METHOD FOR FORMING CARBON-CONTAINING FILM, AND METHOD FOR FORMING HARD MASK USING THE CARBON-CONTAINING FILM

A method for forming a carbon-containing film includes: preparing a substrate on which a metal-containing film is formed; performing a modification process of modifying a surface of the metal-containing film by supplying a silicon-containing gas to the substrate and by exposing the substrate to the silicon-containing gas during a first period of time; and forming the carbon-containing film having a film stress of 1 GPa or more on the modified surface of the substrate by exposing the substrate subjected to the modification process to plasma of a processing gas including a carbon-containing gas.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-085600, filed on May 24, 2023, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a method for forming a carbon-containing film, and a method for forming a hard mask using the carbon-containing film.

BACKGROUND

Patent Document 1 discloses that an a-CF film has very poor adhesion with an insulating film or a metal film, and therefore, an adhesion layer needs to be indispensably formed between the a-CF film and the insulating layer or the metal layer. As the adhesion layer, a stacked structure of a silicon-rich oxide film and a diamond-like carbon (DLC) film has been proposed. The silicon-rich oxide film has adhesion with an underlying oxide film and the metal film and also has adhesion with the DLC film. The DLC film has adhesion with the a-CF film.

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY

According to an embodiment of the present disclosure, a method for forming a carbon-containing film includes: preparing a substrate on which a metal-containing film is formed; performing a modification process of modifying a surface of the metal-containing film by supplying a silicon-containing gas to the substrate and by exposing the substrate to the silicon-containing gas during a first period of time; and forming the carbon-containing film having a film stress of 1 GPa or more on the modified surface of the substrate by exposing the substrate subjected to the modification process to plasma of a processing gas including a carbon-containing gas.

DETAILED DESCRIPTION

Aspects for carrying out the present disclosure will now be described with reference to the accompanying drawings. In each of the drawings, the same components will be denoted by the same reference symbols, and redundant descriptions thereof may be omitted. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.

A processing system100used for a substrate processing method according to an embodiment will be described with reference toFIG.1.FIG.1is a diagram showing an example of the processing system100according to the embodiment.

The processing system100includes processing devices101to104, a vacuum transfer chamber105, load lock chambers301to303, an atmospheric-side transfer chamber400, load ports501to504, and a control device600.

The processing devices101to104are connected to the vacuum transfer chamber105via gate valves G11to G14, respectively. Interiors of the processing devices101to104are depressurized to a predetermined vacuum atmosphere. A substrate W is subjected to a desired processing in the interior of each of the processing devices101to104.

The processing device101is a processing device (film forming device) that forms a metal-containing film22(seeFIG.3which will be described later) on a base21of the substrate W (seeFIG.3which will be described later) by executing step S12inFIG.2described later. The metal-containing film22is, for example, a TiN film.

Specifically, the processing device101alternately supplies a Ti-containing gas (for example, a TiCl4 gas) and a reaction gas (a nitriding gas, for example, an ammonia gas or a N2 gas) into a processing container of the processing device101to form the TiN film (the metal-containing film22) on the substrate W by an atomic layer deposition (ALD) method. While the processing device101has been described as the film forming device that forms the metal-containing film22on the substrate W by the ALD method, the present disclosure is not limited thereto. For example, the processing device101may be a film forming device that forms the metal-containing film22on the substrate W by a chemical vapor deposition (CVD) method or may be a film forming device that forms the metal-containing film22on the substrate W by a physical vapor deposition (PVD) method.

The processing device102is a processing device that modifies a surface of the metal-containing film22formed on the substrate W using a Si-containing gas to adsorb at least one of Si or SiHx, which corresponds to a monolayer, onto the surface of the substrate W by executing step S13inFIG.2described later. An example of the processing device102will be described later with reference toFIG.4.

The processing device103is a processing device (film forming device) that forms a carbon-containing film24(seeFIG.3which will be described later) on the metal-containing film22of the substrate W by executing step S14inFIG.2described later. The carbon-containing film24is, for example, a diamond-like carbon (DLC) film. An example of the processing device103will be described later with reference toFIG.4.

The processing device104may be a processing device that executes the same process as that executed by any one of the processing devices101to103or a processing device (for example, an annealing device or an etching device) that executes a process different from that executed by any one of the processing devices101to103. A process of forming the metal-containing film22on the substrate W and a process of modifying the surface of the metal-containing film22formed on the substrate W using the Si-containing gas may be performed by the same processing device.

An interior of the vacuum transfer chamber105is depressurized to a predetermined vacuum atmosphere. The vacuum transfer chamber105is an example of a transfer device that transfers the substrate W. The vacuum transfer chamber105is provided with a transfer mechanism106capable of transferring the substrate W in a depressurized state. The transfer mechanism106transfers the substrate W among the processing devices101to104and the load lock chambers301to303.

The load lock chambers301to303are connected to the vacuum transfer chamber105via gate valves G21to G23, respectively, and to the atmospheric-side transfer chamber400via gate valves G31to G33, respectively. Interiors of the load lock chambers301to303are configured to be switched between an atmospheric environment and a vacuum atmosphere.

An interior of the atmospheric-side transfer chamber400is kept in an atmospheric environment. For example, a down-flow of clean air is formed in the interior of the atmospheric-side transfer chamber400. An aligner (not shown) that aligns the substrate W is provided in the interior of the atmospheric-side transfer chamber400. The atmospheric-side transfer chamber400is provided with a transfer mechanism402. The transfer mechanism402transfers the substrate W among the load lock chambers301to303, carriers C of the load ports501to504(to be described later), and the aligner.

The load ports501to504are provided in a wall surface of the atmospheric-side transfer chamber400. The carrier C in which the substrates W are accommodated or an empty carrier C is attached to the load ports501to504via respective gate valves G41to G44. As the carrier C, for example, a front opening unified pod (FOUP) may be used.

The control device600controls each part of the processing system100. For example, the control device600executes operations of the processing devices101to104, operations of the transfer mechanisms106and402, opening and closing of the gate valves G11to G14, G21to G23, G31to G33, and G41to G44, and switching of internal atmospheres of the load lock chambers301to303.

Next, an example of a substrate processing method using the processing system100shown inFIG.1will be described with reference toFIGS.2and3.FIG.2is a flowchart showing an example of the substrate processing method according to an embodiment.FIG.3is an example of a schematic cross-sectional view of the substrate W processed by the substrate processing method according to the embodiment.

As shown inFIG.3, the metal-containing film22and the carbon-containing film24are formed on the substrate W including the base21. The base21may be formed of, for example, a silicon substrate, or may be formed by, for example, a silicon oxide film or a silicon nitride film. Further, the base21may be formed to have a structure of a semiconductor device such as a magnetic tunnel junction (MTJ) element or a magneto-resistive random access memory (MRAM).

The metal-containing film22is, for example, a TiN film. The carbon-containing film24is, for example, a DLC film. The metal-containing film22and the carbon-containing film24may be used as a hard mask for the base21(for example, an MTJ element). In this case, a thickness of the TiN film (metal-containing film22) may be 20 nm to 100 nm. Further, a thickness of the DLC film (carbon-containing film24) may be 20 nm to 100 nm. The metal-containing film22may be other metal-containing films. For example, the metal-containing film may be a film containing tungsten (W), cobalt (Co), copper (Cu), ruthenium (Ru), magnesium (Mg), iron (Fe), or titanium (Ti), an oxide thereof, a nitride thereof, or an oxynitride thereof.

Here, the DLC film (the carbon-containing film24) has high compressive stress. Therefore, when the DLC film (the carbon-containing film24) is formed on the TiN film (the metal-containing film22), the DLC film (the carbon-containing film24) may peel off from the TiN film (the metal-containing film22) due to the high compressive stress. In this regard, in the substrate processing method according to the embodiment shown inFIG.2, a stacked film of the TiN film (metal-containing film22) and the DLC film (carbon-containing film24) may be formed by suppressing the peeling of the DLC film (the carbon-containing film24).

In step S11, the substrate W is prepared. Here, the substrate W to be prepared has the base21(seeFIG.3). In this case, the carrier C in which the substrate W including the base21is accommodated is attached to any one of the load ports501to504. Then, the control device600controls the transfer mechanism402to transfer the substrate W from the carrier C to any one of the load lock chambers301to303. Further, the control device600controls the transfer mechanism106to transfer the substrate W from any one of the load lock chambers301to303to the processing device101.

In step S12, a metal-containing film forming process of forming the metal-containing film22on the substrate W is performed. The control device600controls the processing device101to form the metal-containing film22(the TiN film) on the base21of the substrate W. Specifically, the metal-containing film22is formed on the substrate W by an ALD method. A method of forming the metal-containing film22is not limited to the ALD method as described above. For example, the metal-containing film22may be formed on the substrate W by a CVD method or a PVD method.

In step S13, a modification process of modifying a surface of the substrate W is performed with a Si-containing gas. First, the control device600controls the transfer mechanism106to transfer the substrate W from the processing device101to the processing device102. Then, the control device600controls the processing device102to modify the surface of the substrate W by supplying the Si-containing gas.

Here, an example of the processing device102that modifies the surface of the substrate W will be described with reference toFIG.4.FIG.4is a schematic cross-sectional view showing an example of the processing device102. The processing device102is a device for modifying a surface of the metal-containing film22(the TiN film) formed on the substrate W (a surface bonded to the carbon-containing film24) by supplying the Si-containing gas into a processing container702in a state in which the substrate W in the processing container702kept in a depressurized state is heated to a predetermined temperature (for example, 400 degrees C. or higher).

The processing device102includes a substantially cylindrical airtight processing container702. An exhaust chamber721is provided in a central portion of a bottom wall of the processing container702. The exhaust chamber721has, for example, a substantially cylindrical shape that projects downward. An exhaust flow path722is connected to the exhaust chamber721on, for example, a side surface of the exhaust chamber721. An exhauster724is connected to the exhaust flow path722via a pressure adjuster723. The pressure adjuster723includes, for example, a pressure adjustment valve such as a butterfly valve. The exhaust flow path722is configured to depressurize an interior of the processing container702by the exhauster724. A transfer port725is provided in a side surface of the processing container702. The transfer port725is open and closed by a gate valve726. Loading and unloading of the substrate W between the interior of the processing container702and a transfer chamber (not shown) is performed via the transfer port725.

A stage703configured to hold the substrate W substantially horizontally is provided inside the processing container702. The stage703has a substantially circular shape when viewed in a plan view and is supported by a support member731. A substantially circular concave portion732in which the substrate W having a diameter of 300 mm is placed is formed in a front surface of the stage703. The concave portion732has an inner diameter slightly larger (by, for example, about 1 mm to 4 mm) than that of the substrate W. A depth of the concave portion732may be approximately identical to, for example, a thickness of the substrate W. The stage703is made of a ceramic material such as aluminum nitride (AlN). In addition, the stage703may be formed of a metallic material such as nickel (Ni). Instead of the concave portion732, a guide ring for guiding the substrate W may be provided at a peripheral portion of the front surface of the stage703.

A lower electrode733is embedded in the stage703. A temperature adjustment mechanism734is embedded below the lower electrode733. The temperature adjustment mechanism734adjusts a temperature of the substrate W placed on the stage703to a set temperature based on a control signal from a controller709.

A radio-frequency (RF) power supply735is connected to the lower electrode733via a matcher735a. The RF power supply735applies low-frequency (LF) power having a frequency lower than that of an RF power supply751(to be described later) to the lower electrode733. The LF power generated by the RF power supply735is used as bias LF power for drawing ions into the substrate W. The frequency of the RF power supply735may be in a range of 450 kHz to 27 MHz, for example, 13.56 MHz.

The stage703is provided with a plurality of (for example, three) lifting pins741for holding, and raising and lowering the substrate W placed on the stage703. A material of the lifting pins741may be, for example, ceramics such as alumina (Al2O3), quartz, or the like. A lower end of the lifting pin741is attached to a support plate742. The support plate742is connected to a lifting mechanism744provided outside the processing container702via a lifting shaft743.

The lifting mechanism744is installed, for example, below the exhaust chamber721. A bellows745is provided between an opening721afor the lifting shaft743formed on a lower surface of the exhaust chamber721and the lifting mechanism744. The support plate742may have a shape that is raised and lowered without interfering with the support member731of the stage703. The lifting pins741are configured to be moved upward and downward with respect to the front surface of the stage703by the lifting mechanism744. In other words, the lifting pins741are configured to protrude from the upper surface of the stage703.

Further, a lower end of the support member731passes through an opening721bof the exhaust chamber721and is supported by a lifting mechanism746via a lifting plate747disposed below the processing container702. A bellows748is provided between a bottom of the exhaust chamber721and the lifting plate747. The interior of the processing container702is hermetically sealed even when the elevating plate747moves upward and downward.

The lifting mechanism746may raise and lower the stage703by raising and lowering the lifting plate747. Thus, a gap between the stage703and a lower surface of an upper electrode plate705may be adjusted.

The upper electrode plate705is provided on a ceiling wall727of the processing container702via an insulating member728. The upper electrode plate705constitutes an upper electrode and is disposed in parallel to face the lower electrode733. The RF power supply751is connected to the upper electrode plate705via a matcher751a. The RF power supply751supplies high-frequency (HF) power having a frequency higher than that of the RF power supply735to the upper electrode plate705. The HF power generated by the RF power supply751is used as HF power for plasma generation necessary to form a film on the substrate W. The frequency of the RF power supply751is, for example, 450 kHz to 2.45 GHz. RF power is applied to the upper electrode plate705from the RF power supply751. Thus, an RF electric field is generated between the stage703and the upper electrode plate705. The upper electrode plate705includes a hollow gas diffusion chamber752. A plurality of holes753through which a processing gas is dispersedly supplied into the processing container702may be evenly formed in a lower surface of the gas diffusion chamber752. A heating mechanism754is embedded in the upper electrode plate705, for example, above the gas diffusion chamber752. The heating mechanism754is heated to a set temperature with power from a power supply (not shown) based on a control signal from the controller709.

The gas diffusion chamber752A is provided with a gas supply path706. The gas supply path706is in communication with the gas diffusion chamber752. A gas source761is connected to an upstream side of the gas supply path706via a gas line762. The gas source761includes, for example, sources of various processing gases, mass flow controllers, and valves (all not shown). Here, in the modification process of modifying the surface of the substrate W, a processing gas containing silicon (Si) and hydrogen (H) may be used. Further, gas containing a Si—H bond may be used as the processing gas. Specifically, the processing gas includes at least any one selected from the group consisting of silane (SiH4), disilane (Si2H6), trisilane (Si3H8), higher-order silane, dichlorosilane (SiH2Cl2, hereinafter also referred to as DCS), trichlorosilane SiHCl3, and an organic Si precursor such as tris(dimethylamide) silane (((CH3)2N)3SiH, hereinafter also referred to as TDMAS). The processing gases may include an inert gas or a diluent gas (for example, H2, Ar, He, O2, or N2). Various gases are introduced into the gas diffusion chamber752from the gas source761via the gas line762.

The processing device102includes the controller709. The controller709is, for example, a computer, and includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and an auxiliary memory device. The CPU operates based on a program stored in the ROM or the auxiliary memory device, and controls the operation of the processing device102. The controller709may be provided inside the processing device102or outside the processing device102. When the controller709is provided outside the processing device102, the controller709may control the processing device102using a communication means based on a wired or wireless manner.

The controller709controls the temperature adjustment mechanism734to set the temperature of the substrate W to a predetermined temperature. The temperature adjustment mechanism734controls the pressure adjuster723and the exhauster724to set the interior of the processing container702to a predetermined pressure. The controller709controls the gas source761to supply the Si-containing gas into the processing container702during a predetermined period of time (the first period of time).

With such a configuration, the processing device102modifies the surface of the metal-containing film22(the TiN film) formed on the substrate W (the surface bonded to the carbon-containing film24) by supplying the Si-containing gas into the processing container702in a state in which the substrate W is heated to a predetermined temperature (for example, 400 degrees C. or higher).

Here, an example of processing conditions used when modifying the surface of the metal-containing film22(the TiN film) is as follows.First period of time: 2 sec to 30 secTemperature of Substrate: 400 degrees C. to 700 degrees C.Processing pressure: 1,000 mT to 5,000 mT

FIG.5is an example of a schematic cross-sectional view showing a state of the surface of the substrate W subjected to the modification process.

Here, the TiN film (the metal-containing film22) is a hydrophilic film. By supplying the Si-containing gas onto the surface of the substrate W, a hydrophobic group23having Si atoms23aand H atoms23bis physically adsorbed onto and/or chemically bonded to the surface of the TiN film (the metal-containing film22). That is, Ti in the TiN film and SiHx (where x is an arbitrary number) are chemically bonded to each other to form Ti—SiHx. In other words, a terminal group of the metal-containing film22is (—SiHx). Further, Si and/or SiHx (where x is an arbitrary number) is physically adsorbed onto the surface of the TiN film. As a result, the surface of the TiN film (the metal-containing film22), which is a hydrophilic film, is modified into a hydrophobic surface. That is, in step S13, the surface of the substrate W is modified into the hydrophobic surface by supplying the Si-containing gas to the substrate W.

Further, the processing device102may modify the surface of the substrate W into the hydrophobic surface by generating plasma of the Si-containing gas. Specifically, the controller709forms the hydrophobic group23on the surface of the metal-containing film22using plasma of the Si-containing gas. The controller709controls the temperature adjustment mechanism734to set the temperature of the substrate W to a predetermined temperature (for example, 300 degrees C. or lower). In addition, the temperature adjustment mechanism734controls the pressure adjuster723and the exhauster724to set the interior of the processing container702to a predetermined pressure. Further, the controller709controls the gas source761to supply the Si-containing gas into the processing container702during the predetermined period of time (the first period of time). The controller709controls the RF power supply751to apply the HF power to the upper electrode plate705. The controller709controls the RF power supply735to apply the LF power to the lower electrode733. As a result, plasma of the Si-containing gas is generated, and the hydrophobic group23are formed on the surface of the metal-containing film22of the substrate W by that plasma. Further, the modification process may be performed at a low temperature with the plasma.

Here, an example of processing conditions used when modifying the surface of the metal-containing film22(the TiN film) is as follows.First period of time: 2 sec to 20 secTemperature of substrate: 300 degrees C. to 500 degrees C.Processing pressure: 100 mT to 5,000 mTPlasma power: 10 W to 2,000 W

While the example in which the HF power is applied to the upper electrode plate705and the LP power is applied to the lower electrode733has been described above, the present disclosure is not limited thereto. For example, two frequencies of HF power and LF power may be applied to the upper electrode plate705, and two frequencies of HF power and LF power may be applied to the lower electrode733.

In step S14, the substrate W is exposed to plasma of the processing gas including the carbon-containing gas to form the carbon-containing film24having a film stress of 1 GPa or more on the hydrophobic surface of the substrate W (in a carbon-containing film forming process). The film stress may be in a compressive direction or in a tensile direction. That is, the carbon-containing film24having a film stress, an absolute value of which is 1 GPa or more, is formed. First, the control device600controls the transfer mechanism106to transfer the substrate W from the processing device102to the processing device103. The control device600controls the processing device103to form the carbon-containing film24on the substrate W, the surface of which has been modified by plasma of the carbon-containing gas.

Here, the processing device103that forms the carbon-containing film24may be similar in configuration to, for example, the processing device102shown inFIG.4. However, in the processing device103, the type of a processing gas supplied from the gas source761is different.

The processing gas used in the carbon-containing film forming process includes a carbon-containing gas. The carbon-containing gas include at least one selected from the group consisting of gas CxHy containing carbon (C) and hydrogen (H), gas CxFy containing carbon (C) and fluorine (F), gas (for example, CO2) containing carbon (C) and oxygen (O), or gas (for example, an organometallic precursor such as TDMAT) containing carbon (C) and a metal (where x and y are arbitrary numbers). The carbon-containing gas includes, for example, CH4, C2H2, C2H4, C3H6, and C6H6. In addition, the processing gas may include an inert gas or a diluent gas (for example, H2, Ar, He, O2, or N2). The processing gas may further include a hydrogen gas. Various gases are introduced into the gas diffusion chamber752from the gas source761via the gas line762.

With such a configuration, the processing device103forms the carbon-containing film on the surface of the substrate W. Specifically, the controller709forms the carbon-containing film with the plasma of the carbon-containing gas. The controller709controls the temperature adjustment mechanism734to set the temperature of the substrate W to a predetermined temperature. The temperature adjustment mechanism734controls the pressure adjuster723and the exhauster724to set the interior of the processing container702to a predetermined pressure. The controller709controls the gas source761to supply the carbon-containing gas into the processing container702. Further, the controller709controls the RF power supply751to apply the HF power to the upper electrode plate705. The controller709controls the RF power supply735to apply the LF power to the lower electrode733. As a result, the plasma of the carbon-containing gas is generated, and the carbon-containing film is formed on the substrate W by that plasma.

Here, an example of film forming conditions used when forming the carbon-containing film24having a film stress of 1 GPa or more is as follows.Processing pressure: 5 mT to 200 mTPower of plasma: 10 W to 3,000 WThickness of carbon-containing film: 20 nm to 100 nm

While the example in which the HF power is applied to the upper electrode plate705and the LF power is applied to the lower electrode733has been described above, the present disclosure is not limited thereto. For example, two frequencies of HF power and LF power may be applied to the upper electrode plate705, and two frequencies of HF power and LF power may be applied to the lower electrode733.

As described above, the hard mask including the metal-containing film22and the carbon-containing film24is formed on the substrate W. Thereafter, the control device600controls the transfer mechanism106to transfer the substrate W from the processing device103to any one of the load lock chambers301to303. The control device600controls the transfer mechanism402to transfer the substrate W from any one of the load lock chambers301to303to the carrier C.

While the processing system100has been described such that the carrier C in which the substrate W including the base21is accommodated is attached to the load ports501to504and the substrate W on which the metal-containing film22and the carbon-containing film24have been formed is accommodated again in the carrier C, the present disclosure is not limited thereto. The processing system100may include at least the processing device102and the processing device103, and may be configured such that the carrier C in which the substrate W including the metal-containing film22and the base21is accommodated is attached to the load ports501to504, and the surface of the metal-containing film22is modified to accommodate the substrate W on which the carbon-containing film24has been formed on the metal-containing film22in the carrier C again.

InFIG.1, the example in which the substrate W is transferred in a vacuum atmosphere after the metal-containing film22is formed and before the modification process is performed has been described. However, the present disclosure is not limited thereto. After the metal-containing film22is formed and before the modification process is performed, the substrate W may be transferred in an atmospheric environment. Further, while the configuration in which the substrate W is transferred in a vacuum atmosphere after the modification process is performed and before the carbon-containing film24is formed has been described as an example, the present disclosure is not limited thereto. The substrate W may be transferred in an atmospheric environment after the modification process is performed and before the carbon-containing film24is formed.

FIG.6is a schematic diagram showing adhesion between the metal-containing film22and the carbon-containing film24in the substrate processing method of the embodiment. InFIG.6, an adhesion force31between the metal-containing film22and the carbon-containing film24is schematically shown by a size of an arrow. In the substrate processing method of the embodiment, the surface of the metal-containing film22is modified using the Si-containing gas (see step S13) and then the carbon-containing film24is formed (see step S14) by the substrate processing method shown inFIG.2.

FIG.7is a schematic diagram showing adhesion between the metal-containing film22and the carbon-containing film24in a substrate processing method of a reference example. InFIG.7, an adhesion force32between the metal-containing film22and the carbon-containing film24is schematically indicated by a size of an arrow. In the substrate processing method of the reference example, the carbon-containing film24is formed on the metal-containing film22without performing the modification process (see step S13).

In the reference example shown inFIG.7, the TiN film (metal-containing film22) is a hydrophilic film. In contrast, the DLC film (carbon-containing film24) is an organic film mainly composed of a C═C bond, a C—C bond, or a C—H bond, and is a hydrophobic film. Therefore, the hydrophilic film and the hydrophobic film are bonded to each other in a bonding surface between the TiN film (the metal-containing film22) and the DLC film (the carbon-containing film24), so that adhesion is poor and the adhesion force32is small. For this reason, when a DLC film having a film stress of 1 GPa or more is formed on the TiN film, peeling of the DLC film occurs due to the film stress of the DLC film itself.

On the other hand, in the embodiment shown inFIG.6, the hydrophobic group23(SiHx) having the Si atoms23aand the H atoms23bis physically adsorbed onto and/or chemically bonded to the surface of the TiN film (the metal-containing film22). Therefore, the hydrophobic surface and the hydrophobic film are bonded to each other on a bonding surface between the TIN film (the metal-containing film22) and the DLC film (the carbon-containing film24), so adhesion is good and the adhesion force31is high. For this reason, even when the DLC film having a film stress of 1 GPa or more is formed on the TiN film, peeling of the DLC film may be suppressed.

FIG.8is a diagram showing a state of the carbon-containing film24formed on the surface of the substrate W.

InFIG.8, Case (a) represents that the TiN film is formed by the ALD method and the DLC film is formed on the TiN film without performing the modification process (“As Depo TiN”). Case (b) represents that the TiN film is formed by the ALD method, and the DLC film is formed on the TiN film after performing the modification process by supplying DCS for 2.5 seconds at a substrate temperature of 600 degrees C. (“DCS flow 2.5 sec”). Case (c) represents that the TiN film is formed by the ALD method, and the DLC film is formed on the TiN film after performing the modification process by supplying DCS for 20 seconds at a substrate temperature of 600 degrees C. (“DCS flow 20 sec”). In addition, for each of Cases (a) to (c), peeling of the DLC film was observed in a state after the formation of the DLC film and before exposure to the atmosphere, a state immediately after exposure to the atmosphere, and a state after 10 minutes from exposure to the atmosphere. InFIG.8, symbol “O” indicates that there was no peeling of the film, and symbol “X” indicates that there was peeling of the film. The DLC film was formed with a film compressive stress of −3 GPa, a film density of 2.1 g/cm3, and a film thickness of 40 nm.

As shown in Case (a) ofFIG.8, when the DLC film is formed on the TiN film without the modification process, the film peeled off immediately after exposure to the atmosphere, and, after 10 minutes have elapsed from the exposure to the atmosphere, the entire surface of the DLC film was peeled off.

In contrast, as shown in Cases (b) and (c) ofFIG.8, when the DLC film is formed on the TiN film subjected to the modification process, no peeling of the DLC film occurred both immediately after the exposure to the atmosphere and after 10 minutes from the exposure to the atmosphere. Although not shown, in any of both Cases (b) and (c), no peeling of the DLC film occurred even after one month had elapsed from the exposure to the atmosphere.

FIG.9is a graph showing an example of results of mass spectrometry.

Here, the TiN film was analyzed using a time-of-flight secondary ion mass spectrometry (TOF-SIMS). Cases (a) and (b) show analysis results in the substrate W after forming the TiN film by the ALD method and before supplying DCS (“DCS 0 sec”). Cases (c) and (d) show analysis results in the substrate W after forming the TiN film by the ALD method and subsequently supplying DCS for 20 seconds at a substrate temperature of 600 degrees C. to perform the modification process (“DCS 20 sec”). In addition, Cases (a) and (c) show analysis results for Si (m/z=28), and Cases (b) and (d) show analysis results for Si—H (m/z=29).

As shown inFIG.9, it was confirmed that Si—H was physically adsorbed onto and/or chemically bonded to the surface of the TiN film by supplying DCS for 20 seconds at a substrate temperature of 600 degrees C. to perform the modification process. Although not shown, it was confirmed that Si—H was physically adsorbed onto and/or chemically bonded to the surface of the TiN film by supplying DCS for 2.5 seconds at a substrate temperature of 600 degree C. to perform the modification process, similar to the case in which DCS was supplied for 20 seconds to perform the modification process.

As described above, before forming the carbon-containing film24on the surface of the substrate W, the surface of the metal-containing film22is first modified into the hydrophobic surface by the modification process. Then, the carbon-containing film24is formed on the hydrophobic surface, thereby improving adhesion between the metal-containing film22and the carbon-containing film24. This makes it possible to suppress the peeling of the carbon-containing film24.

In addition, as film density of the DLC film becomes higher, stress of the DLC film tends to increase. According to the substrate processing method according to the embodiment, film peeling may be suppressed even in the DLC film with a high film density and high stress of 1 GPa or more.

According to the present disclosure in some embodiments, it is possible to provide a method for forming a carbon-containing film while suppressing film peeling.

While embodiments of the method of forming the carbon-containing film24on the metal-containing film22have been described, the present disclosure is not limited the above-described embodiments. Various changes and modifications may be made within the scope of the claims.