Etching method and plasma processing apparatus

Abstract

The invention provides a technique for improving an etching shape. Provided is an etching method including: a step of providing a substrate including a first film and a second film on the first film, the first film including silicon, and the second film including at least one opening; and a step for etching the first film by generating plasma from a processing gas containing a hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, the first halogen-containing gas containing at least carbon and a halogen other than fluorine.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to an etching method and a plasma processing apparatus. Background Art

[0002] Patent Document 1 discloses a method for etching a film on a substrate. The film contains silicon. The substrate has a mask provided on the film. The mask contains amorphous carbon or an organic polymer. The etching uses plasma generated by a process gas containing a hydrocarbon gas and a fluorinated hydrocarbon.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-39310 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a technique for improving etching profile.

[0008] Means used to solve problems

[0009] In an exemplary embodiment of the present disclosure, an etching method is provided, which includes the following steps: a step of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and a step of generating plasma from a processing gas and etching the first film, wherein the processing gas includes hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

[0010] Effects of the Invention

[0011] According to an exemplary embodiment of the present disclosure, a technique for improving an etching shape can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram for explaining a configuration example of a plasma processing system.

[0013] Figure 2 This is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0014] Figure 3 is a flow chart illustrating method MT1.

[0015] Figure 4 1 is a diagram showing an example of a cross-sectional structure of the substrate W provided in step ST11.

[0016] Figure 51 is a diagram showing an example of a cross-sectional structure of the substrate W when step ST12 is completed.

[0017] Figure 6 The figures are for explaining the embodiments and reference examples. DETAILED DESCRIPTION

[0018] Hereinafter, each embodiment of the present disclosure will be described.

[0019] In an exemplary embodiment, an etching method is provided, which includes the following steps: a step of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and a step of generating plasma from a processing gas and etching the first film, wherein the processing gas includes hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

[0020] In an exemplary embodiment, the first halogen-containing gas comprises C s H t Br u Cl v F w A gas represented by (s is an integer greater than or equal to 1 and less than or equal to 7, the sum of u and v is an integer greater than or equal to 1, and t, u, v, and w are each an integer greater than or equal to 0 and less than or equal to 16).

[0021] In an exemplary embodiment, the first halogen-containing gas includes bromine as a halogen other than fluorine.

[0022] In an exemplary embodiment, the first halogen-containing gas includes chlorine as a halogen other than fluorine.

[0023] In an exemplary embodiment, the first halogen-containing gas further comprises fluorine.

[0024] In an exemplary embodiment, the first halogen-containing gas includes at least one selected from the group consisting of CHCl 3 gas, CH 2 Cl 2 gas, and CF 2 Br 2 Cl 2 gas.

[0025] In an exemplary embodiment, the phosphorus-containing gas includes a phosphorus halide gas.

[0026] In an exemplary embodiment, the phosphorus-containing gas comprises a phosphorus oxyhalide gas.

[0027] In an exemplary embodiment, the phosphorus oxyhalide gas includes at least one selected from the group consisting of POCl 3 gas, POCl 2 F gas, POClF 2 gas, and POF 3 gas.

[0028] In an exemplary embodiment, the phosphorus-containing gas includes a phosphorus oxyhalide gas and a phosphorus halide gas.

[0029] In an exemplary embodiment, the ratio of the partial pressure of the phosphorus halide gas to the partial pressure of the phosphorus oxyhalide gas is 0.1 or more and 3.0 or less.

[0030] In an exemplary embodiment, the ratio of the flow rate of the phosphorus-containing gas and the first halogen-containing gas to the total flow rate of the process gas is 20 volume % or less.

[0031] In an exemplary embodiment, the process gas further includes a second halogen-containing gas different from the first halogen-containing gas.

[0032] In an exemplary embodiment, the second halogen-containing gas does not contain carbon.

[0033] In an exemplary embodiment, the second halogen-containing gas includes a halogen of a different kind from the halogen included in the first halogen-containing gas.

[0034] In one exemplary embodiment, the first film includes at least one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a polysilicon film.

[0035] In an exemplary embodiment, the second film is a film including at least one of carbon and metal.

[0036] In an exemplary embodiment, an etching method is provided, comprising the following steps: a step of providing a substrate comprising a first film and a second film on the first film, wherein the first film comprises silicon and the second film comprises at least one opening; and a step of generating plasma from a processing gas and etching the first film, wherein the processing gas comprises one or more gases containing fluorine and hydrogen and capable of generating hydrogen fluoride in the plasma, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas comprises at least carbon and a halogen other than fluorine, and the phosphorus-containing gas comprises phosphorus and a halogen.

[0037] In an exemplary embodiment, the process gas further comprises a third halogen-containing gas, and the third halogen-containing gas does not contain carbon and phosphorus.

[0038] In an exemplary embodiment, a plasma processing apparatus is provided, which includes a chamber and a control unit, wherein the control unit is configured to perform the following control: controlling a substrate including a first film and a second film on the first film to be provided into the chamber, wherein the first film includes silicon and the second film includes at least one opening; and controlling generation of plasma from a processing gas and etching of the first film, wherein the processing gas includes hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

[0039] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same or identical elements are marked with the same symbols in the various drawings, and repeated descriptions are omitted. Unless otherwise stated, the positional relationships such as up, down, left, and right are 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.

[0040] <Configuration Example of Plasma Processing System>

[0041] Figure 1 1 is a diagram for illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support portion 11, and a plasma generating portion 12. The plasma processing chamber 10 has a plasma processing space. In addition, 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 exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to the gas supply portion 20 described later, and the gas exhaust port is connected to the exhaust system 40 described later. The substrate support portion 11 is arranged in the plasma processing space, and has a substrate supporting surface for supporting a substrate.

[0042] The plasma generating 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 a capacitively coupled plasma (CCP; Capacitively Coupled Plasma), an inductively coupled plasma (ICP; Inductively Coupled Plasma), an ECR plasma (Electron-Cyclotron-resonance plasma, electron cyclotron resonance plasma), a helicon wave excited plasma (HWP: Helicon Wave Plasma) or a surface wave plasma (SWP: Surface Wave Plasma), etc. In addition, various types of plasma generating units including an AC (Alternating Current, alternating current) plasma generating unit and a DC (Direct Current, direct current) plasma generating unit may be used. In one embodiment, the AC signal (AC power) used by the AC plasma generating unit has a frequency in the range of 100kHz to 10GHz. Therefore, the AC signal includes an RF (Radio Frequency, radio frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100kHz to 150MHz.

[0043] The control unit 2 processes computer executable instructions that cause the plasma processing device 1 to perform various processes described in the present disclosure. The control unit 2 can be configured as follows: control the various elements of the plasma processing device 1 so as to perform the various processes described herein. In one embodiment, a part or all of the control unit 2 can be included in the plasma processing device 1. The control unit 2 can include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, using a computer 2a. The processing unit 2a1 can be configured as follows: various control actions are performed by reading a program from the storage unit 2a2 and executing the read program. The program can be pre-stored in the storage unit 2a2, or it can be obtained with the help of a medium when necessary. The obtained program is stored in the storage unit 2a2, and is read and executed from the storage unit 2a2 by the processing unit 2a1. The medium can be various storage media that can be read by the computer 2a, or it can be a communication line connected to the communication interface 2a3. The processing unit 2a1 can be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0044] Hereinafter, a configuration example of a capacitive coupling type plasma processing apparatus will be described as an example of the plasma processing apparatus 1 . Figure 2 This is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0045] A 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. In addition, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas inlet unit. The gas inlet unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet unit includes a shower head 13. The substrate support unit 11 is disposed in 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 portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a shower head 13, a plasma processing space 10s defined by a side wall 10a of the plasma processing chamber 10 and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the shell of the plasma processing chamber 10.

[0046] The substrate support portion 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central area 111a for supporting a substrate W and an annular area 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular area 111b of the main body 111 surrounds the central area 111a of the main body 111 in a plan view. The substrate W is arranged on the central area 111a of the main body 111, and the ring assembly 112 is arranged on the annular area 111b of the main body 111 in a manner of surrounding the substrate W on the central area 111a of the main body 111. Therefore, the central area 111a is also referred to as a substrate supporting surface for supporting the substrate W, and the annular area 111b is also referred to as a ring supporting surface for supporting the ring assembly 112.

[0047] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive component. The conductive component of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is arranged on the base 1110. The electrostatic chuck 1111 includes a ceramic component 1111a and an electrostatic electrode 1111b arranged in the ceramic component 1111a. The ceramic component 1111a has a central area 111a. In one embodiment, the ceramic component 1111a has an annular area 111b. It should be noted that other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck and an annular insulating component, can have an annular area 111b. In this case, the ring assembly 112 can be arranged on the annular electrostatic chuck or the annular insulating component, or can be arranged on both the electrostatic chuck 1111 and the annular insulating component. In addition, at least one RF / DC electrode connected to the RF power supply 31 and / or DC power supply 32 described later can be arranged in the ceramic component 1111a. In this case, at least one RF / DC electrode functions as a lower electrode. In the case where the bias RF signal and / or DC signal described later is supplied to at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. It should be noted that the conductive component of the base 1110 and at least one RF / DC electrode can function as multiple lower electrodes. In addition, the electrostatic electrode 1111b can also function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0048] The ring assembly 112 includes one or more ring-shaped components. In one embodiment, the one or more ring-shaped components include one or more edge rings and at least one cover ring. The edge ring is formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0049] In addition, the substrate support portion 11 may include a temperature control 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 control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are arranged in the ceramic component 1111a of the electrostatic chuck 1111. In addition, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas to the gap between the back side of the substrate W and the central area 111a.

[0050] The shower head 13 is configured to introduce at least one processing gas from the gas supply part 20 into the plasma processing space 10s. The shower head 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 processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c through the gas diffusion chamber 13b. In addition, the shower head 13 includes at least one upper electrode. It should be noted that the gas introduction part may further include one or more side gas injection parts (SGI: Side Gas Injector) installed in one or more openings formed in the side wall 10a on the basis of the shower head 13.

[0051] 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 as follows: at least one process gas is supplied from the respective gas source 21 to the shower head 13 by means of the respective flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include at least one flow modulation device for modulating or pulsing the flow of at least one process gas.

[0052] The power supply 30 includes an RF power supply 31 connected to the plasma processing chamber 10 by means of 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. Thus, plasma is formed by 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 generating unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, and ion components in the formed plasma can be introduced into the substrate W.

[0053] 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 configured as follows: it is connected to at least one lower electrode and / or at least one upper electrode by means of at least one impedance matching circuit, and generates 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 can be configured to generate a plurality of source RF signals with 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.

[0054] The second RF generating unit 31b is configured as follows: it is connected to at least one lower electrode by means of at least one impedance matching circuit 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 100kHz to 60MHz. In one embodiment, the second RF generating 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 at least one lower electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0055] In addition, the power supply 30 may include a DC power supply 32 connected to the plasma processing chamber 10. The DC power supply 32 includes a first DC generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to at least one lower electrode and generates a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generating unit 32b is connected to at least one upper electrode and generates a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0056] In various embodiments, the first DC signal and the second DC signal can 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 pulse may have a pulse waveform of a rectangle, a trapezoid, a triangle or a combination thereof. In one embodiment, a waveform generator for generating a voltage pulse sequence from a DC signal is connected between the first DC generator 32a and at least one lower electrode. Therefore, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. In the case where 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 pulse may have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses within one cycle. It should be noted that the first DC generator 32a and the second DC generator 32b may be provided on the basis of the RF power supply 31, and the first DC generator 32a may also be provided instead of the second RF generator 31b.

[0057] The exhaust system 40 may be connected to a gas outlet 10e provided at the bottom of the plasma processing chamber 10, for example. 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.

[0058] <An Example of Plasma Treatment Method>

[0059] Figure 3 1 is a flow chart showing an example of a plasma processing method (hereinafter also referred to as "method MT1") according to an exemplary embodiment. Figure 3 As shown, method MT1 includes a step ST11 of providing a substrate and a step ST12 of performing etching. The processing in each step can be performed by Figure 1 , Figure 2 The plasma processing device 1 shown in the figure is used for executing the following. Figure 2 The case where the method MT1 is executed by each component of the plasma processing apparatus 1 shown will be described as an example.

[0060] (Step ST11: Providing a Substrate)

[0061] In step ST11, a substrate W is provided to a plasma processing chamber 10 (hereinafter also referred to as "chamber 10"). In an exemplary embodiment, the substrate W is carried into the chamber 10 by a carrying arm and is placed on the substrate support 11 by a lifting mechanism. Figure 2 As shown, the substrate is held by suction on the substrate support portion 11 .

[0062] Figure 4 1 is a diagram showing an example of a cross-sectional structure of a substrate W provided in step ST11. The substrate W has a silicon-containing film SF and a mask MK disposed on the silicon-containing film SF. The silicon-containing film SF can be formed on the base film UF. The substrate W can be used to manufacture a semiconductor device. The semiconductor device includes, for example, a storage device such as a DRAM, a 3D-NAND flash memory, and a logic device.

[0063] In an exemplary embodiment, the base film UF is a silicon wafer, an organic film formed on a silicon wafer, a dielectric film, a metal film, a semiconductor film, etc. In an exemplary embodiment, the base film UF may be formed by stacking a plurality of films.

[0064] The silicon-containing film SF is a film constituting the object of etching based on the method MT1. The silicon-containing film SF is an example of a first film. In an exemplary embodiment, the silicon-containing film SF may be a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polysilicon film, or a carbon-containing silicon film. In an exemplary embodiment, the silicon-containing film SF may be composed of one or more films stacked in two or more layers. For example, the silicon-containing film SF may be composed of a silicon oxide film and a silicon nitride film alternately stacked. For example, the silicon-containing film SF may be composed of a silicon oxide film and a polysilicon film alternately stacked. For example, the silicon-containing film SF may also be a stacked film including a silicon nitride film, a silicon oxide film, and a polysilicon film. For example, the silicon-containing film SF may be composed of a silicon oxide film and a silicon carbonitride film stacked. For example, the silicon-containing film SF may also be a stacked film including a silicon oxide film, a silicon nitride film, and a silicon carbonitride film. In an exemplary embodiment, the silicon-containing film SF may be doped with elements such as phosphorus, boron, or nitrogen.

[0065] The mask MK is formed on the silicon-containing film SF. The mask MK is an example of a second film. The mask MK has at least one opening OP. The opening OP is a space on the silicon-containing film SF and is surrounded by the sidewalls of the mask MK. That is, the upper surface of the silicon-containing film SF has an area covered by the mask MK and an area exposed at the bottom of the opening OP. The opening OP can be a hole or a slit.

[0066] In an exemplary embodiment, the mask MK may be a carbon-containing film. The carbon-containing film, for example, includes at least one selected from the group consisting of a spin-on carbon (SOC) film, tungsten carbide, an amorphous carbon (ACL) film, a boron carbide film, and a photoresist film. In one example, the ACL film may be doped with elements such as boron, arsenic, tungsten, and xenon.

[0067] In an exemplary embodiment, the mask MK may be a metal-containing film. The metal-containing film includes at least one metal selected from the group consisting of tungsten, molybdenum, ruthenium and titanium. The metal-containing film may, for example, include a carbide or silicide of tungsten, molybdenum or titanium. The metal-containing film may, for example, be a tungsten-containing film. The metal-containing film may further include tungsten and at least one selected from the group consisting of silicon, carbon and nitrogen. In one example, the metal-containing film includes at least one selected from the group consisting of WC (tungsten carbide), WSi (tungsten silicide), WSiN and WSiC. The mask MK may be a single-layer mask formed by one layer, or a multilayer mask formed by two or more layers.

[0068] The base film UF, the silicon-containing film SF and the mask MK can be formed by any method, respectively. For example, the base film UF, the silicon-containing film SF and the mask MK can be formed by CVD method, ALD method, PVD method, spin coating method, etc., respectively. The mask MK can be formed, for example, by photolithography. In addition, the opening OP of the mask MK can be formed by etching the mask MK. The base film UF, the silicon-containing film SF and the mask MK can be flat films, respectively, or films with projections and depressions. It should be noted that the substrate W can further have other films under the base film UF. In this case, a recessed portion having a shape corresponding to the opening OP can be formed in the silicon-containing film SF and the base film UF and used as a mask for etching the other films.

[0069] In an exemplary embodiment, at least a part of the process of forming the base film UF, the silicon-containing film SF, and the mask MK of the substrate W may be performed as a part of the step ST11 in the chamber 10. For example, in the case where the opening OP of the mask MK is formed by etching, the etching in the step ST11 and the etching in the step ST12 described later may be continuously performed in the chamber 10. In an exemplary embodiment, after all or a part of the substrate W is formed in an apparatus or chamber outside the plasma processing apparatus 1, the substrate W may be provided in the chamber 10.

[0070] In an exemplary embodiment, after the substrate W is provided to the central area 111a of the substrate support part 11, the substrate support part 11 is controlled to a set temperature by a temperature control module. The set temperature may be, for example, below room temperature (e.g., 25°C), below 0°C, below -10°C, below -20°C, below -30°C, below -40°C, below -50°C, below -60°C, or below -70°C. The set temperature may be, for example, above -100°C or above -90°C.

[0071] In an exemplary embodiment, controlling the temperature of the substrate support part 11 to a set temperature includes: making the temperature of the heat transfer fluid flowing through the flow path 1110a and the temperature of the heater to the set temperature; or making them to be different from the set temperature. It should be noted that the time point of starting to make the heat transfer fluid flow into the flow path 1110a can be before, after, or at the same time as the substrate W is placed on the substrate support part 11. In addition, the temperature of the substrate support part 11 can be controlled to the set temperature before step ST11. That is, the substrate W can be provided to the substrate support part 11 after the temperature of the substrate support part 11 is controlled to the set temperature.

[0072] In an exemplary 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 heat transfer fluid flowing through the substrate support 11 and the flow path 1110a and / or the heater temperature to a set temperature; or setting them to a temperature different from the set temperature.

[0073] (Step ST12: Etching)

[0074] In step ST12, the silicon-containing film SF is etched using plasma generated from the processing gas. First, the processing gas is supplied into the plasma processing space 10s from the gas supply unit 20. The processing gas includes hydrogen fluoride (HF) gas, phosphorus-containing gas, and a first halogen-containing gas.

[0075] In an exemplary embodiment, the HF gas may have the largest flow rate (partial pressure) in the process gas except for the inert gas. In one example, the flow rate of the HF gas may be 50% by volume or more, 60% by volume or more, 70% by volume or more, 80% by volume or more, 90% by volume or more, or 95% by volume or more relative to the total flow rate of the process gas (when the process gas includes the inert gas, the flow rate of the total gas after deducting these gases). The flow rate of the HF gas may be less than 100% by volume, 99.5% by volume or less, 98% by volume or less, or 96% by volume or less relative to the total flow rate of the process gas. In one example, the flow rate of the HF gas is 70% by volume or more and 96% by volume or less relative to the total flow rate of the process gas.

[0076] In an exemplary embodiment, the processing gas may include a gas capable of generating hydrogen fluoride species (HF species) in plasma instead of part or all of the HF gas. The HF species includes at least one of hydrogen fluoride gas, radicals, and ions.

[0077] The gas that can generate HF species may be, for example, a hydrofluorocarbon gas. The carbon number of the hydrofluorocarbon gas may also be 2 or more, 3 or more, or 4 or more. In one example, the hydrofluorocarbon gas is selected from CH2F2 gas, C3H2F4 gas, C3H2F6 gas, C3H3F5 gas, C4H2F6 gas, C4H5F5 gas, C4H2F8 gas, C5H2F6 gas, C5H2F 10 The hydrofluorocarbon gas is at least one selected from the group consisting of CH2F2 gas, C3H2F4 gas, C3H2F6 gas and C4H2F6 gas.

[0078] The gas that can generate HF species can be, for example, a mixed gas containing a hydrogen source and a fluorine source. The hydrogen source can be, for example, at least one selected from the group consisting of H2 gas, NH3 gas, H2O gas, H2O2 gas and hydrocarbon gas (CH4 gas, C3H6 gas, etc.). The fluorine source can be, for example, a fluorine-containing gas that does not contain carbon, such as NF3 gas, SF6 gas, WF6 gas or XeF2 gas. In addition, the fluorine source can also be a fluorine-containing gas containing carbon, such as fluorocarbon gas and hydrofluorocarbon gas. Fluorocarbon gas can be, in one example, at least one selected from the group consisting of CF4 gas, C2F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas and C5F8 gas. In one example, the hydrofluorocarbon gas may be at least one selected from the group consisting of CHF3 gas, CH2F2 gas, CH3F gas, C2HF5 gas, and hydrofluorocarbon gases containing three or more Cs (C3H2F4 gas, C3H2F6 gas, C4H2F6 gas, etc.).

[0079] In an exemplary embodiment, the phosphorus-containing gas may include a phosphorus oxyhalide gas. In one embodiment, the phosphorus oxyhalide gas may be POCl x F y The gas represented by (wherein 0≤x≤3, 0≤y≤3, x+y=3). For example, the oxyhalogenated phosphorus gas may be at least one selected from the group consisting of POCl3 gas, POCl2F gas, POClF2 gas, and POF3 gas. In one example, the oxyhalogenated phosphorus gas may be POCl3 gas or POF3 gas.

[0080] In an exemplary embodiment, the phosphorus-containing gas may further include a phosphorus halide gas on the basis of the above-mentioned oxyphosphorus halide gas. In an exemplary embodiment, the phosphorus halide gas is a gas containing phosphorus and fluorine and / or chlorine but not containing oxygen. For example, the phosphorus halide gas may be at least one selected from the group consisting of PF3 gas, PF5 gas, PCl3 gas, PCl5 gas, PClF2 gas, PCl2F gas and PCl2F3. In one example, the phosphorus halide gas may be PF3 gas, PF5 gas or PCl3 gas.

[0081] In an exemplary embodiment, when the phosphorus-containing gas includes an oxyphosphorus halide gas and a phosphorus halide gas, the ratio of the flow rate (partial pressure) of the phosphorus halide gas to the flow rate (partial pressure) of the oxyphosphorus halide gas may be greater than 0.1, greater than 0.2, or greater than 0.3. In addition, the ratio of the flow rate (partial pressure) of the phosphorus halide gas to the flow rate (partial pressure) of the oxyphosphorus halide gas may be less than 3.0, less than 2.0, or less than 1.0. In one example, the ratio of the flow rate (partial pressure) of the phosphorus halide gas to the flow rate (partial pressure) of the oxyphosphorus halide gas is greater than 0.2 and less than 3.0. By controlling the flow rate (partial pressure) of the phosphorus halide gas relative to the flow rate (partial pressure) of the oxyphosphorus halide gas within the above range, abnormalities in etching shapes such as bowing can be suppressed.

[0082] In an exemplary embodiment, the first halogen-containing gas contains at least carbon and a halogen gas other than fluorine. The halogen other than fluorine may be at least one selected from the group consisting of bromine (Br), chlorine (Cl) and iodine (I). The halogen other than fluorine may contain a halogen different from the halogen contained in the phosphorus-containing gas when the phosphorus-containing gas contains the halogen.

[0083] In an exemplary embodiment, the first halogen-containing gas may be C s H t Br u Cl v F w The gas represented by (s is an integer greater than 1 and less than 7, the sum of u and v is an integer greater than 1, and t, u, v, and w are integers greater than 0 and less than 16, respectively). For example, the first halogen-containing gas can be a gas obtained by replacing a part or all of the hydrogen atoms of methane (CH4) with bromine or bromine and a halogen other than bromine. That is, it can be a gas that satisfies s=1 and t+u+v+w=4 in the above chemical formula. In one example, the first halogen-containing gas can be at least one gas selected from the group consisting of CH3Br gas, CH2BrF gas, CBr2F2 gas, CBr2ClF gas, and CHBrCl2 gas.

[0084] In addition, for example, the first halogen-containing gas can be at least one selected from the group consisting of CCl4 gas, CH2Cl2 gas, CHCl3 gas, CF2Cl2 gas, CH2ClF gas, CHCl2F gas, C2F5Br gas, CF3I gas, C2F5I gas and C3F7I gas.

[0085] In an exemplary embodiment, the ratio of the flow rate (partial pressure) of the first halogen-containing gas to the flow rate (partial pressure) of the phosphorus-containing gas can be appropriately set by the film species of the silicon-containing film SF, the flow rate (partial pressure) of the HF gas, the type and atomic ratio of the halogen contained in the phosphorus-containing gas and the first halogen-containing gas, the shape of the target, etc. In an exemplary embodiment, the ratio of the flow rate (partial pressure) of the first halogen-containing gas to the flow rate (partial pressure) of the phosphorus-containing gas can be greater than 0.1, greater than 0.2, or greater than 0.3. In addition, the ratio of the flow rate (partial pressure) of the first halogen-containing gas to the flow rate (partial pressure) of the phosphorus-containing gas can be less than 1.5, less than 1.2, or less than 1.0. In one example, the ratio of the flow rate (partial pressure) of the halogen-containing gas to the flow rate (partial pressure) of the phosphorus-containing gas is greater than 0.1 and less than 1.5.

[0086] In an exemplary embodiment, the ratio of the total flow rate of the phosphorus-containing gas and the first halogen-containing gas to the total flow rate of the processing gas (the total flow rate of all gases after deducting the inert gas when the processing gas contains an inert gas) can be controlled to be less than 20 volume %, less than 15 volume % or less than 10 volume %.

[0087] In an exemplary embodiment, the process gas may include a gas other than HF gas, phosphorus-containing gas and first halogen-containing gas. For example, the process gas may further include at least one gas selected from the group consisting of a second halogen-containing gas, a carbon-containing gas, a tungsten-containing gas and an oxygen-containing gas.

[0088] The second halogen-containing gas is a gas different from the first halogen-containing gas. For example, the second halogen-containing gas contains halogens other than the halogens contained in the first halogen-containing gas. For example, in the case where the first halogen-containing gas contains bromine (Br) but not chlorine (Cl), the second halogen-containing gas may contain at least chlorine (Cl). In addition, in the case where the first halogen-containing gas contains chlorine (Cl) but not bromine (Br), the second halogen-containing gas may contain at least bromine (Br). In an exemplary embodiment, at least one of the first halogen-containing gas and the second halogen-containing gas may contain chlorine (Cl). In an exemplary embodiment, at least one of the first halogen-containing gas and the second halogen-containing gas may contain bromine (Br).

[0089] In addition, for example, the second halogen-containing gas may contain halogens other than fluorine. For example, the second halogen-containing gas may be a chlorine-containing gas, a bromine-containing gas and / or an iodine-containing gas. The chlorine-containing gas may be at least one gas selected from the group consisting of Cl2, SiCl2, SiCl4, CCl4, SiH2Cl2, Si2Cl6, CHCl3, SO2Cl2, BCl3, PCl3, PCl5 and POCl3. The bromine-containing gas may be at least one gas selected from the group consisting of Br2, HBr, CBr2F2, C2F5Br, PBr3, PBr5, POBr3 and BBr3. The iodine-containing gas may be at least one gas selected from the group consisting of HI, CF3I, C2F5I, C3F7I, IF5, IF7, I2, and PI3. In one example, the second halogen-containing gas may be at least one selected from the group consisting of Cl2 gas, Br2 gas and HBr gas. In one example, the second halogen-containing gas is Cl 2 gas or HBr gas.

[0090] The carbon-containing gas may be, for example, either or both of a fluorocarbon gas and a hydrofluorocarbon gas. In one example, the fluorocarbon gas may be at least one selected from the group consisting of CF4 gas, C2F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas, and C5F8 gas. In one example, the hydrofluorocarbon gas may be selected from the group consisting of CHF3 gas, CH2F2 gas, CH3F gas, C2HF5 gas, C2H2F4 gas, C2H3F3 gas, C2H4F2 gas, C3HF7 gas, C3H2F2 gas, C3H2F4 gas, C3H2F6 gas, C3H3F5 gas, C4H2F6 gas, C4H5F5 gas, C4H2F8 gas, C5H2F6 gas, C5H2F 10 Gas and C5H3F7 gas composed of at least one. In addition, the carbon-containing gas can be a straight chain with unsaturated bonds. The straight chain carbon-containing gas with unsaturated bonds can be, for example, selected from the group consisting of C3F6 (hexafluoropropylene) gas, C4F8 (octafluoro-1-butene, octafluoro-2-butene) gas, C3H2F4 (1,3,3,3-tetrafluoropropylene) gas, C4H2F6 (trans-1,1,1,4,4,4-hexafluoro-2-butene) gas, C4F8O (pentafluoroethyl trifluorovinyl ether) gas, CF3COF gas (1,2,2,2-tetrafluoroethane-1-one), CHF2COF (difluoroacetyl fluoride) gas and COF2 (carbonyl fluoride) gas.

[0091] The tungsten-containing gas may be, for example, a gas containing tungsten and halogen. Specifically, as a tungsten-containing gas, it may be a gas containing tungsten and fluorine, such as tungsten difluoride (WF2) gas, tungsten tetrafluoride (WF4) gas, tungsten pentafluoride (WF5) gas, tungsten hexafluoride (WF6) gas, or a gas containing tungsten and chlorine, such as tungsten dichloride (WCl2) gas, tungsten tetrachloride (WCl4) gas, tungsten pentachloride (WCl5) gas, tungsten hexachloride (WCl6) gas. Among these, at least one of the WF6 gas and the WCl6 gas may be used. The flow rate of the tungsten-containing gas may be less than 5% by volume of the total flow rate of the process gas. It should be noted that the process gas may replace the tungsten-containing gas or may further include at least one of a titanium-containing gas, a ruthenium-containing gas and / or a molybdenum-containing gas on the basis of the tungsten-containing gas.

[0092] The oxygen-containing gas may be, for example, at least one gas selected from the group consisting of O2, CO, CO2, H2O, and H2O2. In one example, the oxygen-containing gas may be an oxygen-containing gas other than H2O, for example, at least one gas selected from the group consisting of O2, CO, CO2, and H2O2.

[0093] In an exemplary embodiment, the processing gas may further include an inert gas. In one example, the inert gas may be a rare gas such as Ar gas, He gas, Kr gas, or nitrogen gas.

[0094] During the processing of step ST12, the gas contained in the processing gas and its flow rate (partial pressure) may be changed or not. For example, in the case where the silicon-containing film SF is composed of a stacked film formed by different types of silicon-containing films, the composition of the processing gas and the flow rate (partial pressure) of each gas may be changed as the etching proceeds (i.e., according to the type of film being etched). It should be noted that during the processing of step ST12, the temperature of the substrate support 11 may be maintained at the set temperature adjusted in step ST11, or may be changed.

[0095] In step ST12, after the above-mentioned processing gas is supplied into the plasma processing space 10s, plasma is generated by the processing gas. Thus, the substrate W is etched. In an exemplary embodiment, the generation of plasma can be performed as follows. First, a source RF signal is supplied to the lower electrode of the substrate support part 11 and / or at least one upper electrode in the shower head 13. Thus, a high-frequency electric field is generated between the shower head 13 and the substrate support part 11, and plasma is generated from the processing gas in the chamber 10. A bias signal is also supplied to the lower electrode of the substrate support part 11. Thus, active species in the plasma are attracted to the substrate W, and the silicon-containing film SF is etched.

[0096] In an exemplary embodiment, the bias signal may be a bias RF signal supplied by the second RF generating unit 31b. In addition, the bias signal may also be a bias DC signal supplied by the DC generating unit 32a. The source RF signal and the bias signal may be both continuous waves or pulse waves, or one may be a continuous wave and the other may be a pulse wave. In the case where both the source RF signal and the bias signal are pulse waves, the periods of the pulse waves of both may be synchronized or asynchronous. The duty cycle of the source RF signal and / or the bias signal pulse wave may be appropriately set, for example, it may be 1 to 80%, or it may be 5 to 50%. It should be noted that the duty cycle is the ratio of the period of high power or voltage level in the period of the pulse wave. In addition, when a bias DC signal is used as the bias signal, the pulse wave may have a rectangular, trapezoidal, triangular or a combination thereof waveform. The polarity of the bias DC signal may be negative or positive as long as the potential of the substrate W is set in a manner that forms a potential difference between the plasma and the substrate to attract ions.

[0097] Figure 5 1 is a diagram showing an example of a cross-sectional structure of the substrate W at the end of step ST12. Figure 5 As shown, through the process of step ST12, the portion of the silicon-containing film SF exposed at the opening OP is thinned in the depth direction ( Figure 5 In the direction from top to bottom in the middle, it is etched to form a recessed portion RC. Figure 5 This is an example in which the bottom BT of the recess RC reaches the base film UF and exposes the base film UF by etching in step ST12. The aspect ratio of the recess RC in this state may be, for example, 20 or more, 30 or more, 40 or more, 50 or more, or 100 or more.

[0098] As described above, the processing gas includes HF gas, phosphorus-containing gas and a first halogen-containing gas. HF gas generates HF species in plasma, which functions as an etchant for the silicon-containing film SF. The phosphorus-containing gas promotes the reaction of HF species with the silicon-containing film SF. It should be noted that, when the phosphorus-containing gas is an oxyhalogenated phosphorus gas and / or a halogenated phosphorus gas, the phosphorus-containing gas promotes the reaction of HF species with the silicon-containing film SF, and can help improve the etching shape and suppress clogging of the opening OP. In addition, the first halogen-containing gas helps improve the etching shape and protect the mask MK. It should be noted that improving the etching shape can be to increase roundness, suppress bending and / or suppress bowing.

[0099] The first halogen-containing gas or phosphorus-containing gas (oxyhalogenated phosphorus gas and / or halogenated phosphorus gas) is a gas having multiple functions in etching as described above. Since these gases are gases formed by one molecule, the partial pressure in the processing gas can be suppressed to a lower level compared to the case where two or more different gases are combined to obtain the same function. As a result, the partial pressure of the HF gas as an etchant in the processing gas can be increased. Therefore, according to method MT1, it is possible to achieve improvement of the etching shape, suppression of clogging, or protection of the mask while maintaining the partial pressure of the HF gas at a high level.

[0100] According to an exemplary embodiment of the present disclosure, a technique for improving an etching shape can be provided.

[0101] <Example>

[0102] Next, examples are described. The present disclosure is not limited in any way by the following examples. Figure 6 The figures are for explaining the embodiments and reference examples.

[0103] (Example 1)

[0104] use Figure 2 The plasma processing device 1 shown in FIG. Figure 3 The flowchart described in Figure 4 The substrate W shown in FIG. 1 is etched. First, in step ST11, the substrate W is provided on the substrate support portion 11. The silicon-containing film SF of the substrate W is a multilayer laminated film formed of a silicon oxide film and a silicon nitride film. The mask MK is an amorphous carbon film having a hole-shaped opening OP. Next, in step ST12, the substrate W is etched using a mask made of Figure 6 The silicon-containing film SF is etched by the plasma generated by the processing gas shown in the "Example 1" column.

[0105] (Example 2)

[0106] Example 2 is used in step ST12 Figure 6 The same as Example 1 except for the processing gas shown in the "Example 2" column.

[0107] (Reference example)

[0108] Reference example is used in step ST12 Figure 6 The same as Example 1 except for the processing gas shown in the "Reference Example" column.

[0109] exist Figure 6In the figure, “etching rate” is the etching rate of each example when the etching rate of the reference example is taken as 1. In addition, “undercut” shows the CD (critical dimension) of the undercut generated on the silicon-containing film SF of each example when the CD of the undercut generated on the silicon-containing film SF of the reference example is taken as 1. Figure 6 As shown, both Examples 1 and 2 achieved an etching rate comparable to that of the reference example. In addition, both Examples 1 and 2 suppressed undercuts comparable to that of the reference example.

[0110] The embodiments of the present disclosure also include the following aspects.

[0111] (Note 1)

[0112] An etching method comprising the following steps:

[0113] A step of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and

[0114] The first film is etched by generating plasma from a processing gas, wherein the processing gas includes a hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, and the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

[0115] (Note 2)

[0116] The etching method according to Supplement 1, wherein the first halogen-containing gas comprises C s H t Br u Cl v F w A gas represented by (s is an integer greater than or equal to 1 and less than or equal to 7, the sum of u and v is an integer greater than or equal to 1, and t, u, v, and w are each an integer greater than or equal to 0 and less than or equal to 16).

[0117] (Note 3)

[0118] The etching method according to Supplementary Note 1 or Supplementary Note 2, wherein the first halogen-containing gas contains bromine as the halogen other than fluorine.

[0119] (Note 4)

[0120] The etching method according to any one of Supplementary Notes 1 to 3, wherein the first halogen-containing gas contains chlorine as the halogen other than fluorine.

[0121] (Note 5)

[0122] The etching method according to any one of Supplementary Notes 1 to 4, wherein the first halogen-containing gas further contains fluorine.

[0123] (Note 6)

[0124] The etching method according to any one of Supplementary Notes 1 to 5, wherein the first halogen-containing gas includes at least one selected from the group consisting of CHCl 3 gas, CH 2 Cl 2 gas, and CF 2 Br 2 Cl 2 gas.

[0125] (Note 7)

[0126] The etching method according to any one of Supplementary Notes 1 to 6, wherein the phosphorus-containing gas includes a phosphorus halide gas.

[0127] (Note 8)

[0128] The etching method according to any one of Supplementary Notes 1 to 7, wherein the phosphorus-containing gas includes a phosphorus oxyhalide gas.

[0129] (Note 9)

[0130] The etching method according to Supplementary Note 8, wherein the phosphorus oxyhalide gas includes at least one selected from the group consisting of POCl3 gas, POCl2F gas, POClF2 gas and POF3 gas.

[0131] (Note 10)

[0132] The etching method according to any one of Supplementary Notes 1 to 9, wherein the phosphorus-containing gas includes a phosphorus oxyhalide gas and a phosphorus halide gas.

[0133] (Note 11)

[0134] The etching method according to Supplementary Note 10, wherein a ratio of a partial pressure of the phosphorus halide gas to a partial pressure of the phosphorus oxyhalide gas is 0.1 or more and 3.0 or less.

[0135] (Note 12)

[0136] The etching method according to any one of Supplementary Notes 1 to 11, wherein a ratio of flow rates of the phosphorus-containing gas and the first halogen-containing gas to a total flow rate of the processing gas is 20% by volume or less.

[0137] (Note 13)

[0138] The etching method according to any one of Supplementary Notes 1 to 12, wherein the processing gas further includes a second halogen-containing gas different from the first halogen-containing gas.

[0139] (Note 14)

[0140] The etching method according to Supplementary Note 13, wherein the second halogen-containing gas does not contain carbon.

[0141] (Note 15)

[0142] The etching method according to Supplementary Note 13 or Supplementary Note 14, wherein the second halogen-containing gas contains a halogen of a different type from the halogen contained in the first halogen-containing gas.

[0143] (Note 16)

[0144] The etching method according to any one of Supplementary Notes 1 to 15, wherein the first film includes at least one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a polysilicon film.

[0145] (Note 17)

[0146] The etching method according to any one of Supplementary Notes 1 to 16, wherein the second film is a film containing at least one of carbon and metal.

[0147] (Note 18)

[0148] An etching method comprising the following steps:

[0149] A step of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and

[0150] A process of generating plasma from a processing gas and etching the first film, wherein the processing gas includes one or more gases containing fluorine and hydrogen and capable of generating hydrogen fluoride in the plasma, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine, and the phosphorus-containing gas includes phosphorus and a halogen.

[0151] (Note 19)

[0152] The etching method according to Supplementary Note 18, wherein the processing gas further comprises a third halogen-containing gas, and the third halogen-containing gas does not contain carbon and phosphorus.

[0153] (Note 20)

[0154] A plasma processing device includes a chamber and a control unit.

[0155] The control unit is configured to perform the following control:

[0156] controlling to provide a substrate including a first film and a second film on the first film into the chamber, wherein the first film includes silicon and the second film includes at least one opening; and,

[0157] The first film is etched by controlling a process gas to generate plasma, wherein the process gas includes a hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, and the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

[0158] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. The above embodiments may be modified in various ways without departing from the scope and purpose of the present disclosure. For example, a part of the constituent elements in a certain embodiment may be added to other embodiments. In addition, a part of the constituent elements in a certain embodiment may be replaced with corresponding constituent elements in other embodiments.

[0159] Explanation of symbols

[0160] 1 ... plasma processing device, 2 ... control unit, 10 ... plasma processing chamber, 10s ... plasma processing space, 11 ... substrate support unit, 13 ... shower head, 20 ... gas supply unit, 31a ... first RF generating unit, 31b ... second RF generating unit, 32a ... first DC generating unit, SF ... silicon-containing film, MK ... mask, OP ... opening, RC ... recess, UF ... base film, W ... substrate

Claims

1. An etching method comprising the following steps: A process of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and The first film is etched by generating plasma from a processing gas, wherein the processing gas includes a hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

2. The etching method according to claim 1, wherein: The first halogen-containing gas comprises C s H t Br u Cl v F w A gas represented by: wherein s is an integer greater than or equal to 1 and less than or equal to 7, the sum of u and v is an integer greater than or equal to 1, and t, u, v and w are integers greater than or equal to 0 and less than or equal to 16 respectively.

3. The etching method according to claim 1, wherein: The first halogen-containing gas contains bromine as the halogen other than fluorine.

4. The etching method according to claim 1, wherein: The first halogen-containing gas contains chlorine as the halogen other than fluorine.

5. The etching method according to claim 1, wherein: The first halogen-containing gas further comprises fluorine.

6. The etching method according to claim 1, wherein: The first halogen-containing gas includes at least one selected from the group consisting of CHCl 3 gas, CH 2 Cl 2 gas, and CF 2 Br 2 Cl 2 gas.

7. The etching method according to any one of claims 1 to 6, wherein: The phosphorus-containing gas includes a phosphorus halide gas.

8. The etching method according to any one of claims 1 to 6, wherein: The phosphorus-containing gas includes a phosphorus oxyhalide gas.

9. The etching method according to claim 8, wherein: The phosphorus oxyhalide gas includes at least one selected from the group consisting of POCl3 gas, POCl2F gas, POClF2 gas and POF3 gas.

10. The etching method according to any one of claims 1 to 6, wherein: The phosphorus-containing gas includes phosphorus oxyhalide gas and phosphorus halide gas.

11. The etching method according to claim 10, wherein: The ratio of the partial pressure of the phosphorus halide gas to the partial pressure of the phosphorus oxyhalide gas is 0.1 or more and 3.0 or less.

12. The etching method according to any one of claims 1 to 6, wherein: A ratio of the flow rate of the phosphorus-containing gas and the first halogen-containing gas to the total flow rate of the processing gas is 20 volume % or less.

13. The etching method according to any one of claims 1 to 6, wherein: The process gas also includes a second halogen-containing gas different from the first halogen-containing gas.

14. The etching method according to claim 13, wherein: The second halogen-containing gas does not contain carbon.

15. The etching method according to claim 13, wherein: The second halogen-containing gas contains a halogen of a different kind from the halogen contained in the first halogen-containing gas.

16. The etching method according to any one of claims 1 to 6, wherein: The first film includes at least one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a polysilicon film.

17. The etching method according to any one of claims 1 to 6, wherein: The second film is a film containing at least one of carbon and metal.

18. An etching method comprising the following steps: A process of providing a substrate including a first film and a second film on the first film, wherein the first film includes silicon and the second film includes at least one opening; and A process of generating plasma from a processing gas and etching the first film, wherein the processing gas includes one or more gases containing fluorine and hydrogen and capable of generating hydrogen fluoride in the plasma, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine, and the phosphorus-containing gas includes phosphorus and a halogen.

19. The etching method according to claim 18, wherein: The process gas further includes a third halogen-containing gas, wherein the third halogen-containing gas does not contain carbon and phosphorus.

20. A plasma processing device comprising a chamber and a control unit, The control unit is configured to perform the following control: controlling to provide a substrate including a first film and a second film on the first film into the chamber, wherein the first film includes silicon and the second film includes at least one opening; and, A process gas is controlled to generate plasma and etch the first film, wherein the process gas includes a hydrogen fluoride gas, a first halogen-containing gas, and a phosphorus-containing gas, wherein the first halogen-containing gas includes at least carbon and a halogen other than fluorine.

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