Organometallic compounds

Abstract

Certain organometallic compounds in the form of imino complexes are provided. Such complexes are particularly suitable for use as vapor deposition precursors. Also provided are methods of depositing thin films, such as by ALD and CVD, using such compounds.

Description

EXAMPLE 1

Tantalum bis(di-isopropylacetamidinate)-(dimethylamino)-(2-diisopropylamino)-ethylimide, (i-Pr)₂NCH₂CH₂NTa(amd)₂(NMe₂), is expected to be synthesized as follows:

(2-Diisopropylaminoethyl)(trimethylsilyl)amine is added to TaCl₅ in toluene at low temperature (approximately −30 to −40° C.). A 3-neck round bottom flask is used. It is equipped with magnetic or mechanical stirring and effective heating/cooling system to control the rate of reaction. After the mixture is stirred for 1 hour at room temperature, excess pyridine is added. The resulting mixture is then stirred overnight under an inert atmosphere of nitrogen. The reagents are added in continuous and dropwise manner, and are allowed to mix slowly to control the exothermicity of the reaction. The crude intermediate product is then expected to separate from the reaction mass after filtration with a high yield expected. Next, the intermediate is taken into hexane. To this, lithium di-isopropyl acetamidinate (Li-amd, which is prepared from N,N′-diisopropylcarbodiimide and methyl lithium in diethyl ether) suspended in hexane is added slowly. The mixture is expected to turn brown gradually as it is stirred overnight. Lithium dimethylamide which is prepared from dimethylamine and n-butyl lithium in hexane is then added to the reaction mixture. After filtration, the filtrate is concentrated. Purification by vacuum distillation is expected to give a pure compound. The target product is expected to be obtained in high yield and is expected to be substantially free of organic solvents (<0.5 ppm) as determined by FT-NMR and also substantially free of metallic impurities (<10 ppb) as determined by ICP-MS/ICP-OES.

EXAMPLE 2

Bis(2-diisopropylaminoethylimino)-bis(dimethylamino)tungsten(VI) is expected to be synthesized according to the following reaction scheme.

(2-Diisopropylaminoethyl)(trimethylsilyl)amine is slowly added to WCl₆ in toluene at low temperature (approximately −30 to −40° C.). A 3-neck round bottom flask is used. It is equipped with magnetic or mechanical stirring and effective heating/cooling system to control the rate of reaction. After the mixture is stirred for a few hours at room temperature, excess pyridine is added. The resulting mixture is then stirred overnight under an inert atmosphere of nitrogen. The reagents are added in continuous and dropwise manner, and are allowed to mix slowly to control the exothermicity of the reaction. The crude intermediate product is then expected to separate from the reaction mass after filtration with a high yield expected. Next, the intermediate is taken into hexane. To this, LiNMe₂ suspended in hexane or LiNMe₂ powder which is prepared from dimethylamine and n-butyl lithium in hexane is added slowly. The mixture is expected to turn dark brown as it is stirred overnight. After filtration, the filtrate is concentrated. Purification by vacuum distillation is expected to give the desired compound. The target product is expected to be obtained in reasonably high yield and is expected to be substantially free of organic solvents (<0.5 ppm) as determined by FT-NMR and also substantially free of metallic impurities (<10 ppb) as determined by ICP-MS/ICP-OES.

EXAMPLE 3

Organometallic compounds of the formula (EDG-(CR¹R²)_y—N=)_nM^+mL¹_x′L²_x″L³_p listed in the following table are expected to be prepared according to the procedures in one or more of U.S. Patent Application No. 2004/0202171, and International Patent Applications WO 2004/007796 and WO 2005/112101.

Sample	M	n	EDG	y	R1	R2	L1	L2	L3
A	Mg	1	N(Et)Me	0	—	—	OEt	—	—
B	Al	1	CH═C(Et)Me	0	—	—	H	—	—
C	Si	1	O—C(O)Me	0	—	—	AMD	—	—
D	Te	2	Py	0	—	—	KIM	—	—
E	Cu	1	N(H)—C(O)Et	0	—	—	PAMD	—	VTMS
F	Sc	1	OH	0	—	—	N(Et)Me	—	—
G	La	1	OK	0	—	—	DMAE	—	—
H	Ti	1	N(Me)Li	0	—	—	Cp	—	—
I	Hf	1	NH(t-Bu)	0	—	—	NO3	—	isoprene
J	V	1	BiPy	0	—	—	MMP	—	—
K	Ta	1	Ph	0	—	—	MP	—	—
L	W	2	Ph-NMe2	0	—	—	BDK	—	—
M	Ni	1	NH2	1	H	H	Pyrazo	—	Bz, CO
N	W	2	NMe2	2	H, Me	H, H	O-i-Pr	NMe2	—
AMD = N,N′-dimethyl-methyl-amidinate;
PAMD = N,P-dimethyl-methylphosphoamidinate;
KIM = β-diketiminate;
DMAE = dimethylaminoethyl;
MMP = 1-methoxy-2-methyl-propoxy;
MP = N-methylpyrrolidine;

In the above table, ligands separated by a comma denote that each ligand is present in that compound.

EXAMPLE 4

Compositions suitable for use in ALD or direct liquid injection processes are prepared by combining certain of the compounds of Example 3 with certain organic solvents. The particular compositions are shown in the following table. The organometallic compounds are typically present in a concentration of 0.1 M for direct liquid injection.

	Composition	Organometallic
	Sample	Compound Sample	Solvent
	1	D	THF
	2	D	1,4-Dioxane
	3	D	2-Methoxyethyl acetate
	4	E	Diglyme
	5	E	Octane
	6	F	THF
	7	F	Diglyme
	8	G	Octane
	9	G	THF
	10	G	n-Butyl acetate
	11	H	n-Butyl acetate
	12	H	2-Methoxyethoxy acetate
	13	I	THF
	14	J	Octane
	15	K	Diglyme
	16	L	n-Butyl acetate
	17	M	2-Methoxyethoxy acetate
	18	M	Octane
	19	N	THF

Claims

1. An organometallic compound having the formula (EDG-(CR1R2)n—N=)nM+mL1x′L2x″L3p, wherein each R1 and R2 are independently chosen from H, (C1-C6)alkyl and EDG; EDG is an electron donating group; M=a metal; L1=an anionic ligand; L2 is a ligand chosen from amino, alkylamino, dialkylamino and alkoxyalkyldialkylamino; L3=a neutral ligand; y=0-6; m=the valence of M; n=1-2; x′≧0; x″≧0; m=2n+x′+x″; p=0-3; wherein n=1 when m=2-3, and wherein n=1-2 when m≧4; L1 # L2; provided that x′≧1 when m≧3 and EDG=amino, alkylamino, dialkylamino, pyridyl or alkoxy.

2. The compound of claim 1 wherein L1 is chosen from hydride, halide, azide, alkyls, alkenyl, alkynyl, carbonyl, dialkylaminoalkyl, imino, hydrazido, phosphido, nitrosyl, nitryl, nitrate, nitrile, alkoxy, dialkylaminoalkoxy, siloxy, diketonates, ketoiminates, cyclopentadienyls, silyls, pyrazolates, guanidinates, phosphoguanidinates, amidinates and phosphoamidinates.

3. The compound of claim 1 wherein EDG comprises one or more of oxygen, phosphorus, sulfur, nitrogen, alkenes, alkynes and aryl groups.

4. The compound of claim 1 wherein M is chosen from a Group 2 to Group 16 metal.

5. A composition comprising the compound of claim 1 and an organic solvent.

6. A method of depositing a film comprising the steps of: providing a substrate in a vapor deposition reactor; conveying as a precursor the organometallic compound of claim 1 in a gaseous form to the reactor; and depositing a film comprising the metal on the substrate.

7. A method of depositing a film comprising the steps of: providing a substrate in a reactor; conveying the composition of claim 5 into the reactor using direct liquid injection; and depositing a film comprising the metal on the substrate.

8. A method of depositing a film comprising the steps of: providing a substrate in a vapor deposition reactor; conveying as a first precursor the organometallic compound of claim 1 in a gaseous form to the reactor; chemisorbing the first precursor compound on the surface of the substrate; removing any non-chemisorbed first precursor compound from the reactor; conveying a second precursor in a gaseous form to the reactor; reacting the first and second precursors to form a film on the substrate; and removing any unreacted second precursor.

9. The method of claim 8 wherein the second precursor is chosen from oxygen, ozone, water, peroxide, alcohols, nitrous oxide and ammonia.

10. A delivery device for delivering a precursor in the vapor phase to a vapor deposition reaction comprising the compound of claim 1.