Articles coated with fluorine annealed films

Abstract

The invention relates to an article coated with a fluorine annealed film. Articles and methods related to coatings having excellent chemical resistance and structural integrity can be prepared by atomic layer deposition and fluorine annealing at low processing temperatures between about 150 DEG C and less than 300 DEG C. The film comprises a fluorinated metal oxide comprising yttrium.

Description

[0001] This application is a divisional application of an invention patent application with an application date of January 15, 2018, application number 201880006748.9, and invention name “Product coated with fluorine annealed film”. Technical Field

[0002] The present invention generally relates to semiconductor manufacturing components including protective yttrium fluoride metal oxide films and methods of forming protective yttrium fluoride metal oxide films on surfaces of semiconductor manufacturing components. Background Art

[0003] Semiconductor manufacturing components need to have high purity, chemical resistance, and good temperature stability and structural integrity. Coatings can be applied to various components to extend the life of the components and improve purity and temperature stability. However, the coating itself requires high temperature treatment to deposit it. Despite chemical resistance, the coating can experience degradation during use or cleaning and periodic maintenance. Etching agent gases, cleaning solutions and thermal cycles can shorten the life of the coated components and can also cause contamination when the components are reinstalled in the manufacturing tool. There is a continuous need for improved coatings for semiconductor manufacturing components. Summary of the invention

[0004] The present invention generally relates to semiconductor manufacturing components including a protective yttrium fluoride metal oxide film and a method of forming a protective yttrium fluoride metal oxide film on a surface of a semiconductor manufacturing component by first depositing a yttrium-containing metal oxide film on the surface of the component via atomic layer deposition (ALD), and then fluorine annealing the yttrium-containing ALD metal oxide film at a low processing temperature to form a protective yttrium fluoride metal oxide film on the surface of the semiconductor manufacturing component.

[0005] According to various embodiments, an article includes a substrate and a protective film covering at least a portion of the substrate. The article may be a component in a semiconductor manufacturing system, such as a chamber, a chamber component, a wafer pedestal, a chuck, a showerhead, a liner, a ring, a nozzle, a baffle, a fastener, or a wafer transfer component, and may be formed of quartz, alumina, aluminum, steel, a metal, a metal alloy, a ceramic, or a plastic suitable for semiconductor manufacturing. In one embodiment, the article may be a reactive ion etching chamber.

[0006] The protective film may be a yttrium metal oxide fluoride film having a thickness between 0.01 micrometers and less than 1 micrometer. The protective film may be fully fluorinated or partially fluorinated. In some embodiments, the film may be yttrium oxyfluoride or yttrium aluminum oxyfluoride.

[0007] In some embodiments, the film may be a gradient film, wherein the fluorine content of the film decreases over the thickness of the film so that an outer portion of the protective film has a higher fluorine content than an inner portion of the film that is in direct contact with the substrate. For example, in some embodiments, the film may have an outer portion that is yttrium oxyfluoride and an inner portion that is yttrium oxide, with the fluorine content gradually decreasing from the outer portion to the inner portion. In other embodiments, the film may have an outer portion that is fluorinated yttrium aluminum oxide (i.e., yttrium aluminum oxyfluoride) and an inner portion that is (unfluorinated) yttrium aluminum oxide.

[0008] In another embodiment, a method includes depositing a yttrium-containing metal oxide onto a surface of a substrate by atomic layer deposition to provide a yttrium-containing ALD metal oxide film, and fluorine annealing the yttrium-containing ALD metal oxide film to form a yttrium-containing fluorinated metal oxide film.

[0009] The fluorine annealing may be performed at a temperature of about 150° C. to less than about 300° C., and more particularly at a temperature of about 200° C. to 250° C. The fluorination process may be fluorine ion implantation followed by annealing, fluorine plasma treatment, fluoropolymer combustion, fluorine gas reaction at high temperature, UV treatment with fluorine gas, or any combination thereof.

[0010] The foregoing summary is provided to aid in understanding some of the innovative features characteristic of the present invention, but is not intended to be a complete description. A comprehensive understanding of the present invention can be obtained by taking the entire specification, claims, drawings and abstract as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention may be more fully understood from the following description of various illustrative embodiments considered in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is an x-ray diffraction (XRD) pattern of an atomic layer deposition (ALD) yttrium oxide film before undergoing fluorine annealing according to one embodiment of the present invention; and

[0013] Figure 2 FIG. 1 is an x-ray diffraction (XRD) pattern of an atomic layer deposition (ALD) yttrium oxide film after fluorine annealing at a relatively low processing temperature according to one embodiment of the present invention.

[0014] Although the present invention allows various modifications and alternative forms, its particularity has been shown in the drawings by way of example and will be described in detail. However, it should be understood that it is not intended to limit the aspects of the present invention to the specific illustrative embodiments described. On the contrary, it is intended to cover all modifications, equivalents and alternatives within the spirit and scope of the present invention. DETAILED DESCRIPTION

[0015] It must also be noted that, as used herein and in the appended claims, the singular forms "a / an" and "the" include multiple references unless the context clearly indicates otherwise. Thus, for example, a reference to "film" is a reference to one or more films and equivalents thereof known to those skilled in the art, and so on. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those of ordinary skill in the art. Methods and materials similar to or equivalent to the methods and materials described herein can be used to practice or test variations of the present invention. All disclosures mentioned herein are incorporated herein by reference in their entirety. Nothing herein should be construed as an admission that the present invention is not entitled to such disclosures prior to prior inventions. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, and the description includes situations where the event occurs as well as situations where the event does not occur. Regardless of whether it is clearly indicated, all numerical values ​​herein may be modified by the term "about". The term "about" generally refers to a numerical range that a person skilled in the art would consider equivalent to the stated value (i.e., having the same function or result). In some variations, the term "about" refers to ±10% of the stated value, and in other variations, the term "about" refers to ±2% of the stated value. Although compositions and methods are described in terms of "comprising" various components or steps (interpreted to mean "including but not limited to"), compositions and methods may also "consist essentially of" or "consist of" the various components and steps, and such terms should be interpreted as defining substantially closed groups of members.

[0016] According to various embodiments, an article, such as a component in a semiconductor manufacturing system, includes a substrate having a protective film covering at least a portion of the substrate. The substrate may be a component in a semiconductor manufacturing system, such as a chamber, a chamber component, a wafer pedestal, a chuck, a showerhead, a liner, a ring, a nozzle, a baffle, a fastener, or a wafer transfer component, and may be formed of quartz, alumina, aluminum, steel, a metal, a metal alloy, a ceramic, or a plastic suitable for semiconductor manufacturing. In one embodiment, the article may be a reactive ion etching (RIE) chamber. In other embodiments, the substrate may be a vacuum compatible substrate. In many cases, the protective film may be a fluorinated metal oxide film containing yttrium, such as an yttrium oxyfluoride film, a fluorinated yttrium aluminum oxide film, or an aluminum oxyfluoride film. These are just some examples. The protective film may be fully fluorinated or partially fluorinated.

[0017] According to various embodiments, a protective film is formed on the surface of a component by first depositing a yttrium-containing metal oxide film on the surface of the component via atomic layer deposition (ALD), and then fluorine annealing the yttrium-containing ALD metal oxide film at a low process temperature to form a protective yttrium fluoride-containing metal oxide film on the surface of a semiconductor component (e.g., a RIE component).

[0018] Fluorine annealed yttrium-containing metal oxide films offer several advantages and have several desirable features, including high fluorine plasma etch resistance (e.g., about 0.1 to about 0.2 microns / hour), high wet chemical etch resistance (e.g., about 5 to about 120 minutes in 5% HCl), good adhesion to chamber components (e.g., about 5N to about 15N second critical load (LC2) adhesion), and conformal coating capability. In addition, fluorine annealed yttrium-containing metal oxide films are tunable in terms of materials, mechanical properties, and microstructure. For example, the etch resistance of fluorinated yttrium oxide increases with the fluorine content in the film. Fluorine annealed yttrium-containing metal oxide films also provide the additional advantages of excellent crack resistance and improved integrity at high temperatures relative to non-fluorinated yttrium oxide films.

[0019] Fluorine annealed yttrium-containing metal oxide films formed by atomic layer deposition (ALD) provide the additional advantage of crack resistance after thermal cycling at high temperatures, as well as the ability to be prepared at lower processing temperatures compared to fluorine annealed films made from yttrium-containing metal oxide films deposited by PVD. The ability to process yttrium-containing metal oxide films at low processing temperatures prevents cracking by reducing the thermal stresses formed between the film and the substrate. The lower processing temperature increases the range of substrate materials on which yttrium-containing metal oxide films can be deposited and subsequently fluorinated by fluorine annealing, as some substrate materials may be incompatible at higher temperatures. In addition, atomic layer deposited fluorine annealed yttrium-containing metal oxide films can be extremely thin, highly dense and highly conformal films that are substantially free of pinholes.

[0020] According to various embodiments of the present invention, a film of a metal oxide containing yttrium (such as yttrium oxide and yttrium aluminum oxide) is first deposited onto a substrate. The deposition of the metal oxide film can be performed by atomic layer deposition (ALD) or plasma assisted ALD. The metal oxide coating containing yttrium can be prepared with a substrate maintained at a temperature between 100°C and 350°C and in some cases maintained at a temperature between 140°C and 200°C, which is beneficial for temperature sensitive substrates. The thickness of the metal oxide containing yttrium (e.g., yttrium oxide coating) can be in the following ranges: about 0.001 micrometer (1nm) to less than 1 micrometer; about 0.01 micrometer (10nm) to less than 1 micrometer; about 0.01 micrometer (10nm) to about 0.7 micrometer; about 0.01 micrometer (10nm) to about 0.5 micrometer; and in some cases, about 0.01 micrometer (10nm) to 0.25 micrometer (250nm).

[0021] After deposition, the film of the metal oxide containing yttrium is subjected to a fluorine anneal in a fluorine-containing environment at a temperature in the range of about 150°C to less than about 300°C. In some cases, the film of the metal oxide containing yttrium is subjected to a fluorine anneal in a fluorine-containing environment at a temperature in the following ranges: about 150°C to less than about 300°C; about 200°C to less than about 300°C; about 200°C to about 275°C; and more specifically, about 200°C to about 250°C. The heating ramp rate of the fluorine annealing process can be between 50°C per hour and 200°C per hour. In some variations, the fluorine annealing process includes introducing fluorine into the metal oxide containing yttrium by annealing the film at between 200°C and up to but less than 300°C in a fluorine-containing atmosphere. The fluorination process can be performed by several methods, including, for example, fluorine ion implantation followed by annealing, fluorine plasma treatment below 300°C, fluoropolymer combustion methods, fluorine gas reaction at high temperature, and UV treatment with fluorine gas, or any combination of the foregoing.

[0022] Depending on the fluorine annealing method employed, a variety of fluorine sources can be used. For the fluoropolymer combustion method, a fluoropolymer material is required and can be, for example, polyvinylfluoride (PVF), polyvinylidenefluoride (PVDF), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), PFA, perfluoroalkoxy polymer (MFA), fluorinated ethylene-propylene (FEP), polyethylenetetrafluoroethylene (ETFE), polyethylenechlorotrifluoroethylene (ECTFE), perfluorinated elastomer [perfluoroelastomer] (FFPM / FFKM), fluorocarbon [chlorotrifluoroethylenevinylidene fluoride] (FPM / FKM), perfluoropolyether (PFPE), perfluorosulfonic acid (PFPE), and the like. acid, PFSA) and perfluoropolyoxetane.

[0023] For other fluorine annealing methods, including fluorine ion implantation followed by annealing, fluorine plasma treatment below 300°C, fluorine gas reaction at high temperature, and UV treatment with fluorine gas, the reaction requires fluorinated gas and oxygen. The fluorinated gas can be, for example, hydrofluorocarbon (HFC), perfluorocarbon (PFC), sulfur hexafluoride (SF6), HF vapor, NF3, and gases from the combustion of fluoropolymers.

[0024] The structure of the yttrium oxide or yttrium aluminum oxide film is preferably columnar so that the structure allows fluorine to penetrate the film through the grain boundaries during the fluorine annealing process. An amorphous yttrium oxide structure (ie, non-columnar or less columnar) does not allow fluorine to penetrate as easily during the fluorine annealing process.

[0025] The fluorine annealed film is tunable, wherein the fluorine annealing process allows the depth and density of fluorination of the film to be varied. In one variation of the invention, the fluorine annealed film is fully fluorinated (fully saturated), wherein the fluorine is localized throughout the depth of the film. In another variation of the invention, the fluorine annealed film is partially fluorinated, wherein the fluorine is localized along the outer portion of the film rather than throughout the entire depth of the film. Additionally, the film may be a gradient film, wherein the fluorine content varies over the depth of the film. For example, the top (outermost) portion of the film may include the highest fluorine content, wherein the fluorine content gradually decreases over the depth of the film toward the bottom (innermost) portion of the film that is closest to the film and interfaces with the substrate. The outermost portion of the film is divided into a portion that faces the etching environment.

[0026] The film provides a protective layer covering the substrate, which is the outermost layer of the coated article that is in contact with the environment inside the semiconductor component, such as the environment inside a vacuum chamber.

[0027] Example 1

[0028] Fluorination of Yttrium Oxide by Atomic Layer Deposition Vapor Deposition

[0029] During ALD deposition, ALD yttrium oxide films were prepared on aluminum substrate coupons maintained at a temperature between 140° C. and 200° C. The thickness of the yttrium oxide films on the various coupons varied from 0.01 micrometers to less than 1 micrometer. Figure 1 Shown is the x-ray diffraction (XRD) pattern of yttrium oxide thin film before fluorine annealing (ALD).

[0030] The coupons with the ALD yttrium oxide film were then fluorinated by fluorine annealing the coupons in a boiler containing a fluorine source. The samples were cycled five times in air in a boiler with a fluorine source. Each cycle included a ramp at 100°C / hour, a soak at 250°C for 1 hour, a ramp down at 100°C / hour, and a soak at 100°C for 10 minutes before the next ramp up to 250°C.

[0031] Fluorinated ALD yttrium oxide films have excellent crack resistance. Thermal cycling between room temperature and 250°C of a control coupon of yttrium oxide grown on aluminum without fluorination treatment had the yttrium oxide film crack, while the fluorinated ALD yttrium oxide film prepared as above did not crack under the same thermal cycling. Figure 2 An x-ray diffraction pattern of an atomic layer deposited (ALD) yttrium oxide film after fluorine annealing is shown. The XRD film of the fluorine annealed ALD film shows that the yttrium oxide film becomes a gradient film with an outer portion that is fluorinated yttrium aluminum oxide (i.e., yttrium aluminum fluoride) and an inner portion that is (unfluorinated) yttrium aluminum oxide.

[0032] The results of this example show that crack resistant films containing yttrium and oxygen formed by an ALD process can be fluorinated at lower temperatures between 150° C. and below 300° C., compared to higher temperatures such as 300° C. to 650° C. for CVD or PVD deposited yttrium and oxygen-containing films. Lower ALD deposition temperatures and lower fluorine annealing temperatures are beneficial for coating temperature sensitive substrates, such as polymers and substrates with large CTE (coefficient of thermal expansion) mismatches with the film.

[0033] Having thus described several illustrative embodiments of the invention, one skilled in the art will readily appreciate that other embodiments may be made and used within the scope of the appended claims. The foregoing description has set forth many of the advantages of the invention covered by this document. However, it should be understood that the invention is in many respects merely illustrative. Changes may be made in the details, particularly in the shape, size and arrangement of the parts, without exceeding the scope of the invention. Of course, the scope of the invention is defined in the language in which the appended claims are expressed.

Claims

1. A method for forming a protective film, the method comprising: depositing an atomic layer of a metal oxide containing yttrium onto a surface of a semiconductor manufacturing component, the metal oxide forming a metal oxide-containing coating overlying the substrate having a thickness between 0.01 micrometers and 0.7 micrometers; and performing fluorine annealing on the metal oxide-containing coating in a fluorine-containing atmosphere while maintaining the temperature of the substrate between 150° C. and below 275° C., while performing the fluorine annealing to form a protective film from the metal oxide-containing coating, wherein the protective film is a gradient film having a fluorine content that decreases over the thickness of the protective film from an outer portion of the protective film to an inner portion of the protective film adjacent to the surface, and wherein the protective film does not contain pinholes.

2. The method of claim 1, wherein the fluorine annealing is performed on the substrate, the substrate being maintained at a temperature between 200°C and 250°C in a fluorine-containing atmosphere. The method according to claim 1 , wherein the protective film is fully fluorinated or partially fluorinated. The method according to claim 1 , wherein the inner portion of the protective film directly contacts the substrate.

5. The method of claim 1, wherein the fluorine annealing is performed while maintaining the temperature of the substrate between 150°C and 250°C.

6. A product made by the method according to any one of claims 1 to 5.

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