Thin film deposition method, thin film deposition apparatus, and thin film deposition system

Abstract

This invention provides a technology that can reduce the deformation of a metal-containing resist film when forming a carbon film on top of a metal-containing resist film using plasma. [Solution] A film formation method according to one aspect of the present disclosure comprises: preparing a substrate having a silicon-containing film and a metal-containing resist film formed on the silicon-containing film and having an upper surface and side surfaces; supplying a first processing gas containing a silicon-containing gas to the substrate to form a silicon adsorption protective layer on the upper surface and side surfaces of the metal-containing resist film; and generating plasma from a second processing gas containing a carbon-containing gas, and forming a carbon-containing film on the upper surface of the metal-containing resist film with the generated plasma.

Description

Technical Field

[0001] The present disclosure relates to a film forming method, a film forming apparatus, and a film forming system.

Background Art

[0002] Patent Document 1 discloses selectively forming a passivation layer containing a carbon-containing material on the upper surface of a patterned photoresist layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of reducing deformation of a metal-containing resist film when forming a carbon film using plasma on the metal-containing resist film.

Means for Solving the Problems

[0005] A film forming method according to an aspect of the present disclosure includes preparing a substrate having a silicon-containing film and a metal-containing resist film formed on the silicon-containing film and having an upper surface and side surfaces, forming a silicon adsorption protection layer on the upper surface and the side surfaces of the metal-containing resist film by supplying a first processing gas containing a silicon-containing gas to the substrate, and generating plasma from a second processing gas containing a carbon-containing gas and forming a carbon-containing film on the upper surface of the metal-containing resist film by the generated plasma.

Effects of the Invention

[0006] According to the present disclosure, deformation of a metal-containing resist film when forming a carbon film using plasma on the metal-containing resist film can be reduced. [Brief explanation of the drawing]

[0007] [Figure 1] This is a flowchart showing the film deposition method according to the embodiment. [Figure 2] This is a cross-sectional view (1) showing the film deposition method according to the embodiment. [Figure 3] This is a cross-sectional view (2) showing the film deposition method according to the embodiment. [Figure 4] This is a cross-sectional view (3) showing the film deposition method according to the embodiment. [Figure 5] This figure shows an example of the gas supply timing in step S2. [Figure 6] This figure shows another example of the gas supply timing in step S2. [Figure 7] This is a schematic cross-sectional view showing a film deposition apparatus according to an embodiment. [Figure 8] This figure shows the results of observing the surface of each sample. [Figure 9] This figure shows the results of observing the cross-section of each sample. [Modes for carrying out the invention]

[0008] Hereinafter, exemplary embodiments of the present disclosure, not limited to those described herein, will be described with reference to the attached drawings. In all attached drawings, identical or corresponding members or components are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted.

[0009] [Film formation method] The film deposition method according to the embodiment will be described with reference to Figures 1 to 6. Figure 1 is a flowchart of the film deposition method according to the embodiment. Figures 2 to 4 are cross-sectional views showing the film deposition method according to the embodiment. The film deposition method according to the embodiment has steps S1 to S3 shown in Figure 1.

[0010] In step S1, the substrate 100 is prepared as shown in Figure 2. The substrate 100 has a silicon substrate 101, a silicon oxide film (e.g., a coated silicon oxide film (Spin On Glass: SOG)) 102, and a metal oxide resist (MOR) film 103. The SOG film 102 is provided on the silicon substrate 101. The MOR film 103 is provided on the SOG film 102. The MOR film 103 is patterned. The MOR film 103 has a top surface 103a and a side surface 103b. The MOR film 103 has through holes 103h. The side surface 103b forms the inner surface of the through holes 103h. The SOG film 102 has an exposed surface 102a. The exposed surface 102a is exposed from the MOR film 103 through the through holes 103h. The MOR film 103 contains, for example, tin (Sn) as a metal. The SOG film 102 is an example of a silicon-containing film. The MOR film 103 is an example of a metal-containing resist film.

[0011] In step S2, as shown in Figure 3, a silicon adsorption protective layer 104 is formed on the upper surface 103a and side surface 103b of the MOR film 103 and on the exposed surface 102a of the SOG film 102. The silicon adsorption protective layer 104 covers the upper surface 103a and side surface 103b of the MOR film 103 and the exposed surface 102a of the SOG film 102. The silicon adsorption protective layer 104 is formed conformally, for example, along the upper surface 103a and side surface 103b of the MOR film 103 and the exposed surface 102a of the SOG film 102. The surface of the silicon adsorption protective layer 104 may be hydrophobic. In this case, in step S3, which will be described later, it is easier to form a thicker amorphous carbon film 105 on the upper surface 103a than on the side surface 103b of the MOR film 103. The silicon adsorption protective layer 104 can be formed by placing the substrate 100 in a processing container and supplying a first processing gas containing dichlorosilane (DCS) gas and argon (Ar) gas to the substrate 100 within the processing container without using plasma. The temperature of the substrate 100 when forming the silicon adsorption protective layer 104 is a temperature at which aggregation of the MOR film 103 does not occur, for example, 360°C or lower. The temperature of the substrate 100 when forming the silicon adsorption protective layer 104 may be lower than the temperature of the substrate 100 when forming the amorphous carbon film 105, which will be described later. DCS gas is an example of a silicon-containing gas. Argon gas is an example of an inert gas.

[0012] Figure 5 shows an example of the gas supply timing in step S2. As shown in Figure 5, in step S2, DCS gas is supplied intermittently. In this case, it is easy to form the silicon adsorption protective layer 104 conformally to the shape of the through-hole 103h. In particular, the conformability of the silicon adsorption protective layer 104 to the through-hole 103h is improved when the through-hole 103h has a high aspect ratio. When DCS gas is supplied intermittently, DCS gas may be stored in a storage tank during periods when DCS gas is not being supplied. In this case, a large flow rate of DCS gas can be supplied in a short time when DCS gas is supplied. The supply time T1 when DCS gas is supplied intermittently may be shorter than the stop time T2. For example, the supply time T1 is 2 seconds and the stop time T2 is 6 seconds. In step S2, when DCS gas is supplied intermittently, argon gas may be supplied continuously. In this case, the pressure inside the processing container is less likely to fluctuate when DCS gas is supplied. In step S2, DCS gas may be continuously supplied to the substrate 100.

[0013] Figure 6 shows another example of the gas supply timing in step S2. As shown in Figure 6, in step S2, when DCS gas is supplied intermittently, hydrogen (H2) gas may be supplied, and RF power may be supplied during periods when DCS gas is not supplied to generate plasma from the hydrogen gas. When DCS gas is used in step S2, chlorine (Cl) derived from the DCS gas may remain inside or on the surface of the silicon adsorption protective layer 104. When plasma is generated from hydrogen gas, the hydrogen radicals in the plasma can remove the chlorine remaining inside or on the surface of the silicon adsorption protective layer 104. Therefore, in a subsequent process, when etching the SOG film 102 using the MOR film 103 and the amorphous carbon film 105 (described later) as etching masks, the contribution of chlorine to etching can be reduced. In step S2, the supply of hydrogen gas may be started before the time when RF power is supplied. In this case, since no pressure fluctuation occurs inside the processing vessel when RF power is supplied, the stability of plasma ignition is improved. For example, in step S2, hydrogen gas may be supplied continuously.

[0014] In step S3, as shown in FIG. 4, an amorphous carbon film 105 is formed on the upper surface 103a of the MOR film 103. In step S3, for example, the amorphous carbon film 105 is formed thicker on the upper surface 103a than on the side surface 103b of the MOR film 103. When the silicon adsorption protection layer 104 is formed using the first processing gas containing DCS gas, the amorphous carbon film 105 can be formed thicker on the upper surface 103a than on the side surface 103b of the MOR film 103. An amorphous carbon film 105 thinner than the upper surface 103a may be formed on the side surface 103b of the MOR film 103. The amorphous carbon film 105 can be formed by accommodating the substrate 100 in a processing vessel, generating plasma from a second processing gas containing acetylene (C2H2) gas, argon gas, and hydrogen gas in the processing vessel, and supplying the generated plasma to the substrate 100. The amorphous carbon film 105 is an example of a carbon-containing film. Acetylene gas is an example of a carbon-containing gas.

[0015] As described above, the amorphous carbon film 105 can be selectively formed on the upper surface 103a of the MOR film 103.

[0016] According to the film formation method according to the embodiment, first, the silicon adsorption protection layer 104 is formed on the upper surface 103a and the side surface 103b of the MOR film 103 by supplying the first processing gas containing DCS gas to the substrate 100. Next, plasma is generated from the second processing gas containing acetylene gas, and the generated plasma forms the amorphous carbon film 105 on the upper surface 103a of the MOR film 103. Thus, before forming the amorphous carbon film 105 on the upper surface 103a of the MOR film 103 using plasma, the silicon adsorption protection layer 104 is formed on the upper surface 103a and the side surface 103b of the MOR film 103 without using plasma. In this case, when forming the amorphous carbon film 105, since the MOR film 103 is covered with the silicon adsorption protection layer 104, the MOR film 103 is not exposed to the plasma. Therefore, deformation of the MOR film 103 when forming the amorphous carbon film 105 on the MOR film 103 using plasma can be reduced.

[0017] 〔Film Forming Apparatus〕 Referring to FIG. 7, a film forming apparatus 1 capable of executing steps S2 and S3 of the film forming method according to the embodiment will be described. FIG. 7 is a schematic cross-sectional view showing the film forming apparatus 1 according to the embodiment.

[0018] The film forming apparatus 1 includes a substantially cylindrical airtight processing vessel 2. An exhaust chamber 21 is provided at the central portion of the bottom wall of the processing vessel 2.

[0019] The exhaust chamber 21 has a shape, for example, substantially cylindrical, protruding downward. An exhaust flow path 22 is connected to the exhaust chamber 21, for example, on the side surface of the exhaust chamber 21.

[0020] An exhaust portion 24 is connected to the exhaust flow path 22 via a pressure adjustment portion 23. The pressure adjustment portion 23 includes a pressure adjustment valve such as a butterfly valve. The exhaust portion 24 includes, for example, a vacuum pump. The exhaust flow path 22 is configured to be able to decompress the inside of the processing vessel 2 by the exhaust portion 24. A transfer port 25 is provided on the side surface of the processing vessel 2. The transfer port 25 is configured to be openable and closable by a gate valve 26. The loading and unloading of the substrate W between the inside of the processing vessel 2 and a transfer chamber (not shown) are performed via the transfer port 25.

[0021] Inside the processing vessel 2, a mounting table 3 for holding the substrate W substantially horizontally is provided. The mounting table 3 is formed in a substantially circular shape in plan view. The mounting table 3 is supported by a support member 31. On the upper surface 3a of the mounting table 3, a substantially circular recess 32 for mounting a substrate W having a diameter of, for example, 300 mm is formed. 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, for example. The mounting table 3 is formed of a ceramic material such as aluminum nitride (AlN), for example. The mounting table 3 may be formed of a metal material such as nickel (Ni). Instead of the recess 32, a guide ring for guiding the substrate W may be provided at the peripheral portion of the upper surface 3a of the mounting table 3.

[0022] A lower electrode 33, for example, is embedded in the mounting base 3. A temperature control mechanism 34 is embedded below the lower electrode 33. The temperature control mechanism 34 adjusts the mounting base 3 or the mounted substrate W to a set temperature based on a control signal from the control unit 9. If the entire mounting base 3 is made of metal, the entire mounting base 3 functions as the lower electrode, so the lower electrode 33 does not need to be embedded in the mounting base 3. The mounting base 3 is provided with a plurality (for example, three) of lifting pins 41 for holding and raising and lowering the substrate W placed on the mounting base 3. The material of the lifting pins 41 may be, for example, ceramics such as alumina (Al2O3) or quartz. The lower ends of the lifting pins 41 are attached to a support plate 42. The support plate 42 is connected to a lifting mechanism 44 provided outside the processing container 2 via a lifting shaft 43.

[0023] The lifting mechanism 44 is installed, for example, at the bottom of the exhaust chamber 21. The bellows 45 is provided between the opening 21a for the lifting shaft 43 formed on the lower surface of the exhaust chamber 21 and the lifting mechanism 44. The shape of the support plate 42 may be such that it can move up and down without interfering with the support member 31 of the mounting base 3. The lifting pin 41 is configured to move up and down freely between the upper side of the upper surface 3a of the mounting base 3 and the lower side of the upper surface 3a of the mounting base 3 by the lifting mechanism 44. In other words, the lifting pin 41 is configured to protrude from the upper surface 3a of the mounting base 3.

[0024] A gas supply unit 5 is provided on the top wall 27 of the processing container 2 via an insulating member 28. The gas supply unit 5 forms the upper electrode and faces the lower electrode 33. An RF power supply 51 is connected to the gas supply unit 5 via a matching unit 52. The frequency band of the RF power supply 51 is, for example, 450 kHz to 2.45 GHz. By supplying RF power from the RF power supply 51 to the gas supply unit 5, an RF electric field is generated between the gas supply unit 5 and the lower electrode 33. The gas supply unit 5 includes a hollow gas diffusion chamber 53. On the lower surface of the gas diffusion chamber 53, numerous holes 54 are evenly arranged, for example, for distributing and supplying processing gas into the processing container 2. A heating mechanism 55 is embedded above the gas diffusion chamber 53 in the gas supply unit 5. The heating mechanism 55 is heated to a set temperature by being powered from a power supply unit (not shown) based on a control signal from the control unit 9.

[0025] A gas supply passage 6 is provided in the gas diffusion chamber 53. The gas supply passage 6 is in communication with the gas diffusion chamber 53. A gas source 61 is connected to the upstream side of the gas supply passage 6 via a gas line 62. The gas source 61 includes, for example, a supply source for various processing gases, a mass flow controller, and valves (none of which are shown). The processing gas includes the gas used in the film deposition method according to the embodiment described above. The processing gas is introduced from the gas source 61 to the gas diffusion chamber 53 via the gas line 62.

[0026] The film deposition 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), auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or auxiliary storage device and controls the operation of the film deposition apparatus 1. The control unit 9 may be located inside or outside the film deposition apparatus 1. If the control unit 9 is located outside the film deposition apparatus 1, the control unit 9 can control the film deposition apparatus 1 by communication means such as wired or wireless.

[0027] Although the film deposition apparatus 1 was described using a device that generates capacitively coupled plasma (CCP) as an example, it is not limited to this. It may also be a device that generates remote plasma using high frequency (RF, VHF) or microwave (MW). The device that generates remote plasma may be a device that generates remote plasma in a processing container containing the substrate W, or a device that supplies the generated remote plasma into the processing container containing the substrate W.

[0028] [Operation of the film deposition apparatus] The operation of the film deposition apparatus 1 when performing steps S2 and S3 of the film deposition method according to the embodiment will be described.

[0029] First, the control unit 9 opens the gate valve 26 and uses a transport mechanism (not shown) to transport the substrate W into the processing container 2 and place it on the mounting table 3. The substrate W may be the substrate 100 prepared in step S1 described above. After the control unit 9 retracts the transport mechanism from the processing container 2, it closes the gate valve 26.

[0030] Next, the control unit 9 controls each part of the film deposition apparatus 1 to perform the aforementioned steps S2 and S3 on the substrate W placed on the mounting table 3 inside the processing container 2.

[0031] Next, the control unit 9 removes the substrate W from the processing container 2 in the reverse order of loading the substrate W into the processing container 2. Thus, steps S2 and S3 are performed for one substrate W.

[0032] [Experimental results] In the experiment, samples A1-A3, B1-B3, C1-C3, and D1-D3 were prepared, and the surface and cross-section of each sample A1-A3, B1-B3, C1-C3, and D1-D3 were observed.

[0033] (Sample A1) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0034] Next, a silicon adsorption protective layer 104 was formed on the prepared substrate 100 by performing step S2 of the film formation method according to the embodiment using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 are as follows.

[0035] <Conditions for forming the silicon adsorption protective layer 104> ·Substrate temperature: 100℃ • First treatment gas: DCS gas and argon gas • DCS gas supply method: Intermittent supply (8 cycles) • Argon gas supply method: Continuous supply • Plasma presence: None

[0036] (Sample A2) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0037] Next, on the prepared substrate 100, the silicon adsorption protective layer 104 and the amorphous carbon film 105 were formed by performing steps S2 and S3 of the film formation method according to the embodiment in this order using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 were the same as for sample A1. The conditions for forming the amorphous carbon film 105 were as follows.

[0038] <Conditions for forming amorphous carbon film 105> ·Substrate temperature: 250℃ • Second processing gas: A mixture of acetylene gas, argon gas, and hydrogen gas. • Plasma presence: Yes

[0039] (Sample A3) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0040] Next, on the prepared substrate 100, the silicon adsorption protective layer 104 and the amorphous carbon film 105 were formed by performing steps S2 and S3 of the film formation method according to the embodiment in this order using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 were the same as for sample A1. The conditions for forming the amorphous carbon film 105 were as follows.

[0041] <Conditions for forming amorphous carbon film 105> ·Substrate temperature: 300℃ • Second processing gas: A mixture of acetylene gas, argon gas, and hydrogen gas. • Plasma presence: Yes

[0042] (Sample B1) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0043] Next, a silicon adsorption protective layer 104 was formed on the prepared substrate 100 by performing step S2 of the film formation method according to the embodiment using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 are as follows.

[0044] <Conditions for forming the silicon adsorption protective layer 104> ·Substrate temperature: 100℃ • First processing gas: Trisilylamine (TSA) gas and argon gas • TSA gas supply method: Intermittent supply (8 cycles) • Argon gas supply method: Continuous supply • Plasma presence: None

[0045] (Sample B2) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0046] Next, on the prepared substrate 100, the silicon adsorption protective layer 104 and the amorphous carbon film 105 were formed by performing steps S2 and S3 of the film formation method according to the embodiment in that order using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 were the same as for sample B1. The conditions for forming the amorphous carbon film 105 were the same as for sample A2.

[0047] (Sample B3) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0048] Next, on the prepared substrate 100, the silicon adsorption protective layer 104 and the amorphous carbon film 105 were formed by performing steps S2 and S3 of the film formation method according to the embodiment in that order using the aforementioned film formation apparatus 1. The conditions for forming the silicon adsorption protective layer 104 were the same as those for sample B1. The conditions for forming the amorphous carbon film 105 were the same as those for sample A3.

[0049] (Sample C1) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0050] Next, a silicon oxide film was formed on the prepared substrate 100 as a protective layer using the aforementioned film deposition apparatus 1, instead of step S2 of the film deposition method according to the embodiment. The silicon oxide film was formed by atomic layer deposition (ALD) by alternately supplying diisopropylaminosilane (DIPAS) gas and oxygen plasma. The conditions for forming the silicon oxide film are as follows.

[0051] <Conditions for forming a silicon oxide film> ·Substrate temperature: 100℃ • Number of ALD recurrences: 8

[0052] (Sample C2) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0053] Next, a silicon oxide film was formed on the prepared substrate 100 as a protective layer using the aforementioned film deposition apparatus 1, instead of step S2 of the film deposition method according to the embodiment. The silicon oxide film was formed by ALD, which involves alternately supplying DIPAS gas and oxygen plasma. Subsequently, an amorphous carbon film 105 was formed by performing step S3 of the film deposition method according to the embodiment. The conditions for forming the silicon oxide film were the same as for sample C1. The conditions for forming the amorphous carbon film 105 were the same as for sample A2.

[0054] (Sample C3) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0055] Next, a silicon oxide film was formed on the prepared substrate 100 as a protective layer using the aforementioned film deposition apparatus 1, instead of step S2 of the film deposition method according to the embodiment. The silicon oxide film was formed by ALD, which involves alternately supplying DIPAS gas and oxygen plasma. Subsequently, an amorphous carbon film 105 was formed by performing step S3 of the film deposition method according to the embodiment. The conditions for forming the silicon oxide film were the same as for sample C1. The conditions for forming the amorphous carbon film 105 were the same as for sample A3.

[0056] (Sample D1) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102. In sample D1, step S2 of the film formation method according to the embodiment was not performed.

[0057] (Sample D2) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0058] Next, without performing step S2 of the film deposition method according to the embodiment on the prepared substrate 100, an amorphous carbon film 105 was formed by performing step S3 of the film deposition method according to the embodiment using the aforementioned film deposition apparatus 1. The conditions for forming the amorphous carbon film 105 were the same as those for sample A2.

[0059] (Sample D3) First, a substrate 100 was prepared on which an SOG film 102 was formed on a silicon substrate 101, and a MOR film 103 having an upper surface 103a and a side surface 103b was formed on the SOG film 102.

[0060] Next, without performing step S2 of the film deposition method according to the embodiment on the prepared substrate 100, an amorphous carbon film 105 was formed by performing step S3 of the film deposition method according to the embodiment using the aforementioned film deposition apparatus 1. The conditions for forming the amorphous carbon film 105 were the same as those for sample A3.

[0061] Figure 8 shows the results of observing the surface of each sample. The surface of each sample was observed using a scanning electron microscope (SEM). Figure 8 schematically shows the SEM image of the surface of each sample. In Figure 8, the results of observing each sample with the SEM were judged as "very good" if there were no cracks or aggregation, "good" if there were cracks but no aggregation, and "poor" if there was aggregation.

[0062] As shown in Figure 8, no cracking or aggregation of the MOR film 103 was observed in samples A1 and A2, and although cracking was observed in sample A3, aggregation was not. From these results, it can be said that covering the MOR film 103 with a silicon adsorption protective layer 104 formed using DCS gas can reduce the deformation of the MOR film 103 when forming the amorphous carbon film 105.

[0063] As shown in Figure 8, no cracking or aggregation of the MOR film 103 was observed in sample B1, cracking was observed in sample B2 but no aggregation was observed in sample B2, and aggregation of the MOR film 103 was observed in sample B3. From these results, it can be said that covering the MOR film 103 with a silicon adsorption protective layer 104 formed using TSA gas can reduce the deformation of the MOR film 103 when forming the amorphous carbon film 105. However, it can be said that the silicon adsorption protective layer 104 formed using DCS gas is preferable to the silicon adsorption protective layer 104 formed using TSA gas for protecting the MOR film 103.

[0064] As shown in Figure 8, no cracking or aggregation of the MOR film 103 was observed in samples C1, C2, and C3. From this result, it can be said that covering the MOR film 103 with a silicon oxide film can reduce the deformation of the MOR film 103 when forming the amorphous carbon film 105. However, since the silicon oxide film is thicker than the silicon adsorption protective layer 104, the pore diameter of the through-holes 103h tends to become smaller. For this reason, the silicon adsorption protective layer 104 is preferable to the silicon oxide film from the viewpoint of hardly changing the pore diameter of the through-holes 103h. For example, the thickness of the silicon adsorption protective layer 104 is about 0.2 nm, while the thickness of the silicon oxide film is about 2 nm.

[0065] As shown in Figure 8, no cracking or aggregation of the MOR film 103 was observed in sample D1, while aggregation of the MOR film 103 was observed in samples D2 and D3. From these results, it can be said that deformation of the MOR film 103 occurs when an amorphous carbon film 105 is formed without covering the MOR film 103 with a protective layer.

[0066] Figure 9 shows the results of observing the cross-sections of each sample. The cross-sections of each sample were observed using a transmission electron microscope (TEM). Figure 9 schematically shows the TEM images of the cross-sections of each sample.

[0067] As shown in Figure 9, in samples A2 and A3, the amorphous carbon film 105 was deposited vertically on the upper surface 103a of the MOR film 103. From this result, it can be said that when the amorphous carbon film 105 is formed after covering the MOR film 103 with a silicon adsorption protective layer 104 formed using DCS gas, deformation of the MOR film 103 can be reduced. Furthermore, when the amorphous carbon film 105 is formed after covering the MOR film 103 with a silicon adsorption protective layer 104 formed using DCS gas, the amorphous carbon film 105 is formed thicker on the upper surface 103a than on the side surface 103b of the MOR film 103. Since the surface of the silicon adsorption protective layer 104 formed using DCS gas is hydrophobic, the adsorption reaction of active species generated from the acetylene gas used when forming the amorphous carbon film 105 proceeds more easily. In this case, since it is difficult for active species to reach deep positions in the through-holes 103h, it is thought that the amorphous carbon film 105 is formed thicker on the upper surface 103a than on the side surface 103b of the MOR film 103.

[0068] As shown in Figure 9, sample A3 has less amorphous carbon film 105 deposited on the side surface 103b of the MOR film 103 compared to sample A2. From this result, it can be said that setting the substrate temperature to 300°C when forming the amorphous carbon film 105 results in a thicker amorphous carbon film 105 being formed on the top surface 103a of the MOR film 103 than when the substrate temperature is set to 250°C.

[0069] As shown in Figure 9, in sample B2, amorphous carbon film 105 was deposited on the upper surface 103a and side surface 103b of the MOR film 103. From this result, it can be said that when amorphous carbon film 105 is formed after covering the MOR film 103 with a silicon adsorption protective layer 104 formed using TSA gas, the amorphous carbon film 105 is formed in a way that fills the through-holes 103h. Since the surface of the silicon adsorption protective layer 104 formed using TSA gas is hydrophilic, the adsorption reaction of active species generated from the acetylene gas used when forming the amorphous carbon film 105 is less likely to proceed. In this case, it is thought that the active species can easily reach deeper positions in the through-holes 103h, and therefore the amorphous carbon film 105 is formed in a way that fills the through-holes 103h.

[0070] As shown in Figure 9, in sample C3, the amorphous carbon film 105 was deposited more thickly on the side surface 103b than on the top surface 103a of the MOR film 103. From this result, it can be said that when the amorphous carbon film 105 is formed after covering the MOR film 103 with a silicon oxide film, the amorphous carbon film 105 is formed in a way that fills the through-pores 103h. Since the surface of the silicon oxide film is hydrophilic, the adsorption reaction of active species generated from the acetylene gas used when forming the amorphous carbon film 105 is hindered. In this case, it is thought that the amorphous carbon film 105 is formed in a way that fills the through-pores 103h because the active species can easily reach deeper positions in the through-pores 103h.

[0071] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0072] In the embodiments described above, the case in which the silicon-containing film is an SOG film 102 was explained, but the disclosure is not limited thereto. The silicon-containing film may be a silicon oxide film formed by chemical vapor deposition (CVD) or ALD.

[0073] In the embodiments described above, the case in which the metal-containing resist film is a MOR film 103 was explained, but the disclosure is not limited thereto. The metal-containing resist film is, for example, a negative-type resist film for EUV (Extreme Ultraviolet) irradiation. The metal-containing resist film may also be an oxide resist film containing a metal such as tin (Sn), hafnium (Hf), zirconium (Zr), or zinc (Zn).

[0074] In the embodiments described above, the case in which the carbon-containing film is an amorphous carbon film 105 was explained, but the disclosure is not limited thereto. The carbon-containing film may also be graphene.

[0075] In the embodiments described above, the case where the silicon-containing gas is DCS gas was explained, but the disclosure is not limited thereto. The silicon-containing gas may be TSA gas, HCD gas (Si2Cl6), PCDS gas (Si2HCl5), silane gas (SiH4), disilane gas (Si2H6), or higher-order silane gas (Si3H8, etc.).

[0076] In the embodiments described above, the case where the inert gas is argon gas was explained, but the disclosure is not limited thereto. The inert gas may be nitrogen (N2) gas, helium (He) gas, or xenon (Xe) gas.

[0077] In the embodiments described above, the case where the carbon-containing gas is acetylene gas was explained, but the disclosure is not limited thereto. The carbon-containing gas may also be CxHy gas (where x and y are natural numbers).

[0078] In the above embodiment, a case in which steps S2 and S3 are carried out in the same film deposition apparatus 1 has been described, but the disclosure is not limited thereto. For example, in a film deposition system comprising a first film deposition apparatus and a second film deposition apparatus, step S2 may be carried out in the first film deposition apparatus and step S3 may be carried out in the second film deposition apparatus. [Explanation of Symbols]

[0079] 100 circuit boards 102 SOG membrane 103 MOR membrane 103a Top side 103b Side 104 Silicone Adsorption Protective Layer 105 Amorphous carbon film

Claims

1. A substrate is prepared having a silicon-containing film and a metal-containing resist film formed on the silicon-containing film, having an upper surface and side surfaces. By supplying a first processing gas containing a silicon-containing gas to the substrate, a silicon adsorption protective layer is formed on the upper surface and the side surface of the metal-containing resist film. A plasma is generated from a second processing gas containing a carbon-containing gas, and a carbon-containing film is formed on the upper surface of the metal-containing resist film using the generated plasma. A film formation method having the following characteristics.

2. When forming the silicon adsorption protective layer, the silicon adsorption protective layer is formed conformally. The method for forming a film according to claim 1.

3. When forming the carbon-containing film, the carbon-containing film is formed thicker on the upper surface than on the side surface of the metal-containing resist film. The method for forming a film according to claim 1.

4. When forming the aforementioned silicon adsorption protective layer, plasma is not used. The method for forming a film according to claim 1.

5. When forming the silicon adsorption protective layer, the silicon-containing gas is intermittently supplied to the substrate. The method for forming a film according to claim 1.

6. The first processing gas further contains an inert gas, When forming the silicon adsorption protective layer, the inert gas is continuously supplied to the substrate. The method for forming a film according to claim 5.

7. When forming the silicon adsorption protective layer, hydrogen radicals are supplied to the substrate during periods when the silicon-containing gas is not being supplied. The method for forming a film according to claim 5.

8. When forming the silicon adsorption protective layer, hydrogen gas is continuously supplied to the substrate. The method for forming a film according to claim 7.

9. The surface of the aforementioned silicon adsorption protective layer is hydrophobic. The method for forming a film according to any one of claims 1 to 8.

10. The temperature at which the silicon adsorption protective layer is formed is lower than the temperature at which the carbon-containing film is formed. The method for forming a film according to any one of claims 1 to 8.

11. The silicon-containing gas is dichlorosilane gas. The carbon-containing gas is acetylene gas. The method for forming a film according to any one of claims 1 to 8.

12. The metal-containing resist film is a metal oxide resist film. The method for forming a film according to any one of claims 1 to 8.

13. The carbon-containing film is an amorphous carbon film. The method for forming a film according to any one of claims 1 to 8.

14. A film deposition apparatus for forming a carbon-containing film on a substrate, The substrate has a silicon-containing film and a metal-containing resist film formed on the silicon-containing film, having an upper surface and side surfaces. The film deposition apparatus is A control is performed to form a silicon adsorption protective layer on the upper surface and the side surface of the metal-containing resist film by supplying a first processing gas containing a silicon-containing gas to the substrate, Control to generate a plasma from a second processing gas containing a carbon-containing gas, and to form a carbon-containing film on the upper surface of the metal-containing resist film using the generated plasma, A control unit configured to perform the following actions: Film deposition equipment.

15. A film deposition system for forming a carbon-containing film on a substrate, The substrate has a silicon-containing film and a metal-containing resist film formed on the silicon-containing film, having an upper surface and side surfaces. The film deposition system is A first film deposition apparatus that forms a silicon adsorption protective layer on the upper surface and side surface of the metal-containing resist film by supplying a first processing gas containing a silicon-containing gas to the substrate, A second film deposition apparatus that generates plasma from a second processing gas containing a carbon-containing gas, and forms a carbon-containing film on the upper surface of the metal-containing resist film using the generated plasma, Equipped with, Thin film deposition system.

Images