Synthesis method of high-purity metal complex precursor

Abstract

The invention belongs to the field of electronic materials, and particularly relates to a synthesis method of a high-purity metal complex precursor. Compared with a synthesis method in the prior art, the synthesis method provided by the invention changes a reaction route, substituted cyclopentadiene is prepared firstly, then the substituted cyclopentadiene reacts with butyl lithium and metal chloride in sequence to obtain a substituted cyclopentadienyl metal trichloride intermediate, and finally the substituted cyclopentadienyl metal trichloride intermediate reacts with lithium dialkylamino to obtain the substituted cyclopentadienyl metal trichloride. The target product substituted cyclopentadienyl tri (dialkylamino) metal complex is obtained, and the prepared product is high in yield and purity. The synthesis method provided by the invention is convenient for large-scale production in factories, improves the productivity, and meets the ever-increasing market demand.

Description

Technical Field

[0001] The invention belongs to the field of electronic materials, and in particular relates to a method for synthesizing a high-purity metal complex precursor. Background Art

[0002] In the field of ultra-large-scale integrated circuits (ULSI), the application of high dielectric constant materials (High-K) is crucial. As the size of devices continues to shrink, the planar structure area A decreases accordingly. In order to maintain sufficient capacitance, high dielectric constant materials must be used. Common high dielectric constant materials include oxides of hafnium (Hf), zirconium (Zr), tantalum (Ta), titanium (Ti), and yttrium (Y). In addition, new materials such as titanates doped with alkaline earth metal materials, such as barium strontium titanate (BST) and barium zirconate titanate (BZT), have also attracted much attention. These materials are usually deposited by atomic layer deposition (ALD) or chemical vapor deposition (CVD) technology using precursor materials of elements such as Hf, Zr, Ta, Ti, and Y. Therefore, high-quality precursor materials are the core guarantee for achieving High-K thin film deposition.

[0003] Zirconium dioxide film is considered to be one of the most promising new gate dielectric materials due to its moderate dielectric constant (K is about 25) and good compatibility with traditional silicon-based integrated circuit processes. As an advanced nanostructure manufacturing technology, atomic layer deposition (ALD) technology can produce smooth, uniform, controllable and high-quality films with good repeatability through orderly self-limiting saturated chemical reactions on the substrate surface. Therefore, it has been widely used in many fields such as microelectronics science, optical films and nanotechnology. In ALD technology, the process of preparing oxide films is mainly to first introduce gas-phase precursors, and then the precursors react chemically on the wafer surface to form the desired film structure.

[0004] When using atomic layer deposition (ALD) technology to prepare zirconium dioxide thin films, commonly used precursor sources include tetrakis(dimethylamino)zirconium, tetrakis(diethylamino)zirconium, tetrakis(methylethylamino)zirconium, cyclopentadienyltri(dimethylamino)zirconium, etc. However, these high-purity precursor sources are expensive. Moreover, when using tetrakis(dimethylamino)zirconium, tetrakis(diethylamino)zirconium, and tetrakis(methylethylamino)zirconium as precursors to deposit zirconium oxide films, although the film growth rate can reach 0.1nm / cycle, this rate still cannot fully meet actual needs. Therefore, the development of a source material with a faster deposition rate, a simpler synthesis process, and more stable properties is of great significance for improving production efficiency and reducing costs.

[0005] In the prior art, several methods for synthesizing cyclopentadienyl tris(dimethylamino)zirconium are also disclosed: Method 1: The Chinese patent application with publication number CN107188908A, the invention name is: Preparation method of tri(dimethylamino)cyclopentadienyl zirconium, the method disclosed in this invention includes the following steps: 1) preparing dimethylamine lithium, adding a solution of n-butyl lithium in n-hexane to a reactor, stirring and protecting under an inert atmosphere, and then introducing dimethylamine gas to prepare dimethylamine lithium; 2) preparing tetra(dimethylamino) zirconium, adding zirconium tetrachloride to the solution of dimethylamine lithium under stirring and protecting under an inert atmosphere; 3) adding cyclopentadiene monomer dropwise to tetra(dimethylamino) zirconium to react to generate tri(dimethylamino)cyclopentadienyl zirconium; 4) distilling tri(dimethylamino)cyclopentadienyl zirconium. This method adopts a one-pot feeding method, without separating the intermediates, and directly desolventizing after the reaction is completed, and then distilling the product, thereby reducing the contact between the intermediates and the air, shortening the process steps, and improving the production efficiency. However, the yield of this method is significantly lower than that of the traditional method, with a maximum of only 35%. At the same time, it is difficult to clean the container after the reaction, which increases labor costs. At the same time, when this method is used, the by-product bis(n-propylcyclopentadiene)bis(dimethylamino)zirconium exists in the reaction.

[0006] Method 2: The publication number is CN117186136A, and the name of the invention is: A new preparation method for tris(dimethylamino)cyclopentadienyl zirconium. The method disclosed in this invention includes the following steps: first reacting cyclopentadiene monomer with zirconium tetrachloride to prepare dichlorodicyclopentadienyl zirconium, and then reacting it with zirconium tetrachloride to prepare cyclopentadienyl zirconium trichloride, and then reacting it with dimethylamino lithium to obtain the target product. This method uses THF as a solvent. Since the commercially available n-butyl lithium is a n-hexane solution, it is necessary to drain the solvent and add tetrahydrofuran. This process increases the cost of hazardous waste disposal and has a high safety risk. At the same time, a modified polytetrafluoroethylene membrane filter element is used. Since the filter element needs to be manufactured separately, the complexity of the process is further increased.

[0007] Therefore, it is necessary to provide a new method for synthesizing a high-purity metal complex precursor. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for synthesizing a high-purity metal complex precursor. The entire process of the present invention has convenient operating conditions, a mild reaction process, low energy consumption, and high safety; the raw material source is wide and cheap, the product yield is high, and the process stability is good.

[0009] The present invention provides a method for synthesizing a substituted cyclopentadienyl tris(dialkylamino) metal complex. Compared with the synthesis method in the prior art, the reaction route is changed, a substituted cyclopentadiene is first prepared, then reacted with butyl lithium and a metal chloride in sequence to obtain a substituted cyclopentadienyl metal trichloride intermediate, and finally reacted with dialkylamino lithium to obtain a target product, and the product yield and purity are both high.

[0010] The technical solution of the present invention to solve the technical problem is as follows: The present invention provides a method for synthesizing a high-purity metal complex precursor, and the method specifically comprises the following steps: (1) Using alkyl halide, cyclopentadiene monomer and sodium hydroxide as raw materials, a substituted cyclopentadiene is prepared by a substitution reaction; (2) Using substituted cyclopentadiene as raw material, react with n-butyl lithium and metal chloride MCl in sequence 4 Reaction to obtain substituted cyclopentadienyl metal trichloride; (3) First, dialkylamine HNR 5 R 6 and n-butyl lithium as raw materials, reacting to obtain dialkylamino lithium, and then reacting the dialkylamino lithium with the substituted cyclopentadienyl metal trichloride obtained in step (2) to prepare a substituted cyclopentadienyl tris(dialkylamino) metal complex as shown in formula I; Among them, the structural formula of substituted cyclopentadiene is: The structural formula of the substituted cyclopentadienyl metal trichloride is: The structural formula of the substituted cyclopentadienyl tris(dialkylamino) metal complex is shown in Formula I: Formula Ⅰ.

[0011] The substituted cyclopentadiene is a monosubstituted, trisubstituted or tetrasubstituted cyclopentadiene; When the substituted cyclopentadiene is a monosubstituted cyclopentadiene, R1 is Me, Et, nPr or iPr; R2, R3 and R4 are all H; R5 is Me or Et; R6 is Me or Et; M is Ti, Zr or Hf; When the substituted cyclopentadiene is a trisubstituted cyclopentadiene, R1, R2 and R4 are nPr or iPr, and R1, R2 and R4 are the same; R3 is H; R5 is Me or Et; R6 is Me or Et; M is Ti, Zr or Hf; When the substituted cyclopentadiene is tetrasubstituted cyclopentadiene, R 1 , R 2 , R 3 and R 4 All are Me; R 5 Me or Et; R 6 is Me or Et; M is Ti, Zr or Hf.

[0012] Wherein, Me represents a methyl group, Et represents an ethyl group, n Pr represents n-propyl, iPr represents isopropyl.

[0013] The reaction route for the synthesis of the substituted cyclopentadienyl tris(dialkylamino) metal complex as shown in Formula I is as follows: In the reaction scheme, the substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 As defined above for M, R is selected from an alkyl group of not more than 3 carbon atoms or H.

[0014] In some preferred embodiments, the reaction in step (1) is carried out under a nitrogen atmosphere at a reaction temperature of -10 to 30° C. This helps to reduce the polymerization of cyclopentadiene during the reaction.

[0015] In some preferred embodiments, the reaction of step (2) is carried out under a nitrogen atmosphere. When the substituted cyclopentadiene reacts with n-butyl lithium, the reaction temperature is -10~10°C and the reaction time is 1-3 hours. When metal chloride is added for reaction, the reaction temperature is -10~30°C and the reaction time is 8-14 hours. The metal chloride is added to the reaction system in batches. The metal chloride is selected from any one of titanium tetrachloride, zirconium tetrachloride and hafnium tetrachloride. Step (3) is performed after the reaction solution is filtered. Since the temperature will rise during the addition process, temperature control and batch addition will help reduce the occurrence of side reactions.

[0016] In some preferred embodiments, the reaction of step (3) is carried out under a nitrogen atmosphere. 5 R 6 When reacting with n-butyl lithium, the reaction temperature is -20~10°C and the reaction time is 1-3 hours; when adding substituted cyclopentadienyl metal trichloride, the reaction temperature is -20~30°C and the reaction time is 8-14 hours; the substituted cyclopentadienyl metal trichloride is added to the reaction system in batches, and the obtained reaction solution is filtered and vacuum distilled to obtain the final product. Since the temperature will rise during the addition process, temperature control and batch addition will help reduce the occurrence of side reactions.

[0017] In some preferred embodiments, in the step (1), the molar ratio of alkyl halide, cyclopentadiene monomer, and sodium hydroxide is 1: (1.0-5.0): (1.0-6.0). In the step (2), the molar ratio of metal chloride, n-butyl lithium, and substituted cyclopentadiene is 1: (1.0-1.5): (1.0-1.5). In the step (3), the molar ratio of substituted cyclopentadienyl metal trichloride, n-butyl lithium, and dialkylamine is 1: (3.0-3.2): (3.0-4.0). By controlling the molar ratio between the reaction materials, the reaction is made highly selective, which will help to mainly produce a compound with a specific structure.

[0018] In some preferred embodiments, in step (1), the reaction solvent is one of DMSO, acetonitrile and N,N-dimethylformamide. Using a solvent with a high boiling point will help to separate the substituted cyclopentadiene.

[0019] In some preferred embodiments, in the step (2), the reaction solvent of the first reaction is selected from any one of n-hexane, n-pentane and n-heptane, and the reaction solvent of the second reaction is tetrahydrofuran. Adding tetrahydrofuran helps the raw metal chloride to better participate in the reaction.

[0020] In some preferred embodiments, in the step (3), the reaction solvents of the two reactions are selected from any one of n-hexane, n-pentane and n-heptane. Using an alkane non-coordinating solvent avoids coordination between the solvent and the product, which is beneficial to the purification of the product.

[0021] In some preferred embodiments, the metal complex of formula I is selected from any one or more of the following compounds: (1,2,3,4-tetramethylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,3,4-tetramethylcyclopentadienyl)tris(dimethylamino)zirconium; (1,2,3,4-tetramethylcyclopentadienyl)tris(dimethylamino)hafnium; (1,2,3,4-tetramethylcyclopentadienyl)tris(diethylamino)titanium; (1,2,3,4-tetramethylcyclopentadienyl)tris(diethylamino)zirconium; (1,2,3,4-tetramethylcyclopentadienyl)tris(diethylamino)hafnium; (1,2,3,4-tetramethylcyclopentadienyl)tris(methylethylamino)titanium; (1,2,3,4-tetramethylcyclopentadienyl)tris(methylethylamino)titanium; (1,2,3,4-tetramethylcyclopentadienyl)tris(methylethylamino)hafnium; (methylcyclopentadienyl)tris(dimethylamino)titanium; (methylcyclopentadienyl)tris(dimethylamino)zirconium; (methylcyclopentadienyl)tris(dimethylamino)hafnium; (methylcyclopentadienyl)tris(diethylamino)titanium; (methylcyclopentadienyl)tris(diethylamino)zirconium; (methyl (Methylcyclopentadienyl)tris(dimethylamino)hafnium; (Methylcyclopentadienyl)tris(methylethylamino)titanium; (Methylcyclopentadienyl)tris(methylethylamino)zirconium; (Methylcyclopentadienyl)tris(methylethylamino)hafnium; (Ethylcyclopentadienyl)tris(dimethylamino)titanium; (Ethylcyclopentadienyl)tris(dimethylamino)zirconium; (Ethylcyclopentadienyl)tris(dimethylamino)hafnium; (Ethylcyclopentadienyl)tris(dimethylamino)titanium; (ethylcyclopentadienyl)tris(diethylamino)titanium; (ethylcyclopentadienyl)tris(diethylamino)zirconium; (ethylcyclopentadienyl)tris(diethylamino)hafnium; (ethylcyclopentadienyl)tris(methylethylamino)titanium; (ethylcyclopentadienyl)tris(methylethylamino)zirconium; (ethylcyclopentadienyl)tris(methylethylamino)hafnium; (n-propylcyclopentadienyl)tris(dimethylamino)titanium; (n-propylcyclopentadienyl)tris(dimethylamino)zirconium; (n-propylcyclopentadienyl)tris(dimethylamino)hafnium; (n-propylcyclopentadienyl)tris(diethylamino)titanium; (n-propylcyclopentadienyl)tris(diethylamino)zirconium; (n-propylcyclopentadienyl)tris(diethylamino)hafnium; (n-propylcyclopentadienyl)tris(methylethylamino)titanium; (n-propylcyclopentadienyl)tris(diethylamino) (Methylamino)zirconium; (n-propylcyclopentadienyl)tris(methylethylamino)hafnium; (isopropylcyclopentadienyl)tris(dimethylamino)titanium; (isopropylcyclopentadienyl)tris(dimethylamino)zirconium; (isopropylcyclopentadienyl)tris(dimethylamino)hafnium; (isopropylcyclopentadienyl)tris(diethylamino)titanium; (isopropylcyclopentadienyl)tris(diethylamino)zirconium; (isopropylcyclopentadienyl)tris(diethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)zirconium;(1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)hafnium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)hafnium; (1,2,4-tri-n-propylcyclopentadienyl)tris(methylethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(methylethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(methylethylamino)hafnium; (1,2,4-triisopropylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,4-triisopropylcyclopentadienyl) tris(dimethylamino) zirconium; (1,2,4-triisopropylcyclopentadienyl) tris(dimethylamino) hafnium; (1,2,4-triisopropylcyclopentadienyl) tris(diethylamino) titanium; (1,2,4-triisopropylcyclopentadienyl) tris(diethylamino) zirconium; (1,2,4-triisopropylcyclopentadienyl) tris(diethylamino) hafnium; (1,2,4-triisopropylcyclopentadienyl) tris(methylethylamino) titanium; (1,2,4-triisopropylcyclopentadienyl) tris(methylethylamino) zirconium; (1,2,4-triisopropylcyclopentadienyl) tris(methylethylamino) hafnium. ;

[0022] In one preferred embodiment of the present invention, the metal complex of formula I is n-propylcyclopentadienyltris(dimethylamino)zirconium, and its preparation method comprises the following steps: (1) Under nitrogen atmosphere, sodium hydroxide and cyclopentadiene monomer are first reacted at 0°C for 3 hours, and then 1-bromopropane is added and reacted at room temperature for 12 hours, filtered, and distilled under reduced pressure to obtain n-propylcyclopentadiene; wherein the molar ratio of 1-bromopropane, cyclopentadiene monomer, and sodium hydroxide is 1:1.16:1.04; (2) Under nitrogen atmosphere, first react n-butyl lithium with n-propyl cyclopentadiene at 0°C for 2 hours, then add zirconium tetrachloride in batches, react at room temperature for 12 hours, filter, and obtain n-propyl cyclopentadienyl zirconium trichloride; wherein the molar ratio of zirconium tetrachloride, n-butyl lithium, and n-propyl cyclopentadiene is 1:1.1:1.05; (3) Under nitrogen atmosphere, n-butyl lithium and dimethylamine are first reacted at -10 °C for 2 hours, and then the n-propylcyclopentadienyl zirconium trichloride prepared in the previous step is added in batches, and the reaction is carried out at room temperature for 12 hours. The mixture is filtered and subjected to vacuum distillation to obtain n-propylcyclopentadienyl tris(dimethylamino)zirconium, wherein the molar ratio of n-propylcyclopentadienyl zirconium trichloride, n-butyl lithium and dimethylamine is 1:3.1:3.5.

[0023] In another preferred embodiment of the present invention, the metal complex of formula I is isopropylcyclopentadienyl tris(dimethylamino)zirconium, and its preparation method comprises the following steps: (1) Under a nitrogen atmosphere, sodium hydroxide and cyclopentadiene monomer are first reacted at 0°C for 3 hours, and then 2-bromopropane is added and reacted at room temperature for 12 hours, filtered, and distilled under reduced pressure to obtain n-propylcyclopentadiene; wherein the molar ratio of 2-bromopropane, cyclopentadiene monomer, and sodium hydroxide is 1:1.16:1.04; (2) Under nitrogen atmosphere, first react n-butyl lithium with isopropylcyclopentadiene at 0°C for 2 hours, then add zirconium tetrachloride in batches, react at room temperature for 12 hours, filter, and obtain isopropylcyclopentadienyl zirconium trichloride; wherein the molar ratio of zirconium tetrachloride, n-butyl lithium, and isopropylcyclopentadiene is 1:1.1:1.05; (3) Under nitrogen atmosphere, n-butyl lithium and dimethylamine were first reacted at -10 °C for 2 hours, and then the isopropylcyclopentadienyl zirconium trichloride prepared in the previous step was added in two batches, and the mixture was reacted at room temperature for 12 hours. The mixture was filtered and subjected to vacuum distillation to obtain isopropylcyclopentadienyl tris(dimethylamino)zirconium, wherein the molar ratio of isopropylcyclopentadienyl zirconium trichloride, n-butyl lithium and dimethylamine was 1:3.1:3.5.

[0024] The beneficial effects of the present invention are as follows: (1) The synthetic method of the present invention has simple and easy-to-obtain raw materials, convenient operation, simple post-processing process, and high product yield. The yield of the synthetic method of the present invention is about 80%, which is higher than the yield of about 70% of the traditional method; (2) Even if the present invention uses an ordinary filtering device, the purity of the final product can reach 5N, and there is no need to prepare a tetrafluoroethylene membrane filter element filter; (3) Using the synthesis method of the present invention, no dicyclopentadiene impurity was found in the nuclear magnetic resonance. At the same time, the comparative example is a traditional synthesis method. The comparative experiment proves that there is a by-product bis(n-propylcyclopentadiene)bis(dimethylamino)zirconium in the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the gas chromatography detection result of n-propylcyclopentadiene.

[0026] Figure 2 This is the result of NMR detection of n-propylcyclopentadienyltri(dimethylamino)zirconium.

[0027] Figure 3 This is the gas phase detection result of isopropylcyclopentadiene.

[0028] Figure 4 This is the result of nuclear magnetic resonance detection of isopropylcyclopentadienyltri(dimethylamino)zirconium. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] The materials used in the present invention can all be purchased from domestic reagent suppliers, wherein the cyclopentadiene monomer is prepared by high temperature cracking of cyclopentadiene dimer.

[0032] The "room temperature" mentioned in the present invention is generally 20-25 degrees.

[0033] Example 1 The synthesis of n-propylcyclopentadienyl tris(dimethylamino)zirconium includes three steps: (1) Add sodium hydroxide (104 g, 2.6 mol) and 1.5 liters of DMSO to a 5 L multi-mouth reaction bottle under nitrogen atmosphere, cool to 0 °C, add the newly depolymerized cyclopentadiene monomer (191.7 g, 2.9 mol) to the reaction system, continue stirring for 3 hours, add 1-bromopropane (307.5 g, 2.5 mol) to the system, slowly return to room temperature and continue stirring for 12 hours, continue to add dilute hydrochloric acid (30 mL HCl, 400 mL water) to the system, filter, separate the liquids, dry the organic phase with anhydrous sodium sulfate, filter, and distill under reduced pressure. The vacuum degree is controlled at 13-15 Torr. Collect 178.5 g of the fraction with an internal temperature of 26 °C. The purity of n-propylcyclopentadiene is 97% and the yield is 66% as determined by gas chromatography. The gas chromatography detection results of n-propylcyclopentadiene are as follows: Figure 1 As shown; (2) In a 2 L multi-mouth reaction bottle under nitrogen atmosphere, n-butyl lithium (420 mL, 1.05 mol) and 0.5 L of n-hexane with a molar concentration of 2.5 mol were added, the temperature was lowered to 0 °C, n-propylcyclopentadiene (108.2 g, 1.0 mol) was added dropwise to the reaction system, and a white precipitate was quickly generated in the system. After the addition was completed and the reaction was continued for 2 hours, 0.2 L of tetrahydrofuran was added, and zirconium tetrachloride (221.4 g, 0.95 mol) was added in two batches. After the addition was completed, the room temperature was slowly restored and the reaction was continued for 12 hours. The mixture was then filtered in anhydrous and oxygen-free conditions, and the filtrate was drained to obtain 214.2 g of n-propylcyclopentadienyl zirconium trichloride with a yield of 74%; The intermediate was subjected to elemental analysis, theoretical values: C: 31.53, H: 3.64, Cl: 34.90; measured values: C: 31.42, H: 3.72, Cl: 34.81; (3) In a 2 L multi-mouth reaction flask under nitrogen atmosphere, n-butyl lithium (496 mL, 1.24 mol) and 0.5 L n-hexane were added at a molar concentration of 2.5 mol / L. The temperature was lowered to -10 °C, and liquefied dimethylamine (63.1 g, 1.4 mol) was added dropwise to the reaction system. A white precipitate was rapidly generated in the system. After the addition was completed and the reaction was continued for 2 hours, n-propylcyclopentadienylzirconium trichloride (121.9 g, 0.4 mol) was added in two batches. After the addition was completed, the room temperature was slowly restored and the reaction was continued for 12 hours. The mixture was then filtered in anhydrous and oxygen-free conditions. The filtrate was drained of solvent and subjected to vacuum distillation (method: 316 stainless steel theta rings were used as fillers in the glove box, and the filler height in the distillation column was 40 cm. Vacuum distillation was performed). 107.1 g of n-propylcyclopentadienyl tris(dimethylamino)zirconium was obtained with a yield of 81%.

[0034] 1 HNMR (C 6 D 6 ): 5.92(m, 2 H), 5.83(m, 2H), 2.87(s, 18H), 2.37(t, 2H),1.46(m, 2H), 0.82(t, 3H). The results of the NMR test of n-propylcyclopentadienyltris(dimethylamino)zirconium are shown in Figure 2 .

[0035] The purity of the product was tested using inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that the metal purity of the product was 5N.

[0036] Example 2 The synthesis of isopropylcyclopentadienyl tris(dimethylamino)zirconium includes three steps: (1) Synthesis of isopropylcyclopentadiene: The same as step (1) of Example 1, except that the 1-bromopropane in Example 1 was replaced with an equal amount of 2-bromopropane to prepare isopropylcyclopentadiene; the yield was 64%; Isopropylcyclopentadiene test results are shown in Figure 3 , GC purity 97%; (2) The same as step (2) of Example 1, except that the n-propylcyclopentadiene in Example 1 is replaced by an equal amount of isopropylcyclopentadiene to prepare isopropylcyclopentadienyl zirconium trichloride; elemental analysis of the intermediate is performed, theoretical value: C: 31.53, H: 3.64, Cl: 34.90; measured value: C: 31.39, H: 3.59, Cl: 34.85; (3) In a nitrogen atmosphere, n-butyl lithium (496 mL, 1.24 mol) and 0.5 liter of n-hexane were added to a 2L multi-mouth reaction bottle at a molar concentration of 2.5 mol / L. The temperature was lowered to -10 °C, and liquefied dimethylamine (63.1 g, 1.4 mol) was added dropwise to the reaction system. A white precipitate was quickly generated in the system. After the addition was completed, the reaction was continued for 2 hours. Isopropylcyclopentadienyl zirconium trichloride (121.9 g, 0.4 mol) was added in two batches. After the addition was completed, the room temperature was slowly restored and the reaction was continued for 12 hours. The mixture was then filtered in anhydrous and oxygen-free conditions. The filtrate was drained of solvent and then subjected to vacuum distillation to obtain 100.5 g of isopropylcyclopentadienyl tris(dimethylamino)zirconium with a yield of 76%. The test results of isopropylcyclopentadienyl tris(dimethylamino)zirconium are shown in Figure 4 .

[0037] 1 HNMR (C 6 D 6 ): 6.04 (m, 6H), 5.98 (m, 6H), 2.87 (s, 18H), 2.75 (m, 3H), 1.09 (d, 18H).

[0038] The purity of the product was tested using inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that the metal purity of the product was 5N.

[0039] Example 3 The treated silicon wafer was placed in an atomic layer deposition chamber; the room temperature of the atomic layer deposition chamber was adjusted to 250°C and vacuumed; 500 g of the zirconium source isopropylcyclopentadienyl tris(dimethylamino)zirconium prepared in Example 2 was taken and heated to 140°C, and the evaporated precursor molecules were sent into the atomic layer deposition chamber using high-purity argon gas (pulse time 0.2 s). After the zirconium source molecules were introduced, argon gas was continued to be introduced for 10 s to clean the residual zirconium source and reaction by-products; H 2O pulse enters the atomic layer deposition chamber (pulse time 0.3 s), and waits for the pulse H 2 After the O molecules were introduced, argon was introduced for 10 s to clean the residual H 2 O molecules and reaction by-products; the above process was repeated, and a good zirconium dioxide film was obtained after 100 cycles. The film growth rate reached 0.14nm / cycle, the thickness of the film was 13.7nm, and the inhomogeneity of the film was 0.88% as measured by ellipsometer.

[0040] Comparative Example 1 n-propylcyclopentadienyl tris(dimethylamino)zirconium was prepared by a traditional method: tetrakis(dimethylamino)zirconium (93.6 g, 0.35 mol) and 0.4 L of n-hexane were added to a 1L multi-mouth reaction bottle under a nitrogen atmosphere, and n-propylcyclopentadiene (37.9 g, 0.35 mol) was added dropwise at room temperature. After the addition was complete, the reaction was carried out at room temperature for 12 hours, and the mixture was filtered in anhydrous and oxygen-free conditions. After the solvent was drained from the filtrate, it was distilled under reduced pressure to obtain 78.7 g of n-propylcyclopentadienyl tris(dimethylamino)zirconium with a yield of 68%.

[0041] Nuclear magnetic resonance imaging revealed that the product contained the by-product bis(n-propylcyclopentadiene)bis(dimethylamino)zirconium.

[0042] 1 HNMR (C 6 D 6 ): 5.87(m, 2H), 5.80(m, 2H), 2.93(s, 18H), 2.45(t, 2H), 1.40(m, 2H), 0.80(t, 3H).

[0043] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be listed as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for synthesizing a high-purity metal complex precursor, characterized in that: The synthetic method specifically comprises the following steps: (1) Using alkyl halide, cyclopentadiene monomer and sodium hydroxide as raw materials, a substituted cyclopentadiene is prepared by a substitution reaction; (2) Using substituted cyclopentadiene as a raw material, reacting with n-butyl lithium and metal chloride MCl4 in sequence to obtain substituted cyclopentadienyl metal trichloride; (3) firstly reacting dialkylamine HNR5R6 and n-butyllithium as raw materials to obtain dialkylamino lithium, and then reacting the dialkylamino lithium with the substituted cyclopentadienyl metal trichloride obtained in step (2) to obtain a substituted cyclopentadienyl tris(dialkylamino)metal complex as shown in formula I; Among them, the structural formula of substituted cyclopentadiene is: The structural formula of the substituted cyclopentadienyl metal trichloride is: The structural formula of the substituted cyclopentadienyl tris(dialkylamino) metal complex is shown in Formula I: Formula Ⅰ.

2. The method for synthesizing a high-purity metal complex precursor according to claim 1, characterized in that: The substituted cyclopentadiene is a monosubstituted, trisubstituted or tetrasubstituted cyclopentadiene, When the substituted cyclopentadiene is a monosubstituted cyclopentadiene, R1 is Me, Et, nPr or iPr; R2, R3 and R4 are all H; R5 is Me or Et; R6 is Me or Et; M is Ti, Zr or Hf; When the substituted cyclopentadiene is a trisubstituted cyclopentadiene, R1, R2 and R4 are n Pr or i Pr, and R1, R2 and R4 are the same; R3 is H; R5 is Me or Et; R6 is Me or Et; M is Ti, Zr or Hf; When the substituted cyclopentadiene is tetrasubstituted cyclopentadiene, R1, R2, R3 and R4 are all Me; R5 is Me or Et; R6 is Me or Et; and M is Ti, Zr or Hf.

3. The method for synthesizing a high-purity metal complex precursor according to claim 1, characterized in that: In the step (1), the reaction is carried out under a nitrogen atmosphere at a reaction temperature of -10 to 30°C; In the step (2), the reaction is carried out under a nitrogen atmosphere. When the substituted cyclopentadiene reacts with n-butyl lithium, the reaction temperature is -10~10°C and the reaction time is 1-3 hours. When a metal chloride is added for reaction, the reaction temperature is -10~30°C and the reaction time is 8-14 hours. The metal chloride is added to the reaction system in batches. The metal chloride is selected from any one of titanium tetrachloride, zirconium tetrachloride and hafnium tetrachloride. After filtering the reaction solution, step (3) is carried out. In the step (3), the reaction is carried out under a nitrogen atmosphere. When the dialkylamine HNR5R6 and n-butyl lithium react, the reaction temperature is -20~10°C and the reaction time is 1-3 hours. When the substituted cyclopentadienyl metal trichloride is added for reaction, the reaction temperature is -20~30°C and the reaction time is 8-14 hours. The substituted cyclopentadienyl metal trichloride is added to the reaction system in batches, and the obtained reaction solution is filtered and subjected to vacuum distillation to obtain the final product.

4. The method for synthesizing a high-purity metal complex precursor according to claim 1, characterized in that: In the step (1), the molar ratio of the alkyl halide, the cyclopentadiene monomer, and the sodium hydroxide is 1:(1.0-5.0):(1.0-6.0); In the step (2), the molar ratio of the metal chloride, n-butyl lithium and substituted cyclopentadiene is 1:(1.0-1.5):(1.0-1.5); In the step (3), the molar ratio of substituted cyclopentadienyl metal trichloride, n-butyl lithium and dialkylamine is 1:(3.0-3.2):(3.0-4.0).

5. The method for synthesizing a high-purity metal complex precursor according to claim 1, characterized in that: In the step (1), the reaction solvent is one of DMSO, acetonitrile and N,N-dimethylformamide; In the step (2), the reaction solvent of the first reaction is selected from any one of n-hexane, n-pentane and n-heptane, and the reaction solvent of the second reaction is tetrahydrofuran; In the step (3), the reaction solvents for both reactions are selected from any one of n-hexane, n-pentane and n-heptane.

6. The method for synthesizing a high-purity metal complex precursor according to claim 1, characterized in that: The metal complex of formula I is selected from any one or more of the following compounds: (1,2,3,4-Tetramethylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(dimethylamino)zirconium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(dimethylamino)hafnium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(diethylamino)titanium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(diethylamino)zirconium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(diethylamino)hafnium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(methylethylamino)titanium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(methylethylamino)zirconium; (1,2,3,4-Tetramethylcyclopentadienyl)tris(methylethylamino)hafnium; (Methylcyclopentadienyl)tris(dimethylamino)titanium; (Methylcyclopentadienyl)tris(dimethylamino)zirconium; (Methylcyclopentadienyl)tris(dimethylamino)hafnium; (Methylcyclopentadienyl)tris(diethylamino)titanium; (Methylcyclopentadienyl)tris(diethylamino)zirconium; (Methylcyclopentadienyl)tris(diethylamino)hafnium; (Methylcyclopentadienyl)tri(methylethylamino)titanium; (Methylcyclopentadienyl)tri(methylethylamino)zirconium; (Methylcyclopentadienyl)tris(methylethylamino)hafnium; (Ethylcyclopentadienyl)tris(dimethylamino)titanium; (Ethylcyclopentadienyl)tris(dimethylamino)zirconium; (Ethylcyclopentadienyl)tris(dimethylamino)hafnium; (Ethylcyclopentadienyl)tris(diethylamino)titanium; (Ethylcyclopentadienyl)tris(diethylamino)zirconium; (Ethylcyclopentadienyl)tris(diethylamino)hafnium; (Ethylcyclopentadienyl)tri(methylethylamino)titanium; (Ethylcyclopentadienyl)tri(methylethylamino)zirconium; (Ethylcyclopentadienyl)tris(methylethylamino)hafnium; (n-propylcyclopentadienyl)tris(dimethylamino)titanium; (n-propylcyclopentadienyl)tris(dimethylamino)zirconium; (n-propylcyclopentadienyl)tris(dimethylamino)hafnium; (n-propylcyclopentadienyl)tris(diethylamino)titanium; (n-propylcyclopentadienyl)tris(diethylamino)zirconium; (n-propylcyclopentadienyl)tris(diethylamino)hafnium; (n-propylcyclopentadienyl)tri(methylethylamino)titanium; (n-propylcyclopentadienyl)tri(methylethylamino)zirconium; (n-propylcyclopentadienyl)tris(methylethylamino)hafnium; (Isopropylcyclopentadienyl)tris(dimethylamino)titanium; (Isopropylcyclopentadienyl)tris(dimethylamino)zirconium; (Isopropylcyclopentadienyl)tris(dimethylamino)hafnium; (Isopropylcyclopentadienyl)tris(diethylamino)titanium; (Isopropylcyclopentadienyl)tris(diethylamino)zirconium; (Isopropylcyclopentadienyl)tris(diethylamino)hafnium; (Isopropylcyclopentadienyl)tri(methylethylamino)titanium; (Isopropylcyclopentadienyl)tri(methylethylamino)zirconium; (Isopropylcyclopentadienyl)tris(methylethylamino)hafnium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(dimethylamino)hafnium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(diethylamino)hafnium; (1,2,4-tri-n-propylcyclopentadienyl)tri(methylethylamino)titanium; (1,2,4-tri-n-propylcyclopentadienyl)tri(methylethylamino)zirconium; (1,2,4-tri-n-propylcyclopentadienyl)tris(methylethylamino)hafnium; (1,2,4-Triisopropylcyclopentadienyl)tris(dimethylamino)titanium; (1,2,4-Triisopropylcyclopentadienyl)tris(dimethylamino)zirconium; (1,2,4-Triisopropylcyclopentadienyl)tris(dimethylamino)hafnium; (1,2,4-triisopropylcyclopentadienyl)tris(diethylamino)titanium; (1,2,4-Triisopropylcyclopentadienyl)tris(diethylamino)zirconium; (1,2,4-Triisopropylcyclopentadienyl)tris(diethylamino)hafnium; (1,2,4-triisopropylcyclopentadienyl)tris(methylethylamino)titanium; (1,2,4-Triisopropylcyclopentadienyl)tris(methylethylamino)zirconium; (1,2,4-Triisopropylcyclopentadienyl)tris(methylethylamino)hafnium.

7. The method for synthesizing a high-purity metal complex precursor according to any one of claims 1 to 6, characterized in that: R1 is n Pr; R2, R3 and R4 are all H; R5 and R6 are all Me; M is Zr; the metal complex of formula I is n-propylcyclopentadienyltri(dimethylamino)zirconium, and its preparation method comprises the following steps: (1) Under nitrogen atmosphere, sodium hydroxide and cyclopentadiene monomer are first reacted at 0°C for 3 hours, then 1-bromopropane is added, reacted at room temperature for 12 hours, filtered, and distilled under reduced pressure to obtain n-propylcyclopentadiene; (2) Under a nitrogen atmosphere, first react n-butyl lithium with n-propylcyclopentadiene at 0°C for 2 hours, then add zirconium tetrachloride in batches, react at room temperature for 12 hours, filter, and obtain n-propylcyclopentadienyl zirconium trichloride; (3) Under nitrogen atmosphere, n-butyl lithium and dimethylamine are first reacted at -10 °C for 2 hours, and then the n-propylcyclopentadienyl zirconium trichloride prepared in the previous step is added in batches and reacted at room temperature for 12 hours. The mixture is filtered and subjected to vacuum distillation to obtain n-propylcyclopentadienyl tri(dimethylamino) zirconium.

8. The method for synthesizing a high-purity metal complex precursor according to claim 7, characterized in that: In the step (1), the molar ratio of 1-bromopropane, cyclopentadiene monomer and sodium hydroxide is 1:1.16:1.04; In the step (2), the molar ratio of zirconium tetrachloride, n-butyl lithium and n-propylcyclopentadiene is 1:1.1:1.05; In the step (3), the molar ratio of n-propylcyclopentadienylzirconium trichloride, n-butyllithium and dimethylamine is 1:3.1:3.

5.

9. The method for synthesizing a high-purity metal complex precursor according to any one of claims 1 to 6, characterized in that: R1 is i Pr; R2, R3 and R4 are all H; R5 and R6 are all Me; M is Zr; the metal complex of formula I is isopropylcyclopentadienyl tris(dimethylamino)zirconium, and its preparation method comprises the following steps: (1) Under nitrogen atmosphere, sodium hydroxide and cyclopentadiene monomer are first reacted at 0°C for 3 hours, then 2-bromopropane is added, reacted at room temperature for 12 hours, filtered, and distilled under reduced pressure to obtain n-propylcyclopentadiene; (2) Under a nitrogen atmosphere, first react n-butyl lithium with isopropylcyclopentadiene at 0°C for 2 hours, then add zirconium tetrachloride in batches, react at room temperature for 12 hours, filter, and obtain isopropylcyclopentadienyl zirconium trichloride; (3) Under nitrogen atmosphere, n-butyl lithium and dimethylamine were first reacted at -10 °C for 2 hours, and then the isopropylcyclopentadienyl zirconium trichloride prepared in the previous step was added in two batches and reacted at room temperature for 12 hours. The mixture was filtered and subjected to vacuum distillation to obtain isopropylcyclopentadienyl tris(dimethylamino)zirconium.

10. The method for synthesizing a high-purity metal complex precursor according to claim 9, characterized in that: In the step (1), the molar ratio of 2-bromopropane, cyclopentadiene monomer and sodium hydroxide is 1:1.16:1.04; In the step (2), the molar ratio of zirconium tetrachloride, n-butyl lithium and isopropylcyclopentadiene is 1:1.1:1.05; In the step (3), the molar ratio of isopropylcyclopentadienylzirconium trichloride, n-butyl lithium and dimethylamine is 1:3.1:3.5.

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