Novel compounds, precursor compositions comprising the same and methods of manufacturing thin films using the same

Abstract

The present application relates to a vapor deposition compound capable of thin film deposition by vapor deposition in a gas phase, and particularly relates to a novel compound which is capable of being applied to Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD) and which is excellent in reactivity, volatility and thermal stability, a precursor composition containing the novel compound, a method for manufacturing a thin film using the precursor composition, and a thin film manufactured from the precursor composition.

Description

Technical Field

[0001] This invention relates to vapor-phase deposition compounds capable of thin film deposition via vapor-phase evaporation, and more specifically, to novel compounds that are applicable to atomic layer evaporation or chemical vapor deposition and exhibit excellent reactivity, volatility, and thermal stability; precursor compositions comprising the novel compounds; methods for manufacturing thin films using the precursor compositions; and thin films manufactured from the precursor compositions. Background Technology

[0002] With the development of high integration and high precision in semiconductor devices, it has become important to form metal and metal oxide thin films of uniform thickness that can be applied to various technologies such as microelectronics, magnetic information storage, and catalysts.

[0003] To fabricate thin films of metals and metal oxides, chemical vapor deposition (CVD) or atomic layer evaporation (ALD) is used. ALD, in particular, allows for the formation of desired films by sequentially injecting and removing reactants into a chamber, making composition easily adjustable and enabling the formation of films of uniform thickness. Furthermore, ALD offers excellent step coverage, enabling the uniform growth of thin films on complex and precise components.

[0004] To fabricate thin films using atomic layer evaporation (ALPE), precursors play a crucial role, requiring high volatility, high thermal stability, and high reactivity within the vapor chamber. To date, various ligands have been used for precursor development, including halogens, alkoxides, cyclopentadiene, β-diketones, amides, and amidines. However, due to the fact that most known precursors are solid compounds, exhibit poor volatility or stability, or may introduce contamination during thin film deposition, there is a continuous need to develop new precursors.

[0005] In particular, the necessity of late transition metal (Mn, Fe, Co, Ni, Cu) precursors with excellent properties has been emphasized for many years, but their development has lagged behind other metal precursors due to the difficulty of development.

[0006] For example, cobalt precursors in post-transition metal precursors exhibit diverse oxidation states, ranging from -1 to +5, typically with +2 or +3, enabling the formation of cobalt oxide and nitride thin films for use in semiconductor devices. Cobalt metal thin films can be used in electrode materials, magnetic materials, magnetic random access memories (MRAM), diluted magnetic semiconductors (DMS), perovskites, catalysts, and photocatalysts. Furthermore, due to the high integration of semiconductor devices, cobalt metal thin films can be used as copper diffusion prevention films and capping layers in metal wiring processes, attracting considerable attention as a next-generation material to replace copper metal thin films.

[0007] Currently known representative cobalt precursors include carbonyl compound CCTBA (Dicobalt hexacarbonyl t-butylacetylene), Co(CO)3(NO), cyclopentadiene compound CpCo(CO)2, β-diketone compound Co(tmhd)2, Co(acac)2, and diene compound Co( tBu2 DAD)2, etc. Most of them are solid compounds with high melting points and low stability. Furthermore, they may cause contamination of the film during vapor deposition.

[0008] In particular, although CCTBA, which is commonly used, has a high vapor pressure, the film is heavily contaminated with C and O after evaporation. CpCo(CO)2 is a liquid compound with the advantage of high vapor pressure, but it decomposes at 140℃ and has very poor thermal stability.

[0009] Therefore, the reality is that there is a need to develop new post-transition metal precursors with superior properties that improve upon the shortcomings of these existing cobalt precursors.

[0010] [Existing technical documents]

[0011] [Patent Literature]

[0012] (Patent Document 1) Korean Patent Publication No. 2010-0061183

[0013] (Patent Document 2) Korean Patent Publication No. 2004-0033337

[0014] (Patent Document 3) Korean Patent Registration No. 10-1962355

[0015] (Patent Document 4) Korean Patent No. 10-2123331 Summary of the Invention

[0016] Technical issues

[0017] The present invention addresses the problems of conventional post-transition metal precursors mentioned above, and aims to provide post-transition metal precursor compounds for thin film deposition that exhibit excellent reactivity, thermal stability, and volatility.

[0018] In particular, the goal is to improve the volatility and thermal stability that are drawbacks of previous post-transition metal precursors by using imidazoline ligands, which have not been used before.

[0019] Furthermore, the present invention aims to provide a method for manufacturing thin films using the aforementioned post-transition metal precursor compounds, and the thin films themselves.

[0020] However, the problems to be solved in this application are not limited to those mentioned above, and those skilled in the art should be able to clearly understand other problems not mentioned through the following description.

[0021] Methods for solving problems

[0022] The present invention aims to develop novel compounds and precursor compositions containing imidazoline ligands that, although liquid or solid, have low melting points, can be purified at low temperatures, and exhibit excellent volatility and thermal stability. The present invention aims to provide novel precursors containing imidazoline ligands.

[0023] One aspect of this application provides a compound represented by the following chemical formula 1:

[0024] [Chemical Formula 1]

[0025]

[0026] M is Mn, Fe, Co, Ni, or Cu;

[0027] R1 and R2 are each independently hydrogen or straight-chain or branched alkyl groups having 1 to 4 carbon atoms;

[0028] L is either -OR3 or -NR4R5;

[0029] R3 is a hydrogen or a straight-chain or branched alkyl group having 1 to 4 carbon atoms;

[0030] R4 and R5 are each independently hydrogen, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or a straight-chain or branched alkylsilyl group having 1 to 6 carbon atoms.

[0031] Another aspect of this application provides a precursor composition for vapor phase evaporation comprising the above-described compounds.

[0032] Another aspect of this application provides a method for manufacturing a thin film including the step of introducing the above-described precursor composition for vapor deposition into a chamber.

[0033] Another aspect of this application provides a thin film manufactured using the aforementioned precursor composition for vapor phase evaporation.

[0034] Invention Effects

[0035] The novel compounds of the present invention and the precursor compositions containing the novel compounds exhibit excellent reactivity, volatility and thermal stability. Although they are liquids or solids, they have low melting points and can be deposited into uniform thin films with excellent properties, thereby ensuring excellent film properties, thickness and step coverage.

[0036] The physical properties described above provide suitable post-transition metal precursors for atomic layer evaporation and chemical vapor deposition, contributing to excellent thin film properties. Attached Figure Description

[0037] Figure 1 It is Co(EtMeSIm)2(O) of Embodiment 1 of this application. t Nuclear magnetic resonance (NMR) data of the Bu)2 compound.

[0038] Figure 2 It is Co(EtMeSIm)2(O) of Embodiment 1 of this application. t Thermogravimetric analysis (TGA) chart of compound Bu)2.

[0039] Figure 3 It is Co(iPrMeSIm)2(O) in Embodiment 2 of this application. t NMR data of the Bu)2 compound.

[0040] Figure 4 It is Co(iPrMeSIm)2(O) in Embodiment 2 of this application. t Thermogravimetric analysis (TGA) chart of compound Bu)2.

[0041] Figure 5 These are the NMR data for the Co(MeMeSIm)2(btsa)2 compound of Example 3 of this application.

[0042] Figure 6 This is a thermogravimetric analysis (TGA) chart of the Co(MeMeSIm)2(btsa)2 compound of Example 3 of this application.

[0043] Figure 7 These are the NMR data for the Co(iPrMeSIm)2(btsa)2 compound of Example 4 of this application.

[0044] Figure 8 This is a thermogravimetric analysis (TGA) chart of the Co(iPrMeSIm)2(btsa)2 compound in Example 4 of this application. Detailed Implementation

[0045] Best Implementation of the Invention

[0046] The following details the implementation methods and embodiments of this application so that those skilled in the art can easily carry it out. However, this application can be implemented in various different ways and is not limited to the implementation methods and embodiments described herein.

[0047] This invention relates to novel compounds that can be applied to atomic layer evaporation or chemical vapor deposition and have excellent reactivity, volatility and thermal stability; precursor compositions containing the novel compounds; methods for manufacturing thin films using the precursor compositions; and thin films manufactured from the precursor compositions.

[0048] Throughout this specification, the term "alkyl" includes straight-chain or branched alkyl groups and all their possible isomers. Examples of alkyl groups include methyl (Me), ethyl (Et), and n-propyl (...). n Pr), isopropyl ( i Pr), n-butyl ( n Bu), tert-butyl ( t Bu), isobutyl ( i Bu), sec-butyl ( sec Bu) and their isomers, but not limited to these.

[0049] Throughout this application specification, the term "Im" is short for "imidazoline" and the term "btsa" is short for "bis(trimethylsilyl)amide".

[0050] One aspect of this application provides a compound represented by the following chemical formula 1.

[0051] [Chemical Formula 1]

[0052]

[0053] Of the above chemical formula 1, the preferred option is:

[0054] M is Mn, Fe, Co, Ni, or Cu;

[0055] R1 and R2 are each independently hydrogen or straight-chain or branched alkyl groups having 1 to 4 carbon atoms;

[0056] L is either -OR3 or -NR4R5;

[0057] R3 is a hydrogen or a straight-chain or branched alkyl group having 1 to 4 carbon atoms;

[0058] R4 and R5 are each independently hydrogen, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or a straight-chain or branched alkylsilyl group having 1 to 6 carbon atoms.

[0059] In one embodiment of this application, more preferably, R1, R2 and R3 can each be independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, but are not limited thereto.

[0060] In one embodiment of this application, more preferably, R4 and R5 can each be independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, methylsilyl, dimethylsilyl, trimethylsilyl, and triethylsilyl, but are not limited thereto.

[0061] In one embodiment of this application, the above-mentioned compound can be a liquid or a solid at room temperature. The above-mentioned compound of this invention has a low melting point and excellent volatility at low temperatures.

[0062] In one embodiment of this application, the compound represented by the above chemical formula 1 may be an M (imidazoline) (alkoxide) compound characterized by the following chemical formula 1-1.

[0063] [Chemical Formula 1-1]

[0064]

[0065] In the above chemical formula 1-1, M is preferably Mn, Fe, Co, Ni or Cu; R1, R2 and R3 are each independently hydrogen or straight-chain or branched alkyl groups having 1 to 4 carbon atoms.

[0066] For example, R1, R2 and R3 are each more preferably selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0067] In one embodiment of this application, the compound represented by the above chemical formula 1-1 can be manufactured by a reaction as shown in formula 1.

[0068] [Reaction Formula 1]

[0069]

[0070] In the above reaction formula 1, M is Mn, Fe, Co, Ni or Cu; X is a halogen element (e.g., Cl, Br or I); R1, R2 and R3 are each independently hydrogen or straight-chain or branched alkyl groups having 1 to 4 carbon atoms.

[0071] For example, an example of a Co (imidazoline) (alkoxide) compound represented by the above chemical formula 1-1 could be a cobalt compound as shown below, but it is not limited to this:

[0072] Bis(1-Ethyl-3-methyl-imidazolin-2-ylidene)cobalt di-tert-butoxide: Co(EtMeSIm)2(O t Bu)2];

[0073] Bis(1-isopropyl-3-methyl-imidazolin-2-ylidene)cobalt di-tert-butoxide: Co(iPrMeSIm)2(O t Bu)2).

[0074] In one embodiment of this application, the compound represented by the above chemical formula 1 may be an M(imidazoline)(amide) compound characterized by the following chemical formulas 1-2.

[0075] [Chemical Formula 1-2]

[0076]

[0077] In the above chemical formulas 1-2, M is preferably Mn, Fe, Co, Ni or Cu; R1 and R2 are each independently hydrogen or a straight-chain or branched alkyl group having 1 to 4 carbon atoms; R4 and R5 are each independently hydrogen, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or a straight-chain or branched alkylsilyl group having 1 to 6 carbon atoms.

[0078] For example, R1 and R2 are each more preferably selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; R4 and R5 are each more preferably selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, methylsilyl, dimethylsilyl, trimethylsilyl, and triethylsilyl.

[0079] In one embodiment of this application, the compounds represented by the above chemical formulas 1-2 can be manufactured by a reaction as shown in formula 2.

[0080] [Reaction 2]

[0081]

[0082] In the above reaction formula 2, M is Mn, Fe, Co, Ni or Cu; X is a halogen element (e.g., Cl, Br or I); R1 and R2 are each independently hydrogen or a straight-chain or branched alkyl group having 1 to 4 carbon atoms; R4 and R5 are each independently hydrogen, a straight-chain or branched alkyl group having 1 to 4 carbon atoms, or a straight-chain or branched alkylsilyl group having 1 to 6 carbon atoms.

[0083] For example, an example of a Co(imidazoline)(amide) compound represented by the above chemical formulas 1-2 could be a cobalt compound as shown below, but it is not limited to this:

[0084] Bis(1-Methyl-3-methyl-imidazolin-2-ylidene)Cobalt di-Hexamethyldisilazide: Co(MeMeSIm)2(btsa)2;

[0085] Bis(1-isopropyl-3-methyl-imidazolin-2-ylidene)cobalt di-Hexamethyldisilazide[Bis(1-isopropyl-3-methyl-imidazolin-2-ylidene)Cobalt di-Hexamethyldisilazide:Co(iPrMeSIm)2(btsa)2].

[0086] Another aspect of this application provides a precursor composition for vapor phase evaporation comprising the above-described compounds.

[0087] Another aspect of this application provides a method for manufacturing a thin film including the step of introducing the above-described vapor deposition precursor composition into a chamber. The step of introducing the above-described vapor deposition precursor into the chamber may include physical adsorption, chemical adsorption, or a combination of physical and chemical adsorption.

[0088] Another aspect of this application provides a thin film manufactured using the aforementioned precursor composition for vapor phase evaporation.

[0089] The precursor for vapor deposition, the method for manufacturing the thin film, and the thin film of the present invention are all applicable to the description of the above-mentioned compounds. Detailed descriptions of repeated parts will be omitted, but even if the descriptions are omitted, the application is equally valid.

[0090] In one embodiment of this application, the method for manufacturing the above-mentioned thin film may include atomic layer deposition (ALD) in which the vapor deposition precursor and reactive gas of the present invention are sequentially introduced, and chemical vapor deposition (CVD) in which the vapor deposition precursor and reactive gas of the present invention are continuously injected to form a film.

[0091] More specifically, the above-mentioned vapor deposition methods may include, but are not limited to, metal-organic chemical vapor deposition (MOCVD), low-pressure chemical vapor deposition (LPCVD), pulsed chemical vapor deposition (P-CVD), plasma-enhanced atomic layer deposition (PE-ALD), or combinations thereof.

[0092] In one embodiment of this application, the method for manufacturing the above-mentioned thin film may further include the step of injecting as a reactant gas selected from one or more of hydrogen (H2), oxygen (O) atom-containing compounds (or mixtures), nitrogen (N) atom-containing compounds (or mixtures) or silicon (Si) atom-containing compounds (or mixtures) as a reactant gas.

[0093] More specifically, one or more of the following can be used as the reactant gas: water (H2O), oxygen (O2), hydrogen (H2), ozone (O3), ammonia (NH3), hydrazine (N2H4), or silane, but not limited thereto.

[0094] Specifically, water (H2O), oxygen (O2), and ozone (O3) can be used as reaction gases for evaporating oxide thin films, while ammonia (NH3) or hydrazine (N2H4) can be used as reaction gases for evaporating nitride thin films.

[0095] In addition, hydrogen (H2) can be used as the reaction gas for depositing metal thin films, and silane compounds can also be used.

[0096] The thin film manufactured by the thin film manufacturing method of the present invention can be a metal thin film, an oxide thin film, a nitride thin film or a silicide thin film, but is not limited thereto.

[0097] Implementation of the invention

[0098] The present invention will be further described in detail below through embodiments. However, the following embodiments are for the purpose of illustrating the present invention more specifically, and the scope of the present invention is not limited to the following embodiments.

[0099] Example 1: Co(EtMeSIm)2(O t Synthesis of Bu)2

[0100] In a Schlenk flask, CoCl2 (1 eq, 3 g), 1-ethyl-3-methylimidazolium bromide (2 eq), potassium 2-butoxide (4 eq), and THF were added and stirred overnight at room temperature. After the reaction was completed, the solvent was removed using a vacuum filter to obtain a purple liquid compound.

[0101] The NMR data and thermogravimetric analysis results of the compound synthesized in Example 1 are as follows: Figure 1 and 2 As shown.

[0102] Example 2: Co(iPrMeSIm)2(O t Synthesis of Bu)2

[0103] In a Schlenk flask, CoCl2 (1 eq, 3 g), 1-isopropyl-3-methylimidazolium bromide (2 eq), potassium 2-butoxide (4 eq), and THF were added and stirred overnight at room temperature. After the reaction was completed, the solvent was removed using a vacuum filter to obtain a purple solid compound.

[0104] The NMR data and thermogravimetric analysis results of the compounds synthesized in Example 2 are as follows: Figure 3 and 4 As shown.

[0105] The properties of the Co (imidazoline) (alkoxide) compounds synthesized in Examples 1 and 2 above are summarized in Table 1 below.

[0106] [Table 1]

[0107] Example 1 Example 2 Compound types <![CDATA[Co(EtMeSIm)2(OtBu)2]]> <![CDATA[Co(iPrMeSIm)2(OtBu)2]]> Molecular weight (MW) 429.51 457.56 State (phase) liquid solid Solubility hexane hexane Decomposition temperature (°C) 198 232 <![CDATA[T 1 / 2 (℃)]]> 211 242

[0108] T in Table 1 above 1 / 2 It is the temperature at which the weight is reduced to half as a result of thermogravimetric analysis.

[0109] Example 3: Synthesis of Co(MeMeSIm)2(btsa)2

[0110] In a Schlenk flask, CoCl2 (1 eq, 3 g), 1,3-dimethylimidazolium iodide (2 eq), potassium bis-trimethylsilylamide (4 eq), and THF were added and stirred overnight at room temperature. After the reaction was completed, the solvent was removed using a vacuum filter to obtain a purple solid compound.

[0111] The NMR data and thermogravimetric analysis results of the compounds synthesized in Example 3 are as follows: Figure 5 and 6 As shown.

[0112] Example 4: Synthesis of Co(iPrMeSIm)2(btsa)2

[0113] In a Schlenk flask, CoCl2 (1 eq, 3 g), 1-isopropyl-3-methylimidazolium bromide (2 eq), Potassium bis-trimethylsilylamide (4 eq), and THF were added and stirred overnight at room temperature. After the reaction was completed, the solvent was removed using a vacuum filter to obtain a purple liquid compound.

[0114] The NMR data and thermogravimetric analysis results of the compounds synthesized in Example 4 are as follows: Figure 7 and 8 As shown.

[0115] The properties of the Co(imidazoline)(amide) compounds synthesized in Examples 3 and 4 above are summarized in Table 2 below.

[0116] [Table 2]

[0117] Example 3 Example 4 Compound types <![CDATA[Co(MeMeSIm)2(btsa)2]]> <![CDATA[Co(iPrMeSIm)2(btsa)2]]> Molecular weight (MW) 575.99 632.10 State (phase) solid liquid Solubility hexane hexane Melting point (mp) 126 - Decomposition temperature (°C) 217 190 <![CDATA[T 1 / 2 (℃)]]> 215 196

[0118] T in Table 2 above 1 / 2 It is the temperature at which the weight is reduced to half as a result of thermogravimetric analysis.

[0119] Manufacturing Example 1: Fabrication of Cobalt-Containing Thin Films Using Atomic Layer Deposition (ALD)

[0120] Cobalt oxide thin films were fabricated by alternately supplying the novel cobalt precursors of Examples 1 to 4 and oxygen-containing (O2) reactive gases onto a substrate. After supplying the precursors and reactive gases, argon was supplied as a purge gas to remove any remaining precursors and reactive gases from the evaporation chamber. The supply time of the precursors and the supply time of the reactive gases were both adjusted to 8–15 seconds. The pressure in the evaporation chamber was adjusted to 1–20 torr, and the evaporation temperature was adjusted to 80–300°C.

[0121] Most conventional post-transition metal compounds are solid compounds at room temperature and have low volatility. In contrast, the novel post-transition metal precursors containing imidazoline ligands of the present invention have the advantages of low melting point and excellent volatility, whether in liquid or solid form.

[0122] Furthermore, the novel precursor containing imidazoline ligands of the present invention enables uniform thin film deposition, thereby ensuring excellent thin film properties, thickness, and step coverage.

[0123] The scope of this invention is defined by the scope of the claims described below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and their equivalents shall be interpreted as being included within the scope of this invention.

[0124] Industrial availability

[0125] The novel compounds of the present invention and the precursor compositions containing the novel compounds exhibit excellent reactivity, volatility and thermal stability. Although they are liquids or solids, they have low melting points and can be deposited into uniform thin films with excellent properties, thereby ensuring excellent film properties, thickness and step coverage.

[0126] The physical properties described above provide suitable post-transition metal precursors for atomic layer evaporation and chemical vapor deposition, contributing to excellent thin film properties.

Claims

1. A compound represented by the following chemical formula 1: [Chemical Formula 1] In the chemical formula 1, M stands for Co; And, the compound is selected from (i)-(iv): (i) R1 is methyl, R2 is ethyl, L is -OR3, and R3 is tert-butyl; (ii) R1 is methyl, R2 is isopropyl, L is -OR3, and R3 is tert-butyl; (iii) R1 is methyl, R2 is methyl, L is -NR4R5, and both R4 and R5 are trimethylsilyl; or (iv) R1 is methyl, R2 is isopropyl, L is -NR4R5, and R4 and R5 are both trimethylsilyl.

2. A precursor composition for vapor phase deposition comprising the compound of claim 1.

3. A method for manufacturing a thin film, comprising the step of introducing the precursor composition for vapor phase evaporation as described in claim 2 into a chamber.

4. The method for manufacturing a thin film according to claim 3, wherein the method for manufacturing a thin film includes atomic layer evaporation (ALD) or chemical vapor deposition (CVD).

5. The method for manufacturing a thin film according to claim 3, further comprising the step of injecting one or more of H2, oxygen (O) atom-containing compounds, nitrogen (N) atom-containing compounds or silicon (Si) atom-containing compounds as a reactant gas.

6. The method for manufacturing a thin film according to claim 5, wherein the reactant gas is selected from one or more of water (H2O), O2, H2, O3, NH3, N2H4 and silane.

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