Raw materials for forming thin films using atomic layer deposition, thin films, methods for manufacturing thin films, and ruthenium compounds

Abstract

Provided is a thin film-forming material, for use in atomic layer deposition, that contains a ruthenium compound represented by general formula (1).　(In the formula: R1 represents a hydrogen atom or a methyl group; and R2 and R3 independently represent a hydrogen atom or an alkyl group having 1-5 carbon atoms.)

Description

[Technical Field]

[0001] The present invention relates to a raw material for forming thin films using atomic layer deposition containing a specific ruthenium compound, a method for producing thin films using the raw material for forming thin films using atomic layer deposition, a thin film, and a ruthenium compound. [Background technology]

[0002] Ruthenium is a low-resistance, thermally and chemically stable metal. Thin films containing ruthenium atoms (hereinafter sometimes referred to as "ruthenium-containing thin films") exhibit unique electrical properties and are used in a variety of applications. For example, they are known to be used as electrode materials, wiring materials, and resistive films for memory elements such as DRAM elements, as well as diamagnetic films used in the recording layer of hard disks, catalyst materials for polymer electrolyte fuel cells, and metal gate materials for MOS-FETs.

[0003] Methods for manufacturing ruthenium-containing thin films include sputtering, ion plating, MOD methods such as coating pyrolysis and sol-gel methods, and chemical vapor deposition (CVD). Among these, chemical vapor deposition (CVD) and atomic layer deposition (ALD) are the most suitable manufacturing processes due to their many advantages, including excellent composition control, superior step coverage, suitability for mass production, and the possibility of hybrid integration.

[0004] While various raw materials have been reported that can be used in chemical vapor deposition (CVD) and ALD (Advanced Laser Development) methods, thin-film forming raw materials applicable to the ALD method must have a sufficiently wide temperature range known as the ALD window. It is common technical knowledge in this field that thin-film forming raw materials that can be used in the CVD method are often unsuitable for the ALD method.

[0005] Various compounds are known as raw materials for forming ruthenium-containing thin films. For example, Patent Document 1 discloses a ruthenium complex coordinated with cyclohexadiene. Patent Document 2 discloses a ruthenium compound composed of two six-membered rings containing two carbonyl groups, a ruthenium atom, and a ketoimine group in the ring structure. Patent Document 3 discloses a ruthenium-containing thin film produced by thermal CVD using a ruthenium complex mixture and a reducing gas. Non-Patent Document 1 discloses a ruthenium complex in which a ketoimine group having two carbonyl groups and two five-membered ring structures is bonded to ruthenium. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2008 / 078296 [Patent Document 2] International Publication No. 2015 / 093177 [Patent Document 3] Japanese Patent Publication No. 2014-118605 [Non-patent literature]

[0007] [Non-Patent Document 1] Chemistry of Materials (2003), 15(12), 2454-2462,“Synthesis and Characterization of Ruthenium Complexes with Two Fluorinated Amino Alkoxide Chelates. The Quest To Design Suitable MOCVD Source Reagents” [Overview of the project] [Problems that the invention aims to solve]

[0008] However, when producing a thin film by ALD using the ruthenium complex or ruthenium compound described in Patent Documents 1 to 3, there was a problem that it was difficult to obtain a high-quality ruthenium-containing thin film with little residual carbon. In addition, neither the fact that the ruthenium complex described in Non-Patent Document 1 has an ALD window nor the use of the ruthenium complex in the ALD method is specifically described in Non-Patent Document 1.

[0009] Therefore, an object of the present invention is to provide a raw material for forming a thin film for atomic layer deposition that can produce a high-quality ruthenium-containing thin film with little residual carbon by ALD, and a method for producing a thin film using the same.

Means for Solving the Problems

[0010] As a result of intensive studies, the present inventors have found that by using a raw material for forming a thin film for atomic layer deposition containing a ruthenium compound having a specific structure, the above problems can be solved, and the present invention has been completed.

[0011] That is, the present invention is a raw material for forming a thin film for atomic layer deposition containing a ruthenium compound represented by the following general formula (1).

[0012]

Chemical formula

[0013] (In the formula, R 1 represents a hydrogen atom or a methyl group, and R 2 and R 3 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

[0014] The present invention is a thin film obtained by using the above raw material for forming a thin film for atomic layer deposition.

[0015] The present invention is a method for producing a thin film, which includes forming a thin film containing ruthenium atoms on the surface of a substrate using the above raw material for forming a thin film for atomic layer deposition.

[0016] The present invention relates to a ruthenium compound represented by the following general formula (2).

[0017] [ka]

[0018] (In the formula, R 4 (This represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

[0019] The present invention relates to a raw material for forming thin films containing a ruthenium compound represented by the above general formula (2).

[0020] The present invention is a thin film made using the above-mentioned raw materials for forming thin films.

[0021] The present invention is a method for producing a thin film, comprising forming a thin film containing ruthenium atoms on the surface of a substrate using the above-mentioned raw materials for forming thin films. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a raw material for forming a thin film using atomic layer deposition, which can form a high-quality ruthenium-containing thin film with low residual carbon content, and a method for manufacturing a thin film using the same. [Brief explanation of the drawing]

[0023] [Figure 1] Figure 1 is a schematic diagram showing an example of an ALD apparatus used in the thin film manufacturing method of the present invention. [Figure 2] Figure 2 is a schematic diagram showing another example of an ALD apparatus used in the thin film manufacturing method of the present invention. [Figure 3] Figure 3 is a schematic diagram showing another example of an ALD apparatus used in the thin film manufacturing method of the present invention. [Figure 4] Figure 4 is a schematic diagram showing another example of an ALD apparatus used in the thin film manufacturing method of the present invention. [Modes for carrying out the invention]

[0024] [Raw material for thin film formation by atomic layer deposition method] The raw material for thin film formation by the atomic layer deposition method of the present invention is characterized by containing a ruthenium compound represented by the above general formula (1).

[0025] In the above general formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 and R 3 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0026] R 2 and R 3 Examples of the alkyl group having 1 to 5 carbon atoms represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and the like.

[0027] From the viewpoint of easily producing a high-quality ruthenium-containing thin film that is smooth and has little residual carbon with good productivity, R 1 is preferably a methyl group. From the viewpoint of easily producing a high-quality ruthenium-containing thin film that has a high vapor pressure, is smooth and has little residual carbon with good productivity, R 2 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. From the viewpoint of easily producing a high-quality ruthenium-containing thin film that has a high vapor pressure, is smooth and has little residual carbon with good productivity, R 3 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a methyl group.

[0028] Preferred specific examples of the ruthenium compound represented by general formula (1) used as a raw material for thin film formation in atomic layer deposition according to the present invention include the compounds No. 1 to No. 12 listed below, but the present invention is not limited to these ruthenium compounds. In the compounds listed below, "Me" represents a methyl group and "Et" represents an ethyl group.

[0029] [ka]

[0030] The ruthenium compound represented by general formula (1) used as a raw material for forming thin films for atomic layer deposition in the present invention is not particularly limited by its manufacturing method and can be produced by well-known synthesis methods. For example, it can be obtained by mixing RuCl2 (benzene) or RuCl2 (toluene) with sodium carbonate and any alcohol in the presence or absence of a solvent, stirring and reacting the mixture, and then further mixing, stirring and reacting any diene compound.

[0031] The raw material for forming a thin film using atomic layer deposition according to the present invention may contain a ruthenium compound represented by the above general formula (1) as a precursor for the thin film, and its composition varies depending on the type of thin film to be produced. For example, when producing a thin film containing only ruthenium atoms as the metal, the raw material for forming a thin film using atomic layer deposition does not contain any metal compounds other than ruthenium or metalloid compounds. On the other hand, when producing a thin film containing ruthenium atoms and metals and / or metalloids other than ruthenium atoms, the raw material for forming a thin film using atomic layer deposition may contain, in addition to the ruthenium compound represented by the above general formula (1), compounds containing the desired metal and / or metalloids (hereinafter sometimes referred to as "other precursors").

[0032] In the case of a multi-component ALD method using multiple precursors, there are no particular restrictions on the other precursors that can be used with the ruthenium compound represented by the general formula (1) above, and any well-known general precursors used as raw materials for thin film formation in the ALD method can be used.

[0033] Other precursors include, for example, compounds of silicon or metals with one or more compounds selected from the group consisting of compounds used as organic ligands such as alcohol compounds, glycol compounds, β-diketone compounds, cyclopentadiene compounds, and organic amine compounds. Furthermore, examples of precursor metals include lithium, sodium, potassium, magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, osmium, ruthenium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, aluminum, gallium, indium, germanium, lead, antimony, bismuth, radium, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, or lutetium.

[0034] Alcohol compounds used as organic ligands for other precursors include, for example, alkyl alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, sec-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, pentyl alcohol, isopentyl alcohol, and tert-pentyl alcohol; 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-methoxy-1-methylethanol, 2-methoxy-1,1-dimethylethanol, 2-ethoxy-1,1-dimethylethanol, and 2-isopropoxy-1,1-dimethylethanol. Examples include ether alcohols such as 2-butoxy-1,1-dimethylethanol, 2-(2-methoxyethoxy)-1,1-dimethylethanol, 2-propoxy-1,1-diethylethanol, 2-sec-butoxy-1,1-diethylethanol, and 3-methoxy-1,1-dimethylpropanol; and dialkylamino alcohols such as dimethylaminoethanol, ethylmethylaminoethanol, diethylaminoethanol, dimethylamino-2-pentanol, ethylmethylamino-2-pentanol, dimethylamino-2-methyl-2-pentanol, ethylmethylamino-2-methyl-2-pentanol, and diethylamino-2-methyl-2-pentanol.

[0035] Examples of glycol compounds used as organic ligands for other precursors include 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 2,4-hexanediol, 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, and 2,4-dimethyl-2,4-pentanediol.

[0036] Examples of β-diketone compounds used as organic ligands for other precursors include acetylacetone, hexane-2,4-dione, 5-methylhexane-2,4-dione, heptane-2,4-dione, 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-dimethyloctane-3,5-dione, 2,9-dimethylnonane-4,6-dione, and 2-methyl-6- Examples include alkyl-substituted β-diketones such as ethyldecane-3,5-dione and 2,2-dimethyl-6-ethyldecane-3,5-dione; fluorine-substituted alkyl β-diketones such as 1,1,1-trifluoropentane-2,4-dione, 1,1,1-trifluoro-5,5-dimethylhexane-2,4-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, and 1,3-diperfluorohexylpropane-1,3-dione; and ether-substituted β-diketones such as 1,1,5,5-tetramethyl-1-methoxyhexane-2,4-dione, 2,2,6,6-tetramethyl-1-methoxyheptane-3,5-dione, and 2,2,6,6-tetramethyl-1-(2-methoxyethoxy)heptane-3,5-dione.

[0037] Examples of cyclopentadiene compounds used as organic ligands for other precursors include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, sec-butylcyclopentadiene, isobutylcyclopentadiene, tert-butylcyclopentadiene, dimethylcyclopentadiene, tetramethylcyclopentadiene, and pentamethylcyclopentadiene.

[0038] Examples of organic amine compounds used as organic ligands for other precursors include methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, and isopropylmethylamine.

[0039] Other precursors are known in the art, and their manufacturing methods are also known. For example, when an alcohol compound is used as an organic ligand, the precursor can be produced by reacting an inorganic salt or hydrate of the aforementioned metal with an alkali metal alkoxide of the alcohol compound. Examples of inorganic salts or hydrates of metals include metal halides and nitrates. Examples of alkali metal alkoxides include sodium alkoxide, lithium alkoxide, and potassium alkoxide.

[0040] In the multi-component ALD method described above, there are two methods: one in which raw materials for forming thin films for atomic layer deposition are vaporized and supplied independently for each component (hereinafter sometimes referred to as the "single-source method"), and another in which mixed raw materials, which are pre-mixed in a desired composition, are vaporized and supplied (hereinafter sometimes referred to as the "cocktail-source method"). In the case of the single-source method, other precursors that exhibit similar thermal and / or oxidative decomposition behavior to the ruthenium compound represented by the general formula (1) above are preferred. In the case of the cocktail-source method, other precursors that exhibit similar thermal and / or oxidative decomposition behavior to the ruthenium compound represented by the general formula (1) above are preferred, as well as compounds that do not undergo alteration due to chemical reactions during mixing.

[0041] In the case of the cocktail source method in the multi-component ALD method, a mixture of the ruthenium compound represented by the above general formula (1) and other precursors, or a mixed solution obtained by dissolving the mixture in an organic solvent, can be used as a raw material for forming thin films for atomic layer deposition.

[0042] There are no particular restrictions on the organic solvent used; any commonly known organic solvent can be used. Examples of such organic solvents include acetic acid esters such as ethyl acetate, butyl acetate, and methoxyethyl acetate; ethers such as tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, dibutyl ether, and dioxane; ketones such as methyl butyl ketone, methyl isobutyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, and methylcyclohexanone; hydrocarbons such as hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, heptane, octane, toluene, and xylene; hydrocarbons having a cyano group such as 1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyanocyclohexane, cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, 1,6-dicyanohexane, 1,4-dicyanocyclohexane, and 1,4-dicyanobenzene; and pyridine, lutidine, and the like. These organic solvents may be used individually or in mixtures of two or more, depending on factors such as the solubility of the solute, the relationship between the operating temperature and boiling point, and the flash point.

[0043] When the raw material for forming a thin film using atomic layer deposition according to the present invention is a mixed solution containing an organic solvent, the total amount of precursor in the raw material for forming a thin film using atomic layer deposition should be adjusted to 0.01 mol / liter to 2.0 mol / liter, and particularly to 0.05 mol / liter to 1.0 mol / liter. This is because it facilitates the formation of high-quality ruthenium-containing thin films with low residual carbon content.

[0044] Here, the total amount of precursors refers to the amount of the ruthenium compound represented by general formula (1) when the raw material for forming a thin film for atomic layer deposition does not contain precursors other than the ruthenium compound represented by general formula (1). When the raw material for forming a thin film for atomic layer deposition contains other precursors in addition to the ruthenium compound represented by general formula (1), it refers to the total amount of the ruthenium compound represented by general formula (1) and the other precursors.

[0045] The raw materials for forming thin films using atomic layer deposition according to the present invention may optionally contain a nucleophilic reagent to improve the stability of the ruthenium compound represented by the above general formula (1) and other precursors. Examples of the nucleophilic reagent include ethylene glycol ethers such as glyme, diglyme, triglyme, and tetraglyme; crown ethers such as 18-crown-6, dicyclohexyl-18-crown-6, 24-crown-8, dicyclohexyl-24-crown-8, and dibenzo-24-crown-8; ethylenediamine, N,N'-tetramethylethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,1,4,7,7-pentamethyldiethylenetriamine, and 1,1,4,7,10,10-hexamethyltriethylenetetramine. Examples include polyamines such as triethoxytriethyleneamine, cyclic polyamines such as cyclam and cyclene, heterocyclic compounds such as pyridine, pyrrolidine, piperidine, morpholine, N-methylpyrrolidine, N-methylpiperidine, N-methylmorpholine, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, oxazole, thiazole, and oxathiolane, β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, and 2-methoxyethyl acetoacetate, or β-diketones such as acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, and dipivaloylmethane. From the viewpoint of easy adjustment of stability, the amount of these nucleophilic reagents used is preferably in the range of 0.1 mole to 10 moles, and more preferably in the range of 1 mole to 4 moles, per 1 mole of the total amount of precursor.

[0046] In the raw materials for forming thin films using atomic layer deposition according to the present invention, it is desirable to minimize the inclusion of impurity metal elements other than the constituent components, impurity halogens such as impurity chlorine, and impurity organic components. For impurity metal elements, the amount per element is preferably 100 ppb or less, more preferably 10 ppb or less, and the total amount is preferably 1 ppm or less, more preferably 100 ppb or less. In particular, when used as gate insulating films, gate films, barrier layers, or wiring layers for LSIs, it is necessary to reduce the content of alkali metal elements and alkaline earth metal elements, which affect the electrical properties of the resulting thin film. For impurity halogens, the amount is preferably 100 ppm or less, more preferably 10 ppm or less, and even more preferably 1 ppm or less. For impurity organic components, the total amount is preferably 500 ppm or less, more preferably 50 ppm or less, and even more preferably 10 ppm or less. Furthermore, since moisture can cause particle generation in the raw materials for forming thin films using atomic layer deposition and during thin film formation, it is preferable to remove as much moisture as possible from the precursor, organic solvent, and nucleophilic reagent before use in order to reduce their respective moisture content. The moisture content of the precursor, organic solvent, and nucleophilic reagent is preferably 10 ppm or less, and more preferably 1 ppm or less. This is because, by keeping the impurity metal element content, impurity halogen content, impurity organic content, and moisture content of the raw materials for forming thin films using atomic layer deposition of the present invention below the above-mentioned values, it becomes easier to form high-quality ruthenium-containing thin films with low residual carbon.

[0047] Furthermore, in order to reduce or prevent particle contamination of the ruthenium-containing thin film formed in the atomic layer deposition method of the present invention, it is preferable that the raw material for forming the atomic layer deposition method contains as few particles as possible. Specifically, in particle measurement using a light scattering type liquid particle detector in the liquid phase, it is preferable that the number of particles larger than 0.3 μm is 100 or less per 1 ml of the raw material for forming the atomic layer deposition method, and it is preferable that the number of particles larger than 0.2 μm is 100 or less per 1 ml of the raw material for forming the atomic layer deposition method. This is because a uniform ruthenium-containing thin film is more easily obtained.

[0048] [Method for producing thin films using raw materials for atomic layer deposition containing a ruthenium compound represented by general formula (1)] Next, a method for producing a thin film according to the present invention will be described, which includes forming a ruthenium-containing thin film on the surface of a substrate using the raw materials for forming thin films for atomic layer deposition described above. The method for manufacturing a thin film of the present invention is not particularly limited as long as it includes forming a ruthenium-containing thin film using a thin film formation material for atomic layer deposition, for example, A raw material introduction step involves vaporizing raw materials for forming thin films using atomic layer deposition and introducing the resulting raw material gas into a film deposition chamber where a substrate is installed. A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (1) contained in the raw material gas to form a ruthenium-containing thin film on the surface of the substrate, It is preferable that it has the following characteristics: In particular, the process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using raw materials for atomic layer deposition thin film formation, between the raw material introduction step and the thin film formation step. It is more preferable that the thin film formation process involves reacting a precursor thin film with a reactive gas to form a ruthenium-containing thin film on the surface of the substrate. This is because it is easier to obtain a high-quality ruthenium-containing thin film with low residual carbon content.

[0049] There are no particular restrictions on the methods of transporting and supplying raw materials, the methods of storage, the manufacturing conditions, the manufacturing equipment, etc., and generally known conditions and methods can be used.

[0050] The apparatus for manufacturing thin films using the raw materials for atomic layer deposition (ALD) of the present invention can be a well-known ALD apparatus. Specific examples of apparatus include apparatus capable of bubbling the precursor, as shown in Figures 1 and 3, and apparatus having a vaporization chamber, as shown in Figures 2 and 4. Also, apparatus capable of plasma treatment of reactive gases, as shown in Figures 3 and 4, can be used. Furthermore, the apparatus is not limited to single-wafer apparatuses equipped with a deposition chamber (sometimes called a "deposition reaction section") as shown in Figures 1 to 4; apparatuses capable of processing multiple sheets simultaneously using a batch furnace can also be used. These can also be used as CVD apparatuses.

[0051] The following describes each step in the manufacturing method of such a thin film.

[0052] The raw material introduction step in this invention is a step of introducing a raw material gas, obtained by vaporizing raw materials for forming thin films for atomic layer deposition, into a film formation chamber in which a substrate is installed. Methods for introducing raw material gas, obtained by vaporizing raw materials for thin film formation using atomic layer deposition, into a deposition chamber where a substrate is installed include gas transport methods, liquid transport methods, single-source methods, and cocktail-source methods.

[0053] As for the gas transport method, for example, as shown in Figures 1 and 3, the raw materials for forming thin films for atomic layer deposition according to the present invention are heated and / or vaporized in a raw material container where the raw materials for forming thin films for atomic layer deposition according to the present invention are stored to produce a raw material gas, and the raw material gas is introduced into the film deposition chamber where the substrate is installed, together with a carrier gas such as argon, nitrogen, or helium as needed. As an example of a liquid transport method, as shown in Figures 2 and 4, the raw materials for forming thin films for atomic layer deposition are transported in a liquid or solution state to a vaporization chamber, heated and / or vaporized in the vaporization chamber to become a raw material gas, and this raw material gas is introduced into the film formation chamber.

[0054] The single-source method is a method for transporting and supplying raw materials for thin film formation using atomic layer deposition, which includes a multi-component precursor, and includes a method in which each precursor is vaporized and supplied independently. The cocktail source method includes, for example, a method of vaporizing and supplying a mixed raw material in which multiple precursors are pre-mixed in a desired composition. These raw materials for forming thin films for atomic layer deposition, which include multiple precursors, may also contain nucleophilic reagents, etc.

[0055] The step of vaporizing the raw material for forming a thin film using the atomic layer deposition method of the present invention to obtain a raw material gas may be carried out in the raw material container as described above, or in the vaporization chamber. In either case, it is preferable to vaporize the raw material for forming a thin film using the atomic layer deposition method of the present invention at 0°C to 200°C. This is because it facilitates the formation of high-quality ruthenium-containing thin films. Furthermore, when vaporizing the raw materials for forming thin films using atomic layer deposition (ADD) within a raw material container or vaporization chamber to obtain a raw material gas, the pressure inside the raw material container and the pressure inside the vaporization chamber are preferably within the range of 1 Pa to 10,000 Pa. This is because it ensures good vaporization of the raw materials for forming thin films using ADD.

[0056] Examples of materials for the substrate placed in the film deposition chamber include silicon; ceramics such as silicon nitride, titanium nitride, tantalum nitride, titanium oxide, ruthenium oxide, zirconium oxide, hafnium oxide, and lanthanum oxide; glass; and metals such as metallic cobalt and metallic ruthenium. The substrate can take the shape of a plate, sphere, fiber, or flake. The substrate surface may be planar or have a three-dimensional structure such as a trench structure.

[0057] The thin film formation step in the present invention is a step of forming a ruthenium-containing thin film on the surface of a substrate by decomposing and / or chemically reacting a ruthenium compound represented by general formula (1) contained in the raw material gas. As shown in Figures 1 to 4, the thin film formation process is carried out in a deposition chamber where a substrate is placed. A raw material gas and a reactive gas are introduced into the deposition chamber, and a ruthenium-containing thin film is formed on the substrate in the deposition chamber by the action of the reactive gas or by the action of the reactive gas and heat. If the process includes a precursor thin film formation step, described later, between the raw material introduction step and the thin film formation step, it is preferable that the thin film formation step is a step in which a precursor thin film is reacted with a reactive gas to form a ruthenium-containing thin film on the surface of the substrate. This is because it is easier to obtain a high-quality ruthenium-containing thin film with low residual carbon content.

[0058] In the thin-film formation process, when a ruthenium compound represented by general formula (1) is reacted with a reactive gas using heat, the substrate and / or the film formation chamber should be heated. The heating temperature can be in the range of room temperature to 500°C, but from the viewpoint of easily forming a high-quality ruthenium-containing thin film, the range of 100°C to 450°C is preferred.

[0059] Examples of reactive gases include oxygen, ozone, nitrogen dioxide, nitric oxide, water vapor, hydrogen peroxide, formic acid, acetic acid, acetic anhydride, hydrogen, organic amine compounds such as monoalkylamines, dialkylamines, trialkylamines, and alkylenediamines, as well as hydrazine and ammonia. These reactive gases may be used individually or in mixtures of two or more types. In the thin-film formation process, the reactive gas is preferably a gas containing at least one selected from the group consisting of hydrogen, ammonia, oxygen, and ozone. This is because it facilitates the formation of high-quality ruthenium-containing thin films with low residual carbon content.

[0060] The present invention's method for manufacturing a thin film preferably further includes a precursor thin film formation step between the raw material introduction step and the thin film formation step, in which a precursor thin film is formed on the surface of a substrate using raw materials for thin film formation for atomic layer deposition. The precursor thin film only needs to be capable of forming a ruthenium-containing thin film during the thin film formation process. In this method of forming a precursor thin film, a ruthenium compound represented by the above general formula (1) is deposited (adsorbed) onto the surface of the substrate in a raw material gas introduced into a deposition chamber in which the substrate is placed, thereby forming a precursor thin film on the surface of the substrate. At this time, heat may be applied by heating the substrate or by heating the inside of the deposition chamber. The conditions for forming the precursor thin film are not particularly limited, and for example, the reaction temperature (substrate temperature), reaction pressure, deposition rate, etc., can be appropriately determined according to the type of raw material for forming the thin film for atomic layer deposition. The reaction temperature is preferably in the range of 0°C to 500°C, and more preferably in the range of 100°C to 450°C, because it makes it easier to form the precursor thin film uniformly.

[0061] The rate at which the ruthenium compound represented by general formula (1) is deposited in the raw material gas can be controlled by the supply conditions of the raw material for forming the thin film for atomic layer deposition (vaporization temperature, vaporization pressure), reaction temperature, and reaction pressure. If the deposition rate is too high, the properties of the resulting precursor thin film may deteriorate, and if it is too low, productivity problems may occur. Therefore, the deposition rate in the precursor thin film formation process is preferably in the range of 0.005 nm / min to 100 nm / min, and more preferably in the range of 0.01 nm / min to 50 nm / min.

[0062] The present invention's method for manufacturing a thin film preferably further includes a step of exhausting unreacted reactive gases, raw material gases, and by-product gases from the deposition chamber after the formation of the precursor thin film in the precursor thin film formation step or after the formation of the ruthenium-containing thin film in the thin film formation step. This is because it is easier to obtain a high-quality ruthenium-containing thin film with low residual carbon. Ideally, the unreacted reactive gases, raw material gases, and by-product gases should be completely exhausted from the deposition chamber, but complete exhaust is not always necessary. Examples of exhaust methods include purging the deposition chamber system with an inert gas such as helium, nitrogen, or argon, exhausting by reducing the pressure inside the system, and methods combining these. When reducing the pressure inside the system, the degree of pressure is preferably in the range of 0.01 Pa to 300 Pa, and more preferably in the range of 0.01 Pa to 100 Pa from the viewpoint of promoting the exhaust of unreacted reactive gases, raw material gases, and by-product gases.

[0063] The method for manufacturing a thin film of the present invention may further include a step of applying energy such as plasma, light, or voltage, or a step of using a catalyst. The timing of applying the energy and the timing of using the catalyst are not particularly limited and may be, for example, when introducing the raw material gas in the raw material gas introduction step, when heating in the precursor thin film formation step or thin film formation step, when exhausting the system in the exhaust step, when introducing the reactive gas in the thin film formation step, or in between any of the above steps.

[0064] In the thin film manufacturing method of the present invention, when plasma treatment is performed, if the output is too high, damage to the substrate will be significant, so 10W to 1,500W is preferred, and 50W to 600W is more preferred.

[0065] The method for manufacturing a thin film of the present invention may further include an annealing step after thin film formation in order to improve the electrical properties of the ruthenium-containing thin film. In the annealing step, the annealing treatment may be carried out under an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere, and a reflow step may be provided if step filling is necessary. From the viewpoint of easily producing a high-quality ruthenium-containing thin film with low residual carbon, the temperature in the annealing step is preferably in the range of 200°C to 1,000°C, and more preferably in the range of 250°C to 500°C.

[0066] The method for manufacturing a thin film of the present invention may involve performing the thin film formation step only once, or performing the thin film formation step two or more times, but it is preferable to perform the thin film formation step two or more times. In the present invention, the raw material gas introduction step, precursor thin film formation step, exhaust step, thin film formation step and exhaust step are performed in order, and the formation of a ruthenium-containing thin film by a series of operations constitutes one cycle. This cycle is repeated multiple times until a ruthenium-containing thin film of the required thickness is obtained, thereby forming a ruthenium-containing thin film with the desired thickness. The thickness of the formed ruthenium-containing thin film can be controlled by the number of cycles. The deposition rate of the ruthenium-containing thin film obtained per cycle is preferably in the range of 0.001 nm / min to 100 nm / min, and more preferably in the range of 0.005 nm / min to 50 nm / min. This is because a uniform ruthenium-containing thin film is easily obtained by setting the deposition rate within the above range.

[0067] [Thin film formed using raw materials for thin film formation in atomic layer deposition] Thin films produced using the raw materials for atomic layer deposition of the present invention include thin films of ruthenium metal, ruthenium oxide, or ruthenium nitride. However, the above-described method for producing thin films can efficiently form thin films of ruthenium metal. The thin films of the present invention can be of any desired type by appropriately selecting other precursors, reactive gases, and manufacturing conditions in the above-described method for producing thin films. Because the thin films of the present invention have excellent electrical and optical properties, they can be widely used in the production of electrode materials for memory elements such as DRAM elements, wiring materials for semiconductor elements, diamagnetic films used in the recording layer of hard disks, and catalyst materials for polymer electrolyte fuel cells.

[0068] [Ruthenium compounds] The ruthenium compound of the present invention is a ruthenium compound represented by the above general formula (2). The ruthenium compound of the present invention can be preferably used as a raw material for forming thin films for chemical vapor deposition, and since it has an ALD window, it can be more preferably used as a raw material for forming thin films for atomic layer deposition.

[0069] In the above general formula (2), R 4 Examples of alkyl groups with 1 to 5 carbon atoms represented by include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, and the like.

[0070] In the above general formula (2), R 4 The appropriate selection is made depending on the method of manufacturing the thin film to be applied. When used in a method of manufacturing a thin film that includes a step of vaporizing a ruthenium compound, the vapor pressure is high and the melting point is low. 4 By selecting this option, it becomes easier to manufacture high-quality ruthenium-containing thin films with high productivity.

[0071] From the perspective of being able to efficiently manufacture high-quality ruthenium-containing thin films with high vapor pressure, smoothness, and low residual carbon content, R 4 It is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a methyl group.

[0072] Furthermore, when used in a thin film manufacturing method by the MOD method that does not involve a vaporization step, R 4 These can be arbitrarily selected depending on their solubility in the solvent used, the thin film formation reaction, etc.

[0073] Preferred specific examples of the ruthenium compounds represented by the above general formula (2) include, for example, the ruthenium compounds No. 7 to No. 9 described above, but the present invention is not limited to these ruthenium compounds.

[0074] The ruthenium compound represented by the above general formula (2) is not particularly limited by its manufacturing method and can be produced by well-known synthesis methods. Specifically, it can be produced by the same method as the ruthenium compound represented by the above general formula (1).

[0075] [Raw material for thin film formation] The thin-film forming raw material of the present invention is characterized by containing a ruthenium compound represented by the above general formula (2). The composition of the thin-film forming raw material of the present invention varies depending on the type of thin film to be produced. For example, when producing a thin film containing only ruthenium atoms as the metal, the thin-film forming raw material does not contain metal compounds other than ruthenium or metalloid compounds. On the other hand, when producing a thin film containing ruthenium atoms and metals and / or metalloids other than ruthenium atoms, the thin-film forming raw material may contain, in addition to the ruthenium compound represented by the above general formula (2), compounds containing the desired metal and / or metalloids (hereinafter sometimes referred to as "other precursors"). Since the physical properties of the ruthenium compound represented by the above general formula (2), which is a precursor, are suitable for the CVD method, the thin-film forming raw material of the present invention is useful as a thin-film forming raw material for the CVD method. In particular, since the ruthenium compound represented by the above general formula (2) has an ALD window, the thin-film forming raw material of the present invention is especially useful as a thin-film forming raw material for atomic layer deposition.

[0076] In the case of a multi-component CVD method using multiple precursors, there are no particular restrictions on the other precursors that can be used with the ruthenium compound represented by the general formula (2) above, and any well-known general precursors used as raw materials for thin film formation in CVD methods can be used.

[0077] Other precursors that can be used are the same as those listed in the section [Materials for forming thin films for atomic layer deposition] above.

[0078] In the multi-component CVD method described above, there are two methods: one in which the thin-film forming raw materials are vaporized and supplied independently for each component (hereinafter sometimes referred to as the "single-source method"), and another in which the multi-component raw materials are pre-mixed in a desired composition and then vaporized and supplied (hereinafter sometimes referred to as the "cocktail-source method"). In the single-source method, other precursors that exhibit similar thermal and / or oxidative decomposition behavior to the ruthenium compound represented by the general formula (2) above are preferred. In the cocktail-source method, other precursors that exhibit similar thermal and / or oxidative decomposition behavior to the ruthenium compound represented by the general formula (2) above are preferred, as well as compounds that do not undergo alteration due to chemical reactions during mixing.

[0079] In the case of the cocktail source method in multi-component CVD, a mixture of the ruthenium compound represented by the above general formula (2) and other precursors, or a mixed solution obtained by dissolving the mixture in an organic solvent, can be used as a raw material for thin film formation.

[0080] As for the organic solvent, the same organic solvents as those listed in the above section [Materials for forming thin films using atomic layer deposition] can be used.

[0081] When the thin-film forming raw material of the present invention is a mixed solution containing an organic solvent, the total amount of precursor in the thin-film forming raw material should be adjusted to 0.01 mol / liter to 2.0 mol / liter, and particularly to 0.05 mol / liter to 1.0 mol / liter. This is because it facilitates the formation of high-quality ruthenium-containing thin films with low residual carbon content.

[0082] Here, the total amount of precursors refers to the amount of the ruthenium compound represented by general formula (2) if the thin film forming raw material does not contain precursors other than the ruthenium compound represented by general formula (2). If the thin film forming raw material contains other precursors in addition to the ruthenium compound represented by general formula (2), it refers to the total amount of the ruthenium compound represented by general formula (2) and the other precursors.

[0083] The thin film forming raw material of the present invention may optionally contain a nucleophilic reagent to improve the stability of the ruthenium compound represented by the general formula (2) and other precursors. The nucleophilic reagent can be the same as the nucleophilic reagent listed in the section [Thin Film Forming Raw Material for Atomic Layer Deposition] above.

[0084] It is desirable that the raw materials for forming thin films of the present invention contain as few impurity metal elements, impurity halogens such as impurity chlorine, and impurity organic components as possible, other than the components that constitute them. For impurity metal elements, the amount is preferably 100 ppb or less per element, more preferably 10 ppb or less, and for the total amount, preferably 1 ppm or less, more preferably 100 ppb or less. In particular, when used as gate insulating films, gate films, barrier layers, or wiring layers for LSIs, it is necessary to reduce the content of alkali metal elements and alkaline earth metal elements, which affect the electrical properties of the resulting ruthenium-containing thin film. For impurity halogens, the amount is preferably 100 ppm or less, more preferably 10 ppm or less, and even more preferably 1 ppm or less. For impurity organic components, the total amount is preferably 500 ppm or less, more preferably 50 ppm or less, and even more preferably 10 ppm or less. Furthermore, since moisture can cause particle generation in the raw materials for thin film formation and during thin film formation, it is preferable to remove as much moisture as possible from the precursor, organic solvent, and nucleophilic reagent before use in order to reduce their respective moisture content. The moisture content of the precursor, organic solvent, and nucleophilic reagent is preferably 10 ppm or less, and more preferably 1 ppm or less. This is because the raw materials for thin film formation of the present invention make it easier to form high-quality ruthenium-containing thin films with low residual carbon by keeping the impurity metal element content, impurity halogen content, impurity organic content, and moisture content below the above-mentioned values.

[0085] Furthermore, in order to reduce or prevent particle contamination of the ruthenium-containing thin film formed, it is preferable that the thin film forming material of the present invention contains as few particles as possible. Specifically, in particle measurement using a light scattering type liquid particle detector in the liquid phase, it is preferable that the number of particles larger than 0.3 μm is 100 or less per 1 ml of the thin film forming material, and that the number of particles larger than 0.2 μm is 100 or less per 1 ml of the thin film forming material. This is because a uniform ruthenium-containing thin film is more easily obtained.

[0086] [Method for producing a thin film using a thin film formation raw material containing a ruthenium compound represented by general formula (2)] Next, a method for producing a thin film according to the present invention will be described, which includes forming a ruthenium-containing thin film on the surface of a substrate using the thin film formation raw materials described above. The method for manufacturing a thin film of the present invention is not particularly limited as long as it includes forming a ruthenium-containing thin film using a thin film forming raw material, for example, A raw material introduction step involves introducing a raw material gas, obtained by vaporizing the raw materials for thin film formation, into a film formation chamber where the substrate is installed. A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (2) contained in the raw material gas to form a ruthenium-containing thin film on the surface of the substrate, It is preferable that it has the following characteristics: In particular, the process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using a raw material for thin film formation, between the raw material introduction step and the thin film formation step. It is more preferable that the thin film formation process involves reacting a precursor thin film with a reactive gas to form a ruthenium-containing thin film on the surface of the substrate. This is because it is easier to obtain a high-quality ruthenium-containing thin film with low residual carbon content.

[0087] There are no particular restrictions on the methods of transporting and supplying raw materials, the methods of storage, the manufacturing conditions, the manufacturing equipment, etc., and generally known conditions and methods can be used.

[0088] A well-known ALD apparatus can be used to manufacture a thin film using the thin film formation raw material of the present invention. Specific examples of such apparatus include those similar to the ALD apparatus described in the section "[Method for manufacturing a thin film using a thin film formation raw material for atomic layer deposition containing a ruthenium compound represented by general formula (1)]" above. These can also be used as CVD apparatuses.

[0089] The following describes each step in the method for forming such a thin film.

[0090] The raw material introduction step in this invention is a step of introducing a raw material gas obtained by vaporizing the raw material for thin film formation into a film formation chamber in which a substrate is installed. The method for introducing the raw material for thin film formation can be the same as the method described in the above section [Method for manufacturing a thin film using a raw material for atomic layer deposition containing a ruthenium compound represented by general formula (1)], so the explanation is omitted here.

[0091] The thin film formation step in the present invention is a step of forming a ruthenium-containing thin film on the surface of a substrate by decomposing and / or chemically reacting a ruthenium compound represented by general formula (2) contained in the raw material gas. The method for forming the thin film can be the one described in the above section [Method for manufacturing a thin film using a raw material for forming a thin film for atomic layer deposition containing a ruthenium compound represented by general formula (1)], so the explanation is omitted here.

[0092] The present invention's method for manufacturing a thin film preferably further includes a precursor thin film formation step between the raw material introduction step and the thin film formation step, in which a precursor thin film is formed on the surface of a substrate using a raw material for thin film formation. The precursor thin film only needs to be capable of forming a ruthenium-containing thin film during the thin film formation process. Regarding the method for forming such precursor thin films, the methods listed in the section above [Method for manufacturing thin films using raw materials for atomic layer deposition containing a ruthenium compound represented by general formula (1)] can be used, so a detailed explanation is omitted here.

[0093] The present invention's method for manufacturing a thin film preferably further includes an exhaust step after the formation of the precursor thin film in the precursor thin film formation step or after the formation of the ruthenium-containing thin film in the thin film formation step, in which unreacted reactive gases, raw material gases, and by-product gases are exhausted from the film deposition chamber. This is because it is easier to obtain a high-quality ruthenium-containing thin film with low residual carbon. Ideally, the unreacted reactive gases, raw material gases, and by-product gases should be completely exhausted from the film deposition chamber, but complete exhaust is not always necessary. The exhaust step here is the same as the exhaust step described in the section [Method for manufacturing a thin film using raw materials for forming a thin film for atomic layer deposition containing a ruthenium compound represented by general formula (1)] above, so the explanation is omitted here.

[0094] The method for manufacturing a thin film of the present invention may further include an energy application step of applying energy such as plasma, light, or voltage, or a step of using a catalyst. The energy application step or the step of using a catalyst described here is the same as the energy application step or the step of using a catalyst described in the section [Method for manufacturing a thin film using raw materials for forming a thin film for atomic layer deposition containing a ruthenium compound represented by general formula (1)] above, so the explanation is omitted here.

[0095] The method for manufacturing a thin film of the present invention may further include an annealing step after thin film formation in order to improve the electrical properties of the ruthenium-containing thin film. The annealing step here is the same as the annealing step described in the section [Method for manufacturing a thin film using raw materials for forming a thin film for atomic layer deposition containing a ruthenium compound represented by general formula (1)] above, so a detailed explanation is omitted here.

[0096] The method for manufacturing a thin film of the present invention may involve performing the thin film formation step only once, or performing the thin film formation step two or more times, but it is preferable to perform the thin film formation step two or more times. In the present invention, the raw material gas introduction step, precursor thin film formation step, exhaust step, thin film formation step and exhaust step are performed in order, and the formation of a thin film by a series of operations constitutes one cycle. This cycle is repeated multiple times until a ruthenium-containing thin film of the required thickness is obtained, thereby forming a ruthenium-containing thin film with the desired thickness. The thickness of the formed ruthenium-containing thin film can be controlled by the number of cycles. The deposition rate of the ruthenium-containing thin film obtained per cycle is preferably in the range of 0.001 nm / min to 100 nm / min, and more preferably in the range of 0.005 nm / min to 50 nm / min. This is because a uniform ruthenium-containing thin film is easily obtained by setting the deposition rate within the above range.

[0097] [Thin film formed using raw materials for thin film formation] Thin films produced using the thin-film forming raw materials of the present invention include thin films of ruthenium metal, ruthenium oxide, or ruthenium nitride, but the above-described method for producing thin films can efficiently form thin films of ruthenium metal. The thin films of the present invention can be of any desired type by appropriately selecting other precursors, reactive gases, and manufacturing conditions in the above-described method for producing thin films. Because the thin films of the present invention have excellent electrical and optical properties, they can be widely used in the manufacture of electrode materials for memory elements such as DRAM elements, wiring materials for semiconductor elements, diamagnetic films used in the recording layer of hard disks, and catalyst materials for polymer electrolyte fuel cells.

[0098] <Other> The following aspects are included in this disclosure: [1] A raw material for forming thin films for atomic layer deposition, containing a ruthenium compound represented by the following general formula (1).

[0099] [ka]

[0100] (In the formula, R 1 R represents a hydrogen atom or a methyl group. 2 and R 3 Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0101] [2] R in the general formula (1) 2 A raw material for forming a thin film for atomic layer deposition, as described in [1], wherein the atom is a hydrogen atom.

[0102] [3] R in the general formula (1) 3 A raw material for forming a thin film for atomic layer deposition according to [1] or [2], wherein is an alkyl group having 1 to 5 carbon atoms.

[0103] [4] R in the general formula (1) 3 A raw material for forming thin films for atomic layer deposition according to any one of [1] to [3], wherein the group is a methyl group.

[0104] A thin film made using a raw material for forming a thin film for atomic layer deposition described in any of [5][1] to [4].

[0105] A method for producing a thin film, comprising forming a thin film containing ruthenium atoms on the surface of a substrate using a raw material for forming a thin film for atomic layer deposition described in any of [6][1] to [4].

[0106] [7] A raw material introduction step in which the raw material gas obtained by vaporizing the raw material for forming a thin film for atomic layer deposition is introduced into a film formation chamber in which the substrate is installed, A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (1) contained in the raw material gas to form a thin film containing ruthenium atoms on the surface of the substrate, A method for manufacturing a thin film according to [6], including the method described in [6].

[0107] [8] The process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using the raw material for forming a thin film for atomic layer deposition between the raw material introduction step and the thin film formation step, The method for producing a thin film according to [7], wherein the thin film formation step is a step of reacting the precursor thin film with a reactive gas to form a thin film containing ruthenium atoms on the surface of the substrate.

[0108] [9] Ruthenium compounds represented by the following general formula (2).

[0109] [ka]

[0110] (In the formula, R 4 (This represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

[0111] A raw material for forming thin films containing the ruthenium compound described in

[10] [9].

[0112] A thin film made using the thin film forming raw materials described in

[11]

[10] .

[0113] A method for producing a thin film, comprising forming a thin film containing ruthenium atoms on the surface of a substrate using the thin film forming raw materials described in

[12]

[10] .

[0114]

[13] A raw material introduction step in which the raw material gas obtained by vaporizing the raw material for forming the thin film is introduced into a film formation chamber in which the substrate is installed, A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (2) contained in the raw material gas to form a thin film containing ruthenium atoms on the surface of the substrate, A method for producing a thin film according to

[12] , including the method described in

[12] .

[0115]

[14] The process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using the raw material for thin film formation between the raw material introduction step and the thin film formation step, The method for producing a thin film according to

[13] , wherein the thin film formation step is a step of reacting the precursor thin film with a reactive gas to form a thin film containing ruthenium atoms on the surface of the substrate. [Examples]

[0116] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited by the following examples.

[0117] [Example 1] Preparation of Ruthenium Compound No. 7 In a reaction flask, 22.14 g of [RuCl2 (toluene)], 2.57 g of sodium carbonate, and 18.0 ml of 2-propanol were added and dissolved, then the mixture was stirred at room temperature for 2 hours. 21.4 ml of butadiene / 15% hexane solution was added to this solution and the mixture was stirred under reflux conditions for 6 hours. The reaction mixture was desolvated under reduced pressure in an oil bath at 90°C, and 50.0 ml of hexane was added to the resulting residue and filtered. The filtrate was desolvated under reduced pressure in an oil bath at 65°C. The resulting ruthenium complex was distilled in an oil bath at 110°C and 90 Pa to obtain compound No. 7 as a yellow liquid (yield 0.80 g, yield 40%).

[0118] (Analysis values) (1) Atmospheric pressure TG-DTA Mass reduction by 50% Temperature: 200℃ (760Torr, Ar flow rate: 100ml / min, temperature increase 10℃ / min) (2) Reduced pressure TG-DTA Mass reduction by 50% Temperature: 111℃ (10Torr, Ar flow rate: 50ml / min, temperature increase 10℃ / min) (3) 1 H-NMR (Deuterated benzene) 0.275-0.310ppm (2H, double doublet), 1.782ppm (3H, singlet), 1.850-1.898ppm (2H, double doublet), 4.716-4.760ppm(3H,multiplet), 4.914-4.928ppm(2H,multiplet), 4.997-5.024ppm(2H,multiplet) (4) Elemental analysis results by ICP-AES Ru: 40.87 mass% (theoretical value 40.89 mass%), C: 53.42 mass% (theoretical value 53.41 mass%), H: 5.71 mass% (theoretical value 5.70 mass%)

[0119] [Example 2] Preparation of Ruthenium Compound No. 8 In a reaction flask, 25.00 g of [RuCl2 (toluene)], 6.01 g of sodium carbonate, and 24.0 ml of 2-propanol were added and dissolved, then the mixture was stirred at room temperature for 2 hours. 4.73 ml of isoprene was added to this solution and the mixture was stirred under reflux conditions for 6 hours. The reaction mixture was desolvated under reduced pressure in an oil bath at 90°C, and 50.0 ml of hexane was added to the resulting residue and filtered. The filtrate was desolvated under reduced pressure in an oil bath at 65°C. The resulting ruthenium complex was distilled in an oil bath at 110°C and 90 Pa to obtain compound No. 8 as a yellow liquid (yield 1.96 g, 40% yield).

[0120] (Analysis values) (1) Atmospheric pressure TG-DTA Mass reduction by 50% Temperature: 200℃ (760Torr, Ar flow rate: 100ml / min, temperature increase 10℃ / min) (2) Reduced pressure TG-DTA Mass reduction by 50% Temperature: 111℃ (10Torr, Ar flow rate: 50ml / min, temperature increase 10℃ / min) (3) 1 H-NMR (Deuterated benzene) 0.145-0.168ppm(1H,double doublet), 0.341ppm(1H,singlet), 1.744ppm(3H,singlet), 1.823-1.842ppm(1H,double doublet), 1.943ppm(4H,singlet), 4.693-4.754ppm(2H,multiplet), 4.798-4.826ppm(2H,multiplet), 4.887-4.915ppm(1H,multiplet), 5.067-5.094ppm(1H,triplet) (4) Elemental analysis results by ICP-AES Ru: 38.70 mass% (theoretical value 38.68 mass%), C: 55.14 mass% (theoretical value 55.15 mass%), H: 6.16 mass% (theoretical value 6.17 mass%)

[0121] [Example of evaluation] Evaluation of the physical properties of compounds The following evaluations were performed on ruthenium compounds No. 1, No. 2, No. 4, No. 7, No. 8, and No. 10, as well as comparative compounds 1 and 2 described below. In the chemical formulas below, "Me" represents a methyl group, "Et" represents an ethyl group, and "iPr" represents an isopropyl group. (1) Melting point evaluation The state of the compounds at atmospheric pressure and 25°C was observed visually. For solids at 25°C, the melting point was measured using a micromelting point analyzer. The results are shown in Table 1. (2) Temperature (°C) when TG-DTA at normal pressure decreases by 50% by mass Using TG-DTA, measurements were taken at 10 Torr, Ar flow rate: 50 mL / min, heating rate: 10°C / min, and scanning temperature range: 30°C to 600°C. The temperature (°C) at which the weight of the test compound decreased by 50% by mass was evaluated as "Temperature at atmospheric pressure TG-DTA 50% mass decrease (°C)". A lower temperature at atmospheric pressure TG-DTA 50% mass decrease (°C) indicates that vapor can be obtained at a lower temperature. The results are shown in Table 1.

[0122] [ka]

[0123] [Table 1]

[0124] As shown in Table 1, the temperatures of comparative compound 1 and comparative compound 2 when TG-DTA was reduced by 50% by mass at atmospheric pressure were 208°C or higher. In contrast, ruthenium compounds No. 1, No. 2, No. 4, No. 7, No. 8, and No. 10 all had temperatures of 203°C or lower when TG-DTA was reduced by 50% by mass at atmospheric pressure, indicating that they are compounds with high vapor pressure. Furthermore, ruthenium compounds No. 7, No. 8, and No. 10 had melting points below 50°C, indicating that they are compounds with low melting points. In particular, ruthenium compounds No. 7 and No. 8 were liquid at 25°C, indicating that they are compounds with especially low melting points.

[0125] [Manufacturing of thin films using the ALD method] Next, the compounds evaluated above were used as raw materials for thin film formation using atomic layer deposition to produce thin films.

[0126] [Example 3] Ruthenium compound No. 8 was used as a raw material for thin film formation using atomic layer deposition (ALD), and a thin film was fabricated on the surface of a silicon wafer under the following conditions using the ALD apparatus shown in Figure 1. Analysis of the thin film composition using X-ray electron spectroscopy confirmed that the thin film was a ruthenium metal thin film with a residual carbon content below the detection limit of 0.1 atom%. Furthermore, scanning electron microscopy measured the film thickness, revealing that the thin film formed on the silicon wafer surface was a smooth film with a thickness of 11 nm, and the film thickness obtained per cycle was approximately 0.11 nm.

[0127] (conditions) Manufacturing method: ALD method Reaction temperature (substrate temperature): 230℃ Reactive gas: oxygen

[0128] (Process) The following series of steps (1) to (4) constituted one cycle, and this was repeated 100 times. (1) The vaporized raw material for thin film formation (raw material gas) is introduced into the film formation chamber under the conditions of raw material container temperature: 100°C and pressure inside the raw material container: 100 Pa (raw material introduction step), and the raw material gas is deposited on the surface of the substrate for 20 seconds at a system pressure of 100 Pa to form a precursor thin film (precursor thin film formation step). (2) The undeposited raw material gas is exhausted from the system by argon purging for 15 seconds (exhaust process). (3) The reactive gas is introduced into the film formation chamber, and the precursor thin film is reacted with the reactive gas at a system pressure of 100 Pa for 20 seconds (thin film formation process). (4) Unreacted reactive gases and by-product gases are purged from the system by argon purging for 15 seconds (exhaust process).

[0129] [Example 4] A thin film was fabricated on the surface of a silicon wafer in the same manner as in Example 3, except that ruthenium compound No. 7 was used as the raw material for forming a thin film using atomic layer deposition instead of ruthenium compound No. 8. Analysis of the composition of the thin film using X-ray electron spectroscopy confirmed that the thin film was a thin film of ruthenium metal, and that the residual carbon content was less than the detection limit of 0.1 atom%. Furthermore, when the thickness of the thin film was measured using scanning electron microscopy, the thin film formed on the surface of the silicon wafer was a smooth film with a thickness of 10 nm, and the thickness obtained per cycle was approximately 0.10 nm.

[0130] [Example 5] A thin film was fabricated on the surface of a silicon wafer in the same manner as in Example 3, except that ruthenium compound No. 10 was used as the raw material for thin film formation using atomic layer deposition instead of ruthenium compound No. 8, the reactive gas was changed to hydrogen plasma (plasma output: 100W), and the ALD apparatus was changed to the ALD apparatus shown in Figure 3. Analysis of the composition of the thin film using X-ray electron spectroscopy confirmed that the thin film was a thin film of ruthenium metal, and the residual carbon content was less than the detection limit of 0.1 atom%. Furthermore, when the thickness of the thin film was measured using scanning electron microscopy, the thin film formed on the surface of the silicon wafer was a smooth film with a thickness of 9 nm, and the thickness obtained per cycle was approximately 0.09 nm.

[0131] [Comparative Example 1] A thin film was fabricated on the surface of a silicon wafer in the same manner as in Example 3, except that comparative compound 1 was used as the raw material for forming the thin film using atomic layer deposition instead of ruthenium compound No. 8, and the raw material container temperature was changed to 110°C. Analysis of the composition of the thin film using X-ray electron spectroscopy revealed that the thin film contained ruthenium and had a residual carbon content of 2.7 atom%. Furthermore, when the film thickness of the thin film was measured using scanning electron microscopy, the thin film formed on the surface of the silicon wafer was a non-smooth film with a thickness of 6-7 nm.

[0132] [Comparative Example 2] A thin film was fabricated on the surface of a silicon wafer in the same manner as in Example 3, except that comparative compound 2 was used as the raw material for forming a thin film using atomic layer deposition instead of ruthenium compound No. 8, and the raw material container temperature was changed to 125°C. Analysis of the composition of the thin film using X-ray electron spectroscopy revealed that the thin film contained ruthenium and had a residual carbon content of 3.2 atom%. Furthermore, when the film thickness of the thin film was measured using scanning electron microscopy, the thin film formed on the surface of the silicon wafer was a non-smooth film with a thickness of 5-6 nm.

[0133] Because comparative compounds 1 and 2 have low vapor pressures, the raw material container temperature had to be higher in comparative examples 1 and 2 than in examples 3 to 5. As a result, comparative compounds 1 and 2 underwent thermal decomposition, and it is thought that a ruthenium-containing thin film that was not smooth and had a high residual carbon content was formed.

[0134] From the above, it has been shown that when a ruthenium-containing thin film is produced using the raw materials for atomic layer deposition of the present invention, a smooth, high-quality ruthenium-containing thin film with low residual carbon content can be obtained with high productivity. In particular, when ruthenium compounds No. 7 and No. 8 are used as raw materials for atomic layer deposition, it has been shown that a smooth, high-quality ruthenium-containing thin film with significantly low residual carbon content can be obtained with extremely high productivity.

Claims

1. A raw material for forming thin films for atomic layer deposition, containing a ruthenium compound represented by the following general formula (1). 【Chemistry 1】 (In the formula, R 1 R represents a hydrogen atom or a methyl group. 2 and R 3 Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

2. In the above general formula (1), R 2 The raw material for forming a thin film for atomic layer deposition according to claim 1, wherein is a hydrogen atom.

3. In the above general formula (1), R 3 The raw material for forming a thin film for atomic layer deposition according to claim 1, wherein is an alkyl group having 1 to 5 carbon atoms.

4. In the above general formula (1), R 3 The raw material for forming a thin film for atomic layer deposition according to claim 1, wherein the group is a methyl group.

5. A thin film made using a raw material for forming a thin film for atomic layer deposition according to any one of claims 1 to 4.

6. A method for producing a thin film, comprising forming a thin film containing ruthenium atoms on the surface of a substrate using a raw material for forming a thin film for atomic layer deposition according to any one of claims 1 to 4.

7. A raw material introduction step involves vaporizing the raw materials for forming the thin film for atomic layer deposition and introducing the resulting raw material gas into a film deposition chamber in which the substrate is installed. A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (1) contained in the raw material gas to form a thin film containing ruthenium atoms on the surface of the substrate, A method for manufacturing a thin film according to claim 6, including the method described in claim 6.

8. Between the raw material introduction step and the thin film formation step, the process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using the raw material for forming a thin film for atomic layer deposition, The method for producing a thin film according to claim 7, wherein the thin film formation step is a step of reacting the precursor thin film with a reactive gas to form a thin film containing ruthenium atoms on the surface of the substrate.

9. A ruthenium compound represented by the following general formula (2). 【Chemistry 2】 (In the formula, R 4 (This represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

10. A raw material for forming thin films containing the ruthenium compound described in claim 9.

11. A thin film made using the thin film forming raw material described in claim 10.

12. A method for producing a thin film, comprising forming a thin film containing ruthenium atoms on the surface of a substrate using the thin film forming raw material described in claim 10.

13. A raw material introduction step involves introducing a raw material gas obtained by vaporizing the raw material for thin film formation into a film formation chamber in which a substrate is installed. A thin film formation step involves decomposing and / or chemically reacting a ruthenium compound represented by general formula (2) contained in the raw material gas to form a thin film containing ruthenium atoms on the surface of the substrate, A method for manufacturing a thin film according to claim 12, including the method described in claim 12.

14. Between the raw material introduction step and the thin film formation step, the process further includes a precursor thin film formation step in which a precursor thin film is formed on the surface of the substrate using the thin film forming raw material, The method for producing a thin film according to claim 13, wherein the thin film formation step is a step of reacting the precursor thin film with a reactive gas to form a thin film containing ruthenium atoms on the surface of the substrate.

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