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Erosion resistant textured chamber surfaceRelated Patent Categories: Stock Material Or Miscellaneous Articles, Composite (nonstructural Laminate), Of MetalErosion resistant textured chamber surface description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060105182, Erosion resistant textured chamber surface. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND [0001] In the processing of substrates such as semiconductor wafers and displays, a substrate is placed in a process chamber and exposed to an energized gas to deposit or etch material on the substrate. During such processing, process residues are generated and can deposit on internal surfaces in the chamber. For example, in sputter deposition processes, material sputtered from a target for deposition on a substrate also deposits on other component surfaces in the chamber, such as on deposition rings, shadow rings, wall liners, and focus rings. In subsequent process cycles, the deposited process residues can "flake off" of the chamber surfaces to fall upon and contaminate the substrate. To reduce the contamination of the substrates by process residues, the surfaces of components in the chamber can be textured. Process residues adhere to the textured surface and inhibit the process residues from falling off and contaminating the substrates in the chamber. [0002] In one version, the textured component surface is formed by directing an electromagnetic energy beam onto a surface of a process chamber component surface to form depressions and protrusions to which process deposits adhere. An example of such a surface is a Lavacoat.TM. surface, as described for example in U.S. Patent Publication No. 2003-0173526 to Popiolkowski et al, published on Sep. 18, 2003, and filed on Mar. 13, 2002; and U.S. Patent Publication No. 2004-0056211 to Popiolkowski et al, published on Mar. 25, 2004, and filed on Jul. 17, 2003--both commonly assigned to Applied Materials, Inc, and both of which are incorporated herein by reference in their entireties. The Lavacoat.TM. surface comprises depressions and protrusions to which process residues can adhere to reduce the contamination of substrates during their processing. [0003] While components having textured surfaces provide improved residue adherence over other types of process components, performance issues can arise when the components are cleaned to remove accumulated process residues. In an exemplary cleaning process, the component comprising the textured surface is immersed in a cleaning solution, such as an acidic solution. However, cleaning solutions that are capable of cleaning process residues can also erode the textured surface to alter the surface features, and consequently, reduce the adherence of process residues thereto. For example, textured component surfaces comprising aluminum and titanium can be eroded by an acidic solution of HNO.sub.3 and HF--which is used to remove tantalum-containing process residues from the component surfaces. Because the eroded surfaces can exhibit poor residue adhesion, the components may require replacement or refurbishment after only a few cleaning cycles, thereby increasing substrate processing costs and chamber downtime. [0004] Accordingly, it is desirable to have a component comprising a textured surface that provides good adherence of process residues, to improve processing results and reduce contamination of substrates. It is further desirable to be able to effectively clean accumulated process residues from the component surface without erosion of the residues during cleaning. It is further desirable to have a method of fabricating a component having a textured surface that has improved erosion resistance during cleaning processes and provides good results in the processing of substrates. SUMMARY [0005] In one version, a component for a substrate processing chamber has a structure having an overlying metal coating. The metal coating has a plurality of electron beam textured features that are formed by scanning an electron beam across a surface of the metal coating. The textured features include a plurality of depressions and protuberances that are capable of accumulating process deposits during processing of a substrate to reduce contamination of the substrate. The component having the metal coating provides improved processing results, and exhibits reduced erosion during cleaning processes performed to remove process deposits from the component. [0006] In another version, a process kit for a substrate processing chamber has a ring adapted to at least partially surround a substrate in the processing chamber. The ring is of a metallic material, and has a stainless steel coating. The stainless steel coating has electron beam textured features thereon, the electron beam textured features having a plurality of depressions and protuberances. The process kit provides improved erosion resistance in the substrate processing chamber. [0007] In yet another version, a process chamber shield for a substrate processing chamber has a shield structure that is adapted to at least partially shield a process chamber wall. The shield structure is of a metallic material, and has a stainless steel coating. The stainless steel coating has electron beam textured features thereon, the electron beam textured features having a plurality of depressions and protuberances. The process chamber shield provides improved erosion resistance in the substrate processing chamber. [0008] In another version, a method of fabricating a component for a substrate processing chamber includes providing a component structure and forming a metal coating on the component structure. An electron beam is scanned across a surface of the metal coating to form a plurality of textured features including depressions and protuberances on the surface. The metal coating can be formed by at least partially melting a coating material and propelling the coating material onto the component structure. DRAWINGS [0009] These features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings, which illustrate examples of the invention. However, it is to be understood that each of the features can be used in the invention in general, not merely in the context of the particular drawings, and the invention includes any combination of these features, where: [0010] FIG. 1a is a sectional side view of a component having a metal coating and a textured surface formed by scanning an electromagnetic energy beam across the layer; [0011] FIG. 1b is a sectional top view of an embodiment of the component of FIG. 1a; and [0012] FIG. 2 is a sectional side view of an embodiment of a substrate processing chamber having one or more components comprising electron beam textured features on a metal coating. DESCRIPTION [0013] A process chamber component 22 having a textured surface 20 is provided for the processing of substrates in an energized gas in a process chamber 106, as shown for example in FIGS. 1a and 1b. The component 22 having the textured surface reduces particle generation in the process chamber 106 by providing a "sticky" surface to which process deposits 24 adhere, thus allowing the deposits 24 to accumulate on the textured surface 20. Process deposits 24 that adhere to the textured surface 20 can include metal-containing deposits, such as deposits comprising at least one of tantalum, tantalum nitride, titanium, titanium nitride, aluminum, copper, tungsten, and tungsten nitride. The chamber components 22 having the textured surface 20 can comprise, for example, a portion of a gas delivery system 112 that provides process gas in the chamber 106, a substrate support 114 that supports the substrate 104a in the chamber 106, a process kit 139, a gas energizer 116 that energizes the process gas, chamber enclosure walls 118 and shields 120, or a gas exhaust 122 that exhausts gas from the chamber 106. [0014] Referring to FIG. 2, which illustrates an exemplary version of a physical vapor deposition chamber 106, components 22 having the textured surface 20 can include a chamber enclosure wall 118, a chamber shield 120, a target 124, a target rim 125, a component of a process kit 139 such as at least one of a cover ring 126 and a deposition ring 128, a support ring 130, insulator ring 132, a coil 135, coil support 137, shutter disk 104b, clamp shield 141, and a portion of the substrate support 114. For example, components having the textured surface can include Applied Material's part numbers 0020-50007, 0020-50008, 0020-50010, 0020-50012, 0020-50013, 0020-48908, 0021-23852, 0020-48998, 0020-52149, 0020-51483, 0020-49977, 0020-52151, 0020-48999, 0020-48042 and 0190-14818, from Applied Materials, Santa Clara, Calif. This list of components is merely exemplary and the other components or components from other types of chambers can also have the textured surface, thus, the present invention should not be limited to the components listed or described herein. [0015] In one version, one or more process chamber components 22 comprise a surface that is textured by scanning an electromagnetic energy beam 40 such as an electron beam 40 across the surface 20, to form electron beam textured features 25 on the surface. An example of such a textured surface 20 is that formed by a Lavacoat.TM. process, as described for example in U.S. patent application Ser. No. 10/653,713 to West, et al, filed on Sep. 2, 2003, entitled "Fabricating and Cleaning Chamber Components Having Textured Surfaces," and aforementioned U.S. Patent Publication Nos. 2003/0173526 and 2004/0056211, all commonly assigned to Applied Materials, Inc., and all of which are incorporated herein by reference in their entireties. The electron beam textured features 25 of the Lavacoat.TM. process comprise a plurality of depressions 23 and protuberances 26 to which process deposits 24 generated during processing can adhere, as shown for example in FIG. 1a. [0016] The Lavacoat.TM. textured surface 20 can be formed by generating an electromagnetic energy beam 40, such as an electron beam 40, and directing the beam onto the surface 20 of the component 22. While the electromagnetic energy beam is preferably an electron beam, it can also comprise protons, neutrons and X-rays and the like. The beam 40 is typically focused on a region of the surface 20 for a period of time, during which time the beam 40 interacts with the surface 20 to form the textured features 25 on the surface 20. It is believed that the beam 40 forms the features 25 by rapidly heating the region of the surface 20, typically to a melting temperature of the surface material. At least a portion of the surface material may even be evaporated or ablated from the surface 20 by the rapid heating. The rapid heating causes some of the surface material to be ejected outwards, which forms depressions 23 in the regions the material was ejected from, and protuberances 26 in areas where the ejected material re-deposits. After the desired features in the region are formed, the beam 40 is scanned to a different region of the component surface 20 to form features in the new region. [0017] The electromagnetic energy beam 40 can be scanned across the surface 20 to form a desired pattern of textured features 25 on the surface 20, such as a honeycomb-like structure of depressions 23 and protuberances 26, as shown for example in FIG. 1a. The features 25 formed by this method are typically macroscopically sized. For example, the depressions 23 can have a depth d as measured from a base level 28 of the surface 20 of from about 20 micrometers to about 1600 micrometers. A surface diameter w of the depressions 23 may be from about 120 micrometers to about 2600 micrometers and even from about 200 micrometers to about 2300 micrometers. The protuberances 26 can comprise a height h above the base surface 28 of from about 50 micrometers to about 1600 micrometers, and even from about 100 micrometers to about 1200 micrometers. The Lavacoat.TM. textured surface 20 can have an overall surface roughness average of from about 60 micrometers to about 100 micrometers, the roughness average of the surface 20 being defined as the mean of the absolute values of the displacements from the mean line of the features along the surface 20. The textured surface 20 can also be further roughened after scanning with the electromagnetic energy beam 40 to provide different levels of texture on the surface 20, as described for example in the patent applications to Popiolkowski et al. and West et al. that are incorporated by reference above. For example, the surface 20 can be grit blasted by propelling grit particles towards the surface 20 with pressurized gas, or can be chemically roughened, to form a relatively fine texture overlying the macroscopically sized features 25 on the surface 20. The roughened surface 20 improves the adhesion of process deposits 24 to reduce contamination of the processed substrates 104a. [0018] In one version, the textured surface 20 can be formed on a metal coating 30 on the component 22, as shown for example in FIG. 1a. The metal coating 30 desirably comprises a material that is resistant to erosion by the energized gases provided to process a substrate 104a or clean the process chamber 106, and is also desirably resistant to erosion from cleaning solutions that may be used to clean the component 20, such as acidic or basic cleaning solutions. The metal coating 30 can be formed on a surface 33 of an underlying structure 32 of the component 30 to protect the underlying structure 32. For example, the underlying structure 32 may comprise a first material having desired properties, such as desired thermal and mechanical properties, and the metal coating 30 may comprise a second material having higher erosion resistance than the first material. The metal coating 30 may also comprise a material that can be treated to provide a desired texture of the metal coating surface, such as for example a desired roughness or textured pattern on the surface 20, that could not otherwise be desirably provided by the material of the underlying structure 32. For example, the material of the metal coating may be selected to allow for a finer or rougher texturing of the metal coating surface 20. A suitable material for the metal coating 30 can be selected with respect to the substrate processing requirements to provide the desired properties, and can comprise for example at least one of stainless steel, copper, nickel, tantalum and titanium. [0019] A material having suitable properties for the underlying structure 32 may be a metallic material, such as for example at least one of titanium, stainless steel; copper, tantalum and aluminum; and can also comprise a ceramic material, such as at least one of aluminum oxide, aluminum nitride, and quartz. The underlying structure is selected according to desired properties such as desired thermal and mechanical properties. For example, an underlying structure 32 comprising aluminum may be desirable because aluminum is typically a relatively cheap material having good thermal conductivity. An underlying structure 32 comprising stainless steel may provide good erosion resistance and thermal conductivity. An underlying structure 32 comprising titanium may provide a desired relatively low thermal coefficient of expansion. Also, an underlying structure 32 comprising copper may provide good thermal conductivity as well as a relatively low thermal coefficient of expansion. Underlying structures 32 comprising a ceramic material, such as aluminum oxide, may provide a desired level of thermal insulation and/or thermal conductivity, and a desired relatively low thermal coefficient of expansion. In one suitable embodiment, a metal coating 30 comprising stainless steel is formed over an underlying structure 32 comprising aluminum or titanium, such as a process kit or shield structure, to provide a component 22 having a textured surface 20 with improved erosion resistance while maintaining the desired overall mechanical and thermal properties of the component 22. In another suitable embodiment, a metal coating 30 comprising stainless steel is formed over an underlying structure 32 comprising aluminum oxide. [0020] In one version, the metal coating 30 can be providing by spraying a coating of material over the surface 33 of the underlying component structure 32. Suitable spraying methods can include thermal spraying methods, such as for example at least one of HVOF (high velocity oxygen fuel), flame spraying, plasma spraying, twin wire or single wire arc spraying, welding methods such as TIG, and other thermal spraying methods, which are capable of forming well-bonded coatings. In a typical thermal spraying method, the coating material in powder or wire form is heated to a molten or near-molten state, for example by a torch. A pressurized gas is used to propel the coating material onto the surface 33 of the underlying structure 32. For example, in the HVOF method, an HVOF spray gun ignites an oxygen-fuel mixture to heat and at least partially melt the coating material as it is propelled towards the structure surface 33. A HVOF spray gun that may be suitable for forming the metal coating 30 is the HVOF spray gun available from Sulzer Metco Holding AG in Winterthur, Switzerland. Alternatively, the metal coating 30 can be formed by other methods, such as by electroplating metal coating material on the underlying structure 32, or by a physical or chemical vapor deposition method. Continue reading about Erosion resistant textured chamber surface... Full patent description for Erosion resistant textured chamber surface Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Erosion resistant textured chamber surface patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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