Method for forming molybdenum sulfide film

Abstract

Disclosed is a method for forming a molybdenum sulfide film by sulfurizing a molybdenum-containing film, the method comprising: (a) a step for providing a substrate; (b) a step for forming a molybdenum-containing film on the substrate, wherein the molybdenum-containing film contains MoO3, and the content of MoO3 in the molybdenum-containing film is 60% or more; and (c) a step for annealing the substrate in a first atmosphere that contains at least one sulfurizing gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds after the step (b).

Description

Method for forming a molybdenum sulfide film

[0001] An exemplary embodiment of the present disclosure relates to a method for forming a molybdenum sulfide (MoS ,

[0007] , ,

[0006] , ３ , ３ ,

[0005] , ２ , ) film.

[0002] Patent Document 1 discloses a technique for forming a transition metal oxide film on a substrate surface and then converting the transition metal oxide film into a transition metal dichalcogenide.

[0003] Japanese Patent Application Laid-Open No. 2024-526208

[0004] The present disclosure provides a technique capable of improving the crystallinity of a molybdenum sulfide film.

[0005] In one exemplary embodiment of the present disclosure, a method for sulfiding a molybdenum-containing film to form a molybdenum sulfide film includes: (a) providing a substrate; and (b) forming a molybdenum-containing film on the substrate, wherein the molybdenum-containing film contains MoO ２ and MoO ３ and the MoO ３ content rate in the molybdenum-containing film is 60% or more; and (c) after (b), annealing the substrate in a first atmosphere containing at least one sulfide gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds.

[0006] According to one exemplary embodiment of the present disclosure, a technique capable of improving the crystallinity of a molybdenum sulfide film can be provided.

[0007] It is a diagram for explaining a configuration example of a substrate processing apparatus. It is a flowchart showing an example of a method for forming a molybdenum sulfide film. It is a diagram for explaining an example of a cross-sectional structure of a substrate W provided in step ST1. It is a diagram for explaining an example of a cross-sectional structure of a substrate W during the execution of step ST2. It is a diagram for explaining an example of a cross-sectional structure of a substrate W after the execution of step ST2. It is a diagram for explaining an example of a cross-sectional structure of a substrate W during the execution of step ST3. It is a diagram for explaining an example of a cross-sectional structure of a substrate W after the execution of step ST3. It is a flowchart showing a modification example of a method for forming a molybdenum sulfide film. It is a diagram for explaining an example of a cross-sectional structure of a substrate W during the execution of step ST4 after the execution of step ST3. It is a diagram for explaining an example of a cross-sectional structure of a substrate W after executing step ST4 through step ST3. The relationship between the MoO ２ content rate and the full width at half maximum measured for Reference Example 1 and Examples 1 to 14 is shown in the graph.

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, there is provided a method of sulfiding a molybdenum-containing film to form a molybdenum sulfide film, comprising: (a) a step of providing a substrate; (b) a step of forming a molybdenum-containing film on the substrate, wherein the molybdenum-containing film contains MoO ３ and the MoO ３ content rate in the molybdenum-containing film is 60% or more; and (c) a step of annealing the substrate in a first atmosphere containing at least one sulfurization gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds after (b).

[0010] In one exemplary embodiment, the MoO ３ content rate is 75% or more.

[0011] In one exemplary embodiment, in the emission spectrum obtained by photoluminescence measurement of the molybdenum sulfide film, the full width at half maximum of the emission peak corresponding to MoS ２ is 0.28 eV or less.

[0012] In one exemplary embodiment, the full width at half maximum is 0.22 eV or less.

[0013] In one exemplary embodiment, the film formation temperature of the molybdenum-containing film in (b) above is 100°C or higher.

[0014] In one exemplary embodiment, (b) above is performed in an oxygen atmosphere.

[0015] In one exemplary embodiment, (d) further includes the step of annealing the substrate in a second atmosphere that does not contain chalcogenizing gas after (c).

[0016] In one exemplary embodiment, in (c) above, the substrate is annealed at a first temperature, and the film formation temperature of the molybdenum-containing film in (b) above is lower than the first temperature.

[0017] In one exemplary embodiment, in (c) above, the substrate is annealed at a first temperature, and in (d) above, the substrate is annealed at a second temperature, wherein the second temperature is higher than the first temperature.

[0018] In one exemplary embodiment, in (c) above, the substrate is annealed at a first pressure, and in (d) above, the substrate is annealed at a second pressure, the second pressure being higher than the first pressure.

[0019] In one exemplary embodiment, the second atmosphere contains a noble gas.

[0020] In one exemplary embodiment, the annealing process is performed in at least one of the steps (c) and (d) above for a period of 1 minute to 480 minutes.

[0021] In one exemplary embodiment, steps (b) and (c) are performed in the same chamber.

[0022] Hereinafter, each embodiment of this disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are denoted by the same reference numeral, and redundant explanations are omitted. Unless otherwise specified, positional relationships such as top, bottom, left, and right will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and actual ratios are not limited to those shown.

[0023] <Example of a substrate processing apparatus> Figure 1 is a diagram illustrating an example of the configuration of a substrate processing apparatus 1. In one embodiment, the substrate processing apparatus 1 includes a chamber 10, a substrate support section 11, a gas introduction section 13, an exhaust section 14, a gas supply section 15, a power supply 16, and a control section 2.

[0024] The chamber 10 is configured to form a processing space 10s inside. The substrate support 11 is located inside the chamber 10. The substrate support 11 is located at the bottom of the processing space 10s.

[0025] In one embodiment, the substrate support portion 11 has a disc shape with thickness in the vertical direction (up and down direction). The substrate support portion 11 is equipped with a heat source 30 inside. The heat source 30 is, for example, a heater and is configured to generate heat when power is supplied from the power supply 16.

[0026] In one embodiment, the gas introduction section 13 is located above the substrate support section 11. The gas introduction section 13 includes at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. Gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the processing space 10s through the plurality of gas introduction ports 13c. The plurality of gas introduction ports 13c are connected to the gas supply section 15.

[0027] The gas supply unit 15 comprises at least one gas source 50 and at least one flow controller 51. In one embodiment, the gas supply unit 15 is configured to supply at least one processing gas to the gas introduction unit 13 from the corresponding gas source 50 via the corresponding flow controller 51. Each flow controller 51 includes, for example, a mass flow controller or a pressure-controlled flow controller. The processing gas is appropriately selected depending on the process to be performed. In one embodiment, the processing gas may be at least one selected from the group consisting of oxygen gas, sulfur gas, and noble gas.

[0028] The exhaust section 14 is connected to a gas outlet 10e, for example, located at the bottom of the chamber 10. The exhaust section 14 includes a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0029] The control unit 2 processes computer-executable instructions that cause the substrate processing apparatus 1 to perform the various processes described herein. The control unit 2 may be configured to control each element of the substrate processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the substrate processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control operations by reading a program from the storage unit 2a2 and executing the read program. This program may be stored in the storage unit 2a2 in advance, or it may be obtained via a medium when needed. The obtained program is stored in the storage unit 2a2 and read from the storage unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or it may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the substrate processing device 1 via a communication line such as a LAN (Local Area Network).

[0030] <Example of a method for forming a molybdenum sulfide film> Figure 2 is a flowchart showing an example of a method for forming a molybdenum sulfide film (hereinafter also referred to as "this method") according to one exemplary embodiment. As shown in Figure 2, in one embodiment, this method includes a step ST1 of providing a substrate W, a step ST2 of forming a molybdenum-containing film, and a step ST3 of annealing the substrate W in a first atmosphere (hereinafter also referred to as "first annealing treatment"). This method may be performed as a method for manufacturing a substrate W containing a molybdenum sulfide film. In one embodiment, this method may be performed using a substrate processing apparatus 1 shown in Figure 1. Below, the case in which a control unit 2 controls each part of the substrate processing apparatus 1 to perform this method on the substrate W will be described as an example.

[0031] (Step ST1: Provision of Substrate) In one embodiment, in step ST1, as shown in Figure 1, the substrate W is provided into the chamber 10 of the substrate processing apparatus 1. The substrate W is placed on the substrate support 11. The substrate W may be used in the manufacture of semiconductor devices. Semiconductor devices include, for example, memory devices such as DRAM and 3D-NAND flash memory, and logic devices. The size of the substrate W may be adjusted according to the application, and for example, it may have a diameter of 150 mm or more or 300 mm or more.

[0032] Figure 3 is a diagram illustrating an example of the configuration of the substrate W in process ST1. In the example in Figure 3, the substrate W includes at least one first film F1 selected from the group consisting of silicon-containing films and metal-containing films. Examples of silicon-containing films include spin-on-glass (SOG) films, Si-containing anti-reflective films (SiARC), silicon oxide films, silicon nitride films, silicon oxynitride films, silicon carbide films, silicon carbonitride films, polycrystalline silicon films, and amorphous silicon films. In one embodiment, the silicon-containing film may be a part (surface layer) of a single-crystal silicon wafer. In this case, by performing this method, a molybdenum sulfide film can be directly formed on a part (surface layer) of a single-crystal silicon wafer. Examples of metal-containing films include tungsten, hafnium, zirconium, tin, and titanium.

[0033] In one embodiment, the substrate W may include another film (not shown) in place of, or in addition to, the first film F1. In one embodiment, the other film is a silicon wafer or an organic film, dielectric film, metal film, semiconductor film, etc. formed on a silicon wafer. As an example, the other film is a silicon oxide film. The first film F1 and the other film may each be composed of multiple films stacked on top of each other. In one embodiment, the substrate W may further include another film below the first film F1.

[0034] The first film F1 and the other films are each formed by any method. In one embodiment, the first film F1 and the other films may be formed by CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), MLD (Molecular Layer Deposition), PVD (Physical Vapor Deposition), spin coating, etc. The first film F1 and the other films may each be flat films or films with irregularities.

[0035] At least a portion of the process for forming the first film F1 or other films on the substrate W may be carried out in the chamber 10 as part of step ST1. For example, the first film F1 is formed in step ST1. In this case, the substrate processing apparatus 1 is equipped with the function of forming the first film F1. In one embodiment, after all or part of the first film F1 or other films on the substrate W have been formed in an apparatus or chamber outside the substrate processing apparatus 1, the substrate W is provided into the chamber 10.

[0036] In one embodiment, after the substrate W is provided to the substrate support 11, the temperature of the substrate support 11 or the substrate W is controlled to a given temperature by the heat source 30. Controlling the temperature of the substrate support 11 or the substrate W to a given temperature may include setting the temperature of the heat source 30 to a given temperature or to a temperature different from the given temperature. The given temperature may be within the range of 0°C to 1100°C. The timing at which the temperature of the substrate support 11 or the substrate W begins to be controlled to a given temperature may be before, after, or simultaneously with the placement of the substrate W on the substrate support 11. The temperature of the substrate support 11 or the substrate W may be changed during the execution of step ST1, or it may be changed in any of steps ST2, ST3, and ST4 described later.

[0037] (Step ST2: Formation of molybdenum-containing film) In step ST2, a molybdenum-containing film MF is formed on the substrate W. In one embodiment, step ST2 is performed in an oxygen atmosphere. In one embodiment, the molybdenum-containing film MF is a film containing molybdenum oxide. As an example, the molybdenum-containing film MF is MoO ３ It is a membrane containing MoO. For example, a molybdenum-containing membrane MF is MoO ２ and MoO ３ It is a membrane containing MoO. For example, a molybdenum-containing membrane MF is MoO ２ Mo ２ O ５ and MoO ３ It is a membrane containing [something].

[0038] Figure 4 is a diagram illustrating an example of the cross-sectional structure of a substrate W during process ST2. In the example in Figure 4, process ST2 is performed with the substrate W containing the first film F1 placed in an oxygen atmosphere OA. The method for forming the molybdenum-containing film MF on the first film F1 (deposition conditions for the molybdenum-containing film MF) is not particularly limited, but examples include the ALD method and the PVD method. The molybdenum-containing film MF may be a flat film or a film with irregularities.

[0039] Figure 5 is a diagram illustrating an example of the cross-sectional structure of the substrate W after performing step ST2. In the example of Figure 5, by performing step ST2, a molybdenum-containing film MF is formed on the first film F1. That is, a substrate W containing the first film F1 and the molybdenum-containing film MF can be obtained. In one embodiment, the molybdenum-containing film MF is MoO ２ and MoO ３ It contains and MoO in molybdenum-containing film MF ３ The content is 60% or more. In one embodiment, MoO in a molybdenum-containing film MF ３ The content is 75% or more. (See above for MoO) ３ When the content is 60% or more, the crystallinity of the molybdenum sulfide film obtained by sulfidating the molybdenum-containing film MF (the molybdenum sulfide film formed via step ST3 described later) tends to be high. ３ When the content is 60% or more, the above crystallinity tends to be higher. The above MoO ３ The content can be measured based on the method described in the examples below. ３ The content can be adjusted to the above range by, for example, the film deposition conditions for the molybdenum-containing film MF on the first film F1. For example, if the temperature (deposition temperature) when depositing the molybdenum-containing film MF by the ALD method or PVD method is high, MoO ３ The content tends to be high. The above film deposition temperature may be 100°C or higher, 125°C or higher, 200°C or higher, or 250°C or higher. Also, the above film deposition temperature may be less than 350°C or 325°C or lower. In one embodiment, the molybdenum-containing film MF before the subsequent step ST3 (first annealing treatment) may be in an amorphous state. In order to promote crystallization from the amorphous state, the film deposition temperature of the molybdenum-containing film MF may be lower than the temperature during the first annealing treatment (first temperature). The above film deposition temperature may be controlled, for example, by the ambient temperature in an oxygen atmosphere OA, or by the temperature of the heat source 30. Also, as an example, if the amount of oxygen supplied to the oxygen atmosphere OA when depositing the molybdenum-containing film MF by the ALD method or PVD method is large, MoO ３The content tends to be higher. The oxygen supply amount may be 20 sccm or more, or 30 sccm or more. The oxygen supply amount can be adjusted, for example, by a flow rate controller 51. As an example, when the oxygen supply amount is 30 sccm or more, the film deposition temperature may be around room temperature. As another example, when depositing a molybdenum-containing film MF by the ALD method, compared to supplying only the precursor, the oxidizing agent H ２ By alternately supplying precursors such as O and extending the supply time of the oxidizing agent, MoO ３ The content tends to be high.

[0040] (Step ST3: First annealing treatment) In step ST3, the substrate W is annealed (first annealing treatment) in a first atmosphere containing chalcogenizing gas.

[0041] During the execution of process ST3, the temperature of the substrate W is adjusted to a first temperature. After the substrate W is provided to the substrate support 11 shown in Figure 1, or before the substrate W is provided to the substrate support 11, the temperature of the substrate W or the substrate support 11 may be adjusted to a first temperature by the heat source 30. The first temperature may be in the range of room temperature or higher and 700°C or lower. The first temperature may be in the range of 20°C or higher and 700°C or lower. In one embodiment, the first temperature is higher than the film formation temperature of the molybdenum-containing film MF. In this case, the amorphous molybdenum-containing film MF formed in process ST2 tends to become more crystallin after going through process ST3. As an example, the first temperature is in the range of 325°C or higher and 700°C or lower. As an example, the first temperature is in the range of 350°C or higher and 700°C or lower.

[0042] During the execution of process ST3, the pressure inside the chamber 10 is adjusted to a first pressure. The first pressure may be in the range of 1 kPa or more and 200 kPa or less. In one embodiment, the first pressure is adjusted by exhausting the atmosphere inside the chamber 10 with the exhaust unit 14.

[0043] The first annealing process may be performed for a period of 10 minutes or more and 480 minutes or less. The first annealing process may be performed for 480 minutes or more.

[0044] Figure 6 is a diagram illustrating an example of the cross-sectional structure of the substrate W during process ST3. As shown in Figure 6, the chamber 10 is adjusted to a first atmosphere A1. The first atmosphere A1 is an atmosphere containing at least one sulfur gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds. In one embodiment, the first atmosphere A1 is adjusted by supplying a sulfur gas into the chamber 10 from the gas introduction section 13.

[0045] Figure 7 is a diagram illustrating an example of the cross-sectional structure of the substrate W after performing step ST3. In step ST3, the molybdenum-containing film MF on the substrate W is heated in a first atmosphere A1 containing sulfur gas (e.g., hydrogen sulfide gas), causing the molybdenum-containing film MF to be sulfurized. As a result, a molybdenum sulfide film TD is formed on the first film F1 on the substrate W. In this way, the molybdenum sulfide film TD is MoO ３ Because it is obtained as a sulfide of molybdenum-containing film MF with a content of 60% or more, it tends to have high crystallinity. One of the reasons for this is MoO ３ The density of MoO ２ YaMo ２ O ５ Compared to the density of MoS ２ It is thought that the density is close to that of MoO, which tends to suppress film expansion due to sulfidation. Another reason is that MoO ３ Because it is sublimable, it is thought to be prone to reacting with the sulfur gas supplied during the first annealing treatment. However, this does not mean that the mechanism of action in this method is limited to the above, and as long as step ST3 is performed after step ST2, a highly crystalline molybdenum sulfide film TD tends to be formed.

[0046] In one embodiment, in the emission spectrum obtained by photoluminescence measurement of a molybdenum sulfide film TD, MoS ２The full width at half maximum (FMAX) of the corresponding emission peak may be 0.28 eV or less, or 0.22 eV or less. When the FMAX is 0.28 eV or less, the crystallinity of the molybdenum sulfide film TD tends to be higher. When the FMAX is 0.22 eV or less, the crystallinity tends to be even higher. The FMAX can be measured based on the method described in the examples below. The FMAX is, for example, in step ST2, MoO ３ The above range can be adjusted by adjusting the content ratio, etc. As an example, MoO ３ When the content is 60% or higher, the above-mentioned full width at half maximum tends to be 0.28 eV or less.

[0047] After the completion of process ST3, the substrate W is removed from the chamber 10 to the outside.

[0048] <Modified Method> Figure 8 is a flowchart showing a modified method for forming a molybdenum sulfide film. As shown in Figure 8, this modified method includes a step ST1 for providing a substrate W, a step ST2 for forming a molybdenum-containing film, a step ST3 for annealing the substrate W in a first atmosphere, and a step ST4 for annealing the substrate W in a second atmosphere A2 (second annealing). Steps ST1, ST2, and ST3 in this modified method may be performed in the same manner as steps ST1, ST2, and ST3 described above for the present method.

[0049] In step ST4, the substrate W is annealed (second annealing treatment) in a second atmosphere A2 that does not contain chalcogenizing gas.

[0050] During process ST4, the temperature of the substrate W is adjusted to a second temperature. After process ST3, the temperature of the substrate W or the substrate support 11 shown in Figure 1 is adjusted to a second temperature by the heat source 30. The second temperature may be higher than the first temperature. The second temperature may be in the range of 900°C to 1100°C.

[0051] During the execution of process ST4, the pressure inside the chamber 10 is adjusted to a second pressure. The second pressure may be in the range of 0 kPa or more and 200 kPa or less. The second pressure may be a vacuum pressure. The second pressure may be 200 kPa or more. The second pressure may be higher than the first pressure. In one embodiment, the second pressure is adjusted by exhausting the atmosphere inside the chamber 10 by the exhaust unit 14.

[0052] The second annealing process may be performed for a period of 1 minute or more and 480 minutes or less. The first annealing process may be performed for 480 minutes or more.

[0053] The chamber 10 is adjusted to a second atmosphere A2. The second atmosphere A2 is an atmosphere that is substantially free of chalcogenized gas. In one embodiment, the second atmosphere A2 is adjusted by exhausting the sulfur gas from the chamber 10 using the exhaust unit 14 and supplying a treatment gas into the chamber 10 from the gas introduction unit 13. A noble gas may be used as the treatment gas. The noble gas may be argon gas.

[0054] Figure 9 is a diagram illustrating an example of the cross-sectional structure of the substrate W after step ST3 has been performed and during step ST4. Figure 10 is a diagram illustrating an example of the cross-sectional structure of the substrate W after step ST4 has been performed via step ST3. As shown in Figure 9, during step ST4, the molybdenum sulfide film TD may be subjected to the action of the second atmosphere A2. When the substrate W is heated in this state, crystallization of the molybdenum sulfide film TD progresses. After step ST4 has been performed, as shown in Figure 10, a molybdenum sulfide film TDa is formed on the first film F1. The molybdenum sulfide film TDa may be a film with higher crystallinity than the molybdenum sulfide film TD. The molybdenum sulfide film TD and the molybdenum sulfide film TDa may each be thin films of one atomic layer or multiple atomic layers. The molybdenum sulfide film TD and the molybdenum sulfide film TDa may each be thin films of 10 nm or less. The molybdenum sulfide film TD and the molybdenum sulfide film TDa may each be a two-dimensional material.

[0055] Steps ST3 and ST4 may be carried out in the same chamber. In this case, after step ST3, step ST4 can be performed immediately afterward without the substrate W being exposed to the atmosphere. This tends to result in the formation of a molybdenum sulfide film with higher crystallinity.

[0056] <Examples> Next, examples will be described. This disclosure is not limited in any way by the following examples.

[0057] (Example 1) An apparatus having the same configuration as the substrate processing apparatus 1 shown in Figure 1 was prepared. Inside the chamber 10 of the apparatus, a substrate having a silicon-containing film including a silicon oxide film on its surface was placed on the substrate support part 11. The following process was performed on the substrate. That is, the chamber 10 was set to a base vacuum of 10 at a substrate temperature of 150°C. －３ The chamber 10 is then subjected to a vacuum atmosphere of the first half of Pa, followed by the introduction of 40 sccm of oxygen, and the chamber 10 is subjected to a vacuum of 10 －３ The atmosphere was set to an oxygen atmosphere in the upper Pa range. In this oxygen atmosphere, a molybdenum oxide-containing film was deposited on a silicon-containing film by electron beam deposition using Mo metal as the raw material. To confirm the composition of the molybdenum oxide-containing film formed on the silicon-containing film, XPS (X-ray photoelectron spectroscopy) measurements were performed, and a spectrum was obtained with the x-axis representing binding energy and the y-axis representing intensity. In this spectrum, MoO ２ and MoO ３ Peaks were observed at the corresponding positions. In the obtained spectrum, Mo ２ O ５ Since no peak was observed at the location of MoO ２ and MoO ３ Based on the peak intensity, 100 × MoO ３ Peak intensity of (MoO ２ Peak intensity + MoO ３ As the peak intensity of MoO ３ The content was calculated. As a result, MoO ３The content was 92%. Next, a first annealing treatment was performed for 10 minutes at 600°C and 50 kPa while supplying hydrogen sulfide, thereby chalcogenizing molybdenum nitride and forming a molybdenum sulfide-containing film on the silicon-containing film. Furthermore, a second annealing treatment was performed for 10 minutes at 1100°C and 100 kPa while supplying argon gas. The molybdenum sulfide-containing film thus obtained was subjected to photoluminescence (PL) measurement, and an emission spectrum was obtained with the horizontal axis representing light energy and the vertical axis representing PL intensity. In the obtained emission spectrum, MoS ２ The corresponding emission peak was identified. The full width at half maximum of this emission peak was 0.122 eV.

[0058] (Example 2) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 1, except for the following point. That is, in the deposition of the molybdenum oxide-containing film by electron beam deposition, the amount of oxygen introduced when changing from a vacuum atmosphere to an oxygen atmosphere was increased to 60 sccm. －２ Except for using an oxidizing atmosphere in the first half of Pa, a substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 1. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the result was that MoO ３ The content is 98%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.119 eV.

[0059] (Example 3) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 1, except for the following point. That is, the film deposition when forming the molybdenum oxide-containing film on the silicon-containing film was carried out by the ALD method. At this time, in a vacuum atmosphere at a substrate temperature of 150°C, the Mo precursor MoO ２ Cl ２ And the oxidizing agent H ２ A molybdenum oxide-containing film was formed by alternately supplying oxygen. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the results showed that MoO ３ The content is 92%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.088 eV.

[0060] (Reference Example 1) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 1, except for the following point. That is, the film deposition conditions for forming the molybdenum oxide-containing film on the silicon-containing film were sputtering. A molybdenum oxide-containing film was formed by sputtering a Mo target in an Ar flow rate of 40 sccm and then exposing the film to air. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the result was that MoO ３ The content is 7%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.327 eV.

[0061] (Example 4) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Reference Example 1, except for the following point: the target during sputter deposition was MoO ３ The atmosphere was set to Ar 40 sccm, and the oxygen introduction amount was set to 4 sccm. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the result was that MoO ３ The content is 68%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.269 eV.

[0062] (Example 5) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 4, except for the following point. Specifically, the atmosphere during sputter deposition was set to Ar 40 sccm with an oxygen introduction amount of 10 sccm. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the result was that MoO ３ The content is 78%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.216 eV.

[0063] (Example 6) A substrate having a molybdenum sulfide-containing film was prepared in the same manner as in Example 4, except for the following point. Specifically, the atmosphere during sputter deposition was changed to Ar 40 sccm with an oxygen introduction amount of 20 sccm. The molybdenum oxide-containing film and the molybdenum sulfide-containing film were analyzed in the same manner as in Example 1, and the result was that MoO ３ The content is 85%, MoS ２ The full width at half maximum of the corresponding emission peak was 0.175 eV.

[0064] Figure 11 shows the MoO measurements taken for Reference Example 1 and Examples 1-6. ３ This graph shows the relationship between the content and the full width at half maximum. From the comparison between Reference Example 1 and Examples 1-6, the following can be seen: MoO in molybdenum-containing films ３ The higher the content, the more MoS ２ A tendency was observed for the full width at half maximum of the corresponding emission peak to decrease. In other words, in molybdenum-containing films, MoO ３ A tendency was observed for the crystallinity of the final molybdenum sulfide-containing film to increase with higher content. According to this method, first, MoO ３ A molybdenum-containing film with a high molybdenum content is formed, and then this molybdenum-containing film is sulfurized to form a molybdenum sulfide-containing film, thereby improving the crystallinity of the molybdenum sulfide film.

[0065] Embodiments of this disclosure further include the following embodiments:

[0066] (Note 1) A method for forming a molybdenum sulfide film by sulfidizing a molybdenum-containing film, comprising: (a) a step of providing a substrate; and (b) a step of forming a molybdenum-containing film on the first film, wherein the molybdenum-containing film is MoO ２ and MoO ３ It contains and the MoO in the molybdenum-containing film ３ A method comprising: (c) a step in which the content is 60% or more; and a step in which, after (b), the substrate is annealed in a first atmosphere containing at least one sulfur gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds.

[0067] (Note 2) The aforementioned MoO ３ The method described in Appendix 1, wherein the content is 75% or more.

[0068] (Note 3) In the emission spectrum obtained by photoluminescence measurement of the molybdenum sulfide film, MoS ２ The method according to Appendix 1 or 2, wherein the full width at half maximum of the corresponding emission peak is 0.28 eV or less.

[0069] (Note 4) The method according to Note 3, wherein the full width at half maximum is 0.22 eV or less.

[0070] (Note 5) The method according to any one of Notes 1 to 4, wherein the film formation temperature of the molybdenum-containing film in (b) is 100°C or higher.

[0071] (Note 6) The method according to any one of Notes 1 to 5, wherein (b) is performed in an oxygen atmosphere.

[0072] (Note 7) (d) The method according to any one of Notes 1 to 6, further comprising the step of annealing the substrate in a second atmosphere that does not contain chalcogenizing gas after (c).

[0073] (Note 8) The method according to Note 7, wherein in (c) above, the substrate is annealed at a first temperature, and the film formation temperature of the molybdenum-containing film in (b) above is lower than the first temperature.

[0074] (Note 9) The method according to Note 7 or 8, wherein in (c) above, the substrate is annealed at a first temperature, and in (d) above, the substrate is annealed at a second temperature, the second temperature being higher than the first temperature.

[0075] (Note 10) The method according to any one of Notes 7 to 9, wherein in (c) above, the substrate is annealed at a first pressure, and in (d) above, the substrate is annealed at a second pressure, the second pressure being higher than the first pressure.

[0076] (Note 11) The method according to any one of Notes 7 to 10, wherein the second atmosphere contains a noble gas.

[0077] (Note 12) The method according to any one of Notes 7 to 11, wherein in at least one of the steps (c) and (d), an annealing treatment is performed for a period of 1 minute or more and 480 minutes or less.

[0078] (Note 13) The method according to any of Notes 7 to 12, wherein step (b) and step (c) are performed in the same chamber.

[0079] The embodiments described above are for illustrative purposes only and are not intended to limit the scope of this disclosure. The embodiments described above can be modified in various ways without departing from the scope and spirit of this disclosure. For example, some components of one embodiment can be added to other embodiments, or some components of one embodiment can be replaced with corresponding components of other embodiments.

[0080] 10... Chamber, W... Substrate, F1... First film, MF... Molybdenum-containing film, TD... Molybdenum sulfide film, TDa... Molybdenum sulfide film after second annealing treatment, OA... Oxygen atmosphere, A1... First atmosphere, A2... Second atmosphere

Claims

1. A method for forming a molybdenum sulfide film by sulfidizing a molybdenum-containing film, comprising: (a) a step of providing a substrate; and (b) a step of forming a molybdenum-containing film on the substrate, wherein the molybdenum-containing film is MoO ３ It contains MoO in the molybdenum-containing film ３ A method comprising: (c) a step in which the content is 60% or more; and a step in which, after (b), the substrate is annealed in a first atmosphere containing at least one sulfur gas selected from the group consisting of hydrogen sulfide and organic sulfur compounds.

2. The aforementioned MoO ３ The method according to claim 1, wherein the content is 75% or more.

3. In the emission spectrum obtained by photoluminescence measurement of the molybdenum sulfide film, MoS ２ The method according to claim 1, wherein the full width at half maximum of the corresponding emission peak is 0.28 eV or less.

4. The method according to claim 3, wherein the full width at half maximum is 0.22 eV or less.

5. The method according to claim 1, wherein the film formation temperature of the molybdenum-containing film in (b) is 100°C or higher.

6. The method according to claim 1, wherein (b) is performed in an oxygen atmosphere.

7. (d) The method according to claim 1, further comprising the step of annealing the substrate in a second atmosphere that does not contain chalcogenizing gas after (c).

8. The method according to claim 7, wherein in (c), the substrate is annealed at a first temperature, and the film formation temperature of the molybdenum-containing film in (b) is lower than the first temperature.

9. The method according to claim 7, wherein in (c), the substrate is annealed at a first temperature, and in (d), the substrate is annealed at a second temperature, the second temperature being higher than the first temperature.

10. The method according to claim 7, wherein in (c), the substrate is annealed at a first pressure, and in (d), the substrate is annealed at a second pressure, the second pressure being higher than the first pressure.

11. The method according to claim 7, wherein the second atmosphere contains a noble gas.

12. The method according to claim 7, wherein in at least one of step (c) and step (d), an annealing treatment is performed for a period of 1 minute or more and 480 minutes or less.

13. The method according to claim 7, wherein step (b) and step (c) are performed in the same chamber.

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