DEVICES HAVING A RARE EARTH (OXY) FLUORIDE COATING FOR IMPROVED RESISTANCE TO CORROSIVE CHEMICAL ENVIRONMENTS AND METHODS FOR MAKING AND USING THESE DEVICES

Abstract

A genus of rare earth containing chemicals is disclosed. These rare earth containing chemicals are suitable for use in sequential vapor deposition processes to form rare earth fluoride or rare earth oxyfluoride films. Such films may be used to protect materials and devices from corrosive chemicals.

Claims

1. A chemical of the formula:
M(FAB).sub.3.Math.D.sub.Y wherein M is a rare earth element, wherein FAB is a Fluorinated Anionic Bidentate, and wherein D is a neutral ligand with y=0 to 4.

2. The chemical of claim 1, wherein M is Yttrium.

3. The chemical of claim 2, wherein the FAB is a β-diketonate.

4. The chemical of claim 3, wherein the β-diketonate has a chemical formula I: ##STR00007## wherein each R may independently be CF.sub.3 or a fluorocarbyl.

5. The chemical of claim 2, wherein the FAB has a chemical formula II: ##STR00008## wherein each E is independently O, S, or N—R‘ where R’ is H, a linear or branched C.sub.1-C.sub.6 alkyl, wherein each Q is independently N, P, CH, CF, CR‘ where R’ is an a linear or branched C.sub.1-C.sub.6 alkyl, and wherein each R may independently be CF.sub.3 or a fluorocarbyl.

6. The chemical of claim 1, wherein at least one FAB is selected from the group consisting of hexafluoroacetylacetone (hfac), trifluoroacetylacetonate (tfac), 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (fod), and combinations thereof.

7. The chemical of claim 1, wherein at least one D is selected from the group consisting of monoglyme (1,2-dimethoxyethane; dme), diglyme (bis(2-methoxyethyl) ether), dmp (1,2-dimethoxypropane), 1-(2-Methoxyethoxy)propane and Ethylene glycol ethyl methyl ether (2-Methoxyethanol), and combinations thereof.

8. The chemical of claim 1, wherein y=1 or 2.

9. The chemical of claim 1, wherein at least one D comprises a phosphorus.

10. The chemical of claim 9, wherein the at least one D is selected from the group consisting of TriMethyl Phosphate, Tri-n-ButylPhosphate, Tri-(2,2,2-TriFluoroethyl) Phosphate, Tri-(3,3,3,2,2-pentaFluoroPropyl) Phosphate, and combinations thereof.

11. The chemical of claim 1, wherein the chemical is a liquid at 1 atmosphere pressure and 50 degrees C. or less, preferably liquid at 25 degrees C. or less, more preferably liquid at 20 degrees C. or less.

12. The chemical of claim 1 selected from the group consisting of a. Yttrium(III) hexafluoroacetylacetonate 1,2-dimethoxyethane, b. Yttrium(III) hexafluoroacetylacetonate 1,2-dimethoxypropane, c. Yttrium(III) hexafluoroacetylacetonate 2-Methoxyethanol, and d. Yttrium(III) hexafluoroacetylacetonate 1-(2-Methoxyethoxy)propane.

13.-17. (canceled)

18. A chemical composition comprising a chemical according to claim 1.

19. The chemical composition of claim 18, wherein the chemical is 95% or more of the chemical composition by weight, by molar percent, or both.

20.-22. (canceled)

23. A method of depositing a conformal and adherent MOF or MF.sub.3 thin film on a surface of a chemically reactive material that forms all or part of an article of manufacture, the method comprising the steps of: e. first exposing the surface to a vapor of a metal containing chemical composition according to claim 18, f. second exposing the surface to an oxidant gas, preferably ozone, and g. repeating steps a. and b., preferably sequentially a. then b., to form a desired thickness of the conformal and adherent MOF or MF.sub.3 film on the surface.

24. The method of claim 23, wherein a temperature during step a. and/or step b. is from 200 degrees C.

25. The method of claim 2, wherein the conformal and adherent MOF or MF.sub.3 film comprises an atomic percentage of less than 15% for oxygen and less than 3% for carbon.

26. (canceled)

27. The method of claim 23, wherein there is no purge of the vapor of a metal containing chemical composition from step a., prior to step b.

28.-29. (canceled)

30. The method of claim 15, wherein the final MOF or MF.sub.3 film is 95% to 100% conformal by scanning electron microscopy measurements.

31.-32. (canceled)

33. An article of manufacture comprising an chemically reactive material, the article of manufacture further comprising a conformal and adherent MOF or MF.sub.3 layer coating the article of manufacture, wherein M is a rare earth element, and wherein the MOF or MF.sub.3 coating layer covers more than 99% of a surface of the chemically reactive material.

34.-47. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0082] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the various aspects, briefly summarized above, may be had by reference to example embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0083] FIG. 1 is a schematic showing the calculation of conformality (defined here as the side step coverage at aspect ratio of 6:1) for surfaces having structures with an aspect ratio;

[0084] FIG. 2 DTA and TGA for Y(hfac).sub.3(H.sub.2O).sub.2 (atmospheric pressure) are shown;

[0085] FIG. 3 DTA and TGA for Y(hfac).sub.3(dme) (atmospheric pressure) are shown;

[0086] FIGS. 4A & 4B Vapor Pressure of Y(hfac).sub.3(dme) was determined by the step isotherm method;

[0087] FIG. 5 DTA and TGA for Y(hfac).sub.3(dmp) (atmospheric pressure) are shown;

[0088] FIGS. 6A & 6B Vapor Pressure of Y(hfac).sub.3(dmp) was determined by the step isotherm method;

[0089] FIG. 7 DTA and TGA for Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) (atmospheric) are shown;

[0090] FIGS. 8A & 8B Vapor Pressure of Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) was determined by the step isotherm method;

[0091] FIG. 9 DTA and TGA for Y(hfac).sub.3(TMPO).sub.2 (atmospheric) are shown;

[0092] FIGS. 10A & 10B Vapor Pressure of Y(hfac).sub.3(TMPO).sub.2 was determined by the step isotherm method;

[0093] FIG. 11 DTA and TGA for Y(hfac).sub.3(tfep).sub.2 (atmospheric) are shown;

[0094] FIGS. 12A & 12B Vapor Pressure of Y(hfac).sub.3(tfep).sub.2 was determined using the step isotherm method;

[0095] FIG. 13 DTA and TGA for Y(fod).sub.3(dme) (atmospheric) are shown;

[0096] FIG. 14 DTA and TGA for Y(fod).sub.3(dmp) (atmospheric) are shown;

[0097] FIG. 15 a Schematic of the CVD reactor used in the film deposition experiments is shown;

[0098] FIG. 16 a graph of film thickness as a function of the number of CVD deposition cycles is show;

[0099] FIG. 17 a summary of the atomic composition of films as a function of temperature is shown for one precursor under otherwise uniform deposition conditions and parameters;

[0100] FIG. 18 a scanning electron micrograph of a thin film deposited by sequential injection deposition at 250 degrees C.;

[0101] FIG. 19 a scanning electron micrograph of a thin film deposited by sequential injection deposition at 275 degrees C.;

[0102] FIG. 20 a scanning electron micrograph a thin film deposited by sequential injection deposition at 300 degrees C.; and

[0103] FIG. 21 a scanning electron micrograph a thin film deposited by continuous/simultaneous injection deposition at 300 degrees C.

DISCLOSURE OF INVENTION

[0104] Definitions, Standards and Criteria

[0105] Thermogravimetric analysis or thermal gravimetric analysis (TGA) is a method of thermal analysis in which the mass of a sample is measured over time as the temperature changes. ASTM E1131-08(2014), Standard Test Method for Compositional Analysis by Thermogravimetry, ASTM International, West Conshohocken, Pa., 2014.

[0106] Differential scanning calorimetry (DSC) is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. ASTM E794-06(2018), Standard Test Method for Melting And Crystallization Temperatures By Thermal Analysis, ASTM International, West Conshohocken, Pa., 2018,

[0107] Differential thermal analysis (DTA) is a thermoanalytic technique that is similar to differential scanning calorimetry. In DTA, the material under study and an inert reference are made to undergo identical thermal cycles, (i.e., same cooling or heating programme) while recording any temperature difference between sample and reference. This differential temperature is then plotted against time, or against temperature (DTA curve, or thermogram). Changes in the sample, either exothermic or endothermic, can be detected relative to the inert reference. Thus, a DTA curve provides data on the transformations that have occurred, such as glass transitions, crystallization, melting and sublimation. The area under a DTA peak is the enthalpy change and it's not affected by the heat capacity of the sample. ASTM E794-06(2018), Standard Test Method for Melting And Crystallization Temperatures By Thermal Analysis, ASTM International, West Conshohocken, Pa., 2018,

[0108] Conformality and Step Coverage both refer to the degree of variability in the thickness of a film on a surface, especially topologically different areas of a surface. This is especially relevant to surfaces with microstructures having various Aspect Ratios. An exemplary diagram for the different elements and calculations for conformality of a film is shown in FIG. 1. Complete (100%) conformality for the above example means there is zero cusping and the top surface, the trench sidewall and when applicable the trench bottom, have all identical thicknesses. If a single conformality percentage is given, it is the least conformal measurement corresponding to the greatest deviation in relative thickness of the overall film at two selected points on the surface. The two points may correspond to the highest Aspect Ratio points or, for example, points having a specific Aspect Ratio such as 6:1 or less. Thicknesses of films are assessed by a number of methods, for example scanning electron microscopy of sectioned substrates. A film is generally “conformal” if the film is at least 20% conformality, preferably at least 50%.

[0109] Film Density and Porosity are measurements of the density of a thin film i.e. kg/m.sup.3. X-ray reflectometry and other techniques are used to assess density/porosity. See, e.g., Rouessac, Vincent, et al. “Three characterization techniques coupled with adsorption for studying the nanoporosity of supported films and membranes.” Microporous and mesoporous materials 111.1-3 (2008): 417-428. Porosity is generally expressed as a percentage based on the density of a known, nonporous control or the theoretical density of a nonporous film.

[0110] Film Adhesion is the measurement of the conditions or forces required to cause a thin film to detach, flake, peel, or bubble from an underlying surface. A common measurement is the peel test using an adhesive tape. Hull, T. R., J. S. Colligon, and A. E. Hill. “Measurement of thin film adhesion.” Vacuum 37.3-4 (1987): 327-330. See, for example, ASTM B905-00(2016), Standard Test Methods for Assessing the Adhesion of Metallic and Inorganic Coatings by the Mechanized Tape Test, ASTM International, West Conshohocken, Pa., 2016

[0111] The Aspect Ratio of a geometric shape is the ratio of its sizes in different dimensions. The aspect ratio is most often expressed as two integer numbers separated by a colon (x:y). The values x and y do not represent actual widths and heights but, rather, the proportion between width and height. As an example, 8:5, 16:10, 1.6:1 are all ways of representing the same aspect ratio. In objects of more than two dimensions, such as hyperrectangles, the aspect ratio can still be defined as the ratio of the longest side to the shortest side.

[0112] Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas phase chemical process; it is a subclass of chemical vapour deposition. The majority of ALD reactions use two chemicals called precursors (also called “reactants”). These precursors react with the surface of a material one at a time in a sequential, self-limiting, manner. Through the repeated exposure to separate precursors, a thin film is slowly deposited.

[0113] Chemical Vapor Deposition (CVD) is an atmosphere controlled process conducted at elevated temperatures in a CVD reactor. During this process, thin-film coatings are formed as the result of reactions between various gaseous phases and the heated surface of substrates within the CVD reactor.

[0114] Precursors for CVD

[0115] In general, CVD precursors suitable for use in depositing MOF/MF.sub.3 thin film coatings are Metal (M) fluorine-containing Anionic Bidentate (FAB) compounds, of the form M(FAB).sub.xD.sub.y(hereafter called M(FAB)): [0116] M is a IIIA or IIIB element. Preferably M is specifically a Rare Earth, incl. Sc, Y, and La—Lu. Most preferably M is Yttrium. [0117] FAB are Fluorinated Anionic Bidentates and are exemplified by chemical moieties such as β-diketonates, β-diketiminates, and β-ketoiminates. [0118] x is an integer between 1 and 3, preferably x is three. [0119] When x=2 or 3, each FAB within the M(FAB) molecule can be identical or different from one another. [0120] Preferably all FABs are the same. [0121] FAB, Fluorine-containing Anionic Bidentates are represented by the formula:

##STR00003## [0122] In the above formula: [0123] Each E can be independently O, S, or N—R‘ where R’ is H, an C1-C6 alkyl (linear or branched). [0124] The alkyl may be fluorinated or incorporate another heteroatom. [0125] Each Q can be independently N, P, CH, CF, CR‘ where R’ is an C1-C6 alkyl (linear or branched). [0126] The alkyl may be fluorinated or incorporate another heteroatom. [0127] In preferred FABs, at least one R or R′ is CF.sub.3 or a fluorocarbyl, preferably a fluorinated C1-C4 alkyl. [0128] More preferably, both R or R′ are a fluorocarbyl, such as a fluorinated C1-C4 alkyl.  M Most preferably each R are independently CF.sub.3 or C.sub.2F.sub.5. [0129] FAB, Fluorine-containing Anionic Bidentates, may be preferably defined by E=O and Q=CH, e.g. fluorine-containing β-diketonates having the general formula:

##STR00004## [0130] In the above formula, at least one R is CF.sub.3 or a fluorocarbyl, preferably a fluorinated C1-C4 (linear or branched) alkyl. [0131] More preferably both R are a fluorocarbyl, preferably a fluorinated C1-C4 [0132] In these embodiments, each R is preferably, independently, CF.sub.3 or C.sub.2F.sub.5.  Most preferably, both R are CF.sub.3, and thus the FAB is Hexafluoroacetylacetone (hfac). [0133] D is a donor neutral ligand and is preferably an alcohol, an ether, a sulfide, an amine, a nitrile, an amide(R.sub.2N—C(═O)H), a phosphine, a phosphate, a diene, a cyclodiene, each of which may optionally be also fluorinated. [0134] y is between 0 and 4, preferably y is 1 or 2. [0135] Donor ligands may be protic or non-protic H [0136] Phosphates are preferably in the form of P(═O)(OR) with R═C1-C8 [0137] Preferred D are of the form R.sup.1—O—R.sup.2—O—R.sup.3 where each R.sup.1, R.sup.2, R.sup.3 are independently H or a linear, branched or cyclic C1-C8, preferably C1-C4 [0138] Most preferably R.sup.1 and R.sup.2 are independently H, methyl or ethyl [0139] Most preferably R.sup.3 is a C1-C4 [0140] Examples of Donor ligands can also be:

##STR00005## [0141] Other examples of Donor ligands containing CF.sub.3 groups are:

##STR00006##

[0142] Particularly preferred embodiments of D are monoglyme (1,2-dimethoxyethane; dme), diglyme (bis(2-methoxyethyl) ether), dmp (1,2-dimethoxypropane), 1-(2-Methoxyethoxy)propane and Ethylene glycol ethyl methyl ether (2-Methoxyethanol).

[0143] Preferred species of the subgenus where D is a Phosphate [M(FAB).sub.3(Phosphate)] have for D:

[0144] TMP: TriMethyl Phosphate

[0145] TBP: Tri-n-ButylPhosphate

[0146] TFEP: Tri-(2,2,2-TriFluoroethyl) Phosphate,

[0147] TFPP: Tri-(3,3,3,2,2-pentaFluoroPropyl) Phosphate

[0148] Particular species include: Y(hfac).sub.3(TMP), Y(hfac).sub.3(TMP).sub.2, La(hfac).sub.3(TMP).sub.2, Ce(hfac).sub.3(TMP).sub.2, Y(hfac).sub.3(TFEP), Y(hfac).sub.3(TFEP).sub.2, La(hfac).sub.3(TFEP).sub.2, Ce(hfac).sub.3(TFEP).sub.2, Y(hfac).sub.3(TFPP), Y(hfac).sub.3(TFPP).sub.2, La(hfac).sub.3(TFPP).sub.2, and Ce(hfac).sub.3(TFPP).sub.2.

[0149] The above species may also have tfac and fod as the FAB.

[0150] Exemplary species of precursors for different rare earth element include: [0151] Y: [0152] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane Yttrium; [0153] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane Yttrium, [0154] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol Yttrium [0155] Tris(hexafluoroacetylacetonato) Yttrium [0156] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) Yttrium [0157] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) Yttrium [0158] Tris(hexafluoroacetylacetonato) (trimethylphosphate) Yttrium [0159] Tris(hexafluoroacetylacetonato) (tfep) Yttrium [0160] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) Yttrium [0161] Tris(hexafluoroacetylacetonato) (diglyme) Yttrium [0162] Tris(hexafluoroacetylacetonato) (triglyme) Yttrium [0163] Sc: [0164] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane scandium; [0165] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane scandium, [0166] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol scandium [0167] Tris(hexafluoroacetylacetonato) scandium [0168] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) scandium [0169] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) scandium [0170] Tris(hexafluoroacetylacetonato) (trimethylphosphate) scandium [0171] Tris(hexafluoroacetylacetonato) (tfep) scandium [0172] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) scandium [0173] Tris(hexafluoroacetylacetonato) (diglyme) scandium [0174] Tris(hexafluoroacetylacetonato) (triglyme) scandium [0175] La: [0176] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane lanthanum; [0177] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane lanthanum, [0178] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol lanthanum [0179] Tris(hexafluoroacetylacetonato) lanthanum [0180] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) lanthanum [0181] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) lanthanum [0182] Tris(hexafluoroacetylacetonato) (trimethylphosphate) lanthanum [0183] Tris(hexafluoroacetylacetonato) (tfep) lanthanum [0184] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) lanthanum [0185] Tris(hexafluoroacetylacetonato) (diglyme) lanthanum [0186] Tris(hexafluoroacetylacetonato) (triglyme) lanthanum [0187] Ce: [0188] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane cerium; [0189] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane cerium, [0190] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol cerium [0191] Tris(hexafluoroacetylacetonato) cerium [0192] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) cerium [0193] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) cerium [0194] Tris(hexafluoroacetylacetonato) (trimethylphosphate) cerium [0195] Tris(hexafluoroacetylacetonato) (tfep) cerium [0196] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) cerium [0197] Tris(hexafluoroacetylacetonato) (diglyme) cerium [0198] Tris(hexafluoroacetylacetonato) (triglyme) cerium [0199] Pr: [0200] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane praseodymium; [0201] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane praseodymium, [0202] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol praseodymium [0203] Tris(hexafluoroacetylacetonato) praseodymium [0204] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) praseodymium [0205] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) praseodymium [0206] Tris(hexafluoroacetylacetonato) (trimethylphosphate) praseodymium [0207] Tris(hexafluoroacetylacetonato) (tfep) praseodymium [0208] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) praseodymium [0209] Tris(hexafluoroacetylacetonato) (diglyme) praseodymium [0210] Tris(hexafluoroacetylacetonato) (triglyme) praseodymium [0211] Nd: [0212] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane neodymium; [0213] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane neodymium, [0214] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol neodymium [0215] Tris(hexafluoroacetylacetonato) neodymium [0216] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) neodymium [0217] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) neodymium [0218] Tris(hexafluoroacetylacetonato) (trimethylphosphate) neodymium [0219] Tris(hexafluoroacetylacetonato) (tfep) neodymium [0220] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) neodymium [0221] Tris(hexafluoroacetylacetonato) (diglyme) neodymium [0222] Tris(hexafluoroacetylacetonato) (triglyme) neodymium [0223] Sm: [0224] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane samarium; [0225] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane samarium, [0226] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol samarium [0227] Tris(hexafluoroacetylacetonato) samarium [0228] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) samarium [0229] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) samarium [0230] Tris(hexafluoroacetylacetonato) (trimethylphosphate) samarium [0231] Tris(hexafluoroacetylacetonato) (tfep) samarium [0232] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) samarium [0233] Tris(hexafluoroacetylacetonato) (diglyme) samarium [0234] Tris(hexafluoroacetylacetonato) (triglyme) samarium [0235] Eu: [0236] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane europium; [0237] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane europium, [0238] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol europium [0239] Tris(hexafluoroacetylacetonato) europium [0240] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) europium [0241] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) europium [0242] Tris(hexafluoroacetylacetonato) (trimethylphosphate) europium [0243] Tris(hexafluoroacetylacetonato) (tfep) europium [0244] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) europium [0245] Tris(hexafluoroacetylacetonato) (diglyme) europium [0246] Tris(hexafluoroacetylacetonato) (triglyme) europium [0247] Gd: [0248] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane gadolinium; [0249] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane gadolinium, [0250] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol gadolinium [0251] Tris(hexafluoroacetylacetonato) gadolinium [0252] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) gadolinium [0253] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) gadolinium [0254] Tris(hexafluoroacetylacetonato) (trimethylphosphate) gadolinium [0255] Tris(hexafluoroacetylacetonato) (tfep) gadolinium [0256] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) gadolinium [0257] Tris(hexafluoroacetylacetonato) (diglyme) gadolinium [0258] Tris(hexafluoroacetylacetonato) (triglyme) gadolinium [0259] Tb: [0260] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane terbium; [0261] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane terbium, [0262] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol terbium [0263] Tris(hexafluoroacetylacetonato) terbium [0264] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) terbium [0265] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) terbium [0266] Tris(hexafluoroacetylacetonato) (trimethylphosphate) terbium [0267] Tris(hexafluoroacetylacetonato) (tfep) terbium [0268] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) terbium [0269] Tris(hexafluoroacetylacetonato) (diglyme) terbium [0270] Tris(hexafluoroacetylacetonato) (triglyme) terbium [0271] Dy: [0272] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane dysprosium; [0273] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane dysprosium, [0274] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol dysprosium [0275] Tris(hexafluoroacetylacetonato) dysprosium [0276] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) dysprosium [0277] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) dysprosium [0278] Tris(hexafluoroacetylacetonato) (trimethylphosphate) dysprosium [0279] Tris(hexafluoroacetylacetonato) (tfep) dysprosium [0280] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) dysprosium [0281] Tris(hexafluoroacetylacetonato) (diglyme) dysprosium [0282] Tris(hexafluoroacetylacetonato) (triglyme) dysprosium [0283] Ho: [0284] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane holmium; [0285] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane holmium, [0286] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol holmium [0287] Tris(hexafluoroacetylacetonato) holmium [0288] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) holmium [0289] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) holmium [0290] Tris(hexafluoroacetylacetonato) (trimethylphosphate) holmium [0291] Tris(hexafluoroacetylacetonato) (tfep) holmium [0292] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) holmium [0293] Tris(hexafluoroacetylacetonato) (diglyme) holmium [0294] Tris(hexafluoroacetylacetonato) (triglyme) holmium [0295] Er: [0296] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane erbium; [0297] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane erbium, [0298] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol erbium [0299] Tris(hexafluoroacetylacetonato) erbium [0300] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) erbium [0301] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) erbium [0302] Tris(hexafluoroacetylacetonato) (trimethylphosphate) erbium [0303] Tris(hexafluoroacetylacetonato) (tfep) erbium [0304] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) erbium [0305] Tris(hexafluoroacetylacetonato) (diglyme) erbium [0306] Tris(hexafluoroacetylacetonato) (triglyme) erbium [0307] Tm: [0308] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane thulium; [0309] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane thulium, [0310] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol thulium [0311] Tris(hexafluoroacetylacetonato) thulium [0312] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) thulium [0313] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) thulium [0314] Tris(hexafluoroacetylacetonato) (trimethylphosphate) thulium [0315] Tris(hexafluoroacetylacetonato) (tfep) thulium [0316] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) thulium [0317] Tris(hexafluoroacetylacetonato) (diglyme) thulium [0318] Tris(hexafluoroacetylacetonato) (triglyme) thulium [0319] Yb: [0320] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane ytterbium; [0321] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane ytterbium, [0322] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol ytterbium [0323] Tris(hexafluoroacetylacetonato) ytterbium [0324] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) ytterbium [0325] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) ytterbium [0326] Tris(hexafluoroacetylacetonato) (trimethylphosphate) ytterbium [0327] Tris(hexafluoroacetylacetonato) (tfep) ytterbium [0328] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) ytterbium [0329] Tris(hexafluoroacetylacetonato) (diglyme) ytterbium [0330] Tris(hexafluoroacetylacetonato) (triglyme) ytterbium [0331] Lu: [0332] Tris(hexafluoroacetylacetonato) 1,2-Dimethoxyethane lutetium; [0333] Tris(hexafluoroacetylacetonato) 1,2-dimethoxypropane lutetium, [0334] Tris(hexafluoroacetylacetonato) 2-Methoxyethanol lutetium [0335] Tris(hexafluoroacetylacetonato) lutetium [0336] Tris(hexafluoroacetylacetonato) 1-(2-Methoxyethoxy) lutetium [0337] Tris(hexafluoroacetylacetonato)(Ethylene glycol ethyl methyl ether) lutetium [0338] Tris(hexafluoroacetylacetonato) (trimethylphosphate) lutetium [0339] Tris(hexafluoroacetylacetonato) (tfep) lutetium [0340] Tris(hexafluoroacetylacetonato) (1-(2-methoxyethoxy)propane) lutetium [0341] Tris(hexafluoroacetylacetonato) (diglyme) lutetium [0342] Tris(hexafluoroacetylacetonato) (triglyme) lutetium [0343] The above exemplary species may also have tfac and/or fod in place of one or more of the hexafluoroacetylacetonato groups.

[0344] Properties of Precursors for CVD

[0345] The above precursors are thermally stable such that they are suitable for purification and/or isotopic enrichment. The range of precursors allow one to tune the desired physical properties such as: [0346] The melting point of the precursor is below 100 degrees C., preferably below 50 degrees C. (such as 25 degrees C.), most preferably at or below 20 degrees C. [0347] The vapor pressure of the precursor can be raised to 1 torr or more prior to reaching a precursor's thermal degradation temperature; preferably a temperature of 100 degrees C. to 150 degrees C., such as 110 degrees C. to 140 degrees C. or 115 degrees C. to 125 degrees C.

[0348] Preferred Deposition Conditions And Exemplary Process Description

[0349] An MOF or MF.sub.3 film is deposited by supplying vapors of the above M(FAB).sub.xD.sub.y precursors into a chemical vapor deposition reactor to deposit a film having the metal, fluorine and optionally oxygen (i.e. MF.sub.3 or MOF). For example the films may be yttrium fluoride (YF.sub.3) or yttrium oxyfluoride (YOF) films. [0350] Preferably, the CVD process includes at least one oxidant co-reactant chosen among H.sub.2O, O.sub.2, and O.sub.3. Ozone is highly preferred because of the unexpected CVD film quality achievable, as is further described below. [0351] The MF.sub.3 or MOF film is uniformly and conformally deposited by CVD on Si, compound SCs, steel (including stainless steel), ceramics, glass, conductive layers; with or without an interface layer.

[0352] Most preferably: MF.sub.3 or MOF films are deposited, in a layer by layer deposition mode that may include an Atomic Layer Deposition component, by supplying M(FAB).sub.xD.sub.y vapors into a CVD reactor, sequentially between precursor and co-reactant, each injection step being separated by purges or not, to deposit a uniform, adherent and conformal thin film. The layer by layer mode (or sequential injection) ensures the deposition of a film with excellent conformality as well as access to low process temperatures. Some preferred deposition process conditions include one or more of the following, in any combination: [0353] The deposition process temperature is between 150 degrees C. and 500 degrees C., preferably between 200 degrees C. and 350 degrees C., most preferably between 250 degrees C. and 300 degrees C. The minimum temperature is selected based in part on the rate of CVD film growth and the maximum temperature is based in part on the thermal stability of the precursor. [0354] The deposition process pressure is between 0.01 Torr and 1000 Torr, preferably between 0.2 Torr and 200 Torr, most preferably between 0.5 Torr and 20 Torr. [0355] At least one co-reactant is ozone (O.sub.3). [0356] The resulting film is uniform, conformal, and adhered to the substrate. [0357] The substrate surface is made of one or more of Si, compound SCs, steel (preferably stainless steel), ceramic, glass, or conductive layers with or without an interface layer. [0358] The film contains less than 3% Carbon by XPS analysis (as described below); preferably Carbon is below the detection limit (about <1.5%). [0359] The as-deposited oxygen content in MOF films is lower than 15%, most preferably lower than 5%. [0360] To further densify the films and reinforce their etch erosion resistance, the CVD film is annealed after deposition at a temperature of between 300 degrees C. and 1000 degrees C., preferably between 450 degrees C. and 800 degrees C., most preferably between 550 degrees C. and 700 degrees C. [0361] The precursor M(FAB).sub.xD.sub.y has a melting point of less than 100 degrees C., preferably lower than 50 degrees C., most preferably lower than 15 degrees C. [0362] The molecule smoothly vaporizes or sublimates (e.g. with no step observed in TGA conditions) with a residue amount less than 3%, preferably less than 2%, most preferably 1% (w/w %) by TGA (as described below).

WORKING EXAMPLES

Exemplary Precursor Syntheses

Synthesis of Y(hfac).SUB.3.(H.SUB.2.O).SUB.2

[0363] Prepare a solution of Hexafluoroacetylacetone (43.76 g, 210.33 mmol) in Et.sub.2O (500 mL). Separately YCl.sub.3(H.sub.2O).sub.6 (21.27 g, 70.11 mmol) is dissolved in deionized water (200 mL). Aqueous ammonia (42.07 mL, 210.33 mmol, 5N solution in water) added by portions to a stirred solution of yttrium trichloride so pH is 7-7.5 at the end of ammonia addition. Then solution of hexafluoroacetylacetone in ether is added to aqueous suspension. The two phase mixture vigorously stirred for 60 min and then organic phase separated using the separatory funnel and collected in 1 L flask. All volatiles from organic fraction are removed under vacuum, the remaining solid vacuumed at 60° C. during 60 min under vacuum. Obtained 40.0 g of white solid, yield 76.5% for Y(hfac).sub.3(H.sub.2O).sub.2. .sup.1H NMR (ppm, CD.sub.6): 6.22 (3H, hfac), 2.19 (4H, H.sub.2O).

Synthesis of Y(hfac).SUB.3.(dme) (“Synthesis #2”)

[0364] Prepared suspension of Y(hfac).sub.3(H.sub.2O).sub.2 (20.18 g, 27.5 mmol) in toluene (220 mL), then added dme (4.14 g, 46.0 mmol). All solid is dissolved under stirring giving a turbid solution and then SOCl.sub.2 (7.08 g, 59.5 mmol) added to the stirred solution drop by drop. Stirring continues 1 hour at room temperature, a small amount of deposited solid filtered and all volatiles are removed from filtrate under dynamic vacuum leaving 16.69 g of crude reaction product. Crude Y(hfac).sub.3(dme) (16.37 g) is placed in the sublimation apparatus. The sublimation apparatus is connected to the liquid nitrogen trap, the latter is connected to the vacuum line. The crude is heated under vacuum up to 80° C. to remove volatile organic compounds in the liquid nitrogen trap and then dry ice/IPA is placed in the cold finger of sublimation apparatus. The sublimation of Y(hfac).sub.3(dme) proceeds in the range 100-140° C., 3.3-4.4 mTorr Vacuum. Yield of Y(hfac).sub.3(dme) 14.71 g, 68% from Y(hfac).sub.3(H.sub.2O).sub.2. M.P. 75.8° C. (DSC). .sup.1H NMR (ppm, CD.sub.6): 6.22 (3H, hfac), 3.02 (6H, dme), 2.65 (4H, dme). .sup.19F NMR: −75.7 ppm (s, —CF.sub.3). FTIR of neat solid corresponds to that reported in Eur. J. Inorg. Chem. 2004, 500-509. Small differences in peak positions and no reported signals for C—H stretch are since FTIR in prior art was reported for nujol mull or hexachlorobutadiene solution. Hence FTIR of neat solid is reported here: 3314 (w), 3297 (w), 3147 (w), 2991 (w, sh), 2963 (w), 2936 (vw), 2903 (vw), 2870 (vw), 2860 (vw), 1670 (w), 1648 (s), 1610 (w), 1574 (w), 1560 (m), 1534 (m), 1500 (s), 1472 (m), 1454 (m), 1352 (w), 1326 (w), 1249 (s), 1195 (s), 1160 (m), 1136 (vs), 1100 (s), 1044 (s), 1023 (m), 1007 (w), 953 (w), 870 (m), 833 (w), 801 (s), 772 (w), 763 (w), 742 (m), 659 (s), 585 (s), 528 (m), 472 (m). mp: 85° C.

Synthesis of Y(hfac).SUB.3.(1,2-dimethoxypropane)

[0365] 1,2-dimethoxypropane is abbreviated herein as “dmp”. Prepared suspension of Y(hfac).sub.3(H.sub.2O).sub.2 (15.31 g, 20.3 mmol) in toluene (150 g), then added 1,2-dimethoxypropane (3.72 g, 35.7 mmol). All solid is dissolved under stirring giving a turbid solution and then Molecular Sieves (26.4 g, 3A, freshly regenerated) added to the stirred solution. Stirring continued 2 hours at room temperature, then the reaction mixture filtered from Molecular Sieves and small amount of formed solid and then all volatiles are removed from filtrate under dynamic vacuum leaving 14.99 g of crude solid containing about 90% of Y(hfac).sub.3(dmp) according to .sup.1H NMR. Crude Y(hfac).sub.3(dmp) is placed in the parent flask of short path distillation apparatus containing the heat traced short path adapter to the receiver being 100 mL two necked glass flask. The apparatus is connected to the vacuum line via the liquid nitrogen trap. The crude is heated under vacuum up to 70° C. to remove volatile organic compounds in the liquid nitrogen trap and then the receiving flask is placed in dry ice/IPA. The distillation of Y(hfac).sub.3(dmp) proceeds at 3.1-3.4 mTorr Vacuum and temperatures 120-140° C. in the receiver cooled with dry ice; the short path is heat traced and kept at 95-110° C. during the distillation. Collected in the receiver 13.54 g, 16.63 mmol of Y(hfac).sub.3(dmp). Yield: 81% from Y(hfac).sub.3(H.sub.2O).sub.2. M.P. 46.6° C. (DSC). .sup.1H NMR (ppm, CD.sub.6): 6.23 (s, 3H, hfac), 3.16 (s, 3H, Me-0), 3.03 (s, 3H, Me-O), 2.77-2.83 (m, 2H, O—CH.sub.2—CH), 2.61 (m, 1H, O—CH.sub.2—CH), 0.40 (d, 3H, Me-CH). .sup.19F NMR: −75.7 ppm (s, —CF.sub.3). FTIR of neat solid (measurement in Golden Gate FTIR probe): 3317 (vw), 3303 (vw), 3145 (vw), 3114 (vw), 2991 (w), 2962 (w), 2931 (vw), 2905 (sh, w), 2859 (vw), 1732 (br, w), 1688 (br, w), 1671 (m), 1649 (s), 1608 (m), 1573 (sh), 1561 (m), 1534 (m), 1501 (s), 1476 (m), 1455 (m), 1387 (w), 1352 (w), 1326 (w), 1282 (sh), 1251 (s), 1193 (s), 1136 (vs), 1104 (s), 1078 (m), 1053 (sh), 1048 (m), 1039 (m), 1029 (m), 953 (m), 941 (sh), 921 (m), 908 (w), 892 (w), 802 (s), 771 (w), 742 (m), 659 (s), 586 (s), 559 (w), 528 (m), 503 (w), 490 (w), 473 (m), 455 (w). Abbreviations: dmp: 1,2-dimethoxypropane; vw —very weak, w—weak, m—medium, s—strong, vs—very strong, sh—shoulder, br—broad.

Synthesis of Y(hfac).SUB.3.(Ethylene glycol ethyl methyl ether)

[0366] Synthesis according to procedure in Synthesis #2. Yield: 84% from Y(hfac).sub.3(H.sub.2O).sub.2. M.P. 42.0° C. (DSC). .sup.1H NMR (ppm, CD.sub.6): 6.24 (s, 3H, hfac), 3.60 (q, 2H, CH.sub.3—CH.sub.2—O), 3.06 (s, 3H, Me-O), 2.50-2.90 (m, 4H, O—CH.sub.2—CH.sub.2—O), 0.82 (t, 3H, O—CH.sub.2—CH.sub.3). .sup.19F NMR: −75.8 ppm (s, —CF.sub.3). FTIR of neat solid (measurement in Golden Gate FTIR probe): 3318 (vw), 3303 (vw), 3152 (w), 3117 (vw), 3081 (vw), 3052 (vw), 3022 (vw), 2985 (br, w), 2963 (w), 2946 (w), 2925 (vw), 2907 (w), 2898 (sh), 2881 (vw), 2867 (vw), 2859 (sh), 1734 (vw), 1686 (br, w), 1670 (m), 1648 (sh), 1609 (m), 1574 (sh), 1562 (m), 1534 (m), 1503 (s), 1480 (br, m), 1471 (m), 1449 (m), 1415 (vw), 1395 (w), 1380 (sh), 1352 (w), 1327 (w), 1305 (w), 1259 (sh), 1247 (s), 1227 (w), 1205 (sh), 1194 (s), 1175 (w), 1134 (vs), 1101 (s), 1092 (s), 1036 (s), 1027 (sh), 1011 (m), 954 (w), 924 (m), 862 (m), 817 (sh), 803 (s), 794 (sh), 773 (m), 741 (m), 659 (s), 587 (s), 528 (m), 505 (vw), 470 (m), 432 (vw). Abbreviations: vw—very weak, w—weak, m—medium, s—strong, vs—very strong, sh—shoulder, br—broad.

Synthesis of Y(hfac).SUB.3.(TMPO).SUB.2

[0367] Y(hfac).sub.3(H.sub.2O).sub.2 (1.00 g, 1.35 mmol) and 200 mg of Molecular Sieves (MS4) were added to heptane (120 mL). To the resulting suspension, HMPO (0.41 g, 2.95 mmol) was added in one portion. After stirring for 3 h during which most solids dissolved, the suspension was filtered through a glass filter to afford a colorless solution. All volatiles were subsequently removed under vacuum to generate 1.10 g of a white solid which corresponds to the formulation Y(hfac).sub.3(TMPO).sub.2. .sup.1H NMR (ppm, CD.sub.6): 6.33 (3H, s; hfac), 3.35 (18H, d, .sup.3J.sub.H-P=11.4 Hz; —O—CH.sub.3). .sup.19F NMR (ppm, CD.sub.6): −76.79 (s; —CF.sub.3). .sup.31P{.sup.1H} NMR (ppm, CD.sub.6): −2.39 (s; TMPO). A sublimation apparatus equipped with a cold finger was charged with 832 mg of crude Y(hfac).sub.3(TMPO).sub.2. The sublimation apparatus was attached to a liquid nitrogen cold trap before connecting to the vacuum line, and subsequently submerged to an oil bath. Under high vacuum (˜1 Pa), The oil bath was gradually warmed up to 60° C. during which the crude began Y(hfac).sub.3(TMPO).sub.2 to liquefy. The temperature of the cold finger, which used an ethylene glycol/water mixture as a coolant, was set to 0° C. before increasing the oil bath temperature up to 150° C. Sublimation of Y(hfac).sub.3(TMPO).sub.2 proceeded at a temperature range of 90-150° C. After the sublimation was complete, the setup was cleaned and brought inside the glovebox. Pure Y(hfac).sub.3(TMPO).sub.2 (566 mg, 0.57 mmol) was isolated as a white solid in 51% overall yield. .sup.1H NMR (ppm, CD.sub.6): 6.33 (3H, s; hfac), 3.35 (18H, d, .sup.3J.sub.H-P=11.4 Hz; —O—CH.sub.3). .sup.13C{.sup.1H} NMR (ppm, CD.sub.6): 177.62 (q, .sup.2J.sub.C-F=34 Hz; —C—CF.sub.3), 119.00 (q, .sup.1J.sub.C-F=284 Hz; —CF.sub.3), 91.11 (s; hfac CH), 55.32 (s; —O—CH.sub.3 19F NMR (ppm, CD.sub.6): −76.82 (s; —CF.sub.3). .sup.31P{.sup.1H} NMR (ppm, CD.sub.6): −2.45 (s; TMPO).

Synthesis of Y(hfac).SUB.3.(tfep)

[0368] The following procedure was carried out in air. Y(hfac).sub.3(H.sub.2O).sub.2 (10.03 g, 13.4 mmol) was added to a biphasic mixture of 700 mL of cyclohexane and 200 mL of deionized water. To the resulting suspension, TFEP (12.66 g, 36.8 mmol) was added in one portion. The reaction mixture was stirred for 3 h during which a cloudy oil formed at the bottom of the flask. The cloudy oil, which was later confirmed to consist TFEP and Y(hfac).sub.3(TFEP).sub.2, aqueous layer and cyclohexane layer were separated, and the aqueous layer was extracted with 200 mL of chloroform and 200 mL of diethyl ether. The organic layers were combined along with the oil containing the product, and dried over MgSO.sub.4 for 1 h. The solids were removed over a glass filter and washed with two portions of 100 mL of diethyl ether. The resulting filtrate was first concentrated by rotary evaporation and the remaining volatiles were removed under high vacuum (˜1 Pa) at 50° C. to afford 18.05 g of white solid which corresponds to the formulation Y(hfac).sub.3(TFEP).sub.2. For further purification, the crude Y(hfac).sub.3(TFEP).sub.2 was subjected to sublimation by following the same procedure as Y(hfac).sub.3(TMPO).sub.2 (10.76 g, 7.7 mmol, 57% yield). .sup.1H NMR (ppm, CD.sub.6): 6.29 (3H, s; hfac), 4.00 (15H by integration, pseudo pentet). .sup.13C{.sup.1H} NMR (ppm, CD.sub.6): 178.78 (q, .sup.2J.sub.C-F=34.8 Hz; hfac-C—CF.sub.3), 122.46 (dq, .sup.1J.sub.C-F=276 Hz, .sup.3J.sub.C-P=9.6 Hz; TFEP-C—CF.sub.3), 118.62 (q, .sup.1J.sub.C-F=283 Hz; hfac-CF.sub.3), 92.29 (s; hfac CH), 65.69 (dq, .sup.2J.sub.C-F=38.9 Hz, .sup.2J.sub.C-P=5.0 Hz; TFEP —CH.sub.2—CF.sub.3). .sup.19F NMR (ppm, CD.sub.6): −75.83 (18H, t, .sup.3J.sub.H-F=8 Hz; CH.sub.2—CF.sub.3), −77.13 (18H, s; hfac-CF.sub.3). .sup.31P{.sup.1H} NMR (ppm, CD.sub.6): −8.10 (s; TFEP).

Synthesis of Y(fod).SUB.3.(H.SUB.2.O)

[0369] The following procedure was carried out in air. A 500 mL round-bottom flask was charged with 200 mL of water and Na.sub.2CO.sub.3 (2.678 g, 25.3 mmol). To the clear solution, H(fod) (15 g, 50.6 mmol) was added in one portion, resulting in immediate precipitation of a white solid. The pH of the aqueous layer at this point was −7. After stirring for 15 min, YCl.sub.3(H.sub.2O).sub.6 (4.948 g, 16.3 mmol) was added portionwise to generate a white creamy suspension. The reaction mixture was stirred for another 2 h and 200 mL of Et.sub.2O was subsequently added. The flask was sealed with a stopper and the biphasic mixture was stirred overnight. Acetic acid (˜3 mL) was added dropwise until all remaining solids dissolved in solution. The pH of the aqueous layer was lowered to ˜5. 50 mL of brine was added and the two layers were separated. The aqueous layer was extracted twice with Et.sub.2O (50 mL each) and the combined organic layer was subsequently washed with brine (100 mL). Finally, volatiles were removed in vacuo at room temperature (first by rotary evaporator followed by high vacuum) to afford Y(fod).sub.3(H.sub.2O) (15.863 g, 16.0 mmol) as a white solid in 98% yield.

[0370] .sup.1H NMR (ppm, CD.sub.6): 6.23 (s, 3H, fod CH), 3.43 (s, 3H, dmp OCH.sub.3), 3.26 (s, 3H, dmp OCH.sub.3), 3.09 (m, 2H, dmp CH.sub.2), 2.9 (m, 1H, dmp CH), 1.06 (s, 9H, fod C(CH.sub.3).sub.3), (d, 3H, .sup.2J=6.2 Hz, dmp CH.sub.3)

[0371] .sup.19F NMR (ppm, CD.sub.6): −80.8 (t, 9F, .sup.3J=29.9 Hz), −119.4 (pseudo q, 6F), −126.4 (s, 6F)

Synthesis of Y(fod).SUB.3.(dme)

[0372] Y(fod).sub.3(dme) was prepared by a similar procedure to synthesize Y(hfac).sub.3(dme) (Synthesis #2). A two-neck flask was charged with Y(fod).sub.3(H.sub.2O).sub.2 (928 mg, 0.92 mmol), toluene (50 mL) and Molecular Sieves (MS4, 300 mg) inside the glove box. dme (1 mL, ˜0.868 g, ˜9.6 mmol) was subsequently added and the resulting mixture was stirred for 1 h. All solids were removed by filtration and volatiles of the filtrate were removed under vacuum (˜3 Pa) at room temperature to generate a sticky colorless solid (0.966 g). The resulting crude material was then transferred to a sublimation apparatus. The temperature was gradually increased to 60° C. under dynamic vacuum to completely remove volatile organic compounds.

[0373] Crude Y(fod).sub.3(dme) (16.37 g) is placed in the sublimation apparatus. The sublimation apparatus is connected to the liquid nitrogen trap, the latter is connected to the vacuum line. The crude is heated under vacuum up to 80° C. to remove volatile organic compounds. The chiller was set at −5° C. and the temperature was further increased incrementally to 150° C. The sublimed product, which corresponds to the formula Y(fod).sub.3(dme), was obtained as waxy colorless solid (228 mg, 0.21 mmol) in 23% yield from Y(fod).sub.3(H.sub.2O).sub.2.

[0374] .sup.1H NMR (ppm, CD.sub.6): 6.16 (3H, fod C—H), 3.26 (6H, dme —CH.sub.3), 2.96 (4H, dme —CH.sub.2-), 1.05 (27H, fod tBu). .sup.19F NMR (ppm, CD.sub.6): −80.76 ppm (t9F; —CF.sub.3), −119.77 (m, 6F; —CF.sub.2—CF.sub.3), −126.34 (m, 6F; —CF.sub.2—CF.sub.2—CF.sub.3).

Synthesis of Y(fod).SUB.3.(dmp)

[0375] In the glove box, Y(fod).sub.3(H.sub.2O) (1.22 g, 1.2 mmol) and dmp (0.21 mL, ˜0.21 g, 18 2.1 mmol) were dissolved in 30 mL of toluene. In turn, freshly regenerated molecular sieves (MS4A; ˜0.5 g) were added and the resulting mixture was stirred for 2 h. After removing all solids via filtration, volatiles of the filtrate were removed in vacuo to generate a pale yellow gel which solidified after drying under vacuum (˜3 Pa) at 50° C. for 1 h. The crude material was then purified by sublimation under dynamic vacuum (˜3 Pa) at a temperature range of 100 to 120° C. Pure product was collected as a white solid (323 mg, 3 mmol) in 24% yield.

[0376] .sup.1H NMR (ppm, CD.sub.6): 6.15 (s, 3H, fod CH), 3.43 (s, 3H, dmp OCH.sub.3), 3.26 (s, 3H, dmp OCH.sub.3), 3.09 (m, 2H, dmp CH.sub.2), 2.9 (m, 1H, dmp CH), 1.06 (s, 9H, fod C(CH.sub.3).sub.3), 0.60 (d, .sup.2J=6.2 Hz, dmp CH.sub.3), .sup.19F NMR (ppm, CD.sub.6): −80.8 (t, 9F, .sup.3J=29.9 Hz), −119.4 (pseudo q, 6F), −126.4 (s, 6F)

[0377] The following additional Rare Earth element analogs were synthesized and purified using the same synthesis procedures as the detail examples above: La(hfac).sub.3(H.sub.2O).sub.3, La(hfac).sub.3(dmp), Ce(hfac).sub.3(H.sub.2O).sub.2, Ce(hfac).sub.3(dmp), Sm(hfac).sub.3(H.sub.2O).sub.2, Sm(hfac).sub.3(dmp), Tb(hfac).sub.3(H.sub.2O).sub.2, Tb(hfac).sub.3(dmp), Yb(hfac).sub.3(H.sub.2O).sub.2, and Yb(hfac).sub.3(dmp).

[0378] Properties of the genus appear to be consistent for all Rare Earth metals. For example, the M(hfac).sub.3(dmp) shows similar properties:

TABLE-US-00001 RE = Y RE = La RE = Ce RE = Sm RE = Tb RE = Yb OVERALL 62% 55% 78% 71% 84% 85% YIELD MAGNETIC diamagnetic diamagnetic paramagnetic paramagnetic paramagnetic paramagnetic STATE mp (° C.) 47 54 53 53 52 Liquid @ rt (40° C. by DSC) VP 1 Torr @ 118° C. 1 Torr @ 137° C. 1 Torr @ 130° C. 1 Torr @ 132° C. 1 Torr @ 130° C. 1 Torr @ 126° C. (step-isotherm) ΔH 74.3 kJ/mol or 70.8 kJ/mol or 60.0 kJ/mol or 78.2 kJ/mol or 77.0 kJ/mol or 77.2 kJ/mol or (evaporation) 17.7 kcal/mol 16.9 kcal/mol 14.3 kcal/mol 18.7 kcal/mol 18.4 kcal/mol 18.5 kcal/mol Residue at <1% 1% 1% <1% <1% <1% 300° C.

[0379] Exemplary Precursor Properties

[0380] Y(hfac).sub.3(H.sub.2O).sub.2 was characterized by TGA both at atmospheric conditions (“atm-TG”, “atm-DTA”) and in vacuum (“vac-TG”, “vac DTA”), e.g. in conditions representative of bubbling mode (canister pressure ˜25-50 Torr). The product seems to liquefy at 125 degrees C., with an irregular evolution of the precursors or its different components, and with about 10% w/w of residues at 270 degrees C., making it inconvenient for its delivery in stable conditions, from the canister to a CVD reactor, especially in high volume manufacturing.

DTA and TGA for Y(hfac).sub.3(H.sub.2O).sub.2 (atmospheric pressure) are shown in FIG. 2. [0381] Melting Point: 125 degrees C. [0382] Y(hfac).sub.3(H.sub.2O).sub.2 left about 10% w/w of residues at 270 degrees C.
DTA and TGA for Y(hfac).sub.3(dme) (atmospheric pressure) are shown in FIG. 3. [0383] Y(hfac).sub.3(dme) melting point was 85° C. [0384] Y(hfac).sub.3(dme) fully evaporated at 258.9° C., leaving less than 1% w/w of residue. [0385] Thermal decomposition (without co-reactants) after 30 minutes at 300 degrees C. and thermally stable at 250 degrees C.
Vapor Pressure of Y(hfac).sub.3(dme) was determined by the step isotherm method (FIGS. 4A and 4B). [0386] Vapor pressure of 1 torr at 124.4 degrees C.

[0387] DTA and TGA for Y(hfac).sub.3(dmp) (atmospheric pressure) are shown in FIG. 5. [0388] Y(hfac).sub.3(dmp) melting point was 42° C. [0389] Y(hfac).sub.3(dmp) fully evaporated at 242° C., leaving less than 1% w/wof residue.
Vapor Pressure of Y(hfac).sub.3(dmp) was determined by the step isotherm method (FIGS. 6A and 6B). [0390] T(1 Torr)=118° C. [0391] ΔH(evaporation)=74.3 kJ/mol or 17.7 kcal/mol
DTA and TGA for Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) (atmospheric) are shown in FIG. 7. [0392] Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) melting point was 42° C. [0393] Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) fully evaporated at 255° C., leaving less than 1% w/w of residue.

[0394] Vapor Pressure of Y(hfac).sub.3(Ethylene glycol ethyl methyl ether) WAS determined by the step isotherm method (FIGS. 8A and 8B). [0395] T(1 Torr)=119° C. [0396] ΔH(evaporation)=78.3 kJ/mol or 18.7 kcal/mol
DTA and TGA for Y(hfac).sub.3(TMPO).sub.2 (atmospheric) are shown in FIG. 9. [0397] Y(hfac).sub.3(TMPO).sub.2 melting point was 55.7° C. [0398] Y(hfac).sub.3(TMPO).sub.2 fully evaporated at 258.9° C., leaving less than 1% w/w of residue.
Vapor Pressure of Y(hfac).sub.3(TMPO).sub.2 WAS determined by the step isotherm method (FIGS. 10A and 10B). [0399] VP is estimated to be 1 torr at 142.3° C. (step isotherm).
DTA and TGA for Y(hfac).sub.3(tfep).sub.2 (atmospheric) are shown in FIG. 11. [0400] Y(hfac).sub.3(tfep).sub.2 melting point was 150.7° C. [0401] Y(hfac).sub.3(tfep).sub.2 fully evaporated at 258.9° C., leaving less than 1% w/w of residue.
Vapor Pressure of Y(hfac).sub.3(tfep).sub.2 was determined using the step isotherm method (FIGS. 12A and 12B). [0402] VP is estimated to be 1 torr at 123.0° C. (step isotherm).
DTA and TGA for Y(fod).sub.3(dme) (atmospheric) are shown in FIG. 13. [0403] Y(fod).sub.3(dme) fully evaporated at approximately 265° C., leaving less than 1% w/w of residue.
DTA and TGA for Y(fod).sub.3(dmp) (atmospheric) are shown in FIG. 14. [0404] Y(fod).sub.3(dmp) fully evaporated at 269.7° C., leaving less than 1% w/w of residue.

[0405] Exemplary Thin Film Depositions

[0406] Materials and Methods: [0407] Chemicals [0408] Precursor: Y(hfac).sub.3 dme [0409] Canister T: 114° C. [0410] Canister P: 20 torr [0411] N.sub.2 bubbling: 40 sccm [0412] Co-reactant: O.sub.3 [0413] Concentration: 200 g/m.sup.3 [0414] Flow: 100 sccm [0415] Schematic of reactor structure is shown in FIG. 15.
Rutherford Backscattering was by X-ray photo-electron spectroscopy (XPS) using a Thermo Scientific™ K-Alpha™ X-ray Photoelectron Spectrometer (XPS) System with the following settings: [0416] Monochromatic Al X-ray [0417] Ion beam: Ar [0418] Ion gun energy: 500 eV [0419] Current: Medium [0420] Etch time: 10 s/cycle

Deposition Examples 1-3: Sequential Injection Deposition of Yttrium Oxyfluoride at 225 Degrees C

[0421] Film depositions were attempted on a bare silicon substrate by self-decomposition in the following conditions:

Reactor temperature 225° C.;
Reactor Pressure: 10 torr;
N.sub.2 carrier gas FR: 40 sccm
Y(hfac).sub.3 dme: 1 sccm;
O.sub.3: 100 sccm
CVD sequence:
Y(hfac).sub.3 dme: variable

N.SUB.2 .Purge: 20 s

O.SUB.3.: 5 s

[0422] N.sub.2 purge: 5 s
Number of cycles: 300

[0423] The Growth per Cycle is dependent on the precursor pulse, e.g, the precursor dose, varying from 0.11 to 0.14A after 15 s of precursor dose. Film thickness is linear with the number of pulse-purge cycles (FIG. 16).

[0424] Based on XPS analyses, the film deposited in these conditions leads to an atomic percentage of Y: 28.9%, 0: 12.3%, F: 45.7%, C: <DL (<1.5%). Refractive index: 1.53 (near that of bulk YF.sub.3). In these conditions, the material deposited is thus an oxyfluoride.

Deposition Examples 4-8: Sequential Injection Deposition of Yttrium Oxyfluoride at 250 Degrees C

[0425] Following the same experimental conditions with the exception that the deposition temperature was 250 degrees C.

[0426] The Growth per Cycle is dependent on the precursor pulse, e.g, the precursor dose, varying from 0.24 to 0.29 ångströms after 15 s of precursor dose. Furthermore, the Growth per Cycle is also dependent on the total pressure. The excellent conformality achieved thanks to the sequential injection makes the process very attractive for different applications, especially etch resistant materials. In contrast, films deposited with continuous injection of precursors and co-reactant lead to non-conformal films which cannot be used for applications requiring conformality, such as anti-corrosion coating of semiconductor parts and especially showerheads. Thus the inventive deposition process at low temperature has the benefit of deposition speed characteristic of a CVD process, while deposition highly conformal films on high aspect ratio substrates, normally only achieved with a pure ALD deposition reaction.

[0427] Further, the deposition process gives access to conformal, low oxygen containing Yttrium oxyfluoride and Yttrium fluoride, which are typically not reported at such low temperature. Based on XPS analyses, the film deposited in these conditions leads to an atomic percentage of Y: 32.5%, 0: 3.2%, F: 61.1%, C<DL (<1.5%). Refractive index: 1.52 (near that of bulk YF.sub.3). In these conditions, the material deposited is thus a yttrium oxyfluoride, or better described as a slightly oxygen doped yttrium fluoride.

[0428] The above film obtained on a patterned wafer (aspect ratio: 10:1) had a perfect conformality (100%). Considering the absence of a self-limited regime, the perfect conformality in such an aggressive aspect ratio on a patterned structure is very unexpected, and has never been reported to our knowledge. All past studies included, the inventors are not aware of high conformality being reported for thin films of yttrium oxyfluoride or yttrium fluorides, and even more at such low temperature.

[0429] Additional Y(hfac).sub.3 dme depositions by sequential injection, varying only the temperature, are summarized in FIG. 17. [0430] At T<200° C., Y(hfac).sub.3 dme does not react with O.sub.3. [0431] At T>250° C., Y(hfac).sub.3 dme begins to be partially oxidized or thermally decomposed. [0432] O ratio is increased as dep. T increases, while F ratio is decreased as dep. T increases. [0433] C remains just around XPS DL (less than 1.5%). [0434] O.sub.2 co-reactant does not result in film depositions in the 250-300 degree C. temperature range.

[0435] Conformality Analysis of Representative Sequential Injection Film Samples

[0436] Sequential injection films were deposited on blank wafers having a trench with an aspect ratio of 6.25:1, 10:1 or 20:1. Under the above conditions, with 30 second precursor pulses, no film deposited at 200 degrees C. and very slow deposition occurred at 225 degrees C. At 300 degrees C., film step coverage was about 63% on a 6.25:1 aspect ratio trench, however the trench bottom film thickness was 51 nm versus 81 nm thickness on the wafer surface. While not perfectly conformal, this film could be functionally adequate for some applications. No film at the bottom of the trench deposited at 325 degrees C. Thus the practical deposition temperature range under the above conditions is 225 degrees C. to 300 degrees C. Best results were seen from 250 to 275 degrees C. Exemplary Scanning Electron Micrographs of films deposited at 250 degrees C. and 275 degrees C. are reproduced in FIG. 18 and FIG. 19, respectively:

250 degrees C. (FIG. 18): [0437] 10:1 aspect ratio [0438] 100% conformal film
275 degrees C. (FIG. 19): [0439] 6.25:1 aspect ratio [0440] 100% conformal film

[0441] Unexpectedly, eliminating the N.sub.2 gas purge between pulses of precursor and ozone did not significantly impact film thickness or conformality at 250 degrees C. and 275 degrees C. Skipping the inert gas purge would make the overall process more rapid and efficient.

[0442] Representative films deposited with Y(hfac).sub.3 dme and Y(hfac).sub.3 dmp were tested using the “peel test” with commercial adhesive tape. Both scored and unscored films did not peel off SiN, SiO.sub.2, TiN or SUS surfaces.

[0443] FIG. 20 shows a film formed at 300 degrees C. Conformality is approximately 63%, which is not suitable for all applications, but could be acceptable in certain cases.

Deposition Examples 9-12: Deposition of Yttrium Oxyfluoride at 100 Degrees C. To 700 Degrees C. With Simultaneous Injection of Reactants

[0444] In contrast, films deposited by continuous CVD (i.e. simultaneous rather than sequential injection) resulted in vastly different deposition outcomes with very low conformality and no depositions in low temperature conditions.

[0445] Continuous CVD films were deposited on blank wafers having a trench with an aspect ratio of 6.25:1, 10:1 or 20:1. Temperature was varied from 100° C. to 700° C. and deposition was carried for 30 min at 10 Torr pressure and with 1 sccm of Y(hfac).sub.3:dme and 100 sccm of O.sub.3 injected simultaneously.

[0446] At 100° C., 200° C. and 250° C., no or very thin films were observed.

[0447] At 300° C., a 32 nm YOF layer was obtained, with Y, F, O concentration respectively at 45%, 35% and 20%. Films were only deposited on top of the surface and no deposition was obtained in the trenches (example shown in FIG. 21). At 400° C., 500° C. and 600° C., YOF layers were obtained. Again, films were only deposited on top of the surface and no deposition was obtained in the trenches.

[0448] These results indicate that sequential injection of precursor and ozone is important when one wants a conformal film on high aspect ratio surfaces.

INDUSTRIAL APPLICABILITY

[0449] The present invention is at least industrially applicable to the manufacture of semiconductor dry etching equipment.

[0450] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0451] The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

[0452] “Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of “comprising”). “Comprising” as used herein may be replaced by the more limited transitional terms “consisting essentially of” and “consisting of”unless otherwise indicated herein.

[0453] “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0454] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0455] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

[0456] All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.