Region-selective thin film formation method, thin film formation inhibitor, starting material for thin film formation, and reactive gas

Abstract

Provided is a region-selective thin film formation method including: a step (preceding step) in which (step 1) and (step 2) described below are performed at least once in this order; and a step (succeeding step) in which (step 3), (step 4), (step 5), and (step 6) described below are performed at least once in this order after the preceding step.　(Step 1) A step for supplying a thin film formation inhibitor to the inside of a chamber in which a substrate is disposed and causing the thin film formation inhibitor to be adsorbed in a non-growth region of the substrate; (Step 2) a step for purging the inside of the chamber; (Step 3) a step for supplying a starting material for thin film formation to the inside of the chamber and causing the starting material for thin film formation to be adsorbed in a growth region of the substrate; (Step 4) a step for purging the inside of the chamber; (Step 5) a step for supplying a reactive gas to the inside of the chamber and causing the adsorbed starting material for thin film formation to react with the reactive gas so as to form a thin film; and (Step 6) a step for purging the inside of the chamber.

Description

Region-selective thin film formation method, thin film formation inhibitor, thin film formation raw material and reactive gas

[0001] This disclosure relates to a region-selective thin film formation method using a thin film formation inhibitor, a thin film formation raw material, and a reactive gas.

[0002] In recent years, as the integration density of semiconductor devices such as DRAM, NAND, and Logic has increased, complex three-dimensional structure formation technologies have become increasingly necessary. In semiconductor devices, a process is generally required to finely pattern thin films of conductive materials such as electrodes and wiring, and electrical insulating materials such as dielectric films and insulating films.

[0003] When forming a thin film only at a desired location on the substrate surface of a semiconductor device, an existing method involves forming a thin film over the entire substrate and then etching away the unwanted portion of the film using a patterning process, leaving the film intact in the desired areas. However, with the recent acceleration of semiconductor device miniaturization, conventional patterning methods are facing increasing defects due to patterning misalignment, as well as increased process costs due to plasma-induced defects in the etching process. As a solution to these problems, the Area Selective Deposition (ASD) process is attracting attention. Examples of methods for forming thin films using the ASD process include the processes described in Patent Document 1 and Non-Patent Document 1, among others.

[0004] U.S. Patent Application Publication No. 2015 / 0299848

[0005] Appl. Phys. Lett. 121,082102 (2022)

[0006] However, when using the processes described in Patent Document 1 and Non-Patent Document 1, it is not possible to apply the process to the growth region and non-growth region of the substrate simultaneously, which leads to a large number of steps and high costs, as well as difficulties in obtaining thin films with excellent region selectivity.

[0007] Therefore, the present disclosure aims to provide a region-selective thin film formation method that can be applied simultaneously to growth regions and non-growth regions of a substrate and can form a thin film with excellent region selectivity.

[0008] As a result of diligent research, the present inventors have found that the above problems can be solved by using a region-selective thin film formation method having a specific process, and have completed this disclosure.

[0009] In other words, the present disclosure is a region-selective thin film formation method comprising a step (pre-step) in which the following steps (1) and (2) are performed at least once in this order, and a step (post-step) in which the following steps (3), (4), (5), and (6) are performed at least once in this order after the pre-step. (1) A step of supplying a thin film formation inhibitor into the interior of a chamber in which a substrate is placed, and adsorbing the thin film formation inhibitor onto the non-growth region of the substrate; (2) A step of purging the interior of the chamber; (3) A step of supplying a thin film forming raw material into the interior of the chamber, and adsorbing the thin film forming raw material onto the growth region of the substrate; (4) A step of purging the interior of the chamber; (5) A step of supplying a reactive gas into the interior of the chamber, and reacting the adsorbed thin film forming raw material with the reactive gas to form a thin film; (6) A step of purging the interior of the chamber.

[0010] Another embodiment of the present disclosure is a thin film formation inhibitor used in the region-selective thin film formation method described above.

[0011] Another embodiment of this disclosure is a thin film formation material used in the region-selective thin film formation method described above.

[0012] Another embodiment of the present disclosure is a reactive gas used in the above-mentioned region-selective thin film formation method.

[0013] This disclosure provides a method for forming thin films with excellent regional selectivity.

[0014] Figure 1 is a schematic diagram showing an example of an atomic layer deposition (ALD) apparatus used in a region-selective thin film formation method according to one embodiment of the present disclosure. Figure 2 is a schematic diagram showing another example of an ALD apparatus used in a region-selective thin film formation method according to one embodiment of the present disclosure. Figure 3 is a schematic diagram showing another example of an ALD apparatus used in a region-selective thin film formation method according to one embodiment of the present disclosure. Figure 4 is a schematic diagram showing another example of an ALD apparatus used in a region-selective thin film formation method according to one embodiment of the present disclosure.

[0015] [Region-Selective Thin Film Formation Method] The region-selective thin film formation method of the present disclosure includes a step (pre-step) in which the following steps (1) and (2) are performed at least once in this order, and a step (post-step) in which the following steps (3), (4), (5), and (6) are performed at least once in this order after the pre-step. (1) A step of supplying a thin film formation inhibitor into the interior of a chamber in which a substrate is placed, and adsorbing the thin film formation inhibitor onto the non-growth region of the substrate; (2) A step of purging the interior of the chamber; (3) A step of supplying a thin film forming raw material into the interior of the chamber, and adsorbing the thin film forming raw material onto the growth region of the substrate; (4) A step of purging the interior of the chamber; (5) A step of supplying a reactive gas into the interior of the chamber, and reacting the adsorbed thin film forming raw material with the reactive gas to form a thin film; (6) A step of purging the interior of the chamber.

[0016] The following describes each step in the region-selective thin film formation method of this disclosure with reference to Figures 1 to 4.

[0017] [Step 1] In this step, a gas obtained by vaporizing a thin film formation inhibitor (M1) is supplied into a chamber (100), and the thin film formation inhibitor (M1) is adsorbed onto a non-growth region of a substrate (S). The substrate (S) only needs to have a non-growth region and a growth region on the surface; for example, it may be 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, tungsten selenide, and metallic ruthenium.

[0018] [Thin Film Formation Inhibitor] The thin film formation inhibitor (M1) preferably contains a compound represented by the following general formula (1).

[0019]

[0020] (In the formula, R 1 to R 4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thioalkyl group having 1 to 10 carbon atoms.)

[0021] R 1 , R 2 , R 3 and R 4 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, and a bromine atom.

[0022] R 1 , R 2 , R 3 and R 4Examples of alkyl groups having 1 to 10 carbon atoms represented by 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, n-hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, heptyl group, 4,4-dimethylpentyl group, octyl group, 2,2,4-trimethylpentyl group, nonyl group, decyl group, and the like.

[0023] R 1 , R 2 , R 3 and R 4 Examples of amino groups having 1 to 10 carbon atoms, represented by , include dimethylamino group, ethylmethylamino group, and diethylamino group.

[0024] R 1 , R 2 , R 3 and R 4 Examples of alkoxy groups having 1 to 10 carbon atoms represented by include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, and tert-butoxy groups.

[0025] R 1 , R 2 , R 3 and R 4 Examples of thioalkyl groups having 1 to 10 carbon atoms represented by include methylthio group, ethylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, tert-butylthio group, and the like.

[0026] From the perspective of easily adsorbing the thin-film formation inhibitor (M1) in the non-growth region and easily forming a thin film in the growth region (hereinafter sometimes abbreviated as "excellent region selectivity"), R 1 ~R 4 Preferably, three of them are alkyl groups having 1 to 10 carbon atoms, and one is an amino group having 1 to 10 carbon atoms. 1 ~R 4It is more preferable that three of these are alkyl groups having 1 to 4 carbon atoms, and one is an amino group having 1 to 6 carbon atoms. 1 ~R 4 It is more preferable that three of these are methyl or ethyl groups, and one is an amino group having 1 to 3 carbon atoms, R 1 ~R 4 It is most preferable that three of these groups are methyl groups and one is a dimethylamino group.

[0027] From the viewpoint of excellent region selectivity, the non-growth region of the substrate (S) is preferably a silicon oxide film, a silicon nitride film, or a metallic silicon film. Examples of substrate (S) shapes include plate-like, spherical, fibrous, flake-like, plate-like, fibrous, cylindrical, prismatic, tubular, helical, spherical, ring-like, and three-dimensional structures such as trench structures.

[0028] One method for vaporizing the thin film formation inhibitor (M1) is to heat and / or reduce the pressure of the thin film formation inhibitor (M1).

[0029] Regarding the temperature range for heating, from the viewpoint of easily suppressing the thermal decomposition of the thin film formation inhibitor (M1), it is preferable to have a temperature of 300°C or less, more preferably 20°C to 250°C, and even more preferably 20°C to 100°C.

[0030] When reducing pressure, the vacuum conditions are preferably 1 Pa or more and 10,000 Pa or less, more preferably 10 Pa or more and 5,000 Pa or less, and even more preferably 100 Pa or more and 1,200 Pa or less.

[0031] Methods for introducing the thin film formation inhibitor (M1) into the chamber (100) include gas transport methods and liquid transport methods.

[0032] As a gas transport method, for example, as shown in Figures 1 and 3, the thin film formation inhibitor (M1) is vaporized by heating and / or reducing the pressure in a raw material container (101), and introduced into the chamber (100) together with a carrier gas such as argon, nitrogen, or helium as needed.

[0033] As a liquid transport method, for example, as shown in Figures 2 and 4, the thin film formation inhibitor (M1) is transported in liquid or solution form to the vaporization chamber (102), where it is vaporized by heating and / or reducing the pressure, and introduced into the chamber (100) along with a carrier gas such as argon, nitrogen, or helium as needed. The flow rate of each gas is appropriately adjusted by a mass flow controller (104).

[0034] [Step 2] In this step, the inside of the chamber (100) is purged and any unadsorbed thin-film formation inhibitor is exhausted from inside the chamber (100).

[0035] In this process, it is ideal for any unadsorbed thin-film formation inhibitor to be completely evacuated from the chamber (100), but complete evacuation is not necessarily required.

[0036] Examples of exhaust methods include purging the chamber (100) with an inert gas (204) such as helium, nitrogen, or argon; exhausting the chamber (100) by reducing the pressure while controlling the degree of pressure reduction using a vacuum pump (107) and an automatic pressure controller (108); and methods combining these. From the viewpoint of excellent range selectivity, the degree of pressure reduction when reducing the pressure inside the chamber (100) is preferably 0.01 Pa or more and 300 Pa or less, more preferably 0.05 Pa or more and 200 Pa or less, and even more preferably 0.1 Pa or more and 150 Pa or less.

[0037] [Step 3] In this step, the gas obtained by vaporizing the thin film forming raw material (M2) is supplied into the chamber (100), and the thin film forming raw material (M2) is adsorbed onto the growth region of the substrate (S) to form a thin film precursor.

[0038] [Materials for forming thin films] The materials for forming thin films (M2) preferably contain a compound represented by the following general formula (2).

[0039]

[0040] (In the formula, X represents a halogen atom, L represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an imino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, a cyclopentadienyl group having 5 to 17 carbon atoms, an amidinate group having 1 to 10 carbon atoms, or an aryl group having 6 to 11 carbon atoms, and M represents a metal atom of group 3 to 14. The sum of n and m is the same as the valence of the metal atom represented by M, where n is 0 or greater and m is 1 or greater.)

[0041] Examples of halogen atoms represented by X and L include fluorine atoms, chlorine atoms, and bromine atoms.

[0042] Examples of alkyl groups with 1 to 10 carbon atoms represented by L include R 1 , R 2 , R 3 and R 4 Examples of groups similar to alkyl groups having 1 to 10 carbon atoms, as represented by [formula].

[0043] Examples of amino groups with 1 to 10 carbon atoms represented by L include R 1 , R 2 , R 3 and R 4 Examples of groups similar to amino groups with 1 to 10 carbon atoms, represented by [the formula shown], include [the formula shown].

[0044] Examples of imino groups represented by L that have 1 to 10 carbon atoms include sec-butylamino group, tert-butylamino group, tert-pentylamino group, and tert-heptylamino group.

[0045] Examples of alkoxy groups with 1 to 10 carbon atoms represented by L include R 1 , R 2 , R 3 and R 4 Examples of similar groups include alkoxy groups with 1 to 10 carbon atoms represented by [formula].

[0046] Examples of thioalkyl groups with 1 to 10 carbon atoms represented by L include R 1 , R 2 , R 3 and R 4Examples of groups similar to thioalkyl groups having 1 to 10 carbon atoms, as represented by [formula], include [formula].

[0047] Examples of cyclopentadienyl groups having 5 to 17 carbon atoms represented by L include cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, pentamethylcyclopentadienyl group, ethylcyclopentadienyl group, n-propylcyclopentadienyl group, isopropylcyclopentadienyl group, and the like.

[0048] Examples of amidinate groups with 1 to 10 carbon atoms represented by L include isopropyl sec-butylamidinate group and diisopropylamidinate group.

[0049] Examples of aryl groups with 6 to 11 carbon atoms represented by L include phenyl group, methylphenyl group, dimethylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, sec-butylphenyl group, tert-butylphenyl group, and the like.

[0050] From the viewpoint of excellent regional selectivity, it is preferable that X is a chlorine atom.

[0051] From the viewpoint of excellent regional selectivity, L is preferably a halogen atom or an amino group having 1 to 10 carbon atoms, more preferably a chlorine atom or an amino group having 1 to 6 carbon atoms, even more preferably a chlorine atom or an ethylmethylamino group, and most preferably a chlorine atom.

[0052] From the viewpoint of excellent region selectivity, M is preferably a metal atom of Group 4, and more preferably titanium.

[0053] From the viewpoint of excellent regional selectivity, when M is a metal atom of group 4, it is preferable that n is 1 and m is 3.

[0054] From the viewpoint of superior region selectivity, the growth region of the substrate (S) is preferably a metal oxide film, a metal nitride film, or a metal film, and more preferably a metal nitride film. From the viewpoint of superior region selectivity, the metal oxide film is preferably a titanium oxide film, a vanadium oxide film, a niobium oxide film, or a tantalum oxide film, the metal nitride film is preferably a titanium nitride film, a vanadium nitride film, a niobium nitride film, or a tantalum nitride film, and more preferably a titanium nitride film or a tantalum nitride film, and the metal film is preferably a copper metal film, a cobalt metal film, a molybdenum metal film, a tungsten metal film, or a ruthenium metal film. The shape of the substrate (S) can be a plate-like, spherical, fibrous, flaky, flat, or disc-like shape, a fibrous, cylindrical, prismatic, tubular, spiral, spherical, ring-like shape, or a three-dimensional structure such as a trench structure.

[0055] One method for vaporizing the thin film formation raw material (M2) is, for example, a method similar to the method for vaporizing the thin film formation inhibitor (M1).

[0056] One method for introducing the thin film formation raw material (M2) into the chamber (100) is, for example, a method similar to the method for introducing the thin film formation inhibitor (M1) into the chamber (100).

[0057] [Step 4] In this step, the inside of the chamber (100) is purged and any unadsorbed thin film forming raw materials are exhausted from inside the chamber (100).

[0058] In this process, it is ideal for the unadsorbed thin-film forming material to be completely evacuated from the chamber (100), but complete evacuation is not necessarily required.

[0059] As for the exhaust method, for example, a method similar to the method used to exhaust unadsorbed thin-film formation inhibitors can be used.

[0060] [Step 5] In this step, a reactive gas (202) is supplied into the chamber (100) and reacted with the thin film precursor to form a thin film.

[0061] [Reactive gas] Examples of reactive gas (202) include alcohol compounds, ozone, water, etc., and it is preferable that the reactive gas contains an alcohol compound or water.

[0062] From the viewpoint of excellent regional selectivity, the alcohol compound used for the reactive gas (202) is preferably an alcohol compound having 1 to 10 carbon atoms, more preferably an alcohol compound having 1 to 6 carbon atoms, even more preferably an alcohol compound having 4 to 6 carbon atoms, and is particularly preferably selected from the group consisting of tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, 3-methyl-3-pentanol, and mixtures thereof.

[0063] A method for vaporizing the alcohol compound or water used in the reactive gas (202) is, for example, a method similar to the method for vaporizing the thin film formation inhibitor (M1).

[0064] One method for introducing the reactive gas (202) into the chamber (100) is, for example, a method similar to the method for introducing the thin film formation inhibitor (M1) into the chamber (100).

[0065] [Step 6] In this step, the inside of the chamber (100) is purged and unreacted reactive gas is exhausted from inside the chamber (100).

[0066] In this process, it is ideal for unreacted reactive gases to be completely evacuated from the chamber (100), but complete evacuation is not always necessary.

[0067] As for the exhaust method, for example, a method similar to the method used to exhaust unadsorbed thin-film formation inhibitors can be used.

[0068] The region-selective thin film formation method of this disclosure includes a step (pre-step) in which steps (1) and (2) are performed in this order at least once, and a step (post-step) in which steps (3), (4), (5), and (6) are performed in this order at least once after the pre-step. However, from the viewpoint of excellent region selectivity, it is preferable that the pre-step is a step in which steps (1) and (2) are performed in this order at least twice. Furthermore, there is no particular upper limit on the number of times steps (1) and (2) are performed in this order in the pre-step, but from the viewpoint of avoiding an unnecessarily large number of steps or high costs, it is preferable that it be four times or less, and more preferably three times or less.

[0069] When steps (1) and (2) are performed in this order at least twice as a pre-processing step, the thin film formation inhibitor used in the first pre-processing step and the thin film formation inhibitor used in the second and subsequent pre-processing steps may be the same or different. From the viewpoint of superior regional selectivity, it is preferable that the thin film formation inhibitor used in the first pre-processing step and the thin film formation inhibitor used in the second and subsequent pre-processing steps are different. In particular, from the viewpoint of superior regional selectivity, it is more preferable to use diisopropylaminosilane as the thin film formation inhibitor in the first pre-processing step and N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor in the second and subsequent pre-processing steps.

[0070] <Other Processes> The region-selective thin film formation method of this disclosure may include other processes such as an annealing process and a reflow process.

[0071] [Annealing and Reflow Processes] The region-selective thin film formation method of the present disclosure may further include an annealing process after thin film formation. In the annealing process, the annealing may be performed under an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere. The region-selective thin film formation method of the present disclosure may further include a reflow process if step filling is required after thin film formation.

[0072] The thin films formed by the region-selective thin film formation method of this disclosure exhibit excellent electrical properties and can be used in various semiconductor devices.

[0073] Examples of the above-mentioned semiconductor devices include DRAM, NAND, Logic, etc. Furthermore, the above-mentioned semiconductor device may include other layers (for example, an insulating layer, a conductive layer, a semiconductor layer, a buffer layer, or other intermediate layers).

[0074] The following embodiments can be cited in this disclosure: [1] A region-selective thin film formation method comprising: a step (pre-step) in which the following (step 1) and (step 2) are performed at least once in this order; and a step (post-step) in which the following (step 3), (step 4), (step 5) and (step 6) are performed at least once in this order after the pre-step. (step 1) A step of supplying a thin film formation inhibitor into the interior of a chamber in which a substrate is placed, and adsorbing the thin film formation inhibitor onto the non-growth region of the substrate; (step 2) A step of purging the interior of the chamber; (step 3) A step of supplying a thin film forming raw material into the interior of the chamber, and adsorbing the thin film forming raw material onto the growth region of the substrate; (step 4) A step of purging the interior of the chamber; (step 5) A step of supplying a reactive gas into the interior of the chamber, and reacting the adsorbed thin film forming raw material with the reactive gas to form a thin film; (step 6) A step of purging the interior of the chamber. [2] The region-selective thin film formation method according to [1], wherein the preceding step is a step of performing (step 1) and (step 2) in this order at least twice. [3] The region-selective thin film formation method according to [1] or [2], wherein the thin film formation inhibitor comprises a compound represented by the following general formula (1). (In the formula, R 1 ~R 4 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thioalkyl group having 1 to 10 carbon atoms.) [4] The R 1 ~R 4The region-selective thin film formation method according to [3], wherein three of them are alkyl groups having 1 to 10 carbon atoms and one is an amino group having 1 to 10 carbon atoms. [5] The region-selective thin film formation method according to any one of [2] to [4], wherein the thin film formation inhibitor used in the first pre-step is different from the thin film formation inhibitor used in the second and subsequent pre-steps. [6] The region-selective thin film formation method according to any one of [1] to [5], wherein the thin film formation raw material comprises a compound represented by the following general formula (2). (In the formula, X represents a halogen atom, L represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an imino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, a cyclopentadienyl group having 5 to 17 carbon atoms, an amidinate group having 1 to 10 carbon atoms, or an aryl group having 6 to 11 carbon atoms, and M represents a metal atom of group 3 to 14. The sum of n and m is the same as the valence of the metal atom represented by M, n is 0 or greater, and m is 1 or greater.) [7] The region-selective thin film formation method according to [6], wherein M is a metal atom of group 4. [8] The region-selective thin film formation method according to any one of [1] to [7], wherein the reactive gas comprises an alcohol compound or water. [9] The region-selective thin film formation method according to [8], wherein the alcohol compound is an alcohol compound having 1 to 10 carbon atoms.

[10] A region-selective thin film formation method according to any one of [1] to [9], wherein the growth region is a metal oxide film, a metal nitride film, or a metal film.

[11] A region-selective thin film formation method according to

[10] , wherein the growth region is a titanium nitride film or a tantalum nitride film.

[12] A region-selective thin film formation method according to any one of [1] to

[11] , wherein the non-growth region is a silicon oxide film, a silicon nitride film, or a metallic silicon film.

[13] A thin film formation inhibitor used in a region-selective thin film formation method according to any one of [1] to

[12] .

[14] A thin film formation inhibitor according to

[13] , wherein the thin film formation inhibitor comprises a compound represented by the following general formula (1). (In the formula, R 1 ~R 4Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thioalkyl group having 1 to 10 carbon atoms.)

[15] A thin film forming raw material used in the region-selective thin film forming method described in any of [1] to

[12] .

[16] The thin film forming raw material according to

[15] , wherein the thin film forming raw material comprises a compound represented by the following general formula (2). (In the formula, X represents a halogen atom, L represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an imino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, a cyclopentadienyl group having 5 to 17 carbon atoms, an amidinate group having 1 to 10 carbon atoms, or an aryl group having 6 to 11 carbon atoms, and M represents a metal atom of group 3 to 14. The sum of n and m is the same as the valence of the metal atom represented by M, n is 0 or greater, and m is 1 or greater.)

[17] A reactive gas used in a region-selective thin film formation method according to any one of [1] to

[12] .

[18] The reactive gas according to

[17] , wherein the reactive gas comprises an alcohol compound or water.

[0075] The present disclosure will be further described below with reference to examples. However, the present disclosure is not limited by the following examples. [Example 1] Formation of a titanium oxide thin film A titanium oxide thin film was formed on a substrate using the ALD apparatus shown in Figure 1 by a region-selective thin film formation method under the following conditions. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0076] (Conditions) Reaction temperature (substrate temperature): 200°C Thin film formation inhibitor: N-(trimethylsilyl)dimethylamine Thin film formation raw material: Titanium tetrachloride Reactive gas: Vaporized tert-butyl alcohol Non-growth region: SiN, SiO2, Si Growth region: TaN, TiN

[0077] (Process) After performing the following processes (1) to (2) for one cycle (preceding process 1), a series of processes consisting of the following (3) to (6) was performed for 200 cycles (sequential processes). (1) A gas of the thin film formation inhibitor, vaporized at a raw material container temperature of 25°C, was introduced into the chamber and adsorbed for 1 second at a system pressure of 160 Pa or less (process 1). (2) Unadsorbed thin film formation inhibitor was purged from the chamber by argon purging for 10 seconds (process 2). (3) A gas of the thin film formation raw material, vaporized at a raw material container temperature of 25°C, was introduced into the chamber and adsorbed for 1 second at a system pressure of 160 Pa or less (process 3). (4) Unadsorbed thin film formation raw material was purged from the chamber by argon purging for 10 seconds (process 4). (5) A reactive gas was introduced into the chamber and reacted for 1 second at a system pressure of 160 Pa (process 5). (6) Unreacted reactive gases were evacuated from the chamber by argon purging for 10 seconds. (Step 6)

[0078] [Example 2] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 1, except that triethylsilane was used instead of N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0079] [Example 3] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 1, except that bromotrimethylsilane was used instead of N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0080] [Example 4] A titanium oxide thin film was formed under the same conditions as in Example 1, except that ozone was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0081] [Comparative Example 1] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 1, except that steps (1) and (2) were omitted. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0082] [Comparative Example 2] A titanium oxide thin film was formed under the same conditions as in Comparative Example 1, except that ozone was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity derived from titanium atoms was measured in the obtained thin film by X-ray fluorescence analysis (XRF). The results are shown in Table 1.

[0083]

[0084] [Example 5] Formation of Titanium Oxide Thin Film A titanium oxide thin film was formed on a substrate using a region-selective thin film formation method under the following conditions. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS). The selectivity ratio (S) = (spectral intensity area of ​​the growth region - spectral intensity area of ​​the non-growth region) / (spectral intensity area of ​​the growth region + spectral intensity area of ​​the non-growth region) was calculated using the spectral intensity area of ​​the growth region and the spectral intensity area of ​​the non-growth region. The results are shown in Table 2.

[0085] (Conditions) Reaction temperature (substrate temperature): 200°C Thin film formation inhibitor: N-(trimethylsilyl)dimethylamine Thin film formation raw material: Titanium tetrachloride Reactive gas: Vaporized tert-butyl alcohol Non-growth region: SiO2 Growth region: TaN

[0086] (Process) After performing the following steps (1) to (2) for one cycle (preceding step 1), the series of steps (3) to (6) below were repeated 50 times as one cycle (sequential process). (1) A gas of the thin film formation inhibitor vaporized at a raw material container temperature of 25°C was introduced into the chamber and adsorbed for 1 second at a system pressure of 160 Pa or less (step 1). (2) Unadsorbed thin film formation inhibitor was exhausted from the chamber by argon purging for 10 seconds (step 2). (3) A gas of the raw material for thin film formation vaporized at a raw material container temperature of 25°C was introduced into the chamber and adsorbed for 1 second at a system pressure of 160 Pa or less (step 3). (4) Unadsorbed raw material for thin film formation was exhausted from the chamber by argon purging for 10 seconds (step 4). (5) A reactive gas was introduced into the chamber and reacted for 1 second at a system pressure of 160 Pa (step 5). (6) Unreacted reactive gases were evacuated from the chamber by argon purging for 10 seconds (step 6).

[0087] [Example 6] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 5, except that diisopropylaminosilane was used instead of N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this. The results are shown in Table 2.

[0088] [Example 7] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 5, except that silicon tetrachloride was used instead of N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this. The results are shown in Table 2.

[0089] [Example 8] A titanium oxide thin film was formed under the same conditions as in Example 5, except that vaporized sec-butyl alcohol was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this. The results are shown in Table 2.

[0090] [Example 9] A titanium oxide thin film was formed under the same conditions as in Example 5, except that vaporized water (water vapor) was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this. The results are shown in Table 2.

[0091] [Example 10] A titanium oxide thin film was formed under the same conditions as in Example 5, except that vaporized tert-amyl alcohol was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this. The results are shown in Table 2.

[0092] [Example 11] A titanium oxide thin film was formed under the same conditions as in Example 5, except that vaporized 3-methyl-3-pentanol was used as the reactive gas for forming the titanium oxide thin film instead of vaporized tert-butyl alcohol. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this area. The results are shown in Table 2.

[0093] [Example 12] A titanium oxide thin film was formed under the same conditions as in Example 5, except that vaporized 3-pentanol was used instead of vaporized tert-butyl alcohol as the reactive gas for forming the titanium oxide thin film. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS), and the selectivity ratio (S) was calculated using this area. The results are shown in Table 2.

[0094]

[0095] [Example 13] Formation of a Titanium Oxide Thin Film A titanium oxide thin film was formed under the same conditions as in Example 5, except that in pre-step 1 of Example 5, silicon tetrachloride was used instead of N-(trimethylsilyl)dimethylamine as the thin film formation inhibitor, and pre-step 2, consisting of the following steps (1') and (2'), was performed once between pre-step 1 and the post-step of Example 5. The spectral intensity area (Area) derived from titanium atoms was measured for the obtained thin film by X-ray photoelectron spectroscopy (XPS). The results are shown in Table 4. (1') The gas of the thin film formation inhibitor, vaporized under the condition of a raw material container heating temperature of 25°C, was introduced into the chamber and adsorbed for 1 second at a system pressure of 160 Pa or less (step 1'). (2') Unadsorbed thin film formation inhibitor was exhausted from the chamber by argon purging for 10 seconds (step 2'). In step 1', diisopropylaminosilane was used as the thin film formation inhibitor.

[0096] [Examples 14-18] Formation of Titanium Oxide Thin Films Titanium oxide thin films were formed under the same conditions as in Example 13, except that the thin film formation inhibitors used in pre-steps 1 and 2 of Example 13 were changed to the thin film formation inhibitors shown in Table 3. The obtained thin films were measured by X-ray photoelectron spectroscopy (XPS) to determine the spectral intensity area (Area) derived from titanium atoms, and the selectivity ratio (S) was calculated using this area. The results are shown in Table 4.

[0097]

[0098]

[0099] As shown in Tables 1, 2, and 4, in Examples 1 to 18, compared to Comparative Examples 1 to 2, the spectral intensity derived from titanium atoms in the non-growth region was significantly reduced compared to the spectral intensity derived from titanium atoms in the growth region, indicating excellent region selectivity. Furthermore, it was found that adding a pre-step 2 between pre-step 1 and the post-step, i.e., performing the pre-step twice, further improved region selectivity.

[0100] From the above, it has been found that the region-selective thin film formation method of this disclosure can provide a method for forming thin films with excellent region selectivity.

[0101] 100 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 Reactive gas 203 Exhaust 204 Inert gas M1 Thin film formation inhibitor M2 Raw material for thin film formation S Substrate

Claims

1. A region-selective thin film formation method comprising: a step (preceding step) in which the following (step 1) and (step 2) are performed at least once in this order; and a step (postceding step) in which the following (step 3), (step 4), (step 5), and (step 6) are performed at least once in this order after the preceding step. (step 1) A step of supplying a thin film formation inhibitor into the interior of a chamber in which a substrate is placed, and adsorbing the thin film formation inhibitor onto the non-growth region of the substrate; (step 2) A step of purging the interior of the chamber; (step 3) A step of supplying a thin film formation raw material into the interior of the chamber, and adsorbing the thin film formation raw material onto the growth region of the substrate; (step 4) A step of purging the interior of the chamber; (step 5) A step of supplying a reactive gas into the interior of the chamber, and reacting the adsorbed thin film formation raw material with the reactive gas to form a thin film; (step 6) A step of purging the interior of the chamber.

2. The region-selective thin film formation method according to claim 1, wherein the preceding step is a step of performing (step 1) and (step 2) in this order at least twice.

3. The region-selective thin film formation method according to claim 1 or 2, wherein the thin film formation inhibitor comprises a compound represented by the following general formula (1). (In the formula, R 1 ~R 4 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thioalkyl group having 1 to 10 carbon atoms.

4. The aforementioned R 1 ~R 4 The method for forming a region-selective thin film according to claim 3, wherein three of these are alkyl groups having 1 to 10 carbon atoms, and one is an amino group having 1 to 10 carbon atoms.

5. The region-selective thin film formation method according to claim 2, wherein the thin film formation inhibitor used in the first pre-processing step is different from the thin film formation inhibitor used in the second and subsequent pre-processing steps.

6. The region-selective thin film formation method according to claim 1 or 2, wherein the raw material for thin film formation includes a compound represented by the following general formula (2). (In the formula, X represents a halogen atom, L represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an imino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, a cyclopentadienyl group having 5 to 17 carbon atoms, an amidinate group having 1 to 10 carbon atoms, or an aryl group having 6 to 11 carbon atoms, and M represents a metal atom of group 3 to 14. The sum of n and m is the same as the valence of the metal atom represented by M, where n is 0 or greater and m is 1 or greater.) 7. The region-selective thin film formation method according to claim 6, wherein M is a metal atom of group 4.

8. The region-selective thin film formation method according to claim 1 or 2, wherein the reactive gas comprises an alcohol compound or water.

9. The region-selective thin film formation method according to claim 8, wherein the alcohol compound is an alcohol compound having 1 to 10 carbon atoms.

10. The region-selective thin film formation method according to claim 1 or 2, wherein the growth region is a metal oxide film, a metal nitride film, or a metal film.

11. The region-selective thin film formation method according to claim 10, wherein the growth region is a titanium nitride film or a tantalum nitride film.

12. The region-selective thin film formation method according to claim 1 or 2, wherein the non-growth region is a silicon oxide film, a silicon nitride film, or a metallic silicon film.

13. A thin film formation inhibitor used in the region-selective thin film formation method according to claim 1 or 2.

14. The thin film formation inhibitor according to claim 13, wherein the thin film formation inhibitor comprises a compound represented by the following general formula (1). (In the formula, R 1 ~R 4 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a thioalkyl group having 1 to 10 carbon atoms.

15. A raw material for forming a thin film used in the region-selective thin film formation method according to claim 1 or 2.

16. The thin film forming raw material according to claim 15, wherein the thin film forming raw material comprises a compound represented by the following general formula (2). (In the formula, X represents a halogen atom, L represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an amino group having 1 to 10 carbon atoms, an imino group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, a cyclopentadienyl group having 5 to 17 carbon atoms, an amidinate group having 1 to 10 carbon atoms, or an aryl group having 6 to 11 carbon atoms, and M represents a metal atom of group 3 to 14. The sum of n and m is the same as the valence of the metal atom represented by M, where n is 0 or greater and m is 1 or greater.) 17. A reactive gas used in the region-selective thin film formation method according to claim 1 or 2.

18. The reactive gas according to claim 17, wherein the reactive gas comprises an alcohol compound or water.

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