Film forming method and film forming apparatus

Abstract

To provide a technique preferentially etching a part of an object film with respect to another part of the object film.SOLUTION: A film forming method has the following (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 (D) includes: (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).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a film forming method and a film forming apparatus. [Background technology]

[0002] The film forming method described in Patent Document 1 includes the following steps (1) to (4). (1) A substrate is prepared having a surface having 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) A fluorine-containing organic compound, which is a raw material of a self-assembled monolayer, is supplied to the surface of the substrate, and the self-assembled monolayer is selectively formed in the second region among the first region and the second region. (3) The self-assembled monolayer is used to form the target film in the first region while inhibiting the formation of the target film in the second region. (4) A gas containing H2O is supplied to the surface of the substrate, and an end of the target film protruding from the first region is etched.

[0003] The etching method described in Patent Document 2 includes a step of supplying a mixed gas containing hydrogen fluoride (HF) gas and ammonia (NH3) gas to the surface of a silicon oxide film to modify the silicon oxide film and generate a reaction product, and a step of heating and removing the reaction product.The etching method described in Patent Document 3 includes a step of forming an etching product made of ammonium silicofluoride salt by reacting one or more gases selected from NF3, H2, N2, HF, and NH3 with the oxide film, and a step of sublimating the etching product at a temperature of 100°C or higher. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-055462 A [Patent Document 2] JP 2007-180418 A [Patent Document 3] JP 2009-140944 A Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0006] A film forming method according to an embodiment of the present disclosure includes the following steps (A) to (D). (A) A substrate is prepared having a first film and a second film formed of a material different from the first film in different regions of its surface. (B) A film formation inhibiting film that inhibits formation of a target film is selectively formed on the surface of the second film relative to the surface of the first film. (C) The target film is selectively formed on the surface of the first film relative to the surface of the second film using the film formation inhibiting film. (D) A part of the target film is preferentially etched relative to another part 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; (Db) generating hydrogen fluoride by supplying H2O gas to the surface of the target film after the step (Da); and (Dc) supplying a plasmatized gas to the surface of the target film after the step (Db). Effect of the Invention

[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. [Brief description of the drawings]

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

[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 the description thereof may be omitted.

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

[0011] Step S101 includes preparing a substrate 1 as shown in FIG. 4(A). 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 includes an insulating film 11 and a conductive film 12 in different regions of a 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, but is not limited to, 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 Si to O in the 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 also mean that they contain each element, and are not limited to a stoichiometric ratio. The insulating film 11 has a recess on the substrate surface 1a. The recess is a trench, a contact hole, or a via hole.

[0013] The conductive film 12 fills, for example, the recesses of 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 be a cap film. That is, as shown in FIG. 6(A), a second conductive film 15 may be embedded in the recesses of 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 have 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, but is not limited to, a TaN film or a TiN film. Here, the TiN film means a film containing titanium (Ti) and nitrogen (N). The atomic ratio of Ti to N in the TiN film is usually 1:1, but is not limited to 1:1. The TaN film also means that it contains each element, and is not limited to a stoichiometric ratio.

[0015] The substrate 1 may further have a fourth film on the substrate surface 1a. The fourth film is, for example, a liner film 14 (see FIG. 5(A) and FIG. 6(A)). 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] As shown in Figures 4(A), 5(A) and 6(A), contaminants 22 may be present on the substrate surface 1a. The contaminants 22 are, 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 is, 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 on the substrate surface 1a as shown in Fig. 4(B), Fig. 5(B) and Fig. 6(B). In the first pre-treatment, a cleaning gas is supplied to the substrate surface 1a. A plurality of 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 a reducing gas such as H2 gas, and may contain a nitrogen-containing gas such as N2 gas in addition to the reducing gas. 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. H2 gas flow rate: 50sccm~5000sccm N2 gas flow rate: 50sccm~10000sccm Ar gas flow rate: 20sccm to 10,000sccm Proportion of H2 gas in the first cleaning gas: 10% to 60% by volume Proportion of N2 gas in the first cleaning gas: 10% to 80% by volume Power supply frequency for plasma generation: 10MHz~100MHz Power for plasma generation: 50W~400W Processing time: 5 to 120 seconds Processing temperature (substrate temperature): 80℃~350℃ Processing pressure: 50Pa~2000Pa.

[0020] The second cleaning gas contains an oxygen-containing gas. The oxygen-containing gas contains at least one selected from O2 gas, O3 gas, H2O gas, NO gas, NO2 gas, and N2O gas. The oxygen-containing gas is supplied to the substrate surface 1a without being turned into plasma.

[0021] An example of the treatment conditions using the second cleaning gas is shown below. O2 gas flow rate: 100sccm~2000sccm Processing time: 10 seconds to 5 minutes Processing temperature (substrate temperature): 80℃~350℃ Processing pressure: 50Pa~665Pa.

[0022] The third cleaning gas includes 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 "RP(=O)(OH)2". The nitro compound is represented by the general formula "R-NO2". 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 replaced with fluorine. Specifically, for example, R is "CF3-(CF2) X -", "CF3-(CF2) X -CH2-CH2-" or "CH3-(CH2) X -". X is an integer from 1 to 17. Specific examples of carboxylic acid compounds include PFBA (CF3(CF2)2COOH), formic acid (HCOOH), acetic acid (CH3COOH), propionic acid (CH3CH2COOH), and octanoic acid (CH3(CH2)6COOH). Specific examples of nitro compounds include PFNO (CF3(CF2)5CH2CH2NO2).

[0024] An example of the treatment conditions for the third cleaning gas is shown below. PFBA gas flow rate: 10sccm to 100sccm Processing time: 30 seconds to 10 minutes Processing temperature (substrate temperature): 80℃~350℃ Processing pressure: 100Pa~300Pa.

[0025] Step S103 includes performing a second pre-treatment to remove the residue of the cleaning gas supplied in step S102. The residue of the cleaning gas is mainly organic matter. In the second pre-treatment, a plasma gas is supplied to the substrate surface 1a. The gas contains at least a reducing gas such as H2 gas, and may contain a nitrogen-containing gas such as N2 gas in addition to the reducing gas. The process conditions of step S103 are the same as the process conditions using the first cleaning gas in step S102, and therefore will not be described.

[0026] Step S104, as shown in Fig. 4(C), Fig. 5(C) and Fig. 6(C), 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. Hereinafter, the self-assembled monolayer (SAM) 17 may be referred to as SAM17. The SAM17 is formed by supplying an organic compound gas to the substrate surface 1a. The organic compound gas is a raw material gas for the SAM17.

[0027] The source gas of the SAM17 is not particularly limited, but includes, for example, a thiol-based compound. Specific examples of the thiol-based compound include CF3(CF2)5CH2CH2SH (1H,1H,2H,2H-perfluorooctanethiol: PFOT) and CH3(CH2)5SH (hexanethiol: HT). The thiol-based compound is more likely to be chemically adsorbed to the surface of the conductive film 12 than to the surface of the insulating film 11. Therefore, the SAM17 is selectively formed on the surface of the conductive film 12 with respect to the surface of the insulating film 11. The SAM17 is hardly formed on the surface of the insulating film 11. The SAM17 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 FIG. 5(C) and FIG. 6(C).

[0028] The source gas for SAM17 is not limited to a thiol compound. The source gas for SAM17 may include a phosphonic acid compound, a carboxylic acid compound, or a nitro compound. The third cleaning gas and the source gas for SAM17 may include the same organic compound or different organic compounds, but preferably include the same organic compound. Using the same organic compound can reduce costs, such as by reducing the number of chambers used.

[0029] The source gas for SAM17 may contain an olefin-based compound or an organic silane-based compound. An olefin-based compound is represented by the general formula "R-CH=CH2". An organic silane-based compound is, for example, a trichlorosilane-based, methoxysilane-based, or ethoxysilane-based compound. A trichlorosilane-based organic compound is represented by the general formula "R-SiCl3". A methoxysilane-based organic compound is represented by the general formula "R-Si(OCH3)3". An ethoxysilane-based organic compound is represented by the general formula "R-Si(OCH2CH3)3".

[0030] An example of the processing conditions in step S104 is shown below. HT gas flow rate: 50sccm~200sccm Processing time: 10 seconds to 600 seconds Processing temperature: 80℃~350℃ Processing pressure: 50Pa~4000Pa.

[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 the SAM, and may be, for example, a graphene-containing film or a boron-containing film.

[0032] Step S105 includes selectively forming a second insulating film 18 on the surface of the insulating film 11 with respect to the surface of the conductive film 12 using a SAM 17, as shown in Fig. 4(D), Fig. 5(D), and Fig. 6(D). The second insulating film 18 is an example of a target film. The second insulating film 18 is formed by a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) 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 means a film containing aluminum (Al) and oxygen (O). The atomic ratio of Al to O in the AlO film is usually 2:3, but is not limited to 2:3. Similarly, the SiO film, the SiN film, the ZrO film, and the HfO film also mean that they contain each element, and are not limited to the 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 a 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. Specifically, an organoaluminum compound gas and an organotitanium compound gas can be mentioned. The organoaluminum compound gas can be, for example, trimethylaluminum (TMA) gas, triethylaluminum (TEA) gas, dimethylaluminum chloride gas, or dimethylaluminum isopropoxide (DMAI). The organotitanium compound gas can be, for example, tetrakis(dimethylamino)titanium (TDMAT) gas.

[0036] The silanol group-containing gas is not particularly limited, but for example, tris(tert-pentoxy)silanol (TPSOL), triethylsilanol, methyl bis(tert-pentoxy)silanol, or tris(tert-butoxy)silanol (TBSOL) may be used.

[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 in step S105a is shown below. TMA gas flow rate: 10sccm to 100sccm Processing time: 0.05 seconds to 100 seconds Processing temperature: 80℃~350℃ Processing pressure: 133Pa~1200Pa.

[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 in step S105b is shown below: Note that the TPSOL gas is supplied by vaporizing TPSOL liquid. TPSOL gas flow rate: 0.1g / min~0.5g / min Processing time: 3 to 120 seconds Processing temperature: 80℃~350℃ Processing pressure: 133Pa~1200Pa.

[0042] In step S105a and step 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, for example, supplying an Al-containing gas to the substrate surface 1a, and step S105b includes, for example, supplying 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, H2O gas.

[0043] The etching rate of the AlO film is slower than that of the SiO film in step S106. In order to facilitate etching of unnecessary portions of the AlO film (portions deposited on the surface of the conductive film 12) in step S106, it is preferable that the thickness of the AlO film formed in one step S105 is thin. The set number of times (K times) of step S105c may be reduced, and the set number of times (N times) of step S107 may 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] Incidentally, as shown in Fig. 4(D), Fig. 5(D) and Fig. 6(D), 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 protrude laterally from the surface of the insulating film 11 and cover a part of the surface of the conductive film 12. This narrows the opening width of the second insulating film 18, and increases the wiring resistance of the substrate 1. In particular, the resistance of the via wiring penetrating between layers increases and the yield of good vias decreases. 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. Thus, 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 or a boron-containing film 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 influenced by the film-formation-inhibiting film and has its growth inhibited, becoming thinner or less dense.

[0048] As shown in FIG. 3, step S106 includes, for example, supplying a fluorine-containing gas (step S106a), supplying an H2O gas (step S106b), and supplying a gas in plasma form (step S106c). Step S106 includes performing step S106b and step S106c a set number of times (M times). M may be an integer of 2 or more, and the above steps S106b to S106c may be repeatedly performed a set number of times. Step S106 also includes performing step S106a once, and performing step S106b and step S106c M times, a set number of times (L times). L may be an integer of 2 or more, and the above steps S106a to S106c may be repeatedly performed a set number of times.

[0049] 4(E), 5(E), and 6(E), 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. Instead of forming the fluorine-containing layer 19 on the surface of the second insulating film 18, fluorine may be adsorbed on the surface of the second insulating film 18.

[0050] The fluorine-containing gas is, for example, a mixed gas of HF gas and NH3 gas. A fluorine-containing layer 19 is formed by a reaction between the mixed gas of HF gas and NH3 gas and 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 contains ammonium silicofluoride ((NH4)2SiF6).

[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 the 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 a mixed gas of HF gas and NH3 gas, but it may not contain NH3 gas and 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 in step S106a is shown below. HF gas flow rate: 10sccm to 100sccm NH3 gas flow rate: 10sccm to 100sccm Processing 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) Processing pressure: 50Pa~1200Pa.

[0054] Step S106b includes generating hydrogen fluoride by supplying H2O gas to the surface of the second insulating film 18. Hydrogen fluoride is generated by a reaction between the fluorine-containing layer 19 and H2O gas. It is also possible to generate hydrogen fluoride by a reaction between fluorine adsorbed on the surface of the second insulating film 18 and H2O gas instead of the fluorine-containing layer 19. H2O2 gas may be used in addition to H2O gas in step S106b. It is preferable not to plasma-ize H2O gas in step S106b. This can prevent the generation of oxygen plasma and the oxidation of the conductive film 12.

[0055] An example of the processing conditions in step S106b is shown below. H2O gas flow rate: 10sccm~500sccm Processing time: 0.1sec~120sec Processing temperature: 80℃~350℃ Processing pressure: 50Pa~1200Pa.

[0056] Step S106c includes supplying gas in plasma form to the surface of the second insulating film 18. By sequentially performing Step S106b and Step S106c, it is possible to prevent the H2O gas from becoming plasma, prevent the generation of oxygen plasma, and prevent the conductive film 12 from being oxidized.

[0057] In order to prevent the generation of oxygen plasma, the gas to be turned into plasma in step S106c preferably does not contain an oxygen-based gas. The gas to be turned into plasma is, for example, H2 gas, a rare gas, or a mixed gas of H2 gas and a rare gas. The rare gas is, for example, Ar gas or He gas. The plasma promotes the decomposition of the fluorine-containing layer 19 or the desorption of fluorine, and promotes the generation of hydrogen fluoride. This can promote the 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. The unnecessary portion of the second insulating film 18 (the portion deposited on the surface of the conductive film 12) is etched, whereas 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. H2 gas flow rate: 200sccm~3000sccm Ar gas flow rate: 100sccm to 6000sccm The ratio of H2 gas in the mixture of H2 gas and Ar gas: 0% to 90% by volume Power frequency for plasma generation: 10MHz~60MHz Power for plasma generation: 50W~600W Processing time: 2sec~120sec Processing temperature: 80℃~350℃ Processing pressure: 50Pa~1200Pa.

[0060] Although not shown, step S106c preferably includes, in a desired order, turning only H2 gas or a mixed gas of H2 gas and a rare gas into plasma and supplying it to the surface of the second insulating film 18 (step S106c1) and turning only rare gas into plasma and supplying it to the surface of the second insulating film 18 (step S106c2). The order may be either first or second, 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 second insulating film 18 remaining after step S106c is reduced. Note that, in step S106c1, only H2 gas may be turned into plasma and supplied to the surface of second insulating film 18 as described above, but from the viewpoint of promoting plasma generation, it is preferable to turn a mixed gas of H2 gas and a rare gas into plasma and supply it to the surface of 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 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 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, and preferably 2 to 50 times. When M is an integer of 2 or more, steps S106b to S106c are repeated multiple times. The decomposition of the fluorine-containing layer 19 or the desorption of fluorine can be gradually promoted, 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 enlarged, 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. The fluorine-containing layer 19 can be regenerated, and hydrogen fluoride can be generated for a long period of time. As a result, the opening width of the second insulating film 18 can be enlarged, 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 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 of times, the thickness of second insulating film 18 has reached the target thickness, so the current process ends.

[0067] Next, referring to FIG. 7, a film forming apparatus 100 for carrying out the above-mentioned film forming method will be described. As shown in FIG. 7, the film forming apparatus 100 has a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a fourth processing unit 200D, a transfer unit 400, and a control unit 500. The first processing unit 200A carries out steps S102 to S103 in FIG. 1. The second processing unit 200B carries out step S104 in FIG. 1. The third processing unit 200C carries out step S105 in FIG. 1. The fourth processing unit 200D carries out step S106 in 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 the same structure or different structures. It is also possible to carry out all of steps S102 to S106 in FIG. 1 only by the first processing unit 200A. The transfer unit 400 transfers 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 transfer 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 an air atmosphere. 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 a rail 404. The rail 404 extends in the arrangement direction of the carriers C.

[0069] The transfer unit 400 also includes 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 first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the fourth processing unit 200D are connected to the second transfer chamber 411 via different gate valves G.

[0070] Furthermore, the transfer section 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 air 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 to perform the above-mentioned film forming method.

[0072] Next, the operation of the film forming apparatus 100 will be described. First, the first transport mechanism 402 takes out the substrate 1 from the carrier C, transports the taken out substrate 1 to the load lock chamber 421, and exits from 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. After that, the second transport mechanism 412 takes out the substrate 1 from the load lock chamber 421, and transports the taken out substrate 1 to the first processing unit 200A.

[0073] Next, first processing unit 200A performs steps S102 to S103. Thereafter, second transport mechanism 412 removes substrate 1 from first processing unit 200A and transports it to second processing unit 200B. During this time, the atmosphere around substrate 1 can be maintained as a vacuum atmosphere, and unintended oxidation of substrate 1 can be suppressed.

[0074] Next, the second processing unit 200B performs step S104. After that, the second transport mechanism 412 removes the substrate 1 from the second processing unit 200B and transports the removed substrate 1 to the third processing unit 200C. During this time, the atmosphere around the substrate 1 can be maintained as a vacuum atmosphere, and the deterioration of the blocking performance of the SAM 17 can be suppressed.

[0075] Next, the third processing unit 200C performs step S105. After that, 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 around the substrate 1 can be maintained as a vacuum atmosphere, and unintended oxidation of the substrate 1 can be suppressed.

[0076] Next, fourth processing apparatus 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 number of times has not reached the set number of times, second transport mechanism 412 removes substrate 1 from fourth processing apparatus 200D and transports substrate 1 to second processing apparatus 200B. Thereafter, control unit 500 controls second processing apparatus 200B, third processing apparatus 200C, fourth processing apparatus 200D, and transport unit 400 to perform steps S104 to S106 again.

[0077] On the other hand, if the number of times has reached the set number (N times), the second transport mechanism 412 takes out the substrate 1 from the fourth processing unit 200D, transports the taken out substrate 1 to the load lock chamber 421, and exits from the load lock chamber 421. Then, the internal atmosphere of the load lock chamber 421 is switched from a vacuum atmosphere to an air atmosphere. After that, the first transport mechanism 402 takes out the substrate 1 from the load lock chamber 421, and stores the taken out substrate 1 in the carrier C. Then, the processing of the substrate 1 is completed.

[0078] Next, the first processing unit 200A will be described with reference to Fig. 8. Note that the second processing unit 200B, the third processing unit 200C, and the fourth processing unit 200D are configured similarly to the first processing unit 200A, and therefore will not be illustrated or described.

[0079] 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.

[0080] 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 inside of the processing vessel 210 can be depressurized by the exhaust source 272. The pressure controller 271 and the exhaust source 272 configure a gas exhaust mechanism 270 that exhausts gas inside the processing vessel 210.

[0081] A transfer port 215 is provided on a side surface of the processing vessel 210. The transfer port 215 is opened and closed by a gate valve G. The substrate 1 is loaded and unloaded through the transfer port 215 between the processing vessel 210 and a second transfer chamber 411 (see FIG. 7).

[0082] A stage 220, which is a holder for holding the substrate 1, is provided in 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 having a diameter of, for example, 300 mm 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). The stage 220 may also be formed of a metal material such as nickel (Ni). Instead of the recess 222, a guide ring for guiding the substrate 1 may be provided on the periphery of the surface of the stage 220.

[0083] A grounded lower electrode 223 is embedded in the stage 220. A heating mechanism 224 is embedded below the lower electrode 223. The heating mechanism 224 heats the substrate 1 placed on the stage 220 to a set temperature by being supplied with power from a power supply unit (not shown) based on a control signal from the control unit 500 (see FIG. 7). When the entire stage 220 is made of metal, the entire stage 220 functions as the lower electrode, so that 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) lift pins 231 for holding and lifting the substrate 1 placed on the stage 220. The material of the lift pins 231 may be, for example, ceramics such as alumina (Al2O3) or quartz. The lower end of the lift pin 231 is attached to a support plate 232. The support plate 232 is connected to a lifting mechanism 234 provided outside the processing vessel 210 via a lifting shaft 233 .

[0084] The lifting mechanism 234 is installed, for example, at the bottom of 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 bottom 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 freely raised and lowered between above the surface of the stage 220 and below the surface of the stage 220 by the lifting mechanism 234.

[0085] 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 source 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 source 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, and capacitively coupled plasma is generated. A plasma generation unit 250 that generates plasma includes the matching unit 251 and the high-frequency power source 252. The plasma generation unit 250 is not limited to capacitively coupled plasma, and may generate other plasmas such as inductively coupled plasma. In steps that do not generate plasma (for example, steps S104 and S105), it is not necessary for the gas supply unit 240 to serve as an upper electrode, and the lower electrode 223 is also not necessary.

[0086] The gas supply unit 240 includes a hollow gas supply chamber 241. A number of holes 242 for dispersively supplying a processing gas into the processing vessel 210 are arranged, for example, evenly, on the bottom surface of the gas supply chamber 241. A heating mechanism 243 is embedded, for example, above the gas supply chamber 241 in the gas supply unit 240. The heating mechanism 243 is heated to a set temperature by being supplied with power from a power supply unit (not shown) based on a control signal from the control unit 500.

[0087] 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 in FIG. 1 to the gas supply chamber 241 via the gas supply path 261. Although not shown, the gas supply mechanism 260 includes an individual pipe for each type of gas, an opening / closing valve provided midway through the individual pipe, and a flow rate controller provided midway through the individual pipe. When the opening / closing valve opens the individual pipe, 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 opening / closing valve closes the individual pipe, the supply of gas from the supply source to the gas supply path 261 is stopped.

[0088] [Example] 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 on 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.

[0089] [Table 1]

[0090] In Examples 1 to 6, steps S102 to S105 were set under the same conditions. In step S102, a mixed gas containing H2 gas and N2 gas was turned into plasma and supplied for 15 seconds, then O2 gas was supplied for 30 seconds, and then PFBA gas was supplied. In step S103, a mixed gas containing H2 gas and Ar gas was turned into plasma 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.

[0091] In Example 1, after the above steps S102 to S105, steps S106b and S106c were repeated six times without performing step S106a. In step S106b, H2O gas was supplied for 10 seconds. In step S106c, a mixed gas containing H2 gas and Ar gas was turned into plasma and supplied for 30 seconds. In Example 1, the set number of times (M times) of step S106d was 6 times, and the set number of times (N times) of step S107 was 1 time. Since step S106a was not performed, the set number of times (L times) of step S106e was 0 times.

[0092] In Example 2, similarly to Example 1, except that the set number of times (N times) of step S107 was two, steps S106b and S106c were repeated six times after steps S102 to S105 without performing step S106a.

[0093] In Example 3, after the above steps S102 to S105, step S106a was performed, and then steps S106b and S106c were repeated three times. In step S106a, HF gas was supplied for 60 seconds. In Example 3, the set number of times (M times) of step S106d was 3 times, the set number of times (L times) of step S106e was 1 time, and the set number of times (N times) of step S107 was 1 time.

[0094] In Example 4, like 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.

[0095] In Example 5, after the above steps S102 to S105, step S106a was performed, and then steps S106b and S106c were repeated three times. In step S106a, a mixed gas of HF gas and NH3 gas was supplied for seven seconds. In Example 5, the set number of times (M times) of step S106d was three, the set number of times (L times) of step S106e was one, and the set number of times (N times) of step S107 was one.

[0096] In Example 6, like 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.

[0097] In Example 6, the number of times (N times) of step S107 is 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.

[0098] 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 increased by performing all of steps S106a, S106b, and S106c.

[0099] Moreover, as is clear from a comparison of the opening widths of the SiO film obtained in Example 3 and Example 5 in Table 1, when a mixed gas of HF gas and NH3 gas is used in step S106a, the opening width of the SiO film can be made wider than when only HF gas is used in step S106a.

[0100] Next, Examples 7 to 9 will be described. 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) of step S106e was 0 times in Example 7, and 1 time 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.

[0101] [Table 2]

[0102] In Table 2, the etching amount is the amount of change in the 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.

[0103] Next, examples 10 to 13 will be described. In examples 10 to 13, a substrate in which a SiO film (film thickness: 5.3 nm) was formed on the entire surface of a silicon wafer was prepared, 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 formation of the SiO film (step S105) and before the etching of the SiO film (step S106). The SiO film was modified using a mixed gas containing H2 gas and Ar gas that was turned into plasma.

[0104] [Table 3]

[0105] 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. Fig. 9 shows the relationship between the gas supply time in S106a and the amount of etching in Examples 10 to 13. Note that in Fig. 9, the amount of etching in some data is slightly negative due to measurement error.

[0106] 9, when only HF gas is used in S106a, the necessary portion of the SiO film (portion without SAM contamination) is more likely to remain for a long time than when a mixture of HF gas and NH3 gas is used in S106a. Also, when a mixture of HF gas and NH3 gas is used in S106a, the necessary portion of the SiO film (portion without SAM contamination) remains almost entirely if the mixture gas is supplied for a short period of time.

[0107] In addition, when a mixed gas of HF gas and NH3 gas is used in S106a, the mixed gas may be supplied for a long time. It is sufficient that the necessary portion of the SiO film (a portion without SAM contamination) remains even if only a little after S106. The etching speed of the necessary portion of the SiO film is slower than the etching speed of the unnecessary portion of the SiO film (a portion with SAM contamination). Therefore, even when a mixed gas of HF gas and NH3 gas is used in S106a, it is possible to leave the necessary portion of the SiO film.

[0108] Next, examples 14 to 15 will be described. 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) of step S106e was set to 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. Unlike example 14, example 15 was different from example 14 in that in step S106c, a mixed gas of H2 gas and a rare gas was turned into plasma and supplied to the surface of the second insulating film 18 (step S106c1), and only the rare gas was turned into plasma and supplied to the surface of the second insulating film 18 (step S106c2), in this order.

[0109] [Table 4]

[0110] In Examples 14 and 15, the etching of the SiO film (step S106) was performed 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.

[0111] Next, examples 16 to 17 will be described. In examples 16 to 17, substrates having a low-k film and a Co film in different regions on the substrate surface were prepared, and the substrates were treated under the conditions shown in Table 5. Example 16 is an embodiment, and Example 17 is a comparative example.

[0112] [Table 5]

[0113] In Examples 16 and 17, steps S102 to S104 were set under the same conditions. In step S102, a mixed gas containing H2 gas and N2 gas was turned into plasma and supplied for 15 seconds, and then acetic acid gas was supplied for 300 seconds. In step S103, a mixed gas containing H2 gas and Ar 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.

[0114] In Examples 16 and 17, step S105 was set under the same conditions, 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 H2O gas was supplied for 1.0 second, which was repeated multiple times to selectively form an AlO film on the surface of the low-k film. K in Example 16 was 1 / 3 times that of Example 17. Note that N in Example 16 was 3 times that of Example 17, so the total number of times step S105 was performed was the same in Examples 16 and 17.

[0115] In Example 16, after the above steps S102 to S105, step S106a was performed, and then steps S106b and S106c were repeated three times. In step S106a, a mixed gas of HF gas and NH3 gas was supplied for 30 seconds. In step S106b, H2O gas was supplied for 10 seconds. In step S106c, a mixed gas containing H2 gas and Ar gas was turned into plasma and supplied for 10 seconds, and then only Ar gas was turned into plasma and supplied for 20 seconds. In Example 16, the set number of times (M times) of step S106d was 3 times, and the set number of times (L times) of step S106e was 1 time.

[0116] In Example 17, after the above 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) of step S106d was three, and the set number of times (L times) of step S106e was one.

[0117] 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.

[0118] Although the embodiments of the film forming method and the film forming apparatus according to the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Naturally, these also fall within the technical scope of the present disclosure. [Explanation of symbols]

[0119] 1 Board 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) 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 film-formation 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 the surface of the second film using the film formation inhibiting film; (D) preferentially etching a portion of the target film relative to another portion of the target film; having The (D) is (Da) supplying a fluorine-containing gas to a surface of the target film to adsorb fluorine onto the surface of the target film or to form a fluorine-containing layer on the surface of the target film; (Db) After (Da), H is applied to the surface of the target film. ２ Producing hydrogen fluoride by supplying O gas; (Dc) after (Db), supplying a plasmatized gas to the surface of the target film; The film forming method includes the steps of:

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 a surface of the second film.

3. The film forming method according to claim 1 , 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 , wherein the steps (B), (C) and (D) are repeated a plurality of times.

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

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

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

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

10. The film forming method according to claim 1 , 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 converted into plasma in (Dc) is H ２ Gas, rare 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 (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 processing vessel; a holder for holding the substrate inside the processing vessel; a gas supply mechanism for supplying a gas into the processing chamber; a plasma generating unit for generating plasma from a gas supplied to the inside of the processing chamber; a gas exhaust mechanism for exhausting gas from inside the processing vessel; a transport mechanism for transporting the substrate into and out of the processing vessel; a control unit that controls the gas supply mechanism, the plasma generating unit, the gas exhaust mechanism, and the transport mechanism to perform the film forming method according to claim 1 or 2; A film forming apparatus comprising:

Images