Plasma processing apparatus and plasma processing method

Abstract

Provided is a technique for increasing the film forming rate of a precoat. Provided is a plasma processing apparatus. The plasma processing apparatus comprises a chamber, a gas supply unit, a substrate support unit disposed in the chamber, a plasma generation unit configured to generate plasma in the chamber, and a control unit. The control unit is configured to execute: (a) control for supplying a first processing gas from the gas supply unit to the chamber, the first processing gas including an alkyne gas having three or more carbon atoms; (b) control for generating plasma from the first processing gas by means of the plasma generation unit to form a precoat including a carbon-containing film on a constituent member in the chamber; (c) control for providing a substrate on the substrate support unit; (d) control for supplying a second processing gas from the gas supply unit to the chamber; and (e) control for generating plasma from the second processing gas by means of the plasma generation unit and performing plasma processing on the substrate.

Description

Plasma processing apparatus and plasma processing method

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and a plasma processing method.

[0002] Patent Document 1 discloses a technique for pre-coating a plasma processing chamber.

[0003] Special Publication No. 2008-505490

[0004] The present disclosure provides a technique for improving the deposition rate of the precoat.

[0005] In one exemplary embodiment of the present disclosure, there is provided a plasma processing apparatus including: a chamber; a gas supply unit; a substrate support disposed within the chamber; a plasma generation unit configured to generate plasma in the chamber; and a controller configured to: (a) control a first process gas to be supplied from the gas supply unit to the chamber, where the first process gas includes an alkyne gas having three or more carbon atoms; (b) control a plasma generation unit to generate plasma from the first process gas to form a precoat including a carbon-containing film on a component within the chamber; (c) control a substrate to be provided on the substrate support unit; (d) control a second process gas to be supplied from the gas supply unit to the chamber; and (e) control a plasma generation unit to generate plasma from the second process gas to plasma process the substrate.

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

[0007] It is a diagram for explaining a configuration example of a plasma processing apparatus. It is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. It is a flowchart showing an example of a method MT. It is a diagram showing an example of a cross-sectional structure of a component CP at the end of process ST2.

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided, comprising: a chamber; a gas supply; a substrate support disposed within the chamber; a plasma generation unit configured to generate plasma in the chamber; and a controller configured to: (a) control a first process gas to be supplied from the gas supply unit to the chamber, the first process gas comprising an alkyne gas having three or more carbon atoms; (b) control a plasma generation unit to generate plasma from the first process gas to form a precoat including a carbon-containing film on a component within the chamber; (c) control a substrate to be provided on the substrate support; (d) control a second process gas to be supplied from the gas supply unit to the chamber; and (e) control a plasma generation unit to generate plasma from the second process gas to plasma process the substrate.

[0010] In one exemplary embodiment, the alkyne gas comprises at least one gas selected from the group consisting of propyne gas, butyne (1-butyne, 2-butyne) gas, and pentyne (1-pentyne, 2-pentyne) gas.

[0011] In one exemplary embodiment, the first process gas comprises at least 50% by volume of an alkyne gas.

[0012] In one exemplary embodiment, the first process gas comprises at least 95% by volume of an alkyne gas.

[0013] In one exemplary embodiment, the first process gas further comprises a halogen-containing gas.

[0014] In one exemplary embodiment, the halogen-containing gas is a chlorine-containing gas and / or a fluorine-containing gas.

[0015] In one exemplary embodiment, the halogen-containing gas is Cl ２ Gas, HF gas, NF ３ Gas, C ４ F ６ Gas, CF ４ Gas and PF ３ The gas is at least one gas selected from the group consisting of:

[0016] In one exemplary embodiment, in (b), a bias signal is provided to the substrate support.

[0017] In one exemplary embodiment, (b) is performed with a substrate disposed on the substrate support that is different from the substrate provided in (c).

[0018] In one exemplary embodiment, (b) is performed with a surface of the substrate support exposed to the space within the chamber.

[0019] In one exemplary embodiment, the component within the chamber is the part exposed to the plasma in (e).

[0020] In one exemplary embodiment, the second process gas comprises hydrogen fluoride gas.

[0021] In one exemplary embodiment, the second process gas includes at least 50% by volume of hydrogen fluoride gas.

[0022] In one exemplary embodiment, a plasma processing method is provided that includes: (a) supplying a first process gas into a chamber, the first process gas comprising an alkyne gas having three or more carbon atoms; (b) generating a plasma from the first process gas to form a precoat comprising a carbon-containing film on a component in the chamber; (c) providing a substrate on a substrate support in the chamber; (d) supplying a second process gas into the chamber; and (e) generating a plasma from the second process gas to plasma process the substrate.

[0023] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, 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 the actual ratios are not limited to the ratios shown in the drawings.

[0024] <Configuration Example of a Plasma Processing Apparatus> FIG. 1 is a diagram illustrating a configuration example of a plasma processing apparatus. In one embodiment, the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a control unit 2, a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust 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.

[0025] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0026] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be configured as a system external to 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 may be implemented, for example, by a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or 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 random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with each element of the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0027] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0028] The capacitively coupled plasma processing apparatus 1 includes a controller 2, a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms 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 showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0029] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0030] 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 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. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may 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 called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0031] 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 or insulating material, and the cover rings are formed of an insulating material.

[0032] The substrate support 11 may also include a temperature adjustment 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 adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0033] The showerhead 13 is configured to introduce at least one process 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 multiple gas inlets 13c. The process 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 multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0034] 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 process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0035] 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 generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0036] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to 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 generating unit 31a may be configured to generate multiple 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.

[0037] The second RF generator 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more 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.

[0038] 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 generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0039] 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 generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either 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 generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0040] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided 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 in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0041] In one embodiment, the plasma processing chamber 10 (hereinafter also referred to as "chamber 10") may include a shield 50. The shield 50 may be removably provided along the sidewall 10a of the chamber 10. The shield 50 defines a portion of the plasma processing space 10s. The shield 50 can suppress adhesion of etching by-products to the sidewall 10a. The shield 50 may further be removably provided along the outer periphery of the substrate support 11.

[0042] In one embodiment, the chamber 10 may include a baffle plate 60. The baffle plate 60 separates the interior of the chamber 10 into a plasma processing space 10s and an exhaust space including a region near the gas exhaust port 10e. The baffle plate 60 can prevent plasma from entering the exhaust space downstream of the baffle plate 60. The baffle plate 60 may be provided near the bottom of the chamber 10, between the substrate support 11 and the sidewall 10a of the chamber 10. The baffle plate 60 may be an annular plate. The baffle plate 60 may be provided with openings such as through holes or slits for exhaust.

[0043] In one embodiment, the chamber 10 may include a GND block 70. The GND block 70 is provided so as to be exposed to the plasma processing space 10s from the shield 50. For example, the GND block 70 may be provided in a ring shape around the inner circumference of the shield 50. The GND block 70 may be provided in a ring shape around the outer periphery of the shower head 13 or in the vicinity thereof as long as it is exposed to the plasma processing space 10s. The GND block 70 is a conductive member. For example, the GND block may be formed of a silicon-containing material. Examples of silicon-containing materials include silicon (Si) and silicon carbide (SiC). The GND block 70 is connected to a ground potential via the shield 50 and the sidewall 10a. The GND block 70 is electrically connected to the upper electrode or the lower electrode via plasma generated in the plasma processing space 10s and may function to suppress abnormal discharge within the chamber 10.

[0044] <Example of Plasma Processing Method> A plasma processing method (hereinafter also referred to as "method MT") according to an exemplary embodiment of the present disclosure will be described. The processing in each step may be performed by the plasma processing apparatus shown in Figures 1 and 2. The following describes an example in which a control unit 2 controls each unit of a capacitively coupled plasma processing apparatus 1 (see Figure 2) to perform this processing method.

[0045] 3 is a flowchart illustrating an example of the method MT. As shown in FIG. 3, the method MT includes a step ST1 of supplying a first process gas and a step ST2 of forming a precoat. In one embodiment, the method MT may include, after the step ST2, a step ST3 of providing a substrate, a step ST4 of supplying a second process gas, and a step ST5 of plasma-processing the substrate. In one embodiment, the method MT may further include, after the step ST5, a step ST6 of cleaning the interior of the chamber.

[0046] (Step ST1) In step ST1, a first process gas is supplied. In one embodiment, the first process gas is supplied from the gas supply unit 20 into the plasma processing space 10s of the chamber 10 via the shower head 13. The first process gas includes an alkyne gas having three or more carbon atoms (hereinafter also referred to as "alkyne gas AG"). The alkyne gas AG includes one or more carbon triple bonds in its molecule. In the alkyne gas AG, a terminal carbon may have a triple bond, or a carbon other than the terminal carbon may have a triple bond. In one embodiment, the alkyne gas AG includes at least one gas selected from the group consisting of propyne (methylacetylene) gas, butyne (1-butyne, 2-butyne) gas, and pentyne (1-pentyne, 2-pentyne) gas.

[0047] The alkyne gas AG is more stable and less ignitable than acetylene gas. Therefore, the flow rate (partial pressure) of the alkyne gas AG in the first process gas can be increased. In one embodiment, the alkyne gas AG may have the highest flow rate (partial pressure) of the first process gas. For example, the flow rate of the alkyne gas AG may be 50% by volume or more, 60% by volume or more, 70% by volume or more, 80% by volume or more, 90% by volume or more, or 95% by volume or more of the total flow rate of the first process gas. In one embodiment, the first process gas contains 100% by volume of the alkyne gas AG.

[0048] In one embodiment, the first process gas may further include a halogen-containing gas as an additive gas. The halogen-containing gas may be, for example, at least one of a chlorine-containing gas and a fluorine-containing gas. In one example, the chlorine-containing gas may be Cl. ２The fluorine-containing gas is, for example, Cl ２ Gas, HF gas, NF ３ Gas, C ４ F ６ Gas, CF ４ Gas and PF ３ The flow rate of the halogen-containing gas may be less than the flow rate of the alkyne gas.

[0049] As described above, the alkyne gas AG is more stable and less likely to ignite than acetylene gas. Therefore, the first process gas does not need to contain a diluent gas such as Ar gas, He gas, or Kr gas. However, the first process gas may contain a diluent gas such as Ar gas, He gas, or Kr gas.

[0050] In one embodiment, the first process gas may further include a hydrocarbon gas different from the alkyne gas AG and / or a halogenated hydrocarbon gas. The hydrocarbon gas may be, for example, CH ４ Gas, C ２ H ２ Gas, C ２ H ４ The flow rate of the hydrocarbon gas may be smaller than that of the alkyne gas. The halogenated hydrocarbon gas is a gas in which hydrogen atoms in hydrocarbon molecules are substituted with halogen, and may be, for example, a CHF-based gas, a CHCl-based gas, a CHBr-based gas, or the like. The flow rate of the halogenated hydrocarbon gas may be smaller than that of the alkyne gas.

[0051] (Step ST2) In step ST2, a precoat including a carbon-containing film is formed on the components in the chamber by plasma generated from the first process gas.

[0052] In one embodiment, a source RF signal is supplied from the first RF generator 31a to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. This generates plasma from the first process gas. Carbon contained in the alkyne gas AG, etc. in the first process gas dissociates in the plasma and deposits on the surfaces of the components in the chamber 10. This forms a precoat. The precoat is a carbon-containing film. The precoat can function as a protective film, for example, in the plasma processing of the substrate W in step ST5, which will be described later.

[0053] In one embodiment, the precoat is formed on some or all of the plasma-exposed surfaces (surfaces exposed to the plasma processing space 10s) of components of the chamber 10 (hereinafter, the components on which the precoat is formed are also referred to as "components CP"). The components CP may be, for example, the substrate support 11, the showerhead 13, the ring assembly 112, the sidewall 10a, the shield 50, the baffle plate 60, and / or the GND block 70. The components CP may be made of, for example, a silicon-containing material such as silicon or silicon carbide. The components CP may be made of, for example, a metal material such as aluminum.

[0054] In one embodiment, step ST2 may be performed in a state where a dummy substrate is placed on the substrate support 11. In this case, in step ST2, no precoat is formed on the plasma-exposed surface of the substrate support 11. The dummy substrate may have the same dimensions and shape as the substrate W provided in step ST3.

[0055] In one embodiment, process ST2 may be performed while a bias signal is supplied to the chamber 10. In one embodiment, the bias signal may be a bias RF signal supplied from the second RF generator 31b to the lower electrode of the substrate support 11. In one embodiment, the bias signal may be a bias DC signal supplied from the DC generator 32a to the lower electrode of the substrate support 11. The bias DC signal may have a negative polarity. In one embodiment, the bias signal may be supplied directly to the component CP (e.g., the ring assembly 112).

[0056] In one embodiment, the temperature of the substrate support member 11 may be controlled in the range of −70° C. or more and 100° C. or less in step ST2.

[0057] 4 is a diagram showing an example of the cross-sectional structure of a component at the end of step ST2. As shown in FIG. 4, a precoat PC is formed on the surface of the component CP. The film thickness of the precoat PC may be adjusted depending on the component on which the precoat PC is formed and the processing conditions in step ST3. The film thickness of the precoat PC is, for example, 100 nm or more. The film thickness of the precoat PC is, for example, 1500 nm or less. As an example, a precoat PC of such a thickness may be formed on the surface of the edge ring.

[0058] In step ST2, a precoat is formed by generating plasma from a first process gas containing an alkyne gas AG. Therefore, compared to forming a precoat by generating plasma from a hydrocarbon gas with a smaller carbon number, such as methane gas, the carbon ratio per unit flow rate can be increased. This can improve the precoat deposition rate. Furthermore, the alkyne gas AG has a carbon triple bond, and when dissociated in the plasma, it forms a precursor containing active species of ethynyl groups. These precursors can bond with each other inside the film and contribute to the formation of the precoat. This reaction does not require hydrogen abstraction, as occurs when forming a precoat from, for example, methane gas. Therefore, alkyne gas AG tends to require less energy to form the precoat compared to, for example, using methane gas. This can improve the precoat deposition rate. Furthermore, a precoat formed from a precursor containing active species of ethynyl groups can be formed by SP ２ It tends to have a high carbon (graphite) ratio and a low hydrogen ratio, which can result in high conductivity precoat and high film density (hardness).

[0059] When the first process gas contains a halogen-containing gas as an additive gas, hydrogen in the precoat can be scavenged by halogen dissociated in the plasma in step ST2. This can improve the film quality of the precoat. ２The improvement in conductivity can be attributed to an increase in the proportion of carbon (graphite) in the bonds, and the improvement in film quality can be attributed to an increase in film density (hardness) due to a decrease in the hydrogen ratio in the film.

[0060] When a bias signal is supplied in step ST2, ions in the plasma can be bombarded into the precoat formed on the surface of the component. The kinetic energy of the ions is converted into thermal energy, which can change the bonding state of the carbon-containing film in the precoat. This can improve the film quality of the precoat. The improvement in film quality can be achieved by SP ２ The improvement in conductivity can be attributed to an increase in the proportion of carbon (graphite) in the bonds, and the improvement in film quality can be attributed to an increase in film density (hardness) due to a decrease in the hydrogen ratio in the film.

[0061] (Step ST3) In step ST3, a substrate W is provided in the chamber 10. In one embodiment, the substrate W is carried into the chamber 10 by a transfer arm, placed on the substrate support 11 by a lifter, and held by suction on the substrate support 11 as shown in FIG. 2. The substrate W may be used in the manufacture of semiconductor devices. Examples of semiconductor devices include memory devices such as DRAMs and 3D-NAND flash memories, and logic devices. In one embodiment, the substrate W may include a silicon-containing film.

[0062] (Step ST4) In step ST4, a second process gas is supplied. In one embodiment, the second process gas is supplied from the gas supply unit 20 into the plasma processing space 10s of the chamber 10 via the shower head 13. The second process gas is appropriately selected depending on the plasma processing to be performed on the substrate W in step ST5.

[0063] In one embodiment, the second process gas includes hydrogen fluoride (HF) gas. The HF gas may have the highest flow rate (partial pressure) of all components of the second process gas, excluding the inert gas. In one embodiment, the second process gas may include a gas capable of generating activated species of hydrogen fluoride (HF species) in plasma, instead of part or all of the HF gas. The HF species include at least one of hydrogen fluoride gas, radicals, and ions. In one embodiment, the second process gas further includes, in addition to HF gas, at least one gas selected from the group consisting of a phosphorus-containing gas, a metal-containing gas, a halogen-containing gas other than fluorine, a carbon-containing gas, an oxygen-containing gas, and an inert gas.

[0064] (Step ST5) In step ST5, the substrate W is plasma-processed. In one embodiment, a source RF signal is supplied to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. When a high-frequency electric field is generated between the shower head 13 and the substrate support 11, plasma is generated from the second process gas in the chamber 10. The substrate W is plasma-processed by the plasma. For example, the plasma processing may be an etching process for etching a film on the substrate W. For example, the plasma processing may be a film deposition process for forming a film on the substrate W.

[0065] In step ST5, the precoat formed on the plasma-exposed surface of the component CP can function as a protective film against the plasma generated from the second process gas, as described above. As an example, a case will be described in which the plasma-exposed surface of the component CP contains silicon and the second process gas contains HF gas. In this case, the precoat can prevent silicon on the plasma-exposed surface of the component CP from reacting with HF species in the plasma and volatilizing as a silicon fluoride compound. This can prevent the plasma-exposed surface of the component CP from being scraped (damaged). Furthermore, the HF species in the plasma can be prevented from being consumed in locations other than the substrate W. This can facilitate plasma processing of the substrate W.

[0066] After the plasma processing in step ST5, the substrate W is transferred out of the chamber 10 by the transfer device.

[0067] (Step ST6) In step ST6, the inside of the chamber 10 is cleaned. In one embodiment, a cleaning gas is introduced into the plasma processing space 10s from the gas supply unit 20 via the shower head 13. The cleaning gas may be, for example, an oxygen-containing gas. Plasma is then generated from the cleaning gas. This can remove some or all of the precoat and reaction products formed on the plasma-exposed surfaces of the components of the chamber 10. Note that when multiple substrates W are processed as a single unit (lot), step ST6 may be performed after steps ST3 to ST5 have been performed on one or more substrates W included in the lot. That is, step ST6 may be performed after steps ST3 to ST5 have been repeatedly performed.

[0068] According to one embodiment, a technique for improving the deposition rate of the precoat can be provided.

[0069] Embodiments of the present disclosure further include the following aspects.

[0070] (c) providing a substrate on the substrate support; (d) supplying a second process gas from the gas supply unit to the chamber; and (e) generating plasma from the second process gas to plasma process the substrate by the plasma generation unit.

[0071] [Supplementary Note 2] The plasma processing apparatus according to Supplementary Note 1, wherein the alkyne gas includes at least one gas selected from the group consisting of propyne gas, butyne (1-butyne, 2-butyne) gas, and pentyne (1-pentyne, 2-pentyne) gas.

[0072] [Supplementary Note 3] The plasma processing apparatus according to Supplementary Note 1 or 2, wherein the first processing gas contains 50% by volume or more of the alkyne gas.

[0073] [Supplementary Note 4] The plasma processing apparatus according to any one of Supplementary Notes 1 to 3, wherein the first processing gas contains 95% by volume or more of the alkyne gas.

[0074] [Supplementary Note 5] The plasma processing apparatus according to any one of Supplementary Notes 1 to 4, wherein the first processing gas further contains a halogen-containing gas.

[0075] [Supplementary Note 6] The plasma processing apparatus according to Supplementary Note 5, wherein the halogen-containing gas is at least one of a chlorine-containing gas and a fluorine-containing gas.

[0076] [Supplementary Note 7] The halogen-containing gas is Cl ２ Gas, HF gas, NF ３ Gas, C ４ F ６ Gas, CF ４ Gas and PF ３ 6. The plasma processing apparatus according to claim 5, wherein the gas is at least one gas selected from the group consisting of gases.

[0077] [Supplementary Note 8] The plasma processing apparatus according to any one of Supplementary Notes 1 to 7, wherein in (b), a bias signal is supplied to the substrate support.

[0078] [Supplementary Note 9] The plasma processing apparatus according to any one of Supplementary Notes 1 to 8, wherein (b) is performed in a state where a substrate different from the substrate provided in (c) is placed on the substrate support.

[0079] [Supplementary Note 10] The plasma processing apparatus according to any one of Supplementary Notes 1 to 8, wherein (b) is performed in a state where a surface of the substrate support part is exposed to the space within the chamber.

[0080] [Supplementary Note 11] The plasma processing apparatus according to any one of Supplementary Notes 1 to 10, wherein the component in the chamber is a part exposed to plasma in (e).

[0081] [Supplementary Note 12] The plasma processing apparatus according to any one of Supplementary Notes 1 to 11, wherein the second processing gas contains hydrogen fluoride gas.

[0082] [Supplementary Note 13] The plasma processing apparatus according to Supplementary Note 12, wherein the second processing gas contains 50% by volume or more of hydrogen fluoride gas.

[0083] [Supplementary Note 14] A plasma processing method comprising: (a) supplying a first process gas into a chamber, the first process gas including an alkyne gas having three or more carbon atoms; (b) generating a plasma from the first process gas to form a precoat including a carbon-containing film on a component in the chamber; (c) providing a substrate on a substrate support in the chamber; (d) supplying a second process gas into the chamber; and (e) generating a plasma from the second process gas to plasma-process the substrate.

[0084] [Supplementary Note 15] A method for forming a precoat, comprising: (a) supplying a first process gas into a chamber, the first process gas including an alkyne gas having three or more carbon atoms; and (b) generating plasma from the first process gas to form a precoat including a carbon-containing film on a component in the chamber.

[0085] [Supplementary Note 16] A precoat, which is a carbon-containing film formed on a plasma-exposed surface of a component in a chamber, is formed using plasma generated from a process gas containing an alkyne gas having three or more carbon atoms.

[0086] [Supplementary Note 17] A device manufacturing method, comprising: (a) supplying a first process gas into a chamber, the first process gas containing an alkyne gas having three or more carbon atoms; (b) generating plasma from the first process gas to form a precoat containing a carbon-containing film on a component in the chamber; (c) providing a substrate on a substrate support in the chamber; (d) supplying a second process gas into the chamber; and (e) generating plasma from the second process gas to plasma-process the substrate.

[0087] [Supplementary Note 18] A program causing a computer of a plasma processing apparatus having a chamber and a control unit to execute the following: (a) control of supplying a first process gas to the chamber, wherein the first process gas contains an alkyne gas having three or more carbon atoms; (b) control of generating plasma from the first process gas to form a precoat containing a carbon-containing film on a component in the chamber; (c) control of providing a substrate on a substrate support in the chamber; (d) control of supplying a second process gas to the chamber; and (e) control of generating plasma from the second process gas to plasma process the substrate.

[0088] [Supplementary Note 19] A storage medium storing the program according to Supplementary Note 18.

[0089] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments.

[0090] REFERENCE SIGNS LIST 1: Plasma processing apparatus, 2: Control unit, 10: Plasma processing chamber, 10a: Side wall, 10s: Plasma processing space, 11: Substrate support, 112: Ring assembly, 13: Shower head, 20: Gas supply unit, 31a: First RF generation unit, 31b: Second RF generation unit, 32a: First DC generation unit, 32b: Second DC generation unit, 50: Shield, 60: Baffle plate, 70: GND block 70, CP: Constituent member, PC: Precoat, W: Substrate

Claims

1. A plasma processing apparatus comprising: a chamber; a gas supply unit; a substrate support unit disposed within the chamber; a plasma generation unit configured to generate plasma within the chamber; and a control unit configured to perform the following: (a) control the gas supply unit to supply a first process gas to the chamber, the first process gas including an alkyne gas having three or more carbon atoms; (b) control the plasma generation unit to generate plasma from the first process gas to form a precoat including a carbon-containing film on a component within the chamber; (c) control the provision of a substrate on the substrate support unit; (d) control the gas supply unit to supply a second process gas to the chamber; and (e) control the plasma generation unit to generate plasma from the second process gas to plasma process the substrate.

2. The plasma processing apparatus according to claim 1, wherein the alkyne gas includes at least one gas selected from the group consisting of propyne gas, butyne (1-butyne, 2-butyne) gas, and pentyne (1-pentyne, 2-pentyne) gas.

3. The plasma processing apparatus according to claim 1, wherein the first processing gas contains 50% by volume or more of the alkyne gas.

4. The plasma processing apparatus according to claim 1, wherein the first processing gas contains 95% by volume or more of the alkyne gas.

5. The plasma processing apparatus according to claim 1, wherein the first processing gas further contains a halogen-containing gas.

6. The plasma processing apparatus according to claim 5, wherein the halogen-containing gas is at least one of a chlorine-containing gas and a fluorine-containing gas.

7. The halogen-containing gas is Cl ２ Gas, HF gas, NF ３ Gas, C ４ F ６ Gas, CF ４ Gas and PF ３ 6. The plasma processing apparatus according to claim 5, wherein the gas is at least one gas selected from the group consisting of gases.

8. The plasma processing apparatus according to any one of claims 1 to 4, wherein in step (b), a bias signal is supplied to the substrate support.

9. The plasma processing apparatus according to any one of claims 1 to 4, wherein (b) is performed with a substrate different from the substrate provided in (c) placed on the substrate support.

10. The plasma processing apparatus according to any one of claims 1 to 4, wherein (b) is performed in a state where the surface of the substrate support is exposed to the space within the chamber.

11. The plasma processing apparatus according to any one of claims 1 to 4, wherein the component in the chamber is a part that is exposed to plasma in (e).

12. The plasma processing apparatus according to claim 1, wherein the second processing gas contains hydrogen fluoride gas.

13. The plasma processing apparatus according to claim 12, wherein the second processing gas contains 50% by volume or more of hydrogen fluoride gas.

14. A plasma processing method comprising: (a) supplying a first process gas into a chamber, the first process gas including an alkyne gas having three or more carbon atoms; (b) generating a plasma from the first process gas to form a precoat including a carbon-containing film on a component in the chamber; (c) providing a substrate on a substrate support in the chamber; (d) supplying a second process gas into the chamber; and (e) generating a plasma from the second process gas to plasma process the substrate.

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