Group 5 metal precursor compounds for thin film deposition and method for forming Group 5 metal-containing thin films using the same

Abstract

According to an embodiment of the present invention, the group 5 metal precursor compound is represented by the following chemical formula 1. Therefore, the group 5 metal precursor compound according to one embodiment of the present invention has the advantages of excellent thermal stability, existing in a liquid state at room temperature, and high volatility, making it advantageous for application in thin film formation processes. Furthermore, when using the group 5 metal precursor compound according to one embodiment of the present invention, it is possible to obtain a group 5 metal thin film with a low residue content and uniform physical properties, and the thickness of the thin film can be easily adjusted. JPEG2026508884000017.jpg62170

Description

Technical Field

[0001] The present invention relates to a Group 5 metal precursor compound and a method for forming a Group 5 metal-containing thin film using the same. More specifically, the present invention relates to a Group 5 metal compound capable of forming a Group 5 metal-containing thin film having excellent thermal stability, a low growth rate per cycle (GPC) of the thin film during the deposition process, and a high residue content, and a method for forming a Group 5 metal-containing thin film using the same.

Background Art

[0002] As electronic technology develops, the demand for miniaturization and weight reduction of electronic devices used in various electronic devices has increased rapidly. In order to form fine electronic devices, various physical and chemical vapor deposition methods have been proposed, and various studies for manufacturing various electronic devices such as metal thin films, metal oxide thin films, or metal nitride thin films are underway by such vapor deposition methods.

[0003] In the manufacture of semiconductor devices, thin films containing Group 5 metal compounds are generally formed using a metal organic chemical vapor deposition (MOCVD) or atomic layer deposition (ALD) process.

[0004] Compared with the MOCVD deposition process, the ALD deposition process has the advantages of excellent step coverage because it undergoes a self-limiting reaction and can avoid deterioration of device characteristics due to thermal diffusion because it is a relatively low-temperature process.

[0005] To deposit thin films containing vanadium (V), niobium (Nb), and tantalum (Ta) from the Group 5 metal compounds, it is crucial to select a precursor compound suitable for the deposition process. Currently, a wide variety of Group 5 metal precursors exist in the semiconductor industry. Conventional Group 5 metal precursor compounds have the disadvantage of easily decomposing during the thin film formation process due to their low thermal stability, resulting in a high carbon content in the thin film. Furthermore, their high thin film growth rate (GPC) makes precise thickness control difficult, thus posing a challenge in forming Group 5 metal-containing thin films required for next-generation semiconductor devices. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a group 5 metal compound that is suitable for thin film growth, has robust thermal stability, has a high vapor pressure, exists in a liquid state at room temperature, and can solve the process problems associated with using conventional group 5 metal compounds.

[0007] Furthermore, an object of the present invention is to provide a group 5 metal compound for thin film deposition that can provide a high-quality, uniform thin film with a low carbon content using the group 5 metal compound. Furthermore, an object of the present invention is to provide a method for forming a Group 5 metal-containing thin film that allows for fine thickness adjustment using the aforementioned Group 5 metal composition for thin film deposition.

[0008] The problems addressed by the present invention are not limited to those mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] One embodiment of the present invention provides a group 5 metal compound represented by the following chemical formula 1.

[0010] [ka]

[0011] (In the above chemical formula 1, M is one selected from among the Group 5 metallic elements, R1 is selected from among linear alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms, R2 and R3 are each independently selected from linear alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and X is each independently a halogen element.) Another embodiment of the present invention provides a precursor composition for thin film deposition containing a group 5 metal element, and the precursor composition for thin film deposition according to one embodiment of the present invention contains a group 5 metal element compound represented by the formula 1 above.

[0012] Another embodiment of the present invention provides a method for forming a group 5 metal-containing thin film by depositing a thin film onto a substrate through a metal-organic chemical vapor deposition (MOCVD) process or an atomic layer deposition (ALD) process using a group 5 metal precursor compound represented by the above formula 1.

[0013] Specific details of other embodiments are included in the detailed description and drawings. [Effects of the Invention]

[0014] One embodiment of the present invention provides a group 5 metal compound that exhibits excellent thermal stability, exists in a liquid state at room temperature, and has a high vapor pressure, which is advantageous for forming thin films during the deposition process. In particular, the group 5 metal precursor compound of the present invention has a lower thin film growth rate (Growth Per Cycle, GPC) during deposition than conventional group 5 metal precursor compounds having amine ligands. Therefore, when forming a thin film in an MOCVD deposition process or an ALD deposition process, a high-quality group 5 metal thin film with a low carbon content can be formed, allowing for easy fine-tuning of the thickness and easy formation of a thin film of the desired thickness.

[0015] When performing an ALD deposition process using a Group 5 metal precursor compound according to an embodiment of the present invention, it has a constant thin film growth rate over a wider temperature range than conventional Group 5 metal precursor compounds, and the quality of the thin film can be further improved.

[0016] In addition, a Group 5 metal compound containing an asymmetrically disubstituted cyclopentadiene ligand according to an embodiment of the present invention is more advantageous for liquefaction than a Group 5 metal compound having a conventional M-Cl (M is any one selected from Group 5 metal elements) ligand, and has the advantages of excellent thermal stability and ease of the Group 5 metal thin film formation process.

[0017] In addition, a Group 5 metal thin film formed of a Group 5 metal compound according to an embodiment of the present invention has excellent thermal stability, excellent morphological characteristics, low diffusivity, low leakage, and low charge trapping properties, and thus can be used for various applications such as dielectrics, barrier films, and electrodes.

[0018] The effects according to the present invention are not limited to the contents exemplified above, and further various effects are included within the present invention.

Brief Description of Drawings

[0019] [Figure 1] It is a graph showing the growth rate of a thin film depending on the deposition temperature during an atomic layer deposition process using each niobium precursor compound according to Example 1 and Comparative Example 1. [Figure 2] It is a photograph showing the thermal stability of each specimen according to Example 1 and Comparative Example 1. [Figure 3] It is a graph showing the thermogravimetric analysis (TGA) results of the niobium precursor compound according to Example 1. [Figure 4] It is a graph showing the thermogravimetric analysis (TGA) results of the niobium precursor compound according to Comparative Example 1. [Figure 5] It is a graph showing the thermogravimetric analysis (TGA) results of the niobium precursor compound according to Comparative Example 2. [Figure 6] It is a graph showing the thermogravimetric analysis (TGA) results of the niobium precursor compound according to Comparative Example 3. [Figure 7]It is a graph showing the thermogravimetric analysis (TGA) results of the tantalum precursor compound according to Example 4. [Figure 8] It is a graph showing the growth rate of a thin film depending on the deposition temperature during an atomic layer deposition process using the tantalum precursor compound according to Example 4.

Mode for Carrying Out the Invention

[0020] The advantages and features of the present invention, and the method for achieving them, will become clear by referring to the examples described in detail below together with the attached drawings. However, the present invention is not limited to the examples disclosed below, and is embodied in various different shapes. Merely, these examples are provided so that the disclosure of the present invention becomes complete, and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is only defined by the scope of the claims.

[0021] In explaining the present invention, when it is determined that a specific explanation of related known technologies may obscure the gist of the present invention, the detailed explanation thereof is omitted. When terms such as "including", "having", "being made" etc. mentioned in the present invention are used, unless "only" is used, other parts can be added. When a component is expressed in the singular, it includes the case of including a plurality unless there is a specific description to the contrary.

[0022] In interpreting a component, it is interpreted as including an error range even without a separate explicit description. Throughout the present specification, the term "room temperature" means a temperature of 15°C to 30°C, or 20°C to 27°C.

[0023] The group 5 metal precursor compound according to one embodiment of the present application can be represented by Chemical Formula 1 below.

[0024]

Chemical Formula

[0025] In chemical formula 1, M is one selected from among the Group 5 metallic elements, R1 is selected from among linear alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms, R2 and R3 are each independently selected from linear alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and X is each independently selected from among the halogen elements.

[0026] The compound in Chemical Formula 1 will be explained in detail below. In chemical formula 1, M may be any one selected from the Group 5 metallic elements. For example, M may be any one selected from niobium (Nb), tantalum (Ta), and vanadium (V), preferably Nb or Ta. More preferably, M may be Nb, in which case a high-quality thin film can be provided with excellent thermal stability of the precursor compound while having a low residue content.

[0027] In chemical formula 1, R1 may be one selected from a linear alkyl group having 1 to 4 carbon atoms and a branched alkyl group having 3 to 4 carbon atoms. For example, R1 may be a branched alkyl group having 3 to 4 carbon atoms. In this case, the thermal stability is even better, the vapor pressure is high, and the precursor compound can remain in a liquid state without solidifying during the thin film formation process.

[0028] In chemical formula 1, R2 and R3 may each be independently selected from a linear alkyl group having 1 to 6 carbon atoms and a branched alkyl group having 3 to 6 carbon atoms. When the cyclopentadiene ligand is substituted with substituents R2 and R3 in this way, the binding force between the Group 5 metal and the ligand compound may decrease compared to a Group 5 metal compound containing an unsubstituted cyclopentadiene ligand. This may reduce the content of unwanted residues in the thin film formed during the vapor deposition process.

[0029] Preferably, in Chemical Formula 1, R2 and R3 may each be linear alkyl groups having 1 to 6 carbon atoms. In this case, the content of unwanted residues in the thin film is further reduced during the deposition process, making it possible to provide a high-quality Group 5 metal thin film.

[0030] In chemical formula 1, R2 and R3 can be different from each other. When substituents R2 and R3 attached to the cyclopentadiene ligand have different asymmetric structures, the melting point of the precursor compound is lowered, allowing it to exist in a liquid state at room temperature. This enables the formation of a highly reproducible group 5 metal thin film with uniform physical properties.

[0031] In one embodiment of the present invention, in the case of a group 5 metal compound in which R2 and R3 are substituted with different alkyl groups, the group 5 metal compound with an asymmetric structure in which one of R2 and R3 is hydrogen has the characteristic of having a high vapor pressure.

[0032] Furthermore, under the condition that the sum of the number of carbon atoms in R2 and R3 is the same, in the case of a group 5 metal compound with an asymmetric structure in which R2 and R3 are different, as in one embodiment, the vapor pressure is even higher than in the case of a group 5 metal compound with a symmetric structure in which R2 and R3 are the same. Therefore, a high-quality group 5 metal thin film can be easily formed through the vapor deposition process.

[0033] In Chemical Formula 1, the sum of the number of carbon atoms in R2 and R3 may be 3 or less. In this case, the vapor pressure is high while maintaining excellent thermal stability, allowing it to exist in a liquid state at room temperature, and thus a Group 5 metal thin film can be easily formed through the deposition process. In Chemical Formula 1, if the sum of the number of carbon atoms in R2 and R3 is greater than 3, the Group 5 metal compound may exhibit high viscosity, although it can exist in a liquid state at room temperature. Therefore, in terms of ease of process and the formation of a high-quality Group 5 metal thin film, in Chemical Formula 1, the sum of the number of carbon atoms in R2 and R3 may be 3 or less.

[0034] In chemical formula 1, each of X may be an independent halogen element. Specifically, for example, each of X may be independently selected from fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), preferably, for example, each of X may be chlorine (Cl).

[0035] Conventionally, precursor compounds such as MCl5 (where M is one of the metal elements selected from Group 5) consist only of MX (where X is a halogen element, which may be one of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I)), which have higher bond energies than MN and NC bonds. While these compounds exhibit excellent thermal stability, they have problems such as a high content of residues, existing as a solid at room temperature, making the deposition process difficult, and resulting in non-uniform thin film quality.

[0036] One embodiment of the present invention contains an MX, M=N bond, and a cyclopentadiene substituted with two substituents is bonded to the M central metal. This provides superior thermal stability compared to conventional group 5 metal precursors, while remaining in a liquid state at room temperature, facilitating the deposition process, and enabling the formation of a group 5 metal thin film with uniform and homogeneous physical properties.

[0037] More specifically, the Group 5 metal compounds can be selected from the compounds represented by the following chemical formulas 2, 3, and 4.

[0038] [ka]

[0039] In chemical formulas 2, 3, and 4, M may be independently selected from the group metal elements niobium (Nb), tantalum (Ta), and vanadium (V). More preferably, the group 5 metal compound may be a compound represented by the following chemical formula 2. This provides a group 5 metal thin film with the best thermal stability, even lower residue content, and superior physical properties, and has the advantage of a low thin film growth rate (GPC) and easy thickness control.

[0040] A group 5 metal compound represented by chemical formula 1 according to one embodiment of the present invention exists in a liquid state at room temperature, making it easy to store and handle, and can be advantageously applied to forming thin films using a vapor deposition process.

[0041] Therefore, the group 5 metal compound represented by chemical formula 1 according to one embodiment of the present invention can be used as a precursor for producing group 5 metal thin films through MOCVD deposition processes or ALD deposition processes. Furthermore, the Group 5 metal compounds represented by Chemical Formula 1 exhibit a constant thin film growth rate (Growth Per Cycle, GPC) over a wide temperature range during the vapor deposition process. They have the advantage of being easy to adjust in thickness due to their low growth rate (GPC), and allowing for fine thickness control.

[0042] Therefore, the group 5 metal compound represented by Chemical Formula 1 can be used as a precursor composition for deposition of group 5 metal-containing thin films. The following describes in detail a method for forming a Group 5 metal-containing thin film according to one embodiment of the present invention. The method for forming a Group 5 metal-containing thin film uses the Group 5 metal compound described above, and redundant explanations related to the Group 5 metal compound will be omitted.

[0043] A method for forming a Group 5 metal-containing thin film according to one embodiment of the present invention involves depositing a thin film onto a substrate through a deposition process using a Group 5 metal precursor compound represented by Chemical Formula 1. The deposition process can be carried out by atomic layer deposition (ALD) or chemical vapor deposition (CVD), such as metal-organic vapor deposition (MOCVD). The deposition process can be carried out at 50 to 700°C.

[0044] First, the group 5 metal precursor compound represented by Chemical Formula 1 is transferred onto the substrate. For example, the group 5 metal precursor compound can be supplied onto the substrate by methods such as bubbling, vapor phase mass flow controller, direct gas injection (DGI), direct liquid injection (DLI), or liquid transfer by dissolving it in an organic solvent, but is not limited to these methods.

[0045] If necessary, the Group 5 metal precursor compound may be supplied with a carrier gas or a diluent gas. The carrier gas is inactive with the Group 5 metal precursor compound, is lighter than the Group 5 metal precursor compound, and easily transports the vaporized Group 5 metal precursor compound to the reaction chamber. The diluent gas is inactive with the Group 5 metal precursor compound and does not induce side reactions, and its flow rate can be easily controlled to control reactions such as the thin film growth rate. For example, the carrier gas and diluent gas may each be one or more selected from argon (Ar), nitrogen (N2), helium (He), and hydrogen (H2).

[0046] For example, a Group 5 metal precursor compound can be mixed with a carrier gas or diluent gas containing one or more selected from argon (Ar), nitrogen (N2), helium (He), and hydrogen (H2), and then transferred onto a substrate by bubbling or direct gas injection.

[0047] In the deposition process for forming Group 5 metal thin films, a reaction gas can be supplied as needed to form a variety of Group 5 metal-containing thin films, such as Group 5 metal oxide thin films, Group 5 metal carbon oxide thin films, and Group 5 metal nitride thin films. The reaction gas can be supplied during the thin film deposition step.

[0048] For example, the reaction gas may include one or more selected from water vapor (H2O), oxygen (O2), ozone (O3), hydrogen peroxide (H2O2), ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), and nitrogen (N2).

[0049] For example, when attempting to manufacture a Group 5 metal oxide thin film or a Group 5 metal carbon oxide thin film, an oxygen-containing reaction gas can be supplied. For instance, the oxygen-containing reaction gas may include one or more selected from water vapor (H2O), oxygen (O2), oxygen plasma, ozone (O3), and hydrogen peroxide (H2O2). Such a reaction gas can react with a Group 5 metal compound in the thin film deposition process to form a Group 5 metal oxide thin film or a Group 5 metal carbon oxide thin film.

[0050] As another example, when attempting to manufacture a Group 5 metal nitride thin film, a reaction gas containing nitrogen can be supplied. For example, the reaction gas containing nitrogen may include one or more selected from ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), and nitrogen (N2). Such a reaction gas can react with a Group 5 metal compound in the thin film deposition process to form a Group 5 metal nitride thin film.

[0051] After the Group 5 metal precursor compound shown in Chemical Formula 1 is supplied onto the substrate, applying thermal energy, plasma, electrical bias, etc., causes the Group 5 metal precursor compound to undergo decomposition and condensation reactions, thereby forming a Group 5 metal-containing thin film.

[0052] Once a thin film of the desired thickness is formed, the process may include a step of purging the reaction chamber with an inert gas such as argon (Ar), nitrogen (N2), helium (He), and / or hydrogen (H2) to remove any unreacted Group 5 metal precursor compounds.

[0053] A Group 5 metal thin film produced by the thin film formation method according to one embodiment of the present invention can provide a high-quality thin film with an effectively reduced amount of residue. Furthermore, the thin film formation method according to one embodiment of the present invention can provide a Group 5 metal thin film with a constant thin film growth rate over a wide thin film growth temperature range and with more uniform physical properties, and allows for fine thickness control at a low thin film growth rate.

[0054] In the following, the Group 5 metal precursor compounds according to the present invention will be described in more detail through the following examples. However, these are presented only to aid in understanding the present invention, and the present invention is not limited to the following examples.

[0055] [Example 1] In a flame-dried 1000 mL Schlenk flask, 68.2 g (0.252 mol, 1 equivalent) of niobium tetrachloride (NbCl) and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 49.9 g (0.278 mol, 1.1 equivalents) of (EtMeCp)Si(Me) was added dropwise to the flask at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (EtMeCp)Nb(Cl)4 was obtained. Next, 55.4 g (0.757 mol, 3 equivalents) of tert-butylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 28.3 g of the red liquid compound.

[0056] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (tBuN)Nb(EtMeCp)(Cl)2, represented by formula 2a below, was confirmed by 1H NMR.

[0057] [ka]

[0058] [Example 2] In a flame-dried 1000 mL Schlenk flask, 68.2 g (0.252 mol, 1 equivalent) of niobium tetrachloride (NbCl) and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 353.8 g (0.278 mol, 1.1 equivalents) of (nPrMeCp)Si(Me) was added dropwise to the flask at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (nPrCp)Nb(Cl)4 was obtained. Next, 55.4 g (0.757 mol, 3 equivalents) of tert-butylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 24.3 g of the red liquid compound.

[0059] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (tBuN)Nb(nPrMeCp)(Cl)2, represented by the following chemical formula 3a, was confirmed by 1H NMR.

[0060] [ka]

[0061] [Example 3] In a flame-dried 1000 mL Schlenk flask, 68.2 g (0.252 mol, 1 equivalent) of niobium tetrachloride (NbCl) and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 353.8 g (0.278 mol, 1.1 equivalents) of (Et2Cp)Si(Me) was added dropwise to the flask at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (Et2Cp)Nb(Cl)4 was obtained. Next, 55.4 g (0.757 mol, 3 equivalents) of tert-butylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 21.5 g of the red liquid compound.

[0062] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (tBuN)Nb(Et2Cp)(Cl)2, represented by the following chemical formula 4, was confirmed by 1H NMR.

[0063] [ka]

[0064] [Example 4] In a flame-dried 1000 mL Schlenk flask, 590.3 g (0.252 mol, 1 equivalent) of tantalum tetrachloride (TaCl) and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 349.9 g (0.278 mol, 1.1 equivalents) of (EtMeCp)Si(Me) was added dropwise at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (EtMeCp)Nb(Cl)4 was obtained. Next, 55.4 g (0.757 mol, 3 equivalents) of tert-butylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 22.3 g of a bright yellow liquid compound.

[0065] Nuclear magnetic resonance analysis ( 1 The synthesis of the tantalum precursor compound (tBuN)Ta(EtMeCp)(Cl)2, represented by chemical formula 2b below, was confirmed by 1H NMR.

[0066] [ka]

[0067] [Comparative Example 1] In a flame-dried 2000 mL Schlenk flask, 565.0 g (0.241 mol, 1 equivalent) of niobium tetrachloride (NbCl) and 78.7 g (0.577 mol, 2.4 equivalents) of zinc chloride (ZnCl2) were mixed with 500 mL of toluene. Subsequently, 52.8 g (0.722 mol, 3 equivalents) of tert-butylamine was added dropwise at -20°C or below, and the mixture was stirred at room temperature for 4 hours. Then, 45.5 g (0.505 mol, 2.1 equivalents) of dimethoxyethane was added dropwise at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours.

[0068] Subsequently, 466 ml (0.746 mol, 3.1 equivalents) of a 1.6 M lithium dimethylamine solution dissolved in tetrahydrofuran was added dropwise to the flask at -20°C or below. The reaction solution was then stirred at room temperature for 12 hours. 17.5 g (0.265 mol, 1.1 equivalents) of cyclopentadiene was added dropwise at -20°C or below. The reaction solution was then stirred at room temperature for 12 hours. After filtering to separate the substances dissolved in the solvent, the mixture was distilled under reduced pressure to obtain 23.4 g of a yellow liquid compound.

[0069] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (tBuN)Nb(Cp)(DMA)2, represented by the following formula 5, was confirmed by 1H NMR.

[0070] [ka]

[0071] [Comparative Example 2] In a flame-dried 1000 mL Schlenk flask, 68.2 g (0.252 mol, 1 equivalent) of niobium tetrachloride (NbCl) 5 and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 49.9 g (0.278 mol, 1.1 equivalents) of (EtMeCp)Si(Me) 3 was added dropwise at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (EtMeCp)Nb(Cl) 4 was obtained. Subsequently, 66.0 g (0.757 mol, 3 equivalents) of tert-amylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 30.4 g of the red liquid compound.

[0072] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (t-AmylN)Nb(EtMeCp)(Cl)-2, represented by the following chemical formula 6, was confirmed by 1H NMR.

[0073] [ka]

[0074] [Comparative Example 3] In a flame-dried 1000 mL Schlenk flask, 68.2 g (0.252 mol, 1 equivalent) of niobium tetrachloride (NbCl) and 500 mL of dichloromethane were added and the mixture was stirred at room temperature. 49.9 g (0.278 mol, 1.1 equivalents) of (PrCp)Si(Me) was added dropwise to the flask at -20°C or below, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and a reddish-black solid compound represented by (PrCp)Nb(Cl)4 was obtained. Thereafter, 55.4 g (0.757 mol, 3 equivalents) of tert-butylamine was added, and the reaction solution was stirred at room temperature for 12 hours. Thereafter, the solvent was removed under reduced pressure, and 300 mL of nucleic acid (Hexane) was added, followed by stirring for 1 hour. Subsequently, the substance dissolved in hexane was filtered, and then distilled under reduced pressure to obtain 27.1 g of the red liquid compound.

[0075] Nuclear magnetic resonance analysis ( 1 The synthesis of the niobium precursor compound (tBuN)Nb(PrCp)(Cl)2, represented by the following chemical formula 7, was confirmed by 1H NMR.

[0076] [ka]

[0077] [Example of experiment] 1. Thermal stability evaluation To investigate the thermal stability of the compounds in Example 1 and Comparative Example 1, samples were prepared by adding 0.7 ml each of the compound from Example 1 to three high-pressure reactors, and 0.7 ml each of the compound from Comparative Example 1 to three high-pressure reactors. The samples from Example 1 and Comparative Example 1 were heated in furnaces heated to 170°C, 180°C, and 200°C for 1 hour, and then cooled to room temperature. Photographs of each sample after cooling to room temperature are shown in Figure 2.

[0078] Referring to Figure 2, in the case of the Group 5 metal precursor compound of Example 1, it can be confirmed that there was no color change at 170°C, but the color changed slightly at 180°C and 200°C. In contrast, in the case of the Group 5 metal precursor compound of Comparative Example 1, it can be confirmed that the color became darker at 170°C compared to room temperature, the color became even darker at 180°C, and at 200°C it changed to a very dark color that was almost black.

[0079] The Group 5 metal precursor of Example 1 contains an M-Cl bond, which has a higher bond energy than the MN bond contained in the Group 5 metal precursor of Comparative Example 1. Therefore, it can be concluded that the Group 5 metal precursor compound of Example 1 exhibits high thermal stability because it contains an M-Cl bond with a larger bond energy compared to the Group 5 metal precursor compound of Comparative Example 1.

[0080] 2.Thermogravimetric analysis Thermogravimetic analysis (TGA) was performed to investigate the thermal properties of the compounds in each of the above-mentioned Examples 1 to 4 and Comparative Examples 1 to 3. First, the thermogravimetic analysis equipment was stored in a nitrogen glove box where the moisture and oxygen content was maintained at less than 1 ppm. After placing a 10 mg sample in a crucible, measurements were taken while increasing the temperature from 35°C to 350°C at a rate of 10°C / min. The mass loss of the sample was monitored as a function of the crucible temperature. The results are shown in Table 1 and Figures 3 to 7.

[0081] Figure 3 is a graph showing the thermogravimetric analysis (TGA) results of the group 5 metal precursor compound according to Example 1, Figure 4 is a graph showing the thermogravimetric analysis (TGA) results of the group 5 metal precursor compound according to Comparative Example 1, Figure 5 is a graph showing the thermogravimetric analysis (TGA) results of the group 5 metal precursor compound according to Comparative Example 2, Figure 6 is a graph showing the thermogravimetric analysis (TGA) results of the group 5 metal precursor compound according to Comparative Example 3, and Figure 7 is a graph showing the thermogravimetric analysis (TGA) results of the group 5 metal precursor compound according to Example 4.

[0082] [Table 1]

[0083] [Table 1]

[0084] Referring to both Table 1 and Figures 3 to 7, it can be confirmed that the Group 5 metal compound precursors in Examples 1 to 4 have higher thermal decomposition temperatures compared to the Group 5 metal compound precursors in Comparative Examples 1 to 3. This indicates that the compounds in Examples 1 to 4 have superior thermal stability compared to the comparative examples. In particular, the compounds in Examples 1 to 3, which contain niobium metal, can be confirmed to have even greater thermal stability than Example 4, which contains tantalum metal. Furthermore, referring to Figures 3 to 7, it can be confirmed that the Group 5 metal precursor compounds produced by Examples 1, 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3 each have a residual content of less than approximately 4% by weight at temperatures above 350°C, and the residual content of the compounds in Examples 1 and 4 is less than that of the compounds in Comparative Examples 1 to 3. Additionally, looking at Figures 3 and 7, it can be confirmed that, when the type of ligand is the same, the compound in Example 1, which contains niobium metal, has superior thermal stability and even less residual content than the compound in Example 4, which contains tantalum metal. Furthermore, although the vapor pressure difference between the compound in Example 1 and the compound in Comparative Example 1 is not large, it can be confirmed that the thermal decomposition temperature of the compound in Example 1 is about 30°C higher than that of the compound in Comparative Example 1.

[0085] Furthermore, comparing the results of Example 1 and Comparative Example 2, it can be confirmed that in Chemical Formula 1, when R1 is a tert-butylamine group with 4 carbon atoms, the vapor pressure is higher and the thermal decomposition temperature is also higher than that of a compound to which a tert-amylamine group with 5 carbon atoms is attached.

[0086] Furthermore, although the compounds in Example 1 and Comparative Example 3 each have the same total number of carbon atoms in the substituents substituted on cyclopentadiene (4), it can be confirmed that when methyl and ethyl groups are asymmetrically bonded to cyclopentadiene, as in Example 1, the vapor pressure is higher and the thermal decomposition temperature is also higher compared to the compound with only a propyl group bonded, as in Comparative Example 3.

[0087] On the other hand, although the compounds in Example 1 and Example 3 have the same total number of carbon atoms (4), in Example 1, a methyl group and an ethyl group are asymmetrically bonded to cyclopentadiene, while in Example 3, two ethyl groups are bonded to cyclopentadiene. Comparing the results of Example 1 and Example 3, the thermal decomposition temperature of Example 3 is higher than that of Example 1, but it can be confirmed that Example 1 is even more advantageous in terms of process because it satisfies both the thermal decomposition temperature and vapor pressure simultaneously.

[0088] Furthermore, while the compounds in Example 1 and Example 3 are similar in that two substituents are asymmetrically bonded to cyclopentadiene, the compound in Example 1, which has a total of three carbon atoms in the substituents bonded to cyclopentadiene, can be found to be more advantageous in the process by simultaneously satisfying the thermal decomposition temperature and vapor pressure. In addition, the compound in Example 1, which has a total of three carbon atoms in the substituents bonded to cyclopentadiene, has a viscosity of 32.15 cP, while the compound in Example 2, which has a total of four carbon atoms in the substituents bonded to cyclopentadiene, has a higher viscosity of 84.33 cP. From this, it can be seen that the compound in Example 1, which has a total of three carbon atoms in the substituents bonded to cyclopentadiene and two substituents bonded to cyclopentadiene in an asymmetric structure, has a lower viscosity and is more advantageous during the vapor deposition process.

[0089] 3. Thin film deposition properties The growth rate of the thin films was analyzed during the atomic layer deposition process using the group 5 metal precursor compounds described in Example 1, Example 4, and Comparative Example 1. The results are shown in Figures 1 and 8.

[0090] First, Figure 1 is a graph showing the thin film growth rate (Growth Per Cycle, GPC) with respect to the deposition temperature during the atomic layer deposition process using the respective Group 5 metal precursor compounds for Example 1 and Comparative Example 1.

[0091] The deposition conditions involved filling canisters with the respective niobium precursor compounds from Example 1 and Comparative Example 1, heating them to 110°C, and using ozone (O3) as the oxidizing agent. A silicon wafer was used as the reaction substrate, and deposition was carried out by heating it from 250°C to 400°C. After introducing a pulse of the precursor for 10 seconds, argon (Ar) was purged for 10 seconds. Then, an ozone (O3) pulse was introduced into the reaction chamber for 15 seconds, followed by argon (Ar) purging for 10 seconds. This procedure was repeated for 80 to 100 cycles. Using this method, thin films of the same thickness of Group 5 metal oxides were formed for each precursor.

[0092] Referring to Figure 1, it can be confirmed that when using the Group 5 metal precursor compound according to Example 1 during the atomic layer deposition process, the thin film growth rate is lower compared to when using the Group 5 metal precursor compound of Comparative Example 1, and the thin film growth rate is maintained at a constant rate over a wide temperature range.

[0093] In the atomic layer deposition process, maintaining a constant thin film growth rate means that a thin film is formed stably without incidental reactions such as incomplete reactions, deposition in a precursor state without chemical reaction, or decomposition due to heat. In other words, Figure 1 shows that when using the group 5 metal precursor compound according to Example 1, a more stable thin film deposition process is possible compared to when using the group 5 metal precursor compound according to Comparative Example 1.

[0094] In particular, when using the group 5 metal precursor compound according to Example 1, it is observed that the thin film growth rate is almost constant within the deposition temperature range, and a group 5 metal thin film with superior physical properties and uniformity can be obtained. This can be attributed to the fact that the group 5 metal precursor compound of Example 1, represented by chemical formula 2a, contains an M-Cl bond and forms a more stable structure than the compound of Comparative Example 1, which contains an MN bond.

[0095] Figure 8 is a graph showing the thin film growth rate (GPC) as a function of deposition temperature during the atomic layer deposition process using the group 5 metal precursor compound according to Example 4. The deposition conditions in Example 4 involved filling a canister with the compound represented by chemical formula 2b, a Group 5 metal precursor compound, and heating it to 110°C, using ozone (O3) as the oxidizing agent. A silicon wafer was used as the reaction substrate, and deposition was carried out by heating it from 300°C to 550°C. After introducing a pulse of the precursor for 3 seconds, argon (Ar) was purged for 15 seconds. Then, after introducing a pulse of ozone (O3) into the reaction chamber for 3 seconds, argon (Ar) was purged for 15 seconds. This method was carried out for 100 cycles.

[0096] Referring to Figure 8, it can be confirmed that when the atomic layer deposition process is carried out using the precursor compound represented by chemical formula 2b in Example 4, the growth rate of the thin film is maintained at a constant rate over a very wide temperature range. In particular, compared to the compound of Comparative Example 1 shown in Figure 1, it can be confirmed that the growth rate of the thin film is relatively low and constant even above 500°C.

[0097] Therefore, it can be seen that when using the precursor compound represented by chemical formula 2b in Example 4, a nearly constant thin film growth rate is observed within the deposition temperature range, and a more uniform Group 5 metal thin film with superior physical properties can be obtained. This can be attributed to the fact that the Group 5 metal precursor compound of Example 4, represented by chemical formula 2b, contains an M-Cl bond and forms a stable structure.

[0098] The various embodiments of the present invention, including the Group 5 metal precursor compound, the Group 5 metal-containing thin film deposition precursor composition, and the method for forming the Group 5 metal-containing thin film, can be described as follows. A Group 5 metal-containing precursor compound according to one embodiment of the present invention is represented by the following chemical formula 1.

[0099] [ka]

[0100] In Chemical Formula 1, M is one of the Group 5 metallic elements selected from niobium (Nb), tantalum (Ta), and vanadium (V); R1 is selected from linear alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms; R2 and R3 are each independently selected from linear alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms; and X is each independently a halogen element.

[0101] According to another feature of the present invention, in Chemical Formula 1, R1 may be a branched alkyl group having 3 to 4 carbon atoms, and R2 and R3 may each be a linear alkyl group having 1 to 6 carbon atoms. According to another feature of the present invention, R2 and R3 may be different from each other.

[0102] According to another feature of the present invention, the sum of the number of carbon atoms in R2 and R3 may be 3 or less. According to another feature of the present invention, the Group 5 metal precursor compound can be selected from the compounds represented by the following chemical formulas 2, 3, and 4.

[0103] [ka]

[0104] In chemical formulas 2, 3, and 4, M may be independently selected from among the Group 5 metallic elements niobium (Nb), tantalum (Ta), and vanadium (V). According to another feature of the present invention, the group 5 metal precursor compound may be liquid at room temperature.

[0105] A precursor composition for thin film deposition containing a group 5 metal according to one embodiment of the present invention comprises a group 5 metal precursor compound represented by Chemical Formula 1. One embodiment of the present invention provides a method for forming a Group 5 metal-containing thin film, which involves depositing a thin film onto a substrate using a Group 5 metal precursor compound represented by Chemical Formula 1 through a Metal Organic Chemical Vapor Deposition (MOCVD) process or an Atomic Layer Deposition (ALD) process.

[0106] According to another feature of the present invention, the deposition process can be carried out in a temperature range of 50 to 700°C. According to another feature of the present invention, the deposition process may include a step of transferring the group 5 metal precursor compound to the substrate through one method selected from a bubbling method, a vapor phase mass flow controller (MFC) method, a direct gas injection (DGI) method, a direct liquid injection (DLI) method, and an organic solution supply method in which the group 5 metal precursor compound is dissolved in an organic solvent and then transferred.

[0107] According to another feature of the present invention, the group 5 metal precursor compound is moved onto the substrate together with a transport gas by the bubbling method or the direct gas injection method, and the transport gas may include one or more selected from argon (Ar), nitrogen (N2), helium (He), and hydrogen (H2).

[0108] According to another feature of the present invention, the deposition process may include the step of supplying one or more reaction gases selected from water vapor (H2O), oxygen (O2), ozone (O3), and hydrogen peroxide (H2O2) when forming a group 5 metal-containing thin film.

[0109] According to another feature of the present invention, the deposition process may include the step of supplying one or more reaction gases selected from ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), and nitrogen (N2) when forming a group 5 metal-containing thin film.

[0110] Although the present invention has been described in detail above through examples, the present invention is not necessarily limited to these examples and can be modified and implemented in various ways within the scope of the technical concept of the present invention. Accordingly, the examples disclosed herein are for illustrative purposes only, not to limit the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such examples. Therefore, the examples described above should be understood to be illustrative and non-limiting in all respects. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within an equivalent scope should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. A group 5 metal precursor compound represented by the following chemical formula 1. 【Chemistry 1】 In the above formula 1, M is one of the Group 5 metallic elements selected from niobium (Nb), tantalum (Ta), and vanadium (V). R １ It is selected from linear alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms. R ２ and R ３ Each of these is independently selected from linear alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms. Each of the elements X is a halogen element, independently of the others.

2. In the above formula 1, R １ R is a branched alkyl group having 3 to 4 carbon atoms. ２ and R ３ The group 5 metal precursor compound according to claim 1, wherein each of them is a linear alkyl group having 1 to 6 carbon atoms.

3. R ２ and R ３ The group 5 metal precursor compounds described in claim 1 are different from each other.

4. The aforementioned R ２ and the sum of the number of carbon atoms of R ３ is 3 or less. The Group 5 metal precursor compound according to claim 1.

5. The group 5 metal precursor compound according to claim 1, wherein the group 5 metal precursor compound is selected from the compounds represented by the following chemical formulas 2, 3, and 4. 【Chemistry 2】 (In the above formulas 2, 3, and 4, M is independently selected from among the Group 5 metallic elements niobium (Nb), tantalum (Ta), and vanadium (V).)

6. The group 5 metal precursor compound according to claim 1, wherein the group 5 metal precursor compound is a liquid at room temperature.

7. A precursor composition for thin film deposition containing a group 5 metal, comprising a group 5 metal precursor compound according to any one of claims 1 to 6.

8. A method for forming a Group 5 metal-containing thin film, comprising depositing a thin film onto a substrate through a Metal Organic Chemical Vapor Deposition (MOCVD) step or an Atomic Layer Deposition (ALD) step using a Group 5 metal precursor compound according to any one of claims 1 to 6.

9. The method for forming a group 5 metal-containing thin film according to claim 8, wherein the deposition step is carried out in a temperature range of 50 to 700°C.

10. The method for forming a Group 5 metal-containing thin film according to claim 8, wherein the deposition step includes transferring the Group 5 metal precursor compound to the substrate through one method selected from a bubbling method, a vapor phase mass flow controller (MFC) method, a direct gas injection (DGI) method, a direct liquid injection (DLI) method, and an organic solution supply method in which the Group 5 metal precursor compound is dissolved in an organic solvent and then transferred.

11. The group 5 metal precursor compound is moved onto the substrate together with the transport gas by the bubbling method or the direct gas injection method. The transport gas is argon (Ar), nitrogen (N ２ ), helium (He) and hydrogen (H ２ A method for forming a Group 5 metal-containing thin film according to claim 10, comprising one or more selected from the following.

12. The aforementioned deposition process involves the formation of the Group 5 metal-containing thin film using water vapor (H ２ O), oxygen (O ２ ), ozone (O ３ ) and hydrogen peroxide (H ２ O ２ A method for forming a Group 5 metal-containing thin film according to claim 8, comprising the step of supplying one or more reaction gases selected from among the following.

13. The aforementioned deposition process involves the formation of the Group 5 metal-containing thin film, during which ammonia (NH ３ ), hydrazine (N ２ H ４ ), nitrous oxide ( ２ O) and nitrogen (N) ２ A method for forming a Group 5 metal-containing thin film according to claim 8, comprising the step of supplying one or more reaction gases selected from among the following.

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