Plasma processing apparatus and method for suppressing abnormal discharge

Abstract

To control the generation of abnormal discharge.SOLUTION: In a chamber, a plasma processing is performed inside the chamber. A mounting stage is arranged in the chamber, and a ring assembly is mounted at a substrate and the circumference of the substrate. A fixation portion is provided in the mounting stage, and fixes at least one of the substrate and the ring assembly to the mounting stage. A heat transfer gas supply portion supplies heat transfer gas to between the mounting stage and at least one of the substrate and the ring assembly. A heat transfer gas exhaust portion exhausts the heat transfer gas from the mounting stage and at least one of the substrate and the ring assembly. An RF power source supplies an RF (Radio Frequency) signal for generating a plasma in the chamber. A control portion controls pressure of the heat transfer gas supplied from the heat transfer supply portion so that the pressure of heat transfer gas supplied becomes lower than that at the time of a plasma processing for the substrate when at least one of the substrate and the ring assembly is mounted on the mounting stage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus and a method for suppressing abnormal discharge. [Background technology]

[0002] Patent Document 1 discloses a configuration in which gases such as He, Ar, and Xe are supplied from a gas supply insulating boss to the back side of a focus ring. Patent Document 1 also discloses that the gas supply insulating boss is a part where abnormal discharge is likely to occur because the gas pressure therein is relatively high. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2008 / 0236751 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for suppressing the occurrence of abnormal discharge. [Means for solving the problem]

[0005] A plasma processing apparatus according to one aspect of the present disclosure includes a chamber, a mounting table, a fixing unit, a heat transfer gas supply unit, a heat transfer gas exhaust unit, an RF power supply, and a control unit. The chamber is configured to perform plasma processing. The mounting table is disposed within the chamber, and a substrate and a ring assembly are mounted around the substrate. The fixing unit is attached to the mounting table and fixes at least one of the substrate and the ring assembly to the mounting table. The heat transfer gas supply unit supplies a heat transfer gas between the mounting table and at least one of the substrate and the ring assembly. The heat transfer gas exhaust unit exhausts the heat transfer gas from between the mounting table and at least one of the substrate and the ring assembly. The RF power supply supplies a radio frequency (RF) signal for plasma generation into the chamber. When at least one of the substrate and the ring assembly is mounted on the mounting table, the control unit controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to be lower than that during plasma processing of the substrate before performing plasma processing on the substrate. [Effects of the Invention]

[0006] According to the present disclosure, the occurrence of abnormal discharge can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of a schematic configuration of a plasma processing system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of occurrence of abnormal discharge according to the embodiment. [Figure 3] FIG. 3 is a diagram schematically illustrating an example of a state during seasoning according to a comparative example. [Figure 4] FIG. 4 is a diagram schematically illustrating an example of a state during seasoning according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a flow of removing impurities according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a processing sequence of the abnormal discharge suppression method according to the embodiment. [Figure 7]FIG. 7 is a diagram illustrating another example of the flow of removing impurities according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating another example of the processing order of the abnormal discharge suppression method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the plasma processing apparatus and the method for suppressing abnormal discharge disclosed in the present application will be described in detail with reference to the drawings. Note that the disclosed plasma processing apparatus and the method for suppressing abnormal discharge are not limited to the embodiments.

[0009] A plasma processing apparatus is known that reduces the pressure inside a chamber and performs plasma processing such as plasma etching on a substrate. The plasma processing apparatus includes a mounting stage inside the chamber. The substrate is placed on the mounting stage, and a ring assembly such as a focus ring is mounted on the mounting stage to surround the substrate. A heat transfer gas such as helium is supplied between the mounting stage and the substrate or ring assembly for heat transfer.

[0010] In plasma processing apparatuses, abnormal discharge such as arcing may occur between the substrate or ring assembly and the stage, and therefore, a technique for suppressing the occurrence of abnormal discharge is desired.

[0011] [Embodiment] [Device configuration] An example of a plasma processing apparatus according to the present disclosure will be described. In the embodiment described below, the plasma processing apparatus according to the present disclosure is used as a plasma processing system. Fig. 1 is a diagram showing an example of a schematic configuration of a plasma processing system according to the embodiment.

[0012] An example of the configuration of a plasma processing system will be described below: Fig. 1 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus.

[0013] The plasma processing system includes a capacitively coupled plasma processing device 1 and a controller 2. The capacitively coupled plasma processing device 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing device 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 has at least one gas inlet for supplying at least one process gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically isolated from the plasma processing chamber 10 enclosure.

[0014] 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.

[0015] The substrate support 11 has a fixing portion. The fixing portion fixes at least one of the substrate W and the ring assembly 112. In this embodiment, the fixing portion fixes at least one of the substrate W and the ring assembly 112 to the substrate support 11 by electrostatic attraction. 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. In this embodiment, the electrostatic chuck 1111 corresponds to the fixing portion of the present disclosure. When electrostatically attracting the substrate W and the ring assembly 112, a voltage is applied to the electrostatic chuck 1111 from a DC power supply (not shown). The electrostatic chuck 1111 fixes the substrate W and the ring assembly 112 by electrostatic attraction. Note that another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 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. Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (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 (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. The conductive member of the base 1110 and at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0016] 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.

[0017] 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 path 1110a, or a combination thereof. A heat transfer fluid, such as brine or gas, flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed 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 unit configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a. The substrate support 11 may also be configured to supply a heat transfer gas from the heat transfer gas supply unit to a gap between the backside of the ring assembly 112 and the annular region 111b.

[0018] For example, a gas supply port 111d for discharging a heat transfer gas is formed in the central region 111a of the substrate support 11. A gas supply port 111e for discharging a heat transfer gas is formed in the annular region 111b of the substrate support 11. The substrate support 11 is provided with supply flow paths 115a and 115b, such as pipes, for supplying the heat transfer gas. The supply flow path 115a is connected to the gas supply port 111d. The supply flow path 115b is connected to the gas supply port 111e. The supply flow paths 115a and 115b are connected to a gas supply unit 116. The gas supply unit 116 is configured to supply a heat transfer gas, such as helium (He) gas or hydrogen (H2) gas, to the supply flow paths 115a and 115b by individually controlling the flow rate of the heat transfer gas. The gas supply unit 116 is also configured to exhaust the heat transfer gas from the supply flow paths 115a and 115b. The heat transfer gas supplied through the supply flow path 115a is discharged from the gas supply port 111d and supplied to the space between the substrate W and the central region 111a. The heat transfer gas supplied through the supply flow path 115b is discharged from the gas supply port 111e and supplied to the space between the ring assembly 112 and the annular region 111b. The heat transfer gas supplied to the space between the substrate W and the central region 111a is exhausted through the supply flow path 115a. The heat transfer gas supplied to the space between the ring assembly 112 and the annular region 111b is exhausted through the supply flow path 115b. The gas supply unit 116 corresponds to the heat transfer gas exhaust unit and the heat transfer gas exhaust unit of the present disclosure. The gas supply unit 116 may be configured as being divided into a section that supplies the heat transfer gas and a section that exhausts the heat transfer gas.

[0019] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and 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 showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0020] 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 one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0021] 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 process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. In addition, 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.

[0022] 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.

[0023] 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 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.

[0024] 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 bias 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.

[0025] In various embodiments, at least one of 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 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 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.

[0026] 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 regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0027] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The controller 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 controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include a processor 2a1, a storage unit 2a2, and a communication interface 2a3. The controller 2 may be implemented by, for example, a computer 2a. The processor 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 processor 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 processor 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).

[0028] Next, a flow of performing plasma processing, such as plasma etching, on a substrate W using the plasma processing system according to the embodiment will be briefly described. The substrate W is placed on the substrate support 11 by a transfer mechanism, such as a transfer arm (not shown). When performing plasma processing on the substrate W, the plasma processing apparatus 1 reduces the pressure inside the plasma processing chamber 10 using the exhaust system 40. The electrostatic chuck 1111 fixes the substrate W and the ring assembly 112 by electrostatic attraction. The controller 2 controls the power supply 30 to apply high-frequency power for attraction to the substrate support 11 when the electrostatic chuck 1111 electrostatically attracts the substrate W and the ring assembly 112. For example, the controller 2 controls the power supply 30 to apply high-frequency power to the substrate support 11 so that the electrostatic chuck 1111 can electrostatically attract the substrate W and the ring assembly 112. The plasma processing apparatus 1 supplies a process gas from the gas supply unit 20 and introduces the process gas into the plasma processing chamber 10 through the showerhead 13. The plasma processing apparatus 1 generates plasma in the plasma processing space 10s by supplying at least one RF signal from the RF power supply 31, and performs plasma processing on the substrate W.

[0029] In the plasma processing apparatus 1, problems may occur between the substrate W or the ring assembly 112 and the substrate support part 11. For example, abnormal discharge such as arcing may occur between the substrate W or the ring assembly 112 and the substrate support part 11.

[0030] FIG. 2 is a diagram illustrating an example of the occurrence of abnormal discharge according to the embodiment. FIG. 2 is an enlarged schematic view of the vicinity of a substrate support 11 of a plasma processing chamber 10. The substrate support 11 has a central region 111a on which a substrate W is placed, and an annular region 111b on which a ring assembly 112 is placed so as to surround the periphery of the substrate W. A gas supply port 111d is formed in the central region 111a of the substrate support 11. A gas supply port 111e is formed in the annular region 111b of the substrate support 11. The gas supply port 111d communicates with a supply passage 115a, and a heat transfer gas is supplied from a gas supply unit 116 via the supply passage 115a. The gas supply port 111e communicates with a supply passage 115b, and a heat transfer gas is supplied from a gas supply unit 116 via the supply passage 115b. The gas supply ports 111d and 111e discharge the heat transfer gas supplied from the gas supply unit .

[0031] The substrate support surface 111a is provided with an annular band along the outer periphery of the substrate W, and the band supports the outer periphery of the substrate W. In addition, the substrate support surface 111a is formed with dots (not shown) that support the substrate W. A space is formed between the substrate W and the central region 111a, through which a heat transfer gas can flow.

[0032] In the annular region 111b, annular bands are provided along the inner and outer peripheries of the ring assembly 112, and the bands support the inner and outer peripheries of the ring assembly 112. In addition, in the annular region 111b, dots (not shown) are formed to support the ring assembly 112. A space is formed between the ring assembly 112 and the annular region 111b, through which a heat transfer gas can flow.

[0033] In the plasma processing apparatus 1, the ring assembly 112 gradually wears out due to plasma processing. When the ring assembly 112 wears out, it is replaced. The replaced ring assembly 112 has moisture attached to it. When the ring assembly 112 is replaced in the plasma processing apparatus 1, seasoning (start-up processing) is performed by repeatedly generating plasma to remove moisture and stabilize the conditions inside the plasma processing chamber 10. For example, when performing seasoning, the plasma processing apparatus 1 reduces the pressure inside the plasma processing chamber 10 using the exhaust system 40, as in the case of plasma processing. The electrostatic chuck 1111 fixes the substrate W and the ring assembly 112 by electrostatic attraction. When the electrostatic chuck 1111 electrostatically attracts the substrate W, the power supply 30 applies high-frequency power for attraction to the substrate support member 11 in the plasma processing apparatus 1. The plasma processing apparatus 1 supplies a process gas from the gas supply unit 20 and introduces the process gas into the plasma processing chamber 10 from the showerhead 13. The process gas may be the same as that used in plasma processing, or a specific type of gas for seasoning. The plasma processing apparatus 1 then performs seasoning by supplying at least one RF signal from the RF power supply 31 to generate plasma in the plasma processing space 10s. In seasoning, plasma generation is repeatedly performed until a stable state is reached inside the plasma processing chamber 10. Seasoning is performed before performing plasma processing on the substrate W in the manufacturing process for manufacturing semiconductor devices. Seasoning may be performed by placing a substrate W, such as a dummy wafer, on the substrate support 11.

[0034] However, during seasoning, residual moisture may cause abnormal discharge such as arcing between the ring assembly 112 and the substrate support 11. For example, when the ring assembly 112 is replaced, abnormal discharge such as arcing may occur near the gas supply port 111e or in the supply flow path 115b.

[0035] Furthermore, defects may occur due to impurities adhering to the rear surface of the substrate W or the ring assembly 112. For example, when the substrate W or the ring assembly 112 is replaced, abnormal discharge such as arcing may occur near the gas supply port 111d, near the gas supply port 111e, or inside the supply flow path 115a and the supply flow path 115b.

[0036] Therefore, in this embodiment, when the control unit 2 replaces at least one of the substrate W and the ring assembly 112, before performing plasma processing on the substrate W, it controls the pressure of the heat transfer gas supplied from the gas supply unit 116 to be lower than that during plasma processing on the substrate W.

[0037] For example, when the ring assembly 112 is replaced, the control unit 2 controls the pressure of the heat transfer gas supplied from the gas supply unit 116 between the substrate support unit 11 and the ring assembly 112 during seasoning to be lower than that during plasma processing of the substrate W, and controls the power of the high-frequency power supplied from the power source 30 to be lower than that during plasma processing of the substrate W.

[0038] In addition, when the substrate W or the ring assembly 112 is replaced, the control unit 2 controls the gas supply unit 116 to supply and exhaust heat transfer gas between the replaced substrate W or ring assembly 112 and the substrate support unit 11 at least once before performing plasma processing on the substrate W.

[0039] The amount of moisture released from the silicon surface increases at temperatures above 200°C, and becomes even larger at temperatures between 300°C and 400°C. Therefore, during seasoning, the temperature of the ring assembly 112 is preferably 200°C or higher, and more preferably 300°C or higher. For example, during seasoning, the temperature of the ring assembly 112 is more preferably 300°C to 400°C.

[0040] As a comparative example, the plasma processing apparatus 1 performs seasoning by setting the pressure of the heat transfer gas supplied from the gas supply unit 116 and the power of the high-frequency power supplied from the power supply 30 to the same values ​​as those used during plasma processing of the substrate W. In this case, the heat input from the plasma can sufficiently increase the temperature of the ring assembly 112, allowing moisture adhering to the ring assembly 112 to be removed in a short time. FIG. 3 is a schematic diagram illustrating an example of a state during seasoning according to the comparative example. FIG. 3 schematically illustrates the state near the annular region 111b of the substrate support unit 11. FIG. 3 illustrates a case in which the pressure of the heat transfer gas supplied from the gas supply unit 116 and the power of the high-frequency power supplied from the power supply 30 during seasoning are the same as those used during plasma processing of the substrate W. In FIG. 3, the temperature of the ring assembly 112 is 350°C. This allows moisture to be rapidly released from the ring assembly 112. However, moisture released from the ring assembly 112 may cause abnormal discharges such as arcing near the gas supply port 111e or in the supply flow path 115b. Therefore, it is conceivable to suppress the occurrence of abnormal discharges by reducing the power of the high-frequency power supplied from the power supply 30 during seasoning compared to that during plasma processing of the substrate W. However, if the power of the high-frequency power is reduced, the heat input from the plasma to the ring assembly 112 decreases, and the temperature of the ring assembly 112 does not rise sufficiently. While this can suppress the occurrence of abnormal discharges, it takes longer to remove the moisture, and therefore the seasoning time becomes longer.

[0041] Therefore, in this embodiment, when the ring assembly 112 is replaced, the control unit 2 controls the pressure of the heat transfer gas supplied from the gas supply unit 116 between the substrate support unit 11 and the ring assembly 112 during seasoning to be lower than that during plasma processing of the substrate W, and controls the power of the high-frequency power supplied from the power source 30 to be lower than that during plasma processing of the substrate W.

[0042] For example, during seasoning, the control unit 2 controls the pressure of the heat transfer gas supplied from the gas supply unit 116 between the substrate support unit 11 and the ring assembly 112 to 15 Torr or less. For example, the control unit 2 controls the supply of heat transfer gas from the gas supply unit 116 to be stopped or to be minimized to minimize the supply of heat transfer gas. This reduces heat transfer from the substrate W to the annular region 111b of the substrate support unit 11, and makes it possible to sufficiently increase the temperature of the ring assembly 112 even when the radio frequency power is reduced.

[0043] As described above, the amount of moisture released from the silicon surface increases at temperatures above 200°C. During seasoning, the control unit 2 controls the power supply 30 to supply high-frequency power at a power level equal to or lower than that used during plasma processing of the substrate W and at which the temperature of the substrate W is 200°C or higher. For example, even when the pressure of the heat transfer gas is reduced, the high-frequency power level at which the temperature of the substrate W is 200°C or higher is determined in advance through experiments and simulations. As an example, the high-frequency power level at which the temperature of the substrate W is 300°C to 400°C is determined. The control unit 2 controls the power supply 30 to supply high-frequency power at the previously determined power level. FIG. 4 is a schematic diagram illustrating an example of a state during seasoning according to this embodiment. FIG. 4 schematically illustrates a state near the annular region 111b of the substrate support unit 11. FIG. 4 illustrates a case in which the pressure of the heat transfer gas supplied from the gas supply unit 116 is reduced to a level lower than that used during plasma processing of the substrate W, and the power of the high-frequency power supplied from the power supply 30 is reduced to a level lower than that used during plasma processing of the substrate W. 4, the temperature of the ring assembly 112 is 400°C. This allows moisture adhering to the ring assembly 112 to be removed in a short time. Furthermore, by lowering the pressure of the heat transfer gas, it is possible to suppress the occurrence of abnormal discharge such as arcing near the gas supply port 111e and within the supply flow path 115b.

[0044] Furthermore, as described above, defects may occur due to impurities adhering to the rear surface of the substrate W or the ring assembly 112. For example, when the substrate W or the ring assembly 112 is replaced, abnormal discharge such as arcing may occur near the gas supply port 111d, near the gas supply port 111e, or inside the supply flow path 115a and the supply flow path 115b.

[0045] Therefore, in this embodiment, when the substrate W or the ring assembly 112 is replaced, the control unit 2 controls the gas supply unit 116 to supply and exhaust a heat transfer gas at least once between the replaced substrate W or ring assembly 112 and the substrate support unit 11 before performing plasma processing on the substrate W. For example, the control unit 2 controls the gas supply unit 116 to alternately supply and exhaust a heat transfer gas multiple times. FIG. 5 is a diagram illustrating an example of a flow of removing impurities according to this embodiment. FIG. 5 schematically illustrates a state near the annular region 111b of the substrate support unit 11. The upper side of FIG. 5 illustrates a state in which a heat transfer gas is supplied between the ring assembly 112 and the substrate support unit 11. The lower side of FIG. 5 illustrates a state in which the heat transfer gas is exhausted between the ring assembly 112 and the substrate support unit 11. In the upper side of FIG. 5, impurities 120 are attached to the rear surface of the ring assembly 112. The heat transfer gas is exhausted to reduce the pressure of the heat transfer gas, and by reducing the pressure of the heat transfer gas to a level lower than that during plasma processing of the substrate W, the impurities 120 flow into the supply flow path 115b and are removed, as shown in the lower part of Fig. 5. This makes it possible to suppress abnormal discharge such as arcing caused by the impurities 120.

[0046] Next, a process flow of the abnormal discharge suppression method performed by the plasma processing apparatus 1 according to the embodiment will be described. FIG. 6 is a diagram illustrating an example of the process sequence of the abnormal discharge suppression method according to the embodiment. FIG. 6 shows the process of the abnormal discharge suppression method applied to suppressing abnormal discharge in the ring assembly 112. The ring assembly 112 is placed on the substrate support 11, for example, when the plasma processing apparatus 1 is newly started up, during maintenance of the plasma processing apparatus 1, or when the ring assembly 112 is replaced due to wear. When the ring assembly 112 is placed on the substrate support 11, the plasma processing apparatus 1 seasons the ring assembly 112. The process shown in FIG. 6 is performed when seasoning the ring assembly 112.

[0047] The control unit 2 controls the exhaust system 40, and the exhaust system 40 reduces the pressure inside the plasma processing chamber 10 (S10).

[0048] The control unit 2 fixes the ring assembly 112 to the substrate support unit 11 (S11). For example, the control unit 2 controls a DC power supply (not shown) to apply a voltage to the electrostatic chuck 1111, and also controls the power supply 30 to apply high-frequency power for attraction from the power supply 30 to the substrate support unit 11, thereby fixing the ring assembly 112 to the substrate support unit 11 by electrostatic attraction.

[0049] The control unit 2 controls the gas supply unit 116 to supply a heat transfer gas between the ring assembly 112 and the substrate support unit 11 from the gas supply unit 116 (S12). The control unit 2 controls the gas supply unit 116 to exhaust the heat transfer gas between the ring assembly 112 and the substrate support unit 11 by the gas supply unit 116 (S13).

[0050] The control unit 2 determines whether the supply and exhaust of the heat transfer gas have been repeated a predetermined number of times (S14). The predetermined number of times is determined in advance through experiments or simulations as the number of times that can remove the impurities 120. If the predetermined number of times has not been performed (S14: No), the process proceeds to the process of S12 described above.

[0051] On the other hand, if the predetermined number of times has been performed (S14: Yes), the control unit 2 executes a process to remove moisture (S15). For example, the control unit 2 controls the gas supply unit 20 to supply a process gas from the gas supply unit 20 and introduce the process gas into the plasma processing chamber 10 through the shower head 13. The control unit 2 also controls the gas supply unit 116 to reduce the pressure of the heat transfer gas supplied from the gas supply unit 116 between the substrate support unit 11 and the ring assembly 112 to a level lower than that used during plasma processing of the substrate W. The control unit 2 also controls the power supply 30 to reduce the power of the high-frequency power supplied from the power supply 30 to a level lower than that used during plasma processing of the substrate W. For example, the control unit 2 controls the power supply 30 to supply an RF signal with a power lower than that used during plasma processing of the substrate W and that will raise the temperature of the substrate W to 200°C or higher. The control unit 2 may also execute the process of S15 in parallel with the processes of S12 and S13. As a result, in the plasma processing apparatus 1, plasma is generated in the plasma processing chamber 10, and moisture is removed from the ring assembly 112.

[0052] This makes it possible to suppress the occurrence of abnormal discharge such as arcing between the ring assembly 112 and the substrate support portion 11.

[0053] In the above embodiment, the abnormal discharge suppression method is described as an example of performing the process during seasoning. However, this is not limiting. The abnormal discharge suppression method may also be performed when the substrate W is replaced. For example, impurities 120 adhering to the rear surface of the substrate W may cause defects. Therefore, when the substrate W is replaced, the control unit 2 may control the gas supply unit 116 to supply and exhaust a heat transfer gas between the replaced substrate W and the substrate support unit 11 at least once before performing plasma processing on the substrate W. FIG. 7 is a diagram illustrating another example of the flow of impurity removal according to the embodiment. FIG. 7 schematically illustrates a state near the central region 111a of the substrate support unit 11. The upper side of FIG. 7 illustrates a state in which a heat transfer gas is supplied between the substrate W and the substrate support unit 11. The lower side of FIG. 7 illustrates a state in which the heat transfer gas is exhausted between the substrate W and the substrate support unit 11. In the upper side of FIG. 7, impurities 120 are adhering to the rear surface of the substrate W. The heat transfer gas is exhausted to reduce the pressure of the heat transfer gas, and by reducing the pressure of the heat transfer gas to a level lower than that during plasma processing of the substrate W, the impurities 120 flow into the supply flow path 115a and are removed, as shown in the lower part of Fig. 7. This makes it possible to remove the impurities 120 adhering to the rear surface of the substrate W, and to suppress abnormal discharge such as arcing caused by the impurities 120.

[0054] 8 is a diagram illustrating another example of the processing order of the abnormal discharge suppression method according to the embodiment. FIG. 8 shows the application of the processing of the abnormal discharge suppression method according to the embodiment to suppress abnormal discharge in a substrate W. For example, when performing plasma processing in the plasma processing apparatus 1, the substrate W is placed on the substrate support part 11. When the substrate W is placed on the substrate support part 11, the plasma processing apparatus 1 performs the processing shown in FIG. 8 before performing plasma processing on the substrate W.

[0055] The control unit 2 controls the exhaust system 40, and the exhaust system 40 reduces the pressure inside the plasma processing chamber 10 (S20).

[0056] The control unit 2 controls the gas supply unit 116 to introduce a processing gas from the gas supply unit 116 into the plasma processing chamber 10 (S21). For example, the control unit 2 controls the gas supply unit 116 to supply a processing gas from the gas supply unit 116 to introduce Ar gas into the plasma processing chamber 10.

[0057] The control unit 2 controls the power supply 30 to supply an RF signal having a power lower than that used during plasma processing of the substrate W from the RF power supply 31 into the plasma processing chamber 10 (S22). For example, the control unit 2 supplies an RF signal having a relatively low power, such as 300 W, from the RF power supply 31 to the conductive member functioning as the lower electrode of the base 1110 to generate weak plasma, and causes this weak plasma to act on the substrate W.

[0058] In the process of S21, Ar gas is used as the processing gas, and the Ar gas plasma is applied to the substrate W. However, the type of processing gas is not limited to this. The processing gas may be, for example, O2 gas, CF4 gas, N2 gas, or the like. However, the processing gas must be a gas type that generates plasma that has little undesirable effects, such as etching, on the substrate W and the inner wall of the plasma processing chamber 10. The processing gas must also be a gas type that easily ignites the plasma. Furthermore, the optimal type of processing gas may vary depending on the type of processing that the substrate W to be plasma-processed underwent in a previous process. It is preferable to select the processing gas appropriately, taking these factors into consideration.

[0059] The reason why a weak plasma is applied to the substrate W is as follows: The state of the substrate W to be subjected to plasma processing is not uniform, depending on the processing state in the previous process (for example, a film formation process such as CVD). For example, the substrate W may have accumulated electric charge inside. If a strong plasma is applied to a substrate W with accumulated electric charge inside, there is a high possibility that surface arcing or the like will occur. For this reason, a weak plasma is applied to the substrate W before a strong plasma is applied. When the weak plasma is applied to the substrate W, the state of the electric charge accumulated inside the substrate W is uniformly adjusted (initialized).

[0060] A weak plasma is applied to the substrate W without applying a DC voltage (HV) to the electrostatic chuck 1111. This makes it possible to facilitate the movement of charges inside the substrate W.

[0061] The RF signal power required to generate such a weak plasma is 0.15 W / cm2 to 1.0 W / cm2. 2 The power is, for example, about 100 to 500 W. The time for which the weak plasma is applied to the substrate W is, for example, about 5 to 20 seconds.

[0062] The control unit 2 fixes the substrate W to the substrate support unit 11 by electrostatic adsorption (S23). For example, the control unit 2 controls a DC power supply (not shown) to apply a voltage to the electrostatic chuck 1111, thereby fixing the substrate W to the substrate support unit 11 by electrostatic adsorption.

[0063] The control unit 2 controls the gas supply unit 116 to supply a heat transfer gas between the substrate W and the substrate support unit 11 from the gas supply unit 116 (S24). The control unit 2 controls the gas supply unit 116 to exhaust the heat transfer gas between the substrate W and the substrate support unit 11 by the gas supply unit 116 (S25).

[0064] The control unit 2 determines whether the supply and exhaust of the heat transfer gas have been repeated a predetermined number of times (S26). The predetermined number of times is determined in advance through experiments or simulations as the number of times that can remove the impurities 120. If the predetermined number of times has not been performed (S26: No), the process proceeds to the above-mentioned S24.

[0065] On the other hand, if the predetermined number of times has been performed (S26: Yes), the control unit 2 executes a process for removing moisture (S27). For example, the control unit 2 controls the gas supply unit 20 to supply a process gas from the gas supply unit 20 and introduce the process gas into the plasma processing chamber 10 through the shower head 13. The control unit 2 also controls the gas supply unit 116 to reduce the pressure of the heat transfer gas supplied from the gas supply unit 116 between the substrate support unit 11 and the substrate W to a level lower than that used during plasma processing of the substrate W. The control unit 2 also controls the power supply 30 to reduce the power of the high-frequency power supplied from the power supply 30 to a level lower than that used during plasma processing of the substrate W. For example, the control unit 2 controls the power supply 30 to supply an RF signal with a power lower than that used during plasma processing of the substrate W and that will raise the temperature of the substrate W to 200°C or higher. The control unit 2 also supplies a bias RF signal from the RF power supply 31 to the substrate support unit 11 during steps S24, S25, and S27. The control unit 2 may perform the process of S27 in parallel with the processes of S24 and S25. As a result, in the plasma processing apparatus 1, plasma is generated in the plasma processing chamber 10, and moisture is removed from the substrate W.

[0066] This makes it possible to prevent abnormal discharge such as arcing between the substrate W and the substrate support 11.

[0067] As described above, the plasma processing apparatus 1 according to the embodiment includes the plasma processing chamber 10, the substrate support 11 (mounting table), the electrostatic chuck 1111 (fixing unit), the gas supply unit 116 (heat transfer gas supply unit, heat transfer gas exhaust unit), the power supply 30 (RF power supply), and the controller 2. The plasma processing chamber 10 is used for plasma processing. The substrate support 11 is disposed within the plasma processing chamber 10, and the substrate W and the ring assembly 112 are mounted around the substrate W. The electrostatic chuck 1111 is provided on the substrate support 11 and fixes at least one of the substrate W and the ring assembly 112 to the substrate support 11. The gas supply unit 116 supplies a heat transfer gas between the substrate W support 11 and at least one of the substrate W and the ring assembly 112. The gas supply unit 116 exhausts the heat transfer gas from between the substrate W support 11 and at least one of the substrate W and the ring assembly 112. The power supply 30 supplies an RF signal for generating plasma into the plasma processing chamber 10. When at least one of the substrate W and the ring assembly 112 is placed on the substrate support part 11, the control part 2 controls the pressure of the heat transfer gas supplied from the gas supply part 116 to be lower than that during plasma processing of the substrate W, before performing plasma processing on the substrate W. This allows the plasma processing apparatus 1 to suppress the occurrence of abnormal discharges such as arcing between the substrate W or the ring assembly 112 and the substrate support part 11.

[0068] The control unit 2 executes (a) a step (S12) of supplying a heat transfer gas between the substrate support unit 11 and the ring assembly 112, and (b) a step (S13) of lowering the pressure of the heat transfer gas supplied between the substrate support unit 11 and the ring assembly 112 to a level lower than that in (a). This allows the plasma processing apparatus 1 to suppress the occurrence of abnormal discharge such as arcing between the ring assembly 112 and the substrate support unit 11.

[0069] Furthermore, the control unit 2 controls the gas supply unit 116 to supply and exhaust the heat transfer gas at least once between the ring assembly 112 and the substrate support unit 11 before performing plasma processing on the substrate W. This allows the plasma processing apparatus 1 to remove impurities 120 adhering to the rear surface of the ring assembly 112, and suppress the occurrence of abnormal discharges such as arcing caused by the impurities 120.

[0070] In steps (a) and (b) (S12 and S13), the control unit 2 controls the power source 30 to supply an RF signal with a power that is equal to or lower than that during plasma processing of the substrate W and that raises the temperature of the substrate W to 200° C. or higher. This allows the plasma processing apparatus 1 to quickly remove moisture adhering to the ring assembly 112.

[0071] In step (S13) of (b), the control unit 2 controls the pressure of the heat transfer gas supplied from the gas supply unit 116 to between the substrate support unit 11 and the ring assembly 112 to 15 Torr or less. This allows the plasma processing apparatus 1 to suppress the occurrence of abnormal discharge such as arcing between the ring assembly 112 and the substrate support unit 11 even when an RF signal is supplied into the plasma processing chamber 10.

[0072] The control unit 2 controls the gas supply unit 116 to alternately supply and exhaust the heat transfer gas multiple times. This allows the plasma processing apparatus 1 to remove impurities 120 adhering to the rear surface of the substrate W or the ring assembly 112.

[0073] The electrostatic chuck 1111 fixes the ring assembly 112 to the substrate support 11 by electrostatic attraction. This allows the plasma processing apparatus 1 to stably fix the ring assembly 112 to the substrate support 11.

[0074] The heat transfer gas is helium gas or hydrogen gas, which allows the plasma processing apparatus 1 to stably transfer heat between the substrate W support part 11 and the substrate W and ring assembly 112.

[0075] When the substrate W is placed on the substrate support part 11, the control part 2 controls the gas supply part 116 to supply and exhaust a heat transfer gas between the substrate W and the substrate support part 11 at least once before performing plasma processing on the substrate W. This allows the plasma processing apparatus 1 to remove impurities 120 adhering to the back surface of the substrate W and suppress the occurrence of abnormal discharge such as arcing caused by the impurities 120.

[0076] The electrostatic chuck 1111 fixes the substrate W to the substrate support part 11 by electrostatic attraction. This allows the plasma processing apparatus 1 to fix the substrate W to the substrate support part 11 stably.

[0077] The control unit 2 executes the following steps: (a) introducing a processing gas into the plasma processing chamber 10 (S21), (b) supplying an RF signal from an RF power source into the plasma processing chamber 10 with a power lower than that used during plasma processing on the substrate W (S22), (c) electrostatically attracting the substrate W to the substrate support member 11 (S23), (d) supplying and exhausting a heat transfer gas between the substrate W and the substrate support member 11 at least once (S24, S25), and (e) supplying the processing gas and an RF signal for plasma generation into the plasma processing chamber 10 (S26). As a result, the plasma processing apparatus 1 can suppress the occurrence of abnormal discharge such as arcing between the substrate W and the substrate support member 11.

[0078] Between steps S24, S25, and S27, the control unit 2 executes a step of supplying a bias RF signal (bias signal) from the RF power supply 31 (bias power supply) to the substrate support unit 11. As a result, the plasma processing apparatus 1 generates a bias potential on the substrate W, and can attract ion components in the formed plasma to the substrate W.

[0079] Although the embodiments have been described above, the disclosed embodiments should be considered to be illustrative in all respects and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the claims.

[0080] For example, in the above embodiment, the plasma processing is performed on a semiconductor wafer as the substrate W, but the present invention is not limited to this. The substrate W may be any type.

[0081] In the above embodiment, the supply flow paths 115a and 115b are used to supply and exhaust the heat transfer gas, but this is not limiting. Separate flow paths may be provided for supplying and exhausting the heat transfer gas.

[0082] In the above embodiment, the substrate W and the ring assembly 112 are fixed to the substrate support part 11 by electrostatic attraction using the electrostatic chuck 1111, but the present invention is not limited to this. The substrate W and the ring assembly 112 may also be fixed to the substrate support part 11 by a physical fixing mechanism such as a hook.

[0083] In the above embodiment, the plasma processing apparatus 1 is described as performing plasma etching as a plasma process, but the present invention is not limited to this. The plasma processing apparatus 1 may be any apparatus that performs plasma processing on a substrate W. For example, the plasma processing apparatus 1 may be a film forming apparatus that generates plasma and forms a film.

[0084] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0085] In addition, the following supplementary notes are disclosed regarding the above-described embodiment.

[0086] (Appendix 1) a chamber in which the plasma processing is performed; a mounting table disposed within the chamber, on which the substrate and the ring assembly are mounted around the substrate; a fixing portion provided on the mounting table for fixing at least one of the substrate and the ring assembly to the mounting table; a heat transfer gas supply unit that supplies a heat transfer gas between the mounting table and at least one of the substrate and the ring assembly; a heat transfer gas exhaust unit configured to exhaust the heat transfer gas from between the mounting table and at least one of the substrate and the ring assembly; an RF (Radio Frequency) power supply that supplies an RF signal for generating plasma into the chamber; a control unit that, when at least one of the substrate and the ring assembly is placed on the mounting table, controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to be lower than that during the plasma processing of the substrate before performing plasma processing on the substrate; A plasma processing apparatus comprising:

[0087] (Appendix 2) The control unit (a) supplying a heat transfer gas between the mounting table and the ring assembly; (b) reducing the pressure of the heat transfer gas supplied between the mounting table and the ring assembly to a level lower than that of (a); 2. The plasma processing apparatus according to claim 1,

[0088] (Appendix 3) The control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit to supply and exhaust a heat transfer gas between the ring assembly and the mounting table at least once before performing plasma processing on the substrate. 3. The plasma processing apparatus according to claim 2.

[0089] (Appendix 4) The control unit controls the RF power source to supply an RF signal with a power equal to or lower than that during plasma processing of the substrate and that will raise the temperature of the substrate to 200° C. or higher in the steps (a) and (b). 3. The plasma processing apparatus according to claim 2.

[0090] (Appendix 5) In the step (b), the control unit controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to between the mounting table and the ring assembly to 15 Torr or less. 3. The plasma processing apparatus according to claim 2.

[0091] (Appendix 6) The control unit controls the heat transfer gas supply unit so that the supply and exhaust of the heat transfer gas are alternately performed multiple times. 4. The plasma processing apparatus according to claim 3.

[0092] (Appendix 7) The fixing portion fixes the ring assembly to the mounting table by electrostatic attraction. 7. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus.

[0093] (Appendix 8) The heat transfer gas is helium gas or hydrogen gas. 8. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus.

[0094] (Appendix 9) When the substrate is placed on the stage, the control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit so that a heat transfer gas is supplied and exhausted between the substrate and the stage at least once before plasma processing is performed on the substrate. 2. The plasma processing apparatus according to claim 1.

[0095] (Appendix 10) The control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit so that the supply and exhaust of the heat transfer gas are alternately performed multiple times. 10. The plasma processing apparatus according to claim 9.

[0096] (Appendix 11) The fixing unit fixes the substrate to the mounting table by electrostatic adsorption. 11. The plasma processing apparatus according to claim 1.

[0097] (Appendix 12) The control unit (a) introducing a process gas into the chamber; (b) supplying an RF signal from the RF power source into the chamber, the RF signal having a power lower than that used during plasma processing of the substrate; (c) electrostatically attracting the substrate to the mounting table; (d) supplying and exhausting a heat transfer gas between the substrate and the stage at least once; (e) supplying a process gas and an RF signal for generating the plasma into the chamber. 12. The plasma processing apparatus according to claim 11.

[0098] (Appendix 13) a bias power supply; the control unit executes a step of supplying a bias signal from the bias power supply to the mounting table between steps (d) and (e). 13. The plasma processing apparatus according to claim 12.

[0099] (Appendix 14) placing at least one of a substrate and a ring assembly placed around the substrate on a stage disposed in a chamber in which plasma processing is performed; before performing plasma processing on the substrate, reducing the pressure of a heat transfer gas supplied between the stage and at least one of the substrate and the ring assembly to a level lower than that during plasma processing on the substrate; The abnormal discharge suppression method includes:

[0100] (Appendix 15) a chamber in which the plasma processing is performed; a mounting table disposed in the chamber and on which the substrate and a ring-shaped ring assembly are mounted around the substrate; a fixing portion provided on the mounting table and configured to fix at least one of the substrate and the ring assembly; a supply unit for supplying a heat transfer gas between the stage and at least one of the substrate and the ring assembly; a power supply unit that supplies high-frequency power for generating plasma in the chamber; a control unit that controls a pressure of the heat transfer gas supplied from the supply unit to be lower than that during the plasma processing of the substrate when at least one of the substrate and the ring assembly is replaced and before performing the plasma processing of the substrate; A plasma processing apparatus comprising:

[0101] (Appendix 16) the supply unit supplies a heat transfer gas between the mounting table and the ring assembly; When the ring assembly is replaced, the control unit controls, during seasoning of the chamber, the pressure of the heat transfer gas supplied from the supply unit between the mounting table and the ring assembly to be lower than that during plasma processing of the substrate, and controls the power of the high frequency power supplied from the power supply unit to be equal to or lower than that during plasma processing of the substrate. 16. The plasma processing apparatus according to claim 15.

[0102] (Appendix 17) When the substrate or the ring assembly is replaced, the control unit controls the supply unit to supply and exhaust a heat transfer gas between the replaced substrate or the ring assembly and the mounting table at least once before performing plasma processing on the substrate. 18. The plasma processing apparatus according to claim 16 or 17.

[0103] (Appendix 18) The control unit controls the power supply unit to supply high-frequency power during the seasoning process, the high-frequency power being equal to or lower than that during plasma processing of the substrate and at a power level that will raise the temperature of the substrate to 200° C. or higher. 17. The plasma processing apparatus according to claim 16.

[0104] (Appendix 19) The control unit controls the pressure of the heat transfer gas supplied from the supply unit to between the mounting table and the ring assembly during the seasoning to 15 Torr or less. 19. The plasma processing apparatus according to any one of claims 16 to 18.

[0105] (Appendix 20) The control unit controls the supply unit to alternately supply and exhaust the heat transfer gas multiple times. 18. The plasma processing apparatus according to claim 17.

[0106] (Appendix 21) The fixing portion fixes at least one of the substrate and the ring assembly to the mounting table by electrostatic attraction. 21. The plasma processing apparatus according to claim 15, wherein the plasma processing apparatus is a plasma processing apparatus.

[0107] (Appendix 22) the power supply unit is capable of supplying high-frequency power to the mounting table, The control unit controls the power supply unit to apply high-frequency power for adsorption to the mounting table when the fixing unit electrostatically adsorbs. 22. The plasma processing apparatus according to claim 21.

[0108] (Appendix 23) The heat transfer gas is helium gas or hydrogen gas. 23. The plasma processing apparatus according to claim 15, wherein the plasma processing apparatus is a plasma processing apparatus.

[0109] (Appendix 24) a step of exchanging at least one of a substrate placed on a mounting table disposed in a chamber in which plasma processing is performed and a ring-shaped ring assembly placed around the substrate; when at least one of the substrate and the ring assembly has been replaced, before performing plasma processing on the substrate, reducing the pressure of a heat transfer gas supplied between the mounting table and at least one of the substrate and the ring assembly to a level lower than that during plasma processing on the substrate; The abnormal discharge suppression method includes: [Explanation of symbols]

[0110] 1. Plasma processing equipment 2. Control Unit 10 Plasma Processing Chamber 11 Substrate support 30 power supply 112 Ring Assembly 116 Gas Supply Unit 1111 Electrostatic chuck W substrate

Claims

1. a chamber in which the plasma processing is performed; a mounting table disposed within the chamber, on which the substrate and the ring assembly are mounted around the substrate; a fixing portion provided on the mounting table for fixing at least one of the substrate and the ring assembly to the mounting table; a heat transfer gas supply unit that supplies a heat transfer gas between the mounting table and at least one of the substrate and the ring assembly; a heat transfer gas exhaust unit configured to exhaust the heat transfer gas from between the mounting table and at least one of the substrate and the ring assembly; an RF (Radio Frequency) power supply that supplies an RF signal for generating plasma into the chamber; a control unit that, when at least one of the substrate and the ring assembly is placed on the mounting table, controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to be lower than that during plasma processing of the substrate before plasma processing of the substrate is performed; and The control unit, before performing plasma processing on the substrate, (a) supplying a heat transfer gas between the stage and the ring assembly; (b) reducing the pressure of the heat transfer gas supplied between the mounting table and the ring assembly to a level lower than that of (a); In the steps (a) and (b), the RF power source is controlled to supply an RF signal with a power that is equal to or lower than that during plasma processing of the substrate and that raises the temperature of the substrate to 200° C. or higher. Plasma processing equipment.

2. The control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit to supply and exhaust a heat transfer gas between the ring assembly and the mounting table at least once before performing plasma processing on the substrate. The plasma processing apparatus according to claim 1 .

3. In the step (b), the control unit controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to between the mounting table and the ring assembly to 15 Torr or less. The plasma processing apparatus according to claim 1 .

4. The control unit controls the heat transfer gas supply unit so as to alternately supply and exhaust the heat transfer gas multiple times. The plasma processing apparatus according to claim 2 .

5. The fixing portion fixes the ring assembly to the mounting table by electrostatic attraction. The plasma processing apparatus according to claim 1 .

6. The heat transfer gas is helium gas or hydrogen gas. The plasma processing apparatus according to claim 1 .

7. A plasma processing system comprising: a chamber in which plasma processing is performed; a mounting table disposed within the chamber, on which the substrate and the ring assembly are mounted around the substrate; a fixing portion provided on the mounting table for fixing at least one of the substrate and the ring assembly to the mounting table; a heat transfer gas supply unit that supplies a heat transfer gas between the mounting table and at least one of the substrate and the ring assembly; a heat transfer gas exhaust unit configured to exhaust the heat transfer gas from between the mounting table and at least one of the substrate and the ring assembly; an RF (Radio Frequency) power supply that supplies an RF signal for generating plasma into the chamber; a control unit that, when at least one of the substrate and the ring assembly is placed on the mounting table, controls the pressure of the heat transfer gas supplied from the heat transfer gas supply unit to be lower than that during plasma processing of the substrate before plasma processing of the substrate is performed; and When the substrate is placed on the stage, the control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit so that a heat transfer gas is supplied and exhausted between the substrate and the stage at least once before plasma processing is performed on the substrate. Plasma processing equipment.

8. The control unit controls the heat transfer gas supply unit and the heat transfer gas exhaust unit so that the supply and exhaust of the heat transfer gas are alternately performed multiple times. The plasma processing apparatus according to claim 7 .

9. The fixing unit fixes the substrate to the mounting table by electrostatic adsorption. The plasma processing apparatus according to claim 7 .

10. The control unit (a) introducing a process gas into the chamber; (b) supplying an RF signal from the RF power source into the chamber, the RF signal having a power lower than that during plasma processing of the substrate; (c) electrostatically attracting the substrate to the stage; (d) supplying and exhausting a heat transfer gas between the substrate and the stage at least once; (e) supplying a process gas and an RF signal for generating the plasma into the chamber. The plasma processing apparatus according to claim 9 .

11. a bias power supply; the control unit executes a step of supplying a bias signal from the bias power supply to the mounting table between steps (d) and (e). The plasma processing apparatus according to claim 10.

12. placing at least one of a substrate and a ring assembly placed around the substrate on a stage disposed in a chamber in which plasma processing is performed; before performing plasma processing on the substrate, reducing the pressure of a heat transfer gas supplied between the stage and at least one of the substrate and the ring assembly to a level lower than that during plasma processing on the substrate; and The lowering step includes: (a) supplying a heat transfer gas between the stage and the ring assembly; (b) reducing the pressure of the heat transfer gas supplied between the mounting table and the ring assembly to a level lower than that of (a); In the steps (a) and (b), an RF power supply that supplies an RF (Radio Frequency) signal for generating plasma into the chamber is controlled to supply an RF signal with a power that is lower than that during plasma processing of the substrate and that raises the temperature of the substrate to 200° C. or higher. Abnormal discharge suppression method.

13. placing at least one of a substrate and a ring assembly placed around the substrate on a stage disposed in a chamber in which plasma processing is performed; before performing plasma processing on the substrate, reducing the pressure of a heat transfer gas supplied between the stage and at least one of the substrate and the ring assembly to a level lower than that during plasma processing on the substrate; and In the lowering step, when the substrate is placed on the stage, a heat transfer gas is supplied and exhausted between the substrate and the stage at least once before plasma processing is performed on the substrate. Abnormal discharge suppression method.

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