Substrate processing method and substrate processing device

Abstract

A technique for controlling film formation performed on the surface of a concave portion of an etching target film is provided. A substrate processing method comprises: (a) a process of providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber; (b) a process of exposing the substrate to a first processing gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a process of exposing the substrate to a plasma generated from a second processing gas including a second halogen and a group 14 element to form a second layer including a second halogen and a group 14 element on the surface of the concave portion.

Description

Technology Field

[0001] An exemplary embodiment of the present disclosure relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] Patent Document 1 discloses a technique for forming a carbon film on the surface of a concave portion of an etching target film. Prior art literature

[0003] Japanese Patent Publication No. 2016-21546 The problem to be solved

[0004] The present disclosure provides a technique for controlling film formation performed on the surface of a concave portion of an etching target film. means of solving the problem

[0005] A substrate treatment method according to one exemplary embodiment of the present disclosure comprises: (a) a step of providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber; (b) a step of exposing the substrate to a first treatment gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a step of exposing the substrate to a plasma generated from a second treatment gas including a second halogen and a group 14 element to form a second layer including a second halogen and a group 14 element on the surface of the concave portion. Effects of the invention

[0006] According to one exemplary embodiment of the present disclosure, a technique for controlling film formation performed on the surface of a concave portion of an etching target film can be provided. Brief explanation of the drawing

[0007] Figure 1 is a diagram illustrating an example of the configuration of a plasma processing system. Figure 2 is a diagram illustrating an example of the configuration of an inductively coupled plasma processing device. Figure 3 is a flowchart showing an example of a substrate processing method. Figure 4 is a diagram showing an example of the substrate cross-sectional structure of process ST1. Figure 5 is a diagram showing an example of the substrate cross-sectional structure of process ST2. Figure 6 is a diagram showing an example of the substrate cross-sectional structure of process ST3. Figure 7 is a diagram showing an example of the substrate cross-sectional structure of process ST4. Specific details for implementing the invention

[0008] Each embodiment of the present disclosure will be described below.

[0009] In one exemplary embodiment, a substrate treatment method is provided, comprising: (a) a step of providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber; (b) a step of exposing the substrate to a first treatment gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a step of exposing the substrate to a plasma generated from a second treatment gas including a second halogen and a group 14 element to form a second layer including a second halogen and a group 14 element on the surface of the concave portion.

[0010] In one exemplary embodiment, the surface of the concave portion includes a first region and a second region located above the first region, and the thickness of the second layer formed in the first region is greater than the thickness of the second layer formed in the second region.

[0011] In one exemplary embodiment, the first region includes the surface of the bottom portion of the concave part, and the second region includes the surface of the side wall of the concave part.

[0012] In one exemplary embodiment, (b) the temperature of the substrate support or the temperature of the substrate is controlled to 250°C or lower during the process.

[0013] In one exemplary embodiment, (c) a bias signal is supplied to the substrate support in the process.

[0014] In one exemplary embodiment, (b) plasma is generated from the first processing gas in the process, and a bias signal is not supplied to the substrate support.

[0015] In one exemplary embodiment, (d) after process (c), a process of etching the film to be etched is additionally included.

[0016] In one exemplary embodiment, a cycle including process (c) and process (d) is repeated.

[0017] In one exemplary embodiment, the first treatment gas comprises at least one selected from the group consisting of HF gas, HCl gas, HBr gas, and HI gas.

[0018] In one exemplary embodiment, the second treatment gas comprises at least one selected from the group consisting of CF-based gas, CHF-based gas, CBr-based gas, CHBr-based gas, CCl-based gas, CHCl-based gas, CI-based gas, CHI-based gas, and SiCl-based gas.

[0019] In one exemplary embodiment, the etching target film is a film comprising at least one selected from the group consisting of silicon, carbon, and metal.

[0020] In one exemplary embodiment, (c) 10 in the process 15 / m 3 The substrate is exposed to a plasma having a high electron density.

[0021] In one exemplary embodiment, the etching target film has a plurality of concave portions with different width dimensions.

[0022] In one exemplary embodiment, the concave portion of the etching target film has a trench shape or a hole shape.

[0023] In one exemplary embodiment, a substrate processing apparatus is provided, comprising a chamber, a substrate support disposed within the chamber, a plasma generating unit, and a control unit, wherein the control unit is configured to perform: (a) a control to provide a substrate including an etching target film having a concave portion onto a substrate support within the chamber; (b) a control to expose the substrate to a first processing gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a control to expose the substrate to a plasma generated from a second processing gas including a second halogen and a group 14 element to form a second layer including a second halogen and a group 14 element on the surface of the concave portion.

[0024] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In addition, identical or similar elements in each drawing are given the same reference numerals, and redundant descriptions are omitted. Unless otherwise stated, positional relationships such as up, down, left, and right are described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and actual ratios are not limited to the ratios shown in the drawings.

[0025] An example of a plasma processing system

[0026] FIG. 1 is a drawing for explaining an example configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device (1) and a control unit (2). The plasma processing system is an example of a substrate processing system, and the plasma processing device (1) is an example of a substrate processing device. The plasma processing device (1) includes a plasma processing chamber (10), a substrate support unit (11), and a plasma generation unit (12). The plasma processing chamber (10) has a plasma processing space. In addition, the plasma processing chamber (10) has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas discharge port for discharging gas from the plasma processing space. The gas supply port is connected to a gas supply unit (20) described later, and the gas discharge port is connected to an exhaust system (40) described later. The substrate support unit (11) is disposed within the plasma processing space and has a substrate support surface for supporting a substrate.

[0027] 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 excited plasma (HWP), or a surface wave plasma (SWP). Additionally, various types of plasma generation units may be used, including an alternating current (AC) plasma generation unit and a direct current (DC) plasma generation unit. 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. Accordingly, 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.

[0028] The control unit (2) processes commands executable by a computer to execute various processes described in the present disclosure in the plasma processing device (1). The control unit (2) may be configured to control each element of the plasma processing device (1) to execute various processes described herein. In one embodiment, part or all of the control unit (2) may be included in the plasma processing device (1). The control unit (2) may include, for example, a computer (2a). The computer (2a) may include, for example, a processing unit (CPU: Central Processing Unit) (2a1), a memory unit (2a2), and a communication interface (2a3). The processing unit (2a1) may be configured to perform various control operations by reading a program from the memory unit (2a2) and executing the read program. This program may be stored in the memory unit (2a2) in advance, or may be acquired through a medium when necessary. The acquired program is stored in the memory unit (2a2) and is read from the memory unit (2a2) and executed by the processing unit (2a1). The medium may be various storage media readable by the computer (2a) or a communication line connected to the communication interface (2a3). The memory unit (2a2) may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface (2a3) may communicate with the plasma processing device (1) through a communication line such as a LAN (Local Area Network).

[0029] Hereinafter, an example of the configuration of an inductively coupled plasma processing device is described as an example of a plasma processing device (1). FIG. 2 is a drawing for explaining an example of the configuration of an inductively coupled plasma processing device. The inductively coupled plasma processing device (1) includes a plasma processing chamber (10), a gas supply unit (20), a power source (30), and an exhaust system (40). The plasma processing chamber (10) includes a dielectric window (101). In addition, the plasma processing device (1) includes a substrate support (11), a gas introduction unit, and an antenna (14). The substrate support (11) is placed within the plasma processing chamber (10). The antenna (14) is placed above the plasma processing chamber (10) or above it (i.e., above 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 (11). The plasma treatment chamber (10) is grounded.

[0030] 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 a substrate (W) and a ring-shaped region (111b) for supporting a ring assembly (112). A wafer is an example of a substrate (W). The ring-shaped region (111b) of the main body portion (111) surrounds the central region (111a) of the main body portion (111) when viewed in a planar 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 ring-shaped region (111b) of the main body portion (111) to surround the substrate (W) on the central region (111a) of the main body portion (111). Accordingly, the central region (111a) is also referred to as a substrate support surface for supporting the substrate (W), and the ring-shaped region (111b) is also referred to as a ring support surface for supporting the ring assembly (112).

[0031] In one embodiment, the main body (111) includes a base (1110) and an electrostatic chuck (1111). The base (1110) includes a conductive member. The conductive member of the base (1110) can function as a bias electrode. The electrostatic chuck (1111) is disposed on the base (1110). The electrostatic chuck (1111) includes a ceramic member (1111a) and an electrostatic electrode (1111b) disposed within the ceramic member (1111a). The ceramic member (1111a) has a central region (111a). In one embodiment, the ceramic member (1111a) also has a ring-shaped region (111b). Additionally, another member surrounding the electrostatic chuck (1111), such as a ring-shaped electrostatic chuck or a ring-shaped insulating member, may have a ring-shaped region (111b). In this case, the ring assembly (112) may be placed on a ring-shaped electrostatic chuck or a ring-shaped insulating member, or on both the electrostatic chuck (1111) and the ring-shaped insulating member. Additionally, an RF or DC electrode may be placed within the ceramic member (1111a), in which case the RF or DC electrode functions as a bias electrode. Furthermore, both the conductive member of the base (1110) and the RF or DC electrode may function as two bias electrodes.

[0032] The ring assembly (112) includes one or more ring-shaped members. In one embodiment, the one or more ring-shaped members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0033] Additionally, the substrate support (11) may include a temperature control module configured to control at least one of the electrostatic chuck (1111), ring assembly (112), and 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 disposed within the ceramic member (1111a) of the electrostatic chuck (1111). Additionally, the substrate support (11) may include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate (W) and the central region (111a).

[0034] A gas inlet is configured to introduce at least one processing gas from a gas supply unit (20) into a plasma processing space (10s). In one embodiment, the gas inlet includes a center gas injector (CGI) (13). The center gas injector (13) is positioned above a substrate support (11) and is mounted in a central opening formed in a dielectric window (101). The center gas injector (13) has at least one gas supply port (13a), at least one gas flow path (13b), and at least one gas inlet port (13c). Processing gas supplied through the gas supply port (13a) passes through the gas flow path (13b) and is introduced into the plasma processing space (10s) through the gas inlet port (13c). In addition, the gas introduction section may include one or more side gas injectors (SGI) mounted in one or more openings formed in the side wall (102) in addition to or instead of the central gas injection section (13).

[0035] 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 from each corresponding gas source (21) to the gas introduction unit through each corresponding flow controller (22). Each flow controller (22) may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit (20) may include at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas.

[0036] The power supply (30) includes an RF power supply (31) coupled to the plasma processing chamber (10) through at least one impedance matching circuit. The RF power supply (31) is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to at least one bias electrode and antenna (14). Accordingly, plasma is 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 the plasma generation unit (12). Additionally, by supplying the bias RF signal to at least one bias electrode, a bias potential is generated in the substrate (W), thereby attracting ions in the formed plasma to the substrate (W).

[0037] In one embodiment, the RF power supply (31) includes a first RF generating unit (31a) and a second RF generating unit (31b). The first RF generating unit (31a) is coupled to the antenna (14) through at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for generating plasma. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit (31a) may be configured to generate a plurality of source RF signals having different frequencies. One or more generated source RF signals are supplied to the antenna (14).

[0038] The second RF generation unit (31b) is configured to generate a bias RF signal (bias RF power) by being coupled to at least one bias electrode through at least one impedance matching circuit. 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. One or more of the generated bias RF signals are supplied to at least one bias electrode. In addition, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0039] Additionally, 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 generating unit (32a). In one embodiment, the bias DC generating unit (32a) is configured to be connected to at least one bias electrode to generate a bias DC signal. The generated bias DC signal is applied to at least one bias electrode.

[0040] In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of DC-based 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 generator for generating a sequence of voltage pulses from a DC signal is connected between the bias DC generator (32a) and at least one bias electrode. Thus, the bias DC generator (32a) and the waveform generator constitute a voltage pulse generator. The voltage pulses may have positive polarity or negative polarity. Additionally, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. Furthermore, the bias DC generator (32a) may be additionally installed in the RF power supply (31) or installed in place of the second RF generator (31b).

[0041] The antenna (14) includes one or more coils. In one embodiment, the antenna (14) may include an outer coil and an inner coil positioned coaxially. In this case, the RF power supply (31) may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generator may be connected to both the outer coil and the inner coil, or separate RF generators may be connected to the outer coil and the inner coil, respectively.

[0042] The exhaust system (40) may be connected, for example, to a gas outlet (10e) installed 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 within the plasma processing space (10s) is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0043] <An Example of a Substrate Processing Method>

[0044] FIG. 3 is a flowchart illustrating an example of a substrate processing method (hereinafter also referred to as the "present processing method") related to an exemplary embodiment. As shown in FIG. 3, in one embodiment, the present processing method includes a process ST1 for providing a substrate, a process ST2 for forming a first layer in a concave portion of the substrate, a process ST3 for forming a second layer in a concave portion of the substrate, and an etching process ST4. The processing in each process can be performed in the plasma processing system shown in FIG. 2. Hereinafter, an example is described in which a control unit (2) controls each part of the plasma processing device (1) to perform the present processing method on a substrate (W).

[0045] (Process ST1: Provision of substrate)

[0046] In process ST1, as shown in FIG. 2, a substrate (W) is provided to a plasma treatment chamber (10) (hereinafter also referred to as the 'chamber (10)'). In one embodiment, the substrate (W) is brought into the chamber (10) by a transport arm, placed on a substrate support (11) by a lifter, and maintained by adsorption on the substrate support (11).

[0047] FIG. 4 is a diagram showing an example of a cross-sectional structure of a substrate (W). On the substrate (W), an etching target film (EF) and a mask (MK) are stacked from the bottom in this order on a base film (UF). The substrate (W) can be used to manufacture semiconductor devices. Semiconductor devices include, for example, memory devices such as DRAM and 3D-NAND flash memory, and logic devices.

[0048] The mask (MK) may be a film that functions as a mask during the etching of the etching target film (EF). The mask (MK) may have a sidewall (S1) that defines at least one opening (OP1) on the etching target film (EF). That is, the mask (MK) may have an opening (OP1). The opening (OP1) may be a space above the concave portion (R1) of the etching target film (EF) and may be surrounded by the sidewall (S1) of the mask (MK).

[0049] The opening (OP1) can have any shape when viewed from a planar view of the substrate (W), that is, when viewed from the top to the bottom of FIG. 4. The shape can be, for example, a circle, an ellipse, a rectangle, a line, or a shape that is a combination of one or more of these. The mask (MK) has a plurality of side walls (S1), and the plurality of side walls (S1) may define a plurality of openings (OP1). Each of the plurality of openings (OP1) may have a line shape and may form a line-and-space pattern in parallel at regular or different intervals. Additionally, each of the plurality of openings (OP1) may have a hole shape and may form an array pattern.

[0050] The mask (MK) may be a film comprising at least one selected from the group consisting of silicon, carbon, and metal. The silicon-containing film may be a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polycrystalline silicon film, or a carbon-containing silicon film. The silicon-containing film may be doped with elements such as phosphorus, boron, or nitrogen. The carbon-containing film may be a spin-on carbon (SOC) film, an amorphous carbon (ACL) film, a photoresist film, a tungsten carbide film, or a boron carbide film. The metal-containing film may be a film comprising at least one metal selected from the group consisting of tungsten, molybdenum, ruthenium, titanium, and aluminum. The mask (MK) may be a single-layer mask consisting of one layer, or it may be a multilayer mask consisting of two or more layers.

[0051] The etching target film (EF) may have at least one recess (R1). The recess (R1) may be positioned to correspond to an opening (OP1) of the mask (MK). The recess (R1) may have a side wall (S2) and a bottom portion (B2). The etching target film (EF) may have a plurality of recesses (R1) with different width dimensions. The plurality of recesses (R1) may have a relatively wide width dimension and a relatively narrow width dimension. The recess (R1) may have a trench shape or a hole shape.

[0052] The etching target film (EF) may be a film comprising at least one selected from the group consisting of silicon, carbon, and metal. The silicon-containing film may be a silicon oxide film, a silicon nitride film, a silicon carbonitride film, a polycrystalline silicon film, or a carbon-containing silicon film. The silicon-containing film may be doped with elements such as phosphorus, boron, or nitrogen. The carbon-containing film may be a spin-on carbon (SOC) film, an amorphous carbon (ACL) film, a photoresist film, a tungsten carbide film, or a boron carbide film. The metal-containing film may be a film comprising at least one metal selected from the group consisting of tungsten, molybdenum, ruthenium, titanium, and aluminum.

[0053] The base film (UF) may be a silicon wafer or an organic film, dielectric film, metal film, semiconductor film, etc. formed on a silicon wafer. The base film (UF) may be composed of a plurality of films stacked together.

[0054] Each film constituting the substrate (W) can be formed by any method. The base film (UF), the etching target film (EF), and the mask (MK) can be formed by CVD, ALD, PVD, spin coating, etc. The opening (OP1) of the mask (MK) and the concave portion (R1) of the etching target film (EF) can be formed by etching. The opening (OP1) of the mask (MK) and the concave portion (R1) of the etching target film (EF) may also be formed by lithography. In addition, each film may be a flat film or a film with irregularities. Furthermore, the substrate (W) may additionally have another film under the base film (UF).

[0055] At least part of the process of forming the base film (UF), the etching target film (EF), and the mask (MK) of the substrate (W) may be performed within the chamber (10) as part of process ST1. For example, the opening (OP1) of the mask (MK) and / or the recess (R1) of the etching target film (EF) may be formed through etching in process ST1. In this case, the etching of the mask (MK) and / or the etching target film (EF) in process ST1, and the processes ST2, ST3, and ST4 described later may be performed sequentially within the chamber (10). In one embodiment, the substrate (W) may be provided within the chamber (10) after all or part of the film of the substrate (W) is formed in a device or chamber outside the plasma processing device (1).

[0056] In one embodiment, after the substrate (W) is provided to the substrate support (11), the temperature of the substrate support (11) or the substrate (W) is controlled to a predetermined temperature by a temperature control module. Controlling the temperature of the substrate support (11) or the substrate (W) to a predetermined temperature may include setting the temperature of the heat transfer fluid flowing through the flow path (1110a) or the heater temperature to a predetermined temperature, or setting it to a temperature different from the predetermined temperature. The predetermined temperature may be, for example, 50°C or lower, or -50°C or higher. The predetermined temperature may be room temperature (e.g., 25°C) or lower, or 0°C or lower. Additionally, the timing at which the temperature of the substrate support (11) or the substrate (W) begins to be controlled to a predetermined temperature may be before, after, or simultaneously with the substrate (W) being placed on the substrate support (11). The temperature of the substrate support (11) or the substrate (W) may be changed in each process ST1 to ST4.

[0057] (Process ST2: Formation of the first layer)

[0058] FIG. 5 is a diagram illustrating an example of a cross-sectional structure of a substrate (W) in which a first layer (L1) is formed on the surface of a concave portion (R1) of an etching target film (EF) in process ST2. In one embodiment, in process ST2, the substrate (W) is exposed to a first treatment gas to form a first layer (L1) on the surface of the concave portion (R1).

[0059] In one embodiment, in process ST2, a first processing gas is supplied into the chamber (10) from the central gas injection unit (13) shown in FIG. 2. The temperature of the substrate support (11) or the substrate (W) can be controlled to a first temperature. The first temperature may be in the range of -70°C to 250°C. The first temperature may be 10°C or lower or 0°C or lower. The pressure inside the chamber (10) can be adjusted to a first pressure. The first pressure may be in the range of 1 mTorr to 1000 mTorr or in the range of 1 mTorr to 100 mTorr.

[0060] The first treatment gas may be a gas comprising a first halogen and hydrogen. The first halogen may be any one of F, Cl, Br, and I. The first treatment gas may include hydrogen halide. As hydrogen halide, the first treatment gas may include at least one selected from the group consisting of HF gas, HCl gas, HBr gas, and HI gas. The first treatment gas may be a gas comprising a single gas of the first halogen and a single gas of hydrogen. The first treatment gas may additionally include an inert gas. The inert gas may be a noble gas such as Ar gas, He gas, and Kr gas, or N2 gas.

[0061] A substrate (W) in a chamber (10) is exposed to a first treatment gas, and a first layer (L1) is formed on the surface of a concave portion (R1) as shown in FIG. 5. The first layer (L1) is formed by halogenating the surface of the concave portion (R1) and / or adsorbing hydrogen halide onto the surface of the concave portion (R1). The first layer (L1) may include at least one of a halogenated surface and a surface on which hydrogen halide is adsorbed. The first layer (L1) can suppress the chemical adsorption of dissociated neutral species in the plasma and the formation of their polymers.

[0062] The first processing gas exposed to the substrate (W) in process ST2 may not be in a plasma state. That is, plasma may not be generated from the first processing gas supplied into the chamber (10). Meanwhile, the first processing gas exposed to the substrate (W) in process ST2 may be in a plasma state. That is, plasma may be generated from the first processing gas supplied into the chamber (10) in process ST2. In this case, a source RF signal is supplied from the first RF generation unit (31a) to the antenna (14). As a result, a high-frequency electric field is generated between the antenna (14) and the substrate support (11), and plasma is generated from the processing gas in the plasma processing space (10s). At this time, a bias signal may not be supplied to the substrate support (11).

[0063] (Process ST3: Formation of the second layer)

[0064] FIG. 6 is a diagram illustrating an example of a cross-sectional structure of a substrate (W) in which a second layer (L2) is formed on the surface of a concave portion (R1) of an etching target film (EF) in process ST3. In one embodiment, in process ST3, the substrate (W) is exposed to plasma generated from a second processing gas so that a second layer (L2) is formed on the surface of the concave portion (R1).

[0065] In one embodiment, in process ST3, a second processing gas is supplied into the chamber (10) from the central gas injection unit (13) shown in FIG. 2. The temperature of the substrate support (11) or the substrate (W) can be controlled to a second temperature. The second temperature may be within a range of 250°C or lower and -70°C or higher, and within a range of 80°C or lower and 0°C or higher. The second temperature may be higher than the first temperature. The pressure inside the chamber (10) may be adjusted to a second pressure. The second pressure may be within a range of 1 mTorr or higher and 10,000 mTorr or lower, and within a range of 50 mTorr or higher and 500 mTorr or lower. The second pressure may be greater than the first pressure.

[0066] The second treatment gas may be a gas containing a second halogen and a Group 14 element. The second halogen may be any one of F, Cl, Br, or I. The second halogen included in the second treatment gas may be the same as or different from the first halogen included in the first treatment gas. The Group 14 element may be any one of C, Si, Ge, or Sn. The second treatment gas may include at least one selected from the group consisting of CF-based gas, CHF-based gas, CBr-based gas, CHBr-based gas, CCl-based gas, CHCl-based gas, CI-based gas, CHI-based gas, and SiCl-based gas. The CF-based gas (fluorocarbon gas) may include at least one selected from the group consisting of CF4 gas, C2F2 gas, C2F4 gas, C3F6 gas, C3F8 gas, C4F6 gas, C4F8 gas, and C5F8 gas. The CHF-based gas (hydrofluorocarbon gas) may include at least one selected from CH2F2 gas, CH3F gas, and CHF3 gas. The CCl-based gas may include CCl4 gas. The CHCl-based gas may include at least one selected from CHCl3 gas, CH2Cl2 gas, and CH3Cl gas. The CI-based gas may include CI4 gas. The CHI-based gas may include at least one selected from CHI3 gas, CH2I2 gas, and CH3I gas. The CBr-based gas may include CBr4 gas. The CHBr-based gas may include at least one selected from CHBr3 gas, CH2Br2 gas, and CH3Br gas. The C-containing gas may include any one of Si, Ge, or Sn instead of C. The second treatment gas may include a gas that can be expressed as Xn-Hm-Yl (X=C, Si, Ge, Sn, Y=F, Cl, Br, I, n, m, l are integers greater than or equal to 0). The second treatment gas may additionally include an inert gas.The inert gas may be a noble gas such as Ar gas, He gas and Kr gas, or N2 gas.

[0067] In one embodiment, plasma is generated from a second processing gas supplied into the chamber (10). In this case, a source RF signal is supplied from the first RF generating unit (31a) to the antenna (14), and accordingly, a high-frequency electric field is generated between the antenna (14) and the substrate support (11), thereby generating plasma from the processing gas in the plasma processing space (10s). The source RF signal may have a power of 1 kW or more. The source RF signal may have a power of 1 kW or more and 10 kW or less. The plasma is 10 15 / m 3 It can have a high electron density of more than 10 17 / m 3 It can have a high electron density.

[0068] The first layer (L1) is modified by ions or dissociated neutral species in the plasma, and a second layer (L2) is formed on the surface of the concave portion (R1) as shown in FIG. 6. The second layer (L2) can be a protective film containing a second halogen and a Group 14 element.

[0069] When plasma is generated, a bias signal may be supplied to the substrate support (11). The bias signal may be a bias RF signal supplied from an RF power source (31) or a bias DC signal supplied from a DC power source (32). In this case, a bias potential is generated between the plasma and the substrate (W). Ions or dissociated neutral species in the plasma are attracted to the substrate (W) and supplied into the concave portion (R1).

[0070] Ions of atoms and molecules containing Group 14 elements or dissociated neutral species in the plasma are supplied to the concave portion (R1) in a state where chemical adsorption and the formation of polymer species are suppressed by the hydrogen halide of the first layer (L1). As much as is not consumed at the side wall (S2) of the concave portion (R1), a large amount of ions in the plasma can reach and be deposited at the bottom portion (B2) of the concave portion (R1).

[0071] For example, a second layer (L2) thicker than the side wall (S2) is formed on the bottom portion (B2) of the concave portion (R1).

[0072] (Process ST4: Etching)

[0073] FIG. 7 is a diagram illustrating an example of a cross-sectional structure of a substrate (W) in which a concave portion (R1) of an etching target film (EF) is etched in process ST4. In one embodiment, a concave portion (R1) of an etching target film (EF) is etched in process ST4. Accordingly, etching of the bottom portion (B2) of the concave portion (R1) proceeds in the depth direction, and a deeper concave portion (R1) is formed in the etching target film (EF). Additionally, an opening is formed in the etching target film (EF), and a base film (UF) can be exposed through the opening.

[0074] In one embodiment, in process ST4, an etching gas is supplied into the chamber (10) from the central gas injection unit (13) shown in FIG. 2. The etching gas may include a gas containing carbon and fluorine. The CF-based gas (fluorocarbon gas) may be at least one selected from the group consisting of C4F6 gas, C4F8 gas, C3F8 gas, CF4 gas, C2F2 gas, C2F4 gas, C3F6 gas, and C5F8 gas. CHF-based gases (hydrofluorocarbon gases) include CHF3 gas, CH2F2 gas, CH3F gas, C3H2F4 gas, C4H2F6 gas, C2HF5 gas, C2H2F4 gas, C2H3F3 gas, C2H4F2 gas, C3HF7 gas, C3H2F2 gas, C3H2F6 gas, C3H3F5 gas, C4H5F5 gas, C4H2F8 gas, C5H2F6 gas, and C5H2F10 It may be at least one selected from the group consisting of gas and C5H3F7 gas.

[0075] Plasma can be generated from the etching gas supplied into the chamber (10). In this case, a source RF signal is supplied to the antenna (14), and accordingly, a high-frequency electric field is generated between the antenna (14) and the substrate support (11), thereby generating plasma from the processing gas in the plasma processing space (10s). At this time, a bias signal can be supplied to the substrate support (11). The bias signal may be a bias RF signal supplied from the RF power source (31) or a bias DC signal supplied from the DC power source (32). In this case, a bias potential is generated between the plasma and the substrate (W). Active species such as ions and radicals in the plasma are attracted to the substrate (W), and the bottom portion (B2) of the concave portion (R1) of the etching target film (EF) is etched in the depth direction by said active species.

[0076] The substrate (W) that has completed process ST4 can be removed from the chamber (10) to the outside. In one embodiment, the substrate (W) can be removed from the substrate support (11) to the outside of the chamber (10) by means of a lifter and a transport arm.

[0077] Process ST2 and Process ST3 can be performed as separate processes, and in one example, can be performed continuously. They can also be performed simultaneously.

[0078] The present processing method may repeat a cycle including process ST3 and process ST4 a predetermined number of times. Additionally, the present processing method may repeat a cycle including process ST2, process ST3, and process ST4 a predetermined number of times.

[0079] According to the present exemplary embodiment, the substrate processing method comprises: (a) a process of providing a substrate (W) including an etching target film (EF) onto a substrate support (11) in a chamber (10) (ST1 process); (b) a process of exposing the substrate (W) to a first processing gas including a first halogen and hydrogen to form a first layer (L1) on the surface of a concave portion (R1) (ST2 process); and (c) a process of exposing the substrate (W) to a plasma generated from a second processing gas including a second halogen and a group 14 element to form a second layer (L2) including a second halogen and a group 14 element on the concave portion (R1) (ST3 process). In the ST2 process, the first layer (L1) comprises a halogenated surface and / or a surface on which hydrogen halides are adsorbed.

[0080] By forming a first layer (L1) comprising a halogenated surface and / or a surface adsorbed with hydrogen halides on the surface of the concave portion (R1) of the substrate (W), it is possible to suppress the chemical attachment of plasma ions or dissociated neutral species to the upper portion (e.g., sidewall) of the concave portion (R1) with a high probability. As a result, plasma ions or dissociated neutral species are supplied to the bottom portion (B2) of the concave portion (R1), allowing film formation to be performed at the bottom portion (B2). Through this, the thickness of the second layer (L2) at the bottom portion (B2) (thickness of the protective film) is appropriately formed regardless of the width (width dimension) or depth of the bottom portion (B2). That is, the phenomenon in which the thickness of the second layer (L2) at the bottom portion (B2) depends on the CD (line width) or aspect ratio of the etching target film (EF) (CD (line width) dependency or aspect ratio dependency) can be reduced. Since the second layer (L2) is secured at a deep position of the concave portion (R1), the bowing phenomenon can be suppressed. This allows for control of the film formation performed on the surface of the concave portion of the etching target film.

[0081] According to the present exemplary embodiment, the temperature of the substrate support (11) or the temperature of the substrate (W) is controlled to 50°C or lower during the ST2 process. This increases the amount of hydrogen halide adsorbed on the surface of the concave portion (R1), and as a result, the chemical attachment of the dissociated neutral species of plasma to the sidewall of the concave portion (R1) with a high probability during the ST3 process can be suppressed.

[0082] According to the exemplary embodiment, a bias signal is supplied to the substrate support (11) in the ST3 process, thereby enabling anisotropic incidence of plasma dissociation species, and allowing for proper film formation on the bottom portion (B2) of the concave portion (R1).

[0083] According to the present exemplary embodiment, plasma is generated from the first processing gas in the ST2 process, and a bias signal is not supplied to the substrate support (11). As a result, the amount of hydrogen halide adsorbed on the upper (sidewall) of the concave portion (R1) increases, and as a result, the chemical attachment of dissociated neutral species of plasma to the sidewall of the concave portion (R1) with a high probability can be suppressed in the ST3 process.

[0084] According to the present exemplary embodiment, by exposing the substrate (W) to a plasma having high electron density and high dissociation degree in the ST3 process, a film can be properly formed on the bottom portion (B2) of the concave portion (R1).

[0085] In the above embodiments, the processing method is not limited to an inductively coupled plasma processing device and can be performed in other types of plasma processing devices, for example, a plasma processing device that generates capacitively coupled plasma, a plasma processing device that generates ECR plasma, a plasma processing device that generates helicon wave excited plasma, or a plasma processing device that generates surface wave plasma.

[0086] The present disclosure may include, for example, the following configurations.

[0087] (Appendix 1)

[0088] (a) a process of providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber, and

[0089] (b) a process of exposing the substrate to a first treatment gas comprising a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed, and

[0090] (c) A substrate treatment method comprising the process of exposing the substrate to a plasma generated from a second treatment gas containing a second halogen and a group 14 element to form a second layer containing the second halogen and the group 14 element on the surface of the concave portion.

[0091] (Appendix 2)

[0092] In Book 1,

[0093] The surface of the above-mentioned concave portion includes a first region and a second region located above the first region, and

[0094] A substrate processing method in which the thickness of the second layer formed in the first region is greater than the thickness of the second layer formed in the second region.

[0095] (Appendix 3)

[0096] In Book 2,

[0097] The first region above includes the surface of the bottom portion of the concave portion, and

[0098] A substrate processing method in which the second region above includes the surface of the sidewall of the concave portion.

[0099] (Appendix 4)

[0100] In any one of Appendix 1 to 3,

[0101] A substrate processing method in which, in the above process (b), the temperature of the substrate support or the temperature of the substrate is controlled to 250°C or lower.

[0102] (Appendix 5)

[0103] In any one of Appendix 1 to 4,

[0104] A substrate processing method in which a bias signal is supplied to the substrate support in the above process (c).

[0105] (Appendix 6)

[0106] In any one of Appendix 1 to 5,

[0107] A substrate processing method in which, in the above process (b), plasma is generated from the first processing gas and a bias signal is not supplied to the substrate support.

[0108] (Appendix 7)

[0109] In any one of Appendix 1 to 6,

[0110] (d) A substrate processing method further comprising, after the process (c) above, a process of etching the etching target film.

[0111] (Appendix 8)

[0112] In Book 7,

[0113] A substrate processing method that repeats a cycle including the above (c) process and the above (d) process.

[0114] (Appendix 9)

[0115] In any one of Appendix 1 to 8,

[0116] A substrate treatment method wherein the first treatment gas comprises at least one selected from the group consisting of HF gas, HCl gas, HBr gas, and HI gas.

[0117] (Appendix 10)

[0118] In any one of Appendix 1 to 9,

[0119] A substrate treatment method wherein the second treatment gas comprises at least one selected from the group consisting of CF-based gas, CHF-based gas, CBr-based gas, CHBr-based gas, CCl-based gas, CHCl-based gas, CI-based gas, CHI-based gas, and SiCl-based gas.

[0120] (Appendix 11)

[0121] In any one of Appendix 1 to 10,

[0122] A substrate processing method in which the etching target film is a film comprising at least one selected from the group consisting of silicon, carbon, and metal.

[0123] (Appendix 12)

[0124] In any one of Appendix 1 to 11,

[0125] In the above process (c), 10 15 / m 3 A substrate processing method that exposes the substrate to a plasma having a high electron density.

[0126] (Appendix 13)

[0127] In any one of Appendix 1 to 12,

[0128] A substrate processing method in which the above-mentioned etching target film has a plurality of the above-mentioned concave portions having different width dimensions.

[0129] (Appendix 14)

[0130] In any one of Appendix 1 to 13,

[0131] A substrate processing method in which the concave portion of the etching target film has a trench shape or a hole shape.

[0132] (Appendix 15)

[0133] A substrate processing apparatus comprising a chamber, a substrate support disposed within the chamber, a plasma generating unit, and a control unit,

[0134] The above control unit is,

[0135] (a) control for providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber, and

[0136] (b) a control for exposing the substrate to a first treatment gas comprising a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed, and

[0137] (c) A substrate processing apparatus configured to perform control to form a second layer containing the second halogen and the group 14 element on the surface of the concave portion by exposing the substrate to a plasma generated from a second processing gas containing the second halogen and the group 14 element.

[0138] In the exemplary embodiments above, the plasma treatment apparatus and the plasma treatment method may be modified in various ways without departing from the scope and spirit of the present disclosure. For example, some components of one embodiment may be added to another embodiment within the scope of the ordinary creative ability of those skilled in the art. In addition, some components of one embodiment may be substituted with corresponding components of another embodiment. Explanation of the symbols

[0139] 1: Plasma processing device, 2: Control unit, 10: Plasma processing chamber, 11: Substrate support, 12: Plasma generating unit, W: Substrate, R1: Recess, EF: Etching target film, L1: First layer, L2: Second layer.

Claims

Claim 1 (a) a process of providing a substrate including an etching target film having a concave portion onto a substrate support in a chamber; (b) a process of exposing the substrate to a first treatment gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a process of exposing the substrate to a plasma generated from a second treatment gas including a second halogen and a group 14 element to form a second layer including the second halogen and the group 14 element on the surface of the concave portion. Claim 2 A substrate processing method according to claim 1, wherein the surface of the concave portion comprises a first region and a second region located above the first region, and the thickness of the second layer formed in the first region is greater than the thickness of the second layer formed in the second region. Claim 3 A substrate processing method according to paragraph 2, wherein the first region includes the surface of the bottom portion of the concave portion, and the second region includes the surface of the sidewall of the concave portion. Claim 4 A substrate processing method according to claim 1, wherein in the above process (b), the temperature of the substrate support or the temperature of the substrate is controlled to 250°C or lower. Claim 5 A substrate processing method according to claim 1, wherein in the above process (c), a bias signal is supplied to the substrate support. Claim 6 A substrate processing method according to claim 1, wherein in the process (b) above, plasma is generated from the first processing gas and a bias signal is not supplied to the substrate support. Claim 7 A substrate processing method according to claim 1, wherein (d) after the process of (c), a process of etching the etching target film is additionally included. Claim 8 A substrate processing method according to claim 7, which repeats a cycle including the above (c) process and the above (d) process. Claim 9 A substrate treatment method according to claim 1, wherein the first treatment gas comprises at least one selected from the group consisting of HF gas, HCl gas, HBr gas, and HI gas. Claim 10 A substrate treatment method according to claim 1, wherein the second treatment gas comprises at least one selected from the group consisting of CF-based gas, CHF-based gas, CBr-based gas, CHBr-based gas, CCl-based gas, CHCl-based gas, CI-based gas, CHI-based gas, and SiCl-based gas. Claim 11 A substrate processing method according to claim 1, wherein the etching target film is a film comprising at least one type selected from the group consisting of silicon, carbon, and metal. Claim 12 In claim 1, in the above process (c), 10 15 / m 3 A substrate processing method that exposes the substrate to a plasma having a high electron density. Claim 13 A substrate processing method according to claim 1, wherein the etching target film has a plurality of concave portions having different width dimensions. Claim 14 A substrate processing method according to claim 1, wherein the concave portion of the etching target film has a trench shape or a hole shape. Claim 15 A substrate processing apparatus comprising a chamber, a substrate support member disposed within the chamber, a plasma generating member, and a control member, wherein the control member is configured to perform: (a) a control to provide a substrate including an etching target film having a concave portion onto a substrate support member within the chamber; (b) a control to expose the substrate to a first processing gas including a first halogen and hydrogen to form a first layer on the surface of the concave portion, wherein the first layer comprises at least one of a halogenated surface and a surface on which hydrogen halogen is adsorbed; and (c) a control to expose the substrate to a plasma generated from a second processing gas including a second halogen and a group 14 element to form a second layer including the second halogen and the group 14 element on the surface of the concave portion.

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