A method for preparing an organic amine-based tantalum / niobium precursor

Abstract

This invention belongs to the field of transition metal organometallic compound synthesis technology, specifically relating to a method for preparing an organic amine-based tantalum / niobium precursor. The structure of the organic amine-based tantalum / niobium precursor is represented as M(NR) 1 R 2 5. The method involves reacting a metal halide MCl5, a solvent, and a dialkylamine HNR under a protective atmosphere and at a low temperature where no reaction occurs. 1 R 2 The mixture was prepared by mixing and kept at a low, non-reactive temperature. A solution of n-butyllithium was added dropwise to the mixture. After the addition was complete, the temperature was raised to the reaction temperature T2, and the mixture was stirred. After the reaction was complete, the mixture was filtered and purified to obtain the desired organic amine-based tantalum / niobium precursor. This application provides a novel one-pot synthesis method for M(NR) 1 R 2 The method described in section 5 is characterized by mild reaction throughout, simple operation, high stability, and improved product yield. It is suitable for industrial scale-up and has excellent prospects for widespread application.

Description

Technical Field

[0001] This invention belongs to the field of transition metal organometallic compound synthesis technology, specifically relating to a method for preparing an organic amine-based tantalum / niobium precursor. Background Technology

[0002] As semiconductor integrated circuit technology continues to evolve towards nanometer nodes and device feature sizes continue to shrink, increasingly stringent requirements are being placed on the performance of thin film materials. Among numerous thin film materials, tantalum (Ta) and niobium (Nb) films, such as tantalum nitride (TaN), niobium nitride (NbN), tantalum oxide (Ta2O5), and niobium oxide (Nb2O5), play a crucial role in modern semiconductor manufacturing due to their excellent physicochemical properties. For example, TaN and NbN films, as diffusion barrier layers for copper interconnects, can effectively suppress the diffusion of copper atoms into silicon substrates and low-dielectric-constant dielectric layers, significantly improving device reliability and lifespan. Ta2O5 and Nb2O5 films possess high dielectric constants and low leakage current characteristics, making them suitable for high-density capacitor dielectric layers in dynamic random access memory (DRAM) and high-dielectric-constant (High-k) gate dielectric layers in logic devices. These applications also require films with extremely high density, good step coverage, low resistivity, and excellent thermal stability.

[0003] Currently, the mainstream manufacturing processes for high-quality tantalum / niobium thin films are chemical vapor deposition (CVD) and atomic layer deposition (ALD). Both processes require the use of metal-organic precursors with high volatility, high thermal stability, and controllable reactivity. The general formula is M(NR... 1 R 2 )5 (M is Ta or Nb, R 1 R 2 Five-coordinate organic amide precursors (alkyl groups) are considered ideal CVD / ALD precursor materials because they are halogen-free, highly volatile, and easily decomposed during deposition.

[0004] However, the preparation methods of organic amine-based tantalum / niobium precursors still face many challenges, which restrict their large-scale industrial application and the improvement of thin film performance.

[0005] Taking pentamethylaminotantalum (PDMAT) as an example, the currently disclosed synthesis methods include the following: The first is the lithium salt method (Patrick N. Riley et al., Organometallics 1999, 18, 3579-3583), which involves replacing Cl in TaCl5 with dimethylaminolithium (LiNMe2). -The first method, which generates the target product, requires only one step but is highly exothermic, difficult to control, prone to side reactions, and difficult to remove impurities, resulting in limited yield and difficulty in scaling up production. The second method, as seen in patent CN116854727A, uses (Me)3SiNMe2 instead of LiNMe2, making the reaction process milder. However, the preparation cost of (Me)3SiNMe2 is high, and the byproduct TMSCl is hazardous to handle, generating large amounts of hydrochloric acid, significantly increasing the cost of raw material and waste treatment, which is detrimental to market competitiveness and industrialization. The third method, as seen in patent CN114957014A, employs a two-step process, first using dimethylamine (HNMe2) to replace part of the Cl in tantalum pentachloride (TaCl5). - Then, Cl is completely replaced by dimethylaminolithium (LiNMe2). - The first method, described in patent CN120098029A, involves the reaction of tantalum pentachloride (TaCl5) and dimethylamine (HNMe2) to form an intermediate, followed by a trialkylamine complexation reaction to obtain the product. While this method is mild, it requires half the time to be controlled at extremely low temperatures (<-20℃) and a slow dropping rate, resulting in a low yield (<50%), which is also unfavorable for market competitiveness and industrialization. The fifth method, described in patent CN106916072A, involves the reaction of tantalum pentachloride (TaCl5) and dimethylamine (HNMe2) to form an intermediate, followed by complete amination with n-butyllithium (n-BuLi) to obtain the product. However, this method has extremely high requirements for the amount and control of n-BuLi, and is difficult to scale up for production.

[0006] In summary, existing methods for synthesizing organic amine-based tantalum / niobium precursors generally suffer from problems such as low yield, unstable reaction process, low product purity, and high purification difficulty.

[0007] It is essential to develop a high-yield and simple method for synthesizing organic amine-based tantalum / niobium precursors. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects in the prior art, such as difficulty in scaling up products, low synthesis yield, difficulty in purification, and difficulty in removing specific impurities.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for preparing an organic amine-based tantalum / niobium precursor, wherein the structure of the organic amine-based tantalum / niobium precursor is represented as: M(NR 1 R 2 )5, where M is Ta or Nb, R 1and R 2 Independently selected from C1-C4 alkyl or R 1 and R 2 The process of linking carbon atoms to form a ring with 2-5 carbon atoms includes the following steps: S1. Under a protective atmosphere, metal halide MX5 is dispersed in a solvent, cooled to temperature T1, and then dialkylamine HNR is added. 1 R 2 Stir until homogeneous to obtain a mixture; X in the metal halide MX5 is any one of Cl, Br, and I, and T1 is to ensure the consistency of MX5 and HNR. 1 R 2 The temperature at which mixing occurs without any reaction; S2. Add a predetermined amount of n-butyllithium solution dropwise to the mixed solution. After the addition is complete, raise the temperature to T2 and stir the reaction. T2 is the temperature at which the reaction proceeds completely and the product does not decompose. S3. After the reaction is complete, filter the solution and purify the filtrate to obtain the desired organic amine-based tantalum / niobium precursor M(NR). 1 R 2 5.

[0010] The reaction mechanism of this preparation method is as follows: In step S1, the metal halide and dialkylamine are mixed, and the coexistence temperature of the two is strictly controlled to ensure that they do not react. That is, the dialkylamine does not substitute any amount of halogen atoms in the metal halide. Theoretically, the two are only mixed, or form a complex intermediate through weak intermolecular interactions. The dialkylamine promotes the dissolution of the metal halide. After adding n-butyllithium in step S2, the highly active n-butyllithium will rapidly react with the dialkylamine in situ to form a dialkylamino lithium salt. The dialkylamino lithium salt will directly react with the metal halide to generate the precursor. The molecular migration path in the reaction is shorter, and the activation energy required to overcome is also lower. This method, by changing the order of material addition and strictly controlling the temperature under a specific program, allows the reaction to proceed slowly and gradually through liquid-liquid, liquid-solid, and solid-solid reactions. The liquid-liquid and liquid-solid reactions occupy most of the reaction stages, while the solid-solid reaction only exists at the end of the reaction. This effectively increases the degree of reaction and improves the reaction yield. At the same time, it was found that the above reaction path can also avoid the generation of difficult-to-remove impurities that exist only in a single solid-solid reaction, simplifying the purification operation and significantly improving purification efficiency and product purity.

[0011] Preferably, the MX5 and HNR 1 R 2 The equivalent ratio is 1:(6~10).

[0012] Preferably, T1 is -90℃ to -35℃, more preferably -50℃ to -35℃; optional values ​​include -80℃±2℃, -75℃±2℃, -70℃±2℃, -65℃±2℃, -60℃±2℃, -55℃±2℃, -50℃±2℃, -45℃±2℃, -40℃±2℃, -37℃±2℃, etc.

[0013] Preferably, the HNR 1 R 2 The equivalence ratio of lithium to n-butyllithium is (1~3):1, more preferably (1~2):1, and can be 1:1, 1.2:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.2:1, 2.5:1, 2.7:1, 3:1, etc.

[0014] Preferably, T2 is 40℃~80℃, more preferably 45℃~70℃, and even more preferably 45℃~65℃; optional values ​​include 45℃, 50℃, 52℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, etc.

[0015] Preferably, in step S2, the stirring reaction time is at least 4 hours, and more preferably at least 8 hours.

[0016] Preferably, in step S1, the solvent is a polar solvent and / or a non-polar solvent, including but not limited to any one or a combination of methanol, ethanol, isopropanol, acetic acid, pyridine, dichloromethane, chloroform, tetrahydrofuran, 2-methyltetrahydrofuran, benzene, toluene, acetonitrile, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, petroleum ether, and ethyl acetate.

[0017] More preferably, the solvent is any one or a combination of several of the following: dichloromethane, tetrahydrofuran, benzene, toluene, acetonitrile, diethyl ether, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether.

[0018] Preferably, the solvent in the n-butyllithium solution is a polar solvent and / or a non-polar solvent, including but not limited to any one or a combination of several of n-hexane, n-pentane, dichloromethane, tetrahydrofuran, toluene, xylene, trimethylbenzene, acetonitrile, diethyl ether, ethylene glycol dimethyl ether, and methyl tert-butyl ether.

[0019] Preferably, the purification method includes any one or a combination of several of adsorption, distillation, recrystallization, and sublimation; more preferably, the purification method is distillation and recrystallization.

[0020] Preferably, the organic amine-based tantalum / niobium precursor M(NR) 1 R2 )5 is Ta[N(Me)2]5, Ta[N(Me)(Et)]5, Ta[N(Me)(n-Pr)]5, Ta[N(Me)(i-Pr)]5, Ta[N(Et)2]5, Ta[N(Et)(n-Pr)]5, T a[N(Et)(i-Pr)]5, Ta[N(n-Pr)2]5, Ta[N(i-Pr)2]5, Nb[N(Me)2]5, Nb[N(Me)(Et)]5, Nb[N(Me)(n-Pr)]5, Nb[N(M Any one of the following: [e)(i-Pr)]5, Nb[N(Et)2]5, Nb[N(Et)(n-Pr)]5, Nb[N(Et)(i-Pr)]5, Nb[N(n-Pr)2]5, Nb[N(i-Pr)2]5, Ta[N(CH2)2]5, Ta[N(CH2)4]5, Ta[N(CH2)5]5, Nb[N(CH2)2]5, Nb[N(CH2)4]5, Nb[N(CH2)5]5, where n represents alkyl normal and i represents alkyl isomer.

[0021] In the formula, Me is methyl, Et is ethyl, Pr is propyl, n-Pr is n-propyl, and i-Pr is isopropyl.

[0022] Preferred, R 1 and R 2 The organic amine tantalum / niobium precursor M(NR) is independently selected from C1-C3 alkyl groups. 1 R 2 )5 is Ta[N(Me)2]5, Ta[N(Me)(Et)]5, Ta[N(Me)(n-Pr)]5, Ta[N(Me)(i-Pr)]5, Ta[N( Et)2]5, Ta[N(Et)(n-Pr)]5, Ta[N(Et)(i-Pr)]5, Ta[N(n-Pr)2]5, Ta[N(i-Pr)2]5, N b[N(Me)2]5, Nb[N(Me)(Et)]5, Nb[N(Me)(n-Pr)]5, Nb[N(Me)(i-Pr)]5, Nb[N(Et)2] 5. Any one of Nb[N(Et)(n-Pr)]5, Nb[N(Et)(i-Pr)]5, Nb[N(n-Pr)2]5, Nb[N(i-Pr)2]5.

[0023] Preferred, R 1 and R 2 The organic amine-based tantalum / niobium precursor M(NR) forms a three-membered ring with two carbon atoms. 1 R 2 )5 is either Ta[N(CH2)2]5 or Nb[N(CH2)2]5.

[0024] The beneficial effects of this invention are as follows: (1) Compared with the traditional solid-solid reaction, this invention provides a novel organic amine-based tantalum / niobium precursor M(NR) 1 R 2 5. Synthesis method, which first involves reacting metal halide MX5 with HNR at a non-reactive low temperature. 1 R 2 The two are mixed as a complex intermediate (MX5·x HNR) 1 R 2 It exists in the form of ), thus promoting the dissolution of MX5. After the addition of n-butyllithium, it rapidly reacts with HNR. 1 R 2 Dialkylamine lithium is generated in situ, and the newly formed dialkylamine lithium immediately undergoes an amination substitution reaction with MX5 to generate the target product. The above reaction pathway proceeds step by step through liquid-liquid reaction, liquid-solid reaction, and solid-solid reaction. Among them, liquid-liquid reaction and liquid-solid reaction account for most of the reaction stages, while solid-solid reaction only exists in the final stage of the reaction. This effectively improves the degree of reaction progress, enabling the yield of large-scale reaction to be increased to 80% or even more than 85%, which exceeds the level of existing technology by 15-20%.

[0025] (2) The method of the present invention is mild throughout the reaction process, does not involve intermediate reaction filtering or other operations, is simple to operate, has high stability, improves product yield, and is suitable for industrial scale-up.

[0026] (3) In the reaction pathway of the method of the present invention, not only are the resulting byproduct solid salt particles larger and easier to filter and remove, but also the generation of difficult-to-remove impurities that exist only in a single solid-solid reaction (these impurities) are avoided. 1 The H NMR shift is around 3.35-3.25 ppm, which simplifies the purification process, significantly improves purification efficiency and product purity, reduces purification costs, and effectively enhances product profitability.

[0027] (4) This method is applicable to M(NR) 1 R 2 The preparation of various organic amine-based tantalum / niobium structures with 5-structures has strong process compatibility and can bring high industrial application value. Attached Figure Description

[0028] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the PDMAT product prepared in Example 1.

[0029] Figure 2 The 1H NMR spectrum of the PDMAT product prepared for Comparative Example 1. Detailed Implementation

[0030] Unless otherwise stated, the terms used herein have the meanings commonly understood by those skilled in the art. Unless otherwise specified, all experimental materials and reagents used in the experiments are commercially available. For experiments where specific techniques or conditions are not specified, the procedures described in the literature in this field or the product instructions should be followed.

[0031] The technical solution of the present invention will be described in more detail below with reference to the embodiments.

[0032] Example 1 An organic amine-based tantalum / niobium precursor, specifically pentapentanyl(dimethylamino)tantalum precursor (PDMAT), with the chemical formula Ta[N(Me)2]5, is prepared as follows: S1. Under nitrogen protection, TaCl5 (2000 g) and toluene (18 L) were mixed and cooled to -35°C. Dimethylamine (1700 g) was added dropwise and stirred until homogeneous to obtain a mixture. S2. Keep the temperature of the mixed solution at -35℃, add n-butyllithium in n-hexane (2.5M, 11.7L) solution dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 55℃ and stir the reaction for 8 h; After 3.8 h, the filtrate was filtered, and the solvent and low-boiling impurities were removed by de-evaporation. The crude PDMAT was then recrystallized from n-hexane to obtain the desired PDMAT product (1945 g), with a yield of 86.8%.

[0033] The 1H NMR spectrum of the prepared PDMAT product is shown in Figure 1. The peak area of ​​the impurity peak accounts for 9.85%, while the peak area of ​​the product peak accounts for 90.15%. The prepared product has low impurity content and high purity. 1 H NMR (400 MHz, C6D6): δ 3.30 (s,30H).

[0034] Example 2 An organic amine-based tantalum / niobium precursor, specifically penta(dimethylamino)tantalum precursor (PDMAT), with the chemical formula Ta[N(Me)2]5, is prepared as follows: S1. Under nitrogen protection, TaCl5 (2000 g) and n-hexane (18 L) were mixed and cooled to -40℃, and dimethylamine (2011 g) was added dropwise. The mixture was stirred until homogeneous to obtain a solution. S2. Keep the temperature of the mixed solution at -40℃, add n-butyllithium in n-hexane (2.5M, 11.7L) solution dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 45℃ and stir the reaction for 8 h; S3. After the reaction is complete, the filtrate is filtered, and the solvent and low-boiling impurities are removed by de-evaporation. The crude PDMAT is then recrystallized from n-hexane to obtain the desired product (1802 g), with a yield of 80.4%.

[0035] Example 3 An organic amine-based tantalum / niobium precursor, specifically penta(dimethylamino)tantalum precursor (PDMAT), with the chemical formula Ta[N(Me)2]5, is prepared as follows: S1. Under nitrogen protection, TaCl5 (2000 g) and ethylene glycol dimethyl ether (17 L) were mixed and cooled to -60℃, and dimethylamine (2262 g) was added dropwise. The mixture was stirred until homogeneous to obtain a solution. S2. Adjust and maintain the temperature of the mixed solution at -40℃, add n-butyllithium in n-hexane (2.5M, 11.7 L) solution dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 55℃ and stir the reaction for 8 h; S3. After the reaction is complete, the filtrate is filtered, and the solvent and low-boiling impurities are removed by de-evaporation. The crude PDMAT is then recrystallized from n-hexane to obtain the desired product (1850 g), with a yield of 82.6%.

[0036] Example 4 An organic amine-based tantalum / niobium precursor, specifically a penta(methylethylamino)tantalum precursor with the chemical formula Ta[N(Me)(Et)]5, is prepared as follows: S1. Under nitrogen protection, TaCl5 (2000 g) and toluene (18 L) were mixed and cooled to -50℃, and methyl ethylamine (2142 g) was added dropwise. The mixture was stirred until homogeneous to obtain a solution. S2. Keep the temperature of the mixed solution at -45℃, add n-butyllithium in n-hexane (2.5M, 11.7L) solution dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 70℃ and stir the reaction for 8 h; S3. After the reaction is complete, the filtrate is filtered, and the solvent and low-boiling impurities are removed by de-evaporation. Then, the crude Ta[N(Me)(Et)]5 is recrystallized from n-hexane to obtain the desired product (1723 g), with a yield of 76.9%.

[0037] Example 5 An organic amine-based tantalum / niobium precursor, specifically a penta(dimethylamino)niobium precursor with the chemical formula Nb[N(Me)2]5, is prepared as follows: S1. Under nitrogen protection, NbCl5 (500 g) and toluene (5 L) were mixed and cooled to -65°C. Dimethylamine (542 g) was added dropwise and stirred until homogeneous to obtain a mixture. S2. Keep the temperature of the mixed solution at -45℃, add n-butyllithium in n-hexane (2.5M, 3.7L) dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 40℃ and stir the reaction for 8 h; S3. After the reaction is complete, the filtrate is filtered, and the solvent and low-boiling impurities are removed by de-evaporation. Then, the crude Nb[N(Me)2]5 is recrystallized from n-hexane to obtain the desired product (493 g), with a yield of 85.1%.

[0038] Comparative Example 1 A method for preparing a penta(dimethylamino)tantalum precursor (PDMAT) is consistent with the conditions in Example 1, except that the reaction temperature in step S2 is set to -10°C, i.e., a solution of n-butyllithium in n-hexane is added dropwise at a mixed solution temperature of -10°C.

[0039] The final recrystallization yielded 1450 g of penta(dimethylamino)tantalum product, with a yield of 64.7%.

[0040] The 1H NMR spectrum of the prepared PDMAT product is shown in the figure. Figure 2 Among them, the peak area of ​​impurity peaks accounted for 19.09%, while the peak area of ​​product peaks accounted for 80.91%. Compared with the results of PDMAT product prepared in Example 1, there were more impurities. This is because at -10°C, the mixed solution had already partially reacted, producing a solid phase, which not only led to a decrease in yield but also affected the generation of impurities.

[0041] Comparative Example 2 A method for preparing a penta(dimethylamino)tantalum precursor (PDMAT) is consistent with the conditions in Example 1, except that the reaction temperature in step S2 is set to -30°C, i.e., a solution of n-butyllithium in n-hexane is added dropwise at a mixed solution temperature of -30°C.

[0042] The final recrystallization yielded 1569 g of penta(dimethylamino)tantalum product, with a yield of 70.0%.

[0043] Comparative Example 3 A method for preparing a penta(dimethylamino)tantalum precursor (PDMAT): S1. Under nitrogen protection, TaCl5 (2000 g) and toluene (18 L) were mixed and cooled to -25°C. Dimethylamine (1700 g) was added dropwise and stirred. At this temperature, TaCl5 and toluene reacted, so the resulting mixed solution was a turbid liquid containing solids. S2. Keep the temperature of the turbid liquid at -25℃, add n-butyllithium in n-hexane (2.5M, 11.7L) solution dropwise to the mixed solution, and after the addition is complete, raise the temperature of the system to 65℃ and stir the reaction for 8 h; After 3.8 h, the solution was filtered. Due to the large amount of solids in the system, the filtration operation was difficult. The filtrate was distilled to remove low-boiling substances and then recrystallized to obtain penta(dimethylamino)tantalum product (1376 g), with a yield of 61.4%.

[0044] Comparative Example 4 A method for preparing a penta(dimethylamino)tantalum precursor (PDMAT) is consistent with the conditions in Example 1, except that the amount of dimethylamine added in step S1 is 1307 g.

[0045] The final recrystallization yielded 1300 g of penta(dimethylamino)tantalum product, with a yield of 58.0%.

[0046] In Comparative Example 4, the amount of dimethylamine used was too low, which not only reduced the utilization rate of raw materials, but also failed to fully promote the dissolution of TaCl5, thus resulting in a low yield.

[0047] Through extensive large-scale synthesis practice, the inventors discovered two key factors hindering large-scale synthesis and product efficiency in the traditional synthetic route (i.e., first reacting dialkylamines and n-butyllithium to prepare dialkylamine lithium salts, then adding metal halide salts to prepare alkylamine metal precursors). First, both dialkylamine lithium salts and metal halide salts are in suspension in conventional reaction solvents (such as n-hexane and toluene), making a solution-like state impossible. The reaction involves a solid-solid reaction, which, according to reaction kinetics, lacks freely moving particles; the reaction occurs only at the interface, requiring a high activation energy to detach from the reaction surface. Therefore, the yield of this large-scale synthesis is very low. Second, the solid-solid reaction generates a specific impurity (its ¹H NMR shift is around 3.35–3.25 ppm, as shown in the attached image). Figure 2 As shown in the 1H NMR spectrum, it is difficult to remove in subsequent purification processes, reducing purification efficiency, process efficiency, and product benefits.

[0048] This application creatively combines metal halide MX5 with HNR 1 R 2 First, the mixture is mixed at a temperature where no reaction occurs to fully promote the solubility of metal halides. Then, an in-situ reaction is carried out, allowing the reaction to proceed slowly and gradually through liquid-liquid, liquid-solid, and solid-solid reactions. The liquid-liquid and liquid-solid reactions account for the majority of the reaction stages, while the solid-solid reaction only exists at the end of the reaction. This effectively increases the degree of reaction and improves the reaction yield. This method also avoids the generation of difficult-to-remove impurities that exist only in a single solid-solid reaction, resulting in a product with fewer impurities and higher purity. It avoids complex purification operations, significantly improving purification efficiency and product purity. This method is suitable for industrial-scale production and has a promising prospect for widespread application.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an organic amine-based tantalum / niobium precursor, wherein the structure of the organic amine-based tantalum / niobium precursor is represented as: M(NR 1 R 2 )5, where M is Ta or Nb, R 1 and R 2 Independently selected from C1-C4 alkyl or R 1 and R 2 They are linked together to form a ring with 2-5 carbon atoms, characterized in that... Includes the following steps: S1. Under a protective atmosphere, metal halide MX5 is dispersed in a solvent, cooled to temperature T1, and then dialkylamine HNR is added. 1 R 2 Stir until homogeneous to obtain a mixture; X in the metal halide MX5 is any one of Cl, Br, and I, and MX5 and HNR 1 R 2 The equivalent ratio is 1:(6~10); T1 is to ensure MX5 and HNR 1 R 2 The temperature at which mixing occurs without reaction, T1, is -90℃ to -35℃. S2. Add a predetermined amount of n-butyllithium solution dropwise to the mixed solution. After the addition is complete, raise the temperature to T2 and stir the reaction. T2 is the temperature at which the reaction proceeds completely and the product does not decompose. T2 is 40℃~80℃. S3. After the reaction is complete, filter the solution and purify the filtrate to obtain the desired organic amine-based tantalum / niobium precursor M(NR). 1 R 2 5.

2. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, The HNR 1 R 2 The equivalence ratio of lithium to n-butyllithium is (1~3):

1.

3. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, In step S2, the stirring reaction time is at least 4 hours.

4. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, In step S1, the solvent is a polar solvent and / or a non-polar solvent, including any one or a combination of several of methanol, ethanol, isopropanol, acetic acid, pyridine, dichloromethane, chloroform, tetrahydrofuran, 2-methyltetrahydrofuran, benzene, toluene, acetonitrile, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, methyl tert-butyl ether, petroleum ether, and ethyl acetate.

5. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, The solvent in the n-butyllithium solution is a polar solvent and / or a non-polar solvent, including any one or a combination of several of the following: n-hexane, n-pentane, dichloromethane, tetrahydrofuran, toluene, xylene, trimethylbenzene, acetonitrile, diethyl ether, ethylene glycol dimethyl ether, and methyl tert-butyl ether.

6. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, The purification method includes any one or a combination of several of the following: adsorption, distillation, recrystallization, and sublimation.

7. The method for preparing an organic amine-based tantalum / niobium precursor as described in claim 1, characterized in that, The organic amine-based tantalum / niobium precursor M(NR) 1 R 2 )5 is Ta[N(Me)2]5, Ta[N(Me)(Et)]5, Ta[N(Me)(n-Pr)]5, Ta[N(Me)(i-Pr)]5, Ta[N(Et)2]5, Ta[N(Et)(n-Pr)]5, T a[N(Et)(i-Pr)]5, Ta[N(n-Pr)2]5, Ta[N(i-Pr)2]5, Nb[N(Me)2]5, Nb[N(Me)(Et)]5, Nb[N(Me)(n-Pr)]5, Nb[N(M Any one of the following: [e)(i-Pr)]5, Nb[N(Et)2]5, Nb[N(Et)(n-Pr)]5, Nb[N(Et)(i-Pr)]5, Nb[N(n-Pr)2]5, Nb[N(i-Pr)2]5, Ta[N(CH2)2]5, Ta[N(CH2)4]5, Ta[N(CH2)5]5, Nb[N(CH2)2]5, Nb[N(CH2)4]5, Nb[N(CH2)5]5, where n represents alkyl normal and i represents alkyl isomer.

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