TW201815801A - Raw material for forming film and method for producing the same - Google Patents

Abstract

Provided is a starting material for the thin film formation, which contains a compound represented by general formula (1). In general formula (1), R1-R4 may be the same or different, and each represents an alkyl group having 1-5 carbon atoms; R5-R7 may be the same or different, and each represents an alkyl group having 1-5 carbon atoms; and M represents titanium, zirconium or hafnium. Compounds represented by general formula (1) wherein all of the R1-R4 moieties and R5-R7 moieties are methyl groups are preferable since these compounds have a wide ALD window and are capable of forming a high-quality metal-containing thin film.

Description

   Raw material for film formation and manufacturing method of film   

The present invention relates to a raw material for forming a thin film containing a specific compound and a method for producing the thin film using the raw material for forming a thin film.

Metal oxides such as zirconia or titanium oxide are used as gate insulating films in semiconductor memory materials. In addition, thin films containing metal carbides such as zirconium carbide, hafnium carbide, and titanium carbide can be used for wiring or electrodes for cutting tools and electronic materials. For example, they have been reviewed for semiconductor memory materials and electrodes for lithium-air batteries. application.

Examples of the method for manufacturing the thin film include a sputtering method, an ion plating method, a MOD method such as a coating thermal decomposition method or a sol-gel method, a chemical vapor growth method, and the like, but include ALD (Atomic Layer Deposition, atomic layer). Chemical vapor phase growth (hereinafter sometimes referred to simply as "CVD") method, because it has many advantages such as excellent composition control, step coverage, suitable for mass production, and can be mixed into a stack, etc. For the most suitable manufacturing process.

In Patent Literature 1 and Patent Literature 2, Ti (C ₅ Me ₅ ) (Me) ₃ is disclosed as a raw material for forming a titanium-containing thin film by the ALD method. However, the Ti (C ₅ Me ₅ ) (Me) ₃ system has poor thermal stability. Therefore, a residual carbon component, which is an organic substance, is mixed into the film, and there is a problem that a high-quality film cannot be formed.

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2006-310865

[Patent Document 2] Japanese Patent Publication No. 2009-545135

What is required in the method for manufacturing a metal-containing thin film using a chemical vapor growth method is that the raw material for thin film formation used has no spontaneous combustion property, and a thin film can be formed safely. It has good reactivity and / or productivity. In addition, a low carbon content is mixed into the obtained metal-containing film, and high quality is also required. Conventionally, there has not been a satisfactory raw material for forming a thin film and a method for producing a thin film by these points.

As a result of repeated review by the present inventors, it was found that a raw material for forming a thin film containing a specific compound and a method for manufacturing a thin film containing a metal using the raw material for thin film formation can solve the above problems, and thus completed the present invention.

The present invention provides a raw material for forming a thin film, which is formed by containing a compound represented by the following general formula (1):

(In the formula, R ¹ to R ⁴ are alkyl groups having 1 to 5 carbon atoms which may be the same or different, and R ⁵ to R ⁷ are alkyl groups having 1 to 5 carbon atoms which may be the same or different, M represents titanium, zirconium or hafnium).

The present invention provides a method for manufacturing a thin film, which comprises introducing a vapor containing a compound represented by the general formula (1) obtained by vaporizing the raw material for forming a thin film into the film-forming chamber provided with a substrate, and The compound is decomposed and / or chemically reacted to form a thin film containing at least one metal selected from titanium, zirconium and hafnium on the surface of the substrate.

According to the present invention, it is possible to provide a raw material for forming a thin film, which is suitable for a raw material for forming a thin film for chemical vapor growth used to form a thin film containing a metal, so that the contained metal having excellent productivity and good quality can be further safely produced. Thin film.

[Fig. 1] Fig. 1 is a schematic diagram showing an example of a chemical vapor growth apparatus that can be used in the method for producing a metal-containing film of the present invention.

[Fig. 2] Fig. 2 is a schematic diagram showing another example of an apparatus for chemical vapor growth that can be used in the method for producing a metal-containing film of the present invention.

[Fig. 3] Fig. 3 is a schematic diagram showing another example of an apparatus for chemical vapor growth that can be used in the method for producing a metal-containing film of the present invention.

[Fig. 4] Fig. 4 is a schematic diagram showing another example of a chemical vapor growth apparatus that can be used in the method for producing a metal-containing film of the present invention.

The raw material for thin film formation of the present invention is a raw material for thin film formation containing a compound represented by the general formula (1), and is preferably used as a precursor for a thin film manufacturing method having a gasification step such as a CVD method or the like. The ALD method forms a thin film.

In the above general formula (1), R ¹ to R ⁴ represent an alkyl group having 1 to 5 carbon atoms which may be the same or different, and R ⁵ to R ⁷ represent an identical carbon group having 1 to 5 carbon atoms. The alkyl group, M represents titanium, zirconium or hafnium.

Examples of the alkyl system having 1 to 5 carbon atoms represented by R ¹ to R ⁴ and R ⁵ to R ⁷ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and Dibutyl, tertiary butyl, pentyl, isopentyl and the like.

In the above general formula (1), when at least one of R ¹ to R ⁴ is a primary alkyl group or when at least one of R ⁵ to R ⁷ is a primary alkyl group, it is represented by the general formula (1) Since the vapor pressure of the compound is high, it is preferable to produce a metal-containing thin film having high productivity. Among them, when all of R ¹ to R ⁴ are primary alkyl groups or when all of R ⁵ to R ⁷ are primary alkyl groups, the vapor pressure of the compound represented by the general formula (1) is particularly high, so It is preferable to produce a metal-containing film having high productivity. Further, when all of R ¹ to R ⁴ and R ⁵ to R ⁷ are methyl groups, it is applicable to a wide temperature range of the ALD method called an ALD window, and it is possible to produce high-quality thin films.

The compound represented by the general formula (1) is not particularly limited in accordance with the production method, and is produced by applying a known reaction. For example, when M is titanium, in a tetraalkylcyclopentadienyltrichlorotitanium, it is obtained by reacting it at -20 ° C to 50 ° C, preferably 0 ° C to 30 ° C. Alkyl lithium. When M is zirconium or hafnium, it can be produced by the same method.

Preferred specific examples of the compound represented by the general formula (1) include, for example, compounds represented by the following compounds No. 1 to No. 12. In the following compounds No. 1 to No. 12, "Me" represents a methyl group, and "Et" represents an ethyl group.

The raw material for forming a thin film of the present invention is a compound represented by the general formula (1) as a precursor for a chemical vapor growth method for forming a metal-containing thin film, and the form can be determined by the raw material for forming a thin film Applicable manufacturing processes vary. For example, when producing a thin film containing at least one metal selected from titanium, zirconium and hafnium, the raw material for forming a thin film of the present invention does not contain metal compounds and semi-metal compounds other than the compound represented by the general formula (1). On the other hand, when producing a thin film containing a metal and / or semimetal other than titanium, zirconium, and hafnium and at least one metal selected from titanium, zirconium, and hafnium, in addition to the compound represented by the general formula (1), The film-forming raw material of the present invention contains a compound containing a metal other than titanium, zirconium, and hafnium and / or a compound containing a semimetal (hereinafter also referred to as "other precursors"). The raw material for film formation of the present invention is described later, and may further contain an organic solvent and / or a nucleophilic reagent. The raw materials for film formation of the present invention are as described above. Since the physical properties of the compound represented by the general formula (1) applicable to precursors are CVD method and ALD method, they are particularly useful as raw materials for chemical vapor growth (hereinafter also referred to as " CVD raw materials ") useful.

The form of the raw material for forming a thin film of the present invention can be appropriately selected according to a method such as a transport and supply method of a CVD method used.

As the above-mentioned conveying and supplying method, there is a method in which a raw material for CVD is heated and / or reduced in pressure in a container storing the raw material (hereinafter sometimes simply referred to as a "raw material container") to vaporize the vapor, and the vapor is used as necessary. The carrier gas such as argon, nitrogen, and helium is introduced into the film-forming chamber (hereinafter sometimes referred to as a "stacking reaction part") by a gas transfer method, and the raw materials for CVD are transferred to the gas in a liquid or solution state. A vaporization chamber is a liquid transport method for vaporizing a vapor in a vaporization chamber by heating and / or reducing pressure, and introducing the vapor into a film forming chamber. In the gas transport method, the compound represented by the general formula (1) itself can be used as a raw material for CVD. In the case of the liquid transport method, the compound itself represented by the general formula (1) or a solution in which the compound is dissolved in an organic solvent can be used as a raw material for CVD. These raw materials for CVD can also be included in a section containing other precursors or nucleophilic reagents.

In addition, in the multi-component CVD method, there are a method in which each component of a raw material for CVD is independently vaporized and supplied (hereinafter sometimes referred to as a "single-source method"), and a multi-component raw material is mixed in advance with a desired composition. Method for gasifying and supplying raw materials (hereinafter sometimes referred to as "mixed source method"). In the case of the mixed source method, a mixture of the compound represented by the general formula (1) and other precursors or a mixed solution in which the mixture is dissolved in an organic solvent can be used as a raw material for CVD. The mixture or mixed solution may further include a nucleophilic reagent and the like.

The organic solvent is not particularly limited, and a known general organic solvent can be used. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, and n-butanol; acetates such as ethyl acetate, butyl acetate, and methoxyethyl acetate; tetrahydrofuran and tetrahydropyran , Ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, dibutyl ether, dioxane and other ethers; methylbutyl ketone, methyl isobutyl ketone, ethyl Ketones such as methyl butyl ketone, dipropyl ketone, diisobutyl ketone, methylpentyl ketone, cyclohexanone, methyl cyclohexanone; hexane, cyclohexane, methylcyclohexane, two Methylcyclohexane, ethylcyclohexane, heptane, octane, toluene, xylene and other hydrocarbons; 1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyano ring Hexane, cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, 1,6-dicyanohexane, 1,4-dicyanocyclohexane, 1,4 -Cyano-containing hydrocarbons such as dicyanobenzene; pyridine, lutidine and the like. These organic solvents can be used alone or as a mixture of two or more types according to the solubility of the solute, the relationship between the use temperature and the boiling point, and the ignition point. When using such an organic solvent, the total amount of the precursor in the CVD raw material in which the precursor is dissolved in the solution of the organic solvent is preferably 0.01 to 2.0 mol / liter, and particularly preferably 0.05 to 1.0 mol / liter. The total amount of the precursor is the amount of the compound represented by the general formula (1) when the raw material for forming a thin film of the present invention does not contain a metal compound and a semimetal compound other than the compound represented by the general formula (1). When the raw material for forming a thin film of the present invention contains a compound containing a metal other than the compound represented by the general formula (1) and / or a compound containing a semimetal (other precursors), it is represented by the general formula (1) The total amount of compounds and other precursors.

Moreover, in the multi-component CVD method, the other precursors used together with the compound represented by the general formula (1) are not particularly limited, and they can be used as well-known general precursors used in CVD raw materials. The ligand used in this precursor does not contain oxygen atoms in the structure, but it can reduce the amount of oxygen contained in the resulting metal-containing film, which is particularly preferred.

Examples of the other precursors mentioned above are selected from the group consisting of alcohol compounds, diol compounds, β-diketone compounds, cyclopentadiene compounds, and compounds that can be used as organic ligands such as organic amine compounds. One or more types of compounds with silicon or metal (except titanium, zirconium and hafnium). Examples of the metal species of the precursor include magnesium, calcium, strontium, barium, vanadium, niobium, tantalum, aluminum, manganese, iron, ruthenium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, Gold, zinc, gallium, indium, germanium, tin, lead, antimony, bismuth, thorium, yttrium, lanthanum, cerium, praseodymium, neodymium, giant, thorium, thorium, thorium, thorium, thorium, ', thorium, thorium, thorium, thorium, Wait

Examples of the alcohol compound that can be used as the organic ligand include methanol, ethanol, propanol, isopropanol, butanol, second butanol, isobutanol, third butanol, pentanol, isoamyl alcohol, Alkanols such as 3rd pentanol; 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2- (2-methoxyethoxy) ethanol, 2-methoxy 1-methylethanol, 2-methoxy-1,1-dimethylethanol, 2-ethoxy-1,1-dimethylethanol, 2-isopropoxy-1,1-dimethyl Ethyl alcohol, 2-butoxy-1,1-dimethylethanol, 2- (2-methoxyethoxy) -1,1-dimethylethanol, 2-propoxy-1,1- Ether alcohols such as diethyl ethanol, 2-s-butoxy-1,1-diethyl ethanol, and 3-methoxy-1,1-dimethylpropanol.

Examples of the diol compound that can be used as the organic ligand of the other precursors mentioned above include 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2,4-hexanediol, and 2, 2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,3-butanediol, 2,4-butanediol, 2,2-diethyl- 1,3-butanediol, 2-ethyl-2-butyl-1,3-propanediol, 2,4-pentanediol, 2-methyl-1,3-propanediol, 2-methyl-2, 4-pentanediol, 2,4-hexanediol, 2,4-dimethyl-2,4-pentanediol and the like.

Examples of β-diketone compounds include acetone, hexane-2,4-dione, 5-methylhexane-2,4-dione, heptane-2,4-dione, and 2 -Methylheptane-3,5-dione, 5-methylheptane-2,4-dione, 6-methylheptane-2,4-dione, 2,2-dimethylheptane -3,5-dione, 2,6-dimethylheptane-3,5-dione, 2,2,6-trimethylheptane-3,5-dione, 2,2,6, 6-tetramethylheptane-3,5-dione, octane-2,4-dione, 2,2,6-trimethyloctane-3,5-dione, 2,6-dimethyl Octane-3,5-dione, 2,9-dimethylnonane-4,6-dione, 2-methyl-6-ethyldecane-3,5-dione, 2,2 Alkyl-substituted β-diketones such as -dimethyl-6-ethyldecane-3,5-dione; 1,1,1-trifluoropentane-2,4-dione, 1,1 1,1-trifluoro-5,5-dimethylhexane-2,4-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, 1,3 -Fluorin-substituted alkyl β-diketones such as diperfluorohexylpropane-1,3-diones; 1,1,5,5-tetramethyl-1-methoxyhexane-2,4-dione Ketone, 2,2,6,6-tetramethyl-1-methoxyheptane-3,5-dione, 2,2,6,6-tetramethyl-1- (2-methoxyethyl Ethyl) heptane-3,5-dione and the like are substituted for β-diketones and the like.

Examples of the cyclopentadiene compound system include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, and butylcyclopentadiene. Alkenes, 2butylcyclopentadiene, isobutylcyclopentadiene, 3butylcyclopentadiene, dimethylcyclopentadiene, tetramethylcyclopentadiene, etc .; as the above-mentioned organic compound Examples of organic amine compounds that can be used as the methyl group include methylamine, ethylamine, propylamine, isopropylamine, butylamine, second butylamine, third butylamine, isobutylamine, and diamine. Methylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, isopropylmethylamine, and the like.

Examples of the organic amine compound that can be used as the organic ligand include ketimine compounds, amido compounds, methylamines, ethylamines, propylamines, isopropylamines, butylamines, Second butylamine, third butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, Isopropylmethylamine, bis (trimethylsilyl) amine, and the like.

The other precursors mentioned above are known in the art, and their manufacturing methods are also known. For example, when an alcohol compound is used as an organic ligand, for example, a precursor can be produced by reacting the aforementioned metal inorganic salt or a hydrate thereof with an alkali metal alkoxide of the alcohol compound. Here, examples of the inorganic salt or hydrate of the metal include halides and nitrates of the metal, and examples of the alkali metal alkoxide include sodium alkoxide, lithium alkoxide, and potassium alkoxide.

For the other precursors mentioned above, in the single-source method, the compound represented by the general formula (1) above is preferably a compound with similar thermal and / or oxidative decomposition behavior. In the mixed-source method, except for the thermal and / or oxidative decomposition behavior, Other than that, those that do not cause deterioration such as chemical reactions during mixing are preferred.

In addition, the film-forming material of the present invention may contain a nucleophilic reagent in order to impart stability to the raw material, if necessary. Examples of the nucleophilic reagent include glycol ethers such as glycol dimethyl ether, diglyme, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether, 18-crown ether-6, Crown ethers such as dicyclohexyl-18-crown ether-6, 24-crown ether-8, dicyclohexyl-24-crown ether-8, dibenzo-24-crown ether-8, ethylenediamine, N , N'-Tetramethylethylenediamine, Diethylenetriamine, Triethylenetetraamine, Tetraethylenepentamine, Pentaethylenehexamine, 1,1,4,7,7-Pentamethyldiamine Polyamines such as ethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, triethoxytriethyleneamine, etc., tetraazacyclotetradecane (cyclam), Tetraazacyclododecane (cyclicn) and other cyclic polyamines, pyridine, pyrrolidine, piperidine, morpholine, N-methylpyrrolidine, N-methylpiperidine, N-methylmorpholine, Heterocyclic compounds such as tetrahydrofuran, tetrahydropyran, 1,4-dioxane, oxazole, thiazole, oxathiolane, etc., methyl ethyl acetate, ethyl ethyl acetate, ethyl Β-ketoesters such as 2-methoxyacetic acid or acetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, and dipentazone Β-II Class, such nucleophilic reagent is used in an amount of, a compound represented by the above general formula (1) 1 mole, 0.1 mole to 10 mole range of preferably 1 to 4 mole is more preferable. When using such a nucleophilic reagent, it is preferable that the structure of the nucleophilic reagent does not include an oxygen atom, and it is further preferable that the structure includes a nitrogen atom.

The raw material for forming a thin film of the present invention does not contain impurities such as impurity metal elements other than components constituting the impurities, impurity impurities such as chlorine, and impurity organic components as much as possible. The impurity metal element is preferably 100 ppb or less per element, more preferably 10 ppb or less, the total amount is preferably 1 ppm or less, and more preferably 100 ppb or less. In particular, when gate insulation films, gate films, and barrier layers used as LSIs are used, it is necessary to reduce the content of alkali metal elements, alkaline earth metal elements, and congener elements that affect the electrical characteristics of the obtained thin film. The impurity halogen is preferably 100 ppm or less, more preferably 10 ppm or less, and most preferably 1 ppm or less. The total amount of organic impurities is preferably 500 ppm or less, more preferably 50 ppm or less, and most preferably 10 ppm or less. In addition, due to the occurrence of particles in the raw materials for chemical vapor growth or particles in the formation of thin films, in the precursors, organic solvents, and nucleophilic reagents, in order to reduce the respective moisture, it is better to use them in advance. Remove as much water as possible. The water content of each of the precursor, the organic solvent and the nucleophilic reagent is preferably 10 ppm or less, and more preferably 1 ppm or less.

The raw material for forming a thin film of the present invention preferably contains no particles as much as possible in order to reduce or prevent particle contamination of the formed thin film. Specifically, in the liquid phase particle measurement by a light scattering type liquid particle detector, the number of particles larger than 0.3 μm is preferably 100 or less in 1 ml of liquid phase, and the number of particles larger than 0.2 μm is 1 ml in liquid phase. It is more preferable that the number is less than 1,000, and that the number of particles larger than 0.2 μm is more preferably less than 100 in 1 ml of the liquid phase.

As the method for manufacturing the thin film of the present invention, the vaporized vapor of the compound represented by the general formula (1) and the reactive gas used as required are introduced into a film-forming chamber provided with a substrate. A CVD method that decomposes and / or chemically reacts on the substrate and / or in the film-forming chamber and / or near the gas inlet to grow on the surface of the substrate and deposit a metal-containing film. The method of conveying and supplying raw materials, stacking method, manufacturing conditions, manufacturing equipment, etc. are not particularly limited, and known general conditions and methods can be used.

Examples of the reactive gas used as needed include oxygen, ozone, nitrogen dioxide, nitric oxide, water vapor, hydrogen peroxide, formic acid, acetic acid, and acetic anhydride. Examples of the reducing gas include: Hydrogen, and as a nitride producer, examples include organic amine compounds such as monoalkylamine, dialkylamine, trialkylamine, butanediamine, hydrazine, ammonia, and the like, and one or two or more of these can be used. Before reacting the reactive gas with the precursor, a plasma treatment may be performed in advance.

Furthermore, examples of the above-mentioned transportation and supply method include the aforementioned gas transportation method, liquid transportation method, single-source method, and mixed-source method.

In addition, as the above-mentioned deposition method, for example, thermal CVD in which a raw material gas or a raw material gas and a reactive gas react only by heat to deposit a thin film, plasma CVD using heat and plasma, and light using heat and light CVD, using photo-plasma CVD of heat, light and plasma, divides the CVD stacking reaction into basic processes, and performs ALD at a molecular level for staged stacking.

Examples of the material of the above substrate are, for example, silicon; indium arsenide, indium gallium arsenide, silicon dioxide, silicon nitride, silicon carbide, titanium nitride, tantalum oxide, tantalum nitride, titanium oxide, titanium nitride, ruthenium oxide, Ceramics such as zirconia, hafnium oxide, lanthanum oxide, gallium nitride; glass; platinum-ruthenium, aluminum, copper, nickel, cobalt, tungsten, molybdenum and other metals. Examples of the shape of the substrate include a plate shape, a spherical shape, a fibrous shape, and a scaly shape. The surface of the substrate may be a flat surface or a three-dimensional structure such as a groove structure.

In addition, examples of the production conditions include a reaction temperature (substrate temperature), a reaction pressure, and a deposition rate. The reaction temperature is preferably 100 ° C or higher, and more preferably 150 ° C to 400 ° C, at which the compound represented by the general formula (1) is sufficiently reacted. When the reaction pressure is thermal CVD or photo CVD, atmospheric pressure to 10 Pa is preferred, and when plasma is used, 2000 Pa to 10 Pa is preferred. The deposition rate can be controlled by the supply conditions of the raw materials (gasification temperature, gasification pressure), reaction temperature, and reaction pressure. If the deposition rate is too large, the characteristics of the obtained thin film may be deteriorated, and if it is too small, productivity may be problematic. Therefore, 0.01 to 100 nm / minute is preferable, and 1 to 50 nm / minute is more preferable. In the ALD method, the number of cycles is controlled to obtain a desired film thickness.

As said manufacturing conditions, the temperature or pressure at the time of vaporizing the raw material for film formation to vapor | steam are further exemplified. The step of vaporizing the raw material for film formation into vapor may be performed in a raw material container or in a gasification chamber. In either case, it is preferable that the raw material for forming a thin film used in the method for producing a thin film of the present invention is evaporated at 0 to 150 ° C. In addition, when the raw material for film formation is vaporized into vapor in the raw material container or the gasification chamber, the pressure in the raw material container and the pressure in the gasification chamber are preferably 1 to 10,000 Pa.

The method for producing a thin film of the present invention may include an ALD method, in which the raw material for film formation is vaporized into vapor by the above-mentioned conveying and supplying method, and the raw material introduction step of introducing the vapor into the film-forming chamber may also include using the vapor. A step of forming a precursor film on the surface of the substrate by a compound represented by the above general formula (1), a step of exhausting an unreacted compound gas represented by the above general formula (1), and an exhaust step, and The precursor film is chemically reacted with a reactive gas to form a metal-containing film forming step on the surface of the substrate, the film containing at least one metal selected from titanium, zirconium and hafnium.

Hereinafter, for each of the above steps, a case where a metal-containing thin film is formed by an ALD method is described in detail as an example. When forming a metal-containing thin film by the ALD method, first, the raw material introduction step described above is performed. The preferred temperature or pressure for making the film-forming raw material into vapor is the same as that described above. Then, a precursor film is formed on the surface of the substrate by using the compound represented by the general formula (1) introduced into the film formation chamber portion (precursor film formation step). In this case, heat may be applied by heating the substrate or the film forming chamber portion.

The precursor film formed in this step is a film formed by the compound represented by the general formula (1) adsorbed on the surface of the substrate or the compound or a part of the compound is decomposed and / or reacted. Metal thin films have different compositions. The substrate temperature during this step is preferably room temperature to 600 ° C, and more preferably 150 to 400 ° C. The pressure of the system (in the film forming chamber) when performing this step is preferably 1 ~ 10000Pa, and more preferably 10 ~ 1000Pa.

Then, an unreacted compound gas represented by the above-mentioned general formula (1) or a by-product gas is discharged from the film forming chamber (exhaust step). The unreacted compound gas or by-product gas represented by the above-mentioned general formula (1) is desirably completely exhausted from the film forming chamber, but it is not necessary to exhaust completely. The exhaust method includes a method of blowing the inside of the system with an inert gas such as nitrogen, helium, and argon, a method of exhausting the system by reducing the pressure in the system, and a combination of these methods. The decompression degree during decompression is preferably 0.01 to 300 Pa, and more preferably 0.01 to 100 Pa.

Then, a reactive gas is introduced into the film forming chamber, and a metal-containing film is formed from the precursor film obtained from the previous precursor film film forming step by using the reactive gas or the reaction gas and heat. Metal-containing thin film forming step). In this step, a room temperature to 600 ° C., which is a temperature at which heat is applied, is more preferable, and 150 to 400 ° C. is more preferable. The pressure of the system (in the film forming chamber) when performing this step is preferably 1 ~ 10000Pa, and more preferably 10 ~ 1000Pa.

In the thin film manufacturing method of the present invention, when the ALD method is used as described above, the film stacking of a series of operations formed by the above-mentioned raw material introduction step, precursor thin film formation step, exhaust step, and metal-containing thin film formation step is set as 1 cycle, this cycle can be repeated several times until a necessary film thickness is obtained. In this case, after performing one cycle, the unreacted compound gas represented by the general formula (1) and the reactive gas are discharged from the film forming chamber in the same manner as the above-mentioned exhausting step, and the by-product gas is discharged into one section. It is better to perform the next cycle.

In addition, in the method for manufacturing a thin film of the present invention, when the above-mentioned ALD method is used, energy such as plasma, light, and voltage may be applied, and a catalyst may also be used. The period of applying such energy is not particularly limited, and it is preferably, for example, the system of the exhaust step when the compound gas is introduced in the material introduction step, the precursor film formation step or the metal-containing film formation step is heated, In the case of internal exhaust, when a reactive gas is introduced in the metal-containing thin film forming step, it may be between the above steps. Before the reactive gas is introduced, such energy may be applied to the reactive gas.

In addition, in the method for manufacturing a thin film of the present invention, when the plasma ALD method is used as described above, a reactive gas can continuously flow into the film forming chamber between all steps in the manufacturing method, and is formed only on a thin film containing a metal. In the step, a person who plasma-processes the reactive gas may be introduced into the film forming chamber. High-frequency (hereinafter, sometimes referred to as RF) output is too low, it is not easy to become a film containing good metal, too high will damage the substrate, so 0 ~ 1500W is better, 50 ~ 600W is better . In the manufacturing method of the present invention, when the plasma ALD method is used, a thin film containing a very high-quality metal can be used.

In addition, in the method for manufacturing a thin film of the present invention, in order to obtain better electrical characteristics after the thin film is deposited, an annealing treatment may be performed in an inert environment, and when a step difference must be buried, a reflow step may be provided. In this case, the temperature is preferably 200 to 1000 ° C, preferably 250 to 500 ° C.

As a device for manufacturing a thin film containing a metal using the raw material for forming a thin film of the present invention, a known device for a chemical vapor growth method can be used. As an example of a specific device, for example, a device capable of performing precursor supply by bubbling as shown in FIG. 1 or a device having a gasification chamber as shown in FIG. 2 is exemplified. In addition, an example is a device capable of performing plasma treatment on a reactive gas as shown in FIGS. 3 and 4. It is not limited to the single-chip device as shown in FIG. 1, FIG. 2, FIG. 3, and FIG.

The metal-containing thin film produced by using the film-forming raw material of the present invention can be used for wiring or electrodes for cutting tools and electronic materials, for example, for semiconductor memory materials or electrodes for lithium-air batteries.

    [Example]    

Examples and evaluation examples are given below to explain the present invention in more detail. However, the present invention is not limited in any way by the following examples and the like.

    [Evaluation example 1]    

The presence of the self-ignitability was confirmed by leaving the compound No. 1 in the air. The results are shown in Table 1.

Based on the results in Table 1, it was found that the compound No. 1 did not show spontaneous combustion, and it was understood that the compound No. 1 can be safely used as a raw material for chemical vapor growth even in the atmosphere.

    [Example 1]    

Using compound No. 1 as a raw material for chemical vapor growth, a titanium oxide thin film was produced on a silicon wafer by an ALD method under the following conditions using the apparatus shown in FIG. 3. For the obtained thin film, when the film thickness was measured by the X-ray reflectance method, and the film structure and the film composition were confirmed by the X-ray diffraction method and X-ray Photoelectron Spectroscopy, the film thickness was 4.0 nm. The film composition is titanium oxide, and the lower detection limit of carbon content is less than 0.1 atom%. The film thickness obtained per cycle was 0.08 nm.

    (Condition)    

Reaction temperature (substrate temperature): 200 ° C, reactive gas: ozone

    (Step)    

Set one of the following steps (1) to (4) as one cycle and repeat 50 cycles: (1) Under the conditions of the temperature of the raw material container: 70 ° C and the pressure of the raw material container: 0.6 Torr (80Pa), The vapor of the vaporized chemical vapor phase growth raw material is introduced into the film forming chamber, and is deposited on the surface of the silicon wafer for 10 seconds under a system pressure of 0.5 Torr (67Pa); (2) the argon is blown for 15 seconds to remove Reaction raw materials; (3) introducing a reactive gas and reacting at a system pressure of 0.5 Torr (67 Pa) for 10 seconds; (4) removing unreacted raw materials by blowing with argon for 15 seconds.

    [Comparative Example 1]    

A titanium oxide film was produced under the same conditions as in Example 1 except that (pentamethylcyclopentadienyl) (trimethyl) titanium was used as a raw material for the chemical vapor growth method.

For the obtained thin film, the film thickness was measured by the X-ray reflectance method, and the film structure and the film composition were confirmed by the X-ray diffraction method and the X-ray photoelectron spectroscopy. The film thickness was 3.0 nm, and the film composition was titanium oxide. The carbon content is 10 atom%. The film thickness obtained per cycle was 0.06 nm.

The film obtained in Example 1 had very low residual carbon content as an organic substance, and was a high-quality titanium oxide film. On the other hand, the thin film obtained in Comparative Example 1 had a large amount of residual carbon component as an organic substance, and was a low-quality titanium oxide thin film. Moreover, it can be understood that the film thickness obtained in each cycle of Example 1 is greater than that of Comparative Example 1.

Still, this international application claims priority based on Japanese Patent Application No. 2016-133140 filed on July 5, 2016, and the entire contents of this Japanese international application are incorporated into this international application.

Claims (2)

A raw material for forming a thin film, which is formed by containing a compound represented by the following general formula (1): (In the formula, R ¹ to R ⁴ are alkyl groups having 1 to 5 carbon atoms which may be the same or different, and R ⁵ to R ⁷ are alkyl groups having 1 to 5 carbon atoms which may be the same or different, M represents titanium, zirconium or hafnium).     A method for manufacturing a thin film, which comprises introducing a vapor containing a compound represented by the general formula (1) obtained by vaporizing a raw material for forming a thin film as claimed in claim 1, and introducing the vapor into a film-forming chamber provided with a substrate, so that the compound Decompose and / or chemically react to form a thin film containing at least one metal selected from titanium, zirconium and hafnium on the surface of the substrate.