Substrate processing method and substrate processing device

Abstract

The purpose of the present invention is to provide a substrate processing method and a substrate processing device for selectively etching a silicon compound film.　A substrate processing method comprising the steps of: preparing a substrate having a base film, a first silicon compound film formed on the base film, and a photoresist film that is formed on the first silicon compound film and has an opening pattern; forming an aluminum oxide film covering the photoresist film and the bottom of the opening of the photoresist film; supplying a fluorine-containing gas or a fluorine-containing mixed gas to the substrate and forming the opening pattern in the first silicon compound film by chemical vapor phase etching using the aluminum oxide film formed on the bottom of the opening of the photoresist film as a catalyst of an aluminum compound; and removing the aluminum oxide film covering the photoresist film and the aluminum compound in the opening of the first silicon compound film.

Description

Substrate processing method and substrate processing apparatus

[0001] The present disclosure relates to a substrate processing method and a substrate processing apparatus.

[0002] Patent Document 1 discloses a method for etching silicon oxynitride to transfer a photoresist pattern.

[0003] Special Publication No. 2001-526461

[0004] In one aspect, the present disclosure provides a substrate processing method and a substrate processing apparatus for selectively etching a silicon compound film.

[0005] In order to solve the above problem, according to one aspect, there is provided a substrate processing method comprising the steps of: preparing a substrate having an underlayer film, a first silicon compound film formed on the underlayer film, and a photoresist film formed on the first silicon compound film and having an opening pattern; forming an aluminum oxide film covering the bottom of the opening in the photoresist film and the photoresist film; supplying a fluorine-containing gas or a fluorine-containing mixed gas to the substrate and forming an opening pattern in the first silicon compound film by chemical vapor etching using the aluminum oxide film formed on the bottom of the opening in the photoresist film as a catalyst for an aluminum compound; and removing the aluminum oxide film covering the photoresist film and the aluminum compound in the opening in the first silicon compound film.

[0006] According to one aspect, it is possible to provide a substrate processing method and a substrate processing apparatus for selectively etching a silicon compound film.

[0007] An example of a flowchart showing a substrate processing method according to the present embodiment. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. An example of a schematic cross-sectional view of a substrate W in each process. SiO ２ Graph showing an example of the etching amount of an Al film.２ O ３ The film thickness and SiO ２ 1 is a graph showing an example of an etching amount of a 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 Method] The substrate processing method according to this embodiment will be described with reference to Figures 1 and 2A to 2I. Figure 1 is an example of a flowchart showing the substrate processing method according to this embodiment. Figures 2A to 2I are example of schematic cross-sectional views of the substrate W in each step. In the substrate processing method according to this embodiment, a pattern of openings 225 is formed in the first silicon compound film 220. Furthermore, in the substrate processing method according to this embodiment, a pattern of openings 215 is formed in the base film 210.

[0010] In step S101, a substrate W is prepared. The substrate W has a base material 200 and an undercoat film 210 (see FIG. 2A). Note that, before the process of step S101, a process of forming the undercoat film 210 on the substrate W having the base material 200 may be performed.

[0011] The substrate 200 is, for example, a wafer made of silicon (Si).

[0012] The base film 210 is made of a material that has an etching selectivity with respect to the first silicon compound film 220 described below. The base film 210 is, for example, a carbon (C)-containing film (carbon film). Alternatively, the base film 210 may be an SOC (spin-on-carbon) film.

[0013] The carbon film (underlying film 210) is used as a carbon hard mask in which a pattern of openings 215 (see FIG. 2G) is formed by a process described later (see S110). This carbon hard mask may be used as a mask when etching the substrate 200.

[0014] The base film 210 is not limited to a carbon-containing film (SOC film), but may be made of any material that can achieve a selectivity with the underlying film (substrate 200). For example, the base film 210 may be made of Ti, W, Mo, Hf, Zr, Al, Ru, In, Ga, Zn, or the like, or an oxide, nitride, carbide, boride, or oxynitride thereof, or may be Si-based (a-Si, p-Si). The base film 210 may also be composed of a stacked film of a carbon-containing film (SOC film) and a TiN film or the like.

[0015] In step S102, a first silicon compound film 220 is formed. Here, the first silicon compound film 220 is formed (deposited) on the base film 210 (see FIG. 2A). The first silicon compound film 220 may be a SOG (spin-on-glass) film.

[0016] The first silicon compound film 220 is not limited to an SOG film (silicon oxide), but may be a film made of silicon oxide (SiO), silicon nitride (SiN), or silicon oxynitride (SiON). The first silicon compound film 220 may be a laminated film of an SOG film (silicon oxide film) and a silicon nitride film and / or a silicon oxynitride film.

[0017] In step S103, a photoresist film 230 is formed. Here, the photoresist film 230 is formed (deposited) on the first silicon compound film 220 (see FIG. 2A ). The photoresist film 230 is, for example, a chemically amplified resist (CAR) film. The photoresist film 230 may be a positive photoresist film that forms a mask by removing the photoresist film in the exposed areas and leaving the photoresist film in the unexposed areas, or a negative photoresist film that forms a mask by removing the photoresist film in the unexposed areas and leaving the photoresist film in the exposed areas. In the following description, the photoresist film is assumed to be a positive photoresist film.

[0018] In step S104, a pattern of openings 235 is formed in the photoresist film 230. Here, the pattern of openings 235 is formed in the photoresist film 230 by performing exposure processing, post-exposure bake processing (PEB), and development processing.

[0019] 2A is an example of a schematic cross-sectional view of the substrate W during exposure processing. In the exposure processing, light 300 such as EUV (Extreme Ultraviolet) is irradiated onto the photoresist film 230 through a photomask (not shown) having a predetermined pattern in a nitrogen atmosphere, thereby forming exposed portions irradiated with light and unexposed portions not irradiated with light in the photoresist film 230.

[0020] In the post-exposure bake treatment, the substrate W is baked (heat-treated) to promote the catalytic reaction after exposure.

[0021] The development process selectively removes either the exposed portion or the unexposed portion of the photoresist film 230. The development process can be performed using at least one of a wet process and a dry process.

[0022] 2B is an example of a schematic cross-sectional view of the substrate W after development processing. In this example, the substrate W is a positive photoresist film 230, and exposed portions are removed by development processing to form a pattern of openings 235. The pattern of the openings 235 is, for example, a trench pattern.

[0023] As described above, by the processing of steps S101 to S104, a substrate W is prepared which has a base material 200, an undercoat film 210, a first silicon compound film 220 formed on the undercoat film 210, and a photoresist film 230 formed on the first silicon compound film 220 and having a pattern of openings 235.

[0024] In step S105, a second silicon compound film 240 is formed. Here, the second silicon compound film 240 is formed (deposited) on the substrate W by ALD (Atomic Layer Deposition). This forms the second silicon compound film 240 that covers the bottom of the opening 235 in the photoresist film 230 and the upper and side surfaces of the photoresist film 230. The second silicon compound film 240 is made of any of silicon oxide (SiO), silicon nitride (SiN), and silicon oxynitride (SiON). Note that the step of forming the second silicon compound film 240 shown in step S105 is not essential, and step S105 may be omitted.

[0025] The first silicon compound film 220 and the second silicon compound film 240 may be films made of the same material, or may be films made of different materials.

[0026] The process of forming the second silicon compound film 240 by ALD includes a process of supplying a raw material gas (precursor gas) to the substrate W, a process of supplying a purge gas, a process of supplying a reactive gas (oxidizing gas, nitriding gas) to the substrate W, and a process of supplying a purge gas.

[0027] In the process of supplying the source gas, a source gas containing silicon (Si) is supplied into a processing vessel accommodating a mounting table on which the substrate W is placed. As a result, the source gas is adsorbed onto the surface of the substrate W, and an adsorption layer of the source gas is formed on the surface of the substrate W.

[0028] In the step of supplying the purge gas, the purge gas (N ２ As a result, excess source gas and the like in the processing chamber are purged with the purge gas.

[0029] In the step of supplying the reactive gas, the reactive gas is supplied into a processing vessel accommodating a mounting table on which the substrate W is placed. The step of supplying the reactive gas may be configured to generate plasma of the reactive gas and supply activated species (ions, radicals, etc.) of the reactive gas to the substrate W. This reacts (oxidizes, nitrides) with the adsorption layer on the surface of the substrate W, forming a monoatomic layer of silicon compound (SiO, SiN, SiON) on the surface of the substrate W.

[0030] In the step of supplying the purge gas, the purge gas (N ２ As a result, excess reactive gas and the like in the processing chamber are purged with the purge gas.

[0031] Then, a process of supplying a source gas, a process of supplying a purge gas, a process of supplying a reaction gas, and a process of supplying a purge gas constitute one cycle, and this cycle is repeated a predetermined number of times to form a second silicon compound film 240 having a desired film thickness.

[0032] When a silicon oxide (SiO) film is formed as the second silicon compound film 240, examples of the combination of source gas and reactive gas (oxidizing gas containing oxygen (O)) include the following: [Source gas] [Reactive gas] (Me ２ N) ３ Si-SiH ３ O ３ or O ２ Plasma (Me ２ SiO) ４ O ２ Plasma MeOSi(NCO) ３ H ２ O ２ Si(NCO) ４ H ２ OSi(OEt) ４ O ２ Plasma Si(OMe) ４ H ２ O Si ２ Cl ６ O ３ SiCl ４ H２ O SiH(NMe ２ ) ３ O ３ or H ２ O or O ２ Plasma SiH ２ (NEt ２ ) ２ O ３ or O ２ Plasma SiH ３ N (iPr) ２ O ３ or O ２ Plasma SiH ４ N ２ O plasma or CO ２ plasma

[0033] When a silicon nitride (SiN) film is formed as the second silicon compound film 240, examples of the combination of source gas and reactive gas (nitriding gas containing nitrogen (N)) include the following: [Source gas] [Reactive gas] N(Si ２ H ５ ) ３ N ２ Plasma or NH ３ Plasma N(SiH ３ ) ３ N ２ Plasma Si(SiH ３ ) ４ N ２ Plasma SiH(NMe ２ ) ３ N ２ Plasma SiH ２ (NEt ２ ) ２ N ２ Plasma SiH ４ N ２ Plasma SiHMe ３ NH ３ Plasma Si ２ Cl ６ NH ３

[0034] 2C is an example of a schematic cross-sectional view of the substrate W after the formation of the second silicon compound film 240. The second silicon compound film 240 is a protective film for protecting the photoresist film 230 from the aluminum oxide film 250 when the aluminum oxide film 250, which will be described later, is formed. As shown in FIG. 2C , the aluminum oxide film 250 is formed on the upper surface of the photoresist film 230, the side surfaces of the photoresist film 230 (the side surfaces of the opening 235), and a portion of the upper surface of the first silicon compound film 220 that is exposed from the opening 235 (the bottom of the opening 235).

[0035] In step S106, an aluminum oxide film 250 is formed. Here, the aluminum oxide film 250 is formed (deposited) on the substrate W by the ALD method. As a result, the aluminum oxide film 250 is formed to cover the bottom of the opening 235 of the photoresist film 230 covered with the second silicon compound film 240 and the upper and side surfaces of the photoresist film 230 covered with the second silicon compound film 240. The aluminum oxide film 250 is made of, for example, Al ２ O ３ When the step of forming the second silicon compound film 240 shown in step S105 is omitted, an aluminum oxide film 250 is formed in step S106 to cover the bottom of the opening 235 in the photoresist film 230 and the upper and side surfaces of the photoresist film 230.

[0036] The process of forming the aluminum oxide film 250 by ALD includes a process of supplying a raw material gas (precursor gas) to the substrate W, a process of supplying a purge gas, a process of supplying a reactive gas (oxidizing gas) to the substrate W, and a process of supplying a purge gas.

[0037] In the process of supplying the source gas, a source gas containing silicon (Si) is supplied into a processing vessel accommodating a mounting table on which the substrate W is placed. As a result, the source gas is adsorbed onto the surface of the substrate W, and an adsorption layer of the source gas is formed on the surface of the substrate W.

[0038] In the step of supplying the purge gas, the purge gas (N ２ As a result, excess source gas and the like in the processing chamber are purged with the purge gas.

[0039] In the step of supplying the reactive gas, the reactive gas is supplied into a processing vessel accommodating a mounting table on which the substrate W is placed. The step of supplying the reactive gas may be configured to generate plasma of the reactive gas and supply activated species (ions, radicals, etc.) of the reactive gas to the substrate W. This reacts (oxidizes) with the adsorption layer on the surface of the substrate W, and forms a monoatomic layer of aluminum oxide (e.g., Al ２ O ３ ) is formed.

[0040] In the step of supplying the purge gas, the purge gas (N ２ As a result, excess reactive gas and the like in the processing chamber are purged with the purge gas.

[0041] Then, a process of supplying a source gas, a process of supplying a purge gas, a process of supplying a reaction gas, and a process of supplying a purge gas are repeated a predetermined number of times, thereby forming an aluminum oxide film 250 having a desired thickness.

[0042] When forming the aluminum oxide film 250, examples of the combination of source gas and reactive gas (oxidizing gas) include the following: [Source gas] [Reactive gas] AlMe ３ H ２ O, O ３ , O ２ Plasma, N ２ O, NO ２ Al(NEt ２ ) ３ H ２ O, O ３ AlMe ２ ClH ２ O, O ３

[0043] 2D is an example of a schematic cross-sectional view of the substrate W after the formation of the aluminum oxide film 250. The aluminum oxide film 250 is formed on the upper surface of the photoresist film 230, the side surfaces of the photoresist film 230 (the side surfaces of the openings 235), and the portion of the upper surface of the first silicon compound film 220 that is exposed from the openings 235 (the bottom of the openings 235).

[0044] In step S107, the first silicon compound film 220 and the second silicon compound film 240 are etched (removed) using the photoresist film 230 with the pattern of the openings 235 formed therein as a mask, thereby forming a pattern of the openings 225 in the first silicon compound film 220. Note that if the process of forming the second silicon compound film 240 shown in step S105 is omitted, the first silicon compound film 220 is etched (removed) in step S107 to form a pattern of the openings 225 in the first silicon compound film 220.

[0045] The step of etching the first silicon compound film 220 and the second silicon compound film 240 includes a step of supplying an etching gas to the substrate W and a step of supplying a purge gas.

[0046] In the step of supplying an etching gas, an etching gas is supplied into a processing vessel accommodating a stage on which a substrate W is placed. The etching gas may be a fluorine-containing gas or a fluorine-containing mixed gas. For example, HF gas may be used as the fluorine-containing gas. For example, HF gas and H may be used as the fluorine-containing mixed gas. ２ A mixed gas of H and O gas can be used. ２ By adding O gas, H is added to the first silicon compound film 220 and the second silicon compound film 240. ２ O gas can be adsorbed, and etching with HF gas can be promoted.

[0047] In addition, HF gas and H ２ O gas may be supplied as a mixed gas at the same time. ２ After the step of supplying O gas, the step of supplying HF gas may be performed. ２ The step of supplying O gas and the step of supplying HF gas may be repeated.

[0048] The etching temperature may be in the range of 20°C to 100°C, more preferably 40°C to 80°C.

[0049] In the step of supplying the purge gas, the purge gas (N２ As a result, excess etching gas and the like in the processing chamber are purged with the purge gas.

[0050] 2E is an example of a schematic cross-sectional view of the substrate W after etching the first silicon compound film 220 and the second silicon compound film 240. The aluminum oxide film 250 formed on the bottom of the opening 235 is made into an aluminum compound 251, and the first silicon compound film 220 is etched using this aluminum compound 251 as a catalyst. By using the aluminum compound 251 as a catalyst, the first silicon compound film 220 is selectively etched in the vertical direction (downward) relative to the horizontal direction. This forms (transfers) the pattern of the opening 225 in the first silicon compound film 220. Furthermore, the second silicon compound film 240 formed on the surface of the photoresist film 230 is also etched using the aluminum oxide film 250 covering the upper and side surfaces of the second silicon compound film 240 as a catalyst.

[0051] Here, an example of anisotropic etching according to a reference example will be described. When the first silicon compound film is anisotropically etched using plasma (selective etching in the vertical direction relative to the horizontal direction), the photoresist film is damaged and consumed by the plasma. In particular, when the photoresist film has a fine pattern, a strong electric field gradient is formed near the shoulders of the lines (corners where the upper surface of the photoresist film connects with the side surface of the photoresist film), and ions are attracted from the plasma, causing the shoulders of the lines to drop sharply. Therefore, the selectivity of the first silicon compound film relative to the photoresist film decreases.

[0052] 1 and 2A to 2I, in step S107, the first silicon compound film 220 is etched by chemical vapor etching without using plasma. This prevents the photoresist film 230 from being consumed by plasma. Furthermore, ions are not attracted to the shoulders of the lines, and the shoulders of the photoresist film 230 are prevented from dropping. This prevents the photoresist film 230 from being consumed, and increases the etching selectivity of the first silicon compound film 220 to the photoresist film 230.

[0053] 1 and 2A to 2I, the upper surface, side surfaces, and shoulder portions where the upper surface and side surfaces of the photoresist film 230 are connected are covered with an aluminum oxide film 250, as shown in FIGS. 2D and 2E. This suppresses consumption of the photoresist film 230 by the etching gas. This makes it possible to increase the etching selectivity of the first silicon compound film 220 relative to the photoresist film 230.

[0054] FIG. 3 shows SiO ２ 1 is a graph showing an example of the etching amount of a film. ２ The film is then treated with HF gas and H ２ In the graph of FIG. 3, the horizontal axis represents the etching time, and the vertical axis represents the SiO ２ The solid line indicates the etching amount of the SiO ２ The Al film (corresponding to the first silicon compound film 220) ２ O ３ When a SiO film (corresponding to the aluminum oxide film 250) is formed ２ The dashed line indicates the etching amount of the Al film. ２ O ３ SiO without film formed ２ In the case of the first silicon compound film 220, ２ The etching amount of the film thickness is shown.

[0055] As shown in FIG. 3, the SiO ２ Al on the film ２ O ３ When a film is formed, the SiO ２ Compared with the case of only the film, Al ２ O ３ The etching rate is increased by approximately 10 times by functioning as a catalyst.

[0056] That is, when the first silicon compound film 220 is etched in step S107, the etching rate Es in the horizontal direction corresponds to the graph shown by the dashed line in Fig. 3. On the other hand, the etching rate Ev in the vertical direction (the direction perpendicular to the substrate W) corresponds to the graph shown by the solid line in Fig. 3 because the aluminum compound 251 functions as a catalyst. As a result, the etching rate Ev in the vertical direction is larger than the etching rate Es in the horizontal direction (Ev>Es), and the first silicon compound film 220 can be anisotropically etched as shown in Fig. 2E.

[0057] FIG. ２ O ３ The film thickness and SiO ２ 1 is a graph showing an example of the etching amount of a film. ２ The film is then treated with HF gas and H ２ In the graph of FIG. 4, the horizontal axis represents the amount of Al in step S106. ２ O ３ The vertical axis indicates the number of ALD cycles for forming a film, and the vertical axis indicates SiO ２ The etching amount of the film is shown. The measurement results are indicated by black circles. The curve fitted to the measurement results is shown by a dashed line.

[0058] As shown in FIG. 4, the number of ALD cycles was 6 (Al ２ O ３ (corresponding to a film thickness of about 1 nm) ２ The amount of etching of the film increases, i.e., the catalytic function improves.

[0059] Also, Al ２ O ３ If the film is too thick, it functions as a protective film that inhibits etching rather than acting as a catalyst. Therefore, the number of ALD cycles is set to 1 to 10 (Al ２ O ３ The thickness of the film is in the range of 0.1 nm to 1.5 nm, more preferably 0.15 nm to 1.3 nm, so that Al ２ O ３ acts as a catalyst, and SiO ２In other words, the first silicon compound film 220 can be anisotropically etched. ２ The etch rate of the layer may be in the range of 5 nm / min to 25 nm / min.

[0060] 1 and 2A to 2I, in step S108, the aluminum oxide film 250 and the aluminum compound 251 are removed. ２ O ３ Here, the case where Al(CH ３ ) ３ The metal (Al) is removed from the substrate W by utilizing the high vapor pressure of the metal.

[0061] In the process of removing the aluminum oxide film 250 and the aluminum compound 251, a mixed gas containing hydrocarbon and hydrogen is supplied as a processing gas into a processing vessel accommodating a stage on which a substrate W is placed. Specifically, CH ４ and H ２ Then, a mixed gas containing Al(CH) is supplied. By generating plasma of the processing gas, the metal (Al) of the aluminum oxide film 250 and the aluminum compound 251 reacts with the plasma of the processing gas, and Al(CH ３ ) ３ Forms Al(CH ３ ) ３ The gas is exhausted from the processing chamber by the exhaust device. This removes the aluminum oxide film 250 and the aluminum compound 251 from the substrate W. Note that a rare gas such as He or Ar may be added to the processing gas. In addition, N ２ , Cl ２ Gases such as the above may also be added.

[0062] 2F is an example of a schematic cross-sectional view of the substrate W after removal of the aluminum compound 251. The aluminum oxide film 250 covering the photoresist film 230 and the aluminum compound 251 in the opening 225 are removed.

[0063] In steps S109 to S112, the base film 210 is etched using the first silicon compound film 220 having the pattern of the openings 225 as a mask, to form (transfer) the pattern of the openings 215 in the base film 210. As shown in step S109, the processing differs depending on whether the material of the base film 210 is a carbon film or not.

[0064] If the material of the base film 210 is a carbon film (S109: YES), the process proceeds to step S110.

[0065] In step S110, the base film 210 is etched (removed) using the photoresist film 230 in which the pattern of the opening 235 has been formed and the first silicon compound film 220 in which the opening 225 has been formed as a mask.

[0066] In step S110, a processing gas containing oxygen (O) (for example, O ２ Then, plasma of the processing gas is generated to remove the photoresist film 230 and to form (transfer) a pattern of the opening 215 in the base film 210.

[0067] 2G is an example of a schematic cross-sectional view of the substrate W after the processing of step S110. As shown in FIG. 2G, the photoresist film 230 is removed, and the pattern of the opening 215 is formed (transferred) in the base film 210.

[0068] If the material of the base film 210 is not a carbon film (S109: NO), the process proceeds to step S111.

[0069] In step S111, the photoresist film 230 is ashed (removed).

[0070] In step S111, O is introduced into a processing vessel accommodating a stage on which a substrate W is placed. ２ A processing gas containing the compound is supplied, and a plasma of the processing gas is generated to remove the photoresist film 230.

[0071] Fig. 2H is an example of a schematic cross-sectional view of the substrate W after the processing in step S111. As shown in Fig. 2H, the photoresist film 230 is removed.

[0072] In step S112, the base film 210 is etched (removed) using the first silicon compound film 220 with the opening 225 formed therein as a mask.

[0073] In step S112, O is introduced into the processing vessel accommodating the stage on which the substrate W is placed. ２ Then, plasma of the processing gas is generated to remove the photoresist film 230 and to form (transfer) a pattern of the opening 215 in the base film 210.

[0074] 2I is an example of a schematic cross-sectional view of the substrate W after the processing in step S112. As shown in FIG.

[0075] As described above, the substrate processing method shown in FIGS. 1 and 2A to 2I allows selective etching of the first silicon compound film 220 while suppressing consumption of the photoresist film 230. In other words, the thickness of the photoresist film 230 can be reduced. That is, the aspect ratio of the photoresist pattern (height of the photoresist / width of the photoresist in the photoresist provided between parallel trenches) can be reduced (e.g., less than 1). This prevents the photoresist from collapsing even when the photoresist film 230 has a fine pattern. Furthermore, by preventing the photoresist film 230 from collapsing, the pattern of the opening 225 can be formed (transferred) in the first silicon compound film 220 with high precision. Furthermore, the pattern of the opening 225 can be formed (transferred) in the base film 210 with high precision.

[0076] [Substrate Processing Apparatus] Next, an example of a substrate processing apparatus 500 that performs the substrate processing shown in Fig. 1 will be described with reference to Fig. 5. Fig. 5 is a schematic cross-sectional view showing an example of the configuration of the substrate processing apparatus 500.

[0077] The substrate processing apparatus 500 includes a first chamber 510 , a second chamber 520 , a transfer path 530 , and a control unit 540 .

[0078] In the first chamber 510, a plasma process is performed on the substrate W. The first chamber 510 is provided with a mounting table 511, a gas supply unit 512, a gas supply source 513, an exhaust device 514, a high-frequency power supply 515, and a high-frequency power supply 516.

[0079] The first chamber 510 is a processing vessel that accommodates a mounting table 511. A substrate W is placed on the mounting table 511. An openable and closable gate valve 510a is provided on a sidewall of the first chamber 510. A transfer device (not shown) is configured to transfer the substrate W from the transfer path 530 into the first chamber 510 via the gate valve 510a and place the substrate W on the mounting table 511. The transfer device is also configured to transfer the substrate W placed on the mounting table 511 from the first chamber 510 to the transfer path 530 via the gate valve 510a.

[0080] A gas supply unit 512 (e.g., a shower head) is provided facing the mounting table 511. The gas supply unit 512 introduces various process gases supplied from a gas supply source 513 into the first chamber 510. The exhaust device 514 exhausts gas from the first chamber 510.

[0081] The mounting table 511 has a lower electrode. The gas supply unit 512 facing the mounting table 511 has an upper electrode. High frequency power is supplied to the lower electrode from a high frequency power supply 515. High frequency power is supplied to the upper electrode from a high frequency power supply 516.

[0082] A processing gas is supplied from the gas supply unit 512 into the first chamber 510, and high-frequency power (e.g., 13 MHz) for plasma generation is supplied to the lower electrode and / or the upper electrode, thereby generating a capacitively coupled plasma (CCP) in the processing space P1 within the first chamber 510. This performs plasma processing on the substrate W. Additionally, ions may be attracted from the plasma to the substrate W by supplying high-frequency bias power to the lower electrode.

[0083] In the second chamber 520, a chemical vapor process is performed on the substrate W. The second chamber 520 is provided with a mounting table 521, a gas supply unit 522, a gas supply source 523, and an exhaust device 524.

[0084] The second chamber 520 is a processing vessel that accommodates a mounting table 521. A substrate W is placed on the mounting table 521. An openable and closable gate valve 520a is provided on a sidewall of the second chamber 520. A transfer device (not shown) is configured to transfer the substrate W from the transfer path 530 into the second chamber 520 via the gate valve 520a and place the substrate W on the mounting table 521. The transfer device is also configured to transfer the substrate W placed on the mounting table 521 from the second chamber 520 to the transfer path 530 via the gate valve 520a.

[0085] A gas supply unit 522 (e.g., a shower head) is provided facing the mounting table 521. The gas supply unit 522 introduces various process gases supplied from a gas supply source 523 into the second chamber 520. The exhaust device 524 exhausts gas from the second chamber 520.

[0086] The processing gas is supplied from the gas supply unit 522 into the second chamber 520, thereby supplying the processing gas to the processing space P21 in the second chamber 520. In this way, the substrate W is subjected to chemical vapor processing.

[0087] The transfer path 530 is connected to the first chamber 510 via a gate valve 510a, and is connected to the second chamber 520 via a gate valve 520a. A transfer device (not shown) for transferring the substrate W is provided on the transfer path 530.

[0088] The control unit 540 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 500. The control unit 540 may be provided inside or outside the substrate processing apparatus 500. When the control unit 540 is provided outside the substrate processing apparatus 500, the control unit 540 can control the substrate processing apparatus 500 via communication means such as wired or wireless.

[0089] In the substrate processing apparatus 500 , a substrate W (see FIG. 2B ) that has been subjected to the processes up to step S104 is prepared and placed on a table 511 in a first chamber 510 .

[0090] The process of forming the second silicon compound film 240 shown in step S105 and the process of forming the aluminum oxide film 250 shown in step S106 are performed in the first chamber 510, for example.

[0091] Thereafter, the substrate W is transferred from the first chamber 510 to the second chamber 520 and placed on the mounting table 521 in the second chamber 520 .

[0092] The process of etching the first silicon compound film 220 by chemical vapor etching without using plasma shown in step S107 is performed in the second chamber 520.

[0093] Thereafter, the substrate W is transferred from the second chamber 520 to the first chamber 510 and placed on the mounting table 511 in the first chamber 510 .

[0094] The process of plasma etching the aluminum oxide film 250 and the aluminum compound film 251 shown in step S108 is performed in the first chamber 510.

[0095] Also, O shown in step S110 ２ The process of generating plasma and forming a pattern of openings 215 in the base film 210 (carbon film) is performed in the first chamber 510 .

[0096] Furthermore, the processes shown in steps S111 and S112 may be performed in either the first chamber 510 or the second chamber 520 as appropriate.

[0097] 5, the substrate processing apparatus 500 is described as having two chambers 510 and 520, but the configuration of the substrate processing apparatus is not limited to this. One or more of all or part of the processes from step S105 to step S112 may be performed in the same chamber (processing vessel). Alternatively, all processes may be performed in separate chambers.

[0098] The substrate processing method and substrate processing apparatus have 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 described in the claims.

[0099] This application claims priority based on Japanese Patent Application No. 2024-135087, filed on August 13, 2024, the entire contents of which are incorporated herein by reference.

[0100] 200 Base material 210 Undercoat film 220 First silicon compound film 230 Photoresist film 240 Second silicon compound film 250 Aluminum oxide film 251 Aluminum compound 215, 225, 235 Opening 300 Light 500 Substrate processing apparatus 510, 520 Chamber (processing vessel) 511, 521 Mounting table 512, 522 Gas supply unit 513, 523 Gas supply source 514, 524 Exhaust unit 515, 516 High frequency power source (plasma generation unit) 530 Transfer path 540 Control unit W Substrate

Claims

1. A substrate processing method comprising the steps of: preparing a substrate having an underlayer film, a first silicon compound film formed on the underlayer film, and a photoresist film formed on the first silicon compound film and having an opening pattern; forming an aluminum oxide film covering the bottoms of the openings in the photoresist film and the photoresist film; supplying a fluorine-containing gas or a fluorine-containing mixed gas to the substrate and forming an opening pattern in the first silicon compound film by chemical vapor etching using the aluminum oxide film formed on the bottoms of the openings in the photoresist film as a catalyst for aluminum compounds; and removing the aluminum oxide film covering the photoresist film and the aluminum compounds in the openings in the first silicon compound film.

2. The substrate processing method according to claim 1, wherein the first silicon compound film is a film made of any one of silicon oxide, silicon nitride, and silicon oxynitride.

3. The substrate processing method according to claim 1, wherein the step of forming the aluminum oxide film comprises the steps of: supplying a source gas containing aluminum to the substrate; and supplying a reactive gas containing oxygen to the substrate.

4. The substrate processing method according to claim 3, wherein the step of forming the aluminum oxide film comprises a cycle of supplying a source gas containing aluminum to the substrate and a reaction gas containing oxygen to the substrate, and the cycle is repeated 1 to 10 times.

5. The substrate processing method according to claim 1, wherein the aluminum oxide film formed in the step of forming the aluminum oxide film has a thickness in the range of 0.1 nm to 1.5 nm.

6. The substrate processing method according to claim 5, wherein the aluminum oxide film formed in the step of forming the aluminum oxide film has a thickness in the range of 0.15 nm to 1.3 nm.

7. In the step of forming an opening pattern in the first silicon compound film, the fluorine-containing gas is HF, and the fluorine-containing mixed gas is a mixture of HF and H ２ The substrate processing method according to claim 1 , wherein the gas mixture is a mixture of O and HCl.

8. The substrate processing method according to claim 1, wherein the step of forming an opening pattern in the first silicon compound film is anisotropic etching in which the etching rate in the vertical direction is greater than the etching rate in the horizontal direction.

9. The step of removing the aluminum oxide film and the aluminum compound comprises: ４ and H ２ The method of claim 1 , further comprising generating a plasma of a process gas comprising:

10. The substrate processing method according to claim 1, further comprising the step of forming a second silicon compound film on the substrate after the step of preparing the substrate and before the step of forming the aluminum oxide film.

11. The substrate processing method according to claim 10, wherein the step of forming the aluminum oxide film covers the bottom of the opening in the photoresist film and the photoresist film covered with the second silicon compound film, and the step of forming an opening pattern in the first silicon compound film also removes the second silicon compound film.

12. The substrate processing method according to claim 10, wherein the step of forming the second silicon compound film comprises the steps of: supplying a source gas containing silicon to the substrate; and supplying a reactive gas containing oxygen or nitrogen to the substrate.

13. The substrate processing method according to claim 12, wherein the step of supplying the reactive gas to the substrate generates plasma of the reactive gas.

14. The substrate processing method according to claim 1, wherein the undercoat film is a carbon film.

15. The substrate processing method according to claim 14, further comprising the step of forming an opening pattern in the base film after the step of removing the aluminum oxide film and the aluminum compound.

16. A substrate processing apparatus comprising: a processing vessel; a mounting table disposed within the processing vessel and on which a substrate is placed; a gas supply unit that supplies gas into the processing vessel; a plasma generation unit that generates plasma of the gas; and a control unit, wherein the control unit is configured to perform the following steps for a substrate having an underlayer, a first silicon compound film formed on the underlayer, and a photoresist film formed on the first silicon compound film and having an opening pattern: controlling the gas supply unit to form an aluminum oxide film that covers bottoms of the openings in the photoresist film and the photoresist film; controlling the gas supply unit to supply a fluorine-containing gas or a fluorine-containing mixed gas to the substrate, and forming an opening pattern in the first silicon compound film by chemical vapor etching using the aluminum oxide film formed on the bottoms of the openings in the photoresist film as a catalyst for aluminum compounds; and controlling the gas supply unit and the plasma generation unit to remove the aluminum oxide film that covers the photoresist film and the aluminum compounds in the openings of the first silicon compound film.

17. The substrate processing apparatus according to claim 16, wherein the control unit is configured to be able to control the gas supply unit to execute a step of forming a second silicon compound film on the substrate before the step of forming the aluminum oxide film.

18. The substrate processing apparatus according to claim 16, wherein the control unit is configured to be able to execute a step of controlling the gas supply unit to form an opening pattern in the base film after the step of removing the aluminum oxide film and the aluminum compound.

19. The substrate processing apparatus according to claim 16, wherein all or part of one or more of the steps of forming the aluminum oxide film, forming an opening pattern in the first silicon compound film, and removing the aluminum oxide film and the aluminum compound are performed in the same processing vessel.

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