Film forming method and film forming apparatus

Abstract

This film forming method comprises the following steps (A) to (D). (A) A substrate is prepared, the substrate having, in different regions of the surface thereof, a first film and a second film that is formed of a different material from the first film. (B) A film formation inhibitory film for inhibiting the formation of an object film is selectively formed on the surface of the second film with respect to the surface of the first film. (C) The object film is selectively formed on the surface of the first film with respect to the surface of the second film by using the film formation inhibitory film. (D) A part of the object film is preferentially etched with respect to another part of the object film. The step (D) comprises: (Da) supplying a fluorine-containing gas to the surface of the object film; (Db) supplying an H2O gas to the surface of the object film after the (Da); and (Dc) supplying a plasma-converted gas to the surface of the object film after the (Db).

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 film forming method described in Patent Document 1 includes the following steps (1) to (4): (1) preparing a substrate having, on its surface, a first region where a first film is exposed and a second region where a second film formed of a material different from the first film is exposed; (2) supplying a fluorine-containing organic compound, which is a raw material for a self-assembled monolayer, to the surface of the substrate, and selectively forming the self-assembled monolayer in the second region out of the first region and the second region; (3) using the self-assembled monolayer to form the target film in the first region while inhibiting the formation of the target film in the second region; (4) applying H to the surface of the substrate; ２ A gas containing O is supplied to etch the end portion of the target film that protrudes from the first region.

[0003] The etching method described in Patent Document 2 uses hydrogen fluoride (HF) gas and ammonia (NH ３ The etching method described in Patent Document 3 includes a step of supplying a mixed gas containing NF gas to the surface of the silicon oxide film to modify the silicon oxide film and generate a reaction product, and a step of removing the reaction product by heating. ３ , H ２ , N ２ , H.F., N.H. ３ and sublimating the etching product at a temperature of 100° C. or higher.

[0004] Japanese Patent Publication No. 2022-055462 Japanese Patent Publication No. 2007-180418 Japanese Patent Publication No. 2009-140944

[0005] One aspect of the present disclosure provides a technique for preferentially etching a portion of a target film relative to another portion of the target film.

[0006] A film forming method according to one aspect of the present disclosure includes the following steps (A) to (D): (A) preparing a substrate having a first film and a second film formed of a material different from the first film in different regions of its surface; (B) selectively forming a film-formation-inhibiting film that inhibits the formation of a target film on the surface of the second film relative to the surface of the first film; (C) selectively forming the target film on the surface of the first film relative to the surface of the second film using the film-formation-inhibiting film; and (D) preferentially etching a portion of the target film relative to another portion of the target film. The step (D) includes: (Da) supplying a fluorine-containing gas to the surface of the target film to adsorb fluorine to the surface of the target film or to form a fluorine-containing layer on the surface of the target film; and (Db) after step (Da), applying H ２ (Dc) generating hydrogen fluoride by supplying O gas, and (Db) supplying a gas in plasma form to the surface of the target film after (Db).

[0007] According to one aspect of the present disclosure, a portion of a target film may be preferentially etched relative to another portion of the target film.

[0008] FIG. 1 is a flowchart illustrating a film forming method according to an embodiment. FIG. 2 is a flowchart illustrating an example of a subroutine of S105. FIG. 3 is a flowchart illustrating an example of a subroutine of S106. FIG. 4A is a cross-sectional view illustrating a first example of S101. FIG. 4B is a cross-sectional view illustrating first examples of S102 and S103. FIG. 4C is a cross-sectional view illustrating a first example of S104. FIG. 4D is a cross-sectional view illustrating a first example of S105. FIG. 4E is a cross-sectional view illustrating a first example of S106a. FIG. 4F is a cross-sectional view illustrating a first example of S106b and S106c. FIG. 5A is a cross-sectional view illustrating a second example of S101. FIG. 5B is a cross-sectional view illustrating a second example of S102 and S103. FIG. 5C is a cross-sectional view illustrating a second example of S104. FIG. 5D is a cross-sectional view illustrating a second example of S105. FIG. 5E is a cross-sectional view illustrating a second example of S106a. FIG. 5F is a cross-sectional view illustrating a second example of S106b and S106c. FIG. 6A is a cross-sectional view showing a third example of S101. FIG. 6B is a cross-sectional view showing a third example of S102 and S103. FIG. 6C is a cross-sectional view showing a third example of S104. FIG. 6D is a cross-sectional view showing a third example of S105. FIG. 6E is a cross-sectional view showing a third example of S106a. FIG. 6F is a cross-sectional view showing a third example of S106b and S106c. FIG. 7 is a plan view showing a film forming apparatus according to an embodiment. FIG. 8 is a cross-sectional view showing an example of the first processing unit of FIG. 7. FIG. 9 is a view showing the relationship between the gas supply time and the etching amount of the SiO film in S106a of Examples 10 to 13.

[0009] 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.

[0010] A film formation method according to one embodiment will be described mainly with reference to Figures 1 to 6. The film formation method includes, for example, steps S101 to S107 shown in Figure 1. Note that the film formation method may include at least steps S101 and S104 to S107, and does not necessarily include steps S102 to S103. Furthermore, the film formation method may include steps other than steps S101 to S107 shown in Figure 1.

[0011] Step S101 includes preparing a substrate 1, as shown in FIG. 4A . 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 an insulating film 11 and a conductive film 12 in different regions of its substrate surface 1a. 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. Another functional film may be formed between the base substrate 10 and the insulating film 11 or between the base substrate 10 and the conductive film 12. The insulating film 11 is an example of a first film, and the conductive film 12 is an example of a second film. Note that the materials of the first film and the second film are not particularly limited.

[0012] 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 refers to a film containing silicon (Si) and oxygen (O). The atomic ratio of Si to O in a SiO film is usually 1:2, but is not limited to 1:2. Similarly, the SiN film, the SiOC film, the SiON film, and the SiOCN film refer to the film containing each element 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.

[0013] 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. 6A , 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.

[0014] The substrate 1 may further include a third film on the substrate surface 1a. The third film is, for example, a barrier film 13. 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.

[0015] The substrate 1 may further include a fourth film on the substrate surface 1a. The fourth film is, for example, a liner film 14 (see FIGS. 5A and 6A). 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.

[0016] 4A, 5A, and 6A, contaminants 22 may be present on the substrate surface 1a. The contaminants 22 may be, for example, metal oxides. The metal oxides are formed, for example, by a reaction between the conductive film 12 and the atmosphere. The contaminants 22 may be organic matter. The organic matter may be, for example, a deposit containing carbon, which adheres to the substrate 1 during processing. The organic matter may be in the form of a layer.

[0017] Step S102 includes performing a first pre-treatment to remove contaminants 22 from the substrate surface 1a, as shown in FIGS. 4B, 5B, and 6B. In the first pre-treatment, a cleaning gas is supplied to the substrate surface 1a. Multiple cleaning gases may be supplied in sequence. In this embodiment, a first cleaning gas, a second cleaning gas, and a third cleaning gas are supplied in this order.

[0018] The first cleaning gas contains at least H ２ In addition to the reducing gas, N ２ The first cleaning gas may contain a nitrogen-containing gas such as a nitrogen-containing gas, etc. The first cleaning gas is preferably turned into plasma before being supplied to the substrate surface 1a.

[0019] An example of the treatment conditions for the first cleaning gas is shown below. ２ Gas flow rate: 50 sccm to 5000 sccm N ２ Gas flow rate: 50 sccm to 10,000 sccm Ar gas flow rate: 20 sccm to 10,000 sccm H in the first cleaning gas ２ Gas ratio: 10% to 60% by volume N in the first cleaning gas ２ Gas ratio: 10% to 80% by volume; Power supply frequency for plasma generation: 10 MHz to 100 MHz; Power for plasma generation: 50 W to 400 W; Processing time: 5 seconds to 120 seconds; Processing temperature (substrate temperature): 80°C to 350°C; Processing pressure: 50 Pa to 2000 Pa.

[0020] The second cleaning gas includes an oxygen-containing gas. ２ Gas, O ３ Gas, H ２ O gas, NO gas, NO ２ Gas and N ２ The oxygen-containing gas is supplied to the substrate surface 1a without being converted into plasma.

[0021] An example of the processing conditions using the second cleaning gas is shown below. ２ Gas flow rate: 100 sccm to 2000 sccm Processing time: 10 seconds to 5 minutes Processing temperature (substrate temperature): 80° C. to 350° C. Processing pressure: 50 Pa to 665 Pa.

[0022] The third cleaning gas contains at least one selected from, for example, a carboxylic acid compound, a phosphonic acid compound, a nitro compound, and a thiol compound. The carboxylic acid compound is represented by the general formula "R-COOH". The phosphonic acid compound is represented by the general formula "R-P(=O)(OH) ２ Nitro compounds are represented by the general formula "R-NO ２ The thiol compound is represented by the general formula "R-SH".

[0023] In these general formulas, R is, for example, a hydrocarbon group or a hydrocarbon group in which at least a portion of the hydrogen atoms has been substituted with fluorine. Specifically, for example, R is "CF ３ -(CF ２) Ｘ -," "CF ３ -(CF ２ ) Ｘ -CH ２ -CH ２ -" or "CH ３ - (CH ２ ) Ｘ -". X is an integer of 1 to 17. Specific examples of carboxylic acid compounds include PFBA (CF ３ (CF ２ ) ２ COOH), formic acid (HCOOH), acetic acid (CH ３ COOH), propionic acid (CH ３ CH ２ COOH), octanoic acid (CH ３ (CH ２ ) ６ COOH). Specific examples of nitro compounds include PFNO(CF ３ (CF ２ ) ５ CH ２ CH ２ NO ２ ) are listed.

[0024] An example of the processing conditions for the third cleaning gas is as follows: PFBA gas flow rate: 10 sccm to 100 sccm, processing time: 30 seconds to 10 minutes, processing temperature (substrate temperature): 80° C. to 350° C., processing pressure: 100 Pa to 300 Pa.

[0025] Step S103 includes performing a second pre-treatment to remove residues of the cleaning gas supplied in step S102. The residues of the cleaning gas are mainly organic substances. In the second pre-treatment, a plasma gas is supplied to the substrate surface 1a. The gas contains at least H ２ In addition to the reducing gas, N ２ The process conditions for step S103 are the same as those for step S102 using the first cleaning gas, and therefore will not be described here.

[0026] Step S104 includes selectively forming a self-assembled monolayer 17 on the surface of the conductive film 12 relative to the surface of the insulating film 11, as shown in FIGS. 4C, 5C, and 6C. Hereinafter, the self-assembled monolayer (SAM) 17 may be referred to as SAM 17. The SAM 17 is formed by supplying an organic compound gas to the substrate surface 1a. The organic compound gas is a raw material gas for the SAM 17.

[0027] The source gas for the SAM 17 is not particularly limited, but may include, 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), and CH ３ (CH ２ ) ５ Examples of suitable thiol compounds include hexanethiol (HT) and hexanethiol (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 17 is selectively formed on the surface of the conductive film 12 relative to the surface of the insulating film 11. The SAM 17 is hardly formed on the surface of the insulating film 11. The SAM 17 may be formed not only on the surface of the conductive film 12 but also on the surface of the liner film 14, as shown in FIGS. 5C and 6C .

[0028] The source gas for the SAM 17 is not limited to a thiol-based compound. The source gas for the SAM 17 may also include a phosphonic acid-based compound, a carboxylic acid-based compound, or a nitro-based compound. The third cleaning gas and the source gas for the SAM 17 may contain the same organic compound or different organic compounds, but preferably contain the same organic compound. Using the same organic compound can reduce costs, for example by reducing the number of chambers used.

[0029] The source gas for the SAM 17 may contain an olefin-based compound or an organic silane-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

[0030] An example of the processing conditions for step S104 is as follows: HT gas flow rate: 50 sccm to 200 sccm; processing time: 10 seconds to 600 seconds; processing temperature: 80° C. to 350° C.; processing pressure: 50 Pa to 4000 Pa.

[0031] Step S104 may include selectively forming a deposition-inhibiting film that inhibits the formation of the target film on the surface of the second film relative to the surface of the first film. The insulating film 11 is an example of the first film, the conductive film 12 is an example of the second film, and the SAM 17 is an example of the deposition-inhibiting film. The deposition-inhibiting film is not limited to a SAM and may be, for example, a graphene-containing film or a boron-containing film.

[0032] 4D, 5D, and 6D, step S105 includes selectively forming a second insulating film 18 on the surface of the insulating film 11 relative to the surface of the conductive film 12 using a SAM 17. The second insulating film 18 is an example of a target film. The second insulating film 18 is formed by a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method.

[0033] The second insulating film 18 is not particularly limited, but may be, for example, an AlO film, a SiO film, a SiN film, a ZrO film, or a HfO film. Here, the AlO film refers to a film containing aluminum (Al) and oxygen (O). The atomic ratio of Al to O in an AlO film is usually 2:3, but is not limited to 2:3. Similarly, the SiO film, SiN film, ZrO film, and HfO film also refer to the film containing each element and are not limited to a stoichiometric ratio.

[0034] From the viewpoint of lowering the k value (dielectric constant), the second insulating film 18 is preferably an oxide film such as SiO or SiOC, and more preferably a film containing SiO. The SiO film contains at least silicon (Si) and oxygen (O). The SiO film is formed, for example, using a metal catalyst-containing gas and a silanol group-containing gas. The metal catalyst-containing gas contains a metal catalyst. The metal catalyst promotes the dehydration condensation reaction of the silanol groups contained in the silanol group-containing gas. The SiO film is formed by the dehydration condensation reaction of the silanol groups. The SiO film may contain a metal catalyst in addition to silicon (Si) and oxygen (O).

[0035] The metal catalyst-containing gas is preferably an organometallic compound gas. Specific examples include an organoaluminum compound gas and an 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.

[0036] The silanol group-containing 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).

[0037] 2, step S105 includes supplying a metal catalyst-containing gas (step S105a) and supplying a silanol group-containing gas (step S105b) K times (K is an integer of 1 or more). K may be an integer of 2 or more, and steps S105a to S105b may be repeated multiple times. K is preferably 1 to 5.

[0038] Step S105a includes supplying a metal catalyst-containing gas to the substrate surface 1a to adsorb the metal catalyst onto the surface of the insulating film 11. The SAM 17 inhibits the metal catalyst from being adsorbed onto the surface of the conductive film 12.

[0039] An example of the processing conditions for step S105a is as follows: TMA gas flow rate: 10 sccm to 100 sccm; processing time: 0.05 seconds to 100 seconds; processing temperature: 80° C. to 350° C.; processing pressure: 133 Pa to 1200 Pa.

[0040] Step S105b includes supplying a silanol group-containing gas to the substrate surface 1a. The metal catalyst adsorbed on the surface of the insulating film 11 promotes a dehydration condensation reaction of the silanol groups contained in the silanol group-containing gas. As a result, the second insulating film 18 is selectively formed on the surface of the insulating film 11 relative to the surface of the conductive film 12.

[0041] An example of the processing conditions for step S105b is shown below. The TPSOL gas is supplied by vaporizing TPSOL liquid. Flow rate of TPSOL gas: 0.1 g / min to 0.5 g / min Processing time: 3 seconds to 120 seconds Processing temperature: 80° C. to 350° C. Processing pressure: 133 Pa to 1200 Pa.

[0042] In steps S105a and S105b, a gas corresponding to the material of the second insulating film 18 may be supplied to the substrate surface 1a. When the second insulating film 18 is an AlO film, step S105a includes supplying, for example, an Al-containing gas to the substrate surface 1a, and step S105b includes supplying, for example, an oxygen-containing gas to the substrate surface 1a. The Al-containing gas is, for example, an organoaluminum compound gas. The oxygen-containing gas is, for example, H ２ It is O gas.

[0043] The etching rate of an AlO film is slower than that of a SiO film in step S106. It is preferable that the thickness of the AlO film formed in one step S105 is thin so that unnecessary portions of the AlO film (portions deposited on the surface of the conductive film 12) can be easily etched in step S106. The set number of times (K times) of step S105c can be reduced, and the set number of times (N times) of step S107 can be increased accordingly.

[0044] Step S105 may include a step of supplying a purge gas to the substrate surface 1a after the n-th step S105a and before the n-th step S105b. Step S105 may also include a step of supplying a purge gas to the substrate surface 1a after the n-th step S105b and before the (n+1)-th step S105a. By supplying the purge gas, the gas used immediately before can be discharged.

[0045] 4D, 5D, and 6D, the SAM 17 inhibits the formation of the second insulating film 18, but the blocking performance of the SAM 17 is not perfect, and the second insulating film 18 may extend laterally beyond the surface of the insulating film 11 and cover part of the surface of the conductive film 12. This narrows the opening width of the second insulating film 18, increasing the wiring resistance of the substrate 1. In particular, this increases the wiring resistance of vias that penetrate between layers and reduces the yield of non-defective vias. Therefore, the substrate processing method includes step S106.

[0046] Step S106 includes preferentially etching the portion 18a of the second insulating film 18 relative to another portion 18b of the second insulating film 18. The portion 18a of the second insulating film 18 includes a portion deposited on the surface of the conductive film 12 and includes a portion of the SAM 17. Therefore, the portion 18a of the second insulating film 18 has more defects and is etched at a faster rate than the other portion 18b of the second insulating film 18.

[0047] Even when a graphene-containing film, a boron-containing film, or the like is formed in step S104 instead of SAM 17 as a film-formation-inhibiting film that inhibits the formation of second insulating film 18, part 18a of second insulating film 18 has a faster etching rate than another part 18b of second insulating film 18. This is because the second insulating film (part 18a of second insulating film 18) in the vicinity of the film-formation-inhibiting film is affected by the film-formation-inhibiting film, and its growth is inhibited, resulting in a thinner film or lower density.

[0048] As shown in FIG. 3, step S106 includes, for example, supplying a fluorine-containing gas (step S106a) and ２ The process includes supplying O gas (step S106b) and supplying plasmatized gas (step S106c). Step S106 includes performing steps S106b and S106c a set number of times (M times). M may be an integer of 2 or greater, and steps S106b to S106c may be repeated a set number of times. Step S106 also includes performing step S106a once, and performing steps S106b and S106c M times, a set number of times (L times). L may be an integer of 2 or greater, and steps S106a to S106c may be repeated a set number of times.

[0049] 4E, 5E, and 6E, step S106a includes supplying a fluorine-containing gas to the surface of the second insulating film 18 to form a fluorine-containing layer 19 on the surface of the second insulating film 18. The fluorine-containing layer 19 may be deposited not only on the surface of the second insulating film 18 but also on the surface of the SAM 17. Note that instead of forming the fluorine-containing layer 19 on the surface of the second insulating film 18, fluorine may be adsorbed onto the surface of the second insulating film 18.

[0050] The fluorine-containing gas is, for example, HF gas and NH ３ It is a mixture of HF gas and NH ３ The fluorine-containing layer 19 is formed by the reaction of the mixed gas with the second insulating film 18. When the second insulating film 18 is a film containing silicon (Si) and oxygen (O), the fluorine-containing layer 19 is formed by the reaction of ammonium silicofluoride (NH ４ ) ２ SiF ６) is included.

[0051] The fluorine-containing layer 19 may be formed to such an extent that unnecessary portions of the second insulating film 18 (portions deposited on the surface of the conductive film 12) can be etched in steps S106b to S106c. Step S106a is preferably performed at a lower temperature than steps S106b to S106c so that the amount of fluorine-containing layer 19 formed can be adjusted. The temperature of the substrate 1 in step S106a is, for example, 50°C to 100°C.

[0052] In this embodiment, the fluorine-containing gas is HF gas and NH ３ It is a mixture of gases, but NH ３ The second insulating film 18 may not contain any gas, or may contain only HF gas. In this case, instead of forming the fluorine-containing layer 19 on the surface of the second insulating film 18, fluorine can be adsorbed on the surface of the second insulating film 18.

[0053] An example of the processing conditions for step S106a is as follows: HF gas flow rate: 10 sccm to 100 sccm NH ３ Gas flow rate: 10 sccm to 100 sccm Treatment time: 0.05 seconds to 100 seconds Treatment temperature: 30°C to 150°C (preferably 30°C to 100°C, more preferably 50°C to 100°C) Treatment pressure: 50 Pa to 1200 Pa.

[0054] Step S106b is a step of forming a H ２ The hydrogen fluoride is generated by supplying O gas. The hydrogen fluoride reacts with the fluorine-containing layer 19 and H ２ It should be noted that instead of the fluorine-containing layer 19, the fluorine and H adsorbed on the surface of the second insulating film 18 are generated by the reaction of the fluorine and H ２ It is also possible to generate hydrogen fluoride by the reaction of O gas. ２ O gas plus H ２ O ２ In step S106b, H ２ It is preferable not to convert the O gas into plasma, as this can prevent the generation of oxygen plasma and prevent the conductive film 12 from being oxidized.

[0055] An example of the processing conditions in step S106b is shown below. ２ O gas flow rate: 10 sccm to 500 sccm; processing time: 0.1 sec to 120 sec; processing temperature: 80°C to 350°C; processing pressure: 50 Pa to 1200 Pa.

[0056] Step S106c includes supplying plasma gas to the surface of the second insulating film 18. By performing steps S106b and S106c in order, H ２ This can prevent the O gas from becoming plasma, can prevent the generation of oxygen plasma, and can prevent the conductive film 12 from being oxidized.

[0057] The gas to be converted into plasma in step S106c preferably does not contain an oxygen-based gas in order to prevent the generation of oxygen plasma. ２ gas, noble gas, or H ２ The plasma is a mixed gas of a gas and a rare gas. The rare gas is, for example, Ar gas or He gas. The plasma promotes decomposition of the fluorine-containing layer 19 or desorption of fluorine, and promotes the generation of hydrogen fluoride. This can promote etching of the second insulating film 18 by hydrogen fluoride.

[0058] According to this embodiment, a portion 18a of the second insulating film 18 is etched preferentially relative to another portion 18b of the second insulating film 18. While the unnecessary portion of the second insulating film 18 (the portion deposited on the surface of the conductive film 12) is etched, the necessary portion of the second insulating film 18 (the portion deposited on the surface of the insulating film 11) is hardly etched. Therefore, the unnecessary portion of the second insulating film 18 can be selectively removed.

[0059] An example of the processing conditions in step S106c is shown below. 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: 0% 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: 80°C to 350°C; Treatment pressure: 50 Pa to 1200 Pa.

[0060] Although not shown in the figure, step S106c is ２ Gas only or H ２ It is preferable that the method includes, in a desired order, converting a mixed gas of the gas and a rare gas into plasma and supplying the plasma to the surface of second insulating film 18 (step S106c1) and converting only the rare gas into plasma and supplying the plasma to the surface of second insulating film 18 (step S106c2). The order does not matter, but step S106c2 may be performed after step S106c1.

[0061] Although details will be described in the section of Examples, by including steps S106c1 and S106c2 in step S106c, the leakage current of the second insulating film 18 remaining after step S106c is reduced. ２ Although only the gas may be plasmatized and supplied to the surface of the second insulating film 18, from the viewpoint of facilitating plasma generation, H ２ It is preferable to convert a mixed gas of the gas and the rare gas into plasma and supply it to the surface of the second insulating film 18 .

[0062] Step S106d includes checking whether steps S106b to S106c have been performed a set number of times (M times). If the number of times has not reached the set number of times (M times), etching of the second insulating film 18 is insufficient, so steps S106b to S106c are performed again. On the other hand, if the number of times has reached the set number of times (M times), etching of the second insulating film 18 is sufficient, so the processes from step S106e onwards are performed.

[0063] The set number of times (M times) in step S106d is, for example, 1 to 50 times, preferably 2 to 50 times. When M is an integer equal to or greater than 2, steps S106b to S106c are repeated multiple times. This allows the decomposition of the fluorine-containing layer 19 or the desorption of fluorine to proceed gradually, and hydrogen fluoride can be generated over a long period of time. As a result, the opening width of the second insulating film 18 can be increased, and the wiring resistance of the substrate 1 can be reduced.

[0064] Step S106e includes performing step S106a once, performing steps S106b to S106c M times, and checking whether these steps have been performed a set number of times (L times). If the number of times has not reached the set number of times (L times), etching of the second insulating film 18 is insufficient, so steps S106a to S106c are performed again. On the other hand, if the number of times has reached the set number of times (L times), etching of the second insulating film 18 is sufficient, so the processes from step S107 onwards are performed.

[0065] The set number of times (L times) in step S106e is, for example, 1 to 50 times, and preferably 2 to 50 times. When L is an integer equal to or greater than 2, steps S106a to S106c are repeated multiple times. This allows the fluorine-containing layer 19 to be regenerated, and hydrogen fluoride to be generated over a long period of time. As a result, the opening width of the second insulating film 18 can be increased, and the wiring resistance of the substrate 1 can be reduced.

[0066] Step S107 involves checking whether steps S104 to S106 have been performed a set number of times (N times). If the number of times has not reached the set number, the thickness of the second insulating film 18 has not reached the target thickness, so steps S104 to S106 are performed again. On the other hand, if the number of times has reached the set number, the thickness of the second insulating film 18 has reached the target thickness, so this processing ends.

[0067] Next, with reference to FIG. 7 , a film formation apparatus 100 for carrying out the above-described film formation method will be described. As shown in FIG. 7 , the film formation apparatus 100 includes a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a fourth processing unit 200D, a transport unit 400, and a control unit 500. The first processing unit 200A performs steps S102 to S103 of FIG. 1 . The second processing unit 200B performs step S104 of FIG. 1 . The third processing unit 200C performs step S105 of FIG. 1 . The fourth processing unit 200D performs step S106 of FIG. 1 . The first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the fourth processing unit 200D may have similar structures or different structures. It is also possible for the first processing unit 200A alone to perform all of steps S102 to S106 of FIG. 1 . The transport unit 400 transports the substrate 1 to the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the fourth processing unit 200D. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, the fourth processing unit 200D, and the transport unit 400.

[0068] 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.

[0069] 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 vertically and horizontally and rotatable about a vertical axis. The second transfer chamber 411 is connected to a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, and a fourth processing unit 200D via different gate valves G.

[0070] 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.

[0071] 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, the fourth processing unit 200D, and the transport unit 400, and performs the above-described film forming method.

[0072] 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.

[0073] 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.

[0074] Next, the first processing unit 200A performs steps S102 and S103. 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, and unintended oxidation of the substrate 1 can be suppressed.

[0075] Next, second processing unit 200B performs step S104. Thereafter, second transport mechanism 412 removes substrate 1 from second processing unit 200B and transports the removed substrate 1 to third processing unit 200C. During this time, the atmosphere surrounding substrate 1 can be maintained at a vacuum atmosphere, and degradation of the blocking performance of SAM 17 can be suppressed.

[0076] Next, the third processing unit 200C performs step S105. Thereafter, the second transport mechanism 412 removes the substrate 1 from the third processing unit 200C and transports the removed substrate 1 to the fourth processing unit 200D. During this time, the atmosphere surrounding the substrate 1 can be maintained at a vacuum atmosphere, and unintended oxidation of the substrate 1 can be suppressed.

[0077] Next, fourth processing unit 200D performs step S106. Thereafter, control unit 500 checks whether steps S104 to S106 have been performed a set number of times (N times). If the set number of times has not been reached, second transport mechanism 412 removes substrate 1 from fourth processing unit 200D and transports the removed substrate 1 to second processing unit 200B. Thereafter, control unit 500 controls second processing unit 200B, third processing unit 200C, fourth processing unit 200D, and transport unit 400 to perform steps S104 to S106 again.

[0078] On the other hand, if the number of times has reached the set number (N times), the second transport mechanism 412 removes the substrate 1 from the fourth processing unit 200D, 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.

[0079] Next, the first processing unit 200A will be described with reference to Fig. 8. The second processing unit 200B, the third processing unit 200C, and the fourth processing unit 200D are configured in the same manner as the first processing unit 200A, and therefore will not be illustrated or described here.

[0080] 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.

[0081] 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.

[0082] 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. 7 ) via the transfer port 215.

[0083] 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.

[0084] 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. 7), 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.

[0085] 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.

[0086] 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 steps that do not generate plasma (e.g., steps S104 and S105), the gas supply unit 240 does not need to serve as the upper electrode, and the lower electrode 223 is also not required.

[0087] 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.

[0088] 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 S106 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.

[0089] [Examples] Next, experimental data will be described. First, Examples 1 to 6 will be described with reference to Table 1. In Examples 1 to 6, substrates having a low-k film and a Cu film in different regions of the substrate surface were prepared, and the substrates were processed under the conditions shown in Table 1. Examples 1 and 2 are comparative examples, and Examples 3 to 6 are working examples.

[0090]

[0091] In Examples 1 to 6, steps S102 to S105 were set under the same conditions. ２ Gas and N ２ A mixed gas containing O was plasmatized and supplied for 15 seconds. ２ The gas was supplied for 30 seconds, and then PFBA gas was supplied. ２ A mixed gas containing Cu gas and Ar gas was plasmatized and supplied for 30 seconds. In step S104, HT gas was supplied for 60 seconds to selectively form a SAM on the surface of the Cu film. In step S105, TMA gas was supplied for 10 seconds, and then TPSOL gas was supplied for 15 seconds to selectively form a SiO film on the surface of the low-k film.

[0092] In Example 1, after steps S102 to S105, steps S106b and S106c were repeated six times without performing step S106a. ２ O gas was supplied for 10 seconds. ２ A mixed gas containing Ar gas and the gas was plasmatized and supplied for 30 seconds. In Example 1, the set number of times (M times) for step S106d was 6, and the set number of times (N times) for step S107 was 1. Note that, since step S106a was not performed, the set number of times (L times) for step S106e was 0.

[0093] In Example 2, similar to Example 1, except that the set number of times (N times) of step S107 was 2, steps S106b and S106c were repeated six times after steps S102 to S105 without performing step S106a.

[0094] In Example 3, after steps S102 to S105, step S106a was performed, followed by steps S106b and S106c, which were repeated three times. In step S106a, HF gas was supplied for 60 seconds. In Example 3, the set number of times (M times) for step S106d was 3, the set number of times (L times) for step S106e was 1, and the set number of times (N times) for step S107 was 1.

[0095] In Example 4, similar to Example 3, except that the set number of times (N times) of step S107 was two, step S106a was performed after steps S102 to S105, and then steps S106b and S106c were repeated three times.

[0096] In Example 5, after steps S102 to S105, step S106a was performed, and then steps S106b and S106c were repeated three times. ３ The gas mixture was supplied for 7 seconds. In Example 5, the set number of times (M times) of step S106d was 3, the set number of times (L times) of step S106e was 1, and the set number of times (N times) of step S107 was 1.

[0097] In Example 6, similar to Example 5, except that the set number of times (N times) of step S107 was three, step S106a was performed after steps S102 to S105, and then steps S106b and S106c were repeated three times.

[0098] In Example 6, the number of times (N times) of step S107 was set to 3 in order to make the thickness of the SiO film obtained in Example 6 approximately the same as the thickness of the SiO film obtained in Examples 2 and 4.

[0099] As is clear from a comparison of the opening widths of the SiO film obtained in Examples 1, 3, and 5 in Table 1, it can be seen that the opening width of the SiO film can be widened by performing all of steps S106a, S106b, and S106c.

[0100] Furthermore, as is clear from a comparison of the opening widths of the SiO films obtained in Examples 3 and 5 in Table 1, the HF gas and NH ３It can be seen that the use of a gas mixture can widen the opening width of the SiO film compared to the use of only HF gas in step S106a.

[0101] Next, Examples 7 to 9 will be described with reference to Table 2. In Examples 7 to 9, a substrate was prepared in which a SiO film (film thickness: 8.0 nm) was formed over the entire surface of a silicon wafer, and the SiO film was etched under the conditions shown in Table 2. Examples 7 to 9 are reference examples. The set number of times (L times) for step S106e was 0 in Example 7 and 1 in Examples 8 and 9. The SiO film was formed by supplying TMA gas and TPSOL gas in this order to the surface of the silicon wafer. The SiO film was dense and free of SAM contamination.

[0102]

[0103] In Table 2, the etching amount is the amount of change in the film thickness of the SiO film. It can be seen from Table 2 that the etching amount of the SiO film can be increased by performing all of steps S106a, S106b, and S106c.

[0104] Next, Examples 10 to 13 will be described with reference to Table 3. In Examples 10 to 13, a substrate was prepared in which a SiO film (film thickness: 5.3 nm) was formed on the entire surface of a silicon wafer, and the SiO film was etched under the conditions shown in Table 3. Examples 10 to 13 are reference examples. The number of times (L times) set for step S106e was 1. The SiO film was formed by supplying TMA gas and TPSOL gas to the surface of the silicon wafer in this order. The SiO film was dense and free of SAM contamination. In Examples 11 and 13, unlike Examples 10 and 12, the SiO film was modified after the SiO film was formed (step S105) and before the SiO film was etched (step S106). The SiO film was modified using H ２ The plasma was generated by using a mixed gas containing Ar gas and the gas mixture.

[0105]

[0106] In Examples 10 to 13, the SiO film was etched (step S106) under the same conditions except for the type of gas and its supply time in S106a. Figure 9 shows the relationship between the gas supply time in S106a and the etching amount in Examples 10 to 13. Note that in Figure 9, the etching amount in some data is slightly negative due to measurement error.

[0107] 9, when only HF gas is used in S106a, HF gas and NH ３ It can be seen that the areas where the SiO film is required (areas free of SAM contamination) tend to remain for a long time compared to when a mixed gas of HF gas and NH ３ Even when a mixture of gases is used, if the supply time of the mixture gas is short, it is understood that most of the necessary portions of the SiO film (portions free of SAM contamination) remain.

[0108] In step S106a, HF gas and NH ３ When a mixed gas of gases is used, the supply time of the mixed gas may be long. It is sufficient that at least some portions of the SiO film that are necessary (portions without SAM contamination) remain after S106. The etching rate of the portions that require the SiO film is slower than the etching rate of the portions that do not require the SiO film (portions with SAM contamination). Therefore, in S106a, HF gas and NH ３ Even when a mixture of gases is used, it is possible to leave necessary portions of the SiO film.

[0109] Next, Examples 14 to 15 will be described with reference to Table 4. In Examples 14 to 15, silicon wafers were prepared and processed under the conditions shown in Table 4. Examples 14 to 15 are reference examples. The number of times (L times) set for step S106e was 1. The SiO film was formed by supplying TMA gas and TPSOL gas in this order to the surface of the silicon wafer. The SiO film was dense and free of SAM contamination. In Example 15, unlike Example 14, H ２The mixed gas of the gas and the rare gas was plasmatized and supplied to the surface of the second insulating film 18 (step S106c1), and then only the rare gas was plasmatized and supplied to the surface of the second insulating film 18 (step S106c2).

[0110]

[0111] In Examples 14 and 15, the SiO film was etched (step S106) under the same conditions except for the type of gas and its supply time in S106c. As a result, the SiO film remained in all of Examples 14 and 15. However, when a voltage was applied in the thickness direction of the SiO film to measure the leakage current of the SiO film, a large amount of current flowed in Example 14, and the voltage did not reach 5 MV. On the other hand, in Example 15, the leakage current when the voltage reached 5 MV was very small. This shows that the quality of the SiO film can be improved by performing S106c1 and S106c2 in S106c.

[0112] Next, Examples 16 to 17 will be described with reference to Table 5. In Examples 16 and 17, substrates having a low-k film and a Co film in different regions of the substrate surface were prepared, and the substrates were treated under the conditions shown in Table 5. Example 16 is an example, and Example 17 is a comparative example.

[0113]

[0114] In Examples 16 and 17, steps S102 to S104 were set under the same conditions. ２ Gas and N ２ A mixed gas containing H was plasmatized and supplied for 15 seconds, and then acetic acid gas was supplied for 300 seconds. ２ A mixed gas containing Ar gas and Co gas was turned into plasma and supplied for 30 seconds. In step S104, HT gas was supplied for 300 seconds to selectively form a SAM on the surface of the Co film.

[0115] In Examples 16 and 17, the same conditions were set for step S105 except for the number of times (K times) set for step S105c. In step S105, TMA gas was supplied for 0.5 seconds, and then H ２By repeatedly supplying O gas for 1.0 second multiple times, an AlO film was selectively formed on the surface of the low-k film. K in Example 16 was 1 / 3 of K in Example 17. Note that N in Example 16 was three times N in Example 17, so the total number of times step S105 was performed was the same in Examples 16 and 17.

[0116] In Example 16, after steps S102 to S105, step S106a was performed, and then steps S106b and S106c were repeated three times. ３ The mixed gas of H was supplied for 30 seconds. ２ O gas was supplied for 10 seconds. ２ In Example 16, the set number of times (M times) of step S106d was 3, and the set number of times (L times) of step S106e was 1.

[0117] In Example 17, after steps S102 to S105, steps S106b and S106c were repeated three times without performing step S106a. In Example 17, steps S106b and S106c were performed under the same conditions as in Example 16. In Example 17, the set number of times (M times) for step S106d was three, and the set number of times (L times) for step S106e was one.

[0118] As shown in Table 5, in Example 16, unlike Example 17, the AlO film on the Co film could be removed by performing all of steps S106a, S106b, and S106c.

[0119] 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.

[0120] This application claims priority based on Japanese Patent Application No. 2023-105828 filed with the Japan Patent Office on June 28, 2023, and Japanese Patent Application No. 2024-075701 filed with the Japan Patent Office on May 8, 2024. The entire contents of Japanese Patent Application Nos. 2023-105828 and 2024-075701 are incorporated by reference into this application.

[0121] REFERENCE SIGNS LIST 1 Substrate 1a Substrate surface 11 Insulating film (first film) 12 Conductive film (second film) 17 SAM (self-assembled monolayer) 18 Second insulating film (target film)

Claims

1. A method for manufacturing a substrate, comprising: (A) preparing a substrate having a first film and a second film formed of a material different from that of the first film in different regions of its surface; (B) selectively forming a deposition-inhibiting film that inhibits formation of a target film on a surface of the second film relative to a surface of the first film; (C) selectively forming the target film on the surface of the first film relative to a surface of the second film using the deposition-inhibiting film; and (D) preferentially etching a portion of the target film relative to another portion of the target film, wherein (D) comprises: (Da) supplying a fluorine-containing gas to the surface of the target film to adsorb fluorine to the surface of the target film or to form a fluorine-containing layer on the surface of the target film; and (Db) applying H to the surface of the target film after (Da). ２ A film forming method comprising: generating hydrogen fluoride by supplying O gas; and (Dc) after (Db), supplying a gas plasma to a surface of the target film.

2. The film forming method according to claim 1, wherein the portion of the target film that is preferentially etched in (D) includes a portion deposited on the surface of the second film.

3. The film forming method according to claim 1 or 2, wherein in (D), (Db) and (Dc) are repeated a plurality of times.

4. The film forming method according to claim 3, wherein in (D), (Da), (Db) and (Dc) are repeated a plurality of times.

5. The film forming method according to claim 1 or 2, wherein steps (B), (C) and (D) are repeated a number of times.

6. The film forming method according to claim 1 or 2, wherein the first film is an insulating film and the second film is a conductive film.

7. The film formation method according to claim 1 or 2, wherein the film formation inhibiting film is a self-assembled monolayer.

8. The film formation method according to claim 1 or 2, wherein the film formation inhibiting film is a graphene-containing film.

9. The film formation method according to claim 1 or 2, wherein the film formation inhibiting film is a boron-containing film.

10. The film forming method according to claim 1 or 2, wherein the target film is an oxide film.

11. The film forming method according to claim 10, wherein the target film is a film containing silicon (Si) and oxygen (O).

12. The film forming method according to claim 10, wherein the target film is a film containing aluminum (Al) and oxygen (O).

13. The fluorine-containing gas is HF gas and NH ３ 3. The method of claim 1, wherein the gas is a mixed gas of gases.

14. The gas to be plasmatized in (Dc) is H ２ Gas, noble gas, or H ２ The method of claim 1 or 2, further comprising a mixed gas of a gas and a rare gas.

15. The above (Dc) is H ２ Gas only or H ２ The film forming method according to claim 14, comprising: converting a mixed gas of a gas and a rare gas into plasma and supplying the plasma to the surface of the target film; and converting only the rare gas into plasma and supplying the plasma to the surface of the target film, in a desired order.

16. 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 plasma generation unit that converts the gas supplied into the processing vessel into plasma; 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 plasma generation unit, the gas exhaust mechanism, and the transport mechanism, and performs the film formation method according to claim 1 or 2.

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