Substrate processing method and substrate processing apparatus

Abstract

The substrate processing method includes: a step (a) of preparing a substrate including a first region containing a first material and a second region containing a second material different from the first material; a step (b) in which a metal-containing deposit is formed on the first region using a first plasma generated from a first processing gas containing carbon and / or hydrogen, fluorine, and a metal; (c) after the step (b), modifying at least the surface of the metal-containing deposit using a second plasma generated from a second processing gas different from the first processing gas; and a step (d) in which steps (b) and (c) are repeated.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a substrate processing method and a substrate processing apparatus. Background Art

[0002] Patent Document 1 discloses a method of etching an insulating film using plasma. In this method, etching is performed while forming a conductive layer on the surface of the insulating film during etching. During etching, a plasma generated from a mixed gas of WF 6 and C 4 F 8 is used.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 9-50984 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The present disclosure provides a substrate processing method and a substrate processing apparatus capable of controlling the thickness of a metal-containing deposit.

[0008] Solutions to the Problems

[0009] In one exemplary embodiment, the substrate processing method includes the following steps: step (a) of preparing a substrate including a first region containing a first material and a second region containing a second material different from the first material; step (b) of forming a metal-containing deposit on the first region using a first plasma generated from a first processing gas containing at least one of carbon and hydrogen, fluorine, and a metal; step (c) of modifying at least the surface of the metal-containing deposit using a second plasma generated from a second processing gas different from the first processing gas after step (b); and step (d) of repeating steps (b) and (c).

[0010] Effects of the Invention

[0011] According to one exemplary embodiment, there is provided a substrate processing method and a substrate processing apparatus capable of controlling the thickness of a metal-containing deposit. Brief Description of the Drawings

[0012] Figure 1 is a diagram schematically showing a substrate processing apparatus according to an exemplary embodiment.

[0013] Figure 2 is a diagram schematically showing a substrate processing apparatus according to an exemplary embodiment.

[0014] Figure 3 is a flowchart of a substrate processing method according to an exemplary embodiment.

[0015] Figure 4 is applicable Figure 3 to a partial enlarged cross-sectional view of a substrate which is an example of the method.

[0016] Figure 5 is a cross-sectional view showing a process of a substrate processing method according to an exemplary embodiment.

[0017] Figure 6 is a cross-sectional view showing a process of a substrate processing method according to an exemplary embodiment.

[0018] Figure 7 is a cross-sectional view showing a process of a substrate processing method according to an exemplary embodiment.

[0019] Figure 8 is a cross-sectional view showing a process of a substrate processing method according to an exemplary embodiment.

[0020] Figure 9 is a cross-sectional view showing a process of a substrate processing method according to an exemplary embodiment. Detailed Description of the Embodiments

[0021] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts are denoted by the same reference numerals in the respective drawings.

[0022] Figure 1 is a diagram for explaining a structural example 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 portion 11, and a plasma generation portion 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 portion 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0023] 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 plasma (HWP), surface wave plasma (SWP), or the like. In addition, 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 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.

[0024] The control unit 2 processes computer-executable commands for causing the plasma processing apparatus 1 to execute the various processes described in the present disclosure. The control unit 2 can be configured to control the respective elements 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 implemented by a computer 2a, for example. The processing unit 2a1 can be configured to perform various control operations by reading out a program from the storage unit 2a2 and executing the read-out program. This program may be pre-stored in the storage unit 2a2 or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read out and executed by the processing unit 2a1 from the storage unit 2a2. The medium may be various storage media readable by the computer 2a or may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0025] Next, a structural example of a capacitively coupled plasma processing apparatus, which is an example of the plasma processing apparatus 1, will be described. Figure 2 FIG. is for explaining a structural example of a capacitively coupled plasma processing apparatus.

[0026] 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. In addition, the plasma processing apparatus 1 includes a substrate support portion 11 and a gas introduction portion. The gas introduction portion is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction portion includes a shower head 13. The substrate support portion 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support portion 11. In one embodiment, the shower head 13 constitutes at least a part 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 wall 10a of the plasma processing chamber 10, and the substrate support portion 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support portion 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0027] 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 a ring-shaped region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The ring-shaped 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 disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the ring-shaped 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 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.

[0028] In one embodiment, the main body portion 111 includes a base 1110 and an electrostatic chuck 1111 (chuck: holding disk). 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 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 an annular region 111b. In addition, other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck and an annular insulating member, may also have an annular region 111b. In this case, the ring assembly 112 can be disposed either on the annular electrostatic chuck or the annular insulating member, or on both the electrostatic chuck 1111 and the annular insulating member. Additionally, at least one RF / DC electrode coupled to the RF power supply 31 and / or the DC power supply 32, which will be described later, can also be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Further, the conductive member of the base 1110 and the at least one RF / DC electrode can also function as a plurality of lower electrodes. Additionally, the electrostatic electrode 1111b can also function as a lower electrode. Thus, the substrate support portion 11 includes at least one lower electrode.

[0029] 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 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.

[0030] Additionally, the substrate support portion 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 also 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 in 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 portion 11 may also include a heat transfer gas supply portion configured to supply a heat transfer gas to the gap between the back surface of the substrate W and the central region 111a.

[0031] 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 introduction ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c. In addition, the showerhead 13 includes at least one upper electrode. Further, the gas introduction unit may include one or more side gas injectors (SGI) in addition to the showerhead 13, and the one or more side gas injectors (SGI) are installed in one or more openings formed in the side wall 10a.

[0032] The gas supply unit 20 may also 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 their respective corresponding gas sources 21 to the showerhead 13 via their respective corresponding flow controllers 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. And the gas supply unit 20 may also include at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas.

[0033] 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. Thereby, plasma is generated from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power supply 31 can function as at least a part of the plasma generation unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, thereby attracting the ion component in the formed plasma to the substrate W.

[0034] 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 configured to be coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, thereby generating 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 generation unit 31a may also be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0035] The second RF generation unit 31b is configured to be coupled to at least one lower electrode via at least one impedance matching circuit, thereby generating 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 also be configured to generate a plurality of bias RF signals having different frequencies. The one or more generated bias RF signals are supplied to at least one lower electrode. Additionally, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0036] Additionally, the power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is configured to be connected to at least one lower electrode 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 configured to be connected to at least one upper electrode to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0037] In various embodiments, the first DC signal and the second DC signal may also 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 also have a rectangular, trapezoidal, triangular, or a pulse waveform combining these shapes. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses based on 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. In the case where 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 either a positive or a negative polarity. Additionally, the sequence of voltage pulses may also include one or more positive-polarity voltage pulses and one or more negative-polarity voltage pulses within one cycle. Furthermore, either the first DC generation unit 32a and the second DC generation unit 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided to replace the second RF generation unit 31b.

[0038] The exhaust system 40 can be connected, for example, to the gas outlet 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may also include a pressure regulating valve and a vacuum pump. The pressure regulating valve is used to adjust the pressure within the plasma processing space 10s. The vacuum pump may also include a turbo molecular pump, a dry pump, or a combination thereof.

[0039] Figure 3 is a flowchart of a substrate processing method according to an exemplary embodiment. It can be executed by the plasma processing apparatus 1 of the above embodiment. Figure 3 The substrate processing method MT1 (hereinafter referred to as "method MT1") shown. The method MT1 can be applied to the substrate W.

[0040] Figure 4 is applicable Figure 3 An enlarged partial cross-sectional view of a substrate as an example of the method. As Figure 4 shown, in one embodiment, the substrate W includes a first region R1 and a second region R2. The first region R1 may have at least one recess R1a. The first region R1 may also have a plurality of recesses R1a. Each recess R1a may also be a recess for forming a contact hole. The second region R2 may be present within the recess R1a or may be embedded within the recess R1a. The second region R2 may also be provided so as to cover the first region R1.

[0041] The first region R1 contains a first material. The first material may contain silicon and nitrogen. The first region R1 may also contain silicon nitride (SiN x ). The first region R1 can be, for example, a region formed by film deposition such as CVD or a region obtained by silicon nitridation. The first region R1 includes a first part containing silicon nitride (SiN x ) and a second part containing silicon carbide (SiC). In this case, the first part has the recess R1a.

[0042] The second region R2 contains a second material. The second material is different from the first material. The second material may contain silicon and oxygen. The second region R2 may also contain silicon oxide (SiO x ). The second region R2 can be, for example, a region formed by film deposition such as CVD or a region obtained by silicon oxidation. The second region R2 may have a recess R2a. The recess R2a has a width larger than the width of the recess R1a.

[0043] The substrate W may also include a base region UR and at least one raised region RA provided on the base region UR. The base region UR and the at least one raised region RA are covered by a first region R1. The base region UR may also contain silicon. A plurality of raised regions RA are located on the base region UR. The recess R1a of the first region R1 is located between the plurality of raised regions RA. Each raised region RA may also form a gate region of a transistor.

[0044] The substrate W may also include a mask MK. The mask MK is provided on a second region R2. The mask MK may contain metal or silicon. The mask MK may have an opening OP. The opening OP corresponds to the recess R2a of the second region R2.

[0045] Next, with reference to Figures 3 to 9 , the method MT1 will be described by taking the case where the plasma processing apparatus 1 of the above-described embodiment is used to apply the method MT1 to the substrate W as an example. Figures 3 to 9 FIG. is a cross-sectional view showing one step of a substrate processing method according to an exemplary embodiment. In the case of using the plasma processing apparatus 1, the method MT1 can be executed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 using the control unit 2. In the method MT1, as Figure 2 shown, the substrate W placed on the substrate support portion 11 disposed in the plasma processing chamber 10 is processed.

[0046] As Figure 3 shown, the method MT1 can include a step ST1, a step ST2, a step ST3, a step ST4, and a step ST5. The steps ST1 to ST5 can be executed in sequence. The method MT1 may not include the step ST5.

[0047] (Step ST1)

[0048] In the step ST1, the substrate W as Figure 4 shown is prepared. The substrate W can be supported by the substrate support portion 11 in the plasma processing chamber 10. The substrate W may have become the Figure 4 shown shape as a result of plasma etching, or may have become the Figure 4 shown shape from the beginning when it is provided to the plasma processing chamber 10. In the step ST1, the second region R2 can be provided so as to cover the first region R1. In the step ST1, the second region R2 may also be etched to expose the upper surface of the first region R1 and the upper surface of the second region R2.

[0049] (Step ST2)

[0050] In the step ST2, as Figure 5As shown, a first plasma PL1 generated from a first processing gas is used to form a metal-containing deposit DP on a first region R1. The second region R2 can also be etched using the first plasma PL1. It is difficult to form the metal-containing deposit DP on the second region R2. At the end of process ST2, the supply of the first processing gas is stopped.

[0051] The first processing gas contains at least one of carbon and hydrogen, fluorine, and a metal. The metal can include at least one selected from the group consisting of tungsten and molybdenum. The first processing gas can also contain at least one of a carbon-containing gas and a hydrogen-containing gas, and a metal-containing gas. Fluorine can be contained in the carbon-containing gas, the hydrogen-containing gas, or the metal-containing gas.

[0052] The carbon-containing gas contained in the first processing gas can include at least one selected from the group consisting of hydrocarbon (C x H y ) gas, fluorocarbon (C x F y ) gas, hydrofluorocarbon gas (C x H y F Z ), and carbon monoxide (CO) gas. The hydrocarbon (C x H y ) gas can include at least one selected from the group consisting of CH 4 gas, C 2 H 6 gas, C 2 H 4 gas, C 3 H 8 gas, C 3 H 6 gas, C 4 H 8 gas, and C 4 H 6 gas. The fluorocarbon (C x F y ) gas can include at least one selected from the group consisting of CF 4 gas, C 3 F 6 gas, C 3 F 8 gas, C 4 F 8 gas, and C 4 F 6 gas. The hydrofluorocarbon (C x H y F Z ) gas can include at least one selected from the group consisting of CH 2 F2 Gas, CHF 3 Gas and CH 3 At least one selected from the group consisting of F gas. x, y, and z are natural numbers.

[0053] The hydrogen-containing gas contained in the first processing gas may include at least one selected from the group consisting of hydrogen gas, B 2 H 6 Gas, SiH 4 Gas and HF gas.

[0054] The metal-containing gas contained in the first processing gas may include at least one selected from the group consisting of tungsten halide gas and molybdenum halide gas. The tungsten halide gas may include at least one selected from the group consisting of tungsten hexafluoride (WF 6 ) gas, tungsten hexabromide (WBr 6 ) gas, tungsten hexachloride (WCl 6 ) gas, and WF 5 Cl gas. The metal-containing gas may also include tungsten hexacarbonyl (W(CO) 6 ) gas. The molybdenum halide gas may include at least one selected from the group consisting of molybdenum hexafluoride (MoF 6 ) gas and molybdenum hexachloride (MoCl 6 ) gas.

[0055] The first processing gas may further contain a noble gas. The noble gas may include at least one selected from the group consisting of argon, helium, xenon, and neon.

[0056] The metal-containing deposit DP may also contain a metal oxide. The metal oxide may include at least one selected from the group consisting of tungsten oxide and molybdenum oxide. The metal-containing deposit DP may also contain a metal nitride. The metal nitride may include at least one selected from the group consisting of tungsten nitride and molybdenum nitride.

[0057] (Process ST3)

[0058] In process ST3, as Figure 6 shown, the second plasma PL2 generated from the second processing gas is used to modify at least the surface of the metal-containing deposit DP. The second plasma PL2 can modify a part of the metal-containing deposit DP or the whole of the metal-containing deposit DP. By modifying the metal-containing deposit DP, a modified region MR is formed from the metal-containing deposit DP. The modified region MR may be a metal region or a metal layer. The modified region MR may also be a tungsten layer or a molybdenum layer. It may also be that the second region R2 is not etched by the second plasma PL2. At the end of process ST3, the supply of the second processing gas is stopped.

[0059] The second processing gas in process ST3 is different from the first processing gas in process ST2. The second processing gas may include a hydrogen-containing gas. The hydrogen-containing gas may include at least one selected from the group consisting of hydrogen gas, B 2 H 6 gas, SiH 4 gas, SiH 2 F 2 gas, GeH 4 gas, and HF gas. When the metal-containing deposit DP contains a metal oxide, the second processing gas may include a reducing gas for reducing the metal oxide. Examples of the reducing gas include hydrogen-containing gases. The second processing gas may not contain metal or fluorine.

[0060] The processing time of process ST3 may also be shorter than the processing time of process ST2.

[0061] (Process ST4)

[0062] In process ST4, processes ST2 and ST3 are repeated. In process ST2 of process ST4, as Figure 7 shown, the first plasma PL1 is used to form a metal-containing deposit DP on the modified region MR. In process ST3 of process ST4, as Figure 8 shown, the second plasma PL2 is used to modify at least the surface of the metal-containing deposit DP. Thus, a modified region MR is formed from the metal-containing deposit DP. When a part of the metal-containing deposit DP is modified, the upper part including the surface of the metal-containing deposit DP is modified, and the remaining part (lower part) of the metal-containing deposit DP is not modified. In this case, through process ST4, the metal-containing deposit DP and the modified region MR are alternately laminated.

[0063] (Process ST5)

[0064] In process ST5, as Figure 9 shown, the third plasma PL3 generated from the third processing gas is used to etch the second region R2.

[0065] The third processing gas in process ST5 is different from the first processing gas in process ST2 and the second processing gas in process ST3. The third processing gas may include a fluorine-containing gas. The fluorine-containing gas may include at least one selected from the group consisting of a fluorocarbon gas and a hydrofluorocarbon gas. The fluorocarbon (C x F y ) gas may include at least one selected from the group consisting of CF 4 gas, C 3 F 6 gas, C3 F 8 Gas, C 4 F 8 Gas and C 4 F 6 At least one selected from the group consisting of gas. Hydrofluorocarbon (C x H y F Z ) gas may include at least one selected from the group consisting of CH 2 F 2 gas, CHF 3 gas, and CH 3 F gas. x, y, and z are natural numbers.

[0066] In process ST5, since the first region R1 is already covered by the modified region MR, it is difficult to be etched. The second region R2 is more easily etched than the first region R1. By etching the second region R2, contact holes HL are formed as shown. The contact holes HL correspond to the recesses R1a of the first region R1. In this way, processes ST1 to ST5 can be carried out in the etching of a self-aligned contact (SAC) structure. After removing the second region R2 in the recesses R1a, a metal-containing deposit DP or a modified region MR may remain on the first region R1. In this case, etching of the first region R1 can be suppressed in process ST5. The metal-containing deposit DP or the modified region MR can be removed by cleaning after process ST5. Figure 9

[0067] According to the above method MT1, the modified region MR is formed in process ST3. Then, in process ST2 of process ST4, a metal-containing deposit DP is further formed on the modified region MR. Compared with the case without the modified region MR, a thicker metal-containing deposit DP is formed on the modified region MR. Therefore, by adjusting the number of repetitions of processes ST2 and ST3, the thickness of the metal-containing deposit (metal-containing deposit DP or modified region MR) formed on the first region R1 can be controlled. As a result, a thick enough metal-containing deposit can be formed so that the metal-containing deposit on the first region R1 remains after the etching in process ST5.

[0068] Next, various experiments conducted to evaluate the method MT1 will be described. The experiments described below are not used to limit the present disclosure.

[0069] (First Experiment)

[0070] In the first experiment, a substrate W was prepared, and the substrate W included a first region R1 containing silicon nitride (SiN x ) and a second region R2 containing silicon oxide (SiO) and a second region R2 containing silicon oxide (SiO xThe second region R2 of (). Thereafter, the substrate W was subjected to process ST2 and process ST3 using the plasma processing apparatus 1.

[0071] In process ST2, a first plasma PL1 was generated from a first processing gas. The first plasma PL1 was used to form a metal-containing deposit DP on the first region R1. On the other hand, the second region R2 was etched. The first processing gas was a mixed gas of tungsten hexafluoride (WF 6 ) gas, C 4 F 8 gas, argon (Ar), and hydrogen (H 2 ). The metal-containing deposit DP contained tungsten oxide.

[0072] In process ST3, a second plasma PL2 was generated from a second processing gas. The second plasma PL2 was used to modify the metal-containing deposit DP to form a modified region MR. The second processing gas was hydrogen (H 2 ). The modified region MR was a tungsten layer.

[0073] (Second experiment)

[0074] In the second experiment, after process ST3, the same method as in the first experiment was performed except that processes ST2 and ST3 were repeated once. The number of executions of processes ST2 and ST3 was two each.

[0075] (Third experiment)

[0076] In the third experiment, after process ST3, the same method as in the first experiment was performed except that processes ST2 and ST3 were repeated twice. The number of executions of processes ST2 and ST3 was three each.

[0077] (Experimental results)

[0078] In the first to third experiments, TEM images of the cross-section of the substrate W after the performed method were observed. The thickness of the metal-containing deposit formed on the first region R1 was measured from the TEM images. In the first experiment, the thickness of the metal-containing deposit was 2.7 nm. In the second experiment, the thickness of the metal-containing deposit was 3.5 nm. In the third experiment, the thickness of the metal-containing deposit was 3.9 nm. Therefore, it was found that by adjusting the number of repetitions of processes ST2 and ST3, the thickness of the metal-containing deposit could be controlled.

[0079] The above has described various exemplary embodiments, but is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and changes can be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0080] For example, the substrate W may also include a first region R1 and a second region R2 having an opening on the first region R1. The first region R1 may also include at least one selected from the group consisting of a carbon-containing film and a metal-containing film. The second region R2 may also be a laminated film including a silicon oxide film and a silicon nitride film.

[0081] Hereinafter, various exemplary embodiments included in the present disclosure are described in [E1] to [E8].

[0082] [E1] A substrate processing method, comprising the following steps:

[0083] Step (a), preparing a substrate including a first region containing a first material and a second region containing a second material different from the first material;

[0084] Step (b), forming a metal-containing deposit on the first region using a first plasma generated from a first processing gas containing at least one of carbon and hydrogen, fluorine, and a metal;

[0085] Step (c), after step (b), modifying at least the surface of the metal-containing deposit using a second plasma generated from a second processing gas different from the first processing gas; and

[0086] Step (d), repeating step (b) and step (c).

[0087] The first processing gas may contain carbon and not hydrogen, may contain hydrogen and not carbon, or may contain both carbon and hydrogen.

[0088] According to the above substrate processing method, in step (c), a modified region is formed on at least the surface of the metal-containing deposit. Then, in step (b) of step (d), a metal-containing deposit is further formed on the modified region. Compared with the case without a modified region, a thicker metal-containing deposit is formed on the modified region. Therefore, by adjusting the number of repetitions of step (b) and step (c), the thickness of the metal-containing deposit formed on the first region can be controlled.

[0089] [E2] The substrate processing method according to [E1], wherein

[0090] the second processing gas contains a hydrogen-containing gas.

[0091] [E3] The substrate processing method according to [E1] or [E2], wherein

[0092] the metal-containing deposit contains a metal oxide, and the second processing gas contains a reducing gas for reducing the metal oxide.

[0093] In this case, a metal region can be formed as the modified region.

[0094] [E4] The substrate processing method according to any one of [E1] to [E3], wherein

[0095] the metal includes at least one selected from the group consisting of tungsten and molybdenum.

[0096] [E5] The substrate processing method according to [E4], wherein

[0097] the first processing gas includes at least one selected from the group consisting of tungsten halide gas and molybdenum halide gas.

[0098] [E6] The substrate processing method according to any one of [E1] to [E5], wherein

[0099] the first processing gas includes a fluorine-containing gas.

[0100] [E7] The substrate processing method according to any one of [E1] to [E6], wherein

[0101] the first processing gas includes at least one of a carbon-containing gas and a hydrogen-containing gas.

[0102] [E8] The substrate processing method according to any one of [E1] to [E7], wherein

[0103] the first material includes silicon nitride and the second material includes silicon oxide.

[0104] [E9] The substrate processing method according to any one of [E1] to [E8], wherein

[0105] in the step (b), the second region is etched by the first plasma.

[0106] [E10] The substrate processing method according to any one of [E1] to [E9], wherein

[0107] the first region has a recess and the second region is present in the recess.

[0108] [E11] A substrate processing apparatus, comprising:

[0109] a chamber;

[0110] a substrate support portion for supporting a substrate in the chamber, the substrate including a first region containing a first material and a second region containing a second material different from the first material;

[0111] A gas supply unit configured to supply a first processing gas and a second processing gas different from the first processing gas into the chamber, the first processing gas containing at least one of carbon and hydrogen, fluorine, and a metal;

[0112] A plasma generation unit configured to generate a first plasma and a second plasma from the first processing gas and the second processing gas, respectively, in the chamber; and

[0113] A control unit

[0114] wherein the control unit is configured to control the gas supply unit and the plasma generation unit to perform the following processes:

[0115] Form a metal-containing deposit on the first region using the first plasma,

[0116] After forming the metal-containing deposit, modify at least the surface of the metal-containing deposit using the second plasma,

[0117] Repeat the process of forming the metal-containing deposit and the process of modifying at least the surface of the metal-containing deposit.

[0118] It should be understood from the above description that various embodiments of the present disclosure have been described in this specification for the purpose of explanation, and various changes can be made to the various embodiments of the present disclosure without departing from the scope and gist of the present disclosure. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and gist are represented by the appended claims.

[0119] Description of Reference Numerals

[0120] 1: Plasma processing apparatus; 2: Control unit; 10: Plasma processing chamber; 11: Substrate support unit; 12: Plasma generation unit; 20: Gas supply unit; DP: Metal-containing deposit; PL1: First plasma; PL2: Second plasma; R1: First region; R2: Second region; W: Substrate.

Claims

1. A substrate processing method, comprising the following steps: Step (a), preparing a substrate, the substrate comprising a first region comprising a first material and a second region comprising a second material different from the first material; Step (b) forming a metal-containing deposit on the first region using a first plasma generated from a first process gas containing at least one of carbon and hydrogen, fluorine, and a metal; Step (c), after step (b), modifying at least a surface of the metal-containing deposit using a second plasma generated from a second process gas different from the first process gas; and Step (d), repeating the steps (b) and (c).

2. The substrate processing method according to claim 1, in, The second process gas includes a hydrogen-containing gas.

3. The substrate processing method according to claim 1 or 2, in, The metal-containing deposit comprises a metal oxide, The second process gas includes a reducing gas that reduces the metal oxide.

4. The substrate processing method according to claim 1 or 2, in, The metal includes at least one selected from the group consisting of tungsten and molybdenum.

5. The substrate processing method according to claim 4, in, The first process gas includes at least one selected from the group consisting of a tungsten halide gas and a molybdenum halide gas.

6. The substrate processing method according to claim 1 or 2, in, The first process gas includes a fluorine-containing gas.

7. The substrate processing method according to claim 1 or 2, in, The first process gas includes at least one of a carbon-containing gas and a hydrogen-containing gas.

8. The substrate processing method according to claim 1 or 2, in, The first material comprises silicon nitride, The second material includes silicon oxide.

9. The substrate processing method according to claim 1 or 2, in, In the step (b), the second region is etched by the first plasma.

10. The substrate processing method according to claim 1 or 2, in, The first region has a recessed portion, and the second region exists in the recessed portion.

11. A substrate processing device comprising: Chamber; a substrate support portion for supporting a substrate in the chamber, the substrate comprising a first region including a first material and a second region including a second material different from the first material; a gas supply unit configured to supply a first processing gas and a second processing gas different from the first processing gas into the chamber, wherein the first processing gas contains at least one of carbon and hydrogen, fluorine, and a metal; a plasma generating unit configured to generate a first plasma and a second plasma from the first process gas and the second process gas, respectively, in the chamber; and Control Department, in, The control unit is configured to control the gas supply unit and the plasma generation unit to perform the following processing: using the first plasma to form a metal-containing deposit on the first region, After forming the metal-containing deposit, modifying at least a surface of the metal-containing deposit using the second plasma, The steps of forming the metal-containing deposit and modifying at least the surface of the metal-containing deposit are repeated.

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