Titanium complex, its production method, and titanium-containing thin film production method

Abstract

To provide a titanium complex useful for producing a titanium-containing thin film under low-temperature deposition conditions without using an oxidative gas.SOLUTION: The titanium complex is represented by general formula (1) (where each of R1 and R2 independently represents a C1-6 alkyl group which may be bonded to each other to form a ring; X represents CR3 or a N atom; Y represents CR4 or a N atom; Z represents CR5 or a N atom; each of R3, R4 and R5 independently represents a hydrogen atom or a C1-6 alkyl group; and n represents an integer from 1 to 3).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a titanium complex useful as a raw material for manufacturing semiconductor devices, a method for producing the same, and a method for producing a titanium-containing thin film by using the titanium complex as a material. [Background technology]

[0002] In current semiconductor device manufacturing, physical vapor deposition (PVD) by sputtering is mainly used to form thin films for wiring barriers, capacitor dielectrics, and electrodes. However, in the manufacturing of next-generation semiconductors and beyond, it is required to form uniform, thin films on the surfaces of the complex three-dimensional structures of miniaturized devices, so the PVD method, which has difficulty in forming uniform films on uneven surfaces, is not suitable. For this reason, thin film formation methods using chemical vapor deposition (CVD), which deposits films by decomposing source gases, or atomic layer deposition (ALD), which deposits films by decomposing sources adsorbed on the substrate surface, have recently been considered. Furthermore, low-temperature film formation (200°C) is a necessary condition for forming uniform thin films with excellent continuity.

[0003] For the production raw materials used to form thin films by the CVD or ALD method, raw materials that have an appropriate vapor pressure and thermal stability and can be vaporized at a stable supply rate are selected. Furthermore, in order to stably vaporize at a constant supply rate, it is preferable that the raw materials are liquid.

[0004] Titanium, titanium nitride, and silicon-containing titanium nitride are considered as candidates for the materials of capacitor electrodes, transistor gate electrodes, and copper wiring barrier layers of next-generation semiconductor elements. When these titanium-containing thin films are oxidized, problems such as poor conduction with transistors due to an increase in resistance value occur.

[0005] Non-Patent Document 1 describes dimethylbis(3,5-di-tert-butylpyrazolato)titanium and isopropylimidobis(3,5-di-tert-butylpyrazolato)(pyridine)titanium as compounds having a structure similar to that of the titanium complex (1) of the present invention in that they have a pyrazolato ligand, but these are different from the titanium complex of the present invention in that they have an alkyl ligand or an imide ligand. In addition, there is no description of using these titanium complexes as raw materials for the CVD method or the ALD method.

[0006] Non-Patent Document 2 describes trichloro(3,5-di-tert-butylpyrazolato)titanium and tetrakis(3,5-dimethylpyrazolato)titanium as compounds having a structure similar to that of the titanium complex (1) of the present invention in that they have a pyrazolato ligand, but these are different from the titanium complex of the present invention in that they have a chloro ligand or four pyrazolato ligands. In addition, there is no description of using these titanium complexes as raw materials for the CVD method or the ALD method.

[0007] Non-Patent Document 3 describes tris(3,5-di-tert-butylpyrazolato)(3,5-dimethyl-1,2,4-triazolato)titanium and the like, but these differ from the titanium complex of the present invention in that they have four nitrogen-containing heterocyclic ligands. In addition, there is no description of using these titanium complexes as raw materials for the CVD method or ALD method.

[0008] For these reasons, there is a need for a material that enables the production of titanium-containing thin films under low-temperature film-forming conditions without using oxidizing gases such as oxygen or ozone as reactive gases. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Organometallics, Volume 18, Page 1168 (1999) [Non-Patent Document 2] Inorganic Chemistry, Vol. 38, p. 1871 (1999) [Non-Patent Document 3] Inorganic Chemistry, Vol. 40, p. 6451 (2001) Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a titanium complex that is useful for producing a titanium-containing thin film under low-temperature film-forming conditions without using an oxidizing gas. [Means for solving the problem]

[0011] As a result of intensive investigations aimed at solving the above problems, the inventors have found that a titanium complex represented by general formula (1) is useful as a material for producing a titanium-containing thin film under low-temperature film formation conditions without using an oxidizing gas, particularly under low-temperature film formation conditions using a reducing gas, and have thus completed the present invention.

[0012] That is, the present invention relates to a compound represented by the general formula (1)

[0013] [ka]

[0014] (In the formula, R 1 and R 2 Each of X and X represents an alkyl group having 1 to 6 carbon atoms, and may be bonded to each other to form a ring. 3 or N atom. Y is CR 4 or N atom. Z is CR 5 or N atom. 3 , R 4 and R 5 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and n represents an integer of 1 to 3.

[0015] The present invention also relates to a compound represented by general formula (2)

[0016] [ka]

[0017] (In the formula, R 1 and R 2 each independently represents an alkyl group having 1 to 6 carbon atoms, and may be bonded to each other to form a ring.) and an amide complex represented by general formula (3):

[0018] [ka]

[0019] (Wherein, X is CR 3 or N atom. Y is CR 4 or N atom. Z is CR 5 or N atom. 3 , R 4 and R 5 and each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0020] The present invention also relates to a method for producing a titanium-containing thin film, which comprises using a titanium complex represented by the general formula (1) in a vapor phase deposition method based on a chemical reaction.

[0021] The present invention will be described in more detail below. First, the titanium complex (1) of the present invention has a vapor pressure and thermal stability suitable for use as a CVD material or ALD material, and X, Y, and Z are each CR 3 , C.R. 4 and CR 5 is preferred.

[0022] Next, R in general formula (1) 1 , R 2 , R 3 , R 4 and R 5 The definition of R is explained below. 1 , R 2, R 3 , R 4 and R 5 The alkyl group having 1 to 6 carbon atoms represented by the formula (1) may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group, a pentyl group, a 1-ethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, a cyclobutylmethyl group, a hexyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, a 1,1-dimethylbutyl group, a 1,2-dimethylbutyl group, a 1,3-dimethylbutyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a 3,3-dimethylbutyl group, a cyclohexyl group, a cyclopentylmethyl group, a 1-cyclobutylethyl group, and a 2-cyclobutylethyl group. 1 and R 2 The group in which alkyl groups having 1 to 6 carbon atoms are bonded to each other to form a ring may be either linear or branched, and examples thereof include a 1,2-ethylene group, a 1-methyl-1,2-ethylene group, a 1,1-dimethyl-1,2-ethylene group, a 1,2-dimethyl-1,2-ethylene group, a 1,3-trimethylene group, a 1-methyl-1,3-trimethylene group, a 2-methyl-1,3-trimethylene group, a 1,1-dimethyl-1,3-trimethylene group, a 1,2-dimethyl-1,3-trimethylene group, a 1,3-dimethyl-1,3-trimethylene group, Examples of the titanium complex (1) of the present invention include a 2,2-dimethyl-1,3-trimethylene group, a 1,4-tetramethylene group, a 1-methyl-1,4-tetramethylene group, a 2-methyl-1,4-tetramethylene group, a 1,5-pentamethylene group, a 1-methyl-1,5-pentamethylene group, a 2-methyl-1,5-pentamethylene group, a 3-methyl-1,5-pentamethylene group, a 1,6-hexamethylene group, a 1-methyl-1,6-hexamethylene group, a 2-methyl-1,6-hexamethylene group, and a 3-methyl-1,6-hexamethylene group. The titanium complex (1) of the present invention has a vapor pressure and thermal stability suitable for use as a CVD material or an ALD material, and therefore R 1 and R 2is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. In addition, R 3 , R 4 and R 5 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0023] Next, the definition of n in the general formula (1) will be described. n represents an integer of 1 to 3, and n is preferably 2 or 3, and more preferably 3, in that the titanium complex (1) of the present invention has a vapor pressure and thermal stability suitable for use as a CVD material or ALD material.

[0024] The pyrazolato ligand in the titanium complex (1) of the present invention has an η 1 -coordination and η 2 -coordination is possible, but in this specification, η 2 -Coordination will be shown.

[0025] [ka]

[0026] (In the formula, R 1 , R 2 , X, Y, Z and n are as defined above. Specific examples of the titanium complex (1) of the present invention include:

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] The titanium complex (1) of the present invention has a vapor pressure and thermal stability suitable for use as a CVD material or ALD material, and is therefore suitable for use as a CVD material or ALD material. 0) to (1-62), (1-64), (1-66), (1-67), (1-71) to (1-73), (1-75), (1-77), (1-80), and (1-88) are preferred, and (1-1), (1-2), (1-6), (1-8), (1-19), (1-20), (1-24), (1-26), (1-37), (1-38), (1-42), and (1-44) are more preferred.

[0032] Next, a method for producing the titanium complex (1) of the present invention will be described.

[0033] The titanium complex (1) can be produced by the production method 1.

[0034] The production method 1 of the present invention is a method for producing a titanium complex (1) by reacting an amide complex (2) with an unsaturated cyclic amine (3).

[0035] Manufacturing method 1

[0036] [ka]

[0037] (In the formula, R 1 , R 2 , X, Y, Z and n are as defined above. Examples of the amide complex (2) that can be used in Production Method 1 of the present invention include

[0038] [ka]

[0039] In terms of the good yield of the titanium complex (1) of the present invention, (2-1), (2-2), (2-7), (2-14) or (2-15) is preferred, and (2-1), (2-2) or (2-7) is more preferred.

[0040] The amide complex (2) that can be used in the production method 1 of the present invention can be obtained by purchasing a commercially available product or by using a method similar to that described in, for example, European Polymer journal, vol. 7, p. 289 (1971), Organometallics, vol. 24, p. 5383 (2005), or Journal of the Chemical Society, p. 3857 (1960).

[0041] Examples of the unsaturated cyclic amine (3) that can be used in Production Method 1 of the present invention include

[0042] [ka]

[0043] In terms of the high yield of the titanium complex (1) of the present invention, (3-1), (3-2), (3-7) to (3-9), and (3-12) are preferred, and (3-1), (3-2), (3-7), and (3-9) are more preferred.

[0044] The unsaturated cyclic amine (3) that can be used in the production method 1 of the present invention can be obtained by purchasing a commercially available product or by following the methods described in CN106316956A or Bulletin of the Chemical Society of Japan, Vol. 64, p. 719 (1991), for example.

[0045] The molar ratio of the amide complex (2) and the unsaturated cyclic amine (3) when carrying out the production method 1 of the present invention will be described. When n is 1, the yield of the titanium complex (1) of the present invention is good, so that 2.5 to 3.5 molar equivalents of the unsaturated cyclic amine (3) are preferably used per molar equivalent of the amide complex (2), and more preferably 2.9 to 3.1 molar equivalents. When n is 2, the yield of the titanium complex (1) of the present invention is good, so that 1.5 to 2.5 molar equivalents of the unsaturated cyclic amine (3) are preferably used per molar equivalent of the amide complex (2), and more preferably 1.9 to 2.1 molar equivalents. When n is 3, the yield of the titanium complex (1) of the present invention is good, so that 0.8 to 1.5 molar equivalents of the unsaturated cyclic amine (3) are preferably used per molar equivalent of the amide complex (2), and more preferably 0.9 to 1.1 molar equivalents.

[0046] The production method 1 of the present invention is preferably carried out in an inert gas atmosphere, since it provides a good yield of the titanium complex (1) of the present invention. Specific examples of the inert gas include helium, neon, argon, krypton, xenon, and nitrogen gas. Nitrogen gas or argon is preferred because it is inexpensive.

[0047] The production method 1 of the present invention is preferably carried out in an organic solvent, since it provides a good yield of the titanium complex (1) of the present invention. There is no particular limitation on the type of organic solvent that can be used, as long as it does not inhibit the reaction. Examples of solvents that can be used include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, and petroleum ether, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, 2-methylpropylbenzene, 1-methylpropylbenzene, tert-butylbenzene, and 1,3,5-trimethylbenzene (mesitylene), and ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether (CPME), cyclopentyl ethyl ether (CPEE), tert-butyl methyl ether (MTBE), THF, dioxane, and 1,2-dimethoxyethane. One of these organic solvents can be used alone, or a mixture of two or more of them can be used in any ratio. As the organic solvent, hexane, heptane, toluene or ether is preferred, and hexane is more preferred, in view of the good yield of the titanium complex (1) of the present invention.

[0048] In the production method 1 of the present invention, the reaction temperature and reaction time are not particularly limited, and general conditions used by those skilled in the art when producing organometallic complexes can be used. As a specific example, the titanium complex (1) of the present invention can be produced in good yield by appropriately selecting a reaction temperature from the temperature range of -80°C to 120°C and an appropriate reaction time from the range of 10 minutes to 120 hours.

[0049] The titanium complex (1) of the present invention produced by Production Method 1 of the present invention can be purified by a purification method generally used by those skilled in the art for purifying organometallic complexes, which can be appropriately selected and used. Specific purification methods include filtration, extraction, centrifugation, decantation, distillation, sublimation, crystallization, etc.

[0050] Next, a method for producing a titanium-containing thin film, which is characterized by using the titanium complex (1) of the present invention in a vapor phase deposition method based on a chemical reaction, will be described in detail. In this specification, the vapor phase deposition method based on a chemical reaction means a method for producing a titanium-containing thin film by decomposing the vaporized titanium complex (1) on a substrate. Specifically, CVD methods such as thermal CVD, plasma CVD, and photo CVD, and ALD methods can be exemplified. The CVD method is particularly preferred in terms of its good film formation speed, and the ALD method is particularly preferred in terms of its good step coverage. For example, when producing a titanium-containing thin film by the CVD method or ALD method, the titanium complex (1) is vaporized and supplied to a reaction chamber, and the titanium complex (1) is decomposed on a substrate installed in the reaction chamber, thereby producing a titanium-containing thin film on the substrate. As a method for decomposing the titanium complex (1), a normal technical means used by a person skilled in the art for producing a metal-containing thin film can be exemplified. Specifically, a method of reacting the titanium complex (1) with a reactive gas, and a method of applying heat, plasma, light, etc. to the titanium complex (1) can be exemplified.

[0051] In the case where a reactive gas is used, examples of the reactive gas that can be used include a reducing gas and an oxidizing gas. As the reactive gas, a reducing gas is preferable in that it can prevent deterioration of a substrate when forming a film on the substrate made of a material that is easily oxidized, such as a metal or a metal nitride. Specific examples of reducing gases include ammonia, hydrogen, monosilane, hydrazine, formic acid, borane-amine complexes such as borane-dimethylamine complex and borane-trimethylamine complex, 1-butene, 2-butene, 2-methylpropene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene, 2-methyl-2-pentene, 4-methyl-2-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 3-methyl-2-pentene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2,3-dimethyl-2-butene, 3,3-dimethyl-1-butene, buta-1,3-diene, penta-1,3-diene, penta-1,4-diene, Chain unsaturated hydrocarbons such as cyclohexa-1,3-diene, 2-methylbuta-1,3-diene, hexa-1,3-diene, hexa-2,4-diene, 2-methylpenta-1,3-diene, 3-methylpenta-1,3-diene, 4-methylpenta-1,3-diene, 2-ethylbuta-1,3-diene, 3-methylpenta-1,4-diene, and 2,3-dimethylbuta-1,3-diene; Examples of the cyclic unsaturated hydrocarbons include cyclohexa-1,4-diene, 1-methylcyclohexa-1,3-diene, 2-methylcyclohexa-1,3-diene, 5-methylcyclohexa-1,3-diene, 3-methylcyclohexa-1,4-diene, α-phellandrene, β-phellandrene, α-terpinene, β-terpinene, γ-terpinene, and limonene. A plurality of reactive gases may be used simultaneously. In terms of being less restricted by the specifications of the film forming apparatus and being easy to handle, the reducing gas is preferably ammonia, hydrogen, formic acid, cyclohexa-1,3-diene, cyclohexa-1,4-diene, α-terpinene, β-terpinene, γ-terpinene, or limonene. In terms of being able to form a titanium nitride thin film, it is preferable to use ammonia.The flow rate of the reaction gas is appropriately adjusted according to the reactivity of the material and the volume of the reaction chamber. For example, when the volume of the reaction chamber is 1 to 10 L, the flow rate of the reaction gas is not particularly limited, and 1 to 10,000 sccm is preferable for economic reasons. In this specification, sccm is a unit that represents the flow rate of gas, and 1 sccm represents that the gas moves at a speed of 2.68 mmol / h when converted into an ideal gas.

[0052] When producing a titanium-containing thin film by the CVD method or the ALD method, the titanium-containing thin film can be produced by appropriately selecting and using these decomposition methods. A combination of multiple decomposition methods can also be used. The method of supplying the titanium complex (1) to the reaction chamber includes, for example, methods commonly used by those skilled in the art, such as bubbling and liquid vaporization supply systems, and is not particularly limited.

[0053] The carrier gas and dilution gas used in producing a titanium-containing thin film by CVD or ALD are preferably rare gases such as helium, neon, argon, krypton, and xenon, or nitrogen gas, and more preferably nitrogen gas or argon for economic reasons. The flow rates of the carrier gas and dilution gas are appropriately adjusted according to the volume of the reaction chamber. For example, when the volume of the reaction chamber is 1 to 10 L, the flow rate of the carrier gas is not particularly limited, and is preferably 1 to 10,000 sccm for economic reasons.

[0054] The substrate temperature when producing a titanium-containing thin film by the CVD method or the ALD method is appropriately selected depending on the use of heat, plasma, light, etc., the type of reactive gas, etc. For example, when ammonia is used as the reactive gas without using light or plasma, there is no particular limitation on the substrate temperature, and 50°C to 1000°C is preferable for economic reasons. 100°C to 300°C is preferable in terms of good film formation speed, and 150°C to 250°C is more preferable for forming a uniform thin film with excellent continuity. In addition, by appropriately using light, plasma, hydrazine, etc., a titanium-containing thin film can be produced at an even lower temperature range.

[0055] When a titanium-containing thin film is produced by a CVD method or an ALD method, the film formation pressure is preferably a reduced pressure condition, preferably 1 to 100 Torr, and more preferably 1 to 10 Torr, in terms of achieving good film thickness uniformity, step coverage (coating ability), and film quality.

[0056] The titanium-containing thin film obtained by the method for producing a titanium-containing thin film of the present invention includes, for example, a metallic titanium thin film, a titanium nitride thin film, a silicon-containing titanium nitride thin film, and a titanium silicide thin film. After producing the metallic titanium thin film, a titanium-containing composite film can be obtained by heating the substrate at an arbitrary temperature. For example, a titanium-containing composite film can be obtained by combining with other metal materials. For example, a titanium silicide thin film can be obtained by combining the titanium complex (1) of the present invention with a silicon material. Examples of the silicon material include monosilane, disilane, trisilane, tetraethoxysilane, dimethyldimethoxysilane, bis(tert-butylamino)silane, bis(diethylamino)silane, and tris(dimethylamino)silane. Furthermore, by combining the titanium complex (1) of the present invention with a metal material containing a typical metal such as aluminum or germanium, a transition metal such as zirconium, hafnium, niobium, tantalum, or tungsten, or a rare earth metal such as lanthanum or neodymium, a titanium-containing composite film containing these metal elements can also be obtained. When a titanium-containing composite thin film is produced by a CVD method or an ALD method, the titanium complex (1) of the present invention and the other metal material may be supplied separately to a reaction chamber, or may be mixed and then supplied.

[0057] By using the titanium-containing thin film of the present invention as a component, it is possible to manufacture high-performance semiconductor devices with improved reliability and responsiveness. Examples of semiconductor devices include semiconductor memory devices such as DRAM, FeRAM, PRAM, MRAM, ReRAM, and flash memory, and field effect transistors. Examples of components for these devices include capacitor electrodes, transistor gate electrodes, and copper wiring barrier layers. Effect of the Invention

[0058] By using the titanium complex (1) of the present invention as a material, it is possible to produce a titanium-containing thin film under low-temperature film-forming conditions without using an oxidizing gas. [Brief description of the drawings]

[0059] [Figure 1] 1 is a DSC chart of tris(dimethylamido)(3,5-dimethylpyrazolato)titanium (1-8) in Evaluation Example 1. [Diagram 2] 1 is a DSC chart of tris(ethylmethylamido)(3-methylpyrazolato)titanium (1-20) of Evaluation Example 2. [Diagram 3] 1 is a DSC chart of tetrakis(dimethylamido)titanium of Comparative Example 1. [Figure 4] 1 is a DSC chart of tetrakis(ethylmethylamido)titanium in Comparative Example 2. [Diagram 5] 1 is a DSC chart of tetrakis(diethylamido)titanium in Comparative Example 3. [Figure 6] FIG. 1 is a diagram showing a CVD apparatus used in Example 14 and Comparative Example 4. EXAMPLES

[0060] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. All of the compounds described in Reference Examples 1 to 4 and Examples 1 to 13 were produced under an argon atmosphere. The hexane and tetrahydrofuran (THF) used were dehydrated products manufactured by Kanto Chemical Co., Ltd. Dimethylamine, ethylmethylamine, and pyrrolidine were purchased from Tokyo Chemical Industry Co., Ltd., and diethylamine was purchased from Fujifilm Wako Pure Chemical Industries, Ltd.

[0061] Reference example 1

[0062] [ka]

[0063] To 200.0 mL (2.00 mol / L, 400.0 mmol) of a THF solution of dimethylamine, 245 mL (1.59 mol / L, 389.6 mmol) of a hexane solution of butyllithium was added at -78°C. This mixture was stirred at 25°C for 1 hour, and then a hexane (50 mL) solution of 17.3 g (91.2 mmol) of titanium tetrachloride was added at -78°C. This mixture was stirred at 25°C for 18 hours. After filtering this suspension, the solvent was distilled from the filtrate under reduced pressure. The remaining liquid was distilled (heating temperature 60°C / back pressure 49 Pa) to obtain 15.7 g of tetrakis(dimethylamido)titanium (2-1) as a yellow liquid. Yield 77%. 1 H-NMR (400MHz, C6D6, δ): 3.11 (s, 24H).

[0064] Reference example 2

[0065] [ka]

[0066] To a solution of 36.3 mL (422.5 mmol) of ethylmethylamine in hexane (120 mL), 266.0 mL (1.59 mol / L, 422.3 mmol) of butyllithium in hexane was added at -78°C. After stirring this mixture at 25°C for 1 hour, a solution of 19.0 g (100.2 mmol) of titanium tetrachloride in hexane (40 mL) was added at -78°C. This mixture was stirred at 25°C for 18 hours. After filtering this suspension, the solvent was removed from the filtrate under reduced pressure. The remaining liquid was distilled (heating temperature 90°C / back pressure 19 Pa) to obtain 22.4 g of tetrakis(ethylmethylamido)titanium (2-2) as an orange liquid. Yield 80%. 1 H-NMR (400MHz, C6D6, δ): 3.47 (q, 8H), 3.13 (s, 12H), 1.12 (t, 12H).

[0067] Reference example 3

[0068] [ka]

[0069] To a solution of 43.7 mL (422.7 mmol) of diethylamine in hexane (120 mL), 266.0 mL (1.59 mol / L, 422.3 mmol) of butyllithium in hexane was added at -78°C. After stirring this mixture at 25°C for 1 hour, a solution of 19.0 g (100.2 mmol) of titanium tetrachloride in hexane (40 mL) was added at -78°C. This mixture was stirred at 25°C for 18 hours. After filtering this suspension, the solvent was removed from the filtrate by distillation under reduced pressure. The remaining liquid was distilled (heating temperature 120°C / back pressure 42 Pa) to obtain 18.9 g of tetrakis(diethylamido)titanium (2-7) as a red liquid. Yield 56%. 1 H-NMR(400MHz,C6D6,δ):3.59(q,16H),1.12(t ,24H).

[0070] Reference example 4

[0071] [ka]

[0072] To a solution of 23.0 g (323.4 mmol) of pyrrolidine in hexane (50 mL), 220.0 mL (1.59 mol / L, 349.8 mmol) of butyllithium in hexane was added at -78°C. After stirring this mixture at 25°C for 1 hour, it was added to a solution of 15.4 g (81.2 mmol) of titanium tetrachloride in hexane (25 mL) at -78°C. This mixture was stirred at 25°C for 18 hours. After filtering this suspension, the solvent was removed from the filtrate under reduced pressure. The remaining liquid was distilled (heating temperature 160°C / back pressure 68 Pa) to obtain 13.5 g of tetrakis(pyrrolidinato)titanium (2-14) as a yellow liquid. Yield 51%. 1 H-NMR (400MHz, C6D6, δ): 3.79 (t, 16H), 1.56 (t, 16H).

[0073] Example 1

[0074] [ka]

[0075] A solution of 0.31 g (4.6 mmol) of pyrazole in THF (16 mL) was added to a solution of 1.0 g (4.5 mmol) of tetrakis(dimethylamido)titanium synthesized in Reference Example 1 in THF (33 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining solid was sublimated (heating temperature 100°C / back pressure 32 Pa), to obtain 0.4 g of tris(dimethylamido)(pyrazolato)titanium (1-1) as a red solid. Yield 36%. 1 H-NMR (400MHz, C6D6, δ): 7.75 (d, 2H), 6.54 (t, 1H), 3.24 (s, 18H).

[0076] Example 2

[0077] [ka]

[0078] A solution of 0.46 g (5.7 mmol) of 3-methylpyrazole in THF (20 mL) was added to a solution of 1.3 g (5.8 mmol) of tetrakis(dimethylamido)titanium synthesized in Reference Example 1 in THF (40 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 80°C / back pressure 30 Pa) to obtain 0.4 g of tris(dimethylamido)(3-methylpyrazolato)titanium (1-2) as a red liquid. Yield 28%. 1 H-NMR (400MHz, C6D6, δ): 7.68 (s, 1H), 6.33 (s, 1H), 3.26 (s, 18H), 2.30 (s, 3H).

[0079] Example 3

[0080] [ka]

[0081] A solution of 0.39 g (4.0 mmol) of 3,5-dimethylpyrazole in THF (15 mL) was added to a solution of 0.9 g (4.0 mmol) of tetrakis(dimethylamido)titanium synthesized in Reference Example 1 in THF (30 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 100°C / back pressure 25 Pa) to obtain 0.2 g of tris(dimethylamido)(3,5-dimethylpyrazolato)titanium (1-8) as a red liquid. Yield 21%. 1 H-NMR(400MHz,C6D6,δ):6.11(s,1H),3.28(s,18H),2.28(s,6H). 13 C-NMR (400MHz, C6D6, δ): 146.58, 111.88, 46.24, 13.12.

[0082] Example 4

[0083] [ka]

[0084] A solution of 0.44 g (6.5 mmol) of pyrazole in THF (24 mL) was added to a solution of 1.8 g (6.4 mmol) of tetrakis(ethylmethylamido)titanium synthesized in Reference Example 2 in THF (47 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 90°C / back pressure 19 Pa) to obtain 0.7 g of tris(ethylmethylamido)(pyrazolato)titanium (1-19) as a red liquid. Yield 37%. 1 H-NMR(400MHz,C6D6,δ):7.76(d,2H),6.54(t,1H),3.59(q,6H),3.28(s,9H),1.07(t,9H). 13 C-NMR (400MHz, C6D6, δ): 135.82, 111.77, 53.05, 42.13, 15.16.

[0085] Example 5

[0086] [ka]

[0087] A solution of 3.5 g (42.8 mmol) of 3-methylpyrazole in THF (90 mL) was added to a solution of 12.0 g (42.9 mmol) of tetrakis(ethylmethylamido)titanium synthesized in Reference Example 2 in THF (190 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 103°C / back pressure 38 Pa) to obtain 9.6 g of tris(ethylmethylamido)(3-methylpyrazolato)titanium (1-20) as a red liquid. Yield 74%. 1 H-NMR(400MHz,C6D6,δ):7.69(d,1H),6.33(d,1H),3.62(q,6H),3.30(s,9H),2.31(s,3H),1.08(t,9H). 13 C-NMR (400MHz, C6D6, δ): 145.86, 136.52, 111.67, 53.14, 42.20, 15.23, 12.90.

[0088] Example 6

[0089] [ka]

[0090] A solution of 0.71 g (7.4 mmol) of 3,5-dimethylpyrazole in THF (27 mL) was added to a solution of 2.1 g (7.5 mmol) of tetrakis(ethylmethylamido)titanium synthesized in Reference Example 2 in THF (54 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 110°C / back pressure 18 Pa) to obtain 1.2 g of tris(ethylmethylamido)(3,5-dimethylpyrazolato)titanium (1-26) as a red liquid. Yield 51%. 1 H-NMR(400MHz,C6D6,δ):6.12(s,1H),3.64(q,6H),3.32(s,9H),2.30(s,6H),1.10(t,9H). 13 C-NMR (400MHz, C6D6, δ): 146.43, 111.62, 53.22, 42.27, 15.30, 13.07.

[0091] Example 7

[0092] [ka]

[0093] A solution of 1.00 g (14.7 mmol) of pyrazole in THF (54 mL) was added to a solution of 4.9 g (14.6 mmol) of tetrakis(diethylamido)titanium synthesized in Reference Example 3 in THF (108 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 120°C / back pressure 20 Pa) to obtain 3.2 g of tris(diethylamido)(pyrazolato)titanium (1-37) as a red liquid. Yield 66%. 1 H-NMR(400MHz,C6D6,δ):7.76(d,2H),6.55(t,1H),3.69(q,12H),1.07(t,18H). 13 C-NMR (400MHz, C6D6, δ): 135.84, 111.45, 47.82, 15.49.

[0094] Example 8

[0095] [ka]

[0096] A solution of 0.23 g (2.8 mmol) of 3-methylpyrazole in THF (10 mL) was added to a solution of 0.9 g (2.8 mmol) of tetrakis(diethylamido)titanium synthesized in Reference Example 3 in THF (20 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 120°C / back pressure 38 Pa) to obtain 0.3 g of tris(diethylamido)(3-methylpyrazolato)titanium (1-38) as a red liquid. Yield 33%. 1 H-NMR (400MHz, C6D6, δ): 7.69 (d, 1H), 6.33 (d, 1H), 3.71 (q, 12H), 2.32 (s, 3H), 1.08 (t, 18H).

[0097] Example 9

[0098] [ka]

[0099] A solution of 0.47 g (4.9 mmol) of 3,5-dimethylpyrazole in THF (18 mL) was added to a solution of 1.7 g (5.0 mmol) of tetrakis(diethylamido)titanium synthesized in Reference Example 3 in THF (36 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 130°C / back pressure 22 Pa) to obtain 0.7 g of tris(diethylamido)(3,5-dimethylpyrazolato)titanium (1-44) as a red liquid. Yield 40%. 1 H-NMR(400MHz,C6D6,δ):6.12(s,1H),3.74(q,12H),2.31(s,6H),1.10(t,18H). 13 C-NMR (400MHz, C6D6, δ): 146.29, 111.37, 48.01, 15.61, 13.03.

[0100] Example 10

[0101] [ka]

[0102] A solution of 0.32 g (3.9 mmol) of 3-methylpyrazole in THF (10 mL) was added to a solution of 1.3 g (4.0 mmol) of tetrakis(pyrrolidinato)titanium synthesized in Reference Example 4 in THF (20 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. The remaining liquid was distilled (heating temperature 114°C / back pressure 28 Pa) to obtain 0.3 g of tris(pyrrolidinato)(3-methylpyrazolato)titanium (1-56) as a red liquid. Yield 24%. 1 H-NMR (400MHz, C6D6, δ): 7.74 (d, 1H), 6.38 (d, 1H), 4.00 (t, 12H), 2.34 (s, 3H), 1.53 (t, 12H).

[0103] Example 11

[0104] [ka]

[0105] A solution of 0.63 g (9.2 mmol) of pyrazole in THF (35 mL) was added to a solution of 1.0 g (4.6 mmol) of tetrakis(dimethylamido)titanium synthesized in Reference Example 1 in THF (35 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. Bis(dimethylamido)bis(pyrazolato)titanium (1-77) was obtained as a dark red liquid. Yield 48%. 1 H-NMR (400MHz, C6D6, δ): 7.81 (d, 4H), 6.59 (t, 2H), 3.28 (s, 12H).

[0106] Example 12

[0107] [ka]

[0108] A solution of 0.79 g (8.2 mmol) of 3,5-dimethylpyrazole in THF (30 mL) was added to a solution of 0.9 g (4.0 mmol) of tetrakis(dimethylamido)titanium synthesized in Reference Example 1 in THF (30 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. Bis(dimethylamido)bis(3,5-dimethylpyrazolato)titanium (1-80) was obtained as a dark red liquid. Yield 51%. 1 H-NMR (400MHz, C6D6, δ): 6.09 (s, 2H), 3.47 (s, 12H), 2.23 (s, 12H).

[0109] Example 13

[0110] [ka]

[0111] A solution of 0.62 g (6.45 mmol) of 3,5-dimethylpyrazole in THF (25 mL) was added to a solution of 1.1 g (3.3 mmol) of tetrakis(diethylamido)titanium synthesized in Reference Example 3 in THF (25 mL) at -78°C. The solution was stirred at 25°C for 1 hour, and the solvent was distilled off under reduced pressure. Bis(diethylamido)bis(3,5-dimethylpyrazolato)titanium (1-88) was obtained as a dark red liquid. Yield 56%. 1 H-NMR (400MHz, C6D6, δ): 6.10 (s, 2H), 3.89 (q, 8H), 2.25 (s, 12H), 0.99 (t, 12H).

[0112] Evaluation example 1 Thermal analysis of tris(dimethylamido)(3,5-dimethylpyrazolato)titanium(1-8) As a sample, 8.3 mg of (1-8) synthesized in Example 3 was used for differential scanning calorimetry (DSC).

[0113] The results of DSC measurements taken in a closed vessel in an argon atmosphere at a heating rate of 10°C / min are shown in Figure 1. The DSC results show that the thermal decomposition onset temperature is 152°C.

[0114] Evaluation example 2 Thermal analysis of tris(ethylmethylamido)(3-methylpyrazolato)titanium(1-20) As a sample, 5.8 mg of (1-20) synthesized in Example 5 was used for differential scanning calorimetry (DSC).

[0115] The results of DSC measurements taken in a closed vessel in an argon atmosphere at a heating rate of 10°C / min are shown in Figure 2. The DSC results show that the thermal decomposition onset temperature is 147°C.

[0116] Comparative Example 1 Thermal analysis of tetrakis(dimethylamido)titanium. As a sample, 2.5 mg of (2-1) synthesized in Reference Example 1, which is not the titanium complex (1) of the present invention, was used for DSC as Comparative Example 1.

[0117] The results of DSC measurements taken in a closed vessel in an argon atmosphere at a heating rate of 10°C / min are shown in Figure 3. The DSC results show that the thermal decomposition onset temperature is 229°C.

[0118] Comparative Example 2 Thermal analysis of tetrakis(ethylmethylamido)titanium. As a sample, 4.4 mg of (2-2) synthesized in Reference Example 2, which is not the titanium complex (1) of the present invention, was used for Comparative Example 2 for DSC.

[0119] The results of DSC measurements taken in a closed vessel in an argon atmosphere at a heating rate of 10°C / min are shown in Figure 4. The DSC results show that the thermal decomposition onset temperature is 242°C.

[0120] Comparative Example 3 Thermal analysis of tetrakis(diethylamido)titanium. As a sample for Comparative Example 3, 3.0 mg of (2-7) synthesized in Reference Example 3, which is not the titanium complex (1) of the present invention, was used for DSC.

[0121] The results of DSC measurements taken in a closed vessel in an argon atmosphere at a heating rate of 10°C / min are shown in Figure 5. The DSC results show that the thermal decomposition onset temperature is 232°C.

[0122] The results of Evaluation Examples 1 and 2 and Comparative Examples 1 to 3 show that the titanium complex (1) of the present invention has a lower thermal decomposition onset temperature than tetrakis(dimethylamido)titanium, tetrakis(diethylamido)titanium, and tetrakis(ethylmethylamido)titanium, and is therefore a complex more suitable for low-temperature film formation.

[0123] Example 14 A titanium-containing thin film was produced by thermal CVD using tris(ethylmethylamido)(3-methylpyrazolato)titanium(1-20) synthesized in Example 5 as the material. The outline of the apparatus used for thin film production is shown in Figure 6. The thin film production conditions are as follows. Carrier gas flow rate: 20sccm, ammonia flow rate: 40sccm, dilution gas flow rate: 140sccm, substrate material: SiO2, deposition time: 60min, total pressure in reaction chamber: 1.3kPa, material container temperature: 50℃, total pressure in material container: 6.7kPa, material supply rate: 0.01sccm, substrate temperature: 200℃. Argon was used as the carrier gas and dilution gas. When the produced thin film was confirmed by fluorescent X-ray analysis, characteristic X-rays based on titanium were detected. The wavelength was calculated to be 53nm from the intensity of the detected X-rays.

[0124] From the results of Example 14, it is clear that the titanium complex (1) of the present invention is a material that can be used to produce a titanium-containing film at a low temperature of 200° C. without using an oxidizing gas or light or plasma.

[0125] Comparative Example 4 A titanium-containing thin film was produced by thermal CVD using the tetrakis(dimethylamido)titanium (2-1) synthesized in Reference Example 1 as the material. The apparatus used for thin film production is shown in Figure 6. The thin film production conditions are as follows. Carrier gas flow rate: 20sccm, ammonia flow rate: 40sccm, dilution gas flow rate: 140sccm, substrate material: SiO2, deposition time: 60min, total pressure in reaction chamber: 1.3kPa, material container temperature: 40℃, total pressure in material container: 13.3kPa, material supply rate: 0.064sccm, substrate temperature: 200℃. Argon was used as the carrier gas and dilution gas. When the produced thin film was confirmed by fluorescent X-ray analysis, characteristic X-rays based on titanium were detected. The distance was calculated from the intensity of the detected X-rays to be 36nm.

[0126] The results of Example 14 and Comparative Example 4 show that the titanium complex (1) of the present invention has a lower material supply rate than tetrakis(dimethylamido)titanium, but has a faster film formation rate at 200°C, and is therefore a complex suitable for forming a titanium-containing thin film at low temperatures. [Explanation of symbols]

[0127] 1 Material container 2 Constant temperature bath 3. Reaction chamber 4. Board 5 Reaction gas inlet 6 Dilution gas inlet 7 Carrier gas inlet 8 Mass Flow Controller 9 Mass Flow Controller 10 Mass Flow Controller 11 Oil rotary pump 12 Exhaust

Claims

1. General formula (2) 【Chemistry 1】 (wherein R 1 and R 2 each independently represent an alkyl group having 1 to 6 carbon atoms, and may be bonded to each other to form a ring), General formula (3) 【Chemistry 2】 (wherein X represents CR 3 or an N atom; Y represents CR 4 or an N atom; Z represents CR 5 or an N atom; and R 3 , R 4 and R 5 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) with an unsaturated cyclic amine represented by the following formula (I) at a temperature range of -80°C to 120°C for 10 minutes to 120 hours: 【Chemistry 3】

2. A method for producing the titanium complex described in claim 1, wherein the titanium complex is a titanium complex represented by the following structure. 【Chemistry 4】

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