Method for manufacturing thin film

Abstract

To provide a method for manufacturing a thin film that has a further reduced resistivity.SOLUTION: A method for manufacturing a thin film includes: a deposition treatment step of depositing a raw material compound on a substrate with an atomic layer deposition method using a raw material compound; and a film deposition treatment step of depositing a thin film by reduction with a reducing gas having a pressure of 4.5 Torr or more after the deposition treatment step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a thin film. [Background technology]

[0002] 2. Description of the Related Art As a method for forming films on various substrates, a method for producing a thin film by atomic layer deposition (hereinafter also referred to as "ALD") is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-184449 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, thin films have been produced by ALD by subjecting a metal thin film formed on a substrate to a reducing gas treatment using a reducing gas, but the resulting thin film may contain impurities to some extent, resulting in a high resistivity.

[0005] An object of the present disclosure is to provide a method for producing a thin film with further reduced resistivity. [Means for solving the problem]

[0006] The present disclosure includes the following aspects. [1] a deposition process for depositing a raw material compound on a substrate by an atomic layer deposition method using the raw material compound, and a film formation process for forming a thin film by reducing the raw material compound with a reducing gas at a pressure of 4.5 Torr or more after the deposition process; A method for producing a thin film, comprising: [2] The method for producing a thin film according to [1], wherein the pressure of the reducing gas is 7.8 Torr or more. [3] The atomic layer deposition method includes a vaporization process for vaporizing a raw material liquid containing the raw material compound before the deposition process. A method for producing a thin film according to [1] or [2], comprising: [4] The reducing gas is H 2 , N.H. 3 The method for producing a thin film according to any one of [1] to [3], wherein the compound is at least one selected from the group consisting of hydrazine, monomethylhydrazine, dimethylhydrazine, formic acid, carboxylic acid compounds, formaldehyde, organic ammonia, silane compounds, diborane compounds, and alcohol compounds. [5] The method for producing a thin film according to any one of [1] to [4], wherein the raw material compound has a vapor pressure of 0.4 Torr or more at 100° C. [6] The raw material compound contains a metal atom, The method for producing a thin film according to any one of [1] to [5], wherein the metal atoms are cobalt, ruthenium, tungsten, palladium, or molybdenum. [7] The raw material compound includes a metal atom and a ligand including a coordination element that is coordinated to the metal atom, The coordination element is at least one selected from C, N, O, and Si; A method for producing a thin film according to any one of [1] to [6]. [8] The raw material compound includes a ligand, The ligand includes at least one of a monodentate ligand and a polydentate ligand. A method for producing a thin film according to any one of [1] to [7]. [9] The monodentate ligand is at least one selected from carbonyl, alkyne, alkyl, amine, aminoalkyl, and hydride; A method for producing a thin film according to [8].

[10] the polydentate ligand is a bidentate ligand, The bidentate ligand is at least one selected from an alkyldiene, a cyclopentadiene, and an acetylacetonate. A method for producing a thin film according to [8].

[11] the polydentate ligand is a tridentate ligand, The tridentate ligand is an amidinate. A method for producing a thin film according to [8].

[12] The raw material compound is [ka] [ka] The method for producing a thin film according to any one of [1] to

[11] , wherein the method is at least one selected from the following:

[13] The relationship between resistivity and thickness of a cobalt thin film is: ρ = ρ 0 +a / t [In the formula, ρ is resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), and a is a constant] Room temperature bulk resistivity ρ 0 The method for producing a thin film according to [6] or

[12] , wherein the resistivity is 15 μΩ·cm or less.

[14] The relationship between resistivity and thickness of a cobalt thin film is: ρ = ρ 0 +a / t [In the formula, ρ is resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), and a is a constant] Room temperature bulk resistivity ρ 0 is less than 15 μΩ·cm, thin film.

[15] The thin film according to

[14] , wherein the impurity content is 2.0 atomic % or less.

[16] A laminate comprising the thin film according to

[14] or

[15] . Effect of the Invention

[0007] According to the manufacturing method of the present disclosure, a thin film with low resistivity can be obtained. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a film forming apparatus according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present disclosure will be described below. Note that the following description does not limit the invention according to the present disclosure unless otherwise specified.

[0010] <Manufacturing method> A method for producing a thin film according to one aspect of the present disclosure includes the steps of: By ALD using raw material compounds, a deposition process for depositing a source compound on a substrate; and a film formation process in which a thin film is formed by reducing the deposited material with a reducing gas at a pressure of 4.5 Torr or more after the deposition process; Includes.

[0011] In the method for producing a thin film of the present disclosure, the pressure of the reducing gas is high, 4.5 Torr or more. The high pressure can reduce the content of impurities contained in the thin film to be formed, and the resistivity of the thin film can be reduced. For example, the reducing gas can remove ligands contained in the thin film. A thin film with reduced resistivity can be advantageously used, for example, in semiconductor applications. The impurities are generated from raw material compounds and the like, and include, for example, carbon, oxygen, nitrogen, and the like.

[0012] The pressure of the reducing gas is 4.5 Torr or more, preferably 7.0 Torr or more, more preferably 7.8 Torr or more, for example, 8.0 Torr or more, specifically 8.3 Torr or more, and more specifically 10 Torr or more. The upper limit of the pressure is not particularly limited, but is, for example, 15 Torr or less, preferably 12 Torr or less, for example, 10 Torr or less.

[0013] ALD preferably includes a vaporization process in which a source liquid containing a source compound is vaporized prior to the deposition process.

[0014] (Film forming equipment) The formation process for forming a thin film using the ALD is usually performed by a film formation apparatus as shown in FIG. 1. In the film formation chamber 1, a deposition process is performed in which a source compound vaporized in a source container 2 is deposited on a substrate prepared in advance, and the source compound is deposited on the substrate. Thereafter, in the film formation chamber 1, a film formation process is performed in which a thin film is formed by reduction using a reducing gas, and a thin film is formed. Note that, although there is only one source container 2 in FIG. 1, there may be two or more source containers, for example, when two or more types of source compounds are used. The film formation apparatus will be specifically described below.

[0015] In the source container 2, the liquid source 25 containing the source compound is heated and vaporized as necessary. The vaporized source compound is carried to the film formation chamber 1 by an inert carrier gas. The source container 2 may be heated to, for example, 30°C or higher, 45°C or higher, 200°C or lower, or 120°C or lower in order to vaporize the liquid source 25. The liquid source 25 may be heated to 45°C to 120°C, or 30°C to 200°C.

[0016] The inert carrier gas is, for example, nitrogen, argon, helium, etc. The flow rate of the inert carrier gas is adjusted by a mass flow controller (hereinafter also referred to as "MFC") 3. The pressure inside the source container 2 is adjusted by a needle valve 4. The flow rate of the inert carrier gas is, for example, 10 sccm to 100 sccm. The pressure inside the source container 2 is measured by a pressure gauge 26, and the pressure value is, for example, 10 Torr to 100 Torr.

[0017] The source material container 2 is connected to a supply line 5 leading to the film formation chamber 1 and a gas exhaust line 6. The supply line 5 and the gas exhaust line 6 have valves 7 and 8, respectively, and the supply and gas exhaust of the source material are switched by opening and closing the valves 7 and 8. The supply line 5 and the gas exhaust line 6 may have a heating mechanism. The heating mechanism may be a heater arranged around the piping, typically a jacket heater.

[0018] The supply line 5 and exhaust line 6 can be purged with an inert purge gas. The inert purge gas is, for example, nitrogen, argon, helium, or the like. The flow rate of the inert purge gas is adjusted by an MFC 9. The flow rate of the inert purge gas is, for example, 10 sccm to 100 sccm. The purge destination is switched to the supply line 5 or the exhaust line 6 by opening and closing valves 10 and 11. A sequence is set so that when the raw material compound flows through the supply line 5, the inert purge gas flows into the exhaust line 6, and when the raw material compound flows through the exhaust line 6, the inert purge gas flows into the supply line 5.

[0019] When the reducing gas is a high-pressure gas such as hydrogen, the flow rate is adjusted by the MFC 12. The flow rate is, for example, 10 sccm to 1000 sccm. When the reducing gas is a liquid at room temperature and normal pressure such as formic acid, the reducing gas is supplied using an inert carrier gas in the same manner as the raw material compound.

[0020] The supply line for the reducing gas branches into a supply line 13 connected to the film formation chamber 1, and an exhaust line 14. The supply line 13 and the exhaust line 14 have valves 15 and 16, respectively, and the supply and exhaust of the reducing gas are switched by opening and closing the valves 15 and 16. The supply line 13 and the exhaust line 14 may have a heating mechanism. The heating mechanism may be a heater disposed around the piping, typically a jacket heater.

[0021] The supply line 13 and exhaust line 14 can be purged with an inert purge gas. The inert purge gas is, for example, nitrogen, argon, helium, or the like. The flow rate of the inert purge gas is adjusted by the MFC 17. The flow rate of the inert purge gas is, for example, 10 sccm to 100 sccm. The purge destination is switched to the supply line 13 or the exhaust line 14 by opening and closing the valves 18 and 19. A sequence is set so that when the reducing gas flows through the supply line 13, the inert purge gas flows into the exhaust line 14, and when the reducing gas flows through the exhaust line 14, the inert purge gas flows into the supply line 13.

[0022] An inert balance gas line for adjusting the flow rate may be connected to the film formation chamber 1. The inert balance gas is, for example, nitrogen, argon, helium, etc. The flow rate of the inert balance gas is adjusted by the MFC 20. The flow rate of the inert balance gas is, for example, 10 sccm to 100 sccm.

[0023] The film formation chamber 1 includes a film formation table 21. Before the introduction of the raw material compound, the second main surface of the substrate on which the film is to be formed is usually brought into contact with the film formation table 21. The second main surface of the substrate is the surface opposite to the first main surface.

[0024] In the film formation chamber 1, a source compound vaporized in a source container 2 is introduced. That is, the vaporized source compound comes into contact with the first main surface of the substrate, and a deposition process is performed in which the vaporized source compound is deposited on the substrate.

[0025] In the film formation chamber 1, after the deposition process, a film formation process is carried out in which the deposit is reduced with a reducing gas to form a thin film.

[0026] The film formation chamber 1 may be equipped with a heating mechanism, and is heated to, for example, 100°C to 300°C.

[0027] The film formation chamber 1 has an exhaust line 22 for exhausting gas. The exhaust line 22 exhausts raw material compounds, carrier gas, reducing gas, etc. remaining in the film formation chamber 1. Examples of the exhaust method include a method of purging the system with an inert gas such as nitrogen or argon, a method of exhausting by reducing the pressure in the system, a combination of these, etc.

[0028] The exhaust line 22 includes a butterfly valve 23 for adjusting the pressure in the film formation chamber 1. The pressure in the film formation chamber 1 is adjusted by the opening degree of the butterfly valve 23. The pressure in the film formation chamber 1 is, for example, 10 Torr to 30 Torr.

[0029] The exhaust line 22 is connected to the exhaust line 6 and the exhaust line 14 downstream of the butterfly valve 23 (i.e., in the opposite direction to the film formation chamber 1). The exhaust line 22 has a pump 24 downstream of the connection point with the exhaust line 6 and the exhaust line 14.

[0030] As described above, the source liquid 25 containing the source compound is present in the source container 2, and the source compound vaporized in the source container 2 is transferred by the carrier gas through the supply line 5 to the film formation chamber 1. In the film formation chamber 1, the source compound vaporized in the source container 2 is deposited on a substrate prepared in advance. Thereafter, in the film formation chamber 1, a thin film is formed by reduction with a reducing gas. This process is repeated a specified number of times to obtain a thin film with a desired thickness.

[0031] (raw material liquid 25) The above-mentioned raw material liquid 25 is a liquid containing a raw material compound. The raw material liquid 25 may contain impurities.

[0032] The raw material liquid 25 preferably consists essentially of the raw material compounds. Incidentally, "consists essentially of the raw material compounds" means that the raw material liquid 25 may consist only of the raw material compounds, or may contain other compounds, such as impurities, at 2.0 atomic % or less. The content of the impurities is a value measured using an organic trace elemental analyzer, an inductively coupled plasma mass spectrometry (ICP-MS), or the like. Specifically, the weight of the metal elements contained in the raw material compounds is calculated by elemental analysis, and the weight of elements other than the metal elements (main raw material components) contained in the raw material compounds is calculated. The weight of the remaining weight is calculated by subtracting the metal elements and main raw material components calculated above from the weight of the raw material compounds, and the ratio of the weight to the raw material compounds is taken as the ratio of the impurities.

[0033] Examples of the impurities include carbon monoxide and organic compounds which are ligands of the raw material compounds.

[0034] The above raw material compounds may be used alone or in combination of two or more.

[0035] The raw material compound preferably contains metal atoms. Examples of metal atoms include transition metals, specifically, cobalt, ruthenium, tungsten, palladium, and molybdenum. By using such metal atoms, a film of high-purity metal atoms can be formed. Furthermore, by using such metal atoms, the resistivity of the thin film can be reduced. When the metal atoms are used to form a film on wiring, breakage of the wiring can be prevented.

[0036] More preferably, the metal atom is cobalt, tungsten, palladium, or molybdenum. The use of such metal atoms can reduce the resistivity of the thin film. In addition, when the thin film is formed on a wiring, the wiring can be prevented from being broken.

[0037] More preferably, the metal atom is cobalt or tungsten. Further preferably, the metal atom is cobalt. When the metal atom is formed on a copper wiring, the copper wiring can be prevented from being broken.

[0038] The metal atoms may be, for example, cobalt or molybdenum. When the metal atoms are deposited on a copper wiring, breakage of the copper wiring can be prevented.

[0039] The vapor pressure of the raw material compound at 100°C is preferably 0.4 Torr or more, more preferably 1.0 Torr or more. The raw material compound has, for example, a ligand, and impurities may be generated by decomposition of the ligand. The amount of the impurities can be reduced by increasing the vapor pressure of the raw material compound.

[0040] The raw material compound is preferably an organometallic compound having a metal atom and a ligand coordinated to the metal atom.

[0041] In the above ligand, the coordinating element coordinated to the metal atom is preferably at least one selected from C, N, O, and Si.

[0042] The ligand specifically includes at least one of a monodentate ligand and a polydentate ligand.

[0043] Examples of the monodentate ligand include halogen, hydride, alkyne, alkyl, alkenyl, cycloalkyl, aryl, alkynyl, alkylimino, amine, aminoalkyl, dialkylaminoalkyl, monoalkylamino, dialkylamino, alkoxy, alkoxyalkyl, hydrazide, hydride, phosphide, nitrile, silyl, carbonyl, etc. Preferably, the monodentate ligand is at least one selected from carbonyl, alkyne, alkyl, amine, aminoalkyl, and hydride, more preferably at least one selected from carbonyl and alkyne.

[0044] Examples of the polydentate ligand include a bidentate ligand and a tridentate ligand.

[0045] The bidentate ligand may be diamine, di(silyl-alkyl)amino, di(alkyl-silyl)amino, disilylamino, dialkylaminoalkoxy, alkyldiene, alkoxyalkyldialkylamino, siloxy, diketonate, cyclopentadiene, cyclopentadienyl, pyrazolate, ketoiminate, diketiminate, acetylacetonate, etc. The bidentate ligand is preferably at least one selected from alkyldiene, cyclopentadiene, and acetylacetonate. In one embodiment, the bidentate ligand is an alkyldiene. In one embodiment, the bidentate ligand is cyclopentadiene. In one embodiment, the bidentate ligand is acetylacetonate.

[0046] Examples of the tridentate or higher ligand include amidinate, guanidinate, phosphoguanidinate, phosphoamidinate, etc. A preferred example of the tridentate ligand is amidinate.

[0047] The ligand preferably comprises at least one of a monodentate ligand, a bidentate ligand, and a tridentate ligand.

[0048] The organometallic compound is preferably at least one selected from the following compounds. These organometallic compounds have high vapor pressure, so ALD can be performed at low temperatures. By performing ALD at low temperatures, decomposition of the raw material compounds can be suppressed, and the content of impurities derived from the raw material compounds can be reduced. [ka] [ka]

[0049] (Carrier gas) The carrier gas may be an inert gas such as nitrogen or a rare gas, and preferably nitrogen or argon gas is used.

[0050] (reducing gas) The reducing gas is not particularly limited as long as it can react with the raw material compound. For example, H 2 , N.H. 3 The reducing gas may be at least one selected from the group consisting of hydrazine, monomethylhydrazine, dimethylhydrazine, formic acid, carboxylic acid compounds, formalin, organic ammonia, silane compounds, diborane compounds, and alcohol compounds. 2 The reducing gas is at least one selected from the group consisting of dimethylhydrazine and dimethylhydrazine. By using such a reducing gas, decomposition of the reducing gas can be suppressed, generation of impurities can be suppressed, and incorporation of impurities into the thin film to be formed can be prevented. As a result, the resistivity of the thin film can be reduced. The content of impurities contained in the thin film can be measured using an X-ray photoelectron spectrometer, an organic trace element analyzer, an inductively coupled plasma mass spectrometry (ICP-MS), or the like, and preferably measured using an X-ray photoelectron spectrometer.

[0051] In one embodiment, the reducing gas is NH 3 By using such a reducing gas, decomposition of the reducing gas can be suppressed, generation of impurities can be suppressed, and incorporation of impurities into the thin film to be formed can be prevented. As a result, the resistivity of the thin film can be reduced. The content of impurities can be measured using the method described above.

[0052] The reducing gas may be one kind of gas or a combination of multiple gases. When the reducing gas is a combination of multiple gases, the pressure of the reducing gas means the total pressure of all the gases.

[0053] (base material) The reducing gas reacts with the source compound deposited on the substrate to reduce the source compound, thereby forming a metal film (thin film) on the substrate.

[0054] The material constituting the substrate is not particularly limited, but examples thereof include metals such as copper, silver, gold, platinum, nickel, palladium, and aluminum; silicon; ceramics such as indium arsenide, indium gallium arsenide, silicon oxide, silicon nitride, silicon carbide, titanium nitride, tantalum oxide, tantalum nitride, titanium oxide, titanium nitride, ruthenium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, and gallium nitride; and glass.

[0055] In one embodiment, the material constituting the substrate is copper, silver, gold, platinum, nickel, palladium, or aluminum, and is preferably copper.

[0056] The shape of the substrate is not particularly limited, and may be plate-like, rod-like, spherical, layer-like, fibrous, scale-like, or the like.

[0057] In one embodiment, the base material may be in the form of a layer provided on a substrate, for example, wiring on a wiring board.

[0058] The temperature of the substrate when the raw material compound is deposited on the substrate can be, for example, 20 to 600°C, preferably 50 to 500°C, more preferably 100 to 450°C, and further preferably 100 to 400°C.

[0059] The temperature of the substrate when the reducing gas is introduced into the film formation chamber 1 may be, for example, 20 to 600° C., preferably 50 to 500° C., more preferably 100 to 450° C., and even more preferably 100 to 400° C. By conducting the process within the above temperature range, decomposition of the reducing gas can be suppressed, generation of impurities can be suppressed, and incorporation of impurities into the thin film to be formed can be prevented. As a result, the resistivity of the thin film can be reduced.

[0060] Depending on the desired film thickness, the deposition process and the film-forming process may be repeated, or the deposition process may be repeated, or the film-forming process may be repeated.

[0061] For a cobalt thin film, the relationship between resistivity ρ and thickness t is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Room temperature bulk resistivity ρ 0 is preferably 20 μΩ·cm or less, and more preferably 15 μΩ·cm or less. 0 is more preferably 12 μΩ·cm or less, for example 10 μΩ·cm or less. 0 The lower limit of is not particularly limited, but is, for example, 9 μΩ·cm, preferably 7 μΩ·cm, and more preferably 6 μΩ·cm. As described above, by suppressing the inclusion of impurities, a thin film with reduced resistivity can be formed. Note that the above formula is the relationship that generally holds between resistivity ρ and film thickness t in a cobalt thin film.

[0062] For ruthenium thin films, the relationship between resistivity ρ and thickness t is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Bulk resistivity ρ at 0 is preferably 17 μΩ·cm or less. 0 is more preferably 14 μΩ·cm or less, and further preferably 12 μΩ·cm or less. 0The lower limit of is not particularly limited, but is, for example, 10 μΩ·cm, preferably 8 μΩ·cm, and more preferably 7.5 μΩ·cm. As described above, by suppressing the inclusion of impurities, a thin film with reduced resistivity can be formed. Note that the above formula is a relationship that generally holds between resistivity and film thickness in a ruthenium thin film.

[0063] For tungsten thin films, the relationship between resistivity ρ and film thickness t is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Bulk resistivity ρ at 0 is preferably 13 μΩ·cm or less. 0 is more preferably 10 μΩ·cm or less, and further preferably 9 μΩ·cm or less. 0 The lower limit of is not particularly limited, but is, for example, 8 μΩ·cm, preferably 6 μΩ·cm, and more preferably 5 μΩ·cm. As described above, by suppressing the inclusion of impurities, a thin film with reduced resistivity can be formed. Note that the above formula is the relationship that generally holds between resistivity and film thickness in tungsten thin films.

[0064] The relationship between resistivity ρ and film thickness t for a thin palladium film is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Bulk resistivity ρ at 0 is preferably 32 μΩ·cm or less. 0is more preferably 26 μΩ·cm or less, and further preferably 21 μΩ·cm or less. 0 The lower limit of is not particularly limited, but is, for example, 19 μΩ·cm, preferably 15 μΩ·cm, and more preferably 13 μΩ·cm. As described above, by suppressing the inclusion of impurities, a thin film with reduced resistivity can be formed. Note that the above formula is the relationship that generally holds between resistivity and film thickness for a palladium thin film.

[0065] For a molybdenum thin film, the relationship between resistivity ρ and film thickness t is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Bulk resistivity ρ at 0 is preferably 12 μΩ·cm or less. 0 is more preferably 10 μΩ·cm or less, and further preferably 8 μΩ·cm or less. 0 The lower limit of is not particularly limited, but is, for example, 7 μΩ·cm, preferably 6 μΩ·cm, and more preferably 5 μΩ·cm. As described above, by suppressing the inclusion of impurities, a thin film with reduced resistivity can be formed. Note that the above formula is the relationship that generally holds between resistivity and film thickness for a molybdenum thin film.

[0066] <Thin film> In the present disclosure, the thin film is produced by the above-mentioned production method. The thin film contains, for example, cobalt, ruthenium, tungsten, palladium, or molybdenum.

[0067] In the cobalt thin film according to one embodiment of the present disclosure, the relationship between resistivity ρ and film thickness t is: ρ = ρ 0 +a / t [In formula: ρ is the resistivity, ρ 0 is the bulk resistivity at room temperature, t is the film thickness (cm), a is a constant. Bulk resistivity ρ at 0 The resistivity of the thin film is preferably 20 μΩ·cm or less, and more preferably 15 μΩ·cm or less. The thin film is formed by the manufacturing method of the present disclosure, and has the resistivity as described above because the amount of impurities contained in the thin film is very small.

[0068] The thickness of the thin film is preferably 10 nm to 30 nm, more preferably 10 nm to 20 nm, and even more preferably 10 nm to 15 nm.

[0069] The thin film is formed from the raw material compounds as described above.

[0070] In the thin film, the content of impurities is preferably 2.0 atomic % or less. The lower limit of the content is not particularly limited, but is, for example, 0.01 atomic % or more. The content of impurities was measured in the same manner as above. The content of impurities in the thin film is a value measured using an X-ray photoelectron spectrometer, an organic trace element analyzer, an inductively coupled plasma mass spectrometry (ICP-MS), or the like, and is preferably a value measured using an X-ray photoelectron spectrometer.

[0071] <Laminate> A laminate according to one aspect of the present disclosure includes a thin film formed by the above-described manufacturing method, for example, the above-described cobalt thin film.

[0072] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to such embodiments and various modifications are possible. EXAMPLES

[0073] The present disclosure will be described below with reference to examples, but the present disclosure is not limited to the following examples.

[0074] [Film formation process 1] The film formation process was carried out using the following method. 1. The film formation chamber was opened to the atmosphere, a substrate was placed on the film formation stage, and then a vacuum was drawn. 2. Next, the temperature inside the film formation chamber was set to 100° C., the bubbler temperature was set to 45° C., and the following conditions were set. N 2 Flow rate: 10sccm ·CCTBA Carrier N 2 Flow rate: 10sccm H 2 Flow rate: 100sccm Total pressure: 3 to 10 Torr, Bubbler pressure: 3 to 10 Torr 3. CCTBA supply (5 seconds), purge (3 seconds), H 2 One cycle consisted of supply (10 seconds) and purging (3 seconds), and this cycle was repeated. CCTBA is the following compound. [ka]

[0075] [Metal element concentration and impurity concentration measurement] The concentrations of metal elements and impurities contained in the thin film were calculated using an X-ray photoelectron spectrometer (ULVAC-PHI, PHI-1600C).

[0076] Example 1 The film was formed according to the above-mentioned film formation process. In Example 1, the reducing gas H 2 The pressure was 8.3 Torr. On the substrate, Co was 98.8 atomic % and carbon was 1.2 atomic %.

[0077] Example 2 The film was formed according to the above-mentioned film formation process. The temperature of the substrate was 150° C., and the total pressure in the furnace was the value shown in Table 1. In Example 2, the reducing gas H 2 The pressure was 6.0 Torr. On the substrate, Co was 98.0 atomic % and carbon was 2.0 atomic %.

[0078] Comparative Example 1 The film was formed according to the above-mentioned film formation process. The total pressure in the furnace was set to the value shown in Table 1. In Comparative Example 1, reducing gas H 2 The pressure was 4.2 Torr.

[0079] The results are shown in Table 1.

[0080] [Table 1]

[0081] The pressure of the reducing gas was 4.5 Torr or more in Examples 1 and 2, and less than 4.5 Torr in Comparative Example 1. The resistivity was lower in Examples 1 and 2 than in Comparative Example 1. In addition, the ratio of impurities (carbon) contained on the obtained substrate was reduced by increasing the pressure.

[0082] [Film formation process 2] Instead of CCTBA in the film formation process 1, the following compound was used, and NH was used as the reducing gas. 3 The film formation process was carried out in the same manner as in the film formation process 1, except that the above was used. [ka] The metal element concentrations and impurity concentrations were measured in the same manner as above.

[0083] Example 3 The film was formed according to the above-mentioned film formation process. The total pressure in the furnace was set to the value shown in Table 2.

[0084] Comparative Example 2 The film was formed according to the above-mentioned film formation process. The total pressure in the furnace was set to the value shown in Table 2.

[0085] The results are shown in Table 2.

[0086] [Table 2]

[0087] The pressure of the reducing gas was 4.5 Torr or more in Example 3, and less than 4.5 Torr in Comparative Example 2. [Industrial Applicability]

[0088] According to the film formation method of the present disclosure, a thin film having a low resistivity can be efficiently formed, and therefore the film formation method of the present disclosure can be used for various applications, such as the manufacture of circuit boards. [Explanation of symbols]

[0089] 1... Film forming chamber 2...Raw material container 3,9,12,17,20…Mass flow controller 4...Needle valve 5,13…Supply line 6,14…Exhaust line 7,8,10,11,15,16,18,19… Valves 21... Film formation table 22…Discharge line 23…Butterfly valve 24…Pump 25…raw material liquid 26,27…Pressure gauge

Claims

1. a deposition process for depositing a raw material compound on a substrate by an atomic layer deposition method using the raw material compound, and a film formation process for forming a thin film by reducing the raw material compound with a reducing gas at a pressure of 4.5 Torr or more after the deposition process; A method for producing a thin film, comprising:

2. The method for producing a thin film according to claim 1 , wherein the pressure of the reducing gas is 7.8 Torr or more.

3. The atomic layer deposition method includes a vaporization process for vaporizing a raw material liquid containing the raw material compound before the deposition process. The method for producing a thin film according to claim 1 or 2, comprising:

4. The reducing gas is H ２ , N.H. ３ 3. The method for producing a thin film according to claim 1 or 2, wherein the compound is at least one selected from the group consisting of hydrazine, monomethylhydrazine, dimethylhydrazine, formic acid, carboxylic acid compounds, formalin, organic ammonia, silane compounds, diborane compounds, and alcohol compounds.

5. 3. The method for producing a thin film according to claim 1, wherein the raw material compound has a vapor pressure of 0.4 Torr or more at 100°C.

6. The raw material compound contains a metal atom, 3. The method for producing a thin film according to claim 1, wherein the metal atoms are cobalt, ruthenium, tungsten, palladium, or molybdenum.

7. The raw material compound includes a metal atom and a ligand including a coordination element that is coordinated to the metal atom, The coordination element is at least one selected from C, N, O, and Si; The method for producing a thin film according to claim 1 or 2.

8. The raw material compound includes a ligand, The ligand includes at least one of a monodentate ligand and a polydentate ligand. The method for producing a thin film according to claim 1 or 2.

9. The monodentate ligand is at least one selected from carbonyl, alkyne, alkyl, amine, aminoalkyl, and hydride; The method for producing a thin film according to claim 8 .

10. the polydentate ligand is a bidentate ligand, The bidentate ligand is at least one selected from an alkyldiene, a cyclopentadiene, and an acetylacetonate. The method for producing a thin film according to claim 8 .

11. the polydentate ligand is a tridentate ligand, The tridentate ligand is an amidinate. The method for producing a thin film according to claim 8 .

12. The raw material compound is 【Chemistry 1】 【Chemistry 2】 The method for producing a thin film according to claim 1 or 2, wherein the method is at least one selected from the following:

13. The relationship between resistivity and film thickness for cobalt thin films is: p=p ０ +a / t [In the formula, ρ is resistivity, ρ ０ is the bulk resistivity at room temperature, t is the film thickness (cm), and a is a constant. Room temperature bulk resistivity ρ ０ The method for producing a thin film according to claim 6, wherein the resistivity is 15 μΩ·cm or less.

14. The relationship between resistivity and film thickness for cobalt thin films is: p=p ０ +a / t [In the formula, ρ is resistivity, ρ ０ is the bulk resistivity at room temperature, t is the film thickness (cm), and a is a constant. Room temperature bulk resistivity ρ ０ A thin film having a resistivity of 15 μΩ·cm or less.

15. The thin film according to claim 14, wherein the impurity content is 2.0 atomic % or less.

16. A laminate comprising the thin film according to claim 14 or 15.

Images