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

Abstract

To provide a titanium complex useful in producing a titanium-containing thin film under a low-temperature film deposition condition without oxidized gas.SOLUTION: The titanium complex is represented by the general formula (1) in the figure. (In the formula, R1, R2 and R3 each independently represent a C1-6 alkyl group or tri(C1-6 alkyl)silyl group; and n represents an integer from 0 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 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 (around 200°C) is a necessary condition for forming uniform thin films with excellent continuity.

[0003] The raw materials used to form thin films by the CVD or ALD method must have an appropriate vapor pressure and thermal stability, and must be capable of being vaporized at a stable supply rate. In order to stably vaporize the raw materials 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] Patent Document 1 and Non-Patent Document 1 disclose tetrakis(dimethylamido)titanium Ti(NMe2)4, tetrakis(diethylamido)titanium Ti(NEt2)4, and tetrakis(ethylmethylamido)titanium Ti(NEtMe)4 as compounds having a structure similar to that of the titanium complex (1) of the present invention in that they have an amide ligand. However, these compounds differ from the titanium complex of the present invention in that they have a dialkylamido ligand.

[0006] Non-Patent Document 2 suggests that titanium nitride thin films formed at 235°C using Ti(NMe2)4 and ammonia, which are different from the titanium complex of the present invention, have the problem of carbon being incorporated as an impurity in the film. Carbon-containing films have high resistivity and do not meet the required characteristics of electrodes and barrier layers. In other words, these tetrakis(dialkylamido)titaniums are not suitable as materials for forming titanium-containing thin films under low-temperature film formation conditions.

[0007] 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] [Patent documents]

[0008] [Patent Document 1] Special publication H05-502695 [Non-patent literature]

[0009] [Non-Patent Document 1] Chemistry of Materials, Volume 9, Page 76 (1997) [Non-Patent Document 2] Chemistry of Materials, Volume 8, Page 2712 (1996) 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] (1) (In the formula, R 1 , R 2 and R 3 each independently represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; and n represents an integer of 0 to 3.

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

[0016] [ka]

[0017] (2) (In the formula, R 1 and R 2 each independently represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; n represents an integer of 0 to 3; and X represents a halogen atom.

[0018] [ka]

[0019] (3) (In the formula, R 3 represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms. M represents an alkali metal.

[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, R 1 , R 2 and R 3 The definition of R is explained below. 1 , R 2 and R 3 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 , R 2 and R 3The alkyl group having 1 to 6 carbon atoms in the tri(alkyl having 1 to 6 carbon atoms)silyl group represented by the formula (I) may be any of linear, branched, and cyclic. Specific examples of the tri(alkyl having 1 to 6 carbon atoms)silyl group include a trimethylsilyl group, an ethyldimethylsilyl group, a diethyl(methyl)silyl group, a dimethyl(propyl)silyl group, an isopropyldimethylsilyl group, a triethylsilyl group, a butyldimethylsilyl group, an isobutyldimethylsilyl group, a sec-butyldimethylsilyl group, a tert-butyldimethylsilyl group, a cyclobutyldimethylsilyl group, a diethyl(propyl)silyl group, a diethyl(isopropyl)silyl group, a tripropylsilyl group, a triisopropylsilyl group, a pentyldimethylsilyl group, a pentyldiethylsilyl group, a tripentylsilyl group, a hexyldimethylsilyl group, a cyclohexyldimethylsilyl group, a hexyldiethylsilyl group, a cyclohexyldiethylsilyl group, and a trihexylsilyl group. The titanium complex (1) of the present invention has a vapor pressure and thermal stability suitable for use as a CVD or ALD material, and therefore R 1 and R 2 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. In addition, R 3 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group or a tert-butyl group, and particularly preferably a tert-butyl group.

[0022] Next, the definition of n in the general formula (1) will be described. n represents an integer of 0 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.

[0023] Specific examples of the titanium complex (1) of the present invention include:

[0024] [ka]

[0025] In terms of having a suitable vapor pressure and thermal stability as a CVD material or ALD material, (1-1) to (1-5) and (1-11) to (1-15) are preferred, (1-11) to (1-15) are more preferred, and (1-15) is particularly preferred.

[0026] Next, a method for producing the titanium complex (1) of the present invention will be described.

[0027] The titanium complex (1) can be produced by the production method 1.

[0028] The production method 1 of the present invention is a method for producing a titanium complex (1) by reacting a halo complex (2) with a metal amide (3).

[0029] Manufacturing method 1

[0030] [ka]

[0031] (In the formula, R 1 , R 2 , R 3 , X, M and n are as defined above. First, the definition of X in the general formula (2) will be described. X represents a halogen atom, and examples thereof include chlorine, bromine, and iodine. Chlorine is preferred because it provides a good yield of the titanium complex (1) of the present invention.

[0032] In the general formula (2), n represents an integer of 0 to 3. In terms of providing a good yield for the titanium complex (1) of the present invention, n is preferably 2 or 3, and more preferably 3.

[0033] Examples of the halo complex (2) that can be used in Production Method 1 of the present invention include

[0034] [ka]

[0035] In terms of good yield, (2-1), (2-2), (2-5) or (2-6) is preferred, and (2-1) or (2-5) is more preferred.

[0036] The halo complex (2) that can be used in the production method 1 of the present invention can be obtained according to the method described in, for example, Canadian Journal of Chemistry, Vol. 69, p. 357 (1991), Organometallics, Vol. 24, p. 5383 (2005), or Organometallics, Vol. 28, p. 4269 (2009).

[0037] Next, the definition of M in the general formula (3) will be described. M represents an alkali metal, and examples thereof include lithium, sodium, and potassium, and lithium is preferred because it provides a good yield of the titanium complex (1) of the present invention.

[0038] Examples of metal amide (3) that can be used in the production method 1 of the present invention include lithium methylamide, sodium methylamide, potassium methylamide, lithium ethylamide, sodium ethylamide, potassium ethylamide, lithium propylamide, sodium propylamide, potassium propylamide, lithium isopropylamide, sodium isopropylamide, potassium isopropylamide, lithium butylamide, sodium butylamide, potassium butylamide, lithium isobutylamide, sodium isobutylamide, potassium isobutylamide, lithium sec-butylamide, sodium sec-butylamide, potassium sec-butylamide, lithium tert-butylamide, sodium tert-butylamide, potassium tert-butylamide, lithium trimethylsilylamide, sodium trimethylsilylamide, potassium trimethylsilylamide, etc. In terms of good yield of the titanium complex (1) of the present invention, lithium methylamide, lithium ethylamide, lithium propylamide, lithium isopropylamide, and lithium tert-butylamide are preferred, and lithium tert-butylamide is more preferred.

[0039] The metal amide (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 method described in Inorganic Chemistry, Vol. 50, p. 636 (2011), for example.

[0040] There is no particular limitation on the molar ratio of halo complex (2) and metal amide (3) when carrying out Production Method 1 of the present invention. From the viewpoint of a good yield of titanium complex (1) of the present invention, 0.8 to 1.5 molar equivalents of metal amide (3) per molar equivalent of halo complex (2) are preferred, and 0.9 to 1.1 molar equivalents of metal amide (3) are more preferred.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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 reducing gas include cyclic unsaturated hydrocarbons such as 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. 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. The flow rate of the reactive 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 is preferably 1 to 10,000 sccm for economic reasons. In this specification, sccm is a unit of gas flow rate, and 1 sccm indicates that the gas moves at a rate of 2.68 mmol / h when converted into an ideal gas.

[0047] 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.

[0048] 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.

[0049] 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, ozone, hydrogen peroxide, etc., a titanium-containing thin film can be produced at an even lower temperature range.

[0050] 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.

[0051] 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.

[0052] 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

[0053] 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]

[0054] [Figure 1] 1 is a DSC chart of tris(diethylamido)(tert-butylamido)titanium (1-15) in Evaluation Example 1. [Diagram 2] 1 is a DSC chart of tetrakis(dimethylamido)titanium of Comparative Example 1. [Diagram 3] 1 is a DSC chart of tetrakis(diethylamido)titanium of Comparative Example 2. [Figure 4] 1 is a DSC chart of tetrakis(ethylmethylamido)titanium in Comparative Example 3. EXAMPLES

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. All the preparations of the compounds described in Reference Example 1 and Example 1 were carried out under an argon atmosphere. The hexane used was a dehydrated product manufactured by Kanto Chemical Co., Ltd. Diethylamine and tert-butylamine were manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Tetrakis(dimethylamido)titanium, tetrakis(diethylamido)titanium, and tetrakis(ethylmethylamido)titanium were purchased from STREM CHEMICALS.

[0056] Reference example 1

[0057] [ka]

[0058] To a solution of 14.8 mL (143.0 mmol) of diethylamine in hexane (50 mL), 92.3 mL (1.55 mol / L, 143.0 mmol) of butyllithium in hexane was added at -65°C. After stirring this mixture at 25°C for 1 hour, it was added to a solution of 9.05 g (47.7 mmol) of titanium tetrachloride in hexane (50 mL) at -65°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 120°C / back pressure 39 Pa) to obtain 6.86 g of tris(diethylamido)titanium chloride (2-5) as a red liquid. Yield 48%. 1 H-NMR(400MHz,C6D6,δ):3.53(q,12H),1.05(t,18H). Example 1

[0059] [ka]

[0060] To a solution of 1.9 mL (18.0 mmol) of tert-butylamine in hexane (15 mL), 9.7 mL (1.55 mol / L, 15.0 mmol) of butyllithium in hexane was added at -65°C. After stirring this mixture at 25°C for 1 hour, it was added to a solution of 3.84 g (12.8 mmol) of tris(diethylamido)titanium chloride synthesized in Reference Example 1 in hexane (40 mL) at -65°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 120°C / back pressure 36 Pa) to obtain 0.81 g of tris(diethylamido)(tert-butylamido)titanium (1-15) as a red liquid. Yield 17%. 1 H-NMR(400MHz,C6D6,δ):5.78(brs,1H),3.60(q,12H),1.31(s,9H),1.13(t,18H). Evaluation example 1 Thermal analysis of tris(diethylamido)(tert-butylamido)titanium(1-15) As a sample, 5.3 mg of (1-15) synthesized in Example 1 was used for differential scanning calorimetry (DSC).

[0061] 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 224°C.

[0062] Comparative Example 1 Thermal analysis of tetrakis(dimethylamido)titanium. Tetrakis(dimethylamido)titanium was used in the DSC in an amount of 2.5 mg.

[0063] 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 229°C.

[0064] Comparative Example 2 Thermal analysis of tetrakis(diethylamido)titanium. Tetrakis(diethylamido)titanium was used in the DSC in an amount of 3.0 mg.

[0065] 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 232°C.

[0066] Comparative Example 3 Thermal analysis of tetrakis(ethylmethylamido)titanium. Tetrakis(ethylmethylamido)titanium was used in the DSC at 4.4 mg.

[0067] 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.

[0068] The results of Evaluation Example 1 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.

Claims

1. General formula (1) 【Chemistry 1】 （１） (In the formula, R １ and R ２ is a methyl group or an ethyl group, R ３ is a tert-butyl group, and n is 3.

2. General formula (2) 【Chemistry 2】 （２） (In the formula, R １ , and R ２ each independently represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; n represents an integer of 0 to 3; and X represents a halogen atom. 【Chemistry 3】 （３） (In the formula, R ３ represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; M represents an alkali metal; 【Chemistry 4】 （１） A method for producing a titanium complex represented by general formula (1). (In the formula, R １ , R ２ and R ３ each independently represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; and n represents an integer of 0 to 3.

3. General formula (1) 【Chemistry 5】 （１） (In the formula, R １ , R ２ and R ３ each independently represents an alkyl group having 1 to 6 carbon atoms or a tri(alkyl)silyl group having 1 to 6 carbon atoms; and n represents an integer of 0 to 3. A method for producing a titanium-containing thin film, comprising using a titanium complex represented by the following formula (I):

4. The method for producing a titanium-containing thin film according to claim 3, wherein the vapor deposition method based on a chemical reaction is a chemical vapor deposition method.

5. The method for producing a titanium-containing thin film according to claim 3 or 4, characterized in that a reactive gas is used in a vapor phase deposition method based on a chemical reaction.

6. The method for producing a titanium-containing thin film according to claim 5, wherein a reducing gas is used as the reactive gas.

7. The method for producing a titanium-containing thin film according to any one of claims 3 to 6, wherein the titanium-containing thin film is a titanium nitride thin film.

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