Film formation method and film formation device

Abstract

This film formation method includes: preparing a substrate having, at different regions on a surface thereof, a first film and a second film, the second film being formed of a material different than that of the first film; selectively forming on a surface of the second film, as opposed to a surface of the first film, an inhibition film that inhibits the formation of a subject film as a result of containing boron (B); and, using the inhibition film, selectively forming on a surface of the first film, as opposed to a surface of the second film, the subject film. The formation of the inhibition film includes supplying an organic boron compound containing three or more B atoms per molecule to the surface of the substrate. The organic boron compound includes one or more functional groups that selectively adsorb to the surface of the second film as opposed to the surface of the first film.

Description

Film forming method and film forming apparatus

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

[0002] The film formation method described in Patent Document 1 forms a self-assembled monolayer (SAM) that inhibits the formation of a target film on a partial region of a substrate, and forms the target film on the remaining region of the substrate.

[0003] Japanese Patent Application Publication No. 2022-91523

[0004] One aspect of the present disclosure provides a technique that can form an inhibition film that is excellent in selectivity, resistance, and inhibition.

[0005] A film forming method according to one aspect of the present disclosure includes: preparing a substrate having a first film and a second film formed of a material different from the first film on different regions of its surface; selectively forming an inhibitor film containing boron (B) on the surface of the second film relative to the surface of the first film to inhibit the formation of a target film; and using the inhibitor film to selectively form the target film on the surface of the first film relative to the surface of the second film. Forming the inhibitor film includes supplying an organoboron compound containing three or more B atoms per molecule to the surface of the substrate. The organoboron compound contains one or more functional groups that selectively adsorb to the surface of the second film relative to the surface of the first film.

[0006] According to one aspect of the present disclosure, an inhibition film with excellent selectivity, resistance, and inhibition properties can be formed.

[0007] FIG. 1 is a flowchart showing a film forming method according to an embodiment. FIG. 2 is a cross-sectional view showing a film forming method according to an embodiment. FIG. ２ B １０ H １２ FIG. 4 shows an example of an organoboron compound in which two H atoms of C are substituted with two thiol groups (—SH). ２ B １０ H １２ 5 is a cross-sectional view showing an example of selective adsorption of the organoboron compound shown in FIG. 3. FIG. 6 is a cross-sectional view showing an example of selective adsorption of the organoboron compound shown in FIG. 3. ２ B １０ H１２ Two H atoms are connected to one p-benzyne group (-C ６ H ４ 7 shows an example of an organoboron compound substituted with 7,8-C. ２ B ９ H １３ FIG. 8 shows an example of the structure of 5,6,7-C ３ B ７ H １３ 1 is a diagram showing an example of the structure of FIG. 9 is a flowchart showing a film formation method according to a first modified example. FIG. 10 is a cross-sectional view showing a film formation method according to the first modified example. FIG. 11 is a flowchart showing a film formation method according to a second modified example. FIG. 12 is a cross-sectional view showing a film formation method according to the second modified example. FIG. 13 is a flowchart showing a film formation method according to a third modified example. FIG. 14 is a cross-sectional view showing a film formation method according to the third modified example. FIG. 15 is a plan view showing a film formation apparatus according to one embodiment. FIG. 16 is a cross-sectional view showing an example of a first processing unit.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In the specification, the symbol "to" indicating a range of values ​​means that the values ​​before and after the symbol "to" are included as the lower and upper limits. The range of values ​​includes the range rounded up or down.

[0009] A film formation method according to one embodiment will be described with reference to FIGS. 1 and 2. The film formation method includes, for example, steps S101 to S105 shown in FIG. 1. Note that the film formation method may include at least steps S101 to S103, and may not include, for example, steps S104 to S105. The film formation method may also include steps other than steps S101 to S105 shown in FIG. 1. For example, the film formation method may include removing contaminants adhering to the substrate surface 1a immediately before step S102. Furthermore, in order to promote the formation of an inhibitor film in S102, the film formation method may also include a modification treatment of the substrate surface 1a immediately before S102.

[0010] Step S101 includes preparing a substrate 1, as shown in FIG. 2 . The substrate 1 has a base substrate 10. The base substrate 10 is, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. The substrate 1 has a surface of a first film 11 and a surface of a second film 12 in different regions of its substrate surface 1a. The substrate surface 1a is, for example, the upper surface of the substrate 1. The first film 11 and the second film 12 are formed on the base substrate 10. Another functional film may be formed between the base substrate 10 and the first film 11 or between the base substrate 10 and the second film 12.

[0011] The first film 11 and the second film 12 are formed of different materials. For example, the first film 11 is an insulating film, and the second film 12 is a conductive film. In this embodiment, the first film 11 is an insulating film and the second film 12 is a conductive film, but the combination of materials for the first film 11 and the second film 12 is not particularly limited. The first film 11 may be a conductive film, and the second film 12 may be an insulating film. Furthermore, both the first film 11 and the second film 12 may be insulating films. Furthermore, both the first film 11 and the second film 12 may be conductive films. Furthermore, either the first film 11 or the second film 12 may be a semiconductor film. Furthermore, a semiconductor film may be provided as a third film different from the first film 11 and the second film 12.

[0012] The first film 11 is, for example, an interlayer insulating film. The first film 11 is not particularly limited, but may be, for example, a SiO film, a SiN film, a SiOC film, a SiON film, or a SiOCN film. Here, the SiO film refers to a film containing silicon (Si) and oxygen (O). The atomic ratio of Si to O in a SiO film is usually 1:2, but is not limited to 1:2. Similarly, the SiN film, the SiOC film, the SiON film, and the SiOCN film refer to the film containing each element and are not limited to a stoichiometric ratio. The interlayer insulating film is preferably a low-dielectric-constant (Low-k) film. The first film 11 has a recess in the substrate surface 1a. The recess is a trench, a contact hole, or a via hole.

[0013] The second film 12 fills, for example, the recesses of the first film 11. The second film 12 is, for example, a metal film. The metal film is not particularly limited, but may be, for example, a Cu film, a Co film, a Ru film, a W film, a Mo film, or a Ti film.

[0014] The second film 12 may be, for example, a metal compound film. The metal compound film includes a metal compound such as a metal oxide, a metal nitride, a metal carbide, or a metal sulfide. The metal oxide film is not particularly limited, but may be, for example, an AlO film, a ZrO film, a HfO film, or a TiO film. The metal nitride film is not particularly limited, but may be, for example, a TiN film or a TaN film. Here, the TiN film refers to a film containing titanium (Ti) and nitrogen (N). The atomic ratio of Ti to N in a TiN film is usually 1:1, but is not limited to 1:1. The AlO film, ZrO film, HfO film, TiO film, and TaN film also refer to the film containing each element and are not limited to a stoichiometric ratio.

[0015] Although not shown, the substrate 1 may further have a surface of a third film on the substrate surface 1a. The third film is formed of a material different from the first film 11 and the second film 12. The third film is, for example, a semiconductor film. The semiconductor film is not particularly limited, but may be, for example, a Si film, a SiGe film, or a GaN film. The semiconductor film may be any of a single crystal film, a polycrystalline film, and an amorphous film. The substrate surface 1a may be made of two or more different materials.

[0016] 2, step S102 includes selectively forming an inhibitor film 17 on the surface of the second film 12 relative to the surface of the first film 11. As will be described in detail later, the inhibitor film 17 contains boron (B) and inhibits the formation of the target film 13. The inhibitor film 17 is formed by supplying a SAM material containing an organic boron compound to the substrate surface 1a. In this embodiment, the SAM material containing an organic boron compound is supplied in a gas phase, but it may also be supplied in a liquid phase.

[0017] Here, the SAM material is a molecule having a functional group that inhibits the formation of the target film 13 and a functional group that selectively adsorbs to the surface of the second film 12. Conventionally, alkyl SAM materials have been used as SAM materials. Alkyl SAM materials have a methyl group (-CH ３ ) as an adsorption functional group, and a thiol group (-SH) or a trichlorosilane group (-SiCl ３) and the like. Specific examples of alkyl SAM materials include dodecanethiol (CH ３ (CH ２ ) １１ SH), and octadecyltrichlorosilane (CH ３ (CH ２ ) １７ SiCl ３ ) etc.

[0018] The alkyl SAM material is adsorbed on the surface of the second film 12 to form a molecular layer, thereby forming an inhibitory film. However, when forming the target film 13, the reaction gas used to form the target film 13 reacts with the inhibitory functional group, and the inhibitory functional group is sometimes volatilized and lost. For example, when the reaction gas used to form the target film 13 contains oxygen, the oxygen reacts with the methyl group (CH ３ ) reacts to form CO ２ This can cause the methyl groups to volatilize and be lost. Furthermore, when forming the target film 13, the inhibiting functional groups can be altered by continuous exposure to the source gas and the reactive gas used to form the target film 13, resulting in the loss of their inhibitory properties in film formation. Furthermore, when the substrate temperature is high, the SAM is prone to decomposition, resulting in the loss of the terminal inhibiting functional groups.

[0019] The SAM material containing an organoboron compound used in this embodiment contains three or more B atoms in one molecule. For example, a carborane SAM material can be mentioned. The carborane SAM material has a skeletal structure of a carborane molecule as an inhibitory functional group, and a thiol group (-SH) or a trichlorosilane group (-SiCl) as an adsorptive functional group that substitutes a part of the carborane molecule. ３ ) and the like. Carborane molecules contain B atoms and CH ３Similarly, carborane molecules inhibit the formation of the target film 13. Carborane molecules are highly stable and heat-resistant, and are resistant to deterioration by exposure to source gases and reactant gases during the formation of the target film 13, and are also resistant to thermal decomposition. Even in the case of a carborane SAM material in which a portion of the carborane molecule is substituted with an adsorptive functional group, the carborane molecular skeleton possesses excellent stability and heat resistance. Therefore, compared with alkyl SAM materials, carborane SAM materials can form an inhibition film 17 that is more resistant to source gases, reactant gases, and heat, and has excellent inhibition ability. Furthermore, even if the carborane molecular skeleton of a carborane SAM material decomposes, the inhibition ability is maintained because the B atoms have inhibition ability.

[0020] Carborane SAM materials are carboranes in which the H atoms are replaced with functional groups such as thiol groups (-SH). Carboranes are clusters composed of B atoms and C atoms. Carboranes often have a polyhedral structure. However, carboranes do not necessarily have a polyhedral structure. For example, carboranes may have at least one missing vertex of a polyhedron.

[0021] The carborane SAM material may be a carborane in which the H atom has been substituted with a functional group, and may further be a carborane in which the B atom or the C atom has been substituted with another element, such as an Mg atom, an Al atom, a Si atom, a Co atom, an Fe atom, or a Ni atom.

[0022] As shown in Figure 3, the organoboron compound has a polyhedral structure, and the polyhedral structure has at least five vertices (12 in Figure 3), and preferably has B atoms at at least three vertices (10 in Figure 3). The organoboron compound has a polyhedral structure, which allows B atoms to be stably incorporated into one molecule. The polyhedral structure has, for example, 8 to 20 polyhedral faces, each of which is triangular.

[0023] The polyhedral structure may have either a B atom or a C atom at each vertex of the polyhedron. However, the polyhedral structure may have an atom other than a B atom or a C atom at at least one vertex of the polyhedron. Examples of atoms other than a B atom or a C atom include an Mg atom, an Al atom, a Si atom, a Co atom, an Fe atom, and a Ni atom.

[0024] As shown in Figure 3, the polyhedron structure is preferably an icosahedron structure, each face of the polyhedron being triangular, the number of vertices of the polyhedron being 12, and the polyhedron structure preferably has B atoms at 10 vertices and C atoms at 2 vertices. The organoboron compound shown in Figure 3 is preferably an o-C ２ B １０ H １２ where two H atoms are replaced with two thiol groups (-SH).

[0025] As shown in Figure 3, a thiol group may be bonded to each of two C atoms constituting two vertices of the polyhedral structure. In this case, the organoboron compound has two thiol groups in one molecule and is selectively adsorbed to a metal film, which is an example of the second film 12, as shown in Figure 5. Note that a functional group such as a thiol group can also be bonded to a B atom or the like constituting a vertex of the polyhedral structure, rather than to a C atom constituting a vertex of the polyhedral structure. Although both thiol groups are adsorbed to the substrate surface in Figure 5, it is also possible for only one thiol group to be adsorbed to the substrate.

[0026] One functional group basically bonds to an atom constituting one vertex of the polyhedral structure, but may also bond across multiple atoms constituting multiple vertices of the polyhedral structure. An example of the latter functional group is a p-benzyne group (-C ６ H ４ The p-benzyne group can be bonded across two atoms that constitute two vertices of the polyhedral structure.

[0027] The organoboron compound does not have to have a polyhedral structure. For example, the organoboron compound may have a polyhedral structure in which at least one vertex is missing, and the structure may have at least four vertices, with B atoms at at least three vertices. For example, the organoboron compound may have a 7,8-C ２ B ９ H １３ , or 5,6,7-C shown in FIG. ３ B ７ H １３ The hydrogen atom substituted for the adsorptive functional group may be a hydrogen atom shown in FIG. 7 or 8 or a hydrogen atom not shown.

[0028] The carborane SAM material contains one or more functional groups that selectively adsorb to the surface of the second film 12 relative to the surface of the first film 11. The functional group is not particularly limited, but may be, for example, a thiol group (—SH). Thiol groups readily bond with metal elements exposed on the surface of the second film 12 and are more likely to chemisorb to the surface of a metal film made of metal elements such as Cu, Co, Mo, W, Ti, Hf, or Zr than to the surface of the interlayer insulating film, which is the surface of the first film 11 containing at least one element selected from N, C, and O and Si. Therefore, the inhibitor film 17 is selectively formed on the surface of the metal film relative to the surface of the interlayer insulating film. The inhibitor film 17 is hardly formed on the surface of an interlayer insulating film that does not contain metal elements. The surface of the first film 11 may be the surface of a Si film.

[0029] Thiol groups easily bond with metal elements exposed on the second film 12. Therefore, when the functional group is a thiol group, the second film 12 is preferably a metal film composed solely of metal elements. However, when the functional group is a thiol group, the second film 12 may be a metal compound film. A metal compound film includes a metal compound such as a metal oxide, metal nitride, or metal carbide. Because a metal compound contains oxygen atoms, nitrogen atoms, or carbon atoms, fewer metal elements are required for adsorption. However, when the first film 11 is, for example, an interlayer insulating film containing at least one element of N, C, or O and Si, it is expected that more thiol groups will adsorb to the surface of the second film 12 than to the surface of the first film 11. Therefore, when the first film 11 is, for example, an interlayer insulating film containing at least one element of N, C, or O and Si, the second film 12 may be a metal compound film.

[0030] When the functional group is a thiol group, the first film 11 is preferably an interlayer insulating film formed from Si and at least one element selected from N, C, and O. However, if the second film 12 is a metal film, the first film 11 may be a metal compound film. If the second film 12 has a higher metal content than the first film 11, it can be expected that more thiol groups will be adsorbed on the surface of the second film 12 than on the surface of the first film 11. Note that an inhibitor film 17 unintentionally formed on the surface of the first film 11 may be removed by post-processing.

[0031] The delay time until film formation actually begins on the substrate surface is called the incubation time. The incubation time varies depending on the material forming the substrate surface. It is also possible to form an inhibitor film 17 only on the surface of the second film 12 by utilizing the difference in incubation time between the surfaces of the first film 11 and the second film 12. However, it is difficult to form a thick inhibitor film 17 using this method, and the combinations of the first film 11 and the second film 12 that can selectively form the inhibitor film 17 are limited. According to this embodiment, the adsorption selectivity of functional groups is utilized, so the inhibitor film 17 can be formed in a specific region, improving the selectivity of the inhibitor film 17 compared to when differences in incubation time are utilized. Furthermore, according to this embodiment, the selectivity of functional groups is utilized, so the options for material combinations for the first film 11 and the second film 12 can be expanded.

[0032] The functional group is not limited to a thiol group. Examples of the functional group include a thiol group (-SH), a phosphonic acid group (-P(=O)(OH) ２ ), carboxylic acid group (-COOH), nitro group (-NO ２ ), aryl group, methylamino group (—NH ２ , -NH(CH ３ ), -N(CH ３ ) ２ ), -SiCl ３ , -SiCl ２ H, -SiClH ２ , -SiH ３ , -SiH ２ (OCH ２ CH ３ ), -SiH(OCH ２ CH ３ ) ２ , -Si(OCH ２ CH ３ ) ３ , an isocyanate group (—NCO), and a hydroxyl group (—OH). The aryl group is a phenyl group (—C ６ H ５ ) is included.

[0033] Phosphonic acid groups, carboxylic acid groups, and nitro groups are likely to bond with metal elements and are likely to chemically adsorb to the surface of a film containing metal elements such as Cu, Co, Mo, W, Ti, Hf, and Zr. Therefore, the inhibitor film 17 is likely to selectively bond to metal films and metal compound films formed only from metal elements. Methylamino groups are likely to bond to SiO ２ , and easily bond selectively to the surface of an insulating film such as a low-k material.

[0034] The adsorption of the carborane SAM material onto the substrate surface 1a may be performed by vaporizing the carborane SAM material and supplying it into a vacuum device. ２ This may be carried out by supplying the gas into a vacuum apparatus together with a carrier gas such as the above.

[0035] The adsorption of the carborane SAM material onto the substrate surface 1a may be carried out in a liquid phase by dissolving the carborane SAM material in a solvent and applying it onto the substrate by wet dipping or spin coating. The solvent may be an organic solvent such as benzene, diethyl ether, or ethanol.

[0036] The carborane SAM material supplied to the substrate surface 1 a may contain multiple types of molecules. For example, a carborane SAM material having a thiol group and a carborane SAM material having a carboxyl group may be supplied to the substrate surface 1 a simultaneously or alternately.

[0037] Before supplying the carborane SAM material in gas or liquid phase in step S102, the substrate surface 1a may be modified in a vacuum chamber. The surface may be modified by exposure to a reactive gas containing oxygen, hydrogen, or nitrogen. The reactive gas may also be converted into plasma for surface treatment. This modification treatment is expected to modify the surface terminal groups with hydrogen groups (-H), hydroxyl groups (-OH), etc., thereby improving the adsorption of the carborane SAM material.

[0038] As shown in FIG. 2 , step S103 includes selectively forming a target film 13 on the surface of the first film 11 relative to the surface of the second film 12 using an inhibitor film 17. The target film 13 can be formed, for example, by atomic layer deposition (ALD). In the ALD method, the target film 13 is formed by repeatedly supplying a source gas and a reactive gas alternately to the substrate surface 1a. Alternatively, chemical vapor deposition (CVD) may be used. In the CVD method, a source gas and a reactive gas are simultaneously supplied to the substrate surface 1a.

[0039] The source gas contains, for example, a halogen and an element X other than a halogen. The halogen is fluorine, chlorine, bromine, or iodine. The element X is not particularly limited, but is preferably a metal element, more preferably a transition metal element. The element X is, for example, Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, or Sb. A specific example of the source gas is TiCl. ４ Gas, WCl ６ Gas, WF ６Gas, VCl ４ Gas, AlCl ３ Gas, MoCl ５ Gas, SnCl ４ Gas, HfCl ４ Gas, TaCl ５ Gas, NbCl ５ Gas, ZrCl ４ Gas, InCl ３ Gas, GaCl ３ gas or SbCl ３ Gas is one example.

[0040] The element X may be a semiconductor element, specifically Si or Ge. The source gas is a silicon halide gas or a germanium halide gas. Specific examples of silicon halide gas include SiCl. ４ Gas, SiHCl ３ Gas, SiH ２ Cl ２ Gas, SiH ３ Cl gas, Si ２ Cl ６ gas 、 Si ２ HCl ５ Gas, Si ２ Cl ３ CH ３ Gas, SiCl ３ CCl ３ Gas, SiCl ３ CH ３ gas, or SiH ２ I ２ Specific examples of germanium halide gas include GeCl ４ Gas, etc.

[0041] The source gas may be supplied together with a dilution gas, such as Ar gas or N ２ It's gas.

[0042] The reactive gas reacts with the element X contained in the adsorbate of the source gas to form a target film 13 containing the element X. Examples of the reactive gas include an oxygen-containing gas, a nitrogen-containing gas, and 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, O３ Gas, CO ２ Gas, N ２ O gas, NO gas, or H ２ The nitrogen-containing gas contains nitrogen and forms a nitride film of element X. The nitrogen-containing gas is, for example, NH ３ Gas or N ２ H ４ The hydrogen-containing gas contains hydrogen and forms a film (for example, a metal film or a semiconductor film) containing the element X as a main component. The hydrogen-containing gas is, for example, H ２ Gas or H ２ It is S gas.

[0043] The reaction gas may be supplied together with a dilution gas, such as Ar gas or N ２ The reactive gas may be plasma. Depending on the material of the target film 13, the reactive gas may not be necessary.

[0044] For the inhibitor film 17 to inhibit the formation of the target film 13, it is important that the source gas is weakly or not adsorbed to the inhibitor film 17, and as a result, the adsorbate of the source gas is desorbed from the surface of the inhibitor film 17 without advancing the film formation reaction (formation of the target film 13). Alternatively, it is important that the source gas is not adsorbed to the surface of the inhibitor film 17, or that dissociation of the source gas is unlikely to occur on the surface of the inhibitor film 17. If dissociation of the source gas occurs, the film formation reaction is more likely to proceed.

[0045] Since the inhibitor film 17 contains boron, it is believed that adsorption of halides does not occur, or if it does occur, it is weak, or that dissociation of halides is difficult to occur on the inhibitor film 17. As a result, the formation of the target film 13 is inhibited on the surface of the inhibitor film 17.

[0046] On the other hand, since the first film 11 does not substantially contain boron, it is believed that halides are strongly adsorbed or that dissociation of halides occurs easily on the first film 11. As a result, it is believed that the formation of the target film 13 progresses on the surface of the first film 11.

[0047] TiCl ４ Halides such as Ti[N(CH ３ ) ２ ]４ Compared to organometallic complexes such as those mentioned above, the source gas is less likely to decompose due to the heat of the substrate 1. If the source gas decomposes after being adsorbed onto the inhibitor film 17, the formation of the target film 13 will proceed. Therefore, in order to inhibit the formation of the target film 13 on the surface of the inhibitor film 17, a gas containing a halogen is suitable as the source gas for the target film 13.

[0048] In the plasma CVD method in which both the halide and the reactive gas are converted into plasma, active species such as ions or radicals are generated by dissociation of the halide. The active species generated from the halide are highly reactive, and it is thought that the film formation reaction is likely to proceed not only on the surface of the first film 11 but also on the surface of the inhibitor film 17. Therefore, it is preferable not to convert the source gas into plasma, and it is important to use the thermal ALD method, the plasma ALD method, or the thermal CVD method.

[0049] The temperature of the substrate 1 may be controlled to 100°C or higher to promote desorption of the source gas from the surface of the inhibitor film 17. If the temperature of the substrate 1 is lower than 100°C, the source gas will not be sufficiently desorbed from the surface of the inhibitor film 17, resulting in physical adsorption of the source gas, and the target film 13 will also be formed on the surface of the inhibitor film 17. The temperature of the substrate 1 is preferably 300°C or higher. The temperature of the substrate 1 is preferably 800°C or lower.

[0050] 2, step S104 includes removing the inhibition film 17 while leaving the target film 13. Step S104 includes removing the inhibition film 17 using dry etching or wet etching. The dry etching may be either plasma etching or thermal etching.

[0051] The plasma etching is performed using, for example, CHF ３ or CF ４ In addition to the etching gas, H ２ Or O ２ An additive gas such as N ２ Alternatively, a dilution gas such as Ar may be used. In plasma etching, the temperature of the substrate 1 is preferably 100° C. or less.

[0052] Thermal etching is performed using, for example, Cl ２ or ClF ３ In addition to the etching gas, N ２ Alternatively, a dilution gas such as Ar may be used. In the thermal etching, the temperature of the substrate 1 is preferably 150° C. or higher.

[0053] Wet etching is performed using, for example, HF or HNO ３ A chemical solution is used in which a solvent that contributes to etching such as the above is dissolved in water or an organic solvent.

[0054] The target film 13 does not substantially contain boron, whereas the inhibition film 17 contains boron. B atoms are formed in halides, such as BF ３ or BCl ３ These are highly volatile and easily etched, so it is possible to remove the inhibitor film 17 while leaving the target film 13.

[0055] The film forming method may include forming a second target film on the surface of the second film 12 after step S104.

[0056] Step S105 checks whether steps S102 to S104 have been performed a set number of times (N times). If the number of times has not reached the set number, the film thickness of the target film 13 has not reached the target value, so steps S102 to S104 are performed again. On the other hand, if the number of times has reached the set number, the film thickness of the target film 13 has reached the target value, so this processing ends. N may be an integer of 1 or greater, but is preferably an integer of 2 or greater.

[0057] Next, a film forming method according to a first modified example will be described with reference to Figures 9 and 10. In Figure 10, 17A indicates a modified inhibitor film. Below, differences from the above embodiment will be mainly described. The film forming method of this modified example includes step S102A after step S102 and before step S103. Step S102A includes modifying the inhibitor film 17 with plasma or heat. By destroying the polyhedron structure with plasma or heat, the spacing between B atoms is narrowed to form a dense B-containing film, improving inhibitory properties.

[0058] Next, a film formation method according to a second modified example will be described with reference to Figures 11 and 12. Differences from the first modified example will be mainly described below. The film formation method of this modified example includes step S102B after step S102A and before step S103. Step S102B includes selectively forming a B-containing film 18 on the surface of the inhibitor film 17A relative to the surface of the first film 11. The B-containing film 18 can further improve the inhibitory properties of the inhibitor film 17A.

[0059] The B-containing film 18 may be formed by a method different from that of the inhibitor film 17. For example, the B-containing film 18 may be selectively formed on the surface of the inhibitor film 17 relative to the surface of the first film 11 by utilizing the difference in incubation time. The inhibitor film 17 contains B atoms, whereas the first film 11 does not contain B atoms, resulting in a large difference in incubation time. The formation of a film containing B, like the inhibitor film 17, proceeds quickly on the inhibitor film 17, allowing the B-containing film 18 to be selectively formed relative to the first film 11.

[0060] The method for forming the B-containing film 18 is, for example, the ALD method. In the ALD method, the B-containing film 18 is formed by alternately and repeatedly supplying a source gas and a reaction gas to the substrate surface 1a. The source gas for the B-containing film 18 is, for example, trisdimethylaminoborane (TDMAB:C ６ H １８ BN ３ The source gas may be supplied together with a dilution gas. The dilution gas may be, for example, Ar gas or N ２ It's gas.

[0061] The source gas for the B-containing film 18 is not limited to that containing TDMAB, and may be, for example, diborane (B ２ H ６ ), boron trichloride (BCl ３ ), boron trifluoride (BF ３ ), trisethylmethylaminoborane (C ９ H ２４ BN ３ ), trimethylborane (C ３ H ９ B), or triethylborane (C ６ H １５ B), cyclotriborazane (B３ N ３ H ６ ) etc.

[0062] The reactive gas for the B-containing film 18 reacts with the adsorbate of the source gas on the substrate surface 1a to form the B-containing film 18. The reactive gas contains, for example, at least one of a nitrogen-containing gas, an oxygen-containing gas, and a reducing gas. The nitrogen-containing gas nitrides the source 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 The oxygen-containing gas oxidizes the source gas to form a boron oxide film. ２ , O ３ , H ２ O, NO or N ２ The reducing gas contains O. The reducing gas reduces the source gas to form a boron film. The reducing gas is, for example, H ２ , SiH ４ or H ２ Contains S gas.

[0063] The reaction gas may be supplied together with a dilution gas, such as Ar gas or N ２ The reactive gas may be plasmatized. Note that the reactive gas may not be necessary depending on the material of the B-containing film 18.

[0064] Next, a film formation method according to a third modification will be described with reference to Figures 13 and 14. Differences from the second modification will be mainly described below. The film formation method of this modification does not include step S102A but includes step S102B after step S102 and before step S103. The B-containing film 18 can also be selectively formed on the inhibition film 17 having a polyhedral structure.

[0065] Next, with reference to FIG. 15 , a film formation apparatus 100 for carrying out the above-described film formation method will be described. As shown in FIG. 15 , the film formation apparatus 100 includes a first processing unit 200A, a second processing unit 200B, a third processing unit 200C, a transport unit 400, and a control unit 500. The first processing unit 200A performs step S102 of FIG. 1 . The second processing unit 200B performs step S103 of FIG. 1 . The third processing unit 200C performs step S104 of FIG. 1 . The first processing unit 200A, the second processing unit 200B, and the third processing unit 200C may have similar structures or different structures. The first processing unit 200A may perform steps S102 to S104 of FIG. 1 . The film formation apparatus 100 can also carry out the film formation method shown in FIG. 9 , FIG. 11 , or FIG. 13 .

[0066] The transport unit 400 transports the substrate 1 to the first processing unit 200A, the second processing unit 200B, and the third processing unit 200C. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400.

[0067] The transfer section 400 has a first transfer chamber 401 and a first transfer mechanism 402. The internal atmosphere of the first transfer chamber 401 is atmospheric. The first transfer mechanism 402 is provided inside the first transfer chamber 401. The first transfer mechanism 402 includes an arm 403 that holds the substrate 1, and travels along rails 404. The rails 404 extend in the arrangement direction of the carriers C.

[0068] The transfer unit 400 also has a second transfer chamber 411 and a second transfer mechanism 412. The internal atmosphere of the second transfer chamber 411 is a vacuum atmosphere. The second transfer mechanism 412 is provided inside the second transfer chamber 411. The second transfer mechanism 412 includes an arm 413 that holds the substrate 1, and the arm 413 is arranged to be movable in the vertical and horizontal directions and rotatable around a vertical axis. The second transfer chamber 411 is connected to a first processing unit 200A, a second processing unit 200B, and a third processing unit 200C via different gate valves G.

[0069] Furthermore, the transfer unit 400 has a load lock chamber 421 between the first transfer chamber 401 and the second transfer chamber 411. The internal atmosphere of the load lock chamber 421 can be switched between a vacuum atmosphere and an atmospheric atmosphere by a pressure adjustment mechanism (not shown). This allows the interior of the second transfer chamber 411 to be constantly maintained in a vacuum atmosphere. Also, it is possible to prevent gas from flowing from the first transfer chamber 401 into the second transfer chamber 411. Gate valves G are provided between the first transfer chamber 401 and the load lock chamber 421, and between the second transfer chamber 411 and the load lock chamber 421.

[0070] The control unit 500 is, for example, a computer, and includes an arithmetic unit 501 such as a CPU (Central Processing Unit) and a storage unit 502 such as a memory. The storage unit 502 stores programs that control various processes executed in the film forming apparatus 100. The control unit 500 controls the operation of the film forming apparatus 100 by causing the arithmetic unit 501 to execute the programs stored in the storage unit 502. The control unit 500 controls the first processing unit 200A, the second processing unit 200B, the third processing unit 200C, and the transport unit 400 to perform the above-described film forming method.

[0071] The control unit 500 includes electronic circuits such as a CPU, a GPU (Graphics Processing Unit), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit), and performs the various control operations described in this specification by executing instruction codes stored in memory or by being a circuit designed for a specific application.

[0072] Next, the operation of the film forming apparatus 100 will be described. First, the first transport mechanism 402 removes the substrate 1 from the carrier C, transports the removed substrate 1 to the load lock chamber 421, and exits the load lock chamber 421. Next, the internal atmosphere of the load lock chamber 421 is switched from the air atmosphere to a vacuum atmosphere. Thereafter, the second transport mechanism 412 removes the substrate 1 from the load lock chamber 421 and transports the removed substrate 1 to the first processing unit 200A.

[0073] Next, first processing unit 200A performs step S102. 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 surrounding substrate 1 can be maintained at a vacuum atmosphere, thereby preventing unintended oxidation of substrate 1 and organic compound contamination.

[0074] Next, second processing unit 200B performs step S103. Thereafter, second transport mechanism 412 removes substrate 1 from second processing unit 200B and transports it to third processing unit 200C. During this time, the atmosphere surrounding substrate 1 can be maintained at a vacuum atmosphere, thereby preventing unintended oxidation of substrate 1 and organic compound contamination.

[0075] Next, third processing unit 200C performs step S104. Subsequently, control unit 500 checks whether steps S102 to S104 have been performed a set number of times (N times). If the set number of times has not been reached, second transport mechanism 412 removes substrate 1 from third processing unit 200C and transports the removed substrate 1 to first processing unit 200A. Thereafter, control unit 500 controls first processing unit 200A, second processing unit 200B, third processing unit 200C, and transport unit 400 to perform steps S102 to S104 again.

[0076] On the other hand, if the number of times has reached the set number, the second transport mechanism 412 removes the substrate 1 from the third processing unit 200C, transports the removed substrate 1 to the load lock chamber 421, and exits from the load lock chamber 421. The internal atmosphere of the load lock chamber 421 is then switched from a vacuum atmosphere to an atmospheric atmosphere. Thereafter, the first transport mechanism 402 removes the substrate 1 from the load lock chamber 421 and stores the removed substrate 1 in the carrier C. Then, the processing of the substrate 1 is completed.

[0077] Next, the first processing unit 200A will be described with reference to Fig. 16. The second processing unit 200B and the third processing unit 200C are configured in the same manner as the first processing unit 200A, and therefore will not be illustrated or described here.

[0078] 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.

[0079] 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.

[0080] A transfer port 215 is provided on the side surface of the processing vessel 210. The transfer port 215 is opened and closed by a gate valve G. The substrate 1 is transferred in and out between the processing vessel 210 and the second transfer chamber 411 (see FIG. 15 ) via the transfer port 215.

[0081] A stage 220, which serves as a holder for holding the substrate 1, is provided within the processing vessel 210. The stage 220 holds the substrate 1 horizontally with the substrate surface 1a facing upward. The stage 220 is formed in a substantially circular shape in a plan view and is supported by a support member 221. A substantially circular recess 222 for placing the substrate 1, e.g., 300 mm in diameter, is formed on the surface of the stage 220. The recess 222 has an inner diameter slightly larger than the diameter of the substrate 1. The depth of the recess 222 is configured to be substantially the same as the thickness of the substrate 1, for example. The stage 220 is formed of a ceramic material such as aluminum nitride (AlN). Alternatively, the stage 220 may be formed of a metal material such as nickel (Ni). Note that instead of the recess 222, a guide ring for guiding the substrate 1 may be provided around the periphery of the surface of the stage 220.

[0082] A grounded lower electrode 223, for example, is embedded in the stage 220. A heating mechanism 224 is embedded below the lower electrode 223. The heating mechanism 224 receives power from a power supply unit (not shown) based on a control signal from the control unit 500 (see FIG. 15), thereby heating the substrate 1 placed on the stage 220 to a set temperature. If the entire stage 220 is made of metal, the entire stage 220 functions as the lower electrode, so the lower electrode 223 does not need to be embedded in the stage 220. The stage 220 is provided with a plurality of (for example, three) lifting pins 231 for holding and lifting up and down the substrate 1 placed on the stage 220. The lifting pins 231 are made of a material such as alumina (Al ２ O ３ The lift pins 231 may be made of ceramics such as quartz or the like. The lower ends of the lift pins 231 are attached to a support plate 232. The support plate 232 is connected to a lift mechanism 234 provided outside the processing vessel 210 via a lift shaft 233.

[0083] 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.

[0084] A gas supply unit 240 is provided on the ceiling wall 217 of the processing vessel 210 via an insulating member 218. The gas supply unit 240 serves as an upper electrode and faces the lower electrode 223. A high-frequency power supply 252 is connected to the gas supply unit 240 via a matching unit 251. By supplying high-frequency power of 450 kHz to 100 MHz from the high-frequency power supply 252 to the upper electrode (gas supply unit 240), a high-frequency electric field is generated between the upper electrode (gas supply unit 240) and the lower electrode 223, generating capacitively coupled plasma. A plasma generation unit 250 that generates plasma includes the matching unit 251 and the high-frequency power supply 252. Note that the plasma generation unit 250 is not limited to capacitively coupled plasma, and may generate other types of plasma, such as inductively coupled plasma. Note that in steps that do not generate plasma (e.g., step S102), the gas supply unit 240 does not need to serve as the upper electrode, and the lower electrode 223 is also unnecessary.

[0085] The gas supply unit 240 includes a hollow gas supply chamber 241. A number of holes 242 are arranged, for example, evenly, on the bottom surface of the gas supply chamber 241 to distribute and supply the processing gas into the processing vessel 210. A heating mechanism 243 is embedded in the gas supply unit 240, for example, above the gas supply chamber 241. The heating mechanism 243 is heated to a set temperature by receiving power from a power supply unit (not shown) based on a control signal from the control unit 500.

[0086] A gas supply mechanism 260 is connected to the gas supply chamber 241 via a gas supply path 261. The gas supply mechanism 260 supplies gas used in at least one of steps S102 to S104 of FIG. 1 to the gas supply chamber 241 via the gas supply path 261. Although not shown, the gas supply mechanism 260 includes individual pipes for each type of gas, on-off valves provided midway through the individual pipes, and flow rate controllers provided midway through the individual pipes. When the on-off valves open the individual pipes, gas is supplied from the supply source to the gas supply path 261. The supply amount is controlled by the flow rate controller. On the other hand, when the on-off valves close the individual pipes, the supply of gas from the supply source to the gas supply path 261 is stopped.

[0087] 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.

[0088] This application claims priority based on Japanese Patent Application No. 2024-030893 filed with the Japan Patent Office on March 1, 2024, the entire contents of which are incorporated herein by reference.

[0089] REFERENCE SIGNS LIST 1 substrate 1a surface 11 first film 12 second film 13 target film 17 inhibition film

Claims

1. A film forming method comprising: preparing a substrate having a first film and a second film formed of a material different from the first film on different regions of its surface; selectively forming an inhibitory film containing boron (B) on the surface of the second film relative to the surface of the first film, thereby inhibiting the formation of a target film; and using the inhibitory film to selectively form the target film on the surface of the first film relative to the surface of the second film, wherein forming the inhibitory film includes supplying an organic boron compound containing three or more B atoms in one molecule to the surface of the substrate, and the organic boron compound contains one or more functional groups that selectively adsorb to the surface of the second film relative to the surface of the first film.

2. The film forming method according to claim 1, wherein the organoboron compound has a polyhedral structure, the polyhedral structure having at least five vertices, and at least three vertices have B atoms.

3. The film forming method according to claim 2, wherein the polyhedron structure is an icosahedron structure, each face of the polyhedron is triangular, the number of vertices of the polyhedron is 12, and the polyhedron structure has B atoms at 10 vertices and C atoms at 2 vertices.

4. The film forming method according to claim 1, wherein the organic boron compound has a polyhedral structure in which at least one vertex is missing, the structure having at least four vertices, and at least three vertices having B atoms.

5. The film forming method according to any one of claims 2 to 4, wherein the functional group is bonded to an element that constitutes a vertex of the polyhedral structure.

6. The functional group is a thiol group (-SH), a phosphonic acid group (-P(=O)(OH) ２ ), carboxylic acid group (-COOH), nitro group (-NO ２ ), aryl group, methylamino group (—NH ２ , -NH(CH ３ ), -N(CH ３ ) ２ ), -SiCl ３ , -SiCl ２ H, -SiClH ２ , -SiH ３ , -SiH ２ (OCH ２ CH ３ ), -SiH(OCH ２ CH ３ ) ２ , -Si(OCH ２ CH ３ ) ３ 5. The film forming method according to claim 1, wherein the compound has at least one of an isocyanate group (--NCO) and a hydroxyl group (--OH).

7. A film forming method according to any one of claims 1 to 4, further comprising modifying the inhibitor film with plasma or heat after forming the inhibitor film and before forming the target film.

8. The film forming method according to claim 7, further comprising selectively forming a B-containing film on the surface of the inhibitor film relative to the surface of the first film after modifying the inhibitor film and before forming the target film.

9. A film forming method according to any one of claims 1 to 4, comprising selectively forming a B-containing film on the surface of the inhibitor film relative to the surface of the first film after forming the inhibitor film and before forming the target film.

10. A film formation apparatus comprising: a processing vessel that accommodates the substrate; a holding unit that holds the substrate inside the processing vessel; a supply unit that supplies gas to the surface of the substrate held by the holding unit; and a control unit that controls the supply unit, wherein the control unit controls the implementation of the film formation method described in any one of claims 1 to 4.

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