KR20190092269A - The organometallic compounds and the thin film using thereof - Google Patents

Abstract

An organometallic compound and a thin film using the same of the present invention have high volatility and excellent chemical and thermal stability, and at the same time, have a significantly improved film deposition rate even at a low temperature. In addition, the deterioration of properties due to by-products is alleviated and the step coverage is excellent. Furthermore, the organometallic compound and the thin film have a high dielectric constant, thereby being able to realize the thin film having an equivalent oxide thickness (EOT) but without occurrence of physical tunneling.

Description

Organometallic Compound and Thin Film Using the Same {THE ORGANOMETALLIC COMPOUNDS AND THE THIN FILM USING THEREOF}

The present invention relates to an organometallic compound and a thin film using the same, which are capable of depositing a thin film at a significantly improved speed even at low temperatures while satisfying excellent chemical and thermal stability.

Recently, various thin films such as metals, semiconductors, and oxides have been studied for the fabrication of nanoscale integrated devices. In the process of forming these various thin films, the necessity and conformity of the thin film deposition process in which the thickness is controlled at the atomic layer level on the complex type structure at the nanoscale as the continuous miniaturization of the device and the new type of device are continuously proposed. The importance of conformality is also increasing. Currently, gate oxide, which is used for the gate structure of a metal-oxidesemiconductor field effect transistor (MOSFET), which is the core of electronic devices, is based on silicon oxide. However, as the device size is nanoscaled, problems such as an increase in leakage current and formation of a gate depletion layer are generated, and many attempts to use a new oxide having a high dielectric constant have been made to solve such problems. Among the various high dielectric constant oxides, the most studied materials are HfO _x N _y doped with nitrogen based on HfO ₂ , and HfSi _x O _y , which is a silicate material, to increase charge mobility and reliability by applying these materials. Although the results are good, they still show problems in increasing dielectric constant, thermal stability, and interfacial properties. In order to solve these problems, the research focuses on the deposition process of high-k dielectric thin film using atomic layer deposition, its characteristics, the development of various high-k dielectric materials, the development of new process methods, and the application to nano devices.

As a precursor for depositing metal thin films or metal oxides or metal nitrides using organometallic chemical vapor deposition or atomic layer deposition, metal pentachloride, MCl ₅ (M = V, Nb, Ta)). However, these metal contaminants are 1) compounds with low vapor pressure at room temperature, which are difficult to apply to semiconductor production process due to low film deposition rate and 2) chloride contamination.

On the other hand, as a typical precursor compound for depositing a metal oxide, there is a metal alkoxide-based compound. In particular, the metal-ethoxide precursor compound represented by the formula of M ₂ (OEt) ₁₀ (M = Nb, Ta) exists as a highly volatile liquid at room temperature and is most widely used for depositing metal oxide films using MOCVD and ALD processes. Compounds. However, these metal-alkoxide compounds have a problem of 1) poor step coverage due to decomposition of the precursor at a substrate temperature of 300 ° C. or higher due to low thermal stability, and 2) increased carbon contamination.

In addition, the metal-imido / amide-based compound 1) possible ALD process temperature is less than 325 ℃, 2) low crystallinity of the thin film 3) high contamination of carbon in the deposited thin film had a problem. In addition, 4) there is a problem of high leakage current in order to be applied as a gate and capacitor dielectric material in the flash memory field as well as a DRAM process of 50 nm or less.

In the manufacture of semiconductor devices, thin films containing aluminum play a very important role. The aluminum-containing thin film includes an aluminum film, an aluminum nitride film, an aluminum carbide nitride film, an aluminum oxide film, and an aluminum oxynitride film, and the aluminum nitride film and aluminum oxide film play an important role as a passivation layer, an interlayer insulating film, or a capacitor dielectric layer. In the current process, trimethylaluminum (TMA) is mainly used as a precursor for depositing a thin film containing aluminum.

Republic of Korea Patent Application Publication No. 10-2006-0046471 (Published Date 2006.05.17.)

The present invention has been made to solve the above problems, and an object of the present invention is to provide a novel organic metal compound for thin film deposition excellent in chemical and thermal stability, and a thin film using the same.

The organometallic compound of the present invention for solving the above problems has a structure represented by the following formula (1).

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, C ₁ ~ C ₁₀ linear alkyl group, C ₃ ~ C ₁₀ Crushed alkyl group, C ₆ ~ C ₁₀ cyclo alkyl group or hetero alkyl group, R ³ is a hydrogen atom or a straight chain alkyl group of C ₁ to C ₃ , R ⁴ is a straight chain alkyl group of C ₁ to C ₄ or a ground alkyl group of C ₃ to C ₅ , and the dotted line is an Al atom and an O atom coordination bond. That means you can have

As a preferred embodiment of the present invention, R ¹ and R ² of Formula 1 are each independently a hydrogen atom, a straight chain alkyl group of C ₁ ~ C ₅ or C ₃ ~ C ₆ crushed alkyl group, R ³ is C ₁ - a straight-chain alkyl group of C _2, R ⁴ may be a C ₁ ~ C ₃ straight chain alkyl group or branched alkyl group of C _3.

As a preferred embodiment of the present invention, when the thermal decomposition temperature (T1 / 2) of the organometallic compound is measured by a thermogravimetric analyzer, the thermal decomposition temperature may be 150 ~ 175 ℃.

As a preferred embodiment of the present invention, when the pyrolysis temperature is measured by a thermogravimetric analyzer, a residual amount of the organometallic compound having the structure represented by Formula 1 may be 1.500% or less.

In one preferred embodiment of the present invention, the organometallic compound may be used as a precursor for thin film deposition of CVD (chemical vapor deposition) or ALD (atomic layer deposition).

Another object of the present invention is to provide a chemical vapor deposition (CVD) or atomic layer deposition (ALD) method using the precursor for thin film deposition.

Another object of the present invention is to provide an alumina (Al ₂ O ₃ ) thin film formed by depositing the thin film deposition precursor.

Another object of the present invention is to provide a semiconductor structure including the alumina thin film.

In a preferred embodiment of the present invention, the semiconductor structure may include at least one selected from an electrode, a barrier, a capacitor, and a metal plug.

The terms used herein are briefly described.

The term "alkyl" refers to an aliphatic hydrocarbon group. The alkyl moiety can be a "saturated alkyl" group, meaning that it does not contain any alkenes or alkyne moieties. The alkyl moiety may be an "unsaturated alkyl" moiety, meaning that it contains at least one alkene or alkyne moiety. "Alkene" moiety means a group of at least two carbon atoms consisting of at least one carbon-carbon double bond, and an "alkyne" moiety means at least two carbon atoms having at least one carbon-carbon triple bond Means a group. The alkyl moiety, whether saturated or unsaturated, may be ground, straight chain or cyclic. In addition, alkyl includes both “substituted or unsubstituted alkyls”.

The term "substituted or unsubstituted", unless stated otherwise, means including both substituted and unsubstituted, in which case the substituents are alkyl, acyl, cycloalkyl (dicyclicalkyl and tri Cyclic alkyl), perhaloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy, azide, amine, ketone, ether, amide, ester, triazole, isocyanate, arylalkyloxy, aryloxy, Merceto, alkylthio, arylthio, cyano, halogen, carbonyl, thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N- Amido, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, cyryl, trihalomethanesulfonyl, Pyrrolidinone, pyrrolidine, piperidine, piperazine, morpholine, Min, amino, amido, nitro, ether, ester, halogen, thiol, aldehyde, carbonyl, phosphorus, sulfur, phosphate, phosphate, phosphite, sulfate, disulfide, oxy, mercapto and hydrocarbyl mono- And various substituents commonly used in the art, including but not limited to, amino, including di-substituted amino groups, and one or more groups individually and independently selected from protective derivatives thereof. It is meant to include the substituted case. In some cases, they may also be substituted or unsubstituted.

The term “heteroatom” means atoms other than carbon and hydrogen.

The term “heteroalkyl” refers to a form in which one or more of the carbon atoms of an alkyl group is substituted with another hetero atom.

The term "depending on atom" means satisfying a valence, and "satisfying atom" means a state in which a certain number of electrons enter the outermost shell of the atom so that the bonded atom can exist in its most stable state. do.

The organometallic compound of the present invention and the thin film using the same satisfy the excellent chemical and thermal stability and at the same time have an excellent thin film deposition rate. In addition, it is possible to implement a thin film having a thickness that is not physically tunneled while having an equivalent oxide thickness (EOT) while having an equivalent oxide thickness (EOT).

FIG. 1A is ¹ H-NMR measurement data measured before the experiment of Example 1 (Formula 1-1), and FIGS. 1B and 1C are each ¹ H-NMR measurement measured after leaving Example 1 in an open and closed system. Data.
2A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 1 (TMA), and FIG. 2B is ¹ H-NMR measurement data measured after leaving Comparative Example 1 (TMA) in a closed system.
3A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 2 (Formula 2), and FIGS. 3B and 3C are ¹ H-NMR measurement data measured after leaving Comparative Example 2 in an open system and a closed system. .
4A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 3 (Formula 3), and FIG. 4B is ¹ H-NMR measurement data measured after leaving Comparative Example 3 in a closed system.
5A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 4 (Formula 4), and FIGS. 5B and 5C are ¹ H-NMR measurement data measured after leaving Comparative Example 4 in an open system and a closed system. .
6A and 6B are respectively measured photographs of Example 1 before and after experimenting in a closed system and an open system.
7 is a photograph of measurement for Comparative Example 1 before and after experimenting in a closed system.
8A and 8B are respectively measured photographs of Comparative Example 2 before and after experimenting in a closed system and an open system.
9 is a photograph of measurement for Comparative Example 3 before and after experimenting in a closed system.
10A and 10B are respectively measured photographs of Example 1 before and after experimenting in a closed system and an open system.
11 to 14 each show vaporization measurement data of Example 1, Comparative Example 2, and Comparative Example 3 which were carried out in Experimental Example 3. FIG.
15A is a graph of growth rate measurement of a thin film according to temperature prepared in Preparation Example 1, and FIG. 15B is a graph of measurement of thickness change rate of a thin film.
Each of A to D of FIGS. 16A and 16B is an FE-SEM image of the Al ₂ O ₃ thin film of Preparation Example 1 according to the deposition temperature measured in Experimental Example 4. FIG.
17A and 17B are EDS measurement data of the Al ₂ O ₃ thin film of Preparation Example 1 according to the deposition temperature measured in Experimental Example 4, and FIG. 17C is Al ₂ according to the precursor canister temperature (deposition temperature). It is a graph showing the change in composition ratio of the O ₃ thin film.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. However, the examples are not intended to limit the scope of the present invention, which will be construed as to help the understanding of the present invention.

As described above, conventional metal contaminants, metal-alkoxide compounds, or metal-imido / amide-based compounds are solid-state compounds having low vapor pressure at room temperature, and are difficult to apply to semiconductor production processes due to low thin film deposition rate. Due to the low thermal stability, there was a problem of poor step coverage due to decomposition of the precursor at high substrate temperature during deposition, and low reliability and efficiency of the process due to high contamination in the process and the deposited thin film. .

Accordingly, the present invention seeks to solve the above problems by applying an organometallic compound having a structure of Formula 1 as a precursor of a thin film deposition process.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, C ₁ ~ C ₁₀ linear alkyl group, C ₃ ~ C ₁₀ Crushed alkyl group, C ₆ ~ C ₁₀ cyclo alkyl group or hetero alkyl group, Preferably, R ¹ and R ² are each independently a hydrogen atom, a straight chain alkyl group of C ₁ ~ C ₅ or C ₃ ~ C ₆ crushed alkyl group, more preferably R ¹ and R ² are each independently C ₁ ~ it is a straight-chain alkyl group of C _3.

In addition, R ³ of Formula 1 is a hydrogen atom or a straight alkyl group of C ₁ to C ₃ , preferably a straight alkyl group of C ₁ to C ₂ .

In addition, R ⁴ of Formula 1 is a straight chain alkyl group of C ₁ ~ C ₄ or a ground alkyl group of C ₃ ~ C ₅ , preferably a straight chain alkyl group of C ₁ ~ C ₃ or C ₃ ~ C ₄ alkyl group, more preferably a straight-chain alkyl group or branched alkyl group of C ₃ of the C ₁ ~ C _3.

In addition, the point island of Formula 1 means that the Al atom and the O atom may have a coordination bond, and may have a resonance structure as shown in the following formula.

[expression]

When the pyrolysis temperature of the organometallic compound of the present invention is measured by a thermogravimetric analyzer, the pyrolysis temperature may be 150 ° C to 175 ° C, preferably 152 ° C to 170 ° C, and more preferably 153 ° C to 168 ° C. have.

In addition, the organometallic compound of the present invention may be a residual amount of the organometallic compound having a structure represented by the formula (1) when measuring the pyrolysis temperature, the pyrolysis temperature measurement by the thermogravimetric analyzer, preferably the residual amount 0.040% to 1.350%, more preferably, the residual amount may be 0.050 to 1.200%.

In addition, the organometallic compound of the present invention may have a boiling point (B.P) of less than 30 ° C, preferably 10 ° C to 25 ° C, and more preferably 15 ° C to 20 ° C under 0.01 torr.

In addition, the organometallic compound of the present invention is placed in a sealed non-reactive container, and when left for 3 days at a temperature of 150 ℃, ¹ H-NMR change rate is 2.5% or less, preferably 0.10 to 1.5%, more preferably Is 0.30 to 1.20% can have a very good thermal stability.

In addition, the organometallic compound of the present invention is put in an unsealed non-reactive container, and when left for 3 hours at a temperature of 110 ℃, ¹ H-NMR change rate is less than 1.30%, preferably 0.05 to 1.00%, more Preferably from 0.05 to 0.70% can have a very good thermal stability.

At this time, the ¹ H-NMR measurement method is measured based on the following equation (1).

[Equation 1]

¹ H-NMR rate of change (%) = ¹ H-NMR measurement of the organometallic compound before the experiment 100% of the total area- ¹ H-NMR measurement area (%) of impurities after the experiment

In Equation 1, ¹ H-NMR measurement The total area of the organic metal compound refers to a ¹ H-NMR measurement area of the organometallic compound prior to input to the non-sealed non-reactive containers and, ¹ H-NMR of the experiment and then proceeds impurities as measured area (%) is the input to the organic metal compound to the non-sealed non-reactive container, and then, measuring the ¹ H-NMR of the organic metal compound after left to stand at a temperature of 110 ℃ for 3 hours occurred newly as the impurity ¹ It means the area of the H-NMR peak.

The organometallic compound of the present invention described above may be widely used as long as it can be generally used, but preferably may be included or used in the process of manufacturing a semiconductor material in the semiconductor field. More preferably, it can be used for the production of semiconductor metal-containing thin films.

Specifically, the organometallic compounds may be used as precursors to form thin films included in semiconductors. Precursor means a material before a specific material in the metabolism or reaction, and may form a thin film used for a semiconductor by physically / chemically adsorbing the organometallic compound precursor on a substrate, for example, It may be used as a precursor for thin film deposition of a chemical vapor deposition (CVD) or atomic layer deposition (ALD).

In addition, when used as a precursor, the organometallic compound of the present invention may be included in the metal-containing thin film as it is, the final shape may be modified during the process. That is, when using the organometallic compound of the present invention as a precursor when used in the manufacture of a thin film included in a semiconductor, the final form may exist in various ways, preferably the final form may be an alumina (Al ₂ O ₃ ) thin film. .

That is, a thin film formed by depositing the organometallic compound of the present invention as a precursor, preferably, an alumina thin film has excellent uniformity and improved step film characteristics, thereby having an excellent efficiency.

In addition, the present invention may provide a semiconductor structure including the thin film, for example, an electrode, a barrier, a capacitor, a metal plug, and the like applied in the semiconductor structure.

On the other hand, in this regard, the present invention comprises the steps of: a) providing a vapor comprising the organometallic compound represented by Formula 1 as a precursor; And b) reacting the vapor with a substrate according to a deposition method to form a ceramic-containing complex layer on at least one surface of the substrate.

Through the above manufacturing method, the substrate adsorption efficiency may be improved and the safety may be increased when the substrate is formed, and the process speed may be shortened by increasing the thin film deposition rate. In addition, it can be used in a wide temperature range while reducing process contamination, and can significantly improve the reliability and efficiency of the manufacturing process. Furthermore, through the above manufacturing method, a thin film having excellent uniformity and improved step film characteristics can be obtained.

It will be described in detail below except for the content overlapping with the above-described content.

First, step a) is explained.

Carrier gas (transport gas) is introduced into a heated container by introducing a precursor containing the organometallic compound of the present invention to realize evaporation of the precursor as a metal source. At this time, the vessel is preferably heated to a temperature at which the precursor (metal source) can be obtained at a sufficient vapor pressure. The carrier gas may be selected from Ar, He, H ₂ , N ₂ or mixtures thereof. The precursor can be mixed with a solvent or another metal source or mixture thereof in a vessel. The vessel may preferably be heated at a temperature in the range of 25 ° C. to 200 ° C., and the temperature of the vessel may be adjusted to control the amount of precursor evaporated. The pressure in the vessel can be changed to control the level of evaporation in the vessel. By reducing the pressure in the vessel, it is possible to increase the level of evaporation (vaporization) of the metal source. Preferably, the pressure in the vessel may vary from 0.001 Torr to 800 Torr.

In addition, the precursor may be supplied to an evaporator in which evaporation takes place in a liquid state. The precursor may or may not be mixed with a solvent. The precursor may also be mixed with another metal source. In addition, the precursor may be mixed with a stabilizer. The solvents are alkanes such as hexane, heptane, octane, aromatic solvents such as benzene, toluene, mesitylene, xylene, silicon containing solvents such as hexamethyldisiloxane, hexamethyldisilazane, tetramethylsilane, sulfur containing solvents such as Dimethyl sulfoxide, oxygen-containing solvents such as tetrahydrofuran, dioxane. Meanwhile, the concentration of the mixed solution including the solvent may preferably include 50 to 99.9 wt% of the precursor.

Next, b) reacting the vapor with a substrate according to a deposition method to form a ceramic-containing complex layer on at least one surface of the substrate.

A precursor, the vaporized metal source, is introduced into the reaction chamber, where it is contacted with the surface of the substrate. The substrate may be heated to a temperature sufficient to obtain a desired thin film having the desired physical state and composition at a sufficient growth rate. The heating temperature may be usually heated to a temperature for obtaining a desired thin film, preferably in the range of 100 ℃ to 700 ℃, more preferably 250 ~ 450 ℃, more preferably 300 ~ 400 ℃ Can be. On the other hand, the process can be assisted by a plasma technique selected without limitation to improve the reactivity of the vaporized metal source and / or the reactivity of other gas species used in the process.

On the other hand, the deposition method in step b) is not limited as long as it can form a ceramic-containing complex layer on the surface of the substrate, preferably chemical vapor deposition (Chemical Vapor Deposition, CVD) or atomic layer deposition (Atomic Layer deposition method) Deposition, ALD) can be used.

First, atomic layer deposition (ALD) is a method of growing a thin film by cross-injecting a raw material containing a precursor and a reaction gas, a method of growing the atomic unit thin film by reacting the raw material and the gas and repeatedly adjusting the thickness of the thin film to be. Specifically, the organometallic compound according to the present invention may be injected into a vaporizer and then transferred to a chamber in a vapor phase. The vaporized film forming composition can be transferred to the chamber. In this case, the delivery method of the precursor material is a method of transferring a volatilized gas using a vapor pressure, a direct liquid injection method, or a liquid delivery system (LDS) in which the precursor material is dissolved and transported in an organic solvent. Can be used. In this case, the transport gas or dilution gas for moving the precursor material onto the substrate may preferably use one or more inert gases selected from Ar, N ₂ , He or H ₂ , more preferably from Ar or N ₂ . Can be selected. Meanwhile, the N ₂ canister flow rate may be preferably in the range of 30 to 5000 sccm, and more preferably in the range of 30 sccm to 300 sccm.

Next, the transferred precursor material may be adsorbed onto the substrate and the unabsorbed precursor material may be purged. As the purge gas, an inert gas such as Ar or He may be used. Next, the reactant may be supplied. The reactant may include an oxidizing agent such as H ₂ O, H ₂ O ₂ , O ₂ , O ₃ , N ₂ O, and the like. The reactant and the adsorbed precursor material may react to form a thin film, and the thin film may include zirconium, titanium, or hafnium. Next, purge the unreacted material. Thus, excess reactants and generated byproducts can be removed.

Meanwhile, the adsorption step, purge, reactant supply step, and purge are used as unit cycles. In order to form a thin film of a desired thickness, the unit cycle can be repeated, preferably 10 to 10,000 times can be repeated. For example, the precursor may be repeated for 6 to 8 seconds by adsorption, purge 8 to 12 seconds, reactant ozone (O ₃ ) 6 to 8 seconds, and purge 8 to 12 seconds as a unit cycle.

In addition, when using the atomic layer deposition method, the temperature may be preferably 100 ℃ to 450 ℃, more preferably 300 to 400 ℃ range. The pulse time in the ALD is preferably 3-15 seconds and the pressure may be 0.01 Torr-800 Torr.

Next, chemical vapor deposition (CVD) is performed by supplying a gas containing an element constituting the thin film material to be formed on the substrate and subjecting the substrate through chemical reactions such as thermal decomposition, photolysis, redox reactions, and substitution at the gas phase or the substrate surface. It is a method of forming a thin film on the surface. In the case of using the chemical vapor deposition method, the temperature may be preferably 100 ° C to 700 ° C, and more preferably 200 ° C to 500 ° C. In addition, the pressure may be preferably 0.01 Torr to 800 Torr, more preferably 1 Torr to 200 Torr. In addition, the carrier gas may preferably be N ₂ , He, Ar, H ₂ , more preferably Ar or N ₂ . Preferred canister flow rates can range from 30 to 300 sccm, more preferably 50 sccm to 100 sccm.

By using an organic metal compound of the present invention, the precursor deposition 10-30 minutes by CVD deposition Al ₂ O ₃ in the thin film during the deposition temperature 40 ℃ Al ₂ O ₃ thin film growth rate is 2.00 ~ 3.80 nm / min, the deposition temperature of 50 Al ₂ O ₃ thin film growth rate is 2.50 ~ 5.70 nm / min at ℃, Al ₂ O ₃ thin film growth rate is 5.0 ~ 6.0 nm / min at 55 ℃, and Al ₂ O ₃ thin film growth rate is 5.2 ~ 7.4 at 60 ℃ nm / min. And, preferably, by 20 minutes deposition by CVD deposition using the organometallic compounds of this invention as a precursor Al ₂ O ₃ thin film during the deposition temperature of 40 ℃ the Al ₂ O ₃ thin film growth rate is 2.00 ~ 2.85 nm / min, the deposition The growth rate of Al ₂ O ₃ thin film was 2.70 ~ 3.80 nm / min at 50 ℃, the growth rate of Al ₂ O ₃ thin film was 5.0 ~ 6.5 nm / min at 55 ℃, and the growth rate of Al ₂ O ₃ thin film was 5.40 at 60 ℃. ~ 7.00 nm / min.

Furthermore, the present invention comprises 0.1% to 99.9% by weight of the organometallic compound, saturated or unsaturated hydrocarbons, cyclic ethers, acyclic ethers, esters, alcohols, cyclic amines, acyclic amines, Provided are a composition comprising a residual amount of one or more organic compounds selected from cyclic sulfides, acyclic sulfides, phosphines, beta-dikitones, and beta-chitoesters, and a method for producing a thin film using the same. .

When manufacturing a thin film using the composition containing the organometallic compound has the effect of increasing the substrate adsorption efficiency and safety of the compound and shorten the process time. In addition, since the physical properties and composition of the thin film manufactured by adjusting the content of the composition can be adjusted, a thin film suitable for the purpose and means can be easily manufactured.

As a result, the present invention not only increases the reliability and efficiency of the deposition process by providing a novel organometallic compound as a precursor for thin film deposition, but also satisfies improved chemical and thermal stability, and at the same time improves the thin film deposition rate even at low temperatures. Can be improved. In addition, the formed thin film is improved in deterioration of properties due to by-products, has excellent step coverage, has a high dielectric constant, and may have an equivalent oxide film thickness (EOT) electrically, and has a thickness that does not physically tunnel. It is possible to provide a semiconductor structure including the same.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples should not be construed as limiting the scope of the present invention, the following examples are intended to help the understanding of the present invention.

EXAMPLE

Example 1 Preparation of Organometallic Compound

10 g (0.1387 mol, 1.00 equiv) of TMA (trimethylaluminium) was added to a 2 L Schlenk flask containing 500 ml of hexane, and the mixture was cooled to -50 ° C with stirring. 19.86 g of ethyl β-oxobutanate (0.1526 mol, 1.10 equiv) was slowly added and stirred to prepare a mixed reaction solution.

Next, the mixed reaction solution was slowly heated to 25 ° C. to 26 ° C., stirred at 25 ° C. to 26 ° C. for 12 hours, and then the reaction was terminated.

Next, the solvent was completely removed under reduced pressure to obtain 20 g of the organometallic compound represented by Chemical Formula 1-1 as a reaction product (yield: 80%).

[Formula 1-1]

In Formula 1-1, R ¹ to R ² are methyl groups, R ³ is a methyl group, and R ⁴ is an ethyl group.

Example  2

Prepared in the same manner as in Example 1, using methyl β-oxobutanate (Methyl β-oxobutanate) instead of the ethyl β-oxobutanate (organic metal represented by the following formula 1-2) The compound (yellow solid phase) was prepared.

[Formula 1-2]

In Formula 1-2, R ¹ to R ² are a methyl group, R ³ is a methyl group, R ⁴ is a methyl group.

Example  3

Prepared in the same manner as in Example 1, using triisopropylaluminum instead of the TMA (triisopropylaluminium), to prepare an organometallic compound (solid state) represented by the following formula 1-3.

 [Formula 1-3]

In Formula 1-3, R ¹ to R ² is an isopropyl group, R ³ is a methyl group, R ⁴ is an ethyl group.

Example  4

Prepared in the same manner as in Example 1, using triethylaluminium (triethylaluminium) instead of the TMA, and isopropyl β-oxobutanate (Isopropyl β-oxobutanate) instead of the ethyl β-oxobutanate, the following formula An organometallic compound (solid phase) represented by 1-4 was prepared.

 [Formula 1-4]

In Formula 1-4, R ¹ to R ² are ethyl groups, R ³ is a methyl group, and R ⁴ is an isopropyl group.

Comparative example  One

Trimethylaluminum (TMA, manufactured by Aldrich), a precursor commercially available for depositing a thin film, was prepared as an organometallic compound.

Comparative Example 2

An organometallic compound represented by Chemical Formula 2 was prepared (manufacturer: Aldrich).

 [Formula 2]

Comparative Example 3

An organometallic compound represented by Chemical Formula 3 was prepared (manufacturer: Aldrich).

[Formula 3]

Comparative example  4

An organometallic compound represented by Chemical Formula 4 was prepared (manufacturer: Aldrich).

[Formula 4]

Comparative example  5

Prepared in the same manner as in Example 1, using n-butyl β-oxobutanate (n-butyl β-oxobutanate) instead of the ethyl β-oxobutanate, an organometallic compound represented by the following formula 1-5 ( Solid phase) was prepared.

 [Formula 1-5]

In Formula 1-5, R ¹ to R ² is a methyl group, R ³ is a methyl group, R ⁴ is n-butyl group.

Experimental Example 1 Measurement of Thermal Stability of Organometallic Compounds 1

In order to measure thermal stability of each of the organometallic compounds of Examples and Comparative Examples, the rate of change of ¹ H-NMR before and after leaving in an open system and a closed system atmosphere is calculated based on Equation 1 below. It was.

 [Equation 1]

¹ H-NMR rate of change (%) = ¹ H-NMR measurement of the organometallic compound before the experiment 100% of the total area- ¹ H-NMR measurement area (%) of impurities after the experiment

Here, the open system is 20g of the organometallic compound in a flask containing, and left for 3 hours at 110 ℃. In the closed system, 20 g of the organometallic compound was added to a sealed container (SUS vail), and then left for 3 days at 150 ° C. At this time, a vent line is provided in the open system, and the highly vaporizable component is designed to vaporize to the outside.

Figure 1a is the ¹ H-NMR measurement data measured before the experiment of Example 1 (Formula 1-1), Figure 1b is the ¹ H-NMR measurement data measured after leaving Example 1 in an open system, Figure 1c ¹ H-NMR measurement data measured after leaving Example 1 in a closed system.

2A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 1 (TMA), and FIG. 2B is ¹ H-NMR measurement data measured after leaving Comparative Example 1 (TMA) in a closed system.

Figure 3a is ¹ H-NMR measurement data measured before the experiment of Comparative Example 2 (Formula 2), Figure 3b is ¹ H-NMR measurement data measured after leaving Comparative Example 2 in an open system, Figure 3c is a comparative example ¹ H-NMR measurement data measured after leaving 2 in a closed system.

4A is ¹ H-NMR measurement data measured before the experiment of Comparative Example 3 (Formula 3), and FIG. 4B is ¹ H-NMR measurement data measured after leaving Comparative Example 3 in a closed system.

Figure 5a is the ¹ H-NMR measurement data measured before the experiment of Comparative Example 4 (Formula 4), Figure 5b is the ¹ H-NMR measurement data measured after leaving Comparative Example 4 in an open system, Figure 5c is a comparative example ¹ H-NMR measurement data measured after leaving 4 in a closed system.

In addition, the ¹ H-NMR change rate (%) measurement results are shown in Table 1 below.

division ¹ H-NMR of the rate of change in the open system (%) % Change of ¹ H-NMR in Closed System Example 1 0.17% 0.57% Example 2 0.35% 0.78% Example 3 0.35% 0.79% Example 4 0.29% 0.87% Comparative Example 2 1.36% 2.95% Comparative Example 3 - 1.72% Comparative Example 4 1.90% 63.34% Comparative Example 5 1.42% 3.20%

Looking at the NMR measurement results of Table 1, in Examples 1 to 4, the thermal stability was 1.30% or less in the open atmosphere, 1.5% or less in the closed system atmosphere. On the contrary, Comparative Examples 2 to 5 showed a high NMR change rate of more than 1.40% in both open and closed systems, and especially in Comparative Example 4, the change rate in the closed system was very high. It means that impurities are present.

Experimental Example 2 Measurement of Thermal Stability of Organometallic Compounds 2

The change over time of the organometallic compounds of Example 1 and Comparative Examples 1 to 4 (color change, foreign matter generation, viscosity change) under the same open and closed atmospheres as in Experimental Example 1 was measured, and the results are shown in Table 2 below. Shown in

In addition, Figure 6a shows a measurement picture for Example 1 before and after experimenting in a closed system, Figure 6b shows a measurement picture for Example 1 after the experiment in an open system.

And the measurement photograph about the comparative example 1 before and after experimenting in the closed system is shown in FIG.

In addition, FIG. 8A shows measurement pictures for Comparative Example 2 before and after experimenting in a closed system, and FIG. 8B shows measurement pictures for Comparative Example 2 after experimenting in an open system.

And the measurement photograph about the comparative example 3 before and after experimenting in the closed system is shown in FIG.

division Open system Closed system Color change Foreign substance generation Viscosity change Color change Foreign substance generation Viscosity change Example 1 O X X O X X Example 2 O X X O X X Example 3 O X X O X X Example 4 O X X O X X Comparative Example 1 X X X X X X Comparative Example 2 X X X O X X Comparative Example 3 - - - X X X Comparative Example 4 O X X O O X Comparative Example 5 O X X O X X

In Examples 1 to 4, there were no foreign matter and viscosity changes under open and closed atmospheres, but color changes were observed. In Comparative Example 1, open and closed atmospheres, Comparative Example 3 did not change over time in the closed system, and in Comparative Example 2, color change was observed in the closed system. However, in the case of Comparative Example 4, there was a problem that foreign matter is generated in the closed system.

Experimental Example 3 Measurement of Vaporization of Organometallic Compound

The thermal gravimetric analysis (TGA) of each of the organometallic compounds was measured under the set values shown in Table 3 to measure the vaporization properties of Examples 1 to 4 and Comparative Examples 2 to 5.

Set value Initial temperature 30 ℃ Highest temperature 360 ℃ Temperature rise rate (℃ / min) 10.0 ℃ / min Input sample volume
(Sample to be measured) See Table 4 N ₂ dosage (ml / min) 20 ml / min

The measured pyrolysis temperature (T1 / 2) and the remaining amount of undissolved sample (residue,%) are shown in Table 4 below, and the graphs of the results are shown in FIGS. 11 (Example 1), 12 (Comparative Example 2), and FIG. 13. (Comparative Example 3) and FIG. 14 (Comparative Example 4), respectively.

division Pyrolysis Temperature (T1 / 2, ℃) Input sample amount (mg) % Of sample remaining Example 1 160 ℃ 25.676 mg 0.328 mg (1.295%) Example 2 165 ℃ 16.224 mg 0.841 mg (5.18%) Example 3 163 ℃ 17.264 mg 0.883 mg (5.11%) Example 4 170 ℃ 18.562 mg 0.942 mg (5.07%) Comparative Example 2 210 ℃ 15.045 mg 0.414 mg (2.580%) Comparative Example 3 140 ℃ 22.945 mg 0.313 mg (2.482%) Comparative Example 4 170 ℃ 26.213 mg 1.792 mg (6.906%) Comparative Example 5 152 ℃ 15.887 mg 5.432 mg (34.24%)

After vaporizing in a canister by applying heat to deposit and thin a precursor for chemical vapor deposition (CVD) or atomic layer deposition (ALD) thin film deposition, the vaporized precursor is passed through a chamber from a canister through a pipe. Will be moved to. However, if the pyrolysis temperature is high, the vaporization is inferior, and when the deposition process is performed for a long time, the pipe may be clogged. In addition, in general, when the pyrolysis temperature is high, the thermal stability tends to be excellent. When the residual amount of the sample is high in Table 4, the thermal stability is lowered.

In the case of Comparative Example 2, the pyrolysis temperature is high, but not only the vaporization property is lowered, but the residual amount of the sample is almost twice as high as that of Example 1.

In addition, in the case of Comparative Example 3, the thermal decomposition temperature is low, but excellent vaporization, but there was a problem that the sample residual amount is too high when compared with Example 1, and in Comparative Example 4 and Comparative Example 5, the sample residual amount is compared with Example 1 When there was a problem of sharp increase.

Preparation Example 1

The alumina thin film layer was formed by chemical vapor deposition (CVD) of the organometallic compound serving as the precursor of Example 1 on a Si wafer. In this case, CVD deposition conditions are shown in Table 5 below.

division Process conditions Test chamber AMAT P5000 deposition system (using dual shower heads) Precursor type Example 1 pressure 0.2 torr Precursor canister temperature
(Deposition temperature) 45 ℃ ~ 60 ℃ Deposition time 10 to 30 minutes Precursor input flow rate 200 sccm H ₂ O can temperature 0 ℃ H ₂ O input flow 200 sccm Carrier and Purge Gas Flow Rate Ar 200 sccm Line temperature 110 ℃ temperament Si wafer

In addition, the growth rate (nm / min) and thickness (nm) change of the alumina thin film according to the CVD deposition temperature (precursor canister temperature) were measured, and the results are shown in Table 6 and FIG. 15A (thin film growth rate), and FIG. 15. It is shown in B (thickness change), respectively.

Precursor
Canister temperature
(℃) Precursor
input
flux
(Sccm) H ₂ O
Canister temperature
(℃) H ₂ O
input
flux
(Sccm) pressure
(Torr) deposition
time
(Min, min) Deposited
Al ₂ O ₃ Thin Film
thickness
(nm) Al ₂ O ₃ Thin Film
Growth rate
(nm / min) 45 200 0 200 0.2 10 35.8 3.58 45 200 0 200 0.2 20 48.9 2.45 45 200 0 200 0.2 30 76.1 2.54 50 200 0 200 0.2 10 27.5 2.75 50 200 0 200 0.2 30 109.6 3.65 55 200 0 200 0.2 10 55 5.50 55 200 0 200 0.2 20 110 - 55 200 0 200 0.2 30 170 5.67 60 200 0 200 0.2 10 72.2 7.22 60 200 0 200 0.2 20 137.4 6.87 60 200 0 200 0.2 30 182.5 6.08

Referring to Tables A and B of FIG. 15 and FIG. 15, thin film growth rates and thin film thicknesses were increased in proportion to the deposition temperature (precursor canister temperature) from 45 ° C. to 60 ° C., but 55 ° C. and 60 ° C. When comparing the ℃, the thin film growth rate was slightly reduced at 60 ℃, it is determined that the remaining amount of the precursor used in the CVD deposition process was insufficiently added.

In addition, referring to Table 6 and B of FIG. 15, an equipment error occurred in the deposition process under a condition of 55 ° C. (deposition time 20 minutes), and thus a problem in that the thin film thickness measurement was impossible.

In addition, using the organometallic compound of the present invention as a precursor by 10 minutes to 30 minutes by CVD deposition method, the Al ₂ O ₃ thin film growth rate at the deposition temperature of 40 ℃ Al ₂ O ₃ thin film growth rate of 2.00 ~ 3.80 nm / min, deposition temperature in 50 ℃ Al ₂ O ₃ thin film growth rate is 2.50 ~ the 5.70 nm / min, the deposition temperature of 55 ℃ Al ₂ O ₃ thin film growth rate of 5.0 to the 6.0 nm / min, the deposition temperature of 60 ℃ Al ₂ O ₃ thin film growth rate is 5.2 It was confirmed that the excellent at ~ 7.4 nm / min.

In addition, when the Al ₂ O ₃ thin film was formed by the CVD deposition process using the precursor of Example 1, it was confirmed that the thin film growth rate and the thin film thickness were performed at 55 to 60 ° C. deposition temperature.

Experimental Example 4: Al deposited by CVD ₂ O ₃  FE-SEM Measurement and Energy Dispersive Spectroscopy (EDS) Analysis of Thin Films

FE-SEM measurement of Al ₂ O ₃ thin film CVD deposited in Preparation Example 1, A (deposition temperature 45 ℃), B (deposition temperature 50 ℃), C (deposition temperature 55 ℃) and 16A and 16B It was shown in D (deposition temperature 60 degreeC) D, respectively. In this case, the upper image of FIGS. 16A and 16B is a measured image of the cut surface of the thin film, and the lower image is a planar image of the thin film.

In addition, EDS measurement data of the thin film measured by the FE-SEM is shown in FIGS. 17A and 17B, respectively. 17A to 17B, when the composition ratio of Al and O based on Atomic% is 45 ° C, Al: O = 1.13: 13.12 and 50 ° C, Al: O = 1.62: 17.96, and 55 ° C: Al: O = 2.92 At 26.94 and 60 ° C., Al: O = 2.69: 25.79, and it was confirmed that the composition ratio of Al to O tends to increase slightly with increasing temperature. In addition, a graph showing the composition ratio of the Al ₂ O ₃ thin film according to the precursor canister temperature (deposition temperature) is shown in FIG. 17C.

Preparation Examples 2 to 4 and Comparative Preparation Examples 2 to 5

Performing a CVD deposition process under the same conditions as in Preparation Example 1 (Table 5), but using the precursors of Examples 2 to 4 and Comparative Examples 2 to 5 instead of Example 1 to form an Al ₂ O ₃ thin film, respectively I was.

In addition, the Al ₂ O ₃ thin film growth rate was measured by CVD deposition under the same conditions as in Tables 7 and 8.

division Precursor
Canister temperature
(℃) Precursor
input
flux
(Sccm) H ₂ O
Canister temperature
(℃) H ₂ O
input
flux
(Sccm) pressure
(Torr) deposition
time
(Min, min) Deposited
Al ₂ O ₃ Thin Film
thickness
(nm) Al ₂ O ₃ Thin Film
Growth rate
(nm / min) Preparation Example 2 45 200 0 200 0.2 20 41.4 2.07 50 200 0 200 0.2 20 70.0 3.50 55 200 0 200 0.2 20 112 5.60 60 200 0 200 0.2 20 128 6.40 Preparation Example 3 45 200 0 200 0.2 20 44.4 2.22 50 200 0 200 0.2 20 68.2 3.41 55 200 0 200 0.2 20 124 6.20 60 200 0 200 0.2 20 130 6.50 Preparation Example 4 45 200 0 200 0.2 20 42.4 2.12 50 200 0 200 0.2 20 54.0 2.70 55 200 0 200 0.2 20 104.2 5.21 60 200 0 200 0.2 20 108.8 5.44

division Precursor
Canister temperature
(℃) Precursor
input
flux
(Sccm) H ₂ O
Canister temperature
(℃) H ₂ O
input
flux
(Sccm) pressure
(Torr) deposition
time
(Min, min) Deposited
Al ₂ O ₃ Thin Film
thickness
(nm) Al ₂ O ₃ Thin Film
Growth rate
(nm / min) compare
Preparation Example 2 45 200 0 200 0.2 20 45.2 2.26 50 200 0 200 0.2 20 84.6 4.23 55 200 0 200 0.2 20 104.2 5.21 60 200 0 200 0.2 20 112.4 5.62 compare
Preparation Example 3 45 200 0 200 0.2 20 46.2 2.31 50 200 0 200 0.2 20 88.6 4.43 55 200 0 200 0.2 20 102.6 5.13 60 200 0 200 0.2 20 114.6 5.73 compare
Preparation Example 4 45 200 0 200 0.2 20 42.8 2.14 50 200 0 200 0.2 20 95 4.75 55 200 0 200 0.2 20 107.8 5.39 60 200 0 200 0.2 20 109 5.45 compare
Preparation Example 5 45 200 0 200 0.2 20 39.6 1.98 50 200 0 200 0.2 20 62.0 3.10 55 200 0 200 0.2 20 104 5.20 60 200 0 200 0.2 20 122 6.10

Looking at the Al ₂ O ₃ thin film growth rate of Table 7 and Table 8, it can be seen that the growth rate of the thin film increases as the canister temperature of the precursor increases, in particular, Preparation Example 2 and / or Preparation Example 3 As shown in Example 1, it showed a high film growth rate of 6.00 nm / min or more at 60 ℃.

Through the above examples and experimental examples, it was confirmed that the organometallic compound of the present invention satisfies the excellent chemical and thermal stability, it can be formed a thin film at the deposition rate and deposition rate when manufacturing a thin film using this. In addition, when the thin film is formed by using the organometallic compound of the present invention, the deterioration of properties due to by-products is improved, the step coverage is excellent, and the dielectric constant has a high dielectric constant (EOT). In addition, it was confirmed that a thin film having a thickness without physically tunneling can be realized.

Claims (10)

An organometallic compound having a structure represented by Formula 1 below;
[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, C ₁ ~ C ₁₀ linear alkyl group, C ₃ ~ C ₁₀ Crushed alkyl group, C ₆ ~ C ₁₀ cyclo alkyl group or hetero alkyl group, R ³ is a hydrogen atom or a straight chain alkyl group of C ₁ to C ₃ , R ⁴ is a straight chain alkyl group of C ₁ to C ₄ or a ground alkyl group of C ₃ to C ₅ , and the dotted line represents an Al atom and an O atom coordination bond. That means you can have
According to claim 1, R ¹ and R ² of Formula 1 are each independently a hydrogen atom, a straight alkyl group of C ₁ ~ C ₅ or C ₃ ~ C ₆ Crushed alkyl group, R ³ is C ₁ ~ C ₂ An organometallic compound, wherein R ⁴ is a straight chain alkyl group of C ₁ to C ₃ , or a ground alkyl group of C ₃ .
The organometallic compound according to claim 1, wherein the pyrolysis temperature is 150 ° C. to 175 ° C. when the pyrolysis temperature of the organometallic compound is measured by a thermogravimetric analyzer.
The organometallic compound according to claim 3, wherein when the pyrolysis temperature is measured by the thermogravimetric analyzer, a residual amount of the organometallic compound having the structure represented by Formula 1 is 1.500% or less.
The organometallic compound according to any one of claims 1 to 4, wherein the organometallic compound is used as a precursor for thin film deposition of chemical vapor deposition (CVD) or atomic layer deposition (ALD).
Chemical vapor deposition using the thin film deposition precursor of claim 5.
An atomic layer deposition method using the precursor for thin film deposition of claim 5.
An alumina (Al ₂ O ₃ ) thin film formed by depositing the thin film deposition precursor of claim 5.
A semiconductor structure comprising the alumina thin film of claim 8.
The semiconductor structure of claim 9, wherein the semiconductor structure comprises at least one selected from an electrode, a barrier, a capacitor, and a metal plug.

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