Film forming method and film forming apparatus

Abstract

This film forming method has the following steps (A) to (C). (A) A substrate is prepared, the substrate having a surface that includes a first region in which an insulating film is exposed and a second region in which a conductive film is exposed. (B) A catalyst layer for promoting the formation of an object film that contains silicon (Si) and oxygen (O) is selectively formed, among the first region and the second region, in a specific region of the first region, the specific region being at a distance from the boundary between the first region and the second region. (C) After the step (B), a precursor gas that contains a silanol group (SiOH group) is supplied to the surface of the substrate so as to grow the object film from the specific region toward the boundary.

Description

Film forming method and film forming apparatus

[0001] The present disclosure relates to a film formation method and a film formation apparatus.

[0002] The method of forming a film described in Patent Document 1 includes exposing a heated substrate to silanol vapor to form a silica layer on specific regions of the substrate, the specific regions containing a metal or metalloid compound with Lewis acid properties.

[0003] The film formation method described in Patent Document 2 includes, in this order, forming a polyimide film or a self-assembled monolayer selectively on the surface of a metal film relative to the surface of a dielectric film, and forming a silicon oxide film selectively on the surface of the dielectric film relative to the surface of the metal film. The silicon oxide film is formed using a metal catalyst and silanol.

[0004] The film forming method described in Patent Document 3 includes forming a metal-containing catalyst layer on the surface of a metal oxide layer covering the surface of a metal film and on the surface of a dielectric film, removing the metal oxide layer to remove the metal-containing catalyst layer on the metal oxide layer, and depositing SiO on the metal-containing catalyst layer remaining on the surface of the dielectric film. ２ and forming a film.

[0005] The film formation method described in Patent Document 4 includes supplying a metal-containing catalytic gas to a substrate surface, supplying hydrogen radicals to the substrate surface, and supplying a silicon precursor gas containing silanol to the substrate surface.

[0006] The film formation method described in Patent Document 5 includes, in this order, forming a passivation film selectively on the surface of a metal film relative to the surface of a dielectric film, and forming a target film selectively on the surface of the dielectric film relative to the surface of the metal film. The target film is an oxide film or a nitride film.

[0007] The film forming method described in Patent Document 6 includes selectively forming a Ru film on the surface of a conductive film relative to the surface of an insulating film. ２ Gas and O ２ The insulating film is formed by alternately supplying the Ru(EtCp) gas and the Ru(EtCp) gas to the surface of the substrate.２ Since the Ru film inhibits gas adsorption, it is selectively formed on the surface of the conductive film.

[0008] Japanese Patent Publication No. 2005-521792 U.S. Patent Application Publication No. 2021 / 301392 Specification Japanese Patent Publication No. 2019-096881 Japanese Patent Publication No. 2022-159050 Japanese Patent Publication No. 2020-056104 Japanese Patent Publication No. 2020-147829

[0009] One aspect of the present disclosure provides techniques for forming a target film containing silicon (Si) and oxygen (O) in a desired area.

[0010] A film formation method according to one aspect of the present disclosure includes the following steps (A) to (C): (A) preparing a substrate having, on its surface, a first region where an insulating film is exposed and a second region where a conductive film is exposed; (B) selectively forming a catalyst layer that promotes the formation of a target film containing silicon (Si) and oxygen (O) in a specific region of the first region, of the first region and the second region, that is away from the boundary between the first region and the second region; (C) after step (B), supplying a precursor gas containing silanol groups (SiOH groups) to the surface of the substrate, thereby growing the target film from the specific region toward the boundary.

[0011] According to one aspect of the present disclosure, a target film containing silicon (Si) and oxygen (O) can be formed in a desired region.

[0012] FIG. 1 is a flowchart showing a film forming method according to an embodiment. FIG. 2 is a cross-sectional view showing steps S101 to S104 according to an embodiment. FIG. 3 is a cross-sectional view showing steps S101 to S104 according to a first modified example. FIG. 4 is a cross-sectional view showing steps S101 to S104 according to a second modified example. FIG. 5 is a flowchart showing a first example of step S102 shown in FIG. 1. FIG. 6 is a cross-sectional view showing a first example of step S102 shown in FIG. 1. FIG. 7 is a cross-sectional view showing a first example of step S102a shown in FIGS. 5 and 6. FIG. 8 is a cross-sectional view showing a second example of step S102a shown in FIGS. 5 and 6. FIG. 9 is a flowchart showing a second example of step S102 shown in FIG. 1. FIG. 10 is a cross-sectional view showing a second example of step S102 shown in FIG. 1. FIG. 11 is a plan view showing a film forming apparatus according to an embodiment. FIG. 12 is a cross-sectional view showing an example of the first processing unit shown in FIG. 11.

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0014] A film formation method according to one embodiment will be described mainly with reference to Figures 1 and 2. The film formation method includes, for example, steps S101 to S104 shown in Figure 1. Note that the film formation method does not necessarily have to include all of steps S101 to S104 shown in Figure 1, and for example, it may not include step S103. Furthermore, the film formation method may include steps other than steps S101 to S104 shown in Figure 1.

[0015] Step S101 includes preparing a substrate 1, as shown in FIG. 2 . The substrate 1 includes a base substrate 10. The base substrate 10 is, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. The substrate 1 has, on its substrate surface 1a, a first region A1 where the insulating film 11 is exposed and a second region A2 where the conductive film 12 is exposed. The substrate surface 1a is, for example, the upper surface of the substrate 1. The insulating film 11 and the conductive film 12 are formed on the base substrate 10. A functional film (not shown) may be formed between the base substrate 10 and the insulating film 11 or between the base substrate 10 and the conductive film 12.

[0016] The insulating film 11 is, for example, an interlayer insulating film. The interlayer insulating film is preferably a low dielectric constant (Low-k) film. The insulating film 11 is not particularly limited, but may be, for example, a SiO film, a SiN film, a SiOC film, a SiON film, or a SiOCN film. Here, the SiO film means a film containing silicon (Si) and oxygen (O). The atomic ratio of silicon (Si) to oxygen (O) in a SiO film is usually 1:2, but is not limited to 1:2. The SiN film, the SiOC film, the SiON film, and the SiOCN film similarly mean that they contain the respective elements and are not limited to a stoichiometric ratio. The insulating film 11 has a recess in the substrate surface 1a. The recess is a trench, a contact hole, or a via hole.

[0017] The conductive film 12 fills, for example, recesses in the insulating film 11. The conductive film 12 is, for example, a metal film. The metal film is, for example, a Cu film, a Co film, a Ru film, a W film, or a Mo film. The conductive film 12 may also be a cap film. That is, as shown in FIG. 4 , a second conductive film 15 may be embedded in the recesses in the insulating film 11, and the second conductive film 15 may be covered by the conductive film 12. The second conductive film 15 is formed of a metal different from that of the conductive film 12. For example, the second conductive film 15 is a Cu film, and the conductive film 12 (cap film) is a Co film or a Ru film. Furthermore, the surfaces of the conductive film 12 and the insulating film 11 do not need to be flush with each other, and may have a step.

[0018] The substrate surface 1a may have a region where the barrier film 13 is exposed at the boundary between the first region A1 and the second region A2. The barrier film 13 is formed between the insulating film 11 and the conductive film 12 and suppresses metal diffusion from the conductive film 12 to the insulating film 11. The barrier film 13 is not particularly limited, but may be, for example, a TaN film or a TiN film. Here, the TiN film refers to a film containing titanium (Ti) and nitrogen (N). The atomic ratio of Ti to N in a TiN film is usually 1:1, but is not limited to 1:1. Similarly, the TaN film refers to a film containing each element and is not limited to a stoichiometric ratio.

[0019] 3 and 4, the substrate surface 1a may have a region where the liner film 14 is exposed at the boundary between the first region A1 and the second region A2. The liner film 14 is formed between the conductive film 12 and the barrier film 13. The liner film 14 is formed on the barrier film 13 and assists in the formation of the conductive film 12. The conductive film 12 is formed on the liner film 14. For example, the conductive film 12 is a Cu film and the liner film 14 is a Co film or a Ru film.

[0020] 2, step S102 includes selectively forming a catalyst layer 17 in a specific region A3 of the first region A1 out of the first region A1 and the second region A2. The specific region A3 of the first region A1 is a region away from the boundary between the first region A1 and the second region A2. As will be described in detail later, the catalyst layer 17 can be formed over the entire substrate surface 1a and then removed from regions other than the specific region A3, so that the catalyst layer 17 remains only in the specific region A3.

[0021] The catalyst layer 17 is formed using, for example, a metal catalyst-containing gas. The metal catalyst-containing gas contains a metal catalyst. The metal catalyst-containing gas is preferably an organometallic compound gas. Specific examples include organoaluminum compound gas and organotitanium compound gas. The organoaluminum compound gas is, for example, trimethylaluminum (TMA) gas, triethylaluminum (TEA) gas, dimethylaluminum chloride gas, or dimethylaluminum isopropoxide (DMAI). The organotitanium compound gas is, for example, tetrakis(dimethylamino)titanium (TDMAT) gas.

[0022] In this embodiment, the catalyst layer 17 is formed using only a metal catalyst-containing gas and contains only a metal catalyst. However, the metal catalyst may be oxidized with an oxidizing gas, or oxygen (O) may be contained in addition to the metal catalyst. In other words, the catalyst layer 17 may be a metal oxide layer. By oxidizing the metal catalyst, it is possible to suppress the desorption or diffusion of the metal catalyst. The oxidizing gas may be, for example, H２ O gas, O ２ Gas or O ３ Gas, etc.

[0023] Step S103 includes activating the catalyst layer 17 by supplying a plasma-converted gas to the substrate surface 1a on which the catalyst layer 17 is formed. In this embodiment, the plasma-converted gas is hydrogen gas, but is not limited to hydrogen gas and may be a rare gas or a mixed gas of hydrogen gas and a rare gas. The rare gas is, for example, Ar gas or He gas. It is preferable that the gas to be plasma-converted in step S103 does not contain an oxygen-based gas in order to suppress oxidation of the conductive film 12. Activation of the catalyst layer 17 is particularly effective when the catalyst layer 17 is a metal oxide layer.

[0024] An example of the processing conditions in step S103 is shown below. ２ Gas flow rate: 200 sccm to 3000 sccm Ar gas flow rate: 0 sccm to 6000 sccm H ２ H in the mixed gas of Ar and H ２ Gas ratio: 0% to 100% by volume; Power supply frequency for plasma generation: 10 MHz to 60 MHz; Power for plasma generation: 50 W to 600 W; Treatment time: 2 sec to 120 sec; Treatment temperature: 80°C to 350°C; Treatment pressure: 50 Pa to 1200 Pa.

[0025] In step S104, as shown in FIG. 2, a precursor gas is supplied to the substrate surface 1a, causing the target film 16 to grow from the specific region A3 toward the boundary between the first region A1 and the second region A2. The precursor gas contains silanol groups (SiOH groups). The catalyst layer 17 promotes the dehydration condensation reaction of the silanol groups, thereby promoting the formation of the target film 16. The target film 16 is preferably formed over the entire first region A1. However, it is preferable that the target film 16 does not extend into the second region A2.

[0026] The silanol group-containing gas used as the precursor gas is not particularly limited, but examples thereof include tris(tert-pentoxy)silanol (TPSOL), triethylsilanol, methyl bis(tert-pentoxy)silanol, and tris(tert-butoxy)silanol (TBSOL).

[0027] An example of the processing conditions for step S104 is shown below: TPSOL gas flow rate: 0.1 g / min to 0.5 g / min, processing time: 3 seconds to 300 seconds, processing temperature: 80° C. to 350° C., processing pressure: 133 Pa to 1200 Pa.

[0028] According to this embodiment, prior to step S104, the catalyst layer 17 that promotes the growth of the target film 16 is formed in a confined area to the specific area A3 of the first area A1. Therefore, even if the target film 16 grows from the specific area A3 toward the second area A2 in step S104, the target film 16 can be prevented from extending into the second area A2. This allows the target film 16 to be formed in a confined area to a desired area (e.g., the first area A1). When the target film 16 has insulating properties, narrowing of the opening width of the insulating target film 16 can be prevented, and an increase in via resistance can be prevented when forming via wiring in the second area A2.

[0029] Next, a first example of step S102 shown in Fig. 1 will be described with reference to Fig. 5 and Fig. 6. Step S102 includes, for example, steps S102a to S102c shown in Fig. 5 and Fig. 6. Note that step S102 does not necessarily include all of steps S102a to S102c shown in Fig. 5 and Fig. 6. Furthermore, step S102 may include steps other than steps S102a to S102c shown in Fig. 5 and Fig. 6.

[0030] 6, step S102a includes forming a sacrificial film 18 on at least the first region A1 excluding the specific region A3 and the entire second region A2. As will be described in detail later, the sacrificial film 18 is selectively formed on the second region A2 of the first region A1 and the second region A2. However, this selectivity is not perfect, and the sacrificial film 18 is formed to extend from the second region A2 into the first region A1. It is preferable that the sacrificial film 18 be formed on the entire substrate surface 1a excluding the specific region A3.

[0031] Step S102b includes forming a catalyst layer 17 in the first region A1 and the second region A2, as shown in FIG. 6 . In this embodiment, the catalyst layer 17 is formed using only a metal catalyst-containing gas and contains only a metal catalyst. However, the metal catalyst may be oxidized with an oxidizing gas, or oxygen (O) may be contained in addition to the metal catalyst. In other words, the catalyst layer 17 may be a metal oxide layer. The catalyst layer 17 is preferably formed over the entire substrate surface 1a.

[0032] The sacrificial film 18 may be an inhibitory film that inhibits the formation of the catalyst layer 17, as will be described in detail later. Therefore, the density of the catalyst layer 17 may be different between the specific region A3 where no inhibitory film is formed and the region other than the specific region A3 where the inhibitory film is formed. The catalyst layer 17 may be densely formed in the specific region A3 and sparsely formed in the region other than the specific region A3. Since it is sufficient that the catalyst layer 17 remains only in the specific region A3 upon completion of step S102, the catalyst layer 17 may be sparsely formed in the region other than the specific region A3.

[0033] 6, step S102c includes removing the sacrificial film 18 and selectively leaving the catalyst layer 17 in the specific region A3. By removing the sacrificial film 18, the catalyst layer 17 deposited on the sacrificial film 18 can be removed. The method for removing the sacrificial film 18 is appropriately selected depending on the type of the sacrificial film 18. For example, if the sacrificial film 18 is a self-assembled monolayer, the self-assembled monolayer is decomposed and removed by supplying a plasma gas to the substrate surface 1a. Also, if the sacrificial film 18 is a metal film, ClF ３ Gas or O ３By supplying gas to the substrate surface 1a, the metal film is transformed into a volatile substance and removed.

[0034] Next, a first example of step S102a shown in FIGS. 5 and 6 will be described with reference to FIG. 7 . In this first example of step S102a, the sacrificial film 18 is a self-assembled monolayer 18A. Hereinafter, the self-assembled monolayer (SAM) 18A may be referred to as SAM 18A. As shown in FIG. 7 , the first example of step S102a includes applying an organic compound, which is a raw material for the SAM 18A, in the form of liquid L to the substrate surface 1a (step S102a1) and drying the applied liquid L (step S102a2).

[0035] The organic compound is not particularly limited, but includes, for example, a thiol-based compound. Specific examples of the thiol-based compound include CF ３ (CF ２ ) ５ CH ２ CH ２ SH (1H,1H,2H,2H-perfluorooctanethiol: PFOT), CH ３ (CH ２ ) ５ SH (hexanethiol: HT), and CH ３ (CH ２ ) １７ Examples of suitable thiol compounds include octadecanethiol (SH). Thiol compounds are more likely to chemically adsorb to the surface of the conductive film 12 than to the surface of the insulating film 11. Therefore, the SAM 18A is selectively formed in the second region A2 of the first region A1 and the second region A2. However, this selectivity is not perfect, and the SAM 18A is formed so as to extend from the second region A2 into the first region A1.

[0036] The organic compound is not limited to a thiol-based compound. The organic compound may include a phosphonic acid-based compound, a carboxylic acid-based compound, or a nitro-based compound. The organic compound may include an olefin-based compound or an organosilane-based compound. The olefin-based compound is a compound represented by the general formula "R-CH=CH ２The organic silane compound is, for example, a trichlorosilane, a methoxysilane, or an ethoxysilane. The trichlorosilane organic compound is represented by the general formula "R-SiCl ３ ". Methoxysilane-based organic compounds are represented by the general formula "R-Si(OCH ３ ) ３ " Ethoxysilane-based organic compounds are represented by the general formula "R-Si(OCH ２ CH ３ ) ３ " is expressed as

[0037] As described above, the organic compound is applied in the form of liquid L. Liquid L is applied to the entire substrate surface 1a. In this embodiment, the method for applying liquid L is spin coating, but dip coating, die coating, or other methods may also be used, and is not particularly limited. The organic compound is used by dissolving it in an organic solvent. The organic solvent is, for example, IPA (isopropyl alcohol). The concentration of the organic compound in liquid L is, for example, 0.1% by volume to 10% by volume. Liquid L can supply a larger amount of organic compound to the substrate surface 1a than gas. Therefore, the SAM 18 is likely to protrude from the second region A2 into the first region A1.

[0038] Drying the liquid L includes heating the substrate 1. The heating temperature of the substrate 1 is preferably increased in stages. The heating temperature of the substrate 1 preferably includes a temperature equal to or higher than the boiling point of the organic solvent. When the substrate 1 is heated, the organic solvent evaporates. During this process, the liquid L selectively collects in the second region A2 of the first region A1 and the second region A2. The liquid L forms an upwardly convex curved surface due to surface tension. The liquid L has a height and spread according to the surface tension, and overflows from the second region A2. Therefore, the SAM 18A is formed by overflowing from the second region A2 into the first region A1.

[0039] Step S102a may include cleaning the substrate surface 1a with a chemical solution or pure water before applying the liquid L. This allows foreign matter to be removed. Step S102a may also include supplying an organic solvent to the substrate surface 1a after drying the applied liquid L, thereby dissolving and removing organic compounds that have not reacted with the substrate surface 1a. Note that since the SAM 18A reacts with and is chemically adsorbed to the substrate surface 1a, it is difficult for the SAM 18A to dissolve in the organic solvent and remains on the substrate surface 1a.

[0040] A specific example of steps S102a1 and S102a2 is as follows. First, while the substrate 1 is held by vacuum chuck with the spin chuck, a thiol-based compound-containing solution, such as IPA, is dropped onto the center of the substrate surface 1a while the substrate 1 is being rotated. The substrate 1 is continued to rotate at the same rotation speed as during the dropping or at a faster speed, so that unreacted thiol-based compound-containing solution is shaken off from the substrate surface 1a, and the IPA solvent is vaporized in the portions of the substrate surface 1a where the thiol-based compound has reacted. Next, the substrate 1 is heated to further vaporize the IPA. Thereafter, while the substrate 1 is again held by vacuum chuck with the spin chuck, an organic solvent, such as IPA, is dropped onto the center of the substrate surface 1a while the substrate 1 is being rotated, further removing the unreacted organic compound. The substrate 1 is then heated again to vaporize and remove the organic solvent, such as IPA, and strengthen the reaction between the substrate surface 1a and the thiol-based compound, thereby improving the phobicity of the SAM 18A.

[0041] An example of the processing conditions for steps S102a1 and S102a2 is shown below: Rotation speed during solution dropping: 100 to 3000 rpm Solution dropping time: 3 to 120 seconds Substrate heating temperature: 80° C. to 350° C. Substrate heating time: 30 to 1800 seconds.

[0042] When the sacrificial film 18 is a SAM 18A, the SAM 18A functions as an inhibiting film that inhibits the formation of the catalyst layer 17 in step S102b. Therefore, in step S102b, the catalyst layer 17 is densely formed in the specific region A3, and is sparsely formed in regions other than the specific region A3. In this embodiment, the catalyst layer 17 is hardly formed in regions other than the specific region A3, but it is also possible that the catalyst layer 17 is not formed at all.

[0043] If the sacrificial film 18 is a SAM 18A, step S102c decomposes and removes the SAM 18A by supplying a plasma gas to the substrate surface 1a. The plasma gas used is the same as that used in step S103. Therefore, step S102c can also serve as step S103 (activation of the catalyst layer 17).

[0044] 5 and 6 will be described with reference to Fig. 8. In the second example of step S102a, the sacrificial film 18 is a metal film 18B. The metal film 18B is advantageous in that even if it is not completely removed from the second region A2 in step S102c and remains, it does not reduce the resistance of the via during via formation.

[0045] A second example of step S102a includes, as shown in FIG. 8, supplying a metal-containing gas that selectively adsorbs to the conductive film 12 out of the insulating film 11 and the conductive film 12 to the substrate surface 1a, thereby forming a metal film 18B that extends from the second region A2 into the first region A1 (step S102a3).

[0046] The metal film 18B preferably contains one or more elements selected from Ru, W, and Mo, and is more preferably a Ru film. The Ru film is preferably Ru(EtCp) ２ Gas and O ２ The insulating film 11 has an OH group on its surface, and the OH group is a Ru(EtCp) ２ Inhibits gas adsorption. Ru(EtCp) ２ The gas is not adsorbed to the surface where OH groups are present, but is adsorbed to the surface where OH groups are not present. Therefore, the Ru film is selectively formed in the second region A2 of the first region A1 and the second region A2. However, this selectivity is not perfect, and the Ru film is formed by extending from the second region A2 into the first region A1. The film formation conditions described in Patent Document 6 can be used for the Ru film formation conditions.

[0047] Ru(EtCp) ２Gases are not generally adsorbed in the first region A1. However, if defects exist in the first region A1, Ru(EtCp) ２ The defects include metal remaining after polishing such as CMP, or damage. ２ Since the gas is adsorbed, island-shaped metal grains 19 are also formed in the first region A1. These metal grains 19 contain Ru.

[0048] 8, the second example of step S102a may include removing the metal particles 19 formed in the first region A1 in step S102a3 with an etching gas (step S102a4). The etching gas may be, for example, ClF ３ Gas or O ３ Since the metal particles 19 are smaller than the metal film 18B, it is possible to remove the metal particles 19 while leaving the metal film 18B. The etching conditions for the metal particles 19 can be the same as those described in Patent Document 6.

[0049] If the sacrificial film 18 is the metal film 18B, step S102c is performed using ClF ３ Gas or O ３ By supplying the gas to the substrate surface 1a, the metal film 18B can be transformed into a volatile substance and removed. ３ Gas and O ３ The gas does not remove the catalyst layer 17. Therefore, the catalyst layer 17 remains in the specific area A3. If the catalyst layer 17 does not completely cover the metal film 18B, the ClF ３ Gas or O ３ The gas can remove the metal film 18B.

[0050] Next, a second example of step S102 shown in Fig. 1 will be described with reference to Fig. 9 and Fig. 10. Step S102 includes, for example, steps S102a' to S102c' shown in Fig. 9 and Fig. 10. Note that step S102 does not necessarily include all of steps S102a' to S102c' shown in Fig. 9 and Fig. 10. Furthermore, step S102 may include steps other than steps S102a' to S102c' shown in Fig. 9 and Fig. 10.

[0051] As shown in FIG. 10 , step S102a′ includes selectively forming an inhibitor film 21 that inhibits the formation of the catalyst layer 17 in the second region A2 relative to the first region A1. The inhibitor film 21 is, for example, a self-assembled monolayer. The self-assembled monolayer is formed by supplying an organic compound, such as a thiol-based compound, in a gaseous state to the substrate surface 1a. When the organic compound is supplied in a gaseous state, any organic compound that is not adsorbed to the substrate 1 is exhausted from the substrate 1, making it difficult for the self-assembled monolayer to extend from the first region A1 to the second region A2. Note that the inhibitor film 21 is not limited to a self-assembled monolayer and may be, for example, a graphene-containing film. In this embodiment, the inhibitor film 21 is not formed on the exposed surface of the barrier film 13, but may be formed thereon.

[0052] Step S102b' includes forming a catalyst layer 17 in the first region A1, as shown in FIG. 10 . As described above, the catalyst layer 17 is formed using, for example, a metal catalyst-containing gas. In this embodiment, the catalyst layer 17 is formed using only a metal catalyst-containing gas and contains only a metal catalyst. However, the metal catalyst may be oxidized with an oxidizing gas, or oxygen (O) may be contained in addition to the metal catalyst. In other words, the catalyst layer 17 may be a metal oxide layer.

[0053] 10, step S102c' includes etching the end of the catalyst layer 17 facing the inhibitor film 21 using components of the inhibitor film 21 while decomposing the inhibitor film 21. By using the components of the inhibitor film 21, the catalyst layer 17 can be etched only in the vicinity of the inhibitor film 21. The catalyst layer 17 is etched away from the boundary between the first region A1 and the second region A2. As a result, the catalyst layer 17 remains in the specific region A3 of the first region A1.

[0054] If the inhibition film 21 contains fluorine, step S102c' is ２ The method includes supplying a gas containing O to the substrate surface 1a. ２Hydrofluoric acid is generated by the reaction between the O-containing gas and the inhibition film 21. The generated hydrofluoric acid can etch away unnecessary portions of the catalyst layer 17. The products produced by the etching are volatile and can be removed by exhaust. ２ The O-containing gas is preferably supplied to the substrate surface 1a without being converted into plasma in order to suppress the generation of oxygen plasma, thereby suppressing oxidation of the conductive film 12.

[0055] Step S102c' is H ２ The O-containing gas and the plasma gas may be alternately supplied to the substrate surface 1a. The plasma gas may be, for example, hydrogen gas, a rare gas, or a mixture of hydrogen gas and a rare gas. The plasma gas can decompose the inhibiting film 21 and promote the generation of hydrofluoric acid. ２ By alternately supplying O-containing gas and plasma gas, ２ There is no need to convert the O-containing gas into plasma, and oxidation of the conductive film 12 can be suppressed.

[0056] An example of the processing conditions of step S102c' is shown below. <Step 1> H ２ Flow rate of O gas: 10 sccm to 500 sccm, Processing time: 0.1 sec to 120 sec, Processing temperature: 100°C to 350°C, Processing pressure: 50 Pa to 1200 Pa. <Step 2> H ２ Gas flow rate: 200 sccm to 3000 sccm, Ar gas flow rate: 100 sccm to 6000 sccm, H ２ H in the mixed gas of Ar and H ２ Gas ratio: 20% to 90% by volume, Power supply frequency for plasma generation: 10 MHz to 60 MHz, Power for plasma generation: 50 W to 600 W, Treatment time: 2 sec to 120 sec, Treatment temperature: 100°C to 350°C, Treatment pressure: 50 Pa to 1200 Pa. <Number of times steps 1 and 2 are repeated> 1 to 50 times.

[0057] Next, with reference to FIG. 11 , a film formation apparatus 100 for carrying out the above-described film formation method will be described. As shown in FIG. 11 , the film formation apparatus 100 includes a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a transport unit 400, and a control unit 500. The first processing unit 200A performs step S102 of FIG. 1 . The second processing unit 200B performs step S103 of FIG. 1 . The third processing unit 200C performs step S104 of FIG. 1 . The first processing unit 200A, the second processing unit 200B, and the third processing unit 200C may have similar structures or different structures. It is also possible for the first processing unit 200A alone to carry out all of steps S102 to S104 of FIG. 1 . The transport unit 400 transports the substrate 1 to the first processing unit 200A, the second processing unit 200B, and the third processing unit 200C. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400.

[0058] The transfer section 400 has a first transfer chamber 401 and a first transfer mechanism 402. The internal atmosphere of the first transfer chamber 401 is atmospheric. The first transfer mechanism 402 is provided inside the first transfer chamber 401. The first transfer mechanism 402 includes an arm 403 that holds the substrate 1, and travels along rails 404. The rails 404 extend in the arrangement direction of the carriers C.

[0059] The transfer unit 400 also has a second transfer chamber 411 and a second transfer mechanism 412. The internal atmosphere of the second transfer chamber 411 is a vacuum atmosphere. The second transfer mechanism 412 is provided inside the second transfer chamber 411. The second transfer mechanism 412 includes an arm 413 that holds the substrate 1, and the arm 413 is arranged to be movable in the vertical and horizontal directions and rotatable around a vertical axis. The second transfer chamber 411 is connected to a first processing unit 200A, a second processing unit 200B, and a third processing unit 200C via different gate valves G.

[0060] Furthermore, the transfer unit 400 has a load lock chamber 421 between the first transfer chamber 401 and the second transfer chamber 411. The internal atmosphere of the load lock chamber 421 can be switched between a vacuum atmosphere and an atmospheric atmosphere by a pressure adjustment mechanism (not shown). This allows the interior of the second transfer chamber 411 to be constantly maintained in a vacuum atmosphere. Also, it is possible to prevent gas from flowing from the first transfer chamber 401 into the second transfer chamber 411. Gate valves G are provided between the first transfer chamber 401 and the load lock chamber 421, and between the second transfer chamber 411 and the load lock chamber 421.

[0061] The control unit 500 is, for example, a computer, and includes an arithmetic unit 501 such as a CPU (Central Processing Unit) and a storage unit 502 such as a memory. The storage unit 502 stores programs that control various processes executed in the film forming apparatus 100. The control unit 500 controls the operation of the film forming apparatus 100 by causing the arithmetic unit 501 to execute the programs stored in the storage unit 502. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400 to perform the above-described film forming method.

[0062] The control unit 500 includes electronic circuits such as a CPU, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC), and performs the various control operations described in this specification by executing instruction codes stored in memory or by being a circuit designed for a specific application.

[0063] Next, the operation of the film forming apparatus 100 will be described. First, the first transport mechanism 402 removes the substrate 1 from the carrier C, transports the removed substrate 1 to the load lock chamber 421, and exits the load lock chamber 421. Next, the internal atmosphere of the load lock chamber 421 is switched from the air atmosphere to a vacuum atmosphere. Thereafter, the second transport mechanism 412 removes the substrate 1 from the load lock chamber 421 and transports the removed substrate 1 to the first processing unit 200A.

[0064] Next, the first processing unit 200A performs step S102. Thereafter, the second transport mechanism 412 removes the substrate 1 from the first processing unit 200A and transports the removed substrate 1 to the second processing unit 200B. During this time, the atmosphere surrounding the substrate 1 can be maintained at a vacuum atmosphere, thereby preventing contamination of the substrate 1.

[0065] Next, second processing unit 200B performs step S103. Thereafter, second transport mechanism 412 removes substrate 1 from second processing unit 200B and transports it to third processing unit 200C. During this time, the atmosphere surrounding substrate 1 can be maintained at a vacuum atmosphere, thereby preventing contamination of substrate 1.

[0066] Next, the third processing unit 200C performs step S104. Thereafter, the second transport mechanism 412 removes the substrate 1 from the third processing unit 200C, transports the removed substrate 1 to the load lock chamber 421, and exits from the load lock chamber 421. The internal atmosphere of the load lock chamber 421 is then switched from a vacuum atmosphere to an atmospheric atmosphere. Thereafter, the first transport mechanism 402 removes the substrate 1 from the load lock chamber 421 and stores the removed substrate 1 in the carrier C. Then, the processing of the substrate 1 is completed.

[0067] Next, the first processing unit 200A will be described with reference to Fig. 12. The second processing unit 200B and the third processing unit 200C are configured in the same manner as the first processing unit 200A, and therefore will not be illustrated or described here.

[0068] The first processing unit 200A includes a substantially cylindrical, airtight processing vessel 210. An exhaust chamber 211 is provided in the center of the bottom wall of the processing vessel 210. The exhaust chamber 211 has, for example, a substantially cylindrical shape that protrudes downward. An exhaust pipe 212 is connected to the exhaust chamber 211, for example, at a side surface of the exhaust chamber 211.

[0069] An exhaust source 272 is connected to the exhaust pipe 212 via a pressure controller 271. The pressure controller 271 includes a pressure adjustment valve such as a butterfly valve. The exhaust pipe 212 is configured so that the pressure inside the processing vessel 210 can be reduced by the exhaust source 272. The pressure controller 271 and the exhaust source 272 constitute a gas exhaust mechanism 270 that exhausts gas inside the processing vessel 210.

[0070] A transfer port 215 is provided on the side surface of the processing vessel 210. The transfer port 215 is opened and closed by a gate valve G. The substrate 1 is transferred in and out between the processing vessel 210 and the second transfer chamber 411 (see FIG. 11 ) via the transfer port 215.

[0071] A stage 220, which serves as a holder for holding the substrate 1, is provided within the processing vessel 210. The stage 220 holds the substrate 1 horizontally with the substrate surface 1a facing upward. The stage 220 is formed in a substantially circular shape in a plan view and is supported by a support member 221. A substantially circular recess 222 for placing the substrate 1, e.g., 300 mm in diameter, is formed on the surface of the stage 220. The recess 222 has an inner diameter slightly larger than the diameter of the substrate 1. The depth of the recess 222 is configured to be substantially the same as the thickness of the substrate 1, for example. The stage 220 is formed of a ceramic material such as aluminum nitride (AlN). Alternatively, the stage 220 may be formed of a metal material such as nickel (Ni). Note that instead of the recess 222, a guide ring for guiding the substrate 1 may be provided around the periphery of the surface of the stage 220.

[0072] A grounded lower electrode 223, for example, is embedded in the stage 220. A heating mechanism 224 is embedded below the lower electrode 223. The heating mechanism 224 receives power from a power supply unit (not shown) based on a control signal from the control unit 500 (see FIG. 11), thereby heating the substrate 1 placed on the stage 220 to a set temperature. If the entire stage 220 is made of metal, the entire stage 220 functions as the lower electrode, so the lower electrode 223 does not need to be embedded in the stage 220. The stage 220 is provided with a plurality of (for example, three) lifting pins 231 for holding and lifting up and down the substrate 1 placed on the stage 220. The lifting pins 231 are made of a material such as alumina (Al ２ O ３ The lift pins 231 may be made of ceramics such as quartz or the like. The lower ends of the lift pins 231 are attached to a support plate 232. The support plate 232 is connected to a lift mechanism 234 provided outside the processing vessel 210 via a lift shaft 233.

[0073] The lifting mechanism 234 is installed, for example, below the exhaust chamber 211. The bellows 235 is provided between the lifting mechanism 234 and an opening 219 for the lifting shaft 233 formed in the lower surface of the exhaust chamber 211. The support plate 232 may be shaped so that it can be raised and lowered without interfering with the support member 221 of the stage 220. The lifting pins 231 are configured to be able to be raised and lowered by the lifting mechanism 234 between above and below the surface of the stage 220.

[0074] A gas supply unit 240 is provided on the ceiling wall 217 of the processing vessel 210 via an insulating member 218. The gas supply unit 240 serves as an upper electrode and faces the lower electrode 223. A high-frequency power supply 252 is connected to the gas supply unit 240 via a matching unit 251. By supplying high-frequency power of 450 kHz to 100 MHz from the high-frequency power supply 252 to the upper electrode (gas supply unit 240), a high-frequency electric field is generated between the upper electrode (gas supply unit 240) and the lower electrode 223, generating capacitively coupled plasma. A plasma generation unit 250 that generates plasma includes the matching unit 251 and the high-frequency power supply 252. Note that the plasma generation unit 250 is not limited to capacitively coupled plasma, and may generate other types of plasma, such as inductively coupled plasma. Note that in processes that do not generate plasma, the gas supply unit 240 does not need to serve as an upper electrode, and the lower electrode 223 is also unnecessary.

[0075] The gas supply unit 240 includes a hollow gas supply chamber 241. A number of holes 242 are arranged, for example, evenly, on the bottom surface of the gas supply chamber 241 to distribute and supply the processing gas into the processing vessel 210. A heating mechanism 243 is embedded in the gas supply unit 240, for example, above the gas supply chamber 241. The heating mechanism 243 is heated to a set temperature by receiving power from a power supply unit (not shown) based on a control signal from the control unit 500.

[0076] A gas supply mechanism 260 is connected to the gas supply chamber 241 via a gas supply path 261. The gas supply mechanism 260 supplies gas used in at least one of steps S102 to S104 of FIG. 1 to the gas supply chamber 241 via the gas supply path 261. Although not shown, the gas supply mechanism 260 includes individual pipes for each type of gas, on-off valves provided midway through the individual pipes, and flow rate controllers provided midway through the individual pipes. When the on-off valves open the individual pipes, gas is supplied from the supply source to the gas supply path 261. The supply amount is controlled by the flow rate controller. On the other hand, when the on-off valves close the individual pipes, the supply of gas from the supply source to the gas supply path 261 is stopped.

[0077] Although the embodiments of the film forming method and film forming apparatus according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0078] This application claims priority based on Japanese Patent Application No. 2023-202355 filed with the Japan Patent Office on November 30, 2023, the entire contents of which are incorporated herein by reference.

[0079] REFERENCE SIGNS LIST 1 substrate 1a substrate surface 11 insulating film 12 conductive film 16 target film 17 catalyst layer A1 first region A2 second region

Claims

1. A film forming method comprising: (A) preparing a substrate having a surface having a first region where an insulating film is exposed and a second region where a conductive film is exposed; (B) selectively forming a catalyst layer that promotes the formation of a target film containing silicon (Si) and oxygen (O) in a specific region of the first region that is away from the boundary between the first region and the second region; and (C) after (B), supplying a precursor gas containing a silanol group (SiOH group) to the surface of the substrate, thereby growing the target film from the specific region toward the boundary.

2. The film forming method of claim 1, wherein (B) comprises: (Ba) forming an inhibitory film that inhibits formation of the catalyst layer in an area of ​​the first region excluding the specific region and in the entire second region; (Bb) after (Ba), forming the catalyst layer in the specific region; and (Bc) after (Bb), removing the inhibitory film and selectively leaving the catalyst layer in the specific region.

3. The film forming method according to claim 2, wherein the inhibition film is a self-assembled monolayer, (Ba) includes applying an organic compound, which is a raw material of the self-assembled monolayer, in a liquid state to the surface of the substrate and drying the applied liquid, and (Bc) includes supplying a plasmatized gas to the surface of the substrate.

4. The film forming method of claim 1, wherein (B) comprises: (Ba) forming a sacrificial film in an area of ​​the first region excluding the specific area and in the entire second region; (Bb) after (Ba), forming the catalyst layer in the first region and the second region; and (Bc) after (Bb), removing the sacrificial film and selectively leaving the catalyst layer in the specific area.

5. The sacrificial film is a metal film, and (Ba) includes supplying a metal-containing gas that selectively adsorbs to the conductive film out of the insulating film and the conductive film to the surface of the substrate, and (Bc) includes supplying ClF ３ Gas or O ３ The method of claim 4 , further comprising supplying a gas.

6. The film forming method according to claim 5, wherein the metal film contains one or more elements selected from the group consisting of Ru, W and Mo.

7. The film forming method of claim 1, wherein (B) comprises: (Ba') selectively forming an inhibitory film that inhibits formation of the catalyst layer in the second region relative to the first region; (Bb') after (Ba'), forming the catalyst layer in the first region; and (Bc') after (Bb'), etching an end of the catalyst layer facing the inhibitory film using components of the inhibitory film while decomposing the inhibitory film.

8. The film forming method of claim 1, further comprising (D) activating the catalytic layer by supplying a plasma-converted gas to the surface of the substrate on which the catalytic layer is formed, after (B) and before (C).

9. A film formation apparatus comprising: a processing vessel; a holding unit that holds the substrate inside the processing vessel; a gas supply mechanism that supplies gas into the processing vessel; a gas exhaust mechanism that exhausts gas from the processing vessel; a transport mechanism that loads the substrate into and out of the processing vessel; and a control unit that controls the gas supply mechanism, the gas exhaust mechanism, and the transport mechanism, and performs the film formation method according to any one of claims 1 to 8.

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