Etching method and plasma processing apparatus

Abstract

Provided is a technology that suppresses the blockage of openings in a mask. An etching method is provided. This method comprises: (a) a step for providing, onto a substrate support unit within a chamber, a substrate having a carbon-containing film and a mask on the carbon-containing film; and (b) a step for etching the carbon-containing film using a plasma generated from a first process gas, wherein the first process gas contains a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas or contains a phosphorus halide gas and an oxygen- and sulfur-containing gas.

Description

Etching method and plasma processing apparatus

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

[0002] In Patent Document 1, ２ A technique for etching an organic film using a gas and a COS gas is disclosed.

[0003] Japanese Patent Application Laid-Open No. 2018-200925

[0004] The present disclosure provides a technique for preventing mask opening occlusion.

[0005] In one exemplary embodiment of the present disclosure, there is provided an etching method including: (a) providing a substrate having a carbon-containing film on a substrate support in a chamber and a mask on the carbon-containing film; and (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas includes a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas.

[0006] According to one exemplary embodiment of the present disclosure, a technique for suppressing occlusion of a mask opening can be provided.

[0007] FIG. 1 is a diagram for explaining an example of the configuration of a plasma processing apparatus. FIG. 2 is a diagram for explaining an example of the configuration of an inductively coupled plasma processing apparatus. FIG. 3 is a diagram for explaining an example of opening blocking. FIG. 4 is a flowchart according to the first embodiment. FIG. 5 is a diagram showing an example of the cross-sectional structure of a substrate W provided in process ST11. FIG. 6 is a diagram for explaining an example of a phenomenon occurring in process ST12. FIG. 7 is a flowchart according to the second embodiment. FIG. 8 is a diagram for explaining an example of a phenomenon occurring in a repeated cycle of process ST22 and process ST23. FIG. 9 is a flowchart according to a modified example of the second embodiment. FIG. 10 is a diagram showing the results of etching according to Example 1 and Reference Example 1. FIG. 11 is a diagram showing the results of etching according to Example 2 and Reference Example 1. FIG. 12 is a diagram showing the results of etching according to Example 2 and Reference Example 1.

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

[0009] In one exemplary embodiment, an etching method is provided that includes: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in a chamber; and (b) etching the carbon-containing film using a plasma generated from a first process gas, wherein the first process gas includes a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas.

[0010] In one exemplary embodiment, (c) further comprises etching the carbon-containing film using a plasma generated from a second process gas different from the first process gas, wherein the second process gas comprises an oxygen-containing gas and a sulfur-containing gas, or comprises oxygen and a sulfur-containing gas.

[0011] In one exemplary embodiment, the second process gas does not include a phosphorus halide gas.

[0012] In one exemplary embodiment, the second process gas includes a phosphorus halide gas at a flow rate that is less than the phosphorus halide gas included in the first process gas.

[0013] In one exemplary embodiment, the ratio of the etching time in step (c) to the etching time in step (b) is 0.8 or more and 1.2 or less.

[0014] In one exemplary embodiment, a cycle comprising steps (b) and (c) is repeated multiple times.

[0015] In one exemplary embodiment, in at least one cycle from the second onwards, the ratio of the etching duration in step (c) to the etching duration in step (b) is greater than the ratio in the first cycle.

[0016] In one exemplary embodiment, the temperature of the substrate support in at least one of the second and subsequent cycles is set to be higher than the temperature of the substrate support in the first cycle.

[0017] In one exemplary embodiment, the phosphorus halide gas comprises at least one gas selected from the group consisting of phosphorus fluoride gas, phosphorus chloride gas, phosphorus oxyfluoride gas, and phosphorus oxychloride gas.

[0018] In one exemplary embodiment, the halogenated phosphorus gas is PF ３ Gas, PF ５ Gas and PCl ３ The gas mixture includes at least one gas selected from the group consisting of:

[0019] In one exemplary embodiment, the flow rate of the phosphorus halide gas in the first process gas is 5% by volume or less of the total flow rate of the first process gas.

[0020] In one exemplary embodiment, the oxygen-containing gas is O ２ gas, CO gas and CO ２ The gas comprises at least one gas selected from the group consisting of:

[0021] In one exemplary embodiment, the oxygen and sulfur containing gas is COS gas and SO ２ The gas is at least one of the following gases.

[0022] In one exemplary embodiment, the sulfur-containing gas is SF ６ It's gas.

[0023] In one exemplary embodiment, the mask comprises a silicon-containing film or a metal-containing film.

[0024] In one exemplary embodiment, the carbon-containing film comprises an amorphous carbon film.

[0025] In one exemplary embodiment, in step (b), the temperature of the substrate support is set to 0 degrees or less.

[0026] In one exemplary embodiment, in step (c), the temperature of the substrate support is set to 0 degrees or less.

[0027] In one exemplary embodiment, a plasma processing apparatus is provided that has a chamber and a controller, wherein the controller performs the following operations: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in the chamber; and (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas includes a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas.

[0028] In one exemplary embodiment, the control unit further controls (c) etching the carbon-containing film using plasma generated from a second process gas different from the first process gas, wherein the second process gas includes an oxygen-containing gas and a sulfur-containing gas, or includes oxygen and a sulfur-containing gas.

[0029] 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.

[0030] <Configuration Example of a Plasma Processing Apparatus> FIG. 1 is a diagram illustrating a configuration example of a plasma processing apparatus. In one embodiment, the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a control unit 2, a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. 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 unit 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0031] 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.

[0032] 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 configured as a system external to 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, for example, by 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. The 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 each element of the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0033] The following describes a configuration example of an inductively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of an inductively coupled plasma processing apparatus.

[0034] The inductively coupled plasma processing apparatus 1 includes a control unit 2, a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing chamber 10 includes a dielectric window 101. The plasma processing apparatus 1 also includes a substrate support 11, a gas inlet, and an antenna 14. The substrate support 11 is disposed within the plasma processing chamber 10 (hereinafter also referred to as "chamber 10"). The antenna 14 is disposed on or above the plasma processing chamber 10 (i.e., on or above the dielectric window 101). The plasma processing chamber 10 has a plasma processing space 10s defined by the dielectric window 101, a sidewall 102 of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded.

[0035] 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.

[0036] 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 bias 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 bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple bias electrodes. Alternatively, the electrostatic electrode 1111b may function as a bias electrode. Therefore, the substrate support 11 includes at least one bias electrode.

[0037] 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.

[0038] 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.

[0039] The gas inlet is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. In one embodiment, the gas inlet includes a center gas injector (CGI) 13. The center gas injector 13 is disposed above the substrate support 11 and attached to a central opening formed in the dielectric window 101. The center gas injector 13 has at least one gas supply port 13a, at least one gas flow path 13b, and at least one gas inlet port 13c. The process gas supplied to the gas supply port 13a passes through the gas flow path 13b and is introduced into the plasma processing space 10s from the gas inlet port 13c. Note that the gas inlet may include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 102 in addition to or instead of the center gas injector 13.

[0040] 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 gas inlet through 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.

[0041] 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 bias electrode and the antenna 14. This causes a plasma to be formed 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 generating unit 12. Furthermore, by supplying a bias RF signal to the at least one bias electrode, a bias potential is generated on the substrate W, thereby attracting ions in the formed plasma to the substrate W.

[0042] 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 the antenna 14 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 the antenna 14.

[0043] The second RF generator 31b is coupled to at least one bias 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 bias electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0044] 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 bias DC generator 32a. In one embodiment, the bias DC generator 32a is connected to at least one bias electrode and configured to generate a bias DC signal. The generated bias DC signal is applied to the at least one bias electrode.

[0045] In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one bias electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the bias DC generator 32a and at least one bias electrode. Thus, the bias DC generator 32a and the waveform generator constitute a voltage pulse generator. The voltage pulses may have 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 cycle. Note that the bias DC generator 32a may be provided in addition to the RF power supply 31 or may be provided instead of the second RF generator 31b.

[0046] The antenna 14 includes one or more coils. In one embodiment, the antenna 14 may include an outer coil and an inner coil arranged coaxially. In this case, the RF power supply 31 may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generator may be connected to both the outer coil and the inner coil, or separate RF generators may be connected to the outer coil and the inner coil separately.

[0047] 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.

[0048] <Mask Opening Closure> It is known that mask openings may narrow or become blocked (hereinafter also referred to as "opening clogging") during plasma etching. Opening clogging can cause etching to stop or shape abnormalities such as bowing. Opening clogging can occur when deposition material in the plasma adheres to the opening sidewall, or when mask material sputtered by ions in the plasma re-adheses to the opening sidewall.

[0049] FIG. 3 is a diagram showing an example of opening closure. ２ 3 shows an example of etching a substrate W using plasma generated from a process gas consisting of a carbon-containing gas and a COS gas. The substrate W has an undercoat film UF, a carbon-containing film OF, and a mask MK having an opening OP. In this example, the carbon-containing film OF is an amorphous carbon film, and the mask MK is a silicon oxynitride (SiON) film. As shown from the left to the right of FIG. 3 , as etching progresses, deposits DP adhere to the sidewalls S1 of the mask MK, blocking the openings OP. The deposits DP may include, for example, a mask material (silicon in this example) sputtered by ions in the plasma.

[0050] An etching method according to an exemplary embodiment of the present disclosure (hereinafter referred to as "the method") can suppress such clogging of openings. An example of the method will be described below with reference to the drawings.

[0051] First Embodiment Fig. 4 is a flowchart according to a first embodiment of the present method. As shown in Fig. 4, the present method may include a step ST11 of providing a substrate and a step ST12 of performing a first etching. The processes in each step may be performed by the plasma processing apparatus 1 described above. The following describes an example in which the control unit 2 controls each part of the inductively coupled plasma processing apparatus 1 (see Fig. 2) to perform the present method on a substrate W.

[0052] (Step ST11: Providing a Substrate) In step ST11, a substrate W is provided in the plasma processing space 10s of the plasma processing apparatus 1. The substrate W is carried into the chamber 10 by a transport arm and placed on the central region 111a of the substrate support part 11. The substrate W is attracted and held on the substrate support part 11 by the electrostatic chuck 1111.

[0053] 5 is a diagram showing an example of the cross-sectional structure of a substrate W provided in step ST11. The substrate W has a carbon-containing film OF and a mask MK. The substrate W may further include an undercoat film UF. The substrate W may be used in the manufacture of semiconductor devices. The semiconductor devices include, for example, semiconductor memory devices such as DRAMs and 3D-NAND flash memories.

[0054] In one embodiment, the base film UF is a silicon wafer, an organic film, a dielectric film, a metal film, a semiconductor film, or a laminated film thereof formed on a silicon wafer. In one embodiment, the base film UF may include a silicon-containing film. The silicon-containing film may be, for example, a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polycrystalline silicon film, or a laminated film including two or more of these films. The silicon-containing film may be, for example, a silicon oxide film and a silicon nitride film laminated alternately. The silicon-containing film may be, for example, a silicon oxide film and a polycrystalline silicon film laminated alternately. The silicon-containing film may be, for example, a laminated film including a silicon nitride film, a silicon oxide film, and a polycrystalline silicon film.

[0055] The carbon-containing film OF is an organic film. The carbon-containing film OF is a film to be etched in the present method. In one embodiment, the carbon-containing film OF is an amorphous carbon film, a spin-on carbon (SOC) film, or a photoresist film. The amorphous carbon (ACL) film may be doped with an element such as boron, and may be, for example, a boron-containing amorphous carbon film (B-doped ACL), an arsenic-containing amorphous carbon film (As-doped ACL), a tungsten-containing amorphous carbon film (W-doped ACL), or a xenon-containing amorphous carbon film (Xe-doped ACL). The carbon-containing film OF may be composed of a single film or may be composed of a plurality of films stacked together.

[0056] In one embodiment, the mask MK is formed from a material having a lower etching rate with respect to the plasma generated in step ST12 than the carbon-containing film OF. In one embodiment, the mask MK includes a silicon-containing film or a metal-containing film. The silicon-containing film may be, for example, a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polycrystalline silicon film, or a stacked film including two or more of these films. The silicon-containing film may be, for example, a silicon oxide film and a silicon nitride film stacked alternately. The silicon-containing film may be, for example, a silicon oxide film and a polycrystalline silicon film stacked alternately. The silicon-containing film may be, for example, a stacked film including a silicon nitride film, a silicon oxide film, and a polycrystalline silicon film. The metal-containing film may be, for example, a film including at least one selected from the group consisting of tungsten, titanium, and molybdenum.

[0057] In one embodiment, the mask MK may have a pattern to be transferred to the carbon-containing film OF by etching. The mask MK may be a single-layer mask consisting of one layer, or may be a multi-layer mask consisting of two or more layers. As shown in FIG. 5 , the mask MK has a sidewall S1 that defines at least one opening OP on the carbon-containing film OF. The opening OP is a space above the carbon-containing film OF and is surrounded by the sidewall S1 of the mask MK. That is, the top surface of the carbon-containing film OF has an area covered by the mask MK and an area exposed at the bottom of the opening OP.

[0058] The openings OP 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. 5 . The shape may be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more of these. The mask MK may have multiple side walls that define multiple openings OP. The multiple openings OP may each have a linear shape and be arranged at regular intervals to form a line-and-space pattern (trench). Alternatively, the multiple openings OP may each have a hole shape and form an array pattern.

[0059] Each of the films constituting the substrate W (the base film UF, the carbon-containing film OF, and the mask MK) may be formed by a CVD method, an ALD method, a PVD method, a spin coating method, or the like. The opening OP in the mask MK may be formed by etching the mask MK, or may be formed by lithography. Each of the films may be flat or may have irregularities. The substrate W may further include another film below the base film UF. In this case, recesses having shapes corresponding to the openings OP may be formed in the carbon-containing film OF and the base film UF, and these recesses may be used as masks for etching the other films.

[0060] At least a part of the process of forming each film on the substrate W may be performed within the space of the chamber 10. In one example, the step of etching the mask MK to form the opening OP may be performed in the chamber 10. That is, the opening OP and the etching of the carbon-containing film OF in step ST12, which will be described later, may be performed consecutively within the same chamber. Alternatively, after all of the films on the substrate W are formed in an apparatus or chamber external to the plasma processing apparatus 1, the substrate W may be loaded into the plasma processing space 10s of the plasma processing apparatus 1 and placed in the central region 111a of the substrate support 11, thereby providing the substrate W.

[0061] In one embodiment, after the substrate W is provided in the central region 111a of the substrate support 11, the substrate support 11 is controlled to a first temperature by a temperature control module. In one example, controlling the temperature of the substrate support 11 to the first temperature includes setting the temperature of the heat transfer fluid flowing through the flow path 1110a or the heater temperature to the first temperature, or to a temperature different from the first temperature. Note that the timing at which the heat transfer fluid starts to flow through the flow path 1110a may be before or after the substrate W is placed on the substrate support 11, or may be simultaneous with the placement of the substrate W on the substrate support 11. Furthermore, the temperature of the substrate support 11 may be controlled to the first temperature before process ST11. That is, the substrate W may be provided to the substrate support 11 after the temperature of the substrate support 11 is controlled to the first temperature.

[0062] The first temperature may be set appropriately depending on the type of carbon-containing film OF and the type of process gas (first process gas) used in step ST12. In one embodiment, the first temperature is 0°C or less and -70°C or more. In one example, the first temperature is -10°C or less, -20°C or less, -30°C or less, -40°C or less, -50°C or less, or -60°C or less.

[0063] In one embodiment, the substrate W may be controlled to the first temperature instead of controlling the substrate support 11 to the first temperature. Controlling the temperature of the substrate W to the first 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 first temperature or to a temperature different from the first temperature.

[0064] (Step ST12: First Etching) In step ST12, the first etching is performed. By the first etching, the carbon-containing film OF of the substrate W is etched to form the recess RC.

[0065] First, a first process gas is supplied into the plasma processing space 10s from the gas supply unit 20. In one embodiment, the first process gas includes a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas. In one embodiment, the first process gas includes a phosphorus halide gas, and an oxygen- and sulfur-containing gas.

[0066] In one embodiment, the oxygen-containing gas is O ２ gas, CO gas and CO ２ The gas comprises at least one gas selected from the group consisting of:

[0067] In one embodiment, the halogenated phosphorus gas is, for example, PF ３ Gas and PF ５ The halogenated phosphorus gas may be a phosphorus fluoride gas containing fluorine as a halogen element, such as PC1 ３ Gas and PCl ５ In one embodiment, the halogenated phosphorus gas may be a phosphorus chloride gas containing chlorine as a halogen element, such as PBr ３ Gas, PBr ５ Gas, PI ３ The halogen element may be a gas containing bromine or iodine. In one embodiment, the phosphorus halide gas is PClF ２ Gas, PCl ２ F gas, PCl ２ F ３ The halogenated phosphorus gas may be a gas containing two or more halogen elements, such as a phosphorus oxyfluoride gas or a phosphorus oxychloride gas. For example, the halogenated phosphorus gas may be POF ３ Gas, POCl ３ Gas, POF ２ Cl ２ Gas, POFC1 ２ Gas or POF ２ It may be Cl gas.

[0068] In one embodiment, the flow rate of the halogenated phosphorus gas is 0.1% by volume or more and 5% by volume or less of the total flow rate of the first process gas (excluding the inert gas if the first process gas contains the inert gas).

[0069] In one embodiment, the sulfur-containing gas is SF ６ It may be a gas.

[0070] In one embodiment, the oxygen and sulfur-containing gas is COS gas or SO ２ It may be a gas.

[0071] In one embodiment, the first process gas may further include an inert gas, which may be, for example, a noble gas such as Ar gas, He gas, or Kr gas, or nitrogen gas.

[0072] Next, a source RF signal is supplied to the antenna 14. This generates a high-frequency electric field in the plasma processing space 10s, generates plasma from the first processing gas, and etches the carbon-containing film OF. 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 activated species such as ions and radicals in the plasma are attracted to the substrate W, which may promote etching of the carbon-containing film OF. The bias signal may be a bias RF signal supplied from the second RF generator 31b. Alternatively, the bias signal may be a bias DC signal supplied from the DC generator 32a.

[0073] In one embodiment, both the source RF signal and the bias signal may be continuous waves or pulse waves, or one may be continuous waves and the other a pulse wave. When both the source RF signal and the bias signal are pulse waves, the periods of the two pulse waves may or may not be synchronized. The duty ratio of the source RF signal and / or bias signal pulse waves may be set appropriately, for example, 1 to 80% or 5 to 50%. Furthermore, when a bias DC signal is used as the bias signal, the pulse wave may have a rectangular, trapezoidal, triangular, or 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 to apply a potential difference between the plasma and the substrate and attract ions.

[0074] In one embodiment, in step ST12, supply and stop of at least one of the source RF signal and the bias signal may be alternately repeated. For example, supply and stop of the bias signal may be alternately repeated while the source RF signal is continuously supplied. Alternatively, for example, supply and stop of the source RF signal may be alternately repeated while the source RF signal is alternately supplied. Alternatively, for example, supply and stop of both the source RF signal and the bias signal may be alternately repeated.

[0075] In one embodiment, during the treatment in step ST12, the temperature of the substrate support part 11 may be controlled to the first temperature set in step ST11. In another embodiment, instead of the temperature of the substrate support part 11, the temperature of the substrate W may be controlled to the first temperature.

[0076] By the treatment in step ST12, the portion of the carbon-containing film OF that is not covered by the mask MK (the portion exposed at the opening OP) is etched, and a recess RC is formed.

[0077] 6 is a diagram for explaining an example of a phenomenon occurring in step ST12. FIG. 6 is a diagram schematically showing a cross-sectional structure of the substrate W in the vicinity of the mask MK during step ST12. As shown in FIG. 6, in step ST12, activated species in plasma (for example, oxygen ions O ＋), the portion of the carbon-containing film OF exposed at the opening OP is etched in the depth direction (from top to bottom in FIG. 6 ), forming a recess RC. The recess RC is a space defined by the sidewall S2 and bottom BT of the carbon-containing film OF.

[0078] 6, in one embodiment, a first deposition film DP1 is formed on the sidewall S1 of the mask MK during the execution of step ST12. The first deposition film DP1 is formed by, for example, ions in the plasma (e.g., oxygen ions O ＋ The first deposition film DP1 may be formed by the mask material sputtered by the mask MK being redeposited on the sidewall S1. For example, if the mask MK includes a silicon-containing film, the deposition film DP may include silicon. During the execution of the process ST, the first deposition film DP1 may be formed by the deposition of activated halogen species (halogen ions X ) in the plasma dissociated from the halogenated phosphorus gas, as schematically shown in FIG. ＋ and halogen radical X ＊ ) and can be volatilized and removed.

[0079] As shown in FIG. 6 , in one embodiment, a second deposition film DP2 is formed on at least a portion of the sidewall S2 and bottom BT of the carbon-containing film OF during step ST12. The second deposition film DP2 may be, for example, a non-volatile by-product (by-product) generated by etching. In one embodiment, the second deposition film DP2 includes a phosphorus oxide compound or an organophosphorus compound. In one embodiment, the second deposition film DP2 is formed bottom-up from the bottom BT during step ST12. That is, as schematically shown in FIG. 6 , the second deposition film DP2 may be formed on the bottom BT and the sidewall S2 near the bottom BT. In one embodiment, the second deposition film DP2 has higher etching resistance to halogen activated species in plasma than the carbon-containing film OF. That is, the second deposition film DP2 may function as a protective film against halogen activated species in plasma on the sidewall S2 and bottom BT on which the second deposition film DP2 is formed.

[0080] According to the first embodiment of the present method, in step ST12, the first deposition film DP1 formed in the opening OP can be removed by activated halogen species in the plasma. Therefore, closure of the opening OP as etching progresses can be suppressed. Furthermore, the second deposition film DP2 formed during step ST12 functions as a protective film, thereby suppressing horizontal etching (left-right direction in FIG. 6 ) of the sidewall S2 on which the second deposition film DP2 is formed.

[0081] 7 is a flowchart according to a second embodiment of the present method. As shown in FIG. 7 , the present method may include a step ST21 of providing a substrate, a step ST22 of performing a first etching, a step ST23 of performing a second etching, and a step ST24 of determining whether an etching stop condition is satisfied. That is, the present method may repeat a cycle including the first etching (step ST22) and the second etching (step ST23) until it is determined in step ST24 that the stop condition is satisfied.

[0082] (Steps ST21 and ST22) Steps ST21 and ST22 may be performed in the same manner as steps ST11 and ST12 of the first embodiment, respectively, and therefore a description thereof will be omitted.

[0083] (Step ST23: Second Etching) In step ST23, the second etching is performed. By the second etching, the recess RC in the carbon-containing film OF of the substrate W is further etched.

[0084] First, a second process gas is supplied from the gas supply unit 20 into the plasma processing space 10s. The second process gas is a gas different from the first process gas. The second process gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas. The second process gas does not contain a halogenated phosphorus gas, or contains a halogenated phosphorus gas at a flow rate lower than the flow rate of the halogenated phosphorus gas contained in the first process gas.

[0085] In one embodiment, the oxygen-containing gas is O ２ gas, CO gas and CO ２When both the first process gas and the second process gas contain an oxygen-containing gas, the oxygen-containing gas contained in the second process gas may be the same type of gas as that of the first process gas, or may be different.

[0086] In one embodiment, the halogenated phosphorus gas is, for example, PF ３ Gas and PF ５ The halogenated phosphorus gas may be a phosphorus fluoride gas containing fluorine as a halogen element, such as PC1 ３ Gas and PCl ５ In one embodiment, the halogenated phosphorus gas may be a phosphorus chloride gas containing chlorine as a halogen element, such as PBr ３ Gas, PBr ５ Gas, PI ３ The halogen element may be a gas containing bromine or iodine. In one embodiment, the phosphorus halide gas is PClF ２ Gas, PCl ２ F gas, PCl ２ F ３ The halogenated phosphorus gas may be a gas containing two or more halogen elements, such as a phosphorus oxyfluoride gas or a phosphorus oxychloride gas. For example, the halogenated phosphorus gas may be POF ３ Gas, POCl ３ Gas, POF ２ Cl ２ Gas, POFC1 ２ Gas or POF ２ When the second process gas contains a phosphorus halide gas, the phosphorus halide gas may be the same type of gas as the first process gas, or may be different.

[0087] In one embodiment, the sulfur-containing gas is SF ６ It may be a gas.

[0088] In one embodiment, oxygen and a sulfur-containing gas, COS gas or SO ２When both the first process gas and the second process gas contain oxygen- and sulfur-containing gases, the oxygen- and sulfur-containing gas contained in the second process gas may be the same type of gas as the first process gas, or may be different.

[0089] In one embodiment, the second process gas may further include an inert gas, which may be, for example, a noble gas such as Ar gas, He gas, or Kr gas, or nitrogen gas.

[0090] Next, a source RF signal is supplied to the antenna 14. This generates a high-frequency electric field in the plasma processing space 10s, generates plasma from the second processing gas, and etches the carbon-containing film OF. 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 activated species such as ions and radicals in the plasma are attracted to the substrate W, which may promote etching of the carbon-containing film OF. The configurations and supply forms of the source signal and bias signal may be the same as or different from those in step ST22 (step ST12).

[0091] In one embodiment, during the treatment in step ST23, the temperature of the substrate support 11 may be controlled to the same temperature (i.e., the first temperature) as that in step ST22. In one embodiment, instead of the temperature of the substrate support 11, the temperature of the substrate W may be controlled.

[0092] (Step ST24: Stop Determination) In step ST24, it is determined whether a stop condition is satisfied. The stop condition may be, for example, whether the number of repetitions of step ST22 and step ST23 as one cycle has reached a given number. The stop condition may be, for example, whether the etching time has reached a given time. The stop condition may be, for example, whether the depth of the recess RC formed by etching has reached a given depth. If it is determined that the stop condition is not satisfied in step ST24, the cycle including step ST22 and step ST23 is repeated. If it is determined that the stop condition is satisfied in step ST24, etching is stopped and the method is terminated.

[0093] FIG. 8 is a diagram for explaining an example of a phenomenon that occurs during the repeated cycle of steps ST22 and ST23.

[0094] As shown in FIG. 8, in the step ST22 (first etching) of the cycle N (N is an integer of 1 or more), the same phenomenon as that described in FIG. 6 may occur. That is, in this step, activated species (e.g., oxygen ions O ＋ ) etch the recess RC in the depth direction. ＋ and halogen radical X ＊ ) can remove the first deposition film DP1 formed on the sidewall S1 of the mask MK. Furthermore, a second deposition film DP2 that functions as a protective film against halogen activated species in plasma can be formed on at least a part of the sidewall S2 and the bottom BT of the carbon-containing film OF.

[0095] In step ST23 (second etching) of cycle N, activated species (e.g., oxygen ions O ＋ ) further etches the recess RC in the depth direction. Here, the second process gas does not contain halogenated phosphorus gas, or contains halogenated phosphorus gas at a flow rate lower than that of the first process gas. Therefore, in step ST23, the amount of halogen activated species in the plasma is reduced compared to step ST22, and the amount of phosphorus activated species is also reduced. As a result, the formation of the first deposition film DP1 is dominant on the sidewall S1 of the mask MK. Furthermore, the second deposition film DP2 is reduced or removed on the sidewall S2 and bottom BT of the carbon-containing film OF.

[0096] In step ST22 of cycle N+1, activated species (e.g., oxygen ions O ＋ ) the recess RC is further etched in the depth direction. Then, similar to step ST22 of cycle N, the first deposition film DP1 formed on the sidewall S1 of the mask MK can be removed. Furthermore, the second deposition film DP2 can be formed again on at least a part of the sidewall S2 and bottom BT of the carbon-containing film OF.

[0097] In step ST23 of cycle N+1, activated species (e.g., oxygen ions O ＋) further etches the recess RC in the depth direction. Then, similar to step ST23 of cycle N, the formation of the first deposition film DP1 predominates on the sidewall S1 of the mask MK. Furthermore, the second deposition film DP2 is reduced or removed on the sidewall S2 and bottom BT of the carbon-containing film OF.

[0098] However, if the activated halogen species in the plasma become excessive, the portion of the sidewall S2 of the carbon-containing film OF that is not covered with the second deposition film DP2 is etched in the horizontal direction, which may cause the opening width (CD) of the recess RC to increase or bowing to occur.Furthermore, it may also cause the upper portion of the mask MK to be excessively etched, which may cause the selectivity to deteriorate.

[0099] In this regard, according to the second embodiment of the present method, a cycle including a first etching (step ST22) and a second etching (step ST23) is alternately repeated. That is, step ST22 containing a phosphorus halide gas as a processing gas and step ST23 containing no phosphorus halide gas or a phosphorus halide gas at a flow rate lower than that of step ST22 are alternately repeated. This makes it possible to adjust the amount of activated halogen species dissociated into the plasma. According to the second embodiment of the present method, it is possible to prevent the above-mentioned problems caused by an excess of activated halogen species in the plasma. That is, it is possible to prevent shape abnormalities (CD enlargement, bowing) due to etching and a decrease in etching selectivity.

[0100] The etching times in steps ST22 and ST23 may be set as appropriate. In one embodiment, the etching times in steps ST22 and ST23 may be set depending on the flow rate of the phosphorus halide gas contained in the first process gas and / or the second process gas, the type of mask MK and the carbon-containing film OF, the depth of the recesses RC, the aspect ratio, and the like. In one embodiment, the ratio of the etching time in step ST23 to the etching time in step ST22 may be 0.8 to 1.2. In one embodiment, the ratio may be 0.9 to 1.1. In one embodiment, the ratio may be set depending on the number of cycles. For example, the ratio may increase when the number of cycles exceeds a certain number or for each certain number of cycles. As a result, the etching time in step ST23 may be longer than that in step ST22 as the depth of the recesses RC formed in the carbon-containing film OF increases. In one embodiment, the ratio may be set depending on the depth or aspect ratio of the recesses RC, rather than the number of cycles. For example, the ratio may be increased when the depth or aspect ratio of the recess RC exceeds a given value or with each increase of the given value.

[0101] In one embodiment, during the process in step ST23, the temperature of the substrate support member 11 may be controlled to a second temperature different from that in step ST22. The second temperature may be higher than the first temperature. In this case, volatilization (removal) of the second deposition film DP2 may be promoted in step ST23. In one embodiment, the first temperature and / or the second temperature may be set according to the number of cycles. For example, the first temperature and / or the second temperature may be increased when the number of cycles exceeds a predetermined number or for each predetermined number of cycles. This may increase the temperature of the substrate support member 11 as the depth of the recess RC formed in the carbon-containing film OF increases. In one embodiment, the first temperature and / or the second temperature may be set according to the depth or aspect ratio of the recess RC rather than the number of cycles. For example, the first temperature and / or the second temperature may be increased when the depth or aspect ratio of the recess RC exceeds a predetermined value or each time the depth or aspect ratio of the recess RC increases by a predetermined value.

[0102] 9 and 10 are flowcharts illustrating a modified example of the second embodiment. FIG. 7 illustrates an example in which the first etching (step ST22) is performed and then the second etching (step ST23) is performed in one cycle. However, as shown in FIG. 9, the second etching (step ST32) may be performed and then the first etching (step ST33) may be performed in one cycle. Furthermore, as shown in FIG. 10, it may be determined whether the stop condition is satisfied during one cycle. That is, it may be determined (step ST43) whether the stop condition is satisfied after the first etching (step ST42) is performed. If the stop condition is satisfied, the etching may be terminated without proceeding to the second etching (step ST44).

[0103] <Examples> Next, examples of the present method will be described. The present disclosure is not limited to the following examples.

[0104] In Example 1, a substrate having a structure similar to that of the substrate W shown in Fig. 5 was etched using the plasma processing apparatus 1 shown in Fig. 2 in accordance with the flowchart described in Fig. 4. The mask MK was a silicon oxynitride film, and the carbon-containing film OF was an amorphous carbon film. The opening OP of the mask MK had a hole shape and a diameter of 80 nm.

[0105] In step ST12, the first processing gas is O ２ Gas, PF ３ It contained PF gas and COS gas. ３ The gas flow rate was 1.3 vol % of the total flow rate of the first process gas. In addition to the source RF signal, a bias RF signal was supplied in step ST12. In step ST12, the pressure in the chamber 10 was controlled to 30 mTorr, and the temperature of the substrate support 11 was controlled to −60° C. The process ST12 was performed for 240 seconds.

[0106] Reference Example 1 In Reference Example 1, a substrate having the same configuration as that of Example 1 was etched using the plasma processing apparatus 1. In Reference Example 1, O ２Etching was carried out under the same conditions as in Example 1, except that SiO 2 gas and COS gas were used.

[0107] 11 is a diagram showing the results of etching according to Example 1 and Reference Example 1. In Fig. 11, (a1) and (b1) are diagrams showing the cross-sectional shapes of the mask MK and the upper part of the recess RC after etching according to Example 1 and Reference Example 1, respectively. (a2) and (b2) are plan views of the mask MK after etching according to Example 1 and Reference Example 1, respectively (views of (a1) and (b1) from above).

[0108] As shown in (a1) and (a2) of Figure 11, in Example 1, blocking of the openings OP of the mask MK was suppressed. The minimum opening diameter of the mask MK in Example 1 was 63.0 nm. In contrast, as shown in (b1) and (b2) of Figure 11, in Reference Example 1, the opening diameter narrowed (necks occurred) in parts of the mask MK, causing significant blocking of the openings OP. The minimum opening diameter of the mask MK in Reference Example 1 was 42.8 nm.

[0109] Example 2 In Example 2, a substrate having the same configuration as Example 1 was etched using the plasma processing apparatus 1 shown in FIG. 2 and in accordance with the flowchart described with reference to FIG.

[0110] In step ST22, a process gas having the same composition as in Example 1 was used as the first process gas. In step ST22, a bias RF signal was supplied in addition to the source RF signal. The pressure in the chamber 10 was controlled to 30 mTorr, and the temperature of the substrate support 11 was controlled to −60° C. In step ST23, the second process gas was O ２ The etching conditions were the same as those in step ST22. In one cycle, etching in step ST22 was performed for 10 seconds, and then etching in step ST23 was performed for 10 seconds. In Example 2, this cycle was repeated 12 times, and etching was performed for a total of 240 seconds.

[0111] 12 is a diagram showing the results of etching according to Example 2 and Reference Example 1. In FIG. 12, (a1) is a diagram showing the cross-sectional shapes of the mask MK and the upper part of the recess RC after etching according to Example 2. (a2) is a plan view of the mask MK after etching according to Example 2 (a view of (a1) from above). Note that (a2) and (b2) in FIG. 12 are reprints of the drawings of Reference Example 1 shown in (a2) and (b2) in FIG. 11 for comparison with Example 2.

[0112] 12, in Example 2, as in Example 1, the blocking of the openings in the mask MK was suppressed compared to Reference Example 1. In Example 2, the minimum opening diameter of the mask MK was 62.6 nm.

[0113] 13 is a diagram showing the results of etching according to Example 2 and Reference Example 1. In FIG. 13, the vertical axis represents the depth D [μm] of the opening OP in the mask film MK and the recess RC formed in the carbon-containing film OF. The vicinity of 0 μm on the vertical axis is the boundary between the mask MK and the carbon-containing film OF. In FIG. 13, the horizontal axis represents the opening diameter CD [nm] of the opening OP in the mask film MK and the recess RC formed in the carbon-containing film OF.

[0114] 13 , in Example 2, the expansion of the opening diameter of the recess RC was suppressed throughout the entire depth direction compared to Reference Example 1. Furthermore, the maximum diameter of the recess RC in Example 2 was 67.5 nm, while the maximum diameter of the recess RC in Reference Example 1 was 77.4 nm. That is, bowing was suppressed in Example 2 compared to Reference Example 1. Furthermore, the etching selectivity (the ratio of the etching rate of the carbon-containing film OF to the etching rate of the mask MK) was 125.4 in Example 2, while it was 75.1 in Reference Example 1. That is, the selectivity was also improved in Example 2 compared to Reference Example 1.

[0115] Embodiments of the present disclosure further include the following aspects.

[0116] (Supplementary Note 1) An etching method comprising: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in a chamber; and (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas.

[0117] (Supplementary Note 2) (c) The etching method according to Supplementary Note 1, further comprising the step of etching the carbon-containing film using plasma generated from a second process gas different from the first process gas, wherein the second process gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas.

[0118] (Supplementary Note 3) The etching method according to Supplementary Note 2, wherein the second process gas does not contain a phosphorus halide gas.

[0119] (Supplementary Note 4) The etching method according to Supplementary Note 2, wherein the second process gas contains a halogenated phosphorus gas at a flow rate lower than that of the halogenated phosphorus gas contained in the first process gas.

[0120] (Supplementary Note 5) The etching method according to any one of Supplementary Note 2 to Supplementary Note 4, wherein a ratio of an etching execution time in the step (c) to an etching execution time in the step (b) is 0.8 or more and 1.2 or less.

[0121] (Supplementary Note 6) The etching method according to any one of Supplementary Note 2 to Supplementary Note 4, wherein a cycle including the step (b) and the step (c) is repeated multiple times.

[0122] (Supplementary Note 7) The etching method according to Supplementary Note 6, wherein in at least one of the cycles from the second onwards, the ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is greater than the ratio in the first cycle.

[0123] (Supplementary Note 8) The etching method according to Supplementary Note 6 or Supplementary Note 7, wherein the temperature of the substrate support part in at least one of the cycles from the second cycle onwards is set higher than the temperature of the substrate support part in the first cycle.

[0124] (Supplementary Note 9) The etching method according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the halogenated phosphorus gas includes at least one gas selected from the group consisting of phosphorus fluoride gas, phosphorus chloride gas, phosphorus oxyfluoride gas, and phosphorus oxychloride gas.

[0125] (Note 10) The halogenated phosphorus gas is PF ３ Gas, PF ５ Gas and PCl ３ 10. The etching method of any one of claims 1 to 9, comprising at least one gas selected from the group consisting of gases.

[0126] (Supplementary Note 11) The etching method according to any one of Supplementary Note 1 to Supplementary Note 10, wherein a flow rate of the halogenated phosphorus gas in the first process gas is 5% by volume or less of a total flow rate of the first process gas.

[0127] (Supplementary Note 12) The oxygen-containing gas is O ２ gas, CO gas and CO ２ 12. The etching method of any one of claims 1 to 11, comprising at least one gas selected from the group consisting of:

[0128] (Supplementary Note 13) The oxygen and sulfur-containing gas is COS gas and SO ２ 13. The etching method according to any one of claims 1 to 12, wherein the gas is at least one of the following gases:

[0129] (Supplementary Note 14) The sulfur-containing gas is SF ６ 14. The etching method of any one of claims 1 to 13, wherein the gas is a gas.

[0130] (Supplementary Note 15) The etching method according to any one of Supplementary Note 1 to Supplementary Note 14, wherein the mask includes a silicon-containing film or a metal-containing film.

[0131] (Supplementary Note 16) The etching method according to any one of Supplementary Note 1 to Supplementary Note 15, wherein the carbon-containing film includes an amorphous carbon film.

[0132] (Supplementary Note 17) The etching method according to any one of Supplementary Note 1 to Supplementary Note 16, wherein in the step (b), the temperature of the substrate support part is set to 0 degrees or less.

[0133] (Supplementary Note 18) The etching method according to any one of Supplementary Note 2 to Supplementary Note 8, wherein in the step (c), the temperature of the substrate support part is set to 0 degrees or less.

[0134] (Supplementary Note 19) A plasma processing apparatus having a chamber and a control unit, wherein the control unit performs the following control operations: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support unit in the chamber; and (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas.

[0135] (Supplementary Note 20) The plasma processing apparatus according to Supplementary Note 19, wherein the control unit further (c) performs control to etch the carbon-containing film using plasma generated from a second processing gas different from the first processing gas, and the second processing gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas.

[0136] (Supplementary Note 21) A device manufacturing method carried out in a plasma processing apparatus having a chamber and a control unit, the device manufacturing method comprising: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in the chamber; and (b) etching the carbon-containing film using plasma generated from a first process gas, the first process gas including a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or including a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas.

[0137] (Supplementary Note 22) A program causing a computer of a plasma processing apparatus having a chamber and a control unit to execute the following controls: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support unit in the chamber; and (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas.

[0138] (Supplementary Note 23) A storage medium storing the program according to Supplementary Note 22.

[0139] 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 the above embodiments 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.

[0140] REFERENCE SIGNS LIST 1: plasma processing apparatus, 2: control unit, 10: plasma processing chamber, 10s: plasma processing space, 11: substrate support unit, 14: antenna, 20: gas supply unit, 31a: first RF generating unit, 31b: second RF generating unit, 32a: first DC generating unit, DP1: first deposited film, DP2: second deposited film, MK: mask, OF: carbon-containing film, OP: opening, RC: recess, UF: base film, W: substrate

Claims

1. 1. An etching method comprising: (a) providing a substrate on a substrate support in a chamber, the substrate having a carbon-containing film including an amorphous carbon film and a mask on the carbon-containing film; (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas; Etching method.

2. 2. The etching method of claim 1, further comprising: (c) etching the carbon-containing film using plasma generated from a second process gas different from the first process gas, wherein the second process gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas.

3. 1. An etching method comprising: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in a chamber; (b) etching the carbon-containing film using plasma generated from a first process gas, the first process gas including a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas; (c) etching the carbon-containing film using plasma generated from a second process gas different from the first process gas; the second process gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas, and the second process gas does not contain a halogenated phosphorus gas, or contains a halogenated phosphorus gas at a flow rate lower than that of the halogenated phosphorus gas contained in the first process gas; Etching method.

4. 4. The etching method according to claim 2, wherein a ratio of an etching time in the step (c) to an etching time in the step (b) is 0.8 or more and 1.2 or less.

5. 4. The etching method according to claim 2, wherein a cycle including the steps (b) and (c) is repeated a plurality of times.

6. 6. The etching method according to claim 5, wherein in at least one of the second or subsequent cycles, the ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is greater than the ratio in the first cycle.

7. 6. The etching method according to claim 5, wherein the temperature of the substrate support part in at least one of the second or subsequent cycles is set higher than the temperature of the substrate support part in the first cycle.

8. 4. The etching method according to claim 1, wherein the halogenated phosphorus gas includes at least one gas selected from the group consisting of phosphorus fluoride gas, phosphorus chloride gas, phosphorus oxyfluoride gas, and phosphorus oxychloride gas.

9. The halogenated phosphorus gas is PF 3 Gas, PF 5 Gas and PCl 3 The etching method according to claim 1 , further comprising at least one gas selected from the group consisting of:

10. 4. The etching method according to claim 1, wherein a flow rate of the halogenated phosphorus gas in the first process gas is 5% by volume or less of a total flow rate of the first process gas.

11. The oxygen-containing gas is O 2 gas, CO gas and CO 2 4. The etching method according to claim 1, further comprising at least one gas selected from the group consisting of:

12. The oxygen and sulfur-containing gas is COS gas and SO 2 4. The etching method according to claim 1, wherein the gas is at least one of the following gases:

13. The sulfur-containing gas is SF 6 The etching method according to claim 1 , wherein the gas is a gas.

14. The etching method according to claim 1 , wherein the mask comprises a silicon-containing film or a metal-containing film.

15. 4. The etching method according to claim 1, wherein in the step (b), the temperature of the substrate support part is set to 0 degrees or less.

16. 4. The etching method according to claim 2, wherein in the step (c), the temperature of the substrate support part is set to 0 degrees or less.

17. An etching method comprising: (a) providing a substrate having a carbon-containing film (excluding a carbon-containing silicon film) and a mask on the carbon-containing film on a substrate support in a chamber; (b) etching the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas; Etching method.

18. The etching method of claim 17, wherein the carbon-containing film comprises an organic film, amorphous carbon, a spin-on carbon film, a photoresist film, a boron-containing amorphous carbon film, an arsenic-containing amorphous carbon film, a tungsten-containing amorphous carbon film, or a xenon-containing amorphous carbon film.

19. A plasma processing apparatus having a chamber and a control unit, The control unit (a) providing a substrate having a carbon-containing film, the carbon-containing film including an amorphous carbon film, and a mask on the carbon-containing film on a substrate support in a chamber; (b) controlling the etching of the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas; Plasma processing equipment.

20. A plasma processing apparatus having a chamber and a control unit, The control unit (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support in a chamber; (b) etching the carbon-containing film using plasma generated from a first process gas, the first process gas containing a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas, or a halogenated phosphorus gas, an oxygen-containing gas, and a sulfur-containing gas; (c) performing control to etch the carbon-containing film using plasma generated from a second process gas different from the first process gas; the second process gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas, and the second process gas does not contain a halogenated phosphorus gas, or contains a halogenated phosphorus gas at a flow rate lower than that of the halogenated phosphorus gas contained in the first process gas; Plasma processing equipment.

21. A plasma processing apparatus having a chamber and a control unit, The control unit (a) providing a substrate having a carbon-containing film (excluding a carbon-containing silicon film) and a mask on the carbon-containing film on a substrate support in a chamber; (b) controlling the etching of the carbon-containing film using plasma generated from a first process gas, wherein the first process gas contains a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas; Plasma processing equipment.

22. 22. The plasma processing apparatus of claim 19, wherein the control unit further performs control to (c) etch the carbon-containing film using plasma generated from a second processing gas different from the first processing gas, and the second processing gas contains an oxygen-containing gas and a sulfur-containing gas, or contains oxygen and a sulfur-containing gas.