Substrate Processing Method and Substrate Processing Apparatus

Abstract

In one illustrative embodiment of the present invention, a substrate processing method comprises: (a) a step for providing a substrate having a metal-containing film and a mask provided on the metal-containing film; (b) a step for forming a protective film on the mask; and (c) a step for etching the metal-containing film after step (b). Step (c) includes: (c1) a step for forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing film, by using a first processing gas including a fluorine-containing gas; and (c2) a step for removing the second metal-containing substance by using a second processing gas including a precursor.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a substrate processing method and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a method of atomic layer etching (ALE). In this method, a substrate is exposed to hydrogen fluoride gas to form a fluorinated surface layer on a metal oxide film. Thereafter, the substrate is exposed to a boron-containing gas to remove the fluorinated surface layer from the metal oxide film.

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 substrate processing method and a substrate processing apparatus capable of selectively etching a metal-containing film with respect to other films.

Means for Solving the Problems

[0005] In one exemplary embodiment, a substrate processing method is provided. The method includes: (a) providing a substrate having a metal-containing film and a mask provided on the metal-containing film; (b) forming a protective film on the mask; and (c) after (b), etching the metal-containing film, where (c) includes: (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing film using a first processing gas containing a fluorine-containing gas; and (c2) removing the second metal-containing substance using a second processing gas containing a precursor.

Effects of the Invention

[0006] According to one exemplary embodiment, a substrate processing method and a substrate processing apparatus are provided that can selectively etch a metal-containing film with respect to other films.

Brief Description of the Drawings

[0007]

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Best Mode for Carrying Out the Invention

[0008] Hereinafter, various exemplary embodiments will be described.

[0009] In one exemplary embodiment, a substrate processing method includes: (a) providing a substrate having a metal-containing film and a mask provided on the metal-containing film; (b) forming a protective film on the mask; and (c) after (b), etching the metal-containing film. The step (c) includes: (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing film using a first processing gas containing a fluorine-containing gas; and (c2) removing the second metal-containing substance using a second processing gas containing a precursor.

[0010] In the method of the above embodiment, when etching the metal-containing film, etching of the mask is suppressed by the protective film. Therefore, the metal-containing film can be selectively etched with respect to other films.

[0011] The substrate processing method may further include: (d) after (c), removing fluorine on the surface of the protective film using a third processing gas. In this case, a further protective film can be formed in a short time thereafter.

[0012] The substrate processing method may further include: (e) after (d), repeating steps (b), (c), and (d). In this case, the etching depth of the metal-containing film can be increased.

[0013] In the step (b), the thickness of the protective film formed on the side surface of the mask may decrease as it goes from the upper surface of the mask toward the metal-containing film. In this case, since the thickness of the protective film formed on the metal-containing film becomes small, the etching rate of the metal-containing film is improved.

[0014] In the above (d), the plasma generated from the third processing gas is used, and the third processing gas may contain at least one of an oxygen-containing gas, a hydrogen-containing gas, and a nitrogen-containing gas.

[0015] The protective film may contain at least one of silicon, carbon, and metal.

[0016] In the above (c1), the first processing gas may be used without generating plasma.

[0017] In the above (c1), the plasma generated from the first processing gas may be used.

[0018] In at least one of the above (c1) and (c2), the substrate may be heated. In this case, the reaction between the first metal-containing substance and the fluorine-containing gas or the reaction between the second metal-containing substance and the precursor is promoted.

[0019] The precursor may include a metal-containing precursor. In this case, the metal-containing precursor can react with the second metal-containing substance at low energy.

[0020] The metal-containing precursor may include a metal complex. In this case, another metal complex with high volatility is generated by the ligand exchange reaction between the second metal-containing substance and the metal complex.

[0021] The metal complex may be a complex having at least one monodentate ligand selected from the group consisting of alkyl, hydride, carbonyl, halide, alkoxide, alkylamide, and silylamide, or at least one chelate selected from the group consisting of β-diketonate, amidinate, acetamidinate, β-diketiminate, diaminoalkoxide, and metallocene.

[0022] The metal contained in the metal-containing precursor may be at least one selected from the group consisting of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr, and Ti.

[0023] The precursor may include a precursor that does not contain a metal. In this case, metal residues are less likely to be generated by the reaction between the second metal-containing substance and the precursor.

[0024] The precursor that does not contain a metal may be at least one β-diketone selected from the group consisting of acac (acetylacetone), hfac (hexafluoroacetylacetone), tfac (trifluoroacetylacetone), and tmhd (tetramethylheptanedione).

[0025] The metal-containing film may include at least one metal selected from the group consisting of Al, Hf, Zr, Fe, Ni, Co, Mn, Mg, Rh, Ru, Cr, Si, Ti, Ga, In, Zn, Pb, Ge, Ta, Cu, W, Mo, Pt, Cd, and Sn.

[0026] The metal-containing film may be an oxide or a nitride of the metal.

[0027] The fluorine-containing gas may include at least one selected from the group consisting of hydrogen fluoride gas, fluorocarbon gas, nitrogen-containing gas, and sulfur-containing gas.

[0028] In one exemplary embodiment, a substrate processing method includes: (a) providing a substrate having an etching target film and a mask provided on the etching target film; (b) forming a metal-containing protective film on the mask; (c) after (b), removing a part of the metal-containing protective film; and (d) after (c), etching the etching target film. The step (b) includes: (b1) forming a precursor layer on a side surface of the mask using a first precursor containing a metal; and (b2) modifying the precursor layer into the metal-containing protective film using a modifying gas containing an oxidizing gas or a reducing gas. The step (c) includes: (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing protective film using a first processing gas containing at least one of a halogen-containing gas and an oxygen-containing gas; and (c2) removing the second metal-containing substance using a second processing gas containing a second precursor.

[0029] In the method of the above embodiment, the metal-containing protective film can be etched with a high selectivity ratio with respect to the etching target film and the mask.

[0030] The first precursor may contain at least one metal selected from the group consisting of Ti, Ta, Ru, Al, Hf, and Sn.

[0031] The halogen-containing gas may contain at least one selected from the group consisting of fluorine, chlorine, and bromine.

[0032] The second precursor may contain at least one metal selected from the group consisting of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr, and Ti or a complex of the metal.

[0033] The etching target film may be a silicon-containing film.

[0034] In one exemplary embodiment, a substrate processing apparatus includes a chamber, a substrate support portion for supporting a substrate within the chamber, the substrate having a metal-containing film and a mask provided on the metal-containing film, a gas supply portion configured to supply a first processing gas containing hydrogen fluoride gas, a second processing gas containing a precursor, a third processing gas, and a fourth processing gas for forming a protective film into the chamber respectively, and a control portion. The control portion is configured to control the gas supply portion to form the protective film on the mask using the fourth processing gas. After the protective film is formed, the control portion is configured to control the gas supply portion to form a second metal-containing substance from a first metal-containing substance contained in the metal-containing film using the first processing gas. After the second metal-containing substance is formed, the control portion is configured to control the gas supply portion to remove the second metal-containing substance using the second processing gas. After the second metal-containing substance is removed, the control portion is configured to control the gas supply portion to remove fluorine on the surface of the protective film using the third processing gas.

[0035] According to the substrate processing apparatus of the above embodiment, when etching a metal-containing film, etching of the mask is suppressed by the protective film. Therefore, the metal-containing film can be selectively etched with respect to other films. Further, using the third processing gas, fluorine on the surface of the protective film is removed. Therefore, a further protective film can be formed in a short time thereafter.

[0036] Hereinafter, various exemplary embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals.

[0037] FIG. 1 and FIG. 2 are diagrams schematically showing a substrate processing apparatus according to one exemplary embodiment. The substrate processing apparatus of the present embodiment is, for example, a plasma processing system.

[0038] In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. Further, the plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas discharge port for discharging gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 described later, and the gas discharge port is connected to an exhaust system 40 described later. The substrate support unit 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0039] The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), ECR plasma (Electron-Cyclotron-resonance plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Also, various types of plasma generation units including an AC (Alternating Current) plasma generation unit and a DC (DirectCurrent) plasma generation unit may be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Accordingly, the AC signal includes an RF (RadioFrequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 200 kHz to 150 MHz.

[0040] The control unit 2 processes computer-executable instructions for causing the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 so as to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0041] A configuration example of the plasma processing system will be described below. The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. Further, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed within the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port for discharging gas from the plasma processing space. The side wall 10a is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the plasma processing chamber 10 housing.

[0042] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region (substrate support surface) 111a for supporting a substrate (wafer) W and an annular region (ring support surface) 111b for supporting the ring assembly 112. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. In one embodiment, the main body portion 111 includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is disposed on the base. The upper surface of the electrostatic chuck has the substrate support surface 111a. The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Also, although not shown, the substrate support portion 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0043] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c. Further, the showerhead 13 includes a conductive member. The conductive member of the showerhead 13 functions as an upper electrode. Note that the gas introduction part may include, in addition to the showerhead 13, one or a plurality of side gas injectors (SGI) attached to one or a plurality of openings formed in the side wall 10a.

[0044] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from the corresponding gas source 21 to the showerhead 13 via the corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one process gas.

[0045] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive member of the substrate support 11 and / or the conductive member of the showerhead 13. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Accordingly, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Further, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0046] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13 via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency within the range of 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support unit 11 and / or the conductive member of the shower head 13. The second RF generation unit 31b is coupled to the conductive member of the substrate support unit 11 via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency within the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to the conductive member of the substrate support unit 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0047] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to a conductive member of the substrate support 11 and is configured to generate a first DC signal. The generated first bias DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the first DC signal may be applied to other electrodes such as the electrodes within the electrostatic chuck. In one embodiment, the second DC generation unit 32b is connected to a conductive member of the shower head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0048] The exhaust system 40 may be connected to, for example, a gas outlet 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure within the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0049] FIG. 3 is a partially enlarged cross-sectional view of an example substrate. As shown in FIG. 3, in one embodiment, the substrate W includes a metal-containing film MF and a mask MK. The mask MK is provided on the metal-containing film MF. The substrate W may include a base region UR. The base region UR may contain silicon. The metal-containing film MF may be provided on the base region UR.

[0050] The metal-containing film MF may contain at least one of oxygen and nitrogen. The metal-containing film MF may contain at least one of a metal oxide and a metal nitride. The metal-containing film MF may contain at least one of Al, Hf, Zr, Fe, Ni, Co, Mn, Mg, Rh, Ru, Cr, Si, Ti, Ga, In, Zn, Pb, Ge, Ta, Cu, W, Mo, Pt, Cd, and Sn.

[0051] The mask MK may contain silicon. The mask MK may contain at least one of silicon oxide and silicon nitride. The mask MK may contain carbon (organic matter). The mask MK may contain at least one of photoresist, spin-on carbon, amorphous carbon, and tungsten carbide. The mask MK may have at least one recess RS. Each recess RS may be an opening.

[0052] FIG. 4 is a flowchart of a substrate processing method according to one exemplary embodiment. The substrate processing method shown in FIG. 4 (hereinafter referred to as "method MT1") can be executed by the substrate processing apparatus of the above embodiment. Method MT1 may include steps ST1 to ST5. Steps ST1 to ST5 may be executed in order. Step ST5 may not be executed.

[0053] Hereinafter, method MT1 will be described with reference to FIGS. 4 to 8. When the plasma processing apparatus 1 is used, method MT1 can be executed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 by the control unit 2. In method MT1, the metal-containing film MF can be etched. Steps ST1 to ST5 may be performed in-situ. That is, method MT1 may be performed without taking out the substrate W out of the plasma processing chamber 10.

[0054] (Step ST1) In step ST1, the substrate W shown in FIG. 3 is provided. The substrate W can be supported by the substrate support portion 11 in the plasma processing chamber 10 as shown in FIG. 2.

[0055] (Engineering ST2) FIG. 5 is a partially enlarged cross-sectional view of a substrate in an example of a process of forming a protective film on a mask. In process ST2, a protective film PR is formed on a mask MK. The protective film PR can be formed by atomic layer deposition (ALD), molecular layer deposition (MLD), or chemical vapor deposition (CVD). A fourth processing gas can be used to form the protective film PR. The fourth processing gas is supplied from a gas supply unit 20 into the plasma processing chamber 10. Inside the plasma processing chamber 10, the substrate W is exposed to the fourth processing gas. When the protective film PR is formed by ALD or MLD, a precursor gas and a modifying gas are used as the fourth processing gas.

[0056] The protective film PR can be formed on the upper surface MKt and the side surface MKs of the mask MK. The thickness of the protective film PR formed on the upper surface MKt of the mask MK is larger than the thickness of the protective film PR formed on the side surface MKs of the mask MK. The thickness of the protective film PR formed on the side surface MKs of the mask MK may decrease as it goes from the upper surface MKt of the mask MK toward the metal-containing film MF. That is, the protective film PR may be a sub-conformal film. At the bottom of the recess RS of the mask MK, the protective film PR does not have to be formed on the metal-containing film MF. The thickness of the protective film PR formed at the bottom of the recess RS of the mask MK is smaller than the thickness of the protective film PR formed on the upper surface MKt and the side surface MKs of the mask MK.

[0057] The protective film PR may be a conformal film. In this case, for example, the protective film PR formed at the bottom of the recess RS of the mask MK can be selectively removed by anisotropic etching. Thereby, while the protective film PR is left on the upper surface MKt and the side surface MKs of the mask MK, the protective film PR at the bottom of the recess RS of the mask MK can be removed.

[0058] The protective film PR may contain at least one of silicon, carbon, and metal.

[0059] When the protective film PR has a silicon oxide film formed by ALD or MLD, a silicon-containing gas such as aminosilane, SiCl4, or SiF4 may be used as the precursor gas, and an oxygen-containing gas such as oxygen gas may be used as the reforming gas.

[0060] When the protective film PR has a silicon nitride film formed by ALD or MLD, a silicon-containing gas such as aminosilane, SiCl4, dichlorosilane, hexachlorodisilane, etc. may be used as the precursor gas. A nitrogen-containing gas such as ammonia gas or nitrogen gas may be used as the reforming gas.

[0061] When the protective film PR has an organic film formed by ALD, an epoxide, carboxylic acid, carboxylic acid halide, carboxylic anhydride, isocyanate, or phenols, etc. may be used as the precursor gas. An inorganic compound gas having an N-H bond, an inert gas, a mixed gas of N2 and H2, H2O gas, or a mixed gas of H2 and O2, etc. may be used as the reforming gas.

[0062] When the protective film PR has an organic film formed by MLD, isocyanate, carboxylic acid, or carboxylic acid halide is used as the precursor gas, and an amine or a compound having a hydroxyl group may be used as the reforming gas. Alternatively, carboxylic anhydride may be used as the precursor gas, and an amine may be used as the reforming gas. Alternatively, bisphenol A may be used as the precursor gas, and diphenyl carbonate or epichlorohydrin may be used as the reforming gas.

[0063] When the protective film PR has a metal-containing film formed by ALD or MLD, a metal-containing gas such as a gas containing a metal such as Ti, Ta, Ru, Al, Hf, or Sn, or a gas containing an oxide, nitride, sulfide, or halide of these metals may be used as the precursor gas. An oxidizing gas or reducing gas such as a hydrogen-containing gas (H2, etc.), an oxygen-containing gas (O2, etc.), a mixed gas of H2 and N2, or a gas containing hydrogen and nitrogen (NH3, etc.) may be used as the reforming gas.

[0064] After the engineering ST2, an engineering ST12 of removing a protective film PR formed on the bottom of a concave portion RS of a mask MK may be performed. The engineering ST12 may be performed before the engineering ST3. For example, when the protective film PR is a silicon-containing film, in the engineering ST12, the protective film PR formed on the bottom of the concave portion RS can be removed by plasma generated from a fluorine-containing gas. For example, when the protective film PR is an organic film, in the engineering ST12, the protective film PR formed on the bottom of the concave portion RS can be removed by O2 gas or H2 gas.

[0065] (Engineering ST3) In the engineering ST3, a metal-containing film MF is etched. The metal-containing film MF can be etched by atomic layer etching (ALE). The engineering ST3 includes an engineering ST31 and an engineering ST32. The engineering ST32 is performed after the engineering ST31. In the engineering ST3, the engineering ST31 and the engineering ST32 may be repeatedly performed alternately.

[0066] (Engineering ST31) FIG. 6 is a partially enlarged cross-sectional view of an example substrate in the process of forming a second metal-containing substance. In the engineering ST31, a second metal-containing substance MS2 is formed from a first metal-containing substance MS1 (see FIG. 5) contained in the metal-containing film MF using a first processing gas G1 containing a fluorine-containing gas. The first metal-containing substance MS1 may be located on the surface of the metal-containing film MF. By etching the protective film PR with the first processing gas G1, the protective film PR on the mask MK becomes thinner while the protective film PR on the metal-containing film MF is removed. As a result, the surface of the metal-containing film MF is exposed to the first processing gas G1. Consequently, the first metal-containing substance MS1 reacts with the first processing gas G1. The first processing gas G1 is supplied from a gas supply unit 20 into the plasma processing chamber 10. In the plasma processing chamber 10, the substrate W is exposed to the first processing gas G1.

[0067] The fluorine-containing gas may contain at least one of hydrogen fluoride gas (HF gas), fluorocarbon gas, nitrogen-containing gas, and sulfur-containing gas. The fluorocarbon gas may contain at least one of C4F6 gas, C4F8 gas, C3F8 gas, and CF4 gas. The nitrogen-containing gas may contain NF3 gas. The sulfur-containing gas may contain SF6 gas.

[0068] Examples of the first metal-containing substance MS1 are the same as examples of the constituent material of the metal-containing film MF. The second metal-containing substance MS2 can be generated by the reaction of the first metal-containing substance MS1 and the fluorine-containing gas. The second metal-containing substance MS2 may contain the same metal as the metal contained in the first metal-containing substance MS1 and fluorine. The second metal-containing substance MS2 is, for example, a metal fluoride. In one example, the first metal-containing substance MS1 contains aluminum oxide, and the fluorine-containing gas contains hydrogen fluoride gas. In this case, the second metal-containing substance MS2 contains aluminum fluoride.

[0069] In step ST31, the surface PRs of the protective film PR can be fluorinated by the reaction of the surface PRs of the protective film PR and the fluorine-containing gas. As a result, fluorine may remain on the surface PRs of the protective film PR.

[0070] In step ST31, the first processing gas G1 may be used without generating plasma, or the plasma generated from the first processing gas G1 may be used. When no plasma is generated, the first processing gas G1 may contain hydrogen fluoride gas.

[0071] In step ST31, the substrate W may be heated. The temperature of the substrate support portion 11 can be 100°C or higher, 150°C or higher, or 200°C or higher. The temperature of the substrate support portion 11 can be 450°C or lower. The heating can be performed by the plasma generated in the plasma processing chamber 10 or the temperature control module in the substrate support portion 11. By heating, the reaction between the first metal-containing substance MS1 and the fluorine-containing gas is promoted.

[0072] After the process ST31, a purge process may be performed. In the purge process, after a purge gas is supplied into the plasma processing chamber 10, the purge gas is exhausted. The purge gas is an inert gas such as nitrogen or argon, for example.

[0073] (Process ST32) FIG. 7 is a partially enlarged cross-sectional view of an example substrate in the process of removing the second metal-containing substance. In the process ST32, the second metal-containing substance MS2 is removed using the second processing gas G2 containing a precursor. The second processing gas G2 is supplied from the gas supply unit 20 into the plasma processing chamber 10. In the process ST32, the second processing gas G2 can be used without generating plasma. Inside the plasma processing chamber 10, the substrate W is exposed to the second processing gas G2.

[0074] The precursor may include a metal-containing precursor. The metal-containing precursor may include a metal complex. The metal complex may be a complex having a monodentate ligand or a chelate. The monodentate ligand can be at least one of alkyl, hydride, carbonyl, halide, alkoxide, alkylamide, and silylamide. The chelate can be at least one of β-diketonate, amidinate, acetamidinato, β-diketiminate, diaminoalkoxide, and metallocene. The β-diketonate can be at least one of acac (acetylacetonate), hfac (hexafluoroacetylacetonate), tfac (trifluoroacetylacetonate), and tmhd (tetramethylheptanedionate).

[0075] The metal contained in the metal-containing precursor can be at least one of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr, and Ti.

[0076] The precursor may include a metal-free precursor. The metal-free precursor may include a carbon-containing precursor. The carbon-containing precursor can be at least one of alcohol, β-diketone, amidine, acetamidine, and β-diketimine. The β-diketone can be at least one of acac (acetylacetone), hfac (hexafluoroacetylacetone), tfac (trifluoroacetylacetone), and tmhd (tetramethylheptanedione).

[0077] In step ST32, a volatile third metal-containing substance MS3 can be generated by the reaction of the second metal-containing substance MS2 and the precursor. Thereby, the second metal-containing substance MS2 is removed. When the precursor includes a metal-containing precursor, the metal-containing precursor can react with the second metal-containing substance at low energy. When the metal-containing precursor includes a metal complex, another metal complex with high volatility is generated by the ligand exchange reaction between the second metal-containing substance MS2 and the metal complex. In one example, the second metal-containing substance MS2 includes aluminum fluoride, and the metal-containing precursor includes tin(II) acetylacetonate (Sn(acac)2). When the precursor includes a metal-free precursor, it is difficult to generate metal residues by the reaction of the second metal-containing substance and the precursor. When the metal-free precursor includes a carbon-containing precursor, residues containing carbon compounds are generated. The residues containing carbon compounds can be removed relatively easily.

[0078] In step ST32, similar to step ST31, the substrate W may be heated. By heating, the reaction between the second metal-containing substance MS2 and the precursor is promoted.

[0079] After step ST32, similar to the purge step performed after step ST31, a purge step may be performed.

[0080] (Step ST4) FIG. 8 is a partially enlarged cross-sectional view of a substrate in an example in the process of modifying the surface of the protective film. In step ST4, the surface PRs of the protective film PR is modified. In step ST4, fluorine on the surface PRs of the protective film PR is removed using a third processing gas. In the present embodiment, in step ST4, plasma PL generated from the third processing gas is used. The plasma PL can be generated from the third processing gas supplied from the gas supply unit 20 into the plasma processing chamber 10 by the plasma generation unit 12. In the plasma processing chamber 10, the substrate W is exposed to the plasma PL. The third processing gas may be used without generating plasma.

[0081] When the protective film PR contains silicon, after step ST31, Si-F bonds may remain on the surface PRs of the protective film PR. In this case, when using the plasma PL generated from the third processing gas containing an oxygen-containing gas, the fluorine atoms on the surface PRs of the protective film PR are replaced by OH groups. As a result, Si-OH bonds are formed on the surface PRs of the protective film PR. When using the plasma PL generated from the third processing gas containing a hydrogen-containing gas, the fluorine atoms on the surface PRs of the protective film PR are replaced by hydrogen atoms. As a result, Si-H bonds are formed on the surface PRs of the protective film PR. When using the plasma PL generated from the third processing gas containing a nitrogen-containing gas, the fluorine atoms on the surface PRs of the protective film PR are replaced by nitrogen atoms. As a result, Si-N bonds are formed on the surface PRs of the protective film PR.

[0082] When the protective film PR contains carbon, after the step ST31, C-F bonds may exist on the surface PRs of the protective film PR. In this case, when using the plasma PL generated from the third processing gas containing an oxygen-containing gas or a hydrogen-containing gas, the fluorine atoms on the surface PRs of the protective film PR are substituted with H groups. As a result, C-H bonds are formed on the surface PRs of the protective film PR. This is because the generated carbon monoxide volatilizes. When using the plasma PL generated from the third processing gas containing a nitrogen-containing gas, the fluorine atoms on the surface PRs of the protective film PR are substituted with nitrogen atoms. As a result, C-N bonds are formed on the surface PRs of the protective film PR. Alternatively, when using the plasma PL generated from the third processing gas containing a nitrogen-containing gas, the surface PRs of the protective film PR are etched. As a result, the constituent material of the protective film PR is exposed on the surface PRs of the protective film PR. When the constituent material contains C-H bonds, C-H bonds are exposed on the surface PRs of the protective film PR.

[0083] (Step ST5) In step ST5, steps ST2, ST3, and ST4 are repeated. Steps ST2, ST3, and ST4 may be repeated multiple times. By step ST5, the etching depth of the metal-containing film MF can be increased.

[0084] According to the above method MT1, when etching the metal-containing film MF, the etching of the mask MK is suppressed by the protective film PR. Therefore, the metal-containing film MF can be selectively etched with respect to other films. Furthermore, by step ST4, the fluorine on the surface PRs of the protective film PR is removed. When fluorine remains on the surface PRs of the protective film PR, the time until the deposition of the protective film PR starts tends to be long. In the above method MT1, since the fluorine on the surface PRs of the protective film PR is removed in step ST4, a further protective film PR can be formed in a short time thereafter.

[0085] In step ST2, when the thickness of the protective film PR formed on the side surface MKs of the mask MK decreases as it goes from the upper surface MKt of the mask MK toward the metal-containing film MF, the thickness of the protective film PR formed on the metal-containing film MF also decreases. Therefore, since the protective film PR on the metal-containing film MF can be removed in a short time, the etching rate of the metal-containing film MF is improved.

[0086] As described above, various exemplary embodiments have been described. However, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and changes may be made. Also, it is possible to form other embodiments by combining elements in different embodiments. Hereinafter, examples of other embodiments will be described. For the same processes and the like as those in the above-described exemplary embodiments, the description will be omitted or simplified.

[0087] (Other Embodiment 1) The substrate processing apparatus may not include the plasma generation unit 12. In this case, plasma processing is not performed in the chamber of the substrate processing apparatus. Method MT1 can also be performed using such a substrate processing apparatus.

[0088] (Other Embodiment 2) The first processing gas G1 may contain a halogen-containing gas. For example, the first processing gas G1 may contain at least one of a chlorine-containing gas and a bromine-containing gas instead of or together with the above-described fluorine-containing gas. The chlorine-containing gas may contain at least one of chlorine (Cl2) gas and hydrogen chloride (HCl) gas. The bromine-containing gas may contain at least one of bromine (Br2) gas and hydrogen bromide (HBr) gas. When plasma is generated from the first processing gas G1 in step ST31, the halogen-containing gas may contain at least one of silicon and carbon.

[0089] When the first processing gas G1 contains a halogen-containing gas, the second metal-containing substance M2 generated in step ST31 can be formed by the reaction of the first metal-containing substance MS1 and the halogen-containing gas. The second metal-containing substance MS2 can contain the same metal as the metal contained in the first metal-containing substance MS1 and a halogen. The second metal-containing substance MS2 is, for example, a metal halide. Specifically, the second metal-containing substance MS2 can be a metal fluoride, a metal chloride, or a metal bromide. Even when the second metal-containing substance MS2 is a metal halide other than a metal fluoride (a metal chloride or a metal bromide), the second metal-containing substance MS2 can be removed by the second processing gas G2 containing the above-described precursor.

[0090] (Other Embodiment 3) The first processing gas G1 may contain an oxygen-containing gas instead of or together with the halogen-containing gas. For example, the first processing gas G1 may contain at least one of oxygen (O2) gas, carbon monoxide (CO) gas, and carbon dioxide gas (CO2) as the oxygen-containing gas.

[0091] When the first processing gas G1 contains an oxygen-containing gas, the second metal-containing substance M2 generated in step ST31 can be formed by the reaction of the first metal-containing substance MS1 and the oxygen-containing gas. The second metal-containing substance MS2 can contain the same metal as the metal contained in the first metal-containing substance MS1 and oxygen. The second metal-containing substance MS2 is, for example, a metal oxide. When the second metal-containing substance MS2 is a metal oxide, the second metal-containing substance MS2 can be removed by the second processing gas G2 containing a precursor that does not contain the above-described metal.

[0092] (Other Embodiment 4) FIG. 9 is a flowchart of a substrate processing method according to another embodiment 4. The substrate processing method shown in FIG. 9 (hereinafter referred to as "method MT2") may include steps ST1 to ST5, similar to method MT1. Method MT2 includes step ST33 after step ST32 and before step ST4. Step ST33 is a step of exposing the substrate W to plasma generated from a fifth processing gas containing at least one of a fluorine-containing gas, an oxygen-containing gas, a hydrogen-containing gas, and a nitrogen-containing gas. The fluorine-containing gas may include at least one of a fluorocarbon gas, a nitrogen-containing gas, and a sulfur-containing gas. The fluorocarbon gas may include at least one of C4F6 gas, C4F8 gas, C3F8 gas, and CF4 gas. The nitrogen-containing gas may include NF3 gas. The sulfur-containing gas may include SF6 gas. The oxygen-containing gas may include at least one of oxygen gas, carbon monoxide gas, and carbon dioxide gas. The hydrogen-containing gas may include hydrogen gas. The nitrogen-containing gas may include nitrogen gas. When the precursor used in step ST32 contains Sn, the fifth processing gas may include at least one of hydrogen gas, CH4 gas, and carbon monoxide gas. When the precursor used in step ST32 contains Si, Ge, or B, the fifth processing gas may include a fluorine-containing gas. When the precursor used in step ST32 contains Pb, Ni, Al, Zn, Hf, or Zr, the fifth processing gas may include at least one of CH4 gas and carbon monoxide gas. When the precursor used in step ST32 includes a precursor that does not contain a metal, the fifth processing gas may include at least one of hydrogen gas and oxygen gas.

[0093] According to the above method MT2, residues (e.g., residues derived from the precursor) present on the substrate W can be removed after removing the second metal-containing substance MS2.

[0094] (Another Embodiment 5) This embodiment can be applied not only to the metal-containing film MF but also to the etching of films containing metals. FIG. 10 is a flowchart of a substrate processing method according to another Embodiment 5. The substrate processing method (hereinafter referred to as "Method MT3") shown in FIG. 10 may include steps ST1a to ST5a. Steps ST1a to ST5a can be executed in order. Method MT3 may not include step ST4a.

[0095] (Step ST1a) In step ST1a, a substrate Wa shown in FIG. 11 is provided. The substrate Wa includes an etching target film EF and a mask MKa. The substrate Wa may further include a base region UR under the etching target film EF. The etching target film EF may be a silicon-containing film. The etching target film EF may be at least one of a silicon oxide film, a silicon nitride film, and a polysilicon film, or may be a laminated film including two or more of these.

[0096] The mask MK may have at least one recess RS. The mask MKa may contain silicon. The mask MKa may include at least one of silicon oxide and silicon nitride. The mask MKa may contain carbon (organic matter). The mask MKa may include at least one of photoresist, spin-on carbon, amorphous carbon, and tungsten carbide. The mask MKa may contain a metal. The mask MKa may include at least one of tin (Sn), tellurium (Te), antimony (Sb), indium (In), silver (Ag), titanium (Ti), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), germanium (Ge), and hafnium (Hf). The mask MKa may include an oxide of Sn or a hydroxide of Sn.

[0097] (Step ST2a) In process ST2a, a metal-containing protective film PRa shown in FIG. 12 is formed on mask MKa. The metal-containing protective film PRa can be formed by atomic layer deposition (ALD), molecular layer deposition (MLD), or chemical vapor deposition (CVD). The metal-containing protective film PRa may be a conformal film or a sub-conformal film. At the bottom of the recess RSa of the mask MKa, the metal-containing protective film PRa may not be formed on the film to be etched EF.

[0098] When the metal-containing protective film PRa is formed by ALD or MLD, process ST2a may include process ST21a and process ST22a. Process ST22a is performed after process ST21a. In process ST2a, processes ST21a and ST22a may be repeatedly performed alternately.

[0099] (Process ST21a) In process ST21a, a precursor layer is formed on mask MKa using a gas of a first precursor containing a metal. The precursor layer may be formed on the side surface of the mask MKa. The precursor layer may be formed on the upper surface of the mask MKa or may not be formed. The precursor layer may be formed at the bottom of the recess RSa of the mask MKa or may not be formed. As the gas of the first precursor, a gas containing a metal such as Ti, Ta, Ru, Al, Hf, or Sn, or a metal-containing gas such as a gas containing an oxide, nitride, sulfide, or halide of these metals can be used.

[0100] (Process ST22a) In process ST22a, the precursor layer is modified using a modifying gas containing an oxidizing gas or a reducing gas to form the metal-containing protective film PRa. As the modifying gas, an oxidizing gas or a reducing gas such as a hydrogen-containing gas (such as H2), an oxygen-containing gas (such as O2), a mixed gas of H2 and N2, or a gas containing hydrogen and nitrogen (such as NH3) can be used.

[0101] (Process ST3a) In step ST3a, a part of the metal-containing protective film PRa is etched. The remaining part of the metal-containing protective film PRa is not etched. A part of the metal-containing protective film PRa can be etched by atomic layer etching (ALE). Step ST3a includes step ST31a and step ST32a. Step ST32a is performed after step ST31a. In step ST3a, step ST31a and step ST32a may be alternately repeated.

[0102] (Step ST31a) In step ST31a, as shown in FIG. 13, a second metal-containing substance MS2 is formed from a first metal-containing substance MS1 contained in the metal-containing protective film PRa using a first processing gas G1a containing at least one of a halogen-containing gas and an oxygen-containing gas. As the first processing gas G1a, the same gas as the first processing gas G1 can be used. The first metal-containing substance MS1 filled in the recess due to the surface roughness of the mask MKa may not react with the first processing gas G1a.

[0103] (Step ST32a) In step ST32a, as shown in FIG. 14, the second metal-containing substance MS2 is removed using a second processing gas G2a containing a second precursor. As the second precursor, the same precursor as the precursor contained in the second processing gas G2 can be used.

[0104] (Step ST4a) In step ST4a, steps ST2a and ST3a are repeated. Each of steps ST2a and ST3a may be repeated a plurality of times. The etching amount of the metal-containing protective film PRa can be controlled by the number of repetitions of steps ST2a and ST3a.

[0105] (Step ST5a) In step ST5a, the film to be etched EF is etched through the recess RS (opening) of the mask MKa on which the metal-containing protective film PRa is formed. The film to be etched EF may be etched by plasma generated from the sixth processing gas. For example, when the film to be etched EF is a silicon-containing film, the sixth processing gas may include a fluorine-containing gas. The fluorine-containing gas may include at least one of hydrogen fluoride gas (HF gas), fluorocarbon gas, and hydrofluorocarbon gas.

[0106] According to method MT3, in step ST3a, the metal-containing protective film PRa can be etched with a high selectivity with respect to the film to be etched EF and the mask MKa. Further, according to method MT3, when the surface roughness of the mask MKa is large, the surface roughness of the mask MKa can be improved.

[0107] From the above description, it will be understood that the various embodiments of the present disclosure are described herein for the purpose of illustration and that various changes can be made without departing from the scope and spirit of the present disclosure. Therefore, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

[0108] Here, various exemplary embodiments included in the present disclosure are described in the following (Appendix 1) to (Appendix 24).

[0109] (Appendix 1) A substrate processing method comprising: (a) providing a substrate having a metal-containing film and a mask provided on the metal-containing film; (b) forming a protective film on the mask; (c) after (b), etching the metal-containing film; wherein (c) comprises (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing film using a first processing gas containing a fluorine-containing gas; A step of removing the second metal-containing substance using a second processing gas containing a precursor; A method comprising the above.

[0110] (Appendix 2) (d) After the step (c), the method according to Appendix 1, further comprising a step of removing fluorine on the surface of the protective film using a third processing gas.

[0111] (Appendix 3) (e) After the step (d), the method according to Appendix 2, further comprising a step of repeating the steps (b), (c), and (d).

[0112] (Appendix 4) In the step (b), the method according to any one of Appendices 1 to 3, wherein the thickness of the protective film formed on the side surface of the mask decreases as it goes from the upper surface of the mask toward the metal-containing film.

[0113] (Appendix 5) In the step (d), the plasma generated from the third processing gas is used, and the third processing gas contains at least one of an oxygen-containing gas, a hydrogen-containing gas, and a nitrogen-containing gas. The method according to Appendix 2.

[0114] (Appendix 6) The method according to any one of Appendices 1 to 5, wherein the protective film contains at least one of silicon, carbon, and metal.

[0115] (Appendix 7) In the step (c1), the method according to any one of Appendices 1 to 6, wherein the first processing gas is used without generating plasma.

[0116] (Appendix 8) In the step (c1), the method according to any one of Appendices 1 to 6, wherein the plasma generated from the first processing gas is used.

[0117] (Appendix 9) The method according to any one of Appendices 1 to 8, wherein the substrate is heated in at least one of the above (c1) and (c2).

[0118] (Appendix 10) The method according to any one of Appendices 1 to 9, wherein the precursor includes a metal-containing precursor.

[0119] (Appendix 11) The method according to Appendix 10, wherein the metal-containing precursor includes a metal complex.

[0120] (Appendix 12) The metal complex is a complex having at least one monodentate ligand selected from the group consisting of alkyl, hydride, carbonyl, halide, alkoxide, alkylamide and silylamide, or at least one chelate selected from the group consisting of β-diketonate, amidinate, acetamidinato, β-diketiminate, diaminoalkoxide and metallocene. The method according to Appendix 11.

[0121] (Appendix 13) The metal contained in the metal-containing precursor is at least one selected from the group consisting of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr and Ti. The method according to any one of Appendices 10 to 12.

[0122] (Appendix 14) The method according to any one of Appendices 1 to 13, wherein the precursor includes a metal-free precursor.

[0123] (Appendix 15) The metal-free precursor is at least one β-diketone selected from the group consisting of acac (acetylacetone), hfac (hexafluoroacetylacetone), tfac (trifluoroacetylacetone) and tmhd (tetramethylheptanedione). The method according to Appendix 14.

[0124] (Appendix 16) The method according to any one of Appendices 1 to 15, wherein the metal-containing film contains at least one metal selected from the group consisting of Al, Hf, Zr, Fe, Ni, Co, Mn, Mg, Rh, Ru, Cr, Si, Ti, Ga, In, Zn, Pb, Ge, Ta, Cu, W, Mo, Pt, Cd, and Sn.

[0125] (Appendix 17) The method according to Appendix 16, wherein the metal-containing film is an oxide or a nitride of the metal.

[0126] (Appendix 18) The method according to any one of Appendices 1 to 17, wherein the fluorine-containing gas contains at least one selected from the group consisting of hydrogen fluoride gas, fluorocarbon gas, nitrogen-containing gas, and sulfur-containing gas.

[0127] (Appendix 19) A substrate processing method, (a) providing a substrate having an etching target film and a mask provided on the etching target film; (b) forming a metal-containing protective film on the mask; (c) after (b), removing a part of the metal-containing protective film; (d) after (c), etching the etching target film; comprising: (b) includes: (b1) forming a precursor layer on a side surface of the mask using a first precursor containing a metal; (b2) reforming the precursor layer into the metal-containing protective film using a reforming gas containing an oxidizing gas or a reducing gas; comprising: (c) includes: (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing protective film using a first processing gas containing at least one of a halogen-containing gas and an oxygen-containing gas; (c2) removing the second metal-containing substance using a second processing gas containing a second precursor; A method including

[0128] (Appendix 20) The method according to Appendix 19, wherein the first precursor contains at least one metal selected from the group consisting of Ti, Ta, Ru, Al, Hf, and Sn.

[0129] (Appendix 21) The method according to Appendix 19 or 20, wherein the halogen-containing gas contains at least one selected from the group consisting of fluorine, chlorine, and bromine.

[0130] (Appendix 22) The method according to any one of Appendices 19 to 21, wherein the second precursor contains a metal containing at least one selected from the group consisting of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr, and Ti or a complex of the metal.

[0131] (Appendix 23) The method according to any one of Appendices 19 to 22, wherein the film to be etched is a silicon-containing film.

[0132] (Appendix 24) A chamber, A substrate support portion for supporting a substrate in the chamber, the substrate having a metal-containing film and a mask provided on the metal-containing film, A gas supply portion configured to supply a first processing gas containing hydrogen fluoride gas, a second processing gas containing a precursor, a third processing gas, and a fourth processing gas for forming a protective film into the chamber, respectively, A control unit, Comprising, The control unit is configured to control the gas supply portion to form the protective film on the mask using the fourth processing gas, After the protective film is formed, the control unit is configured to control the gas supply portion to form a second metal-containing substance from a first metal-containing substance contained in the metal-containing film using the first processing gas, After the second metal-containing substance is formed, the control unit is configured to control the gas supply unit to remove the second metal-containing substance using the second processing gas. After the second metal-containing substance is removed, the control unit is configured to control the gas supply unit to remove fluorine on the surface of the protective film using the third processing gas. A substrate processing apparatus.

Explanation of reference numerals

[0133] 2... Control unit, 10... Plasma processing chamber, 11... Substrate support unit, 20... Gas supply unit, EF... Etching target film, G1, G1a... First processing gas, G2, G2a... Second processing gas, MF... Metal-containing film, MK, MKa... Mask, MS1... First metal-containing substance, MS2... Second metal-containing substance, PR... Protective film, PRa... Metal-containing protective film, PRs... Surface, W, Wa... Substrate.

Claims

1. A substrate processing method, comprising: (a) providing a substrate having an etching target film and a mask provided on the etching target film; (b) forming a metal-containing protective film on the mask; (c) after (b), removing a part of the metal-containing protective film; (d) after (c), etching the etching target film; wherein (b) includes: (b1) forming a precursor layer on a side surface of the mask using a first precursor containing a metal; (b2) modifying the precursor layer into the metal-containing protective film using a modifying gas containing an oxidizing gas or a reducing gas; wherein (c) includes: (c1) forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing protective film using a first processing gas containing at least one of a halogen-containing gas and an oxygen-containing gas; (c2) removing the second metal-containing substance using a second processing gas containing a second precursor; a method.

2. The method according to claim 1, wherein the first precursor contains at least one metal selected from the group consisting of Ti, Ta, Ru, Al, Hf, and Sn.

3. The method according to claim 1 or 2, wherein the halogen-containing gas contains at least one selected from the group consisting of fluorine, chlorine, and bromine.

4. The method according to claim 1 or 2, wherein the second precursor contains at least one metal selected from the group consisting of Sn, Ge, Al, B, Ga, In, Zn, Ni, Pb, Si, Hf, Zr, and Ti or a complex of the metal.

5. The method according to claim 1 or 2, wherein the etching target film is a silicon-containing film.

6. The method according to claim 1 or 2, wherein the etching target film is a metal-containing film.

7. The method according to claim 6, wherein the metal-containing film contains at least one metal selected from the group consisting of Al, Hf, Zr, Fe, Ni, Co, Mn, Mg, Rh, Ru, Cr, Si, Ti, Ga, In, Zn, Pb, Ge, Ta, Cu, W, Mo, Pt, Cd, and Sn.

8. The method according to claim 7, wherein the metal-containing film is an oxide or a nitride of the metal.

9. a chamber, A substrate support portion for supporting a substrate in the chamber, the substrate having a film to be etched and a mask provided on the film to be etched, the substrate support portion; A gas supply portion configured to supply a first precursor containing a metal, a reforming gas containing an oxidizing gas or a reducing gas, a first processing gas containing at least one of a halogen-containing gas and an oxygen-containing gas, and a second processing gas containing a second precursor into the chamber respectively; A control unit; Comprising; The control unit is configured to control the gas supply portion to perform a substrate processing method, and the substrate processing method is as follows: (b) A step of forming a metal-containing protective film on the mask; (c) After the step (b), a step of removing a part of the metal-containing protective film; (d) After the step (c), a step of etching the film to be etched; Including; The step (b) is as follows: (b1) A step of forming a precursor layer on a side surface of the mask using the first precursor; (b2) A step of reforming the precursor layer into the metal-containing protective film using the reforming gas; Including; The step (c) is as follows: (c1) A step of forming a second metal-containing substance from a first metal-containing substance contained in the metal-containing protective film using the first processing gas; (c2) A step of removing the second metal-containing substance using the second processing gas; A substrate processing apparatus including.

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