TITANIUM-CONTAINING PRECURSORS FOR

VAPOR DEPOSITION

Cross-Reference to Related Applications

This application claims priority to U.S. application No. 61/651 ,816, filed May

25, 2012, the entire contents of which are incorporated herein by reference.

Technical Field

Disclosed are titanium-containing precursors, methods of synthesizing the same, and methods of using the same to deposit titanium oxides or oxynitrides or other metal doped oxides containing layers using vapor deposition processes for manufacturing semi-conductors.

Background

One of the challenges the semiconductor industry faces is developing new gate dielectric materials for DRAM and capacitors. For decades, silicon dioxide (S1O2) was a reliable dielectric, but as transistors have continued to shrink and the technology has moved from "Full Si" transistors to "Metal Gate/High-k" transistors, the reliability of the SiO ₂ -based gate dielectric is reaching its physical limits. The need for new high dielectric constant materials and processes is increasing and becoming more relevant as the size of current technology shrinks.

Similarly, high-k dielectrics are required in Metal-lnsulator-Metal architectures for RAM applications. Various metal compositions have been considered to fulfill both the materials requirements (dielectric constant, leakage current, crystallization temperature, charge trapping) and the integration requirements (thermal stability at the interface, dry etching feasibility...).

Standard dielectric materials like TiO ₂ or new dielectric materials such as strontium titanates, such as SrTiO3 or Sr ₂ TiO ₄ , barium strontium titanates, or lead zirconium titanates provide a significant advantage in capacitance compared to conventional dielectric materials. The new dielectric materials are also attractive candidates for several thin film applications, such as high dielectric constant materials for electronic devices, anti-reflection optical coatings, biocompatible coatings, photocatalysis, and solar cells.

Nevertheless, deposition of Ti containing layers is difficult and new materials and processes are needed. For instance, atomic layer deposition, ALD, has been identified as an important thin film growth technique for microelectronics manufacturing, relying on sequential and saturating surface reactions of alternatively applied precursors, separated by inert gas purging. Frequently, an oxygen source such as ozone or water is used in this deposition method. The surface-controlled nature of ALD enables the growth of thin films of high conformality and uniformity with an accurate thickness control.

In STO ALD deposition, available Sr precursors show excellent reactivity with O3 and acceptable reactivity with water. However, the use of ozone as an oxidant may have undesired results with the underlying layer, such as TiN or strontium ruthenium oxide (SRO). When the STO film is deposited at high temperature, it may either oxidize the TiN layer or partially etch Ru from SRO layer.

Although atomic layer deposition (ALD) of Ti compounds has been disclosed, these metal precursors have poor reactivity, especially with moisture, and low stability often requiring low substrate temperatures and strong oxidizers to grow a film, which is often contaminated with carbon or nitrogen.

Air Liquide showed that most of the standard homoleptic Ti molecules have limited ALD process temperature window or no deposition (R. Katamreddy, V. Omarjee, B. Feist, C. Dussarrat, ECS conference 2008). For example, in a water ALD process, the Ti molecules titanium tetrakis(isopropoxide) (TTIP), tetrakis(dimethylamino) titanium (TDMAT), tetrakis(diethylamino) titanium (TDEAT), and tetrakis(ethylmethylamino) titanium (TEMAT) had deposition rates below 0.6 A cycle and process windows that did not exceed 250°C. Id.

New Ti precursors having higher thermal stability at higher process temperatures are needed. High temperature processes are desired to generate high quality T1O2 (doped or undoped) and STO films with very high dielectric constants (preferably with k > 50).

Burger et al. disclose synthesis and characteristics of dialkylamido-titanium-N- heterocycles (Z. anorg. allg. Chemie. Bd. 394, Dec 1972, pp. 209-304).

In DE4120344, Kruck et al. disclose deposition of a Ti-, Zr-, or Hf-containing film on a substrate by decomposition of tris(dialkylamino) pyrrolyl compounds or bis(dialkylamino)dipyrrolyl compounds.

In EP0741 145, Katayama et al. disclose a catalyst system comprising a transition metal compound having at least one of a cyclopentadienyl group or a substituted cyclopentadienyl group and at least one of a cyclic ligand containing a hetero atom and having a delocalized π bond. The extensive listing of exemplary transition metal compounds includes molecules having halide bonds.

In WO2007/141059, Dussarrat et al. disclose Hf, Zr, and Ti compounds having the formula (R ¹ yOp) _x (R ² tCp) _z MR' _4- x-z, wherein 0<x<3; 0<z<3; 1 <(x+z)<4; 0<y<7; 0<t<5; R ¹ _y Op represents a pentad ienyl (Op) ligand; R ² tCp represents a cyclopentadienyl (Cp) ligand; R ¹ and R ² independently represent CI, a linear or branched alkyl group, an N-alkyl amino group, an Ν,Ν-dialkylamino group, a linear or branched alkoxy group, an alkylsilylamide group, an amidinate group, or a carbonyl group; and R' represents H, F, CI, Br, I, a linear or branched alkyl group, an N-alkyl amino group, an Ν,Ν-dialkylamino group, a linear or branched alkoxy group, an alkylsilyl amino group, a dialkylsilyl amino group, a trial kylsilyl amino group, an amidinate group, or a carbonyl group. Representative compounds include M(R ² _t Cp)2(NR ₂ )2 and M(R ² _t Cp)(NR ₂ ) ₃ .

In WO 201 1/156699 A1 , Norman et al. disclose metal complexes utilizing sterically hindered imidazolate ligands, where at least one of carbons of the imidazolate are substituted with a C1-C10 primary, secondary, or tertiary alkyl; C1-C10 primary, secondary or tertiary alkoxy; C1-C10 primary, secondary, or tertiary alkylamine; C1-C10 primary, second, or tertiary alkyl functionalized with a heteroatom substituted ring structure selected from the group consisting of imidazole, pyrrole, pyridine, furan, pyrimidine, pyrazole C1-C10 alkyl functionalized with an amide group; C1-C10 primary, secondary or tertiary alkyl functionalized with an ester group and mixtures thereof.

A need remains for liquid or low melting point (<70°C) group IV precursor compounds, and in particular Ti compounds, that would allow simultaneously a proper distribution (physical state and thermal stability at distribution temperatures), a wide self-limited ALD window, and a deposition of Ti-containing layers either by ALD or MOCVD.

Notation and Nomenclature

Certain abbreviations, symbols, and terms are used throughout the following description and claims, and include:

As used herein, the indefinite article "a" or "an" means one or more.

As used herein, the abbreviation "STO" refers to strontium titanates; the abbreviation "BST" refers to barium strontium titanates; the abbreviation "PZT" refers to lead zirconium titanates; As used herein, the term "alkyl group" refers to saturated functional groups containing exclusively carbon and hydrogen atoms. Further, the term "alkyl group" refers to linear, branched, or cyclic alkyl groups. Examples of linear alkyl groups include without limitation, methyl groups, ethyl groups, propyl groups, butyl groups, etc. Examples of branched alkyls groups include without limitation, t-butyl. Examples of cyclic alkyl groups include without limitation, cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, etc.

As used herein, the abbreviation "Me" refers to a methyl group; the abbreviation "Et" refers to an ethyl group; the abbreviation "Pr" refers to any propyl group (i.e., n-propyl or isopropyl); the abbreviation "iPr" refers to an isopropyl group; the abbreviation "Bu" refers to any butyl group (n-butyl, iso-butyl, t-butyl, sec-butyl); the abbreviation "tBu" refers to a tert-butyl group; the abbreviation "sBu" refers to a sec-butyl group; the abbreviation "iBu" refers to an iso-butyl group; the abbreviation "ph" refers to a phenyl group; the abbreviation "Cp" refers to cyclopentadienyl group; the abbreviation "Cp ^* " refers to a pentamethylcyclopentadienyl group;.

The standard abbreviations of the elements from the periodic table of elements are used herein. It should be understood that elements may be referred to by these abbreviations (e.g., Ti refers to titanium, Al refers to aluminum, Si refers to silicon, C refers to carbon, etc.).

Summary

Disclosed are molecules having the following formula:

Ti(Ri-R ₅ Cp)x(ER ₆ R7)y(Cy-amines)z

wherein:

Ri , R ₂ , R3, R4, R5, R6, and R ₇ are independently selected from the group consisting of H and C1 -C6 alkyl group;

x = 0-2;

y = 0-3;

z = 1 -4;

x+y+z = 4;

E=N or P;

^■ Cy-amines refer to saturated N-containing ring systems or un-saturated N-containing ring systems, the N-containing ring system comprising at least one nitrogen atom and 4-6 carbon atoms in a chain wherein R ₆ and R ₇ ≠ Me when x=0, R6 and R ₇ ≠ Et when x=0, and Cy-amine≠ pyrrolidine when x=4. The disclosed molecules may further include one or more of following aspects:

• the N-containing ring system consisting of at least one nitrogen atom and 4-6 carbon atoms;

· the N-containing ring system being selected from the group consisting of pyrroles, pyrrolidines, and piperidines;

• the N-containing ring system being a pyrrole;

• the N-containing ring system being a pyrrolidine;

• the N-containing ring system being a piperidine;

· the N-containing ring system further comprising one or more substituents independently selected from the group consisting of a C1 -C6 alkyl group;

• the (ER ₆ R ₇ ) ligand being selected from the group consisting of dimethylamino, methylethylamino, diethylamino, methylisopropylamino, dimethylphosphido, methylethylphosphido, diethylphosphido, and methylisopropylphosphido;

· the (ER ₆ R ) ligand being selected from the group consisting of dimethylamino, methylethylamino, diethylamino, and methylisopropylamino,;

• the (ER ₆ R ₇ ) ligand being selected from the group consisting of dimethylphosphido, methylethylphosphido, diethylphosphido, and methylisopropylphosphido;

· the (ER ₆ R ) ligand being selected from the group consisting of methylethylamino, methylisopropylamino, dimethylphosphido, methylethylphosphido, diethylphosphido, and methylisopropylphosphido.

• x=1 , y=0, and z=3;

• x=2, y=0, and z=2;

· x=2, y=1 , and z=1 ;

• x=1 , y=2, and z=1 .

• x=1 , y=1 , and z=2;

• x=0, y=3, and z=1 ;

• x=0, y=2, and z=2;

· x=0, y=1 , and z=3;

• x=0, y=0, and z=4;

• the disclosed molecule being selected from the group consisting of Ti(NMe ₂ ) ₃ (NC ₄ H ₈ ), Ti(NEtMe) ₃ (NC ₄ H ₈ ), Ti(NEt ₂ ) ₃ (NC ₄ H ₈ ), Ti(NMeiPr) ₃ (NC ₄ H ₈ ), (NMe ₂ ) ₃ (NC ₅ H ₁₀ ), Ti(NEtMe)3(NC ₅ Hio), Ti(NEt ₂ ) ₃ (NC ₅ H ₁₀ ),

(NMeiPr) ₃ (NC ₅ Hio), Ti(NMe ₂ )2(NC ₄ H ₈ )2, Ti(NEtMe) ₂ (NC ₄ H ₈ ) ₂ ,

(NEt ₂ ) ₂ (NC ₄ H ₈ ) ₂ , Ti(NMeiPr) ₂ (NC ₄ H ₈ ) ₂ , Ti(NMe ₂ ) ₂ (NC ₅ H ₁₀ ) ₂ ,

(NEtMe)2(NC ₅ Hio)2, Ti(NEt ₂ ) ₂ (NC ₅ H ₁₀ ) ₂ , Ti(NMeiPr) ₂ (NC ₅ Hio) ₂ ,

(NMe ₂ )(NC ₄ H ₈ ) ₃ , Ti(NEtMe)(NC ₄ H ₈ ) ₃ , Ti(NEt ₂ )(NC ₄ H ₈ ) ₃ , Ti(NMeiPr)(NC ₄ H ₈ ) ₃ ,

(NMe ₂ )(NC ₅ H ₁₀ ) ₃ , Ti(NEtMe)(NC ₅ Hio) ₃ Ti(NEt ₂ )(NC ₅ Hio) ₃ (NMeiPr)(NC ₅ H ₁₀ ) ₃ Ti(NMe ₂ )(NC ₄ H ₄ ) ₃ , Ti(NEtMe)(NC ₄ H ₄ ) ₃

(NEt ₂ )(NC ₄ H ₄ ) ₃ , Ti(NMeiPr)(NC ₄ H ₄ ) ₃ , Ti(NC ₄ H ₈ ) ₄ , Ti(NC ₅ Hi ₀ ) , Ti(NC ₄ H ₄ ) ₄ , (Cp)(NMe ₂ ) ₂ (NC ₄ H ₈ ), Ti(Cp)(NEtMe) ₂ (NC ₄ H ₈ ), Ti(Cp)(NEt ₂ ) ₂ (NC ₄ H ₈ ),

(Cp)(NMeiPr) ₂ (NC ₄ H ₈ ), Ti(Cp)(NMe ₂ ) ₂ (NC ₅ Hio), Ti(Cp)(NEtMe) ₂ (NC ₅ Hi ₀ ),

(Cp)(NEt ₂ ) ₂ (NC ₅ H ₁₀ ), Ti(Cp)(NMeiPr) ₂ (NC5H ₁₀ ), Ti(Cp)(NMe ₂ ) ₂ (NC ₄ H ₄ ),

(Cp)(NEtMe) ₂ (NC ₄ H ₄ ), Ti(Cp)(NEt ₂ ) ₂ (NC ₄ H ₄ ), Ti(Cp)(NMeiPr) ₂ (NC ₄ H ₄ ),

(Cp)(NMe ₂ )(NC ₄ H ₈ ) ₂ , Ti(Cp)(NEtMe)(NC ₄ H ₈ ) _2j Ti(Cp)(NEt ₂ )(NC ₄ H ₈ ) ₂ ,

(Cp)(NMeiPr)(NC ₄ H ₈ ) ₂ , Ti(Cp)(NMe ₂ )(NC ₅ Hio) _2j Ti(Cp)(NEtMe)(NC ₅ Hio) ₂ ,

(Cp)(NEt ₂ )(NC ₅ H ₁₀ ) ₂ , Ti(Cp)(NMeiPr)(NC5H ₁₀ ) ₂ , Ti(Cp)(NMe ₂ )(NC ₄ H ₄ ) ₂ ,

(Cp)(NEtMe)(NC ₄ H ₄ ) ₂ , Ti(Cp)(NEt ₂ )(NC ₄ H ₄ ) ₂ , Ti(Cp)(NMeiPr)(NC ₄ H ₄ ) ₂ ,

(Cp) ₂ (NMe ₂ )(NC ₄ H ₈ ), Ti(Cp) ₂ (NEtMe)(NC ₄ H ₈ ), Ti(Cp) ₂ (NEt ₂ )(NC ₄ H ₈ ),

(Cp) ₂ (NMeiPr)(NC ₄ H ₈ ), Ti(Cp) ₂ (NMe ₂ )(NC ₅ Hio), Ti(Cp) ₂ (NEtMe)(NC ₅ Hio),

(Cp) ₂ (NEt ₂ )(NC ₅ H ₁₀ ), Ti(Cp) ₂ (NMeiPr)(NC ₅ Hio), Ti(Cp) ₂ (NMe ₂ )(NC ₄ H ₄ ),

(Cp) ₂ (NEtMe)(NC ₄ H ₄ ), Ti(Cp) ₂ (NEt ₂ )(NC ₄ H ₄ ), Ti(Cp) ₂ (NMeiPr)(NC ₄ H ₄ ), i(Cp)(NC ₄ H ₈ ) ₃ , Ti(Cp)(NC ₅ H ₁₀ ) ₃ , Ti(Cp)(NC ₄ H ₄ ) ₃ , Ti(Cp) ₂ (NC ₄ H ₈ ) ₂ , i(Cp) ₂ (NC ₅ Hio) ₂ , and Ti(Cp) ₂ (NC ₄ H ₄ ) ₂ , wherein the Cp, NC ₄ H ₄ , NC ₄ H ₈ , and NC ₅ H10 ligands may include one or more substituents independently selected from the group consisting of C1 -C6 alkyl group; and

Also disclosed are methods of depositing a Ti-containing layer on a substrate. At least one Ti-containing precursor disclosed above is introduced into a reactor having at least one substrate disposed therein. At least part of the Ti-containing precursor is deposited onto the at least one substrate to form a Ti-containing layer using a vapor deposition process. The disclosed methods may further include one or more of the following aspects:

• introducing into the reactor a vapor comprising at least one second precursor;

• an element of the at least one second precursor being selected from the group consisting of group 2, group 13, group 14, transition metal, lanthanides, and combinations thereof;

• the element of the at least one second precursor being selected from Mg, Ca, Sr, Ba, Zr, Hf, V, Nb, Ta, Al, Si, Ge, Y, or lanthanides;

• introducing into the reactor at least one co-reactant;

• the co-reactant being selected from the group consisting of O2, O3, H ₂ O, H2O2, NO, NO2, a carboxylic acid, and combinations thereof;

• the co-reactant being water;

• the co-reactant being ozone;

• the Ti-containing layer being a titanium oxide layer;

• the vapor deposition process being a chemical vapor deposition process; and

• the vapor deposition process being an atomic layer deposition process.

Description of Preferred Embodiments

Disclosed are titanium-containing precursors, methods of synthesizing the same, and methods of using the same.

The disclosed heteroleptic titanium-containing precursors are derived from different classes of ligand systems, such as cyclopentadienyl, amide, and/or cyclic amide ligands (saturated ring systems or un-saturated ring systems). Precursor design may help improve volatility, reduce the melting point (liquids or very low melting solids), increase reactivity with water, and increase thermal stability for wider process window applications.

The disclosed titanium-containing precursors have the following formula:

Ti(Ri-R ₅ Cp)x(ER ₆ R7)y(Cy-amines)z

wherein:

Ri , R ₂ , R3, R4, R5, R6, and R ₇ are independently selected from the group consisting of H and C1 -C6 alkyl group;

x = 0-2;

y = 0-3;

z = 1 -4;

x+y+z = 4;

E=N or P;

^■ Cy-amines refer to saturated N-containing ring systems or un-saturated N-containing ring systems, the N-containing ring system comprising at least one nitrogen atom and 4-6 carbon atoms in a chain. As defined above, the C1 -C6 alkyl group includes any linear, branched, or cyclic alkyl groups having from 1 to 6 carbon atoms, including but not limited to Me, tBu, or cyclohexyl groups.

The configuration of the disclosed precursors was selected in order to optimize the reactivity (in one embodiment, with H ₂ O) and, at the same time, the stability. The Ti-N bond is weak and will react rapidly on the surface of the substrate. By tuning this molecule, a precursor is obtained that reacts well on the substrate thanks to a weaker site.

The disclose precursors are surprisingly volatile and stabile. Further stability can be controlled via tuning the cyclic amides ring sizes, ring substitutions and saturation and un-saturation of the rings systems.

The (Ri-R ₅ Cp) ligand has the followin chemical structure:

As illustrated, the cyclopentadienyl ligand may include one or more substituents (Rr R ₅ ) independently selected from the group consisting of a C1 -C6 alkyl group. Exemplary (Ri-R ₅ Cp) ligands include 1 -(1 ,1 -dimethylethyl)-1 ,3-Cyclopentadienyl; 1 - butyl-1 ,3-cyclopentadienyl; 1 -propyl-1 ,3-cyclopentadienyl; 1 -(1 -methylpropyl)-1 ,3- cyclopentadienyl; 1 -(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 -ethyl-1 ,3-cyclopentadienyl; 1 ,3-cyclopentadienyl; 1 -methyl-1 ,3-cyclopentadienyl; 1 ,2,4-tris(1 -methylpropyl)-1 ,3- cyclopentadienyl; 1 ,2,3,4-tetrapropyl-1 ,3-cyclopentadienyl; 1 ,2,3-tris(2-methylpropyl)- 1 ,3-cyclopentadienyl; 2,3-bis(2-methylpropyl)-1 ,3-cyclopentadienyl; 1 ,2,3-tris(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 -butyl-2,3-dipropyl-1 ,3-cyclopentadienyl; 3-butyl-

1.2- dipropyl-1 ,3-cyclopentadienyl; 2,3-bis(1 .1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetrakis(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,2,4-tris(1 ,1 -dimethylethyl)-

1.3- cyclopentadienyl; 1 ,2-bis(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,2,4-tris(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetrakis(1 -methylethyl)-1 ,3-cyclopentadienyl; 2,3-bis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,4-bis(1 -methylpropyl)-1 ,3- cyclopentadienyl; 1 ,3-bis(1 -methylpropyl)-1 ,3-cyclopentadine; 2,3-bis(1 -methylpropyl)- 1 ,3-cyclopentadine; 1 ,2-bis(1 -methylpropyl)-1 ,3-cyclopentadine; 1 -ethyl-2-methyl-1 ,3- cyclopentadine; 1 ,2,3,4,5-pentapropyl-1 ,3-cyclopentadine; 2-(1 ,1 -dimethylethyl)-1 ,3- dimethyl-1 ,3-cyclopentadienyl; 2-butyl-1 ,3-dimethyl-1 ,3-cyclopentadienyl; 1 ,2,3- trimethyl-4,5-bis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,5-thmethyl-3,4-bis(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 ,3-dimethyl-2,4,5-ths(1 -methylethyl)-1 ,3- cyclopentadienyl; 2,5-dimethyl-1 ,3,4-tris(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,4,5- trimethyl-2,3-bis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,4-dimethyl-2,3,5-ths(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 -ethyl-2,3,4-thmethyl-1 ,3-cyclopentadienyl; 2- ethyl-3-methyl-1 ,3-cyclopentadienyl; 2-(1 ,1 -dimethylethyl)-5-(1 -methylethyl)-1 ,3- cyclopentadienyl; 1 ,2,3,5-tetramethyl-4-(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,4,5- tetramethyl-3-(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetramethyl-5-(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetramethyl-5-propyl-1 ,3-cyclopentadienyl; 1 -butyl-2-methyl-1 ,3-cyclopentadienyl; 1 ,2,3,5-tetrapropyl-1 ,3-cyclopentadienyl; 1 ,2,4- tris(1 -methyl propyl )-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetrapropyl-1 ,3-cyclopentadienyl;

1.2.3- tris(2-methylpropyl)-1 ,3-cyclopentadienyl; 2,3-bis(2-methylpropyl)-1 ,3- cyclopentadienyl; 1 ,2,3-tris(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 -butyl-2,3,dipropyl- 1 ,3-cyclopentadienyl; 1 -butyl-4,5-dipropyl-1 ,3-cyclopentadienyl; 5-butyl-1 ,2-dipropyl- 1 ,3-cyclopentadienyl; 3-butyl-1 ,2-dipropyl-1 ,3-cyclopentadienyl; 3-butyl-1 -methyl-1 ,3- cyclopentadienyl; 2, 3-bis(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 -ethyl-2,3-dimethyl- 1 ,3-cyclopentadienyl; 4-(1 ,1 -dimethylethyl)-1 ,2-dimethyl-1 ,3-cyclopentadienyl; 1 ,3,5- tris(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4,5-pentakis(1 -methylethyl)-1 ,3- cyclopentadienyl; 1 -methyl-3-propyl-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetrakis(1 ,1 - dimethylethyl)-1 ,3-cyclopentadienyl; 1 , 2, 3,5-tetrakis(1 ,1 -dimethylethyl)-1 ,3- cyclopentadienyl; 1 ,2,4-ths(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 2,3,5-tris(1 ,1 - dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,2-bis(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl;

1.2.4- tris(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,5-bis(1 ,1 -dimethylethyl)-1 ,3- cyclopentadienyl; 1 -(1 ,1 -dimethylethyl)-3-methyl-1 ,3-cyclopentadienyl; 5-butyl-1 ,2,3,4- tetramethyl-1 ,3-cyclopentadienyl; 2-(1 ,1 -dimethylethyl)-5-methyl-1 ,3-cyclopentadienyl; 1 ,2,3,5-tetrakis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4,5-pentaethyl-1 ,3- cyclopentadienyl; 1 -(1 ,1 -dimethylethyl)-4-(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4,5-pentakis(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 5-(2-methylpropyl)-1 ,3- cyclopentadienyl; 1 ,3,5-ths(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 ,4-bis(1 - methylethyl)-1 ,3-cyclopentadienyl; 1 ,2,3,4-tetrakis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,3-bis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,3-dimethyl-2-(1 -methylethyl)-1 ,3- cyclopentadienyl; 1 ,4-diethyl-2,3,5-trinnethyl-1 ,3-cyclopentadienyl; 2,5-bis(1 ,1 - dimethylethyl)-1 ,3-cyclopentadienyl; 5-methyl-2-(1 -methylpropyl)-1 ,3-cyclopentadienyl; 5-methyl-1 -(1 -methylpropyl)-1 ,3-cyclopentadienyl; 5-propyl-1 ,3-cyclopentadienyl; 1 ,2,3,5-tetraethyl-1 ,3-cyclopentadienyl; 1 ,2-dimethyl-3-(2-nnethylpropyl)-1 ,3- cyclopentadienyl; 2,3-bis(1 -methylethyl)-1 ,3-cyclopentadienyl; 1 ,3-diethyl-1 ,3- cyclopentadienyl; 2,3-diethyl-1 ,3-cyclopentadienyl; 5-ethyl-1 ,2,3,4-tetramethyl-1 ,3- cyclopentadienyl; 2-(2-methylpropyl)-1 ,3-cyclopentadienyl; 1 -(2-methylpropyl)-1 ,3- cyclopentadienyl; 2-(1 ,1 -dimethylethyl)-1 ,3-cyclopentadienyl; 1 -(1 ,1 -dimethylethyl)-1 ,3- cyclopentadienyl; 1 -butyl-2,3,4,5-tetramethyl-1 ,3-cyclopentadienyl; 1 ,2,3,5-tetramethyl- 4-propyl-1 ,3-cyclopentadienyl; 1 ,3-diethyl-2,4,5-thmethyl-1 ,3-cyclopentadienyl; 1 -(1 ,1 - dimethylethyl)-1 ,3-cyclopentadienyl; 1 -butyl-1 ,3-cyclopentadienyl; 1 -propyl-1 ,3- cyclopentadienyl; 1 -(1 -methylpropyl)-1 ,3-cyclopentadienyl; 1 -(1 -methylethyl)-1 ,3- cyclopentadienyl; 1 -ethyl-1 ,3-cyclopentadienyl; 1 -methyl-1 ,3-cyclopentadienyl.

The (Cy-amines) ligand refers to saturated N-containing ring systems or unsaturated N-containing ring systems, the N-containing ring system comprising at least one nitrogen atom and 4-6 carbon atoms in a chain. Alternatively, the N-containing ring system may consist of at least one nitrogen atom and 4 or 5 carbon atoms. Structural formula for the Cy-amines include:

As illustrated, the (Cy-amines) ligand may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group.

The (Cy-amines) ligands include pyrrole ligands (also referred to generically herein as NC ₄ H ). The pyrrole ligands may include one or more substituents (R') independently selected from the group consisting a C1 -C4 alkyl group. Exemplary pyrrole ligands include 1 H-Pyrrole; 2-butyl-3-methyl-1 H-Pyrrole; 2-metyl-4-(1 - methylpropyl)-1 H-Pyrrole; 3-(1 ,1 -dimethylethyl)-4-methyl-1 H-Pyrrole; 3-methyl-4-(1 - methylethyl)-1 H-Pyrrole; 2,3,4-triethyl-l H-Pyrrole; 2,4-diethyl-3-propyl-1 H-Pyrrole; 2- ethyl-4-methyl-3-propyl-1 H-Pyrrole; 5-ethyl-2,3-dimethyl-1 H-Pyrrole; 3-methyl-4- propyl-1 H-Pyrrole; 2,3,5-triethyl-4-methyl-1 H-Pyrrole; 2-methyl-4-propyl-1 H-Pyrrole;

2- butyl-4-methyl-1 H-Pyrrole; 2-ethyl-3-(1 -methylethyl)-1 H-Pyrrole; 3-ethyl-4-(1 - methylethyl)-1 H-Pyrrole; 2,3-dimethyl-4-propyl-1 H-Pyrrole; 2-methyl-3,4-dipropyl-1 H- Pyrrole; 3,4-dihydro-5-methyl-3-(1 -methylethylidene)-2H-Pyrrole; 2-ethyl-3,4- dimethyl-1 H-Pyrrole; 2-(1 ,1 -dimethylethyl)-4-methyl-1 H-Pyrrole; 3-butyl-2,4-dimethyl- 1 H-Pyrrole; 2,4-dimethyl-3-propyl-1 H-Pyrrole; 3-butyl-4-methyl-1 H-Pyrrole; 2-methyl- 5-(1 -methylethyl)-1 H-Pyrrole; 2,5-diethyl-3-methyl-1 H-Pyrrole; 3-methyl-2-propyl-1 H- Pyrrole; 2-methyl-4-(1 -methylethyl)-1 H-Pyrrole; 4-ethyl-2-propyl-1 H-Pyrrole; 4- methyl-2-propyl-1 H-Pyrrole; 2,4-diethyl-1 H-Pyrrole; or 2,3-dihydro-3-methylene-1 H- Pyrrole; 2-methyl-3-(1 -methylethyl)-1 H-Pyrrole; 3-methyl-2-(1 -methylethyl)-1 H- Pyrrole; 2-methyl-3-propyl-1 H-Pyrrole; 3-ethyl-2-propyl-1 H-Pyrrole; 2-ethyl-3,4,5- trimethyl-1 H-Pyrrole; 3-ethyl-2,5-dimethyl-1 H-Pyrrole; 2-ethyl-4-methyl-1 H-Pyrrole; 2- ethyl-3methyl-1 H-Pyrrole; 2-(2-methylpropyl)-1 H-Pyrrole; 3-ethyl-2-methyl-1 H- Pyrrole; 2,3-diethyl-2-methyl-1 H-Pyrrole; 2,3-diethyl-4,5-dimethyl-1 H-Pyrrole; 2,4- diethyl-3,5-dimethyl-1 H-Pyrrole; 2,5-dimethyl-3-propyl-1 H-Pyrrole; 2-ethyl-3,5- dimethyl-1 H-Pyrrole; 3-(1 ,1 -dimethylethyl)-2,4-dimethyl-1 H-Pyrrole; 3,4-diethyl-2,5- dimethyl-1 H-Pyrrole; 2,5-diethyl-3,4-dimethyl-1 H-Pyrrole; 2-(1 -methylpropyl)-1 H- Pyrrole; 3,4-diethyl-1 H-Pyrrole; 2,5-dimethyl-3-(1 -methylethyl)-1 H-Pyrrole; 3-(1 ,1 - dimethylethyl)-1 H-Pyrrole; 2,3-diethyl-1 H-Pyrrole; 2,5-bis(1 -methylethyl)-1 H-Pyrrole;

3- (1 -methylethyl)-1 H-Pyrrole; 2-(1 -methylethyl)-1 H-Pyrrole; 2,3,5-tripropyl-1 H- Pyrrole; 4-ethyl-2-methyl-1 H-Pyrrole; 2-(1 ,1 -dimethylethyl)-1 H-Pyrrole; 2,4-diethyl-3- methyl-1 H-Pyrrole; 2,3-diethyl-4-methyl-1 H-Pyrrole; 2,3,4-trimethyl-1 H-Pyrrole; 2,3,5-tris(1 ,1 -dimethylethyl)-1 H-Pyrrole; 2,5-bis(1 ,1 -dimethylethyl)-1 H-Pyrrole; 2,3,5- trimethyl-1 H-Pyrrole; 4-methyl-2-(1 -methylethyl)-1 H-Pyrrole; 3-ethyl-1 H-Pyrrole; 2- butyl-1 H-Pyrrole; 3-propyl-1 H-Pyrrole; 2-propyl-1 H-Pyrrole; 2-ethyl-1 H-Pyrrole; 2,3,4,5-tetramethyl-1 H-Pyrrole; 3-butyl-1 H-Pyrrole; 3,4-dimethyl-1 H-Pyrrole; 2,5- diethyl-1 H-Pyrrole; 2-ethyl-5-methyl-1 H-Pyrrole; 2-methyl-1 H-Pyrrole; 2,5-dimethyl- 1 H-Pyrrole; 2,4-dimethyl-1 H-Pyrrole; 3-methyl-1 H-Pyrrole; 2,3-dimethyl-1 H-Pyrrole; 3-ethyl-2,4,5-trimethyl-1 H-Pyrrole; 3-ethyl-2,4-dimethyl-1 H-Pyrrole; or 3-ethyl-4- methyl-1 H-Pyrrole.

Exemplary (Cy-amines) ligands include pyrrolidine ligands (also referred to generically herein as NC H ₈ ). The pyrrolidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group. Exemplary pyrrolidine ligands include pyrrolidine, 3-methyl-pyrrolidine; 2- methyl-pyrrolidine; 3,3-dimethyl-pyrrolidine; 3,4-dimethyl-pyrrolidine; 3-ethyl- pyrrolidine; 2,2-dimethyl-pyrrolidine; 2-ethyl-pyrrolidine; 3-(1 -methylethyl)-pyrrolidine; 2,3-dimethyl-pyrrolidine; 3-propyl-pyrrolidine; 2-(1 -methylethyl)-pyrrolidine; 3-ethyl-3- methyl-pyrrolidine; 3,3,4-trimethyl-pyrrolidine; 3-ethyl-3-methyl-pyrrolidine; 2-propyl- pyrrolidine; 2,5-dimethyl-pyrrolidine; 2,4-dimethyl-pyrrolidine; 2-propyl-pyrrolidine; 3- (2-methylpropyl)-pyrrolidine; 3-(1 ,1 -dimethylethyl)-pyrrolidine; 2-ethyl-2-methyl- pyrrolidine; 3-(1 -methylpropyl)-pyrrolidine; 3-(2-methylpropyl)-pyrrolidine; 3,3-diethyl- pyrrolidine; 3,3,4,4-tetramethyl-pyrrolidine; 3-methyl-3-(1 -methylethyl)-pyrrolidine; 2- (2-methylpropyl)-pyrrolidine; 2-(1 ,1 -dimethylethyl)-pyrrolidine; 2,2,3-trimethyl- pyrrolidine; 2,3,3-trimethyl-pyrrolidine; 3,4-diethyl-pyrrolidine; 3-methyl-3-propyl- pyrrolidine; 3-butyl-pyrrolidine; 2,4,4-trimethyl-pyrrolidine; 2,2,5-trimethyl-pyrrolidine;

2- ethyl-3-methyl-pyrrolidine; 3-ethyl-3-(1 -methylethyl)-pyrrolidine; 3-ethyl-2-methyl- pyrrolidine; 2-butyl-pyrrolidine; 2-ethyl-5-methyl-pyrrolidine; 4-ethyl-2-methyl- pyrrolidine; 2,3,4-trimethyl-pyrrolidine; 2-ethyl-4-methyl-pyrrolidine; 2,5-diethyl- pyrrolidine; 2,2,3,3-tetramethyl-pyrrolidine; 3-methyl-3-(1 -methylpropyl)-pyrrolidine;

3- methyl-3-(2-methylpropyl)-pyrrolidine; 2,2,5,5-tetramethyl-pyrrolidine; 2,3-diethyl- pyrrolidine; 2,2,4,4-tetramethyl-pyrrolidine; 3-methyl-2-propyl-pyrrolidine; 2,4-diethyl- pyrrolidine; 3-methyl-2-(1 -methylethyl)-pyrrolidine; 3-ethyl-2,2-dimethyl-pyrrolidine; 3,3-dipropyl-pyrrolidine; 2-ethyl-3,3-dimethyl-pyrrolidine; 2-methyl-3-(1 -methylethyl)- pyrrolidine; 2-methyl-3-propyl-pyrrolidine; 3-methyl-4-(2-methylpropyl)-pyrrolidine; 2- methyl-5-propyl-pyrrolidine; 3-ethyl-2,3-dimethyl-pyrrolidine; 2-ethyl-4,4-dimethyl- pyrrolidine; 2-ethyl-5-propyl-pyrrolidine; 4-methyl-2-propyl-pyrrolidine; 2-methyl-4-(1 - methylethyl)-pyrrolidine; 2-ethyl-4,4-dimethyl-pyrrolidine; 2,2-dipropyl-pyrrolidine; 4- methyl-2-(1 -methylethyl)-pyrrolidine; 3-ethyl-2-propyl-pyrrolidine; 3-ethyl-2-(1 - methylethyl)-pyrrolidine; 2-ethyl-3-propyl-pyrrolidine; 2-ethyl-3-(1 -methylethyl)- pyrrolidine; 3-butyl-3-ethyl-pyrrolidine; 4-ethyl-2-propyl-pyrrolidine; 2-ethyl-4-(1 - methylethyl)-pyrrolidine; 2-(1 ,1 -dimethylethyl)-3-methyl-pyrrolidine; 3-methyl-2-(2- methylpropyl)-pyrrolidine; 3-methyl-2-(1 -methylpropyl)-pyrrolidine; 2,3,4,5- tetramethyl-pyrrolidine; 2,5-bis(1 -methylethyl)-pyrrolidine; 3-methyl-2-(2- methylpropyl)-pyrrolidine; 2-methyl-3-(1 -methylpropyl)-pyrrolidine; 2-methyl-3-(2- methylpropyl)-pyrrolidine; 2,3-diethyl-3-methyl-pyrrolidine; 2,2-dimethyl-3-(1 - methylethyl)-pyrrolidine; 3,3-diethyl-2-methyl-pyrrolidine; 2,2-dimethyl-3-propyl- pyrrolidine; 3-ethyl-2,4-dimethyl-pyrrolidine; 2,2-dimethyl-5-propyl-pyrrolidine; 2,2- dimethyl-5-(1 -methylethyl)-pyrrolidine; 3-ethyl-2,2,3-trimethyl-pyrrolidine; 2,3- dimethyl-3-(1 -methylethyl)-pyrrolidine; 4-ethyl-2,3-dimethyl-pyrrolidine; 4,4-dimethyl-

2- propyl-pyrroldine; 3-butyl-2-methyl-pyrroldine; 2-butyl-3-methyl-pyrrolidine; 2,3- dimethyl-3-propyl-pyrrolidine; 4-methyl-2-(2-nnethylpropyl)-pyrrolidine; 2-(1 ,1 - dimethylethyl)-4-nnethyl-pyrrolidine; 4,4-dimethyl-2-(1 -methylethyl)-pyrrolidine; 2- methyl-4-(1 -methylpropyl)-pyrrolidine; 4-methyl-2-(1 -methylpropyl)-pyrrolidine; 4- (1 ,1 -dimethylethyl)-2-nnethyl-pyrrolidine; 3,3-bis(2-methylpropyl)-pyrrolidine; 2-butyl- 5-methyl-pyrrolidine; 2-(1 ,1 -dimethylethyl)-3-ethyl-pyrrolidine; 3-ethyl-2-(2- methylpropyl)-pyrrolidine; 3-ethyl-2-(1 -methylpropyl)-pyrrolidine; 2,3,3-triethyl- pyrrolidine; 2-ethyl-3-(2-methylpropyl)-pyrrolidine; 2-ethyl-3-(1 -methylpropyl)- pyrrolidine; 2-butyl-4-methyl-pyrrolidine; 2,2-bis(1 ,1 -dimethylethyl)-pyrrolidine; 2- ethyl-3-methyl-3-(1 -nnethylethyl)-pyrrolidine; 2,2-dimethyl-3-(2-methylpropyl)- pyrrolidine; 3-ethyl-2-methyl-3-(1 -methylethyl)-pyrrolidine; 2,2-dimethyl-3-(1 - methylpropyl)-pyrrolidine; 3,3-dimethyl-2-(2-nnethylpropyl)-pyrrolidine; 2-(2- methylpropyl)-3-propyl-pyrrolidine; 2,2,3,4,5-pentannethyl-pyrrolidine; 2-butyl-3-ethyl- pyrrolidine; 2,2,3-trimethyl-3-(1 -methylethyl)-pyrrolidine; 2-ethyl-3-methyl-3-propyl- pyrrolidine; 3-(1 -methylethyl)-2-(2-nnethylpropyl)-pyrrolidine; 2,3-dimethyl-3-(2- methylpropyl)-pyrrolidine; 2,3-dimethyl-3-(1 -methylpropyl)-pyrrolidine; 2,2,3-trimethyl-

3- propyl-pyrrolidine; 3-(1 -methylpropyl)-2-(2-nnethylpropyl)-pyrrolidine; 2,3-bis(2- methylpropyl)-pyrrolidine; 2-methyl-3,3-dipropyl-pyrrolidine; 2,3-diethyl-3-(1 - methylethyl)-pyrrolidine; 3-ethyl-3-methyl-2-(2-nnethylpropyl)-pyrrolidine; 5-ethyl- 2,3,3-trimethyl-pyrrolidine; 3-ethyl-2,2-dimethyl-3-(1 -methylethyl)-pyrrolidine; 2,5- dimethyl-3-(1 -nnethylethyl)-pyrrolidine; 2-ethyl-3-methyl-3-(2-nnethylpropyl)- pyrrolidine; 2-ethyl-3-methyl-3-(1 -methylpropyl)-pyrrolidine; 3-methyl-3-(1 - methylethyl)-2-(2-nnethylpropyl)-pyrrolidine; 2-ethyl-3,3-dipropyl-pyrrolidine; 2,2,3- trimethyl-3-(2-methylpropyl)-pyrrolidine; 2,2,3-trimethyl-3-(1 -methylpropyl)- pyrrolidine; 3,3-diethyl-2-(2-methylpropyl)-pyrrolidine; 3-methyl-2-(2-nnethylpropyl)-3- propyl-pyrrolidine; 3-butyl-3-ethyl-2-methyl-pyrrolidine; 2,2-dimethyl-3,3-dipropyl- pyrrolidine; 2-ethyl-5-methyl-3-(1 -methylethyl)-pyrrolidine; 3-(1 ,1 -dimethylethyl)-2,5- dimethyl-pyrrolidine; 3-methyl-3-(1 -methylpropyl)-2-(2-nnethylpropyl)-pyrrolidine; 3- ethyl-3-(1 -nnethylethyl)-2-(2-nnethylpropyl)-pyrrolidine; 2,5-dimethyl-3-(1 - methylpropyl)-pyrrolidine; 3-butyl-2,3-diethyl-pyrrolidine; 3-butyl-3-ethyl-2,2-dimethyl- pyrrolidine; 2,2,5,5-tetrapropyl-pyrrolidine; 2-ethyl-5-methyl-3-(1 -methyl propyl- pyrrolidine; 2-(2-methylpropyl)-3,3-dipropyl-pyrrolidine; 3-(1 ,1 -dimethylethyl)-2-ethyl- 5-methyl-pyrrolidine; or 3-butyl-3-ethyl-2-(2-methylpropyl)-pyrrolidine.

Exemplary (Cy-amines) ligands include piperidine ligands (also referred to generically herein as NC H ₈ ). The piperidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group. Exemplary piperidine ligands include piperidine; 2,3,5,6-tetramethyl- piperidine; 2-(1 ,1 -dimethylethyl)-piperidine; 2-(2-methylpropyl)-piperidine; 2-butyl-4- ethyl-piperidine; 2-methyl-6-(2-methylpropyl)-piperidine; 4-methyl-2-(1 -methylethyl)- piperidine; 3,3-dipropyl-piperidine; 2-(1 ,1 -dimethylethyl)-4-methyl-piperidine; 4-ethyl-

2- propyl-piperidine; 4-butyl-4-ethyl-piperidine; 2-butyl-4-methyl-piperidine; 3-(1 ,1 - dimethylethyl)-3-methyl-piperidine; 3-methyl-2-(2-methylpropyl)-piperidine; 3-methyl-

3- (2-methylpropyl)-piperidine; 4,4-dipropyl-piperidine; 5-methyl-2-(1 -methylethyl)- piperidine; 2-methyl-5-(1 -methylethyl)-piperidine; 2-(1 ,1 -dimethylethyl)-4-ethyl- piperidine; 3-methyl-2-(1 -methylethyl)-piperidine; 2-methyl-5-(2-methylpropyl)- piperidine; 3-methyl-3-(1 -methylethyl)-piperidine; 2-methyl-6-(1 -methylethyl)- piperidine; 3-ethyl-3-(1 -methylethyl)-piperidine; 3-methyl-3-(1 -methylpropyl)- piperidine; 5-methyl-2-(2-methylpropyl)-piperidine; 4-ethyl-2-(2-methyl propyl )- piperidine; 3-(2-methylpropyl)-piperidine; 3-butyl-piperidine; 3-(1 -methylethyl)- piperidine; 3-(1 -methylpropyl)-piperidine; 2,6-dimethyl-piperidine; 2,3-dimethyl- piperidine; 3-(1 ,1 -dimethylethyl)-piperidine; 4-methyl-2-propyl-piperidine; 3-methyl-2- propyl-piperidine; 2-ethyl-6-methyl-piperidine; 2,3-diethyl-piperidine; 2,2,6-trimethyl- piperidine; 4-methyl-4-(2-methylpropyl)-piperidine; 2,3-dimethyl-piperidine hydrochloride; 2,5-dimethyl-piperidine; 3-ethyl-2-propyl-piperidine; 2-(1 ,1 - dimethylethyl)-piperidine; 3-(2-methylpropyl)-piperidine; 2-ethyl-3-methyl-piperidine; 2-ethyl-4,4-dimethyl-piperidine; 3,5-dimethyl-piperidine; 3,4-diethyl-piperidine; 3,4,4- trimethyl-piperidine; 3-ethyl-2-methyl-piperidine; 3,4-diethyl-piperidine; 4-ethyl-2,6- dimethyl-piperidine; 4-(1 -methylpropyl)-piperidine; 3-ethyl-3-methyl-piperidine; 2- ethyl-6-methyl-piperidine; 2,4-dimethyl-piperidine; 2-(1 -methylethyl)-piperidine; 3-(1 - methylethyl)-piperidine; 4-methyl-4-(1 -methylethyl)-piperidine; 2-methyl-6-propyl- piperidine; 2,5,5-trimethyl-piperidine; 2-(1 -methylpropyl)-piperidine; 2-ethyl-5,5- dimethyl-piperidine; 4,4-dimethyl-3-(1 -methylethyl)-piperidine; 2-propyl-piperidine hydrobromide; 3-ethyl-5-methyl-piperidine; 2-methyl-piperidine hydrochloride; 2,2,4,4-tetramethyl-piperidine; 3-butyl-3-ethyl-piperidine; 3-methyl-3-propyl- piperidine; 2-methyl-6-propyl-piperidine; 2-(2-methylpropyl)-piperidine; 2-butyl- piperidine; 3,4-diethyl-piperidine; 2,2,5,5-tetramethyl-piperidine; 2,5-dimethyl- piperidine hydrochloride; 2,5-diethyl-piperidine; 2,4-diethyl-piperidine; 2-methyl-6- propyl-piperidine hydrochloride; 4-methyl-4-propyl-piperidine; or 3-methyl-4-propyl- piperidine.

The (ER6R ₇ ) ligand has the following chemical structure: e/ ^R6

E \

7

Exemplary (ER ₆ R ₇ ) ligands include dialkylamino and dialkylphosphide ligands, such as dimethylamino, ethylmethylamino, diethylamino, methylisopropylamino, dimethylphosphide, ethylmethylphosphide, diethylphosphide, or methylisopropylphosphide.

When x=0, y=0, and z=4 in Formula 1 , exemplary precursors have one of the following generic formula: Ti(NC ₄ H ₈ ) ₄ , Ti(NC ₅ Hi ₀ ) ₄ , or Ti(NC ₄ H ) , wherein the pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group as described above.

When x=0, y=3, and z=1 , exemplary precursors have the following generic formula: Ti(ER ₆ R ₇ )3(Cy-amines), wherein the Cy-amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include Ti(NMe2)3(NC ₄ H ₈ ), Ti(NEtMe) ₃ (NC ₄ H ₈ ), Ti(NEt ₂ ) ₃ (NC ₄ H ₈ ), Ti(NMeiPr) ₃ (NC ₄ H ₈ ), Ti(NMe ₂ )3(NC ₅ H ₁₀ ), Ti(NEtMe) ₃ (NC ₅ Hio), Ti(NEt ₂ ) ₃ (NC ₅ Hi ₀ ), Ti(NMeiPr) ₃ (NC ₅ Hi ₀ ), Ti(PMe ₂ ) ₃ (NC ₄ H ₄ ), Ti(PEtMe) ₃ (NC ₄ H ₄ ), Ti(PEt ₂ ) ₃ (NC ₄ H ₄ ), Ti(PMeiPr) ₃ (NC ₄ H ₄ ), Ti(PMe ₂ ) ₃ (NC ₄ H ₈ ), Ti(PEtMe) ₃ (NC ₄ H ₈ ), Ti(PEt ₂ ) ₃ (NC ₄ H ₈ ), Ti(PMeiPr) ₃ (NC ₄ H ₈ ), Ti(PMe ₂ ) ₃ (NC ₅ Hi ₀ ), Ti(PEtMe) ₃ (NC ₅ H ₁₀ ), Ti(PEt ₂ ) ₃ (NC ₅ H ₁₀ ), and Ti(PMeiPr) ₃ (NC ₅ H ₁₀ ) , wherein the pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group as described above.

When x=0, y=2, and z=2 in Formula 1 , exemplary precursors have the following generic formula: Ti(ER ₆ R ₇ ) ₂ (Cy-amines) ₂ , wherein the Cy-amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include Ti(NMe ₂ )2(NC ₄ H ₈ )2, Ti(NEtMe) ₂ (NC ₄ H ₈ )2, Ti(NEt ₂ )2(NC ₄ H ₈ )2, Ti(NMeiPr) ₂ (NC ₄ H ₈ ) ₂ , Ti(NMe ₂ ) ₂ (NC ₅ H ₁₀ ) ₂ , Ti(NEtMe) ₂ (NC ₅ H ₁₀ ) ₂ , Ti(NEt ₂ ) ₂ (NC ₅ H ₁₀ ) ₂ , Ti(NMeiPr) ₂ (NC ₅ Hio) ₂ , Ti(PMe ₂ ) ₂ (NC ₄ H ₈ ) ₂ , Ti(PEtMe) ₂ (NC ₄ H ₈ ) ₂ , Ti(PEt ₂ ) ₂ (NC ₄ H ₈ ) ₂ , Ti(PMeiPr) ₂ (NC ₄ H ₈ ) ₂ , Ti(PMe ₂ ) ₂ (NC ₅ Hi ₀ ) ₂ , Ti(PEtMe) ₂ (NC ₅ Hi ₀ ) ₂ , Ti(PEt ₂ ) ₂ (NC ₅ Hi ₀ ) ₂ , Ti(PMeiPr) ₂ (NC ₅ Hio) ₂ , Ti(PMe ₂ ) ₂ (NC ₄ H ₄ ) ₂ , Ti(PEtMe) ₂ (NC ₄ H ₄ ) ₂ , Ti(PEt ₂ ) ₂ (NC ₄ H ₄ ) ₂ , and Ti(PMeiPr) ₂ (NC H ₄ ) ₂ ) , wherein the pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group as described above.

When x=0, y=1 , and z=3 in Formula 1 , exemplary precursors have the following generic formula: Ti(ER ₆ R ₇ )(Cy-amines) ₃ , wherein the Cy-amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include Ti(NMe ₂ )(NC ₄ H ₈ ) ₃ , Ti(NEtMe)(NC ₄ H ₈ ) ₃ , Ti(NEt ₂ )(NC ₄ H ₈ ) ₃ ,

Ti(NMeiPr)(NC ₄ H ₈ ) ₃ , Ti(NMe ₂ )(NC ₅ Hi ₀ ) ₃ , Ti(NEtMe)(NC ₅ Hi ₀ ) ₃ , Ti(NEt ₂ )(NC ₅ Hi ₀ ) ₃ , Ti(NMeiPr)(NC ₅ H ₁₀ ) ₃ , Ti(NMe ₂ )(NC ₄ H ₄ ) ₃ , Ti(NEtMe)(NC ₄ H ₄ ) ₃ , Ti(NEt ₂ )(NC ₄ H ₄ ) ₃ , Ti(NMeiPr)(NC ₄ H ₄ ) ₃ , Ti(PMe ₂ )(NC ₄ H ₈ ) ₃ , Ti(PEtMe)(NC ₄ H ₈ ) ₃ , Ti(PEt ₂ )(NC ₄ H ₈ ) ₃ , Ti(PMeiPr)(NC ₄ H ₈ ) ₃ , Ti(PMe ₂ )(NC ₅ Hi ₀ ) ₃ , Ti(PEtMe)(NC ₅ Hi ₀ ) ₃ , Ti(PEt ₂ )(NC ₅ Hi ₀ ) ₃ , Ti(PMeiPr)(NC ₅ Hio) ₃ , Ti(PMe ₂ )(NC ₄ H ₄ ) ₃ , Ti(PEtMe)(NC ₄ H ₄ ) ₃ , Ti(PEt ₂ )(NC ₄ H ₄ ) ₃ , and Ti(PMeiPr)(NC ₄ H ) ₃ , wherein the pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents (R') independently selected from the group consisting of a C1 -C4 alkyl group as described above.

When x=2, y=1 , and z=1 in Formula 1 , exemplary precursors have the following generic formula: TiCp ₂ (ER ₆ R ₇ )(Cy-amines), wherein the Cp ligand and Cy- amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include TiCp ₂ (NMe ₂ )(NC ₄ H ₈ ), TiCp ₂ (NEtMe)(NC ₄ H ₈ ), TiCp ₂ (NEt ₂ )(NC ₄ H ₈ ), TiCp ₂ (NMeiPr)(NC ₄ H ₈ ), TiCp ₂ (NMe ₂ )(NC ₅ Hi ₀ ), TiCp ₂ (NEtMe)(NC ₅ Hi ₀ ),

TiCp ₂ (NEt ₂ )(NC ₅ Hio), TiCp ₂ (NMeiPr)(NC ₅ Hi ₀ ), TiCp ₂ (NMe ₂ )(NC ₄ H ₄ ),

TiCp ₂ (NEtMe)(NC ₄ H ₄ ), TiCp ₂ (NEt ₂ )(NC ₄ H ₄ ), TiCp ₂ (NMeiPr)(NC ₄ H ₄ ),

TiCp ₂ (PMe ₂ )(NC ₄ H ₈ ), TiCp ₂ (PEtMe)(NC ₄ H ₈ ), TiCp ₂ (PEt ₂ )(NC ₄ H ₈ ), TiCp ₂ (PMeiPr)(NC ₄ H ₈ ), TiCp ₂ (PMe ₂ )(NC ₅ Hi ₀ ), TiCp ₂ (PEtMe)(NC ₅ Hi ₀ ),

TiCp ₂ (PEt ₂ ) ₂ (NC ₅ Hio), TiCp ₂ (PMeiPr)(NC ₅ Hi ₀ ), TiCp ₂ (PMe ₂ ) ₂ (NC ₄ H ₄ ),

TiCp ₂ (PEtMe) ₂ (NC ₄ H ₄ ), TiCp ₂ (PEt ₂ ) ₂ (NC ₄ H ₄ ), and TiCp ₂ (PMeiPr) ₂ (NC ₄ H ₄ ), wherein the cydopentadienyl, pyrrole, pyrrolidine, and piperidine ligands may include one or more substitutents independently selected from the group consisting of a C1 -C6 alkyl group as described above.

When x=1 , y=2, and z=1 in Formula 1 , exemplary precursors have the following generic formula: TiCp(ER ₆ R7)2(Cy-amines), wherein the Cp ligand and Cy- amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include TiCp(NMe ₂ )2(NC ₄ H ₈ ), TiCp(NEtMe) ₂ (NC ₄ H ₈ ), TiCp(NEt ₂ ) ₂ (NC ₄ H ₈ ), TiCp(NMeiPr) ₂ (NC ₄ H ₈ ), TiCp(NMe ₂ ) ₂ (NC ₅ Hi ₀ ), TiCp(NEtMe) ₂ (NC ₅ Hi ₀ ),

TiCp(NEt ₂ ) ₂ (NC ₅ H ₁₀ ), TiCp(NMeiPr) ₂ (NC ₅ H ₁₀ ), TiCp(NMe ₂ ) ₂ (NC ₄ H ₄ ),

TiCp(NEtMe) ₂ (NC ₄ H ₄ ), TiCp(NEt ₂ ) ₂ (NC ₄ H ₄ ), TiCp(NMeiPr) ₂ (NC ₄ H ₄ ),

TiCp(PMe ₂ ) ₂ (NC ₄ H ₈ ), TiCp(PEtMe) ₂ (NC ₄ H ₈ ), TiCp(PEt ₂ ) ₂ (NC ₄ H ₈ ), TiCp(PMeiPr) ₂ (NC ₄ H ₈ ), TiCp(PMe ₂ ) ₂ (NC ₅ Hi ₀ ), TiCp(PEtMe) ₂ (NC ₅ Hi ₀ ),

TiCp(PEt ₂ ) ₂ (NC ₅ H ₁₀ ), TiCp(PMeiPr) ₂ (NC ₅ H ₁₀ ), TiCp(PMe ₂ ) ₂ (NC ₄ H ₄ ),

TiCp(PEtMe) ₂ (NC ₄ H ₄ ), TiCp(PEt ₂ ) ₂ (NC ₄ H ₄ ), and TiCp(PMeiPr) ₂ (NC ₄ H ₄ ), wherein the cyclopentadienyl, pyrrole, pyrrolidine, and piperidine ligands may include one or more substitutents independently selected from the group consisting of a C1 -C6 alkyl group as described above.

When x=1 , y=1 , and z=2 in Formula 1 , exemplary precursors have the following generic formula: TiCp(ER ₆ R7)(Cy-amines) ₂ , wherein the Cp ligand and Cy- amines ligand may be substituted or unsubstituted as described above. Exemplary precursors include TiCp(NMe ₂ )(NC ₄ H ₈ ) ₂ , TiCp(NEtMe)(NC ₄ H ₈ ) ₂ , TiCp(NEt ₂ )(NC ₄ H ₈ ) ₂ , TiCp(NMeiPr)(NC ₄ H ₈ ) ₂ , TiCp(NMe ₂ )(NC ₅ H ₁₀ ) ₂ , TiCp(NEtMe)(NC ₅ H ₁₀ ) ₂ ,

TiCp(NEt ₂ )(NC ₅ Hio) ₂ , TiCp(NMeiPr)(NC ₅ Hi ₀ ) ₂ , TiCp(NMe ₂ )(NC ₄ H ₄ ) ₂ ,

TiCp(NEtMe)(NC ₄ H ₄ ) ₂ , TiCp(NEt ₂ )(NC ₄ H ₄ ) ₂ , TiCp(NMeiPr)(NC ₄ H ₄ ) ₂ ,

TiCp(PMe ₂ )(NC ₄ H ₈ ) ₂ , TiCp(PEtMe)(NC ₄ H ₈ ) ₂ , TiCp(PEt ₂ )(NC ₄ H ₈ ) ₂ ,

TiCp(PMeiPr)(NC ₄ H ₈ ) ₂ , TiCp(PMe ₂ )(NC ₅ H ₁₀ ) ₂ , TiCp(PEtMe)(NC ₅ H ₁₀ ) ₂ , TiCp(PEt ₂ )(NC ₅ H io) ₂ , TiCp(PMeiPr)(NC ₅ Hi ₀ ) ₂ , TiCp(PMe ₂ )(NC ₄ H ₄ ) ₂ ,

TiCp(PEtMe)(NC ₄ H ₄ ) ₂ , TiCp(PEt ₂ )(NC ₄ H ₄ ) ₂ , and TiCp(PMeiPr)(NC ₄ H ₄ ) ₂ , wherein the cyclopentadienyl, pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents independently selected from the group consisting of a C1 -C6 alkyl group as described above.

When x=1 , y=0, and z=3 in Formula 1 , exemplary precursors have the following generic formula: TiCp(Cy-amines)3, wherein the Cp ligand and Cy-amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include TiCp(NC ₄ H ₈ ) ₃ , TiCp(NC ₅ Hi ₀ )3, or TiCp(NC ₄ H ₄ ) ₃ , wherein the Cp, pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents independently selected from the group consisting of a C1 -C6 alkyl group as described above.

When x=2, y=0, and z=2 in Formula 1 , exemplary precursors have the following generic formula: TiCp2(Cy-amines)2, wherein the Cp ligand and Cy-amines ligand may be unsubstituted or substituted as described above. Exemplary precursors include TiCp2(NC ₄ H ₈ )2, TiCp2(NC ₅ Hi ₀ )2, or TiCp2(NC ₄ H ₄ ) ₂ , wherein the Cp, pyrrole, pyrrolidine, and piperidine ligands may include one or more substituents independently selected from the group consisting of a C1 -C6 alkyl group as described above.

The disclosed precursors may be synthesized by combining a hydrocarbon solution of Ti(NR ₆ R ₇ ) ₄ or Ti(R R ₅ Cp)(NR ₆ R ₇ )3 with a neat or hydrocarbon solution of ligand compound, such as NC ₄ H ₈ or NC ₅ H10 or NC ₄ H , under atmosphere of nitrogen, the outlet of the mixing flask being connected to an oil bubbler. Ti(NR ₆ R ₇ ) ₄ may be produced by reacting TiCI ₄ with Li(NR ₆ R7). Ti(Ri-R ₅ Cp)(NR ₆ R7) may be produced by reacting Ti(R R ₅ Cp)Cl3 with Li(NR ₆ R ₇ ). Exemplary hydrocarbon solutions include diethyl ether or pentane or toluene. The resulting solution is stirred at room temperature overnight. Solvent and volatiles are removed from the reaction mixture under vacuum. Purification of the resulting liquid or solid is carried out by distillation or sublimation, respectively. Additional synthesis details are provided in the Examples. Applicants believe that similar mechanisms may be used to form the PR ₅ R6 molecules, but due to the nature of phosphorous containing molecules, have not yet had the opportunity to verify these synthesis mechanisms.

Also disclosed are methods of using the disclosed titanium-containing precursors for vapor deposition methods. The disclosed methods provide for the use of the titanium-containing precursors for deposition of titanium-containing layers. The disclosed methods may be useful in the manufacture of semiconductor, photovoltaic, LCD-TFT, or flat panel type devices. The method includes introducing at least one Ti-containing precursor disclosed above into a reactor having at least one substrate disposed therein and depositing at least part of the titanium-containing precursor onto the at least one substrate to form a titanium-containing layer using a vapor deposition process.

The disclosed methods also may be used to form a two element-containing layer on a substrate using a vapor deposition process and, more particularly, for deposition of STO, BST, PZT, or TiMO _x layers, wherein x is 1 -4 and M is the second element and is selected from the group consisting of group 2, group 13, group 14, transition metal, lanthanides, and combinations thereof, and more preferably from Mg, Ca, Sr, Ba, Zr, Hf, V, Nb, Ta, Al, Si, Ge, Y, or lanthanides. The method includes: introducing at least one Ti-containing precursor disclosed above into a reactor having at least one substrate disposed therein, introducing a second precursor into the reactor, and depositing at least part of the titanium-containing precursor and at least part of the second precursor onto the at least one substrate to form the two element-containing layer using a vapor deposition process.

The disclosed titanium-containing precursors may be used to deposit titanium- containing layers using any deposition methods known to those of skill in the art. Examples of suitable deposition methods include without limitation, conventional chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD), atomic layer deposition (ALD), pulsed chemical vapor deposition (P-CVD), plasma enhanced atomic layer deposition (PE-ALD), or combinations thereof. Preferably, the deposition method is ALD or PE-ALD.

The vapor of the titanium-containing precursor is introduced into a reactor containing at least one substrate. The temperature and the pressure within the reactor and the temperature of the substrate are held at suitable conditions so that contact between the titanium-containing precursor and substrate results in formation of a Ti-containing layer on at least one surface of the substrate. A co-reactant may also be used to help in formation of the Ti-containing layer.

The reactor may be any enclosure or chamber of a device in which deposition methods take place, such as, without limitation, a parallel-plate type reactor, a cold- wall type reactor, a hot-wall type reactor, a single-wafer reactor, a multi-wafer reactor, or other such types of deposition systems. All of these exemplary reactors are capable of serving as an ALD reactor. The reactor may be maintained at a pressure ranging from about 0.5 mTorr to about 20 Torr. In addition, the temperature within the reactor may range from about room temperature (20°C) to about 600°C. One of ordinary skill in the art will recognize that the temperature may be optimized through mere experimentation to achieve the desired result.

The temperature of the reactor may be controlled by either controlling the temperature of the substrate holder or controlling the temperature of the reactor wall. Devices used to heat the substrate are known in the art. The reactor wall is heated to a sufficient temperature to obtain the desired film at a sufficient growth rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the reactor wall may be heated includes from approximately 20°C to approximately 600°C. When a plasma deposition process is utilized, the deposition temperature may range from approximately 20°C to approximately 550°C. Alternatively, when a thermal process is performed, the deposition temperature may range from approximately 300°C to approximately 600°C.

Alternatively, the substrate may be heated to a sufficient temperature to obtain the desired titanium-containing layer at a sufficient growth rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the substrate may be heated includes from 150°C to 600°C. Preferably, the temperature of the substrate remains less than or equal to 500°C.

The type of substrate upon which the titanium-containing layer will be deposited will vary depending on the final use intended. In some embodiments, the substrate may be chosen from oxides which are used as dielectric materials in MIM, DRAM, or FeRam technologies (for example, ZrO2 based materials, HfO2 based materials, ΤΊΟ2 based materials, rare earth oxide based materials, ternary oxide based materials, etc.) or from nitride-based layers (for example, TaN) that are used as an oxygen barrier between copper and the low-k layer. Other substrates may be used in the manufacture of semiconductors, photovoltaics, LCD-TFT, or flat panel devices. Examples of such substrates include, but are not limited to, solid substrates such as metal nitride containing substrates (for example, TaN, TiN, WN, TaCN, TiCN, TaSiN, and TiSiN); insulators (for example, S1O2, Si3N ₄ , SiON, Z D2, Ta2O ₅ , HfO2, TiO ₂ , AI ₂ O ₃ , and barium strontium titanate); or other substrates that include any number of combinations of these materials. The actual substrate utilized may also depend upon the specific precursor embodiment utilized. In many instances though, the preferred substrate utilized will be selected from TiN, SRO, Ru, and Si type substrates.

The titanium-containing precursor may be fed in liquid state to a vaporizer where it is vaporized before it is introduced into the reactor. Prior to its vaporization, the titanium-containing precursor may optionally be mixed with one or more solvents, one or more metal sources, and a mixture of one or more solvents and one or more metal sources. The solvents may be selected from the group consisting of toluene, ethyl benzene, xylene, mesitylene, decane, dodecane, octane, hexane, pentane, tertiary amines or others. The resulting concentration may range from approximately 0.05 M to approximately 2 M. The metal source may include any metal-containing precursors now known or later developed.

Alternatively, the titanium-containing precursor may be vaporized by passing a carrier gas into a container containing the titanium-containing precursor or by bubbling the carrier gas into the titanium-containing precursor. The carrier gas and titanium-containing precursor are then introduced into the reactor as a vapor. The carrier gas may include, but is not limited to, Ar, He, N ₂ ,and mixtures thereof. The titanium-containing precursor may optionally be mixed in the container with one or more solvents, second precursors, or mixtures thereof. If necessary, the container may be heated to a temperature that permits the titanium-containing precursor to be in its liquid phase and to have a sufficient vapor pressure. The container may be maintained at temperatures in the range of, for example, 0-150°C. Those skilled in the art recognize that the temperature of the container may be adjusted in a known manner to control the amount of titanium-containing precursor vaporized.

In addition to the optional mixing of the titanium-containing precursor with solvents, second precursors, and stabilizers prior to introduction into the reactor, the titanium-containing precursor may be mixed with co-reactants inside the reactor. Exemplary co-reactants include, without limitation, second precursors such as transition metal containing precursors (e.g. Niobium), rare-earth containing precursors, strontium-containing precursors, barium-containing precursors, aluminum-containing precursors such as TMA, and any combination thereof. These or other second precursors may be incorporated into the resultant layer in small quantities, as a dopant, or as a second or third metal in the resulting layer, such as BST, STO, PZT, or TiMO _x , with M and x having been previously defined herein.

When the desired titanium-containing layer also contains oxygen, such as, for example and without limitation, TiMO _x , with M and x having been previously defined herein, the co-reactants may include an oxygen source which is selected from, but not limited to, O2, O3, H ₂ O, H2O2, acetic acid, formalin, para-formaldehyde, and combinations thereof. Preferably, when an ALD process is performed, the co-reactant is H ₂ O.

The co-reactant may be treated by plasma in order to decompose the co- reactant into its radical form. The plasma may be generated or present within the reaction chamber itself. Alternatively, the plasma may generally be at a location removed from the reaction chamber, for instance, in a remotely located plasma system. One of skill in the art will recognize methods and apparatus suitable for such plasma treatment.

For example, the co-reactant may be introduced into a direct plasma reactor, which generates a plasma in the reaction chamber, to produce the plasma-treated co-reactant in the reaction chamber. Exemplary direct plasma reactors include the Titan™ PECVD System produced by Trion Technologies. The co-reactant may be introduced and held in the reaction chamber prior to plasma processing. Alternatively, the plasma processing may occur simultaneously with the introduction of the co-reactant. In-situ plasma is typically a 13.56 MHz RF capacitively coupled plasma that is generated between the showerhead and the substrate holder. The substrate or the showerhead may be the powered electrode depending on whether positive ion impact occurs. Typical applied powers in in-situ plasma generators are from approximately 100 W to approximately 1000 W. The disassociation of the co- reactant using in-situ plasma is typically less than achieved using a remote plasma source for the same power input and is therefore not as efficient in co-reactant disassociation as a remote plasma system, which may be beneficial for the deposition of metal-nitride-containing films on substrates easily damaged by plasma.

Alternatively, the plasma-treated co-reactant may be produced outside of the reaction chamber. The MKS Instruments' ASTRON ^® i reactive gas generator may be used to treat the co-reactant prior to passage into the reaction chamber. Operated at 2.45 GHz, 7kW plasma power, and a pressure ranging from approximately 3 Torr to approximately 10 Torr, the co-reactant O ₃ may be decomposed into three O ^" radicals. Preferably, the remote plasma may be generated with a power ranging from about 1 kW to about 10 kW, more preferably from about 2.5 kW to about 7.5 kW.

When the desired titanium-containing layer also contains another element, such as, for example and without limitation, Ta, Zr, Hf, V, Nb, Mg, Al, Sr, Y, Ba, Ca, As, Sb, Bi, Sn, Pb, Co, lanthanides (such as Er), or combinations thereof, the co- reactants may include a second precursor which is selected from, but not limited to, metal alkyls, such as Ln(RCp) ₃ or Co(RCp) ₂ , metal amines, such as Nb(Cp)(NtBu)(NMe2)3, and any combination thereof.

In one preferred embodiment, the reactant may be a metal-containing precursor compound having the formula M(L) ₂ or M(L) ₂ .A, wherein M is Sr or Ba, L is selected from (a) substituted cyclopentadienyl ligand systems (R1 R2R3R4R ₅ CP) in which each of Ri to R ₅ is independently selected from H or C1 -C6 linear or branched alkyl chains, or (b) beta-diketonate ligand systems (-O-CR6-CH-CR ₇ -O-), in which each of R6 and R ₇ is independently selected from C1 -C6 linear or branched alkyl chain; and A = is a neutral oxygen containing molecule, including but not limited to tetrahydrofuran, dimethoxyethane, diglyme, triglyme, tetraglyme, or a combination thereof. Preferably, the metal-containing precursor has the formula M(R ₅ Cp)2 with each R being independently selected from H, Me, Et, and nBu.

Exemplary metal-containing precursors include but are not limited to

Sr(iPr ₃ Cp) ₂ , Sr(iPr ₃ Cp) ₂ .thf, Sr(iPr ₃ Cp) ₂ .dme, Sr(tBu ₃ Cp) ₂ , Sr(tBu ₃ Cp) ₂ .thf, Sr(tBu ₃ Cp) ₂ .dme, Sr(thmd) ₂ , Sr(thmd) ₂ .triglyme, Sr(thmd) ₂ .tetraglyme, Sr(Me ₅ Cp) ₂ , Sr(Me ₄ Cp) ₂ , Sr(Me ₄ EtCp) ₂ , Sr(Me ₄ nBuCp) ₂ , Ba(iPr ₃ Cp) ₂ , Ba(iPr ₃ Cp) ₂ .thf, Ba(iPr ₃ Cp) ₂ .dme, Ba(tBu ₃ Cp) ₂ , Ba(tBu ₃ Cp) ₂ .thf, Ba(tBu ₃ Cp) ₂ .dme, Ba(thmd) ₂ , Ba(thmd) ₂ .triglyme, Ba(thmd) ₂ .tetraglyme, Ba(Me ₅ Cp) ₂ , Ba(Me ₄ Cp) ₂ , Ba(Me ₄ EtCp) ₂ , and Ba(Me ₄ nBuCp) ₂ .

The titanium-containing precursor and one or more co-reactants may be introduced into the reactor simultaneously (chemical vapor deposition), sequentially (atomic layer deposition), or in other combinations. For example, the titanium- containing precursor may be introduced in one pulse and two additional precursors may be introduced together in a separate pulse [modified atomic layer deposition]. Alternatively, the reactor may already contain the co-reactant prior to introduction of the titanium-containing precursor. The co-reactant may be passed through a plasma system localized or remotely from the reactor, and decomposed to radicals. Alternatively, the titanium-containing precursor may be introduced to the reactor continuously while other co-reactants are introduced by pulse (pulsed-chemical vapor deposition). In each example, a pulse may be followed by a purge or evacuation step to remove excess amounts of the component introduced. In each example, the pulse may last for a time period ranging from about 0.01 s to about 10 s, alternatively from about 0.3 s to about 3 s, alternatively from about 0.5 s to about 2 s.

In one non-limiting exemplary atomic layer deposition type process, the vapor phase of a titanium-containing precursor is introduced into the reactor, where it is contacted with a suitable substrate. Excess titanium-containing precursor may then be removed from the reactor by purging and/or evacuating the reactor. An oxygen source is introduced into the reactor where it reacts with the absorbed titanium- containing precursor in a self-limiting manner. Any excess oxygen source is removed from the reactor by purging and/or evacuating the reactor. If the desired layer is a titanium oxide layer, this two-step process may provide the desired layer thickness or may be repeated until a layer having the necessary thickness has been obtained.

Alternatively, if the desired TiO layer contains a second element (i.e., TiMO _x ), the two-step process above may be followed by introduction of the vapor of a second precursor into the reactor. The second precursor will be selected based on the nature of the TiMOx layer being deposited. After introduction into the reactor, the second precursor is contacted with the substrate. Any excess second precursor is removed from the reactor by purging and/or evacuating the reactor. Once again, an oxygen source may be introduced into the reactor to react with the second precursor. Excess oxygen source is removed from the reactor by purging and/or evacuating the reactor. If a desired layer thickness has been achieved, the process may be terminated. However, if a thicker layer is desired, the entire four-step process may be repeated. By alternating the provision of the titanium-containing precursor, second precursor, and oxygen source, a TiMO _x layer of desired composition and thickness may be deposited.

Additionally, by varying the number of pulses, layers having a desired stoichiometric M:Ti ratio may be obtained. For example, a TiMO ₂ layer may be obtained by having one pulse of the titanium-containing precursor and one pulse of the second precursor, with each pulse being followed by pulses of the oxygen source. However, one of ordinary skill in the art will recognize that the number of pulses required to obtain the desired layer may not be identical to the stoichiometric ratio of the resulting layer.

The titanium-containing layers resulting from the processes discussed above may include T1O ₂ , STO, BST, PZT, or TiMO _x , wherein M and x are previously defined above. One of ordinary skill in the art will recognize that by judicial selection of the appropriate titanium-containing precursor and co-reactants, the desired Ti-containing layer composition may be obtained.

Examples

The following non-limiting examples are provided to further illustrate

embodiments of the invention. However, the examples are not intended to be all inclusive and are not intended to limit the scope of the inventions described herein. Prophetic Example 1

Ti(NMe ₂ )3(NC ₄ H ₈ ): A Schlenk flask containing Ti(NMe ₂ ) ₄ (15.00g, 66.9 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC ₄ H ₈ , 4.76g, 66.9 mmol) in 20 of diethyl ether. The reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

Prophetic Example 2

Ti(NMe ₂ )2(NC ₄ H ₈ )2: A Schlenk flask containing Ti(NMe ₂ ) ₄ (10.00g, 44.60 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC H ₈ , 6.34g, 89.2 mmol) in 20 of diethyl ether. The reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

Prophetic Example 3

Ti(NEtMe) ₃ (NC ₄ H ₈ ): A Schlenk flask containing Ti(NEtMe) ₄ (10.00g, 35.68 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC H ₈ , 2.54g, 35.68 mmol) in 20 of diethyl ether. The reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

Prophetic Example 4

Ti(Cp)(NMe ₂ )2(NC ₄ H ₈ ): A Schlenk flask containing Ti(Cp)(NMe ₂ ) ₃ (10.00g, 40.78 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC ₄ H ₈ , 2.90g, 40.78 mmol) in 20 of diethyl ether. The reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

Prophetic Example 5

Ti(NMe ₂ )(NC ₄ H ₈ ) ₃ : A Schlenk flask containing Ti(NMe ₂ ) ₄ (30.90 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC ₄ H ₈ , 92.70 mmol) in 20 of diethyl ether. The reaction mixture will be stirred at room temperature. Solvent and volatiles were removed.

Prophetic Example 6

Ti(NC ₄ H ₈ ) ₄ : A Schlenk flask containing Ti(NMe ₂ ) ₄ (30.90 mmol) in 100 mL diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrolidine (NC ₄ H ₈ , 123.60 mmol) in 20 of diethyl ether. The resulting reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

Prophetic Example 7

Ti(NMe ₂ )(NC ₄ H ₄ )3: A Schlenk flask containing Ti(NMe ₂ ) ₄ (30.90 mmol) in 100 ml_ diethyl ether will be cooled to -40 °C. To this cooled solution will be added slowly via cannula a mixture of Pyrrole (NC ₄ H , 92.70 mmol) in 20 of diethyl ether. The resulting reaction mixture will be stirred at room temperature. Solvent and volatiles will be removed.

It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and/or the attached drawings.