Tin compound, raw material for thin film formation, thin film, method for producing thin film, and halogen compound

Abstract

The present invention provides a tin compound which is represented by general formula (1). (In formula (1), each of R1 and R2 independently represents an alkyl group having 1 to 5 carbon atoms or an alkylsilyl group having 3 to 12 carbon atoms; each of R3 and R4 independently represents an alkyl group having 1 to 5 carbon atoms; and R5 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

Description

Technical Field

[0001] The present invention relates to a tin compound, a raw material for forming a thin film containing the tin compound, a thin film formed using the raw material for forming a thin film, a method for manufacturing a thin film, and a halogen compound.

Background Art

[0002] Thin film materials containing metal elements or silicon are used in members of electronic components such as electrode films, resistance films, and barrier films, members for recording media such as magnetic films, and electrode members such as thin film solar cells because of their excellent electrical and optical properties.

[0003] Examples of the method for manufacturing the above thin film include a sputtering method, an ion plating method, a metal organic compound decomposition (MOD) method such as a coating pyrolysis method or a sol-gel method, and a chemical vapor deposition (CVD) method. Among these, the chemical vapor deposition method including the atomic layer deposition (ALD) method is the most suitable manufacturing process because it has many advantages such as excellent composition controllability and step coverage, suitability for mass production, and the ability of hybrid integration.

[0004] Various compounds have been reported as tin compounds used in the chemical vapor deposition method. For example, Patent Document 1 discloses tetrakis(N,N'-dimethylacetamidinate)tin(IV). Further, Patent Document 2 discloses bis(N,N'-diisopropylacetamidinate)tin(II).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a method of forming a thin film by vaporizing a compound such as the CVD method, an important property required for a compound (precursor) used as a raw material for thin film formation is that a high-quality thin film can be produced with good productivity. However, conventional tin compounds have not fully satisfied this point.

[0007] Therefore, an object of the present invention is to provide a novel tin compound having a higher vapor pressure and a lower melting point than conventional tin compounds and capable of producing a high-quality thin film with good productivity when used as a raw material for thin film formation.

Means for Solving the Problems

[0008] As a result of repeated studies, the present inventors have found that a tin compound having a specific structure can solve the above problems, and have reached the present invention.

[0009] That is, the present invention is a tin compound represented by the following general formula (1).

[0010]

Chemical Formula

[0011] (In formula (1), R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms or an alkylsilyl group having 3 to 12 carbon atoms, and R 3 and R 4 each independently represent an alkyl group having 1 to 5 carbon atoms, and R 5 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

[0012] The present invention is a raw material for thin film formation containing the above tin compound.

[0013] The present invention is a thin film formed using the above raw material for thin film formation.

[0014] The present invention is a method for manufacturing a thin film, which uses a source gas obtained by vaporizing the above raw material for thin film formation to form a thin film containing tin atoms on the surface of a substrate.

[0015] The present invention is a halogen compound represented by the following general formula (2).

[0016] [Chemical formula]

[0017] (In formula (2), X represents a halogen atom, and R 6 and R 7 each independently represent an alkyl group having 1 to 5 carbon atoms, and R 8 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) [Advantages of the Invention]

[0018] According to the present invention, it is possible to provide a tin compound that has a higher vapor pressure and a lower melting point than conventional tin compounds and can produce a high-quality thin film with good productivity when used as a raw material for thin film formation. The tin compound of the present invention is suitable as a raw material for thin film formation for the CVD method, and is particularly excellent as a raw material for thin film formation for the ALD method. [Brief Description of the Drawings]

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0020] The tin compound of the present invention is represented by the above general formula (1) and is suitable as a precursor in a method for producing a thin film having a vaporization step such as ALD method which is a kind of CVD method.

[0021] Note that the tin compound represented by the following general formula (3) has the same meaning as the tin compound represented by the above general formula (1).

[0022]

Chemical formula

[0023] In the above general formulas (1) and (3), R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms or an alkylsilyl group having 3 to 12 carbon atoms, and R 3 and R 4 each independently represent an alkyl group having 1 to 5 carbon atoms, and R 5 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0024] Examples of the above "alkyl group having 1 to 5 carbon atoms" include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.

[0025] Examples of the above "alkylsilyl group having 3 to 12 carbon atoms" include trimethylsilyl group, triethylsilyl group, tripropylsilyl group, triisopropylsilyl group, tributylsilyl group, tri-tert-butylsilyl group, dimethylethylsilyl group, dimethylpropylsilyl group, dimethylisopropylsilyl group, butyldimethylsilyl group, tert-butyldimethylsilyl group, pentyldimethylsilyl group, hexyldimethylsilyl group and the like.

[0026] R in the above general formulas (1) and (3) 1 ~R 5 is appropriately selected according to the manufacturing method of the thin film to be applied. When used in a manufacturing method of a thin film having a step of vaporizing a tin compound, R 1 ~R 5 is preferably selected so as to be a tin compound having a high vapor pressure and a low melting point.

[0027] From the viewpoint of having a high vapor pressure and being able to produce a high-quality thin film with good productivity when used as a raw material for thin film formation, R 1 and R 2 are each independently preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms. R 1 and R 2 may be any of linear alkyl groups such as a propyl group and a butyl group, and branched alkyl groups such as an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. However, from the viewpoint of high thermal stability, R 1 and R 2 are preferably a branched alkyl group, more preferably an isopropyl group, an isobutyl group, a sec-butyl group or a tert-butyl group, and particularly preferably an isopropyl group. R 1 and R 2 may be the same or different, but from the viewpoint of high thermal stability, they are preferably the same group.

[0028] From the viewpoint of high thermal stability and being able to produce a high-quality thin film with good productivity when used as a raw material for thin film formation, R 3 and R 4 are each independently preferably an alkyl group having 3 to 5 carbon atoms, more preferably a branched alkyl group having 3 to 5 carbon atoms, particularly preferably an isopropyl group or a tert-butyl group, and most preferably a tert-butyl group. R 3 and R 4may be the same or different, but from the viewpoint of high thermal stability, it is preferably the same group. From the viewpoints of high thermal stability and high vapor pressure, R 5 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0029] In addition, when used in a method for producing a thin film by the MOD method that does not involve a vaporization step, R 1 ~R 5 may be selected according to the solubility in the solvent used, the thin film formation reaction, and the like.

[0030] Preferred specific examples of the tin compound represented by the general formula (1) include the tin compounds of the following No. 1 to No. 120. In the tin compounds of the following No. 1 to No. 120, "Me" represents a methyl group, "Et" represents an ethyl group, "nPr" represents a normal propyl group, "iPr" represents an isopropyl group, "iBu" represents an isobutyl group, "sBu" represents a secondary butyl group, "tBu" represents a tertiary butyl group, "TMS" represents a trimethylsilyl group, and "tAm" represents a group represented by the following formula.

[0031]

Chemical formula

[0032]

Chemical formula

[0033]

Chemical formula

[0034]

Chemical formula

[0035] [Chemistry]

[0036] [Chemistry]

[0037] [Chemistry]

[0038] [Chemistry]

[0039] [Chemistry]

[0040] [Chemistry]

[0041] [Chemistry]

[0042] The tin compound of the present invention is not particularly limited by its production method and can be produced by applying well-known reactions. The tin compound of the present invention can be obtained, for example, by reacting a halogen compound having a corresponding structure, an amine compound having a corresponding structure, and an alkyllithium in a normal hexane solvent, followed by filtration, distilling off the solvent from the obtained filtrate, and then subjecting it to distillation purification.

[0043] Next, the raw material for thin film formation of the present invention will be described. The raw material for thin film formation of the present invention contains a tin compound represented by the above general formula (1) as a precursor for the thin film. The form of the raw material for thin film formation of the present invention varies depending on the manufacturing process to which the raw material for thin film formation is applied. For example, when manufacturing a thin film containing only tin atoms as a metal, the raw material for thin film formation of the present invention does not contain metal compounds and metalloid compounds other than the tin compound represented by the above general formula (1). On the other hand, when manufacturing a thin film containing two or more kinds of metals and / or metalloids, the raw material for thin film formation of the present invention can also contain, in addition to the tin compound represented by the above general formula (1), a compound containing a desired metal and / or a compound containing a metalloid (hereinafter sometimes referred to as "other precursor"). The raw material for thin film formation of the present invention may further contain an organic solvent and / or a nucleophilic reagent as described later. As described above, since the physical properties of the tin compound represented by the above general formula (1) as a precursor are suitable for the CVD method, the raw material for thin film formation of the present invention is useful as a raw material for chemical vapor deposition (hereinafter sometimes referred to as "CVD raw material"). Among them, since the tin compound represented by the above general formula (1) has an ALD window, the raw material for thin film formation of the present invention is particularly suitable for the atomic layer deposition method.

[0044] When the raw material for thin film formation of the present invention is a CVD raw material, its form is appropriately selected by a method such as a transport supply method of the CVD method to be used.

[0045] As the above-described transportation and supply method, the CVD raw material is vaporized by heating and / or depressurizing the CVD raw material in a container in which the CVD raw material is stored (hereinafter, may also be referred to as a "raw material container") to obtain a raw material gas, and together with a carrier gas such as argon, nitrogen, helium, etc. used as necessary, the raw material gas is introduced into a film formation chamber in which a substrate is installed (hereinafter, may also be referred to as a "deposition reaction section") by a gas transportation method. There is also a liquid transportation method in which the CVD raw material is transported to a vaporization chamber in a liquid or solution state, and the CVD raw material is vaporized by heating and / or depressurizing in the vaporization chamber to obtain a raw material gas, and the raw material gas is introduced into the film formation chamber. In the case of the gas transportation method, the tin compound itself represented by the above general formula (1) can be used as the CVD raw material. In the case of the liquid transportation method, the tin compound itself represented by the above general formula (1) or a solution in which the tin compound is dissolved in an organic solvent can be used as the CVD raw material. These CVD raw materials may further contain other precursors, nucleophilic reagents, etc.

[0046] In addition, in a multi-component CVD method, there are a method of vaporizing and supplying each component of the CVD raw material independently (hereinafter, may also be referred to as a "single-source method") and a method of vaporizing and supplying a mixed raw material in which multi-component raw materials are mixed in a desired composition in advance (hereinafter, may also be referred to as a "cocktail-source method"). In the case of the cocktail-source method, a mixture of the tin compound represented by the above general formula (1) and another precursor or a mixed solution in which the mixture is dissolved in an organic solvent can be used as the CVD raw material. This mixture and mixed solution may further contain a nucleophilic reagent, etc.

[0047] As the above-mentioned organic solvent, well-known and common organic solvents can be used without particular limitation. Examples of the organic solvent include acetate 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 methyl cyclohexanone; hydrocarbons such as hexane, cyclohexane, methyl cyclohexane, dimethyl cyclohexane, ethyl cyclohexane, heptane, octane, toluene, and xylene; hydrocarbons having a cyano group such as 1-cyanopropane, 1-cyanobutane, 1-cyanohexane, cyanocyclohexane, cyanobenzene, 1,3-dicyanopropane, 1,4-dicyanobutane, 1,6-dicyanohexane, 1,4-dicyanocyclohexane, and 1,4-dicyanobenzene; 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 use temperature and the boiling point and flash point, and the like.

[0048] When the raw material for thin film formation of the present invention is a mixed solution with the above-mentioned organic solvent, from the viewpoint of being able to produce a high-quality thin film with good productivity, the total amount of the precursor in the raw material for thin film formation is preferably 0.01 mol / liter to 2.0 mol / liter, and more preferably 0.05 mol / liter to 1.0 mol / liter.

[0049] Here, the total amount of the precursor means the amount of the tin compound represented by the above general formula (1) when the raw material for thin film formation of the present invention does not contain other precursors in addition to the tin compound represented by the above general formula (1), and means the total amount of the tin compound represented by the above general formula (1) and other precursors when the raw material for thin film formation of the present invention contains other precursors in addition to the tin compound represented by the above general formula (1).

[0050] In the case of the multi-component CVD method, there is no particular limitation on the other precursor used together with the tin compound represented by the general formula (1), and well-known general precursors used as raw materials for CVD can be used.

[0051] Examples of the other precursors include one or more 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 compounds of silicon or metal. Examples of the metal species of the precursor include lithium, sodium, potassium, magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, aluminum, germanium, tin, lead, antimony, bismuth, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthenium, or lutetium.

[0052] Examples of the alcohol compounds used as the organic ligand of the above 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; 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-s-butoxy-1,1-diethylethanol, and 3-methoxy-1,1-dimethylpropanol; 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.

[0053] Examples of the glycol compounds used as the organic ligand of the above 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.

[0054] Examples of β-diketone compounds used as organic ligands for the above-mentioned other precursors include alkyl-substituted β-diketones such as 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-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-diperfluorohexylpropane-1,3-dione; 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, 2,2,6,6-tetramethyl-1-(2-methoxyethoxy)heptane-3,5-dione, and the like.

[0055] Examples of cyclopentadiene compounds used as organic ligands for the above-mentioned other precursors include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, sec-butylcyclopentadiene, isobutylcyclopentadiene, tert-butylcyclopentadiene, dimethylcyclopentadiene, tetramethylcyclopentadiene, and the like.

[0056] Examples of the organic amine compounds used as the organic ligands of the above other precursors include methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, isopropylmethylamine, and the like.

[0057] The above other precursors 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 above-mentioned metal inorganic salt or its hydrate with the alkali metal alkoxide of the alcohol compound. Here, examples of the metal inorganic salt or its hydrate include metal halides, nitrates, etc., and examples of the alkali metal alkoxide include sodium alkoxide, lithium alkoxide, potassium alkoxide, etc.

[0058] In the case of the single-source method, it is preferable to use, as the above other precursor, a compound whose thermal decomposition and / or oxidative decomposition behavior is similar to that of the tin compound represented by the above general formula (1). In the case of the cocktail-source method, in addition to the thermal decomposition and / or oxidative decomposition behavior of the above other precursor being similar to that of the tin compound represented by the above general formula (1), it is preferable to use a compound that does not cause a change that impairs the desired properties as a precursor due to chemical reactions during mixing, etc., from the viewpoint of producing a high-quality thin film with good productivity.

[0059] In addition, the raw material for thin film formation of the present invention may contain a nucleophilic reagent, if necessary, to improve the stability of the tin compound represented by the above general formula (1) and other precursors. Examples of the nucleophilic reagent include ethylene glycol ethers such as glyme, diglyme, triglyme, and tetraglyme; crown ethers such as 18-crown-6, dicyclohexyl-18-crown-6, 24-crown-8, dicyclohexyl-24-crown-8, and dibenzo-24-crown-8; 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 triethoxytriethylenamine; 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; or β-diketones such as acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, and dipivaloylmethane. From the viewpoint of being able to produce a high-quality thin film with good productivity, the amount of these nucleophilic reagents used is preferably 0.1 mol to 10 mol, more preferably 1 to 4 mol, per 1 mol of the total amount of the precursors.

[0060] In the raw material for thin film formation of the present invention, impurity metal element components other than the components constituting the same, impurity halogen components such as impurity chlorine, and impurity organic components are made to be contained as little as possible. The content of impurity metal element components is preferably 100 ppb or less, more preferably 10 ppb or less, for each element, and preferably 1 ppm or less, more preferably 100 ppb or less, in total. In particular, when used as a gate insulating film, gate film, or barrier layer of 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. The content of impurity halogen components is preferably 100 ppm or less, more preferably 10 ppm or less, and most preferably 1 ppm or less. The content of impurity organic components is preferably 500 ppm or less, more preferably 50 ppm or less, and most preferably 10 ppm or less, in total. Further, since moisture causes particle generation in the raw material for chemical vapor deposition and particle generation during thin film formation, it is preferable to remove moisture as much as possible before using the precursor, organic solvent, and nucleophilic reagent, respectively. From the viewpoint of being able to produce a high-quality thin film with good productivity, the moisture content of each of the precursor, organic solvent, and nucleophilic reagent is preferably 10 ppm or less, and more preferably 1 ppm or less.

[0061] Further, in order to reduce or prevent particle contamination of the thin film formed from the raw material for thin film formation of the present invention, it is preferable to contain as few particles as possible. Specifically, in particle measurement by a light scattering type in-liquid particle detector in the liquid phase, the number of particles larger than 0.3 μm is preferably 100 or less in 1 mL of the liquid phase, more preferably the number of particles larger than 0.2 μm is 1000 or less in 1 mL of the liquid phase, and most preferably the number of particles larger than 0.2 μm is 100 or less in 1 mL of the liquid phase.

[0062] Next, a method for manufacturing a thin film using the raw material for thin film formation of the present invention will be described. The method for manufacturing a thin film of the present invention includes forming a thin film containing tin atoms (hereinafter, sometimes referred to as "tin-containing thin film") on the surface of a substrate using a raw material gas obtained by vaporizing the raw material for thin film formation of the present invention. Preferably, the method for manufacturing a thin film of the present invention includes a step of introducing a raw material gas obtained by vaporizing the raw material for thin film formation of the present invention and a reactive gas used as necessary into a film formation chamber in which a substrate is installed, and a step of decomposing and / or chemically reacting a tin compound represented by the general formula (1) contained in the raw material gas to form a tin-containing thin film on the surface of the substrate. More preferably, the method for manufacturing a thin film of the present invention includes a step of adsorbing (depositing) a tin compound represented by the general formula (1) contained in the raw material gas on the surface of the substrate to form a precursor thin film, and a step of reacting the precursor thin film with a reactive gas to form a tin-containing thin film on the surface of the substrate. The method for transporting and supplying the raw material for thin film formation, the method and conditions for forming the tin-containing thin film, the manufacturing apparatus, etc. are not particularly limited, and well-known general conditions and methods can be used.

[0063] Examples of the reactive gas used as necessary described above include oxidizing gases such as oxygen, ozone, and water vapor, hydrocarbon compounds such as methane and ethane, reducing gases such as hydrogen, carbon monoxide, and organometallic compounds, organic amine compounds such as monoalkylamine, dialkylamine, trialkylamine, and alkylenediamine, and nitriding gases such as hydrazine and ammonia. These reactive gases may be used alone or in combination of two or more. The tin compound represented by the general formula (1) has a property of reacting well with an oxidizing gas, and particularly has a property of reacting well with oxygen, ozone, or water vapor. Therefore, it is preferable to use an oxidizing gas as the reactive gas, and more preferably to use oxygen, ozone, or water vapor.

[0064] In addition, examples of the above-described transport and supply methods include the gas transport method, liquid transport method, single source method, cocktail source method, etc. described above.

[0065] In addition, as a method for forming the above-mentioned tin-containing thin film, there are a thermal CVD method in which a raw material gas is reacted only by heat or a raw material gas and a reactive gas are reacted only by heat to form a tin-containing thin film, a plasma CVD method using heat and plasma, a photo CVD method using heat and light, a photo plasma CVD method using heat, light, and plasma, and an ALD method in which the deposition reaction of the CVD method is divided into elementary processes and deposition is carried out step by step at the molecular level.

[0066] In addition, as conditions for forming the above-mentioned tin-containing thin film, there are a reaction temperature (substrate temperature), a reaction pressure, a film formation rate, and the like. From the viewpoint of being able to produce a high-quality thin film with good productivity, the reaction temperature is preferably from room temperature to 500°C, more preferably from 100°C to 300°C. Also, from the viewpoint of being able to produce a high-quality thin film with good productivity, the reaction pressure is preferably from 10 Pa to atmospheric pressure in the case of thermal CVD or photo CVD, and preferably from 10 Pa to 2,000 Pa in the case of using plasma.

[0067] In addition, the film formation rate can be controlled by the supply conditions (vaporization temperature, vaporization pressure) of the raw material for thin film formation, the reaction temperature, the reaction pressure, and the like. If the film formation rate is too fast, the characteristics of the obtained thin film may deteriorate, and if it is too slow, there may be a problem with productivity. Therefore, it is preferably from 0.01 nm / min to 100 nm / min, more preferably from 1 nm / min to 50 nm / min. In the case of the ALD method, it is controlled by the number of cycles so as to obtain a desired film thickness.

[0068] Other conditions include the temperature and pressure when vaporizing the raw material for thin film formation into a raw material gas. The step of vaporizing the raw material for thin film formation into a raw material gas may be carried out in a raw material container or in a vaporization chamber. In any case, from the viewpoint of being able to produce a high-quality thin film with good productivity, it is preferable to evaporate the raw material for thin film formation of the present invention at 0°C to 150°C. Also, from the viewpoint of being able to produce a high-quality thin film with good productivity, when vaporizing the raw material for thin film formation into a raw material gas in a raw material container or in a vaporization chamber, the pressure in the raw material container and the pressure in the vaporization chamber are both preferably 1 Pa to 10,000 Pa.

[0069] Examples of the material of the substrate include silicon; ceramics such as silicon nitride, titanium nitride, tantalum nitride, titanium oxide, ruthenium oxide, zirconium oxide, hafnium oxide, lanthanum oxide; glass; metals such as metal cobalt. Examples of the shape of the substrate include plate shape, spherical shape, fibrous shape, and flaky shape. The surface of the substrate may be a flat surface or may have a three-dimensional structure such as a trench structure.

[0070] The method for manufacturing the thin film of the present invention preferably employs an ALD method. Specifically, the method for manufacturing a thin film by the ALD method of the present invention includes a step of introducing a raw material gas obtained by vaporizing a raw material for thin film formation into a film formation chamber in which a substrate is installed (raw material introduction step), a step of adsorbing (depositing) a tin compound contained in the raw material gas on the surface of the substrate to form a precursor thin film (precursor thin film formation step), a step of exhausting unreacted raw material gas that has not been adsorbed (deposited) on the surface of the substrate (exhausting step), and a step of introducing a reactive gas into the film formation chamber and reacting the precursor thin film with the reactive gas to form a tin-containing thin film on the surface of the substrate (tin-containing thin film formation step). Further, the method for manufacturing the thin film of the present invention preferably further includes a step of exhausting the gas in the film formation chamber (exhausting step) after the tin-containing thin film formation step.

[0071] Hereinafter, taking the case of forming a tin oxide thin film as an example, each step of the above ALD method will be described in detail. First, the raw material introduction step described above is performed. The preferable temperature and pressure when using the raw material for thin film formation as a raw material gas are the same as those described above.

[0072] In the precursor thin film formation step, the substrate may be heated or the film formation chamber may be heated. From the viewpoint of being able to produce a high-quality thin film with good productivity, the substrate temperature is preferably from room temperature to 500°C, more preferably from 100°C to 300°C. From the viewpoint of being able to produce a high-quality thin film with good productivity, the pressure in the system (inside the film formation chamber) when this step is performed is preferably 1 Pa to 10,000 Pa, more preferably 10 Pa to 1,000 Pa. When the raw material for thin film formation contains other precursors in addition to the tin compound of the present invention, the other precursors are also deposited on the surface of the substrate together with the tin compound.

[0073] Next, the unreacted raw material gas that has not been adsorbed (deposited) on the surface of the substrate is exhausted from the film formation chamber. It is ideal for the unreacted raw material gas to be completely exhausted from the film formation chamber, but it is not necessarily required to be completely exhausted. Examples of the exhaust method include a method of purging the inside of the system with an inert gas such as nitrogen, helium, or argon, a method of exhausting by reducing the pressure inside the system, and a method combining these. From the viewpoint of being able to produce a high-quality thin film with good productivity, the degree of pressure reduction in the case of reducing the pressure is preferably 0.01 Pa to 300 Pa, more preferably 0.01 Pa to 100 Pa.

[0074] Next, an oxidizing gas is introduced into the film formation chamber as a reactive gas, and the precursor thin film is reacted with the oxidizing gas by the action of the oxidizing gas or the action of the oxidizing gas and heat to form a tin oxide thin film. From the viewpoint of being able to produce a high-quality thin film with good productivity, the temperature when this step is carried out is preferably from room temperature to 500 °C, and more preferably from 100 °C to 300 °C. From the viewpoint of being able to produce a high-quality thin film with good productivity, the pressure of the system (inside the film formation chamber) when this step is carried out is preferably from 1 Pa to 10,000 Pa, and more preferably from 10 Pa to 1,000 Pa. Since the tin compound represented by the above general formula (1) has good reactivity with the oxidizing gas, a high-quality tin oxide thin film with less residual carbon can be obtained. As the oxidizing gas, it is preferable to use oxygen, ozone or water vapor.

[0075] After the tin-containing thin film forming step, in order to produce a high-quality thin film, unreacted oxidizing gas and by-product gas are exhausted from the film formation chamber. It is ideal for the unreacted oxidizing gas and by-product gas to be completely exhausted from the film formation chamber, but it is not necessarily required to be completely exhausted. The unreacted oxidizing gas refers to the oxidizing gas that did not react with the precursor thin film in the tin-containing thin film forming step. Also, the by-product gas refers to the gas generated after reacting the precursor thin film with the oxidizing gas in the tin-containing thin film forming step. The exhaust method and the degree of vacuum in the case of reducing the pressure are the same as those in the above-described exhaust step.

[0076] In the method for manufacturing a thin film of the present invention, when the ALD method is adopted as described above, a series of operations including the above raw material introduction step, precursor thin film formation step, exhaust step, tin-containing thin film formation step and exhaust step are taken as one cycle, and this cycle may be repeated until a thin film with a required film thickness is obtained.

[0077] In addition, in the formation of the tin oxide thin film by ALD method, energy such as plasma, light, voltage, etc. may be applied, or a catalyst may be used. The timing of applying energy and the timing of using a catalyst are not particularly limited. For example, it may be when introducing the source gas in the source gas introduction step, when heating in the precursor thin film formation step or the tin-containing thin film formation step, when evacuating the system in the evacuation step, when introducing the reactive gas in the tin-containing thin film formation step, or even between each of the above steps.

[0078] In addition, in the method for manufacturing the thin film of the present invention, after forming the tin-containing thin film, in order to obtain better electrical characteristics, annealing treatment may be performed under an inert atmosphere, an oxidizing atmosphere or a reducing atmosphere. When step filling is required, a reflow process may be provided. The temperature in this case is preferably 200°C to 1,000°C, and more preferably 250°C to 500°C from the viewpoint of being able to produce a high-quality thin film with good productivity.

[0079] Examples of the ALD apparatus used in the method for manufacturing the thin film of the present invention include an apparatus capable of bubbling and supplying a precursor as shown in FIGS. 1 and 3, and an apparatus having a vaporization chamber as shown in FIGS. 2 and 4. In addition, an apparatus capable of performing plasma treatment on the reactive gas as shown in FIGS. 3 and 4 can be mentioned. Note that the present invention is not limited to a single-wafer apparatus equipped with a film formation chamber as shown in FIGS. 1 to 4, and an apparatus capable of simultaneously processing multiple wafers using a batch furnace can also be used. These ALD apparatuses can also be used as CVD apparatuses.

[0080] The thin films produced using the raw materials for thin film formation of the present invention can be made into thin films of desired types such as metals, oxide ceramics, nitride ceramics, glass, etc. by appropriately selecting other precursors, reactive gases, and manufacturing conditions. Since the thin films are excellent in electrical properties, optical properties, etc., they are applied to various uses. For example, metal thin films, metal oxide thin films, gold nitride thin films, alloys, and metal-containing composite oxide thin films, etc. are mentioned. These thin films are widely used in the manufacture of, for example, electrode materials for memory elements typified by DRAM elements, resistance films, antiferromagnetic films used for the recording layer of hard disks, and catalyst materials for solid polymer fuel cells, etc.

[0081] The halogen compound of the present invention is represented by the above general formula (2) and is particularly suitable as a raw material for a precursor used in a method for manufacturing a thin film having a vaporization step such as the CVD method.

[0082] Note that the halogen compound represented by the following general formula (4) has the same meaning as the halogen compound represented by the above general formula (2).

[0083]

Chemical formula

[0084] In the above general formulas (2) and (4), X represents a halogen atom, R 6 and R 7 each independently represents an alkyl group having 1 to 5 carbon atoms, and R 8 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0085] Examples of the above "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0086] Examples of the above "alkyl group having 1 to 5 carbon atoms" include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc.

[0087] Examples of the above "alkyl group having 1 to 3 carbon atoms" include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0088] From the viewpoint of obtaining a precursor having high thermal stability and capable of producing a high-quality thin film with good productivity when used as a raw material for thin film formation, R 6 and R 7 are each independently preferably an alkyl group having 3 to 5 carbon atoms, more preferably a branched alkyl group having 3 to 5 carbon atoms, particularly preferably an isopropyl group or a tert-butyl group, and most preferably a tert-butyl group. R 6 and R 7 may be the same or different, but from the viewpoint of obtaining a precursor having high thermal stability and capable of producing a high-quality thin film with good productivity when used as a raw material for thin film formation, they are preferably the same group. From the viewpoint of obtaining a precursor having high thermal stability and a large vapor pressure, R 8 is preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. From the viewpoint of being able to produce the precursor with good productivity, X is preferably a chlorine atom.

[0089] Preferable specific examples of the halogen compound represented by the above general formula (2) include the halogen compounds of the following Nos. 121 to 135. In the following halogen compounds of Nos. 121 to 135, "Me" represents a methyl group, "Et" represents an ethyl group, "iPr" represents an isopropyl group, and "tBu" represents a tert-butyl group.

[0090]

Chemical formula

[0091] The halogen compound of the present invention is not particularly limited by its production method and can be produced by applying well-known reactions. The halogen compound of the present invention can be obtained, for example, by reacting tin chloride, an amidine compound having a corresponding structure, and alkyllithium in a normal hexane solvent, followed by filtration, distilling off the solvent from the obtained filtrate, and then subjecting to distillation purification.

[0092] The halogen compound of the present invention can be used as a raw material for a metal complex compound used, for example, as a raw material for thin film formation. Further, the halogen compound of the present invention can also be used for applications such as solvents, fragrances, agricultural chemicals, pharmaceuticals, and synthetic raw materials for various polymers.

Examples

[0093] Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples, and Evaluation Examples. However, the present invention is not limited by the following Examples and the like.

[0094] <Production of Halogen Compound> The production results of the halogen compound are shown in Examples 1 to 3 below.

[0095] [Example 1] Production of Halogen Compound No. 131 A 1 L four-necked flask was charged with 35.2 g (0.186 mol) of tin chloride and 110.4 g of normal hexane, and stirred at room temperature. A solution prepared from 30.9 g (0.181 mol) of di-tert-butylacetamidine, 122.6 g of normal hexane, and 114 ml (0.181 mol) of n-butyllithium was added dropwise thereto under ice cooling. After returning to room temperature after the addition dropwise, it was heated at a bath temperature of 50 ° C for 3 hours. Then, it was returned to room temperature and stirred for 16 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 115 ° C, a pressure of 79 Pa, and a column top temperature of 95 ° C to obtain a halogen compound No. 131 as a pale yellow solid. The yield was 49.6 g and the yield was 83%. The results of normal pressure TG-DTA, reduced pressure TG-DTA, elemental analysis, and 1 1H-NMR analysis of the obtained halogen compound are shown below.

[0096] (1) Atmospheric pressure TG-DTA Temperature at 50% mass reduction: 216 °C (argon flow rate: 100 ml / min, heating rate: 10 °C / min, sample amount: 10.217 mg) (2) Vacuum TG-DTA Temperature at 50% mass reduction: 126 °C (10 Torr, argon flow rate: 50 ml / min, heating rate: 10 °C / min, sample amount: 10.055 mg) (3) Elemental analysis (metal analysis: ICP-AES) Tin content: 36.8 mass% (theoretical value: 36.7 mass%) (4) 1 H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: H number) (1.04: s: 18)(1.57: s: 3)

[0097] [Example 2] Preparation of Halogen Compound No. 134 20.0 g (0.105 mol) of tin chloride and 56.0 g of normal hexane were charged into a 500 mL four-necked flask and stirred at room temperature. A solution prepared from 15.9 g (0.101 mol) of tert-butyl-isopropylacetamidine, 50.4 g of normal hexane and 65 ml (0.101 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 18 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 120 °C, a pressure of 67 Pa and a top temperature of 93 °C to obtain a halogen compound No. 134 as a pale yellow liquid. The yield was 26.3 g and the yield rate was 81%. The results of atmospheric pressure TG-DTA, vacuum TG-DTA, elemental analysis and 1 The results of H-NMR analysis are shown below.

[0098] (1) Atmospheric pressure TG-DTA Temperature at 50% mass reduction: 204 °C (argon flow rate: 100 ml / min, heating rate: 10 °C / min, sample amount: 9.859 mg) (2) Vacuum TG-DTA Temperature at 50% mass reduction: 118 °C (10 Torr, argon flow rate: 50 ml / min, heating rate: 10 °C / min, sample amount: 9.432 mg) (3) Elemental analysis (metal analysis: ICP - AES) Tin content: 38.3 mass% (theoretical value: 38.4 mass%) (4) 1 H - NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of H atoms) (0.90 - 0.91: d: 6)(1.04: s: 9)(1.37: s: 3)(3.35 - 3.38: m: 1)

[0099] [Example 3] Production of Halogen Compound No. 132 A 500 mL four - necked flask was charged with 15.0 g (0.079 mol) of tin chloride and 59.8 g of normal hexane, and stirred at room temperature. A solution prepared from 13.9 g (0.075 mol) of di - tert - butyl - propionamidine, 45.8 g of normal hexane and 48 ml (0.075 mol) of n - butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 15 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 125 °C, a pressure of 66 Pa and a top temperature of 99 °C to obtain a halogen compound No. 132 as a pale yellow solid. The yield was 21.2 g and the yield rate was 80%. The results of normal pressure TG - DTA, reduced pressure TG - DTA, elemental analysis and 1 1H - NMR analysis of the obtained halogen compound are shown below.

[0100] (1) Normal pressure TG - DTA Temperature at 50% mass reduction: 223 °C (argon flow rate: 100 ml / min, heating rate: 10 °C / min, sample amount: 9.606 mg) (2) Reduced pressure TG - DTA Temperature at 50% mass reduction: 134 °C (10 Torr, argon flow rate: 50 ml / min, heating rate: 10 °C / min, sample amount: 9.651 mg) (3) Elemental analysis (metal analysis: ICP - AES) Tin content: 35.1 mass% (theoretical value: 35.2 mass%) (4) 1H-NMR (Solvent: Deuterated benzene) (Chemical shift: Multiplicity: Number of H atoms) (0.91 - 0.95: t: 3)(1.08: s: 18)(1.88 - 1.94: q: 2)

[0101] <Production of Tin Compound> The production results of tin compounds are shown in Examples 4 - 12 below.

[0102] [Example 4] Production of Tin Compound No. 8 A 500 mL four-necked flask was charged with 15.0 g (0.046 mol) of Halogen Compound No. 131 and 49.4 g of tetrahydrofuran, and stirred at room temperature. A solution prepared from 23.4 g (0.057 mol) of dimethylamine - tetrahydrofuran solution, 71.5 g of tetrahydrofuran and 32 ml (0.050 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 16 hours. Solvent exchange was carried out with normal hexane, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 100 °C, a pressure of 68 Pa and a top temperature of 71 °C to obtain Tin Compound No. 8 as a pale yellow liquid. The yield was 7.4 g and the yield rate was 48%. The elemental analysis and 1 the results of H-NMR analysis of the obtained tin compound are shown below.

[0103] (1) Elemental analysis (Metal analysis: ICP-AES) Tin content: 35.6 mass% (Theoretical value: 35.8 mass%) (2) 1 H-NMR (Solvent: Deuterated benzene) (Chemical shift: Multiplicity: Number of H atoms) (1.11: s: 18)(1.68: s: 3)(3.20: s: 6)

[0104] [Example 5] Production of Tin Compound No. 20 In a 200 mL four-necked flask, 5.4 g (0.017 mol) of the halogen compound No. 131 and 17.0 g of normal hexane were charged and stirred at room temperature. A solution prepared from 1.4 g (0.019 mol) of diethylamine, 14.7 g of normal hexane and 12 mL (0.018 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 18 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 115 °C, a pressure of 140 Pa, and a column top temperature of 83 °C to obtain the tin compound No. 20 as a pale yellow liquid. The yield was 3.4 g and the yield rate was 56%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0105] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 32.8 mass% (theoretical value: 33.0 mass%) (2) 1 1H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (1.15: s: 18) (1.26~1.29: t: 6) (1.69: s: 3) (3.46~3.51: q: 4)

[0106] [Example 6] Production of tin compound No. 32 In a 200 mL four-necked flask, 10.0 g (0.031 mol) of the halogen compound No. 131 and 29.5 g of normal hexane were charged and stirred at room temperature. A solution prepared from 3.4 g (0.034 mol) of dipropylamine, 25.2 g of normal hexane and 22 mL (0.034 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 17 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 115 °C, a pressure of 72 Pa, and a column top temperature of 85 °C to obtain the tin compound No. 32 as a pale yellow liquid. The yield was 8.0 g and the yield rate was 67%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0107] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 30.7 mass% (theoretical value: 30.6 mass%) (2) 1 H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (0.97~1.01: t: 6)(1.17: s: 18)(1.66~1.71: m: 7)(3.32~3.35: t: 4)

[0108] [Example 7] Production of the tin compound of No. 44 An 8.0 g (0.025 mol) of the halogen compound of No. 131 and 23.4 g of normal hexane were charged into a 200 mL four-necked flask and stirred at room temperature. A solution prepared from 2.9 g (0.028 mol) of diisopropylamine, 27.4 g of normal hexane and 17 ml (0.027 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 22 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 125 °C, a pressure of 60 Pa, and a top temperature of 95 °C to obtain the tin compound of No. 44 as a pale yellow solid. The yield was 5.5 g and the yield rate was 58%. The elemental analysis and 1 the results of 1H-NMR analysis of the obtained tin compound are shown below.

[0109] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 30.6 mass% (theoretical value: 30.6 mass%) (2) 1 H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (1.19: s: 18)(1.39~1.41: d: 12)(1.71: s: 3)(3.82~3.86: m: 2)

[0110] [Example 8] Production of the tin compound of No. 45 An 8.4 g (0.024 mol) of the halogen compound No. 132 and 35.8 g of normal hexane were charged into a 200 mL four-necked flask and stirred at room temperature. A solution prepared from 2.8 g (0.028 mol) of diisopropylamine, 39.5 g of tetrahydrofuran and 19 ml (0.027 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 17 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 135 °C, a pressure of 32 Pa and a top temperature of 83 °C to obtain a tin compound No. 45 as a pale yellow liquid. The yield was 7.8 g and the yield rate was 78%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0111] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 29.3 mass% (theoretical value: 29.5 mass%) (2) 1 1H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (1.03 - 1.07: t: 3) (1.22: s: 18) (1.39 - 1.40: d: 12) (2.06 - 2.12: m: 2) (3.80 - 3.86: m: 2)

[0112] [Example 9] Production of tin compound No. 56 A 7.8 g (0.024 mol) of the halogen compound No. 131 and 30.5 g of normal hexane were charged into a 200 mL four-necked flask and stirred at room temperature. A solution prepared from 3.3 g (0.025 mol) of di-sec-butylamine, 20.4 g of normal hexane and 16 ml (0.025 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 18 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 135 °C, a pressure of 38 Pa and a top temperature of 91 °C to obtain a tin compound No. 56 as a pale yellow liquid. The yield was 6.4 g and the yield rate was 64%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0113] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 28.5 mass% (theoretical value: 28.5 mass%) (2) 1 H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (1.00 - 1.04: t: 6)(1.20: s: 18)(1.34 - 1.39: m: 6)(1.66 - 1.82: m: 7)(3.40 - 3.45: m: 2)

[0114] [Example 10] Preparation of Tin Compound No. 92 A 200 mL four-necked flask was charged with 10.3 g (0.032 mol) of the halogen compound No. 131 and 52.9 g of normal hexane, and stirred at room temperature. A solution prepared from 3.7 g (0.037 mol) of ethyl-tert-butylamine, 50.3 g of normal hexane and 22 ml (0.034 mol) of n-butyllithium was added dropwise thereto under ice cooling. After the addition, the mixture was returned to room temperature and stirred for 18 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 115 °C, a pressure of 63 Pa, and a top temperature of 88 °C to obtain a yellow liquid, Tin Compound No. 92. The yield was 5.6 g and the yield rate was 46%. The elemental analysis and 1 the results of H-NMR analysis of the obtained tin compound are shown below.

[0115] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 30.5 mass% (theoretical value: 30.6 mass%) (2) 1 H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (1.19: s: 18)(1.31 - 1.35: t: 3)(1.50: s: 9)(1.72: s: 3)(3.44 - 3.49: q: 2)

[0116] [Example 11] Preparation of Tin Compound No. 104 30.1 g (0.068 mol) of bis(trimethylsilylamide)tin and 71.9 g of normal hexane were charged into a 300 mL four-necked flask and stirred at room temperature. 13.1 g (0.077 mol) of tert-butylacetamidine was added dropwise thereto under ice cooling, and after the addition, the mixture was returned to room temperature and stirred for 18 hours. Thereafter, the solvent was removed, and the residue was distilled at a bath temperature of 130 °C, a pressure of 44 Pa, and a top temperature of 91 °C to obtain a No. 104 tin compound as a pale yellow liquid. The yield was 27.5 g and the yield rate was 90%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0117] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 26.6 mass% (theoretical value: 26.5 mass%) (2) 1 1H-NMR (solvent: deuterated benzene) (chemical shift: multiplicity: number of Hs) (0.46: s: 18) (1.16: s: 18) (1.61: s: 3)

[0118] [Example 12] Production of No. 119 tin compound 10.0 g (0.032 mol) of a No. 134 halogen compound and 32.1 g of normal hexane were charged into a 200 mL four-necked flask and stirred at room temperature. A solution prepared from 3.5 g (0.034 mol) of diisopropylamine, 25.8 g of normal hexane, and 23 ml (0.035 mol) of n-butyllithium was added dropwise thereto under ice cooling, and after the addition, the mixture was returned to room temperature and stirred for 15 hours, followed by filtration. The solvent was removed from the obtained filtrate, and the residue was distilled at a bath temperature of 110 °C, a pressure of 63 Pa, and a top temperature of 82 °C to obtain a No. 119 tin compound as a pale yellow liquid. The yield was 6.8 g and the yield rate was 56%. The results of elemental analysis and 1 1H-NMR analysis of the obtained tin compound are shown below.

[0119] (1) Elemental analysis (metal analysis: ICP-AES) Tin content: 31.5 mass% (theoretical value: 31.7 mass%) (2) 1H-NMR (Solvent: deuterated benzene) (Chemical shift: multiplicity: number of Hs) (1.02 - 1.04: d: 3) (1.08 - 1.10: d: 3) (1.19: s: 9) (1.39 - 1.41: d: 12) (1.53: s: 3) (3.38 - 3.45: m: 1) (3.84 - 3.91: m: 2)

[0120] [Evaluation Example] For the tin compounds of the present invention obtained in Examples 4 to 12 and the following Comparative Compounds 1 and 2, the following evaluations were conducted. In the following Comparative Compounds 1 and 2, "Me" represents a methyl group, "iPr" represents an isopropyl group, and "tBu" represents a tert-butyl group.

[0121] (1) Melting point evaluation The state of the compound at 20°C was visually observed. For those that were solid at 20°C, the melting point was measured using a micro melting point measuring device. Compounds with a low melting point are considered to have excellent transportability and can be judged to be preferable as raw materials for thin film formation. Compounds that are liquid at 20°C are considered to have particularly excellent transportability and can be judged to be particularly preferable as raw materials for thin film formation. The results are shown in Table 1. (2) Temperature (°C) at 50 mass% weight loss under normal pressure in TG-DTA Using TG-DTA, under normal pressure, with an argon flow rate of 100 mL / min, a heating rate of 10°C / min, and a scanning temperature range of 30°C to 600°C, the temperature (°C) when the weight of the test compound decreased by 50 mass% was evaluated as the "temperature (°C) at 50 mass% weight loss under normal pressure in TG-DTA". Compounds with a low temperature at 50 mass% weight loss under normal pressure in TG-DTA have a high vapor pressure and can be judged to be preferable as raw materials for thin film formation. The results are shown in Table 1. (3) Temperature (°C) at 50 mass% weight loss under reduced pressure in TG-DTA Using TG-DTA, measurements were carried out under the conditions of 10 Torr, argon flow rate: 50 mL / min, heating rate: 10 °C / min, and scanning temperature range of 30 °C to 600 °C. The temperature (°C) at which the weight of the test compound decreased by 50 mass% was evaluated as the "temperature (°C) at 50 mass% weight loss in vacuum TG-DTA". A compound with a lower temperature at 50 mass% weight loss in vacuum TG-DTA has a higher vapor pressure and can be judged to be preferable as a raw material for thin film formation. The results are shown in Table 1.

[0122] [Chemical formula]

[0123] [Table 1]

[0124] As shown in Table 1, it was found that the tin compounds of the present invention obtained in Examples 4 to 12 had lower melting points compared to Comparative Compounds 1 and 2. Also, it was found that the tin compounds of the present invention obtained in Examples 4 to 12 had temperatures at 50 mass% weight loss in normal pressure TG-DTA and temperatures at 50 mass% weight loss in vacuum TG-DTA that were 20 °C or more lower compared to Comparative Compounds 1 and 2. Among them, the tin compounds of No. 8, No. 20, No. 32, No. 44, No. 45, No. 92, and No. 119 were found to have temperatures at 50 mass% weight loss in normal pressure TG-DTA and temperatures at 50 mass% weight loss in vacuum TG-DTA that were 30 °C or more lower compared to Comparative Compounds 1 and 2.

[0125] [Examples 13 to 21, Comparative Examples 1 and 2] Production of tin oxide thin films by ALD method The tin compounds of the present invention obtained in Examples 4 to 12 and Comparative Compounds 1 and 2 were used as raw materials for CVD, and tin oxide thin films were produced on silicon substrates by the ALD method under the following conditions using the ALD apparatus shown in Fig. 1. For the obtained thin films, film thickness measurement by X-ray reflectivity method, confirmation of the compound of the thin film by X-ray diffraction method, and measurement of the residual carbon amount in the thin film by X-ray photoelectron spectroscopy were carried out. The results are shown in Table 2.

[0126] (Condition) Reaction temperature (substrate temperature): 150 °C, reactive gas: water vapor (Process) A series of steps consisting of the following (1) to (4) was repeated 800 cycles as one cycle. (1) The vapor of the chemical vapor deposition raw material vaporized under the conditions of a raw material container heating temperature of 90 °C and a raw material container internal pressure of 100 Pa was introduced and deposited for 20 seconds at a system pressure of 100 Pa. (2) Unreacted raw materials were removed by argon purge for 15 seconds. (3) A reactive gas was introduced and reacted for 1 second at a system pressure of 100 Pa. (4) Unreacted raw materials were removed by argon purge for 90 seconds.

[0127]

Table 2

[0128] As shown in Table 2, in Comparative Examples 1 and 2 using Comparative Compounds 1 and 2 as CVD raw materials, the residual carbon amount in the tin oxide thin film was 5 atm% or more, whereas in Examples 13 to 21 using the tin compound of the present invention as a CVD raw material, the residual carbon amount in the tin oxide thin film was less than 0.1 atm%, which is the detection limit. That is, it was shown that a high-quality tin oxide thin film can be obtained by using the tin compound of the present invention.

[0129] Also, as shown in Table 2, the film thickness of the obtained thin film was 6.5 nm or less in Comparative Examples 1 and 2, whereas it was 9.0 nm or more in Examples 13 to 21. That is, it was shown that a tin oxide thin film can be obtained with high productivity by using the tin compound of the present invention. Among them, when the tin compounds of No. 20, No. 32, and No. 44 were used as raw materials for CVD, a tin oxide thin film could be obtained with higher productivity, indicating that these tin compounds are more excellent as raw materials for CVD. Among them, when the tin compound of No. 44 was used as a raw material for CVD, a tin oxide thin film could be obtained with extremely high productivity, indicating that the tin compound of No. 44 is particularly excellent as a raw material for CVD.

Claims

1. A tin compound represented by the following general formula (1). 【Chemical 1】 (In formula (1), R 1 and R 2 each independently represents an alkyl group having 1 to 5 carbon atoms or an alkylsilyl group having 3 to 12 carbon atoms, and R 3 and R 4 each independently represents an alkyl group having 1 to 5 carbon atoms, and R 5 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

2. A raw material for thin film formation containing the tin compound according to Claim 1.

3. A thin film formed using the raw material for thin film formation according to Claim 2.

4. A method for manufacturing a thin film, comprising forming a thin film containing tin atoms on the surface of a substrate using a source gas obtained by vaporizing the raw material for thin film formation according to Claim 2.

5. A step of introducing a source gas obtained by vaporizing the raw material for thin film formation into a film formation chamber in which a substrate is installed; A step of decomposing and / or chemically reacting the tin compound contained in the source gas to form a thin film containing tin atoms on the surface of the substrate The method for manufacturing a thin film according to Claim 4, comprising.

6. A step of adsorbing the tin compound contained in the source gas on the surface of the substrate to form a precursor thin film; A step of reacting the precursor thin film with a reactive gas to form a thin film containing tin atoms on the surface of the substrate The method for manufacturing a thin film according to Claim 5, comprising.

7. A halogen compound represented by the following general formula (2). 【Chemical 2】 (In formula (2), X represents a halogen atom, and R 6 and R 7 each independently represent an alkyl group having 1 to 5 carbon atoms, and R 8 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

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