JP2024010798A - Plasma processing method and plasma processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for suppressing particles within a chamber.

SOLUTION: A plasma processing method is provided that is performed in a plasma processing device having a chamber. This method includes a step (a) of forming a carbon-containing film on the outer peripheral edge of a substrate, and a step (b) of supplying processing gas into the chamber, and etching the substrate disposed on a substrate support portion in the chamber by the plasma generated from the processing gas, in which the substrate includes an etching film and a mask film on the etching film, the step (b) being performed after the step (a). In the step (b), particles generated in the chamber are deposited on a carbon-containing film at the outer peripheral edge of the substrate.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

BACKGROUND OF THE INVENTION Exemplary embodiments of the present disclosure relate to plasma processing methods and systems.

Patent Document 1 discloses a technique for removing deposits around a wafer.

Japanese Patent Application Publication No. 2013-115269

The present disclosure provides techniques for suppressing particles within a chamber.

In one exemplary embodiment of the present disclosure, a plasma processing method is performed in a plasma processing apparatus having a chamber, comprising: (a) forming a carbon-containing film on an outer peripheral edge of a substrate; After (a), a process of supplying a processing gas into a chamber and etching the substrate disposed on a substrate support in the chamber with plasma generated from the processing gas, the substrate being etched. a film and a mask film on the etching film, and in (b), the particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate; A processing method is provided.

According to one exemplary embodiment of the present disclosure, a technique for suppressing particles within a chamber may be provided.

1 schematically depicts an exemplary plasma processing system. It is a flowchart which shows this processing method. It is a figure which shows typically an example of the cross-sectional structure of the board|substrate W provided in process ST1. FIG. 3 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after processing in step ST1. FIG. 3 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after processing in step ST2. FIG. 3 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after processing in step ST3. FIG. 3 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after processing in step ST4.

Each embodiment of the present disclosure will be described below.

In one exemplary embodiment, a plasma processing method performed in a plasma processing apparatus having a chamber, the method comprising: (a) forming a carbon-containing film on an outer peripheral edge of a substrate; and (b) after (a). , a process in which a processing gas is supplied into a chamber and a plasma generated from the processing gas is used to etch a substrate placed on a substrate supporting part in the chamber, and the substrate has an etched film and a mask film on the etched film. (b), the particles generated in the chamber are deposited on the carbon-containing film at the outer peripheral edge of the substrate.

In one exemplary embodiment, (c) after (b) further includes removing the particles deposited on the carbon-containing film from the substrate together with the carbon-containing film.

In one exemplary embodiment, a plasma processing method is performed in a plasma processing apparatus having a chamber, comprising: (a) forming a carbon-containing film on an outer peripheral edge of a substrate; Afterwards, a processing gas is supplied into the chamber, and plasma generated from the processing gas is used to etch the substrate placed on the substrate support in the chamber, and the substrate is etched by etching the etching film and the mask film on the etching film. and (c) after (b), removing the particles deposited on the carbon-containing film from the substrate together with the carbon-containing film.

In one exemplary embodiment, in (a), a carbon-containing film is formed by a plasma generated from a process gas that includes a carbon-containing gas.

In one exemplary embodiment, the carbon-containing gas is a C _a H _b (a and b are integers greater than or equal to 1) gas or a _C F _d (c and d are integers greater than or equal to 1) gas. .

In one exemplary embodiment, (a) and (b) are performed in the same chamber.

In one exemplary embodiment, (a) and (b) are performed in different chambers.

In one exemplary embodiment, the processing gas provided in (b) includes a phosphorus-containing gas.

In one exemplary embodiment, the processing gas provided in (b) includes a single gas or a mixture of gases including C (carbon), H (hydrogen), and F (fluorine).

In one exemplary embodiment, the gas mixture includes HF gas and carbon-containing gas.

In one exemplary embodiment, the flow rate of HF gas is the highest of the total flow rate of process gases excluding inert gas provided in (b).

In one exemplary embodiment, the plasma generated in (b) includes HF, CF or CHF species and P active species.

In one exemplary embodiment, the HF species is generated from at least one gas selected from the group consisting of HF gas and hydrofluorocarbon gas.

In one exemplary embodiment, HF species are generated from a fluorine-containing gas and a hydrogen-containing gas.

In one exemplary embodiment, the HF species is generated from a hydrofluorocarbon gas having two or more carbon atoms.

In one exemplary embodiment, _{the HF} species is selected _{from the} group consisting of _HF gas, _CH2F2 gas, _C3H2F4 gas _{, C3H2F6} gas, and _C4H2F6 gas _. is produced from at least one type of gas.

In one exemplary embodiment, the etched film is a Si-containing film.

In one exemplary embodiment, the mask film is one of a carbon-containing mask film, a metal-containing mask film, or a silicon-containing mask film.

In one exemplary embodiment, in (a), a carbon-containing film is selectively formed on a surface different from the surface on which the etched film is formed.

In one exemplary embodiment, in (b), the temperature of the substrate support is set to below 0°C.

In one exemplary embodiment, the chamber includes a substrate support, a processing gas supply, and a controller, the controller including: (a) forming a carbon-containing film on an outer peripheral edge of the substrate; (b) A processing gas is supplied into the chamber from the processing gas supply section, and the substrate supported on the substrate support section is etched by the plasma generated from the processing gas. A plasma processing system is provided that performs control, including a mask film, in which particles generated within a chamber are deposited on a carbon-containing film at a peripheral edge of a substrate.

<Configuration example of plasma processing system>
An example of the configuration of the plasma processing system will be described below. FIG. 1 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control section 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply section 20, a power supply 30, and an exhaust system 40. Further, the plasma processing apparatus 1 includes a substrate support section 11 and a gas introduction section. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10 . The gas introduction section includes a shower head 13. Substrate support 11 is arranged within plasma processing chamber 10 . The shower head 13 is arranged above the substrate support section 11 . In one embodiment, showerhead 13 forms at least a portion of the ceiling of plasma processing chamber 10 . The plasma processing chamber 10 has a plasma processing space 10s defined by a shower head 13, a side wall 10a of the plasma processing chamber 10, and a substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s, and at least one gas exhaust port for discharging gas from the plasma processing space. Plasma processing chamber 10 is grounded. The shower head 13 and the substrate support section 11 are electrically insulated from the casing of the plasma processing chamber 10.

The substrate support part 11 includes a main body part 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting the 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 plan view. The substrate W is placed on the central region 111a of the main body 111, and the ring assembly 112 is placed 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.

In one embodiment, body portion 111 includes a base 1110 and an electrostatic chuck 1111. Base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. Electrostatic chuck 1111 is placed on base 1110. Electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within ceramic member 1111a. Ceramic member 1111a has a central region 111a. In one embodiment, ceramic member 1111a also has an annular region 111b. Note that another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, ring assembly 112 may be placed on the annular electrostatic chuck or the annular insulation member, or may be placed on both the electrostatic chuck 1111 and the annular insulation member. Furthermore, at least one RF/DC electrode coupled to an RF (Radio Frequency) power source 31 and/or a DC (Direct Current) power source 32, which will be described later, may be arranged within the ceramic member 1111a. In this case, at least one RF/DC electrode functions as a bottom electrode. An RF/DC electrode is also referred to as a bias electrode if a bias RF signal and/or a DC signal, as described below, is supplied to at least one RF/DC electrode. Note that the conductive member of the base 1110 and at least one RF/DC electrode may function as a plurality of lower electrodes. Further, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

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 ring is made of a conductive or insulating material, and the cover ring is made of an insulating material.

Further, the substrate support unit 11 may include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, a channel 1110a is formed within the base 1110 and one or more heaters are disposed within the ceramic member 1111a of the electrostatic chuck 1111. Further, the substrate support section 11 may include a heat transfer gas supply section configured to supply heat transfer gas to the gap between the back surface of the substrate W and the central region 111a.

The shower head 13 is configured to introduce at least one processing gas from the gas supply section 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c. The showerhead 13 also includes at least one upper electrode. In addition to the shower head 13, the gas introduction section may include one or more side gas injectors (SGI) attached to one or more openings formed in the side wall 10a.

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

Power source 30 includes an RF power source 31 coupled to plasma processing chamber 10 via at least one impedance matching circuit. RF power source 31 is configured to supply at least one RF signal (RF power) to at least one bottom electrode and/or at least one top electrode. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Accordingly, RF power source 31 may function as at least part of a plasma generation unit configured to generate a plasma from one or more process gases in plasma processing chamber 10 . Further, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated in the substrate W, and ion components in the formed plasma can be drawn into the substrate W.

In one embodiment, the RF power source 31 includes a first RF generator 31a and a second RF generator 31b. The first RF generation section 31a is coupled to at least one lower electrode and/or at least one upper electrode via at least one impedance matching circuit, and generates a source RF signal (source RF power) for plasma generation. It is configured as follows. In one embodiment, the source RF signal has a frequency within the range of 10 MHz to 150 MHz. In one embodiment, the first RF generator 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are provided to at least one bottom electrode and/or at least one top electrode.

The second RF generating section 31b is coupled to at least one lower electrode via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same or different than the frequency of the source RF signal. In one embodiment, the bias RF signal has a lower frequency than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency within the range of 100kHz to 60MHz. 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 provided to at least one bottom electrode. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

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

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

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

Control unit 2 processes computer-executable instructions that cause plasma processing apparatus 1 to perform various steps described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is realized by, for example, a computer 2a. The processing unit two a1 may be configured to read a program from the storage unit two a2 and perform various control operations by executing the read program. This program may be stored in the storage unit 2a2 in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2, and is read out from the storage unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or may be 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 RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

FIG. 2 is a flowchart illustrating a plasma processing method (hereinafter also referred to as "this processing method") according to one exemplary embodiment. As shown in FIG. 2, this processing method includes a step ST1 of providing a substrate, a step ST2 of forming a carbon-containing film, and a step ST3 of etching a target film. Furthermore, this processing method may include step ST4 of removing the carbon-containing film. The processing in each step may be performed with the plasma processing system shown in FIG. In the following, a case where the control section 2 controls each section of the plasma processing apparatus 1 to execute the present processing method on the substrate W will be described as an example.

(Process ST1: Provision of substrate)
In step ST1, the substrate W is provided within the plasma processing space 10s of the plasma processing apparatus 1. The substrate W is provided on the upper surface of the substrate support 11 and is held on the substrate support 11 by an electrostatic chuck 1111.

FIG. 3 is a diagram showing an example of the cross-sectional structure of the substrate W provided in step ST1. On the substrate W, an etching film EF and a mask film MF are laminated in this order. The etching film EF may be stacked on the base film UF. The substrate W may be used for manufacturing semiconductor devices including semiconductor memory devices such as DRAM, 3D-NAND flash memory, and the like.

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

The etching film EF may be a silicon-containing film. The etching film EF may be, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film (SiON film), a Si-ARC (Silicon-Anti Reflection Carbon) film, or the like. The etching film EF may be configured by laminating a plurality of films. For example, the etching film EF may be configured by alternately stacking silicon oxide films and polycrystalline silicon films. Further, for example, the etching film EF may be configured by alternately stacking silicon oxide films and silicon nitride films. Note that the substrate W may further have another film under the base film UF, and the laminated film of the etching film EF and the base film UF may function as a multilayer mask. That is, the other films may be etched using the stacking order of the etching film EF and the base film UF as a multilayer mask.

Mask film MF is formed on etching film EF. Mask film MF has at least one opening OP. The opening OP is defined by the side surface of the mask film. The opening OP is a space above the etching film EF surrounded by the side surfaces of the mask film. That is, in FIG. 3, the upper surface of the etching film EF has a portion covered with the mask film MF and a portion exposed through the opening OP.

The opening OP may have any shape in a plan view of the substrate W (when the substrate W is viewed from the top to the bottom in FIG. 3). The shape may be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more of these shapes. Mask film MF may have a plurality of openings OP. The plurality of openings OP each have a hole shape and may constitute an array pattern arranged at regular intervals. Further, the plurality of openings OP each have a linear shape, and may be lined up at regular intervals to form a line and space pattern.

The mask film MF may be, for example, a carbon-containing mask film, a metal-containing mask film, or a silicon-containing mask film. The carbon-containing mask film may be any one of SOC film, WC film, amorphous carbon, and boron carbide. The silicon-containing mask film may be, for example, a polysilicon film, or may be a SiO ₂ film or a Si ₃ N ₄ film.

Each film (base film UF, etching film EF, mask film MF) constituting the substrate W may be formed by a CVD (Chemical Vapor Deposition) method, an ALD (Atomic Layer Deposition) method, a spin coating method, or the like. Each of the above-mentioned films may be a flat film, or may be a film having unevenness. The opening OP in the mask film MF may be formed by etching the mask film MF.

At least a portion of the process of forming each film of the substrate W may be performed within the space of the plasma processing chamber 10. In one example, the step of etching the mask film MF to form the opening OP may be performed in the plasma processing chamber 10. That is, the opening OP and the etching of the etching film EF, which will be described later, may be performed continuously in the same chamber. Further, after all or part of each film on the substrate W is formed in a device or a chamber outside the plasma processing apparatus 1, the substrate W is carried into the plasma processing space 10s and placed on the upper surface of the substrate support section 11. The substrate may be provided by:

FIG. 4 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after the process ST1. The outer peripheral end WE of the substrate W is a part of the outer periphery of the substrate W that is continuous with the main surface WF of the substrate W on which the etching film EF etc. are formed and the back surface WB on the opposite side of the main surface WF. The outer peripheral end WE has an end WE1 that is continuous with the main surface WF and has an inclination in cross-sectional view with respect to the main surface WF, and an end WE2 that is continuous with the back surface WB and has an inclination with respect to the back surface WB. The outer peripheral end portion WE (end portion WE1 and end portion W2) may be a curved surface or may be a tapered surface. The end portion WE1 may be configured by forming some kind of film (for example, a base film UF, an etching film EF, and/or a mask film MF) on the silicon wafer. That is, the silicon wafer does not need to be exposed at the end WE1. No film may be formed on the silicon wafer at the end WE2. That is, the silicon wafer may be exposed at the end WE2.

As shown in FIG. 4, the substrate W is placed on the ceramic member 1111a of the electrostatic chuck 1111 so that the main surface WF of the substrate W faces the plasma processing space 10s. A gap gp is formed between the outer peripheral end WE (end WE1, end WE2) of the substrate W and the ring assembly 112.

(Step ST2: Formation of carbon-containing film)
FIG. 5 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after the process ST2. In step ST2, a first processing gas containing carbon-containing gas is supplied from the gas supply section 20 into the plasma processing space 10s. Then, plasma is generated from the first processing gas to form a carbon-containing film CF on the outer peripheral edge WE of the substrate W. The first processing gas may include a gas other than the carbon-containing gas, and may include a noble gas such as Ar or He.

The carbon-containing gas may be, for example, a C _a H _b (a and b are integers greater than or equal to 1) gas or a C _c F _d (c and d are integers greater than or equal to 1) gas. The C _a H _b gas may be, for example, at least one selected from the group consisting of CH ₄ gas, C ₂ H ₆ gas, C ₂ H ₄ gas, C ₃ H ₈ gas, and C ₄ H ₈ gas. The C _c F _d gas is, for example, at least one selected from the group consisting of CF ₄ gas, C ₂ F ₆ gas, C ₂ F ₄ gas, C ₃ F ₈ gas, C ₄ F ₆ gas, and C ₄ F ₈ gas. One type is enough. The carbon-containing film CF formed from a processing gas containing C _a H _b gas or C _c F _d gas has better adhesion to the substrate W than the carbon-containing film formed from a gas containing HF such as hydrofluorocarbon gas. It has high properties, and peeling from the substrate W in subsequent steps can be further suppressed. Note that when C _a H _b gas was used, a carbon-containing film with higher adhesion to the substrate W was formed than when C _c F _d gas was used.

The carbon-containing film CF may be a film containing carbon, such as a carbon film or a hydrocarbon film.

The carbon-containing film CF may be selectively formed on a surface different from the main surface WF of the substrate W (a surface forming an acute angle, 90 degrees, and/or an obtuse angle). For example, the carbon-containing film CF may be selectively formed on part or all of the outer peripheral edge WE of the substrate W. In one example, the carbon-containing film CF is formed only on the end WE2 on the back surface WB side of the substrate W (see FIG. 5) or on a surface of the outer peripheral end that has an angle of 90 degrees or more with respect to the main surface WF. good. Further, the carbon-containing film may be formed on both the ends WE1 and WE2 of the substrate W. In one example, the carbon-containing film CF is formed by covering a portion of the substrate W exposed to the plasma processing space 10s other than the outer peripheral end WE with a cover member, and selectively plasma is applied to the outer peripheral end WE of the substrate W. This can be done by irradiating.

(Process ST3: Etching the target film)
FIG. 6 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after the process ST3. In step ST3, the etching film EF is etched.

In step ST3, the temperature of the substrate support section 11 is set to a target temperature. The target temperature may be, for example, 0 degrees or less. The target temperature may be -10°C or lower, -20°C or lower, -30°C or lower, -40°C or lower, -50°C or lower, -60°C or lower, or -70°C or lower.

Setting the temperature of the substrate support section 11 to the target temperature means measuring the temperature of the substrate support section 11 and adjusting the temperature of the substrate support section 11 using the temperature control module so that the temperature of the substrate support section 11 becomes the target temperature. including but not limited to adjusting the In one example, setting the temperature of the substrate support 11 to the target temperature means (a) the temperature of the substrate W or the temperature of the heat transfer fluid flowing through the flow path 1110a so that the temperature of the substrate support 11 becomes the target temperature; and (b) setting the temperature of the heat transfer fluid flowing through the substrate support part 11 or the flow path 1110a so that the temperature of the substrate W becomes the target temperature. , including setting the target temperature or a temperature different from the target temperature. Furthermore, "setting" the temperature includes inputting, selecting, or storing the temperature in the control unit 2.

Note that in this processing method, setting the temperature of the substrate to the target temperature may be performed before step ST1. That is, the substrate W may be provided to the substrate support 11 after the temperature of the substrate support 11 is set to the target temperature.

Next, the second processing gas is supplied from the gas supply section 20 into the plasma processing space 10s.

The second processing gas may be one type of single gas or a plurality of types of mixed gas containing C (carbon), H (hydrogen), and F (fluorine). The mixed gas may be, for example, HF gas and a carbon-containing gas. The carbon-containing gas may be at least one selected from the group consisting of fluorocarbon gas, hydrofluorocarbon gas, and hydrocarbon gas. Examples of the carbon-containing gas include CH ₃ F gas, C ₂ H ₅ F gas, CF ₄ gas, C ₂ F ₆ gas, C ₂ F ₄ gas, C ₃ F ₈ gas, C ₄ F ₈ gas, and CH ₄ gas. , C ₃ H ₆ gas.

Among the active gases of the second processing gas, the flow rate of HF gas may be the largest. Further, the flow rate of the HF gas may be 70% or more by volume of the total flow rate of the active gas of the second processing gas (that is, the total flow rate excluding rare gases such as Ar and He, and inert gases such as nitrogen gas). , or 80% by volume or more.

As the second processing gas, a gas capable of generating HF species within the plasma processing chamber 10 may be used instead of or together with the HF gas. The HF species includes at least one of hydrogen fluoride gas, radicals, and ions. The HF species may be generated from at least one gas selected from the group consisting of HF gas and hydrofluorocarbon gas. Further, the HF species may be generated from a hydrofluorocarbon gas having two or more carbon atoms. Examples of gases that can generate HF species include CH ₂ F ₂ gas, C ₃ H ₂ F ₄ gas, C ₃ H ₂ F ₆ gas, C ₃ H ₃ F ₅ gas, C ₄ H ₂ F ₆ gas, At least one selected from the group consisting of C ₄ H ₅ F ₅ gas, C ₄ H ₂ F ₈ gas, C ₅ H ₂ F ₆ gas, C ₅ H ₂ F ₁₀ gas and C ₅ H ₃ F ₇ gas. May be used. In one example, the gas capable of producing HF species is at least one selected from the group consisting of CH ₂ F ₂ gas, C ₃ H ₂ F ₄ gas, C ₃ H ₂ F ₆ gas, and C ₄ H ₂ F ₆ gas. Seeds are used. Further, in one example, a fluorine-containing gas and a hydrogen-containing gas may be used as the gas capable of generating HF species. In one example, a fluorocarbon gas may be used as the fluorine-containing gas. _The fluorocarbon gas is selected from _the group consisting of _C2F2 gas, _C2F4 gas, _C3F6 gas _{, C3F8} gas _{, C4F6} gas _{, C4F8} gas, and _{C5F8 gas .} may contain at least one species. For example, NF ₃ gas or SF ₆ gas may be used as the fluorine-containing gas. As the hydrogen-containing gas, for example, H ₂ gas, CH ₄ gas, or NH ₃ gas may be used.

The second processing gas may further include a phosphorus-containing gas. Phosphorus-containing gases include PF ₃ gas, PF ₅ gas, POF ₃ gas, HPF ₆ gas, PCl ₃ gas, PCl ₅ gas, POCl ₃ gas, PBr ₃ gas, PBr ₅ gas, POBr ₃ gas, PI ₃ gas, P At least one type selected from the group consisting of ₄ O ₁₀ gas, P ₄ O ₈ gas, P ₄ O ₆ gas, PH ₃ gas, Ca ₃ P ₂ gas, H ₃ PO ₄ gas, and Na ₃ PO ₄ gas may be used. . Among these gases, halogenated phosphorus-containing gases such as PF ₃ gas, PF ₅ gas, and PCl ₃ gas may be used, and fluorinated phosphorus gases such as PF ₃ gas and PF ₅ gas may be used. good.

The second processing gas may include a halogen-containing gas. Examples of the halogen-containing gas include Cl ₂ gas, SiCl ₂ gas, SiCl ₄ gas, CCl ₄ gas, SiH ₂ Cl ₂ gas, Si ₂ Cl ₆ gas, CHCl ₃ gas, SO ₂ Cl ₂ gas, BCl ₃ gas, and PCl. ₃ gas, PCl ₅ gas, POCl ₃ gas, Br ₂ gas, HBr gas, CBr ₂ F ₂ gas, C ₂ F ₅ Br gas, PBr ₃ gas, PBr ₅ gas, POBr ₃ gas, BBr ₃ gas, HI gas, At least one selected from the group consisting of CF ₃ I gas, C ₂ F ₅ I gas, C ₃ F ₇ I gas, IF ₅ gas, IF ₇ gas, I ₂ gas and PI ₃ gas may be used.

Next, a source RF signal (RF power) is supplied from the first RF generating section 31a to the lower electrode and/or the upper electrode. As a result, plasma is generated from the second processing gas. Further, as a bias signal (power), a bias RF signal is supplied from the second RF generating section 31b to the lower electrode, and a bias potential is generated in the substrate. As a result, active species such as ions and radicals in the generated plasma are attracted to the substrate W, and the etching film EF is etched through the opening OP of the mask film MF.

In step ST3, at least some of the particles generated within the plasma processing space 10s enter the back surface WB side through the gap gp between the outer peripheral end WE and the ring assembly 112. Such particles may be, for example, particles in the plasma generated from the second processing gas or by-products of etching. As shown in FIG. 4, the particles adhere or deposit on the carbon-containing film CF at the end WE2 to form a deposited film DF. The deposited film DF may contain, for example, a hydrocarbon compound, a nitrogen compound, a phosphorus compound, a halogen compound, a silicon compound, or the like.

Particles deposited on the carbon-containing film CF are deposited directly on the silicon wafer (that is, when the carbon-containing film CF is not formed on the end WE2 and the silicon wafer is exposed). It is more difficult to peel off. Therefore, in the subsequent steps, the deposited film DF deposited on the carbon-containing film CF is less likely to peel off from the end WE2 than when deposited on the silicon wafer. Thereby, the present processing method can suppress the generation of particles within the plasma processing chamber 10.

(Step ST4: Removal of carbon-containing film)
FIG. 7 is a cross-sectional view schematically showing the vicinity of the outer peripheral end WE of the substrate W after the process ST4. In step ST4, the deposited film DF is removed from the substrate W. The deposited film DF may be removed from the substrate W together with the carbon-containing film CF. The process in step ST4 may be performed within the space of the plasma processing chamber 10. For example, by supplying a cleaning gas such as oxygen gas to the plasma processing chamber 10, the carbon-containing film CF and the deposited film DF may be removed at the same time or in the same process. At this time, the substrate W may be lifted and held from the mounting surface of the substrate support section 11 using a lifter or the like. Further, the process in step ST4 may be performed in an apparatus outside the plasma processing apparatus 1. For example, after carrying the substrate W into an external device, the carbon-containing film CF and the deposited film DF are removed at the same time or in the same manner by irradiating the outer peripheral edge WE of the substrate W with a laser or applying a cleaning liquid. May be removed by treatment.

<Other examples of this processing method>
Embodiments of the present disclosure may be modified in various ways without departing from the scope and spirit of the disclosure. For example, this processing method may be executed using a plasma processing apparatus using any plasma source, such as inductively coupled plasma or microwave plasma, in addition to the capacitively coupled plasma processing apparatus 1.

For example, in this processing method, the formation of the carbon-containing film CF and the etching of the etching film EF may be performed in different chambers. That is, the carbon-containing film CF may be formed on the substrate W in a first chamber, and then the substrate W may be provided on a substrate support portion of a second chamber different from the first chamber to etch the etching film EF. . Further, the carbon-containing film CF may be formed before forming the base film UF and the like on the substrate W. Further, the carbon-containing film CF may be formed on part or all of the front surface WF and back surface WB of the substrate W.

Further, the present disclosure includes the following embodiments.

(Additional note 1)
A plasma processing method performed in a plasma processing apparatus having a chamber, the method comprising:
(a) Forming a carbon-containing film on the outer peripheral edge of the substrate; (b) After the step (a), a processing gas is supplied into the chamber, and plasma generated from the processing gas causes the substrate in the chamber to etching the substrate disposed on the support part, the substrate including an etching film and a mask film on the etching film;
The plasma processing method according to (b) above, wherein particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate.

(Additional note 2)
(c) After the step (b), the plasma processing method according to supplementary note 1 further includes the step of removing particles deposited on the carbon-containing film from the substrate together with the carbon-containing film.

(Additional note 3)
A plasma processing method performed in a plasma processing apparatus having a chamber, the method comprising:
(a) forming a carbon-containing film on the outer peripheral edge of the substrate;
(b) After the step (a), a step of supplying a processing gas into the chamber and etching the substrate disposed on the substrate support in the chamber with plasma generated from the processing gas, a step in which the substrate includes an etched film and a mask film on the etched film;
(c) after the step (b), removing the particles deposited on the carbon-containing film from the substrate together with the carbon-containing film;
Plasma treatment methods, including.

(Additional note 4)
The plasma processing method according to any one of Supplementary Notes 1 to 3, wherein in (a), the carbon-containing film is formed by plasma generated from a processing gas containing carbon-containing gas.

(Appendix 5)
The plasma according to appendix 4, wherein the carbon-containing gas is a C _a H _b (a and b are integers of 1 or more) gas or C _c F _d (c and d are integers of 1 or more) gas. Processing method.

(Appendix 6)
The plasma processing method according to any one of Supplementary notes 1 to 5, wherein the above (a) and the above (b) are performed in the same chamber.

(Appendix 7)
The plasma processing method according to any one of Supplementary notes 1 to 5, wherein the above (a) and the above (b) are performed in different chambers.

(Appendix 8)
The plasma processing method according to any one of Supplementary Notes 1 to 7, wherein the processing gas supplied in (b) includes a phosphorus-containing gas.

(Appendix 9)
The processing gas supplied in (b) above is any one of Supplementary Notes 1 to 8, including one type of single gas or a plurality of types of mixed gases containing C (carbon), H (hydrogen), and F (fluorine). The plasma processing method according to item 1.

(Appendix 10)
The plasma processing method according to appendix 9, wherein the mixed gas includes HF gas and carbon-containing gas.

(Appendix 11)
The plasma processing method according to appendix 10, wherein the flow rate of HF gas is the largest among the total flow rates of the processing gas excluding the inert gas supplied in (b).

(Appendix 12)
The plasma processing method according to any one of Supplementary Notes 1 to 11, wherein the plasma generated in the step (b) contains HF species, CF species, or CHF species, and P active species.

(Appendix 13)
The plasma processing method according to appendix 12, wherein the HF species is generated from at least one gas selected from the group consisting of HF gas and hydrofluorocarbon gas.

(Appendix 14)
The plasma processing method according to appendix 12, wherein the HF species is generated from a fluorine-containing gas and a hydrogen-containing gas.

(Appendix 15)
The plasma processing method according to appendix 12, wherein the HF species is generated from a hydrofluorocarbon gas having 2 or more carbon atoms.

(Appendix 16)
The HF species is at least one gas selected from the group consisting of HF gas, CH ₂ F ₂ gas, C ₃ H ₂ F ₄ gas, C ₃ H ₂ F ₆ gas, and C ₄ H ₂ F ₆ gas. The plasma processing method according to appendix 12, wherein the plasma processing method is generated.

(Appendix 17)
The plasma processing method according to any one of Supplementary Notes 1 to 16, wherein the etching film is a Si-containing film.

(Appendix 18)
The plasma processing method according to any one of appendices 1 to 17, wherein the mask film is any one of a carbon-containing mask film, a metal-containing mask film, or a silicon-containing mask film.

(Appendix 19)
The plasma processing method according to any one of Supplementary Notes 1 to 18, wherein in (a), the carbon-containing film is selectively formed on a surface different from the surface on which the etched film is formed.

(Additional note 20)
The plasma processing method according to any one of Supplementary Notes 1 to 19, wherein in (b), the temperature of the substrate support portion is set to 0° C. or lower.

(Additional note 21)
comprising a chamber, a substrate support section provided in the chamber, a processing gas supply section, and a control section,
The control unit includes:
(a) forming a carbon-containing film on the outer peripheral edge of the substrate;
(b) supplying a processing gas into the chamber from the processing gas supply section, and etching the substrate supported on the substrate support section with plasma generated from the processing gas; in the etching, the substrate is comprising an etching film and a mask film on the etching film, performing control in which particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate;
Plasma treatment system.

(Additional note 22)
A device manufacturing method performed in a plasma processing apparatus having a chamber, the method comprising:
(a) Forming a carbon-containing film on the outer peripheral edge of the substrate; (b) After the step (a), a processing gas is supplied into the chamber, and plasma generated from the processing gas causes the substrate in the chamber to etching the substrate disposed on the support part, the substrate including an etching film and a mask film on the etching film;
The device manufacturing method according to (b) above, wherein particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate.

(Additional note 23)
A computer of a plasma processing system including a chamber, a substrate support section provided in the chamber, and a plasma generation section,
(a) forming a carbon-containing film on the outer peripheral edge of the substrate; (b) after the above (a), a processing gas is supplied into the chamber, and plasma generated from the processing gas causes the substrate in the chamber to etching the substrate disposed on the support part, the substrate including an etching film and a mask film on the etching film;
In the above (b), the program causes the particles generated in the chamber to be deposited on the carbon-containing film at the outer peripheral edge of the substrate.

(Additional note 24)
A storage medium storing the program described in Appendix 23.

DESCRIPTION OF SYMBOLS 1... Plasma processing apparatus, 2... Control part, 10... Plasma processing chamber, 10s... Plasma processing space, 11... Substrate support part, 1111... Electrostatic chuck, 112... Ring assembly 13... Shower Head, 20...Gas supply section, EF...Etching film, MF...Mask film, CF...Carbon-containing film, WE...Outer peripheral end, DF...Deposited film, W...Substrate, gp...Gap

Claims (21)

A plasma processing method performed in a plasma processing apparatus having a chamber, the method comprising:
(a) Forming a carbon-containing film on the outer peripheral edge of the substrate; (b) After the step (a), a processing gas is supplied into the chamber, and plasma generated from the processing gas causes the substrate in the chamber to etching the substrate disposed on the support part, the substrate including an etching film and a mask film on the etching film;
The plasma processing method according to (b) above, wherein particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate. 2. The plasma processing method according to claim 1, further comprising: (c) after step (b), removing particles deposited on the carbon-containing film from the substrate together with the carbon-containing film. A plasma processing method performed in a plasma processing apparatus having a chamber, the method comprising:
(a) forming a carbon-containing film on the outer peripheral edge of the substrate;
(b) After the step (a), a step of supplying a processing gas into the chamber and etching the substrate disposed on the substrate support in the chamber with plasma generated from the processing gas, a step in which the substrate includes an etched film and a mask film on the etched film;
(c) after the step (b), removing the particles deposited on the carbon-containing film from the substrate together with the carbon-containing film;
Plasma treatment methods, including. 4. The plasma processing method according to claim 1, wherein in (a), the carbon-containing film is formed by plasma generated from a processing gas containing carbon-containing gas. The carbon-containing gas according to claim 4, wherein the carbon-containing gas is a C _a H _b (a and b are integers of 1 or more) gas or a C _c F _d (c and d are integers of 1 or more) gas. Plasma treatment method. 4. The plasma processing method according to claim 1, wherein the steps (a) and (b) are performed in the same chamber. 4. The plasma processing method according to claim 1, wherein said (a) and said (b) are performed in different chambers. The plasma processing method according to claim 1 or 3, wherein the processing gas supplied in the step (b) includes a phosphorus-containing gas. Claim 1 or Claim 3, wherein the processing gas supplied in (b) includes one type of single gas or a plurality of types of mixed gas containing C (carbon), H (hydrogen), and F (fluorine). The plasma treatment method described in . The plasma processing method according to claim 9, wherein the mixed gas includes HF gas and carbon-containing gas. The plasma processing method according to claim 10, wherein the flow rate of HF gas is the largest among the total flow rates of the processing gas excluding the inert gas supplied in the step (b). 4. The plasma processing method according to claim 1, wherein the plasma generated in the step (b) contains HF species, CF species, or CHF species, and P active species. 13. The plasma processing method according to claim 12, wherein the HF species is generated from at least one gas selected from the group consisting of HF gas and hydrofluorocarbon gas. 13. The plasma processing method of claim 12, wherein the HF species are generated from a fluorine-containing gas and a hydrogen-containing gas. 13. The plasma processing method according to claim 12, wherein the HF species is generated from a hydrofluorocarbon gas having two or more carbon atoms. The HF species is at least one gas selected from the group consisting of HF gas, CH ₂ F ₂ gas, C ₃ H ₂ F ₄ gas, C ₃ H ₂ F ₆ gas, and C ₄ H ₂ F ₆ gas. The plasma processing method according to claim 12, wherein the plasma processing method is generated. 4. The plasma processing method according to claim 1, wherein the etching film is a Si-containing film. 4. The plasma processing method according to claim 1, wherein the mask film is any one of a carbon-containing mask film, a metal-containing mask film, and a silicon-containing mask film. 4. The plasma processing method according to claim 1, wherein in (a), the carbon-containing film is selectively formed on a surface different from the surface on which the etching film is formed. 4. The plasma processing method according to claim 1, wherein in the step (b), the temperature of the substrate support portion is set to 0° C. or lower. comprising a chamber, a substrate support section provided in the chamber, a processing gas supply section, and a control section,
The control unit includes:
(a) forming a carbon-containing film on the outer peripheral edge of the substrate;
(b) supplying a processing gas into the chamber from the processing gas supply section, and etching the substrate supported on the substrate support section with plasma generated from the processing gas; in the etching, the substrate is comprising an etching film and a mask film on the etching film, performing control in which particles generated in the chamber are deposited on the carbon-containing film at an outer peripheral edge of the substrate;
Plasma treatment system.

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