Film formation method

Abstract

To provide a technique capable of forming a molybdenum film on a base layer while suppressing damage to the base layer.SOLUTION: In one exemplary embodiment, a film forming method includes preparing a substrate on which an insulating film is formed, forming a seed layer on the insulating film, and forming a molybdenum film on the seed layer by supplying a molybdenum-containing gas and a reducing gas to the substrate on which the seed layer is formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In order to form a wiring pattern on the surface of a semiconductor wafer or to fill recesses between wirings or recesses for contacts, a thin film is formed by depositing a metal or a metal compound. For example, Patent Document 1 discloses a technique for forming a tungsten film in a filling hole formed in the surface of a semiconductor wafer by alternately supplying a tungsten-containing gas and a reducing gas to the semiconductor wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-193233 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that allows a molybdenum film to be formed on an underlayer while suppressing damage to the underlayer. [Means for solving the problem]

[0005] A film formation method according to one aspect of the present disclosure includes the steps of preparing a substrate on which an insulating film is formed, forming a seed layer on the insulating film, and supplying a molybdenum-containing gas and a reducing gas to the substrate on which the seed layer is formed to form a molybdenum film on the seed layer. [Effects of the Invention]

[0006] According to the present disclosure, a molybdenum film can be formed on an underlayer while suppressing damage to the underlayer. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a flowchart illustrating an example of a film forming method according to an embodiment. [Figure 2] 1A to 1C are cross-sectional views illustrating an example of a film forming method according to an embodiment of the present invention; [Figure 3] An explanatory diagram of a reaction model when a seed layer is formed using a silicon-containing gas. [Figure 4] An explanatory diagram of a reaction model when a seed layer is formed using a boron-containing gas [Figure 5] An explanatory diagram of a reaction model when a seed layer is formed using oxygen gas [Figure 6] FIG. 1 is a diagram showing an example of a film forming apparatus for performing a film forming method according to an embodiment. [Figure 7] Figure showing the relationship between the number of ALD cycles and the thickness of the molybdenum film [Figure 8] Graph showing the measurement results of the resistivity of a molybdenum film DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Molybdenum (Mo) film] Molybdenum films have low resistance and can be formed using fluorine-free gases, so they are attracting attention for their application to MOSFET gate electrodes, source / drain contacts, memory word lines, and other applications.

[0010] Molybdenum films are formed by, for example, atomic layer deposition (ALD) or chemical vapor deposition (CVD). When a molybdenum film is formed on an underlayer, such as a block oxide film of a NAND memory, by ALD or CVD, a molybdenum-containing gas such as molybdenum dioxide dichloride (MoOCl) and a reducing gas such as hydrogen (H) are supplied to the underlayer. During the film formation process, the surface of the underlayer is exposed and therefore exposed to the reducing gas. As a result, oxygen contained in the underlayer is extracted by the reducing gas, which can degrade the properties of the underlayer.

[0011] Therefore, the present disclosure provides a technique that allows a molybdenum film to be formed on an underlayer while suppressing damage to the underlayer.

[0012] [Film formation method] An example of a film forming method according to an embodiment will be described with reference to Figures 1 to 5. Figure 1 is a flowchart showing an example of a film forming method according to an embodiment. Figure 2 is a cross-sectional view showing steps of the example of a film forming method according to an embodiment.

[0013] 1, the film formation method of the embodiment includes forming a molybdenum film on a substrate by performing the following steps in this order: step S1 of preparing a substrate; step S2 of forming a seed layer; and step S3 of forming a molybdenum film. The molybdenum film can be used, for example, as a word line of a NAND memory.

[0014] 2(a), the step S1 of preparing a substrate includes preparing a substrate 100 on which an insulating film 101 is formed. The substrate 100 is, for example, a semiconductor wafer such as a silicon wafer. The insulating film 101 may be, for example, a block oxide film of a NAND memory, and is formed of a metal oxide such as aluminum oxide (AlO).

[0015] 2(b), the step S2 of forming a seed layer includes forming a seed layer 102 on the insulating film 101. The seed layer 102 is formed, for example, by exposing the substrate 100 to at least one of a silicon-containing gas, a boron-containing gas, and an oxygen-containing gas while the substrate temperature is adjusted to a predetermined temperature.

[0016] Examples of silicon-containing gases include silicon hydride gas, halogen-containing silicon gas, and aminosilane-based gas. Examples of silicon hydride gases include SiH4 gas, Si2H6 gas, Si3H8 gas, and Si4H 10 Examples of halogen-containing silicon gases include fluorine-containing silicon gas, chlorine-containing silicon gas, bromine-containing silicon gas, and iodine-containing silicon gas. Examples of fluorine-containing silicon gases include SiF4 gas, SiHF3 gas, SiH2F2 gas, and SiH3F gas. Examples of chlorine-containing silicon gases include SiCl4 gas, SiHCl3 gas, SiH2Cl2 gas, SiH3Cl gas, and Si2Cl6 gas. Examples of bromine-containing silicon gases include SiBr4 gas, SiHBr3 gas, SiH2Br2 gas, and SiH3Br gas. Examples of iodine-containing silicon gases include SiI4 gas, SiHI3 gas, SiH2I2 gas, and SiH3I gas. Examples of aminosilane gases include DIPAS (diisopropylaminosilane), 3DMAS (trisdimethylaminosilane), BTBAS (bisterialbutylaminosilane), and 2-dimethylamino-2,4,6,8-tetramethylcyclotetrasiloxane. Examples of boron-containing gases include B2H6 and BCl3. Examples of oxygen-containing gases include O2, O3, and H2O.

[0017] As shown in FIG. 2(c), the step S3 of forming a molybdenum film includes forming a molybdenum film 103 on the seed layer 102. The molybdenum film 103 is formed on the seed layer 102 by, for example, ALD or CVD, by supplying a molybdenum-containing gas and a reducing gas to the substrate 100 while adjusting the substrate temperature to a predetermined temperature. The molybdenum-containing gas is, for example, MoO2Cl2 gas. The reducing gas is, for example, H2 gas. Since the step S3 of forming a molybdenum film is performed after the seed layer 102 is formed on the insulating film 101, the time delay (hereinafter referred to as the "incubation time") between the start of supply of the molybdenum-containing gas and the start of molybdenum film formation is shortened. This shortens the time the surface of the insulating film 101 is exposed to the reducing gas. This reduces the extraction of oxygen from the insulating film 101 by the reducing gas. As a result, deterioration of the characteristics of the insulating film 101 due to the extraction of oxygen from the insulating film 101 can be suppressed.

[0018] As described above, according to the film formation method of the embodiment, after forming the seed layer 102 on the insulating film 101, a molybdenum-containing gas and a reducing gas are supplied to the substrate 100, thereby forming the molybdenum film 103 on the seed layer 102. This shortens the incubation time, and the time that the surface of the insulating film 101 is exposed to the reducing gas. Therefore, extraction of oxygen from the insulating film 101 by the reducing gas is suppressed. As a result, deterioration of the characteristics of the insulating film 101 due to extraction of oxygen from the insulating film 101 can be suppressed.

[0019] Furthermore, according to the film formation method of the embodiment, the molybdenum film 103 is formed by the ALD method and the CVD method using MoO2Cl2 gas and H2 gas. That is, the molybdenum film 103 is formed using a fluorine-free gas. Therefore, it is possible to prevent the exposed film (e.g., SiO2 film) from being damaged by fluorine when the molybdenum film 103 is formed.

[0020] 〔mechanism〕 3, a mechanism for shortening the incubation time when a substrate 100 on which an insulating film 101 has been formed is exposed to a silicon-containing gas to form a seed layer 102 on the insulating film 101, and then a molybdenum film 103 is formed will be described. The following describes an example in which SiH4 gas is used as the silicon-containing gas, MoO2Cl2 gas is used as the molybdenum-containing gas, and H2 gas is used as the reducing gas.

[0021] First, when the substrate 100 is exposed to SiH 4 gas, the SiH 4 gas is adsorbed onto the surface of the insulating film 101 as the seed layer 102 .

[0022] Next, when MoO2Cl2 gas and H2 gas are supplied to the substrate 100, a molybdenum film 103 is formed on the insulating film 101 by a reaction between the SiH4 gas adsorbed on the surface of the insulating film 101 and the MoO2Cl2 gas, and a reaction between the MoO2Cl2 gas and the H2 gas.

[0023] The reaction between SiH4 gas and MoO2Cl2 gas includes the reaction shown in the following formula (1).

[0024]

number

[0025] The reaction between MoO2Cl2 gas and H2 gas includes the reaction shown in the following formula (2).

[0026]

number

[0027] Here, we will consider the degree of progress of the reaction shown in equation (1) and the reaction shown in equation (2) based on the change in Gibbs energy, ΔG. By checking the change in Gibbs energy, ΔG, we can determine the degree of progress of the spontaneous reaction. Specifically, if ΔG<0, we can determine that the spontaneous reaction is progressing, and the larger the absolute value of ΔG, the more likely the spontaneous reaction is to proceed. Furthermore, if ΔG=0, we can determine that the system is in equilibrium. Furthermore, if ΔG>0, we can determine that the spontaneous reaction is not proceeding.

[0028] The change in Gibbs energy ΔG1 of the reaction shown in formula (1) and the change in Gibbs energy ΔG2 of the reaction shown in formula (2) were calculated by simulation, and both showed negative values ​​(ΔG1<0, ΔG2<0). From this result, it can be determined that the reaction shown in formula (1) and the reaction shown in formula (2) are both spontaneous reactions.

[0029] Furthermore, the absolute value of the change in Gibbs energy ΔG1 of the reaction represented by formula (1) was greater than the absolute value of the change in Gibbs energy ΔG2 of the reaction represented by formula (2) (|ΔG1|>|ΔG2|). From this result, it can be concluded that the reaction represented by formula (1) proceeds more easily than the reaction represented by formula (2).

[0030] From the above results, it is considered that the incubation time is shorter on the surface of the insulating film 101 on which SiH4 gas is adsorbed than on the surface of the insulating film 101 on which SiH4 gas is not adsorbed, and the time that the surface of the insulating film 101 is exposed to the reducing gas is shorter.

[0031] Furthermore, on the surface of the insulating film 101 where SiH4 gas is adsorbed, in the early stage of the formation of the molybdenum film 103, SiO2 is produced by the reaction between SiH4 gas and MoO2Cl2 gas as shown in formula (1), and therefore a very small amount of SiO2 film is formed on the insulating film 101. This is thought to increase the oxygen concentration at the interface between the insulating film 101 and the molybdenum film 103, and to suppress the desorption of oxygen from the insulating film 101.

[0032] 4, a mechanism for shortening the incubation time when a substrate 100 having an insulating film 101 formed thereon is exposed to a boron-containing gas to form a seed layer 102 on the insulating film 101, and then a molybdenum film 103 is formed will be described. The following describes an example in which BCl3 gas is used as the boron-containing gas, MoO2Cl2 gas is used as the molybdenum-containing gas, and H2 gas is used as the reducing gas.

[0033] First, when the substrate 100 is exposed to BCl3 gas, the BCl3 gas is adsorbed onto the surface of the insulating film 101, and a BH termination is formed.

[0034] Next, when MoO2Cl2 gas and H2 gas are supplied to the substrate 100, a molybdenum film 103 is formed on the insulating film 101 by a reaction between the BH termination formed on the surface of the insulating film 101 and the MoO2Cl2 gas, and by a reaction between the MoO2Cl2 gas and the H2 gas.

[0035] The reaction between the BH termination (B2H6 gas) and MoO2Cl2 gas includes the reaction shown in the following formula (3).

[0036]

number

[0037] The reaction between MoO2Cl2 gas and H2 gas includes the reaction shown in the following formula (4).

[0038]

number

[0039] Here, the progress of the reaction shown in formula (3) and the reaction shown in formula (4) will be examined based on the change in Gibbs energy ΔG.

[0040] The Gibbs energy change ΔG3 of the reaction shown in formula (3) and the Gibbs energy change ΔG4 of the reaction shown in formula (4) were calculated by simulation, and both showed negative values ​​(ΔG3<0, ΔG4<0). From this result, it can be determined that the reaction shown in formula (3) and the reaction shown in formula (4) are both spontaneous reactions.

[0041] Furthermore, the absolute value of the change in Gibbs energy ΔG3 for the reaction represented by equation (3) was greater than the absolute value of the change in Gibbs energy ΔG4 for the reaction represented by equation (4) (|ΔG3|>|ΔG4|). From this result, it can be concluded that the reaction represented by equation (3) proceeds more easily than the reaction represented by equation (4).

[0042] From the above results, it is considered that the incubation time is shorter on the surface of the insulating film 101 on which the BH termination is formed than on the surface of the insulating film 101 on which the BH termination is not formed, and the time that the surface of the insulating film 101 is exposed to the reducing gas is shorter.

[0043] 5, a mechanism for shortening the incubation time when a substrate 100 on which an insulating film 101 has been formed is exposed to an oxygen-containing gas to form a seed layer 102 on the insulating film 101, and then a molybdenum film 103 is formed will be described. The following describes an example in which H2O gas is used as the oxygen-containing gas, MoO2Cl2 gas is used as the molybdenum-containing gas, and H2 gas is used as the reducing gas.

[0044] First, when the substrate 100 is exposed to H2O gas, the H2O gas is adsorbed onto the surface of the insulating film 101, thereby resetting the contamination on the surface of the insulating film 101 and generating O terminations and OH groups on the surface of the insulating film 101.

[0045] Next, when MoO2Cl2 gas and H2 gas are supplied to the substrate 100, a molybdenum film 103 is formed on the insulating film 101 through a reaction between the MoO2Cl2 gas and the O terminations and OH groups formed on the surface of the insulating film 101, and between the MoO2Cl2 gas and the H2 gas. At this time, MoO2Cl2 gas is more easily adsorbed on the surface where the contamination has been reset than on a surface where the contamination has not been reset. As a result, the incubation time is shortened, and the time the surface of the insulating film 101 is exposed to the reducing gas is also shortened.

[0046] [Film forming equipment] An example of a film forming apparatus capable of carrying out the film forming method of the embodiment will be described with reference to Fig. 6. As shown in Fig. 6, the film forming apparatus 1 is a batch type apparatus that processes a plurality of substrates at once.

[0047] The film forming apparatus 1 includes a processing chamber 10, a gas supply unit 30, an exhaust unit 40, a heating unit 50, a control unit 80, and the like.

[0048] The processing vessel 10 has an interior that can be depressurized. The processing vessel 10 accommodates a substrate 100. The substrate 100 is, for example, a semiconductor wafer. The processing vessel 10 includes an inner tube 11, an outer tube 12, and the like. The inner tube 11 has a cylindrical shape with a ceiling and an open lower end. The outer tube 12 has a cylindrical shape with a ceiling and an open lower end that covers the outside of the inner tube 11. The inner tube 11 and the outer tube 12 are made of a heat-resistant material such as quartz, and are arranged coaxially to form a double-tube structure.

[0049] The ceiling of the inner pipe 11 is, for example, flat. A storage section 13 for storing a gas nozzle is formed on one side of the inner pipe 11 along its longitudinal direction (vertical direction). The storage section 13 is an area within a protrusion 14 formed by protruding part of the side wall of the inner pipe 11 outward.

[0050] A rectangular opening 15 is formed in the side wall of the inner tube 11 opposite the housing portion 13 along its longitudinal direction (vertical direction).

[0051] The opening 15 is a gas exhaust port formed so as to be able to exhaust gas from the inner tube 11. The length of the opening 15 is the same as the length of the boat 16, or is formed so as to extend in the vertical direction longer than the length of the boat 16.

[0052] The lower end of the processing vessel 10 is supported by a cylindrical manifold 17 made of, for example, stainless steel. A flange 18 is formed at the upper end of the manifold 17, and the lower end of the outer tube 12 is placed on the flange 18 to support it. A seal member 19 such as an O-ring is interposed between the flange 18 and the lower end of the outer tube 12 to keep the inside of the outer tube 12 airtight.

[0053] An annular support 20 is provided on the inner wall of the upper portion of the manifold 17, and the lower end of the inner tube 11 is placed and supported on the support 20. A lid 21 is airtightly attached to the opening at the lower end of the manifold 17 via a sealing member 22 such as an O-ring, so as to airtightly close the opening at the lower end of the processing vessel 10, i.e., the opening of the manifold 17. The lid 21 is made of, for example, stainless steel.

[0054] A rotating shaft 24 that rotatably supports the boat 16 via a magnetic fluid seal 23 penetrates the center of the lid 21. A lower portion of the rotating shaft 24 is rotatably supported by an arm 25A of an elevating mechanism 25 that is a boat elevator.

[0055] A rotating plate 26 is provided at the upper end of the rotating shaft 24, and a boat 16 holding substrates 100 is placed on the rotating plate 26 via a quartz heat retention stand 27. Therefore, by raising and lowering the lifting mechanism 25, the lid 21 and the boat 16 move up and down as a unit, allowing the boat 16 to be inserted into and removed from the processing vessel 10. The boat 16 can be accommodated in the processing vessel 10, and holds a plurality of substrates 100 (e.g., 50 to 150 substrates) approximately horizontally with spacing between them in the vertical direction.

[0056] The gas supply unit 30 includes a gas nozzle 31. The gas nozzle 31 is made of, for example, quartz. The gas nozzle 31 is provided inside the inner tube 11 along its longitudinal direction, and its base end is bent into an L-shape and supported so as to penetrate the manifold 17. The gas nozzle 31 has a plurality of gas holes 32 along its longitudinal direction, and various process gases are ejected from the plurality of gas holes 32 in the horizontal direction. The plurality of gas holes 32 are arranged, for example, at the same intervals as the intervals between the substrates 100 supported by the boat 16. The various process gases include gases used in the film formation method of the embodiment, such as a molybdenum-containing gas, a reducing gas, a silicon-containing gas, a boron-containing gas, and an oxygen-containing gas.

[0057] 6, the gas supply unit 30 includes one gas nozzle 31, but the number of gas nozzles is not limited. For example, the gas supply unit 30 may include multiple gas nozzles. In this case, various process gases may be discharged from the same gas nozzle or from different gas nozzles.

[0058] The exhaust unit 40 exhausts gas that is discharged from the inner tube 11 through the opening 15 and then discharged from a gas outlet 41 via a space P1 between the inner tube 11 and the outer tube 12. The gas outlet 41 is formed on the side wall of the upper part of the manifold 17, above the support unit 20. An exhaust passage 42 is connected to the gas outlet 41. A pressure adjustment valve 43 and a vacuum pump 44 are sequentially disposed in the exhaust passage 42, so that the inside of the processing vessel 10 can be exhausted.

[0059] The heating unit 50 is provided around the outer tube 12. The heating unit 50 is provided, for example, on the base plate 28. The heating unit 50 has a cylindrical shape so as to cover the outer tube 12. The heating unit 50 includes, for example, a heating element and heats the substrate 100 in the processing vessel 10.

[0060] The control unit 80 is configured to control the operation of each part of the film forming apparatus 1. The control unit 80 may be, for example, a computer. A computer program that controls the operation of each part of the film forming apparatus 1 is stored in a storage medium 90. The storage medium 90 may be, for example, a flexible disk, a compact disk, a hard disk, a flash memory, a DVD, or the like.

[0061] [Operation of the Film Forming Apparatus] An example of the operation of the film forming apparatus 1 when carrying out the film forming method of the embodiment will be described.

[0062] First, the control unit 80 controls the lifting mechanism 25 to load the boat 16 holding multiple substrates 100 on which insulating films 101 are formed into the processing vessel 10, and then airtightly seals the opening at the bottom of the processing vessel 10 with the lid 21.

[0063] Next, the control unit 80 controls the gas supply unit 30, the exhaust unit 40, the heating unit 50, etc. to perform step S2 of forming a seed layer. Specifically, first, the control unit 80 controls the exhaust unit 40 to reduce the pressure inside the processing vessel 10 to a predetermined level, and controls the heating unit 50 to stabilize the substrate temperature at a predetermined level. Next, the control unit 80 controls the gas supply unit 30 to supply at least one of a silicon-containing gas, a boron-containing gas, and an oxygen-containing gas into the processing vessel 10. As a result, a seed layer 102 is formed on the insulating film 101.

[0064] Next, the control unit 80 controls the gas supply unit 30, the exhaust unit 40, the heating unit 50, etc. to perform step S3 of forming a molybdenum film. Specifically, first, the control unit 80 controls the exhaust unit 40 to reduce the pressure inside the processing chamber 10 to a predetermined level, and controls the heating unit 50 to stabilize the substrate temperature at a predetermined level. Next, the control unit 80 controls the gas supply unit 30 to alternately and repeatedly supply a molybdenum-containing gas and a reducing gas into the processing chamber 10. As a result, a molybdenum film 103 is formed on the seed layer 102. Note that a purge gas may be supplied between the supply of the molybdenum-containing gas and the supply of the reducing gas.

[0065] Subsequently, the control unit 80 controls the lifting mechanism 25 to unload the boat 16 from the processing vessel 10 .

[0066] As described above, the molybdenum film 103 can be formed on the insulating film 101 in the film forming apparatus 1 by the film forming method of the embodiment.

[0067] [Experimental results] (incubation time) The following describes the results of an experiment conducted to confirm the change in incubation time when a molybdenum film was formed by changing the type of seed layer.

[0068] First, a substrate with an insulating AlO film formed on it was prepared. The substrate was then exposed to various process gases to form a seed layer on the AlO film. The process gases were SiH gas, DIPAS gas, B2H6 gas, BCl3 gas, and O2 gas. ALD cycles were then repeated, including supplying the substrate with the seed layer with a molybdenum-containing gas, MoO2Cl2 gas, and a reducing gas, H2 gas, to form a molybdenum film on the seed layer.

[0069] For comparison, a substrate with an AlO film formed thereon was also prepared. ALD cycles, including the supply of MoO2Cl2 gas and H2 gas, were repeated to form a molybdenum film on the AlO film without forming a seed layer on the substrate.

[0070] Next, the thickness of the formed molybdenum film was measured to obtain the relationship between the number of ALD cycle repetitions (hereinafter referred to as "ALD cycle number") and the thickness of the molybdenum film. Figure 7 shows the relationship between the number of ALD cycles and the thickness of the molybdenum film. In Figure 7, the horizontal axis represents the number of ALD cycles, and the vertical axis represents the thickness of the molybdenum film.

[0071] As shown in Figure 7, by forming a seed layer before forming the molybdenum film, the formation of the molybdenum film began with fewer ALD cycles than when a seed layer was not formed before forming the molybdenum film. This result demonstrates that forming a seed layer before forming the molybdenum film shortens the incubation time.

[0072] Furthermore, as shown in Figure 7, the initial deposition rate of the molybdenum film was increased by using B2H6 gas and BCl3 gas when forming the seed layer. This result indicates that the incubation time can be further shortened by using a boron-containing gas when forming the seed layer.

[0073] (specific resistance) The results of an experiment conducted to confirm the change in resistivity when a molybdenum film is formed by changing the type of seed layer will be described.

[0074] First, a substrate with an AlO film formed on it was prepared. The substrate was then exposed to various process gases to form a seed layer on the AlO film. The process gases were SiH gas, DIPAS gas, B2H6 gas, BCl3 gas, and O2 gas. ALD cycles, including supplying MoO2Cl2 gas and H2 gas, were then repeated to form a molybdenum film on the seed layer.

[0075] For comparison, a substrate with an AlO film formed thereon was also prepared. ALD cycles, including supplying MoOCl gas and H gas, were then repeated to form a molybdenum film on the AlO film without forming a seed layer on the substrate.

[0076] Next, the film thickness and resistivity of the formed molybdenum film were measured to obtain the relationship between the film thickness and resistivity of the molybdenum film. Figure 8 shows the measurement results of the resistivity of the molybdenum film. In Figure 8, the horizontal axis represents the film thickness [nm] of the molybdenum film, and the vertical axis represents the resistivity of the molybdenum film.

[0077] As shown in Figure 8, there is no significant difference in resistivity between when a seed layer is inserted between the AlO film and the molybdenum film and when no seed layer is inserted between the AlO film and the molybdenum film. This result shows that inserting a seed layer between the AlO film and the molybdenum film does not worsen the resistivity.

[0078] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0079] In the above embodiment, the film formation apparatus is described as a batch-type apparatus that processes multiple substrates at once, but the present disclosure is not limited to this. For example, the film formation apparatus may be a single-wafer type apparatus that processes substrates one by one. Furthermore, for example, the film formation apparatus may be a semi-batch type apparatus that processes substrates by rotating multiple substrates placed on a turntable inside a processing chamber using the turntable, passing the substrates sequentially through an area where a first gas is supplied and an area where a second gas is supplied. Furthermore, for example, the film formation apparatus may be a multi-wafer film formation apparatus equipped with multiple mounting tables inside a single processing chamber. [Explanation of symbols]

[0080] 100 boards 101 insulating film 102 seed layer 103 Molybdenum film

Claims

1. A method for manufacturing a semiconductor device, comprising: preparing a substrate on which an insulating film is formed; supplying at least one of a silicon-containing gas, a boron-containing gas, and an oxygen-containing gas onto the insulating film to adsorb the gas onto the insulating film; and after the adsorption step, supplying a molybdenum-containing gas and a reducing gas to the substrate to form a molybdenum film.

2. The film forming method described in claim 1, wherein the silicon-containing gas is at least one selected from SiH 4 gas, Si 2 H 6 gas and aminosilane gas, or the boron-containing gas is at least one selected from B 2 H 6 gas and BCl 3 gas.

3. The film forming method according to claim 1, wherein the oxygen-containing gas includes at least one of O 2 gas, O 3 gas, and H 2 O gas.

4. The film forming method according to claim 1, wherein the molybdenum-containing gas is MoO 2 Cl 2 gas, and the reducing gas is H 2 gas.

5. A film forming method described in any one of claims 1 to 4, wherein the process of forming the molybdenum film is performed by an ALD method or a CVD method.

6. The film forming method according to claim 1, wherein the insulating film is aluminum oxide (AlO).

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