Etching method and plasma processing apparatus

Abstract

A technique for suppressing mask opening blocking is provided. An etching method is provided. The method includes: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion in a chamber; and (b) a step for etching the carbon-containing film using plasma generated from a first processing gas including a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or including a phosphorus halide gas, and an oxygen-containing and sulfur-containing gas.

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 technique for etching an organic film using O 2 gas and COS gas.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-200925 Summary of the Invention

[0006] The present disclosure provides a technique for suppressing clogging of mask openings.

[0007] In an exemplary embodiment of the present disclosure, an etching method is provided, comprising: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion within a chamber; and (b) etching the carbon-containing film using plasma generated by a first processing gas, wherein the first processing gas comprises a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or comprises a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0008] Effects of the Invention

[0009] According to an exemplary embodiment of the present disclosure, a technique for suppressing clogging of mask openings can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram for explaining an example of the configuration of a plasma processing apparatus.

[0011] Figure 2 This is a diagram for explaining a configuration example of an inductively coupled plasma processing apparatus.

[0012] Figure 3 This is a diagram for explaining an example of opening clogging.

[0013] Figure 4 This is a flowchart according to the first embodiment.

[0014] Figure 5 1 is a diagram showing an example of a cross-sectional structure of a substrate W provided in step ST11 .

[0015] Figure 6 This is a diagram for explaining an example of a phenomenon occurring in step ST12.

[0016] Figure 7 This is a flowchart according to the second embodiment.

[0017] Figure 8 This is a diagram for explaining an example of a phenomenon that occurs in the repeated cycle of steps ST22 and ST23.

[0018] Figure 9 This is a flowchart according to a modified example of the second embodiment.

[0019] Figure 10 This is a flowchart according to a modified example of the second embodiment.

[0020] Figure 11 It is a graph showing the etching results according to Example 1 and Reference Example 1.

[0021] Figure 12 It is a graph showing the etching results according to Example 2 and Reference Example 1.

[0022] Figure 13 It is a graph showing the etching results according to Example 2 and Reference Example 1.

[0023] Description of Reference Numerals

[0024] 1…plasma processing device; 2…control unit; 10…plasma processing chamber; 10s…plasma processing space; 11…substrate support unit; 14…antenna; 20…gas supply unit; 31a…first RF generation unit; 31b…second RF generation unit; 32a…first DC generation unit; DP1…first deposited film; DP2…second deposited film; MK…mask; OF…carbon-containing film; OP…opening; RC…recess; UF…base film; W…substrate. DETAILED DESCRIPTION

[0025] Hereinafter, each embodiment of the present disclosure will be described.

[0026] In an exemplary embodiment, an etching method is provided, comprising: (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion in a chamber; and (b) etching the carbon-containing film using plasma generated by a first processing gas, wherein the first processing gas includes a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or includes a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0027] In one exemplary embodiment, the process further includes (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-containing and sulfur-containing gases.

[0028] In one exemplary embodiment, the second process gas does not contain a phosphorus halide gas.

[0029] In one exemplary embodiment, the second process gas includes the phosphorus halide gas at a flow rate less than the phosphorus halide gas included in the first process gas.

[0030] In one exemplary embodiment, the ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is 0.8 or more and 1.2 or less.

[0031] In one exemplary embodiment, a cycle including the steps (b) and (c) is repeated multiple times.

[0032] In one exemplary embodiment, in at least one cycle after the second cycle, the ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is greater than that in the first cycle.

[0033] In an exemplary embodiment, the temperature of the substrate supporting portion in at least one cycle after the second cycle is set to be higher than the temperature of the substrate supporting portion in the first cycle.

[0034] In an exemplary embodiment, the phosphorus halide 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.

[0035] In an exemplary embodiment, the phosphorus halide gas includes at least one gas selected from the group consisting of PF3 gas, PF5 gas, and PCl3 gas.

[0036] In an exemplary embodiment, the flow rate of the phosphorus halide gas in the first process gas is less than or equal to 5 volume % of the total flow rate of the first process gas.

[0037] In an exemplary embodiment, the oxygen-containing gas includes at least one gas selected from the group consisting of O 2 gas, CO gas, and CO 2 gas.

[0038] In an exemplary embodiment, the oxygen-and-sulfur-containing gas is at least one of COS gas and SO 2 gas.

[0039] In an exemplary embodiment, the sulfur-containing gas is SF6 gas.

[0040] In one exemplary embodiment, the mask includes a silicon-containing film or a metal-containing film.

[0041] In one exemplary embodiment, the carbon-containing film includes an amorphous carbon film.

[0042] In one exemplary embodiment, in the step (b), the temperature of the substrate support portion is set to zero degrees or lower.

[0043] In one exemplary embodiment, in the step (c), the temperature of the substrate support portion is set to zero degrees or lower.

[0044] In one exemplary embodiment, a plasma processing apparatus is provided, which has a chamber and a control portion that performs the following controls: (a) control of providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion in the chamber; and (b) control of etching the carbon-containing film using plasma generated by a first process gas, the first process gas including a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or including a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0045] In an exemplary embodiment, the control unit further performs (c) control of etching the carbon-containing film using plasma generated from a second process gas different from the first process gas, the second process gas including an oxygen-containing gas and a sulfur-containing gas, or including oxygen-containing and sulfur-containing gases.

[0046] Below, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Identical or similar elements are denoted by the same reference numerals in the various drawings, and repeated descriptions are omitted. Unless otherwise specified, 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 proportions, and actual proportions are not limited to those shown in the drawings.

[0047] <Configuration Example of Plasma Processing Apparatus>

[0048] Figure 1 1 is a diagram for illustrating an example of the structure of a plasma processing apparatus. In one embodiment, a 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 generating unit 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 unit 20 described later, and the gas exhaust port is connected to the exhaust system 40 described later. The substrate support unit 11 is arranged in the plasma processing space and has a substrate supporting surface for supporting a substrate.

[0049] The plasma generating section 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), 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 sections including an alternating current plasma generating section and a direct current plasma generating section may also be used. In one embodiment, the alternating current signal (AC power) used in the alternating current plasma generating section has a frequency in the range of 100kHz to 10GHz. Therefore, the alternating current signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100kHz to 150MHz.

[0050] The control unit 2 processes computer-executable instructions that cause the plasma processing device 1 to perform the various processes described in the present disclosure. The control unit 2 can be configured to control the various elements of the plasma processing device 1 to perform the various processes described herein. In one embodiment, part or all of the control unit 2 can be configured as an external system of the plasma processing device 1. The control unit 2 can also include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, by a computer 2a. The processing unit 2a1 can be configured to perform various control operations 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 obtained via a medium when necessary. The obtained program is stored in the storage unit 2a2 and read and executed from the storage unit 2a2 by the processing unit 2a1. The medium can be various storage media readable by the computer 2a, and can be a communication line connected to the communication interface 2a3. The processing unit 2a1 can also be a CPU (Central Processing Unit). The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may also communicate with various components of the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0051] Hereinafter, a configuration example of an inductively coupled 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 an inductively coupled plasma processing apparatus.

[0052] An 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. Furthermore, the substrate processing apparatus 1 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.

[0053] 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 when viewed from above. 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 so as to surround 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.

[0054] 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 bias 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 also includes an annular area 111b. In addition, other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating component, may also 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, and 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 may also be arranged in the ceramic component 1111a. In this case, at least one RF / DC electrode functions as a bias electrode. Furthermore, the conductive components of the base 1110 and the at least one RF / DC electrode can also function as multiple bias electrodes. Furthermore, the electrostatic electrode 1111b can also function as a bias electrode. Therefore, the substrate support portion 11 includes at least one bias electrode.

[0055] The ring assembly 112 includes one or more ring components. In one embodiment, the one or more ring 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.

[0056] In addition, the substrate support portion 11 may also include a temperature control module, which is 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 through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are provided in the ceramic component 1111a of the electrostatic chuck 1111. In addition, the substrate support portion 11 may also include a heat transfer gas supply portion, which is configured to supply heat transfer gas to the gap between the back side of the substrate W and the central area 111a.

[0057] The gas inlet portion is configured to introduce at least one processing gas from the gas supply portion 20 into the plasma processing space 10s. In one embodiment, the gas inlet portion includes a central gas injection portion (CGI: Center Gas Injector) 13. The central gas injection portion 13 is arranged above the substrate support portion 11 and is installed in the central opening portion formed in the dielectric window 101. The central gas injection portion 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 processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s from the gas inlet port 13c through the gas flow path 13b. In addition, the gas inlet portion may include one or more side gas injection portions (SGI: Side Gas Injector) installed on one or more opening portions formed in the side wall 102 in addition to or instead of the central gas injection portion 13.

[0058] 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 each corresponding gas source 21 via each corresponding flow controller 22 to the gas inlet unit. Each flow controller 22 may, for example, be a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices for modulating or pulsing the flow of the at least one process gas.

[0059] The power supply 30 includes an RF power supply 31, which is coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to provide at least one RF signal (RF power) to at least one bias electrode 14. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a portion of the plasma generating unit 12. Furthermore, by supplying a bias RF signal to at least one bias electrode, a bias potential is generated on the substrate W, enabling ions in the generated plasma to be introduced into the substrate W.

[0060] In one embodiment, the RF power supply 31 includes a first RF generator 31a and a second RF generator 31b. The first RF generator 31a is configured to couple with the antenna 14 via at least one impedance matching circuit 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 generator 31a may also 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.

[0061] The second RF generating unit 31b is configured to couple with at least one bias electrode via 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 also be configured to generate a plurality of bias RF signals with different frequencies. The generated one or more bias RF signals are supplied to at least one bias electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0062] 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 to generate a bias DC signal. The generated bias DC signal is applied to the at least one bias electrode.

[0063] In various embodiments, the bias DC signal can be pulsed. In this case, a voltage pulse sequence is applied to at least one bias electrode. The voltage pulse can have a pulse waveform of a rectangle, a trapezoid, a triangle, or a combination thereof. In one embodiment, a waveform generating unit for generating a voltage pulse sequence from a DC signal is connected between the bias DC generating unit 32a and at least one bias electrode. Therefore, the bias DC generating unit 32a and the waveform generating unit constitute a voltage pulse generating unit. The voltage pulse can have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses can include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses within one cycle. In addition, the bias DC generating unit 32a can be provided on the basis of the RF power supply 31, or it can be provided instead of the second RF generating unit 31b.

[0064] Antenna 14 includes one or more coils. In one embodiment, antenna 14 may include an outer coil and an inner coil arranged coaxially. In this case, RF power supply 31 may be connected to both the outer coil and the inner coil, or to either one of the outer coil and 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 each of the outer coil and the inner coil.

[0065] The exhaust system 40 can be connected to the gas exhaust port 10e provided at the bottom of the plasma processing chamber 10, for example. The exhaust system 40 can 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 can include a turbomolecular pump, a dry pump, or a combination thereof.

[0066] <Mask openings clogged>

[0067] It is known that during plasma etching, the mask opening may become narrowed or clogged (hereinafter referred to as "opening clogging"). Opening clogging can cause etching to stop or cause shape abnormalities such as bowing. Opening clogging can occur due to deposition of material in the plasma adhering to the sidewalls of the opening, or mask material sputtered by ions in the plasma adhering again to the sidewalls of the opening.

[0068] Figure 3 This is a diagram showing an example of an opening being blocked. Figure 3 The example shown is an example of etching a substrate W using plasma generated by a process gas composed of O2 gas and COS gas. The substrate W includes an underfilm 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. Figure 3As shown in the left to right figures of FIG, as etching proceeds, deposits DP adhere to the sidewalls S1 of the mask MK, blocking the opening OP. The deposits DP may include, for example, mask material (silicon in this example) sputtered by ions in the plasma.

[0069] According to an etching method according to an exemplary embodiment of the present disclosure (hereinafter referred to as "this method"), such clogging of the openings can be suppressed. An example of this method will be described below with reference to the accompanying drawings.

[0070] <First embodiment>

[0071] Figure 4 This is a flow chart of the first embodiment of the present method. Figure 4 As shown in FIG. 1 , the method may include a step ST11 of providing a substrate and a step ST12 of performing a first etching. The processing in each step may be performed in the plasma processing apparatus 1 described above. Hereinafter, the control unit 2 controls the inductively coupled plasma processing apparatus 1 (see FIG. 1 ). Figure 2 ) parts, and the case where this method is performed on substrate W is explained as an example.

[0072] (Step ST11: Providing a Substrate)

[0073] In step ST11 , a substrate W is provided in the plasma processing space 10 s of the plasma processing apparatus 1 . The substrate W is carried into the chamber 10 by the transfer arm and placed on the central region 111 a of the substrate support 11 . The substrate W is held by the electrostatic chuck 1111 on the substrate support 11 .

[0074] Figure 5 This figure shows an example of a cross-sectional structure of a substrate W provided in step ST11. The substrate W includes a carbon-containing film OF and a mask MK. The substrate W may also include an underfilm UF. The substrate W can be used to manufacture semiconductor devices. Semiconductor devices include, for example, semiconductor memory devices such as DRAM and 3D-NAND flash memory.

[0075] In one embodiment, the base film UF is an organic film, a dielectric film, a metal film, a semiconductor film, or a stacked film thereof formed on a silicon wafer or on a silicon wafer. In one embodiment, the base film UF may include a silicon-containing film. The silicon-containing film may, for example, be a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polysilicon film, or a stacked film containing two or more of these films. The silicon-containing film may, for example, be composed of alternating layers of silicon oxide films and silicon nitride films. The silicon-containing film may, for example, be composed of alternating layers of silicon oxide films and polysilicon films. The silicon-containing film may, for example, be a stacked film including silicon nitride films, silicon oxide films, and polysilicon films.

[0076] The carbon-containing film OF is an organic film. The carbon-containing film OF is the film to be etched in this 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 can be doped with elements such as boron, 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 can be composed of a single film or a plurality of films stacked together.

[0077] In one embodiment, the mask MK is formed of a material having a lower etching rate for 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 polysilicon film, or a stacked film containing two or more of these films. The silicon-containing film may be, for example, a silicon oxide film and a silicon nitride film alternately stacked. The silicon-containing film may be, for example, a silicon oxide film and a polysilicon film alternately stacked. The silicon-containing film may be, for example, a stacked film including a silicon nitride film, a silicon oxide film, and a polysilicon 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.

[0078] In one embodiment, the mask MK may have a pattern transferred to the carbon-containing film OF by etching. The mask MK may be a single-layer mask consisting of one layer or a multi-layer mask consisting of two or more layers. Figure 5 As shown, the mask MK has sidewalls S1 defining at least one opening OP in the carbon-containing film OF. The opening OP is a space in the carbon-containing film OF, enclosed by the sidewalls S1 of the mask MK. Specifically, the top surface of the carbon-containing film OF includes an area covered by the mask MK and an area exposed at the bottom of the opening OP.

[0079] The opening OP is viewed from above the substrate W. Figure 5 The mask MK may have any shape when looking down at the substrate W from above. The shape may be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more thereof. The mask MK may have a plurality of sidewalls, and the plurality of sidewalls define a plurality of openings OP. The plurality of openings OP may each have a line shape, or may be arranged at a certain interval to form a line and space pattern (groove). In addition, the plurality of openings OP may each have a hole shape to form an array pattern.

[0080] Each film constituting the substrate W (base film UF, carbon-containing film OF, and mask MK) can be formed by CVD, ALD, PVD, spin coating, or the like. The opening OP of the mask MK can be formed by etching the mask MK or by photolithography. Each film can be a flat film or a film with concave and convex surfaces. The substrate W can also 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 on the carbon-containing film OF and the base film UF to be used as a mask for etching the other film.

[0081] At least a portion of the process for forming the various films on the substrate W can be performed within the chamber 10. In one example, the step of etching the mask MK to form the opening OP can be performed within the chamber 10. That is, the etching of the opening OP and the etching of the carbon-containing film OF in step ST12 described later can be performed continuously within the same chamber. Alternatively, after all the films on the substrate W have been formed by a device or chamber external to the plasma processing apparatus 1, the substrate W can be brought into the plasma processing space 10s of the plasma processing apparatus 1 and positioned in the central region 111a of the substrate support 11, thereby providing the substrate W.

[0082] In one embodiment, after the substrate W is provided to the central area 111a of the substrate support portion 11, the substrate support portion 11 is controlled to a first temperature by a temperature control module. In one example, controlling the temperature of the substrate support portion 11 to the first temperature includes setting the temperature of the heat transfer fluid or the heater flowing through the flow path 1110a to the first temperature, or to a temperature different from the first temperature. Furthermore, the timing of starting the flow of the heat transfer fluid to the flow path 1110a may be before, after, or simultaneously with the placement of the substrate W on the substrate support portion 11. Furthermore, the temperature of the substrate support portion 11 may be controlled to the first temperature before step ST11. That is, the substrate W may be provided to the substrate support portion 11 after the temperature of the substrate support portion 11 has been controlled to the first temperature.

[0083] The first temperature can be appropriately set according to the type of carbon-containing film OF or the type of process gas (first process gas) used in step ST12. In one embodiment, the first temperature is not higher than 0°C and not lower than -70°C. In one example, the first temperature is not higher than -10°C, not higher than -20°C, not higher than -30°C, not higher than -40°C, not higher than -50°C, or not higher than -60°C.

[0084] In one embodiment, instead of controlling the substrate support 11 at the first temperature, the substrate W may be controlled at the first temperature. Controlling the temperature of the substrate W at 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.

[0085] (Step ST12: First Etching)

[0086] In step ST12 , the first etching is performed. By the first etching, the carbon-containing film OF on the substrate W is etched to form the recessed portion RC.

[0087] 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.

[0088] In one embodiment, the oxygen-containing gas includes at least one gas selected from the group consisting of O2 gas, CO gas, and CO2 gas.

[0089] In one embodiment, the phosphorus halide gas can be a phosphorus fluoride gas such as PF3 gas or PF5 gas containing fluorine as a halogen. In one embodiment, the phosphorus halide gas can be a phosphorus chloride gas such as PCl3 gas or PCl5 gas containing chlorine as a halogen. In one embodiment, the phosphorus halide gas can be a gas such as PBr3 gas, PBr5 gas and PI3 gas containing bromine or iodine as a halogen. In one embodiment, the phosphorus halide gas can be a gas comprising two or more halogen elements, such as PClF2 gas, PCl2F gas, PCl2F3 gas, etc. In one embodiment, the phosphorus halide gas can be phosphorus oxyfluoride gas or phosphorus oxychloride gas. For example, the phosphorus halide gas can be POF3 gas, POCl3 gas, POF2Cl2 gas, POFCl2 gas or POF2Cl gas.

[0090] In one embodiment, the flow rate of the phosphorus halide 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 when the first process gas includes the inert gas).

[0091] In one embodiment, the sulfur-containing gas may be SF6 gas.

[0092] In one embodiment, the oxygen and sulfur containing gas may be COS gas or SO 2 gas.

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

[0094] Next, a source RF signal is supplied to antenna 14. This generates a high-frequency electric field within the plasma processing space 10s, generating plasma from the first process gas, and etching the carbon-containing film OF. A bias signal can be supplied to the lower electrode of the substrate support 11. At this point, a bias potential is generated between the plasma and the substrate W, attracting active species such as ions and radicals in the plasma to the substrate W, thereby promoting etching of the carbon-containing film OF. The bias signal can be a bias RF signal supplied by the second RF generator 31b. Alternatively, the bias signal can be a bias DC signal supplied by the DC generator 32a.

[0095] In one embodiment, both the source RF signal and the bias signal can be continuous waves or pulse waves, and one can be a continuous wave and the other can be a pulse wave. In the case where the source RF signal and the bias signal are both pulse waves, the periods of the two pulse waves can be synchronized or asynchronous. The duty cycle of the source RF signal and / or the bias signal pulse wave can be appropriately set, for example, it can be 1 to 80%, or it can be 5 to 50%. In addition, when a bias DC signal is used as the bias signal, the pulse wave can have a rectangular, trapezoidal, triangular or a combination thereof waveform. If the potential of the substrate W is set to introduce ions by applying a potential difference between the plasma and the substrate, the polarity of the bias DC signal can be negative or positive.

[0096] In one embodiment, in step ST12, the supply and stop of at least one of the source RF signal and the bias signal may be alternately repeated. For example, the supply and stop of the bias signal may be alternately repeated while the source RF signal is continuously supplied. Furthermore, for example, the bias signal may be continuously supplied while the supply and stop of the source RF signal are alternately repeated. Furthermore, for example, the supply and stop of both the source RF signal and the bias signal may be alternately repeated.

[0097] In one embodiment, during the processing in step ST12, the temperature of the substrate support 11 may be controlled to the first temperature set in step ST11. In one embodiment, instead of the temperature of the substrate support 11, the temperature of the substrate W may be controlled to the first temperature.

[0098] By the process in step ST12 , the portion of the carbon-containing film OF that is not covered by the mask MK (the portion exposed in the opening OP) is etched to form the recessed portion RC.

[0099] Figure 6 This is a diagram for explaining an example of a phenomenon occurring in step ST12. Figure 6 Schematically shows a cross-sectional structure of the substrate W near the mask MK in step ST12. Figure 6 As shown, in step ST12, active species in the plasma (such as oxygen ions O+ ), in the depth direction ( Figure 6 The portion of the carbon-containing film OF exposed in the opening OP is etched (from top to bottom) to form a recessed portion RC. The recessed portion RC is a space defined by the sidewall S2 and the bottom BT of the carbon-containing film OF.

[0100] like Figure 6 As shown, in one embodiment, during the execution of step ST12, a first deposition film DP1 is formed on the sidewall S1 of the mask MK. The first deposition film DP1 can be formed by, for example, ions (such as oxygen ions O + The mask material sputtered by the mask MK is again attached to the sidewall S1. For example, in the case where the mask MK includes a silicon-containing film, the deposited film DP may include silicon. Figure 6 As shown schematically in FIG, the first deposited film DP1 can be reacted with the halogen active species (halogen ions X + Or halogen free radical X*) combined and volatilized away.

[0101] like Figure 6 As shown, in one embodiment, during the execution of step ST12, a second deposited film DP2 is formed on at least a portion of the sidewall S2 and the bottom BT of the carbon-containing film OF. The second deposited film DP2 may be, for example, a non-volatile by-product (by-product) generated by etching. In one embodiment, the second deposited film DP2 includes a phosphorus oxide compound or an organic phosphorus compound. In one embodiment, during the execution of step ST12, the second deposited film DP2 is formed from the bottom up from the bottom BT. That is, as shown in FIG. Figure 6 As shown schematically, the second deposited film DP2 can be formed on the bottom BT and the sidewalls S2 near the bottom BT. In one embodiment, the second deposited film DP2 has higher etching resistance against halogen active species in plasma than the carbon-containing film OF. In other words, the second deposited film DP2 can function as a protective film against halogen active species in plasma on the sidewalls S2 or bottom BT where it is formed.

[0102] According to the first embodiment of the method, in step ST12, the first deposited film DP1 formed in the opening OP can be removed by the halogen active species in the plasma. Therefore, it is possible to suppress the opening OP from being clogged as the etching proceeds. In addition, the second deposited film DP2 formed in the execution of step ST12 functions as a protective film, which can suppress the side wall S2 formed by the second deposited film DP2 from being occluded in the horizontal direction ( Figure 6 left and right directions) are etched.

[0103] <Second embodiment>

[0104] Figure 7This is a flow chart of the second embodiment of the present method. Figure 7 As shown, the method may include step ST21 of providing a substrate, step ST22 of performing a first etching, step ST23 of performing a second etching, and step ST24 of determining whether an etching stop condition is satisfied. That is, the 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.

[0105] (Step ST21 and Step ST22)

[0106] Step ST21 and step ST22 can be performed similarly to step ST11 and step ST12 of the first embodiment, respectively, and their description is omitted.

[0107] (Step ST23: Second Etching)

[0108] In step ST23 , second etching is performed to further etch the recessed portion RC of the carbon-containing film OF on the substrate W.

[0109] 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 includes an oxygen-containing gas and a sulfur-containing gas, or includes both oxygen-containing and sulfur-containing gases. The second process gas does not contain a phosphorus halide gas, or contains a phosphorus halide gas at a flow rate lower than that of the phosphorus halide gas contained in the first process gas.

[0110] In one embodiment, the oxygen-containing gas includes at least one gas selected from the group consisting of O2 gas, CO gas, and CO2 gas. In the case where 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 the first process gas or may be different.

[0111] In one embodiment, the phosphorus halide gas may be a phosphorus fluoride gas containing fluorine as a halogen, such as PF3 gas or PF5 gas. In one embodiment, the phosphorus halide gas may be a phosphorus chloride gas containing chlorine as a halogen, such as PCl3 gas or PCl5 gas. In one embodiment, the phosphorus halide gas may be a gas containing bromine or iodine as a halogen, such as PBr3 gas, PBr5 gas, and PI3 gas. In one embodiment, the phosphorus halide gas may be a gas comprising two or more halogen elements, such as PClF2 gas, PCl2F gas, PCl2F3 gas, etc. In one embodiment, the phosphorus halide gas may be a phosphorus oxyfluoride gas or a phosphorus oxychloride gas. For example, the phosphorus halide gas may be POF3 gas, POCl3 gas, POF2Cl2 gas, POFCl2 gas, or POF2Cl gas. When the second process gas contains a phosphorus halide gas, the phosphorus halide gas may be a gas of the same type as the first process gas, or may be different.

[0112] In one embodiment, the sulfur-containing gas may be SF6 gas.

[0113] In one embodiment, the first process gas and the second process gas may contain oxygen and sulfur gas, COS gas, or SO2 gas. In the case where both the first process gas and the second process gas contain oxygen and sulfur gas, the oxygen and sulfur gas contained in the second process gas may be the same type of gas as the first process gas, or may be different.

[0114] In one embodiment, the second process gas may further include an inert gas, which may be a rare gas such as Ar gas, He gas, or Kr gas, or nitrogen gas.

[0115] Next, a source RF signal is supplied to antenna 14. This generates a high-frequency electric field within the plasma processing space 10s, generating plasma from the second process gas, and etching the carbon-containing film OF. A bias signal can be supplied to the lower electrode of substrate support 11. At this point, a bias potential is generated between the plasma and substrate W, attracting active species such as ions and radicals in the plasma to substrate W, thereby promoting etching of the carbon-containing film OF. The configuration and supply method of the source signal or bias signal may be the same as or different from that in step ST22 (step ST12).

[0116] In one embodiment, during the processing in step ST23 , the temperature of the substrate support 11 may be controlled to the same temperature (ie, the first temperature) as in step ST22 . In one embodiment, the temperature of the substrate W may be controlled instead of the temperature of the substrate support 11 .

[0117] (Step ST24: Stop Determination)

[0118] In step ST24, a determination is made as to whether a stop condition is satisfied. For example, the stop condition may be whether steps ST22 and ST23 have been repeated a predetermined number of times in a single cycle. For example, the stop condition may be whether the etching time has reached a predetermined time. For example, the stop condition may be whether the depth of the recess RC formed by etching has reached a predetermined depth. If the stop condition is determined not to be satisfied in step ST24, the cycle including steps ST22 and ST23 is repeated. If the stop condition is determined to be satisfied in step ST24, etching is stopped, and the method ends.

[0119] Figure 8 This is a diagram for explaining an example of a phenomenon that occurs in the repeated cycle of steps ST22 and ST23.

[0120] like Figure 8 As shown, in the step ST22 (first etching) of cycle N (N is an integer greater than 1), the same Figure 6 That is, in this process, active species in the plasma (such as oxygen ions O + ), etching the recess RC in the depth direction. Furthermore, the first deposited film DP1 formed on the sidewall S1 of the mask MK can be removed by utilizing the halogen active species (halogen ions X+ or halogen radicals X*) in the plasma. Furthermore, a second deposited film DP2 can be formed on at least a portion of the sidewall S2 and bottom BT of the carbon-containing film OF, functioning as a protective film against the halogen active species in the plasma.

[0121] In step ST23 (second etching) of cycle N, recess RC is further etched in the depth direction using active species in the plasma (e.g., oxygen ions O+). Here, the second process gas does not contain a phosphorus halide gas, or contains a phosphorus halide gas at a lower flow rate than the first process gas. Therefore, in step ST23, the number of halogen active species in the plasma decreases compared to step ST22, and the number of phosphorus active species also decreases. As a result, the formation of the first deposited film DP1 predominates on the sidewalls S1 of the mask MK. Furthermore, the second deposited film DP2 is reduced or even removed from the sidewalls S2 and bottom BT of the carbon-containing film OF.

[0122] In step ST22 of cycle N+1, active species in the plasma (e.g. oxygen ions O + ), further etching the recessed portion RC in the depth direction. Furthermore, similarly to step ST22 of cycle N, the first deposited film DP1 formed on the sidewall S1 of the mask MK can be removed. Furthermore, the second deposited film DP2 can be formed again on at least a portion of the sidewall S2 and bottom BT of the carbon-containing film OF.

[0123] In step ST23 of cycle N+1, active species in the plasma (e.g. oxygen ions O + ), further etching the recess RC in the depth direction. Furthermore, similar to step ST23 of cycle N, the first deposited film DP1 is predominantly formed on the sidewalls S1 of the mask MK. Furthermore, the second deposited film DP2 is reduced or removed from the sidewalls S2 and bottom BT of the carbon-containing film OF.

[0124] However, if there is an excess of halogen active species in the plasma, the portion of the sidewall S2 of the carbon-containing film OF that is not covered by the second deposited film DP2 is etched horizontally, increasing the opening width (CD) of the recess RC and causing bowing. Furthermore, this can also cause the upper portion of the mask MK to be overetched, deteriorating the selectivity.

[0125] In this regard, according to the second embodiment of the present method, a cycle comprising a first etching process (step ST22) and a second etching process (step ST23) is alternately repeated. Specifically, step ST22, in which a phosphorus halide gas is used as a processing gas, and step ST23, in which a phosphorus halide gas is not used or is used at a lower flow rate than in step ST22, are repeated. This allows for adjustment of the amount of halogen active species dissociated in the plasma. According to the second embodiment of the present method, the aforementioned problems caused by an excess of halogen active species in the plasma can be suppressed. Specifically, shape abnormalities (CD expansion, bowing) and a decrease in etching selectivity due to etching can be suppressed.

[0126] The etching execution time in process ST22 and process ST23 can be set appropriately. In one embodiment, the execution time of processes ST22 and ST23 can be set according to 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 carbon-containing film OF, the depth of the recess RC, the aspect ratio, etc. In one embodiment, the ratio of the etching execution time in process ST23 to the etching execution time in process ST22 can be greater than 0.8 and less than 1.2. In one embodiment, the ratio can be greater than 0.9 and less than 1.1. In one embodiment, the ratio can be set according to the number of cycles. For example, if the number of cycles exceeds a given number of times, or for each given number of cycles, the ratio can be made larger. Thus, as the depth of the recess RC formed on the carbon-containing film OF becomes deeper, the etching time of process ST23 can be longer than that of process ST22. In one embodiment, the ratio can be set according to the depth or aspect ratio of the recess RC instead of the number of cycles. For example, when the depth or aspect ratio of the concave portion RC exceeds a given value, or whenever the given value increases, the ratio may be made larger.

[0127] In one embodiment, during the processing in step ST23, the temperature of the substrate support 11 may be controlled at a second temperature that is different from that in step ST22. The second temperature may be a temperature higher than the first temperature. In this case, in step ST23, the volatilization (removal) of the second deposited film DP2 may be promoted. In one embodiment, the first temperature and / or the second temperature may be set according to the number of cycles. For example, if the number of cycles exceeds a given number, or for each given number of cycles, the first temperature and / or the second temperature may be increased. Thus, as the depth of the recess RC formed on the carbon-containing film OF becomes deeper, the temperature of the substrate support 11 may become higher. In one embodiment, the first temperature and / or the second temperature may be set according to the depth and aspect ratio of the recess RC rather than the number of cycles. For example, when the depth or aspect ratio of the recess RC exceeds a given value, or whenever the given value increases, the first temperature and / or the second temperature increases.

[0128] Figure 9 and Figure 10 This is a flowchart showing a modified example of the second embodiment. Figure 7 This is an example in which the second etching (step ST23) is performed after the first etching (step ST22) is performed in one cycle. Figure 9 As shown in FIG. 3 , the first etching (step ST33) may be performed after the second etching (step ST32) in one cycle. Figure 10 As shown, it is possible to determine whether the stop condition is met midway through a cycle. That is, it is possible to determine whether the stop condition is met (step ST43) even after the first etching (step ST42) is performed. Furthermore, if the stop condition is met, the etching process can be terminated without proceeding to the second etching (step ST44).

[0129] <Example>

[0130] Next, examples of the present method are described. The present disclosure is not limited by the following examples.

[0131] (Example 1)

[0132] In Example 1, using Figure 2 The plasma processing device 1 shown in FIG. Figure 4 The flowchart described is for Figure 5 The etching is performed on a substrate having the same structure as the substrate W shown. The mask MK is a silicon oxynitride film, and the carbon-containing film OF is an amorphous carbon film. The opening OP of the mask MK has a hole shape and an opening diameter of 80 nm.

[0133] In step ST12, the first process gas includes O2, PF3, and COS. The flow rate of PF3 is 1.3% by volume of the total flow rate of the first process gas. In step ST12, in addition to the source RF signal, a bias RF signal is also supplied. In step ST12, the pressure within the chamber 10 is controlled at 30 mTorr, and the temperature of the substrate support 11 is controlled at -60°C. Step ST12 is performed for 240 seconds.

[0134] (Reference Example 1)

[0135] In Reference Example 1, a substrate having the same structure as in Example 1 was etched using the plasma processing apparatus 1. In Reference Example 1, etching was performed under the same conditions as in Example 1 except that O2 gas and COS gas were used as processing gases.

[0136] Figure 11 : is a graph showing the etching results of Example 1 and Reference Example 1. Figure 11 , (a1) and (b1) are diagrams showing the cross-sectional shapes of the mask MK and the upper portion of the recess RC after etching according to Example 1 and Reference Example 1, respectively. (a2) and (b2) are top views of the mask MK after etching according to Example 1 and Reference Example 1, respectively (diagrams of (a1) and (b1) viewed from above).

[0137] like Figure 11 As shown in (a1) and (a2), in Example 1, the clogging of the opening OP of the mask MK is suppressed. In Example 1, the minimum opening diameter of the mask MK is 63.0 nm. In contrast, Figure 11 As shown in (b1) and (b2), in Reference Example 1, the opening diameter is narrowed (a neck is formed) in a portion of the mask MK, and the opening OP is largely blocked. In Reference Example 1, the minimum opening diameter of the mask MK is 42.8 nm.

[0138] (Example 2)

[0139] In Example 2, using Figure 2 The plasma processing device 1 shown in FIG. Figure 7 According to the flowchart described in , the substrate with the same structure as Example 1 is etched.

[0140] In process ST22, as the first processing gas, a processing gas having the same composition as that in Example 1 is used. In process ST22, a bias RF signal is supplied in addition to the source RF signal. In addition, the pressure in the chamber 10 is controlled at 30 mTorr, and the temperature of the substrate support portion 11 is controlled at -60°C. In process ST23, the second processing gas includes O2 gas and COS gas. The remaining conditions are the same as those in process ST22. In one cycle, after etching is performed for 10 seconds in process ST22, etching is performed for 10 seconds in process ST23. In Example 2, this cycle is repeated 12 times, and etching is performed for a total of 240 seconds.

[0141] Figure 12 : is a graph showing the etching results of Example 2 and Reference Example 1. Figure 12 In the figure, (a1) is a diagram showing the cross-sectional shape of the mask MK and the upper portion of the recess RC after etching according to Example 2. (a2) is a top view of the mask MK after etching according to Example 2 (a diagram of (a1) viewed from above). Figure 12 (a2) and (b2) are for comparison with Example 2 and are disclosed again. Figure 11 Figures of the accompanying drawings of Reference Example 1 shown in (a2) and (b2).

[0142] like Figure 12 As shown, Example 2, like Example 1, suppressed clogging of the openings of the mask MK compared to Reference Example 1. In Example 2, the minimum opening diameter of the mask MK was 62.6 nm.

[0143] Figure 13 : is a graph showing the etching results of Example 2 and Reference Example 1. Figure 13 In FIG, the vertical axis represents the depth D (μm) of the opening OP of the mask film MK and the recess RC formed in the carbon-containing film OF. The vertical axis 0 μm or so is the boundary between the mask MK and the carbon-containing film OF. Figure 13 In FIG. 1 , the horizontal axis represents the opening OP of the mask film MK and the opening diameter CD (nm) of the recessed portion RC formed in the carbon-containing film OF.

[0144] like Figure 13 As shown, Example 2 suppressed the expansion of the opening diameter throughout the depth direction of the recess RC compared to Reference Example 1. Furthermore, the maximum diameter of the recess RC in Example 2 was 67.5 nm, while that in Reference Example 1 was 77.4 nm. In other words, Example 2 suppressed bowing 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 and 75.1 in Reference Example 1. This indicates that Example 2 also improved the selectivity compared to Reference Example 1.

[0145] The embodiments of the present disclosure also include the following aspects.

[0146] (Note 1)

[0147] An etching method, comprising:

[0148] (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion in a chamber; and

[0149] (b) A step of etching the carbon-containing film using plasma generated from a first process gas comprising a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or comprising a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0150] (Note 2)

[0151] An etching method according to Note 1, wherein the etching method further includes (c) a process of etching the carbon-containing film using plasma generated by a second processing gas different from the first processing gas, the second processing gas including an oxygen-containing gas and a sulfur-containing gas, or including oxygen-containing and sulfur-containing gases.

[0152] (Note 3)

[0153] The etching method according to Supplementary Note 2, wherein the second processing gas does not contain phosphorus halide gas.

[0154] (Note 4)

[0155] The etching method according to Supplementary Note 2, wherein the second process gas includes the phosphorus halide gas at a flow rate smaller than that of the phosphorus halide gas included in the first process gas.

[0156] (Note 5)

[0157] The etching method according to any one of Supplementary Notes 2 to 4, wherein a ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is 0.8 or more and 1.2 or less.

[0158] (Note 6)

[0159] The etching method according to any one of Supplementary Notes 2 to 4, wherein a cycle including the step (b) and the step (c) is repeated a plurality of times.

[0160] (Note 7)

[0161] An etching method according to Note 6, wherein, in at least one of the cycles after the second one, the ratio of the etching execution time in the process (c) to the etching execution time in the process (b) is greater than the ratio in the first cycle.

[0162] (Note 8)

[0163] The etching method according to Supplementary Note 6 or Supplementary Note 7, wherein the temperature of the substrate supporting portion in at least one cycle after the second cycle is set to be higher than the temperature of the substrate supporting portion in the first cycle.

[0164] (Note 9)

[0165] The etching method according to any one of Supplementary Notes 1 to 8, wherein the phosphorus halide 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.

[0166] (Note 10)

[0167] The etching method according to any one of Supplementary Notes 1 to 9, wherein the phosphorus halide gas includes at least one gas selected from the group consisting of PF3 gas, PF5 gas and PCl3 gas.

[0168] (Note 11)

[0169] The etching method according to any one of Supplementary Notes 1 to 10, wherein in the first process gas, a flow rate of the phosphorus halide gas is less than or equal to 5 volume % of a total flow rate of the first process gas.

[0170] (Note 12)

[0171] The etching method according to any one of Supplementary Notes 1 to 11, wherein the oxygen-containing gas includes at least one gas selected from the group consisting of O2 gas, CO gas and CO2 gas.

[0172] (Note 13)

[0173] The etching method according to any one of Supplementary Notes 1 to 12, wherein the oxygen-and-sulfur-containing gas is at least one of COS gas and SO 2 gas.

[0174] (Note 14)

[0175] The etching method according to any one of Supplementary Notes 1 to 13, wherein the sulfur-containing gas is SF6 gas.

[0176] (Note 15)

[0177] The etching method according to any one of Supplementary Notes 1 to 14, wherein the mask comprises a silicon-containing film or a metal-containing film.

[0178] (Note 16)

[0179] The etching method according to any one of Supplementary Notes 1 to 15, wherein the carbon-containing film includes an amorphous carbon film.

[0180] (Note 17)

[0181] The etching method according to any one of Supplementary Notes 1 to 16, wherein in the step (b), the temperature of the substrate supporting portion is set to zero degrees or less.

[0182] (Note 18)

[0183] The etching method according to any one of Supplementary Notes 2 to 8, wherein in the step (c), the temperature of the substrate supporting portion is set to zero degrees or less.

[0184] (Note 19)

[0185] A plasma processing device comprises a chamber and a control unit.

[0186] The control unit performs the following control:

[0187] (a) providing control of a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion within a chamber; and

[0188] (b) Control of etching the carbon-containing film using plasma generated from a first process gas including a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or including a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0189] (Note 20)

[0190] A plasma processing apparatus according to Note 19, wherein the control unit further performs (c) control of etching the carbon-containing film using plasma generated by a second processing gas different from the first processing gas, the second processing gas including an oxygen-containing gas and a sulfur-containing gas, or including oxygen-containing and sulfur-containing gases.

[0191] (Note 21)

[0192] A device manufacturing method is performed in a plasma processing device having a chamber and a control unit, the device manufacturing method comprising:

[0193] (a) providing a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion in a chamber; and

[0194] (b) A step of etching the carbon-containing film using plasma generated from a first process gas comprising a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or comprising a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0195] (Note 22)

[0196] A program for causing a computer of a plasma processing apparatus having a chamber and a control unit to execute the following control:

[0197] (a) providing control of a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion within a chamber; and

[0198] (b) Control of etching the carbon-containing film using plasma generated from a first process gas including a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or including a phosphorus halide gas and oxygen- and sulfur-containing gases.

[0199] (Note 23)

[0200] A storage medium storing the program according to Supplementary Note 22.

[0201] The above embodiments are described for the purpose of illustration and are not intended to limit the scope of the present disclosure. Various modifications may be made to the embodiments without departing from the scope and spirit of the present disclosure. For example, some of the components in a certain embodiment may be added to other embodiments. In addition, some of the components in a certain embodiment may be replaced with corresponding components in other embodiments.

Claims

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 portion in a chamber; and (b) A step of etching the carbon-containing film using plasma generated from a first process gas comprising a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or comprising a phosphorus halide gas and oxygen- and sulfur-containing gases.

2. The etching method according to claim 1, wherein The etching method further includes: (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-containing and sulfur-containing gases.

3. The etching method according to claim 2, wherein: The second process gas does not contain a phosphorus halide gas.

4. The etching method according to claim 2, wherein: The second process gas includes a phosphorus halide gas at a flow rate less than that of the phosphorus halide gas included in the first process gas.

5. The etching method according to any one of claims 2 to 4, wherein The ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is 0.8 or more and 1.2 or less.

6. The etching method according to any one of claims 2 to 4, wherein: The cycle including the step (b) and the step (c) is repeated multiple times.

7. The etching method according to claim 6, wherein: In at least one of the cycles after the second one, the ratio of the etching execution time in the step (c) to the etching execution time in the step (b) is greater than that in the first cycle.

8. The etching method according to claim 6, wherein: The temperature of the substrate supporting portion in at least one of the cycles after the second cycle is set to be higher than the temperature of the substrate supporting portion in the first cycle.

9. The etching method according to any one of claims 1 to 4, wherein: The phosphorus halide 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.

10. The etching method according to any one of claims 1 to 4, wherein: The phosphorus halide gas includes at least one gas selected from the group consisting of PF3 gas, PF5 gas and PCl3 gas.

11. The etching method according to any one of claims 1 to 4, wherein: In the first process gas, the flow rate of the phosphorus halide gas is less than or equal to 5 volume % of the total flow rate of the first process gas.

12. The etching method according to any one of claims 1 to 4, wherein: The oxygen-containing gas includes at least one gas selected from the group consisting of O2 gas, CO gas, and CO2 gas.

13. The etching method according to any one of claims 1 to 4, wherein: The oxygen- and sulfur-containing gas is at least one of COS gas and SO2 gas.

14. The etching method according to any one of claims 1 to 4, wherein: The sulfur-containing gas is SF6 gas.

15. The etching method according to any one of claims 1 to 4, wherein: The mask includes a silicon-containing film or a metal-containing film.

16. The etching method according to any one of claims 1 to 4, wherein: The carbon-containing film includes an amorphous carbon film.

17. The etching method according to any one of claims 1 to 4, wherein: In the step (b), the temperature of the substrate supporting portion is set to be below zero degrees.

18. The etching method according to any one of claims 2 to 4, wherein: In the step (c), the temperature of the substrate supporting portion is set to be below zero degrees.

19. A plasma processing apparatus comprising a chamber and a control unit. The control unit performs the following control: (a) providing control of a substrate having a carbon-containing film and a mask on the carbon-containing film on a substrate support portion within a chamber; and (b) Control of etching the carbon-containing film using plasma generated from a first process gas including a phosphorus halide gas, an oxygen-containing gas, and a sulfur-containing gas, or including a phosphorus halide gas and oxygen- and sulfur-containing gases.

20. The plasma processing apparatus according to claim 19, wherein The control section further performs: (c) control of etching the carbon-containing film using plasma generated by a second process gas different from the first process gas, the second process gas including an oxygen-containing gas and a sulfur-containing gas, or including oxygen-containing and sulfur-containing gases.

Images