Substrate processing method and substrate processing system

Abstract

This substrate processing method comprises the steps of: (a) preparing a substrate, the substrate including an etching target film and a metal-containing mask on the etching target film, the metal-containing mask including at least one opening exposing the etching target film; and (b) forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

Description

Substrate processing method and substrate processing system

[0001] Exemplary embodiments of this disclosure relate to substrate processing methods and substrate processing systems.

[0002] Patent Document 1 discloses a technique for using a halogenated chemical substance in the development of a resist.

[0003] Special Publication No. 2022-538040

[0004] This disclosure provides a technology for improving the shape of a mask.

[0005] In one exemplary embodiment of the present disclosure, a substrate processing method is provided, comprising: (a) a step of preparing a substrate, the substrate comprising a film to be etched and a metal-containing mask on the film to be etched, wherein the metal-containing mask has at least one opening that exposes the film to be etched; and (b) a step of forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

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

[0007] This is a diagram illustrating an example configuration of a plasma processing system. This is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus. This is a flowchart illustrating a substrate processing method according to one exemplary embodiment. This is a diagram illustrating an example of the cross-sectional structure of a substrate W prepared in step ST1. This is an explanatory diagram showing an example of preparing the substrate W in Figure 4 by EUV lithography including EUV exposure. This is an explanatory diagram showing an example of a metal-containing mask MK that can actually be formed on the target region TR of EUV exposure. This is a diagram illustrating an example of the cross-sectional structure of a substrate W after performing step ST2. This is a flowchart illustrating an example of step ST2. This is a diagram illustrating an example of the cross-sectional structure of a substrate W after performing step ST3. This is a block diagram illustrating an example configuration of a substrate processing system SS. This is a block diagram illustrating an example configuration of a substrate processing system PS.

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

[0009] In one exemplary embodiment, a substrate processing method is provided, comprising: (a) a step of preparing a substrate, the substrate comprising a film to be etched and a metal-containing mask on the film to be etched, wherein the metal-containing mask has at least one opening that exposes the film to be etched; and (b) a step of forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

[0010] In one exemplary embodiment, in (b) above, the amount of metal-containing deposit formed on the etchable film is less than the amount of metal-containing deposit formed on the metal-containing mask.

[0011] In one exemplary embodiment, in (b) above, the metal-containing deposit is not formed on the etched film.

[0012] In one exemplary embodiment, the pressure in (b) above is 100 mTorr or more and less than or equal to the vapor pressure of the metal halide.

[0013] In one exemplary embodiment, the temperature in (b) above is 200°C or more and 350°C or less.

[0014] In one exemplary embodiment, the metal-containing mask is an EUV mask.

[0015] In one exemplary embodiment, the metal-containing mask includes at least one selected from the group consisting of Sn, Hf, Ti, and Zr.

[0016] In one exemplary embodiment, the metal halide comprises at least one selected from the group consisting of Sn, Hf, Ti, and Zr, and at least one selected from the group consisting of Cl, Br, and I.

[0017] In one exemplary embodiment, the metal halide is SnCl ４ SnBr ４ and SnI ４ It includes at least one selected from the group consisting of the following.

[0018] In one exemplary embodiment, the first processing gas further comprises an amine group-containing gas.

[0019] In one exemplary embodiment, the amine group-containing gas is NH ３ Contains gas.

[0020] In one exemplary embodiment, (b) includes (b1) a step of exposing the substrate to the first processing gas, and (b2) a step of exposing the substrate to a second processing gas containing an amine group gas.

[0021] In one exemplary embodiment, (b1) and (b2) above are repeated.

[0022] In one exemplary embodiment, the amine group-containing gas in (b2) above is NH ３ Contains gas.

[0023] In one exemplary embodiment, the dimensions of the at least one opening at the end of (b) are smaller than the dimensions of the at least one opening prepared in (a).

[0024] In one exemplary embodiment, the surface roughness of the sidewall of the metal-containing film defining the at least one opening at the end of (b) is less than the surface roughness of the sidewall of the metal-containing film defining the at least one opening prepared in (a).

[0025] In one exemplary embodiment, the metal-containing mask comprises a plurality of openings that expose the film to be etched, wherein the uniformity of the dimensions of the plurality of openings at the end of (b) is greater than the uniformity of the dimensions of the plurality of openings prepared in (a).

[0026] In one exemplary embodiment, the metal-containing mask has a plurality of openings that expose the film to be etched, and the variation in surface roughness of the sidewalls of the metal-containing film defining the plurality of openings at the end of (b) is smaller than the variation in surface roughness of the sidewalls of the metal-containing film defining the plurality of openings prepared in (a).

[0027] In one exemplary embodiment, the film to be etched is a silicon-containing film.

[0028] In one exemplary embodiment, (c) further includes a step of etching the film to be etched with plasma generated from a third processing gas after (b).

[0029] In one exemplary embodiment, the third processing gas includes a fluorine-containing gas.

[0030] In one exemplary embodiment, a substrate processing system is provided, comprising one or more substrate processing apparatuses and a control unit, wherein the control unit is configured to perform controls on the one or more substrate processing apparatuses, including (a) a control for preparing a substrate, wherein the substrate comprises a film to be etched and a metal-containing mask on the film to be etched, the metal-containing mask having at least one opening that exposes the film to be etched, and (b) a control for forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

[0031] 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.

[0032] <Example of the configuration of a plasma processing system>FIG. 1 is a diagram for explaining an example of the 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. Further, 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 in the plasma processing space and has a substrate support surface for supporting a substrate.

[0033] 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 capacitively coupled plasma (CCP), inductively coupled plasma (ICP), ECR plasma (Electron-Cyclotron-resonance plasma), helicon wave excited plasma (HWP: Helicon Wave Plasma), or surface wave plasma (SWP: Surface Wave Plasma), etc. Also, various types of plasma generation units including an AC (Alternating Current) plasma generation unit and a DC (Direct Current) plasma generation unit may be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency within the range of 100 kHz to 10 GHz. Therefore, the AC signal includes RF (Radio Frequency) signals and microwave signals. In one embodiment, the RF signal has a frequency within the range of 100 kHz to 150 MHz.

[0034] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 can be configured to control each element of the plasma processing apparatus 1 to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is realized by, for example, a computer 2a. The processing unit 2a1 can be configured to read a program from the storage unit 2a2 and perform various control operations by executing the read program. This program may be stored in the storage unit 2a2 in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 and executed. The medium may be various storage media readable by the computer 2a, or may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), a SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0035] Next, a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1 will be described. FIG. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0036] The capacitively 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 apparatus 1 also includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is located inside the plasma processing chamber 10. The shower head 13 is located above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side walls 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[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 a 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 lower 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 power supply 31 and / or DC power supply 32 described later, may be placed within the ceramic member 1111a. In this case, at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or DC signal, described later, is supplied to at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and at least one RF / DC electrode may function as multiple lower electrodes. Also, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower 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 showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlet ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s through the plurality of gas inlet ports 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0042] 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 shower head 13 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 at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas.

[0043] 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 lower electrode and / or at least one upper electrode. 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 the plasma generation unit 12. Furthermore, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ionic components in the formed plasma can be drawn into the substrate W.

[0044] 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 at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF 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 at least one lower electrode and / or at least one upper electrode.

[0045] The second RF generation unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same 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 generated bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0046] 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 first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generation unit 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0047] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from the DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Thus, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. When the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. 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 period. The first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0048] 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.

[0049] <Example of Substrate Processing Method> Figure 3 is a flowchart of an example of a substrate processing method (hereinafter also referred to as "this processing method") according to one exemplary embodiment. As shown in Figure 3, this processing method includes a step ST1 of preparing a substrate, a step ST2 of forming a metal-containing deposit on the substrate, and a step ST3 of etching the substrate. In one embodiment, the processing in each step may be performed in the plasma processing apparatus 1 shown in Figure 2. In the following, a case in which the control unit 2 controls each part of the plasma processing apparatus 1 to perform this processing method on the substrate W will be described as an example.

[0050] (Step ST1: Substrate preparation) In step ST1, a substrate W is prepared on the substrate support 11. The substrate W comprises an etching target film EF and a metal-containing mask MK on the etching target film EF. The metal-containing mask MK comprises at least one opening OP that exposes the etching target film EF. The substrate W may be used in the manufacture of semiconductor devices. Semiconductor devices include, for example, memory devices such as DRAM and 3D-NAND flash memory, and logic devices.

[0051] Figure 4 shows an example of the cross-sectional structure of the substrate W prepared in step ST1. As illustrated in Figure 4, the substrate W may be constructed by stacking an etching target film EF and a metal-containing mask MK on an arbitrary underlay film UF in that order.

[0052] In one embodiment, the underlayer film UF is a silicon wafer or an organic film, dielectric film, metal film, semiconductor film, etc. formed on a silicon wafer. For example, the dielectric film may contain SiN, etc. For example, the metal film may contain TiN, TaN, W, WSi, WC, etc. The underlayer film UF may be composed of multiple films stacked on top of each other.

[0053] In one embodiment, the film EF to be etched may be a silicon-containing film. Examples of silicon-containing films include spin-on-glass (SOG) films, Si-containing anti-reflective films (SiARC), silicon oxide films, silicon nitride films, silicon oxynitride films, silicon carbide films, silicon carbonitride films, polycrystalline silicon films, and amorphous silicon films. In one embodiment, the silicon-containing film may contain at least one element selected from the group consisting of H, P, N, and B. As an example, the film EF to be etched includes at least one silicon-containing film selected from the group consisting of SOG films, silicon carbide films, and silicon oxide films. In one embodiment, the film EF to be etched includes at least one silicon-containing film selected from the group consisting of SOG films, silicon carbide films, and silicon oxide films, and the silicon-containing film may be exposed at the opening OP. As an example, the film EF to be etched includes a silicon carbide film, and the silicon carbide film may be exposed at the opening OP. The etchable film EF and the optional undercoat film UF constituting the substrate W may be formed by methods such as CVD, atomic layer deposition (ALD), and spin coating. The etchable film EF and the undercoat film UF may be flat films or films with irregularities.

[0054] The metal-containing mask MK is formed on the etched film EF and has at least one opening OP. The metal-containing mask MK may contain at least one selected from the group consisting of Sn, Hf, Ti, and Zr. In one embodiment, the metal-containing mask MK may be a photoresist. For example, the metal-containing mask MK may be a photoresist exposed to extreme ultraviolet light (EUV exposure) (EUV resist). In one embodiment, the metal-containing mask MK may be formed by etching.

[0055] The opening OP exposes the film EF to be etched. In one embodiment, the metal-containing mask MK has an opening pattern, which may define at least one opening OP on the film EF to be etched. The opening OP may constitute an opening pattern that includes any shape when viewed in plan view of the substrate W, that is, when the substrate W is viewed from top to bottom in Figure 4. For example, the opening pattern of the metal-containing mask MK may include at least one shape selected from the group consisting of circles, ellipses, rectangles, lines, and combinations of one or more of these shapes. The metal-containing mask MK has a plurality of side walls, which may define a plurality of openings OP. In one embodiment, the side walls of the metal-containing mask MK may be perpendicular to the film EF to be etched, and may be inclined at an acute or obtuse angle. The side walls of the metal-containing mask MK may also have irregularities. Even if the sidewalls of the metal-containing mask MK prepared in step ST1 are inclined and / or have irregularities as described above, these inclinations and / or irregularities tend to be reduced by going through step ST2, which will be described later.

[0056] In one embodiment, the aperture pattern of the metal-containing mask MK may be formed by lithography. In this case, for example, first, a photoresist film is formed on the film to be etched EF. Next, using an exposure mask, light (e.g., an EUV excimer laser) is selectively irradiated onto the photoresist film to expose the aperture pattern to the photoresist film. Then, the photoresist film after exposure is developed. This may form a metal-containing mask MK having an aperture pattern.

[0057] Figure 5 is an explanatory diagram showing an example of preparing the substrate W shown in Figure 4 by EUV lithography, including EUV exposure. In the example in Figure 5, the metal-containing mask MK is an EUV resist. The EUV resist may typically include metal oxide resist (MOR). In the EUV exposure in Figure 5, EUV light irradiated from an EUV light source (not shown) is reflected by a mirror (not shown) and controlled to reach the target region TR of the photoresist film PM as reflected light RL. On the other hand, irradiation of the target region TR with EUV light may be insufficient, as follows: In EUV exposure, if the EUV light is absorbed by a mirror or the like before reaching the target region TA of the photoresist film PM, the irradiation of EUV light may be insufficient. Also, when the dose of EUV light is reduced to lower power consumption, the irradiation of EUV light may be insufficient. As shown in Figure 5, when EUV light irradiation is insufficient (see dashed arrow in Figure 5), the irradiation area IR, where EUV light is actually irradiated, tends to be smaller than the target area TR. In that case, as shown in Figure 6, the metal-containing mask MK formed after exposure and development also tends to be smaller than the target area TR. As a result, the aperture dimension CD1 in the metal-containing mask MK tends to be larger than the target aperture dimension CD2, and the shape obtained by subsequent etching (step 3 described later) may be different from the target shape. This tendency can be eliminated by performing steps ST2 and later, which will be described later.

[0058] In step ST1, the substrate W may be prepared in a plasma processing chamber 10 (hereinafter also referred to as "chamber 10"). In one embodiment, the substrate W is transported into the chamber 10 by a transport arm, placed on a substrate support 11 by a lifter, and held by suction on the substrate support 11, for example as shown in Figure 2.

[0059] (Step ST2: Formation of metal-containing deposits on the substrate) In step ST2, metal-containing deposits MD are formed on the metal-containing mask MK (hereinafter, this process is also referred to as the "deposition process"). In one embodiment, the metal-containing deposits MD can be formed by supplying a first processing gas containing a metal halide from the gas supply unit 20 into the plasma processing space 10s. Note that plasma is not necessarily required for the deposition process. That is, the first processing gas containing a metal halide can be supplied from the gas supply unit 20 into the plasma processing space 10s, and this processing gas can be directly reacted with the surface of the metal-containing mask MK, etc., to form the metal-containing deposits MD.

[0060] In one embodiment, the metal contained in the metal halide is the same as at least one of the metals contained in the metal-containing mask MK. For example, the metal in the metal halide may include at least one selected from the group consisting of Sn, Hf, Ti, and Zr. In one embodiment, the halogen contained in the metal halide includes at least one selected from the group consisting of Cl, Br, and I. In one embodiment, the metal halide is SnCl ４ SnBr ４ and SnI ４ It includes at least one selected from the group consisting of the following.

[0061] In one embodiment, in step ST2, the amount of metal-containing deposit MD formed on the etched film EF is less than the amount of metal-containing deposit MD formed on the metal-containing mask MK. In one embodiment, in step ST2, the metal-containing deposit MD is formed thicker on the metal-containing mask MK than on the etched film EF. In one embodiment, in step ST2, the metal-containing deposit MD is not formed on the etched film EF.

[0062] Figure 7 shows an example of the cross-sectional structure of the substrate W after performing process ST2. In the example in Figure 7, a metal-containing deposit MD is formed so as to cover the surface of the metal-containing mask MK. As a result, in the example in Figure 7, the opening dimension CD2 of the opening OP at the end of process ST2 is smaller than the opening dimension CD1 of the opening OP prepared in process ST1. As described above, even if the opening dimension CD1 of the metal-containing mask MK prepared in process ST1 is larger than a predetermined opening dimension CD2, the opening dimension CD1 of the metal-containing mask MK can be reduced by going through process ST2. In addition to this, or instead, even if the roughness (surface roughness) of the side wall defining the opening OP of the metal-containing mask MK prepared in process ST1 exceeds a predetermined roughness, the roughness of the side wall can be reduced by going through process ST2.

[0063] Furthermore, even if the uniformity of the opening dimensions of the metal-containing mask MK is less than a predetermined uniformity when multiple openings are formed in the metal-containing mask MK prepared in step ST1, the uniformity of the opening dimensions of the metal-containing mask MK can be improved by going through step ST2. In other words, even if the variation in the roughness of the side walls defining the openings OP of the metal-containing mask MK is greater than a predetermined variation when multiple openings are formed in the metal-containing mask MK prepared in step ST1, the variation in the roughness of the side walls can be reduced by going through step ST2.

[0064] The uniformity of the opening dimensions can be evaluated based on the degree of unevenness on the side walls of the metal-containing mask MK, and as an example, it can be evaluated based on the method described in the examples below.

[0065] Furthermore, in the example in Figure 7, the metal-containing deposit MD is not formed on the etched film EF. Thus, the metal halides used in the deposition process tend to selectively chemically adsorb and penetrate the metal-containing mask MK onto the etched film EF (hereinafter, this property is also referred to as "selectivity"). Therefore, the deposition process can increase the size of the metal-containing mask MK while suppressing its influence on the etched film EF. Increasing the size of the metal-containing mask MK includes increasing the aperture size of the aperture OP or increasing the thickness of the metal-containing mask MK. As described above, when forming a metal-containing deposit MD by deposition, the size of the metal-containing mask MK can be increased without performing pretreatment such as forming an inhibitory film on the etched film EF. Here, in EUV exposure, a certain dose is required to deliver a sufficient amount of EUV light to the target region TR, but even when this dose is reduced, the narrowing of the metal-containing mask MK can be eliminated. Thus, by reducing the dose (process load) of EUV exposure while improving the mask shape after development, it is possible to contribute to power saving and improved throughput in lithography. In addition, since metal-containing deposits (MD) are less likely to form on open areas of the etched film EF, permeability in those open areas can also be ensured.

[0066] In one embodiment, the pressure in step ST2 is 100 mTorr or higher and less than or equal to the vapor pressure of the metal halide. When the above pressure is 100 mTorr or higher, the deposition rate of the metal-containing deposit MD tends to improve. When the above pressure is less than or equal to the vapor pressure of the metal halide, the handling of the metal halide in the deposition process tends to improve. As an example, the pressure that is less than or equal to the vapor pressure of the metal halide may be 200 mTorr or lower.

[0067] In one embodiment, the temperature in step ST2 is 200°C or higher and 350°C or lower. When the temperature is 200°C or higher, the deposition rate of the metal-containing deposit MD tends to increase. When the temperature is 350°C or lower, the selectivity tends to increase. In one embodiment, the temperature in step ST2 may be adjusted by heating means. As an example, the heating means may include a stage heater, a wall heater, a lamp, and the like. These heating means may be provided in the plasma processing apparatus 1.

[0068] In one embodiment, the first processing gas further includes an amine group-containing gas. The amine group contained in the amine group-containing gas nitrides the surface of the metal-containing mask MK, and thus the selectivity tends to increase. In one embodiment, the amine group-containing gas is NH ３ gas.

[0069] FIG. 8 is a flowchart showing an example of step ST2. As shown in FIG. 8, step ST2 may include a step ST21 of exposing the substrate W to the first processing gas and a step ST22 of exposing the substrate W to the second processing gas containing the amine group-containing gas. In one embodiment, step ST22 may be performed before step ST21, and then step ST21 may be performed. In one embodiment, steps ST21 and ST22 may be repeated. In one embodiment, the amine group-containing gas in step ST22 may contain NH ３ gas. By appropriately adjusting the order of steps ST21 and ST22 and / or repeating them, at least one selected from the group consisting of (i) the amount (deposition amount) of the metal-containing deposit MD formed on the metal-containing mask MK, (ii) the shape of the opening pattern, (iii) the opening dimension, and (iv) the uniformity of the opening dimension can be adjusted.

[0070] In one embodiment, step ST2 may be performed by exposing the substrate W to the first processing gas, or may be performed by exposing the substrate W to the plasma generated from the first processing gas. In one embodiment, the first processing gas is O ３It may include gases, etc. In one embodiment, electromagnetic wave energy, light energy, and other energy may be supplied to the first processing gas to promote its reactivity.

[0071] (Step ST3: Etching the substrate) In step ST3, the film EF to be etched is etched. In step ST3, after step ST2, the film EF to be etched is etched by plasma generated from the third processing gas through the metal-containing mask MK and the metal-containing deposit MD.

[0072] In one embodiment, step ST3 may include supplying a third processing gas to the chamber 10 and generating plasma from the third processing gas. The third processing gas may be supplied to the chamber 10 from, for example, a gas supply unit 20 via a gas inlet 13c of a central gas injection unit 13. In one embodiment, the third processing gas includes a gas capable of selectively etching the etchable film EF from a metal-containing mask MK and a metal-containing deposit MD. As an example, the third processing gas may include a fluorine-containing gas. Examples of fluorine-containing gases include HF-based gases, CF-based gases, and CHF-based gases. In one embodiment, the third processing gas may include a chlorine-containing gas. The third processing gas may also include a noble gas. The pressure inside the chamber 10 may be adjusted to a set pressure. The set pressure may be 15 mTorr or more and 200 mTorr or less.

[0073] Next, plasma is generated from the third processing gas in the chamber 10. In one embodiment, a source RF signal is supplied to the antenna 14, thereby generating a high-frequency electric field 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 be supplied to the substrate support 11. The bias signal may be a bias RF signal supplied from the RF power supply 31 or a bias DC signal supplied from the DC power supply 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 etching target film EF is etched by these active species. In one embodiment, the bias signal may have a power of 300 W to 1500 W, or a power of 300 W to 900 W.

[0074] Figure 9 shows an example of the cross-sectional structure of the substrate W after performing step ST3. In step ST3, the metal-containing mask MK and the metal-containing deposit MD function as masks. That is, the portion of the film EF to be etched that is exposed to the opening OP is selectively etched by active species in the plasma. As a result, the recess RC is formed as shown in Figure 9.

[0075] In one embodiment, while step ST3 is being performed, the temperature of the substrate support 11 may be adjusted to a set temperature by a temperature control module. The set temperature while step ST3 is being performed may be, for example, -30°C to 120°C. In one embodiment, the set temperature while step ST3 is being performed may be greater than 120°C. In one example, adjusting or maintaining the temperature of the substrate support 11 includes adjusting or maintaining the temperature of the heat transfer fluid flowing through the channel 1110a to the set temperature or a temperature different from the set temperature. In one example, adjusting or maintaining the temperature of the substrate support 11 includes controlling the pressure of the heat transfer gas (e.g., He) between the electrostatic chuck 1111 and the back surface of the substrate W. The timing at which the heat transfer fluid begins to flow through the channel 1110a may be before, after, or simultaneously with the substrate W being placed on the substrate support 11. Furthermore, in this processing method, the temperature of the substrate support 11 may be adjusted to a set temperature before step ST3 or before step ST1. In other words, the substrate W may be prepared on the substrate support 11 after the temperature of the substrate support 11 has been adjusted to the set temperature. In one embodiment, instead of controlling the substrate support 11 to the set temperature, the substrate W may be controlled to the set temperature. Controlling the temperature of the substrate W to the set temperature includes setting the temperature of the substrate support 11, the heat transfer fluid flowing through the flow path 1110a, and / or the heater temperature to the set temperature, or to a temperature different from the set temperature. In this processing method, the temperature of the substrate support 11 or the substrate W may be changed in each of steps ST1, ST2, and ST3. In subsequent steps of this processing method, the temperature of the substrate support 11 may be maintained at the set temperature adjusted in step ST1, ST2, or ST3.

[0076] In one embodiment, during the formation process of the recess RC, the bottom of the recess reaches the underlying film UF, thereby exposing at least a portion of the underlying film UF to the opening OP. Step ST3 may be terminated after at least a portion of the underlying film UF is exposed, or before (for example, immediately before) at least a portion of the underlying film UF is exposed. Alternatively, step ST3 may be terminated when a given stop condition is met. The stop condition may be, for example, the etching time, or the depth of the recess RC. At the end of etching, the operation may be the cessation of the supply of the source RF signal, bias RF signal, bias DC signal, and third processing gas.

[0077] <Modification Example 1> Figure 10 is a block diagram illustrating an example configuration of the substrate processing system SS. Process ST2 may be performed in the substrate processing system SS. The substrate processing system SS comprises a first carrier station CS1, a first processing station PS1, a first interface station IS1, an exposure apparatus EX, a second interface station IS2, a second processing station PS2, a second carrier station CS2, and a control unit CT.

[0078] The first carrier station CS1 loads and unloads the first carrier C1 between the first carrier station CS1 and an external system of the substrate processing system SS. The first carrier station CS1 has a mounting platform that includes a plurality of first mounting plates ST1. The first carrier C1 is placed on each first mounting plate ST1, either containing a plurality of substrates W or empty. The first carrier C1 has a housing capable of housing a plurality of substrates W inside. In one example, the first carrier C1 is a FOUP (Front Opening Unified Pod).

[0079] Furthermore, the first carrier station CS1 transports the substrate W between the first carrier C1 and the first processing station PS1. The first carrier station CS1 further comprises a first transport device HD1. The first transport device HD1 is provided in the first carrier station CS1 so as to be located between the mounting table and the first processing station PS1. The first transport device HD1 transports and transfers the substrate W between the first carrier C1 on each first mounting plate ST1 and the second transport device HD2 of the first processing station PS1. The substrate processing system SS may further comprise a load lock module. The load lock module may be provided between the first carrier station CS1 and the first processing station PS1. The load lock module can switch the internal pressure between atmospheric pressure and vacuum. "Atmospheric pressure" may be the internal pressure of the first transport device HD1. "Vacuum" is a pressure lower than atmospheric pressure, and can be, for example, a moderate vacuum of 0.1 Pa to 100 Pa. The inside of the second transport device HD2 can be atmospheric pressure or a vacuum. The load lock module may, for example, transport the substrate W from the first transport device HD1, which is at atmospheric pressure, to the second transport device HD2, which is in a vacuum, and also transport the substrate W from the second transport device HD2, which is in a vacuum, to the first transport device HD1, which is at atmospheric pressure.

[0080] The first processing station PS1 performs various processes on the substrate W. In one embodiment, the first processing station PS1 comprises a pre-processing module PM1, a resist film formation module PM2, and a first heat treatment module PM3 (hereinafter collectively referred to as the "first substrate processing module PMa"). The first processing station PS1 also has a second transport device HD2 for transporting the substrate W. The second transport device HD2 transports and transfers the substrate W between two designated first substrate processing modules PMa, and between the first processing station PS1 and the first carrier station CS1 or the first interface station IS1.

[0081] In the pre-treatment module PM1, the substrate W is subjected to pre-treatment. In one embodiment, the pre-treatment module PM1 includes a temperature control unit for adjusting the temperature of the substrate W, a high-precision temperature control unit for adjusting the temperature of the substrate W with high precision, and a base film formation unit for forming part or all of the base film on the substrate W. In one embodiment, the pre-treatment module PM1 includes a surface modification unit for performing surface modification treatment on the substrate W. Each treatment unit of the pre-treatment module PM1 may include a heat treatment device (not shown), a plasma treatment device 1 (see Figures 1 and 2), and / or a liquid treatment device (not shown).

[0082] In the resist film formation module PM2, a resist film is formed on the substrate W. In one embodiment, the resist film formation module PM2 includes a dry coating unit. The dry coating unit forms a resist film on the substrate W using a dry process such as vapor deposition. In one example, the dry coating unit includes a CVD apparatus or ALD apparatus for chemically depositing the resist film onto the substrate W placed in a chamber, or a PVD apparatus for physically depositing the resist film. The dry coating unit may also be a heat treatment apparatus or a plasma treatment apparatus 1.

[0083] In one embodiment, the resist film formation module PM2 includes a wet coating unit. The wet coating unit forms a resist film on the substrate W using a wet process such as liquid-phase deposition. In one example, the wet coating unit may be a liquid processing device.

[0084] In one embodiment, an example of the resist film formation module PM2 includes both a wet coating unit and a dry coating unit.

[0085] In the first heat treatment module PM3, the substrate W is subjected to heat treatment. In one embodiment, the first heat treatment module PM3 includes one or more of the following: a post-apply bake (PAB) unit that performs heat treatment on the substrate W on which a resist film is formed; a temperature control unit that adjusts the temperature of the substrate W; and a high-precision temperature control unit that adjusts the temperature of the substrate W with high precision. Each of these units may have one or more heat treatment devices. In one example, the multiple heat treatment devices may be stacked. Each heat treatment may be performed at a predetermined temperature using a predetermined gas.

[0086] The first interface station IS1 has a third transport device HD3. The third transport device HD3 transports and transfers substrates W between the first processing station PS1 and the exposure device EX. The third transport device HD3 has a housing for housing the substrates W, and the temperature, humidity, pressure, etc. inside the housing may be configured to be controllable.

[0087] The exposure apparatus EX exposes the resist film on the substrate W using an exposure mask (reticle). The exposure apparatus EX may be, for example, an EUV exposure apparatus having a light source that generates EUV light.

[0088] The second interface station IS2 has a fourth transport device HD4. The fourth transport device HD4 transports and transfers substrates W between the exposure device EX and the second processing station PS2. The fourth transport device HD4 has a housing for housing the substrates W, and the temperature, humidity, pressure, etc. inside the housing may be configured to be controllable.

[0089] The second processing station PS2 performs various processes on the substrate W. In one embodiment, the second processing station PS2 comprises a second heat treatment module PM4, a measurement module PM5, a developing module PM6, and a third heat treatment module PM7 (hereinafter collectively referred to as the "second substrate processing module PMb"). The second processing station PS2 also has a fifth transport device HD5 for transporting the substrate W. The fifth transport device HD5 transports and transfers the substrate W between two designated second substrate processing modules PMb, and between the second processing station PS2 and the second carrier station CS2 or the second interface station IS2.

[0090] In the second heat treatment module PM4, the substrate W is subjected to heat treatment. In one embodiment, the heat treatment module PM4 includes one or more of the following: a Post Exposure Bake (PEB) unit for heat treatment of the substrate W after exposure, a temperature control unit for adjusting the temperature of the substrate W, and a high-precision temperature control unit for adjusting the temperature of the substrate W with high precision. Each of these units may have one or more heat treatment devices. In one example, the multiple heat treatment devices may be stacked. Each heat treatment may be performed at a predetermined temperature using a predetermined gas.

[0091] In the measurement module PM5, various measurements are performed on the substrate W. In one embodiment, the measurement module PM5 includes a mounting stage on which the substrate W is placed, an imaging device, an illumination device, and an imaging unit including various sensors (temperature sensor, reflectance measuring sensor, etc.). The imaging device may be, for example, a CCD camera that images the appearance of the substrate W. Alternatively, the imaging device may be a hyperspectral camera that spectrally separates light into wavelengths and takes images. The hyperspectral camera can measure one or more of the pattern shape, dimensions, film thickness, composition, and film density of the resist film.

[0092] In the developing module PM6, the substrate W is subjected to a developing process. In one embodiment, the developing module PM6 includes a dry developing unit that performs dry developing on the substrate W. The dry developing unit may be, for example, a heat treatment apparatus or a plasma treatment apparatus 1. In one embodiment, the developing module PM6 includes a wet developing unit that performs wet developing on the substrate W. The wet developing unit may be, for example, a liquid treatment apparatus. In one embodiment, the developing module PM6 includes both a dry developing unit and a wet developing unit.

[0093] In the third heat treatment module PM7, the substrate W is subjected to heat treatment. In one embodiment, the third heat treatment module PM7 includes one or more of the following: a post-bake (PB) unit for heat-treating the substrate W after development, a temperature control unit for adjusting the temperature of the substrate W, and a high-precision temperature control unit for adjusting the temperature of the substrate W with high precision. Each of these units may have one or more heat treatment devices. In one example, the multiple heat treatment devices may be stacked. Each heat treatment may be performed at a predetermined temperature using a predetermined gas.

[0094] The second carrier station CS2 loads and unloads the second carrier C2 between the second carrier station CS2 and an external system of the substrate processing system SS. The configuration and functions of the second carrier station CS2 may be the same as those of the first carrier station CS1 described above.

[0095] The control unit CT controls each component of the substrate processing system SS to execute a given process on the substrate W. The control unit CT stores a recipe that sets the process procedure, process conditions, transport conditions, etc., and controls each component of the substrate processing system SS to execute a given process on the substrate W according to the recipe. The control unit CT may perform some or all of the functions of each control unit (control unit 2 shown in Figures 1 and 2).

[0096] In this modified example, the module in the substrate processing system SS in which process ST2 is performed and the module in the substrate processing system SS in which process ST1 is performed may be the same or different. Similarly, the module in the substrate processing system SS in which process ST2 is performed and the module in the substrate processing system SS in which process ST3 is performed may be the same or different. As an example, process ST2 may be performed on the substrate W after development in the development module PM6 without removing the substrate W (at the development module PM6). As another example, process ST2 may be performed on the substrate W after PB in the third heat treatment module PM7 without removing the substrate W (at the third heat treatment module PM7). Furthermore, as yet another example, after performing process ST1, the substrate W may be removed to PM8 (not shown) which may be provided in the second processing station PS2, and process ST2 may be performed at PM8. Furthermore, as an example, the substrate W after PB in the third heat treatment module PM7 may be transported to a heat treatment apparatus or plasma treatment apparatus 1 via a third interface station IS3 (not shown), and process ST2 may be performed in the heat treatment apparatus or plasma treatment apparatus 1.

[0097] <Modification 2> Figure 11 is a block diagram illustrating an example configuration of a substrate processing system PS. Process ST2 may be performed in the substrate processing system PS. The substrate processing system PS includes substrate processing chambers PM10 to PM60 (hereinafter collectively referred to as "substrate processing modules PMc"), a transport module TM, load lock modules LLM1 and LLM2 (hereinafter collectively referred to as "load lock modules LLM"), a loader module LM, and load ports LP1 to LP3 (hereinafter collectively referred to as "load ports LP"). The control unit CT controls each component of the substrate processing system PS to perform a given process on the substrate W. The substrate processing chamber in which process ST2 is performed and the substrate processing chamber in which process ST1 is performed may be the same or different. Also, the substrate processing chamber in which process ST2 is performed and the substrate processing chamber in which process ST3 is performed may be the same or different.

[0098] The substrate processing module PMc performs processes such as etching, trimming, film deposition, annealing, doping, lithography, cleaning, and ashing on the substrate W. Part of the substrate processing module PMc may be a capacitively coupled plasma processing apparatus as shown in Figure 2. That is, at least one of the substrate processing chambers PM10 to PM60 may be coupled to a capacitively coupled plasma generation unit. Part of the substrate processing module PMc may be a measurement module that measures, for example, the film thickness of a film formed on the substrate W or the dimensions of a pattern formed on the substrate W using an optical method.

[0099] The transport module TM has a transport device for transporting substrates W, and transports substrates W between substrate processing modules PMc or between substrate processing modules PMc and load lock module LLM. The substrate processing modules PMc and load lock module LLM are arranged adjacent to the transport module TM. The transport module TM, substrate processing modules PMc, and load lock module LLM are spatially separated or connected by gate valves that can be opened and closed.

[0100] Load lock modules LLM1 and LLM2 are installed between the transport module TM and the loader module LM. The load lock modules LLM can switch the internal pressure between atmospheric pressure and vacuum. "Atmospheric pressure" may be the external pressure of each module included in the substrate processing system PS. "Vacuum" is a pressure lower than atmospheric pressure, for example, a medium vacuum of 0.1 Pa to 100 Pa. The load lock modules LLM transport the substrate W from the loader module LM, which is at atmospheric pressure, to the transport module TM, which is in vacuum, and also transport the substrate from the transport module TM, which is in vacuum, back to the loader module LM, which is at atmospheric pressure.

[0101] The loader module LM has a transport device for transporting substrates W, and transports the substrates W between the load lock module LLM and the load port LP. Inside the load port LP, a FOUP (Front Opening Unified Pod) capable of holding, for example, 25 substrates W, or an empty FOUP can be placed. The loader module LM takes the substrates W from the FOUP inside the load port LP and transports them to the load lock module LLM. Conversely, the loader module LM takes the substrates W from the load lock module LLM and transports them to the FOUP inside the load port LP.

[0102] The control unit CT controls each component of the substrate processing system PS to execute a given process on the substrate W. The control unit CT stores a recipe that sets the process procedure, process conditions, transport conditions, etc., and controls each component of the substrate processing system PS to execute a given process on the substrate W according to the recipe. The control unit CT may also perform some or all of the functions of the control unit 2 shown in Figure 1 or Figure 2.

[0103] In this modified example, step ST2 may be performed in substrate processing chamber PM10. In this case, steps ST1 and ST3 may also be performed in substrate processing chamber PM10, and after steps ST1 and ST2 are performed in substrate processing chamber PM10, step ST3 may be performed in substrate processing chamber PM20. Also in this modified example, step ST2 may be performed in substrate processing chamber PM20. In this case, steps ST1 and ST3 may be performed in substrate processing chamber PM10, and steps ST1 and ST3 may be performed in substrate processing chamber PM10 and substrate processing chamber PM30, respectively.

[0104] <Examples> Next, examples of the processing method will be described. This disclosure is not limited in any way by the following examples.

[0105] (Example 1A) An apparatus having the same configuration as the plasma processing apparatus 1 shown in Figure 2 was prepared. A substrate was placed on the substrate support part 11 of the apparatus. This substrate had the same configuration as the substrate W shown in Figure 4. A Si-containing anti-reflective film was used as the film to be etched EF. A tin oxide-containing film was used as the metal-containing mask MK. Multiple openings OP that expose the film to be etched EF were formed in the metal-containing mask MK. That is, the multiple openings OP were formed to constitute a line and space pattern. Hereafter, the line width, LWR, and LER were evaluated as the average value of the measurement results for the multiple openings OP (the same applies to subsequent examples).

[0106] As a deposition process, SnCl is applied to the above substrate W. ４ Gas was supplied at 200°C and 2 Torr for 2 minutes. Comparing the line width of the substrate W before and after the deposition process, the line width after deposition increased by 10.5% compared to the value before deposition. From this result, it was confirmed that the opening size after deposition decreased compared to before deposition. Furthermore, upon examining the open area of ​​the substrate W (surface of the etched film EF) after deposition, a small amount of Sn-containing deposits was observed. In other words, the amount of metal-containing deposits MD formed on the etched film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0107] (Example 1B) In Example 1B, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1A, except that the deposition process was modified as follows. Specifically, in Example 1B, the deposition process involved applying (i) SnCl to the substrate W. ４ The gas is supplied at 200°C and 2 Torr for 5 seconds, then (ii)O ３Gas was supplied at 200°C and 2 Torr for 5 seconds. Steps (i) and (ii) were repeated 100 times to complete the deposition process. The line width after deposition increased by 21.6% compared to the value before deposition. From these results, it was confirmed that the opening size after deposition decreased compared to before deposition. Furthermore, upon inspection of the open area of ​​the substrate W (surface of the etched film EF) after deposition, a small amount of Sn-containing deposits was observed. That is, the amount of metal-containing deposits MD formed on the etched film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0108] (Example 1C) In Example 1C, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1B, except that the deposition process was modified as follows. Specifically, in Example 1C, the deposition process involved (i) SnCl onto the substrate W. ４ The gas is supplied at 200°C and 2 Torr for 5 seconds, followed by (ii) NH ３ Gas was supplied at 200°C and 2 Torr for 5 seconds. Steps (i) and (ii) were repeated 100 times to complete the deposition process. The line width after deposition increased by 14.2% compared to the value before deposition. From these results, it was confirmed that the aperture size after deposition decreased compared to before deposition. In addition, the LWR after deposition decreased by 5.0% compared to the value before deposition. Furthermore, the LER after deposition decreased by 4.3% compared to the value before deposition. From these results, it was confirmed that the uniformity of the aperture size after deposition was higher than before deposition. When the open area of ​​the substrate W (surface of the etched film EF) was examined after deposition, a small amount of Sn-containing deposits was observed. That is, the amount of metal-containing deposits MD formed on the etched film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0109] (Example 2A) In Example 2A, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1A, except that the etching target film EF was changed to a SiC film. Comparing the line width of the substrate W before and after the deposition process, the line width after the deposition process increased by 6.2% compared to the value before the deposition process. From this result, it was confirmed that the aperture size after the deposition process decreased compared to before the deposition process. In addition, the LWR after the deposition process decreased by 6.0% compared to the value before the deposition process. Furthermore, the LER after the deposition process decreased by 6.8% compared to the value before the deposition process. From these results, it was confirmed that the uniformity of the aperture size after the deposition process was higher than before the deposition process. When the open area of ​​the substrate W (surface of the etching target film EF) was examined after the deposition process, a small amount of Sn-containing deposits was observed. That is, the amount of metal-containing deposits MD formed on the etching target film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0110] (Example 2B) In Example 2B, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1B, except that the etchable film EF was changed to a SiC film. Comparing the line width of the substrate W before and after the deposition process, the line width after the deposition process increased by 23.0% compared to the value before the deposition process. From this result, it was confirmed that the opening dimensions after the deposition process decreased compared to before the deposition process. Furthermore, when the open area of ​​the substrate W (surface of the etchable film EF) was examined after the deposition process, a small amount of Sn-containing deposits was observed. That is, the amount of metal-containing deposits MD formed on the etchable film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0111] (Example 2C) In Example 2C, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1C, except that the etching target film EF was changed to a SiC film. Comparing the line width of the substrate W before and after the deposition process, the line width after the deposition process increased by 16.1% compared to the value before the deposition process. From these results, it was confirmed that the aperture size after the deposition process decreased compared to before the deposition process. In addition, the LWR after the deposition process decreased by 3.9% compared to the value before the deposition process. Furthermore, the LER after the deposition process decreased by 3.4% compared to the value before the deposition process. From these results, it was confirmed that the uniformity of the aperture size after the deposition process was higher than before the deposition process. When the open area of ​​the substrate W (surface of the etching target film EF) was examined after the deposition process, no Sn-containing deposits were observed.

[0112] (Example 2D) In ​​Example 2D, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1B, except that the deposition process in Example 2C was modified as follows. Specifically, in Example 2D, the deposition process involved applying (i) SnCl to the substrate W. ４ The gas is supplied at 300°C and 2 Torr for 5 seconds, followed by (ii) NH ３ Gas was supplied at 300°C and 2 Torr for 5 seconds. Steps (i) and (ii) were performed 100 times to complete the deposition process. Comparing the line width of the substrate W before and after the deposition process, the line width after deposition increased by 16.1% compared to the value before deposition. From these results, it was confirmed that the aperture size after deposition decreased compared to before deposition. In addition, the LWR after deposition decreased by 6.3% compared to the value before deposition. Furthermore, the LER after deposition decreased by 5.1% compared to the value before deposition. From these results, it was confirmed that the uniformity of the aperture size after deposition was higher than before deposition. When the open area of ​​the substrate W (surface of the etched film EF) was examined after deposition, no Sn-containing deposits were observed.

[0113] (Example 3A) In Example 3A, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1A, except that the etching target film EF was changed to an SOG film. Comparing the lines on the substrate W before and after the deposition process, the lines after the deposition process increased by 11.6% compared to the value before the deposition process. From these results, it was confirmed that the aperture size after the deposition process decreased compared to before the deposition process. In addition, the LWR after the deposition process decreased by 7.1% compared to the value before the deposition process. Furthermore, the LER after the deposition process decreased by 6.0% compared to the value before the deposition process. From these results, it was confirmed that the uniformity of the aperture size after the deposition process was higher than before the deposition process. When the open area of ​​the substrate W (surface of the etching target film EF) was examined after the deposition process, no Sn-containing deposits were observed.

[0114] (Example 3B) In Example 3B, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 1B, except that the etching target film EF was changed to an SOG film. Comparing the lines on the substrate W before and after the deposition process, the lines after the deposition process increased by 24.5% compared to the value before the deposition process. From this result, it was confirmed that the opening dimensions after the deposition process decreased compared to before the deposition process. Furthermore, when the open area of ​​the substrate W (surface of the etching target film EF) was examined after the deposition process, a small amount of Sn-containing deposits was observed. That is, the amount of metal-containing deposits MD formed on the etching target film EF was less than the amount of metal-containing deposits MD formed on the metal-containing mask MK.

[0115] (Example 3C) In Example 3C, the pattern shape before and after the deposition process was evaluated in the same manner as in Example 3A, except that the deposition process was modified as follows. Specifically, in Example 3C, the deposition process involved applying (i) SnCl to the substrate W. ４ The gas is supplied at 300°C and 2 Torr for 5 seconds, followed by (ii) NH ３Gas was supplied at 300°C and 2 Torr for 5 seconds. Steps (i) and (ii) were repeated 100 times to complete the deposition process. Comparing the lines on the substrate W before and after the deposition process, the lines after deposition increased by 26.5% compared to the values ​​before deposition. From these results, it was confirmed that the aperture size after deposition decreased compared to before deposition. In addition, the LWR after deposition decreased by 8.6% compared to the values ​​before deposition. Furthermore, the LER after deposition decreased by 5.6% compared to the values ​​before deposition. From these results, it was confirmed that the uniformity of the aperture size after deposition was higher than before deposition. When the open area of ​​the substrate W (surface of the etched film EF) was examined after deposition, no Sn-containing deposits were observed.

[0116] Embodiments of this disclosure further include the following embodiments:

[0117] (Note 1) A substrate processing method comprising: (a) a step of preparing a substrate, wherein the substrate comprises a film to be etched and a metal-containing mask on the film to be etched, and the metal-containing mask has at least one opening that exposes the film to be etched; and (b) a step of forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

[0118] (Note 2) The substrate processing method according to Note 1, wherein, in (b) above, the amount of metal-containing deposit formed on the etchable film is less than the amount of metal-containing deposit formed on the metal-containing mask.

[0119] (Note 3) The substrate processing method according to Note 1, wherein, in (b) above, the metal-containing deposit is not formed on the etchable film.

[0120] (Note 4) The substrate processing method according to any one of Notes 1 to 3, wherein the pressure in (b) is 100 mTorr or more and less than or equal to the vapor pressure of the metal halide.

[0121] (Note 5) The substrate processing method according to any one of Notes 1 to 4, wherein the temperature in (b) above is 200°C or more and 350°C or less.

[0122] (Note 6) The substrate processing method according to any one of Notes 1 to 5, wherein the metal-containing mask is an EUV mask.

[0123] (Note 7) The substrate processing method according to any one of Notes 1 to 6, wherein the metal-containing mask includes at least one selected from the group consisting of Sn, Hf, Ti, and Zr.

[0124] (Note 8) The substrate processing method according to any one of Notes 1 to 7, wherein the metal halide comprises at least one selected from the group consisting of Sn, Hf, Ti, and Zr, and at least one selected from the group consisting of Cl, Br, and I.

[0125] (Note 9) The metal halide is SnCl ４ SnBr ４ and SnI ４ A substrate processing method according to any one of the appendices 1 to 8, comprising at least one selected from the group consisting of the following.

[0126] (Note 10) The substrate processing method according to any one of Notes 1 to 9, wherein the first processing gas further comprises an amine group-containing gas.

[0127] (Note 11) The amine group-containing gas is NH ３ A substrate processing method described in Appendix 10, including gas.

[0128] (Note 12) The substrate processing method according to any one of Notes 1 to 11, wherein (b) comprises: (b1) a step of exposing the substrate to the first processing gas; and (b2) a step of exposing the substrate to a second processing gas containing an amine group gas.

[0129] (Note 13) The substrate processing method described in Note 12, wherein (b1) and (b2) are repeated.

[0130] (Note 14) The amine group-containing gas is NH ３ A substrate processing method according to Appendix 12 or Appendix 13, including gas.

[0131] (Note 15) The substrate processing method according to any one of Notes 1 to 14, wherein the dimensions of the at least one opening at the end of (b) are smaller than the dimensions of the at least one opening prepared in (a).

[0132] (Note 16) The substrate processing method according to any one of Notes 1 to 15, wherein the surface roughness of the side wall of the metal-containing film defining the at least one opening at the end of (b) is smaller than the surface roughness of the side wall of the metal-containing film defining the at least one opening prepared in (a).

[0133] (Note 17) The substrate processing method according to any one of Notes 1 to 16, wherein the metal-containing mask has a plurality of openings that expose the film to be etched, and the uniformity of the dimensions of the plurality of openings at the end of (b) is higher than the uniformity of the dimensions of the plurality of openings prepared in (a).

[0134] (Note 18) The substrate processing method according to any one of Notes 1 to 17, wherein the metal-containing mask has a plurality of openings that expose the film to be etched, and the variation in surface roughness of the side walls of the metal-containing film defining the plurality of openings at the end of (b) is smaller than the variation in surface roughness of the side walls of the metal-containing film defining the plurality of openings prepared in (a).

[0135] (Note 19) The substrate processing method according to any one of Notes 1 to 18, wherein the film to be etched is a silicon-containing film.

[0136] (Note 20) (c) A substrate processing method according to any one of Notes 1 to 19, further comprising the step of etching the film to be etched with plasma generated from a third processing gas after (b).

[0137] (Note 21) The substrate processing method according to Note 20, wherein the third processing gas includes a fluorine-containing gas.

[0138] (Note 22) A substrate processing system comprising one or more substrate processing devices and a control unit, wherein the control unit is configured to execute controls on the one or more substrate processing devices, including: (a) a control for preparing a substrate, wherein the substrate comprises an etching target film and a metal-containing mask on the etching target film, and the metal-containing mask has at least one opening that exposes the etching target film; and (b) a control for forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

[0139] The embodiments described above are for illustrative purposes only and are not intended to limit the scope of this disclosure. Each embodiment can be modified in various ways without departing from the scope and spirit of this disclosure. For example, some components of one embodiment can be added to other embodiments, or some components of one embodiment can be replaced with corresponding components of other embodiments.

[0140] 1...Plasma processing apparatus, 2...Control unit, 10...Plasma processing chamber, 11...Substrate support unit, 20...Gas supply unit, 30...Power supply, MK...Metal-containing mask, TR...Target area, IR...Irradiation area, EF...Etching target film, OP...Aperture, MD...Metal-containing deposit, W...Substrate

Claims

1. A substrate processing method comprising: (a) a step of preparing a substrate, wherein the substrate comprises a film to be etched and a metal-containing mask on the film to be etched, the metal-containing mask having at least one opening that exposes the film to be etched; and (b) a step of forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

2. The substrate processing method according to claim 1, wherein, in (b) above, the amount of metal-containing deposit formed on the etchable film is less than the amount of metal-containing deposit formed on the metal-containing mask.

3. The substrate processing method according to claim 1, wherein, in (b) above, the metal-containing deposit is not formed on the film to be etched.

4. The substrate processing method according to claim 1, wherein the pressure in (b) is 100 mTorr or more and less than or equal to the vapor pressure of the metal halide.

5. The substrate processing method according to claim 1, wherein the temperature in (b) is 200°C or more and 350°C or less.

6. The substrate processing method according to claim 1, wherein the metal-containing mask is an EUV mask.

7. The substrate processing method according to claim 1, wherein the metal-containing mask includes at least one selected from the group consisting of Sn, Hf, Ti, and Zr.

8. The substrate processing method according to claim 1, wherein the metal halide comprises at least one selected from the group consisting of Sn, Hf, Ti, and Zr, and at least one selected from the group consisting of Cl, Br, and I.

9. The metal halide is SnCl ４ SnBr ４ and SnI ４ The substrate processing method according to claim 1, comprising at least one selected from the group consisting of the following.

10. The substrate processing method according to claim 1, wherein the first processing gas further comprises an amine group-containing gas.

11. The amine group-containing gas is NH ３ A substrate processing method according to claim 10, comprising a gas.

12. The substrate processing method according to claim 1, wherein (b) comprises: (b1) a step of exposing the substrate to the first processing gas; and (b2) a step of exposing the substrate to a second processing gas containing an amine group gas.

13. The substrate processing method according to claim 12, wherein (b1) and (b2) are repeated.

14. The amine group-containing gas is NH ３ A substrate processing method according to claim 12, comprising a gas.

15. The substrate processing method according to claim 1, wherein the dimensions of the at least one opening at the end of (b) are smaller than the dimensions of the at least one opening prepared in (a).

16. The substrate processing method according to claim 1, wherein the surface roughness of the side wall of the metal-containing film defining the at least one opening at the end of (b) is less than the surface roughness of the side wall of the metal-containing film defining the at least one opening prepared in (a).

17. The substrate processing method according to claim 1, wherein the metal-containing mask has a plurality of openings that expose the film to be etched, and the uniformity of the dimensions of the plurality of openings at the end of (b) is higher than the uniformity of the dimensions of the plurality of openings prepared in (a).

18. The substrate processing method according to claim 1, wherein the metal-containing mask has a plurality of openings that expose the film to be etched, and the variation in surface roughness of the side walls of the metal-containing film defining the plurality of openings at the end of (b) is smaller than the variation in surface roughness of the side walls of the metal-containing film defining the plurality of openings prepared in (a).

19. The substrate processing method according to claim 1, wherein the film to be etched is a silicon-containing film.

20. (c) A substrate processing method according to any one of claims 1 to 19, further comprising the step of etching the film to be etched with plasma generated from a third processing gas after (b).

21. The substrate processing method according to claim 20, wherein the third processing gas includes a fluorine-containing gas.

22. A substrate processing system comprising one or more substrate processing apparatuses and a control unit, wherein the control unit is configured to perform the following controls on the one or more substrate processing apparatuses: (a) a control for preparing a substrate, wherein the substrate comprises a film to be etched and a metal-containing mask on the film to be etched, and the metal-containing mask has at least one opening that exposes the film to be etched; and (b) a control for forming a metal-containing deposit on the metal-containing mask using a first processing gas containing a metal halide.

Images