WO2012176989A1

WO2012176989A1 - A diamine compound or its salt, preparing method of the same, and uses of the same

Info

Publication number: WO2012176989A1
Application number: PCT/KR2012/003866
Authority: WO
Inventors: Wonyong Koh; Won Seok Han
Original assignee: Up Chemical Co., Ltd.
Priority date: 2011-06-24
Filing date: 2012-05-16
Publication date: 2012-12-27
Also published as: WO2012176988A1

Abstract

The present disclosure relates to a diamine compound or its salt having utility for preparing an organometallic compound suitable for vapor phase deposition processes such as a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method.

Description

A DIAMINE COMPOUND OR ITS SALT, PREPARING METHOD OF THE SAME, AND USES OF THE SAME

Recently, high expectations have been placed on using a metal-containing thin film formed by a CVD method or an ALD method as a memory substance of a resistance random access memory (RRAM). By way of example, Korean Patent No. 10-0647332 entitled "Resistive random access memory enclosing an oxide with variable resistance states" describes that a nickel oxide thin film formed by a CVD method or an ALD method is used as a memory substance of a RRAM.

Further, the CVD method and the ALD method are extensively used for manufacturing semiconductor devices as well as sensors or memories. Organometallic precursor compounds are used to prepare metal oxide thin films such as ZrO₂ for DRAM dielectric. Liquid organometallic precursors are generally preferred for industrial applications. Vaporized liquid can be easily transferred to the surface of a substrate, whereas delivery of solid precursors is prone to problems such as clogging and particle generation.

Liquid organometallic precursors suitable for pure metal deposition are relatively rare. Metal carbonyl compounds may be used for deposition of cobalt and nickel thin films. However, carbonyl compounds of cobalt and nickel have toxicity and limited thermal stability. Further, there is a risk of using oxygen-containing precursors for some applications because an oxygen atom in the precursor might remain in a film or at an interface between a deposited film and a substrate. By way of example, oxygen impurity at an interface between silicon and a deposited cobalt or nickel thin film causes defects during silicide formation. Cyclopentadienyl compounds of cobalt and nickel were used for deposition of cobalt and nickel thin film with large amount of carbon impurities, which are not desirable in general.

There is a need for metal precursors that do not contain oxygen and can generate metal-containing thin films with few carbon impurities.

In view of the foregoing, the present disclosure provides a diamine compound and its salt having utility for preparing an organometallic compound suitable for vapor phase deposition processes such as a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method.

In accordance with a first aspect of the present disclosure, there is provided a diamine compound or its salt as represented by following Formula 1:

[Formula 1]

,

wherein each of R¹ and R² is independently a linear or branched alkyl group having 1 to 5 carbon atoms, or trialkylsilyl group as represented by -SiR⁷R⁸R⁹, each of R³ and R⁴ is independently hydrogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or trialkylsilyl group as represented by -SiR¹⁰R¹¹R¹², each of R⁵ and R⁶ is independently an allyl group or vinyl group, and each of R⁷ to R¹² is independently a linear or branched alkyl group having 1 to 5 carbon atoms.

In accordance with a second aspect of the present disclosure, there is provided a method for preparing the salt of the diamine compound as represented by the Formula 1, the method comprising: a process as represented by following Reaction Formula 1, wherein the process includes: reacting a diazadiene neutral ligand represented by following Formula 2 with each or mixture of R⁵MgX' and R⁶MgX' or each or mixture of R⁵M' and R⁶M':

[Formula 2]

,

[Reaction Formula 1]

;

wherein X' is Cl, Br, or I; M' is Li, Na, or K, the conjugated cation contains a cation as represented by [M³]⁺ or [M⁴X]⁺ in which M³ is an alkali metal, M⁴ is an alkali earth metal, and X is Cl, Br, or I, and R¹ to R⁶ are as defined in the first aspect of the present disclosure.

In accordance with a third aspect of the present disclosure, there is provided a method for preparing the diamine compound as represented by the Formula 1, the method comprising: forming the salt of the diamine compound as represented by the Formula 1 via the Reaction Formula 1; and converting the salt of the diamine compound into the diamine compound as represented by the Formula 1.

In accordance with a fourth aspect of the present disclosure, there is provided a method for preparing a organometallic compound of a metal having an oxidation number of +2 as represented by following Formula 12, comprising: a process as represented by following Reaction Formula 2, wherein the process includes: reacting a bivalent metal halide compound as represented by M¹X₂, the diazadiene neutral ligand as represented by the Formula 2, and the salt of the diamine compound as represented by the Formula 1:

[Formula 12]

,

[Reaction Formula 2]

;

wherein M¹ is a metal having an oxidation number of +2, X is Cl, Br, or I, and R¹ to R⁶ are as defined in the first aspect of the present disclosure.

In accordance with a fifth aspect of the present disclosure, there is provided a method for preparing a organometallic compound of a metal or metalloid having an oxidation number of +4 as represented by following Formula 13, comprising: a process as represented by following Reaction Formula 3, wherein the process includes: reacting a tetravalent metal halide compound as represented by M²X₄, and the salt of the diamine compound as represented by the Formula 1:

[Formula 13]

,

[Reaction Formula 3]

;

wherein M² is a metal having an oxidation number of +4, X is Cl, Br, or I, and R¹ to R⁶ are as defined in the first aspect of the present disclosure.

The diamine compound as represented by the Formula 1 or its salt can be used to prepare an organometallic compound suitable for vapor phase deposition processes such as a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method.

The organometallic compound prepared by using the diamine compound or its salt can be used to deposit metal-containing thin films including, but not limited to, a metal thin film, a metal oxide thin film, and a metal nitride thin film.

Especially a liquid organometallic compound prepared by using the diamine compound or its salt is useful for industrial applications due to its ease of transport. Further, the organometallic compound is useful for film deposition where oxygen incorporation into a deposited film or at an interface between a substrate and the deposited film needs to be avoided.

The metal thin film may be a cobalt or nickel thin film, which may be used as an electrode in a semiconductor device. A cobalt or nickel thin film deposited on silicon may be used to form cobalt silicide or nickel silicide thin film by a heat treatment. The metal oxide thin film may be a cobalt oxide thin film or nickel oxide thin film, which may be used as a resistive ramdom access memory (RRAM).

The metal nitride thin film may be a silicon nitride thin film, which may be used as a dielectric layer in a semiconductor device.

Figure 1 is an Auger electron spectroscope (AES) depth profile of a Co thin film deposited by a sequential CVD method using a Co precursor as represented by the Formula 15; and

Figure 2 is an AES depth profile of a Ni oxide thin film deposited by a sequential CVD method using a Ni precursor as represented by the Formula 14.

Hereinafter, examples of the present disclosure will be described in detail with reference to the accompanying drawings so that the present disclosure may be readily implemented by those skilled in the art. However, it is to be noted that the present disclosure is not limited to the examples but can be embodied in various other ways. In drawings, parts irrelevant to the description are omitted for the simplicity of explanation, and like reference numerals denote like parts through the whole present disclosure.

The term "comprises or includes" and/or "comprising or including" used in the present disclosure means that one or more other components, steps, operation and/or existence or addition of elements are not excluded in addition to the described components, steps, operation and/or elements unless context dictates otherwise.

The term "about or approximately" or "substantially" are intended to have meanings close to numerical values or ranges specified with an allowable error and intended to prevent accurate or absolute numerical values disclosed for understanding of the present disclosure from being illegally or unfairly used by any unconscionable third party. Through the whole present disclosure, the term "step of" does not mean "step for".

Through the whole present disclosure, the term "on" that is used to designate a position of one element with respect to another element includes both a case that the one element is adjacent to the another element and a case that any other element exists between these two elements.

Through the whole present disclosure, the term "combination of" included in Markush type description means mixture or combination of one or more components, steps, operations and/or elements selected from a group consisting of components, steps, operation and/or elements described in Markush type and thereby means that the disclosure includes one or more components, steps, operations and/or elements selected from the Markush group.

Through the whole present disclosure, the term "halo", "halo group" or "halogen" may include, but is not limited to F, Cl, Br, or I.

Through the whole present disclosure, the term "alkyl" or "alkyl group" may include a linear or branched saturated or unsaturated alkyl group having a number of carbon atoms of 1 to 10 or 1 to 5, for example, the alkyl or alkyl group including, but not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, hepxyl, octyl, nonyl, decyl, or isomers thereof.

Through the whole present disclosure, the term "trialkylsilyl group" may include, but is not limited to, a group in which silicon (Si) is bonded to three identical or different alkyl groups.

Through the whole present disclosure, the term "allyl" or "allyl group" may include a form modified such that among alkyl group defined above, an alkyl group having a number of carbon atoms of 3 or more includes one or more unsaturated bonds, for example, CH₂=CH-CH₂-. Each hydrogen of the formula CH₂=CH-CH₂- can be substituted with, but not limited to, another group such as a linear or branched alkyl group having 1 to 5 carbon atoms. By way of example, the term "allyl" or "allyl group" may include, but not limited to, C(Me)₂=CH-CH₂-, CH₂=C(Me)-CH₂-, and C(Et)₂=CH-CH₂-.

Through the whole present disclosure, the term "vinyl" or "vinyl group" may include, but is not limited to, a hydrocarbon group including a double bond, for example, CH₂=CH-. Each hydrogen of the formula CH₂=CH- can be substituted with, but not limited to, another group such as a linear or branched alkyl group having 1 to 5 carbon atoms. By way of example, the term "vinyl" or "vinyl group" may include, but not limited to, C(Me)₂=CH-, CH₂=C(Me)-, and C(Et)₂=CH-.

Through the whole present disclosure, the term "metal-containing thin film" means a thin film containing a pure metal or modified metal in whole or in part and may include, but is not limited to, a metal thin film, a metal oxide thin film, a metal silicide thin film, or a metal nitride thin film.

Through the whole present disclosure, the term "metal thin film" means a thin film containing metal which is not modified by oxidation or nitrification as a principal component unlike metal oxide thin film, metal silicide thin film, or metal nitride thin film, and may include a thin film made of a bivalent or tetravalent metal or metalloid, for example, but not limited to, cobalt, nickel, manganese, magnesium, silicon, copper, zinc, cadmium, mercury, lead, platinum, germanium, tin, titanium, zirconium, or hafnium.

Through the whole present disclosure, the term "metal oxide thin film" means a thin film containing metal oxide as a principal component instead of pure metal, and may include, for example, but not limited to, a cobalt oxide thin film and a nickel oxide thin film.

Through the whole present disclosure, the term "metal silicide thin film" means a thin film containing metal silicide as a principal component instead of pure metal, and may include, for example, but not limited to, a cobalt silicide thin film and a nickel silicide thin film.

Through the whole present disclosure, the term "metal nitride thin film" means a thin film containing nitride of a metal or metalloid as a principal component instead of pure metal, and may include, for example, but not limited to, a cobalt nitride thin film , a nickel nitride thin film, and a silicon nitride thin film.

The present disclosure relates to various aspects of diamine compounds or their salts, which have utility for preparing organometallic compounds suitable for CVD or ALD method.

[Formula 1]

,

R¹ and R² may be the alkyl group having 1 to 5 carbon atoms in order for the organometallic compounds prepared from the diamine compound to have high volatility. R¹ and R² may be, but is not limited to, independently ethyl group, isopropyl group, or tert-butyl group. By way of example, the diamine compound in which R¹ and R² are independently ethyl group, isopropyl group, or tert-butyl group, and R³ and R⁴ are hydrogen is useful for CVD or ALD method due to its high volatility.

Preparing the diamine compound or its salt in which R¹ and R² are the same group can save time and efforts, and thus, it is more economical as compared with preparing the diamine compound or its salt in which R¹ and R² are different. Likewise, preparing the diamine compound or its salt in which R³ and R⁴ are the same group can save time and efforts, and thus, it is more economical as compared with preparing the diamine compound or its salt in which R³ and R⁴ are different.

In accordance with an embodiment of the present disclosure, the diamine compound is represented by following Formula 3 in which each of R¹ and R² is an ethyl group and each of R³ and R⁴ is hydrogen; the diamine compound is represented by following Formula 4 in which each of R¹ and R² is an isopropyl group and each of R³ and R⁴ is hydrogen; or the diamine compound is represented by following Formula 5 in which each of R¹ and R² is a tert-butyl group and each of R³ and R⁴ is hydrogen, but it is not limited thereto:

[Formula 3]

,

[Formula 4]

,

[Formula 5]

;

wherein R⁵ and R⁶ are as defined in the first aspect of the present disclosure.

By way of example, each of R⁵ and R⁶ may be an allyl group. Preparing the diamine compound or its salt in which R⁵ and R⁶ are the same group can save time and efforts, and thus, it is more economical as compared with preparing the diamine compound or its salt in which R⁵ and R⁶ are different.

In accordance with an embodiment of the present disclosure, the diamine compound is represented by following Formula 6, 7, or 8 in which each of R⁵ and R⁶ of

Formula

3, 4, or 5 is an allyl group:

[Formula 6]

,

[Formula 7]

,

[Formula 8]

.

By way of example, the diamine compound or its salt may be a compound represented by the Formula 6 or its salt in which both of R¹ and R² are ethyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are allyl group; a compound represented by the Formula 7 or its salt in which both of R¹ and R² are isopropyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are allyl group; and a compound represented by the Formula 8 or its salt in which both of R¹ and R² are tert-butyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are allyl group, but it is not limited thereto.

In accordance with an embodiment of the present disclosure, the diamine compound is represented by following Formula 9, 10, or 11 in which each of R⁵ and R⁶ of

Formula

3, 4, or 5 is a vinyl group:

[Formula 9]

,

[Formula 10]

,

[Formula 11]

.

By way of example, the diamine compound or its salt may be a compound represented by the Formula 9 or its salt in which both of R¹ and R² are ethyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are vinyl group; a compound represented by the Formula 10 or its salt in which both of R¹ and R² are isopropyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are vinyl group; and a compound represented by the Formula 11 or its salt in which both of R¹ and R² are tert-butyl group, both of R³ and R⁴ are hydrogen, and both of R⁵ and R⁶ are vinyl group, but it is not limited thereto.

In accordance with an embodiment of the present disclosure, the salt of the diamine compound contains a dianion of the compound as represented by the Formula 1 and a cation as represented by [M³]⁺ or [M⁴X]⁺ in which M³ is an alkali metal, M⁴ is an alkali earth metal, and X is Cl, Br, or I, but it is not limited thereto.

In accordance with an embodiment of the present disclosure, the cation as represented by [M³]⁺ or [M⁴X]⁺ contains Li⁺, Na⁺, K⁺, Rb⁺, [MgCl]⁺, [MgBr]⁺, or [MgI]⁺, but it is not limited thereto.

[Formula 2]

,

[Reaction Formula 1]

;

wherein X' is Cl, Br, or I, M' is Li, Na, or K, the conjugated cation contains a cation as represented by [M³]⁺ or [M⁴X]⁺ in which M³ is an alkali metal, M⁴ is an alkali earth metal, and X is Cl, Br, or I, and R¹ to R⁶ are as defined in the first aspect of the present disclosure.

By way of example, converting the salt of the diamine compound into the diamine compound may be performed by work-up procedure, but it is not limited thereto. The work-up procedure known to organic chemists may be utilized including, but not limited to, a use of NH₄Cl or dilute HCl.

[Formula 12]

,

[Reaction Formula 2]

;

[Formula 13]

,

[Reaction Formula 3]

;

The product of the Reaction Formula 1, the salt of the diamine compound, may be used without further separation or purification and may provide a dianion of the diamine compound shown in the Reaction Formula 2 and the Reaction Formula 3. In another preparative method, the dianion of the diamine compound may be generated by a reaction of the diamine compound and a strong base such as n-butyllithium, but it is not limited thereto.

By way of example, each of R⁵ and R⁶ may be, but is not limited to, the same functional group. In this case, the organometallic compound as represented by the Formula 12 can be formed by, but not limited to, making a reaction between a diazadiene neutral ligand represented by the Formula 2 and a two equivalents of the R⁵MgX' or R⁵M' to synthesize the salt of the diamine compound as represented by the Formula 1 and adding one equivalent of the bivalent metal halide compound as represented by M¹X₂ and one equivalent of the diazadiene neutral ligand as represented by the Formula 2 thereto.

By way of example, forming the organometallic compound as represented by the Formula 12 is performed by forming a reaction solution by adding the bivalent metal halide compound as represented by M¹X₂ and the diazadiene neutral ligand as represented by the Formula 2 to an organic solvent, cooling the reaction solution, adding the salt of the diamine compound as represented by the Formula 1 to the cooled reaction solution with stirring, filtering an salt insoluble in the organic solvent, and removing the organic solvent, but it is not limited thereto.

The bivalent metal halide compound as represented by M¹X₂ can be dissolved in the organic solvent and powder thereof can be dispersed in the solvent, but it is not limited thereto. Further, the cooling process may be performed at temperature of from about -80℃ to about 0℃, for example, but not limited to, from about -80℃ to about -60℃, from about -80℃ to about -40℃, from about -80℃ to about -20℃, from about -80℃ to about 0℃, from about -60℃ to about -40℃, from -60℃ to about -20℃, from about -60℃ to about 0℃, from -40℃ to about -20℃, from -40℃ to about 0℃, or from about -20℃ to about 0℃. Furthermore, the adding the salt of the diamine compound as represented by the Formula 1 to the cooled reaction solution with stirring may be performed at, but not limited to, a low speed.

By way of example, the organic solvent may contain, but is not limited to, tetrahydrofuran (THF), 1,2-dimethoxyethane, or 2-methoxyethyl ether. By way of example, the organic solvent may employ various solvents which have been typically used as, but not limited to, a nonpolar organic solvent or a weakly polar organic solvent.

By way of example, the stirring may be performed under, but not limited to, an inert gas in order to suppress a decomposition reaction. By way of example, the inert gas may include, but is not limited to, a nitrogen gas or an argon gas. The inert gas is included in reaction conditions, but not limited to, in order to suppress a decomposition reaction caused by moisture or oxygen during the stirring reaction.

By way of example, each of R⁵ and R⁶ may be, but is not limited to, the same functional group. In this case, the organometallic compound as represented by the Formula 13 can be formed by, but not limited to, making a reaction between a diazadiene neutral ligand represented by the Formula 2 and two equivalents of the R⁵MgX' or R⁵M' to synthesize a salt of the diamine compound as represented by the Formula 1, and adding a tetravalent metal halide compound as represented by M²X₄ thereto.

By way of example, the organometallic compound as represented by the Formula 13 is performed by forming a reaction solution by adding the tetravalent metal halide compound as represented by M²X₄, cooling the reaction solution, adding the salt of the diamine compound as represented by the Formula 1 to the cooled reaction solution with stirring, filtering an salt insoluble in the organic solvent, and removing the organic solvent, but it is not limited thereto.

The tetravalent metal halide compound as represented by M²X₄ can be dissolved in the organic solvent and powder thereof can be dispersed in the solvent, but it is not limited thereto. Further, the cooling process may be performed at temperature of from about -80℃ to about 0℃, for example, but not limited to, from about -80℃ to about -60℃, from about -80℃ to about -40℃, from about -80℃ to about -20℃, from about -80℃ to about 0℃, from about -60℃ to about -40℃, from about -60℃ to about -20℃, from about -60℃ to about 0℃, from about -40℃ to about -20℃, from about -40℃ to about 0℃, or from about -20℃ to about 0℃. Furthermore, the adding the salt of the diamine compound as represented by the Formula 1 to the cooled reaction solution with stirring may be performed at, but not limited to, a low speed.

Hereinafter, the present disclosure will be explained in more detail with reference to examples. However, the following examples will be provided for understanding of the present disclosure but do not limit the present disclosure.

[EXAMPLES]

Example 1. Preparing the diamine compound as represented by the Formula 7

35.0 g of N,N'-diisopropyl-1,4-diaza-1,3-diene (ⁱPr-DAD) [ ⁱPr-N=CH₂CH₂=N-ⁱPr ] (250 mmol, 1 eq) was dissolved in 100 ml of tetrahydrofuran (THF) in a flame-dried 250 mL Schlenk flask and the solution was cooled to -78℃. While keeping the flask at -78℃, 250 mL of 2.0 M allylmagnesium chloride in THF (500 mmol, 2 eq) was slowly added to the flask while stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 12 hours at room temperature. 100 mL of saturated aqueous NH₄Cl solution was added to the flask to quench the reaction. THF and volatile by-products were removed under vacuum after drying the reaction mixture by MgSO₄. The residue was then dissolved in 200 mL of diethyl ether. The diethyl ether solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing diethyl ether under vacuum. A yellowish liquid product as represented by following Formula 7 was obtained:

[Formula 7]

;

Yield: 27.44 g (49%)

Boiling point: 60℃ at 0.3 torr

¹H-NMR (C₆D₆): δ0.977 (d, 12H, HNCH(CH ₃)₂), 2.140, 2.450 (m, 4H, HNCHCH ₂CH=CH₂), 2.197 (s, 2H, HNCH(CH₃)₂), 2.589 (m, 2H, HNCHCH₂CH=CH₂), 2.793 (m, 2H, HNCH(CH₃)₂), 5.054 (m, 4H, HNCHCH₂CH=CH ₂), 5.855 (m, 2H, HNCHCH₂CH=CH₂)

[Reaction Formula 4]

.

Example 2. Preparing the diamine compound as represented by the Formula 11

2.0 g of N,N'-di-tert-butyl-1,4-diaza-1,3-diene (^tBu-DAD) [^tBu -N=CH₂CH₂=N- ^tBu ] was dissolved in 20 mL of THF in a flame-dried 250 mL Schlenk flask and cooled to -78℃. While keeping the solution at -78℃, 35 mL of 1.0 M vinylmagnesium bromide in THF was slowly added to the solution with stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 12 hours at room temperature. After quenching the reaction with water, a resultant product was extracted by chloroform twice. A chloroform solution was treated by MgSO₄ and chloroform was evaporated. The product of 0.5 g as represented by following Formula 11 was obtained by column chromatography using silica and 10:1 mixture of CH₂Cl₂ and CH₃OH:

[Formula 11]

;

¹H-NMR (C₆D₆): δ1.081 (s, 18H, HNC(CH ₃)₃), 3.046 (s, 2H, HNC(CH₃)₃), 4.221 (m, 2H, HNCHCH=CH₂), 5.111, 5.048 (m, 2H, HNCHCH=CH ₂), 5.806 (m, 2H, HNCHCH=CH₂)

Example 3. Preparing organic nickel compound as represented by the Formula 14

10.0 g of anhydrous NiCl2 (77 mmol, 1 eq) and 10.8 g of N,N'-diisopropyl-1,4-diaza-1,3-diene (ⁱPr-DAD) [ ⁱPr-N=CH₂CH₂=N-ⁱPr ] (77 mmol, 1 eq) were dissolved or suspended in 70 mL of 1,2-dimethoxyethane (DME) in a flame-dried 250 mL Schlenk flask and the solution was cooled to -20℃. In another Schlenk flask, 17.3 g of the diamine compound, prepared by the Example 1, (77 mmol, 1 eq) was dissolved in 30 mL of DME and the solution was cooled to 20℃ and then 59 ml of 2.6 M n-butyllithium in hexane (154 mmol, 2 eq) was slowly added to the diamine solution in order to form the salt of the diamine while stirring and keeping the solution at 20℃. The in-situ prepared salt solution of the diamine was slowly added to the mixture of NiCl2 and ⁱPr-DAD in DME at -20℃ while stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 24 hours at room temperature. Then, the DME solvent and volatile by-products were removed under vacuum. The residue was then dissolved in 200 mL of n-hexane. The n-hexane solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing n-hexane under vacuum. The dark red liquid product of 10.53 g as represented by Formula 14 was obtained:

[Formula 14]

;

Yield: 10.53 g (32.4%)

Elemental analysis: estimated value for C₂₂H₄₂N₄Ni: C = 62.72; H = 10.05; N = 13.30, measured value: C = 61.86; H = 10.07; N = 13.54

Boiling point: 80℃ at 0.32 torr

Density: 1.207 g/mL at 25℃

[Reaction Formula 5]

.

Example 4. Preparing organic nickel compound as represented by the Formula 14 from ⁱPr-DAD and allylmagnesium chloride

10.0 g of anhydrous NiBr₂ (46 mmol, 1 eq) and 6.4 g of ⁱPr-DAD (46 mmol, 1 eq) are dissolved or suspended in 70 mL of 1,2-dimethoxyethane (DME) in a flame-dried 250 mL Schlenk flask and the solution was cooled to -20℃. In another Schlenk flask, 6.4 g of ⁱPr-DAD (46 mmol, 1 eq) was dissolved in 30 mL of DME and the solution was cooled to 20℃ and then 57 mL of 2.0 M allylmagnesium chloride in THF (115 mmol, 2.5 eq) was slowly added to the diamine solution in order to form a diamine salt while stirring and keeping the solution at 20℃. The diamine salt solution in-situ prepared from ⁱPr-DAD and allylmagnesium chloride was slowly added to the mixture of NiBr₂ and ⁱPr-DAD in DME at -20℃ while stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 24 hours at room temperature. Then, the DME solvent and volatile by-products were removed under vacuum. The residue was then dissolved in 200 mL of n-hexane. The n-hexane solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing n-hexane under vacuum. The dark red liquid product of 7.11 g as represented by the Formula 14 was obtained.

Yield: 7.11 g (36.9%)

Elemental analysis: estimated value for C₂₂H₄₂N₄Ni: C = 62.72; H = 10.05; N = 13.30, measured value: C = 61.76; H = 10.07; N = 13.79

Boiling point: 80℃ at 0.32 torr

Density: 1.207 g/mL at 25℃

Example 5. Preparing organic cobalt compound as represented by the Formula 15 from ⁱPr-DAD and allylmagnesium chloride

10.0 g of anhydrous CoCl₂ (77 mmol, 1 eq) and 10.8 g of ⁱPr-DAD (77 mmol, 1 eq) were dissolved or suspended in 70 mL of DME in a flame-dried 250 mL Schlenk flask and the solution was cooled to -20℃. In another Schlenk flask, 10.8 g of ⁱPr-DAD (77 mmol, 1 eq) was dissolved in 30 mL of DME and the solution was cooled to 20℃ and then 96 mL of 2.0 M allylmagnesium chloride in THF (193 mmol, 2.5 eq) was slowly added to the diamine solution in order to form a diamine salt while stirring and keeping the solution at 20℃. The diamine salt solution in-situ prepared from ⁱPr-DAD and allylmagnesium chloride was slowly added to the mixture of CoCl₂ and ⁱPr-DAD in DME at -20℃ while stirring. After completion of the addition, the flask was slowly warmed to room temperature and stirred for 24 hours at room temperature. Then the DME solvent and volatile by-products were removed under vacuum. The residue was then dissolved in 200 mL of n-hexane. The n-hexane solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing n-hexane under vacuum. The light brown liquid product of 12.11 g as represented by following Formula 15 was obtained.

[Formula 15]

;

Yield: 12.11 g (37.3%)

Elemental analysis: estimated value for C₂₂H₄₂N₄Co: C = 62.68; H = 10.04; N = 13.29, measured value: C = 61.45; H = 9.98; N = 13.32

Boiling point: 75℃ at 0.32 torr

Density: 1.221 g/mL at 25℃

Test Example 1. Deposition of cobalt thin film by ALD method or sequential CVD method using a Co precursor as represented by the Formula 15

A seed layer was prepared on a silicon substrate heated to 300℃ in an ALD reactor by alternately supplying tetrakis(dimethylamido)titanium (TDMAT) and ammonia (NH₃). No cobalt film was deposited on the silicon substrate (001) without the seed layer.

The silicon substrate with the seed layer was heated to 300℃ in the ALD reactor. A stainless steel bubbler containing a cobalt precursor represented by the Formula 15 was heated to 100℃. The cobalt precursor was vaporized and delivered to the ALD reactor by Ar carrier gas having a flow rate of about 50 sccm. A pressure inside the ALD reactor was maintained at 3 torr. A gas supply sequence includes a Co precursor carried by Ar for 5 sec, an Ar gas purge for 5 sec, ammonia gas for 5 sec, and an Ar gas purge for 5 sec. After performing 300 cycles of the gas supply sequence, the film was analyzed by a scanning electron microscope (SEM) and an Auger electron spectroscope (AES). An AES depth profile of a Co film deposited by using ammonia as a reaction gas was shown in Fig. 1, which indicates that a Co metal film was deposited. Similar AES depth profiles were obtained when a H₂ gas was used as a reaction gas.

Test Example 2. Deposition of nickel oxide thin film by ALD method or sequential CVD method using a Ni precursor as represented by Formula 14

A silicon substrate, on which 100 nm SiO₂ was formed, was heated to 200℃ in an ALD reactor. A stainless steel bubbler containing a Ni precursor as represented by the Formula 14 was heated to 100℃. The Ni precursor was vaporized and delivered to the ALD reactor by an Ar carrier gas having a flow velocity of about 50 sccm. A pressure inside the ALD reactor was maintained at 3 torr. A gas supply sequence includes a Ni precursor carried by Ar for 20 sec, an Ar gas purge for 5 sec, an ozone (O3) gas flow for 5 sec, and an Ar gas purge for 5 sec. After performing 300 cycles of the gas supply sequence, the film was analyzed by a scanning electron microscope (SEM) and an Auger electron spectroscopy (AES). An AES depth profile of a Ni film deposited by using ammonia as a reaction gas was shown in Fig. 2, which indicates that a Ni oxide thin film was deposited.

Comparative Example 1. Preparing organic cobalt compound as represented by the Formula 16

3.90 g of anhydrous CoCl₂ (30 mmol, 1 eq) and 4.20 g of ⁱPr-DAD (30 mmol, 1 eq) were dissolved or suspended in 30 mL of THF in a flame-dried 250 mL Schlenk flask and the solution was cooled to -20℃. In another Schlenk flask, 4.20 g of ⁱPr-DAD (30 mmol, 1 eq) and 0.42 g of lithium metal (60 mmol) was stirred in 30 mL of THF in order to form Li₂(ⁱPr-DAD). The in-situ prepared Li₂(ⁱPr-DAD) solution of the diamine was slowly added to the mixture of CoCl₂ and ⁱPr-DAD in DME at -20℃ while stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 12 hours at room temperature. Then, the solvent and volatile by-products were removed under vacuum. The residue was then dissolved in 60 mL of n-hexane. The n-hexane solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing n-hexane under vacuum. The brown liquid product of 5.31 g as represented by following Formula 16 was obtained:

[Formula 16]

;

Yield: 5.31 g (52.1%)

Elemental analysis: estimated value for C₁₆H₃₂N₄Co: C = 56.62; H = 9.50; N = 16.51, measured value: C = 56.32; H = 9.58; N = 16.61

Boiling point: 80℃ at 0.25 torr

Density: 1.092 g/mL at 25℃

[Reaction Formula 6]

.

Comparative Test Example 1. Attempt to deposit Co-containing thin film by the ALD method or the sequential CVD method using Co precursor represented by the Formula 16

The same film forming procedure was performed as the Test Example 1 except that the Co precursor represented by the Formula 16 was used instead of the Co precursor represented by the Formula 15.

The substrate was examined by a SEM and an energy-dispersive X-ray spectroscope (EDX). It was observed that a Co-containing thin film was not deposited.

Comparative Example 2. Preparing organic nickel compound as represented by the Formula 17

10 g of anhydrous NiBr₂ (46 mmol) and 16.04 g of ⁱPr-DAD (115 mmol) were dissolved or suspended in 100 mL of 2-methoxyethyl ether in a flame-dried 250 mL Schlenk flask and the solution was cooled to -20℃. In another Schlenk flask, 3.46 g of NaBH₄ (92 mmol) was dissolved in 50 mL of 2-methoxyethyl ether. The NaBH₄ solution was slowly added to the mixture of NiBr₂ and ⁱPr-DAD in 2-methoxyethyl ether at -20℃ while stirring. After completion of the addition, the flask was slowly heated to room temperature and stirred for 12 hours at room temperature. Then the solvent and volatile by-products were removed under vacuum. The residue was then dissolved in 100 mL of n-hexane. The n-hexane solution was filtered through a Celite pad and a glass frit. The filtrate was vacuum distilled after removing n-hexane under vacuum. A yellowish brown liquid product as represented by following Formula 17 was obtained.

[Formula 17]

;

Yield: 6.40 g (41.1%)

Elemental analysis: estimated value for C₁₆H₃₄N₄Ni: C = 56.50; H = 9.78; N = 16.47, measured value: C = 56.32; H = 9.88; N = 16.51

Boiling point: 76℃ at 0.32 torr

Density: 1.251 g/mL at 25℃

Comparative Test Example 2. Attempt to deposit Ni-containing thin film by the ALD method or the sequential CVD method using Ni precursor represented by Formula 17

The same film forming procedure was performed as the Test example 2 except that the Ni precursor represented by the Formula 17 was used instead of the Ni precursor represented by the Formula 14.

The substrate was examined by a SEM and an energy-dispersive X-ray spectroscope (EDX). It was observed that a Ni-containing film was not deposited.

Superiority of Co or Ni precursors containing the diamine of the present disclosure as a ligand has been clearly demonstrated by comparisons between the Test Examples 1 and 2 and the Comparative Test Examples 1 and 2, respectively. By the ALD method or the sequential CVD method using Co or Ni precursors containing the diamine of the present disclosure, a Co thin film and a Ni oxide thin film can be deposited. However, by the ALD method or the sequential CVD method using Co or Ni precursors containing a related diamine without allyl groups, no film can be deposited in the same deposition conditions.

Diamine represented by the Formula 1 or its salt can be used to prepare an organometallic compound suitable for vapor phase deposition processes such as a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method. Organometallic precursors with allyl-containing diamine ligands are highly suitable to deposit metal thin films or metal oxide thin films, which can be used as electrodes and various other functional layers in a semiconductor device.

Claims

A diamine compound or its salt as represented by following Formula 1:

[Formula 1]

;

wherein

each of R¹ and R² is independently a linear or branched alkyl group having 1 to 5 carbon atoms, or trialkylsilyl group as represented by -SiR⁷R⁸R⁹,

each of R³ and R⁴ is independently hydrogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or trialkylsilyl group as represented by -SiR¹⁰R¹¹R¹²,

each of R⁵ and R⁶ is independently an allyl group or vinyl group, and

each of R⁷ to R¹² is independently a linear or branched alkyl group having 1 to 5 carbon atoms.
The diamine compound or its salt of claim 1,

wherein the compound is represented by following Formula 3 in which each of R¹ and R² is an ethyl group and each of R³ and R⁴ is hydrogen;

wherein the compound is represented by following Formula 4 in which each of R¹ and R² is an isopropyl group and each of R³ and R⁴ is hydrogen; or

wherein the compound is represented by following Formula 5 in which each of R¹ and R² is a tert-butyl group and each of R³ and R⁴ is hydrogen:

[Formula 3]

,

[Formula 4]

,

[Formula 5]

;

wherein R⁵ and R⁶ are as defined in claim 1.
The diamine compound or its salt of claim 2,

wherein the compound is represented by following Formula 6, 7, or 8 in which each of R⁵ and R⁶ of Formula 3, 4, or 5 is an allyl group:

[Formula 6]

,

[Formula 7]

,

[Formula 8]

.
The diamine compound or its salt of claim 2,

wherein the compound is represented by following Formula 9, 10, or 11 in which each of R⁵ and R⁶ of Formula 3, 4, or 5 is a vinyl group:

[Formula 9]

,

[Formula 10]

,

[Formula 11]

.
The diamine compound or its salt of claim 1,

wherein the salt contains a dianion of the compound as represented by the Formula 1 and a cation as represented by [M³]⁺ or [M⁴X]⁺ in which M³ is an alkali metal, M⁴ is an alkali earth metal, and X is Cl, Br, or I.
The diamine compound or its salt of claim 5,

wherein the cation as represented by [M³]⁺ or [M⁴X]⁺ contains Li⁺, Na⁺, K⁺, Rb⁺, [MgCl]⁺, [MgBr]⁺, or [MgI]⁺.
A method for preparing the salt of the diamine compound as represented by the Formula 1, the method comprising:

a process as represented by following Reaction Formula 1, wherein the process includes:

reacting a diazadiene neutral ligand represented by following Formula 2 with each or mixture of R⁵MgX' and R⁶MgX' or each or mixture of R⁵M' and R⁶M':

[Formula 2]

,

[Reaction Formula 1]

;

wherein

X' is Cl, Br, or I,

M' is Li, Na, or K,

the conjugated cation contains a cation as represented by [M³]⁺ or [M⁴X]⁺ in which M³ is an alkali metal, M⁴ is an alkali earth metal, and X is Cl, Br, or I, and

R¹ to R⁶ are as defined in claim 1.
A method for preparing the diamine compound as represented by the Formula 1, the method comprising:

forming the salt of the diamine compound as represented by the Formula 1 via the Reaction Formula 1; and

converting the salt of the diamine compound into the diamine compound as represented by the Formula 1.
A method for preparing a organometallic compound of a metal having an oxidation number of +2 as represented by following Formula 12, comprising:

a process as represented by following Reaction Formula 2, wherein the process includes:

reacting a bivalent metal halide compound as represented by M¹X₂, the diazadiene neutral ligand as represented by the Formula 2, and the salt of the diamine compound as represented by the Formula 1:

[Formula 12]

,

[Reaction Formula 2]

;

wherein

M¹ is a metal having an oxidation number of +2,

X₂ is Cl, Br, or I, and

R¹ to R⁶ are as defined in claim 1.
A method for preparing a organometallic compound of a metal or metalloid having an oxidation number of +4 as represented by following Formula 13, comprising:

a process as represented by following Reaction Formula 3, wherein the process includes:

reacting a tetravalent metal halide compound as represented by M²X₄, and the salt of the diamine compound as represented by the Formula 1:

[Formula 13]

,

[Reaction Formula 3]

;

wherein

M² is a metal or metalloid having an oxidation number of +4,

X₄ is Cl, Br, or I, and

R¹ to R⁶ are as defined in claim 1.