High entropy rare earth ceramics

Abstract

New high entropy ceramics comprising rare earth oxides are disclosed. The new high entropy ceramic materials generally contain from five to ten different rare earth oxides with each of the rare earth oxides comprising a different rare earth element. The new ceramic materials may be substantially single-phase, polycrystalline materials. The new ceramic materials may realize improved properties, such as plasma etch resistance, among others.

Description

Attorney Docket No.: 195190.020060 / WO HIGH ENTROPY RARE EARTH CERAMICS CROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 560,059, entitled “High Entropy Rare Earth Ceramics,” filed on March 1, 2024, which application is incorporated herein by reference in its entirety. BACKGROUND

[0002] Ceramic materials are used in a variety of industries, including the semiconductor industry. Ceramic materials should be plasma etch resistant when used in plasma etch environments. SUMMARY OF THE DISCLOSURE

[0003] Broadly, the present patent application relates to new high entropy ceramics comprising rare earth oxides. The new high entropy ceramic materials generally contain from five to ten different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. The new ceramic materials may be substantially single-phase, polycrystalline materials. The new ceramic materials may be resistant to erosion by halogen plasmas. The new ceramic materials may be in the form of a monolithic (bulk) material, such as in the form of a shaped body. The shaped body may be suited for use in, for instance, a semiconductor processing apparatus, such as in a plasma processing chamber. In other embodiments, the new ceramic materials may be in the form of a coating. Additional details are provided below. i. Compositions

[0004] As noted above, the new high entropy ceramics generally contain from five to ten different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. Generally, a ceramic material includes at least 5 mol. % of each rare earth oxide. The balance of the ceramic material is generally limited to tolerable or unavoidable impurities that do not materially alter the material characteristics of the ceramic material. Due to the use of from five to ten different rare earth oxides, a high entropy of mixing may be achieved, which may facilitate, for instance, improved ceramic stability.

[0005] In one embodiment, a new ceramic material includes from five to nine different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. In another embodiment, a new ceramic material includes from five to eight different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. In yetAttorney Docket No.: 195190.020060 / WO another embodiment, a new ceramic material includes from five to seven different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. In another embodiment, a new ceramic material includes five or six different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element. In yet another embodiment, a new ceramic material include five different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element.

[0006] In one embodiment, a new ceramic material consist essentially of five different rare earth oxides. In another embodiment, a new ceramic material consist essentially of six different rare earth oxides. In yet another embodiment, a new ceramic material consist essentially of seven different rare earth oxides. In another embodiment, a new ceramic material consist essentially of eight different rare earth oxides. In yet another embodiment, a new ceramic material consist essentially of nine different rare earth oxides. In another embodiment, a new ceramic material consist essentially of ten different rare earth oxides.

[0007] As used herein, the term “rare earth elements” or “REE” includes the elements of yttrium, zirconium, and the Lanthanide series of elements, i.e., elements 57-71 of the periodic table. In one embodiment, the rare earth elements are selected from the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In another embodiment, the rare earth elements are selected from the group consisting of yttrium, zirconium, cerium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In yet another embodiment, the rare earth elements are selected from the group consisting of samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In another embodiment, the rare earth elements are selected from the group consisting of yttrium, cerium, samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, and lutetium. In yet another embodiment, the rare earth elements are selected from the group consisting of samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, and lutetium. In another embodiment, the rare earth elements are selected from the group consisting of gadolinium, dysprosium, holmium, erbium, and ytterbium.

[0008] As noted above, a ceramic material generally includes at least 5 mol. % of each of the rare earth oxides (e.g., from 5-80 mol. % of each of the rare earth oxides). In one embodiment, a ceramic material comprises 8-68 mol. % of each of the rare earth oxides. In another embodiment, a ceramic material comprises 10-60 mol. % of each of the rare earthAttorney Docket No.: 195190.020060 / WO oxides. In yet another embodiment, a ceramic material comprises 12-52 mol. % of each of the rare earth oxides. In another embodiment, a ceramic material comprises 15-40 mol. % of each of the rare earth oxides. In yet another embodiment, a ceramic material comprises 15-35 mol. % of each of the rare earth oxides. In another embodiment, a ceramic material comprises 15- 30 mol. % of each of the rare earth oxides. In yet another embodiment, a ceramic material comprises 15-25 mol. % of each of the rare earth oxides.

[0009] In one embodiment, a ceramic material comprises substantially equimolar amounts of the rare earth oxides, wherein each rare earth oxide is within 5 mol. % of every other rare earth oxide of the ceramic material. In another embodiment, a ceramic material comprises equimolar amounts of the rare earth oxides, wherein each rare earth oxide is within 1 mol. % of every other rare earth oxide of the ceramic material.

[0010] In one approach, a ceramic material comprises an amount of rare earth oxides that results in a low ionic radius. In one embodiment, an average ionic radius of the rare earth oxides of the ceramic material is not greater than 106.5 picometers. A low ionic radius may lead to improved properties, such as improved plasma etch resistance properties.

[0011] As an example, a ceramic material having 20 mol. % each of the sesquioxides of ytterbium, erbium, holmium, dysprosium, and gadolinium, realizes an average ionic radius of 101.7 picometers (the average of 105.3, 102.7, 101.5, 100.4, and 98.5 is 101.7 picometers). Table 1, below, provides various properties of rare earth oxides. Table 1 – Rare Earth Oxide PropertiesAttorney Docket No.: 195190.020060 / WO

[0012] In one embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 106.0 picometers. In another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 105.5 picometers. In yet another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 105.0 picometers. In another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 104.5 picometers. In yet another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 104.0 picometers. In another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 103.5 picometers. In yet another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 103.0 picometers. In another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 102.5 picometers. In yet another embodiment, an average ionic radius of the rare earth oxides of a ceramic material is not greater than 102.0 picometers.

[0013] In one approach, a ceramic material comprises an amount of rare earth oxides having a substantially similar ionic radius. In one embodiment, a standard deviation of the ionic radii of the ceramic material is not greater than 6.0 picometers. A small standard deviation among the ionic radii of the rare earth oxides may lead to improved properties, such as improved plasma etch resistance properties. As an example, a ceramic material having 20 mol. % each of the sesquioxides of ytterbium, erbium, holmium, dysprosium, and gadolinium, realizes an average ionic radius of 101.7 picometers with a standard deviation of 2.3 picometers. Standard deviation is calculated using the formula:where x is the sample mean average (number 1, number 2, …) and n is the sample size.

[0014] In one embodiment, a standard deviation of an average ionic radius is not greater than 5.75 picometers. In another embodiment, a standard deviation of an average ionic radius is not greater than 5.50 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 5.25 picometers. In another embodiment, a standard deviation of an average ionic radius is not greater than 5.0 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 4.75 picometers.Attorney Docket No.: 195190.020060 / WO In another embodiment, a standard deviation of an average ionic radius is not greater than 4.50 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 4.25 picometers. In another embodiment, a standard deviation of an average ionic radius is not greater than 4.0 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 3.75 picometers. In another embodiment, a standard deviation of an average ionic radius is not greater than 3.50 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 3.25 picometers. In another embodiment, a standard deviation of an average ionic radius is not greater than 3.0 picometers. In yet another embodiment, a standard deviation of an average ionic radius is not greater than 2.75 picometers.

[0015] In one approach, a ceramic material may comprise one or more rare earth oxides that are sesquioxides having the formula REE2O3(e.g., Y2O3). In one embodiment, at least two of the rare earth oxides are sesquioxides. In another embodiment, at least three of the rare earth oxides are sesquioxides. In yet another embodiment, at least four of the rare earth oxides are sesquioxides. In another embodiment, at least five of the rare earth oxides are sesquioxides.

[0016] In one approach, a ceramic material may comprise one or more rare earth oxides having a cubic crystalline structure. In one embodiment, at least two of the rare earth oxides have a cubic crystalline structure. In another embodiment, at least three of the rare earth oxides have a cubic crystalline structure. In yet another embodiment, at least four of the rare earth oxides have a cubic crystalline structure. In another embodiment, at least five of the rare earth oxides have a cubic crystalline structure.

[0017] In one approach, a ceramic material may comprise a high amount of heavier rare earth oxides. A high amount of heavy rare earth elements may facilitate improved properties, as shown herein. In one embodiment, at least two of the rare earth elements comprise an atomic mass of from 150 to 175 grams / mol. In another embodiment, at least three of the rare earth elements comprises an atomic mass of from 150 to 175 grams / mol. In yet another embodiment, at least four of the rare earth elements comprises an atomic mass of an atomic mass of from 150 to 175 grams / mol. In another embodiment, at least five of the rare earth elements comprises an atomic mass of an atomic mass of from 150 to 175 grams / mol.

[0018] In one embodiment, a ceramic material comprises at least one of: a ytterbium oxide, an erbium oxide, a holmium oxide, a dysprosium oxide, and a gadolinium oxide. In another embodiment, a ceramic material comprises at least two of: a ytterbium oxide, an erbium oxide, a holmium oxide, a dysprosium oxide, and a gadolinium oxide. In yet another embodiment, aAttorney Docket No.: 195190.020060 / WO ceramic material comprises at least three of: a ytterbium oxide, an erbium oxide, a holmium oxide, a dysprosium oxide, and a gadolinium oxide. In another embodiment, a ceramic material comprises at least four of: a ytterbium oxide, an erbium oxide, a holmium oxide, a dysprosium oxide, and a gadolinium oxide. In another embodiment, a ceramic material comprises all of: a ytterbium oxide, an erbium oxide, a holmium oxide, a dysprosium oxide, and a gadolinium oxide.

[0019] In one embodiment, a ceramic material excludes one or more of yttrium oxide, zirconium oxide and cerium oxide, except as impurities. In one embodiment, a ceramic material excludes two or more of yttrium oxide, zirconium oxide and cerium oxide, except as impurities. In one embodiment, a ceramic material excludes all of yttrium oxide, zirconium oxide and cerium oxide, except as impurities. ii. Microstructure

[0020] As noted above, the new ceramic materials may be substantially single-phase, polycrystalline materials. However, multi-phase materials may also find benefit in some applications.

[0021] As used herein, “substantially single-phase polycrystalline materials” means polycrystalline materials having at least 95 wt. % of a solid solution of the rare earth oxides as determined using x-ray diffraction (XRD). In one embodiment, a substantially single-phase polycrystalline material includes at least 96 wt. % of rare earth oxides in solid solution. In another embodiment, a substantially single-phase polycrystalline material includes at least 97 wt. % of rare earth oxides in solid solution. In yet another embodiment, a substantially single- phase polycrystalline material includes at least 98 wt. % of rare earth oxides in solid solution. In another embodiment, a substantially single-phase polycrystalline material includes at least 98.5 wt. % of rare earth oxides in solid solution. In yet another embodiment, a substantially single-phase polycrystalline material includes at least 99.0 wt. % of rare earth oxides in solid solution. In another embodiment, a substantially single-phase polycrystalline material includes at least 99.5 wt. % of rare earth oxides in solid solution. In yet another embodiment, a substantially single-phase polycrystalline material includes at least 99.9 wt. % of rare earth oxides in solid solution. As may be appreciated, because XRD is used to quantify the amount of rare earth oxides in solid solution, a material may include very small amounts of other phase(s), but those phases may not be detected by XRD. Thus, in some instances, the substantially single-phase polycrystalline material may be considered a 100% solid solution of rare earth oxides, even though some other phases may be present in undetectable quantities.Attorney Docket No.: 195190.020060 / WO iii. Methods of Manufacture

[0022] The new ceramic materials may be produced in a variety of manners, including via various powder processing and sintering techniques. In one embodiment, and referring now to FIG. 1, a method (10) comprises producing a green body (100) and then sintering the green body (200) at a sintering temperature, thereby forming a sintered body. In one embodiment, a method comprises blending from five to ten different rare earth oxides to produce a powder blend and creating a green body from the powder blend, wherein the green body contains at least 5 mol. % of each of the rare earth oxides. The green body may include any amount of rare earth oxides as per Section i, above. The green body may be produced from the powder by, for instance, pressing, extrusion, injection molding, tape casting, roll compaction, gel casting and the like.

[0023] As it relates to the sintering step (200), the sintering may be conducted in any suitable fashion. In one embodiment, the sintering comprises pressureless (ambient pressure) sintering. In another embodiment, the sintering comprises applying pressure during sintering (e.g., hot press sintering; hot isostatic press sintering). In another embodiment, the sintering comprises spark plasma sintering (SPS). The sintering atmosphere may be any suitable gaseous environment. In one embodiment, the sintering comprises sintering in air. In another embodiment, the sintering comprises sintering in a non-oxygen atmosphere (e.g., a hydrogen atmosphere). In another embodiment, the sintering comprises sintering in an inert atmosphere (e.g., an argon atmosphere). The sintering temperature may be, for instance, one or more temperatures within the range of from 1200ºC to 1900°C. In one embodiment, a sintering temperature is not greater than 1850ºC. In another embodiment, a sintering temperature is not greater than 1800ºC. In yet another embodiment, a sintering temperature is not greater than 1750ºC. In another embodiment, a sintering temperature is not greater than 1700ºC. In yet another embodiment, a sintering temperature is not greater than 1650ºC. In another embodiment, a sintering temperature is not greater than 1600ºC.

[0024] In another approach, coatings are produced from a precursor material having from five to ten different rare earth oxides, wherein the coating contains at least 5 mol. % of each of the rare earth oxides. Coatings may be produced by, for instance, thermal or plasma spray techniques. The coating may include any amount of rare earth oxides as per Section i, above. The coatings may be applied to, for instance, a base material, as described herein. iv. PropertiesAttorney Docket No.: 195190.020060 / WO

[0025] As noted above, the new ceramic materials may realize improved properties, such as improved plasma etch resistance properties (e.g., halogen plasma etch resistance). In one approach, a new ceramic material realizes at least equivalent plasma etch resistance as compared to a baseline material, wherein the baseline material is a single-phase polycrystalline material comprising at least 99 mol. % yttria. Plasma etch resistance should be measured in the presence of CF4gas at a flow rate of 50 SCCM under a pressure of 5 Pa (Pascals) at 135 Watts and 13.56 MHz RF power, with a 10W bias. In one embodiment, a new ceramic material realizes at least a 5% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 6% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 7% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 8% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 9% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 10% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 12% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 14% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 16% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 18% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 20% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 22% lower etch rate as compared to the baseline material. In yet another embodiment, a new ceramic material realizes at least a 24% lower etch rate as compared to the baseline material. In another embodiment, a new ceramic material realizes at least a 26% lower etch rate as compared to the baseline material.

[0026] In one approach a new ceramic material realizes a plasma etch rate of not greater than 10.5 nanometers per hour. In one embodiment, a new ceramic material realizes a plasma etch rate of not greater than 10.0 nanometers per hour. In another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 9.8 nanometers per hour. In yet another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 9.6 nanometers per hour. In another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 9.4 nanometers per hour. In yet another embodiment, a new ceramicAttorney Docket No.: 195190.020060 / WO material realizes a plasma etch rate of not greater than 9.2 nanometers per hour. In another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 9.0 nanometers per hour. In yet another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 8.8 nanometers per hour. In another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 8.6 nanometers per hour. In yet another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 8.4 nanometers per hour. In another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 8.2 nanometers per hour. In yet another embodiment, a new ceramic material realizes a plasma etch rate of not greater than 8.0 nanometers per hour.

[0027] The new ceramic materials may realize a high relative density. In one embodiment, a new ceramic material realizes a density of at least 95% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 96% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 96.5% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 97% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 97.5% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 98% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 98.2% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 98.4% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 98.6% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 98.7% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 98.8% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 98.9% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 99.0% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 99.1% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 99.2% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 99.3% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 99.4% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 99.5% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 99.6% of its theoretical density. In another embodiment, a new ceramic material realizes a density ofAttorney Docket No.: 195190.020060 / WO at least 99.7% of its theoretical density. In yet another embodiment, a new ceramic material realizes a density of at least 99.8% of its theoretical density. In another embodiment, a new ceramic material realizes a density of at least 99.9% of its theoretical density. v. Product Form and Applications

[0028] The new ceramic materials having from five to ten different rare earth oxides may take on a variety of product forms and may be used in a variety of industrial applications. In one embodiment, a new ceramic material is a bulk (monolithic) ceramic material (e.g., a bulk, polycrystalline, substantially single-phase material; a bulk, polycrystalline, multi-phase material). In one embodiment, a bulk ceramic material is in the form of a shaped body of a specified geometry (e.g., a regular or irregular geometry). In one embodiment, the shaped body is suited for use in the processing of semiconductors, such as in a semiconductor processing machine fabrication tool. In one embodiment, the shaped body is configured for use in a plasma environment. In one embodiment, the shaped body is a plasma processing chamber component. In one embodiment, the shaped body is in the form of a nozzle blank or a nozzle. In one embodiment, the shaped body is a plasma processing chamber lid. In one embodiment, the shaped body is a plasma processing chamber gas distribution component (e.g., a gas distribution plate). In one embodiment, the shaped body is an electrostatic chuck component.

[0029] In another embodiment, a new ceramic material having from five to ten different rare earth oxides is in the form of a coating. The new coatings made be used in similar product applications as the bulk (monolithic) ceramic materials. For instance, the coatings may be used in a plasma environment, such as on components requiring plasma etch resistance. In one approach, a coating comprises a thickness of from 20 to 1000 micrometers. In one embodiment, a coating comprises a thickness of at least 30 micrometers. In another embodiment, a coating comprises a thickness of at least 40 micrometers. In yet another embodiment, a coating comprises a thickness of at least 50 micrometers. In another embodiment, a coating comprises a thickness of at least 60 micrometers. In yet another embodiment, a coating comprises a thickness of at least 70 micrometers. In another embodiment, a coating comprises a thickness of at least 80 micrometers. In yet another embodiment, a coating comprises a thickness of at least 90 micrometers. In another embodiment, a coating comprises a thickness of at least 100 micrometers.

[0030] In one embodiment, a product comprises a base and a coating at least partially disposed on the base. The base may be any suitable material, for instance, a metal or ceramic material. In one embodiment, the base is in the form of a substrate. The coating may compriseAttorney Docket No.: 195190.020060 / WO the new ceramic material having from five to ten different rare earth oxides, wherein each of the rare earth oxides contains a different rare earth element, wherein the ceramic material comprises 5-80 mol. % of each of the rare earth oxides, such as any of the coatings described previously. In one embodiment, the base is non-porous. In another embodiment, the base comprises porosity. In one embodiment, the base comprises a porous material and at least some of the coating is disposed in pores of the base material. In one embodiment, the base comprises or is a ceramic. In one embodiment, the base comprises alumina or is an alumina base. In one embodiment, the base comprises or is a metal. In one embodiment, the base comprises or is an aluminum base or an aluminum alloy base. In one embodiment, the base comprises or is an anodized aluminum base or an anodized aluminum alloy. In one embodiment, the base is thermally stable, wherein the portion of the base in contact with the coating comprises materially the same microstructure at 25ºC and 300ºC. vi. Material Characterization

[0031] The below standards should be used to determine material properties of the single- phase crystalline materials described herein.

[0032] As noted above, x-ray diffraction (XRD) may be used to determine the amount of crystalline phases of the polycrystalline materials described herein. The XRD instrument should be a Bruker D8 Discover (Bruker Corp., 40 Manning Rd, Billerica, MA 01821) or comparable XRD instrument. The XRD radiation should be copper K-alpha radiation. The power should be 1.6 kW. The scan range should be 20º to 70º (2 theta) (d = 4.5A to 1.35A). Table 2, below, provides the primary and secondary peaks of some pertinent crystalline phases for material characterization purposes. Table 2 – Primary and Secondary XRD peaks for Rare Earth OxidesAttorney Docket No.: 195190.020060 / WO

[0033] Plasma etch resistance should be measured in the presence of CF4gas at a flow rate of 50 SCCM under a pressure of 5 Pa (Pascals) at 135 Watts and 13.56 MHz RF power, with a 10W bias. vii. Miscellaneous

[0034] These and other aspects, advantages, and novel features of this new technology are set forth in part in the descriptions and figures herein and will become apparent to those skilled in the art upon examination of the descriptions and figures herein, or may be learned by practicing one or more embodiments of the technology provided for by the present disclosure.

[0035] Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the descriptions and figures herein. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.

[0036] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases “in one embodiment” and “in some embodiments” as used herein do not necessarily refer to the same embodiment(s), though they may. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although they may. Thus, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0037] In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and / or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references, unless the context clearly dictates otherwise. The meaning of “in” includes “in” and “on”, unless the context clearly dictates otherwise.

[0038] While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that manyAttorney Docket No.: 195190.020060 / WO modifications may become apparent to those of ordinary skill in the art. Further still, unless the context clearly requires otherwise, the various steps may be carried out in any desired order, and any applicable steps may be added and / or eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 illustrates a method for creating sintered products in accordance with the present disclosure.

[0040] FIG. 2 illustrates plasma etch rate results as a function of atomic weight and ionic radius for the Example 3 materials. DETAILED DESCRIPTION

[0041] Example 1 – Production of baseline yttria materials

[0042] A yttria compact was produced by calcining a conventional yttria powder followed by rinsing the powder in methanol, ball milling, drying, screening, and pressing into the final green body (compact) form. The pressed compact was then sintered at a temperature of about 1650°C for about 6 hours. The sintered compact realized a single-phase crystalline structure consisting essentially of yttria. The plasma etch resistance of the sintered yttria product was measured in the presence of CF4gas at a flow rate of 50 SCCM under a pressure of 5 Pa (Pascals) at 135 Watts and 13.56 MHz RF power, with a 10W bias. The average etch rate across triplicate specimens was 10.7 nanometers per hour (nm / hr.), which etch rate is used as a baseline etch rate for comparison to the new materials described below.

[0043] Example 2 – Production of binary materials

[0044] Sintered compacts of materials having two different oxides at the molar ratios specified in Table 3, below, were prepared using generally the same process described in Example 1. X-ray diffraction analyses revealed samples B1 and B3 had a single-phase polycrystalline microstructure while samples B2 and B4 had a multiple phase polycrystalline microstructure. The plasma etch rates of three of the sintered products (B1-B2, B4) were tested as per Example 1, the results of which are also shown in Table 3 (average of at least duplicate specimens). Table 3– Composition of Ex.2 Ceramics (mol. %) and Etch Rates (nm / hr.)Attorney Docket No.: 195190.020060 / WO As illustrated, the tested binary materials did not achieve a superior etch rate relative to the baseline yttria sample. Single phase polycrystalline materials generally realize lower (better) plasma etch rates as compared to multiple-phase materials.

[0045] Example 3 – Production of high entropy materials having five rare earth oxides

[0046] Sintered compacts of materials having five different oxides at the molar ratios specified in Table 4a, below, were prepared using generally the same process described in Example 1. X-ray diffraction analyses revealed that all samples realized a single polycrystalline phase except for samples 52, 56 and 516, which were multi-phase polycrystalline. The plasma etch rates of various ones of the sintered compacts were tested as per Example 1, the results of which are shown in Table 4b (average of at least triplicate specimens).Table 4b – Etch Rate of Various Ex.3 Ceramics (nm / hr.)As shown, many of the quinary, high entropy materials yielded an increased etch rate resistance relative to the yttria control. Sample 515 realized an exceptionally low etch rate relative to the yttria control.Attorney Docket No.: 195190.020060 / WO

[0047] Table 4c, below, compares the atomic mass, ionic radii and etch rate of the rare earth oxides. As shown below and in FIG. 2, materials with a higher atomic mass to ionic radius ratio tend to realize lower etch rates (i.e., improved etch resistance properties). Table 4c – Comparison of Ionic Radii, Molecular Weight and Etch Rate

[0048] Example 4 – Production of high entropy ceramics having six or seven rare earth oxides

[0049] Sintered compacts of materials having six or seven different rare earth oxides at the molar ratios specified in Table 5a, below, were prepared using generally the same process described in Example 1. Table 5a – Composition of Ex.4 Ceramics (mol. %)The plasma etch rates of the sintered products were then tested as per Example 1 and were found to be 12.5 nm / hr. for sample 61 and 12.1 nm / hr. for sample 71 (average of at least triplicate specimens). As shown, the high entropy materials having six or seven rare earth oxides failed to yield improved etch rate resistance properties.

[0050] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present disclosure.

Claims

Attorney Docket No.: 195190.020060 / WO CLAIMS What is claimed is:

1. A ceramic material comprising from five to ten different rare earth oxides, wherein each of the rare earth oxides contains a different rare earth element, wherein the ceramic material comprises 5-80 mol. % of each of the rare earth oxides, and wherein an average ionic radius of the rare earth oxides is not greater than 106.5 picometers with a standard deviation of not greater than 6.0 picometers.

2. The ceramic material of claim 1, wherein the average ionic radius of the rare earth oxides is not greater than 106.0 picometers, or not greater than 105.5 picometers, or not greater than 105.0 picometers, or not greater than 104.5 picometers, or not greater than 104.0 picometers, or not greater than 103.5 picometers, or not greater than 103.0 picometers, or not greater than 102.5 picometers, or not greater than 102.0 picometers.

3. The ceramic material of any of the preceding claims, wherein the standard deviation of the average ionic radius is not greater than 5.75 picometers, or not greater than 5.5 picometers, or not greater than 5.25 picometers, or not greater than 5.0 picometers, or not greater than 4.75 picometers, or not greater than 4.5 picometers, or not greater than 4.25 picometers, or not greater than 4.0 picometers, or not greater than 3.75 picometers, or not greater than 3.5 picometers, or not greater than 3.25 picometers, or not greater than 3.0 picometers, or not greater than 2.75 micrometers.

4. The ceramic material of any of the preceding claims, wherein at least three of the rare earth oxides are a sesquioxide, or wherein at least four of the rare earth oxides are a sesquioxide, or wherein at least five of the rare earth oxides are a sesquioxide.

5. The ceramic material of any of the preceding claims, wherein at least one of the rare earth oxides is an oxide of ytterbium, erbium, holmium, dysprosium, and gadolinium, or wherein at least two of the rare earth oxides is an oxide of ytterbium, erbium, holmium, dysprosium, and gadolinium, or wherein at least three of the rare earth oxides is an oxide of ytterbium, erbium, holmium, dysprosium, and gadolinium, or wherein at least four of the rare earth oxides is an oxide of ytterbium, erbium, holmium, dysprosium, and gadolinium, or wherein at least five of the rare earth oxides is an oxide of ytterbium, erbium, holmium, dysprosium, and gadolinium.

6. The ceramic material of any of the preceding claims, wherein the ceramic material comprises 8-68 mol. % of each of the rare earth oxides, or 10-60 mol. % of each of the rare earth oxides, or 12-52 mol. % of each of the rare earth oxides, or 15-40 mol. % of each of the rare earth oxides, or 15-35 mol. % of each of the rare earth oxides, or 15-30 mol. % of each of the rare earth oxides, or 15-25 mol. % of each of the rare earth oxides.Attorney Docket No.: 195190.020060 / WO 7. The ceramic material of any of the preceding claims, wherein the ceramic material comprises substantially equimolar amounts of the rare earth oxides, wherein each rare earth oxide is within 5 mol. % of every other rare earth oxide of the ceramic material.

8. The ceramic material of any of the preceding claims, wherein the ceramic material comprises equimolar amounts of the rare earth oxides, wherein each rare earth oxide is within 1 mol. % of every other rare earth oxide of the ceramic material.

9. The ceramic material of any of the preceding claims, wherein the ceramic material consists essentially of five rare earth oxides.

10. The ceramic material of any of the preceding claims, wherein the ceramic material excludes cerium oxide except as an impurity.

11. The ceramic material of any of the preceding claims, wherein at least two of the rare earth elements comprise an atomic mass of from 150 to 175 grams / mol., or wherein at least three of the rare earth elements comprises an atomic mass of from 150 to 175 grams / mol., or wherein at least four of the rare earth elements comprises an atomic mass of an atomic mass of from 150 to 175 grams / mol., or wherein or wherein at least five of the rare earth elements comprises an atomic mass of an atomic mass of from 150 to 175 grams / mol.

12. The ceramic material of any of the preceding claims, wherein the ceramic material is polycrystalline.

13. The ceramic material of any of the preceding claims, wherein the ceramic material is substantially single phase.

14. The ceramic material of any of the preceding claims, wherein the ceramic material realizes at least equivalent plasma etch resistance as compared to a baseline material, wherein the baseline material is a single-phase polycrystalline material comprising at least 99 mol. % yttria.

15. The ceramic material of claim 14, wherein the ceramic material realizes or at least a 5% lower etch rate as compared to the baseline material, or at least a 6% lower etch rate as compared to the baseline material, or at least a 7% lower etch rate as compared to the baseline material, or at least 8% lower etch rate as compared to the baseline material, or at least a 9% lower etch rate as compared to the baseline material, or at least a 10% lower etch rate as compared to the baseline material, or at least an 12% lower etch rate as compared to the baseline material, or at least a 14% lower etch rate as compared to the baseline material, or at least an 16% lower etch rate as compared to the baseline material, or at least a 18% lower etch rate as compared to the baseline material, or at least an 20% lower etch rate as compared to the baseline material, or at least a 22% lower etch rate as compared to theAttorney Docket No.: 195190.020060 / WO baseline material, or at least an 24% lower etch rate as compared to the baseline material, or at least a 26% lower etch rate as compared to the baseline material.

16. The ceramic material of any of the preceding claims, wherein the ceramic material realizes a plasma etch rate of not greater than 10.5 nanometers per hour, or not greater than 10.0 nanometers per hour nanometers per hour, or not greater than 9.8 nanometers per hour, or not greater than 9.6 nanometers per hour nanometers per hour, or not greater than 9.4 nanometers per hour, or not greater than 9.2 nanometers per hour nanometers per hour, or not greater than 9.0 nanometers per hour, or not greater than 8.8 nanometers per hour nanometers per hour, or not greater than 8.6 nanometers per hour, or not greater than 8.4 nanometers per hour nanometers per hour, or not greater than 8.2 nanometers per hour, or not greater than 8.0 nanometers per hour nanometers per hour.

17. The ceramic material of any of the preceding claims, wherein the ceramic material realizes a density of at least 95% of its theoretical density, or at least 96% of its theoretical density, or at least 96.5% of its theoretical density, or at least 97% of its theoretical density, or at least 97.5% of its theoretical density, or at least 98% of its theoretical density, or at least 98.2% of its theoretical density, or at least 98.4% of its theoretical density, or at least 98.5% of its theoretical density, or at least 98.6% of its theoretical density, or at least 98.7% of its theoretical density, or at least 98.8% of its theoretical density, or at least 98.9% of its theoretical density, or at least 99.0% of its theoretical density, or at least 99.1% of its theoretical density, or at least 99.2% of its theoretical density, or at least 99.3% of its theoretical density, or at least 99.4% of its theoretical density, or at least 99.5% of its theoretical density, or at least 99.6% of its theoretical density, or at least 99.7% of its theoretical density, or at least 99.8% of its theoretical density, or at least 99.9% of its theoretical density.

18. A shaped body comprising the ceramic material of any of claims 1-17.

19. The shaped body of claim 18, wherein the shaped body is configured for use in a plasma environment of a semiconductor processing apparatus.

20. The shaped body of any of claims 18-19, wherein the shaped body is a plasma processing chamber component of a semiconductor processing apparatus.

21. The shaped body of any of claims 18-20, wherein the shaped body is in the form of a nozzle blank or a nozzle.

22. The shaped body of any of claims 18-20, wherein the shaped body is selected from the group consisting of a plasma processing chamber lid and a gas distribution component.Attorney Docket No.: 195190.020060 / WO 23. The shaped body of any of claims 18-20, wherein the shaped component is an electrostatic chuck component.

24. The shaped body of any of claims 18-23, wherein the shaped body is monolithic.

25. The shaped body of any of claims 18-24, wherein the shaped body is a green body.

26. The shaped body of any of claims 18-24, wherein the shaped body is a sintered body.

27. A coating comprising the ceramic material of any of claims 1-17.

28. The coating of claim 27, wherein the coating has a thickness of from 20 to 1000 micrometers.

29. The coating of claim 28, wherein the coating has a thickness of at least 30 micrometers, or at 40 micrometers, or least 50 micrometers, or at least 60 micrometers, or at least 70 micrometers, or at least 80 micrometers, or at least 90 micrometers, or at least 100 micrometers.

30. A method comprising: (a) preparing a green body from a powder, wherein the powder comprises at least five different rare earth oxides, wherein each of the rare earth oxides comprises a different rare earth element, wherein the powder blend comprises at 5-80 mol. % of each of the rare earth oxides; and (b) sintering the green body at a sintering temperature of from 1200-1900°C, thereby forming a sintered body.

31. The method of claim 30, wherein the sintering comprises one of pressureless sintering, pressure sintering, and spark plasma sintering.

32. The method of any of claims 30-31, wherein the sintering comprises sintering in at least one of air, hydrogen, and an inert gas.

33. The method of any of claims 30-32, wherein the sintering temperature is not greater than 1850ºC, or not greater than 1800ºC, or not greater than 1750ºC, or not greater than 1700ºC, or not greater than 1680ºC, or not greater than 1660ºC, or not greater than 1640ºC, or not greater than 1620ºC, or not greater than 1600ºC.

34. The method of any of claims 30-33, comprising, prior to the preparing step, formulating the powder.

35. The method of claim 34, wherein the formulating step comprises blending from five to ten different rare earth oxide powders to create the powder blend.

36. The method of any of claims 30-35, wherein the sintered body is monolithic.

37. The method of any of claims 30-36, wherein the sintered body is a semiconductor processing component.Attorney Docket No.: 195190.020060 / WO 38. The method of claim 37, wherein the semiconductor processing component is a plasma processing chamber component.

39. The method of any of claims 37-38, wherein the semiconductor processing component is in the form of a nozzle blank or a nozzle.

40. The method of any of claims 37-38, wherein the semiconductor processing component is selected from the group consisting of a plasma processing chamber lid and a gas distribution component.

41. The method of any of claims 37-38, wherein the semiconductor processing component is an electrostatic chuck component.

42. The method of any of claims 30-41, wherein sintered body is substantially single phase.

43. The method of any of claims 30-42, wherein the preparing a green body step comprises one or more of pressing, extrusion, injection molding, tape casting, roll compaction, and gel casting.

44. A method comprising: blending a powder comprising at least five different rare earth oxides thereby creating a powder blend, wherein the powder blend comprises 5-80 mol. % of each of the rare earth oxides, and wherein an average ionic radius of the rare earth oxides is not greater than 106.5 picometers with a standard deviation of not greater than 6.0 picometers; and creating a coating from the powder blend, wherein the coating has a thickness of from 20 to 1000 micrometers.

45. The method of claim 44, wherein the coating is substantially single phase.

46. The method of any of claims 44-45, wherein the creating step comprises: applying the coating to a base, wherein the base is a ceramic or a metal.

47. The method of claim 46, wherein the base is a ceramic, and wherein the ceramic comprises alumina.

48. The method of claim 46, wherein the base is a metal, and wherein the metal comprises aluminum or an aluminum alloy.

49. The method of claim 48, wherein the metal comprises anodized aluminum or an anodized aluminum alloy.

50. A monolithic shaped body consisting essentially of from five to ten different rare earth oxides, wherein each of the rare earth oxides contains a different rare earth element, wherein the monolithic shaped body comprises 5-80 mol. % of each of the rare earth oxides, and wherein the monolithic shaped body is suited for use in a semiconductor processing apparatus.Attorney Docket No.: 195190.020060 / WO 51. The monolithic shaped body of claim 50, wherein the monolithic shaped body is one of a nozzle blank, a nozzle, a plasma processing chamber lid, a gas distribution component and an electrostatic chuck component.

52. The monolithic shaped body of any of claims 50-51, wherein the monolithic shaped body is plasma etch resistant.

53. A coated product comprising: a base; and a coating at least partially disposed on the base, wherein the coating consists essentially of from five to ten different rare earth oxides, wherein each of the rare earth oxides contains a different rare earth element, and wherein the coating comprises 5-80 mol. % of each of the rare earth oxides.

54. The coated product of claim 53, wherein the base comprises a ceramic.

55. The coated product of claim 54, wherein the ceramic comprises alumina.

56. The coated product of claim 53, wherein the base comprises a metal.

57. The coated product of claim 56, wherein the metal comprises aluminum or an aluminum alloy.

58. The coated product of claim 57, wherein the metal comprises anodized aluminum or an anodized aluminum alloy.

59. The coated product of any of claims 53-58, wherein the base is thermally stable such that the portion of the base in contact with the coating comprises materially the same microstructure both at 25ºC and at 300ºC.

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