Film formation method and film formation device

Abstract

This film formation method includes preparing a substrate having, in different regions of a surface thereof, a first film and a second film formed of a material different from that of the first film, forming a third film containing boron selectively on the second film with respect to the first film, improving a film formation inhibition property of the third film with respect to a fourth film by supplying a modification gas for modifying at least the surface of the third film to the substrate, and selectively forming the fourth film on the first film with respect to the third film modified with the modification gas. The forming of the fourth film includes alternately or simultaneously supplying, to the substrate, a raw material gas containing a halogen and an element X other than halogens and a reactant gas that reacts with an adsorbent of the raw material gas and thereby forming the fourth film containing the element X.

Description

Film deposition method and film deposition apparatus 【0001】 This disclosure relates to a film deposition method and a film deposition apparatus. 【0002】 The film formation method described in Patent Document 1 includes the following (A) to (C): (A) A substrate having a first film containing boron and a second film formed of a material different from the first film on its surface is prepared. (B) A raw material gas containing halogen and element X other than halogen is supplied to the surface of the substrate. (C) A reaction gas containing plasma-formed oxygen is supplied to the surface of the substrate. 【0003】 Japanese Patent Application Publication No. 2023-68619 【0004】 One embodiment of the present disclosure provides a technology for improving the selectivity of selective film formation. 【0005】 A film-forming method according to one embodiment of the present disclosure comprises: preparing a substrate having a first film and a second film formed of a different material from the first film in different regions of its surface; selectively forming a third film containing boron on the second film relative to the first film; supplying a modifying gas to the substrate to modify at least the surface of the third film to improve the third film's ability to inhibit the formation of a fourth film; and selectively forming the fourth film on the first film relative to the third film modified with the modifying gas. Forming the fourth film includes forming the fourth film containing element X by alternately or simultaneously supplying to the substrate a source gas containing a halogen and an element X other than a halogen, and a reaction gas that reacts with adsorbents of the source gas. 【0006】 According to one embodiment of the present disclosure, the selectivity of selective film formation can be improved. 【0007】Figure 1 is a flowchart showing a film deposition method according to one embodiment. Figure 2 is a flowchart showing an example of S102 shown in Figure 1. Figure 3 is a flowchart showing an example of S104 shown in Figure 1. Figure 4 is a cross-sectional view showing a film deposition method according to one embodiment. Figure 5 is a cross-sectional view showing a film deposition apparatus according to one embodiment. Figure 6 is a cross-sectional view showing an example of the first processing unit. Figure 7 is a TEM image of a substrate after processing under the conditions of Example 1 shown in Table 1. Figure 8 is a TEM image of a substrate after processing under the conditions of Example 2 shown in Table 1. Figure 9 shows the XPS spectra of a substrate having a Ru film on its surface and a substrate having an SiO film on its surface after processing under the conditions of Example 1 shown in Table 1. Figure 10 shows the XPS spectra of a substrate having a Ru film on its surface and a substrate having an SiO film on its surface after processing under the conditions of Example 2 shown in Table 1. Figure 11 is an SEM image of a substrate after processing under the conditions of Example 3 shown in Table 2. Figure 12 is an SEM image of the substrate after processing under the conditions of Example 4 shown in Table 2. Figure 13 is an SEM image of the substrate after processing under the conditions of Example 5 shown in Table 2. Figure 14 is a flowchart of a first modified example of the film deposition method. Figure 15 is a flowchart of a second modified example of the film deposition method. Figure 16 is a TEM image of the substrate after processing under the conditions of Example 6 and Example 7 shown in Table 3. 【0008】 Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their descriptions may be omitted. 【0009】 First, a film deposition method according to one embodiment will be described, mainly with reference to Figure 1. The film deposition method includes, for example, steps S101 to S105 shown in Figure 1. Note that the film deposition method only needs to include at least steps S101 to S104. Furthermore, the film deposition method may include steps other than steps S101 to S105 shown in Figure 1. 【0010】Step S101 includes preparing a substrate W as shown in Figure 4. The substrate W has a first film W1 and a second film W2 formed of a different material from the first film W1 in different regions of its surface Wa. Hereinafter, the surface Wa of the substrate W may be referred to as the substrate surface Wa. In this embodiment, the surface of the first film W1 is flush with the surface of the second film W2, but it may protrude or be recessed from the surface of the second film W2. 【0011】 The first film W1 and the second film W2 are formed on, for example, a semiconductor substrate (not shown) or a glass substrate. The semiconductor substrate is a silicon wafer or a compound semiconductor wafer. The compound semiconductor wafer is, for example, a GaAs wafer, a SiC wafer, a GaN wafer, or an InP wafer. A functional film (not shown) may be formed between the first film W1 or the second film W2 and the semiconductor substrate (not shown) or glass substrate. 【0012】 The combination of the first film W1 and the second film W2 is not particularly limited, as long as the third film W3 can be selectively formed on the second film W2 relative to the first film W1 in step S102. For example, the first film W1 may be a Si-containing film and the second film W2 may be a metal-containing film. Alternatively, the first film W1 may be a metal-containing film and the second film W2 may be a Si-containing film. Whether the third film W3 is selectively formed on the metal-containing film or the Si-containing film can be adjusted by the type of second reaction gas, as will be described later. Neither the first film W1 nor the second film W2 needs to substantially contain boron (B). Substantially containing no B means that the B content is between 0 atomic% and 5 atomic%. A lower B content is preferable. 【0013】The Si-containing film is not particularly limited, but examples include Si films, SiGe films, SiO films, SiN films, SiOC films, SiON films, or SiOCN films. Here, a SiO film means 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, SiGe films, SiN films, SiOC films, SiON films, and SiOCN films also mean that they contain each element, and are not limited to stoichiometric ratios. The Si-containing film may also be an interlayer insulating film. The interlayer insulating film is preferably a low-dielectric constant (Low-k) film. Si films and SiGe films are semiconductor films. The semiconductor film may be a single-crystal film, a polycrystalline film, or an amorphous film. 【0014】 The metal-containing film is not particularly limited, but is, for example, a metal film. Examples of metal films include Cu films, Co films, Ru films, Mo films, W films, Al films, or Ti films. The metal film may also be an alloy film. The metal-containing film may also be a metal nitride film. Examples of metal nitride films are not particularly limited, but are, for example, a TiN film or a TaN film. Here, a TiN film means 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, a TaN film means that it contains each element, and is not limited to stoichiometric ratios. 【0015】 Furthermore, the first film W1 may be a silicon oxide film, and the second film W2 may be a nitride film. Preferably, the first film W1 is an SiO film containing only silicon (Si) and oxygen (O), but it may also be a film containing other elements in addition to Si and O. However, it is preferable that the first film W1 is substantially free of nitrogen (N). Substantially free of N means that the N content is 0 atomic% to 5 atomic%. The lower the N content, the better. Preferably, the total Si and O content of the first film W1 is 80 atomic% to 100 atomic%. Most preferably, the first film W1 is a thermal oxide film formed by thermal oxidation of a silicon wafer. Thermal oxide films have high stability. 【0016】On the other hand, the nitride film as the second film W2 may be a film containing only a metal element or semiconductor element and nitrogen (N), or it may contain other elements in addition to the metal element or semiconductor element and N. However, it is preferable that the second film W2 is substantially free of oxygen (O). Substantially free of O means that the O content is between 0 atomic% and 5 atomic%. The lower the O content, the better. It is preferable that the second film W2 is a SiN film containing only silicon (Si) and nitrogen (N). Here, a SiN film means a film containing silicon (Si) and nitrogen (N). The atomic ratio of Si to N in a SiN film is usually 3:4, but is not limited to 3:4. Both the first film W1 and the second film W2 may be Si-containing films. The second film W2 may also be an AlN film, a TiN film, a SiCN film, or a SiON film. The same applies to AlN films, TiN films, SiCN films, and SiON films; this means they contain each element, just like SiN films, and is not limited to stoichiometric ratios. 【0017】 Step S102 includes selectively forming a third film W3 on top of the second film W2 relative to the first film W1, as shown in Figure 4. For example, it is possible to selectively form the third film W3 by utilizing the difference in incubation time. Incubation time refers to the time from the start of the film formation process (for example, the start of supplying the second raw material gas or the second reaction gas) until the actual film formation begins. It is also possible to selectively form the third film W3 by adjusting the type of second raw material gas or the type of second reaction gas. In Figure 4, the third film W3 is not formed at all on the first film W1, but it may be formed slightly on the first film W1 as well. 【0018】The third film W3 contains boron (B). The B content in the third film W3 is, for example, 20 atomic % to 100 atomic %, preferably 40 atomic % to 100 atomic %. The third film W3 is, for example, a B film, a BN film, a BNC film, a BO film, a BNO film, a BNOC film, a SiBN film, a SiBCN film, or a SiOBN film. Here, the BN film means a film containing boron (B) and nitrogen (N). The atomic ratio of B to N in the BN film is not limited to 1:1. The same applies to the BNC film and the like other than the BN film, meaning that each element is included and is not limited to the stoichiometric ratio. 【0019】 As shown in FIG. 2, step S102 has, for example, steps S102a to S102e. Note that step S102 only needs to have steps S102a and S102c, and does not necessarily have steps S102b, S102d, and S102e. Hereinafter, steps S102a to S102e will be described. 【0020】 Step S102a includes supplying a second source gas to the substrate W. The second source gas contains boron. The second source gas includes, for example, tris(dimethylamino)borane (TDMAB: C ６ H １８ BN ３ ). The second source gas may be supplied together with a dilution gas. The dilution gas is, for example, an Ar gas or an N ２ gas. 【0021】 Note that the second source gas is not limited to those containing TDMA B, and includes, for example, diborane (B ２ H ６ ), boron trichloride (BCl ３ ), boron trifluoride (BF ３ ), tris(ethylmethylamino)borane (C ９ H ２４ BN ３ ), trimethylborane (C ３ H ９ B), or triethylborane (C ６ H １５ B), cyclotriborazane (B ３ N ３ H ６ ), etc. 【0022】 Step S102b includes supplying a purge gas to the substrate W. The purge gas purges any excess second raw material gas that was not adsorbed on the substrate surface Wa in step S102a. The purge gas may be a noble gas such as Ar gas or N ２ Gas is used. 【0023】 Step S102c includes supplying a second reaction gas to the substrate W. The second reaction gas reacts with adsorbents of the second raw material gas on the substrate surface Wa to form a third film W3. The second reaction gas includes, for example, at least one of a nitrogen-containing gas, an oxygen-containing gas, and a reducing gas. The nitrogen-containing gas nitrides the second raw material gas to form a boron nitride film. The nitrogen-containing gas is, for example, NH ３ , N ２ , N ２ H ４ or N ２ H ２ It contains. The oxygen-containing gas oxidizes the second raw material gas to form a boron oxide film. The oxygen-containing gas is, for example, O ２ , O ３ H ２ O, NO, or N ２ It contains oxygen. The reducing gas forms a boron film by reducing the second raw material gas. The reducing gas is, for example, H ２ SiH ４ or H ２ It contains S gas. The second reaction gas may be supplied together with a diluent gas such as Ar gas. 【0024】 As will be explained in more detail later, for example, H as the second reaction gas ２ By using only gas, a third film W3 can be selectively formed on the metal-containing film, rather than the metal-containing film or the Si-containing film. Furthermore, for example, H can be used as the second reaction gas. ２ Gas and N ２ Gas mixture or N ２By using only gas, a third film W3 can be selectively formed on the Si-containing film, rather than on the metal-containing film. Whether the third film W3 is selectively formed on the metal-containing film or the Si-containing film can be adjusted by the type of second reaction gas. Note that if the first film W1 is a silicon-containing oxide film and the second film W2 is a nitride film, the type of second reaction gas is not particularly limited. Of the silicon-containing oxide film and the nitride film, a third film W3 can be selectively formed on the silicon-containing oxide film. 【0025】 Step S102c may include plasmaizing the second reaction gas, and may also include supplying the plasmaized second reaction gas to the substrate surface Wa. Plasmaizing the second reaction gas can promote the formation of the third film W3. 【0026】 The second reaction gas may be supplied not only in step S102c, but also in all of steps S102a to S102d. However, plasma generation of the second reaction gas is performed only in step S102c. This is because plasma generation of the second reaction gas promotes the reaction of the adsorbed second raw material gas on the substrate surface Wa. 【0027】 Step S102d includes supplying a purge gas to the substrate W. The purge gas purges any excess second reaction gas that did not react with the adsorbed second raw material gas on the substrate surface Wa in step S102c. The purge gas may be, for example, a noble gas such as Ar gas or N ２ Gas is used. 【0028】 In step S102e, it is confirmed whether steps S102a to S102d have been performed K times (where K is an integer of 1 or more). K may be an integer of 2 or more, and steps S102a to S102d may be repeated. The thickness of the third film W3 can be increased. 【0029】If the number of times steps S102a to S102d are performed is less than K (step S102e, NO), the thickness of the third film W3 is less than the target value, so steps S102a to S102d are performed again. The third film W3 inhibits the formation of the fourth film W4 in step S104, and it is desirable that it be formed to be thick enough so that the second film W2 is not exposed. Unlike the third film W3, the second film W2 does not substantially contain B. 【0030】 The third membrane W3 is thought to form when nuclei grow on the surface of the second membrane W2 and adjacent nuclei come into contact with each other. Until the nuclei reach a sufficient size, it is thought that there are dispersed areas where the second membrane W2 is exposed. Therefore, the thickness of the third membrane W3 is preferably 10 Å or more. If the thickness of the third membrane W3 is less than 10 Å, it is thought that there will be areas where the second membrane W2 is exposed, and the effect of inhibiting the formation of the fourth membrane W4 will be weakened. 【0031】 On the other hand, when the number of times steps S102a to S102d has been performed reaches K (step S102e, YES), the thickness of the third film W3 has reached the target value, and therefore step S102 is terminated. 【0032】 The method for forming the third membrane W3 shown in Figure 2 is the ALD method, but the CVD method may also be used. In the ALD method, the supply of the second raw material gas and the supply of the second reaction gas are performed alternately. On the other hand, in the CVD method, the supply of the second raw material gas and the supply of the second reaction gas are performed simultaneously. 【0033】 The third film W3 may be a molecular film formed by chemical or physical adsorption of molecules. The molecules are supplied to the substrate surface in gaseous form. The gas has functional groups in the molecules that are easily selectively adsorbed to desired regions on the substrate surface, and also contains boron (B). The third film W3 may also be formed when the adsorbed molecules are decomposed by the heat of the substrate W. 【0034】Step S103 includes supplying a modifying gas to the substrate W to modify at least the surface (preferably the entire surface) of the third film W3, thereby improving the film formation inhibitory effect of the third film W3 on the fourth film W4. If step S103 is omitted and step S104 is performed after step S102, the fourth film W4 may be formed not only on the first film W1 but also on the third film W3. According to this embodiment, because step S103 is included, the fourth film W4 can be selectively formed on the first film W1 with respect to the third film W3 in step S104. Therefore, the selectivity of selective film formation can be improved. 【0035】 Modifying at least the surface of the third film W3 includes, for example, reducing the content of impurities on at least the surface of the third film W3. The impurities form adsorption sites that adsorb the raw material gas in step S104. The impurities include, for example, hydrogen (H) or halogens. By reducing the content of impurities in the third film W3, the deposition of the fourth film W4 caused by impurities can be suppressed. 【0036】 Furthermore, modifying at least the surface of the third film W3 may include reducing the defect sites of the third film W3. The defect sites of the third film W3 adsorb the raw material gas in step S104. Reducing the defect sites of the third film W3 can suppress the deposition of the fourth film W4 caused by the defect sites. Reducing the defect sites is, in other words, densification. Alternatively, modifying at least the surface of the third film W3 may include reducing the unbonded bonds of the third film W3. This can suppress the deposition of the fourth film W4 caused by the unbonded bonds. 【0037】 Reformed gas is, for example, O ２ Gas, H ２ Gas, NH ３ Gas, H ２ O gas, NO ２ Gas, N ２ Includes gas, Ar gas, or He gas. ２ Gas, H ２ Gas, NH ３ Gas, H ２ O gas, NO ２ Gas, N ２It is preferable to supply the gas, Ar gas, or He gas to the substrate W in plasma form. By plasma-forming the modified gas, ions or radicals are generated. The generated ions or radicals physically knock away impurities, or the generated ions or radicals decompose and remove impurities. 【0038】 Furthermore, reformed gas is ozone gas (O ３ It may contain gas. ３ The gas may be supplied to the substrate W without being converted into plasma. ３ The gas breaks down and removes impurities. 【0039】 It is preferable to expose the substrate W to at least one of a vacuum atmosphere and an inert atmosphere without exposing it to the atmosphere from immediately after the formation of the third film W3 until immediately before the formation of the fourth film W4 (i.e., from immediately after step S102 until immediately before step S104). This prevents organic compounds contained in the atmosphere from contaminating the substrate surface Wa (for example, organic compounds adhering to and covering the substrate surface Wa), and prevents the effect of the third film W3 containing boron (the effect of the third film W3 inhibiting the formation of the fourth film W4, as described later) from being impaired. 【0040】 In this specification, an atmospheric atmosphere is defined as an atmosphere with a pressure of normal pressure (approximately 101 kPa) and an atmosphere proportion of 95% to 100% by volume. An inert atmosphere is defined as an atmosphere with an atmosphere proportion of 5% or less by volume and an inert gas proportion of 95% to 100% by volume (preferably 98% to 100% by volume). The inert gas is N ２ It consists of at least one gas selected from gases and noble gases (e.g., argon or helium). The pressure of the inert atmosphere is not particularly limited, but is, for example, atmospheric pressure. The inert gas is a gas with controlled purity and is supplied, for example, from a cylinder. 【0041】Furthermore, in this specification, a vacuum atmosphere refers to an atmosphere with a pressure of 0 Pa to 10 kPa (preferably 0 Pa to 1 kPa). The vacuum atmosphere may include at least one selected from air, inert gas, hydrogen gas, and ammonia gas. The vacuum atmosphere may also be an atmosphere obtained by reducing the pressure of the air from atmospheric pressure to 10 kPa or less. By removing more than 90% of the air, most of the organic compounds contained in the air can be removed. However, it is preferable that the vacuum atmosphere is an inert atmosphere obtained by reducing the pressure of the air from atmospheric pressure to 10 kPa or less. The gas other than the air (e.g., inert gas, hydrogen gas, and ammonia gas) is a gas whose purity is controlled and is supplied, for example, from a cylinder. 【0042】 As described above, it is preferable to expose the substrate W to at least one of a vacuum atmosphere and an inert atmosphere without exposing it to the atmosphere from immediately after forming the third film W3 until immediately before forming the fourth film W4 (i.e., from immediately after step S102 until immediately before step S104). Therefore, it is preferable that step S103 be carried out in a vacuum atmosphere. As described above, the vacuum atmosphere may include at least one selected from inert gases, hydrogen gas, and ammonia gas. 【0043】 Step S104 includes selectively forming a fourth film W4 on the first film W1 with respect to the third film W3, as shown in Figure 4. Step S104 includes forming a fourth film W4 containing element X by alternately or simultaneously supplying a source gas containing halogen and element X other than halogen, and a reaction gas that reacts with adsorbed substances of the source gas, to the substrate surface Wa. 【0044】 The first film W1 is a conductive film, an insulating film, or a semiconductor film. The fourth film W4 is a conductive film, an insulating film, or a semiconductor film. The combination of the first film W1 and the fourth film W4 is not particularly limited. The first film W1 may be an insulating film and the fourth film W4 may be an insulating film. The first film W1 may be a conductive film and the fourth film W4 may be an insulating film. The first film W1 may be an insulating film and the fourth film W4 may be a conductive film. The first film W1 may be a conductive film and the fourth film W4 may be a conductive film. 【0045】Step S104, as shown in Figure 3, includes, for example, steps S104a to S104e. Step S104 only needs to include steps S104a and S104c; it does not need to include steps S104b, S104d, and S104e. Steps S104a to S104e will be described below. 【0046】 Step S104a includes supplying a raw material gas to the substrate W. The raw material gas contains a halogen and an element X other than a halogen. The halogen is fluorine, chlorine, bromine, or iodine. In this embodiment, the raw material gas contains a compound of a halogen and element X, but it may also contain the halogen and element X separately. The raw material gas may be supplied together with a diluent gas. The diluent gas may be, for example, Ar gas or N ２ It is a gas. 【0047】 Element X is not particularly limited, but is preferably a metallic element, and more preferably a transition metal element. Element X is, for example, Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, or Sb. The raw material gas is, for example, TiCl ４ WCl ６ WF ６ , VCl ４ AlCl ３ MoCl ５ SnCl ４ , HfCl ４ , TaCl ５ NbCl ５ , ZrCl ４ InCl ３ GaCl ３ or SbCl ３ Includes. 【0048】 Element X may be a semiconductor element, specifically Si or Ge. The source gas is silicon halide gas or germanium halide gas. For example, silicon halide gas is SiCl ４ SiHCl ３ SiH ２ Cl ２ SiH ３ Cl, Si ２ Cl ６、 Si ２ HCl５ , SiCl ３ CCl ３ , SiCl ３ CH ３ , or SiH ２ I ２ is included. The germanium halide gas includes, for example, GeCl ４ . 【0049】 Step S104b includes supplying a purge gas to the substrate W. The purge gas purges the excess source gas that did not adsorb to the substrate surface Wa in the above step S104a. As the purge gas, for example, an inert gas such as Ar gas or N ２ gas is used. 【0050】 Step S104c includes supplying a reaction gas to the substrate W. The reaction gas reacts with the element X contained in the adsorbate of the source gas to form a fourth film W4 containing the element X. Examples of the reaction gas include an oxygen-containing gas, a nitrogen-containing gas, or a hydrogen-containing gas. The oxygen-containing gas contains oxygen and forms an oxide film of the element X. The oxygen-containing gas is, for example, O ２ gas, O ３ gas, CO ２ gas, N ２ O gas, NO gas, or H ２ O gas. The nitrogen-containing gas contains nitrogen and forms a nitride film of the element X. The nitrogen-containing gas is, for example, NH ３ gas, or N ２ H ４ gas. The hydrogen-containing gas contains hydrogen and forms a film (for example, a metal film or a semiconductor film) mainly composed of the element X. The hydrogen-containing gas is, for example, H ２ gas, or H ２ S gas. The reaction gas may be supplied together with a dilution gas. The dilution gas is, for example, Ar gas or N ２ gas. 【0051】 Step S104c may include plasmaizing the reaction gas, and may include supplying the plasmaized reaction gas to the substrate W. 【0052】Note that the reaction gas may be supplied not only in the above step S104c but also in all of steps S104a to S104d. However, the plasma generation of the reaction gas is carried out only in the above step S104c. This is because the reaction gas becomes more likely to react with the adsorbed substances of the source gas on the substrate surface Wa by being plasmaized. 【0053】 Step S104c may include supplying the O ３ gas to the substrate surface Wa without plasmaizing it. 【0054】 Step S104d includes supplying a purge gas to the substrate surface Wa. The purge gas purges the excess reaction gas that did not react with the adsorbed substances of the source gas on the substrate surface Wa in the above step S104c. As the purge gas, for example, a noble gas such as Ar gas or N ２ gas is used. 【0055】 In step S104e, it is confirmed whether the above steps S104a to S104d have been carried out L (L is an integer of 1 or more) times. L may be an integer of 2 or more, and the above steps S104a to S104d may be repeatedly carried out. The film thickness of the fourth film W4 can be increased. 【0056】 When the number of times of carrying out the above steps S104a to S104d is less than L times (step S104e, NO), since the film thickness of the fourth film W4 is less than the target value, the above steps S104a to S104d are carried out again. L is preferably 200 or more, more preferably 300 or more. L is preferably 1000 or less. 【0057】 On the other hand, when the number of times of carrying out the above steps S104a to S104d reaches L times (step S104e, YES), since the film thickness of the fourth film W4 has reached the target value, the current step S104 ends. 【0058】The method for forming the fourth film W4 shown in Figure 3 is the ALD (Atomic Layer Deposition) method, but the CVD (Chemical Vapor Deposition) method may also be used. In the ALD method, the supply of the raw material gas (step S104a) and the supply of the reaction gas (step S104c) are performed alternately. On the other hand, in the CVD method, the supply of the raw material gas and the reaction gas are performed simultaneously. 【0059】 To inhibit the formation of the fourth film W4 on the surface of the third film W3, it is important that the adsorption of the source gas onto the third film W3 is weak or nonexistent, and as a result, the adsorbed source gas on the surface of the third film W3 desorbs without advancing the film formation reaction (formation of the fourth film W4). Alternatively, it is important that adsorption of the source gas onto the surface of the third film W3 does not occur, or that dissociation of the source gas on the surface of the third film W3 is unlikely to occur. If dissociation of the source gas occurs, the film formation reaction proceeds easily. 【0060】 Since the third film W3 contains boron and is modified, it is thought that no adsorption of halides occurs on the third film W3, or if it does occur, it is weak, or that dissociation of halides is unlikely to occur. As a result, the formation of the fourth film W4 is inhibited on the surface of the third film W3. 【0061】 On the other hand, since the first film W1 does not substantially contain boron, it is thought that halides are strongly adsorbed on the first film W1, or that dissociation of halides is likely to occur. As a result, it is thought that the formation of the fourth film W4 progresses on the surface of the first film W1. 【0062】 Even if the third film W3 contains boron, if the third film W3 is not modified, the adsorption inhibition of halides by boron is less likely to occur, and the raw material gas is adsorbed on the third film W3. The raw material gas adsorbed on the third film W3 reacts with the reaction gas supplied in S104c, and a fourth film W4 is formed on the third film W3 as well. 【0063】 Also, TiCl ４ Halides such as Ti[N(CH) ３ ) ２ ] ４Compared to organometallic complexes such as those mentioned above, it is less likely to decompose due to the heat of the substrate W. If the raw material gas decomposes after being adsorbed onto the third film W3, the formation of the fourth film W4 will proceed. Therefore, in order to inhibit the formation of the fourth film W4 on the surface of the third film W3, a halogen-containing gas is suitable as the raw material gas for the fourth film W4. 【0064】 In steps S104a to S104d described above, the temperature of the substrate W may be controlled to 100°C or higher in order to promote the desorption of the raw material gas on the surface of the third film W3. If the temperature of the substrate W is less than 100°C, the desorption of the raw material gas will not occur sufficiently on the surface of the third film W3, and the raw material gas will be physically adsorbed, causing the fourth film W4 to be formed on the surface of the third film W3 as well. The temperature of the substrate W is preferably 300°C or higher. The temperature of the substrate W is preferably 800°C or lower. 【0065】 Step S105 includes checking whether the series of processes has been performed N times (where N is an integer of 1 or more). The series of processes includes the formation of the third film W3 (step S102), the supply of reformed gas (step S103), and the formation of the fourth film W4 (step S104). This series of processes is also called the first cycle. If the number of times the first cycle has been performed is less than N (step S105, NO), the film thickness of the fourth film W4 is insufficient, so the first cycle is performed again. On the other hand, if the number of times the first cycle has been performed reaches N (step S105, YES), the current process is terminated. N is preferably an integer of 2 or more. If N is an integer of 2 or more, the film thickness of the fourth film W4 can be increased while replenishing the third film W3. 【0066】 If N is an integer greater than or equal to 2, the first cycle is repeated multiple times. Step S102 from the second time onward includes selectively forming the third film W3 again on top of the third film W3 on the fourth film W4, although this is not shown in the diagram. Note that in the first step S104, the third film W3 may become thinner or disappear. If the third film W3 disappears, step S102 from the second time onward includes selectively forming the third film W3 again on top of the second film W2 instead of the third film W3. 【0067】The second and subsequent steps S104, although not shown, include selectively forming the fourth film W4 again on top of the third film W3. 【0068】 Next, with reference to Figure 14, the film formation method according to the first modified example will be described. The differences from the film formation method shown in Figure 1 will be mainly explained below. The film formation method of this modified example includes step S110. Step S110 is used to confirm whether the second cycle, which will be described later, has been performed P times (P is an integer of 1 or more). The second cycle consists of supplying reformed gas (step S103) and forming the fourth film W4 (step S104). If the number of times the second cycle has been performed is less than P (step S110, NO), the film thickness of the fourth film W4 is insufficient, so the second cycle is performed again. On the other hand, if the number of times the second cycle has been performed reaches P (step S110, YES), step S105 is performed. 【0069】 In step S110, P is preferably an integer of 2 or more. If P is an integer of 2 or more, the second cycle is repeated multiple times. During the formation of the fourth film W4 (step S104), the film formation inhibitory effect of the third film W3 on the fourth film W4 may decrease. This decrease in film formation inhibitory effect occurs, for example, when the reaction gas supplied in step S104c is adsorbed onto the third film W3, and the adsorbed reaction gas reacts with the raw material gas to form the nucleus of the fourth film W4. In the second and subsequent steps S103, the reformed gas removes the reaction gas adsorbed onto the third film W3, thereby suppressing the decrease in film formation inhibitory effect. This improves the selectivity of selective film formation. 【0070】Next, with reference to Figure 15, a film deposition method according to the second modified example will be described. The differences from the film deposition methods shown in Figures 1 and 14 will be mainly explained below. The film deposition method of this modified example includes steps S111 to S112. Step S111 involves supplying etching gas to the substrate W. The etching gas etches the fourth film W4. More specifically, the etching gas removes the nuclei of the fourth film W4 from above the third film W3 while leaving the fourth film W4 on the first film W1. The density of the fourth film W4 is lower on the third film W3 compared to the first film W1. Therefore, the etching gas can remove the nuclei of the fourth film W4 from above the third film W3 while leaving the fourth film W4 on the first film W1. As a result, the selectivity of selective film deposition can be improved. 【0071】 The type of etching gas is set appropriately according to the material of the fourth film W4. If the fourth film W4 is an SiO film, the etching gas is HF and NH ３ Combinations of trimethylaluminum and HF, combination of trimethylamine and HF, HF, NF ３ CF ４ , C ４ F ８ SF ４ , CLF ３ , or F ２ Includes HF gas and NH ３ Etching of SiO films using gas is also called COR (Chemical Oxide Removal). The etching gas may be plasma. For example, NF ３ It is preferable that the gas be plasma-generated. Alternatively, an etching solution may be used instead of the etching gas. An example of the etching solution is DHF (dilute hydrofluoric acid). 【0072】 If the fourth film W4 is a SiN film, the etching gas is HF and NH ３ Combinations of HF and NF ３ CF ４ , C ４ F ８ SF ４ , CLF ３ , or F ２ It includes. The etching gas may be plasma-generated. For example, NF３ It is preferable to ionize the gas into plasma. Alternatively, an etching solution may be used instead of the etching gas. For example, H ３ PO ４ Includes. 【0073】 Step S112 confirms whether the third or fourth cycle, described later, has been performed Q times (where Q is an integer of 1 or more). The third cycle includes repeating the second cycle multiple times and supplying etching gas (step S111). In the third cycle, P in step S110 is an integer of 2 or more. The fourth cycle includes performing the second cycle once and supplying etching gas (step S111). In the fourth cycle, P in step S110 is 1. If the number of times the third or fourth cycle has been performed is less than Q (step S112, NO), the film thickness of the fourth film W4 is insufficient, so the third or fourth cycle is performed again. On the other hand, if the number of times the third or fourth cycle has been performed reaches Q (step S112, YES), step S105 is performed. 【0074】Next, with reference to Figure 5, a film deposition apparatus 100 for carrying out the film deposition method shown in Figure 1 will be described. As shown in Figure 5, the film deposition apparatus 100 includes a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a transport unit 400, and a control unit 500. The first processing unit 200A carries out step S102 in Figure 1. The second processing unit 200B carries out step S103 in Figure 1. The third processing unit 200C carries out step S104 in Figure 1. The first processing unit 200A, the second processing unit 200B, and the third processing unit 200C may have the same structure or different structures. The first processing unit 200A may carry out steps S102 to S104 in Figure 1. In this case, steps S102 to S104 are carried out inside the same processing container 210 (see Figure 6). The film deposition apparatus 100 can also carry out the film deposition method shown in Figure 14 or Figure 15. When the film deposition apparatus 100 performs the film deposition method shown in Figure 15, the film deposition apparatus 100 may have a fourth processing unit 200D. The fourth processing unit 200D performs step S111 in Figure 15. However, the first processing unit 200A may perform steps S102 to S104 and S111 in Figure 15. 【0075】 The transport unit 400 transports the substrate W into the processing container 210 (see Figure 6), such as the first processing unit 200A, and transports the substrate W to the outside of the processing container 210. The transport unit 400 has a first transport chamber 401 and a first transport mechanism 402. The internal atmosphere of the first transport chamber 401 is an atmospheric atmosphere. The first transport mechanism 402 is provided inside the first transport chamber 401. The first transport mechanism 402 includes an arm 403 for holding the substrate W and travels along a rail 404. The rail 404 extends in the direction of the arrangement of the carriers C. 【0076】Furthermore, the transport unit 400 includes a second transport chamber 411 and a second transport mechanism 412. The internal atmosphere of the second transport chamber 411 is a vacuum atmosphere. The second transport mechanism 412 is provided inside the second transport chamber 411. The second transport mechanism 412 includes an arm 413 for holding the substrate W, 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 transport chamber 411 via different gate valves G. 【0077】 Furthermore, the conveying section 400 has a load lock chamber 421 between the first conveying chamber 401 and the second conveying chamber 411. The internal atmosphere of the load lock chamber 421 is switched between a vacuum atmosphere and an atmospheric atmosphere by a pressure regulating mechanism (not shown). This allows the inside of the second conveying chamber 411 to always be maintained in a vacuum atmosphere. It also prevents gas from flowing from the first conveying chamber 401 into the second conveying chamber 411. Gate valves G are provided between the first conveying chamber 401 and the load lock chamber 421, and between the second conveying chamber 411 and the load lock chamber 421. 【0078】 The control unit 500 is, for example, a computer and has an arithmetic unit 501 such as a CPU (Central Processing Unit) and a storage unit 502 such as memory. The storage unit 502 stores programs that control various processes performed in the film deposition apparatus 100. The control unit 500 controls the operation of the film deposition 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 carry out the above-described film deposition method. 【0079】The program, or computer program product, may be supplied in a form recorded on a removable storage medium such as a memory card, optical disc, or HDD (Hard Disk Drive). The control unit 500 reads the program from the storage medium and stores it in the storage unit 502. The storage unit 502 is equipped with a storage medium such as an HDD, SSD (Solid State Drive), or EEPROM (Electronically Erasable Programmable Read Only Memory). The program may be pre-written to the storage medium of the storage unit 502. The control unit 500 may also acquire programs distributed by a remote server device or the like via a network or other communication. 【0080】 The control unit 500 includes electronic circuits such as a CPU, GPU (Graphics Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The control unit 500 performs various control operations described in this specification by executing instruction codes stored in a storage medium such as memory, or by circuit design for special applications. 【0081】 Next, the operation of the film deposition apparatus 100 will be described. First, the first transport mechanism 402 removes the substrate W from the carrier C, transports the removed substrate W 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 an atmospheric atmosphere to a vacuum atmosphere. After that, the second transport mechanism 412 removes the substrate W from the load lock chamber 421 and transports the removed substrate W to the first processing unit 200A. 【0082】 Next, the first processing unit 200A performs step S102 in Figure 1. After that, the second transport mechanism 412 removes the substrate W from the first processing unit 200A and transports the removed substrate W to the second processing unit 200B. During this time, the substrate surface Wa can be protected in a vacuum atmosphere, and contamination of the substrate surface Wa by organic compounds in the atmosphere can be suppressed. 【0083】Next, the second processing unit 200B performs step S103 in Figure 1. After that, the second transport mechanism 412 removes the substrate W from the second processing unit 200B and transports the removed substrate W to the third processing unit 200C. During this time, the substrate surface Wa can be protected in a vacuum atmosphere, and contamination of the substrate surface Wa by organic compounds in the atmosphere can be suppressed. 【0084】 Next, the third processing unit 200C performs step S104 in Figure 1. After that, the second transport mechanism 412 removes the substrate W from the third processing unit 200C, transports the removed substrate W to the load lock chamber 421, and exits the load lock chamber 421. Subsequently, the internal atmosphere of the load lock chamber 421 is switched from a vacuum atmosphere to an atmospheric atmosphere. After that, the first transport mechanism 402 removes the substrate W from the load lock chamber 421 and places the removed substrate W into the carrier C. Then, the processing of the substrate W is completed. 【0085】 As described above, the first processing unit 200A may perform steps S102 to S104 in Figure 1. In this case, steps S102 to S104 are performed inside the same processing container 210 (see Figure 6). Therefore, in this case as well, the substrate surface Wa can be continuously exposed to at least one of a vacuum atmosphere and an inert atmosphere without being exposed to the atmosphere, and contamination of the substrate surface Wa with organic compounds in the atmosphere can be suppressed. 【0086】 Next, the first processing unit 200A will be described with reference to Figure 6. 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 their illustration and description will be omitted. 【0087】 The first processing unit 200A includes a substantially cylindrical, airtight processing container 210. An exhaust chamber 211 is provided in the center of the bottom wall of the processing container 210. The exhaust chamber 211 has a shape that protrudes downward, for example, a substantially cylindrical shape. An exhaust pipe 212 is connected to the exhaust chamber 211, for example, on the side of the exhaust chamber 211. 【0088】An exhaust source 272 is connected to the exhaust piping 212 via a pressure controller 271. The pressure controller 271 includes a pressure regulating valve, such as a butterfly valve. The exhaust piping 212 is configured to reduce the pressure inside the processing container 210 using the exhaust source 272. The pressure controller 271 and the exhaust source 272 constitute a gas discharge mechanism 270 that discharges gas from inside the processing container 210. 【0089】 A transport port 215 is provided on the side of the processing container 210. The transport port 215 is opened and closed by a gate valve G. The substrate W is transported in and out of the processing container 210 and the second transport chamber 411 (see Figure 5) through the transport port 215. 【0090】 A stage 220, which is a holding part for holding the substrate W, is provided inside the processing container 210. The stage 220 holds the substrate W horizontally with the substrate surface Wa facing upward. The stage 220 is formed in a substantially circular shape in plan view and is supported by a support member 221. A substantially circular recess 222 is formed on the surface of the stage 220 for placing a substrate W, for example, with a diameter of 300 mm. The recess 222 has an inner diameter slightly larger than the diameter of the substrate W. The depth of the recess 222 is set to be approximately the same as the thickness of the substrate W, 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 metallic material such as nickel (Ni). Instead of the recess 222, a guide ring for guiding the substrate W may be provided on the peripheral edge of the surface of the stage 220. 【0091】A lower electrode 223, for example, grounded, is embedded in the stage 220. A heating mechanism 224 is embedded below the lower electrode 223. The heating mechanism 224 is powered by a power supply unit (not shown) based on a control signal from the control unit 500 (see Figure 5), and heats the substrate W 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 (e.g., three) lifting pins 231 for holding and raising / lowering the substrate W placed on the stage 220. The material of the lifting pins 231 is, for example, alumina (Al ２ O ３ The material may be ceramics such as quartz or other similar materials. The lower end of the lifting pin 231 is attached to the support plate 232. The support plate 232 is connected to a lifting mechanism 234 provided outside the processing container 210 via a lifting shaft 233. 【0092】 The lifting mechanism 234 is installed, for example, at the bottom of the exhaust chamber 211. The bellows 235 is provided between the opening 219 for the lifting shaft 233 formed on the lower surface of the exhaust chamber 211 and the lifting mechanism 234. The shape of the support plate 232 may be such that it can move up and down without interfering with the support member 221 of the stage 220. The lifting pin 231 is configured to move up and down between the upper surface of the stage 220 and the lower surface of the stage 220 by the lifting mechanism 234. 【0093】A gas supply unit 240 is provided on the top wall 217 of the processing container 210 via an insulating member 218. The gas supply unit 240 forms the 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 100 kHz to 2.45 GHz, preferably 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, and a capacitively coupled plasma is generated. The plasma generation unit 250 that generates the plasma includes a matching unit 251 and a high-frequency power supply 252. Note that the plasma generation unit 250 is not limited to generating capacitively coupled plasma, but may generate other plasmas such as inductively coupled plasma or remote plasma. Note that in processes where plasma is not generated, it is not necessary for the gas supply unit 240 to form the upper electrode, and the lower electrode 223 is also unnecessary. 【0094】 The gas supply unit 240 includes a hollow gas supply chamber 241. On the lower surface of the gas supply chamber 241, numerous holes 242 are evenly arranged, for example, to distribute and supply the processing gas into the processing container 210. Above the gas supply chamber 241 in the gas supply unit 240, for example, a heating mechanism 243 is embedded. The heating mechanism 243 is heated to a set temperature by being powered from a power supply unit (not shown) based on a control signal from the control unit 500. 【0095】 A gas supply mechanism 260 is connected to the gas supply chamber 241 via a gas supply passage 261. The gas supply mechanism 260 supplies the gas used in the process shown in Figures 1, 14, or 15 to the gas supply chamber 241 via the gas supply passage 261. Although not shown, the gas supply mechanism 260 includes individual piping for each type of gas, on-off valves installed in the middle of the individual piping, and flow controllers installed in the middle of the individual piping. When the on-off valve opens the individual piping, gas is supplied from the supply source to the gas supply passage 261. The amount of gas supplied is controlled by the flow controller. On the other hand, when the on-off valve closes the individual piping, the supply of gas from the supply source to the gas supply passage 261 is stopped. 【0096】[Examples] Examples and other details are described below. Examples 2, 4, 5, and 7 below are examples, and Examples 1, 3, and 6 below are comparative examples. 【0097】 Table 1 shows the processing conditions for Examples 1 and 2. Examples 1 and 2 were performed under the same processing conditions as shown in Figure 1, except for the presence or absence of step S103 (supply of reformed gas). In both Examples 1 and 2, N in step S105 shown in Figure 1 was set to 1. In step S102, TDMAB was used as the second raw material gas, and H was used as the second reaction gas. ２ Only gas was used. In step S103, plasma-formed O was used as the reformed gas. ２ A gas was used. In step S104, Si was used as the source gas. ２ Cl ６ Using gas, NH as the reaction gas ３ Gas was used. Step S104 was performed under conditions for depositing a SiN film, but the SiN film was converted to a SiON film by exposure to air after deposition. 【0098】 【0099】 In Table 1, "ON" under "RF" means that the supply gas was plasma-generated using high-frequency power. "OFF" under "RF" means that plasma generation of the supply gas was not performed. The meanings of "ON" and "OFF" are the same in Tables 2 and 3 below. 【0100】 Figure 7 shows a TEM image of the substrate after processing under the conditions of Example 1 shown in Table 1. Figure 8 shows a TEM image of the substrate after processing under the conditions of Example 2 shown in Table 1. As shown in Figures 7 and 8, in step S101, a substrate was prepared having an SiO film and a Ru film in different regions of the substrate surface. As a result, under the conditions of Example 1, where step S103 is not performed, the SiO film was formed on both the SiO film and the Ru film, as shown in Figure 7. On the other hand, under the conditions of Example 2, where step S103 is performed, the SiO film was selectively formed on the SiO film, as shown in Figure 8. 【0101】Figures 7 and 8 show that step S103 improves the selectivity of the selective film formation. In Figures 7 and 8, the third film containing boron was thin and almost invisible. However, as will be explained in more detail later, in Examples 1 and 2, it is thought that the third film was selectively formed on the Ru film relative to the SiO film. 【0102】 Figure 9 shows the XPS spectra of a substrate with a Ru film on its surface and a substrate with an SiO film on its surface after being treated under the conditions of Example 1 shown in Table 1. Figure 10 shows the XPS spectra of a substrate with a Ru film on its surface and a substrate with an SiO film on its surface after being treated under the conditions of Example 2 shown in Table 1. Under the conditions of Example 1, where step S103 is not performed, peaks originating from Si-O bonds (i.e., peaks originating from the SiO film) were observed in both the substrate with an SiO film on its surface and the substrate with a Ru film on its surface, as shown in Figure 9. On the other hand, under the conditions of Example 2, where step S103 is performed, peaks originating from Si-O bonds (i.e., peaks originating from the SiO film) were observed relatively strongly in the substrate with an SiO film on its surface, as shown in Figure 10. From Figures 9 and 10, it can be seen that performing step S103 improves the selectivity of selective film formation. 【0103】 Table 2 shows the processing conditions for Examples 3 to 5. Examples 3 to 5 were performed under the same processing conditions as shown in Figure 1, except for the presence or absence of step S103 (supply of reformed gas) or the type of reformed gas. In Examples 3 to 5, N in step S105 shown in Figure 1 was set to 1. In step S102, TDMAB was used as the second raw material gas and H was used as the second reaction gas. ２ Gas and N ２ A gas mixture was used. In step S103, plasma-formed O was used as the reformed gas. ２ Gaseous or plasma-like H ２ O gas was used. In step S104, Si was used as the source gas. ２ Cl ６ Using gas, NH as the reaction gas ３ Gas was used. Step S104 was performed under conditions for depositing a SiN film, but the SiN film was converted to a SiON film by exposure to air after deposition. 【0104】 【0105】 Figure 11 shows an SEM image of the substrate after processing under the conditions of Example 3 shown in Table 2. Figure 12 shows an SEM image of the substrate after processing under the conditions of Example 4 shown in Table 2. Figure 13 shows an SEM image of the substrate after processing under the conditions of Example 5 shown in Table 2. As shown in Figures 11 to 13, in step S101, a substrate was prepared having an SiO film and a Ru film in different regions of the substrate surface. As a result, under the conditions of Example 3, where step S103 is not performed, the SiO film was formed on both the SiO film and the Ru film, as shown in Figure 11. On the other hand, under the conditions of Example 4 and Example 5, where step S103 is performed, the SiO film was selectively formed on the Ru film, as shown in Figures 12 and 13. 【0106】 Figures 11 to 13 show that step S103 improves the selectivity of selective film formation. In Figures 11 to 13, the third film containing boron was thin and almost invisible. However, as will be explained in more detail later, in Examples 3 to 5, the third film is thought to have been selectively formed on top of the SiO film relative to the Ru film. 【0107】 The SiO film could be selectively formed on the SiO film, as shown in Figure 8, or selectively formed on the Ru film, as shown in Figures 12-13. By changing the deposition conditions for the third film (more specifically, the type of second reaction gas), the region in which the SiO film was formed could be changed. From this, it is considered that the third film W3 was selectively formed on either the Ru film or the SiO film. 【0108】 Table 3 shows the processing conditions for Examples 6 and 7. Examples 6 and 7 were performed under the same processing conditions as shown in Figure 1, except for the presence or absence of steps S102 (formation of the third membrane) and S103 (supply of reformed gas). In Examples 6 and 7, N in step S105 shown in Figure 1 was set to 1. In step S102, TDMAB was used as the second raw material gas and N was used as the second reaction gas. ２ Only gas was used. In step S103, plasma-formed O was used as the reformed gas. ２ A gas was used. In step S104, Si was used as the source gas. ２Cl ６ Using gas, NH as the reaction gas ３ Gas was used. Step S104 was performed under conditions for depositing a SiN film, but the SiN film was converted to a SiON film by exposure to air after deposition. 【0109】 【0110】 Figure 16 shows TEM images of a substrate having a SiN film on its surface and a substrate having an SiO film on its surface after being treated under the conditions of Example 6 or Example 7 shown in Table 3, respectively. As a result, under the conditions of Example 6, where steps S102 and S103 are not performed, the SiON film was formed on both the SiN film and the SiO film, as shown in Figure 16. On the other hand, under the conditions of Example 7, where steps S102 and S103 are performed, the SiON film was not formed on the SiN film, but on the SiO film, as shown in Figure 16. 【0111】 While embodiments of the film deposition method and film deposition apparatus relating to this disclosure have been described above, this 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, too, naturally fall within the technical scope of this disclosure. 【0112】 This application claims priority based on Japanese Patent Application No. 2024-217159, filed with the Japan Patent Office on December 12, 2024, and Japanese Patent Application No. 2025-140250, filed with the Japan Patent Office on August 26, 2025, and the entire contents of Japanese Patent Application No. 2024-217159 and Japanese Patent Application No. 2025-140250 are incorporated herein by reference. 【0113】 W Substrate W1 First film W2 Second film W3 Third film W4 Fourth film

Claims

1. A film formation method comprising: preparing a substrate having a first film and a second film formed of a different material from the first film in different regions of its surface; selectively forming a third film containing boron on the second film relative to the first film; supplying a modifying gas to the substrate to modify at least the surface of the third film to improve the third film's ability to inhibit the formation of a fourth film; and selectively forming the fourth film on the first film relative to the third film modified with the modifying gas, wherein forming the fourth film involves alternately or simultaneously supplying the substrate with a raw material gas containing a halogen and an element X other than a halogen, and a reaction gas that reacts with adsorbents of the raw material gas, thereby forming the fourth film containing the element X.

2. The film formation method according to claim 1, wherein modifying at least the surface of the third film includes supplying the modified gas to the substrate in plasma form.

3. The film formation method according to claim 1, wherein modifying at least the surface of the third film includes supplying ozone gas to the substrate as the modifying gas.

4. The film formation method according to claim 1, wherein modifying at least the surface of the third film reduces the content of impurities in the third film.

5. The film formation method according to claim 1, wherein the first film is a Si-containing film and the second film is a metal-containing film.

6. The film formation method according to claim 1, wherein the first film is a metal-containing film and the second film is a Si-containing film.

7. The film formation method according to claim 1, wherein the first film is an insulating film and the fourth film is an insulating film.

8. The film formation method according to claim 1, wherein the first film is a conductive film and the fourth film is an insulating film.

9. The film formation method according to claim 1, wherein the first film is an insulating film and the fourth film is a conductive film.

10. The film formation method according to claim 1, wherein the first film is a conductive film and the fourth film is a conductive film.

11. The film formation method according to claim 1, comprising exposing the substrate to at least one of a vacuum atmosphere and an inert atmosphere without exposing it to an atmospheric atmosphere from immediately after the formation of the third film until immediately before the formation of the fourth film.

12. The film formation method according to claim 1, comprising repeating the second cycle multiple times, wherein the second cycle includes supplying the reformed gas and forming the fourth film in this order.

13. The film formation method according to claim 12, further comprising supplying an etching gas to the substrate for etching the fourth film after repeating the second cycle multiple times.

14. The film formation method according to claim 13, comprising repeating the third cycle multiple times, wherein the third cycle comprises repeating the second cycle multiple times and supplying the etching gas.

15. The film formation method according to claim 1, comprising, in this order, supplying the modified gas, forming the fourth film, and supplying an etching gas to the substrate for etching the fourth film.

16. The film formation method according to claim 15, comprising repeating the fourth cycle multiple times, wherein the fourth cycle includes supplying the reformed gas, forming the fourth film, and supplying the etching gas.

17. The method for forming a film according to claim 1, wherein the first film is a silicon-containing oxide film and the second film is a nitride film.

18. A film-forming apparatus comprising: a processing unit comprising: a processing container for housing the substrate; a holding unit for holding the substrate inside the processing container; and a gas supply unit for supplying gas to the substrate held in the holding unit; a transport unit for transporting the substrate into the processing container and transporting the substrate out of the processing container; and a control unit for controlling the processing unit and the transport unit, wherein the control unit controls the processing unit and the transport unit to carry out the film-forming method described in any one of claims 1 to 17.

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