Raw material for forming a thin film for atomic layer deposition, thin film, method for manufacturing a thin film, and zinc compound

Abstract

A raw material for forming a thin film for atomic layer deposition containing a compound represented by the following general formula (1) is provided. [Chemical Formula 1] (In Formula (1), R1, R2, and R3 each independently represent an alkyl group having 1 to 4 carbon atoms with a straight chain or branching, A1 represents an alkylene group having 1 to 5 carbon atoms with a straight chain or branching, x1 represents an integer from 0 to 2, y1 represents an integer from 1 to 3, and M represents an indium atom or a zinc atom. However, if M is an indium atom, x1 is 2 and y1 is 1, and compounds in which R1, R2, and R3 are methyl groups are excluded.)

Description

Technology Field

[0001] The present invention relates to a raw material for forming a thin film for atomic layer deposition containing an indium compound or a zinc compound having a specific structure, a thin film obtained using said raw material for forming a thin film for atomic layer deposition, a method for manufacturing a thin film using said raw material for forming a thin film for atomic layer deposition, and a zinc compound. Background Technology

[0002] In this specification, the term "semiconductor" refers to all things capable of functioning by utilizing semiconductor characteristics. Examples include semiconductor devices such as transistors, semiconductor circuits, computing devices, memory devices, imaging devices, display devices, liquid crystal display devices, light-emitting devices, power generation devices such as thin-film solar cells and organic thin-film solar cells, and semiconductors used in electronic devices.

[0003] Indium or zinc is used as a component of compound semiconductors, and various compounds have been reported as raw materials for forming thin films to manufacture thin films containing indium or zinc.

[0004] Methods for manufacturing thin films include, for example, sputtering, ion plating, metal-organic decomposition (MOD) methods such as coating pyrolysis or sol-gel methods, chemical vapor deposition (CVD), and vapor-phase thin film formation methods such as atomic layer deposition (ALD). Among these, the ALD method is the optimal manufacturing process because it has many advantages, such as excellent compositional controllability and step coverage, suitability for mass production, and the ability to perform hybrid integration.

[0005] Although various materials for forming thin films that can be used in vapor phase thin film formation methods such as CVD and ALD have been reported, materials for forming thin films applicable to the ALD method need to have a sufficiently wide temperature range called the ALD window. It is common technical knowledge in the relevant field that even materials for forming thin films applicable to the CVD method are often not suitable for the ALD method.

[0006] As for a method for manufacturing a metal-containing thin film, for example, Patent Document 1 discloses a method for manufacturing a thin film by an ALD method using an indium-containing thin film precursor as a transistor thin film material for realizing a high-precision display.

[0007] In Patent Document 2, trimethylindium is exemplified as an indium-containing precursor for forming a layer of indium oxide (In2O3) by the ALD method.

[0008] Patent Document 3 discloses a method for forming a thin film of zinc oxide by an ALD method using diethyl zinc. Prior art literature

[0009] Korean Patent Application Publication No. 10-2020-0054851, Japanese Patent Publication No. 2016-511936, Japanese Patent Publication No. 2006-310808 The problem to be solved

[0010] The ALD method builds atomic layers one by one by repeating the process of adsorbing molecules of a raw compound onto a gas phase installed in a vacuum vessel or onto a gas surface or a film surface, forming a film through the reaction of molecules adsorbed onto the gas surface or film surface with a reactive gas, and removing excess molecules by purging. Therefore, the ALD method can control the atomic layer at a single-layer level and form a film with high homogeneity and high step coverage. However, compared to the CVD method, the ALD method has the problem that it is difficult to form a film at high temperatures, and carbon tends to remain in the film.

[0011] Patent Document 1 describes that [(3-dimethylamino)propyl]dimethylindium is used as an ALD material or CVD material that is liquid at room temperature and can suppress spontaneous combustion. However, when [(3-dimethylamino)propyl]dimethylindium is used to deposit a film at 300°C to 400°C, there is a problem that the film shrinks and cracks upon cooling, while when deposited at 200°C to 250°C, there were cases where film growth was not performed smoothly.

[0012] In the ALD method using trimethylindium exemplified in Patent Document 2, there was a problem that carbon tended to remain in the membrane.

[0013] In addition, in the ALD method using diethyl zinc disclosed in Patent Document 3, there was a problem that carbon tended to remain in the film.

[0014] Accordingly, the present invention aims to provide a raw material for forming a thin film for atomic layer deposition that can produce a high-quality thin film containing indium atoms (hereinafter referred to as an "indium-containing thin film") or a thin film containing zinc atoms (hereinafter referred to as a "zinc-containing thin film") with low residual carbon using the ALD method, a thin film obtained using the raw material for forming a thin film for atomic layer deposition, and a method for manufacturing the thin film. means of solving the problem

[0015] As a result of repeated careful examination, the inventors discovered that a raw material for forming a thin film for atomic layer deposition containing an indium compound or a zinc compound having a specific structure can solve the above problem, and thus completed the present invention.

[0016] That is, the present invention is a raw material for forming a thin film for an atomic layer deposition method containing a compound represented by the following general formula (1).

[0017] [Chemical Formula 1]

[0018]

[0019] (In Equation (1), R 1 , R 2 and R 3 Each represents, independently, an alkyl group having 1 to 4 carbon atoms having a straight chain or branching, and A 1 ... represents an alkylene group having 1 to 5 carbon atoms, having a straight chain or branching; x1 represents an integer from 0 to 2; y1 represents an integer from 1 to 3; and M represents an indium atom or a zinc atom. Provided that M is an indium atom, x1 is 2, y1 is 1, and also R 1 , R 2 and R 3 Exclude compounds containing this methyl group.)

[0020] The present invention is a thin film obtained using the raw material for forming a thin film for the atomic layer deposition method.

[0021] The present invention is a method for manufacturing a thin film containing indium atoms or a thin film containing zinc atoms on the surface of a gas by an atomic layer deposition method, comprising: a process 1 of forming a precursor thin film by adsorbing a raw material gas, which has been vaporized from the raw material for forming a thin film for the atomic layer deposition method described above, onto the surface of the gas; a process 2 of exhausting unreacted raw material gas; and a process 3 of reacting the precursor thin film with a reactive gas to form a thin film containing indium atoms or a thin film containing zinc atoms on the surface of the gas.

[0022] In the method for manufacturing a thin film according to the present invention, it is preferable that the reactive gas is an oxidizing gas, and that the thin film containing indium atoms is indium oxide, or the thin film containing zinc atoms is zinc oxide.

[0023] In the method for manufacturing a thin film of the present invention, it is preferable that the oxidizing gas is a gas containing at least one selected from the group consisting of oxygen, ozone, and water vapor.

[0024] Also, the present invention is a zinc compound represented by the following general formula (2).

[0025] [Chemical Formula 2]

[0026]

[0027] (In Equation (2), R 4 represents a methyl or ethyl group, and R 5 and R 6 Each independently represents an alkyl group having 2 to 4 carbon atoms having a straight chain or branching, and A 2 represents an alkylene group having 1 to 4 carbon atoms, having a straight chain or branches. Effects of the invention

[0028] According to the present invention, a high-quality indium-containing thin film or a thin film containing zinc atoms with low residual carbon can be manufactured using the ALD method. Brief explanation of the drawing

[0029] FIG. 1 is a schematic diagram showing an example of an ALD apparatus used in the method for manufacturing a thin film of the present invention. FIG. 2 is a schematic diagram showing another example of an ALD device used in the method for manufacturing a thin film of the present invention. FIG. 3 is a schematic diagram showing another example of an ALD device used in the method for manufacturing a thin film of the present invention. FIG. 4 is a schematic diagram showing another example of an ALD device used in the method for manufacturing a thin film of the present invention. Specific details for implementing the invention

[0030] The raw material for forming a thin film for the atomic layer deposition method of the present invention contains a compound represented by the general formula (1) above.

[0031] R in general formula (1) 1 , R 2 and R 3 Examples of alkyl groups having 1 to 4 carbon atoms and having a straight chain or branched structure, represented by, include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups.

[0032] A in general formula (1) 1 Examples of alkylene groups having 1 to 5 carbon atoms, represented by, include methylene groups, ethylene groups, propylene groups, methylethylene groups, butylene groups, 1-methylpropylene groups, 2-methylpropylene groups, 1,2-dimethylpropylene groups, 1,3-dimethylpropylene groups, 1-methylbutylene groups, 2-methylbutylene groups, 3-methylbutylene groups, 4-methylbutylene groups, etc.

[0033] R 1 , R 2 , R 3 and A1 It is desirable to combine the compound represented by general formula (1) so that it becomes a liquid state at room temperature and pressure, and also has a high vapor pressure. Specifically, R 1 , R 2 and R 3 Compounds that are, independently, a methyl group or an ethyl group are preferred because they have a high vapor pressure. Also, A 1 This compound, which is an ethylene group, a propylene group, or a butylene group, is desirable because it has good reactivity with oxidizing gases, and A 1 This, a propylene group compound is more preferable. R 1 , R 2 and R 3 These, each independently, are a methyl group or an ethyl group, and also A 1 This propylene-based compound is more desirable because it facilitates the fabrication of high-quality thin films with low residual carbon. When x1 is 2, multiple R 1 The silver may be identical or different, but it is preferable that it be identical from the perspective of ease of compound synthesis. Also, when y1 is 2 or 3, multiple A 1 , R 2 and R 3 Each may be the same or different, but from the perspective of ease of synthesizing the compound, it is preferable that each be the same.

[0034] Preferred specific examples of the compound represented by general formula (1) used as a raw material for forming a thin film for atomic layer deposition according to the present invention include, for example, No. 1 to No. 423 below, but the present invention is not limited to these compounds. In addition, in the compounds of No. 1 to No. 423 below, “Me” represents a methyl group, “Et” represents an ethyl group, “nPr” represents an n-propyl group, and “iPr” represents an isopropyl group.

[0035] [Chemical Formula 3]

[0036]

[0037] [Chemical Formula 4]

[0038]

[0039] [Chemical Formula 5]

[0040]

[0041] [Chemical Formula 6]

[0042]

[0043] [Chemical Formula 7]

[0044]

[0045] [Chemical Formula 8]

[0046]

[0047] [Chemical Formula 9]

[0048]

[0049] [Chemical Formula 10]

[0050]

[0051] [Chemical Formula 11]

[0052]

[0053] [Chemical Formula 12]

[0054]

[0055] [Chemical Formula 13]

[0056]

[0057] [Chemical Formula 14]

[0058]

[0059] [Chemical Formula 15]

[0060]

[0061] [Chemical Formula 16]

[0062]

[0063] [Chemical Formula 17]

[0064]

[0065] [Chemical Formula 18]

[0066]

[0067] [Chemical Formula 19]

[0068]

[0069] [Chemical Formula 20]

[0070]

[0071] [Chemical Formula 21]

[0072]

[0073] [Chemical Formula 22]

[0074]

[0075] [Chemical Formula 23]

[0076]

[0077] Among the compounds of No. 1 to No. 423, compounds of No. 4, No. 20, No. 24, No. 333, No. 379 and No. 392 are preferred because they are easy to handle at a low melting point, and compounds of No. 4, No. 20, No. 24, No. 333 and No. 392 are even more preferred because they are liquid at 25°C.

[0078] The compound represented by general formula (1) can be prepared using a known reaction. The compound represented by general formula (1) can be obtained, for example, by reacting indium chloride with a Grignard reagent derived from a dialkylamine halide and then reacting it with alkyllithium or a Grignard reagent, or by reacting zinc chloride or a mixture of zinc chloride and dialkyl zinc with a Grignard reagent derived from a dialkylamine halide.

[0079] The raw material for forming a thin film for atomic layer deposition according to the present invention may contain a compound represented by general formula (1), and its composition may vary depending on the type of thin film intended. For example, when manufacturing a thin film containing only indium or zinc as a metal, the raw material for forming a thin film for atomic layer deposition according to the present invention does not contain metal compounds other than the corresponding metal and metalloid compounds. On the other hand, when manufacturing a thin film containing indium or zinc and other metals and / or metalloids, the raw material for forming a thin film for atomic layer deposition according to the present invention may contain a compound containing the desired metal and / or a compound containing a metalloid (hereinafter also referred to as another precursor) by adding it to the compound represented by general formula (1). As described below, the raw material for forming a thin film for atomic layer deposition according to the present invention may additionally contain an organic solvent and / or a nucleating reagent.

[0080] In the case of a multi-component ALD method using multiple precursors, other precursors used together with the compound represented by general formula (1) can be any well-known general precursors used as raw materials for forming thin films for atomic layer deposition, without being particularly limited.

[0081] Other precursors mentioned above may include one or more types 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, and silicon or metal compounds. In addition, metal species of precursors may include lithium, sodium, potassium, magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, aluminum, indium, germanium, tin, lead, antimony, bismuth, scandium, ruthenium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, or lutetium.

[0082] Alcohol compounds used as organic ligands for the other precursors mentioned above include 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; Ether alcohols such as 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-dimethylethanol, 2-butoxy-1,1-dimethylethanol, 2-(2-methoxyethoxy)-1,1-dimethylethanol, 2-propoxy-1,1-diethylethanol, 2-sec-butoxy-1,1-diethylethanol, 3-methoxy-1,1-dimethylpropanol; Examples include 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.

[0083] Glycol compounds used as organic ligands for the other precursors mentioned above 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, 2,4-dimethyl-2,4-pentanediol, etc.

[0084] β-diketone compounds used as organic ligands for the other precursors mentioned above 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, Alkyl-substituted β-diketones such as 2-methyl-6-ethyldecane-3,5-dione, 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, 1,3-diferfluorohexylpropane-1,3-dione; Examples include 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.

[0085] Examples of cyclopentadiene compounds used as organic ligands for other precursors mentioned above include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, sec-butylcyclopentadiene, isobutylcyclopentadiene, tert-butylcyclopentadiene, dimethylcyclopentadiene, tetramethylcyclopentadiene, etc. Examples of organic amine compounds used as organic ligands mentioned above include methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, isopropylmethylamine, etc.

[0086] The other precursors mentioned above are known in the relevant technical field, and their manufacturing methods are also known. As an example of a manufacturing method, for instance, when an alcohol compound is used as an organic ligand, the precursor can be prepared by reacting the inorganic salt of the metal or its hydrate described above with the alkali metal alkoxide of the alcohol compound. Here, examples of the inorganic salt of the metal or its hydrate include metal halides, nitrates, etc., and examples of the alkali metal alkoxide include sodium alkoxide, lithium alkoxide, potassium alkoxide, etc.

[0087] In the multi-component ALD method described above, there is a method of vaporizing and supplying raw materials for forming thin films for atomic layer deposition independently of each component (hereinafter referred to as the "single source method") and a method of vaporizing and supplying mixed raw materials in which multi-component raw materials are mixed in advance to a desired composition (hereinafter referred to as the "cocktail source method"). In the case of the single source method, other precursors mentioned above are preferably compounds whose behavior of thermal and / or oxidative decomposition is similar to that of the compound represented by general formula (1). In the case of the cocktail source method, other precursors mentioned above are preferably compounds that, in addition to having behavior of thermal and / or oxidative decomposition similar to that of the compound represented by general formula (1), do not undergo deterioration due to chemical reactions, etc., when mixed.

[0088] In the case of the cocktail sauce method in the multi-component ALD method, a mixture of a compound represented by general formula (1) and another precursor, or a mixed solution in which the mixture is dissolved in an organic solvent, can be used as a raw material for forming a thin film for atomic layer deposition.

[0089] As for the organic solvents mentioned above, well-known general organic solvents may be used without particular limitation. Examples of such organic solvents include, for instance, 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; and hydrocarbons such as hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, heptane, octane, toluene, and xylene. Examples include 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; pyridine, rutidine, etc. These organic solvents may be used alone or in a mixture of two or more types, depending on the solubility of the solute, the relationship between the operating temperature and boiling point, and the flash point.

[0090] When the raw material for forming a thin film for atomic layer deposition is a mixed solution containing the above-mentioned organic solvent, the total amount of precursor in the raw material for forming a thin film for atomic layer deposition can be adjusted to 0.01 mol / liter to 2.0 mol / liter, particularly 0.05 mol / liter to 1.0 mol / liter.

[0091] Here, the total amount of precursor refers to the amount of the compound represented by general formula (1) when the raw material for forming a thin film for atomic layer deposition does not contain any other precursors other than the compound represented by general formula (1), and when the raw material for forming a thin film for atomic layer deposition contains other precursors in addition to the compound represented by general formula (1), it refers to the total amount of the compound represented by general formula (1) and other precursors.

[0092] In addition, the raw material for forming a thin film for the atomic layer deposition method of the present invention may, if necessary, contain a nucleating agent to improve the stability of the compound represented by general formula (1) and other precursors. The nucleating reagents include ethylene glycol ethers such as glime, diglaime, triglaime, and tetraglaime; crown ethers such as 18-crown-6, dicyclohexyl-18-crown-6,24-crown-8, dicyclohexyl-24-crown-8, and dibenzo-24-crown-8; polyamines such as ethylenediamine, N,N'-tetramethylethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,1,4,7,7-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, and triethoxytriethyleneamine; cyclic polyamines such as cyclam and cyclene; pyridine, pyrrolidine, piperidine, morpholine, N-methylpyrrolidine, N-methylpiperidine, and N-methylmorpholine. Examples include heterocyclic compounds such as tetrahydrofuran, tetrahydropyran, 1,4-dioxane, oxazole, thiazole, and oxathiolan; β-keto esters 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 perspective that an effect corresponding to the amount used is easily obtained, the amount of these nucleating reagents used is preferably in the range of 0.1 mol to 10 mol per 1 mol of the total amount of precursor, and more preferably in the range of 1 mol to 4 mol.

[0093] It is desirable that the raw material for forming a thin film for the atomic layer deposition method according to the present invention minimizes the inclusion of impurity metal element components, impurity halogen components such as impurity chlorine, and impurity organic components other than the constituent components. Regarding the impurity metal element components, it is preferable that the amount per element be 100 ppb or less, more preferably 10 ppb or less, and regarding the total amount, it is preferable that the amount be 1 ppm or less, more preferably 100 ppb or less. In particular, when used as a gate insulating film, gate film, or barrier layer for an LSI, it is necessary to reduce the content of alkali metal elements and alkaline earth metal elements that affect the electrical characteristics of the obtained thin film. Regarding the impurity halogen components, it is preferable that the amount be 100 ppm or less, more preferably 10 ppm or less, and most preferably 1 ppm or less. Regarding the impurity organic components, regarding the total amount, it is preferable that the amount be 500 ppm or less, more preferably 50 ppm or less, and most preferably 10 ppm or less. In addition, since moisture causes particle generation in raw materials for forming thin films for atomic layer deposition or during thin film formation, it is preferable to remove as much moisture as possible from precursors, organic solvents, and nucleating reagents in advance of use to reduce the moisture content of each. The moisture content of each precursor, organic solvent, and nucleating reagent is preferably 10 ppm or less, and more preferably 1 ppm or less.

[0094] In addition, the raw material for forming a thin film for the atomic layer deposition method according to the present invention preferably contains as few particles as possible in order to reduce or prevent particle contamination of the formed thin film. Specifically, in measuring particles 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 liquid phase, more preferable that the number of particles larger than 0.2 μm is 1,000 or less per 1 mL of the liquid phase, and even more preferable that the number of particles larger than 0.2 μm is 100 or less per 1 mL of the liquid phase.

[0095] The form of the raw material for forming a thin film for the atomic layer deposition method of the present invention is appropriately selected by means such as the transport and supply method of the atomic layer deposition method used.

[0096] The above-described transport supply method includes a gas transport method in which the raw material for forming a thin film for atomic layer deposition of the present invention is vaporized by heating and / or depressurizing in a raw material container in which the raw material is stored to form a raw material gas, and the raw material gas is introduced into a film deposition chamber equipped with a gas, together with a carrier gas such as argon, nitrogen, or helium as needed; and a liquid transport method in which the raw material for forming a thin film for atomic layer deposition of the present invention is transported in a liquid or solution state to a vaporization chamber, vaporized by heating and / or depressurizing in the vaporization chamber to form a raw material gas, and the raw material gas is introduced into a film deposition chamber equipped with a gas. In the case of the gas transport method, the compound itself represented by general formula (1) can be used as the raw material for forming a thin film for atomic layer deposition. In the case of the liquid transport method, the compound itself represented by general formula (1) or a mixed solution in which the compound is dissolved in an organic solvent can be used as the raw material for forming a thin film for atomic layer deposition.

[0097] Next, a method for manufacturing a thin film according to the present invention will be described. The method for manufacturing a thin film according to the present invention forms an indium-containing thin film or a zinc-containing thin film on the surface of a gas by an ALD method using the raw material for forming a thin film for atomic layer deposition described above.

[0098] Here, as an embodiment, a method for manufacturing an indium-containing thin film by the ALD method is described. In addition, the method for manufacturing a zinc-containing thin film can be carried out by replacing the indium atoms with zinc atoms in the method for manufacturing an indium-containing thin film.

[0099] Specific examples of the ALD apparatus used in the method for manufacturing a thin film of the present invention include an apparatus shown in FIG. 1 that vaporizes a raw material for forming a thin film for atomic layer deposition in a raw material container by heating and / or depressurizing it to form a raw material gas, and supplies the raw material gas to a deposition chamber together with a carrier gas as needed, or an apparatus shown in FIG. 2 that transports a raw material for forming a thin film for atomic layer deposition in a liquid or solution state to a vaporization chamber, vaporizes it to form a raw material gas by heating and / or depressurizing it in the vaporization chamber, and supplies the raw material gas to a deposition chamber. In addition, the apparatus is not limited to a single-wafer apparatus equipped with a deposition chamber as shown in FIG. 1 and FIG. 2, but may also use an apparatus capable of processing multiple sheets simultaneously using a batch furnace.

[0100] The method for manufacturing a thin film according to the present invention comprises: a process 1 (precursor thin film formation process) in which a raw material gas, obtained by vaporizing the raw material for forming a thin film for the atomic layer deposition method described above, is introduced into a film deposition chamber equipped with a gas, and the raw material gas is adsorbed onto the surface of the gas to form a precursor thin film; a process 2 (exhaust process) in which unreacted raw material gas is exhausted; and a process 3 (indium-containing thin film formation process) in which a reactive gas is introduced into a film deposition chamber and the precursor thin film is reacted with the reactive gas to form an indium-containing thin film on the surface of the gas.

[0101] In addition, the method for manufacturing a thin film according to the present invention preferably has a process 4 (exhaust process) for exhausting gas inside the film deposition chamber after process 3.

[0102] In the method for manufacturing a thin film according to the present invention, deposition by a series of operations, wherein process 1 (precursor thin film formation process), process 2 (exhaust process), process 3 (indium-containing thin film formation process), and process 4 (exhaust process) are performed in sequence, constitutes one cycle, and the thickness of the thin film can be adjusted by repeating this cycle. Below, each process of the method for manufacturing a thin film according to the present invention will be described.

[0103] (Process 1)

[0104] Process 1 is a process of introducing a raw material gas, obtained by vaporizing the raw material for forming a thin film for the atomic layer deposition method described above, into a deposition chamber equipped with a gas, and adsorbing the raw material gas onto the surface of the gas to form a precursor thin film. Methods for introducing the raw material gas, obtained by vaporizing the raw material for forming a thin film for the atomic layer deposition method described above, into a deposition chamber equipped with a gas include a gas transport method, as shown in FIGS. 1 and 3, in which the raw material for forming a thin film for the atomic layer deposition method in a raw material container is vaporized by heating and / or depressurizing to become a raw material gas, and the raw material gas is introduced into the deposition chamber together with a carrier gas such as argon, nitrogen, or helium if necessary; and a liquid transport method, as shown in FIGS. 2 and 4, in which the raw material for forming a thin film for the atomic layer deposition method in a raw material container is transported to a vaporization chamber in a liquid or solution state, and the raw material for forming a thin film for the atomic layer deposition method is vaporized by heating and / or depressurizing in the vaporization chamber to become a raw material gas, and the raw material gas is introduced into the deposition chamber. In the case of the gas transport method, the compound represented by general formula (1) itself can be used as a raw material for forming a thin film for the atomic layer deposition method. In the case of the liquid transport method, the compound represented by general formula (1), or a mixed solution in which the compound is dissolved in an organic solvent, can be used as a raw material for forming a thin film for the atomic layer deposition method. These raw materials for forming a thin film for the atomic layer deposition method may additionally contain nucleating reagents, etc.

[0105] In addition, as a method for introducing a raw material gas into a film deposition chamber, the single source method and the cocktail source method described as a multi-component ALD method containing multiple precursors may be cited. However, regardless of which introduction method is used, it is preferable that the raw material for forming a thin film for atomic layer deposition used in the method for manufacturing a thin film of the present invention be vaporized in a range of 0°C to 200°C for ease of handling. Furthermore, when the raw material for forming a thin film for atomic layer deposition is vaporized into a raw material gas within the raw material container or the vaporization chamber, the pressure within the raw material container and the pressure within the vaporization chamber are preferably 1 Pa to 10,000 Pa for ease of vaporizing the raw material for forming a thin film for atomic layer deposition.

[0106] Here, the material of the gas installed within the membrane chamber may include, for example, 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 shape of the gas may be plate-like, spherical, fibrous, or flake-like. The surface of the gas may be flat or may have a three-dimensional structure such as a trench structure.

[0107] After introducing the source gas into the film deposition chamber, a precursor thin film can be formed on the surface of the gas by adsorbing the source gas onto the surface of the gas. At this time, the gas may be heated, or the inside of the film deposition chamber may be heated. The conditions for forming the precursor thin film are not particularly limited, and, for example, the adsorption temperature (gas temperature), system pressure, etc., can be appropriately determined according to the type of raw material for forming a thin film for the atomic layer deposition method. When using a raw material for forming a thin film for the atomic layer deposition method containing an indium compound represented by general formula (1), it is preferable that process 1 be performed with the gas heated to 50°C or higher and 400°C or lower, and it is more preferable that it be performed with the gas heated to 100°C or higher and 300°C or lower from the viewpoint that a uniform precursor thin film is easily obtained. When using a raw material for forming a thin film for atomic layer deposition containing a zinc compound represented by general formula (1), process 1 is preferably carried out with the gas heated to 50°C or higher and 400°C or lower, and is more preferably carried out with the gas heated to 100°C or higher and 300°C or lower from the viewpoint that a uniform precursor thin film is easily obtained. The system pressure is not particularly limited, but is preferably 1 Pa or higher and 10,000 Pa or lower, and is more preferably 10 Pa or higher and 1,000 Pa or lower from the viewpoint that a uniform precursor thin film is easily obtained.

[0108] (Process 2)

[0109] Process 2 is a process of exhausting unreacted raw gas that has not been adsorbed on the surface of the gas from the deposition chamber after forming a precursor thin film. In this process, it is ideal for the unreacted raw gas to be completely exhausted from the deposition chamber, but it is not strictly necessary to exhaust it completely. Examples of exhaust methods include purging the system of the deposition chamber with an inert gas such as helium, nitrogen, or argon, exhausting by depressurizing the system, and methods combining these. When depressurizing the system, the degree of depressurization is preferably in the range of 0.01 Pa or more and 300 Pa or less, and from the viewpoint that exhausting the unreacted raw gas is promoted, a range of 0.01 Pa or more and 100 Pa or less is more preferable.

[0110] (Process 3)

[0111] Process 3 is a process in which, after Process 2, a reactive gas is introduced into a film-forming chamber, and a precursor thin film formed on the surface of the gas is reacted with the reactive gas to form an indium-containing thin film by the action of the reactive gas and the action of heat.

[0112] Examples of the above reactive gases include oxidizing gases such as oxygen, ozone, nitrogen dioxide, nitric oxide, water vapor, hydrogen peroxide, formic acid, acetic acid, and acetic anhydride; reducing gases such as hydrogen; organic amine compounds such as monoalkylamine, dialkylamine, trialkylamine, and alkylenediamine; and nitrating gases such as hydrazine and ammonia. These reactive gases may be used alone or in a mixture of two or more types. In the method for manufacturing a thin film according to the present invention, the reactive gas is preferably an oxidizing gas, and from the view that the reaction between the precursor thin film and the reactive gas is good, it is more preferable for the gas to contain at least one selected from the group consisting of oxygen, ozone, and water vapor. When an oxidizing gas is used as the reactive gas, an indium oxide thin film is formed as an indium-containing thin film, and a zinc oxide thin film is formed as a zinc-containing thin film.

[0113] When using a raw material for forming a thin film for atomic layer deposition containing an indium compound represented by general formula (1), the temperature (gas temperature) when reacting the precursor thin film with a reactive gas is 50°C or higher and 400°C or lower, and from the view that a high-quality thin film with less residual carbon is obtained, it is more preferable to have a temperature of 100°C or higher and 300°C or lower. When using a raw material for forming a thin film for atomic layer deposition containing a zinc compound represented by general formula (1), the temperature (gas temperature) when reacting the precursor thin film with a reactive gas is 50°C or higher and 400°C or lower, and from the view that a high-quality thin film with less residual carbon is obtained, it is more preferable to have a temperature of 100°C or higher and 300°C or lower. In addition, when process 3 is performed, it is preferable that the pressure inside the film-forming chamber be 1 Pa or more and 10,000 Pa or less, and from the perspective that the reaction between the precursor film and the reactive gas is improved, it is more preferable that the pressure be 10 Pa or more and 1,000 Pa or less.

[0114] (Process 4)

[0115] Process 4 is a process for exhausting unreacted reactive gases and byproduct gases from the film deposition chamber after Process 3 in order to manufacture a high-quality thin film. Unreacted reactive gases refer to reactive gases that did not react with the precursor thin film in Process 3. Also, byproduct gases refer to gases generated after reacting the precursor thin film with the reactive gases in Process 3. In this process, it is ideal for the reactive gases and byproduct gases to be completely exhausted from the film deposition chamber, but complete exhaust is not strictly necessary. The exhaust method and the degree of pressure reduction in the case of pressure reduction are the same as those described in Process 2 above.

[0116] The method for manufacturing a thin film according to the present invention comprises a series of operations of the above-mentioned process 1, process 2, process 3, and any process 4 as one cycle, and the thickness of the indium-containing thin film obtained can be adjusted by the number of such cycles.

[0117] In addition, in the method for manufacturing a thin film according to the present invention, as shown in FIGS. 3 and 4, energy such as plasma, light, or voltage may be applied within the film deposition chamber, or a catalyst may be used. The timing of applying the energy and the timing of using the catalyst are not particularly limited, and for example, when introducing a raw material gas into the film deposition chamber in Process 1, or when heating when forming a precursor thin film; when introducing a reactive gas into the film deposition chamber in Process 3, or when reacting the reactive gas with the precursor thin film; or when exhausting the system in Process 2 or Process 4, or between each of the above processes.

[0118] In addition, in the method for manufacturing a thin film according to the present invention, after forming the thin film, an annealing treatment may be performed under an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere to obtain better electrical properties, and if step filling is required, a reflow process may be formed. In this case, the temperature is preferably 200°C or higher and 1,000°C or lower, and is more preferably 250°C or higher and 500°C or lower from the viewpoint that heat-induced damage to the thin film or gas can be suppressed.

[0119] The thin film produced by the method of manufacturing a thin film according to the present invention can be formed into a desired type of thin film by coating it with a gas such as metal, oxide ceramics, nitride ceramics, or glass by appropriately selecting different precursors, reactive gases, and manufacturing conditions. Since the thin film of the present invention has excellent electrical and optical properties, it can be widely used in the manufacture of, for example, electrode materials for memory devices represented by DRAM devices, resistive films, diamagnetic films used in the recording layer of hard disks, and catalyst materials for solid polymer fuel cells.

[0120] The zinc compound of the present invention is represented by the general formula (2) above, and can be preferably used as a raw material for forming a thin film for atomic layer deposition because it is applicable to atomic layer deposition.

[0121] In general formula (2), R 5 and R 6 Examples of alkyl groups having 2 to 4 carbon atoms that have a straight chain or branch, represented by, include ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, sec-butyl groups, and tert-butyl groups.

[0122] Among general formula (2), A 2Examples of alkylene groups having 1 to 4 carbon atoms and having a straight chain or branched structure, represented by, include methylene groups, ethylene groups, propylene groups, 1,1-dimethylmethylene groups, 1-methylpropylene groups, 2-methylpropylene groups, butylene groups, etc.

[0123] A 2 , R 4 , R 5 and R 6 It is preferable to appropriately combine the zinc compound represented by general formula (2) according to the method of manufacturing the thin film. For example, R 4 ga is a methyl group or an ethyl group, and R 5 and R 6 These zinc compounds, each independently comprising an ethyl group or a propyl group, are preferred because they facilitate obtaining high-quality zinc-containing thin films with low melting points and low residual carbon. In addition, A 2 A zinc compound having an ethylene group, a propylene group, or a butylene group is desirable because it has good reactivity with oxidizing gases, and A 2 a. A zinc compound containing propylene is more preferable. R 4 ga is a methyl group or an ethyl group, and R 5 and R 6 This is an ethyl group, and A 2 Zinc compounds containing propylene groups are more desirable because they facilitate the production of high-quality zinc-containing thin films with low residual carbon.

[0124] Examples of zinc compounds represented by general formula (2) include No. 323, No. 324, No. 325, No. 326, No. 327, No. 328, No. 333, No. 334, No. 335, No. 336, No. 337, No. 338, No. 363, No. 364, No. 365, No. 366, No. 367, No. 368, No. 373, No. 374, No. 375, No. 376, No. 377, and No. 378. Among these zinc compounds, the zinc compound of No. 333 is more preferred in terms of having a low melting point and good vaporability.

[0125] The compound represented by the general formula (2) of the present invention can be prepared using a known reaction. The compound represented by the general formula (2) can be obtained, for example, by Grignard reaction of a Grignard reagent derived from a dialkylamine halide with zinc chloride or a mixture of zinc chloride and dialkyl zinc.

[0126] [Example]

[0127] The present invention will be explained in more detail below with reference to examples. However, the present invention is not limited by the following examples.

[0128] [Example 1]

[0129] Synthesis of No. 4 Indium Compound

[0130] 2.92 g (120.0 ml) of metallic magnesium was added to a 300 ml 4-neck flask under an argon atmosphere, and then 108.17 g (1.50 ml) of dehydrated tetrahydrofuran and 1.88 g (10.0 ml) of dibromoethane were added. After stirring in an oil bath at 60°C, 14.97 g (100.0 ml) of 3-(diethylaminopropyl) chloride was added dropwise, and the mixture was heated under reflux for 4 hours to prepare Grignard's reagent. Next, a mixture of 22.18 g (100.0 mmol) of trichloroindium and 138.21 g (1.50 mmol) of dehydrated toluene was added to a 500 ml four-necked flask and stirred under ice cooling. After the temperature of the mixture reached 10 °C or lower, the aforementioned Grignard reagent was added dropwise. After adding, the temperature was raised to room temperature and stirred for 18 hours. After stirring, the tetrahydrofuran was removed by distillation in an oil bath at 70 °C under reduced pressure. The solution remaining in the flask was filtered and then removed by distillation in an oil bath at 100 °C under reduced pressure. The solution remaining in the flask was returned to room temperature and dried under reduced pressure to obtain 27.32 g (91.1 mmol) of orange solid 3-(diethylaminopropyl)indium dichloride.

[0131] A mixture of 1.16 g (3.9 mmol) of 3-(diethylaminopropyl)indium dichloride and 4.99 g (57.9 mmol) of dehydrated hexane was added to a 100 ml 4-neck flask and stirred under ice cooling. After the temperature of the mixture reached 10 °C or lower, 7.0 ml (8.1 mmol) of methyllithium (1.16 M diethyl ether solution) was added dropwise. After adding, the temperature was raised to room temperature and stirred for 3 hours. After stirring, the solution remaining in the flask was filtered. The obtained filtrate was added to the flask and subjected to reduced pressure treatment in an oil bath at 60 °C to distill off the diethyl ether and hexane. The white liquid remaining in the flask was distilled under reduced pressure (80 Pa), and 0.29 g (1.1 mmol, yield 26%) of a colorless transparent liquid was obtained as the effluent. The obtained colorless transparent liquid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 4, was an indium compound. The obtained colorless transparent liquid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0132] (1) 1 H-NMR (heavy benzene)

[0133]

[0134] (2) ICP-AES

[0135] Indium content: 44.7 mass% (Theoretical value: 44.3 mass%)

[0136] [Example 2] Synthesis of Indium Compound No. 20

[0137] 2.15 g (88.3 mmol) of metallic magnesium was added to a 200 ml four-necked flask and heated under an argon atmosphere, then 79.57 g (1.10 mmol) of dehydrated tetrahydrofuran and 1.38 g (7.4 mmol) of dibromoethane were added and stirred in an oil bath at 60 °C, followed by the dropwise addition of 10.53 g (73.6 mmol) of 3-(dimethylaminopropyl) chloride and heating under reflux for 6 hours to prepare the Grignard reagent. Next, a mixture of 16.27 g (73.6 mmol) of trichloroindium and 101.67 g (1.10 mmol) of dehydrated toluene was added to a 500 ml four-necked flask and stirred under ice cooling. After the temperature of the mixture reached 10 ℃ or lower, the aforementioned Grignard reagent was added dropwise. After adding, the temperature was raised to room temperature and stirred for 20 hours. Tetrahydrofuran was removed by distillation in an oil bath at 70 ℃ under reduced pressure. After filtering the solution remaining in the flask, toluene was removed by distillation in an oil bath at 70 ℃ under reduced pressure, yielding 18.42 g (67.8 mmol) of white solid 3-(dimethylaminopropyl)indium dichloride.

[0138] A mixture of 13.00 g (47.8 mmol) of 3-(dimethylaminopropyl)indium dichloride and 41.21 g (478 mmol) of dehydrated hexane was added to a 300 ml 4-neck flask and stirred under ice cooling. After the temperature of the mixture reached 10 °C or lower, 110.7 ml (105 mmol) of ethyl magnesium bromide (0.95 M tetrahydrofuran solution) was added dropwise as a Grignard reagent. After adding, the temperature was raised to room temperature and stirred for 18 hours. After stirring, the tetrahydrofuran was removed by distillation in an oil bath at 100 °C under reduced pressure. The solution remaining in the flask was filtered, and the hexane was removed by distillation in an oil bath at 100 °C under reduced pressure. The pale yellow liquid remaining in the flask was distilled under reduced pressure (60 Pa), and 2.76 g (10.7 mmol, yield 21%) of a colorless transparent liquid was obtained as the effluent. The obtained colorless transparent liquid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 20, is an indium compound. The obtained colorless transparent liquid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0139] (1) 1 H-NMR (heavy benzene)

[0140]

[0141] (2) ICP-AES

[0142] Indium content: 44.0 mass% (Theoretical value: 44.3 mass%)

[0143] [Example 3] Synthesis of the Indium Compound of No. 24

[0144] 1.31 g (54 mmol) of metallic magnesium was added to a 300 ml four-necked flask and heated under an argon atmosphere, then 53.4 g (740 mmol) of dehydrated tetrahydrofuran and 0.85 g (4.5 mmol) of dibromoethane were added and stirred in an oil bath at 60 °C, then 6.73 g (45 mmol) of 3-(diethylaminopropyl) chloride was added dropwise and heated under reflux for 4 hours to prepare the Grignard reagent. Next, a mixture of 10.00 g (45 mmol) of trichloroindium and 104.12 g (1.13 mmol) of dehydrated toluene was added to a 500 ml four-necked flask and stirred under ice cooling. After the temperature of the mixture reached 10°C or lower, the aforementioned Grignard reagent was added dropwise. After adding, the temperature was raised to room temperature and stirred for 16 hours. After stirring, the tetrahydrofuran was removed by distillation under reduced pressure. The mixture to which 100 ml (760 mmol) of hexane was added was stirred under ice cooling. After the temperature of the mixture reached 10°C or lower, 31.5 ml (95 mmol) of ethyl magnesium bromide (3 M diethyl ether solution) as a Grignard reagent was added dropwise. After adding, the temperature was raised to room temperature and stirred for 20 hours. After stirring, filtration was performed, the resulting filtrate was placed in a flask, and the mixture was treated under reduced pressure in an oil bath at 90°C to remove diethyl ether, hexane, and toluene by distillation. The pale yellow liquid remaining in the flask was distilled under reduced pressure (60 Pa), and 6.32 g (22 mmol, yield 49%) of a colorless transparent liquid was obtained as the effluent. The obtained colorless transparent liquid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 24, is an indium compound. The obtained colorless transparent liquid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0145] (1) 1 H-NMR (heavy benzene)

[0146]

[0147] (2) ICP-AES

[0148] Indium content: 40.2 mass% (Theoretical value: 40.0 mass%)

[0149] [Example 4] Synthesis of the zinc compound of No. 333

[0150] A mixture of 5.93 g (48 mmol) of diethyl zinc, 6.54 g (48 mmol) of dichlorozinc, and 120 ml of dehydrated ether was added to a 500 ml 4-neck flask and stirred under ice cooling. After the temperature of the mixture reached 10 °C or lower, 16.7 g (96 mmol) of 3-diethylamino-propylmagnesium chloride was added dropwise as a Grignard reagent. After adding, the temperature was raised to room temperature and stirred for 22 hours. After stirring, the ether was removed by distillation in an oil bath at 50 °C under atmospheric pressure, and then toluene was added and filtration was performed. The obtained filtrate was added to a flask and subjected to reduced pressure treatment in an oil bath at 100 °C to remove toluene by distillation. The colorless transparent liquid remaining in the flask was distilled under reduced pressure (50 Pa), and 1.50 g (7.2 mmol, yield 7.5%) of colorless transparent liquid was obtained as the effluent. The obtained colorless transparent liquid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 333, is a zinc compound. The obtained colorless transparent liquid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0151] (1) 1 H-NMR (heavy benzene)

[0152]

[0153] (2) ICP-AES

[0154] Zinc content: 31.6 mass% (Theoretical value: 31.3 mass%)

[0155] [Example 5] Synthesis of the zinc compound of No. 379

[0156] 2.20 g (0.0911 mol) of metallic magnesium was added to a 500 ml four-necked flask and heated under an argon atmosphere. Then, 400 ml of dehydrated tetrahydrofuran and 0.06 g (0.00033 mol) of 1,2-dibromoethane were added, the mixture was heated to 60 ℃ to 65 ℃, and 9.30 g (0.0588 mol) of 3-(dimethylamino)propyl chloride hydrochloride was added dropwise, followed by a reflux reaction for 8 hours. After confirming the loss of the metallic magnesium, the reaction mixture was returned to room temperature, and 73.5 ml (0.0294 mol) of zinc chloride (6.5 mass%) ether solution was added dropwise. After the addition, the reaction mixture was heated and reacted at 60 ℃ to 65 ℃ for 8 hours. After the reaction, the solvent was removed by distillation, and after extraction with dehydrated hexane (400 ml), the mixture was separated by filtration using a membrane filter with a pore size of 0.2 μm to obtain a white solid. The obtained white solid was distilled under reduced pressure (20 Pa to 30 Pa) (oil bath 110 °C to 115 °C) to obtain 7.0 g (0.0294 mol, yield 23.3%) of white solid as the fraction. The obtained white solid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 379, is a zinc compound. Of the obtained white solid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0157] (1) 1 H-NMR (heavy benzene)

[0158]

[0159] (2) ICP-AES

[0160] Zinc content: 27.2 mass% (Theoretical value: 27.5 mass%)

[0161] [Example 6] Synthesis of the zinc compound of No. 392

[0162] 3.50 g (0.143 mol) of metallic magnesium was added to a 1000 ml four-necked flask and heated under an argon atmosphere. Then, 500 ml of dehydrated tetrahydrofuran and 0.10 g (0.00053 mol) of 1,2-dibromoethane were added, and the mixture was heated to 60 ℃ to 65 ℃. Subsequently, 20.0 g (0.136 mol) of 3-chloro-N,N-diethylpropane-1-amine was added dropwise, and the mixture was refluxed for 8 hours. After confirming the loss of the metallic magnesium, the reaction mixture was returned to room temperature, and 170 ml (0.0680 mol) of zinc chloride (6.5 mass%) ether solution was added dropwise. After the addition, the reaction mixture was heated and reacted at 60 ℃ to 65 ℃ for 8 hours. After the reaction, the solvent was removed by distillation, and after extraction with dehydrated hexane (500 ml), the mixture was separated by filtration using a membrane filter with a pore size of 0.2 μm to obtain a viscous liquid. The obtained viscous liquid was distilled under reduced pressure (20 Pa to 30 Pa) (oil bath 110 °C to 115 °C, top temperature 95 °C to 99 °C) to obtain 13.0 g (0.0442 mol, yield 65.0 %) of a colorless transparent liquid as an oil fraction. The obtained colorless transparent liquid is, 1 Analysis by H-NMR and ICP-AES confirmed that the target compound, No. 392, was a zinc compound. The obtained colorless transparent liquid 1 The analysis results of H-NMR and ICP-AES are shown below.

[0163] (1) 1 H-NMR (heavy benzene)

[0164]

[0165] (2) ICP-AES

[0166] Zinc content: 22.8 mass% (Theoretical value: 22.3 mass%)

[0167] <Evaluation of Physical Properties of Compounds>

[0168] The following evaluations were performed on the compounds synthesized in Examples 1 to 6 above, and the following Comparative Compound 1 and Comparative Compound 2.

[0169] Comparative Compound 1: Trimethylindium

[0170] Comparative Compound 2: Diethyl Zinc

[0171] (1) Melting point evaluation

[0172] The state of the compound at atmospheric pressure and 25 °C was observed visually. For compounds that were solid at 25 °C, the melting point was measured using a micro-melting point measuring device. These results are shown in Table 1.

[0173] (2) Temperature (°C) when TG-DTA is reduced by 50 mass%

[0174] Measurements were taken using TG-DTA at 10 Torr, an argon flow rate of 50 mL / min, a heating rate of 10 ℃ / min, and an injection temperature range of 30 ℃ to 600 ℃. The temperature (℃) at which the weight of the test compound decreased by 50 mass% was evaluated as the "temperature (℃) at 50 mass% decrease in TG-DTA under reduced pressure." A lower "temperature (℃) at 50 mass% decrease in TG-DTA under reduced pressure" indicates that vapor is obtained at a lower temperature. These results are shown in Table 1.

[0175] (3) Temperature (°C) when TG-DTA decreases by 50 mass% at atmospheric pressure

[0176] Measurements were taken using TG-DTA at 760 Torr, an argon flow rate of 100 mL / min, a heating rate of 10 ℃ / min, and an injection temperature range of 30 ℃ to 600 ℃. The temperature (℃) at which the weight of the test compound decreased by 50 mass% was evaluated as the "temperature (℃) at 50 mass% decrease in TG-DTA at atmospheric pressure." A lower "temperature (℃) at 50 mass% decrease in TG-DTA at atmospheric pressure" indicates that vapor is obtained at a lower temperature. These results are shown in Table 1.

[0177] (4) Thermal decomposition initiation temperature (°C)

[0178] In the DSC chart measured using a differential scanning calorimeter (DSC) with an argon flow rate of 20 mL / min, a heating rate of 10 ℃ / min, and a scanning temperature range of 30 ℃ to 500 ℃, the onset point of exothermic or endothermic activity was evaluated as the thermal decomposition onset temperature (℃). These results are shown in Table 1.

[0179] Next, the compound evaluated above was used as a raw material for forming a thin film for the atomic layer deposition method, and a thin film was manufactured.

[0180] [Example 7]

[0181] Indium compound No. 4 was used as a raw material for thin film formation, and a thin film was fabricated on a silicon wafer in gaseous form using the ALD apparatus shown in Fig. 1 under the following conditions and process. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was an indium oxide thin film and that the residual carbon content in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance, the thin film formed in the gaseous form was a smooth film with a thickness of 40.5 nm, and the film thickness obtained per cycle was approximately 0.081 nm.

[0182] (condition)

[0183] Manufacturing method: ALD method

[0184] Reaction temperature (gas temperature): 200 ℃

[0185] Reactive gas: water vapor

[0186] (process)

[0187] A series of processes consisting of the following processes 1 to 4 was repeated for 500 cycles as one cycle.

[0188] Process 1: Vapor (raw material gas) of a raw material for forming a thin film is introduced into a film deposition chamber under conditions of a raw material container temperature of 200 ℃ and a pressure inside the raw material container of 26.67 Pa, and a precursor thin film is formed by adsorbing the raw material gas onto a gas surface for 20 seconds at a pressure of 26.67 Pa.

[0189] Process 2: Unadsorbed raw material gas is exhausted from the system by argon purging for 30 seconds.

[0190] Process 3: A reactive gas is introduced into the film deposition chamber, and the precursor thin film and the reactive gas are reacted at a system pressure of 100 Pa for 1 second.

[0191] Process 4: Unreacted reactive gases and byproduct gases are exhausted from the system by argon purging for 60 seconds.

[0192] [Example 8]

[0193] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to the indium compound of No. 20. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was indium oxide and that the amount of residual carbon in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 45.6 nm, and the film thickness obtained per cycle was approximately 0.0912 nm.

[0194] [Example 9]

[0195] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to the indium compound of No. 24. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was indium oxide and that the amount of residual carbon in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 39.5 nm, and the film thickness obtained per cycle was approximately 0.079 nm.

[0196] [Example 10]

[0197] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to the zinc compound of No. 333. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was zinc oxide and that the amount of residual carbon in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 60.4 nm, and the film thickness obtained per cycle was approximately 0.121 nm.

[0198] [Example 11]

[0199] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to the zinc compound of No. 379. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was zinc oxide and that the amount of residual carbon in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 63.5 nm, and the film thickness obtained per cycle was approximately 0.127 nm.

[0200] [Example 12]

[0201] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to the zinc compound of No. 392. As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, it was confirmed that the thin film was zinc oxide and that the residual carbon content in the thin film was less than the detection limit of 0.01 atm%. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 59.1 nm, and the film thickness obtained per cycle was approximately 0.118 nm.

[0202] [Comparative Example 1]

[0203] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to Comparative Compound 1 (trimethylindium). As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, the thin film was an indium oxide thin film, but the residual carbon content in the thin film was 20.3 atm%, possibly because trimethylindium has spontaneous combustion properties. In addition, as a result of measuring the film thickness using X-ray reflectance spectroscopy, the thin film formed in the gaseous phase was a smooth film with a thickness of 50.5 nm, and the film thickness obtained per cycle was approximately 0.101 nm.

[0204] [Comparative Example 2]

[0205] A thin film was prepared on a silicon wafer in gaseous form by carrying out the same procedure as in Example 7, except that the indium compound of No. 4 was changed to Comparative Compound 2 (diethyl zinc). As a result of analyzing the composition of the thin film using X-ray photoelectron spectroscopy, the thin film was zinc oxide, but the residual carbon content in the thin film was 15.8 atm%, possibly because diethyl zinc has spontaneous combustion properties. In addition, as a result of measuring the film thickness using X-ray reflectance, the thin film formed in the gaseous phase was a smooth film with a thickness of 60.5 nm, and the film thickness obtained per cycle was approximately 0.121 nm.

[0206]

[0207] From the above, the present invention has confirmed that high-quality indium-containing thin films or zinc-containing thin films with low residual carbon can be produced by an atomic layer deposition method using an indium compound or zinc compound having a specific structure.

Claims

Claim 1 A raw material for forming a thin film for atomic layer deposition containing a compound represented by the following general formula (1). (In Equation (1), R 1 , R 2 and R 3 Each represents, independently, an alkyl group having 1 to 4 carbon atoms having a straight chain or branching, and A 1 ... represents an alkylene group having 1 to 5 carbon atoms, having a straight chain or branching, x1 represents an integer from 0 to 2, y1 represents an integer from 1 to 3, and M represents an indium atom or a zinc atom. Provided that M is an indium atom, x1 is 2, y1 is 1, and also R 1 , R 2 and R 3 Exclude compounds in which this is a methyl group; M is a zinc atom, and A 1 This is an alkylene group of a straight chain with 3 carbon atoms, where x1 is 0 and y1 is 2, and also R 2 and R 3 Excluding compounds containing this methyl group.) Claim 2 A thin film obtained using a raw material for forming a thin film for an atomic layer deposition method as described in claim 1. Claim 3 A method for manufacturing a thin film containing indium atoms or a thin film containing zinc atoms on the surface of a gas by an atomic layer deposition method, comprising: a process 1 of forming a precursor thin film by adsorbing a raw material gas, which is vaporized from the raw material for forming a thin film for the atomic layer deposition method described in claim 1, onto the surface of the gas; a process 2 of exhausting unreacted raw material gas; and a process 3 of reacting the precursor thin film with a reactive gas to form a thin film containing indium atoms or a thin film containing zinc atoms on the surface of the gas. Claim 4 A method for manufacturing a thin film according to claim 3, wherein the reactive gas is an oxidizing gas, and the thin film containing the indium atom is indium oxide, or the thin film containing the zinc atom is zinc oxide. Claim 5 A method for manufacturing a thin film according to claim 4, wherein the oxidizing gas is a gas containing at least one selected from the group consisting of water vapor, oxygen, and ozone. Claim 6 A zinc compound represented by the following general formula (2). (In Equation (2), R 4 represents a methyl or ethyl group, and R 5 and R 6 Each independently represents an alkyl group having 2 to 4 carbon atoms having a straight chain or branching, and A 2 represents an alkylene group having 1 to 4 carbon atoms, having a straight chain or branches.

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