Polysubstituted cyclopentadienyl rare earth complexes as precursors for vapor phase thin film deposition processes

Abstract

The disclosed and claimed subject matter provides precursors having at least one bound cyclopentadienyl ligand ("Cp ligand"), at least one amidino ligand ("Ad ligand"), and a lanthanide and / or lanthanide-like transition metal ("M") having the general formula (i) (Cp ligand) 2-M-(Ad ligand) or (ii) (Cp ligand)-M-(Ad ligand) 2.

Description

background Technical Field

[0002] The disclosed and claimed subject matter relates to organometallic compounds containing lanthanide and / or lanthanide-like transition metals, compositions containing the compounds, and methods of using the compounds as precursors for depositing metal-containing films. Background Art

[0003] Transition metal-containing films are used in semiconductor and electronic applications. Chemical vapor deposition (CVD) and atomic layer deposition (ALD) are used as the main deposition techniques for producing thin films for semiconductor devices. These methods enable conformal films (metals, metal oxides, metal nitrides, metal silicides, etc.) to be achieved through chemical reactions of metal-containing compounds (precursors). The chemical reactions occur on surfaces that may include metals, metal oxides, metal nitrides, metal silicides, and other surfaces. In CVD and ALD, precursor molecules play a vital role in achieving high-quality films with high conformality and low impurities. The temperature of the substrate in the CVD and ALD processes is an important consideration when selecting precursor molecules. Higher substrate temperatures, in the range of 150 to 500 degrees Celsius (°C), promote high film growth rates. Preferred precursor molecules must be stable within this temperature range. Preferred precursors can be delivered to the reaction vessel in a liquid phase. Liquid phase delivery of precursors generally provides more uniform precursor delivery to the reaction vessel compared to solid phase precursors.

[0004] In ALD, thin films can be deposited by the reaction of metal-organic precursors with co-reactants (separated by an inert gas purge). Due to this unique mechanism, ALD can coat three-dimensional (3D) surfaces with atomic precision, making it indispensable to the semiconductor industry.

[0005] US Patent No. 8,283,201 discloses precursor compounds having a cyclopentadienyl ligand having at least one fully aliphatic group as a substituent and an amidine ligand. In particular, the disclosed structure includes the formula Ln(R 1 Cp) m (R 2 —N—C(R 4 )═N—R 2 ) n A lanthanide-containing precursor, wherein (i) Ln is a lanthanide having a to about ionic radius, 3+ charge and coordination number 6 of lanthanide metals, (ii) R 1 is selected from H and a C1-C5 alkyl chain, (iii) R 2 is selected from H and a C1-C5 alkyl chain, (iv) R 4 is selected from H and Me, (v) n and m range from 1 to 2, and (vi) the precursor has a melting point below about 105°C.

[0006] US Patent Application Publication No. 2019 / 0152996 (US Patent Application No. 16 / 251,236) discloses lanthanide-containing compounds of the following formula.

[0007]

[0008] Where R 1 is a hydrogen atom or a C1-C4 straight or branched chain alkyl group, R 2 and R 3 Each independently represents a hydrogen atom or a C1-C5 straight or branched alkyl group, R 2 and R 3 At least one of them is a C3-C5 branched alkyl group, and R 4 is a hydrogen atom or a C1-C4 straight or branched alkyl group. In this regard, during the examination of this application, the USPTO confirmed that USP 8,283,201 failed to teach or suggest that R 2 and R 3 Different asymmetric amidine groups.

[0009] There is a need in the art for thermally stable lanthanide and / or lanthanide-like organometallic compounds suitable as CVD and ALD precursors, which can be preferably delivered in the liquid phase, have low impurities and can produce high quality films with high conformality.

[0010] In this regard, the rare earth (RE) precursors for ALD generally employ THD (2,2,6,6-tetramethyl-3,5-heptanedione), various cyclopentadienyl ligands ("Cp ligands" or "Cp"), and amidino ligands ("Ad ligands" or "AMD"). In the case of La, for example, the precursors La(iPr-Cp)3 (triisopropylcyclopentadienyl lanthanum (III)), La(iPr2-FAMD)3 (tris-diisopropylformamidinyl lanthanum (III)), and isolating La(iPr-Cp)2(iPr2-MeAMD) (di(isopropylcyclopentadienyl)(diisopropylacetamidinyl)lanthanum (III)) can be considered as benchmark precursors. La(iPr-Cp)3 is a volatile, thermally stable, low melting point solid with poor reactivity. For La precursors, good reactivity combined with high volatility can be seen in La(iPr2-FAMD). However, it has no melting point and low stability compared to La(iPr-Cp)3, which is a disadvantage in terms of gasification performance and application in ALD. Therefore, the combination of stable iPr-Cp ligands with reactive amidine groups is used to obtain heteroleptic precursors La(iPr-Cp)2(iPr2-MeAMD), which are liquid at room temperature, but less volatile than La(iPr2-FAMD). A way to increase the volatility of such compounds is by modification of the amidine groups, using an asymmetric alkyl substitution pattern on the ligand.

[0011] It is noteworthy that no one has attempted to use asymmetric substitution on the Cp ring, despite the fact that such asymmetry may have a large impact on volatility, melting point, and thermal stability. The disclosed and claimed subject matter provides such materials. Summary of the invention

[0012] The disclosed and claimed subject matter provides precursors of the general formula (i)(Cp ligand)2-M-(Ad ligand) or (ii)(Cp ligand)-M-(Ad ligand)2 having at least one bound cyclopentadienyl ligand ("Cp ligand"), at least one amidino ligand ("Ad ligand"), and a lanthanide and / or lanthanide-like transition metal ("M"). The disclosed and claimed subject matter further includes compositions containing the compounds, methods of using the compounds as precursors for depositing metal-containing films, and films derived from the precursors.

[0013] In one embodiment, the precursor having at least one tethered cyclopentadienyl ligand and at least one amidino ligand has Formula I:

[0014]

[0015] in

[0016] (i) M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;

[0017] (ii) R 1 , R 2 , R 3 , R 4 and R 5 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl and halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3,

[0018] Where (a) R 1 , R 2 , R 3 , R 4 and R 5 contains at least three different substituents and (b) R 1 , R 2 , R 3 , R 4 and R 5 At least two of them are H;

[0019] (iii) R 6 , R7 and R 8 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl and halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3;

[0020] (iv) n = 1 or 2; and

[0021] (v) The precursor is liquid at a temperature below 80°C.

[0022] Thus, precursors of Formula I include compounds of formula (i) (Cp ligand) 2 -M-(Ad ligand) when n = 2 and (ii) (Cp ligand) -M-(Ad ligand) 2 when n = 1. More specific aspects and embodiments of the precursors of Formula I, respectively (Cp ligand) 2 -M-(Ad ligand) and (Cp ligand) -M-(Ad ligand) 2, are described in detail below.

[0023] Without being bound by theory, it is believed that asymmetrically substituting the Cp ring with at least two different alkyl chains produces a highly asymmetric complex. Due to this asymmetry, the melting point is lowered and the volatility is increased.

[0024] The disclosed and claimed subject matter further includes (i) compositions and formulations comprising the disclosed and claimed precursors, (ii) methods of using the disclosed and claimed precursors in deposition processes, and (iii) metal-containing films derived from the produced disclosed and claimed precursors in deposition processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are included to provide a further understanding of the disclosed subject matter and are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosed subject matter and together with the description serve to explain the principles of the disclosed subject matter. In the drawings:

[0026] Figure 1 Thermogravimetric analysis (TGA) of Comparative Example 1, La(iPr-Me-Cp)3 is shown;

[0027] Figure 2 The diagram shows the synthesis example 1, La(iPr-Me-Cp)2(iPr2-FAMD) 1 H NMR;

[0028] Figure 3 The diagram shows the TGA of Synthesis Example 1, La(iPr-Me-Cp)2(iPr2-FAMD); and

[0029] Figure 4The differential scanning calorimetry (DSC) analysis of Synthesis Example 1, La(iPr-Me-Cp)2(iPr2-FAMD) is shown.

[0030] Figure 5 The thermal decomposition of La(iPr-Me-Cp)2(iPr2-FAMD)Si precursor on a wafer is shown;

[0031] Figure 6 Figure 1 shows the dependence of lanthanum oxide film thickness on Si and SiO2 wafers vs. pulse time of La(iPr-Me-Cp)2(iPr2-FAMD) precursor in atomic layer deposition process; and

[0032] FIG. 7 illustrates a cross-sectional TEM of a structured wafer with lanthanum oxide films deposited at 175 and 275° C. using a La(iPr—Me—Cp) 2 (iPr 2 -FAMD) precursor. DETAILED DESCRIPTION

[0033] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0034] In the context of describing the disclosed and claimed subject matter (especially in the context of the following claims), the use of the terms "one" and "an" and "the" and similar references should be interpreted as including both the singular and the plural, unless otherwise specified herein or clearly contradicted by the context. Unless otherwise specified, the terms "comprising", "having", "including" and "containing" should be understood as open terms (i.e., meaning "including but not limited to"). Unless otherwise specified herein, the enumeration of numerical ranges herein is only used as a shorthand method for individually referring to each individual numerical value within the range, and each individual numerical value is included in this specification as if quoted separately herein. Unless otherwise specified herein or otherwise clearly contradicted by the context, all methods described herein can be implemented in any appropriate order. Unless otherwise required, the use of any and all examples or exemplary language (e.g., "such as") provided herein is only to better illustrate the disclosed and claimed subject matter, and does not limit the scope of the disclosed and claimed subject matter. Any language in the specification should not be interpreted as indicating that any non-declared element is essential to the implementation of the disclosed and claimed subject matter.

[0026] The terms "comprising" or "including" as used in the specification and claims include the narrower language of "consisting essentially of" and "consisting of.

[0035] Embodiments of the disclosed and claimed subject matter are described herein, including the best mode known to the inventor to realize the disclosed and claimed subject matter. After reading the above description, changes in these embodiments may become apparent to those of ordinary skill in the art. The inventor expects that those skilled in the art will appropriately adopt these changes, and the inventor intends to implement the disclosed and claimed subject matter in a manner different from that specifically described herein. Therefore, the disclosed and claimed subject matter includes all changes and equivalents thereof in the attached claims as allowed by applicable law. In addition, unless otherwise specified herein or otherwise clearly contradictory to the context, the disclosed and claimed subject matter covers any combination of the above-mentioned elements in all possible variations thereof.

[0036] It is to be understood that the term "silicon" as the material deposited on a microelectronic device includes polycrystalline silicon.

[0037] For ease of reference, "microelectronic devices" or "semiconductor devices" correspond to semiconductor wafers having integrated circuits, memories, and other electronic structures fabricated thereon, and flat panel displays, phase change memory devices, solar panels, and substrates containing solar cells, photovoltaic devices, and microelectromechanical systems (MEMS) fabricated for microelectronic, integrated circuit, or computer chip applications. Solar substrates include, but are not limited to, silicon, amorphous silicon, polycrystalline silicon, single crystal silicon, CdTe, copper indium selenide, copper indium sulfide, and gallium arsenide on gallium. Solar substrates may be doped or undoped. It should be understood that the terms "microelectronic devices" or "semiconductor devices" are not meant to be limiting in any way, but include any substrate that ultimately becomes a microelectronic device or microelectronic component.

[0038] As defined herein, the term "barrier material" corresponds to any material in the art used to seal metal lines (such as copper interconnects) to minimize the diffusion of the metal (such as copper) into dielectric materials. Preferred barrier layer materials include tantalum, titanium, ruthenium, hafnium and other refractory metals and their nitrides and silicides.

[0039] "Substantially free" is defined herein as less than 0.001 wt.%. "Substantially free" also includes 0.000 wt.%. The term "free" means 0.000 wt.%. As used herein, "about" or "approximately" means within ±5% of the stated value.

[0040] In all such compositions, where specific ingredients of the composition are discussed with reference to weight percentage (or "wt %) ranges including a lower limit of zero, it is understood that such components may or may not be present in various specific embodiments of the composition, and where such components are present, they may be present at a concentration as low as 0.001 wt % based on the total weight of the composition in which such components are used. It should be noted that all percentages of components are weight percentages and are based on the total weight of the composition (i.e., 100%). Any reference to "one or more" or "at least one" includes "two or more" and "three or more", etc.

[0041] Where applicable, unless otherwise indicated, all weight percentages are "neat," meaning that they do not include the aqueous solution in which they are present when added to the composition. For example, "neat" refers to the amount by weight % of the undiluted acid or other material (i.e., 100 g of 85% phosphoric acid is composed of 85 g of acid and 15 grams of diluent).

[0042] In addition, when referring to the compositions described herein in % by weight, it is understood that the % by weight of all components (including non-essential components such as impurities) does not add up to 100 % by weight in any case. In the composition "essentially composed of said components", these components may add up to 100 % by weight of the composition or may add up to less than 100 % by weight. When the components add up to less than 100 % by weight, these components may include some small amounts of non-essential contaminants or impurities. For example, in one such embodiment, the formulation may contain 2 % by weight or less impurities. In another embodiment, the formulation may contain 1 % by weight or less impurities. In a further embodiment, the formulation may contain 0.05 % by weight or less impurities. In other such embodiments, the components may account for at least 90 wt%, more preferably at least 95 wt%, more preferably at least 99 wt%, more preferably at least 99.5 wt%, most preferably at least 99.9 wt%, and may include other ingredients that have no substantial effect on the performance of the wet etchant. Otherwise, if there is no large amount of non-essential impurity components, it is understood that the composition of all essential components substantially adds up to 100 wt%.

[0043] The headings used herein are not intended to be limiting; rather, they are included for organizational purposes only.

[0044] Exemplary embodiments

[0045] One aspect of the disclosed and claimed subject matter relates to precursors of the general formula (i)(Cp ligand)2-M-(Ad ligand) or (ii)(Cp ligand)-M-(Ad ligand)2 having at least one bound cyclopentadienyl ligand ("Cp ligand"), at least one amidine ligand ("Ad ligand"), and a lanthanide and / or lanthanide-like transition metal ("M").

[0046] One aspect of the disclosed and claimed subject matter relates to precursors having at least two bound cyclopentadienyl ligands ("Cp ligands") and at least one amidino ligand ("Ad ligand") of the general formula (Cp ligand)2-M-(Ad ligand), wherein M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. In one aspect of this embodiment, M is one of Sc, Y, La, and Ce. In one aspect of this embodiment, M is Sc. In one aspect of this embodiment, M is Y. In one aspect of this embodiment, M is La. In one aspect of this embodiment, M is Ce.

[0047] One aspect of the disclosed and claimed subject matter relates to precursors having at least one bound cyclopentadienyl ligand ("Cp ligand"), at least two amidino ligands ("Ad ligand") of the general formula (Cp ligand)-M-(Ad ligand)2, wherein M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. In one aspect of this embodiment, M is one of Sc, Y, La, and Ce. In one aspect of this embodiment, M is Sc. In one aspect of this embodiment, M is Y. In one aspect of this embodiment, M is La. In one aspect of this embodiment, M is Ce.

[0048] In some embodiments, the tethered Cp ligand is derived from the structure illustrated in Table 1 below, and the tethered Ad ligand has the structure illustrated in Table 2.

[0049]

[0050]

[0051] Table 1

[0052]

[0053]

[0054] Table 2

[0055] Tables 3 and 4 describe preferred embodiments of the general formula (i) (Cp ligand) 2 -M-(Ad ligand) and (ii) (Cp ligand) -M-(Ad ligand) 2 comprising the ligands shown in Tables 1 and 2:

[0056]

[0057]

[0058]

[0059] Table 3

[0060]

[0061]

[0062]

[0063]

[0064] Table 4

[0065] The disclosed and claimed precursors are not limited to those exemplified in Tables 3 and 4. In addition, the Cp ligands and Ad ligands are also not limited to those exemplified in Tables 1 and 2. Additional embodiments of the disclosed and claimed precursors are described below with reference to Formula I.

[0066] Formula I Embodiment

[0067] Embodiments and aspects of precursors having at least one bound cyclopentadienyl ligand and at least one amidino ligand of Formula I are exemplified below. As previously described, precursors of Formula I include compounds of the general formula (i) (Cp ligand) 2 -M-(Ad ligand) and (ii) (Cp ligand) -M-(Ad ligand) 2, wherein Cp has at least 3 different substituents.

[0068] In one embodiment, the precursor having at least one tethered cyclopentadienyl ligand and at least one amidino ligand has Formula I:

[0069]

[0070] in

[0071] (i) M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;

[0072] (ii) R 1 , R 2 , R 3 , R 4 and R 5 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl and halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3,

[0073] Where (a) R 1 , R2 , R 3 , R 4 and R 5 contains at least three different substituents and (b) R 1 , R 2 , R 3 , R 4 and R 5 At least two of them are H;

[0074] (iii) R 6 , R 7 and R 8 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl and halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3;

[0075] (iv) n = 1 or 2; and

[0076] (v) The precursor is liquid below about 80°C.

[0077] In one aspect of this embodiment, M is one of Sc, Y, La, and Ce. In one aspect of this embodiment, M is La. In another aspect of this embodiment, M is Sc. In another aspect of this embodiment, M is Y. In another aspect of this embodiment, M is Ce. In another aspect of this embodiment, M is Pr. In another aspect of this embodiment, M is Nd. In another aspect of this embodiment, M is Pm. In another aspect of this embodiment, M is Sm. In another aspect of this embodiment, M is Eu. In another aspect of this embodiment, M is Gd. In another aspect of this embodiment, M is Tb. In another aspect of this embodiment, M is Dy. In another aspect of this embodiment, M is Ho. In another aspect of this embodiment, M is Er. In another aspect of this embodiment, M is Tm. In another aspect of this embodiment, M is Yb. In another aspect of this embodiment, M is Lu. Preferably, M is La.

[0078] In one aspect of this embodiment, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 Each is independently selected from H, unsubstituted straight chain C1-C5 straight chain alkyl and unsubstituted branched C3-C6 alkyl.

[0079] In one aspect of this embodiment, R 1 , R 2 , R 3 , R 4 and R 5 In one aspect of this embodiment, three of R 1 , R 2 , R 3 , R 4 and R 5 Two of them are H.

[0080] In one aspect of this embodiment, R 5 , R 6 and R 8 In another aspect of this embodiment, one or more of R 5 , R 6 and R 8 In another aspect of this embodiment, two or more of R 5 , R 6 and R 8 Each is isopropyl.

[0081] In one aspect of this embodiment, n=1. In another aspect of this embodiment, n=2.

[0082] In one embodiment, R 1 , R 6 and R 8 Each is isopropyl, R 3 is methyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1 , R 6 and R 8 Each is isopropyl, R 3 is methyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and n=2, as follows:

[0083]

[0084] In one embodiment, R 1 is tert-butyl, R 3 is methyl; R 2 , R 4, R 5 Each is hydrogen; R 6 and R 8 are each isopropyl, and R 7 is hydrogen. In one aspect of this embodiment, M=La. In one aspect of this embodiment, n=1. In another aspect of this embodiment, n=2. In a preferred aspect of this embodiment, M=La; R 1 is tert-butyl; R 3 is methyl; R 2 , R 4 , R 5 Each is hydrogen; R 6 and R 8 Each is isopropyl; R 7 is hydrogen; and n=2, as follows:

[0085]

[0086] In one embodiment, R 1 , R 6 and R 8 Each is isopropyl, R 3 and R 7 Each is a methyl group, and R 2 , R 4 and R 5 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1 , R 6 and R 8 Each is isopropyl, R 3 and R 7 Each is a methyl group, and R 2 , R 4 and R 5 Each is hydrogen, and n=2, as follows:

[0087]

[0088] In one embodiment, R 1 is sec-butyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1is sec-butyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and n=2, as follows:

[0089]

[0090] In one embodiment, R 1 is isopropyl, R 3 is methyl, R 6 Ethyl and R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1 is isopropyl, R 3 is methyl, R 6 Ethyl and R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and n=2, as follows:

[0091]

[0092] In one embodiment, R 1 Ethyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1 Ethyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and n=2, as follows:

[0093]

[0094] In one embodiment, R 1 and R 6 Each is ethyl, R 3 is methyl, R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen. In one aspect of this embodiment, M = La. In one aspect of this embodiment, n = 1. In another aspect of this embodiment, n = 2. In a preferred aspect of this embodiment, M = La, R 1 and R 6 Each is ethyl, R 3 is methyl, R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and n=2, as follows:

[0095]

[0096] How to use

[0097] The disclosed precursors may be deposited using any chemical vapor deposition process known to those skilled in the art to form a lanthanide-containing film. As used herein, the term "chemical vapor deposition process" refers to any method in which a substrate is exposed to one or more volatile precursors that react and / or decompose on the substrate surface to produce the desired deposition. As used herein, the term "atomic layer deposition process" refers to a self-limiting (e.g., the amount of film material deposited in each reaction cycle is constant) sequential surface chemistry that deposits a film of material onto a substrate of varying composition. Although the precursors, reagents, and sources used herein may sometimes be described as "gaseous," it should be understood that the precursor may be a liquid or solid that is transported to the reactor by direct vaporization, bubbling, or sublimation with or without an inert gas. In some cases, the vaporized precursor may pass through a plasma generator. The term "reactor" as used herein includes, but is not limited to, a reaction chamber, a reaction vessel, or a deposition chamber.

[0098] Chemical vapor deposition processes in which the disclosed and claimed precursors may be used include, but are not limited to, those used to fabricate semiconductor type microelectronic devices, such as ALD, CVD, pulsed CVD, plasma enhanced ALD (PEALD), and / or plasma enhanced CVD (PECVD). Examples of deposition processes suitable for the methods disclosed herein include, but are not limited to, cyclic CVD (CCVD), MOCVD (metal organic CVD), thermal chemical vapor deposition, plasma enhanced chemical vapor deposition ("PECVD"), high density PECVD, photon assisted CVD, plasma-photon assisted chemical vapor deposition ("PPECVD"), low temperature chemical vapor deposition, chemical assisted vapor deposition, hot filament chemical vapor deposition, CVD of liquid polymer precursors, deposition of supercritical fluids, and low energy CVD (LECVD). In certain embodiments, the metal-containing film is deposited by atomic layer deposition (ALD), plasma enhanced ALD (PEALD), or plasma enhanced cyclic CVD (PECCVD) processes.

[0099] In one embodiment, for example, the metal-containing film is deposited using an ALD process. In another embodiment, the metal-containing film is deposited using a CCVD process. In a further embodiment, the metal-containing film is deposited using a thermal CVD process.

[0100] Suitable substrates on which the disclosed and claimed precursors may be deposited are not particularly limited and vary according to the final intended use. For example, the substrate may be selected from oxides such as HfO2-based materials, TiO2-based materials, ZrO2-based materials, rare earth oxide-based materials, ternary oxide-based materials, etc., or from nitride-based films. Other substrates may include solid substrates such as metal substrates (e.g., Au, Pd, Rh, Ru, W, Al, Ni, Ti, Co, Pt) and metal silicides (e.g., TiSi2, CoSi2, and NiSi2); substrates containing metal nitrides (e.g., TaN, TiN, WN, TaCN, TiCN, TaSiN, and TiSiN); semiconductor materials (e.g., Si, SiGe, GaAs, InP, diamond, GaN, and SiC); insulators (e.g., SiO2, Si3N4, SiON, HfO2, Ta2O5, ZrO2, TiO2, Al2O3, and barium strontium titanate); and combinations thereof. Preferred substrates include TiN, Ru and Si type substrates.

[0101] In such deposition methods and processes, an oxidant may be used. The oxidant is usually introduced in gaseous form. Examples of suitable oxidants include, but are not limited to, oxygen, water vapor, ozone, oxygen plasma, or mixtures thereof.

[0102] Deposition methods and processes may also involve one or more purge gases. The purge gas used to purge unconsumed reactants and / or reaction byproducts is an inert gas that does not react with the precursor. Exemplary purge gases include, but are not limited to, argon (Ar), nitrogen (N2), helium (He), neon, and mixtures thereof. For example, a purge gas such as argon is supplied to the reactor for about 0.1 to 10,000 seconds at a flow rate in the range of about 10 to about 2000 sccm to purge unreacted materials and any byproducts that may remain in the reactor.

[0103] Deposition methods and processes require that energy be applied to at least one of the precursor, oxidant, other precursors, or a combination thereof to initiate a reaction and form a metal-containing film or coating on the substrate. Such energy may be provided by, but is not limited to, heat, plasma, pulsed plasma, helicon plasma, high density plasma, inductively coupled plasma, X-ray, electron beam, photon, remote plasma methods, and combinations thereof. In some methods, a secondary RF frequency source may be used to change the plasma characteristics at the substrate surface. When plasma is used, the plasma generation process may include a direct plasma generation process in which the plasma is generated directly in the reactor, or alternatively a remote plasma generation process in which the plasma is generated outside the reactor and supplied to the reactor.

[0104] When used in such deposition method processes, suitable precursors - such as those disclosed and claimed herein - can be delivered to a reaction chamber, such as a CVD or ALD reactor, by various means. In some cases, a liquid delivery system can be used. In other cases, a combined liquid delivery and flash process device, such as a turbo evaporator manufactured by MSP, Shoreview, MN, can be used to achieve quantitative delivery of low-volatility materials, which results in reproducible delivery and deposition without thermal decomposition of the precursor. The precursor compositions described herein can be effectively used as source reagents by direct liquid injection (DLI) to inject vapor streams of these metal precursors into an ALD or CVD reactor.

[0105] When used in these deposition methods and processes, the disclosed and claimed precursors include hydrocarbon solvents, which are particularly desirable because they can be dried to sub-ppm water levels. Exemplary hydrocarbon solvents that can be used in the precursors include, but are not limited to, toluene, mesitylene, cumene (isopropylbenzene), p-cumene (4-isopropyltoluene), 1,3-diisopropylbenzene, octane, dodecane, 1,2,4-trimethylcyclohexane, n-butylcyclohexane, and decalin. The disclosed and claimed precursors can also be stored and used in stainless steel containers. In a particular embodiment, the hydrocarbon solvent is a high boiling point solvent or has a boiling point of 100° C. or higher. The disclosed and claimed precursors can also be mixed with other suitable metal precursors, and the mixture is used to simultaneously deliver two metals for the growth of binary metal-containing films.

[0106] Flows of argon and / or other gases may be used as carrier gases to help deliver vapor containing at least one disclosed and claimed precursor to the reaction chamber during precursor pulses. When delivering precursors, the reaction chamber process pressure is 1 to 50 torr, preferably 5 to 20 torr.

[0107] In the deposition of high quality metal-containing films, substrate temperature can be an important process variable. Typical substrate temperatures range from about 150° C. to about 550° C. Higher temperatures can promote higher film growth rates.

[0108] In view of this, one skilled in the art will recognize that the disclosed and claimed subject matter further includes the use of the disclosed and claimed precursors in chemical vapor deposition processes as follows.

[0109] In one embodiment, the disclosed and claimed subject matter includes a method of forming a transition metal-containing film on at least one surface of a substrate, comprising the steps of:

[0110] a. providing the at least one surface of the substrate in a reaction vessel;

[0111] b. forming a transition metal-containing film on at least one surface by a deposition process selected from a chemical vapor deposition (CVD) process and an atomic layer deposition (ALD) process using one of the disclosed and claimed precursors as a metal source compound for the deposition process.

[0112] In a further aspect of this embodiment, the method includes introducing at least one reactant into the reaction vessel. In a further aspect of this embodiment, the method includes introducing at least one reactant into the reaction vessel, wherein the at least one reactant is selected from water, diatomic oxygen, oxygen plasma, ozone, NO, N2O, NO2, carbon monoxide, carbon dioxide, and combinations thereof. In another aspect of this embodiment, the method includes introducing at least one reactant into the reaction vessel, wherein the at least one reactant is selected from ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine, nitrogen, nitrogen / hydrogen, ammonia plasma, nitrogen plasma, nitrogen / hydrogen plasma, and combinations thereof. In another aspect of this embodiment, the method includes introducing at least one reactant into the reaction vessel, wherein the at least one reactant is selected from hydrogen, hydrogen plasma, a mixture of hydrogen and helium, a mixture of hydrogen and argon, hydrogen / helium plasma, hydrogen / argon plasma, boron-containing compounds, silicon-containing compounds, and combinations thereof.

[0113] In one embodiment, the disclosed and claimed subject matter includes a method of forming a transition metal-containing film via an atomic layer deposition (ALD) process or an ALD-like process, comprising the steps of:

[0114] a. providing a substrate in a reaction vessel;

[0115] b. introducing one or more disclosed and claimed precursors into a reaction vessel;

[0116] c. purging the reaction vessel with a first purge gas;

[0117] d. Introducing source gas into the reaction vessel;

[0118] e. purging the reaction vessel with a second purge gas;

[0119] f. Repeat steps b to e sequentially until a transition metal-containing film of desired thickness is obtained.

[0120] In a further aspect of this embodiment, the source gas is one or more of an oxygen-containing source gas selected from water, diatomic oxygen, oxygen plasma, ozone, NO, N2O, NO2, carbon monoxide, carbon dioxide, and combinations thereof. In another aspect of this embodiment, the source gas is one or more of a nitrogen-containing source gas selected from ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine, nitrogen, nitrogen / hydrogen, ammonia plasma, nitrogen plasma, nitrogen / hydrogen plasma, and mixtures thereof. In a further aspect of this embodiment, the first and second purge gases are each independently selected from one or more of argon, nitrogen, helium, neon, and combinations thereof. In a further aspect of this embodiment, the method further comprises applying energy to at least one of the precursor, the source gas, the substrate, and combinations thereof, wherein the energy is one or more of heat, plasma, pulsed plasma, helicon plasma, high-density plasma, inductively coupled plasma, X-ray, electron beam, photon, remote plasma method, and combinations thereof. In a further aspect of this embodiment, step b of the method further comprises introducing the precursor into the reaction vessel by transporting the vapor of the precursor into the reaction vessel using a carrier gas flow. In a further aspect of this embodiment, step b of the method further comprises using one or more solvent media comprising toluene, mesitylene, isopropylbenzene, 4-isopropyltoluene, 1,3-diisopropylbenzene, octane, dodecane, 1,2,4-trimethylcyclohexane, n-butylcyclohexane and decalin, and combinations thereof.

[0121] In another embodiment, a precursor of Formula I having at least one bound cyclopentadienyl ligand and at least one amidino ligand can be used as a dopant for a metal-containing film such as, but not limited to, a metal oxide film or a metal nitride film. In these embodiments, the metal-containing film is deposited using an ALD, ALD-like, or CVD process such as those described herein using a metal alkoxide, a metal amide, or a volatile organometallic precursor. Examples of suitable metal alkoxide precursors that can be used in the methods disclosed herein include, but are not limited to, Group 3 to 13 metal alkoxides, Group 3 to 13 metal complexes with alkoxy and alkyl substituted cyclopentadienyl ligands, Group 3 to 6 metal complexes with alkoxy and alkyl substituted pyrrolyl ligands, Group 3 to 13 metal complexes with alkoxy and diketone ligands; Group 3 to 13 metal complexes with alkyl ligands. Exemplary Group 3 to 13 metals herein include, but are not limited to, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, Lu, Ti, Hf, Zr, V, Nb, Ta, Cr, Mo, W, Co, Ru, and Al.

[0122] Suitable metal amide precursors that can be used in the methods disclosed herein include, but are not limited to, tetrakis(dimethylamino)zirconium (TDMAZ), tetrakis(diethylamino)zirconium (TDEAZ), tetrakis(ethylmethylamino)zirconium (TEMAZ), tris(dimethylamino)(cyclopentadienyl)zirconium, tetrakis(dimethylamino)hafnium (TDMAH), tetrakis(diethylamino)hafnium (TDEAH), and tetrakis(ethylmethylamino)hafnium (TEMAH), tris(dimethylamino)(cyclopentadienyl)hafnium, tetrakis(dimethylamino)titanium (TDMAT), tetrakis(diethylamino)titanium (TDEAT), tetrakis(ethylmethylamino)titanium (TEMAT), tert-butyliminotris(diethylamino)tantalum (TBTDET), tert-butyliminotris(diethylamino)tantalum (TBTDET), and tert-butyliminotris(diethylamino)tantalum (TBTDET). (dimethylamino) tantalum (TBTDMT), tert-butylimino tris (ethylmethylamino) tantalum (TBTEMT), ethylimino tris (diethylamino) tantalum (EITDET), ethylimino tris (dimethylamino) tantalum (EITDMT), ethylimino tris (ethylmethylamino) tantalum (EITEMT), tert-amylimino tris (dimethylamino) tantalum (TAIMAT), tert-amylimino tris (diethylamino) tantalum, penta (dimethylamino) tantalum, tert-amylimino tris (ethylmethylamino) tantalum, bis (tert-butylimino) bis (dimethylamino) tungsten (BTBMW), bis (tert-butylimino) bis (diethylamino) tungsten, bis (tert-butylimino) bis (ethylmethylamino) tungsten and combinations thereof. Examples of suitable organometallic precursors that can be used in the methods disclosed herein include, but are not limited to, Group 3 metal cyclopentadienyls or alkyl cyclopentadienyls.

[0123] Examples of suitable metal complexes with alkyl ligands that can be used in the methods disclosed herein include, but are not limited to, tri-tert-butylaluminum (TTBA), trimethylaluminum (TMA), triethylaluminum (TEA), dimethylaluminum hydride (DMAH), dimethylethylaminealane (DMEAA), trimethylaminealane (TEAA), N-methylpyrrolidine-alane (MPA), and triisobutylaluminum (TIBA).

[0124] Example

[0125] Reference will now be made to more specific embodiments of the present disclosure, as well as experimental results that provide support for these embodiments.The examples given below are intended to more fully illustrate the disclosed subject matter and should not be construed as limiting the disclosed subject matter in any way.

[0126] It will be apparent to those skilled in the art that various modifications and variations may be made to the disclosed subject matter and the specific examples provided herein without departing from the spirit or scope of the disclosed subject matter. Therefore, the disclosed subject matter, including the description provided by the following examples, is intended to cover modifications and variations of the disclosed subject matter within the scope of any claims and their equivalents.

[0127] Materials and methods:

[0128] Unless otherwise indicated, all solvents and starting materials were purchased from Sigma-Aldrich. Tris-(1-isopropyl-3-methylcyclopentadienyl)lanthanum(III) [La(iPr-Me-Cp)3] was prepared in-house. La(iPr2-FAMD)3 used was purchased from STREM.

[0129] Comparative Example 1: Synthesis of La(iPr-Me-Cp)3

[0130] Tris-trimethylsilyl lanthanum (III) amino (La(HMDS)3) (8.2 g, 13 mmol) was suspended in 30 mL of toluene. Excess 1-isopropyl-3-methylcyclopentadiene (iPr-Me-CpH) (11.1 g, 91 mmol) was added to the suspension. The mixture was stirred at 80°C for 5 days. The solvent and volatile by-products were removed from the mixture under reduced pressure, and the crude product was vacuum distilled (260°C, 2x10 -2 mbar). Yield: 54%.

[0131] Characterization: 1 H NMR (500 MHz, C6D6) δ 6.00–5.78 (m, 9H), 2.85–2.67 (m, 3H), 2.13–2.05 (m, 9H), 1.20–1.09 (m, 19H).; TGA: melting point 55 °C; initial mass: 4.478 mg; T 50％ =280.1℃, see Figure 1 .

[0132] Synthesis Example 1: Synthesis of La(iPr-Me-Cp)2(iPr2-FAMD)

[0133] Tris-(1-isopropyl-3-methylcyclopentadienyl)lanthanum(III)[La(iPr-Me-Cp)3](1.35 g, 2.69 mmol) was dissolved in 15 mL of toluene. Tris-(diisopropylcarboxamidino)lanthanum(III)[La(iPr2-FAMD)3](0.699 g, 1.34 mmol) was dissolved in another 15 mL of toluene, and the two solutions were combined and stirred at 100°C for 72 h. The solvent was removed from the mixture, and the crude product was distilled (90°C, 2x10-2 mbar) to produce 1.38 g of yellow liquid product. Yield: 67.5%.

[0134] Characterization: 1 H NMR (500 MHz, C6D6) δ 6.04 (dt, J = 9.6, 2.8 Hz, 2H), 6.00 (q, J = 2.8 Hz, 2H), 5.92 (dt, J = 15.9, 2.8 Hz, 2H), 3.06 (hept, J = 6.5 Hz, 2H), 2.91 (heptd, J = 6.9, 3.2 Hz, 2H), 2.18 (d, J = 2.9 Hz, 6H), 1.26 (dd, J = 7.0, 4.3 Hz, 12H), 1.08 (d, J = 6.4 Hz, 12H); TGA: initial mass: 8.720 mg, T 50％ =254.9°C; DSC: initial endothermic effect: 365°C.

[0135] It is noteworthy that the product remains liquid after distillation. Figure 2 As shown, NMR showed a clean product. TGA showed clean vaporization, indicating good volatility, and DSC showed good thermal stability up to 365°C (no melting point could be detected between -100°C and 365°C). See respectively Figure 3 and 4 .

[0136] The foregoing description is primarily for illustrative purposes. Although the disclosed and claimed subject matter has been shown and described with respect to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes, omissions, and additions to the foregoing, as well as to form and detail thereof, may be made therein without departing from the spirit and scope of the disclosed and claimed subject matter.

[0137] Synthesis Example 2: Synthesis of La(tBu-Me-Cp)2(iPr2-FAMD)

[0138] Tris-(1-tert-butyl-3-methylcyclopentadienyl)lanthanum(III)[La(tBu-Me-Cp)3](588.5 mg, 1.08 mmol) was dissolved in 15 mL of toluene. Tris-(diisopropylcarboxamidino)lanthanum(III)[La(iPr2-FAMD)3](281.2 mg, 0.54 mmol) was dissolved in another 15 mL of toluene, and the two solutions were combined and stirred at 100°C for 72 h. The solvent was removed from the mixture, and the crude product was distilled (90°C, 2x10 -2 mbar) to produce 240 mg of yellow liquid product. Yield: 27.6%.

[0139] Characterization: 1H NMR (500 MHz, C6D6) δ 8.00 (d, J = 3.3 Hz, 1H), 6.15 (dt, J = 12.8, 2.8 Hz, 2H), 6.10 (dt, J = 9.8, 2.6 Hz, 2H), 5.89 (dt, J = 29.6, 2.9 Hz, 2H), 3.10 (hept, J = 6.4 Hz, 2H), 2.21 (d, J = 8.5 Hz, 6H), 1.32 (d, J = 9.2 Hz, 18H), 1.12 (dd, J = 6.5, 3.7 Hz, 12H). TGA: initial mass: 9.6460 mg, T 50％ =273.7℃; DSC: initial endothermic effect 390℃.

[0140] Notably, the product remained a liquid after distillation. NMR showed a clean product. TGA showed a clean vaporization, indicating good volatility, and DSC showed good thermal stability up to 390°C (no melting point could be detected between -50°C and 365°C).

[0141] ALD of lanthanum oxide films using La(iPr-Me-Cp)2(iPr2-FAMD)

[0142] Atomic Premium CN-1 200mm reactor was used to demonstrate atomic layer deposition of lanthanum oxide films using the precursors of the present invention. The precursor, La(iPr-Me-Cp)2(iPr2-FAMD), was delivered from a SS316 ampoule (container) maintained at 130°C (ampule wall temperature). An argon carrier gas flow of 50sccm was used to deliver the precursor vapor to the reaction chamber. The reaction chamber pressure was 1 torr. Si and SiO2 substrates were used to deposit lanthanum oxide films. The lanthanum oxide film thickness was measured by ellipsometry and X-ray fluorescence (XRF) calibrated with SEM images of cross-sections of deposited lanthanum oxide films.

[0143] Example 3: Precursor thermal decomposition test on Si wafer

[0144] In this experiment, the precursor vapor was delivered to the deposition chamber in a pulsed mode separated by an Argon purge. The pulse sequence was: 5 sec precursor pulse and 20 sec Argon purge. The total number of precursor / Ar purge cycles was 100. Oxidant-free pulses were used in this experiment to demonstrate the good thermal stability of the precursor in the absence of an oxidant. Good thermal stability (lack of deposition in the absence of an oxidant) is an important precursor property for the atomic layer deposition process. The wafer temperature was varied between 200 and 450°C. After the experiment, the lanthanum layer density on the surface was measured by X-ray fluorescence analysis and as shown in FIG. Figure 5No increase in lanthanum concentration on the silicon wafer is observed until at least 450° C., indicating a very good thermal stability of this precursor in the vapor phase and its usefulness for vapor deposition applications.

[0145] Example 4: Precursor saturation behavior during deposition process

[0146] In this experiment, the lanthanum oxide film was deposited by an atomic layer deposition method, which includes the following steps:

[0147] a. Providing a Si or SiO2 substrate in a reaction vessel;

[0148] b. Introducing La(iPr-Me-Cp)2(iPr2-FAMD) precursor into the reaction vessel;

[0149] c. purging the reaction vessel with argon;

[0150] d. introducing ozone into the reaction vessel;

[0151] e. purging the reaction vessel with argon; and

[0152] f. Repeat steps b to e sequentially until a transition metal-containing film of desired thickness is obtained.

[0153] The lanthanum precursor pulse was varied between 0.5 and 3 seconds to demonstrate saturation behavior with increasing pulse time. The Ar purge after the precursor pulse was 10 sec, the ozone pulse was 1 sec, and the Ar purge after the precursor pulse was 30 sec. The number of ALD cycles was 100. Figure 6 It shows very good saturation behavior at temperatures of 200 and 250° C. Saturation behavior is one of the key features of the atomic layer deposition process.

[0154] Example 5: Deposition of lanthanum oxide film

[0155] In this experiment, the lanthanum oxide film was deposited by atomic layer deposition, which included the following steps:

[0156] a. Providing a Si or SiO2 substrate in a reaction vessel;

[0157] b. Introducing La(iPr-Me-Cp)2(iPr2-FAMD) precursor into the reaction vessel;

[0158] c. purging the reaction vessel with argon;

[0159] d. introducing ozone into the reaction vessel;

[0160] e. purging the reaction vessel with argon; and

[0161] f. Repeat steps b to e sequentially until a transition metal-containing film of desired thickness is obtained.

[0162] The lanthanum precursor pulse was 3 seconds. The Ar purge after the precursor pulse was 30 sec, the ozone pulse was 1 sec, and the Ar purge after the precursor pulse was 30 sec. The number of ALD cycles was 100. The wafer temperature was 175 and 275°C. Figure 7 shows cross-sectional TEM images of lanthanum oxide films deposited on structured wafers at 175 and 275°C. Table 5 shows the film thickness at the top, middle, and bottom of the grooves of the patterned wafer. TEM shows the deposition of a smooth, dense film. The experiment also showed that there was only a small change in step coverage between 175 and 275°C, indicating that the ALD performance was good. Without being limited to theory, it is believed that the step coverage can be further improved by process optimization (e.g., longer precursor pulse times).

[0163]

[0164] Table 5

[0165] The foregoing description is primarily for illustrative purposes. Although the disclosed and claimed subject matter has been shown and described with respect to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes, omissions, and additions to the foregoing and to the form and details thereof may be made therein without departing from the spirit and scope of the disclosed and claimed subject matter.

Claims

1. A precursor of the formula (cyclopentadienyl ligand) 2-M-(amidino ligand), wherein M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

2. A precursor of the formula (cyclopentadienyl ligand)-M-(amidine ligand)2, wherein M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

3. The precursor according to claim 1 or 2, wherein M is one of La, Ce, Y and Sm.

4. The precursor according to claim 1 or 2, wherein M is La.

5. The precursor according to claim 1 or 2, wherein M is Ce.

6. The precursor of claim 1 or 2, wherein M is Y.

7. The precursor of claim 1 or 2, wherein M is Sm.

8. The precursor of claim 1 or 2, wherein each cyclopentadienyl ligand is independently derived from a cyclopentadiene as shown in Table 1: Table 1.

9. The precursor of claim 1 or 2, wherein the amidino ligand is selected from the amidino ligands shown in Table 2: Table 2.

10. The precursor of claim 1, wherein the precursor has the structure shown in Table 3: Table 3.

11. The precursor of claim 2, wherein the precursor has the structure shown in Table 4: Table 4.

12. A precursor having formula I: in (i) M is one of La, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; (ii) R 1 , R 2 , R 3 , R 4 and R 5 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl, halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3, Where (a) R 1 , R 2 , R 3 , R 4 and R 5 contains at least three different substituents and (b) R 1 , R 2 , R 3 , R 4 and R 5 At least two of them are H; (iii) R 6 , R 7 and R 8 Each is a substituent independently selected from H, unsubstituted straight-chain C1-C6 alkyl, halogen-substituted straight-chain C1-C6 alkyl, amino-substituted straight-chain C1-C6 alkyl, unsubstituted branched C3-C6 alkyl, halogen-substituted branched C3-C6 alkyl, amino-substituted branched C3-C6 alkyl and -Si(CH3)3; (iv) n = 1 or 2; and (v) The precursor is liquid at a temperature below about 80°C.

13. The precursor of claim 12, wherein M is Sc. The precursor of claim 12 , wherein M is Y.

15. The precursor of claim 12, wherein M is La.

16. The precursor of claim 12, wherein M is Ce.

17. The precursor of claim 12, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 Each is independently selected from H, unsubstituted straight chain C1-C5 straight chain alkyl and unsubstituted branched C3-C6 alkyl.

18. The precursor of claim 12, wherein R 1 , R 2 , R 3 , R 4 and R 5 Three of them are H.

19. The precursor of claim 12, wherein R 1 , R 2 , R 3 , R 4 and R 5 Two of them are H.

20. The precursor of claim 12, wherein R 5 , R 6 and R 8 One or more of them is isopropyl.

21. The precursor of claim 12, wherein R 5 , R 6 and R 8 Two or more of them are isopropyl groups.

22. The precursor of claim 12, wherein R 5 , R 6 and R 8 Each is isopropyl.

23. The precursor of claim 12, wherein n=1.

24. The precursor of claim 12, wherein n=2.

25. The precursor of claim 12, wherein (ii) R 1 , R 6 and R 8 Each is isopropyl, R 3 is methyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen, and (iv) n=2. (See claim 31) 26. The precursor of claim 12, wherein (i) M = La, (ii) R 1 , R 6 and R 8 Each is isopropyl, R 3 is methyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=2.

27. The precursor of claim 12, wherein (ii) R 1 , R 6 and R 8 Each is isopropyl, R 3 and R 7 Each is a methyl group, and R 2 , R 4 and R 5 Each is hydrogen.

28. The precursor of claim 12, wherein (i) M = La, (ii) R 1 , R 6 and R 8 Each is isopropyl, R 3 and R 7 Each is a methyl group, and R 2 , R 4 and R 5 each is hydrogen, and (iv) n=2.

29. The precursor of claim 12, wherein (ii) R 1 is sec-butyl, R 3 Methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen.

30. The precursor of claim 12, wherein (i) M = La, (ii) R 1 For sec-butyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=2.

31. The precursor of claim 12, wherein (ii) R 1 , R 6 and R 8 Each is isopropyl, R 3 is methyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=1.

32. The precursor of claim 12, wherein (i) M = La, (ii) R 1 is isopropyl, R 3 is methyl, R 6 Ethyl, R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=2.

33. The precursor of claim 12, wherein (ii) R 1 Ethyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen.

34. The precursor of claim 12, wherein (i) M = La, (ii) R 1 Ethyl, R 3 is methyl, R 6 and R 8 Each is isopropyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=2.

35. The precursor of claim 12, wherein (ii) R 1 and R 6 Each is ethyl, R 3 is methyl, R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 Each is hydrogen.

36. The precursor of claim 12, wherein (i) M = La, (ii) R 1 and R 6 Each is ethyl, R 3 is methyl, R 8 is tert-butyl, and R 2 , R 4 , R 5 and R 7 each is hydrogen, and (iv) n=2.

37. The precursor of claim 12, wherein the precursor comprises at least one cyclopentadienyl ligand as shown in Table 1.

38. The precursor of claim 12, wherein the precursor comprises at least one amidino ligand as shown in Table 2.

39. The precursor of claim 12, wherein the precursor has a structure as shown in Table 3.

40. The precursor of claim 12, wherein the precursor has a structure as shown in Table 4.

41. A precursor having the following structure:

42. A precursor having the following structure:

43. A precursor having the following structure:

44. A precursor having the following structure:

45. A precursor having the following structure:

46. ​​A precursor having the following structure:

47. A precursor having the following structure:

48. A method for forming a transition metal-containing film on at least one surface of a substrate, comprising: a. providing the at least one surface of the substrate in a reaction vessel; b. forming a transition metal-containing film on at least one surface by a deposition process selected from a chemical vapor deposition (CVD) process and an atomic layer deposition (ALD) process, using a precursor as described in any one of claims 1 to 47 as a metal source compound for the deposition process.

49. The method of claim 48, further comprising introducing at least one reactant into the reaction vessel.

50. The method of claim 48, further comprising introducing at least one reactant selected from the group consisting of water, diatomic oxygen, oxygen plasma, ozone, NO, N2O, NO2, carbon monoxide, carbon dioxide, and combinations thereof into the reaction vessel.

51. The method of claim 48, further comprising introducing at least one reactant selected from the group consisting of ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine, nitrogen, nitrogen / hydrogen, ammonia plasma, nitrogen plasma, nitrogen / hydrogen plasma, and combinations thereof into the reaction vessel.

52. The method of claim 48, further comprising introducing into the reaction vessel at least one reactant selected from the group consisting of hydrogen, hydrogen plasma, a mixture of hydrogen and helium, a mixture of hydrogen and argon, a hydrogen / helium plasma, a hydrogen / argon plasma, a boron-containing compound, a silicon-containing compound, and combinations thereof.

53. A method for forming a transition metal-containing film by an atomic layer deposition (ALD) process or an ALD-like process, the method comprising the steps of: a. providing a substrate in a reaction vessel; b. introducing a precursor as claimed in any one of claims 1 to 47 into the reaction vessel; c. purging the reaction vessel with a first purge gas; d. introducing a source gas into the reaction vessel; e. purging the reaction vessel with a second purge gas; f. Repeat steps b to e sequentially until the transition metal-containing film having a desired thickness is obtained.

54. The method of claim 53, wherein the source gas is one or more oxygen-containing source gases selected from water, diatomic oxygen, oxygen plasma, ozone, NO, N2O, NO2, carbon monoxide, carbon dioxide, and combinations thereof.

55. The method of claim 53, wherein the source gas is one or more nitrogen-containing source gases selected from ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine, nitrogen, nitrogen / hydrogen, ammonia plasma, nitrogen plasma, nitrogen / hydrogen plasma, and mixtures thereof.

56. The method of claim 53, wherein the first and second purge gases are each independently selected from one or more of argon, nitrogen, helium, neon, and combinations thereof.

57. The method of claim 53, further comprising applying energy to at least one of the precursor, the source gas, the substrate, and combinations thereof, wherein the energy is one or more of thermal, plasma, pulsed plasma, helicon plasma, high density plasma, inductively coupled plasma, X-rays, electron beams, photons, remote plasma methods, and combinations thereof.

58. The method of claim 53, wherein step b further comprises introducing the precursor into the reaction vessel by transporting a vapor of the precursor into the reaction vessel using a carrier gas flow.

59. The method of claim 53, wherein step b further comprises using a solvent medium comprising one or more of toluene, mesitylene, isopropylbenzene, 4-isopropyltoluene, 1,3-diisopropylbenzene, octane, dodecane, 1,2,4-trimethylcyclohexane, n-butylcyclohexane and decalin, and combinations thereof.

60. A method for forming a transition metal-containing film on at least one surface of a substrate, comprising: a. providing the at least one surface of the substrate in a reaction vessel; b. forming a transition metal-containing film on at least one surface by a deposition process selected from a chemical vapor deposition (CVD) process and an atomic layer deposition (ALD) process, using a precursor as a metal source compound for the deposition process; and c. Using a precursor as claimed in any one of claims 1 to 47 as a dopant material.

61. A precursor supply package comprising a container and a precursor as claimed in any one of claims 1 to 47, wherein the container is adapted to contain and dispense the precursor.

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