Film deposition method and film deposition apparatus

Abstract

To provide a technology for reducing electric resistance between a first metal film and a second metal film and improving adhesion between a first insulation film and the second metal film.SOLUTION: A film deposition method includes preparing a substrate having a first metal film and a first insulation film in different regions of a surface thereof, forming a first self-assembled monolayer on a surface of the first metal film selectively with respect to a surface of the first insulation film, forming a first coupling film on both of the surface of the first insulation film and a surface of the first self-assembled monolayer using a first molecular binder, removing the first self-assembled monolayer to remove the first coupling film's part in contact with the surface of the first self-assembled monolayer, and forming a second metal film on a surface of the first coupling film's remaining part and the surface of the first insulation film, in this order.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] The film formation method described in Patent Document 1 includes, in this order, forming a TiN film along the recesses of an interlayer insulating film and then filling the recesses of the interlayer insulating film with a Ru film. The TiN film improves the adhesion of the Ru film to the interlayer insulating film.

[0003] The bonding method described in Patent Document 2 bonds a first substrate and a second substrate using a compound that has an OH group or an OH yielding group, an azide group, and a triazine ring in one molecule. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-152438 [Patent Document 2] International Publication No. 2012 / 043631 Summary of the Invention [Problem to be solved by the invention]

[0005] An embodiment of the present disclosure provides a technique for reducing the electrical resistance between a first metal film and a second metal film, and improving the adhesion between the first insulating film and the second metal film. [Means for solving the problem]

[0006] A film forming method according to one embodiment of the present disclosure includes, in this order, preparing a substrate having a first metal film and a first insulating film on different regions of its surface; selectively forming a first self-assembled monolayer on the surface of the first metal film relative to the surface of the first insulating film; forming a first bonding film on both the surface of the first insulating film and the surface of the first self-assembled monolayer using a first molecular binder; removing the first self-assembled monolayer to remove a portion of the first bonding film in contact with the surface of the first self-assembled monolayer; and forming a second metal film on the remaining surface of the first bonding film and the surface of the first insulating film. The first molecular binder is an organic compound having a first functional group and a second functional group in one molecule. The first functional group is more likely to bond to the first insulating film than the second functional group. The second functional group is more likely to bond to the second metal film than the first functional group. [Effects of the Invention]

[0007] According to an embodiment of the present disclosure, it is possible to reduce the electrical resistance between the first metal film and the second metal film, and also improve the adhesion between the first insulating film and the second metal film. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a flowchart showing a film forming method according to a first reference example. [Figure 2] 2(A) is a cross-sectional view showing S101 in FIG. 1, FIG. 2(B) is a cross-sectional view showing S102 in FIG. 1, FIG. 2(C) is a cross-sectional view showing S103 in FIG. 1, and FIG. 2(D) is a cross-sectional view showing S104 in FIG. 1. [Figure 3] FIG. 3 is a flowchart showing the film forming method according to the first embodiment. [Figure 4] 4(A) is a cross-sectional view showing S202 in FIG. 3, FIG. 4(B) is a cross-sectional view showing S203 in FIG. 3, FIG. 4(C) is a cross-sectional view showing S204 in FIG. 3, FIG. 4(D) is a cross-sectional view showing S205 in FIG. 3, and FIG. 4(E) is a cross-sectional view showing S206 in FIG. 3. [Figure 5]FIG. 5 is a flowchart showing a film forming method according to the second reference example. [Figure 6] 6(A) is a cross-sectional view showing S101 in FIG. 5, FIG. 6(B) is a cross-sectional view showing S102 in FIG. 5, FIG. 6(C) is a cross-sectional view showing S103 in FIG. 5, FIG. 6(D) is a cross-sectional view showing S104 in FIG. 5, and FIG. 6(E) is a cross-sectional view showing S105 in FIG. 5. [Figure 7] FIG. 7 is a flowchart showing a film forming method according to the second embodiment. [Figure 8] 8(A) is a cross-sectional view showing S202 in FIG. 7, FIG. 8(B) is a cross-sectional view showing S203 in FIG. 7, FIG. 8(C) is a cross-sectional view showing S204 in FIG. 7, FIG. 8(D) is a cross-sectional view showing S205 in FIG. 7, FIG. 8(E) is a cross-sectional view showing S206 in FIG. 7, and FIG. 8(F) is a cross-sectional view showing S207 in FIG. 7. [Figure 9] FIG. 9 is a flowchart showing a film forming method according to the third reference example, and is a flowchart of the process performed following S103 in FIG. [Figure 10] 10(A) is a cross-sectional view showing S111 in FIG. 9, FIG. 10(B) is a cross-sectional view showing S112 in FIG. 9, FIG. 10(C) is a cross-sectional view showing S113 in FIG. 9, and FIG. 10(D) is a cross-sectional view showing S114 in FIG. 9. [Figure 11] FIG. 11 is a flowchart showing the film forming method according to the third embodiment, and is a flowchart of the process performed following S205 in FIG. [Figure 12] 12(A) is a cross-sectional view showing S211 in FIG. 11, FIG. 12(B) is a cross-sectional view showing S212 in FIG. 11, FIG. 12(C) is a cross-sectional view showing S213 in FIG. 11, FIG. 12(D) is a cross-sectional view showing S214 in FIG. 11, FIG. 12(E) is a cross-sectional view showing S215 in FIG. 11, and FIG. 12(F) is a cross-sectional view showing S216 in FIG. 11. [Figure 13] FIG. 13 is a plan view showing a film forming apparatus according to an embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing an example of the first processing section of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or similar components are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0010] A film formation method according to a first reference example will be described with reference to Figures 1 and 2. The film formation method according to the first reference example forms metal wiring by a dual damascene method. As shown in Figure 1, the film formation method according to the first reference example includes steps S101 to S104. Note that the film formation method may include steps other than steps S101 to S104. For example, the film formation method may include a step of cleaning the substrate surface between steps S101 and S102.

[0011] Step S101 includes preparing a substrate 1, as shown in FIG. 2(A). The substrate 1 includes a semiconductor substrate or a glass substrate (not shown) and various functional films formed on the semiconductor substrate or the glass substrate. The substrate 1 includes a first metal film 11 and a first insulating film 12 in different regions of the substrate surface 1a. The first metal film 11 is, for example, a Ru film. The first metal film 11 may contain Ru, and may also be a Ru alloy film. The first metal film 11 may also be a Cu film, a Co film, a W film, or a Mo film. The first metal film 11 may also be an alloy film containing at least one of Cu, Co, W, and Mo. The first insulating film 12 is, for example, an interlayer insulating film.

[0012] The interlayer insulating film is preferably an SiO film or a low-k (low-k) film having a dielectric constant lower than that of an SiO film. The low-k film is not particularly limited, but may be, for example, an SiCO film, an SiOCH film, or an SiCN film. Here, an SiO film means a film containing silicon (Si) and oxygen (O). The atomic ratio of the elements constituting the SiO film is not limited to a stoichiometric ratio. Similarly, an SiCO film, an SiOCH film, and an SiCN film contain the respective elements, and the atomic ratio of the elements constituting each film is not limited to a stoichiometric ratio.

[0013] The substrate 1 has a recess 1b on its surface 1a. The recess 1b has, for example, a trench 1c and a via hole 1d formed in the bottom surface of the trench 1c. The substrate 1 has a surface of a first metal film 11 on the bottom surface of the recess 1b, and a surface of a first insulating film 12 on the side surface of the recess 1b. The substrate 1 has a top surface of a protrusion 1e on its surface 1a, and a recess 1b recessed from the top surface of the protrusion 1e. The substrate 1 has a surface of the first insulating film 12 on the top surface of the protrusion 1e.

[0014] The substrate 1 may further include a second insulating film 13. The second insulating film 13 is, for example, an interlayer insulating film. A first metal film 11 and a third adhesive film 14 are filled in this order in the recesses of the second insulating film 13. The third adhesive film 14 improves adhesion between the first metal film 11 and an etching stopper film 15, which will be described later. The third adhesive film 14 is, for example, a TiN film or a TaN film. The atomic ratio of the elements constituting the TiN film or the TaN film is not limited to the stoichiometric ratio.

[0015] The substrate 1 may further include an etching stopper film 15. The etching stopper film 15 is formed on the second insulating film 13 and the third adhesive film 14. The etching stopper film 15 stops the etching of the first insulating film 12 to form the recess 1b. The etching stopper film 15 is, for example, a SiN film or a SiCN film. The atomic ratio of elements constituting the SiN film or SiCN film is not limited to the stoichiometric ratio.

[0016] After etching of the first insulating film 12 to form the recess 1b is completed, part of the etching stopper film 15 and part of the third adhesive film 14 are removed to expose the first metal film 11 on the bottom surface of the recess 1b (see FIG. 2(A)). As a result, the substrate 1 may have the surface of the third adhesive film 14 and the surface of the etching stopper film 15 on the side surface of the recess 1b.

[0017] Step S102 includes forming a first adhesive film 16 as shown in FIG. 2(B). The first adhesive film 16 is formed over the entire substrate surface 1a, following the shape of the substrate surface 1a. The first adhesive film 16 improves adhesion between the first insulating film 12 and a second metal film 17, which will be described later. The first adhesive film 16 is, for example, a TiN film or a TaN film. The first adhesive film 16 is formed by, for example, a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) method.

[0018] Step S103 includes forming a second metal film 17 as shown in FIG. 2(C). The second metal film 17 is, for example, a Ru film. The second metal film 17 may contain Ru, and may be a Ru alloy film. The second metal film 17 may be a Cu film, a Co film, a W film, or a Mo film. The second metal film 17 may also be an alloy film containing at least one of Cu, Co, W, and Mo. The second metal film 17 is formed by, for example, a PVD (Physical Vapor Deposition) method, a CVD method, or a plating method.

[0019] The second metal film 17 fills the recess 1b. The second metal film 17 contacts the first adhesive film 16 at the bottom surface of the recess 1b. The second metal film 17 also contacts the first adhesive film 16 at the side surface of the recess 1b and the top surface of the protrusion 1e. The first adhesive film 16 improves the adhesion between the first insulating film 12 and the second metal film 17.

[0020] Step S104 includes polishing the second metal film 17 as shown in FIG. 2(D). The polishing method is, for example, CMP (Chemical Mechanical Polishing). Step S104 includes polishing the second metal film 17 and the first insulating film 12 simultaneously, after polishing the second metal film 17. The surfaces of the second metal film 17 and the first insulating film 12 are aligned in the same plane. Metal wiring can be formed by the second metal film 17 embedded in the first insulating film 12.

[0021] According to the first reference example, as shown in FIG. 2(D), the first adhesive film 16 remains between the second metal film 17 and the first metal film 11. The remaining first adhesive film 16 increases the contact resistance between the second metal film 17 and the first metal film 11. Therefore, in the first example described below, a first bonding film is used instead of the first adhesive film 16, and a first self-assembled monolayer is formed before the formation of the first bonding film. Hereinafter, the first self-assembled monolayer may be referred to as a first SAM (Self-Assembled Monolayer).

[0022] A film formation method according to a first embodiment will be described with reference to Figures 3 and 4. The film formation method according to the first embodiment forms metal wiring by a dual damascene method. As shown in Figure 3, the film formation method according to the first embodiment includes steps S201 to S206. Note that the film formation method may include steps other than steps S201 to S206. For example, the film formation method may include a step of cleaning the substrate surface between steps S201 and S202.

[0023] Step S201 includes preparing a substrate 1. The substrate 1 to be prepared is the same as the substrate 1 (see FIG. 2(A)) prepared in S101 of the first reference example, and therefore illustration and description thereof will be omitted.

[0024] Step S202 includes forming a first SAM 18 as shown in FIG. 4A. The material of the first SAM 18 is, for example, an organic compound containing a thiol group. Specific examples of thiol compounds include CF3(CF2)5CH2CH2SH (1H,1H,2H,2H-perfluorooctanethiol: PFOT) and CH3(CH2)5SH (hexanethiol: HT).

[0025] Thiol compounds are more likely to be chemically adsorbed to the surface of the first metal film 11 than to the surface of the first insulating film 12. Therefore, the first SAM 18 is selectively formed on the surface of the first metal film 11 relative to the surface of the first insulating film 12. The first SAM 18 is hardly formed on the surface of the first insulating film 12.

[0026] The material for the first SAM 18 is not limited to a thiol compound. The source gas for the first SAM 18 may include a phosphonic acid compound, a carboxylic acid compound, or a nitro compound. The material for the first SAM 18 may be supplied in the form of a liquid dissolved in an organic solvent, or in the form of a gas vaporized by heating.

[0027] Step S203 includes forming a first bonding film 19 as shown in FIG. 4(B). The first bonding film 19 is formed on both the surface of the first insulating film 12 and the surface of the first SAM 18. The first bonding film 19 may be formed over the entire substrate surface 1a, following the shape of the substrate surface 1a. The first bonding film 19 may also be formed on the surface of the third adhesive film 14 and the surface of the etching stopper film 15 inside the recess 1b. The material of the first bonding film 19 is a first molecular bonding agent. The first molecular bonding agent may be supplied in a liquid state dissolved in an organic solvent, or in a gaseous state vaporized by heating.

[0028] The first molecular binder is an organic compound having a first functional group and a second functional group in one molecule. The first functional group bonds more easily to the first insulating film 12 than the second functional group. The first functional group is not particularly limited, but includes, for example, at least one of a silanol group and a group that generates a silanol group upon hydrolysis. The group that generates a silanol group upon hydrolysis is, for example, an alkoxysilyl group. A single molecule may contain multiple first functional groups, and the multiple first functional groups may be the same or different.

[0029] The second functional group is more likely to bond to the second metal film 17 than the first functional group. The second functional group is not particularly limited, but includes, for example, at least one of an amino group, an azide group, a mercapto group, an isocyanate group, a ureido group, and an epoxy group. A single molecule may contain a plurality of second functional groups, and the plurality of second functional groups may be the same or different.

[0030] The first molecular binder preferably has a triazine between the first functional group and the second functional group, and may include at least one of benzene, cyclohexane, naphthalene, a spiro compound, a lactone, pyridine, cyclopentane, furan, and thiophene instead of triazine.

[0031] 4(C), step S204 includes removing the first SAM 18, thereby removing the portion of the first bonding film 19 that contacts the surface of the first SAM 18. The remaining portion of the first bonding film 19 covers the surface of the first insulating film 12, and the surface of the first metal film 11 is exposed again at the bottom of the recess 1b.

[0032] Removing the first SAM 18 includes, for example, heating the first SAM 18. The first SAM 18 can be thermally decomposed. The heating temperature is not particularly limited as long as it is higher than the 1% weight loss temperature of the first SAM 18, and is, for example, 300°C to 450°C. The 1% weight loss temperature is the temperature at which the weight of a substance decreases by 1% when heated from room temperature at a temperature increase rate of 10°C / min in a nitrogen atmosphere. The 1% weight loss temperature is measured using a differential thermal analyzer. The holding time at the heating temperature is set depending on the heating temperature, but is, for example, 1 minute to 60 minutes, and preferably 1 minute to 30 minutes.

[0033] The 1% weight loss temperature of the first SAM 18 is preferably lower than the 1% weight loss temperature of the first bonding film 19. Even if the heating temperature is low enough that thermal decomposition of the first bonding film 19 hardly progresses, a portion of the first bonding film 19 can be removed. The heating temperature may be lower than the 1% weight loss temperature of the first bonding film 19.

[0034] Furthermore, removing the first SAM 18 may include supplying acetic acid to the first SAM 18. The acetic acid breaks the bond between the first SAM 18 and the first metal film 11, thereby removing the first SAM 18. The acetic acid breaks, for example, a sulfide bond. Therefore, supplying acetic acid is particularly effective when the first SAM 18 is a thiol-based compound. The supply time for acetic acid is not particularly limited, but is, for example, 1 to 60 minutes, and preferably 1 to 30 minutes.

[0035] The supply of acetic acid to the first SAM 18 is preferably performed after heating the first SAM 18, but may be performed before heating the first SAM 18. Furthermore, step S204 may include only one of heating the first SAM 18 and supplying acetic acid to the first SAM 18.

[0036] Step S205 includes forming a second metal film 17 as shown in FIG. 4(D). The second metal film 17 is, for example, a Ru film. The second metal film 17 may contain Ru, and may be a Ru alloy film. The second metal film 17 may be a Cu film, a Co film, a W film, or a Mo film. The second metal film 17 may also be an alloy film containing at least one of Cu, Co, W, and Mo. The second metal film 17 is formed by, for example, a CVD method or a plating method.

[0037] The second metal film 17 fills the recess 1b. The second metal film 17 contacts the first metal film 11 at the bottom surface of the recess 1b. No other functional film exists between the first metal film 11 and the second metal film 17. The second metal film 17 contacts the first bonding film 19 at the side surface of the recess 1b and the top surface of the protrusion 1e. The first bonding film 19 bonds the first insulating film 12 and the second metal film 17. This makes it possible to suppress peeling of the second metal film 17 from the first insulating film 12. The first bonding film 19 may bond the etching stopper film 15 and the second metal film 17.

[0038] Step S206 includes polishing the second metal film 17 as shown in FIG. 4(E). The polishing method is, for example, CMP. Step S206 includes polishing the second metal film 17 and the first insulating film 12 simultaneously after polishing the second metal film 17. The surfaces of the second metal film 17 and the first insulating film 12 are aligned in the same plane. Metal wiring can be formed from the second metal film 17 embedded in the first insulating film 12.

[0039] According to the first embodiment, as shown in FIG. 4(E), there is no other functional film between the second metal film 17 and the first metal film 11. The second metal film 17 and the first metal film 11 are in continuous contact with each other. Therefore, the contact resistance between the second metal film 17 and the first metal film 11 can be reduced. Furthermore, according to the first embodiment, the remaining portion of the first bonding film 19 can improve the adhesion between the first insulating film 12 and the second metal film 17.

[0040] A film formation method according to a second reference example will be described with reference to Figures 5 and 6. In the film formation method according to the second reference example, metal wiring is formed by a semi-damascene method. The film formation method according to the second reference example has steps S101 to S105, as shown in Figure 5. Differences from the first reference example will be mainly described below.

[0041] Step S101 includes preparing a substrate 1 as shown in FIG. 6(A). The substrate 1 has a recess 1b on its surface 1a. The recess 1b has a via hole 1d as shown in FIG. 2(A) but does not have a trench 1c as shown in FIG. 2(B). The substrate 1 has a surface of a first metal film 11 on the bottom surface of the recess 1b and a surface of a first insulating film 12 on the side surface of the recess 1b. The substrate 1 has a top surface of a protrusion 1e on its surface 1a and a recess 1b recessed from the top surface of the protrusion 1e. The substrate 1 has a surface of a first insulating film 12 on the top surface of the protrusion 1e.

[0042] Step S102 includes forming a first adhesive film 16 as shown in Fig. 6(B) The first adhesive film 16 is formed over the entire substrate surface 1a, following the shape of the substrate surface 1a.

[0043] Step S103 includes forming a second metal film 17 as shown in FIG. 6(C). The second metal film 17 fills the recesses 1b. The second metal film 17 contacts the first adhesive film 16 at the bottom surfaces of the recesses 1b. The second metal film 17 also contacts the first adhesive film 16 at the side surfaces of the recesses 1b and the top surfaces of the protrusions 1e. The first adhesive film 16 improves the adhesion between the first insulating film 12 and the second metal film 17.

[0044] Step S104 includes polishing the second metal film 17 as shown in Fig. 6(D). The second metal film 17 is planarized. The second metal film 17 covers the first insulating film 12, and the surface of the first insulating film 12 is not exposed.

[0045] Step S105 includes patterning the second metal film 17 as shown in FIG. 6(E). For the patterning, for example, photolithography and etching techniques are used. Metal wiring can be formed from the remaining second metal film 17.

[0046] 6(E), the first adhesive film 16 remains between the second metal film 17 and the first metal film 11. The remaining first adhesive film 16 increases the contact resistance between the second metal film 17 and the first metal film 11. Therefore, in the second embodiment described later, a first bonding film is used instead of the first adhesive film 16, and a first self-assembled monolayer is formed before the formation of the first bonding film.

[0047] A film deposition method according to the second embodiment will be described with reference to Figures 7 and 8. In the film deposition method according to the second embodiment, metal wiring is formed by a semi-damascene method. The film deposition method according to the second embodiment includes steps S201 to S207, as shown in Figure 7. Differences from the first embodiment will be mainly described below.

[0048] Step S201 includes preparing a substrate 1. The substrate 1 to be prepared is the same as the substrate 1 prepared in S101 of the second reference example (see FIG. 6(A)), and therefore illustration and description thereof will be omitted.

[0049] 8A, the first SAM 18 is formed on the surface of the first metal film 11 selectively with respect to the surface of the first insulating film 12. The first SAM 18 is hardly formed on the surface of the first insulating film 12.

[0050] Step S203 includes forming a first bonding film 19 as shown in Figure 8(B). The first bonding film 19 is formed on both the surface of the first insulating film 12 and the surface of the first SAM 18. The material of the first bonding film 19 is a first molecular bonding agent.

[0051] 8(C), step S204 includes removing the first SAM 18, thereby removing the portion of the first bonding film 19 that contacts the surface of the first SAM 18. The remaining portion of the first bonding film 19 covers the surface of the first insulating film 12, and the surface of the first metal film 11 is exposed again at the bottom of the recess 1b.

[0052] Step S205 includes forming a second metal film 17 as shown in FIG. 8(D). The second metal film 17 fills the recess 1b. The second metal film 17 contacts the first metal film 11 at the bottom of the recess 1b. No other functional film exists between the first metal film 11 and the second metal film 17. The second metal film 17 contacts the first bonding film 19 at the side of the recess 1b and the top of the protrusion 1e. The first bonding film 19 bonds the first insulating film 12 and the second metal film 17. This can prevent the second metal film 17 from peeling off from the first insulating film 12. The first bonding film 19 may bond the etching stopper film 15 and the second metal film 17.

[0053] Step S206 includes polishing the second metal film 17 as shown in Fig. 8(E). The second metal film 17 is planarized. The second metal film 17 covers the first insulating film 12, and the surface of the first insulating film 12 is not exposed.

[0054] Step S207 includes patterning the second metal film 17 as shown in Fig. 8(F). For the patterning, for example, photolithography and etching techniques are used. Metal wiring can be formed from the remaining second metal film 17.

[0055] According to the second embodiment, as shown in FIG. 8(F), there is no other functional film between the second metal film 17 and the first metal film 11. The second metal film 17 and the first metal film 11 are in continuous contact with each other. Therefore, the contact resistance between the second metal film 17 and the first metal film 11 can be reduced. Furthermore, according to the second embodiment, the remaining portion of the first bonding film 19 can improve the adhesion between the first insulating film 12 and the second metal film 17.

[0056] A film formation method according to a third reference example will be described with reference to Figures 9 and 10. The film formation method according to the third reference example forms metal wiring by a semi-damascene method, which is different from that of the second reference example. As shown in Figure 9, the film formation method according to the third reference example includes steps S111 to S114 following step S103 in Figure 5. Differences from the second reference example will be mainly described below.

[0057] 10(A), step S111 includes polishing the second metal film 17. After polishing the second metal film 17, step S111 includes simultaneously polishing the second metal film 17 and the first insulating film 12. The surface of the second metal film 17 and the surface of the first insulating film 12 are aligned in the same plane.

[0058] Step S112 includes forming a second adhesive film 22 as shown in FIG. 10(B). The second adhesive film 22 is formed on both the surface of the second metal film 17 and the surface of the first insulating film 12. The second adhesive film 22 improves adhesion between the first insulating film 12 and a third metal film 23, which will be described later. The second adhesive film 22 is, for example, a TiN film or a TaN film. The second adhesive film 22 is formed by, for example, a CVD method or an ALD method.

[0059] Step S113 includes forming a third metal film 23 as shown in FIG. 10(C). The third metal film 23 is in contact with the second adhesive film 22. The second adhesive film 22 improves the adhesion between the first insulating film 12 and the third metal film 23. The third metal film 23 is, for example, a Ru film. The third metal film 23 may contain Ru, and may also be a Ru alloy film. The third metal film 23 may also be a Cu film, a Co film, a W film, or a Mo film. The third metal film 23 may also be an alloy film containing at least one of Cu, Co, W, and Mo. The third metal film 23 is formed by, for example, a CVD method or a plating method.

[0060] Step S114 includes patterning the third metal film 23 as shown in Fig. 10(D). For the patterning, for example, photolithography and etching techniques are used. Metal wiring can be formed from the remaining third metal film 23.

[0061] According to the third reference example, as shown in FIG. 10(D), the second adhesive film 22 remains between the third metal film 23 and the second metal film 17. The remaining second adhesive film 22 increases the contact resistance between the third metal film 23 and the second metal film 17. Therefore, in the third embodiment described below, a second bonding film is used instead of the second adhesive film 22, and a second self-assembled monolayer is formed before the formation of the second bonding film. Hereinafter, the second self-assembled monolayer may be referred to as a second SAM (Self-Assembled Monolayer).

[0062] A film formation method according to a third embodiment will be described with reference to Figures 11 and 12. The film formation method according to the third embodiment forms metal wiring by a semi-damascene method, which is different from that of the second embodiment. As shown in Figure 11, the film formation method according to the third embodiment includes steps S211 to S216 following step S205 in Figure 7. Differences from the second embodiment will be mainly described below.

[0063] 12(A), step S211 includes polishing the second metal film 17. After polishing the second metal film 17, step S211 includes simultaneously polishing the second metal film 17 and the first insulating film 12. The surface of the second metal film 17 and the surface of the first insulating film 12 are aligned in the same plane.

[0064] Step S212 includes forming a second SAM 25 as shown in FIG. 12(B). The material of the second SAM 25 is the same as the material of the first SAM 18, and therefore a description thereof will be omitted. The second SAM 25 is selectively formed on the surface of the second metal film 17 relative to the surface of the first insulating film 12. The second SAM 25 is hardly formed on the surface of the first insulating film 12.

[0065] Step S213 includes forming a second bonding film 26 as shown in Figure 12(C). The second bonding film 26 is formed on both the surface of the first insulating film 12 and the surface of the second SAM 25. The material of the second bonding film 26 is a second molecular bonding agent. The second molecular bonding agent may be supplied in a liquid state dissolved in an organic solvent, or in a gaseous state vaporized by heating.

[0066] The second molecular binder is an organic compound having a third functional group and a fourth functional group in one molecule. The third functional group bonds more easily to the first insulating film 12 than the fourth functional group. The third functional group is not particularly limited, but includes, for example, at least one of a silanol group and a group that generates a silanol group upon hydrolysis. The group that generates a silanol group upon hydrolysis is, for example, an alkoxysilyl group. A single molecule may contain multiple third functional groups, and the multiple third functional groups may be the same or different.

[0067] The fourth functional group is more likely to bond to the third metal film 23 than the third functional group. The fourth functional group is not particularly limited, but includes, for example, at least one of an amino group, an azide group, a mercapto group, an isocyanate group, a ureido group, and an epoxy group. A single molecule may contain a plurality of fourth functional groups, and the plurality of fourth functional groups may be the same or different.

[0068] The second molecular binder preferably has a triazine between the third and fourth functional groups, and may include at least one of benzene, cyclohexane, naphthalene, a spiro compound, a lactone, pyridine, cyclopentane, furan, and thiophene instead of triazine.

[0069] 12(D), the second SAM 25 is removed, thereby removing the portion of the second bonding film 26 that contacts the surface of the second SAM 25. The remaining portion of the second bonding film 26 covers the surface of the first insulating film 12, and the surface of the second metal film 17 is exposed again.

[0070] Removing the second SAM 25 includes, for example, heating the second SAM 25. The second SAM 25 can be thermally decomposed. The heating temperature is not particularly limited as long as it is higher than the temperature at which the second SAM 25 loses 1% weight, and is, for example, 300°C to 450°C. The holding time at the heating temperature is set depending on the heating temperature, but is, for example, 1 minute to 60 minutes, and preferably 1 minute to 30 minutes.

[0071] The 1% weight loss temperature of second SAM 25 is preferably lower than the 1% weight loss temperature of second bonding film 26. Even if the heating temperature is low enough that thermal decomposition of second bonding film 26 hardly progresses, a portion of second bonding film 26 can be removed. The heating temperature may be lower than the 1% weight loss temperature of second bonding film 26.

[0072] Furthermore, removing the second SAM 25 may include supplying acetic acid to the second SAM 25. The acetic acid breaks the bond between the second SAM 25 and the second metal film 17, thereby removing the second SAM 25. The acetic acid breaks, for example, a sulfide bond. Therefore, supplying acetic acid is particularly effective when the second SAM 25 is a thiol-based compound. The supply time for acetic acid is not particularly limited, but is, for example, 1 to 60 minutes, and preferably 1 to 30 minutes.

[0073] The supply of acetic acid to the second SAM 25 is preferably performed after heating the second SAM 25, but may be performed before heating the second SAM 25. Furthermore, step S214 may include only one of heating the second SAM 25 and supplying acetic acid to the second SAM 25.

[0074] Step S215 includes forming a third metal film 23 as shown in FIG. 12(E). The third metal film 23 is, for example, a Ru film. The third metal film 23 may be a Ru alloy film as long as it contains Ru. The third metal film 23 may be a Cu film, a Co film, a W film, or a Mo film. The third metal film 23 may also be an alloy film containing at least one of Cu, Co, W, and Mo. The third metal film 23 is formed by, for example, a CVD method or a plating method.

[0075] The third metal film 23 contacts the second metal film 17. There is no other functional film between the second metal film 17 and the third metal film 23. The third metal film 23 also contacts the remainder of the second bonding film 26. The remainder of the second bonding film 26 bonds the first insulating film 12 and the third metal film 23. This makes it possible to prevent the third metal film 23 from peeling off from the first insulating film 12.

[0076] Step S216 includes patterning the third metal film 23 as shown in Fig. 12(F). For the patterning, for example, photolithography and etching techniques are used. Metal wiring can be formed from the remaining third metal film 23.

[0077] According to the third embodiment, as shown in FIG. 12(F), there is no other functional film between the third metal film 23 and the second metal film 17. The third metal film 23 and the second metal film 17 are in continuous contact with each other. Therefore, the contact resistance between the third metal film 23 and the second metal film 17 can be reduced. Furthermore, according to the third embodiment, the remaining portion of the second bonding film 26 can improve the adhesion between the first insulating film 12 and the third metal film 23.

[0078] The film forming method may also include preparing a substrate 1A (see FIG. 12A) obtained in step S211 of the third embodiment. The substrate 1A has no recesses on its surface 1Aa. The surface 1Aa is flat, and the surfaces of the second metal film 17 and the first insulating film 12 are aligned on the flat surface.

[0079] In this case, the second metal film 17, the second SAM 25, and the second bonding film 26 may correspond to the first metal film, the first SAM, and the first bonding film in the claims. Accordingly, in this case, the second bonding agent, the third functional group, and the fourth functional group may correspond to the first bonding agent, the first functional group, and the second functional group in the claims.

[0080] Next, with reference to FIG. 13, a film formation apparatus 100 that performs the above-described film formation method will be described. The film formation apparatus 100 performs, for example, the film formation method shown in FIG. 3. The film formation apparatus 100 may also perform the film formation method shown in FIG. 7 or FIG. 11. As shown in FIG. 13, the film formation apparatus 100 includes a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a transport unit 400, and a control circuit 500. The first processing unit 200A performs, for example, step S202 of FIG. 3. The second processing unit 200B performs, for example, steps S203 and S204 of FIG. 3. The third processing unit 200C performs, for example, step S205 of FIG. 3. The processes from step S206 onward are performed outside the film formation apparatus 100, but can also be performed inside the film formation apparatus 100. First processing unit 200A, second processing unit 200B, and third processing unit 200C may have the same structure or different structures. It is also possible for all of steps S202 to S205 in FIG. 3 to be performed by first processing unit 200A alone. Transport unit 400 transports substrate 1 to first processing unit 200A, second processing unit 200B, and third processing unit 200C. Control circuit 500 controls first processing unit 200A, second processing unit 200B, third processing unit 200C, and transport unit 400.

[0081] The transfer section 400 has a first transfer chamber 401 and a first transfer mechanism 402. The internal atmosphere of the first transfer chamber 401 is atmospheric. The first transfer mechanism 402 is provided inside the first transfer chamber 401. A load port 405 is provided on a wall surface of the first transfer chamber 401. A carrier C accommodating a substrate 1 is attached to the load port 405. For example, a FOUP (Front Opening Unified Pod) or the like can be used as the carrier C. The first transfer mechanism 402 includes an arm 403 that holds the substrate 1 and travels along rails 404. The rails 404 extend in the arrangement direction of the carriers C.

[0082] 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 vertically and horizontally and rotatable around a vertical axis. The second transfer chamber 411 is connected to a first processing unit 200A, a second processing unit 200B, and a third processing unit 200C via different gate valves G.

[0083] 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 atmospheric atmosphere by a pressure adjustment mechanism (not shown). This allows the interior of the second transfer chamber 411 to be constantly maintained in a vacuum atmosphere. Also, it is possible to prevent gas from flowing from the first transfer chamber 401 into the second transfer chamber 411. Gate valves G are provided between the first transfer chamber 401 and the load lock chamber 421, and between the second transfer chamber 411 and the load lock chamber 421.

[0084] The control circuit 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 circuit 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 circuit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400 to perform the above-described film forming method.

[0085] The control circuit 500 includes electronic circuits such as a CPU, a Field Programmable Gate Array (FPGA), or an Application Specific Integrated Circuit (ASIC), and performs the various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0086] Next, the operation of the film forming apparatus 100 will be described. First, the first transfer mechanism 402 removes the substrate 1 from the carrier C, transfers the removed 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. Thereafter, the second transfer mechanism 412 removes the substrate 1 from the load lock chamber 421 and transfers the removed substrate 1 to the first processing unit 200A.

[0087] Next, first processing unit 200A performs step S202. 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 at a vacuum atmosphere, and unintended oxidation of substrate 1 can be suppressed.

[0088] Next, second processing unit 200B performs steps S203 and S204. Thereafter, second transport mechanism 412 removes substrate 1 from second processing unit 200B and transports it to third processing unit 200C. During this time, the atmosphere around substrate 1 can be maintained at a vacuum atmosphere, and unintended oxidation of substrate 1 can be suppressed.

[0089] Next, third processing unit 200C performs step S205. Thereafter, second transport mechanism 412 removes substrate 1 from third processing unit 200C, transports the removed substrate 1 to load lock chamber 421, and exits from load lock chamber 421. Next, the internal atmosphere of load lock chamber 421 is switched from a vacuum atmosphere to an atmospheric atmosphere. Thereafter, first transport mechanism 402 removes substrate 1 from load lock chamber 421 and stores the removed substrate 1 in carrier C. Then, processing of substrate 1 is completed.

[0090] Next, first processing unit 200A will be described with reference to Fig. 14. Second processing unit 200B and third processing unit 200C are configured similarly to first processing unit 200A, and therefore will not be illustrated or described here.

[0091] 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.

[0092] An exhaust source 272 is connected to the exhaust pipe 212 via a pressure controller 271. The pressure controller 271 includes a pressure adjustment valve such as a butterfly valve. The exhaust pipe 212 is configured so that the pressure inside the processing vessel 210 can be reduced by the exhaust source 272. The pressure controller 271 and the exhaust source 272 constitute a gas exhaust mechanism 270 that exhausts gas inside the processing vessel 210.

[0093] A transfer port 215 is provided on the side surface of the processing vessel 210. The transfer port 215 is opened and closed by a gate valve G. The substrate 1 is transferred in and out between the processing vessel 210 and a second transfer chamber 411 (see FIG. 13) via the transfer port 215.

[0094] A stage 220, which is a holder for holding the substrate 1, is provided within the processing vessel 210. The stage 220 holds the substrate 1 horizontally with the substrate surface 1a facing upward. The stage 220 is formed in a substantially circular shape in a plan view and is supported by a support member 221. A substantially circular recess 222 for placing the substrate 1, for example, with a diameter of 300 mm, is formed in 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 made of a ceramic material such as aluminum nitride (AlN). Alternatively, the stage 220 may be made of a metal material such as nickel (Ni). Note that instead of the recess 222, a guide ring for guiding the substrate 1 may be provided around the periphery of the surface of the stage 220.

[0095] A grounded lower electrode 223 is embedded in the stage 220, for example. A heating mechanism 224 is embedded below the lower electrode 223. The heating mechanism 224 receives power from a power supply (not shown) based on a control signal from a control circuit 500 (see FIG. 13), thereby heating the substrate 1 placed on the stage 220 to a set temperature. If the entire stage 220 is made of metal, the entire stage 220 functions as the lower electrode, and 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 lifting the substrate 1 placed on the stage 220. The material of the lifting pins 231 may be, for example, ceramics such as alumina (Al2O3), quartz, or the like. The lower ends of the lifting pins 231 are 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 .

[0096] The lifting mechanism 234 is installed, for example, below the exhaust chamber 211. The bellows 235 is provided between the lifting mechanism 234 and an opening 219 for the lifting shaft 233 formed in the lower surface of the exhaust chamber 211. The support plate 232 may be shaped so that it can be raised and lowered without interfering with the support member 221 of the stage 220. The lifting pins 231 are configured to be able to be raised and lowered by the lifting mechanism 234 between above and below the surface of the stage 220.

[0097] A gas supply unit 240 is provided on the ceiling wall 217 of the processing chamber 210 via an insulating member 218. The gas supply unit 240 serves as an upper electrode and faces the lower electrode 223. A high-frequency power supply 252 is connected to the gas supply unit 240 via a matching unit 251. By supplying high-frequency power of 450 kHz to 100 MHz from the high-frequency power supply 252 to the upper electrode (gas supply unit 240), a high-frequency electric field is generated between the upper electrode (gas supply unit 240) and the lower electrode 223, and capacitively coupled plasma is generated. A plasma generation unit 250 that generates plasma includes the matching unit 251 and the high-frequency power supply 252. Note that the plasma generation unit 250 is not limited to capacitively coupled plasma, and may generate other types of plasma, such as inductively coupled plasma. Note that in processes that do not generate plasma, the gas supply unit 240 does not need to serve as an upper electrode, and the lower electrode 223 is also not required.

[0098] The gas supply unit 240 includes a hollow gas supply chamber 241. A number of holes 242 are arranged, for example, evenly, on the bottom surface of the gas supply chamber 241 to distribute and supply the processing gas into the processing vessel 210. A heating mechanism 243 is embedded in the gas supply unit 240, for example, above the gas supply chamber 241. The heating mechanism 243 is heated to a set temperature by receiving power from a power supply unit (not shown) based on a control signal from the control circuit 500.

[0099] 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 gases used in the film formation method to the gas supply chamber 241 via the gas supply path 261. Although not shown, the gas supply mechanism 260 includes individual pipes for each type of gas, on-off valves provided midway through the individual pipes, and flow rate controllers provided midway through the individual pipes. When the on-off valves open the individual pipes, gas is supplied from the supply source to the gas supply path 261. The supply amount is controlled by the flow rate controller. On the other hand, when the on-off valves close the individual pipes, the supply of gas from the supply source to the gas supply path 261 is stopped.

[0100] Although the embodiments of the film forming method and film forming apparatus according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure. [Explanation of symbols]

[0101] 1 board 1a Substrate surface 11 First metal film 12 First insulating film 17 Second metal film 18 1st SAM 19 First connective membrane

Claims

1. preparing a substrate having a first metal film and a first insulating film on different regions of its surface; selectively forming a first self-assembled monolayer on the surface of the first metal film relative to the surface of the first insulating film; forming a first binding film on both the surface of the first insulating film and the surface of the first self-assembled monolayer using a first molecular binding agent; removing the first self-assembled monolayer to remove a portion of the first binding film that is in contact with the surface of the first self-assembled monolayer; forming a second metal film on a surface of the remaining portion of the first bonding film and on a surface of the first insulating film; in this order, a first molecular binder that is an organic compound and has a first functional group and a second functional group in one molecule, the first functional group being more likely to bond to the first insulating film than the second functional group, and the second functional group being more likely to bond to the second metal film than the first functional group;

2. The film forming method according to claim 1 , wherein removing the first self-assembled monolayer includes heating the first self-assembled monolayer.

3. The film forming method according to claim 2 , wherein the 1% weight loss temperature of the first self-assembled monolayer is lower than the 1% weight loss temperature of the first bonded film.

4. The film forming method according to claim 1 , wherein removing the first self-assembled monolayer includes supplying acetic acid to the first self-assembled monolayer.

5. The film forming method according to claim 1 , wherein the material of the first self-assembled monolayer is an organic compound containing a thiol group.

6. The film forming method according to claim 1 , wherein the first metal film and the second metal film contain Ru.

7. 2. The film forming method according to claim 1, wherein the substrate has a recess on the surface, the surface of the first metal film on a bottom surface of the recess, and the surface of the first insulating film on a side surface of the recess.

8. The film forming method according to claim 1 , wherein the first functional group includes at least one of a silanol group and a group that generates a silanol group by a hydrolysis reaction.

9. The film forming method according to claim 1 , wherein the second functional group includes at least one of an amino group, an azide group, a mercapto group, an isocyanate group, a ureido group, and an epoxy group.

10. The film forming method according to claim 1 , wherein the first molecular binder has a triazine between the first functional group and the second functional group.

11. polishing the second metal film to align a surface of the second metal film and a surface of the first insulating film in the same plane; selectively forming a second self-assembled monolayer on the surface of the second metal film relative to the surface of the first insulating film; forming a second binding film on both the surface of the first insulating film and the surface of the second self-assembled monolayer using a second molecular binding agent; removing the second self-assembled monolayer to remove a portion of the second binding film in contact with the surface of the second self-assembled monolayer; forming a third metal film on a surface of the remaining portion of the second bonding film and on a surface of the second metal film; in this order, 2. The film forming method of claim 1, wherein the second molecular binder is an organic compound having a third functional group and a fourth functional group in one molecule, the third functional group being more likely to bond to the first insulating film than the fourth functional group, and the fourth functional group being more likely to bond to the third metal film than the third functional group.

12. A processing vessel; a holder that holds the substrate inside the processing vessel; a gas supply mechanism that supplies gas into the processing chamber; a gas exhaust mechanism that exhausts gas from the inside of the processing vessel; a transfer mechanism that transfers the substrate into and out of the processing chamber; a control circuit that controls the gas supply mechanism, the gas exhaust mechanism, and the transport mechanism to perform the film formation method according to any one of claims 1 to 11; A film forming apparatus comprising:

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