamber 202 may include an opening 210. One or more metal bodies 212A-B with a bonding layer 214 formed thereon may be inserted into the diffusion bonding chamber 202. Methods for depositing the bonding layer 214 are described in more detail in FIGS. 3-6. A press 215 may then apply pressure to compress the metal bodies 212A-B together. The press 215 (also called a punch) applies pressure while the furnace 206 heats the metal bodies 212A-B and the bonding layer 214. Note that only one upper press 215 is shown. However, in embodiments, a lower press may be used that presses in the opposite direction to the upper press 215. In some embodiments, pressure is applied to the metal bodies, reducing the overall thickness of the metal bodies by 0.1% to 5%. In some embodiments, pressure is applied to the metal bodies, reducing the overall thickness of the metal bodies by about 1%. The heat and pressure cause the bond 214 and the pure metal bodies 212A-B to form a single diffusion bonded article, such as a component of a processing chamber. In some embodiments, the heat and pressure are maintained for several hours. In some embodiments, the heat and pressure are maintained for at least 5 hours. In some embodiments, the heat and pressure are maintained for at least 10 hours. In some embodiments, the heat and pressure are maintained for approximately 2e4 hours.

[0028]

[0035] In some embodiments, conventional techniques are not suitable for manufacturing chamber components. In some conventional systems, components with complex internal structures can be manufactured using brazing techniques. Brazing involves placing a thin foil of a material with a low melting point between two metal bodies and heating the assembly to melt the foil and bond the two metal bodies. Such techniques may not be applicable when the components are used in high temperature applications, especially when the intended use of the components requires a high enough temperature to melt (or weaken) the joining material. In a diffusion bonding system such as system 200, the material used as bonding layer 214 may be a material suitable for high temperature environments. In some embodiments, the material used as bonding layer 214 may have a higher melting temperature than the material of metal bodies 212A-B. Furthermore, brazing materials often contaminate the internal structure of the parts. Brazing materials often do not have high corrosion resistance.

[0029]

[0036] In some embodiments, the metal bodies 212A-B may be comprised of a substantially pure material (e.g., the same substantially pure material). In some embodiments, the metal bodies 212A-B may be comprised of substantially pure nickel. The bonding layer 214 may be comprised of a metal, an alloy, a non-metal, etc., to create a concentration gradient to facilitate diffusion and eliminate interfaces between layers of the diffusion bonded article. In some embodiments, the bonding layer 214 may be comprised of a material such that atoms of the material may substitute for atoms in the lattice that comprises the metal bodies 212A-B. For example, the metal bodies 212A and 212B may each be comprised of pure nickel, and the material of the bonding layer 214 may be selected such that atoms are exchanged between the material of the metal bodies 212A-B and the material of the bonding layer 214. Atoms diffused from the bonding layer 214 may occupy lattice sites of the metal bodies 212A-B, for example, via a substitutional diffusion bond. Gold and copper are examples of materials that may substitute for nickel atoms in a nickel lattice, for example. The material of the bonding layer 214 may be selected such that the material penetrates into the lattice structure of the metal bodies 212A-B, for example, via interstitial diffusion bonding. For example, materials such as aluminum, boron, or titanium may be diffusion bonded to nickel by diffusing the bonding material into the nickel atomic lattice, eliminating the boundary between the layers. The material of the bonding layer 214 may be selected to facilitate diffusion by introducing a concentration gradient using an alloy. For example, the metal bodies 212A-B may be comprised of substantially pure nickel, and the bonding layer 214 may be comprised of a nickel alloy. In some embodiments, the bonding layer 214 may contain phosphorus. In some embodiments, the bonding layer 214 may be electroless nickel plating. The bonding layer 214 may be a thin layer of material. In some embodiments, the deposited bonding layer may be less than 10 μm, less than 5 μm, or less than 1 μm thick. Atoms of the bonding layer 214 may migrate (eg, diffuse) into the metal bodies 212A-B during diffusion bonding, and atoms of the metal bodies 212A-B may migrate into the bonding layer 214.The finished article may have no boundaries between the layers, or more precisely, a material concentration gradient may be created, going from a region of substantially pure metal in the first metal body, to a region of the mixed material, and back to a region of pure metal in the second metal body.

[0030]

[0037] Bonding layer 214 may be applied to the surface of metal body 212A and / or 212B using any method suitable for depositing a layer of material on a surface, including electroplating, vapor deposition (e.g., physical vapor deposition such as sputtering or evaporation, chemical vapor deposition such as atomic layer deposition, etc.), ion-assisted deposition, plasma deposition, electroless plating, or other suitable techniques. Figures 3-6 show some exemplary systems that may be used to deposit thin films on the surface of an article.

[0031]

[0038] 3 illustrates an exemplary architecture of a deposition system 300 for performing aerosol deposition according to some embodiments. The system 300 can be used to apply various coatings to components of processing equipment. The system 300 can be used to apply coatings of many types of materials, including polymeric coatings (e.g., high dielectric strength coatings), ceramic coatings (e.g., plasma resistant coatings), coatings that include multiple components (such as a polymeric phase and a ceramic phase), or other types of coatings. The system 300 can be used to deposit precursor materials that react to form a coating on a surface of a metal body, such as might be used in aerosol-assisted chemical vapor deposition. The system 300 includes a deposition chamber 302. The deposition chamber can include a stage 304 for mounting a component 306 to be coated (e.g., such as the metal body 212 of FIG. 2). The ambient pressure of the interior space 303 of the chamber 302 can be reduced via a vacuum system 308 coupled to the interior space 303 via an exhaust port 309 defined in the body of the chamber 302. The aerosol chamber 310 contains coating powders for coating the component 306, such as polymer powders, metal oxide powders, mixtures of powders, reactants for forming thin layers by chemical vapor deposition. In some embodiments, the materials may be introduced in different ways, for example, liquids may be co-sprayed with a carrier gas through a nozzle 314. The aerosol chamber 310 is coupled to a gas container 312. The coating material in the aerosol chamber 310 may be in the form of a fine powder, for example, having particles with a size of a few microns to hundreds of microns. The carrier gas flows from the gas container 312 through the aerosol chamber 310 into the interior space 303. The carrier gas pushes the coating powder through the nozzle 314, driving the coating powder into the component 306 to form a coating.

[0032]

[0039] The component 306 may be a component used for semiconductor manufacturing. The component 306 may be a component of an etch reactor, a thermal reactor, a semiconductor processing chamber, etc. Examples of possible components include a lid, a substrate support, a process kit ring, a chamber liner, a nozzle, a showerhead, a wall, a base, a gas distribution plate, etc. The component 306 may be formed of materials such as aluminum, silicon, quartz, metal oxides, ceramic compounds, polymers, composites, etc.

[0033]

[0040] In some embodiments, the surface of the component 306 may be polished to reduce the surface roughness of the component 306. Reducing the surface roughness can improve the thickness and uniformity of the coating. In some embodiments, the surface roughness is reduced to below the target thickness of the coating layer. In some embodiments, the surface of the metal body may be cleaned, e.g., to remove any metal oxide layer, before applying the bonding layer. The metal oxide layer (or another surface contaminant) may be removed using any suitable technique, such as acid washing, sputtering, etc. In some embodiments, not all areas of the component 306 are coated. Areas of the component 306 that are not bonded (e.g., areas not adjacent to the bond, such as channels or voids within the finished product) may be masked, shielded, or otherwise removed from areas accessed by the aerosol powder. In some embodiments, the coating material may be removed from the areas that are not coated after coating.

[0034]

[0041] The component 306 may be mounted on a stage 304 of the deposition chamber 302 during deposition of the coating. The stage 304 may be a movable stage (e.g., a motorized stage) that may be moved in one, two, or three dimensions and / or rotated in one or more dimensions such that the stage 304 may be moved to different positions to facilitate coating of the component 306 with a coating powder extruded from a nozzle 314. For example, the stage 304 may be moved to coat different portions or sides of the component 306. The nozzle 314 may be selectively aimed at particular portions of the component 306 from a variety of angles and directions.

[0035]

[0042] In some embodiments, the deposition chamber 302 can be evacuated using a vacuum system 308. Providing a reduced pressure environment in the interior space 303 can facilitate application of the coating. For example, coating powder extruded from the nozzle 314 encounters less resistance in moving to the component 306 when the interior space 303 is under reduced pressure. The coating powder can impact the component 306 more regularly and at a higher velocity, etc., which can promote adhesion to the component 306, promote coating formation, reduce wasted coating material, etc.

[0036]

[0043] The gas container 312 contains a pressurized carrier gas. Acceptable pressurized carrier gases include inert gases such as argon, nitrogen, krypton, etc. The pressurized carrier gas travels under pressure from the gas container 312 to the aerosol chamber 310. As the pressurized gas travels from the aerosol chamber 310 to the nozzle 314, the carrier gas pushes a portion of the coating powder out of the aerosol chamber 310 and towards the nozzle 314.

[0037]

[0044] In some embodiments, the system 300 can be used to deposit a single material on one or more surfaces of the component 306. In some embodiments, the system 300 can be used to deposit multiple materials on the component 306. In some embodiments, a polymer layer including multiple polymers can be deposited on the component 306. In some embodiments, a ceramic layer including multiple ceramic materials can be deposited on the component 306. In some embodiments, a material including a polymer phase and a ceramic phase can be deposited on the component 306. In some embodiments, multiple coating precursors can be deposited. Multiple materials can be co-deposited by feeding a mixture of powder materials to the aerosol chamber 310. In alternative embodiments, two or more aerosol chambers are coupled to a pressurized gas and the nozzle 314, each of which can feed material separately to the nozzle 314. In alternative embodiments, multiple nozzles can receive material from multiple aerosol chambers coupled to a pressurized carrier gas. In these embodiments, multiple materials can be deposited simultaneously. In some embodiments, different materials can be deposited sequentially. In some embodiments, a reaction can proceed to produce a material for a coating. In some embodiments, the coated metal body may be cured (eg, UV cured, oven cured, etc.) to accelerate the reaction to form the desired coating.

[0038]

[0045] As the carrier gas pushing the suspension of coating powder enters the deposition chamber 302 through the nozzle 314, the coating powder is pushed towards the component 306. In some embodiments, the carrier gas is pressurized such that the coating powder is pushed towards the component 306 at a velocity between 150 m / sec and 500 m / sec. In some embodiments, the particle size of the coating powder and the pressure of the carrier gas can be adjusted to match a targeted velocity distribution of the coating powder.

[0039]

[0046] In some embodiments, the nozzle 314 is configured to be wear resistant. The movement of coating powder past the nozzle 314 at high speeds can cause the nozzle 314 to wear and deteriorate quickly. The nozzle 314 can be configured with a shape and material to reduce wear.

[0040]

[0047] In some embodiments, upon impact with the component 306, the particles of the coating powder break up and deform due to kinetic energy, creating a layer that adheres to the component 306. As the application of the coating powder continues, the particles bond with themselves into a coating or film. The coating on the component 306 continues to grow due to the continued collision of the particles of the coating powder on the component 306. In some embodiments, the particles mechanically collide with each other and with the substrate at high speeds under reduced pressure and break up into smaller pieces rather than melting to form a dense layer. In some embodiments, the crystal structure of the particles of the coating powder in the aerosol chamber 310 is preserved throughout application to the component 306. In some embodiments, melting of the particles can occur when kinetic energy is converted to thermal energy. In some embodiments, the aerosol deposition can be performed at room temperature or between 15° C. and 35° C. In some embodiments, the component 306 does not need to be heated and the aerosol application process can not significantly increase the temperature of the component 306. Such applications can be used to coat assemblies that may be damaged in high temperature environments. For example, a component that has multiple parts bonded together with a bonding layer that melts at a lower temperature may be damaged during a deposition process that is performed at a higher temperature. As a further example, a component formed of multiple parts of different materials with different thermal expansion properties may be damaged because the parts expand at different rates and to different sizes during deposition. Such components are less likely to be damaged by coatings at ambient temperatures.

[0041]

[0048] In some embodiments, aerosol deposition may be performed at elevated temperatures. In some embodiments, the component 306 may be heated before or during aerosol deposition. Such heating may facilitate melting of the coating powder. In some embodiments, after deposition has occurred, the component 306 may be placed in an oven to heat the component and coating material for a period of time. The temperature of the component 306 and coating may increase, causing the coating to partially or completely melt. The coating may be made to flow over the surface of the component 306, for example to improve coating uniformity and allow the coating to reach new areas of the surface of the component 306.

[0042]

[0049] In some embodiments, the coated component may be subjected to a post-coating process. For example, the ceramic coating may be polished or ground after application to the component 306. The coated component may be subjected to other post-coating processes, such as heat treatment. The heat treatment in some embodiments forms a coating interface between the coating and the component. For example, an yttria (Y2O3) coating on an alumina (Al2O3) component may form a yttrium aluminum garnet (YAG) layer that aids in adhesion and further protects the component. The barrier layer may reduce the occurrence of delamination, chipping, flaking, peeling, etc. The heat treatment may also change the chemical composition of the coating. For example, a duplex coating of yttria / alumina may be converted to a YAG coating by heat treatment.

[0043]

[0050] 4A-B show mechanisms and apparatus for performing deposition techniques utilizing energetic particles, according to some embodiments. FIG. 4A shows a deposition mechanism applicable to various deposition techniques utilizing energetic 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 coatings as described herein. Any IAD method can be performed in the presence of reactive gas species, such as O2, N2, halogens, etc.

[0044]

[0051] As shown, the thin coating layer 415 is formed by accumulation of deposition material 402 in the presence of energetic particles 403, such as ions. The deposition material 402 may include atoms, ions, radicals, or mixtures thereof. The energetic particles 403 may collide and compress as the thin final coating layer 415 is formed.

[0045]

[0052] In an embodiment, IAD is utilized to form a thin coating layer 415, as previously described elsewhere herein. FIG. 4B is a schematic diagram of an IAD deposition apparatus. As shown, a material source 450 provides a flux of deposition material 452 for deposition on an article 460, while an energetic particle source 455 provides a flux of energetic particles 453, both of which bombard the article 460 throughout the IAD process. The energetic particle source 455 may be an oxygen or other ion source. The energetic particle source 455 may also provide other types of energetic particles, such as inert radicals, neutral atoms, and nano-sized particles coming from a particle generation source (e.g., from a plasma, reactive gas, or from a material source providing the deposition material). The IAD may utilize one or more plasmas or beams to provide the material and energetic ion sources. Reactive species may also be provided during deposition of the coating.

[0046]

[0053] In an IAD process, energetic particles 453 can be controlled by an energetic ion (or other particle) source 455, independent of other deposition parameters. Depending on the energy (e.g., velocity), density, and incidence angle of the energetic ion flux, the composition, structure, crystal orientation, and grain size of the thin protective layer can be manipulated. Additional adjustable parameters are the temperature of the article during deposition and the duration of deposition. Ion energy is broadly divided into low-energy ion assist and high-energy ion assist. In high-energy ion assist, ions are projected at a higher velocity than in low-energy ion assist. In general, superior performance has been shown with high-energy ion assist. Substrate (article) temperature during deposition is broadly divided into low temperature (about 120-150°C in some embodiments) and high temperature (about 270°C in some embodiments).

[0047]

[0054] 5 shows a schematic diagram of a plasma spray deposition apparatus 500 used in a thermal spray deposition technique according to some embodiments. The plasma spray deposition apparatus 500 may include a casing 502 that houses a nozzle anode 506 and a cathode 504. The casing 502 allows a gas flow 508 to flow between the nozzle anode 506 and the cathode 504 through the plasma spray apparatus 500. An external power source may be used to apply an electric potential between the nozzle anode 506 and the cathode 504. This electric potential creates an arc between the nozzle anode 506 and the cathode 504, igniting the gas flow 508 and generating plasma gas. The ignited plasma gas flow 508 generates a high velocity plasma plume 514 that is directed from the nozzle anode 506 toward an article 520.

[0048]

[0055] The plasma spray apparatus 500 can be located in a chamber or atmospheric booth. In some embodiments, the gas stream 508 can be a gas or mixture of gases, including, but not limited to, argon, nitrogen, hydrogen, helium, and combinations thereof. In some embodiments where the spray system is used to perform slurry plasma spraying, the plasma spray apparatus 500 can include one or more fluid lines 512 for delivering a slurry to the plasma plume 514. In some embodiments, a particle stream 516 is generated from the plasma plume 514 and is propelled toward the article 520. Upon impact with the article 520, the particle stream forms a coating 518.

[0049]

[0056] 6 shows a schematic diagram of an electroplating system for applying a bond layer coating, according to some embodiments. The system 600 includes a cathode 602 and an anode 604 extending into a vessel 606. The vessel 606 contains a solution in contact with the cathode 602 and the anode 604. The solution includes ions of a salt that includes the material of the anode 604. For example, if the anode is constructed of copper, the solution may be a solution of a soluble copper salt, such as copper sulfate. In some embodiments, the anode material may resist electrochemical oxidation and instead generate by-products in the solution.

[0050]

[0057] A DC power source 610 draws electrons from the anode 604 and deposits them at the cathode 602. Positively charged metal ions in the solution 608 are attracted to the cathode. Metal atoms are deposited from the solution 608 onto the cathode 602 in a coating layer 612. In this manner, a coating layer 612 of material from the solution 608 is produced on the surface of the cathode 602. In some embodiments, the material of the anode 604 replenishes the ions in the solution 608.

[0051]

[0058] In some embodiments, articles produced by diffusion bonding are made from multiple metal bodies composed of substantially pure metal (e.g., at least 99.9% pure metal). The metal bodies may be machined or otherwise formed into specific shapes, for example, channels or other complex geometries may be formed layer by layer by machining multiple metal bodies to be joined. In some embodiments, the surfaces of the metal bodies (e.g., the surfaces to be joined) are cleaned. Cleaning may include removing an oxide layer from the surfaces of the metal bodies (e.g., removing an oxide layer before applying a bonding layer). Areas that are not to be bonded (or areas that are not to be plated with a bonding layer material) may be masked. Common masking materials include tape, foil, lacquer, wax, etc. The metal bodies may then be used as an anode in an electroplating system, such as system 600, to produce a thin layer of bonding material on the unmasked portions of the metal bodies. In systems where the material of the anode is different from the plating material (e.g., the anode material does not replenish the metal ions in the solution), metal salts may be added to solution 608 as electroplating progresses. The metal bodies to be joined can then be assembled such that they have joining material between them, placed in a diffusion bonding system (e.g., system 200 of FIG. 2 ), and joined into a single article (e.g., a single component of a manufacturing system).

[0052]

[0059] In some embodiments, electroless plating can be used to deposit the bonding layer. In some embodiments of the electroless plating process, a uniform layer of nickel-phosphorus alloy is deposited on the surface of a solid substrate. Unlike electroplating, electroless plating typically does not pass an electric current through the material being plated. In some applications, electroplating may deposit a non-uniform layer of material due to non-uniform current densities that may result from the geometry of the cathode. Electroless plating may not be subject to such limitations.

[0053]

[0060] Electroless plating involves immersing the object to be plated in an ionic solution. The object may be machined, cleaned, masked, etc. prior to plating. The ionic solution includes a source of nickel cations and a reducing agent. In one embodiment, the solution includes nickel sulfate and hypophosphite ions (e.g., sodium hypophosphite). A reaction occurs that produces solid nickel, elemental phosphorus, orthophosphate, protons, and molecular hydrogen. This reaction deposits a layer of nickel-phosphorus alloy on the surface of the object to be plated. Electroless plating can be performed using nickel as a catalyst, and is suitable for coating the surface of a pure nickel object with a nickel alloy to create a concentration gradient and promote atomic diffusion in the diffusion bonding process.

[0054]

[0061] FIG. 7 is a flow diagram of a method 700 for manufacturing a diffusion bonded article comprised of substantially pure metal according to some embodiments. In block 702, a first metal body and a second metal body are formed. The metal bodies can be formed from substantially pure metal. In some embodiments, the metal bodies are comprised of pure nickel. In some embodiments, the first metal body and the second metal body are formed from a pure metal sheet. The composition of the first metal body and the second metal body is the same. Forming the metal bodies can include, for example, machining channels, voids, or other features into one or more metal bodies.

[0055]

[0062] At block 704, a first surface of the first metal body is prepared for application of a bonding layer. The applied bonding layer is of a second composition different from the compositions of the first metal body and the second metal body. The surface is bonded to the second metal body by diffusion bonding. Preparation of the first surface may include cleaning the surface. In some embodiments, contaminants are removed from the surface. Contaminants include organic materials, inorganic materials, metal oxides, etc. In some embodiments, contaminants are removed using a solvent, such as an organic solvent, an acid, a base, etc. In some embodiments, the surface is cleaned using sputtering or another method for removing material from a solid. Preparation of the first surface includes masking portions that will not be bonded, such as masking channels or other machined features, masking sides or areas that are not in contact with the second metal body, etc.

[0056]

[0063] At block 706, a bonding layer is applied to a first surface of the first metal body. The bonding layer includes a second chemical composition that is different from the first chemical composition. The bonding layer is applied to the first surface using any technique suitable for depositing a thin layer of material on a surface. The bonding layer may be applied, for example, by physical vapor deposition, chemical vapor deposition, electroplating, electroless plating, atomic layer deposition, molecular layer deposition, ion-assisted deposition, and the like. In some embodiments, the bonding layer may be less than 10 μm thick. In some embodiments, the bonding layer may be less than 1 μm thick. In some embodiments, the bonding layer may be less than 100 μm thick. In some embodiments, the bonding layer may be about 10 nm, e.g., ±10%) thick.

[0057]

[0064] At block 708, the metal bodies (e.g., a first metal body and a second metal body) are arranged such that the bonding layer is between a first surface of the first metal body and a second surface of the second metal body. In some embodiments, many metal bodies are joined to produce an article. In some embodiments, many pure metal bodies may be stacked such that the coated bonding layer is interspersed between the pure metal bodies. In some embodiments, the article may be composed of alternating layers of pure metal bodies and bonding layers.

[0058]

[0065] At block 710, a diffusion bonded article is produced by performing a diffusion bonding procedure on the metal bodies and the bonding layer. Diffusion bonding is accomplished by applying pressure and temperature to the first metal body for a time sufficient to bond the first metal body to the second metal body. Diffusion bonding systems and techniques are described in more detail in connection with FIG. 2.

[0059]

[0066] 8A-B show cross-sectional views of exemplary articles 800A-B formed from substantially pure metal bodies using diffusion bonding according to some embodiments. The articles 800A-B can be any of a variety of components including manufacturing components, chamber components, etc. In some embodiments, the articles 800A-B are showerheads. The substantially pure metal bodies 802 are comprised of pure metal (e.g., the same metal with a purity of 99.9% or greater). In some embodiments, the metal bodies 802 are comprised of nickel. Prior to diffusion bonding, the one or more metal bodies 802 may be shaped, machined, cleaned, have surface oxides removed, and / or otherwise prepared for diffusion bonding (e.g., surfaces polished to increase diffusion area, etc.). Additionally, the one or more metal bodies 802 may have a thin layer of material added to facilitate diffusion bonding by forming a concentration gradient between the pure metal bodies 802 and the bonding layer 804.

[0060]

[0067] The bonding layer 804 may be composed of several types of materials. The bonding layer 804 may be composed of atoms that can replace atoms in the metal lattice of the metal body 802. In some embodiments, materials such as gold and copper can replace nickel atoms in the lattice of the nickel metal body. In some embodiments, the bonding layer 804 may be composed of atoms that are interstitially located in the lattice of the metal body 802. Materials such as aluminum, boron, or titanium may be interstitially located in the lattice of nickel atoms. In some embodiments, the bonding layer 804 may be composed of an alloy of the material of the metal body 802. Nickel-phosphorous alloys, such as those produced by electroless nickel plating, may generate a concentration gradient and may be used as the bonding layer 804.

[0061]

[0068] 8A is a representation of article 800A before performing the diffusion bonding process and after deposition of bonding layer 804. Article 800A as depicted includes separate layers, but once diffusion bonded, atoms are exchanged between the layers (e.g., from metal body 802 to bonding layer 804, and from bonding layer 804 to metal body 802). The finished article may include gradual changes in composition rather than sharp boundaries, such as, for example, a composition or concentration gradient.

[0062]

[0069] FIG. 8B is a representation of article 800B after a diffusion bonding process has been performed. Article 800B may not include a clear interface between the metal bodies. Article 800B may include a region 806 of essentially the same material as metal body 802 (e.g., as the same region of the article before diffusion bonding). Atoms of metal body 802 and bonding layer 804 may have exchanged, diffused, etc., such that there is no longer a clear interface between the layers. Instead, bonding layer 804 may be replaced by a transition region 808. In transition region 808, a spatial gradient of concentration exists. Near region 806, transition region 808 may be composed of a composition similar to that of pure metal body 802. The composition of portions of article 800B further from region 806 may be more similar to that of bonding layer 804, e.g., an alloy of the materials of metal body 802 and bonding layer 804, or may have a higher concentration of the material of bonding layer 804 than the surrounding regions.

[0063]

[0070] The foregoing description sets forth numerous specific details, such as examples of specific systems, components, methods, and the like, to provide a good understanding of some embodiments of the present invention. However, it will be apparent to one of ordinary skill in the art that at least some embodiments of the present invention may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram form to avoid unnecessarily obscuring the present invention. Thus, the specific details shown are merely exemplary. It is contemplated that certain embodiments may differ from these illustrative details and still be within the scope of the present disclosure.

[0064]

[0071] Throughout this specification, reference to "an embodiment" or "an embodiment" indicates that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the term "about" or "approximately" is used herein, it is intended to mean that the nominal value presented is accurate to within ±10%.

[0065]

[0072] Although the steps of the methods herein are illustrated and described in a particular order, the order of each method step may be altered such that certain steps are performed in reverse order or certain steps are performed at least in part concurrently with other steps. In alternative embodiments, the instructions of separate steps or sub-steps may be intermittent and / or alternating.

[0066]

[0073] It should be understood that the above description is intended to be illustrative, and not limiting. Many other embodiments will be apparent to those of ordinary skill in the art upon reading and understanding the above description. The scope of the present invention should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A method comprising: applying a bonding layer comprising a first chemical composition to a first surface of a first metallic body comprising a second chemical composition, the second chemical composition being different from the first chemical composition; placing the second metal body having the second chemical composition against the first metal body such that the bonding layer is between the first surface of the first metal body and a second surface of the second metal body, the first metal body and the second metal body being resistant to diffusion bonding, and the bonding layer facilitating diffusion bonding of the second metal body to the first metal body; heating the first metal body and the second metal body; applying pressure to press the second metal body against the first metal body; creating a diffusion bond between the second metal body and the first metal body in response to the applying of the heat and the pressure for a period of time. The method includes:

2. The method of claim 1 , wherein the purity of the first metal body and the purity of the second metal body are 99.99% or greater.

3. The method of claim 1 , wherein the bonding layer has a thickness of 5 μm or less.

4. The method of claim 1 , wherein the bonding layer has a thickness of 100 nm or less.

5. The method of claim 1 , wherein at least the first surface of the first metallic body and the second surface of the second metallic body consist of substantially pure nickel.

6. applying the bonding layer performing physical vapor deposition; performing chemical vapor deposition; Carrying out electroplating; performing electroless plating; performing atomic layer deposition; or Performing ion-assisted deposition The method of claim 1 , comprising at least one of:

7. The method further includes preparing the first surface of the first metal body prior to application of the bonding layer, the preparing the first surface comprising: Removing organic surface contaminants; Removing inorganic surface contaminants; polishing the first surface; or removing the metal oxide layer from the first surface; The method of claim 1 , comprising one or more of:

8. The method of claim 1 , further comprising masking areas of the first metallic body prior to applying the bonding layer, the masked areas not adjacent to the diffusion bond.

9. 10. The method of claim 1, wherein the first metal body and the second metal body are heated to a temperature between 50% and 90% of the absolute melting temperature of the first chemical composition.

10. The method of claim 1 further comprising shaping the first metal body prior to applying the bonding layer.

11. 1. A chamber component for a processing chamber, comprising: a first substantially pure metal body having a first chemical composition; a second substantially pure metal body comprising the first chemical composition, the first chemical composition being resistant to diffusion bonding; and A diffusion bond between a first surface of a first metallic body and a second surface of a second metallic body, the diffusion bond including a spatial gradient of the first and second chemical compositions of the bonding layer from the first metallic body through the bonding layer to the second metallic body. A chamber component for a processing chamber comprising:

12. The chamber component of claim 11 , wherein the first metal body has a purity of 99.99% or greater.

13. The chamber component of claim 11 , wherein the first chemistry comprises pure nickel.

14. The chamber component of claim 11 , wherein the second chemical composition is an alloy of nickel.

15. The chamber component of claim 14 , wherein the second chemical composition is a nickel phosphorous alloy.

16. 1. A processing chamber comprising a showerhead, the showerhead comprising: a first substantially pure metal body having a first chemical composition; a second substantially pure metal body comprising the first chemical composition, the first chemical composition being resistant to diffusion bonding; and A diffusion bond between a first surface of a first metallic body and a second surface of a second metallic body, the diffusion bond including a spatial gradient of the first and second chemical compositions of the bonding layer from the first metallic body through the bonding layer to the second metallic body. a processing chamber comprising:

17. 20. The processing chamber of claim 16, wherein the first metal body has a purity of 99.99% or greater.

18. 17. The processing chamber of claim 16, wherein the first chemistry consists essentially of pure nickel.

19. The processing chamber of claim 16 , wherein the second chemical composition comprises an alloy of the first chemical composition.

20. 20. The processing chamber of claim 19, wherein the first chemical composition comprises substantially pure nickel and the second chemical composition comprises a nickel phosphorous alloy.

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