Etching method and plasma processing system

Abstract

Disclosed is an etching method which includes: (a) a step for preparing a substrate, the substrate comprising an etching object film that has a first region and a second region, and a boron-containing film that is on the first region of the etching object film, with at least one first opening being formed on the second region of the etching object film; (b) a step for forming a deposition film in the first opening on the second region of the etching object film, the deposition film containing a metal and oxygen and / or nitrogen; and (c) a step for selectively etching the boron-containing film with respect to the deposition film by plasma that is generated from a first processing gas to form at least one second opening on the first region of the etching object film.

Description

Etching method and plasma processing system

[0001] SUMMARY Exemplary embodiments of the present disclosure relate to an etching method and a plasma processing system.

[0002] Patent Document 1 discloses a technique for patterning a substrate.

[0003] Special table 2016-539361 publication

[0004] The present disclosure provides techniques for reversing a pattern on a substrate.

[0005] In one exemplary embodiment of the present disclosure, there is provided an etching method including: (a) a step of preparing a substrate, the substrate including a film to be etched having a first region and a second region, and a boron-containing film on the first region of the film to be etched, wherein at least one first opening is formed on the second region of the film to be etched; (b) a step of forming a deposited film containing a metal and / or a semiconductor element in the first opening on the second region of the film to be etched; and (c) a step of selectively etching the boron-containing film with respect to the deposited film by using plasma generated from a first process gas, to form at least one second opening on the first region of the film to be etched.

[0006] According to one exemplary embodiment of the present disclosure, a technique for reversing a pattern on a substrate can be provided.

[0007] FIG. 5 is a diagram for explaining an example of the configuration of a plasma processing system. FIG. 6 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus. FIG. 7 is a flowchart showing the present etching method. FIG. 8 is a diagram showing an example of the cross-sectional structure of a substrate W prepared in process ST1. FIG. 9 is a diagram for explaining an example of a method for forming the first opening OP1 shown in FIG. 4. FIG. 10 is a diagram showing an example of the cross-sectional structure of a substrate W after process ST2 has been performed. FIG. 11 is a diagram showing an example of the cross-sectional structure of a substrate W after process ST3 has been performed. FIG. 12 is a diagram showing an example of the cross-sectional structure of a substrate W during process ST4 after process ST3 has been performed.

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, there is provided an etching method including: (a) preparing a substrate, the substrate comprising: a film to be etched having a first region and a second region; and a boron-containing film on the first region of the film to be etched; and at least one first opening formed on the second region of the film to be etched; (b) forming a deposited film containing a metal and / or a semiconductor element in the first opening on the second region of the film to be etched; and (c) selectively etching the boron-containing film with respect to the deposited film using plasma generated from a first process gas, to form at least one second opening on the first region of the film to be etched.

[0010] In one exemplary embodiment, the at least one first opening is formed using a mask having an opening pattern corresponding to the first opening.

[0011] In one exemplary embodiment, the mask is a metal-containing resist.

[0012] In one exemplary embodiment, the mask is a chemically amplified resist.

[0013] In one exemplary embodiment, the mask is configured as an array of pillars.

[0014] In one exemplary embodiment, after performing the step (c), the etching method further includes a step of etching the film to be etched by plasma generated from a second process gas using the deposited film as a mask.

[0015] In one exemplary embodiment, the film to be etched includes at least one selected from the group consisting of a silicon-containing film, a carbon-containing film, and a metal-containing film.

[0016] In one exemplary embodiment, the boron-containing film includes at least one selected from the group consisting of a boron film, a boron nitride film, a boron oxide film, and a boron carbide film.

[0017] In one exemplary embodiment, the deposited film comprises at least one selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

[0018] In one exemplary embodiment, the step (b) includes the steps of: (b1) exposing the substrate to a precursor gas containing a metal; and (b2) exposing the substrate to a reactive gas or a plasma generated from the reactive gas.

[0019] In one exemplary embodiment, the precursor gas comprises at least one halide selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

[0020] In one exemplary embodiment, the precursor gas comprises a halide of at least one metal selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, and Zn, and a halide of at least one semiconductor element selected from the group consisting of Si and Ge.

[0021] In one exemplary embodiment, the precursor gas further comprises an element different from the metal and the semiconductor element.

[0022] In one exemplary embodiment, the reaction gas is NH ３ , N ２ , N ２ H ４ , N ２ H ２ , O ２ , O ３ , H ２ O, NO, N ２ O, H ２ , H ２ S, CH ４ , and SiH ４ The compound includes at least one selected from the group consisting of:

[0023] In one exemplary embodiment, the first process gas comprises at least one selected from the group consisting of a fluorine-containing gas, a chlorine-containing gas, a bromine-containing gas, a carbon-containing gas, and a hydrogen-containing gas.

[0024] In one exemplary embodiment, the first process gas and the second process gas comprise a fluorine-containing gas.

[0025] In one exemplary embodiment, steps (b) and (c) are performed in separate chambers.

[0026] In one exemplary embodiment, steps (a), (b) and (c) are performed in the same chamber.

[0027] In one exemplary embodiment, there is provided a plasma processing system including a chamber, a substrate support provided in the chamber, and a controller, wherein the controller executes the following controls: (a) controlling a substrate preparation, the substrate including a film to be etched having a first region and a second region, and a boron-containing film on the first region of the film to be etched, the boron-containing film having at least one first opening formed on the second region of the film to be etched; (b) controlling a deposition film including a metal and / or a semiconductor element in the first opening on the second region of the film to be etched; and (c) controlling a plasma generated from a first process gas to selectively etch the boron-containing film with respect to the deposition film, thereby forming at least one second opening on the first region of the film to be etched.

[0028] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0029] <Configuration Example of Plasma Processing System> FIG. 1 is a diagram illustrating a configuration example of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0030] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0031] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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 a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0032] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0033] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0034] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0035] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0036] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0037] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0038] 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 multiple gas inlets 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 multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0039] 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 a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0040] 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) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0041] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode 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 in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0042] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0043] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0044] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0045] The exhaust system 40 may be connected to, for example, a gas exhaust port 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 in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0046] <Example of Etching Method> FIG. 3 is a flowchart showing an etching method (hereinafter also referred to as "this etching method") according to an illustrative embodiment. This etching method includes a step ST1 of preparing a substrate, a step ST2 of forming a deposited film, and a step ST3 of etching a boron-containing film. In one embodiment, this etching method may further include a step ST4 of etching a film to be etched after step ST3. Each step may be performed using one of the above-described plasma processing systems (see FIGS. 1 and 2), or may be performed using two or more of these plasma processing systems. For example, this etching method may be performed in the plasma processing system (see FIG. 1). The following description will be given taking as an example a case where the controller 2 controls each component of the plasma processing apparatus 1 to perform this etching method on a substrate W.

[0047] (Step ST1: Preparation of Substrate) In step ST1, a substrate W is prepared. The substrate W may be used for manufacturing semiconductor devices. The semiconductor devices include, for example, memory devices such as DRAMs and 3D-NAND flash memories, and logic devices.

[0048] 4 is a diagram showing an example of a cross-sectional structure of a substrate W prepared in process ST1. As illustrated in Fig. 4, the substrate W includes an etching target film F1 and a boron-containing film F2. The substrate W may be configured by laminating the etching target film F1 and the boron-containing film F2 in this order on an arbitrary base film UF.

[0049] The base film UF is, for example, a silicon wafer, an organic film formed on a silicon wafer, a dielectric film, a metal film, a semiconductor film, etc. The base film UF may be configured by stacking a plurality of films.

[0050] The etching target film F1 has a first region R1 and a second region R2. A boron-containing film F2 is disposed on the first region R1 of the etching target film F1. The etching target film F1 may include, for example, at least one selected from the group consisting of a silicon-containing film, a carbon-containing film, and a metal-containing film. Examples of silicon-containing films include spin-on-glass (SOG) films, Si-containing antireflective coatings (SiARC), silicon oxide films, silicon nitride films, silicon oxynitride films, silicon carbide films, silicon carbonitride films, and polycrystalline silicon films. Examples of carbon-containing films include spin-on-carbon (SOC) films and amorphous carbon films. Examples of metal-containing films include titanium-containing films, tungsten-containing films, ruthenium-containing films, zirconium-containing films, aluminum-containing films, and hafnium-containing films. Examples of titanium-containing films include titanium oxide films and titanium nitride films. Examples of tungsten-containing films include tungsten films, tungsten carbide films, and tungsten silicide films. Examples of ruthenium-containing films include ruthenium films. Examples of zirconium-containing films include zirconium oxide films. Examples of aluminum-containing films include aluminum oxide films. Examples of hafnium-containing films include hafnium oxide films. The etching target film F1 and any base film UF constituting the substrate W may each be formed by a CVD method, an atomic layer deposition method (hereinafter referred to as an "ALD method"), a spin coating method, or the like. The etching target film F1 and any base film UF may each be a flat film or may be a film having irregularities.

[0051] The boron-containing film F2 contains boron (B). Boron tends to inhibit the formation of a deposited film F3 on the boron-containing film F2 in step ST3, which will be described later. Therefore, the boron-containing film F2 tends to contribute to the selective formation of a deposited film in the first opening OP1. The B content in the boron-containing film F2 may be, for example, 20 atomic % to 100 atomic %, or 40 atomic % to 100 atomic %. The boron-containing film F2 may be, for example, a B film, a BN film, a BNC film, a BO film, a BNOC film, a SiBN film, a SiBCN film, or a SiOBN film. Here, the BN film refers to a film containing boron (B) and nitrogen (N), and the atomic ratio of B to N in the BN film is not limited to 1:1. Films other than BN films, such as BNC films, similarly contain the respective elements, and the stoichiometric ratio is not particularly limited. In one embodiment, the boron-containing film F2 may include at least one selected from the group consisting of a boron film, a boron nitride film, a boron oxide film, and a boron carbide film.

[0052] As shown in FIG. 4 , the boron-containing film F2 is disposed on a first region R1 of the etching target film. At least one first opening OP1 is formed in the boron-containing film F2 on a second region R2 of the etching target film F1. The first opening OP1 provides the boron-containing film F2 with a first opening pattern. In one embodiment, the boron-containing film F2 may not be formed on the second region R2 of the etching target film F1. Also, in one embodiment, the boron-containing film F2 may be formed on the second region R2 of the etching target film F1 to a thickness thinner than that formed on the first region R1 of the etching target film F1. The boron-containing film F2 may be formed using various methods, such as an ALD method or a CVD method. In the case of the ALD method, the boron-containing film F2 may be formed by performing one or more cycles of supplying a boron-containing gas, allowing the boron-containing gas to adsorb on the surface of the etching target film, and then supplying a reactive gas and reacting the boron-containing gas with the reactive gas. The boron-containing gas and the reaction gas may be supplied together with a dilution gas. After supplying the boron-containing gas, excess boron-containing gas may be purged before supplying the reaction gas. Examples of the boron-containing gas include trisdimethylaminoborane (TDMAB:C ６ H１８ BN ３ ), diborane (B ２ H ６ ), boron trichloride (BCl ３ ), boron trifluoride (BF ３ ), trisethylmethylaminoborane (C ９ H ２４ BN ３ ), trimethylborane (C ３ H ９ B), or triethylborane (C ６ H １５ B), cyclotriborazane (B ３ N ３ H ６ Examples of the reactive gas include a nitrogen-containing gas, an oxygen-containing gas, and a reducing gas. Examples of the nitrogen-containing gas include NH ３ , N ２ , N ２ H ４ or N ２ H ２ Examples of oxygen-containing gases include O ２ , O ３ , H ２ O, NO or N ２ Examples of the reducing gas include H ２ , H ２ S, CH ４ , SiH ４ Examples of dilution gases include Ar and N ２ In the case of the CVD method, for example, the boron-containing gas and the reactive gas described above may be used to form the boron-containing film F2 on the etching target film F1 by plasma CVD, thermal CVD, or the like.

[0053] The first opening OP1 may have any shape when viewed from above the substrate W, i.e., when the substrate W is viewed from top to bottom in FIG. 4 . The shape may be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more of these. The shape may also be an inverted shape of any of the above shapes. For example, a line-and-space pattern of the boron-containing film F2 may be formed by arranging a plurality of first openings OP1a having a circular shape in a planar view at intervals. Furthermore, an array pattern of the boron-containing film F2 may be formed by arranging a plurality of first openings OP1a having a circular shape in a planar view in a dot pattern. In one example, the boron-containing film F2 may be configured in the form of an array of a plurality of holes. In one example, the boron-containing film F2 may be configured in the form of an array of a plurality of pillars.

[0054] 5 is a diagram illustrating an example of a method for forming the first opening OP1. In one embodiment, the first opening OP1 may be formed using a mask M shown in FIG. 5. The mask M has an opening OP1a formed therein that corresponds to the first opening OP1 in the boron-containing film F2. That is, the mask M may have a first opening pattern, similar to the boron-containing film F2. The opening OP1 may then be formed by etching the boron-containing film F2 using the mask M. The mask M may be removed after the opening OP1 is formed. In this manner, the substrate W shown in FIG. 4 may be prepared.

[0055] In one embodiment, the mask M may be a photoresist. In one embodiment, the mask M may be a photoresist exposed to extreme ultraviolet light (hereinafter referred to as "EUV"). In one embodiment, the mask M may be a metal-containing resist. In one embodiment, the metal contained in the metal-containing resist may be at least one selected from the group consisting of Sn, Hf, and Ti. In one embodiment, the metal-containing resist may contain Sn. As an example, the metal-containing resist may contain tin oxide (Sn—O bond) or tin hydroxide (Sn—OH bond). As an example, the metal-containing resist may be exposed to EUV. In one embodiment, the mask M may be a chemically amplified resist (hereinafter referred to as "CAR"). As an example, the CAR may be exposed to EUV. In one embodiment, the opening OP1a may be formed by lithography. As an example, the opening OP1a may be formed by exposing and developing a photoresist formed on the boron-containing film F2. When an EUV resist is used as the photoresist, the exposure may be EUV exposure using an EUV exposure apparatus. Furthermore, the development may be dry development or wet development. In one embodiment, the opening OP1a may be formed by etching.

[0056] In step ST1, the substrate W may be prepared in a plasma processing chamber 10 (hereinafter also referred to as "chamber 10"). In one embodiment, the substrate W is carried into the chamber 10 by a transport arm, placed on a substrate support 11 by a lifter, and held by suction on the substrate support 11, for example, as shown in FIG.

[0057] After the substrate W is placed on the substrate support 11, the temperature of the substrate support 11 may be adjusted to a set temperature by a temperature control module. The set temperature may be, for example, a temperature of 60°C or less (e.g., room temperature). In one example, adjusting or maintaining the temperature of the substrate support 11 includes adjusting or maintaining the temperature of the heat transfer fluid flowing through the flow path 1110a at a set temperature or a temperature different from the set temperature. In one example, adjusting or maintaining the temperature of the substrate support 11 includes controlling the pressure of a heat transfer gas (e.g., He) between the electrostatic chuck 1111 and the back surface of the substrate W. Note that the timing at which the heat transfer fluid starts flowing through the flow path 1110a may be before, after, or simultaneously with the substrate W being placed on the substrate support 11. In addition, in this etching method, the temperature of the substrate support 11 may be adjusted to the set temperature before step ST1. That is, the substrate W may be prepared on the substrate support 11 after the temperature of the substrate support 11 is adjusted to the set temperature. In the subsequent steps of this etching method, the temperature of the substrate support 11 may be maintained at the set temperature adjusted in step ST1.

[0058] In one embodiment, the substrate W may be controlled to a set temperature instead of controlling the substrate support 11 to a set temperature. Controlling the temperature of the substrate W to a set temperature includes setting the temperature of the substrate support 11, the heat transfer fluid flowing through the flow path 1110a, and / or the heater temperature to the set temperature or to a temperature different from the set temperature.

[0059] At least a part of the process for forming each component of the substrate W may be performed in the chamber 10 as part of step ST1. For example, when the opening OP1a in the mask M is formed by etching, the etching in step ST1 and the processes in steps ST2 and ST3 may be performed consecutively in the chamber 10. In one embodiment, the substrate W may be provided in the chamber 10 after all or some of the components of the substrate W are formed in an apparatus or chamber external to the plasma processing apparatus 1.

[0060] (Step ST2: Formation of Deposited Film) Next, in step ST2, a deposited film F3 is formed on the substrate W. In one embodiment, the deposited film F3 includes a metal and / or a semiconductor element. The deposited film F3 may include at least one element selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, and Sb. The deposited film F3 may include at least one metal element selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, and Zn, and at least one semiconductor element selected from the group consisting of Si and Ge. In addition to the above-mentioned metal and semiconductor elements, the deposited film F3 may further include other elements different from these metal and semiconductor elements. In step ST2, the deposited film F3 is formed on at least one first opening, i.e., the second region of the etching target film F1.

[0061] FIG. 6 shows an example of the cross-sectional structure of a substrate W on which a deposited film F3 is formed. In the example of FIG. 6, the deposited film F3 is not formed on the boron-containing film F2, but is selectively formed on the second region R2 of the etching target film F1. This is because the boron-containing film F2 contains boron, which tends to inhibit the formation of the deposited film F3 on the boron-containing film F2. In one embodiment, the thickness of the deposited film F3 may be set so that the deposited film F3 remains after etching in step ST3 or step ST4. In one embodiment, the thickness of the deposited film F3 may be greater than the thickness of the boron-containing film F2, as shown in FIG. 6. In one embodiment, the thickness of the deposited film F3 may be smaller than the thickness of the boron-containing film F2 or may be the same as the thickness of the boron-containing film F2.

[0062] In one embodiment, the deposited film F3 may be formed by an ALD method. For example, step ST2 may include exposing the substrate W to a precursor gas containing a metal, and exposing the substrate W to a reactive gas or plasma generated from the reactive gas. In one embodiment, the precursor gas may include at least one selected from the group consisting of Ti halide, W halide, V halide, Al halide, Mo halide, Sn halide, Hf halide, Ta halide, Nb halide, Zr halide, In halide, Ga halide, Zn halide, Si halide, Ge halide, and Sb halide. In one embodiment, the reactive gas may include NH ３ , N ２ , N ２ H ４ , N ２ H ２ , O ２ , O ３ , H ２ O, NO, N ２ O, H ２ , H ２ S, CH ４ , and SiH ４ The reactive gas may include, for example, a nitrogen-containing gas, an oxygen-containing gas, a reducing gas, etc. The nitrogen-containing gas may include, for example, NH ３ , N ２ , N ２ H ４ or N ２ H ２ Examples of oxygen-containing gases include O ２ , O ３ , H ２ O, NO or N ２ Examples of the reducing gas include H ２ , H ２ S, CH ４ , SiH ４ Examples of dilution gases include Ar and N ２ etc.

[0063] The precursor gas contains, for example, a halogen and an element X other than a halogen. Examples of halogen include fluorine, chlorine, bromine, and iodine. Examples of the element X include a metal element, and examples of the metal element include a transition metal element. Examples of the element X include Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, and Sb. Specific examples of the precursor gas include TiCl ４ Gas, WCl ６ Gas, WF ６ Gas, VCl ４ Gas, AlCl ３ Gas, MoCl ５ Gas, SnCl ４ Gas, HfCl ４ Gas, TaCl ５ Gas, NbCl ５ Gas, ZrCl ４ Gas, InCl ３ Gas, GaCl ３ gas or SbCl ３ Gas is one example.

[0064] The element X may be a semiconductor element, specifically Si or Ge. As an example, the precursor gas may be a silicon halide gas or a germanium halide gas. Specific examples of silicon halide gas include SiCl. ４ Gas, SiHCl ３ Gas, SiH ２ Cl ２ Gas, SiH ３ Cl gas, Si ２ Cl ６ Gas, Si ２ HCl ５ Gas, Si ２ Cl ３ CH ３ Gas, SiCl ３ CCl ３ Gas, SiCl ３ CH ３ gas, or SiH ２ I ２ Specific examples of germanium halide gas include GeCl ４ Gas, etc.

[0065] The precursor gas may be supplied together with a diluent gas, such as Ar gas or N ２ It's gas.

[0066] In one embodiment, the reactive gas may react with an element X that may be contained in the precursor gas to form a deposited film F3 containing the element X. Examples of the reactive gas include an oxygen-containing gas, a nitrogen-containing gas, and a hydrogen-containing gas. Examples of the oxygen-containing gas include a gas that contains oxygen and forms an oxide film of the element X. Specific examples of the oxygen-containing gas include O ２ Gas, O ３ Gas, CO ２ Gas, N ２ O gas, NO gas, or H ２ Examples of the nitrogen-containing gas include a gas containing nitrogen and forming a nitride film of element X. Specific examples of the nitrogen-containing gas include NH ３ Gas or N ２ H ４ Examples of the hydrogen-containing gas include a gas that contains hydrogen and forms a film (for example, a metal film or a semiconductor film) containing element X as a main component. Specific examples of the hydrogen-containing gas include H ２ Gas or H ２ S gas is an example.

[0067] In one embodiment, the reactive gas may be supplied with a diluent gas, such as Ar gas or N ２ The reactive gas may be plasma. Note that the reactive gas may not be necessary depending on the material of the deposition film F3.

[0068] In one embodiment, the deposited film F3 may be formed by a CVD method. In one embodiment, a precursor gas that can be used in the CVD method can be appropriately selected from the precursor gases exemplified as those that can be used in the ALD method.

[0069] As described above, when the deposited film F3 is formed by the ALD method or the CVD method, metal chlorides or the like may be used in each method. The boron-containing film F2, which contains boron, tends to inhibit the adsorption of metal chlorides or the like, and the formation of the deposited film F3 on the boron-containing film F2 by the ALD method or the CVD method tends to be further inhibited. Therefore, when the ALD method or the CVD method is employed, the selective formation of the deposited film F3 on the second region of the etching target film F1 tends to be further promoted. By selectively forming the deposited film F3 on the second region of the etching target film F1, the opening pattern of the film on the etching target film F1 is reversed after etching of the boron-containing film F2 in the step ST3 described below.

[0070] (Step ST3: Etching of Boron-Containing Film) In step ST3, the boron-containing film F2 is etched. In step ST3, the boron-containing film F2 is selectively etched with plasma generated from a first process gas relative to the deposited film F3, thereby forming at least one second opening OP2 in the first region R1 of the etching target film F1. Step ST3 includes supplying a first process gas to the chamber 10 and generating plasma from the first process gas.

[0071] First, a first process gas is supplied into the chamber 10. The first process gas may be supplied into the chamber 10 from the gas supply unit 20 via the gas inlet 13c of the shower head 13, for example. In one embodiment, the first process gas may include at least one gas selected from the group consisting of a fluorine-containing gas, a chlorine-containing gas, a bromine-containing gas, a carbon-containing gas, and a hydrogen-containing gas. In one embodiment, the first process gas may include a fluorine-containing gas.

[0072] Next, plasma is generated from the first process gas in the chamber 10. For example, a source RF signal is supplied to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. When a high-frequency electric field is generated between the shower head 13 and the substrate support 11, plasma is generated from the first process gas in the chamber 10. At this time, the boron-containing film F2 is selectively etched with respect to the deposited film F3 by activated species in the plasma.

[0073] In one embodiment, a bias signal may be supplied to the lower electrode of the substrate support 11. In this case, a bias potential is generated between the plasma and the substrate W, and ions in the plasma are attracted to the substrate W, thereby promoting etching. The bias signal may be a bias DC signal supplied from the DC generator 32a, or a bias RF signal supplied from the second RF generator 31b. In one embodiment, a bias signal does not need to be supplied to the lower electrode of the substrate support 11.

[0074] 7 shows an example of the cross-sectional structure of the substrate W after step ST3 has been performed. In the example shown in FIG. 7, the boron-containing film F2 on the first region R1 of the etching target film F1 has been selectively removed with respect to the deposited film F3 by etching. As a result, at least one second opening OP2 is formed on the first region R1 of the etching target film F1. The second opening OP2 provides the deposited film F3 with a second opening pattern. The second opening pattern of the deposited film F3 formed by the second opening OP2 is a reverse pattern of the first opening pattern of the boron-containing film F2 formed by the first opening OP1 (see FIG. 4). That is, the opening pattern of the film on the etching target film F1 is reversed between step ST1 and step ST3.

[0075] (Step ST4: Etching of Etching Target Film) In one embodiment, the etching method may further include, after step ST3, step ST4 of etching the etching target film F1. In step ST4, the etching target film F1 is etched by plasma generated from a second process gas using the deposition film F3 as a mask. Step ST4 includes supplying the second process gas to the chamber 10 and generating plasma from the second process gas.

[0076] First, the second process gas is supplied into the chamber 10. The second process gas may be supplied into the chamber 10 from the gas supply unit 20 via the gas inlet 13c of the shower head 13, for example.

[0077] The second process gas may be appropriately selected depending on the type of film to be etched. For example, when the film to be etched is a silicon-containing film, the second process gas may contain a fluorine-containing gas. The fluorine-containing gas may contain at least one gas selected from the group consisting of hydrogen fluoride (HF) gas, a CF-based gas, and a CHF-based gas. In addition to the fluorine-containing gas, the second process gas may contain at least one gas selected from the group consisting of a phosphorus-containing gas, a metal-containing gas, a halogen-containing gas other than fluorine, and an oxygen-containing gas. In one example, the phosphorus-containing gas is a halogenated phosphorus gas. In one example, the metal-containing gas is WF ２ Gas, WF ４ Gas, WF ５ Gas, WF ６ Gas, WCl ２ Gas, WCl ４ Gas, WCl ５ Gas, WCl ６ Gas, MoF ４ Gas, MoF ６ Gas, MoCl ６ Gas, TiCl ４ In one example, the halogen-containing gas other than fluorine is Cl ２ In one example, the oxygen-containing gas is O ２ , CO, CO ２ , H ２ O and H ２ O ２ In one example, when the film to be etched is a carbon-containing film, the second process gas may include an oxygen-containing gas, a hydrogen-containing gas, and a nitrogen-containing gas. In one example, when the film to be etched is a metal-containing film, the second process gas may include a chlorine-containing gas, a carbon-containing gas, a fluorine-containing gas, and an oxygen-containing gas.

[0078] In one embodiment, the second process gas is composed of a gas different from the first process gas, or the second process gas is composed of the same gas as the first process gas. In this case, step ST4 may be performed consecutively from step ST3.

[0079] Next, plasma is generated from the second process gas in the chamber 10. For example, a source RF signal is supplied to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. When a high-frequency electric field is generated between the shower head 13 and the substrate support 11, plasma is generated from the second process gas in the chamber 10. At this time, the deposited film F3 functions as a mask, and the first region R1 of the etching target film, i.e., the portion exposed to the second opening OP2, is etched by activated species in the plasma.

[0080] 8 shows an example of a cross-sectional structure of the substrate W during the process ST4. As shown in Fig. 8, the deposition film F3 functions as a mask in the etching of the etching target film F1, and a recess having a shape corresponding to the second opening OP2 is formed in the etching target film F1.

[0081] According to this etching method, the opening pattern of the film on the etching target film F1 is inverted between steps ST1 and ST3, and is inverted from the first opening pattern (see FIG. 4) formed by the first opening OP1 to the second opening pattern (see FIG. 7) formed by the second opening OP2. As a result, in step ST4, the etching target film F1 can be etched using the "opening pattern inverted from the opening pattern on the etching target film F1 prepared in step ST1."

[0082] This etching method may be applied to the following cases. For example, when the mask M (see FIG. 5) is a metal-containing photoresist, it is often a negative photoresist (exposed portions remain after development). In this case, it is generally difficult to form a "hole pattern" in the mask M by development, and therefore, it is generally difficult to form holes in the etching target film. According to this etching method, even in such cases, holes can be formed in the etching target film F1 by preparing a mask M having an "inverse pattern of the hole pattern" (for example, a pillar pattern mask M configured in an array of multiple pillars). For example, in step ST1, a boron-containing film F2 having a pillar pattern may be prepared using the pillar pattern mask M. Then, in step ST3, a deposited film F3 having a "hole pattern" (an inverse pattern of the pillar pattern) is formed, and in step ST4, the etching target film F1 is etched using the deposited film F3 having the "hole pattern" as a mask. This allows holes (for example, contact holes) to be formed in the etching target film F1.

[0083] This etching method may also be applied when the mask M is a positive photoresist. For example, when the mask M is a positive metal-containing photoresist or a CAR resist, a hole pattern may be formed in the mask M by development. In this case, in step ST1, a boron-containing film F2 having a hole pattern may be prepared using the hole-pattern mask M. Then, in step ST3, a deposited film F3 having a "pillar pattern" (a reverse pattern of the hole pattern) is formed, and in step ST4, the etching target film F1 is etched using the deposited film F3 having the "pillar pattern" as a mask. This allows pillars to be formed in the etching target film F1.

[0084] This etching method may be applied, for example, when the mask M is a CAR resist. In this case, the CAR resist may be either a positive type or a negative type. In addition, in this etching method, the pillar pattern may be circular, polygonal, or a combination thereof in a plan view. In addition, in this etching method, the hole pattern may be circular, polygonal, or a combination thereof in a plan view.

[0085] In one embodiment, steps ST1, ST2, and ST3 may be performed in the same chamber. Also, in one embodiment, steps ST1, ST2, ST3, and ST4 may be performed in the same chamber. Furthermore, in one embodiment, at least steps ST2 and ST3 may be performed in different chambers.

[0086] According to the above embodiment, a technique for reversing a pattern on a substrate can be provided.

[0087] Embodiments of the present disclosure further include the following aspects.

[0088] (Supplementary Note 1) An etching method comprising: (a) preparing a substrate, the substrate comprising: a film to be etched having a first region and a second region; and a boron-containing film on the first region of the film to be etched; and at least one first opening formed on the second region of the film to be etched; (b) forming a deposited film containing a metal and / or a semiconductor element in the first opening on the second region of the film to be etched; and (c) selectively etching the boron-containing film with respect to the deposited film by plasma generated from a first process gas, to form at least one second opening on the first region of the film to be etched.

[0089] (Supplementary Note 2) The etching method according to Supplementary Note 1, wherein the at least one first opening is formed using a mask having an opening pattern corresponding to the first opening.

[0090] (Supplementary Note 3) The etching method according to Supplementary Note 2, wherein the mask is a metal-containing resist.

[0091] (Supplementary Note 4) The etching method according to Supplementary Note 2 or Supplementary Note 3, wherein the mask is a chemically amplified resist.

[0092] (Supplementary Note 5) The etching method according to any one of Supplementary Note 2 to Supplementary Note 4, wherein the mask is configured in an array shape with a plurality of pillars arranged side by side.

[0093] (Supplementary Note 6) The etching method according to any one of Supplementary Note 1 to Supplementary Note 5, further comprising, after carrying out the step (c), a step of etching the film to be etched by plasma generated from a second processing gas using the deposited film as a mask.

[0094] (Supplementary Note 7) The etching method according to any one of Supplementary Note 1 to Supplementary Note 6, wherein the etching target film includes at least one film selected from the group consisting of a silicon-containing film, a carbon-containing film, and a metal-containing film.

[0095] (Supplementary Note 8) The etching method according to any one of Supplementary Note 1 to Supplementary Note 7, wherein the boron-containing film includes at least one selected from the group consisting of a boron film, a boron nitride film, a boron oxide film, and a boron carbide film.

[0096] (Supplementary Note 9) The etching method according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the deposited film contains at least one selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

[0097] (Supplementary Note 10) The etching method according to any one of Supplementary Note 1 to Supplementary Note 9, wherein the step (b) includes: (b1) exposing the substrate to a precursor gas containing a metal; and (b2) exposing the substrate to a reactive gas or plasma generated from the reactive gas.

[0098] (Supplementary Note 11) The etching method according to Supplementary Note 10, wherein the precursor gas contains at least one halide selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

[0099] (Supplementary Note 12) The etching method according to Supplementary Note 11, wherein the precursor gas contains a halide of at least one metal selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, and Zn, and a halide of at least one semiconductor element selected from the group consisting of Si and Ge.

[0100] (Supplementary Note 13) The etching method according to Supplementary Note 12, wherein the precursor gas further contains an element different from the metal and the semiconductor element.

[0101] (Supplementary Note 14) The reactive gas is NH ３ , N ２ , N ２ H ４ , N ２ H ２ , O ２ , O ３ , H ２ O, NO, N ２ O, H ２ , H ２ S, CH ４ , and SiH ４ 13. The etching method according to claim 12, comprising at least one selected from the group consisting of:

[0102] (Supplementary Note 15) The etching method according to any one of Supplementary Note 1 to Supplementary Note 14, wherein the first process gas contains at least one gas selected from the group consisting of a fluorine-containing gas, a chlorine-containing gas, a bromine-containing gas, a carbon-containing gas, and a hydrogen-containing gas.

[0103] (Supplementary Note 16) The etching method according to any one of Supplementary Note 1 to Supplementary Note 15, wherein the first process gas and the second process gas contain a fluorine-containing gas.

[0104] (Supplementary Note 17) The etching method according to any one of Supplementary Note 1 to Supplementary Note 16, wherein the steps (b) and (c) are carried out in different chambers.

[0105] (Supplementary Note 18) The etching method according to any one of Supplementary Note 1 to Supplementary Note 16, wherein the steps (a), (b), and (c) are carried out in the same chamber.

[0106] (Supplementary Note 19) A plasma processing system comprising: a chamber; a substrate support part provided in the chamber; and a control part, wherein the control part executes controls including: (a) control of preparing a substrate, the substrate comprising: a film to be etched having a first region and a second region; and a boron-containing film on the first region of the film to be etched, wherein at least one first opening is formed on the second region of the film to be etched; (b) control of forming a deposited film containing a metal and / or a semiconductor element in the first opening on the second region of the film to be etched; and (c) control of selectively etching the boron-containing film with respect to the deposited film by plasma generated from a first process gas, to form at least one second opening on the first region of the film to be etched.

[0107] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to each embodiment without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments.

[0108] REFERENCE SIGNS LIST 1...plasma processing apparatus, 2...controller, 10...plasma processing chamber, 10a...sidewall, 10s...plasma processing space, 11...substrate support, 112...ring assembly, 13...shower head, 13a...gas supply port, 20...gas supply unit, 31a...first RF generator, 31b...second RF generator, 32a...first DC generator, W...substrate, F1...film to be etched, F2...boron-containing film, F3...deposited film, OP1...first opening, OP2...second opening, R1...first region, R2...second region, M...mask

Claims

1. An etching method comprising: (a) preparing a substrate, the substrate comprising a film to be etched having a first region and a second region, and a boron-containing film on the first region of the film to be etched, the boron-containing film having at least one first opening formed on the second region of the film to be etched; (b) forming a deposited film containing a metal and / or semiconductor element in the first opening on the second region of the film to be etched; and (c) selectively etching the boron-containing film with respect to the deposited film using plasma generated from a first process gas to form at least one second opening on the first region of the film to be etched.

2. The etching method according to claim 1, wherein the at least one first opening is formed using a mask having an opening pattern corresponding to the first opening.

3. The etching method of claim 2, wherein the mask is a metal-containing resist.

4. The etching method according to claim 2, wherein the mask is a chemically amplified resist.

5. The etching method according to claim 2, wherein the mask is configured in the form of an array of pillars.

6. An etching method according to any one of claims 1 to 5, further comprising, after carrying out step (c), a step of etching the film to be etched using the deposited film as a mask and plasma generated from a second processing gas.

7. The etching method according to any one of claims 1 to 5, wherein the film to be etched includes at least one film selected from the group consisting of a silicon-containing film, a carbon-containing film, and a metal-containing film.

8. The etching method according to any one of claims 1 to 5, wherein the boron-containing film comprises at least one film selected from the group consisting of a boron film, a boron nitride film, a boron oxide film, and a boron carbide film.

9. The etching method according to any one of claims 1 to 5, wherein the deposited film contains at least one element selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

10. The etching method according to any one of claims 1 to 5, wherein the step (b) comprises: (b1) exposing the substrate to a precursor gas containing a metal; and (b2) exposing the substrate to a reactive gas or plasma generated from the reactive gas.

11. The etching method of claim 10, wherein the precursor gas contains at least one halide selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, Zn, Si, and Ge.

12. The etching method of claim 11, wherein the precursor gas contains a halide of at least one metal selected from the group consisting of Ti, W, V, Al, Mo, Sn, Hf, Ta, Nb, Zr, In, Ga, Sb, and Zn, and a halide of at least one semiconductor element selected from the group consisting of Si and Ge.

13. The etching method of claim 12, wherein the precursor gas further comprises an element different from the metal and the semiconductor element.

14. The reaction gas is NH ３ , N ２ , N ２ H ４ , N ２ H ２ , O ２ , O ３ , H ２ O, NO, N ２ O, H ２ , H ２ S, C.H. ４ , and SiH ４ The etching method according to claim 12, comprising at least one selected from the group consisting of:

15. The etching method according to any one of claims 1 to 5, wherein the first process gas contains at least one gas selected from the group consisting of a fluorine-containing gas, a chlorine-containing gas, a bromine-containing gas, a carbon-containing gas, and a hydrogen-containing gas.

16. The etching method according to any one of claims 1 to 5, wherein the first process gas and the second process gas comprise a fluorine-containing gas.

17. The etching method according to any one of claims 1 to 5, wherein steps (b) and (c) are carried out in separate chambers.

18. The etching method according to any one of claims 1 to 5, wherein steps (a), (b) and (c) are carried out in the same chamber.

19. A plasma processing system comprising: a chamber; a substrate support provided in the chamber; and a controller, wherein the controller executes controls including: (a) controlling a substrate preparation, the substrate comprising a film to be etched having a first region and a second region, and a boron-containing film on the first region of the film to be etched, wherein at least one first opening is formed on the second region of the film to be etched; (b) controlling a deposition film containing a metal and / or semiconductor element in the first opening on the second region of the film to be etched; and (c) controlling a plasma generated from a first process gas to selectively etch the boron-containing film with respect to the deposition film, thereby forming at least one second opening on the first region of the film to be etched.

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