Thin film forming material, thin film, and method for manufacturing thin film

Abstract

Provided is a thin film-forming material containing a yttrium compound represented by general formula (1).　(In the formula, R1 and R3 each independently represent an alkyl group having 1-6 carbon atoms or an alkoxyalkyl group having 2-6 carbon atoms, R2 represents a hydrogen atom or an alkyl group having 1-3 carbon atoms, R4 represents an alkanediyl group having 1-5 carbon atoms, R5 represents an alkyl group each having 1-3 carbon atoms, and R1, R2, R3, R4, and R5, which are each present in a number of more than one, may be the same or different within each other.)

Description

[Technical Field]

[0001] The present invention relates to a thin film-forming material containing an yttrium compound having a specific structure, a thin film obtained using the same, and a method for producing the same. [Background technology]

[0002] In the semiconductor manufacturing industry, metal-containing complexes are being investigated as raw materials for forming thin films such as metal nitrides, metal oxides, and metal-containing films on substrates such as silicon.

[0003] Yttrium is used as a component for forming compound semiconductors, and various compounds have been reported as raw materials for forming thin films containing yttrium.

[0004] Examples of methods for producing thin films include sputtering, ion plating, metal organic decomposition (MOD) methods such as coating pyrolysis and sol-gel methods, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. Among these, CVD and ALD are mainly used because the quality of the thin films obtained is good.

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

[0006] For example, in Patent Document 1, a thin film-forming material for forming a thin film containing yttrium is described, which has an N side chain with -R 4 -NR 5 R 6 (R 4is an alkylene bridging group, and R 5 and R 6 A metal-containing complex having a β-ketoiminate structure having a β-keto group selected from alkyl groups and the like has been proposed.

[0007] Patent Document 2 proposes a metal-containing complex containing a multidentate ketoimine ligand and an alkoxy ligand or an amino ligand as a precursor for forming a metal film or a metal oxide film.

[0008] Patent Document 3 discloses the use of an yttrium compound having a β-ketoimine ligand as a catalyst for conjugated diene polymerization. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4680953 (JP Patent Publication No. 2007-302656) [Patent Document 2] Patent No. 5698161 (JP 2012-153688 A) [Patent Document 3] Patent No. 6020257 (JP 2014-166967 A) Summary of the Invention [Problem to be solved by the invention]

[0010] Thin film-forming raw materials are required to have a low melting point, high volatility, high thermal stability, be capable of forming high-quality thin films with little residual carbon, etc. However, the thin film-forming raw materials containing yttrium compounds proposed in Patent Documents 1 and 2 do not satisfy these requirements.

[0011] Patent Document 3 does not contain any description suggesting the use of an yttrium compound having a β-ketoimine ligand as a raw material for forming a thin film.

[0012] Therefore, an object of the present invention is to provide a thin film-forming raw material containing an yttrium compound that has a low melting point, high volatility, and high thermal stability, and can be suitably used in a CVD method or an ALD method. Another object of the present invention is to provide a thin film obtained by using the thin film-forming raw material, and a method for producing the thin film. [Means for solving the problem]

[0013] As a result of extensive research, the present inventors have found that a thin film-forming raw material containing an yttrium compound having a specific structure can solve the above problems, and have thus completed the present invention. That is, the present invention is a thin film-forming material containing an yttrium compound represented by the following general formula (1) or (2).

[0014] [ka]

[0015] (In the formula, R 1 and R 3 each independently represents an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 6 carbon atoms, and R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R 4 represents an alkanediyl group having 1 to 5 carbon atoms, and R 5 represents an alkyl group having 1 to 3 carbon atoms, and multiple R 1 , R 2 , R 3 , R 4 and R 5 may be the same or different.)

[0016] [ka]

[0017] (In the formula, R 6 and R 8each independently represents an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 6 carbon atoms, and R 7 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and multiple R 6 , R 7 and R 8 may be the same or different, provided that R 6 and R 8 At least one of these represents an alkoxyalkyl group having 2 to 6 carbon atoms.)

[0018] The thin film-forming material of the present invention is a compound represented by the general formula (1), R 1 and R 3 is an isopropyl group, and R 2 is a hydrogen atom, and R 4 is an ethylene group, and R 5 is a methyl group, or in the above general formula (2), R 6 is a methoxy tert-butyl group, and R 7 is a hydrogen atom, and R 8 The yttrium compound containing an isopropyl group is preferred because it has a low melting point and is highly volatile and thermally stable.

[0019] The present invention also provides a method for producing a thin film, including the steps of: introducing a source gas obtained by vaporizing the above-mentioned thin film-forming source material into a film formation chamber in which a substrate is placed; depositing an yttrium compound in the source gas on the surface of the substrate to form a precursor thin film; and introducing a reactive gas into the film formation chamber and reacting the precursor thin film with the reactive gas to form a thin film containing yttrium atoms on the surface of the substrate.

[0020] In the method for producing a thin film of the present invention, it is preferable that the reactive gas is an oxidizing gas, and the thin film containing yttrium atoms is yttrium oxide.

[0021] Furthermore, in the method for producing a thin film of the present invention, the oxidizing gas is more preferably a gas containing oxygen, ozone or water vapor.

[0022] In the method for producing a thin film of the present invention, it is preferable to react the precursor thin film with the reactive gas at a temperature in the range of 100°C to 400°C. [Effects of the Invention]

[0023] According to the present invention, by containing a specific yttrium compound, it is possible to provide a thin film-forming raw material having a low melting point and high volatility and thermal stability. Furthermore, by using the thin film-forming raw material of the present invention, it is possible to produce a high-quality yttrium-containing thin film with a small amount of residual carbon by a CVD method, particularly an ALD method. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram showing an example of an ALD apparatus used in the thin film manufacturing method according to the present invention. [Figure 2] FIG. 1 is a schematic diagram showing another example of an ALD apparatus used in the thin film manufacturing method according to the present invention. [Figure 3] FIG. 1 is a schematic diagram showing yet another example of an ALD apparatus used in the thin film manufacturing method according to the present invention. [Figure 4] FIG. 1 is a schematic diagram showing yet another example of an ALD apparatus used in the thin film manufacturing method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] <Raw material for thin film formation> The thin film-forming material of the present invention contains the yttrium compound represented by the above general formula (1) or (2).

[0026] In the above general formula (1), R 1 and R 3 each independently represents an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 6 carbon atoms, and R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R 4 represents an alkanediyl group having 1 to 5 carbon atoms, and R5 represents an alkyl group having 1 to 3 carbon atoms, and multiple R 1 , R 2 , R 3 , R 4 and R 5 may be the same or different.

[0027] In the above general formula (2), R 6 and R 8 each independently represents an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 6 carbon atoms, and R 7 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and multiple R 6 , R 7 and R 8 may be the same or different, provided that R 6 and R 8 At least one of these represents an alkoxyalkyl group having 2 to 6 carbon atoms.

[0028] The yttrium compound represented by the general formula (1) or (2) is used as a precursor for forming a thin film by a CVD method or an ALD method, and therefore preferably has a melting point of 100°C or less, and is more preferably a liquid at room temperature. Furthermore, the temperature at which the yttrium compound loses 50% by mass as measured by a reduced pressure thermogravimetric differential thermal analyzer (TG-DTA) is preferably 240°C or less.

[0029] The thermal decomposition initiation temperature of the yttrium compound as measured by a differential scanning calorimeter (DSC) is preferably 250°C or higher, and more preferably 300°C or higher.

[0030] In the above general formula (1), R 1 and R 3Examples of the alkyl group having 1 to 6 carbon atoms represented by the formula (1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an n-pentyl group, a sec-pentyl group, a tert-pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. 1 and R 3 However, yttrium compounds in which R is an alkyl group having 1 to 4 carbon atoms are preferred, 1 is an ethyl group, an isopropyl group, or a tert-butyl group, and R 3 is more preferably an yttrium compound in which R is an ethyl group or an isopropyl group, 1 and R 3 The yttrium compounds in which is an isopropyl group are most preferred.

[0031] In the above general formula (1), R 1 and R 3 Examples of the alkoxyalkyl group having 2 to 6 carbon atoms represented by the formula (1) include a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, a methoxyisopropyl group, a methoxypropyl group, a methoxyisobutyl group, a methoxysec-butyl group, a methoxytert-butyl group, an ethoxyisopropyl group, an ethoxybutyl group, an ethoxyisobutyl group, an ethoxysec-butyl group, and an ethoxytert-butyl group. 1 and R 3 Preferred are yttrium compounds in which is a methoxyisopropyl group or a methoxy tert-butyl group.

[0032] In the above general formula (1), R 2 and R 5 Examples of the alkyl group having 1 to 3 carbon atoms represented by the formula (1) include the alkyl groups having 1 to 3 carbon atoms among the alkyl groups described above. 2 is a hydrogen atom, and R 5is a methyl group.

[0033] In the above general formula (1), R 4 Examples of the alkanediyl group having 1 to 5 carbon atoms represented by the formula (1) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butylene group, a butane-1,2-diyl group, a butane-1,3-diyl group, and a butane-1,4-diyl group. 4 Preferred are yttrium compounds in which is an ethylene group or a propane-1,2-diyl group.

[0034] In the above general formula (2), R 6 and R 8 Examples of the alkyl group having 1 to 6 carbon atoms and the alkoxyalkyl group having 2 to 6 carbon atoms represented by the formula below include the same groups as those mentioned above.

[0035] In the above general formula (2), R 7 Examples of the alkyl group having 1 to 3 carbon atoms represented by the formula include the same as those mentioned above.

[0036] In the above general formula (2), multiple R 6 , R 7 and R 8 may be the same or different, but multiple R 6 and R 8 At least one of the R is an alkoxyalkyl group having 2 to 6 carbon atoms. 6 and R 8 Preferably, two or more of R are alkoxyalkyl groups having 2 to 6 carbon atoms. 6 and R 8 More preferred are yttrium compounds in which three of the groups are alkoxyalkyl groups having 2 to 6 carbon atoms.

[0037] Preferred specific examples of the yttrium compound represented by the general formula (1) or (2) include the following yttrium compounds No. 1 to No. 16, but the present invention is not limited to these yttrium compounds. In the following yttrium compounds No. 1 to No. 16, "Me" represents a methyl group, "Et" represents an ethyl group, "iPr" represents an isopropyl group, and "tBu" represents a tert-butyl group.

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] Among the above yttrium compounds, yttrium compounds No. 1, No. 3, No. 6 and No. 15 are preferred from the viewpoint that the effects of the present invention are particularly remarkable.

[0043] The yttrium compound of the present invention can be produced by utilizing a known reaction. For example, in the above general formula (1), R 1 is a methyl group, and R 2 is a hydrogen atom, and R 3 is a methyl group, and R 4 is a methylene group, and R 5The yttrium compound in which R is a methyl group can be obtained by reacting yttrium-tris-trimethylsilylamide with 4-methoxymethylamino-3-penten-2-one in a solvent, removing the solvent, and purifying by distillation. 6 is a methoxy tert-butyl group, and R 7 is a hydrogen atom, and R 8 The yttrium compound in which is an isopropyl group can be obtained by reacting yttrium-tris-trimethylsilylamide with 5-amino-7-methoxy-4-hepten-3-one in a solvent, removing the solvent, and purifying by distillation.

[0044] The thin film-forming raw material of the present invention may contain a yttrium compound represented by the above general formula (1) or (2), and its composition varies depending on the type of target thin film. For example, when producing a thin film containing only yttrium as the metal, the thin film-forming raw material of the present invention does not contain a compound containing a metal other than yttrium or a compound containing a metalloid. On the other hand, when producing a thin film containing yttrium and a metal and / or metalloid other than yttrium, the thin film-forming raw material of the present invention may contain, in addition to the yttrium compound represented by the above general formula (1) or (2), a compound containing the desired metal and / or a compound containing a metalloid (hereinafter, sometimes referred to as "other precursors").

[0045] In addition, in the case of a multi-component CVD method using multiple precursors, other precursors that can be used together with the yttrium compound represented by the above general formula (1) or (2) are not particularly limited, and well-known general precursors used as raw materials for forming thin films in the CVD method can be used.

[0046] Examples of the other precursors include compounds of silicon or a metal 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. Examples of the metal species of the precursor include lithium, sodium, magnesium, aluminum, potassium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, indium, tin, antimony, barium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, lead, bismuth, radium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0047] Examples of alcohol compounds that can be used as organic ligands for the other precursors 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; 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. 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.

[0048] Examples of glycol compounds used as organic ligands for the 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.

[0049] Examples of the β-diketone compound used as the organic ligand for the 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, 2-methyl- Examples of suitable fluorine-substituted alkyl β-diketones include 6-ethyldecane-3,5-dione and 2,2-dimethyl-6-ethyldecane-3,5-dione; 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 include 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.

[0050] Examples of cyclopentadiene compounds used as organic ligands for the other precursors include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, sec-butylcyclopentadiene, isobutylcyclopentadiene, tert-butylcyclopentadiene, dimethylcyclopentadiene, and tetramethylcyclopentadiene.

[0051] Examples of the organic amine compound used as the organic ligand of the other precursor include methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, and isopropylmethylamine.

[0052] The other precursors mentioned above are known in the art, and their production methods are also known. For example, when an alcohol compound is used as the organic ligand, the precursor can be produced by reacting the inorganic salt of the metal or a hydrate thereof described above with an alkali metal alkoxide of the alcohol compound. Here, examples of the inorganic salt of the metal or a hydrate thereof include metal halides and nitrates, and examples of the alkali metal alkoxide include sodium alkoxide, lithium alkoxide, and potassium alkoxide.

[0053] The multi-component CVD method described above includes a method in which each component of the thin film-forming raw material is vaporized and supplied independently (hereinafter sometimes referred to as the "single-source method"), and a method in which a mixed raw material in which multi-component raw materials are mixed in advance to a desired composition is vaporized and supplied (hereinafter sometimes referred to as the "cocktail-source method"). In the single-source method, the other precursor is preferably a compound whose thermal and / or oxidative decomposition behavior is similar to that of the yttrium compound represented by the general formula (1) or (2) above. In the cocktail-source method, the other precursor is preferably a compound whose thermal and / or oxidative decomposition behavior is similar to that of the yttrium compound represented by the general formula (1) or (2) above and which does not undergo deterioration due to chemical reactions or the like when mixed.

[0054] In the case of a cocktail source method in a multi-component CVD method, a mixture of the yttrium compound represented by the above general formula (1) or (2) with other precursors, or a mixed solution obtained by dissolving the mixture in an organic solvent, can be used as a thin film forming raw material.

[0055] The organic solvent is not particularly limited, and any well-known organic solvent can be used. Examples of the organic solvent include acetates 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-cyanonobutane, 1-cyanohexane, cyanocyclohexane, cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, 1,6-dicyanohexane, 1,4-dicyanocyclohexane, and 1,4-dicyanobenzene; pyridine, lutidine, and the like. These organic solvents may be used alone or in combination of two or more depending on the solubility of the solute, the relationship between the temperature used and the boiling point, the flash point, and the like.

[0056] When the thin film-forming raw material of the present invention is a mixed solution containing the above organic solvent, the total amount of precursors in the thin film-forming raw material may be adjusted to preferably 0.01 mol / L to 2.0 mol / L, more preferably 0.05 mol / L to 1.0 mol / L.

[0057] Here, the total amount of precursors refers to the amount of the yttrium compound represented by the general formula (1) or (2) when the thin film-forming raw material of the present invention does not contain a compound containing a metal other than yttrium or a compound containing a metalloid (however, when the thin film-forming raw material of the present invention further contains another precursor containing yttrium, the total amount of precursors refers to the total amount of the yttrium compound represented by the general formula (1) or (2) and the other precursor containing yttrium). When the thin film-forming raw material of the present invention contains another precursor in addition to the yttrium compound represented by the general formula (1) or (2), the total amount of the yttrium compound represented by the general formula (1) or (2) and the other precursor.

[0058] Furthermore, the thin-film-forming raw material of the present invention may contain a nucleophilic reagent, if necessary, to improve the stability of the yttrium compound represented by the general formula (1) or (2) 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 of suitable nucleophilic reagents include polyamines such as triethoxytriethyleneamine, cyclic polyamines such as cyclam and cyclen, 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, and β-diketones such as acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, and dipivaloylmethane. The amount of these nucleophilic reagents used is preferably 0.1 to 10 moles, more preferably 1 to 4 moles, per mole of the total precursor.

[0059] It is desirable that the thin-film-forming raw material of the present invention contain as little impurity metal elements, impurity halogens such as impurity chlorine, and impurity organic components as possible, other than the components that constitute the thin-film. The impurity metal element content is preferably 100 ppb or less per element, more preferably 10 ppb or less, and the total content is preferably 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, which affect the electrical properties of the resulting thin film. The impurity halogen content is preferably 100 ppm or less, more preferably 10 ppm or less, and even more preferably 1 ppm or less. The total content of impurity organic components 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 CVD raw materials and during thin-film formation, it is recommended to remove as much moisture as possible from precursors, organic solvents, and nucleophilic reagents before use to reduce the moisture content of each. The water content of each of the precursor, the organic solvent and the nucleophilic reagent is preferably 10 ppm or less, more preferably 1 ppm or less.

[0060] Furthermore, in order to reduce or prevent particle contamination of the thin film to be formed, it is preferable that the thin film-forming raw material of the present invention contains as few particles as possible. Specifically, in particle measurement in the liquid phase using a light scattering liquid-borne particle detector, the number of particles larger than 0.3 μm is preferably 100 or less per 1 ml of liquid phase, and the number of particles larger than 0.2 μm is more preferably 100 or less per 1 ml of liquid phase.

[0061] <Method of manufacturing thin films> Next, the method for producing a thin film of the present invention using the above-mentioned thin film-forming raw materials will be described. Here, as one embodiment, a method for producing a thin film containing yttrium atoms (hereinafter, also referred to as an "yttrium-containing thin film") by the ALD method will be described.

[0062] The apparatus used in the thin film manufacturing method of the present invention may be a well-known ALD apparatus. Specific examples of the apparatus include an apparatus capable of supplying a precursor by bubbling, as shown in Figures 1 and 3, and an apparatus having a vaporization chamber, as shown in Figures 2 and 4. Also included are apparatuses capable of performing plasma treatment on reactive gases, as shown in Figures 3 and 4. It should be noted that the apparatus is not limited to the single-wafer apparatus shown in Figures 1 to 4, and an apparatus capable of simultaneously processing multiple wafers using a batch furnace can also be used. These apparatuses can be used as CVD apparatuses.

[0063] The method for producing a thin film of the present invention includes the steps of introducing a source gas obtained by vaporizing the above-mentioned thin film-forming source material into a film formation chamber (hereinafter sometimes referred to as a "deposition reaction section") in which a substrate is placed (source gas introduction step), depositing an yttrium compound in the source gas on the surface of the substrate to form a precursor thin film (precursor thin film formation step), and introducing a reactive gas into the film formation chamber and reacting the precursor thin film with the reactive gas to form an yttrium-containing thin film on the surface of the substrate (yttrium-containing thin film formation step). The method for producing a thin film of the present invention also preferably includes a step of exhausting gas from the film formation chamber between the precursor thin film formation step and the yttrium-containing thin film formation step and / or after the yttrium-containing thin film formation step (exhaust step).

[0064] In one embodiment of the method for producing a thin film of the present invention, a precursor thin film forming step, an evacuation step, an yttrium-containing thin film forming step, and an evacuation step are sequentially performed to form a deposition cycle, and the thickness of the thin film of the present invention can be adjusted by repeating this cycle. Each step of the method for producing a thin film of the present invention will be described below.

[0065] (Source gas introduction process) The source gas introduction step is a step of vaporizing the thin film forming source material to form a source gas, and introducing the source gas into a deposition reaction section in which a substrate is placed. Methods for transporting and supplying thin-film precursors include a gas transport method, as shown in FIGS. 1 and 3, in which the precursor is heated and / or depressurized in a container (hereinafter sometimes referred to as a "source container") in which the precursor is stored to form a source gas, and then introduced into a deposition reactor containing a substrate, optionally together with a carrier gas such as argon, nitrogen, or helium. Another method, as shown in FIGS. 2 and 4, involves transporting the precursor in a liquid or solution state to a vaporization chamber, where it is heated and / or depressurized to form a source gas, and then introducing the source gas into a deposition reactor containing a substrate. In the gas transport method, the yttrium compound represented by the general formula (1) or (2) itself can be used as the thin-film precursor. In the liquid transport method, the yttrium compound represented by the general formula (1) or (2), or a solution of the yttrium compound dissolved in an organic solvent, can be used as the thin-film precursor. These thin-film precursors may further contain a nucleophilic reagent, etc.

[0066] In addition to the gas transport method and liquid transport method, methods that can be used in the source gas introduction step include the single source method and cocktail source method described in <Thin Film Forming Raw Materials> as multi-component ALD methods containing multiple precursors, but whichever introduction method is used, the thin film forming raw material of the present invention is preferably vaporized within a temperature range of 0° C. to 200° C. Furthermore, when the thin film forming raw material is vaporized in a source container or vaporization chamber to form a source gas, the pressure in the source container and the vaporization chamber is preferably within a range of 1 Pa to 10,000 Pa.

[0067] Examples of materials for the substrate placed in the deposition reaction section 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 may have a plate-like, spherical, fibrous, or scale-like shape. The substrate surface may be flat or may have a three-dimensional structure such as a trench structure.

[0068] (Precursor thin film formation process) In the precursor thin film formation step, the yttrium compound represented by the general formula (1) or (2) in the source gas introduced into a deposition reaction section in which a substrate is placed is deposited on the surface of the substrate to form a precursor thin film on the surface of the substrate. At this time, heat may be applied by heating the substrate or the deposition reaction section. The production 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 depending on the type of thin film-forming raw material. The reaction temperature is preferably 100°C or higher, at which the thin film-forming raw material of the present invention reacts sufficiently, and more preferably 100°C to 400°C. The reaction pressure is preferably 1 Pa to 10,000 Pa, and more preferably 10 Pa to 1,000 Pa.

[0069] The deposition rate can be controlled by the supply conditions of the thin film-forming raw material (vaporization temperature, vaporization pressure), reaction temperature, and reaction pressure. A high deposition rate may deteriorate the properties of the resulting thin film, while a low rate may cause problems in productivity. Therefore, a rate of 0.01 nm / min to 100 nm / min is preferred, and 0.1 nm / min to 50 nm / min is more preferred.

[0070] (Exhaust process) After the precursor thin film is formed, the source gas that has not been deposited on the surface of the substrate is exhausted from the deposition reaction zone. Ideally, the source gas is completely exhausted from the deposition reaction zone, but complete exhaust is not always necessary. Examples of exhaust methods include purging the deposition reaction zone system with an inert gas such as helium, nitrogen, or argon, exhausting by reducing the pressure inside the system, or a combination of these. When reducing the pressure, the degree of reduction is preferably in the range of 0.01 Pa to 300 Pa, more preferably 0.01 Pa to 100 Pa.

[0071] (Yttrium-containing thin film formation process) In the yttrium-containing thin film formation process, after the exhaust process, a reactive gas is introduced into the deposition reaction section, and the precursor thin film, i.e., the yttrium compound represented by the general formula (1) or (2) deposited on the surface of the substrate, is reacted with the reactive gas by the action of the reactive gas or the action of the reactive gas and the action of heat, to form the yttrium-containing thin film.

[0072] Examples of the reactive gas 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 monoalkylamines, dialkylamines, trialkylamines, and alkylenediamines; and nitriding gases such as hydrazine and ammonia. These reactive gases may be used alone or in combination of two or more. In the thin film manufacturing method of the present invention, the reactive gas is preferably an oxidizing gas, and more preferably a gas containing oxygen, ozone, or water vapor. When an oxidizing gas is used as the reactive gas, a thin film of yttrium oxide is formed as the yttrium-containing thin film.

[0073] When heat is used in the reaction between the precursor thin film and the reactive gas, the reaction is preferably carried out at a temperature in the range of 50° C. to 500° C., more preferably 100° C. to 400° C. The pressure in the deposition reaction zone during this step is preferably 1 Pa to 10,000 Pa, more preferably 10 Pa to 1,000 Pa.

[0074] (Exhaust process) After the formation of the yttrium-containing thin film, unreacted reactive gases and by-product gases are exhausted from the deposition reaction zone. Ideally, the reactive gases and by-product gases are completely exhausted from the deposition reaction zone, but this is not necessarily the case. The exhaust method and the degree of pressure reduction are the same as those in the exhaust step after the precursor thin film formation step described above.

[0075] As described above, the source gas introduction step, precursor thin film formation step, exhaust step, yttrium-containing thin film formation step, and exhaust step are performed in order, and deposition through a series of operations is considered to be one cycle. This cycle is repeated multiple times until a thin film of the required thickness is obtained, thereby producing an yttrium-containing thin film having a desired thickness. In the thin film production method using the ALD method, the thickness of the formed yttrium-containing thin film can be controlled by the number of cycles.

[0076] In the thin film manufacturing method of the present invention, energy such as plasma, light, or voltage may be applied to the deposition reaction zone, and a catalyst may be used, as shown in Figures 3 and 4. The timing of applying the energy and using the catalyst is not particularly limited, and may be, for example, when introducing the source gas in the source gas introduction step, when heating to form the precursor thin film, when introducing the reactive gas in the yttrium-containing thin film formation step, when reacting the reactive gas with the precursor thin film, when evacuating the system in the evacuation step, or between any of the above steps.

[0077] In the method for producing a thin film of the present invention, after the thin film is formed, annealing may be performed in an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere to obtain better electrical properties, and a reflow step may be performed if step filling is required. In this case, the temperature is preferably 200°C to 1,000°C, more preferably 250°C to 500°C.

[0078] A thin film produced using the thin-film-forming material of the present invention can be coated onto a substrate such as a metal, an oxide ceramic, a nitride ceramic, or a glass to form a desired type of thin film by appropriately selecting other precursors, reactive gases, and production conditions. The thin film of the present invention has excellent electrical and optical properties and can therefore be widely used in the production of, for example, electrode materials for memory elements such as DRAM elements, resistive films, diamagnetic films used in the recording layers of hard disks, and catalyst materials for polymer electrolyte fuel cells. [Example]

[0079] The present invention will be described in more detail below using examples, etc. However, the present invention is not limited to the following examples, etc.

[0080] [Production Example 1] Production of Yttrium Compound No. 1 In a 100 mL three-neck flask, 1.78 g (3.12 mmol) of yttrium-tris-trimethylsilylamide and 5.8 g of dehydrated toluene were added and mixed thoroughly. 2.02 g (10.92 mmol) of 5-((2-methoxyethyl)amino)-4-hepten-3-one was added dropwise to this suspension at room temperature. After stirring at 85°C for 3 hours, the solvent was removed under reduced pressure in an oil bath at 130°C. The resulting yttrium complex (orange viscous liquid) was placed in a flask and connected to a Kugelrohr purification apparatus, and distilled at a heating temperature of 230°C and 55 Pa to obtain a yellow viscous liquid. The resulting yellow viscous liquid was 1 As a result of analysis by H-NMR and ICP-AES, it was confirmed to be yttrium compound No. 1. The analytical results of the obtained yellow viscous liquid are shown below.

[0081] (1) 1 H-NMR (heavy benzene) 0.993-1.031ppm(9H,triplet), 1.204-1.242ppm(9H,triplet), 2.118-2.1754ppm(6H,quartet), 2.183-2.240ppm(6H,qu artet), 3.223ppm(9H,singlet), 3.477-3.501ppm(6H,triplet), 3.690-3.721ppm(6H,triplet), 4.953ppm(3H,singlet)

[0082] (2) Elemental analysis results by ICP-AES Y: 13.9 mass% (theoretical value: 13.66 mass%), C: 55.4 mass% (theoretical value: 55.37 mass%), H: 9.8 mass% (theoretical value: 9.75 mass%), N: 6.4 mass% (theoretical value: 6.46 mass%), O: 14.5 mass% (theoretical value: 14.76 mass%)

[0083] [Production Example 2] Production of Yttrium Compound No. 3 In a 100 mL three-neck flask, 1.57 g (2.76 mmol) of yttrium-tris-trimethylsilylamide and 5.1 g of dehydrated toluene were added and mixed thoroughly. 2.06 g (9.66 mmol) of 5-((2-methoxyethyl)amino)-2,6-dimethyl-4-hepten-3-one was added dropwise to this suspension at room temperature. After stirring at 55°C for 5 hours, the solvent was removed under reduced pressure in an oil bath at 111°C. The resulting yttrium complex (orange viscous liquid) was placed in a flask and connected to a Kugelrohr purification apparatus, and distilled at a heating temperature of 205°C and 21 Pa to obtain a yellow viscous liquid. The resulting yellow viscous liquid became a yellow solid when allowed to cool to room temperature. The resulting yellow viscous liquid was 1 As a result of analysis by H-NMR and ICP-AES, it was confirmed to be yttrium compound No. 3. The analytical results of the obtained yellow viscous liquid are shown below.

[0084] (1) 1 H-NMR (heavy benzene) 1.061-1.077ppm(18H,doublet), 1.228-1.244ppm(18H,doublet), 2.403-2.505ppm(3H,septet), 2.967-3.064ppm(3H,s eptet), 3.213ppm(9H,singlet), 3.430-3.462ppm(6H,triplet), 3.802-3.834ppm(6H,triplet), 5.112ppm(3H,singlet)

[0085] (2) Elemental analysis results by ICP-AES Y: 12.3 mass% (theoretical value: 12.09 mass%), C: 58.4 mass% (theoretical value: 58.84 mass%), H: 10.3 mass% (theoretical value: 10.29 mass%), N: 5.9 mass% (theoretical value: 5.71 mass%), O: 13.1 mass% (theoretical value: 13.07 mass%)

[0086] [Production Example 3] Production of Yttrium Compound No. 6 A 100 mL three-neck flask was charged with 1.41 g (2.47 mmol) of yttrium-tris-trimethylsilylamide and 6.8 g of dehydrated toluene and mixed thoroughly. To this suspension was added dropwise 2.08 g (8.65 mmol) of 2,2,6-trimethyl-5-((1-methoxy-2-propyl)amino)-4-hepten-3-one at room temperature. After stirring at 53°C for 4 hours, the solvent was removed under reduced pressure in an oil bath at 115°C. The resulting yttrium complex (orange viscous substance) was placed in a flask and connected to a Kugelrohr purification apparatus. Distillation was performed at 214°C and 17 Pa to obtain a yellow liquid. The resulting yellow liquid was cooled to room temperature and became a yellow glassy solid. Elemental analysis by ICP emission spectroscopy confirmed that this was yttrium compound No. 6.

[0087] (1) Elemental analysis results by ICP-AES Y: 10.8 mass% (theoretical value: 10.85 mass%), C: 61.7 mass% (theoretical value: 61.58 mass%), H: 10.5 mass% (theoretical value: 10.71 mass%), N: 5.2 mass% (theoretical value: 5.14 mass%), O: 11.8 mass% (theoretical value: 11.72 mass%)

[0088] [Production Example 4] Production of Yttrium Compound No. 15 In a 100 mL three-neck flask, 1.65 g (2.90 mmol) of yttrium-tris-trimethylsilylamide and 8.0 g of dehydrated toluene were added and mixed thoroughly. 2.02 g (10.2 mmol) of 5-amino-1-methoxy-2,2,6-trimethyl-4-hepten-3-one was added dropwise to this suspension at room temperature. After stirring at 86°C for 5 hours, the solvent was removed under reduced pressure in an oil bath at 120°C. The resulting yttrium complex (reddish-brown viscous substance) was placed in a flask and connected to a Kugelrohr purification apparatus, and distilled at a heating temperature of 210°C and 23 Pa to obtain a yellow liquid. The resulting yellow liquid was allowed to cool to room temperature to obtain a yellow solid. The resulting yellow solid was 1 As a result of analysis by H-NMR and ICP-AES, it was confirmed to be yttrium compound No. 15. The analytical results of the obtained yellow solid are shown below.

[0089] (1) 1 H-NMR (heavy benzene) 0.908ppm(18H,broad), 1.393ppm(18H,singlet), 2.079ppm(3H,singlet), 3.239ppm(9H,singlet), 3.525ppm(6H,singlet), 5.269ppm(3H,singlet), 7.378ppm(3H,broad)

[0090] (2) Elemental analysis results by ICP-AES Y: 12.8 mass% (theoretical value: 12.83 mass%), C: 57.5 mass% (theoretical value: 57.21 mass%), H: 10.0 mass% (theoretical value: 10.03 mass%), N: 6.1 mass% (theoretical value: 6.07 mass%), O: 13.6 mass% (theoretical value: 13.86 mass%)

[0091] [Production Example 5] Production of Comparative Compound 1 In a 100 mL three-neck flask, 2.44 g (4.28 mmol) of yttrium-tris-trimethylsilylamide and 7.9 g of dehydrated toluene were added and mixed thoroughly. 1.91 g (15.0 mmol) of 5-amino-4-hepten-3-one was added dropwise to this suspension at room temperature. After stirring at 87°C for 3 hours, the solvent was removed under reduced pressure in an oil bath at 111°C. The resulting yttrium complex (orange viscous liquid) was placed in a flask and connected to a Kugelrohr purification apparatus, and distilled at a heating temperature of 215°C and 50 Pa to obtain a yellow viscous liquid. The obtained yellow viscous liquid was allowed to cool to room temperature to obtain a yellow solid. The obtained yellow solid was 1 As a result of analysis by H-NMR and ICP-AES, it was confirmed to be the following comparative compound 1. The analytical results of the obtained yellow solid are shown below.

[0092] (1) 1 H-NMR (heavy benzene) 0.879-0.916ppm(9H,triplet), 1.232-1.270ppm(9H,triplet), 1.919-1.976ppm(6H,quart et), 2.306-2.363ppm(6H,quartet), 5.025-5.030ppm(3H,doublet), 7.614ppm(3H,singlet)

[0093] (2) Elemental analysis results by ICP-AES Y: 18.9 mass% (theoretical value: 18.66 mass%), C: 52.8 mass% (theoretical value: 52.93 mass%), H: 9.4 mass% (theoretical value: 9.51 mass%), N: 8.7 mass% (theoretical value: 8.82 mass%), O: 10.2 mass% (theoretical value: 10.08 mass%)

[0094] [ka]

[0095] The yttrium compounds Nos. 1, 3, 6, and 15 produced in the above Production Examples 1 to 5 and Comparative Compound 1 were evaluated as follows.

[0096] (1) Melting point evaluation The state of the compound was visually observed at normal pressure and 25°C, and for solid compounds, measurements were taken using a differential scanning calorimeter (DSC) at a heating rate of 10°C / min over a scanning temperature range of 30°C to 600°C. In the resulting chart, the melting point was determined as the temperature at the intersection of a straight line extending the low-temperature baseline toward the high-temperature side and a tangent drawn at the point where the gradient of the curve on the low-temperature side of the endothermic peak is maximum. The results are shown in Table 1.

[0097] (2) Temperature (°C) at 50% mass loss in reduced-pressure TG-DTA Measurements were performed using TG-DTA at 10 Torr, an argon flow rate of 50 mL / min, a heating rate of 10 °C / min, and a scanning temperature range of 30 °C to 600 °C. The temperature (°C) at which the mass of the test compound decreased by 50% was evaluated as the "temperature (°C) at which the mass of the test compound decreased by 50% by mass under reduced pressure TG-DTA." A lower temperature (°C) at which the mass of the test compound decreased by 50% by mass under reduced pressure TG-DTA indicates that vapor can be obtained at a lower temperature. The results are shown in Table 1.

[0098] (3) Thermal decomposition start temperature (℃) A differential scanning calorimeter (DSC) was used to measure the temperature at a rate of 10°C / min over a scanning temperature range of 30°C to 600°C. The starting point of exothermic or endothermic events in the DSC chart was evaluated as the thermal decomposition starting temperature (°C). The results are shown in Table 1.

[0099] [Table 1]

[0100] As can be seen from Table 1, Comparative Compound 1 had a thermal decomposition starting temperature of 267° C., and was poor in thermal stability, making it unsatisfactory as a raw material for forming a thin film.

[0101] In contrast, yttrium compounds No. 1, No. 3, No. 6, and No. 15 had low melting points but thermal decomposition onset temperatures of 300°C or higher, confirming their excellent thermal stability. Furthermore, the temperatures at which these yttrium compounds lost 50% by mass in reduced-pressure TG-DTA were around 230°C, confirming that vapor could be obtained at low temperatures. These results confirm that the yttrium compounds represented by general formula (1) or (2) are useful as raw materials for forming thin films. The appearance of compound No. 6 in Example 3 resembled water glass and had no fluidity.

[0102] [Example 5] Thin film production by ALD method Using yttrium compound No. 15 as a thin-film source, a thin film was fabricated on a silicon dioxide substrate using the ALD apparatus shown in Figure 1 under the following conditions. Analysis of the thin-film composition using X-ray photoelectron spectroscopy confirmed that the thin film contained yttrium oxide and that the residual carbon content was below the detection limit of 0.01 atom%. Furthermore, measurement of the thin-film thickness using X-ray reflectivity revealed that the thin film formed on the substrate was a smooth film with a thickness of 20 nm, and the film thickness obtained per cycle was approximately 0.05 nm.

[0103] (conditions) Manufacturing method: ALD method Reaction temperature (substrate temperature): 300℃ Reactive gas: ozone (Process) A series of steps (1) to (4) below constituted one cycle, and 400 cycles were repeated. (1) The raw material gas obtained by vaporizing the thin film forming raw material under the conditions of a raw material container temperature of 200°C and a raw material container internal pressure of 100 Pa is introduced into the film formation chamber, and the yttrium compound in the raw material gas is deposited on the substrate surface at a system pressure of 100 Pa for 10 seconds to form a precursor thin film. (2) Undeposited source gas is purged from the system by argon purging for 15 seconds. (3) A reactive gas is introduced into the film-forming chamber, and the precursor thin film is reacted with the reactive gas at a system pressure of 100 Pa for 10 seconds. (4) Unreacted reactive gases and by-product gases are purged from the system by argon purging for 15 seconds.

[0104] [Example 6] Thin film production by ALD method Using yttrium compound No. 3 as a thin-film source, a thin film was fabricated on a silicon dioxide substrate using the ALD apparatus shown in Figure 1 under the following conditions. Analysis of the thin-film composition using X-ray photoelectron spectroscopy confirmed that the thin film contained yttrium oxide and that the residual carbon content was below the detection limit of 0.01 atom%. Furthermore, measurement of the thin-film thickness using X-ray reflectivity revealed that the thin film formed on the substrate was a smooth film with a thickness of 16 nm, and the film thickness obtained per cycle was approximately 0.04 nm.

[0105] (conditions) Manufacturing method: ALD method Reaction temperature (substrate temperature): 300℃ Reactive gas: ozone (Process) A series of steps (1) to (4) below constituted one cycle, and 400 cycles were repeated. (1) The raw material gas obtained by vaporizing the thin film forming raw material under the conditions of a raw material container temperature of 200°C and a raw material container internal pressure of 100 Pa is introduced into the film formation chamber, and the yttrium compound in the raw material gas is deposited on the substrate surface at a system pressure of 100 Pa for 10 seconds to form a precursor thin film. (2) Undeposited source gas is purged from the system by argon purging for 15 seconds. (3) A reactive gas is introduced into the film-forming chamber, and the precursor thin film is reacted with the reactive gas at a system pressure of 100 Pa for 10 seconds. (4) Unreacted reactive gases and by-product gases are purged from the system by argon purging for 15 seconds.

[0106] [Comparative Example 2] Thin film production by ALD method A thin film was produced on a silicon dioxide substrate under the same conditions as in Example 5, except that Comparative Compound 1 was used as the thin film-forming raw material. Analysis of the thin film composition using X-ray electron spectroscopy revealed that the thin film contained yttrium oxide, but residual carbon was detected. Furthermore, observation of the thin film condition using a scanning electron microscope revealed that the thin film formed on the substrate was not smooth, making it impossible to measure the film thickness.

[0107] As described above, the thin film-forming raw material containing the yttrium compound of the present invention has a low melting point, can be vaporized at a low temperature, and has excellent thermal stability. Therefore, when a thin film is produced using the thin film-forming raw material of the present invention, a high-quality yttrium-containing thin film with a small amount of residual carbon can be produced.

Claims

1. A thin film-forming material containing an yttrium compound represented by the following general formula (1) or (2): 【Chemistry 1】 (In the formula, R １ and R ３ each independently represents an alkyl group having 1 to 4 carbon atoms; R ２ represents a hydrogen atom, R ４ represents an ethylene group or a propane-1,2-diyl group, and R ５ represents a methyl group, and a plurality of R １ , R ２ , R ３ , R ４ and R ５ may be the same or different.) 【Chemistry 2】 (In the formula, R ６ and R ８ each independently represents an alkyl group having 1 to 4 carbon atoms, a methoxyisopropyl group, or a methoxy tert-butyl group; R ７ represents a hydrogen atom, and a plurality of R ６ , R ７ and R ８ may be the same or different from each other. ６ and R ８ At least one of the groups represents a methoxyisopropyl group or a methoxy tert-butyl group.

2. In the general formula (1), R １ and R ３ is an isopropyl group, and R ２ is a hydrogen atom, and R ４ is an ethylene group, and R ５ is a methyl group, or a yttrium compound in the general formula (2), ６ is a methoxy tert-butyl group, and R ７ is a hydrogen atom, and R ８ 2. The thin film forming material according to claim 1, which contains an yttrium compound in which is an isopropyl group.

3. a step of introducing a raw material gas obtained by vaporizing the thin film forming raw material according to claim 1 or 2 into a film formation chamber in which a substrate is placed; depositing an yttrium compound in the source gas on the surface of the substrate to form a precursor thin film; introducing a reactive gas into the deposition chamber and reacting the precursor thin film with the reactive gas to form a thin film containing yttrium atoms on the surface of the substrate; A method for producing a thin film comprising the steps of:

4. 4. The method for producing a thin film according to claim 3, wherein the reactive gas is an oxidizing gas, and the thin film containing yttrium atoms is yttrium oxide.

5. 5. The method for producing a thin film according to claim 4, wherein the oxidizing gas is a gas containing oxygen, ozone, or water vapor.

6. 6. The method for producing a thin film according to claim 3, wherein the precursor thin film and the reactive gas are reacted at a temperature in the range of 100°C to 400°C.

Images