KR20220063907A - Rare earth precursors, preparation method thereof and process for the formation of thin films using the same - Google Patents

Abstract

The present invention relates to a compound which can deposit a thin film through vapor deposition, and more specifically, to a rare earth compound applicable to an atomic layer deposition (ALD) or a chemical vapor deposition (CVD) and having excellent thermal stability and reactivity, a rare earth precursor comprising the same, a preparation method thereof, and a forming method of the thin film using the same.

Description

Rare earth precursor, method for manufacturing same, and method for forming thin film using same

The present invention relates to a vapor deposition compound capable of depositing a thin film through vapor deposition, and specifically, has volatility and thermal stability applicable to atomic layer deposition (ALD) or chemical vapor deposition (CVD). The present invention relates to a rare-earth precursor excellent in reactivity with a reactive gas, a method for preparing the same, and a method for forming a thin film using the same.

Silicon oxide (SiO ₂ ), which has been used as a dielectric material for the past several decades, is being replaced by “metal gate/high-k” transistors according to the dense packing of semiconductor devices and the unmet channel length.

In particular, there is a need for new gate dielectric materials for dynamic random access memory (DRAM) memory devices and capacitors.

As the device size enters the 20 nm level, the demand for high-k materials and processes is increasing.

Preferably, high-k materials should have high band gap and band offset, high k values, good stability to silicon phase, minimal SiO ₂ interfacial layer, and high quality interfaces on the substrate. Also preferred are amorphous or highly crystalline temperature films.

A representative high-k material that is being actively studied and applied to replace silicon oxide includes hafnium oxide (HfO ₂ ), and in particular, a next-generation high-k material is continuously required in a process of 10 nm or less.

Rare earth-doped hafnium oxide and the like are being discussed as potential candidates for next-generation high-k materials.

In particular, rare earth-containing materials are promising high-k dielectric materials for advanced silicon CMOS, germanium CMOS and III-V transistor devices, and new-generation oxides based on them have been shown to offer significant advantages in capacitance over conventional dielectric materials. is being reported

In addition, the rare earth element-containing material is expected to be applied to the manufacture of perovskite materials having characteristics such as ferroelectricity, pyroelectricity, piezoelectricity, and resistance conversion. That is, ABO ₃ type perovskite is prepared through a vapor deposition process using an organometallic compound precursor, the type or composition of A and B cations (rare earth or transition metal) are controlled, and the dielectric properties, electron conductivity and oxygen Research is being conducted to provide various characteristics such as ion conductivity and use it in various industrial fields such as fuel cells, sensors, and secondary batteries.

In addition, rare earth element-containing materials are being actively studied to be used for encapsulation materials utilizing the excellent resistance to moisture penetration of a multilayer oxide thin film structure or for realization of next-generation non-volatile memories.

However, the deposition of rare earth-containing layers is still difficult, and new materials and processes are constantly in demand. In this regard, rare earth precursors with various ligands have been studied.

Representative examples of ligands constituting the rare-earth precursor include a group of compounds such as amide, amidinate, beta-diketonate, and cyclopentadienyl (Cp). The precursor has disadvantages that are difficult to apply to actual processes, such as high melting point, low deposition temperature, high impurities in the thin film, and relatively low reactivity.

Specifically, lanthanum-2,2,6,6-tetramethylheptanedionate ([La(tmhd) ₃ ]) has a high melting point of 260° C. or higher, and rare earth-2,2,7-trimethyloctanedionate ( [La(tmod) ₃ ]) has a melting point of 197°C. In addition, the transfer efficiency of beta-diketonate is very difficult to control, the thin film growth rate is low, and the thin film purity is low due to the high carbon impurity production rate.

A cyclopentadienyl (Cp) compound can be implemented as a liquid compound, but has a disadvantage in that the carbon impurity content in the thin film is high in process evaluation.

Molecular design can help improve volatility and reduce melting point, but has proven to have limited use in process conditions. For example, La(iPrCp) ₃ (iPr is isopropyl) is not suitable for ALD processes at temperatures higher than 225°C.

The amide-based ligand RE(NR ₂ ) ₃ (RE is a rare earth element) is not suitable for ALD or CVD processes due to structural instability of the compound.

In addition, some of the rare earth-containing precursors currently available present many problems when used in deposition processes. For example, a fluorinated rare earth precursor may produce REF ₃ (RE is a rare earth element) as a by-product. This by-product is known to be difficult to remove.

That is, conventional rare-earth precursors are not thermally stable at high temperatures, and thus have a disadvantage in that they exhibit a low deposition rate during chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes.

Consequently, there is a need to develop alternative precursors for the deposition of rare earth-containing films.

Korean Patent Registration No. 10-2138707

An object of the present invention is to provide a rare-earth precursor compound for deposition that has excellent thermal stability and volatility, and excellent reactivity with a reactive gas, in order to solve the above-mentioned problems with the conventional rare-earth precursor.

Another object of the present invention is to provide a method for manufacturing a thin film using the rare earth precursor compound.

However, the problems to be solved by the present application are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above-mentioned problem of rare earth precursors, various ligands have been studied, but homoleptic rare earth precursors having the same kind of all ligands of the precursor still have the same problems. In addition, the newly appeared heteroleptic compounds have the advantage of having thermal stability and volatility, but have a disadvantage of low reactivity with a reactive gas.

Accordingly, in order to solve this problem, the present inventors synthesized a heteroleptic rare earth precursor capable of maintaining the existing advantages of the heteroraptic compound and compensating for the disadvantage of low reactivity with a reactive gas.

In particular, a rare earth precursor including any one ligand selected from the group consisting of alkoxide, amide, and alkyl and a neutral ligand was synthesized.

Through this, it is possible to obtain a rare-earth precursor having superior volatility and thermal stability, and having high reactivity with a reactive gas, compared to previously known rare-earth precursor compounds.

One aspect of the present application provides a compound represented by the following Chemical Formula 1:

[Formula 1]

In Formula 1,

M is a rare earth element,

R ₁ to R ₆ are each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,

R ₇ to R ₉ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms; -OR ₁₀ ; or -N(R ₁₁ ) ₂ ,

wherein R ₁₀ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,

wherein R ₁₁ is each independently hydrogen; a linear or branched alkyl group having 1 to 6 carbon atoms; or Si(R ₁₂ ) ₃ ,

wherein R ₁₂ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms.

Another aspect of the present application provides a vapor deposition precursor comprising the compound.

Another aspect of the present disclosure provides a method of manufacturing a thin film, comprising introducing the vapor deposition precursor into a chamber.

The novel vapor-deposited rare-earth compound according to the present invention and a precursor comprising the vapor-deposited compound have excellent thermal stability and volatility. In addition, the reaction gas and reactivity are excellent.

The vapor deposition precursor of the present invention enables uniform thin film deposition, thereby ensuring excellent thin film properties, thickness, and step coverage.

Such physical properties provide a precursor suitable for atomic layer deposition and chemical vapor deposition, and contribute to excellent thin film properties.

1 is Example 1 of the present application ((Me,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ ), Example 2 ((Et,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ ) And Example 4 (( ⁱ Pr,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ ) Differential Scanning Calorimetry (DSC) analysis result of the compound is a graph.
2 is a graph showing the results of thermogravimetric (TG) analysis of the compounds of Examples 1 to 5 of the present application (Example 1: (Me,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ , practice Example 2: (Et,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ , Example 3: (Et,Me-NHC)Y[N(SiMe ₃ ) ₂ ] ₃ , Example 4: ( ⁱ Pr ,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ , Example 5: ( ⁱ Pr,Me,Me,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ ).
3 is a graph showing the results of thermogravimetric (TG) analysis of the compounds of Examples 7 and 9 of the present application (Example 7: (Et,Me-NHC)La(O ^t Bu) ₃ , Example 9: ( ⁱ Pr,Me-NHC)La(O ^t Bu) ₃ ).

Hereinafter, embodiments and examples of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, the present application may be embodied in several different forms and is not limited to the embodiments and examples described herein.

Hereinafter, embodiments and examples of the present application will be described in detail. However, the present application is not limited to these embodiments and examples and drawings.

One aspect of the present application provides a compound represented by the following formula (1).

[Formula 1]

In Formula 1,

M is a rare earth element,

R ₁ to R ₆ are each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,

R ₇ to R ₉ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms; -OR ₁₀ ; or -N(R ₁₁ ) ₂ ,

wherein R ₁₀ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,

wherein R ₁₁ is each independently hydrogen; a linear or branched alkyl group having 1 to 6 carbon atoms; Or Si(R ₁₂ ) ₃ ,

wherein R ₁₂ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms.

That is, the compound of the present invention is a heteroleptic compound including two or more ligand types, not all ligand types, and includes N-heterocyclic carbene as a neutral ligand.

In addition, the compound of the present invention contains any one ligand selected from the group consisting of alkoxides, amides, and alkyls.

The N-heterocyclic carbene improves the thermal stability of the compound, and any one ligand selected from the group consisting of alkoxide, amide, and alkyl improves the volatility of the compound and at the same time improves the reaction gas increase reactivity with

In one embodiment of the present application, preferably R ₁ to R ₆ , R ₁₀ to R ₁₂ are each independently selected from the group consisting of hydrogen, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group and tert-butyl group It may be one, but is not limited thereto.

In one embodiment of the present application, preferably, the formula 1

는

Is

It may be any one selected from the group consisting of ligands represented by the following Chemical Formulas 1a to 1j.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

[Formula 1g]

[Formula 1h]

[Formula 1i]

[Formula 1j]

In one embodiment of the present application, preferably, the compound may be any one selected from the group consisting of compounds represented by the following Chemical Formulas 1-1 to 1-7.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

In Formulas 1-1 to 1-7,

M is a rare earth element,

^t Bu is tert-butyl.

In one embodiment of the present application, the rare earth element is Sc (scandium), Y (yttrium), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium ( Eu), gadorinium (Gd), terbium (Tb), disoprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), any one of lutetium (Lu) can be

Another aspect of the present application provides a deposition precursor, preferably a vapor deposition precursor, comprising the compound.

Another aspect of the present application provides a method of manufacturing a thin film comprising introducing the vapor deposition precursor into a chamber. The step of introducing the vapor deposition precursor into the chamber may include physisorption, chemisorption, or physical and chemisorption.

In one embodiment of the present application, the method of manufacturing the thin film may include atomic layer deposition (ALD) or chemical vapor deposition (CVD), and the chemical vapor deposition is an organometallic chemical vapor deposition method. 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 a combination thereof may include, but is not limited thereto.

In one embodiment of the present application, the method of manufacturing the thin film may further include injecting any one or more of a compound containing hydrogen (H ₂ ), an oxygen (O) atom, and a compound containing a nitrogen (N) atom as a reaction gas. can

When the desired rare earth-containing film contains oxygen, the reaction gas may be selected from oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), hydrogen peroxide (H ₂ O ₂ ), and any combination thereof, but , but is not limited thereto.

When the desired rare earth-containing film contains nitrogen, the reactant gas may be selected from, but not limited to, nitrogen (N ₂ ), ammonia (NH ₃ ), hydrazine (N ₂ H ₄ ), and any combination thereof.

It is also possible for the desired rare earth containing film to contain other metals.

Hereinafter, the present application will be described in more detail using Synthesis Examples, Examples, Experimental Examples and Preparation Examples, but the present application is not limited thereto.

<Synthesis Example 1> (NHC)La[N(SiMe ₃ ) ₂ ] ₃ Synthesis

In a flask, add 7.36 g (0.03 mol) of lanthanum (III) chloride and 0.03 mol of alkyl imidazolium chloride or bromide (1-R1-3-R2-4-R3-5-R4-imidazolium chloride or bromide) Quantify and dissolve by adding 200 mL of tetrahydrofuran (THF). To this solution, 22 g (0.12 mol) of sodium bis(trimethylsilyl)amide is dissolved in THF and slowly added at 0°C. After that, the reaction is completed by stirring at room temperature for about 16 hours, and the solvent and volatile side reactants are removed in a vacuum. The residue is diluted by adding hexane, filtered through a filter containing celite, and the filtrate is vacuum dried again. This solid was again dissolved in hexane and recrystallized at -40°C to obtain a colorless or white crystalline solid.

The reaction of Synthesis Example 1 is represented by the following reaction formula (1).

[Reaction Formula 1]

HMDS of Reaction Formula 1 is hexamethyldisilizane.

<Synthesis Example 2> Synthesis of (NHC)La(O ^t Bu)3

(NHC)La[N(SiMe ₃ ) ₂ ] ₃ (0.0045 mol) synthesized in Synthesis Example 1 was dissolved in toluene 50 mL, and tertiary butyl alcohol diluted in toluene 1.28 mL (0.0135) mol) is added slowly at 0°C. After that, the reaction is completed by stirring at room temperature for about 16 hours, and the solvent and volatile side reactants are removed in a vacuum. The residue is diluted by adding hexane, filtered through a filter containing celite, and the filtrate is vacuum dried again. This solid was again dissolved in hexane and recrystallized at -40°C to obtain an orange solid.

The reaction of Synthesis Example 2 is represented by the following reaction formula (2).

[Reaction Formula 2]

In Reaction Formula 2, ^t Bu is tert-butyl, and HMDS is hexamethydisilizane.

<Example 1> (Me,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ Synthesis

It was synthesized according to Synthesis Example 1, and in Reaction Formula 1, R ₁ and R ₂ are each methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), and the chemical formula of the synthesized compound is Same as 3-1.

[Formula 3-1]

The synthesized compound was a colorless crystalline solid, and the yield was 70.51%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 0.35 (s, 54H), δ 3.36 (s, 6H), δ 5.94 (s, 2H).

<Example 2> (Et,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ Synthesis

It was synthesized according to Synthesis Example 1, and in Reaction Formula 1, R ₁ , R ₂ are each ethyl and methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), and the chemical formula of the synthesized compound is It is represented by the following Chemical Formula 3-2.

[Formula 3-2]

The synthesized compound was a colorless crystalline solid, and the yield was 60.26%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 0.36 (s, 54H), δ 1.10 (t, 3H), δ 3.40 (s, 3H), δ 3.86 (q, 2H), δ 6.00 (s, 1H), δ 6.10 (s, 1H).

<Example 3> (Et,Me-NHC)Y[N(SiMe ₃ ) ₂ ] ₃ Synthesis

It was synthesized according to Synthesis Example 1, and in Reaction Formula 1, R ₁ , R ₂ are each ethyl and methyl, R ₃ and R ₄ are each hydrogen, Ln is yttrium (Y), and the chemical formula of the synthesized compound is It is the same as Formula 3-3.

[Formula 3-3]

The synthesized compound was a colorless crystalline solid, and the yield was 57.5%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 0.39 (s, 54H), δ 0.94 (t, 3H), δ 3.52 (s, 3H), δ 3.85 (q, 2H), δ 5.86 (s, 1H), δ 5.98 (s, 1H).

<Example 4> ( ⁱ Pr,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ Synthesis

It was synthesized according to Synthesis Example 1, and in Reaction Formula 1, R ₁ , R ₂ are each iso-propyl, methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), the synthesized compound The chemical formula is as shown in the following Chemical Formula 3-4.

[Formula 3-4]

The synthesized compound was a white crystalline solid, and the yield was 52.44%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 0.35 (s, 54H), δ 1.18 (d, 6H), δ 3.41 (s, 3H), δ 4.71 (m, 1H), δ 6.03 (s, 1H), δ 6.24 (s, 1H).

<Example 5> ( ⁱ Pr,Me,Me,Me-NHC)La[N(SiMe ₃ ) ₂ ] ₃ Synthesis

It was synthesized according to Synthesis Example 1, and in Reaction Formula 1, R ₁ , R ₂ are each iso-propyl, methyl, R ₃ and R ₄ are each methyl, Ln is lanthanum (La), the synthesized compound The chemical formula is as shown in the following Chemical Formula 3-5.

[Formula 3-5]

The synthesized compound was an off-white crystalline solid, and the yield was 77%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 0.30 (s, 54H), δ 1.34 (d, 6H), δ 1.37 (s, 3H), δ 1.58 (s, 3H), δ 3.38 (s, 3H), δ 4.30 (s, 1H).

<Example 6> (Me,Me-NHC)La(O ^t Bu) ₃ Synthesis

It was synthesized according to Synthesis Example 2, and in Reaction Formula 2, R ₁ , R ₂ are each methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), and the chemical formula of the synthesized compound is Same as 4-1.

[Formula 4-1]

(in Formula 4-1, ^t Bu is tert-butyl)

The synthesized compound was an orange crystalline solid, and the yield was 31.77%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 1.41 (s, 27H), δ 3.37 (s, 6H), δ 6.22 (s, 2H).

<Example 7> (Et,Me-NHC)La(O ^t Bu) ₃ Synthesis

It was synthesized according to Synthesis Example 2, and in Reaction Formula 2, R ₁ , R ₂ are each ethyl and methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), and the chemical formula of the synthesized compound is It is represented by the following Chemical Formula 4-2.

[Formula 4-2]

(in Formula 4-2, ^t Bu is tert-butyl)

The synthesized compound was an orange crystalline solid, and the yield was 30.46%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 1.14 (t, 3H), δ 1.45 (s, 27H), δ 3.39 (s, 3H), δ 3.81 (q, 2H), δ 6.26 (s, 1H), δ 6.33 (s, 1H).

<Example 8> (Et,Me-NHC)Y(O ^t Bu) ₃ Synthesis

It was synthesized according to Synthesis Example 2, and in Reaction Formula 2, R ₁ , R ₂ are each ethyl and methyl, R ₃ and R ₄ are each hydrogen, Ln is yttrium (Y), and the chemical formula of the synthesized compound is It is the same as Formula 4-3.

[Formula 4-3]

(In Formula 4-3, ^t Bu is tert-butyl)

The synthesized compound was an orange crystalline solid, and the yield was 95.7%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 1.18 (t, 3H), δ 1.48 (s, 27H), δ 3.64 (s, 3H), δ 4.16 (q, 2H), δ 6.13 (s, 1H), δ 6.22 (s, 1H).

<Example 9> ( ⁱ Pr,Me-NHC)La(O ^t Bu) ₃ Synthesis

It was synthesized according to Synthesis Example 2, and in Reaction Formula 2, R ₁ , R ₂ are each iso-propyl, methyl, R ₃ and R ₄ are each hydrogen, Ln is lanthanum (La), the synthesized compound Chemical formula is the same as the following Chemical Formula 4-4.

[Formula 4-4]

(In Formula 4-4, ^t Bu is tert-butyl)

The synthesized compound was an orange crystalline solid, and the yield was 89.35%, and the measured ¹ H-NMR peak was as follows.

¹ H-NMR (400 MHz, C ₆ D ₆ ): δ 1.25 (d, 6H), δ 1.41 (s, 27H), δ 3.44 (s, 3H), δ 4.48 (m, 1H), δ 6.28 (s, 1H), δ 6.41 (s, 1H).

[Experimental Example 1] Differential Scanning Calorimetry (DSC)

Differential scanning calorimetry (DSC) for measuring the thermal properties of Examples 1-1, 1-2 and 1-4 was performed, and the results are shown in FIG. 1 .

The instrument used was NETZSH's DSC 214 Polyma, weighing about 10 mg of each sample, putting it in a closed high pressure gold-plated Al pan, and measuring from 50°C to 350°C at a temperature increase rate of 10°C.

As a result of the measurement, the melting points of the compounds of Examples 1-1, 1-2 and 1-4 were 153°C, 138°C and 119°C, respectively.

In addition, the decomposition temperatures of the compounds of Example 1-1, Example 1-2, and Example 1-4 were 257°C, 254°C and 257°C, respectively.

It was confirmed that the decomposition temperature of the compounds of Example 1-1, Example 1-2, and Example 1-4 was all at 250° C. or higher, and the thermal stability of the synthesized compound was excellent.

[Experimental Example 2] Thermogravimetric analysis (TGA)

Thermogravimetric analysis (TGA) of the synthesized compounds was performed. The instrument used for thermogravimetric analysis was Mettler Toledo's TGA/DSC 1 STAR System, and an alumina crucible with a capacity of 50 μL was used. The compounds were heated to 400 °C at a rate of 10 °C min, and argon (Ar) gas was injected at a rate of 200 mL/min.

The results according to the thermogravimetric analysis of the compounds of Examples 1-1 to 1-5 are shown in FIG. 2, and the results according to the thermogravimetric analysis of the compounds of Examples 1-7 and 1-9 are shown in FIG. 3 shown in

As a result of thermogravimetric analysis, the temperature at which the weight is reduced by half [T _1/2 ] is 243° C. for the compound of Example 1-1, 247° C. for the compound of Example 1-2, and 324 for the compound of Example 1-3 ℃, the compound of Examples 1-4 was measured at 278°C, the compound of Examples 1-5 was measured at 266°C, the compound of Example 1-7 was measured at 233°C, and the compound of Examples 1-9 was measured at 216°C.

In addition, the amount of the residue at 400°C was 19.47% for the compound of Example 1-1, 17.29% for the compound of Example 1-2, 43.79% for the compound of Example 1-3, and 43.79% for the compound of Example 1-4 25.17%, 18.46% of the compound of Examples 1-5, 11.65% of the compound of Examples 1-7, and 12.64% of the compound of Examples 1-9.

Accordingly, the compounds synthesized by Chemical Reaction Formula 1 were reduced in weight by half at about 240° C. or higher, and the compounds synthesized by Chemical Reaction Formula 2 were reduced in weight by half at about 210° C. or higher, and synthesized by Chemical Scheme 1. T _1/2 of the compounds It was generally higher than T _1/2 of the compounds synthesized by Chemical Reaction Formula 2. In addition, it was confirmed that the thermal stability of the compound synthesized by Chemical Reaction Formula 1 and Chemical Reaction Formula 2 was excellent.

[Production Example 1]

The novel rare-earth precursor and reactant O ₃ synthesized in Examples 1-1 to 1-6 of the present invention were alternately applied to deposit a rare-earth thin film on the substrate. The substrate used in this experiment was a p-type Si wafer, with a resistance of 0.02 Ω·m. Prior to deposition, the p-type Si wafer was cleaned by ultrasonic treatment (Ultra sonic) in acetone-ethanol-DI water for 10 minutes each. The native oxide thin film formed on the Si wafer was removed after being immersed in a solution of HF 10% (HF:H2O=1:9) for 10 seconds.

The substrate was prepared by maintaining a temperature of 150-450°C, and the solid novel rare-earth precursor synthesized in Example 1 was vaporized in a bubbler maintained at a temperature of 90-150°C.

As a purge gas, argon (Ar) was supplied to purge the precursor and reaction gas remaining in the deposition chamber, and the flow rate of argon was 1000 sccm. As a reaction gas, ozone (O ₃ ) with a concentration of 224 g/cm ³ was used, and each reaction gas was injected by controlling the on/off of a pneumatic valve, and a film was formed at the process temperature.

The ALD cycle included a sequence of 10/15 secs of precursor pulses, 10 secs of argon purge, 2/5/8/10 secs of reactant pulses, and 10 secs of argon purge. The pressure of the deposition chamber was adjusted to 1-1.5 torr, and the deposition temperature was adjusted to 150-450°C.

It was confirmed that lanthanum oxide and yttrium oxide thin films were formed using the compounds of Examples 1-1 to 1-6 as precursors.

[Production Example 2]

A lanthanum oxide thin film was deposited on the substrate under the same conditions as in Preparation Example 1, except that the novel rare earth precursor synthesized in Examples 1-7 to 1-9 of the present invention was used.

It was confirmed that lanthanum oxide and yttrium oxide thin films could be formed by using the compounds of Examples 1-7 to 1-9 as precursors.

[Production Example 3]

A thin film containing a rare earth element was prepared by chemical vapor deposition using the novel rare earth precursor synthesized in Examples 1-1 to 1-9 of the present invention. A starting precursor solution containing the precursor synthesized in Examples 1-1 to 1-9 was prepared.

The precursor starting solution was delivered to a vaporizer maintained at a temperature of 90-150° C. at a flow rate of 0.1 cc/min. The vaporized precursor was delivered to the deposition chamber using 50 to 300 sccm helium carrier gas. Hydrogen (H ₂ ) and oxygen (O ₂ ) were used as reaction gases, and were supplied to the deposition chamber at a flow rate of 0.5 L/min (0.5 pm), respectively. The pressure of the deposition chamber was adjusted to 1 to 15 torr, and the deposition temperature was adjusted to 150-450 °C. The deposition process was performed for about 15 minutes under these conditions.

It was confirmed that lanthanum oxide and yttrium oxide thin films could be formed by using the compounds of Examples 1-1 to 1-9 as precursors.

The rare earth-containing precursor and the at least one reactive gas may be simultaneously introduced into the reaction chamber by chemical vapor deposition, atomic layer deposition, or other combination.

In one example, the rare earth containing precursor may be introduced in one pulse, and two additional metal sources may be introduced together in separate pulses. In addition, the reaction chamber may already contain reactant species prior to introduction of the rare earth containing precursor.

The reactant gas may be decomposed into radicals by passing through a plasma system located remote from the reaction chamber. In addition, the rare earth containing precursor may be continuously introduced into the reaction chamber while other metal sources are introduced by pulses.

For example, in an atomic layer deposition type of process, the vapor phase of the rare earth containing precursor may be introduced into a reaction chamber where it contacts a suitable substrate, and then excess rare earth containing precursor may be removed from the reaction chamber by purging the reactor.

An oxygen source is introduced into a reaction chamber where it reacts with the absorbed rare earth precursor in a self-limiting manner. The excess oxygen source may be removed from the reaction chamber by purging and/or degassing the reaction chamber. If the desired film is a rare earth oxide film, the process can be repeated until the desired film thickness is obtained.

Through the above thin film production, the newly synthesized rare earth precursors of Examples 1-1 to 1-9 not only supplement the problems in thin film deposition of the existing rare earth precursors, but also have excellent volatility and thermal stability applicable to ALD as well as CVD and it was confirmed that the reaction gas and reactivity were excellent.

In addition, uniform thin film deposition is possible through the novel rare earth precursor, and thus excellent thin film properties, thickness, and step coverage can be secured.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are interpreted as being included in the scope of the present invention. should be

Claims (10)

A compound represented by the following formula (1):
[Formula 1]

In Formula 1,
M is a rare earth element,
R ₁ to R ₆ are each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,
R ₇ to R ₉ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms; -OR ₁₀ ; or -N(R ₁₁ ) ₂ ,
wherein R ₁₀ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms,
wherein R ₁₁ is each independently hydrogen; a linear or branched alkyl group having 1 to 6 carbon atoms; Or Si(R ₁₂ ) ₃ ,
wherein R ₁₂ is each independently hydrogen; It is a linear or branched alkyl group having 1 to 6 carbon atoms. The method of claim 1,
R ₁ To R ₆ , R ₁₀ to R ₁₂ are each independently selected from the group consisting of hydrogen, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group and tert-butyl group One, the compound. The method of claim 1,
of Formula 1

Is
Any one selected from the group consisting of ligands represented by the following formulas 1a to 1j, the compound.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

[Formula 1g]

[Formula 1h]

[Formula 1i]

[Formula 1j]

The method of claim 1,
The compound is any one selected from the group consisting of compounds represented by the following Chemical Formulas 1-1 to 1-7.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

In Formulas 1-1 to 1-7,
M is a rare earth element,
^t Bu is tert-butyl. The method of claim 1,
The rare earth elements include Sc (scandium), Y (yttrium), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadorinium (Gd) , which is terbium (Tb), disoprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) or lutetium (Lu). A vapor deposition precursor comprising the compound according to claim 1 . A method for producing a thin film comprising introducing the vapor deposition precursor of claim 6 into a chamber. 8. The method of claim 7,
The method for manufacturing the thin film includes atomic layer deposition (ALD) or chemical vapor deposition (CVD). 8. The method of claim 7,
The method of manufacturing a thin film, further comprising injecting at least one of a compound containing hydrogen (H ₂ ), an oxygen (O) atom, and a compound containing a nitrogen (N) atom as a reaction gas. 10. The method of claim 9,
The reaction gas is oxygen (O ₂ ), ozone (O ₃ ), water (H ₂ O), hydrogen peroxide (H ₂ O ₂ ), nitrogen (N ₂ ), ammonia (NH ₃ ) and hydrazine (N ₂ H ₄ ) Any one or more selected from among, the method for producing a thin film.

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