Method for producing thin film and starting material set for forming thin film

Abstract

Provided is a method for producing a thin film, the method including forming a bismuth-antimony alloy thin film using a compound represented by general formula (1) and a compound represented by general formula (2). (In the general formula (1), M1 represents a bismuth atom or an antimony atom, and R11, R12, and R13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.) (In the general formula (2), M2 represents a bismuth atom or an antimony atom, but is different from M1; L represents a ligand selected from among an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms (*-OR1), a monoalkylamino group (*-NHR1), a dialkylamino group (*-NR1R2), and the like; R1 and R2 each independently represent an alkyl group having 1 to 10 carbon atoms; and * represents a bonding position with M2.)

Description

Method for manufacturing thin films and set of raw materials for forming thin films

[0001] This disclosure relates to a method for manufacturing a thin film and a set of raw materials for forming a thin film.

[0002] Thin films containing antimony or bismuth are used in various semiconductor devices, and atomic layer deposition is a known method for manufacturing such thin films. For example, Patent Document 1 discloses a method for manufacturing an antimony oxide thin film by atomic layer deposition. Patent Document 2 discloses a method for manufacturing a germanium-antimony-tellurium film using antimony alkoxide and aminoantimony as one of the multi-component films. Furthermore, Patent Document 3 discloses the formation of a bismuth-antimony alloy thin film using trichloroantimony and tris(triethylsilyl)antimony. Furthermore, Patent Documents 4 and 5 disclose the use of silylbismuth antimony compounds in the manufacture of GST films.

[0003] Japanese Patent Publication No. 2013-84959, Japanese Patent Publication No. 2015-7279, Japanese Patent Publication No. 2013-508555, Japanese Patent Publication No. 2016-84544, Japanese Patent Publication No. 2014-37411

[0004] However, Patent Documents 1 to 5 do not disclose specific methods for manufacturing bismuth-antimony alloy thin films. Conventional manufacturing methods result in bismuth-antimony alloy thin films containing many impurities, so there has been a need for a method to manufacture high-quality bismuth-antimony alloy thin films with fewer impurities.

[0005] Therefore, the present disclosure aims to provide a method for manufacturing a thin film that can form a high-quality bismuth-antimony alloy thin film with few impurities, and a set of raw materials for forming the thin film used in the method for manufacturing the thin film.

[0006] The present disclosure has been made in view of such problems of the prior art. The inventors of the present invention have found that the above problems can be solved by providing a method for producing a thin film using a combination of a specific bismuth compound and a specific antimony compound, and have completed the present disclosure. That is, the present disclosure provides a method for producing a thin film, comprising forming a bismuth-antimony alloy thin film using a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0007]

[0008] In general formula (1), M 1 represents a bismuth atom or an antimony atom, and R 11 , R 12 and R 13 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and the three -SiR 11 R 12 R 13 may be the same or different from each other.

[0009]

[0010] In the above general formula (2), M 2 represents a bismuth atom or an antimony atom, and is different from M 1 ; L is a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms (*-OR 1 ), a monoalkylamino group (*-NHR 1 ), a dialkylamino group (*-NR 1 R 2 ), an alkylene trialkylsilyl group (*-(CH2) m -SiR 1 R 2 R 3 ), a bis(trialkylsilyl)amino group (*-N(SiR 1 R 2 R 3 )2), an alkyl(trimethylsilyl)amino group (*-NR 1 -SiMe3), an aryl group having 6 to 20 carbon atoms, a cyclopentadienyl group, a diketonate structure (*-O-C(R4 ) = C(R 5 )-C(=O)-R 6 ), ketoimaginate structure (*-N(R 4 )-C(R 5 ) = C(R 6 )-C(=O)-R 7 ), dikethiminate structure (*-N(R 4 )-C(R 5 ) = C(R 6 ) - C (= NR 7 )-R 8 ) and amidinate structure (*-N(R 4 )-C(R 5 ) = NR 6 A ligand selected from the group consisting of ), R 1 , R 2 and R 3 Each of these independently represents an alkyl group having 1 to 10 carbon atoms, and R 4 , R 5 , R 6 , R 7 and R 8 Each of the following independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, m represents an integer between 1 and 10, and the three Ls may be the same ligand or different ligands. * represents M 2 This indicates the connection point with [the other element].

[0011] Furthermore, this disclosure provides a set of thin film forming materials, comprising a first thin film forming material containing a compound represented by the general formula (1) and a second thin film forming material containing a compound represented by the general formula (2).

[0012] According to this disclosure, it is possible to form high-quality bismuth-antimony alloy thin films with few impurities.

[0013] This is a schematic diagram showing an example of an ALD apparatus used in the thin film manufacturing method according to this disclosure. This is a schematic diagram showing another example of an ALD apparatus used in the thin film manufacturing method according to this disclosure. This is a schematic diagram showing yet another example of an ALD apparatus used in the thin film manufacturing method according to this disclosure. This is a schematic diagram showing yet another example of an ALD apparatus used in the thin film manufacturing method according to this disclosure.

[0014] The following describes this disclosure. First, the set of thin film forming raw materials used in the thin film manufacturing method according to this disclosure will be described.

[0015] A. Set of materials for forming thin films The method for producing a thin film according to this disclosure uses a set of materials for forming thin films, which includes a first thin film forming material containing a compound represented by the general formula (1) and a second thin film forming material containing a compound represented by the general formula (2). The components constituting the first thin film forming material and the second thin film forming material will be described below.

[0016] A1. First thin film forming raw material The first thin film forming raw material includes a compound represented by the general formula (1). In the method for producing a thin film according to this disclosure, the first thin film forming raw material may include one or more compounds represented by the general formula (1).

[0017] (a) Compound represented by general formula (1) above R 11 , R 12 and R 13 Examples of alkyl groups having 1 to 5 carbon atoms, represented by R, include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, 1,2-dimethylpropyl group, tert-amyl group, etc. 11 , R 12 and R 13 These may be different from each other, or they may be the same group. Three -SiR 11 R 12 R 13 These may be the same or different. In the method for manufacturing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the above R 11 , R 12 and R 13The atom is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a methyl group. Preferred specific examples of the compound represented by the above general formula (1) include bismuth compounds or antimony compounds represented by A-1 to A-10 below.

[0018]

[0019]

[0020]

[0021] In this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the first thin film forming raw material preferably contains one or more selected from the group consisting of A-3, A-4, A-9, and A-10, and more preferably contains one or more selected from the group consisting of A-3 and A-9.

[0022] In this disclosure, the content of the compound represented by the above general formula (1) is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, even more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, particularly preferably 90 parts by mass or more, and most preferably 99 parts by mass or more, in 100 parts by mass of the first thin film forming raw material.

[0023] (b) Other components The first thin film forming raw material may include other precursors or nucleophiles as components other than the compound represented by the general formula (1) above.

[0024] (1) Other Precursors The above other precursors can be compounds different from the compound represented by the above general formula (1). From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the above other precursors can be M in the above general formula (1). 1 It is preferable that the compound has the same metal atoms as [the compound in question].

[0025] Other precursors mentioned above include, for example, compounds having one or more organic ligands selected from the group consisting of alcohol compounds, glycol compounds, β-diketone compounds, cyclopentadiene compounds, organic amine compounds, etc.

[0026] Examples of alcohol compounds used as the above organic ligands 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, 2-isopropoxy-1,1-dimethylethanol, and 2-butoxyethanol. Examples include ether alcohols such as toxic-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.

[0027] Examples of glycol compounds used as the organic ligands mentioned above include 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 2,4-hexanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,3-butanediol, 2,4-butanediol, 2,2-diethyl-1,3-butanediol, 2-ethyl-2-butyl-1,3-propanediol, 2,4-pentanediol, 2-methyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 2,4-hexanediol, and 2,4-dimethyl-2,4-pentanediol.

[0028] Examples of β-diketone compounds used as the above organic ligands include acetylacetone, hexane-2,4-dione, 5-methylhexane-2,4-dione, heptane-2,4-dione, 2-methylheptane-3,5-dione, 5-methylheptane-2,4-dione, 6-methylheptane-2,4-dione, 2,2-dimethylheptane-3,5-dione, 2,6-dimethylheptane-3,5-dione, 2,2,6-trimethylheptane-3,5-dione, 2,2,6,6-tetramethylheptane-3,5-dione, octane-2,4-dione, 2,2,6-trimethyloctane-3,5-dione, 2,6-dimethyloctane-3,5-dione, 2,9-dimethylnonane-4,6-dione, and 2-methyl-6-ethyl Examples include alkyl-substituted β-diketones such as decane-3,5-dione and 2,2-dimethyl-6-ethyldecane-3,5-dione; fluorine-substituted alkyl β-diketones such as 1,1,1-trifluoropentane-2,4-dione, 1,1,1-trifluoro-5,5-dimethylhexane-2,4-dione, 1,1,1,5,5,5-hexafluoropentane-2,4-dione, and 1,3-diperfluorohexylpropane-1,3-dione; and ether-substituted β-diketones such as 1,1,5,5-tetramethyl-1-methoxyhexane-2,4-dione, 2,2,6,6-tetramethyl-1-methoxyheptane-3,5-dione, and 2,2,6,6-tetramethyl-1-(2-methoxyethoxy)heptane-3,5-dione.

[0029] Examples of cyclopentadiene compounds used as the organic ligands mentioned above include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, sec-butylcyclopentadiene, isobutylcyclopentadiene, tert-butylcyclopentadiene, dimethylcyclopentadiene, tetramethylcyclopentadiene, and pentamethylcyclopentadiene.

[0030] Examples of organic amine compounds used as the above-mentioned organic ligands include methylamine, ethylamine, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, ethylmethylamine, propylmethylamine, and isopropylmethylamine.

[0031] The other precursors mentioned above are known in the art, and their manufacturing methods are also known. For example, when an alcohol compound is used as an organic ligand, the M of the compound represented by the general formula (1) above is used. 1 Other precursors can be produced by reacting an inorganic salt or hydrate thereof of the same metal atom with an alkali metal alkoxide of the alcohol compound. Examples of the inorganic salt or hydrate thereof of the metal atom include metal halides and nitrates. Examples of the alkali metal alkoxide include sodium alkoxide, lithium alkoxide, and potassium alkoxide.

[0032] In the method for manufacturing a thin film according to the present disclosure, when a mixture of the compound represented by the general formula (1) and the other precursor is used as the first raw material for forming the thin film, it is preferable that the other precursor is a compound that, in addition to having similar thermal decomposition and / or oxidative decomposition behavior to the compound represented by the general formula (1), does not undergo alteration due to chemical reactions, etc., after being mixed with the compound represented by the general formula (1), from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities.

[0033] When the first thin film forming raw material contains the other precursors, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the content of the other precursors is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the first thin film forming raw material.

[0034] (2) Nucleophile The first thin film forming raw material may contain a nucleophile to stabilize the compound represented by the general formula (1) or the other precursor. Examples of the nucleophile 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, 1,1,4,7,10,10-hexamethyltriethylenetetramine and Examples include polyamines such as riethoxytriethyleneamine; cyclic polyamines such as cyclam and cyclene; heterocyclic compounds such as pyridine, pyrrolidine, piperidine, morpholine, N-methylpyrrolidine, N-methylpiperidine, N-methylmorpholine, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, oxazole, thiazole and oxathiolane; β-ketoesters such as methyl acetoacetate, ethyl acetoacetate and 2-methoxyethyl acetoacetate; and β-diketones such as acetylacetone, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione and dipivaloylmethane.

[0035] When the first thin film forming raw material contains the nucleophile, the amount of the nucleophile is preferably in the range of 0.1 mol to 10 mol, and more preferably in the range of 1 mol to 4 mol, per 1 mol of the total amount of precursor. Here, the total amount of precursor refers to the total amount of precursor contained in the first thin film forming raw material. For example, when the first thin film forming raw material contains the other precursor, the total amount of precursor refers to the sum of the compound represented by the general formula (1) and the other precursor. When the first thin film forming raw material does not contain the other precursor, the total amount of precursor refers to the amount of the compound represented by the general formula (1).

[0036] (3) Impurities The first raw material for forming the thin film, excluding the compound represented by the general formula (1) above, the other precursors above, and the nucleophile above, is preferably free of impurities such as metal atoms, halogens, and organic particles.

[0037] Examples of the impurity metal atoms mentioned above include metal atoms different from the compound represented by the general formula (1), the other precursors, and the nucleophile. The content of impurity metal atoms in the first thin film forming raw material is preferably 100 ppm or less, more preferably 10 ppm or less, even more preferably 1 ppm or less, and particularly preferably 10 ppt or more and 1 ppm or less in terms of metal atoms.

[0038] Examples of the above-mentioned impurity halogens include inorganic compounds having halogen atoms that are different from the compound represented by the above-mentioned general formula (1) and the above-mentioned nucleophile. The content of the impurity halogens in the first thin film forming raw material is preferably 100 ppm or less, more preferably 10 ppm or less, even more preferably 1 ppm or less, and particularly preferably 10 ppt or more and 1 ppm or less.

[0039] The above-mentioned impurity organic components are organic compounds containing carbon and oxygen, excluding carbon monoxide and carbon dioxide, and are organic compounds excluding the compound represented by the above general formula (1) and the above-mentioned nucleophile. Examples of the above-mentioned impurity organic components include the raw materials for the synthesis of the compound represented by the general formula (1), catalysts used during synthesis, by-products during synthesis, and solvents used during synthesis.

[0040] Examples of impurity organic components derived from the above-mentioned synthetic raw materials include amino compounds such as primary amines, secondary amines, tertiary amines, dialkylamines, silylated amines, and amide precursors; alkylating agents such as alkyl halides and aryl halides; β-diketones, imine / amine precursors, diketnate precursors, ketoiminate precursors, diketiminate precursors, amidinate precursors, or their decomposition / residues.

[0041] Examples of impurity organic components derived from the above catalyst include Grignard catalyst, organolithium, organoboron, organozinc, organotin, or decomposition / residue products derived from these catalysts.

[0042] Examples of impurity organic components derived from the above-mentioned by-products include by-products generated in coupling reactions.

[0043] Examples of impurity organic components derived from the above-mentioned solvents include hydrocarbon solvents, ether solvents, halogen solvents, polar solvents, and so on.

[0044] Examples of the hydrocarbon solvents mentioned above include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, and isoparaffin; monocyclic aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, and mesitylene; and polycyclic aromatic hydrocarbon solvents such as naphthalene and biphenylene.

[0045] Examples of the ether-based solvents mentioned above include tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, TBME / MTBE, 1,4-dioxane; DME, diglyme, triglyme, tetraglyme, and other types of glycymes.

[0046] Examples of the halogenated solvents mentioned above include dichloromethane, chloroform, 1,2-dichloroethane, and chlorobenzene.

[0047] Examples of the polar solvents mentioned above include nitrile solvents such as acetonitrile; ketone solvents such as acetone and MEK; hydrocarbon solvents such as ethyl acetate; amide solvents such as DMF, DMAc, and NMP; sulfoxide solvents such as DMSO; and alcohol solvents such as methanol, ethanol, and isopropanol.

[0048] From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the content of impurity organic matter in the first raw material for thin film formation described above is preferably 50,000 ppm or less, more preferably 30,000 ppm or less, even more preferably 10,000 ppm or less, particularly preferably 1,000 ppm or less, and most preferably 10 ppm or more and 1,000 ppm or less, relative to the compound represented by general formula (1).

[0049] Furthermore, since moisture can cause particle generation in the first thin film forming raw material and during thin film formation, it is preferable to remove moisture from the precursor and nucleophile before use in order to reduce their respective moisture content. The moisture content of the precursor and nucleophile is preferably 10 ppm or less, and more preferably 1 ppm or less.

[0050] In the embodiment in which organic impurities, particularly aromatic hydrocarbon solvents such as naphthalene, are reduced in the first thin-film forming raw material described above, the residual carbon content of the resulting bismuth-antimony alloy thin film is suppressed, contributing to an improvement in film quality.

[0051] Furthermore, the first thin film forming raw material described above preferably contains as few particles as possible in order to reduce or prevent particle contamination of the formed thin film. Specifically, in particle measurement using a light scattering type liquid particle detector in the liquid phase, it is preferable that the number of particles larger than 0.3 μm is 100 or less per 1 ml of liquid phase, and it is more preferable that the number of particles larger than 0.2 μm is 100 or less per 1 ml of liquid phase.

[0052] (c) First thin film forming raw material The physical properties of the compound represented by the above general formula (1) are also suitable for the CVD method, so the first thin film forming raw material is useful as a raw material for chemical vapor deposition. Among these, the compound represented by the above general formula (1) has a wide ALD window, so the first thin film forming raw material is particularly suitable for the ALD method. Therefore, the first thin film forming raw material is particularly useful as a thin film forming raw material for the ALD method.

[0053] A2. Second thin film forming raw material The second thin film forming raw material includes a compound represented by the general formula (2). In the method for producing a thin film according to the present disclosure, the second thin film forming raw material may include one or more compounds represented by the general formula (2).

[0054] (a) Compound represented by general formula (2) The compound represented by general formula (2) is M of the compound represented by general formula (1) 1 M is a different metal atom. 2 It has M in the above general formula (1). 1 However, if it is a bismuth atom, then M in the general formula (2) above 2 M is an antimony atom, and in the general formula (1) above, M 1 However, if it is an antimony atom, then M in the general formula (2) above 2 is a bismuth metal atom. The three ligands represented by L in the compound represented by the general formula (2) above may be ligands with different structures or ligands with the same structure.

[0055] Examples of halogen atoms represented by L above include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. In the method for producing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, L is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a chlorine atom.

[0056] Examples of alkyl groups having 1 to 10 carbon atoms represented by L above include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, 1,2-dimethylpropyl group, tert-amyl group, n-hexyl group, isohexyl group, n-heptyl group, 2-heptyl group, 3-heptyl group, tert-heptyl group, n-octyl group, 2-ethylhexyl group, tert-octyl group, n-nonyl group, isononyl group, 3,5,5-trimethylhexyl group, n-decyl group, and isodecyl group. Some or all of the hydrogen atoms in the alkyl group may be substituted with fluorine atoms. Examples of alkyl groups having 1 to 10 carbon atoms in which some or all of the hydrogen atoms are replaced with fluorine atoms include monofluoromethyl groups, difluoromethyl groups, trifluoromethyl groups, and pentafluoroethyl groups. In the method for producing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, L is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group or an ethyl group.

[0057] Examples of the alkoxy group having 1 to 10 carbon atoms represented by L above include methoxy group, ethoxy group, propoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, amyloxy group, isoamyloxy group, tert-amyloxy group, and hexyloxy group. Some or all of the hydrogen atoms of the above alkoxy group may be substituted with fluorine atoms. Examples of the above alkoxy group having 1 to 10 carbon atoms in which some or all of the hydrogen atoms are substituted with fluorine atoms include monofluoromethoxy group, difluoromethoxy group, trifluoromethoxy group, and pentafluoroethoxy group. In the method for producing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, L above is preferably an alkoxy group having 1 to 8 carbon atoms, more preferably an alkoxy group having 2 to 7 carbon atoms, and particularly preferably an alkoxy group having 3 to 6 carbon atoms.

[0058] The monoalkylamino group (*-NHR) represented by L above 1 ) R 1 R in the monoalkylamino group can be a group similar to the alkyl group having 1 to 10 carbon atoms as the ligand represented by L above. 1 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the alkyl group has 1 to 5 carbon atoms, more preferably that it has 1 to 3 carbon atoms, and particularly preferably that it is a methyl group or an ethyl group.

[0059] The dialkylamino group (*-NR) represented by L above 1 R 2 ) in R 1 and R 2 R in the above dialkylamino group can be a group similar to the alkyl group having 1 to 10 carbon atoms as a ligand represented by L above. 1 and R 2From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group or an ethyl group.

[0060] In the alkylenetrialkylsilyl group represented by L above (*-(CH2) m -SiR 1 R 2 R 3 ), R 1 , R 2 and R 3 may be the same groups as the alkyl group having 1 to 10 carbon atoms as the ligand represented by L above. From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, m in the alkylenetrialkylsilyl group is preferably an integer of 1 to 5, and more preferably an integer of 1 to 3.

[0061] In the bis(trialkylsilyl)amino group represented by L above (*-N(SiR 1 R 2 R 3 )2), R 1 , R 2 and R 3 may be the same groups as the alkyl group having 1 to 10 carbon atoms as the ligand represented by L above.

[0062] In the alkyl(trimethylsilyl)amino group represented by L above (*-NR 1 -SiMe3), R 1 may be the same group as the alkyl group having 1 to 10 carbon atoms as the ligand represented by L above. In the alkyl(trimethylsilyl)amino group, R 1 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group or an ethyl group.

[0063] The aryl group having 6 to 20 carbon atoms, represented by L above, can be a monocyclic aromatic ring group such as a phenyl group or a tolyl group (hereinafter sometimes referred to as a "monocyclic aromatic ring group"), a fused aromatic ring group such as a naphthyl group, anthracenyl group, phenentryl group, fluorenyl group, and pyrenyl group (hereinafter sometimes referred to as a "fused aromatic ring group"), a monocyclic aromatic ring group such as a biphenyl group or a benzophenyl group, or a fused aromatic ring group bonded to another monocyclic or fused aromatic ring group via a single bond or a divalent group such as -O-, -S-, -OCO-, and -COO-. In addition, hydrogen atoms in the monocyclic or fused aromatic ring group may be substituted with alkyl groups, such as a tolyl group. The alkyl group substituting the aryl group can be the same as the alkyl group having 1 to 10 carbon atoms represented by L above. Some or all of the hydrogen atoms in the aryl group having 6 to 20 carbon atoms may be substituted with halogen atoms.

[0064] The cyclopentadienyl group represented by L above has a 5-membered cyclopentadienyl group, and some or all of the hydrogen atoms may be substituted with alkyl groups. The above alkyl group may be the same group as the alkyl group having 1 to 10 carbon atoms as the above ligand. Examples of the cyclopentadienyl group include cyclopentadienyl group, methylcyclopentadienyl group, ethylcyclopentadienyl group, propylcyclopentadienyl group, isopropylcyclopentadienyl group, n-butylcyclopentadienyl group, sec-butylcyclopentadienyl group, isobutylcyclopentadienyl group, tert-butylcyclopentadienyl group, dimethylcyclopentadienyl group, tetramethylcyclopentadienyl group and pentamethylcyclopentadienyl group. From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the cyclopentadienyl group is preferably an unsubstituted cyclopentadienyl group or a cyclopentadienyl group in which some or all hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms, more preferably an unsubstituted cyclopentadienyl group or a cyclopentadienyl group in which some or all hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms, and particularly preferably an unsubstituted cyclopentadienyl group or a cyclopentadienyl group in which some or all hydrogen atoms are substituted with an alkyl group having 1 to 4 carbon atoms.

[0065] The diketonate structure represented by L above (*-O-C(R 4 )=C(R 5 )-C(=O)-R 6 ) has the same definition as the structure represented by the following general formula (3).

[0066]

[0067] In the above general formula (3), * represents a bonding position to M 2 , and R 4 , R 5 and R 6 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R in the above diketonate structure 4 and R6 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the alkyl group has 1 to 6 carbon atoms, more preferably that it has 1 to 5 carbon atoms, and particularly preferably that it has 1 to 4 carbon atoms. 5 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0068] The ketoiminate structure (*-N(R) represented by L above 4 )-C(R 5 ) = C(R 6 )-C(=O)-R 7 ) is synonymous with the structure represented by the following general formula (4).

[0069]

[0070] In general formula (4), * represents M 2 This represents the bonding position with R 4 , R 5 , R 6 and R 7 Each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. In the above ketoiminate structure, R 4 , R 5 and R 7 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the alkyl group has 1 to 6 carbon atoms, more preferably that it has 1 to 5 carbon atoms, and particularly preferably that it has 1 to 4 carbon atoms. 6 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0071] The dikethyminate structure (*-N(R) represented by L above 4 )-C(R 5 ) = C(R 6 ) - C (= NR 7 )-R 8 ) is synonymous with the structure represented by the following general formula (5).

[0072]

[0073] In the above general formula (5), * represents M 2 This represents the bonding position with R 4 , R 5 , R 6 , R 7 and R 8 Each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R in the above dikethyminate structure 4 and R 7 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the alkyl group has 3 to 6 carbon atoms, more preferably that it is a branched alkyl group having 3 to 6 carbon atoms, and particularly preferably that it is a branched alkyl group having 3 to 5 carbon atoms. R in the above diketiminate structure 5 and R 8 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the alkyl group has 1 to 4 carbon atoms, more preferably that it is an alkyl group having 1 to 3 carbon atoms, and particularly preferably that it is a methyl group or an ethyl group. In the above diketiminate structure, R 6 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom.

[0074] The amidinate structure represented by L above (*-N(R 4 )-C(R 5 ) = NR 6 ) is synonymous with the structure represented by the following general formula (6).

[0075]

[0076] In general formula (6), * represents M 2 This represents the bonding position with R 4 , R 5 and R 6 Each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R in the above amidinate structure 5 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and particularly preferably a hydrogen atom or a methyl group. 4 and R 6 From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and particularly preferably a hydrogen atom or a methyl group.

[0077] Preferred specific examples of the compound represented by the above general formula (2) include, for example, the compounds B-1 to B-66 below. However, the method for producing a thin film according to this disclosure is not limited to these compounds. In B-1 to B-66 below, "R" is an alkyl group having 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the alkyl group may be substituted with halogen atoms. "X" is a halogen atom. "m" is the number of repeating units of the methylene group, a number from 1 to 10. "n" is the number of substituents, a number from 0 to 5.

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] In the method for manufacturing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the second thin film forming raw material preferably contains one or more selected from the group consisting of B-20, B-21, B-23, B-54, B-54 and B-56, more preferably contains one or more selected from the group consisting of B-21, B-23, B-54 and B-56, and particularly preferably contains one or more selected from the group consisting of B-23 and B-54.

[0095] In the method for producing a thin film according to the present disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the content of the compound represented by the above general formula (2) is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, even more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, particularly preferably 90 parts by mass or more, and most preferably 99 parts by mass or more, in 100 parts by mass of the second thin film forming raw material.

[0096] In the method for producing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the molecular weight of the compound represented by the above general formula (2) is preferably, for example, 100 or more and 1,000 or less, more preferably 150 or more and 500 or less, even more preferably 200 or more and 490 or less, even more preferably 220 or more and 480 or less, and most preferably 230 or more and 400 or less.

[0097] (b) Other components The second thin film forming raw material may include other precursors or nucleophiles as components other than the compound represented by the general formula (2) above.

[0098] (1) Other Precursors The above other precursors can be compounds different from the compound represented by the above general formula (2). From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the other precursors are M in the above general formula (2). 2 It is preferable that the compound has the same metal atoms as the above. The above other precursors can be described in the section "(1) Other Precursors" of "A1. First Thin Film Forming Raw Materials" above by replacing "the compound represented by the above general formula (1)" with "the compound represented by the above general formula (2)".

[0099] When the second thin film forming raw material contains the other precursors, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the content of the other precursors is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the second thin film forming raw material.

[0100] (2) Nucleophile The second thin film forming raw material may include the nucleophile to stabilize the compound represented by the general formula (2) or the other precursor. The nucleophile may be the same as the nucleophile that can be used in the first thin film forming raw material.

[0101] If the second thin film forming raw material contains a nucleophile, the amount of the nucleophile is preferably in the range of 0.1 mol to 10 mol, and more preferably in the range of 1 mol to 4 mol, per 1 mol of the total amount of precursor. Here, the total amount of precursor refers to the total amount of precursor contained in the second thin film forming raw material. For example, if the second thin film forming raw material contains the other precursor, the total amount of precursor refers to the sum of the compound represented by the general formula (2) and the other precursor, and if the second thin film forming raw material does not contain the other precursor, the total amount of precursor refers to the amount of the compound represented by the general formula (2).

[0102] (3) Impurities The second thin film forming raw material described above is preferably free of impurities such as metal atoms, halogens, and organic particles, except for the compound represented by the general formula (2), the other precursors, and the nucleophile. The impurities in the second thin film forming raw material described above may be the same as those in the first thin film forming raw material.

[0103] From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the content of impurity organic matter in the second raw material for thin film formation is preferably 50,000 ppm or less, more preferably 30,000 ppm or less, even more preferably 10,000 ppm or less, particularly preferably 1,000 ppm or less, and most preferably 10 ppm or more and 1,000 ppm or less, relative to the compound represented by general formula (2).

[0104] (c) Second thin film forming raw material The physical properties of the compound represented by the general formula (2) above are also suitable for the CVD method, so the second thin film forming raw material is useful as a raw material for chemical vapor deposition. Among these, the compound represented by the general formula (2) above has a wide ALD window, so the second thin film forming raw material is particularly suitable for the ALD method. Therefore, the second thin film forming raw material is particularly useful as a thin film forming raw material for the ALD method.

[0105] The set of thin-film forming materials comprising the first and second thin-film forming materials of this disclosure can form bismuth-antimony alloy thin films with excellent electrical and optical properties, and these thin films are useful in various semiconductor devices, for example, as electrodes or contact layers. The set of thin-film forming materials of this disclosure is particularly useful as thin-film forming materials for the ALD method.

[0106] B. Method for Manufacturing Thin Films Next, the film deposition process in the method for manufacturing thin films according to this disclosure will be described. The apparatus used in the method for manufacturing thin films according to this disclosure can be a well-known ALD apparatus. Examples of specific apparatuses include apparatuses that can supply a precursor by bubbling, as shown in Figures 1 and 3, and apparatuses that have a vaporization chamber 102, as shown in Figures 2 and 4. Also, apparatuses that can perform plasma treatment on the film deposition chamber 100, as shown in Figures 3 and 4, can be used. Note that the apparatus is not limited to single-wafer apparatuses equipped with a film deposition chamber 100 as shown in Figures 1 to 4, but can also be used with a batch furnace capable of processing multiple sheets simultaneously. These can also be used as CVD apparatuses.

[0107] As an embodiment of the method for manufacturing a thin film according to the present disclosure, for example, it includes a precursor thin film formation step in which a first raw material gas obtained by vaporizing the first thin film forming raw material is introduced into a film formation chamber 100 in which a substrate S is pre-installed, and a compound represented by general formula (1) contained in the first raw material gas is deposited on the surface of the substrate S to form a precursor thin film, and an alloy film formation step in which a second raw material gas obtained by vaporizing the second thin film forming material is introduced into the film formation chamber 100, and a compound represented by general formula (2) contained in the second raw material gas is deposited on the surface of the substrate S on which the precursor thin film has been formed to form a bismuth-antimony alloy thin film.

[0108] In another embodiment, the process includes a precursor thin film formation step in which a second raw material gas obtained by vaporizing the second thin film forming raw material is introduced into a film formation chamber 100 in which a substrate S is pre-installed, and the compound represented by the general formula (2) contained in the second raw material gas is deposited on the surface of the substrate S to form a precursor thin film, and an alloy film formation step in which a first raw material gas obtained by vaporizing the first thin film forming raw material is introduced into the film formation chamber 100, and the compound represented by the general formula (1) contained in the first raw material gas is deposited on the surface of the substrate S on which the precursor thin film has been formed to form a bismuth-antimony alloy thin film.

[0109] The following describes each step of the thin film manufacturing method according to this disclosure with reference to Figures 1 to 4. First, the thin film manufacturing method will be described, which includes a precursor thin film formation step in which a precursor thin film is formed using the first thin film forming raw material M1, and an alloy thin film formation step in which a bismuth-antimony alloy thin film is formed using the second thin film forming raw material M2.

[0110] B1. Precursor Thin Film Formation Process In this process, the first raw material gas obtained by vaporizing the first thin film formation raw material M1 is introduced into the film formation chamber 100, and the compound represented by the general formula (1) contained in the first raw material gas is deposited on the surface of the substrate S to form a precursor thin film.

[0111] (1) Substrate S The substrate S is not particularly limited as long as it can support the precursor thin film. The substrate S may be any known substrate, for example, an organic compound or an inorganic compound. Examples of materials for the substrate S include silicon; ceramics such as silicon nitride, titanium nitride, tantalum nitride, titanium oxide, molybdenum oxide, zirconium oxide, hafnium oxide, and lanthanum oxide; glass; and metals such as metallic cobalt, metallic molybdenum, molybdenum sulfide, molybdenum selenide, tungsten sulfide, and tungsten selenide. Examples of substrate shapes include plate-like shapes such as flakes, flat plates or discs, fibrous shapes, cylindrical shapes, prismatic shapes, tubular shapes, spiral shapes, spherical shapes, ring shapes, or three-dimensional structures such as trench structures. In this specification, "surface of the substrate S" includes not only the surface of the substrate S but also the surfaces of the precursor thin film and the bismuth-antimony alloy thin film formed on the substrate S by each step of the manufacturing method described later.

[0112] (2) Introduction of the first raw material gas The first raw material gas is obtained by vaporizing the first thin film forming raw material M1. A method for obtaining the first raw material gas is, for example, a method of heating and / or reducing the pressure of the first thin film forming raw material M1.

[0113] Methods for heating the first thin film forming raw material M1 include, for example, heating the first thin film forming raw material M1 in the raw material container 101 of the ALD apparatus shown in Figure 1 or Figure 3 using a heater 103 or the like, or heating the first thin film forming raw material M1 in the vaporization chamber 102 of the ALD apparatus shown in Figure 2 or Figure 4. The temperature range for heating the first thin film forming raw material M1 is preferably 130°C or lower, more preferably 60°C to 120°C, and even more preferably 80°C to 100°C, from the viewpoint of avoiding thermal decomposition of the first thin film forming raw material M1, enabling the formation of a high-purity bismuth-antimony alloy thin film with a fast film formation rate and uniform film thickness.

[0114] As a method for reducing the pressure of the first thin film forming raw material M1 described above, for example, a method of reducing the pressure of the first thin film forming raw material M1 in the raw material container 101 of the ALD apparatus described in Figure 1 or Figure 3, or a method of reducing the pressure of the first thin film forming raw material M1 in the vaporization chamber 102 of the ALD apparatus described in Figure 2 or Figure 4. The pressure reduction (vacuum) conditions are preferably in the range of 1 Pa to 10,000 Pa, more preferably in the range of 10 Pa to 5,000 Pa, and even more preferably in the range of 20 Pa to 1,000 Pa. This is because it is possible to form a high-purity bismuth-antimony alloy thin film with a fast film formation rate, uniform film thickness, and low residual carbon.

[0115] Methods for introducing the first raw material gas into the film deposition chamber 100 include gas transport methods and liquid transport methods. As an example of the gas transport method, as shown in Figures 1 and 3, the first thin-film forming raw material M1 is heated and / or vaporized in the raw material container 101 to produce the first raw material gas, and the first raw material gas is introduced into the film deposition chamber 100 along with a carrier gas such as argon, nitrogen, or helium, as needed. As an example of the liquid transport method, as shown in Figures 2 and 4, the first thin-film forming raw material M1 is transported in a liquid or solution state to the vaporization chamber 102, where it is heated and / or depressurized in the vaporization chamber 102 to produce the first raw material gas, and the first raw material gas is introduced into the film deposition chamber 100 along with a carrier gas such as argon, nitrogen, or helium, as needed. Furthermore, if the first thin-film forming raw material M1 contains the other precursors, the first raw material gas can be introduced into the film formation chamber 100, for example, using a single-source method.

[0116] (3) Formation of Precursor Thin Film In the above precursor thin film formation step, as described above, the compound represented by the general formula (1) contained in the first raw material gas introduced into the film formation chamber 100 is deposited on the surface of a substrate S that has been previously placed in the film formation chamber 100 to form a precursor thin film. In this disclosure, "deposit" refers to a concept that includes the chemical adsorption of the compound on the surface of the substrate.

[0117] In this process, it is preferable to heat either the inside of the film deposition chamber 100 or the substrate S. When the metal atom of the compound represented by the general formula (1) contained in the first raw material gas is a bismuth atom, it is preferable to heat the first raw material gas in the range of 25°C to 270°C, more preferably in the range of 25°C to 250°C, and particularly preferably in the range of 25°C to 230°C. This is because it is possible to form a high-purity bismuth-antimony alloy thin film with a fast film deposition rate, uniform film thickness, and low residual carbon.

[0118] When the metal atom of the compound represented by the general formula (1) contained in the first raw material gas is an antimony atom, the heating of the first raw material gas is preferably carried out in the range of 25°C to 400°C, more preferably in the range of 25°C to 300°C, even more preferably in the range of 25°C to 250°C, even more preferably in the range of 25°C to 200°C, and most preferably in the range of 25°C to 150°C. This is because it is possible to form a high-purity bismuth-antimony alloy thin film with a fast film formation rate, uniform film thickness, and low residual carbon.

[0119] In this process, the heating of the first raw material gas is preferably carried out in a non-oxygen atmosphere, more preferably in an inert gas such as nitrogen or argon, and particularly preferably in an inert gas atmosphere. This is because it allows for a fast film deposition rate and facilitates the formation of a uniform, high-purity metal thin film. Furthermore, the heating reaction may be carried out under any of the following conditions: under pressure, under reduced pressure, under normal pressure, or under atmospheric pressure. However, in this process, it is preferable to carry it out under reduced pressure (20 Pa to 1,000 Pa). This is because it allows for a fast film deposition rate and the formation of a high-purity bismuth-antimony alloy thin film with uniform thickness and low residual carbon.

[0120] B2. Alloy Thin Film Formation Process (1) Introduction of the Second Raw Material Gas The second raw material gas is obtained by vaporizing the second raw material M2 for thin film formation. As for the method of obtaining the second raw material gas, the first raw material gas can be replaced with the second raw material gas and the compound represented by general formula (1) can be replaced with the compound represented by general formula (2) as described in "(2) Introduction of the First Raw Material Gas" of "B1. Precursor Thin Film Formation Process," so the explanation here will be omitted. However, if the compound represented by general formula (2) and the compound represented by general formula (1) come into contact, the compound represented by general formula (1), the compound represented by general formula (2), or both may decompose. For example, in the ALD apparatus shown in Figures 1 to 4, it is preferable to separate the supply lines of the raw material for thin film formation from the raw material container 101 to the film formation chamber 100 so that the first raw material M1 for thin film formation and the second raw material M2 for thin film formation do not come into contact.

[0121] (2) Formation of Bismuth-Antimony Alloy Thin Film In this step, the second raw material gas obtained by vaporizing the second thin film forming raw material M2 is introduced into the film formation chamber 100, and the compound represented by general formula (2) contained in the second raw material gas is deposited on the surface of the substrate S on which the precursor thin film has been formed to form a bismuth-antimony alloy thin film. The heating of the second thin film forming raw material and the pressure inside the film formation chamber 100 during heating in this step can be carried out under the same conditions as described in "(3) Formation of Precursor Thin Film" of "B1. Precursor Thin Film Formation Step" above. If the second thin film forming raw material contains a compound in which the ligand represented by L in general formula (2) is a dimethylamino group, the heating of the second thin film forming raw material is preferably carried out in the range of 20°C to 90°C, more preferably in the range of 20°C to 75°C, and even more preferably in the range of 20°C to 60°C.

[0122] In this process, for example, if Bi(SiMe3)3 is used as the compound represented by the above general formula (1) and Bi(SiMe3)3 is deposited on a substrate S to form a precursor thin film, and Sb(NMe2)3 is used as the compound represented by the above general formula (2) and Sb(NMe2)3 is deposited on the substrate S on which the precursor thin film was formed, a bismuth-antimony alloy thin film is formed on the substrate S by the reaction shown in the following formula.

[0123]

[0124] In this embodiment, the process of introducing a first raw material gas into the film deposition chamber 100 to form a precursor thin film, and then introducing a second raw material gas to form a bismuth-antimony alloy thin film has been described. However, the process may also be as follows: introducing a second raw material gas into the film deposition chamber 100, depositing the compound represented by the general formula (2) contained in the second raw material gas onto the surface of the substrate S to form a precursor thin film, and then introducing a first raw material gas into the film deposition chamber 100 to deposit the compound represented by the general formula (1) contained in the first raw material gas onto the surface of the substrate S on which the precursor thin film was formed, thereby forming a bismuth-antimony alloy thin film.

[0125] B3. Purification Process This process involves introducing a reducing gas 202 into a film deposition chamber 100 and reacting the bismuth-antimony alloy thin film with the reducing gas 202 to purify the bismuth-antimony alloy thin film. The purification process here refers to a process that brings the total content of bismuth atoms and antimony atoms in 100 parts by mass of the bismuth-antimony alloy thin film obtained in the previous process close to 100 parts by mass. In the thin film manufacturing method according to this disclosure, one or more types selected from the group consisting of H2, NH3, H2 plasma, and NH3 plasma can be used as the reducing gas 202.

[0126] (1) H2 The above H2 is preferably of 10 ppm or less, more preferably of 1 ppm or less, and particularly preferably of 100 ppb or less, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities. Examples of the above impurities include H2O, O2, CO2, metal atoms other than bismuth atoms and antimony atoms, non-methane hydrocarbons (NMHC), etc.

[0127] (2) NH3 The above NH3 is preferably of a quality bismuth-antimony alloy thin film with few impurities, more preferably of a 1 ppm or less impurity content, and particularly preferably of a 100 ppb or less impurity content.

[0128] (3) H2 Plasma H2 plasma refers to a material containing H radicals. H2 plasma can be produced by, for example, using direct current (DC) current, alternating current (RF) current, microwaves, etc. to create a plasma of H2.

[0129] (4) NH3 Plasma NH3 plasma refers to NH3 containing radicals. NH3 plasma can be produced, for example, by directly reacting H2 and N2 using direct current (DC), alternating current (RF), microwaves, etc.

[0130] (5) Other gases The thin film manufacturing method according to this disclosure may include other gases as reducing gases in addition to H2, NH3, H2 plasma and NH3 plasma. Examples of these other gases include organic amine compounds such as monoalkylamines, dialkylamines, trialkylamines and alkylenediamines; nitriding gases obtained by vaporizing hydrazine, etc.; sulfurizing gases such as sulfur, hydrogen sulfide, dimethyl sulfide, diethyl sulfide and diisopropyl sulfide and other dialkyl sulfides; and inert gases such as argon and nitrogen. In the thin film manufacturing method according to this disclosure, two or more of these other gases may be used in mixture form. In this disclosure, from the viewpoint of easily forming a high-purity bismuth-antimony alloy thin film with a fast film formation rate, uniform film thickness and low residual carbon, the content of the other gases in the reducing gas is preferably 50 volume% or less, more preferably 10 volume% or less, and particularly preferably 5 volume% or less.

[0131] In the method for manufacturing a thin film according to this disclosure, from the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, it is preferable that the reducing gas 202 includes only a selection from the group consisting of H2, NH3, H2 plasma, and NH3 plasma, more preferably a selection from the group consisting of H2 and H2 plasma, and particularly preferable to use only H2 from the viewpoint of high reactivity and suppression of damage to the underlying layer.

[0132] The method for introducing the reducing gas 202 into the film deposition chamber 100 can be the same as that for the first or second raw material gas described above. When introducing H2 plasma or NH3 plasma as the reducing gas 202, for example, after introducing H2 or NH3 into the film deposition chamber 100 as shown in Figure 3 or Figure 4, a voltage may be applied to H2 or NH3 in a plasma treatment step described later to generate plasma.

[0133] In this step, when the bismuth-antimony alloy thin film is reacted with the reducing gas 202, the bismuth-antimony alloy thin film and / or the reducing gas 202 are heated. It is preferable that this heating is performed at the same temperature as the precursor formation step and the alloy thin film formation step, because this allows for the efficient production of high-purity bismuth-antimony alloy thin films.

[0134] B4. Other steps The method for manufacturing a thin film according to this disclosure may include other steps such as a purification step, an exhaust step 1 to 3, a plasma treatment step, an annealing step, a reflow step, etc.

[0135] (1) Purification step This step purifies the first thin film forming raw material containing the compound represented by the general formula (1) or the second thin film forming raw material containing the compound represented by the general formula (2). The purification can be any general purification method, such as filtration, extraction, centrifugation, decantation, distillation, sublimation, crystallization, or column chromatography. From the viewpoint of forming a high-quality bismuth-antimony alloy thin film with few impurities, the method for producing a thin film according to this disclosure preferably includes a distillation step in which the first thin film forming raw material or the second thin film forming raw material is distilled. From the viewpoint of not altering the first thin film forming raw material or the second thin film forming raw material, the distillation is preferably carried out at 30°C to 250°C, more preferably at 40°C to 200°C, and particularly preferably at 50°C to 150°C.

[0136] (2) Evacuation Step 1 This step, performed after the precursor thin film formation step, is to evacuate the unreacted first raw material gas that did not participate in the formation of the precursor thin film from the film formation chamber 100. Ideally, the unreacted first raw material gas should be completely evacuated from the film formation chamber 100 in this step, but it is not always necessary to evacuate it completely. Examples of evacuation methods include purging the system of the film formation chamber 100 with an inert gas such as helium, nitrogen, or argon, evacuating by reducing the pressure inside the system, and methods combining these. When reducing the pressure inside the system, the degree of pressure is preferably in the range of 0.01 Pa to 300 Pa, more preferably in the range of 0.05 Pa to 200 Pa, and particularly preferably in the range of 0.1 Pa to 100 Pa. This is because sufficient evacuation of the first raw material gas is possible, and a high-quality bismuth-antimony alloy thin film with few impurities can be formed.

[0137] (3) Exhaust Process 2 This process, performed after the alloy thin film formation process, involves exhausting the unreacted second raw material gas that did not participate in the formation of the bismuth-antimony alloy thin film, as well as the by-product gas generated by the reaction between the precursor thin film and the second raw material gas, from the film formation chamber 100. Ideally, the unreacted second raw material gas and by-product gas should be completely exhausted from the film formation chamber 100 in this process, but complete exhaust is not necessarily required. The exhaust method and pressure can be carried out under the same conditions as in Exhaust Process 1.

[0138] (4) Exhaust Process 3 This process is performed after the bismuth-antimony alloy thin film purification process described above, and involves exhausting unreacted reducing gases and by-product gases generated during the reduction of the bismuth-antimony alloy thin film from the film deposition chamber 100. Ideally, in this process, unreacted reducing gases and by-product gases should be completely exhausted from the film deposition chamber 100, but complete exhaust is not always necessary. The exhaust method and pressure can be carried out under the same conditions as in Exhaust Process 1.

[0139] (5) Plasma Treatment Step The method for manufacturing a thin film according to the present disclosure may include a plasma treatment step in which a voltage is applied to a first raw material gas or a second raw material gas to induce plasma formation in order to promote the formation of the precursor thin film and the bismuth-antimony alloy thin film. A plasma-formed reducing gas can also be used in this step. As a method for inducing plasma formation of a reducing gas, for example, a method of applying a direct current (DC) current, an alternating current (RF) current, a microwave, etc., to a reactive gas. Specifically, as shown in Figures 3 and 4, an RF matching system 106 connected to a high-frequency (RF) power supply 105 is installed in the film deposition chamber 100, and plasma formation is induced in the film deposition chamber 100.

[0140] In this process, as shown in Figures 3 and 4, an RF matching system 106 connected to a high-frequency (RF) power supply 105 is installed in the deposition chamber 100, allowing the first or second raw material gas to be plasma-generated within the deposition chamber 100. In this process, if the power applied when the voltage is too high, it will cause significant damage to the substrate supporting the precursor thin film or the bismuth-antimony alloy thin film. Therefore, the power applied when the voltage is too high is preferably in the range of 10W to 1,500W, more preferably in the range of 30W to 1,000W, and particularly preferably in the range of 50W to 600W.

[0141] (6) Annealing process The annealing process described above may be a process in which the bismuth-antimony alloy thin film is annealed after the bismuth-antimony alloy thin film has been purified, in order to improve the electrical properties of the metal layer. In the annealing process described above, the bismuth-antimony alloy thin film may be annealed in an inert atmosphere or a reducing atmosphere. The temperature in the annealing process is preferably in the range of 100°C to 270°C, more preferably in the range of 150°C to 260°C, and particularly preferably in the range of 200°C to 250°C. This is because a high-quality bismuth-antimony alloy thin film with few impurities can be formed.

[0142] (7) Reflow process The reflow process described above may be a process in which the bismuth-antimony alloy thin film is heated after the bismuth-antimony alloy thin film has been formed in order to fill in any steps in the bismuth-antimony alloy thin film. The temperature in the reflow process is preferably in the range of 200°C to 600°C, more preferably in the range of 230°C to 550°C, and particularly preferably in the range of 250°C to 500°C. This is because it is possible to form a high-quality bismuth-antimony alloy thin film with few impurities.

[0143] Furthermore, another embodiment of the thin film manufacturing method of this disclosure is a thin film manufacturing method by selective film deposition. The above-mentioned "selective film deposition" refers to a film deposition method in which a difference in the amount of thin film deposited occurs between a film deposition-allowed surface and a film deposition-inhibiting surface due to differences in the adsorption or nucleation behavior of a compound represented by general formula (1) or general formula (2) in multiple types of surface regions on a substrate. Examples of film deposition-allowed surfaces include metal surfaces, semimetallic surfaces, and two-dimensional material surfaces (e.g., MoS2, WS2, MoSe2, etc.). On the other hand, examples of film deposition-inhibiting surfaces include dielectric surfaces (e.g., SiO2, Al2O3, HfO2, etc.), organic resin surfaces, or low surface energy surfaces modified by self-assembled monolayers (SAMs) or small molecule inhibitors (SIMs). The above selective film deposition can be evaluated by a value (Selectivity) calculated using the following formula, where "Tm" is the thickness of the thin film formed on the deposition-allowable surface and "Td" is the thickness of the thin film formed on the deposition-inhibiting surface: Selectivity = |(Tm - Td)| / (Tm + Td) The thickness of the thin film can be measured by X-ray reflectivity (XRR) or spectroscopic ellipsometry.

[0144] The above selectivity is affected by conditions such as the substrate material, substrate surface pretreatment, deposition temperature, and deposition time of the compound represented by general formula (1) or general formula (2). However, the smaller Td is relative to Tm, the higher the selectivity is considered to be. Furthermore, even if the selectivity is around 0.1, if there is a difference in film thickness between the deposition-allowed surface and the deposition-inhibiting surface, selective deposition can be considered to be good. Moreover, in embodiments where the deposition-inhibiting surface is surface-modified with, for example, a SIM such as octadecyltrichlorosilane or a SAM such as alkylthiol, nucleation on the deposition-inhibiting surface is further suppressed, so the selectivity may show a high value of 0.5 to 1.0, which is preferable.

[0145] B5. Film Formation Cycle The method for manufacturing a thin film according to this disclosure comprises a series of operations performed in the following order: a precursor thin film formation step and exhaust step 1, an alloy thin film formation step and exhaust step 2, and a high-purity step and exhaust step 3. This series is repeated until a bismuth-antimony alloy thin film of the required thickness is obtained, thereby forming a bismuth-antimony alloy thin film with the desired thickness. In other words, the thickness of the formed bismuth-antimony alloy thin film can be controlled by the number of cycles. For example, the above cycle may be performed only once to form one layer of bismuth-antimony alloy thin film, or it may be performed two or more times to form a bismuth-antimony alloy thin film of the desired thickness. The thickness of the bismuth-antimony alloy thin film obtained per cycle is preferably in the range of 0.1 Å to 1.0 nm, more preferably in the range of 0.3 Å to 0.5 nm, and particularly preferably in the range of 0.5 Å to 0.1 nm. This is because it is easier to obtain a bismuth-antimony alloy thin film of uniform thickness.

[0146] B6. Methods for manufacturing thin films other than the ALD method In this embodiment, a method for manufacturing a bismuth-antimony alloy thin film by the ALD method has been described, but the method for manufacturing a thin film according to this disclosure is not limited to the above, and for example, the thin film may be manufactured by the CVD method. When the method for manufacturing a thin film according to this disclosure uses the CVD method to manufacture the thin film, the first raw material gas and the second raw material gas may be introduced into the deposition chamber 100 simultaneously.

[0147] The bismuth-antimony alloy thin film produced by the thin film manufacturing method according to this disclosure shall contain a total content of bismuth atoms and antimony atoms of 90 parts by mass or more per 100 parts by mass of the thin film. In this disclosure, it is preferable that the total content of bismuth atoms and antimony atoms per 100 parts by mass of the bismuth-antimony alloy thin film be 96 parts by mass or more, more preferably 97 parts by mass or more, even more preferably 98 parts by mass or more, and even more preferably 99 parts by mass or more. This is because the bismuth-antimony alloy thin film exhibits excellent electrical properties and can be used in various semiconductor devices.

[0148] Examples of the semiconductor devices mentioned above include field-effect transistors (FETs), nanosheet transistors, nanowire transistors, and complementary field-effect (FET) transistors. In this disclosure, it is preferable that the semiconductor device is an FET having a transition metal dichalcogenide such as MoS2, MoSe2, WS2, or WSe2 in its semiconductor layer. It is preferable that the thin film forming raw material of this disclosure is formed as a contact or metal thin film on the upper or lower part of the transition metal dichalcogenide semiconductor layer. This is because the bismuth-antimony alloy thin film produced by the thin film manufacturing method of this disclosure has excellent electrical properties. Furthermore, the semiconductor device may also include other layers (for example, an insulating layer, a conductive layer, a semiconductor layer, a buffer layer, or other intermediate layers).

[0149] The raw materials for thin film formation obtained in Synthesis Examples 1 to 4 below were analyzed for their organic impurity content according to the following procedures (1) to (3).

[0150] (1) 10 mg of the target compound for sample preparation was accurately weighed and dissolved in deuterated benzene (C6D6). After dissolution, the solution was transferred to a standard 5 mm glass tube for NMR measurement and gently stirred to obtain a homogeneous solution.

[0151] (2) 1 For the H-NMR measurement, a Fourier transform nuclear magnetic resonance spectrometer with a proton frequency of 400 MHz was used, and the following conditions were observed: • Measurement frequency: 400 MHz • Temperature: 25°C • Spectral width: +10 ppm to -5 ppm

[0152] (3) Spectral analysis results obtained 1 The chemical shifts (δ values) and integral values ​​of the 1H-NMR spectrum were analyzed to identify the organic impurities (number of protons). Then, the molar ratio was calculated to determine the content of the organic impurities in the sample.

[0153] [Synthesis Example 1] In a 2 L flask, bismuth powder (146.29 g, 0.7 mol), tetrahydrofuran (908.59 g, 12.6 mol), sodium (48.28 g, 2.1 mol), and naphthalene (0.1 mol) were added and stirred at room temperature for 3 days. Then, chlorotrimethylsilane (244.44 g, 2.25 mol) was added and stirred at room temperature for 1 day. Unreacted chlorotrimethylsilane and solvent were removed by heating at 90°C and under reduced pressure. 500 ml of pentane was added and the mixture was filtered. The solvent was removed by heating at 65°C and under reduced pressure. Naphthalene and low-temperature boiling by-products were removed by heating at 90°C and an internal pressure of 500 Pa. Then, distillation purification was performed at 95°C and an internal pressure of 160 Pa to obtain 24.07 g of a thin-film forming raw material mainly containing Bi(SiMe3)3. NMR analysis revealed that the naphthalene content as an organic impurity was 500 ppm relative to Bi(SiMe3)3. The NMR analysis was performed using a Bruker instrument.

[0154] [Synthesis Example 2] Except for changing the bismuth powder to antimony powder (85.23 g, 0.7 mol) and changing the distillation purification to a heating temperature of 90°C and an internal pressure of 170 Pa, the same procedure as in Synthesis Example 1 was followed to obtain 57.34 g of a thin-film forming raw material mainly containing Sb(SiMe3)3. Analysis using NMR showed that the naphthalene content as an impurity organic component was 400 ppm relative to Sb(SiMe3)3.

[0155] [Synthesis Example 3] The same procedure as in Synthesis Example 1 was followed, except that distillation purification was not performed, to obtain 27.53 g of a thin-film forming raw material mainly containing Bi(SiMe3)3. Analysis using NMR revealed that the naphthalene content as an impurity organic component was 22,000 ppm relative to Bi(SiMe3)3.

[0156] [Synthesis Example 4] The procedure was the same as in Synthesis Example 2, except that distillation purification was not performed, to obtain 62.46 g of a thin-film forming raw material mainly containing Sb(SiMe3)3. Analysis using NMR showed that the naphthalene content as an impurity organic component was 23,000 ppm relative to Sb(SiMe3)3.

[0157] [Example 1] As the first thin film formation raw material M1, a thin film formation raw material mainly containing Bi(SiMe3)3 obtained in Synthesis Example 1 was used, and as the second thin film formation raw material M2, Sb(OEt)3 was used. Using the ALD apparatus shown in Figure 1, a bismuth-antimony alloy thin film was manufactured on a silicon substrate as the base material under the following conditions. The composition of the obtained thin film was analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, and it was confirmed that the thin film was a bismuth-antimony alloy thin film. The residual carbon content in the thin film was 1.0 atom%, and the residual oxygen content was 1.0 atom%. Furthermore, when the film thickness of the thin film was measured using X-ray reflectivity or spectroscopic ellipsometry, the thin film formed on the substrate was a smooth film with a thickness of 600 Å, and the film thickness obtained per cycle was approximately 0.6 Å. Generally, if the film thickness obtained per cycle is 0.5 Å or more, it can be said that the film deposition rate is fast. For the X-ray reflectance method, a Rigaku Corporation instrument was used, and for the spectroscopic ellipsometry, a J. A. Wollam Corporation instrument was employed.

[0158] (Conditions) Reaction temperature (substrate temperature): 200°C (Steps 1 to 6) First thin film forming raw material M1: Thin film forming raw material mainly containing Bi(SiMe3)3 (compound A-3) Second thin film forming raw material M2: Sb(OEt)3 (compound B-54) Reducing gas 202: H2 Substrate S: Silicon substrate

[0159] (Process) The following series of processes, consisting of steps 1 to 6, was repeated 1,000 times as one cycle. Step 1: The vapor of the first thin-film forming raw material M1 (first raw material gas), which had been vaporized under the conditions of a heating temperature of 80°C and an internal pressure of 100 Pa in the raw material container 101, was introduced into the film formation chamber 100. Bi(SiMe3)3 contained in the first raw material gas was deposited on the surface of the substrate S for 15 seconds at a system pressure of 100 Pa to form a precursor thin film. Step 2: The first raw material gas that had not been deposited was exhausted from the system by argon purging for 10 seconds. Step 3: The vapor of the second thin-film forming raw material M2 (second raw material gas), which was vaporized under the conditions of a heating temperature of 50°C and an internal pressure of 100 Pa in the raw material container 101, was introduced into the film deposition chamber 100. Sb(OEt)3 contained in the second raw material gas was deposited on the surface of the substrate S on which the precursor thin film was formed in Step 1 for 15 seconds at a system pressure of 100 Pa, thereby forming a bismuth-antimony alloy thin film. Step 4: The second raw material gas and by-product gases that were not deposited were exhausted from the system by argon purging for 10 seconds. Step 5: Reducing gas 202 was introduced into the film deposition chamber 100, and the bismuth-antimony alloy thin film formed in Step 3 was reacted with the reducing gas 202 for 15 seconds at a system pressure of 100 Pa, thereby increasing the purity of the bismuth-antimony alloy thin film. Step 6: Unreacted reducing gas and by-product gases were exhausted from the system by argon purging for 10 seconds.

[0160] [Example 2] As the first thin film formation raw material M1, a thin film formation raw material mainly containing Sb(SiMe3)3 obtained in Synthesis Example 2 was used, and as the second thin film formation raw material M2, Bi(NETMe)3 was used. Using the ALD apparatus shown in Figure 1, a thin film was manufactured on a silicon substrate as the substrate S under the following conditions. The composition of the obtained thin film was analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, and it was confirmed that the thin film was a bismuth-antimony alloy thin film. The residual carbon content in the thin film was 0.5 atom%, and the residual oxygen content was 0.5 atom%. Furthermore, when the film thickness of the thin film was measured using X-ray reflectivity or spectroscopic ellipsometry, the thin film formed on the substrate was a smooth film with a thickness of 500 Å, and the film thickness obtained per cycle was approximately 0.5 Å.

[0161] (Conditions) Reaction temperature (substrate temperature): 200°C (Steps 1 to 6) First thin film forming raw material M1: Thin film forming raw material mainly containing Sb(SiMe3)3 (compound A-9) Second thin film forming raw material M2: Bi(NETMe)3 (compound B-23) Reducing gas 202: H2 Substrate S: Silicon substrate

[0162] (Process) The following series of processes, consisting of steps 1 to 6, was repeated 1,000 times as one cycle. Step 1: The vapor of the first thin-film forming raw material (first raw material gas), which was vaporized under the conditions of a heating temperature of 80°C and an internal pressure of 100 Pa in the raw material container 101, was introduced into the film formation chamber 100, and Sb(SiMe3)3 contained in the first raw material gas was deposited on the substrate S surface for 15 seconds at a system pressure of 100 Pa to form a precursor thin film. Step 2: The first raw material gas that was not deposited was exhausted from the system by argon purging for 10 seconds. Step 3: The vapor of the second thin-film forming raw material M2 (second raw material gas), which was vaporized under the conditions of a heating temperature of 65°C and an internal pressure of 100 Pa in the raw material container 101, was introduced into the film deposition chamber 100. At a system pressure of 100 Pa for 15 seconds, the Bi(NETMe)3 contained in the second raw material gas was deposited on the surface of the substrate S on which the precursor thin film was formed in Step 1, thereby forming a bismuth-antimony alloy thin film. Step 4: The second raw material gas and by-product gases that were not deposited were exhausted from the system by argon purging for 10 seconds. Step 5: Reducing gas 202 was introduced into the film deposition chamber 100, and at a system pressure of 100 Pa for 15 seconds, the bismuth-antimony alloy thin film formed in Step 3 was reacted with the reducing gas 202 to purify the bismuth-antimony alloy thin film. Step 6: Unreacted reducing gases and by-product gases were purged from the system by argon purging for 10 seconds.

[0163] [Example 3] A thin film was fabricated on a silicon substrate S using the same procedure as in Example 1, except that the first thin film formation raw material M1 was changed to a thin film formation raw material mainly containing Bi(SiMe3)3 obtained in Synthesis Example 3. The composition of the obtained thin film was analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, and it was confirmed that the thin film was a bismuth-antimony alloy thin film. The residual carbon content in the thin film was 3.0 atom%, and the residual oxygen content was 1.0 atom%. Furthermore, when the film thickness of the thin film was measured using X-ray reflectivity or spectroscopic ellipsometry, the thin film formed on the substrate was a smooth film with a thickness of 620 Å, and the film thickness obtained per cycle was approximately 0.6 Å.

[0164] [Example 4] A thin film was manufactured on a silicon substrate S using the same procedure as in Example 2, except that the first thin film formation raw material M1 was changed to a thin film formation raw material mainly containing Sb(SiMe3)3 obtained in Synthesis Example 4. The composition of the obtained thin film was analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, and it was confirmed that the thin film was a bismuth-antimony alloy thin film. The residual carbon content in the thin film was 4.0 atom%, and the residual oxygen content was 0.5 atom%. Furthermore, when the film thickness of the thin film was measured using X-ray reflectivity or spectroscopic ellipsometry, the thin film formed on the substrate was a smooth film with a thickness of 530 Å, and the film thickness obtained per cycle was approximately 0.5 Å.

[0165] [Comparative Example 1] As the first thin film forming raw material M1, a thin film forming raw material mainly containing Bi(SiMe3)3 obtained in Synthesis Example 1 was used, and as the comparative material for the second thin film forming raw material M2, a thin film forming raw material mainly containing Sb(SiMe3)3 obtained in Synthesis Example 2 was used. An attempt was made to produce a thin film on a silicon substrate as the base material S using the ALD apparatus shown in Figure 1 in the same procedure as in Example 1, but no thin film was formed.

[0166] The analysis results of the thin film forming raw materials used in Examples 1 to 4 and Comparative Example 1, as well as the obtained thin films, are shown in Table 1 below.

[0167]

[0168] As shown in Comparative Example 1 of Table 1, when the second thin film forming raw material did not contain the compound represented by general formula (2), film formation was not possible. In contrast, as shown in Examples 1 to 4, the thin film manufacturing method according to the present disclosure can form high-quality bismuth-antimony alloy thin films with few impurities. Furthermore, as shown in Examples 1 and 2, when the first thin film forming raw material containing the compound represented by general formula (1) is purified by distillation at 30°C to 250°C, the amount of residual carbon is suppressed, and even higher quality bismuth-antimony alloy thin films can be formed.

[0169] 100 Film deposition chamber 101 Raw material container 102 Vaporization chamber 103 Heater 104 Mass flow controller (MFC) 105 Radio frequency (RF) power supply 106 RF matching system 107 Vacuum pump 108 Automatic pressure controller 109 Cooling trap 201 Carrier gas 202 Reducing gas 203 Exhaust 204 Purge gas M1 First thin film formation raw material M2 Second thin film formation raw material S Substrate

Claims

A method for producing a thin film, comprising forming a bismuth-antimony alloy thin film using a compound represented by the following general formula (1) and a compound represented by the following general formula (2). (In general formula (1), M 1 represents a bismuth atom or an antimony atom, R 11 , R 12 and R 13 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and there are three -SiR 11 R 12 R 13 (They may be the same or they may be different.) (In the above general formula (2), M 2 represents a bismuth atom or an antimony atom, and unlike M 1 , L is selected from the group consisting of a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms (*-OR 1 ), a monoalkylamino group (*-NHR 1 ), a dialkylamino group (*-NR 1 R 2 ), an alkylenetrialkylsilyl group (*-(CH2) m -SiR 1 R 2 R 3 ), a bis(trialkylsilyl)amino group (*-N(SiR 1 R 2 R 3 )2), an alkyl(trimethylsilyl)amino group (*-NR 1 -SiMe3), an aryl group having 6 to 20 carbon atoms, a cyclopentadienyl group, a diketonate structure (*-O-C(R 4 )=C(R 5 )-C(=O)-R 6 ), a ketoiminate structure (*-N(R 4 )-C(R 5 )=C(R 6 )-C(=O)-R 7 ), a diiminate structure (*-N(R 4 )-C(R 5 )=C(R 6 )-C(=NR 7 )-R 8 ), and an amidinate structure (*-N(R 4 )-C(R 5 )=NR 6 ), and R 1 , R 2 and R 3 each independently represent an alkyl group having 1 to 10 carbon atoms, and R 4 , R 5 , R 6 , R 7 and R 8 Each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, m represents an integer between 1 and 10, the three Ls may be the same ligand or different ligands, and * represents M 2 (This indicates the connection position with [the other element].) 　 R in the general formula (1) 11 , R 12 and R 13 A method for producing a thin film according to claim 1, wherein the total number of carbon atoms of the group represented by is 2 or more and 6 or less. 　 The process includes a purification step of purifying the compound represented by the general formula (1) before using the first thin film forming raw material, The method for producing a thin film according to claim 1, wherein the purification step is a step of distilling a first thin film forming raw material containing the compound represented by the general formula (1) at a temperature of 30°C or higher and 250°C or lower. 　 The aforementioned purification process, A precursor thin film formation step involves vaporizing a first thin film forming raw material containing the purified compound represented by the general formula (1) to obtain a first raw material gas, which is then introduced into a film formation chamber where a substrate has been pre-installed, and depositing the compound represented by the general formula (1) contained in the first raw material gas onto the surface of the substrate to form a precursor thin film. A second raw material gas obtained by vaporizing a second thin film forming raw material containing the compound represented by the general formula (2) is introduced into the film formation chamber, and the compound represented by the general formula (2) contained in the second raw material gas is deposited on the surface of the substrate on which the precursor thin film is formed to form a bismuth-antimony alloy thin film, an alloy thin film forming step, A method for manufacturing a thin film according to claim 3, including the following: 　 The aforementioned purification process, A precursor thin film formation step involves vaporizing a second thin film formation raw material containing the compound represented by the general formula (2) and introducing the second raw material gas obtained by vaporizing it into a film formation chamber where a substrate has been pre-installed, and depositing the compound represented by the general formula (2) contained in the second raw material gas onto the surface of the substrate to form a precursor thin film. A first raw material gas obtained by vaporizing a first thin film forming raw material containing the purified compound represented by the general formula (1) is introduced into the film formation chamber, and the compound represented by the general formula (1) contained in the first raw material gas is deposited on the surface of the substrate on which the precursor thin film is formed to form a bismuth-antimony alloy thin film. A method for manufacturing a thin film according to claim 3, including the following: 　 A method for manufacturing a thin film according to claim 4 or 5, further comprising a purification step of introducing a reducing gas into the film deposition chamber and reacting the bismuth-antimony alloy thin film with the reducing gas to purify the bismuth-antimony alloy thin film. 　 A set of thin-film forming raw materials comprising a first thin-film forming raw material containing a compound represented by the following general formula (1), and a second thin-film forming raw material containing a compound represented by the following general formula (2). (In general formula (1), M 1 represents a bismuth atom or an antimony atom, R 11 , R 12 and R 13 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and there are three -SiR 11 R 12 R 13 (They may be the same or they may be different.) (In the above general formula (2), M 2 represents a bismuth atom or an antimony atom, and unlike M 1 , L is selected from a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms (*-OR 1 ), a monoalkylamino group (*-NHR 1 ), a dialkylamino group (*-NR 1 R 2 ), an alkylenetrialkylsilyl group (*-(CH2) m -SiR 1 R 2 R 3 ), a bis(trialkylsilyl)amino group (*-N(SiR 1 R 2 R 3 )2), an alkyl (trimethylsilyl) amino group (*-NR 1 -SiMe3), an aryl group having 6 to 20 carbon atoms, a cyclopentadienyl group, a diketonate structure (*-O-C(R 4 )=C(R 5 )-C(=O)-R 6 ), a ketoiminate structure (*-N(R 4 )-C(R 5 )=C(R 6 )-C(=O)-R 7 ), a diiminate structure (*-N(R 4 )-C(R 5 )=C(R 6 )-C(=NR 7 )-R 8 ), and an amidinate structure (*-N(R 4 )-C(R 5 )=NR 6 ), and is a ligand selected from the group consisting of the above; R 1 , R 2 and R 3 each independently represent an alkyl group having 1 to 10 carbon atoms, and R 4 , R 5 , R 6 , R 7 and R 8 Each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, m represents an integer between 1 and 10, the three Ls may be the same ligand or different ligands, and * represents M 2 (This indicates the connection position with [the other element].) 　 The set of thin film forming raw materials according to claim 7, wherein the content of impurity organic matter in the first thin film forming raw material is 1,000 ppm or less relative to the compound represented by the general formula (1). 　 The set of thin film forming raw materials according to claim 7, wherein the content of impurity organic matter in the second thin film forming raw material is 1,000 ppm or less relative to the compound represented by the general formula (2). 　 The set of raw materials for forming a thin film according to claim 8 or claim 9, wherein the impurity organic component is naphthalene.

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