Substrate processing method, hard mask forming method, and substrate processing device

Abstract

Provided are a substrate processing method for forming a tungsten-containing carbon film, a hard mask forming method, and a substrate processing device.　The substrate processing method for forming a tungsten-containing carbon film includes: a steps for supplying a processing gas including a halogen-containing tungsten gas and an organosilicon compound gas into a processing vessel to generate plasma of the processing gas; and a step for exposing a substrate to the generated plasma to form a tungsten-containing carbon film on the substrate.

Description

Substrate processing method, hard mask forming method, and substrate processing apparatus

[0001] The present disclosure relates to a substrate processing method, a hard mask forming method, and a substrate processing apparatus.

[0002] Patent Literature 1 discloses a method for depositing a metal-doped amorphous carbon hard mask film, the method including: placing a substrate in a processing chamber; supplying a carrier gas to the processing chamber; supplying a hydrocarbon precursor gas to the processing chamber; supplying a metal-based precursor gas to the processing chamber; generating plasma in the processing chamber or supplying plasma to the processing chamber; and depositing the metal-doped amorphous carbon hard mask film on the substrate.

[0003] Japanese Patent Application Laid-Open No. 2016-166405

[0004] In one aspect, the present disclosure provides a substrate processing method for forming a tungsten-containing carbon film, a hard mask forming method, and a substrate processing apparatus.

[0005] In order to solve the above problems, according to one aspect, there is provided a substrate processing method for forming a tungsten-containing carbon film, the substrate processing method comprising the steps of: supplying a processing gas containing a halogen-containing tungsten gas and an organosilicon compound gas into a processing vessel; generating plasma of the processing gas; and exposing a substrate to the generated plasma to form a tungsten-containing carbon film on the substrate.

[0006] According to one aspect, a substrate processing method for forming a tungsten-containing carbon film, a hard mask forming method, and a substrate processing apparatus can be provided.

[0007] 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus according to the present embodiment. ６ and CH ４ 10 is a diagram illustrating the case where a carbon film containing tungsten is formed using WF ６and DMSi. An example of a diagram showing each film formation condition and the crystalline state of a tungsten-containing carbon film. An example of a diagram showing the film composition of a tungsten-containing carbon film. An example of a diagram showing the relationship between the tungsten concentration and film stress of a tungsten-containing carbon film. An example of a diagram showing the evaluation results of the etching resistance of a tungsten-containing carbon film.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [Substrate Processing Apparatus 1] A substrate processing apparatus 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example of the substrate processing apparatus 1 according to this embodiment. The substrate processing apparatus 1 is an apparatus that forms a carbon film containing tungsten (W) on a substrate W such as a wafer by a plasma-enhanced chemical vapor deposition (PECVD) method in a processing chamber 2 under reduced pressure. The carbon film containing tungsten (W) is formed on an etching target film formed on the substrate W and can be used as a hard mask when etching the etching target film.

[0010] The substrate processing apparatus 1 includes a substantially cylindrical airtight processing vessel 2. An exhaust chamber 21 is provided in the center of the bottom wall of the processing vessel 2.

[0011] The exhaust chamber 21 has, for example, a substantially cylindrical shape that protrudes downward. An exhaust flow path 22 is connected to the exhaust chamber 21, for example, at a side surface of the exhaust chamber 21. An exhaust unit 24 is connected to the exhaust flow path 22 via a pressure adjustment unit 23. The pressure adjustment unit 23 includes a pressure adjustment valve such as a butterfly valve. The exhaust flow path 22 is configured so that the pressure inside the processing vessel 2 can be reduced by the exhaust unit 24. A transfer port 25 is provided on a side surface of the processing vessel 2. The transfer port 25 is configured to be freely opened and closed by a gate valve 26. The substrate W is loaded and unloaded between the processing vessel 2 and a transfer chamber (not shown) via the transfer port 25.

[0012] A mounting table (substrate support) 3 for holding a substrate W substantially horizontally is provided within the processing chamber 2. The mounting table 3 is substantially circular in plan view and is supported by a support member 31. A substantially circular recess 32 for mounting a substrate W having a diameter of, for example, 300 mm is formed in the surface of the mounting table 3. The recess 32 has an inner diameter slightly larger (for example, about 1 mm to 4 mm) than the diameter of the substrate W. The depth of the recess 32 is configured to be substantially the same as the thickness of the substrate W. The mounting table 3 is made of a ceramic material such as aluminum nitride (AlN). Alternatively, the mounting table 3 may be made of a metal material such as nickel (Ni). Note that instead of the recess 32, a guide ring for guiding the substrate W may be provided around the periphery of the surface of the mounting table 3.

[0013] A lower electrode 33 is embedded in the mounting table 3. A temperature adjustment mechanism 34 is embedded below the lower electrode 33. The temperature adjustment mechanism 34 adjusts the temperature of the substrate W placed on the mounting table 3 to a set temperature based on a control signal from the control unit 9. If the mounting table 3 is made entirely of metal, the entire mounting table 3 functions as the lower electrode, and therefore the lower electrode 33 does not need to be embedded in the mounting table 3.

[0014] An RF power supply 35 is connected to the lower electrode 33 via a matching box 351. The RF power supply 35 applies low frequency (LF) power, which has a frequency lower than that of an RF power supply 51 (described later), to the lower electrode 33. The high frequency power generated by the RF power supply 35 is used as bias high frequency power for attracting ions into the substrate W. The frequency of the RF power supply 35 is, for example, 13.56 MHz. The lower electrode 33 may be configured to be connected to a bias DC power supply and to be supplied with bias DC power or pulsed DC power, or the lower electrode 33 may be configured to be grounded.

[0015] The mounting table 3 is provided with a plurality of (e.g., three) lift pins 41 for holding and lifting the substrate W mounted on the mounting table 3. The lift pins 41 may be made of, for example, ceramics such as alumina (Al2O3) or quartz. The lower ends of the lift pins 41 are attached to a support plate 42. The support plate 42 is connected via a lift shaft 43 to a lift mechanism 44 provided outside the processing chamber 2.

[0016] The lifting mechanism 44 is installed, for example, at the bottom of the exhaust chamber 21. The bellows 45 is provided between the lifting mechanism 44 and an opening 211 for the lifting shaft 43 formed in the bottom surface of the exhaust chamber 21. The support plate 42 may be shaped so that it can be raised and lowered without interfering with the support member 31 of the mounting table 3. The lifting pins 41 are configured to be able to be raised and lowered between the upper side and the lower side of the surface of the mounting table 3 by the lifting mechanism 44. In other words, the lifting pins 41 are configured to be able to protrude from the top surface of the mounting table 3.

[0017] The lower end of the support member 31 passes through the opening 212 of the exhaust chamber 21 and is supported by a lifting mechanism 46 via a lifting plate 47 disposed below the processing vessel 2. A bellows 48 is provided between the bottom of the exhaust chamber 21 and the lifting plate 47, so that the airtightness inside the processing vessel 2 is maintained even when the lifting plate 47 moves up and down.

[0018] The lifting mechanism 46 lifts and lowers the lifting plate 47, thereby lifting and lowering the mounting table 3. This makes it possible to adjust the gap between the mounting table 3 and the gas supply unit 5.

[0019] A gas supply unit 5 is provided on the ceiling wall 27 of the processing vessel 2 via an insulating member 28. The gas supply unit 5 forms an upper electrode and faces the lower electrode 33. RF power supplies 51 and 56 are connected to the gas supply unit 5 via matchers 511 and 561. The RF power supply 51 applies high-frequency power to the upper electrode (gas supply unit 5). The high-frequency power generated by the RF power supply 51 is used as high-frequency power for generating plasma required for film formation on the substrate W. The frequency of the RF power supply 51 is, for example, 13.56 MHz to 220 MHz (e.g., 13.56 MHz). The RF power supply 56 applies low-frequency power to the upper electrode (gas supply unit 5). The low-frequency power generated by the RF power supply 56 is used as low-frequency power for generating plasma required for film formation on the substrate W. The frequency of the RF power supply 56 is lower than the frequency of the RF power supply 51 (e.g., 400 kHz). An RF electric field is generated between the upper electrode (gas supply unit 5) and the lower electrode 33 by supplying RF power from the RF power source 51 and / or the RF power source 56 to the upper electrode (gas supply unit 5). The number of RF power sources may be two (dual frequency) or one (single frequency). The gas supply unit 5 includes a hollow gas diffusion chamber 52. A number of holes 53 are arranged, for example, evenly, on the bottom surface of the gas diffusion chamber 52 for dispersing and supplying the processing gas into the processing vessel 2. A heating mechanism 54 is embedded in the gas supply unit 5, for example, above the gas diffusion chamber 52. The heating mechanism 54 is heated to a set temperature by receiving power from a power source (not shown) based on a control signal from the control unit 9.

[0020] A gas supply path 6 is provided in the gas diffusion chamber 52. The gas supply path 6 is in communication with the gas diffusion chamber 52. A gas source (gas supply source) 61 is connected to the upstream side of the gas supply path 6 via a gas line 62. The gas source 61 includes, for example, supply sources of various process gases, mass flow controllers, and valves (none of which are shown). The various process gases include a gas containing tungsten (W) and a gas containing carbon (C).

[0021] In addition, various processing gases are used in combination with a carrier gas (e.g., Ar, He, N ２ , H ２The various process gases are introduced into the gas diffusion chamber 52 from a gas source 61 via a gas line 62 .

[0022] The substrate processing apparatus 1 includes a control unit 9. The control unit 9 is, for example, a computer, and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of the substrate processing apparatus 1. The control unit 9 may be provided inside or outside the substrate processing apparatus 1. When the control unit 9 is provided outside the substrate processing apparatus 1, the control unit 9 can control the substrate processing apparatus 1 via communication means such as wired or wireless.

[0023] 2 is a schematic diagram of an example of the substrate processing apparatus 1. As shown in FIG. 2, the apparatus includes an upper electrode (gas supply unit 5) and a lower electrode (lower electrode 33 of the mounting table 3) facing the upper electrode. The lower electrode 33 is grounded (GND). An RF power supply 51 is connected to the upper electrode. The RF power supply 51 supplies RF power of, for example, 450 kHz or 13.56 MHz.

[0024] Here, the tungsten-containing carbon film formed on the substrate W by the substrate processing apparatus 1 will be described.

[0025] In the case of a tungsten-containing carbon film formed by the PECVD method from a tungsten-containing gas and a hydrocarbon gas, the higher the tungsten concentration, the higher the etching selectivity to the film to be etched, which is preferable from the viewpoint of selectivity.

[0026] On the other hand, if the tungsten concentration becomes too high, phase separation of tungsten may occur in the carbon film, resulting in localized areas of high and low tungsten concentration within the surface. As mask patterns become finer, the variation in the tungsten concentration within the surface may degrade the pattern shape.

[0027] In contrast to this, in this embodiment, a carbon film containing high tungsten concentration and amorphous tungsten is formed by mixing a halogen-containing tungsten gas (tungsten precursor) with an organosilicon compound gas (methylsilane precursor or ethylsilane precursor).

[0028] Here, the tungsten gas containing halogen is a gas containing halogen (e.g., fluorine: F) and tungsten (W). Specifically, the tungsten gas containing halogen is WF ６ can be used. ６ The chemical formula is shown below:

[0029]

[0030] The organosilicon compound gas is a gas containing carbon (C) and silicon (Si). The organosilicon compound gas is a gas containing a methyl group (-CH ３ ) and silicon (Si), and / or a methyl group (—C ２ H ５ The organosilicon compound gas is a gas containing Si—C bonds. The organosilicon compound gas may also contain Si—H bonds.

[0031] The organosilicon compound gas may be a methylsilane precursor. Specifically, the organosilicon compound gas (methylsilane precursor) may be at least one selected from the group consisting of dimethylsilane (DMSi: Di ​​Methyl Silane), hexamethyldisilane (HMDSi: Hexa Methyl DiSilane), tetramethylsilane (TMSi: Tetra Methyl Silane), trimethylsilane (3MSi: Tri Methyl Silane), etc. As an example, the chemical formulas of DMSi, HMDSi, TMSi, and 3MSi are shown below.

[0032]

[0033]

[0034]

[0035]

[0036] The organosilicon compound gas may be an ethylsilane precursor. Specifically, the organosilicon compound gas (ethylsilane precursor) may be at least one selected from diethylsilane (DESi: Di ​​Ethyl Silane), triethylsilane (3ESi: Tri Ethyl Silane), hexaethyldisilane (HEDSi: Hexa Ethyl DiSilane), tetraethylsilane (TESi: Tetra Ethyl Silane), etc. As an example, the chemical formulas of DESi, 3ESi, HEDSi, and TESi are shown below.

[0037]

[0038]

[0039]

[0040]

[0041] In addition, various processing gases include tungsten gas containing halogen (WF ６ ) a gas (e.g., H) that promotes halogen desorption from the ２ ) may be included. ２ dissociates in the plasma and reacts with F in WFx, thereby desorbing F (fluorine, halogen) from W (tungsten).

[0042] An example of a process for forming a tungsten-containing carbon film using the substrate processing apparatus 1 will be described.

[0043] First, the substrate W is placed on the mounting table 3 in the processing chamber 2 .

[0044] Next, the control unit 9 controls the gas source 61 to supply tungsten gas (WF ６), a process gas containing an organosilicon compound gas (for example, one or more of DMSi, HMDSi, TMSi, 3MSi, DESi, 3ESi, HEDSi, and TESi) is supplied, and RF power for plasma generation is supplied to the upper electrode by controlling the RF power source 51 and / or the RF power source 56, thereby generating plasma of the process gas in the process chamber 2. The process gas may contain a carrier gas (Ar, He, etc.). The process gas may contain hydrogen (H ２ ) gas.

[0045] The substrate W placed on the mounting table 3 is exposed to the plasma of the processing gas, whereby a carbon film containing tungsten is formed on the substrate W.

[0046] Here, an example of the mechanism for forming a tungsten-containing carbon film will be described.

[0047] First, the formation of a tungsten-containing carbon film according to a reference example will be described with reference to FIG. 3. FIG. 3 is a diagram illustrating the formation of a tungsten-containing carbon film using tungsten gas and a carbon precursor. Here, WF is used as an example of tungsten gas. ６ , CH as an example of a carbon precursor ４ The following will explain the case where the above is used as an example.

[0048] As shown in FIG. 3(a), tungsten gas (WF ６ ) gradually releases halogen (F) from the plasma or the substrate surface, and when the halogen (F) is completely released, it is adsorbed on the surface of the substrate as W (tungsten).

[0049] As shown in FIG. 3(b), the carbon precursor (CH ４ ) releases hydrogen (H). Here, the carbon precursor (CH ４ ) is tungsten gas (WF ６ ) and is uniformly adsorbed onto the surface of the substrate W.

[0050] On the other hand, tungsten gas (WF) has a low adsorption coefficient. ６The halogen (F) migrates on the substrate until the halogen (F) is completely released, and moves to a stable tungsten surface in an attempt to adsorb. This can cause phase separation of tungsten in the carbon film, resulting in localized areas of high and low tungsten concentration within the surface.

[0051] Next, the formation of a tungsten-containing carbon film according to this embodiment will be described with reference to FIG. 4. FIG. 4 is a diagram illustrating the formation of a tungsten-containing carbon film using tungsten gas and an organosilicon compound gas. Here, WF is used as an example of tungsten gas. ６ An example will be described in which dimethylsilane (DMSi) is used as an example of a methylsilane precursor for the organosilicon compound gas.

[0052] As shown in FIG. 4(a), WF ６ The halogen (F) is gradually released from the plasma or the substrate surface, and when the halogen (F) is completely released, it is adsorbed on the surface of the substrate as W (tungsten).

[0053] As shown in FIG. 4B, the Si—C bond of methylsilane precursor (DMSi) is more easily broken than the Si—H bond, and the SiH ２ and CH ３ There will be active species such as SiH ２ reacts with F in WFx to form SiH ２ It is desorbed as a gas such as F2. ６ It also promotes the elimination of F from CH ３ is incorporated into the tungsten film.

[0054] In this way, WF ６ Before tungsten migrates on the substrate and aggregates, WF ６ When the halogen (F) is completely released, it is adsorbed on the surface of the substrate as tungsten (W). This suppresses phase separation of tungsten in the carbon film and prevents localized areas of high and low tungsten concentration from occurring within the surface.

[0055] In addition, SiH ４ When directly used, WF ６ and SiH ４ It cannot be used as a PECVD precursor because thermal CVD occurs due to the thermal reaction with WF. ６ The thermal reaction rate of methylsilane precursor (DMSi) is slow, so it does not react in the gas phase. This gas phase reaction suppression effect is also applicable to other organosilane precursors.

[0056] As mentioned above, WF ６ and organosilicon compound gas (methylsilane precursor, ethylsilane precursor, etc., specifically DMSi, HMDSi, TMSi, 3MSi, DESi, 3ESi, HEDSi, TESi, etc.), ６ It is possible to incorporate carbon (C) into the tungsten film while promoting the removal of F. This makes it possible to suppress phase separation of tungsten in a carbon film with a high tungsten concentration. Furthermore, as shown in FIG. 4, it is possible to prevent Si from being incorporated into the film.

[0057] Next, the crystalline state of the tungsten-containing carbon film will be described with reference to Fig. 5. Fig. 5 is an example of a diagram showing the crystalline state of the tungsten-containing carbon film and each film formation condition. Here, for the gases shown in (a) to (f), a tungsten-containing carbon film was formed, and the crystalline state of the film was measured.

[0058] In (a), WF is used as a tungsten precursor. ６ , C as a carbon precursor ２ H ２ An RF power of 13 MHz for generating plasma was supplied from an RF power source 51 to the upper electrode. ６ C against ２ H ２ Flow rate ratio (C ２ H ２ / WF ６ ) was set in the range of 0.2 to 1. Under these conditions, microcrystals were observed in the tungsten-containing carbon film.

[0059] In (b), WF is used as a tungsten precursor.６ , C as a carbon precursor ３ H ６ An RF power of 13 MHz for generating plasma was supplied from an RF power source 51 to the upper electrode. ６ C against ３ H ６ Flow rate ratio (C ３ H ６ / WF ６ ) was set in the range of 0.2 to 1. Under these conditions, microcrystals were observed in the tungsten-containing carbon film.

[0060] In (c), WF is used as a tungsten precursor. ６ Tetramethylsilane (TMSi) was used as the methylsilane precursor. An RF power of 13 MHz for plasma generation was supplied to the upper electrode from an RF power source 51. ６ The flow rate ratio of TMSi to WF ６ When WF was 0.5, the tungsten-containing carbon film was amorphous. ６ The flow rate ratio of TMSi to WF ６ When the value of the tungsten content is in the range of 1 to 1.5, abnormal crystal growth is observed in the tungsten-containing carbon film.

[0061] In (d), WF is used as a tungsten precursor. ６ Dimethylsilane (DMSi) was used as the methylsilane precursor. An RF power of 13 MHz for plasma generation was supplied to the upper electrode from an RF power source 51. ６ The flow rate ratio of DMSi to WF ６ ) is in the range of 1 to 2, the tungsten-containing carbon film is amorphous. ６ The flow rate ratio of DMSi to WF ６ When the tungsten content was 3, it was confirmed that the tungsten-containing carbon film was a mixture of amorphous and microcrystalline.

[0062] In (e), WF is used as a tungsten precursor. ６Dimethylsilane (DMSi) was used as the methylsilane precursor. An RF power of 450 kHz for plasma generation was supplied from an RF power source 51 to the upper electrode. ６ The flow rate ratio of DMSi to WF ６ ) is within the range of 1, the tungsten-containing carbon film is confirmed to be microcrystalline. ６ The flow rate ratio of DMSi to WF ６ When the value of tungsten content was within the range of 2 to 3, the tungsten-containing carbon film was amorphous.

[0063] In (f), WF is used as a tungsten precursor. ６ Hexamethyldisilane (HMDSi) was used as the methylsilane precursor. An RF power of 13 MHz for plasma generation was supplied to the upper electrode from an RF power source 51. ６ The flow rate ratio of HMDSi to WF ６ ) is within the range of 1, the tungsten-containing carbon film is confirmed to be a mixture of amorphous and microcrystalline. ６ The flow rate ratio of HMDSi to WF ６ ) is in the range of 2 to 3, the tungsten-containing carbon film is confirmed to be microcrystalline.

[0064] In (g), WF is used as a tungsten precursor. ６ Trimethylsilane (3MSi) was used as the methylsilane precursor. An RF power of 13 MHz for plasma generation was supplied to the upper electrode from an RF power source 51. ６ The flow rate ratio of 3MSi to WF ６ When the value of tungsten content was within the range of 1 to 3, the tungsten-containing carbon film was amorphous.

[0065] In (h), WF is used as a tungsten precursor. ６ Diethylsilane (DESi) was used as the ethylsilane precursor. An RF power of 13 MHz for plasma generation was supplied to the upper electrode from an RF power source 51. ６ The flow rate ratio of DESi to WF６ When WF was 0.5, the tungsten-containing carbon film was confirmed to be a mixture of amorphous and microcrystalline. ６ The flow rate ratio of DESi to WF ６ ) is within the range of 1 to 2, the tungsten-containing carbon film is confirmed to be microcrystalline.

[0066] As described above, WF is used as a tungsten precursor. ６ , a hydrocarbon gas (C ２ H ２ , C ３ H ６ When WF was used, a carbon film containing tungsten consisting of microcrystalline crystals was observed over a wide range of gas ratios. ６ and methylsilane precursors (DMSi, HMDSi, TMSi, 3MSi), and WF ６ It was confirmed that when ethylsilane precursor (DESi) was used, a carbon film containing amorphous tungsten could be obtained.

[0067] Therefore, as shown by comparing FIGS. 5(a) and 5(b) with FIGS. 5(c) to 5(h), by using methylsilane precursors (DMSi, HMDSi, TMSi, 3MSi) and ethylsilane precursors (DESi), it is possible to form a carbon film containing amorphous tungsten.

[0068] Furthermore, by using methylsilane precursors (DMSi, HMDSi, TMSi, 3MSi) and ethylsilane precursors (DESi) and appropriately adjusting the frequency of the RF for plasma generation supplied to the upper electrode, the RF power, and the flow rate ratio of the halogen-containing tungsten gas (tungsten precursor) to the organosilicon compound gas (methylsilane precursor, ethylsilane precursor), it is possible to increase the tungsten concentration in the tungsten-containing carbon film (for example, within a range of 30% to 90%), make the crystalline state amorphous (non-crystalline), and suppress phase separation of the tungsten in the carbon film.

[0069] The tungsten-containing carbon film formed using a halogen-containing tungsten gas and an organosilicon compound gas will be further described with reference to Figures 6 to 8. The following description will be made taking as an example a case where dimethylsilane (DMSi) is used as the organosilicon compound gas.

[0070] FIG. 6 is a diagram showing an example of the film composition of a carbon film containing tungsten.

[0071] FIG. 6(a) shows the tungsten precursor WF ６ , a hydrocarbon gas (C ２ H ２ , C ３ H ６ The film composition of the carbon film containing tungsten when using a tungsten-containing film containing tungsten, etc., is shown.

[0072] FIG. 6(b) shows the tungsten precursor WF ６ 1 shows the film composition of an amorphous tungsten-containing carbon film when dimethylsilane (DMSi) is used as a methylsilane precursor.

[0073] As shown in FIG. ６ By using methylsilane precursor (DMSi), it is possible to form a tungsten-containing carbon film in which the ratio of fluorine (F) and hydrogen (H) is reduced and the ratio of tungsten is significantly improved.

[0074] FIG. 7 is an example of a graph showing the relationship between the tungsten concentration and the film stress of a carbon film containing tungsten.

[0075] The square mark (a) indicates that the frequency of the RF for plasma generation supplied to the upper electrode is 13 MHz and WF is used as the tungsten precursor. ６ , a hydrocarbon gas (C ２ H ２ , C ３ H ６ A tungsten-containing carbon film was formed using a tungsten-containing carbon film.

[0076] The diamond mark (b) indicates that the frequency of the RF for plasma generation supplied to the upper electrode is 13 MHz and WF is used as the tungsten precursor.６ A carbon film containing tungsten was formed using dimethylsilane (DMSi) as a methylsilane precursor.

[0077] The circular mark (c) indicates that the frequency of the RF for plasma generation supplied to the upper electrode is 450 kHz and WF is used as the tungsten precursor. ６ A carbon film containing tungsten was formed using dimethylsilane (DMSi) as a methylsilane precursor.

[0078] As shown in FIG. 7, by changing the frequency of the RF for generating plasma supplied to the upper electrode, it is possible to form a carbon film containing tungsten with low stress even if the tungsten concentration is high.

[0079] 8 is an example of a graph showing the results of an evaluation of the etching resistance of a tungsten-containing carbon film. In this evaluation, two different conditions, (a) and (b), were used. In (a), the etching temperature was 40°C, and in (b), the etching temperature was -10°C.

[0080] In the reference example of FIG. 8, WF is used as a tungsten precursor. ６ , a hydrocarbon gas (C ２ H ２ , C ３ H ６ A tungsten-containing carbon film was formed using a tungsten-containing carbon film.

[0081] In the embodiment of FIG. 8, WF is used as the tungsten precursor. ６ A carbon film containing tungsten was formed using dimethylsilane (DMSi) as a methylsilane precursor.

[0082] 8, when the etching rate of the Reference Example is set to 1, the etching rate of the Example is 0.32 in (a) and 0.44 in (b). From these results, it can be said that the etching resistance is high in both cases.

[0083] The substrate processing method for forming a tungsten-containing carbon film has been described above, but the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure as defined in the claims.

[0084] This application claims priority based on Japanese Patent Application No. 2024-087389, filed on May 29, 2024, the entire contents of which are incorporated herein by reference.

[0085] W substrate 1 substrate processing apparatus 2 processing vessel 3 mounting table (substrate support) 5 gas supply unit (upper electrode) 6 gas supply path 61 gas source (gas supply source) 9 control unit 33 lower electrode 35 RF power supply 51 RF power supply 56 RF power supply

Claims

1. A substrate processing method for forming a tungsten-containing carbon film, comprising the steps of: supplying a processing gas containing a halogen-containing tungsten gas and an organosilicon compound gas into a processing vessel and generating plasma of the processing gas; and exposing a substrate to the generated plasma to form a tungsten-containing carbon film on the substrate.

2. The substrate processing method according to claim 1, wherein the organosilicon compound gas is a gas containing one or more Si—C bonds.

3. The substrate processing method according to claim 2, wherein the organosilicon compound gas further contains one or more Si—H bonds.

4. The substrate processing method according to claim 1, wherein the organosilicon compound gas is one of dimethylsilane, hexamethyldisilane, tetramethylsilane, trimethylsilane, diethylsilane, triethylsilane, hexaethyldisilane, and tetraethylsilane.

5. The halogen-containing tungsten gas is WF ６ The substrate processing method according to claim 1 , wherein:

6. The substrate processing method according to any one of claims 1 to 4, wherein the tungsten-containing carbon film is amorphous.

7. The substrate processing method according to claim 1, wherein the processing gas further contains a carrier gas, and the carrier gas is one of Ar and He.

8. The substrate processing method according to any one of claims 1 to 4, wherein the processing gas further contains hydrogen gas.

9. A method for forming a tungsten-containing carbon hard mask, comprising: supplying a process gas containing a halogen-containing tungsten gas and an organosilicon compound gas into a process vessel and generating plasma of the process gas; and exposing a substrate to the generated plasma to form a tungsten-containing carbon hard mask on the substrate.

10. The method for forming a hard mask according to claim 9, wherein the organosilicon compound gas is a gas containing one or more Si—C bonds.

11. The hard mask formation method according to claim 10, wherein the organosilicon compound gas further contains one or more Si—H bonds.

12. The hard mask formation method according to claim 9, wherein the organosilicon compound gas is one of dimethylsilane, hexamethyldisilane, tetramethylsilane, trimethylsilane, diethylsilane, triethylsilane, hexaethyldisilane, and tetraethylsilane.

13. The halogen-containing tungsten gas is WF ６ 13. The method for forming a hard mask according to claim 9, wherein 14. The hard mask forming method according to any one of claims 9 to 12, wherein the tungsten-containing carbon film is amorphous.

15. The hard mask formation method according to any one of claims 9 to 12, wherein the process gas further contains a carrier gas, and the carrier gas is one of Ar and He.

16. The hard mask forming method according to any one of claims 9 to 12, wherein the processing gas further contains hydrogen gas.

17. A substrate processing apparatus for forming a tungsten-containing carbon film, comprising: a substrate support having a lower electrode and supporting a substrate; a processing vessel accommodating the substrate support; a gas supply unit having an upper electrode, disposed opposite the substrate support, and supplying a processing gas into the processing vessel; a gas supply source supplying the processing gas to the gas supply unit; a high-frequency power supply supplying high-frequency power for generating plasma to the upper electrode; and a control unit, wherein the control unit controls the gas supply source to supply the processing gas containing halogen-containing tungsten gas and an organosilicon compound gas into the processing vessel, and controls the high-frequency power supply to generate plasma of the processing gas in the processing vessel, thereby forming a tungsten-containing carbon film on the substrate.

Images