Plasma processing method and plasma processing apparatus

Abstract

To provide a technique to properly etch a substrate including a metal-containing film.SOLUTION: A plasma processing method according to the present disclosure is a plasma processing method implemented in a plasma processing apparatus. The plasma processing method includes: (a) a step for preparing, on a substrate support part in a chamber, a substrate having a film to be etched including a first silicon-containing film and a first metal-containing film on the film to be etched, the first metal-containing film including an opening pattern; and (b) a step for etching the film to be etched. The (b) includes a step for supplying a treatment gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the treatment gas within the chamber and etching the first silicon-containing film to form the opening pattern in the first silicon-containing film, a ratio of the number of hydrogen atoms to the number of fluorine atoms in the treatment gas being 0.3 or more.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] Exemplary embodiments of this disclosure relate to plasma processing methods and plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a technique for making the dimensions of patterns formed on a non-organic resist uniform by trimming the resist using a processing gas containing CH3F or BCl3. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] U.S. Patent No. 9899219 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] This disclosure provides a technique for appropriately etching a substrate containing a metal-containing film. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, a plasma processing method is provided that is performed in a plasma processing apparatus. The plasma processing method includes (a) preparing a substrate having a film to be etched, which includes a first silicon-containing film, and a first metal-containing film on the film to be etched, wherein the first metal-containing film includes an aperture pattern, on a substrate support in a chamber, and (b) etching the film to be etched. Step (b) includes supplying a processing gas containing one or more gases, including carbon, hydrogen, and fluorine, into the chamber to generate plasma from the processing gas in the chamber, and etching the first silicon-containing film to form the aperture pattern in the first silicon-containing film, wherein the ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more. [Effects of the Invention]

[0006] According to exemplary embodiments of this disclosure, a technique for appropriately etching a substrate containing a metal-containing film can be provided. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating an example configuration of a plasma processing system. [Figure 2] This is a diagram illustrating an example of the configuration of a plasma processing apparatus. [Figure 3] This flowchart shows an example of this processing method. [Figure 4A] This figure shows an example of the cross-sectional structure of substrate W. [Figure 4B] This figure shows an example of the cross-sectional structure of substrate W. [Figure 4C] This figure shows an example of the cross-sectional structure of substrate W. [Figure 4D] This figure shows an example of the cross-sectional structure of substrate W. [Figure 4E] This figure shows an example of the cross-sectional structure of substrate W. [Figure 5] This figure schematically shows a cross-section of the substrate W after etching in process ST23. [Figure 6] This graph shows the defect density of the silicon-containing film SF-1. [Figure 7] This graph shows the LWR and LER of the silicon-containing film SF-1. [Modes for carrying out the invention]

[0008] The embodiments of this disclosure are described below.

[0009] In one exemplary embodiment, a plasma processing method executed in a plasma processing apparatus is provided. The plasma processing method includes: (a) preparing a substrate having an etching target film including a first silicon-containing film on a substrate support in a chamber and a first metal-containing film on the etching target film, wherein the first metal-containing film includes an opening pattern; and (b) etching the etching target film. (b) includes supplying a processing gas including one or more gases including carbon, hydrogen, and fluorine into the chamber, generating plasma from the processing gas in the chamber, and etching the first silicon-containing film to form an opening pattern in the first silicon-containing film, and the ratio of the number of hydrogen atoms to the number of fluorine atoms included in the processing gas is 0.3 or more.

[0010] In one exemplary embodiment, the first metal-containing film is a Sn-containing film.

[0011] In one exemplary embodiment, the first silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminated film thereof.

[0012] In one exemplary embodiment, the etching target film includes an intermediate film on the first silicon-containing film, and (b) includes etching the intermediate film using the first metal-containing film as a mask, and the step of forming the opening pattern includes etching the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask.

[0013] In one exemplary embodiment, the intermediate film includes at least one selected from the group consisting of a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film.

[0014] In one exemplary embodiment, the intermediate film includes a carbon-containing film and a second silicon-containing film on the carbon-containing film, and the second silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminated film thereof.

[0015] In one exemplary embodiment, the processing gas includes a hydrogen-containing gas, a carbon-containing gas, and a fluorine-containing gas.

[0016] In one exemplary embodiment, the carbon-containing gas is a gas further containing at least one of hydrogen and fluorine.

[0017] In one exemplary embodiment, the fluorine-containing gas is a gas that does not contain carbon.

[0018] In one exemplary embodiment, the ratio of the number of hydrogen atoms to the number of carbon atoms contained in the processing gas is 0.3 or more.

[0019] In one exemplary embodiment, the pressure in the chamber in the step of forming the opening pattern is lower than the pressure in the chamber in the step of etching the intermediate film.

[0020] In one exemplary embodiment, the step of forming the opening pattern controls the pressure in the chamber to 100 mTorr or less.

[0021] In one exemplary embodiment, in the step of etching the intermediate film, a deposit containing the metal contained in the first metal-containing film is generated, and the step of forming the opening pattern includes removing the deposit attached to the substrate.

[0022] In one exemplary embodiment, in the step of etching the intermediate film, a deposit containing the metal contained in the first metal-containing film is generated, and the step of forming the opening pattern includes removing the deposit attached to the inner wall of the chamber.

[0023] In one exemplary embodiment, the plasma processing apparatus has a first gas injection unit located on the upper surface of the chamber opposite the substrate support unit, and a second gas injection unit located on the side of the chamber, wherein the processing gas comprises one or more gases containing carbon and one or more gases not containing carbon, at least one of the one or more gases containing carbon is supplied from the first gas injection unit, and at least one of the one or more gases not containing carbon is supplied from the second gas injection unit.

[0024] In one exemplary embodiment, the plasma processing apparatus has a first gas injection unit located on the upper surface of the chamber and a second gas injection unit located on the side of the chamber, wherein the processing gas includes at least one carbon-containing gas, and the at least one carbon-containing gas is supplied into the chamber from the first and second gas injection units, and the ratio of the flow rate of the at least one carbon-containing gas supplied into the chamber from the first gas injection unit to the flow rate of the at least one carbon-containing gas supplied into the chamber from the second gas injection unit is less than 1.

[0025] In one exemplary embodiment, the plasma processing apparatus has a plasma generation unit above a substrate support unit, and the process of forming an aperture pattern includes supplying a source RF signal to the plasma generation unit to generate plasma from a processing gas, and supplying a bias signal to the substrate support unit, wherein the effective value of the power of the source RF signal is greater than the effective value of the power of the bias signal.

[0026] In one exemplary embodiment, the plasma generation unit includes electrodes positioned opposite the substrate support unit.

[0027] In one exemplary embodiment, the plasma generation unit includes an antenna positioned above the substrate support unit.

[0028] In one exemplary embodiment, the effective power of the source RF signal is 500W or more.

[0029] In one exemplary embodiment, the bias signal is an RF signal, and the effective power of the bias signal is 200W or less.

[0030] In one exemplary embodiment, during the process of forming an opening, the first silicon-containing film is etched using the first metal-containing film as a mask.

[0031] In one exemplary embodiment, plasma is continuously generated in the chamber from the etching process to the process of forming the openings of the interlayer.

[0032] In one exemplary embodiment, at least one plasma processing apparatus is provided, comprising a chamber, at least one gas supply unit, a plasma generation unit, and a substrate support unit within the chamber. In the plasma processing apparatus, the control unit is configured to perform a process that includes (a) preparing a substrate on the substrate support unit, the substrate having a film to be etched including a first silicon-containing film and a first metal-containing film on the film to be etched, wherein the first metal-containing film includes an aperture pattern, and (b) etching the film to be etched, wherein (b) includes supplying a processing gas containing one or more gases including carbon, hydrogen, and fluorine into the chamber, generating plasma from the processing gas in the chamber, etching the first silicon-containing film to form an aperture pattern in the first silicon-containing film, and controlling the ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas to 0.3 or more.

[0033] Hereinafter, each embodiment of this disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are denoted by the same reference numeral, and redundant explanations are omitted. Unless otherwise specified, positional relationships such as top, bottom, left, and right will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and actual ratios are not limited to those shown.

[0034] <An example of a plasma treatment system> Figure 1 is a diagram illustrating an example configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas outlet for discharging gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20, which will be described later, and the gas outlet is connected to an exhaust system 40, which will be described later. The substrate support unit 11 is located in the plasma processing space and has a substrate support surface for supporting a substrate.

[0035] The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR), a helicon wave plasma (HWP), or a surface wave plasma (SWP), etc. Various types of plasma generation units, including an AC (Alternating Current) plasma generation unit and a DC (Direct Current) plasma generation unit, may also be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes an RF (Radio Frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz. In one embodiment, the plasma processing apparatus 1 may have a plasma generation unit 12 above the substrate support unit 11.

[0036] <An example of a plasma processing device> Figure 2 is a diagram illustrating an example configuration of a plasma processing system. The plasma processing system includes an inductively coupled plasma processing apparatus 1 and a control unit 2. The inductively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing chamber 10 includes a dielectric window. The plasma processing apparatus 1 also includes a substrate support unit 11, a gas introduction unit, and an antenna 14. The substrate support unit 11 is located inside the plasma processing chamber 10. The antenna 14 is located 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, the side wall 102 of the plasma processing chamber 10, and the substrate support unit 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 outlet for discharging gas from the plasma processing space. The plasma processing chamber 10 is grounded.

[0037] The substrate support portion 11 includes a main body portion 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 the substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 in a plan view. The substrate W is placed on the central region 111a of the main body portion 111, and the ring assembly 112 is placed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also called the substrate support surface for supporting the substrate W, and the annular region 111b is also called the ring support surface for supporting the ring assembly 112.

[0038] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a bias electrode. The electrostatic chuck 1111 is placed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b placed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may also have an annular region 111b. In this case, the ring assembly 112 may be placed on the annular electrostatic chuck or the annular insulating member, or on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode, which will be coupled to the RF (Radio Frequency) power supply 31 and / or DC (Direct Current) power supply 32 described later, may be placed within the ceramic member 1111a. In this case, at least one RF / DC electrode will function as a bias electrode. Note that the conductive member of the base 1110 and at least one RF / DC electrode may function as multiple bias electrodes. Also, the electrostatic electrode 1111b may function as a bias electrode. Therefore, the substrate support portion 11 includes at least one bias electrode.

[0039] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one covering ring. The edge rings are formed of a conductive or insulating material, and the covering rings are formed of an insulating material.

[0040] The substrate support section 11 may also 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, the flow path 1110a is formed within the base 1110, and one or more heaters are arranged within the ceramic member 1111a of the electrostatic chuck 1111. The substrate support section 11 may also 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.

[0041] The gas introduction section is configured to introduce at least one processing gas from the gas supply section 20 into the plasma processing space 10s. In one embodiment, the gas introduction section includes a Center Gas Injector (CGI) 13. The Center Gas Injector 131 is located above the substrate support section 11 and is attached to a central opening formed in the dielectric window 101. The Center Gas Injector 131 has at least one gas supply port 131a, at least one gas flow path 131b, and at least one gas inlet 131c. The processing gas supplied to the gas supply port 131a passes through the gas flow path 131b and is introduced into the plasma processing space 10s from the gas inlet 131c. In addition to or instead of the Center Gas Injector 131, the gas introduction section may also include one or more Side Gas Injectors (SGIs) attached to one or more openings formed in the side wall 102.

[0042] The gas inlet may include a peripheral gas injection section 52 as an example of a side gas injection section. The peripheral gas injection section 52 includes a plurality of peripheral inlets 52i. The plurality of peripheral inlets 52i supply gas mainly toward the edge of the substrate W. The plurality of peripheral inlets 52i open toward the edge of the substrate W or toward the edge of the central region 111a that supports the substrate W. The plurality of peripheral inlets 52i are arranged below the gas inlet 131c and above the substrate support section 11, along the circumferential direction of the substrate support section 11. That is, the plurality of peripheral inlets 52i are arranged in an annular shape around the axis of the gas flow path 131b in a region where the electron temperature is lower than directly below the dielectric window 101 (plasma diffusion region). The central gas injection section is an example of a first gas injection section. The side gas injection section is an example of a second gas injection section.

[0043] 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 processing gas to the gas inlet from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one processing gas.

[0044] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one bias electrode and antenna 14. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power supply 31 can function as at least part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to at least one bias electrode, a bias potential is generated on the substrate W, which can attract ions in the formed plasma to the substrate W.

[0045] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the antenna 14 and configured to generate a source RF signal (source RF power) for plasma generation via at least one impedance matching circuit. 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 generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to the antenna 14.

[0046] The second RF generation unit 31b is configured to be coupled to at least one bias electrode via at least one impedance matching circuit and to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one bias electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0047] Furthermore, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a bias DC generation unit 32a. In one embodiment, the bias DC generation unit 32a is connected to at least one bias electrode and configured to generate a bias DC signal. The generated bias DC signal is applied to at least one bias electrode.

[0048] In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one bias electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or a combination thereof pulse waveform. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from a DC signal is connected between the bias DC generation unit 32a and at least one bias electrode. Thus, the bias DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. The voltage pulses may have positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. Note that the bias DC generation unit 32a may be provided in addition to the RF power supply 31, or it may be provided in place of the second RF generation unit 31b.

[0049] The antenna 14 includes one or more coils. In one embodiment, the antenna 14 may include an outer coil and an inner coil arranged coaxially. In this case, the RF power supply 31 may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generation unit may be connected to both the outer coil and the inner coil, or separate RF generation units may be connected to the outer coil and the inner coil separately.

[0050] The exhaust system 40 may be connected to, for example, a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0051] Figure 3 is a flowchart illustrating an example of a plasma processing method (hereinafter referred to as "this processing method") according to one exemplary embodiment. Figures 4A to 4E show examples of the cross-sectional structure of a substrate W. This processing method is performed on a substrate W using, for example, the plasma processing apparatus 1 shown in Figure 2. Below, an example of performing this processing method shown in Figure 3 on a substrate W shown in Figure 4A will be described with reference to each figure. In the following example, the control unit 2 shown in Figures 1 and 2 controls each part of the plasma processing apparatus 1 shown in Figure 2 to perform this processing method.

[0052] (Step ST1: Preparation of the substrate) In step ST1, the substrate W is prepared in the plasma processing space 10s of the plasma processing chamber 10. In step ST1, the substrate W is at least placed on the substrate support 11 and held by the electrostatic chuck 1111. At least a portion of the process for forming each component of the substrate W may be performed in the plasma processing space 10s as part of step ST1. Alternatively, all or part of the components of the substrate W may be formed in an external device or chamber outside the plasma processing apparatus 1, after which the substrate W may be brought into the plasma processing space 10s and placed on the substrate support 11.

[0053] Step ST1 may include a step of setting the temperature of the substrate support section 11. To set the temperature of the substrate support section 11, the control unit 2 may control the temperature control module. For example, the control unit 2 may set the temperature of the substrate support section 11 to 60°C or lower.

[0054] The substrate W has an etching target film containing a first silicon-containing film and a first metal-containing film on the etching target film. The etching target film may consist only of the first silicon-containing film, or it may have an interlayer on the first silicon-containing film. The interlayer may be formed in step ST2 from a material having an etching rate higher than that of the first metal-containing film. Alternatively, the interlayer may be formed in step ST2 from a material having an etching rate lower than that of the first silicon-containing film. The interlayer may be at least one selected from the group consisting of, for example, a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film, and may be a multilayer film containing two or more of these.

[0055] As an example, the substrate W prepared in the plasma processing chamber 10 has the cross-sectional structure shown in Figure 4A. It includes a base film UF, a metal compound film MF, a silicon-containing film SF-1, a carbon-containing film CF, a silicon-containing film SF-2, and a mask film MK. The silicon-containing film SF-1 is an example of a first silicon-containing film. The carbon-containing film CF and the silicon-containing film SF-2 are examples of interlayers. The silicon-containing film SF-2 is an example of a second silicon-containing film. The mask film MK is an example of a first metal-containing film. Note that the silicon-containing films SF-1 and SF-2 are collectively referred to as "silicon-containing film SF". Note that the first silicon-containing film may be a film on which the opening pattern of the first metal-containing film (mask film MK in one example) is formed by etching. The second silicon-containing film (silicon-containing film SF-2 in one example) may be a film that is etched using the first metal-containing film as a mask. Furthermore, the first silicon-containing film (silicon-containing film SF-1 in one example) may be a film etched using a first metal-containing film (mask film MK in one example) as a mask (carbon-containing film CF in one example) as a mask.

[0056] The underlayer film UF may be an organic film, dielectric film, metal film, semiconductor film, etc., formed on a silicon wafer. Alternatively, the underlayer film UF may be a silicon wafer itself. Furthermore, the underlayer film UF may be composed of multiple films stacked on top of each other.

[0057] The silicon-containing films SF-1 and SF-2 may be films containing silicon (Si). The silicon-containing film SF may include films containing silicon and oxygen, such as silicon oxide films, or films containing silicon and nitrogen, such as silicon nitride films. For example, silicon-containing film SF-1 is an SiO2 film, and silicon-containing film SF-2 is an SiON film. The silicon-containing film SF may also contain other types of films as long as they contain silicon. Furthermore, the silicon-containing film SF may include silicon films (e.g., polycrystalline silicon films). Additionally, the silicon-containing film SF may include at least one of silicon nitride films, polycrystalline silicon films, carbon-containing silicon films, and low-dielectric-constant films. The carbon-containing silicon film may include SiC films and / or SiOC films. The low-dielectric-constant film contains silicon and can be used as an interlayer insulating film. Furthermore, the silicon-containing film SF may be a spin-on-glass (SOG) film or a silicon-containing anti-reflective (SiARC) film. Finally, the silicon-containing film SF may be a film doped with impurities such as phosphorus, boron, or nitrogen.

[0058] Furthermore, the silicon-containing film SF may include two or more silicon-containing films having different film types. The two or more silicon-containing films may include silicon oxide films and silicon nitride films. The silicon-containing film SF may be a multilayer film including, for example, one or more silicon oxide films and one or more silicon nitride films that are alternately stacked. The silicon-containing film SF may be a multilayer film including multiple silicon oxide films and multiple silicon nitride films that are alternately stacked. Alternatively, the two or more silicon-containing films may include silicon oxide films and silicon films. The silicon-containing film SF may be a multilayer film including one or more silicon oxide films and one or more silicon films that are alternately stacked. The silicon-containing film SF may be a multilayer film including multiple silicon oxide films and multiple polycrystalline silicon films that are alternately stacked. Alternatively, the two or more silicon-containing films may include silicon oxide films, silicon nitride films, and silicon films.

[0059] Furthermore, silicon-containing film SF-1 may be a film with higher etching resistance than silicon-containing film SF-2. This etching resistance may be, for example, resistance to etching using fluorocarbon gas and / or hydrofluorocarbon gas as the processing gas. For example, silicon-containing film SF-1 may be an SiO2 film, and silicon-containing film SF-2 may be an SOG film. Note that silicon-containing film SF-2 may be thinner than silicon-containing film SF-1. Also, silicon-containing film SF-2 may be thinner than mask film MK and / or carbon-containing film CF.

[0060] A carbon-containing film CF can be a film containing carbon. A carbon-containing film CF may be a film containing organic materials, or a film containing inorganic materials. For example, a carbon-containing film CF may be a spin-on carbon (SOC film) or an amorphous carbon (ACL) film.

[0061] The mask film MK may be a first metal-containing film. The first metal-containing film may be a tin-containing film. In step ST2, the mask film MK is formed from a material having a lower etching rate than the silicon-containing film SF-2. The mask film MK may be an EUV photoresist film. For example, the EUV photoresist film may be a tin-containing film. For example, the tin-containing film may contain tin oxide and / or tin hydroxide. Also, for example, the EUV photoresist film may be a film containing at least one material selected from the group consisting of titanium (Ti), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), germanium (Ge), arsenic (As), silver (Ag), indium (In), antimony (Sb), tellurium (Te), iodine (I), and hafnium (Hf).

[0062] Furthermore, if the interlayer includes a second metal-containing film, the second metal-containing film may, for example, be a metal-containing film containing at least one metal selected from the group consisting of aluminum (Al), titanium (Ti), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), indium (In), tin (Sn), hafnium (Hf), tantalum (Ta), and tungsten (W). The second metal-containing film may also contain at least one material selected from the group consisting of germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and iodine (I).

[0063] The mask film MK has an aperture pattern that defines at least one aperture OP on the silicon-containing film SF. The mask film MK has at least one side wall other than the outer periphery of the mask film MK. The aperture OP is a closed space defined by the side wall. The at least one aperture OP defined by the mask film MK may have any shape in a plan view of the substrate W. This shape may include a circular shape, an elliptical shape, a rectangular shape, a linear shape, etc. The aperture pattern of the mask film MK may include an array pattern in which a plurality of apertures OP having a hole shape are regularly arranged in a plan view of the substrate W. This hole shape may include a circular shape, an elliptical shape, a rectangular shape, etc. Furthermore, the aperture pattern of the mask film MK may include a line-and-space (L / S) pattern in which a plurality of apertures OP having a linear shape are arranged at regular intervals in a plan view of the substrate W. The pitch of the apertures OP (distance between the centers of the mask film MK) may be 100 nm or less. Alternatively, the width of the apertures OP may be 30 nm or less. The width may be the diameter of the hole if the opening OP has a hole shape. Alternatively, if the opening pattern has a line and space pattern, the width may be the width of the line or space. Furthermore, the thickness of the silicon-containing film SF-1 or SF-2 may be 40 nm or less, or 20 nm or less.

[0064] In the opening OP defined by the mask film MK, the silicon-containing film SF-2 has its surface (top surface) exposed. In step ST2, described later, the silicon-containing film SF-2, carbon-containing film CF, silicon-containing film SF-1, and metal compound film MF are etched based on the shape of the opening OP defined by the mask film MK. Then, recesses RC, such as holes and trenches, are formed in each film. Each of the one or more recesses RC formed in each film has a shape based on each of the one or more openings OP in a plan view of the substrate W.

[0065] Furthermore, the opening pattern of the mask film MK may contain defects. For example, defects in the opening pattern may include etching residue generated when the opening pattern was formed on the mask film MK. Etching residue may be present on the side walls of the mask film MK that define the opening OP, or at the bottom of the opening OP (i.e., on the surface of the silicon-containing film SF-2).

[0066] (Step ST2: Etching execution) In step ST2, each film located below the mask film MK on the substrate W is etched. Step ST2 includes a step of etching the silicon-containing film SF-2 (step ST21), a step of etching the carbon-containing film CF (step ST22), a step of etching the silicon-containing film SF-1 (step ST23), and a step of etching the metal compound film MF (step ST24).

[0067] Each step of process ST2 may include steps of supplying a processing gas into the plasma processing chamber 10, supplying a source RF signal, and supplying a bias RF signal. In each of these steps, plasma active species (ions, radicals) are generated from the processing gas, and each film is etched by these active species. The order in which the processing gas, source RF signal, and bias signal are supplied is arbitrary. Furthermore, plasma may be continuously generated in the plasma processing chamber 10 over two or more consecutive steps in process ST2. That is, plasma may be generated without interruption between two or more consecutive steps. This reduces the amount of particles generated in the plasma processing chamber 10. Also, each step of process ST2 may be performed in two or more plasma processing chambers. For example, step ST21 may be performed in the first chamber, step ST22 in the second chamber, step ST23 in the third chamber, and step ST24 in the fourth chamber. Steps ST21 and ST23, which etch the silicon-containing film SF, may be performed in the same chamber. In other words, the first chamber and the third chamber may be the same chamber.

[0068] In each step of process ST2, a processing gas is supplied into the plasma processing chamber 10. The type of processing gas may be appropriately selected in each step based on the material of the film to be etched, the thickness of the film, the material of the film above and / or below the film, the pattern of the mask film, etc.

[0069] In each step of process ST2, the pressure inside the plasma processing chamber 10 may be set as appropriate. For example, the pressure inside the plasma processing chamber 10 in process ST23 may be set lower than the pressure inside the plasma processing chamber 10 in processes ST21 and ST22, which are processes for etching the interlayer. For example, the pressure inside the plasma processing chamber 10 may be set to 100 mTorr or less, 50 mTorr or less, 30 mTorr or less, or 10 mTorr or less.

[0070] (Step ST21: Etching of silicon-containing film SF-2) Next, as shown in Figure 4B, the silicon-containing film SF-2 is etched in step ST21. For example, the silicon-containing film SF-2 may be etched using plasma generated from a processing gas containing fluorocarbon gas and / or hydrofluorocarbon gas. When the substrate W is etched using the plasma generated from the processing gas in step ST21, the silicon-containing film SF-2 is etched using the mask film MK as a mask, and a recess RC is formed in the silicon-containing film SF-2. In addition, the carbon-containing film CF is exposed at the bottom of the recess RC. Note that a part of the mask film MK may be etched during the etching of the silicon-containing film SF-2. Furthermore, if the opening pattern of the mask film MK contains defects including etching residue, the silicon-containing film SF-2 may be etched using the etching residue as a mask. That is, the pattern formed on the silicon-containing film SF-2 by the recess RC may also contain defects based on the etching residue.

[0071] (Step ST22: Etching of carbon-containing film CF) Next, as shown in Figure 4C, the carbon-containing film CF is etched in step ST22. For example, the carbon-containing film CF may be etched using plasma generated from a processing gas containing hydrogen, halogen, and oxygen. For example, the processing gas may contain one or more gases consisting of molecules containing hydrogen, bromine, chlorine, and / or iodine. For example, such gases are H2, Br2, Cl2, HBr, HCl, HI, etc. The processing gas may also contain one or more gases consisting of molecules containing oxygen. For example, such gases are O2, CO2, COS, etc. The processing gas may also contain inert gases such as He, Ar, N2, etc.

[0072] For example, if the mask film MK is a tin-containing film, in step ST22, when the substrate W is etched using plasma generated from the processing gas, the mask film MK is removed as shown in Figure 4C. Then, the carbon-containing film CF is etched using the silicon-containing film SF-2 as a mask, and a recess RC is formed in the carbon-containing film CF. Furthermore, the silicon-containing film SF-1 is exposed at the bottom of the recess RC. Note that during the etching of the carbon-containing film CF, a portion of the silicon-containing film SF-2 may also be etched. In addition, if the opening pattern of the mask film MK contains defects including etching residue, the carbon-containing film CF can be etched using the silicon-containing film SF-2, which contains defects based on the etching residue, as a mask. That is, the pattern formed on the carbon-containing film CF by the recess RC may also contain defects based on the etching residue.

[0073] (Step ST22: Etching of silicon-containing film SF-1) Next, as shown in Figure 4D, the silicon-containing film SF-1 is etched in step ST23. As an example, the silicon-containing film SF-1 may be etched using plasma generated from a processing gas containing one or more gases including carbon, hydrogen, and fluorine. The processing gas contains one or more gases. Here, each of these one or more gases may contain hydrogen, carbon, and fluorine. Furthermore, if the one or more gases are multiple gases, one of the multiple gases may contain one or more of hydrogen, carbon, and fluorine, and part or all of the remaining one or more gases may contain the remainder of hydrogen, carbon, and fluorine.

[0074] The processing gas used in step ST23 may include a gas capable of generating hydrogen fluoride (HF) species within the plasma processing chamber 10 during plasma processing. The hydrogen fluoride species functions as an etchant that etches the silicon-containing film SF-1 in step ST23.

[0075] The gas containing carbon, hydrogen, and fluorine may be at least one gas selected from the group consisting of hydrofluorocarbons. Hydrofluorocarbons are, for example, at least one of CH2F2, CHF3, or CH3F. Hydrofluorocarbons may contain two or more carbon atoms, and may contain two to six carbon atoms. Hydrofluorocarbons may contain two carbon atoms, for example, C2HF5, C2H2F4, C2H3F3, C2H4F2, etc. Hydrofluorocarbons may contain three or four carbon atoms, for example, C3HF7, C3H2F2, C3H2F4, C3H2F6, C3H3F5, C4H2F6, C4H5F5, C4H2F8, etc. Hydrofluorocarbon gases are, for example, C5H2F6, C5H2F 10 It may also contain five carbon atoms such as C5H3F7. In one embodiment, the hydrofluorocarbon gas contains at least one selected from the group consisting of C3H2F4, C3H2F6, C4H2F6, and C4H2F8. The processing gas may contain hydrogen fluoride (HF) as a gas capable of generating hydrogen fluoride (HF) species in the plasma processing chamber 10 during plasma processing. In the processing gas, the ratio of the number of hydrogen atoms to the number of fluorine atoms may be 0.3 or more, 0.4 or more, or 0.5 or more. In addition, in the processing gas, the ratio of the number of hydrogen atoms to the number of carbon atoms may be 1.0 or more, 1.5 or more, or 2.0 or more.

[0076] Furthermore, the processing gas may include a mixed gas containing hydrogen and fluorine, capable of generating hydrogen fluoride species within the plasma processing chamber 10 during plasma processing. The mixed gas capable of generating hydrogen fluoride species may include a hydrogen source and a fluorine source. The hydrogen source may be, for example, H2, NH3, H2O, H2O2, or hydrocarbons (CH4, C3H6, etc.). The fluorine source may be BF3, NF3, PF3, PF5, SF6, WF6, XeF2, or fluorocarbons. As an example, the mixed gas capable of generating hydrogen fluoride species is a mixed gas of nitrogen trifluoride (NF3) and hydrogen (H2).

[0077] In addition, the processing gas may contain, as a carbon-containing gas, at least one carbon-containing gas selected from the group consisting of hydrocarbons (C x H y ), fluorocarbons (C v F w ). Here, each of x, y, v, and w is a natural number. Hydrocarbons may include, for example, CH4, C2H6, C3H6, C3H8, or C4H 10 and the like. Fluorocarbons may include, for example, CF4, C2F2, C2F4, C3F8, C4F6, C4F8, or C5F8 and the like. Chemical species generated from these carbon-containing gases can protect the mask film MK.

[0078] In addition, the processing gas may further contain at least one phosphorus-containing molecule. The phosphorus-containing molecule may be an oxide such as phosphorus pentoxide (P4O 10 ), phosphorus tetraoxide (P4O8), phosphorus hexoxide (P4O6), etc. Phosphorus pentoxide is sometimes called diphosphorus pentoxide (P2O5). The phosphorus-containing molecule may be a halide (phosphorus halide) such as phosphorus trifluoride (PF3), phosphorus pentafluoride (PF5), phosphorus trichloride (PCl3), phosphorus pentachloride (PCl5), phosphorus tribromide (PBr3), phosphorus pentabromide (PBr5), phosphorus iodide (PI3). That is, the molecule containing phosphorus may be a fluoride (phosphorus fluoride) containing fluorine as a halogen element. Alternatively, the molecule containing phosphorus may contain a halogen element other than fluorine as a halogen element. The phosphorus-containing molecule may be a phosphoryl halide such as phosphoryl fluoride (POF3), phosphoryl chloride (POCl3), phosphoryl bromide (POBr3). The phosphorus-containing molecule may be phosphine (PH3), calcium phosphide (such as Ca3P2), phosphoric acid (H3PO4), sodium phosphate (Na3PO4), hexafluorophosphoric acid (HPF6), etc. The phosphorus-containing molecule may be fluorophosphines (H x PF y) may be the case. Here, the sum of x and y is 3 or 5. Examples of fluorophosphines include HPF2 and H2PF3. The processing gas may contain at least one phosphorus-containing molecule, which is one or more of the phosphorus-containing molecules listed above. For example, the processing gas may contain at least one of PF3, PCl3, PF5, PCl5, POCl3, PH3, PBr3, or PBr5, which is at least one phosphorus-containing molecule. If each phosphorus-containing molecule contained in the processing gas is a liquid or solid, each phosphorus-containing molecule may be vaporized by heating or the like and supplied into the plasma processing chamber 10.

[0079] Furthermore, the processing gas may contain halogen-containing molecules. The halogen-containing molecules may contain carbon or not. The halogen-containing molecules may be fluorine-containing molecules, halogen-containing molecules containing halogen elements other than fluorine, or halogen-containing molecules containing fluorine and halogen elements other than fluorine. Fluorine-containing molecules may include, for example, gases such as nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), and boron trifluoride (BF3). Halogen-containing molecules containing halogen elements other than fluorine may be, for example, at least one selected from the group consisting of chlorine-containing gas, bromine-containing gas, and iodine. Chlorine-containing gases include, for example, chlorine (Cl2), hydrogen chloride (HCl), silicon dichloride (SiCl2), silicon tetrachloride (SiCl4), carbon tetrachloride (CCl4), dicyclosilane (SiH2Cl2), disilicon hexachloride (Si2Cl6), chloroform (CHCl3), dichloromethane (CH2Cl2), sulfuryl chloride (SO2Cl2), and boron trichloride (BCl3). Bromine-containing gases include, for example, bromine (Br2), hydrogen bromide (HBr), dibromodifluoromethane (CBr2F2), bromopentafluoroethane (C2F5Br), phosphorus tribromide (PBr3), phosphorus pentabromide (PBr5), oxybromide phosphate (POBr3), and boron tribromide (BBr3). Iodine-containing gases include, for example, hydrogen iodide (HI), trifluoroiodomethane (CF3I), pentafluoroiodoethane (C2F5I), heptafluoropropyl iodide (C3F7I), iodine pentafluoride (IF5), iodine heptafluoride (IF7), iodine (I2), and phosphorus triiodide (PI3). The chemical species produced from these halogen-containing molecules can be used to control the shape of the recesses formed by plasma etching.

[0080] The process gas may contain oxygen-containing molecules. These oxygen-containing molecules may include, for example, O2, CO2, or CO. The process gas may also contain noble gases such as Ar, Kr, and Xe.

[0081] Furthermore, in the plasma processing apparatus 1 shown in Figure 2, the processing gas may be supplied into the plasma processing chamber 10 from either the central gas injection section 131 or the side gas injection section, or both. For example, the flow rate of carbon-containing gas supplied from the side gas injection section may be greater than the flow rate of carbon-containing gas supplied from the central gas injection section 131. That is, the ratio of the flow rate of carbon-containing gas supplied from the central gas injection section 131 to the flow rate of carbon-containing gas contained in the processing gas may be 50% or less, and the ratio of the flow rate of carbon-containing gas supplied from the side gas injection section may be 50% or more. Alternatively, the ratio of the flow rate of carbon-containing gas supplied from the central gas injection section 131 to the flow rate of carbon-containing gas contained in the processing gas may be 20% or less, and the ratio of the flow rate of carbon-containing gas supplied from the side gas injection section may be 80% or more. Alternatively, the ratio of the flow rate of carbon-containing gas supplied from the central gas injection section 131 to the flow rate of carbon-containing gas contained in the processing gas may be 10% or less, and the ratio of the flow rate of carbon-containing gas supplied from the side gas injection section may be 90% or more. Furthermore, the ratio of the flow rate of carbon-containing gas supplied from the central gas injection unit 131 to the flow rate of carbon-containing gas contained in the processed gas may be 5% or less, and the ratio of the flow rate of carbon-containing gas supplied from the side gas injection units may be 95% or more. Also, the ratio of the flow rate of carbon-containing gas supplied from the side gas injection units to the flow rate of carbon-containing gas contained in the processed gas may be 100%.

[0082] As an example, the number of carbon atoms in the carbon-containing gas supplied from the side gas injection section may be greater than the number of carbon atoms in the carbon-containing gas supplied from the central gas injection section 131 among the processing gases supplied into the plasma processing chamber 10.

[0083] By supplying at least a portion of the carbon-containing gas contained in the processing gas into the plasma processing chamber 10 from the side gas injection section, the uniformity of the etching rate of the etching film and / or the uniformity of the dimensions of the recesses formed in the etching film can be improved within the plane of the substrate W.

[0084] Next, the source RF signal and bias signal supplied in process ST23 will be described. The source RF signal supplied in process ST23 may, for example, be supplied to the upper electrode of the plasma processing apparatus 1 in Figure 2 or to the antenna 14 of the plasma processing apparatus 1 in Figure 2. The upper electrode is an example of an electrode. The source RF signal may be a continuous RF wave or a pulsed wave. The power of the source RF signal is greater than the power of the bias signal. For example, the power of the source RF signal may be 300W or more. Alternatively, the power of the source RF signal may be 500W or more, 1,000W or more, or 2,000W or more.

[0085] The bias signal supplied in step ST23 is supplied, for example, to the substrate support section 11 shown in Figure 2. The bias signal may be supplied to a component in the substrate support section 11 that can function as a bias electrode. The bias signal may be an RF signal. The power of the bias signal is less than the power of the source RF signal. For example, the power of the bias signal may be 200W or less. Alternatively, the power of the bias signal may be 100W or less, or 50W or less. For example, the power of the bias signal may be greater than the power of the source RF signal.

[0086] In step ST23, when the substrate W is etched using plasma generated from the processing gas, the silicon-containing film SF-1 is etched using the silicon-containing film SF-2 and / or the carbon-containing film CF as a mask, and a recess RC is formed in the silicon-containing film SF-1. Furthermore, the metal compound film MF is exposed at the bottom of the recess RC. Note that the silicon-containing film SF-2 can be etched under the same etching conditions as the silicon-containing film SF-1. These etching conditions may include the type of processing gas, the power of the source RF signal, the power of the bias signal, and the pressure inside the plasma processing chamber 10.

[0087] In step ST23, metal-containing deposits generated in step ST21 and / or step ST22 may be removed. The metal may be a metal contained in the mask film MK. For example, the metal may be tin (Sn). The deposit may be a residue of a compound containing the metal generated during etching in step ST21 and / or step ST22. The deposit may be a deposit attached to the substrate W, or a deposit attached to the inner wall of the plasma processing chamber 10. By removing the deposit in step ST23, defects in the silicon-containing film SF-1 can be reduced. These defects may be defects that occur in step ST23.

[0088] Next, as shown in Figure 4E, the metal compound film MF is etched in step ST24. For example, the metal compound film MF may be etched using plasma generated from a processing gas containing fluorine or chlorine. When the substrate W is etched using plasma generated from the processing gas in step ST24, the metal compound film MF is etched using the first silicon-containing film SF-1 as a mask, and a recess RC is formed in the metal compound film MF. The underlying film UF is exposed at the bottom of the recess RC. Note that a portion of the silicon-containing film SF-1 may be etched during the etching of the metal compound film MF.

[0089] <Examples of this processing method> A substrate W having the following layered structure was prepared. Mask film MK: Tin-containing film, 10 nm Silicon-containing film SF-2:SOG 8nm Carbon-containing film CF:SOC 44nm Silicon-containing film SF-1: SiO2 15nm Metal compound film MF:TiN 14nm Then, in the plasma processing chamber 10, after etching the silicon-containing film SF-2 and the carbon-containing film CF, the silicon-containing film SF-1 was etched under the conditions of the reference example and the example. Note that the silicon-containing film SF-2 and the carbon-containing film CF were etched under the same conditions in both the reference example and the example. Reference example Equipment: CCP plasma processing device Source RF signal: 0W Bias RF signal: 300W Processed gases: CF4, CHF3, Ar H / F: 0.16 H / C: 0.55 Examples Equipment: ICP plasma processing device (Figure 2) Source RF signal: 1,500W Bias RF signal: 50W Processed gases: C4F6, H2, NF3, N2, Ar H / F: 0.41 H / C:2.04 Note that "H / F" represents the ratio of hydrogen atoms to fluorine atoms in the processed gas, and "H / C" represents the ratio of hydrogen atoms to carbon atoms in the processed gas.

[0090] Figure 5 is a schematic diagram showing a portion of the cross-section of the substrate W after etching in step ST23. In Figure 5, (a) shows the cross-section of the substrate W after performing step ST23 under the conditions of the reference example. (b) shows the cross-section of the substrate W after performing step ST23 under the conditions of the embodiment.

[0091] As shown in Figure 5, the embodiment yielded better results compared to the reference example. Specifically, when etching the silicon-containing film SF-1 using the carbon-containing film CF as a mask, the selectivity ratio was significantly improved in the embodiment. Specifically, after etching the silicon-containing film SF-1, only 39% of the carbon-containing film CF remained in the reference example, while 66% remained in the embodiment. In other words, the selectivity ratio improved by approximately 1.7 times. Furthermore, in another embodiment where H / F was 0.46, the thickness of the carbon-containing film CF after etching the silicon-containing film SF-1 was approximately the same as before etching. Moreover, in another embodiment where H / F was 0.54, the thickness of the carbon-containing film CF after etching the silicon-containing film SF-1 was thicker than before etching.

[0092] Furthermore, the cross-sectional shape of the silicon-containing film SF-1 after etching was significantly improved. Specifically, after etching the silicon-containing film SF-1, the ratio of the top CD (Critical Dimension) to the bottom CD (hereinafter also referred to as the "CD ratio") was 72% in the reference example, while it was 91% in the embodiment. In other words, the cross-sectional shape of the silicon-containing film SF-1 after etching was a gently tapered shape in the reference example, while it was nearly vertical in the embodiment. In addition, in the embodiment, the CD ratio could be controlled by controlling the etching time of the silicon-containing film SF-1. For example, shortening the over-etching time resulted in a tapered cross-sectional shape, while lengthening the over-etching time resulted in an inversely tapered cross-sectional shape. Furthermore, by controlling the over-etching time, it was possible to make the cross-sectional shape nearly vertical.

[0093] Figure 6 is a graph showing the defect density of the silicon-containing film SF-1 after etching the substrate W in step ST23. In Figure 6, the vertical axis represents the density of defects contained in the silicon-containing film SF-1 on the substrate W. As shown in Figure 6, the defect density of the silicon-containing film SF-1 in the example was reduced by approximately 88% compared to the defect density of the silicon-containing film SF-1 in the reference example.

[0094] Figure 7 is a graph showing the line width roughness (LWR) and line edge roughness (LER) of the silicon-containing film SF-1 after etching the substrate W in step ST23. As shown in Figure 7, in the example, both LWR and LER were improved by approximately 10% compared to the reference example. In both the reference example and the example, the aperture pattern of the mask film MK is a line-and-space (L / S) pattern.

[0095] As described above, in this processing method, a metal-containing film such as a tin-containing film is used as the mask film MK during the etching of the substrate W containing the silicon-containing film SF, and a processing gas with a high hydrogen content is used. As a result, the silicon-containing film SF can be etched with a high selectivity ratio. Furthermore, a silicon-containing film with a cross-sectional shape close to a vertical shape can be obtained.

[0096] Furthermore, this processing method allows etching of the silicon-containing film SF while removing metal-containing deposits and / or defects contained in the mask film MK. This reduces the influence of the deposits and / or defects during etching of the silicon-containing film SF, thereby reducing the number of defects in the silicon-containing film SF. The deposits may be compounds containing the metal, etc., generated in the process of etching other films contained in the substrate W. The defects may be etching residues of the mask film MK generated in the process of forming an opening pattern on the mask film MK.

[0097] Furthermore, this processing method allows for etching of the silicon-containing film SF while removing the deposits and / or defects, thereby improving the roughness of the pattern on the silicon-containing film SF.

[0098] Each of the embodiments described above is for illustrative purposes only and can be modified in various ways without departing from the scope and spirit of this disclosure.

[0099] Embodiments of this disclosure further include the following embodiments:

[0100] (Note 1) A plasma processing method performed in a plasma processing apparatus, The aforementioned plasma processing method is (a) A step of preparing a substrate having an etching target film including a first silicon-containing film and a first metal-containing film on the etching target film, wherein the first metal-containing film includes an opening pattern, and the above step, (b) A step of etching the film to be etched, Includes, (b) is a step of supplying a processing gas containing one or more gases, including carbon, hydrogen, and fluorine, into the chamber, generating plasma from the processing gas in the chamber, etching the first silicon-containing film to form the opening pattern in the first silicon-containing film. Includes, A plasma treatment method in which the ratio of the number of hydrogen atoms to the number of fluorine atoms contained in the treatment gas is 0.3 or more.

[0101] (Note 2) The plasma treatment method described in Appendix 1, wherein the first metal-containing film is a Sn-containing film.

[0102] (Note 3) The plasma treatment method according to Appendix 1 or Appendix 2, wherein the first silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminated film thereof.

[0103] (Note 4) The etching target film includes an interlayer on the first silicon-containing film, The (b) above includes a step of etching the interlayer using the first metal-containing film as a mask, The plasma treatment method according to any one of Appendix 1 to 3, wherein the step of forming the aperture pattern is to etch the first silicon-containing film using at least one of the first metal-containing film and the interlayer film as a mask.

[0104] (Note 5) The plasma treatment method according to Appendix 4, wherein the intermediate film includes at least one selected from the group consisting of a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film.

[0105] (Note 6) The interlayer comprises the carbon-containing film and a second silicon-containing film on the carbon-containing film. The plasma treatment method according to Appendix 5, wherein the second silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminated film thereof.

[0106] (Note 7) The plasma treatment method according to any one of the appendices 1 to 6, wherein the treatment gas includes a hydrogen-containing gas, a carbon-containing gas, and a fluorine-containing gas.

[0107] (Note 8) The plasma treatment method according to Appendix 7, wherein the carbon-containing gas is a gas further containing at least one of hydrogen and fluorine.

[0108] (Note 9) The plasma treatment method according to Appendix 7 or Appendix 8, wherein the fluorine-containing gas is a carbon-free gas.

[0109] (Note 10) The plasma treatment method according to any one of the appendices 1 to 9, wherein the ratio of the number of hydrogen atoms to the number of carbon atoms contained in the treatment gas is 0.3 or more.

[0110] (Note 11) The plasma treatment method according to Appendix 4, wherein the pressure in the chamber during the step of forming the aperture pattern is lower than the pressure in the chamber during the step of etching the interlayer.

[0111] (Note 12) The plasma treatment method according to any one of the appendices 1 to 10, wherein the step of forming the opening pattern is to control the pressure in the chamber to 100 mTorr or less.

[0112] (Note 13) In the process of etching the interlayer, deposits containing the metal contained in the first metal-containing film are generated. The plasma treatment method according to Appendix 4 or 5, wherein the step of forming the aperture pattern includes removing the deposits adhering to the substrate.

[0113] (Note 14) In the process of etching the interlayer, deposits containing the metal contained in the first metal-containing film are generated. The plasma treatment method according to Appendix 4 or 5, wherein the step of forming the opening pattern includes removing the deposits adhering to the inner wall of the chamber.

[0114] (Note 15) The aforementioned plasma processing apparatus is Opposite the substrate support portion, a first gas injection portion is located on the upper surface of the chamber, A second gas injection port located on the side of the chamber and It has, The processing gas comprises one or more gases containing carbon and one or more gases that do not contain carbon. At least one of the carbon-containing gases is supplied from the first gas injection unit. The plasma treatment method according to any one of the appendices 1 to 14, wherein at least one of the carbon-free gases is supplied from the second gas injection unit.

[0115] (Note 16) The aforementioned plasma processing apparatus is Within the chamber, a first gas injection unit is located on the upper surface of the chamber, A second gas injection unit located on the side of the chamber within the chamber It has, The processing gas includes at least one carbon-containing gas, The at least one carbon-containing gas is supplied into the chamber from the first gas injection unit and the second gas injection unit. The plasma treatment method according to any one of the appendices 1 to 14, wherein the ratio of the flow rate of the at least one carbon-containing gas supplied from the first gas injection unit into the chamber to the flow rate of the at least one carbon-containing gas supplied from the second gas injection unit into the chamber is less than 1.

[0116] (Note 17) The plasma processing apparatus has a plasma generation section above the substrate support section, The step of forming the aforementioned opening pattern is: A step of supplying a source RF signal to the plasma generation unit to generate plasma from the processing gas, A step of supplying a bias signal to the substrate support section and Includes, The plasma processing method according to Appendix 1 to Appendix 16, wherein the effective value of the power of the source RF signal is greater than the effective value of the power of the bias signal.

[0117] (Note 18) The plasma processing method according to Appendix 17, wherein the plasma generation unit includes an electrode positioned opposite the substrate support unit.

[0118] (Note 19) The plasma processing method according to Appendix 17, wherein the plasma generation unit includes an antenna positioned above the substrate support unit.

[0119] (Note 20) The plasma processing method according to any one of the appendices 17 to 19, wherein the effective value of the power of the source RF signal is 500W or more.

[0120] (Note 21) The bias signal is an RF signal, The plasma processing method according to any one of the appendices 17 to 20, wherein the effective value of the power of the bias signal is 200W or less.

[0121] (Note 22) The plasma treatment method according to any one of the appendices 1 to 21, wherein in the step of forming the opening, the first silicon-containing film is etched using the first metal-containing film as a mask.

[0122] (Note 23) The plasma treatment method according to Appendix 4 or Appendix 5, wherein plasma is continuously generated in the chamber from the step of etching the interlayer to the step of forming the opening.

[0123] (Note 24) A plasma processing apparatus comprising a chamber, at least one gas supply unit, a plasma generation unit, and at least one substrate support unit within the chamber, Control unit and Equipped with, The control unit, (a) A step of preparing a substrate having an etching target film including a first silicon-containing film and a first metal-containing film on the substrate support portion, wherein the first metal-containing film includes an opening pattern, (b) A step of etching the film to be etched, Includes, The (b) above includes the step of supplying a processing gas containing one or more gases, including carbon, hydrogen, and fluorine, into the chamber to generate plasma from the processing gas in the chamber, and etching the first silicon-containing film to form the opening pattern in the first silicon-containing film, The ratio of hydrogen atoms to fluorine atoms in the processed gas is controlled to be 0.3 or higher. A plasma processing apparatus configured to perform a process. [Explanation of Symbols]

[0124] 1…Plasma processing apparatus, 2…Control unit, 10…Plasma processing chamber, 12…Plasma generation unit, 13…Central gas injection unit, 14…Antenna, 20…Gas supply unit, 30…Power supply, 31…RF power supply, 32…DC power supply, 52…Peripheral gas injection unit, 101…Dielectric window, 102…Side wall, 111…Main body, 111a…Central region, 111b…Annular region, 131…Central gas injection unit, CF…Carbon-containing film, MF…Metal compound film, MK…Mask film, OP…Opening, RC…Recess, SF…Silicon-containing film, UF…Undercoat film

Claims

1. A plasma processing method performed in a plasma processing apparatus, comprising: The plasma processing method includes: (a) providing a substrate on a substrate support in a chamber, the substrate having a film to be etched, the film including a first silicon-containing film, and a first metal-containing film on the film to be etched, the first metal-containing film including an opening pattern; (b) etching the etching target film; Including, (b) supplying a process gas containing one or more gases containing carbon, hydrogen, and fluorine into the chamber, generating plasma from the process gas in the chamber, and etching the first silicon-containing film to form the opening pattern in the first silicon-containing film; Including, A plasma processing method, wherein the ratio of the number of hydrogen atoms to the number of fluorine atoms contained in the processing gas is 0.3 or more.

2. The plasma processing method of claim 1 , wherein the first metal-containing film is a Sn-containing film.

3. 2. The plasma processing method according to claim 1, wherein the first silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminate film thereof.

4. the etching target film includes an intermediate film on the first silicon-containing film; the step (b) includes a step of etching the intermediate film using the first metal-containing film as a mask; 4. The plasma processing method according to claim 1, wherein the forming of the opening pattern includes etching the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask.

5. 5. The plasma processing method according to claim 4, wherein the intermediate film includes at least one selected from the group consisting of a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film.

6. the intermediate film includes the carbon-containing film and a second silicon-containing film on the carbon-containing film; 6. The plasma processing method according to claim 5, wherein the second silicon-containing film is at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a laminate film thereof.

7. 2. The plasma processing method of claim 1, wherein the process gas includes a hydrogen-containing gas, a carbon-containing gas, and a fluorine-containing gas.

8. 8. The plasma processing method according to claim 7, wherein the carbon-containing gas further contains at least one of hydrogen and fluorine.

9. 8. The plasma processing method according to claim 7, wherein the fluorine-containing gas is a gas that does not contain carbon.

10. 2. The plasma processing method according to claim 1, wherein the ratio of the number of hydrogen atoms to the number of carbon atoms contained in the processing gas is 0.3 or more.

11. 5. The plasma processing method according to claim 4, wherein the pressure in the chamber in the step of forming the opening pattern is lower than the pressure in the chamber in the step of etching the intermediate film.

12. 2. The plasma processing method according to claim 1, wherein the step of forming the opening pattern includes controlling the pressure in the chamber to 100 mTorr or less.

13. In the step of etching the intermediate film, a deposit containing the metal contained in the first metal-containing film is generated, 5. The plasma processing method according to claim 4, wherein the step of forming the opening pattern includes removing the deposits attached to the substrate.

14. In the step of etching the intermediate film, a deposit containing the metal contained in the first metal-containing film is generated, 5. The plasma processing method according to claim 4, wherein the step of forming the opening pattern includes removing the deposits attached to the inner wall of the chamber.

15. The plasma processing apparatus includes: a first gas injection portion disposed on an upper surface of the chamber opposite the substrate support portion; a second gas inlet disposed on a side of the chamber; and the process gas comprises one or more gases containing carbon and one or more gases not containing carbon; at least one of the one or more carbon-containing gases is supplied from the first gas injection part; The plasma processing method of claim 1 , wherein at least one of the one or more gases not containing carbon is supplied from the second gas injection unit.

16. The plasma processing apparatus includes: a first gas injection port disposed within the chamber on an upper surface of the chamber; a second gas injection port disposed within the chamber on a side of the chamber; and the process gas comprises at least one carbon-containing gas; the at least one carbon-containing gas is supplied into the chamber through the first gas inlet and the second gas inlet; 2. The plasma processing method of claim 1, wherein a ratio of a flow rate of the at least one carbon-containing gas supplied from the first gas injection unit to a flow rate of the at least one carbon-containing gas supplied from the second gas injection unit into the chamber is less than 1.

17. the plasma processing apparatus has a plasma generating unit above the substrate supporting unit, The step of forming the opening pattern includes: supplying a source RF signal to the plasma generating unit to generate plasma from the processing gas; providing a bias signal to the substrate support; Including, 2. The plasma processing method of claim 1, wherein the effective value of the power of the source RF signal is greater than the effective value of the power of the bias signal.

18. The plasma processing method according to claim 17 , wherein the plasma generating unit includes an electrode disposed opposite the substrate support unit.

19. The plasma processing method according to claim 17 , wherein the plasma generating unit includes an antenna disposed above the substrate support unit.

20. 20. The plasma processing method of claim 17, wherein the effective value of the power of the source RF signal is 500 W or more.

21. the bias signal is an RF signal; 20. The plasma processing method according to claim 17, wherein the effective value of the power of the bias signal is 200 W or less.

22. 2. The plasma processing method according to claim 1, wherein in the forming of the opening pattern, the first silicon-containing film is etched using the first metal-containing film as a mask.

23. 5. The plasma processing method according to claim 4, wherein plasma is continuously generated in the chamber from the step of etching the intermediate film to the step of forming the opening.

24. at least one plasma processing apparatus including a chamber, at least one gas supply, a plasma generating section, and a substrate support section within the chamber; A control unit; Equipped with The control unit controls the plasma processing apparatus to: (a) a process for preparing a substrate on the substrate support, the substrate having an etching target film including a first silicon-containing film and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; (b) etching the etching target film; configured to cause the step (b) includes a step of supplying a process gas containing one or more gases containing carbon, hydrogen, and fluorine into the chamber, generating plasma from the process gas in the chamber, and etching the first silicon-containing film to form the opening pattern in the first silicon-containing film; The ratio of the number of hydrogen atoms to the number of fluorine atoms contained in the process gas is 0.3 or greater.

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