Etching method, pre-coating method, and etching apparatus

Abstract

To form a pre-coating that ensures the appropriate level of adhesion between a substrate and a substrate support part.SOLUTION: An etching method includes the steps for (a) forming a carbon-containing film on a surface of an electrostatic chuck inside a chamber, (b) placing a substrate on the carbon-containing film, and (c) plasma etching the substrate. The step (a) includes the steps for (a1) supplying a pre-coating gas into the inside of the chamber and controlling the pressure inside the chamber to be 100 mTorr or more and 1000 mTorr or less, and (a2) generating plasma of the pre-coating gas.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an etching method, a precoating method, and an etching apparatus. [Background technology]

[0002] Patent Document 1 discloses a method for forming a carbon-based coating on a component in a processing chamber. The carbon-based coating is a diamond coating or a diamond-like carbon coating, and the method describes supplying a hydrocarbon gas into the chamber, generating a plasma of the hydrocarbon gas to produce the carbon-based coating, degassing and removing the hydrocarbon gas, and then performing a normal process including etching on the substrate. It also describes that the method can be performed in situ. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 5,952,060 Summary of the Invention [Problem to be solved by the invention]

[0004] The techniques disclosed herein form a precoat that provides an appropriate adhesion between the substrate and the substrate support. [Means for solving the problem]

[0005] One aspect of the present disclosure is an etching method comprising the steps of: (a) forming a carbon-containing film on a substrate support inside a chamber; (b) placing a substrate on the carbon-containing film; and (c) plasma etching the substrate, wherein the step (a) comprises the steps of: (a1) supplying a precoat gas containing carbon and hydrogen into the chamber and controlling a pressure in the chamber to 100 mTorr or more and 1000 mTorr or less; and (a2) generating a plasma of the precoat gas. Effect of the Invention

[0006] According to the present disclosure, a precoat can be formed that provides an appropriate adhesion force between a substrate and a substrate support. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating a configuration example of a plasma processing system according to an embodiment. [Diagram 2] 1 is a cross-sectional view showing a configuration example of a plasma processing apparatus according to an embodiment; [Diagram 3] 1 is a flowchart illustrating an outline of a plasma processing method according to an embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing a schematic outline of the configuration of a main body on which a precoat according to one embodiment is formed. [Diagram 5] FIG. 2 is a cross-sectional view showing a schematic outline of the configuration of a main body on which a precoat according to one embodiment is formed. [Figure 6] FIG. 1 is a ternary diagram showing the ratio of the crystal structures of the precoat. [Figure 7] 1A to 1C are cross-sectional views showing the effect of precoating on the adsorption force between a substrate and an electrostatic chuck in chronological order. [Figure 8] FIG. 2 is a cross-sectional view showing a schematic outline of a substrate support part for forming a precoat and other coating layers according to one embodiment. [Figure 9] 1 is a flowchart illustrating an outline of a plasma processing method according to an embodiment. [Figure 10] 1 is a flowchart illustrating an outline of a plasma processing method according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of semiconductor devices, various processing steps are carried out in which a semiconductor wafer (hereinafter referred to as "substrate") is placed on a substrate support inside a processing chamber and a predetermined process is performed on the substrate using a process gas. In addition, dry cleaning may be performed inside the processing chamber to remove residues remaining in the processing steps.

[0009] The substrate support uses an electrostatic chuck (ESC) that electrically attracts and supports the substrate. The surface of the electrostatic chuck may become fluorinated due to fluorine and other deposits remaining in the processing process. When the surface of the electrostatic chuck becomes fluorinated, it may have an adverse effect on the manufacturing process. Specifically, the fluorinated surface of the electrostatic chuck may be damaged by friction with the substrate, or the electrical properties may change. In this case, the change in the surface area of ​​the electrostatic chuck may cause effects such as improper heat transfer, generation of particles in the substrate processing space, and improper electrostatic attraction. Such effects have become more noticeable in recent years due to the demand for performing the above-mentioned manufacturing process with high power and for a long time. In order to suppress the above-mentioned effects, it has been proposed to form a pre-coat on the surface of the electrostatic chuck.

[0010] In Patent Document 1, a method for performing in situ (in situ) etching on a member in a processing chamber is disclosed. A method for forming a carbon-based film by an in-situ process is disclosed. Specifically, the carbon-based film is a diamond film or a diamond-like carbon film (DLC film), and the method includes supplying a hydrocarbon gas into a chamber, generating a plasma of the hydrocarbon gas to generate a carbon-based film, degassing and removing the hydrocarbon gas, and then performing a normal process including etching on the substrate. This protects components in the processing chamber from damage caused by ionized gas species.

[0011] The inventors of the present invention have conducted extensive research into such precoats and have found that, when forming a precoat on the surface of an electrostatic chuck, it is necessary to consider the electrical adsorption force between the electrostatic chuck and a substrate through which the precoat is sandwiched. Specifically, the electrostatic chuck contacts the substrate lower surface WB at the substrate support surface and electrically adsorbs the substrate, but the precoat is interposed between the substrate support surface and the substrate lower surface WB, and may affect the adsorption force.

[0012] Regarding the influence on the above-mentioned chucking force, for example, if the conductivity of the precoat is too high, charges easily move between the precoat and the substrate, and the potential difference between the electrostatic chuck and the substrate cannot be maintained, resulting in a decrease in the chucking force. If the chucking force decreases, there is a concern that the substrate may shift or the heat transfer gas supplied to the bottom surface of the substrate may leak. On the other hand, if the conductivity of the precoat is too low, there is a concern that a large amount of residual charge may remain on the substrate and the electrostatic chuck during dechucking (terminating the chucking of the substrate by the electrostatic chuck and removing the substrate from the electrostatic chuck), resulting in residual chucking that does not allow normal dechucking. Residual chucking is an example of a state in which the chucking force is not appropriate, and will be described in detail later. Therefore, when forming a precoat, it is required to make the chucking force between the electrostatic chuck and the substrate appropriate.

[0013] Patent Document 1 describes the property of the carbon-based coating to suppress chemical damage caused by ionized gas species, but does not describe the influence on the adhesion force between the electrostatic chuck and the substrate. The carbon-based coating specifically described in Patent Document 1 is a diamond coating of 1 μm to 50 μm or a DLC coating of 0.5 μm to 50 μm. It is described that the DLC in the DLC coating is amorphous carbon (hard carbon or α carbon). After extensive research by the present inventors, it was found that the carbon-based coating described above cannot at least provide an appropriate adhesion force between the electrostatic chuck and the substrate.

[0014] In view of this, the technology disclosed herein forms a precoat capable of optimizing the adhesion force between the electrostatic chuck and the substrate by optimizing the ratio of the crystal structures of the hydrocarbons contained in the precoat and the electrical conductivity of the precoat.

[0015] Hereinafter, the configuration of the substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted.

[0016] FIG. 1 is a diagram for explaining a configuration example of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. 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.

[0017] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR plasma), a helicon wave plasma (HWP), a surface wave plasma (SWP), or the like. Also, various types of plasma generating units may be used, including an alternating current (AC) plasma generating unit and a direct current (DC) plasma generating unit. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Thus, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0018] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to execute various steps described herein. In one embodiment, a 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, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control operations by reading a program from the storage unit 2a2 and 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 is 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 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 the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0019] Next, a configuration example of a capacitively coupled plasma processing apparatus 1 will be described as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining the configuration example of the capacitively coupled plasma processing apparatus 1.

[0020] The capacitively coupled plasma processing apparatus 1 includes 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 processing gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed in 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 part of a 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 a housing of the plasma processing chamber 10.

[0021] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 includes a central region and an annular region, the central region forming a substrate support surface 111a for supporting the substrate W, and the annular region forming a ring support surface 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The ring support surface 111b of the main body 111 surrounds the substrate support surface 111a of the main body 111 in a plan view. The substrate W is disposed on the substrate support surface 111a of the main body 111, and the ring assembly 112 is disposed on the ring support surface 111b of the main body 111 so as to surround the substrate W on the substrate support surface 111a of the main body 111.

[0022] 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 may 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 substrate support surface 111a. In one embodiment, the ceramic member 1111a also has a ring support surface 111b. Note that other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the ring support surface 111b. 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. Also, at least one RF / DC electrode coupled to an RF power source 31 and / or a DC power source 32 described later may be disposed in 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 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. Also, the electrostatic electrode 1111b may function as a lower electrode. Thus, the substrate support 11 includes at least one lower electrode.

[0023] 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.

[0024] 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 W 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 a 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 back surface of the substrate W and the substrate support surface 111a.

[0025] The shower head 13 is configured to introduce at least one processing gas or a pre-coat gas, which will be described later, from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 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 multiple gas inlets 13c. The shower head 13 also includes at least one upper electrode. Note that the gas introduction unit may include, in addition to the shower head 13, one or more side gas injectors (SGI) attached to one or more openings formed in the sidewall 10a.

[0026] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include at least one flow modulation device to modulate or pulse a flow rate of the at least one process gas.

[0027] The gas supply unit 20 may include at least one gas source 21 that supplies a precoat gas, which will be described later, and at least one corresponding flow rate controller 22 .

[0028] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 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 a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of the plasma generating unit 12. In addition, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0029] 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 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.

[0030] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and 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 generating unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0031] 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 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 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.

[0032] 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 of these pulse waveforms. In one embodiment, a waveform generator for generating a 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 a positive polarity or a negative polarity. Also, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses in one period. The first and second DC generating units 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided in place of the second RF generating unit 31b.

[0033] 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 adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0034] <First embodiment> Next, an etching method MT1 according to the first embodiment will be described with reference to Figs. 3 and 4. Fig. 3 is a flow chart showing an outline of the etching method MT1 according to the first embodiment. In the etching method MT1, a precoat PC can be formed inside the plasma processing chamber 10 using the above-mentioned plasma processing system. In the present disclosure, the plasma processing includes a case where a precoat PC is formed prior to processing of the substrate W such as etching or film formation, as well as a case where a precoat PC is formed prior to dry cleaning of the inside of the plasma processing chamber 10. It also includes a case where the formed precoat PC is removed. The precoat PC is an example of a carbon-containing film according to the present disclosure.

[0035] First, a precoat gas is supplied into the reduced pressure plasma processing chamber 10 (step ST1). Hereinafter, a case where a single component gas of a hydrocarbon gas (CH gas) is used as the precoat gas will be described. However, the precoat gas is not limited to the above, and a gas containing desired carbon and hydrogen can be used. Specifically, the gas containing carbon and hydrogen may be a single component gas such as CH gas or hydrofluorocarbon gas (CHF gas), or may be a mixed gas of one selected from CH gas, CHF gas, or fluorocarbon gas (CF gas) and a hydrogen-containing gas such as hydrogen gas (H2) gas. Of the above, it is preferable to use a single component gas of CH gas that does not contain fluorine F or a mixed gas of CH gas as the precoat gas. Note that, as the CH gas, a C gas such as CH4 may be used. n H 2n+2 and unsaturated hydrocarbons (alkenes, alkynes) containing double or triple bonds such as C2H4 or C2H2, and are not particularly limited.

[0036] The precoat gas may also be a mixed gas containing the above single component gas or the above mixed gas and an inert gas in a desired ratio. The inert gas may be a noble gas such as argon (Ar) or nitrogen gas (N2 gas).

[0037] In step ST1, the pressure in the chamber is controlled to 100 mTorr or more by supplying a precoat gas into the chamber. If the pressure in the chamber is lower than 100 mTorr, the precoat PC is mainly composed of graphite, and therefore the adsorption force decreases for the reasons described below. The upper limit of the pressure in the chamber is not particularly limited, but may be 1000 mTorr or less when a general etching device is used.

[0038] Next, plasma of the precoat gas is generated to form a precoat PC inside the plasma processing chamber 10 (step ST2). FIG. 4 is a cross-sectional view showing a schematic outline of the configuration of the main body 111 on which the precoat PC is formed by the etching method MT1 according to this embodiment. In this embodiment, the precoat gas is CH gas, so plasma of the CH gas is formed. The inside of the plasma processing chamber 10 includes at least the substrate support surface 111a (surface of the electrostatic chuck 1111) of the substrate support part 11. In one embodiment, the substrate support surface 111a has a plurality of recesses to which a heat transfer gas is supplied. In one embodiment, the substrate support surface 111a may have a plurality of protrusions 120 (dots) that support the substrate W, or may not have the protrusions 120.

[0039] 5 is a cross-sectional view showing a schematic outline of the configuration of the main body 111 in which a precoat PC is formed by the etching method MT according to this embodiment and the substrate support surface 111a has convex portions 120. In FIG. 5, the precoat PC is formed on at least the upper surfaces of the plurality of convex portions 120. That is, as shown in the figure, the precoat PC is formed only on the portion of the substrate support 11 that contacts the substrate W when the substrate W is supported by the substrate support 11 (electrostatic chuck 1111), and may not be formed on other portions of the convex portions 120 (side surfaces of the convex portions 120) or on the concave portions 122. In this case, the thickness T of the precoat PC is PC is the height H of the protrusion 120 120 It may be formed to be thinner than the distance between the upper surface of the protrusion 120 and the lower surface of the recess 122.

[0040] 3 and 4, when the substrate supporting surface 111a does not have the convex portion 120, the precoat PC may be formed on the entire surface of the substrate supporting surface 111a. Alternatively, the precoat PC may be formed on the surface of a desired component inside the plasma processing chamber 10 that is exposed to the plasma processing space 10s, such as the ceiling or sidewall 10a of the plasma processing chamber 10.

[0041] Pre-coated PC thickness T PC If the thickness is less than 5 nm, a stable film cannot be formed, the surface becomes uneven, and the precoat PC may not be formed on a part of the surface of the substrate support surface 111a. PC More preferably, the thickness T of the precoat PC is 10 nm or more. PC There is no particular upper limit to the thickness T of the precoat PC. PC may be 100 nm or less.

[0042] After forming the precoat PC, the substrate W is etched (step ST3). In step ST3, the substrate W is loaded into the plasma processing chamber 10, placed on the substrate support surface 111a on which the precoat PC is formed, a desired process gas is supplied, plasma is generated from the process gas, and the substrate W is etched. In one embodiment, after the above step ST3 is performed, the substrate W is unloaded from the plasma processing chamber 10, and the precoat PC is removed (step ST4). The method of removing the precoat PC is not particularly limited, and may be dry cleaning under desired conditions. In one embodiment, the dry cleaning may be performed by generating plasma from a gas other than a fluorine-containing gas, for example, an oxygen-containing gas such as O2 gas. In addition, the step ST4 may be performed each time the step ST3 is performed once, or may be performed a predetermined number of times after the step ST3 is performed. That is, the dry cleaning may be performed each time a cycle including a step of placing the substrate W on the substrate support 111a and a step of etching the substrate W is performed once or more. It should be noted that step ST4 is an optional step and is not essential.

[0043] In the etching method MT1, the plasma generation conditions, such as the flow rate of the precoat gas, the temperature in the chamber, the frequency and power of the RF, may be determined in advance for each apparatus configuration. The plasma generation conditions may be determined by an experiment or a simulation. When the plasma generation conditions are determined by an experiment, the experiment may be performed prior to the etching method MT1, and the determined conditions may be stored in the control unit 2. When the etching method MT1 is performed, the above-described stored conditions may be read before the step ST1. The apparatus configuration specifically includes whether the RF electrode is applied to the upper or lower electrode, the distance between the upper and lower electrodes, and the like. The plasma generation conditions refer to conditions under which the precoat PC having the properties described below can be formed by performing the step ST2 of forming the precoat PC, and the plasma of the precoat gas does not damage the electrostatic chuck 1111.

[0044] Next, an example of the properties of the precoat PC formed by the etching method MT1 according to the present embodiment will be described with reference to Fig. 6. Fig. 6 is a ternary diagram showing the ratio [%] of the crystal structure of hydrocarbons (sp3:sp2:H).

[0045] The precoated PC according to this embodiment contains 20 atomic % or more and 50 atomic % or less of H atoms. In addition to the above, in one embodiment, the ratio [%] of the crystal structure in the ternary diagram is specified as a preferable property of the precoated PC.

[0046] In FIG. 6, the precoat PC is within the range enclosed by a rectangle ABCD consisting of four points, point A (sp3:sp2:H) = (80:0:20), point B (sp3:sp2:H) = (0:80:20), point C (sp3:sp2:H) = (0:50:50), and point D (sp3:sp2:H) = (50:0:50), in the ternary diagram of (sp3:sp2:H).

[0047] Here, the (sp3:sp2:H) ternary diagram will be explained. Carbon atoms in DLC mainly form crystals with three types of bonding patterns: sp3 bonds that exhibit a diamond structure, sp2 bonds that exhibit a graphite structure, and bonds with hydrogen atoms. For example, when a pre-coated PC has a ratio [%] shown at point A (sp3:sp2:H) = (80: 0: 20), this indicates that the pre-coated PC has a crystal structure that contains 80% sp3 bonds, 0% sp2 bonds (i.e., no bonds), and 20% bonds with hydrogen atoms.

[0048] The ratio [%] of (sp3:sp2:H) can be obtained by, for example, Raman spectroscopy. In Raman spectroscopy, a visible laser is irradiated onto the precoated PC as excitation light, and a Raman spectrum of scattered light is obtained. The peak intensity ratio ID / IG is obtained from the D band peak and the G band peak in the Raman spectrum, and the ratio [%] of (sp3:sp2:H) can be calculated based on this. The ratio [%] of (sp3:sp2:H) calculated in this way is plotted on the ternary diagram shown in FIG. 6, and it can be determined whether the plot is within the range surrounded by the rectangle ABCD. In the calculated ratio [%], the case where "sp3, sp2, or H is 0%" is not limited to the case where these are actually not contained at all, but may be the case where they are contained to an extent that is not detected by Raman spectroscopy.

[0049] It is considered that the diamond coating specifically described in Patent Document 1 contains almost no hydrogen, and most of the carbon atoms have sp3 bonds that exhibit a diamond structure. In this case, the ratio [%] is typically (sp3:sp2:H) ≒ (100:0:0). In addition, the DLC specifically described in Patent Document 1 is amorphous carbon (hard carbon, or α carbon). It is known that amorphous carbon contains almost no hydrogen and has a crystal structure with a high sp2 ratio. In this case, the ratio [%] is typically (sp3:sp2:H) ≒ (0:100:0). Therefore, the diamond coating and DLC coating specifically described in Patent Document 1 are not included in the pre-coated PC according to this embodiment.

[0050] Next, the significance of configuring the precoat PC according to this embodiment as described above will be explained with reference to Fig. 7. Fig. 7 is a cross-sectional view showing the influence of the precoat PC on the above-mentioned suction force in chronological order. The precoat PC shown in Fig. 7 is a precoat PC according to this embodiment, and has a ratio [%] of the crystal structure contained in the above-mentioned quadrangle ABCD.

[0051] 7(a) shows a state in which a substrate W is placed on the surface of an electrostatic chuck 1111 having a precoat coat PC according to this embodiment formed on its substrate support surface 111a, and the substrate lower surface WB is in contact with the precoat coat PC. In this state, a charge E is supplied to the electrostatic electrode 1111b so that it is positively charged, and a relatively negative charge E is generated on the substrate W. These charges E attract each other and electrically attract each other. A part of the negative charge E on the substrate W is transferred to the precoat coat PC. However, the precoat coat PC has a sufficiently low conductivity (high insulation) and maintains the potential difference caused by the charge E between the electrostatic electrode 1111b and the substrate W, so that the electrostatic attraction is not weakened. Therefore, the substrate can be attracted and supported with a sufficient attracting force.

[0052] In FIG. 7(b), when dechucking, the supply of the positive charge E to the electrostatic chuck 1111 is stopped. At this time, a negative residual charge RE remains on the precoat coat PC, and a relatively positive residual charge RE occurs on the substrate W. In this state, the substrate W is pushed upward by a pin (not shown) provided on the main body 111. At this time, the contact between the substrate lower surface WB and the precoat coat PC moves away from the part close to the part pressed by the pin, and finally the contact is made at one point having a small area. The residual charge RE moves to the one point along with the substrate lower surface WB and the precoat coat PC moving away from each other. Therefore, at the one point, the opposite residual charges RE are concentrated on the substrate lower surface WB and the precoat coat PC, and a relatively large potential difference is generated. The attraction at the one point in the state where the residual charge RE occurs is called residual attraction. After the supply of the electric charge E is stopped, a neutralization process may be performed, if necessary, to reduce the residual electric charge RE on the electrostatic chuck 1111 by using a plasma electric field or by applying a reverse potential to the electrostatic chuck 1111. However, depending on the surface condition of the electrostatic chuck 1111, it may be difficult to completely suppress the residual electric charge even if the neutralization process is performed.

[0053] In Fig. 7(c), the precoat layer PC according to this embodiment has a conductivity sufficient to allow the residual charge RE to move between the substrate and the precoat layer PC at the relatively large potential difference as described above. The double-ended arrows in the figure indicate the movement of the residual charge RE. From the state shown in Fig. 7(b), the residual charge RE moves between the substrate underside WB and the precoat layer PC as shown in Fig. 7(c), and the potential difference is alleviated.

[0054] In Figure 7(d), the residual charge RE moves and the potential difference is alleviated, weakening the residual adhesion, and the pin's pushing force smoothly dechucking the substrate. The strength of such residual adhesion can be evaluated by the output of the pin pushing the substrate, i.e., the torque (pin torque). Specifically, if the pin torque is high during dechucking, the residual adhesion is strong, and if the pin torque is low, the residual adhesion is weak.

[0055] In addition, the movement of the residual charge RE between the substrate W and the precoat film PC according to this embodiment is possible when the substrate lower surface WB and the precoat film PC are in contact with each other at the above-mentioned point in a narrow range and a relatively large potential difference is generated as described above. Therefore, the electrical properties of the precoat film PC according to this embodiment do not impair the chucking force during normal electrostatic chucking by the electrostatic chuck 1111. In other words, the precoat film PC according to this embodiment has an electrical property that maintains the potential difference between the substrate W and the electrostatic electrode 1111b by a sufficiently low conductivity during normal electrostatic chucking as shown in FIG. 7(a), while having an electrical property that allows the residual charge RE to move under a relatively large potential difference when the residual charge RE is concentrated at the above-mentioned point as shown in FIG. 7(b) and (c).

[0056] Here, a case where a precoat PC as a comparative example having low conductivity is formed, unlike the precoat PC according to the present embodiment, will be described. Such a precoat PC as a comparative example has properties such as being included in the area to the left of the line segment AB in FIG. 6. In FIG. 7(b), the conductivity of the precoat PC as a comparative example is low, so the residual charge RE cannot move between the substrate W and the precoat PC. That is, the movement of the residual charge RE as shown by the double-ended arrow in the figure does not occur, and the potential difference cannot be relaxed as shown in FIG. 7(c). If the pin further presses the substrate in this state, it is considered that the chucking is suddenly released and the substrate W jumps up or is scratched. The chucking force in such a state is not appropriate.

[0057] According to the precoat PC of the present embodiment, residual adhesion can be suppressed by facilitating the movement of the residual charge RE during dechucking without weakening the force of the electrostatic chuck 1111 to attract the substrate W. The precoat PC of the present embodiment can be formed to have a surface property and hardness that does not physically damage the substrate lower surface WB due to friction with the substrate W and that makes the precoat PC itself less susceptible to damage. By forming the precoat PC in this manner, the replacement life of the electrostatic chuck 1111 can be extended. The precoat PC of the present embodiment can be formed to have a film density that prevents particles that may be generated from the surface of the electrostatic chuck 1111 from passing through the precoat PC and being released into the plasma processing space 10s. By forming the precoat PC in this manner, contamination can be suppressed.

[0058] <Second embodiment> Next, an etching method MT2 according to the second embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a cross-sectional view showing an outline of an electrostatic chuck 1111 on which a precoat PC and another coating layer CL are formed by the etching method MT2 according to the second embodiment. Fig. 9 is a flowchart showing an outline of the etching method MT2 according to the second embodiment.

[0059] 8, in the etching method MT2, using the above-mentioned plasma processing system, another coating layer CL is formed on the upper surface of the electrostatic chuck 1111, and a precoat PC satisfying the properties of the present disclosure is formed on the outermost surface in contact with the substrate lower surface WB. The precoat PC satisfying the properties of the present disclosure is specifically the precoat PC satisfying the properties described in the first embodiment. In this embodiment, when the above properties are satisfied, the same actions and effects as those described in the first embodiment are achieved.

[0060] The other coating layer CL is an insulating film. The other coating layer CL may not satisfy the properties of the precoat PC of the present disclosure. Specifically, the other coating layer CL may be a Si-containing film made of SiO2 or the like, or a C-containing film made of diamond coating or the like. The thickness of the other coating layer CL is preferably on the order of microns.

[0061] In FIG. 9, in the etching method MT2, another coating layer CL is formed prior to the formation of the precoat PC. Specifically, first, another coating layer forming gas such as a Si-containing gas or a C-containing gas is supplied into the plasma processing chamber 10 (step ST10). Then, plasma of the gas is generated to form another coating layer CL (step ST11). Then, a precoat gas is supplied to form a precoat PC on the other coating layer CL (steps ST12 and ST13). Then, the substrate W is carried into the plasma processing chamber 10 and placed on the substrate support surface 111a on which the precoat PC is formed, and substrate processing including etching is performed on the substrate W (step ST14). Then, the substrate W is carried out from the plasma processing chamber 10, and the precoat PC may be removed (step ST15). Details of the above steps ST12 to ST15 are the same as those of steps ST1 to ST4 in the etching method MT1 according to the first embodiment.

[0062] In one embodiment, after removing the precoat PC, it may be determined whether or not to continue the manufacturing process (step ST16). If it is decided to continue the manufacturing process in step ST16, the sequence of steps ST12 to ST16 is executed again, and the sequence is repeated in the same manner until the manufacturing process is terminated. That is, in this embodiment, the precoat PC is formed and removed every time a substrate process including etching is performed on the substrate W. If it is decided not to continue the manufacturing process in step ST16, the process is terminated.

[0063] In the etching method MT2, the conditions for plasma generation in steps ST10 and ST11, such as the pressure and flow rate of the other coating layer forming gas, the temperature in the chamber, the frequency and power of RF, can be known conditions depending on the type of the other coating layer forming gas and the characteristics of the other coating layer CL to be formed, such as the film thickness and insulating property, etc. In addition, the conditions for plasma generation in steps ST12 and ST13 can be the conditions described in the etching method MT1 according to the first embodiment.

[0064] In the etching method MT2, the other coating layer CL is formed by steps ST10 and ST11, but the present invention is not limited to this. In other words, it is sufficient that the other coating layer CL is formed so as to have the above characteristics and sufficient adhesion described later, and the other coating layer CL may be formed by a desired conventional method.

[0065] Next, in the second embodiment, the significance of configuring the precoat PC and the other coating layer CL as described above will be described. The electrostatic chuck 1111 is composed of a ceramic member 1111a, and particles such as ceramic chips may be generated from the surface of the ceramic member 1111a that has become weak due to continued substrate processing. The ceramic chips have excellent corrosion resistance and cannot be completely removed by dry cleaning, and may remain in the plasma processing chamber 10. Such ceramic chips may cause a loss of adhesion of the precoat PC to the components in the plasma processing chamber 10 on which the precoat PC is to be formed.

[0066] In contrast, in the etching method MT2 according to the second embodiment, another coating layer CL is formed, and a precoat PC is formed on the other coating layer CL. By using another coating layer CL that has sufficient adhesion to the above-mentioned components, the precoat PC formed on the other coating layer CL can be maintained in close contact with the above-mentioned components. The above-mentioned Si-containing film made of SiO2 or the like and the C-containing film made of diamond coat are examples of other coating layers CL that have sufficient adhesion to the above-mentioned components. Such other coating layers CL can maintain the adhesion of the precoat PC even if the above-mentioned ceramic fragments remain.

[0067] From another point of view, when the other coating layer CL is used alone, the other coating layer CL has the above-mentioned problem of residual adhesion because it is insulating. In addition, when the other coating layer CL is used alone, it is worn due to rubbing with the substrate W, etc., and therefore needs to be periodically re-applied (removed and re-formed). However, when the other coating layer CL is re-applied, the other coating layer CL has high mechanical stability, so strong cleaning using halogen gas is required, and such cleaning may damage the electrostatic chuck 1111. In response to this, by forming the pre-coat PC, which is relatively easy to re-apply, on the other coating layer CL, the pre-coat PC has the effect of protecting the other coating layer CL. As a result, only the pre-coat PC, which is relatively easy to re-apply, can be periodically re-applied, and the frequency of re-applying the other coating layer CL can be reduced. That is, in the second embodiment, the pre-coat PC complements the problem of residual adhesion in the other coating layer CL and the problem of difficulty in re-applying, and the other coating layer CL complements the problem of adhesion in the pre-coat PC. As a result, a suitable protective layer can be obtained that solves the problem of residual adhesion, has excellent adhesion, and is easy to maintain for re-applying.

[0068] <Third embodiment> Next, an etching method MT3 according to the third embodiment will be described with reference to Fig. 10. Fig. 10 is a flow chart showing an outline of the etching method MT3 according to the third embodiment. The outline of the configurations of the precoat PC and the other coating layer CL formed on the electrostatic chuck 1111 by the etching method MT3 is similar to that shown in Fig. 8 in the etching method MT2 according to the second embodiment. Moreover, steps ST10 to ST13 and ST15 in Fig. 10 are similar to those in the etching method MT2 according to the second embodiment.

[0069] 10, in the etching method MT3, when another coating layer CL is formed, a first sequence SQ1 including loading of the substrate W (step ST20), substrate processing (step ST21), and unloading of the substrate W (step ST22) is repeatedly executed until a first condition is satisfied. When the first condition is satisfied, the precoat PC is removed, and then a second sequence SQ2 including formation of the precoat PC (steps ST12, ST13), the first sequence SQ1 (steps ST20 to ST23), and removal of the precoat PC (step ST15) is repeatedly executed until a second condition is satisfied.

[0070] Here, the first condition may be the number of times the first sequence SQ1 is repeated (the number of processed substrates W), the number of processed lots of substrates W, or the plasma processing time.

[0071] The second condition may be the number of times the second sequence SQ2 is repeated (the number of processed substrates W), the number of processed lots of substrates W, or the plasma processing time.

[0072] According to the etching method MT3 of the third embodiment, in addition to the actions and effects of the etching methods MT1 and MT2 of the first and second embodiments, the following actions and effects are obtained. That is, the formed precoat layer PC can be continued to be used until the first condition is satisfied, and the precoat layer PC can be reapplied when the first condition is satisfied. This makes it possible to maintain the precoat layer PC having suitable properties. Also, according to the etching method MT3, the formed other coat layer CL can be continued to be used until the second condition is satisfied, and when the second condition is satisfied, the manufacturing process can be terminated and maintenance such as reapplying the other coat layer CL can be performed. This makes it possible to maintain the other coat layer CL having suitable properties and maintain the adhesion of the precoat layer PC in a suitable state.

[0073] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above embodiments may be omitted, substituted, or modified in various forms without departing from the scope of the appended claims, the configuration examples belonging to the technical scope of the present disclosure described below, and the gist thereof. For example, the components of the above embodiments may be arbitrarily combined. From such an arbitrary combination, the actions and effects of each of the components related to the combination can be obtained as a matter of course, and other actions and effects that are obvious to a person skilled in the art from the description of this specification can be obtained.

[0074] For example, in the etching methods MT1 to MT3, the plasma generation conditions such as the flow rate of the precoat gas, the temperature in the chamber, the frequency and power of the RF when forming the precoat PC are not limited, but may be the following conditions. That is, the flow rate of the precoat gas may be about 10 sccm to 1000 sccm. The chamber temperature may be about 10° C. to 80° C. The source RF power of the RF may be 1000 W or less. By adopting such conditions, the proportion of bonds with hydrogen atoms in the crystal structure of the formed precoat PC can be increased, and the ratio [%] can be set within the range of the rectangle ABCD. Also, the damage caused by the plasma to the electrostatic chuck 1111 can be suppressed to a low level.

[0075] For example, the above-mentioned precoat PC is formed as a single layer, that is, a layer of precoat PC formed by plasma of the above-mentioned precoat gas, but the present invention is not limited to this. Specifically, multiple types of precoat PC may be stacked by sequentially supplying multiple types of precoat gas to form a multi-layer precoat PC.

[0076] In addition, the effects described in this specification are merely explanatory or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification in addition to or in place of the above effects.

[0077] The following configurations also fall within the technical scope of the present disclosure.

[0078] (Appendix 1) (a) forming a carbon-containing film on a surface of an electrostatic chuck within a chamber; (b) placing a substrate on the carbon-containing film; (c) plasma etching the substrate; Including, The step (a) comprises: (a1) supplying a precoat gas containing carbon and hydrogen into the chamber and controlling the pressure in the chamber to 100 mTorr or more and 1000 mTorr or less; (a2) generating a plasma of the precoat gas; Etching method.

[0079] (Appendix 2) 2. The etching method according to claim 1, wherein the step (a) includes controlling a surface temperature of the electrostatic chuck to 10° C. or higher and 80° C. or lower.

[0080] (Appendix 3) 3. The etching method according to claim 1, wherein in the step (a1), a flow rate of the precoating gas is controlled to be 10 sccm or more and 1000 sccm or less.

[0081] (Appendix 4) The etching method according to any one of claims 1 to 3, wherein in the step (a2), a source RF power for generating the plasma is set to 1000 W or less.

[0082] (Appendix 5) The etching method according to any one of claims 1 to 4, wherein the precoating gas includes a hydrocarbon gas, a hydrofluorocarbon gas, or a mixed gas of at least one gas selected from the group consisting of a hydrocarbon gas, a hydrofluorocarbon gas, and a fluorocarbon gas, and a hydrogen-containing gas.

[0083] (Appendix 6) 6. The etching method according to claim 1, wherein the precoating gas contains a hydrocarbon gas.

[0084] (Appendix 7) 7. The etching method according to claim 1, wherein the precoating gas further contains an inert gas.

[0085] (Appendix 8) 8. The etching method according to claim 1, wherein the carbon-containing film contains H atoms in an amount of 20 atomic % or more and 50 atomic % or less.

[0086] (Appendix 9) In the carbon-containing film, in a ternary diagram showing the ratio [%] of the crystal structure of hydrocarbons, (sp3:sp2:H), the ratio is Point A(sp3:sp2:H)=(80:0:20), Point B(sp3:sp2:H)=(0:80:20), Point C(sp3:sp2:H)=(0:50:50), Point D(sp3:sp2:H)=(50:0:50) 9. The etching method according to claim 8, wherein the etching is performed within a range surrounded by a rectangle ABCD consisting of the four points.

[0087] (Appendix 10) 10. The etching method according to any one of claims 1 to 9, wherein the carbon-containing film has a thickness of 5 nm or more.

[0088] (Appendix 11) 11. The etching method according to claim 10, wherein the carbon-containing film has a thickness of 10 nm or more and 100 nm or less.

[0089] (Appendix 12) The electrostatic chuck has a plurality of protrusions on a surface thereof, 12. The etching method according to any one of claims 1 to 11, wherein the carbon-containing film is formed on at least an upper surface of the protrusion.

[0090] (Appendix 13) 13. The etching method according to claim 12, wherein a thickness of the carbon-containing film is smaller than a height of the convex portion.

[0091] (Appendix 14) The step (a) further includes, before the step (a1), a step of forming an insulating film on a surface of the electrostatic chuck; 14. The etching method according to any one of claims 1 to 13, wherein the carbon-containing film is formed on the insulating film.

[0092] (Appendix 15) The electrostatic chuck comprises: A ceramic member; at least one electrode disposed within the ceramic member; an insulating film on a surface of the ceramic member; Including, the insulating film is made of a material different from that of the ceramic member, 15. The etching method according to any one of claims 1 to 14, wherein the carbon-containing film is formed on the insulating film.

[0093] (Appendix 16) (d) removing the carbon-containing film; (e) repeating a sequence including the steps (a) to (d).

[0094] (Appendix 17) 17. The etching method according to claim 16, wherein the insulating film contains silicon or carbon.

[0095] (Appendix 18) The etching method according to any one of claims 1 to 13, further comprising the step of removing the carbon-containing film after performing a cycle including the step (b) and the step (c) one or more times.

[0096] (Appendix 19) 19. The etching method according to claim 18, wherein in the step of removing the carbon-containing film, the carbon-containing film is removed by plasma generated from an oxygen-containing gas.

[0097] (Appendix 20) (a) forming an insulating film on a surface of an electrostatic chuck in a chamber; (b) forming a carbon-containing film on the insulating film; (c) Until the first condition is met, (c1) carrying a substrate into the chamber and placing the substrate on the carbon-containing film; (c2) plasma etching the substrate; (c3) removing the substrate from the carbon-containing film and carrying it out of the chamber; repeating a first sequence including: (d) removing the carbon-containing film after the step (c); and (e) repeating a second sequence including steps (b) to (d) until a second condition is satisfied. Etching method.

[0098] (Appendix 21) A precoating method for forming a precoat film on a surface of an electrostatic chuck disposed in a chamber, comprising: supplying a precoat gas containing carbon and hydrogen into the chamber and controlling the pressure in the chamber to 100 mTorr or more and 1000 mTorr or less; and generating a plasma of the precoat gas. Precoat method.

[0099] (Appendix 22) a chamber having at least one gas inlet and at least one gas outlet; an electrostatic chuck disposed within the chamber; A plasma generating unit; A control unit; Equipped with The control unit is (a) forming a carbon-containing film on the electrostatic chuck; (b) disposing a substrate on the carbon-containing film; (c) plasma etching the substrate; configured to perform a process including The step (a) comprises: (a1) supplying a precoat gas containing carbon and hydrogen into the chamber and controlling the pressure in the chamber to 100 mTorr or more and 1000 mTorr or less; (a2) generating a plasma of the precoat gas; Etching equipment. [Explanation of symbols]

[0100] 10 Plasma Processing Chamber 111a Board support surface W substrate PC pre-coating MT Etching Method

Claims

1. A chamber and An electrostatic chuck is placed inside the chamber, A gas supply unit that supplies a precoat gas containing carbon and hydrogen into the chamber, An exhaust system for adjusting the pressure inside the chamber, A plasma generation unit that generates plasma from the precoat gas, Control unit and Equipped with, The control unit, (a) A step of supplying the precoat gas into the chamber using the gas supply unit, (b) A step of adjusting the pressure inside the chamber to 100 mTorr or more and 1000 mTorr or less using the exhaust system, (c) A step of generating plasma from the precoat gas using the plasma generation unit to form a carbon-containing film on the electrostatic chuck, A plasma processing apparatus configured to perform a process including the following.

2. Further comprising a temperature control module for adjusting the surface temperature of the electrostatic chuck, The plasma processing apparatus according to claim 1, wherein the control unit is configured to further perform a process of adjusting the surface temperature of the electrostatic chuck to 10°C or more and 80°C or less using the temperature control module during (c).

3. The electrostatic chuck is placed on a base, The plasma processing apparatus according to claim 2, wherein the temperature control module includes at least one heater disposed within the electrostatic chuck and at least one flow path configured for the circulation of a heat transfer medium within the base.

4. The gas supply unit includes a flow rate controller, The plasma processing apparatus according to claim 1, wherein the control unit controls the flow rate of the precoat gas to 10 sccm or more and 1000 sccm or less using the flow rate controller in (a).

5. The plasma generation unit includes an RF power supply that supplies source RF power for generating the plasma, The plasma processing apparatus according to claim 1, wherein the control unit controls the source RF power to 1000W or less using the RF power supply during (c).

6. The plasma processing apparatus according to claim 1, wherein the precoat gas comprises a hydrocarbon gas, a hydrofluorocarbon gas, or a mixed gas of at least one selected from the group consisting of hydrocarbon gas, hydrofluorocarbon gas, and fluorocarbon gas, and a hydrogen-containing gas.

7. The plasma processing apparatus according to claim 1, wherein the precoat gas includes a hydrocarbon gas.

8. The plasma processing apparatus according to claim 1, wherein the precoat gas further comprises an inert gas.

9. The plasma processing apparatus according to claim 1, wherein the control unit controls the thickness of the carbon-containing film to 5 nm or more using the gas supply unit, the exhaust system and the plasma generation unit in (c).

10. The plasma processing apparatus according to claim 9, wherein the control unit controls the thickness of the carbon-containing film to 10 nm or more and 100 nm or less in (c) using the gas supply unit, the exhaust system and the plasma generation unit.

11. The electrostatic chuck has a plurality of protrusions on its surface, The plasma processing apparatus according to claim 1, wherein the carbon-containing film is formed at least on the upper surface of the protrusion.

12. The plasma processing apparatus according to claim 11, wherein the thickness of the carbon-containing film is thinner than the height of the protrusion.

13. The plasma processing apparatus according to claim 1, wherein the control unit is configured to perform the step of forming an insulating film on the surface of the electrostatic chuck using the gas supply unit, the exhaust system and the plasma generation unit in (a), and then forming the carbon-containing film on the insulating film.

14. The control unit comprises the gas supply unit, the exhaust system and the plasma generation unit, (d) After (c) above, a step of plasma treatment of one or more substrates, (e) After (d) above, a step of removing the carbon-containing film, (f) A process of repeating (a) to (e) above, The plasma apparatus according to claim 13, configured to perform a process including the following:

15. The plasma processing apparatus according to claim 1, wherein the exhaust system includes a pressure regulating valve and a vacuum pump and is connected to a gas outlet located at the bottom of the chamber.

16. A chamber and An electrostatic chuck is placed inside the chamber, A gas supply unit that supplies a precoat gas containing carbon and hydrogen into the chamber, An exhaust system for adjusting the pressure inside the chamber to between 100 mTor and 1000 mTor, A plasma generation unit that generates plasma from the precoat gas and forms a carbon-containing film on the electrostatic chuck, A plasma processing apparatus equipped with the following features.

17. The plasma processing apparatus according to claim 16, further comprising a temperature control module for adjusting the surface temperature of the electrostatic chuck to 10°C or more and 80°C or less.

18. The electrostatic chuck is placed on a base, The plasma processing apparatus according to claim 17, wherein the temperature control module includes at least one heater disposed within the electrostatic chuck and at least one flow path configured for the circulation of a heat transfer medium within the base.

19. The plasma processing apparatus according to claim 16, wherein the plasma generation unit includes an RF power supply that supplies source RF power of 1000 W or less in order to generate the plasma.

20. The plasma processing apparatus according to claim 16, wherein the exhaust system includes a pressure regulating valve and a vacuum pump and is connected to a gas outlet located at the bottom of the chamber.

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