Plasma processing apparatus and control method of the plasma processing apparatus

Abstract

To provide a plasma processing apparatus and a control method of the plasma processing apparatus, which are capable of suitably removing deposits adhering to an annular member.SOLUTION: A plasma processing apparatus includes: a plasma processing chamber; a substrate support unit that is provided in the plasma processing chamber and supports a substrate; an annular member that is disposed so as to surround the substrate supported by the substrate support unit; a lifter that can lift and lower the annular member; a gas introduction unit that introduces a gas into the plasma processing chamber; a plasma generation unit that generates plasma in the plasma processing chamber; and a control unit. The control unit is configured to control the lifter to raise the annular member, and the control unit is configured to control the plasma generation unit to generate plasma of a first cleaning gas in a state in which the annular member is raised to clean a lower surface of the annular member and a mounting surface of the annular member.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus and a method for controlling the plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a plasma processing apparatus in which a focus ring has a first annular member and a second annular member, and the sheath is adjusted by lifting the second annular member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-113753 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a plasma processing apparatus and a method for controlling the plasma processing apparatus that can suitably remove deposits adhering to an annular member. [Means for solving the problem]

[0005] In order to solve the above problem, according to one aspect, a plasma processing apparatus is provided, comprising: a plasma processing chamber; a substrate support section provided in the plasma processing chamber and supporting a substrate; an annular member arranged to surround the substrate supported on the substrate support section; a lifter capable of raising and lowering the annular member; a gas introduction section that introduces gas into the plasma processing chamber; a plasma generation section that generates plasma in the plasma processing chamber; and a control section, wherein the control section controls the lifter to raise the annular member; and when the annular member is raised, the control section controls the plasma generation section to generate plasma of a first cleaning gas and clean the underside of the annular member and the supporting surface of the annular member. [Effects of the Invention]

[0006] According to one aspect, the present disclosure can provide a plasma processing apparatus and a method for controlling a plasma processing apparatus that can suitably remove deposits adhering to an annular member. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an example of a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. [Figure 2] FIG. 4 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly according to the first embodiment. [Figure 3] FIG. 10 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly according to the second embodiment. [Figure 4] 1 is an example of a partially enlarged cross-sectional view showing a plasma processing apparatus during substrate processing. [Figure 5] FIG. 10 is an example of a partially enlarged cross-sectional view of a plasma processing apparatus for explaining a cleaning process according to a reference example. [Figure 6] 10 is an example of a flowchart illustrating a cleaning process. [Figure 7] FIG. 10 is an example of an enlarged cross-sectional view of a portion of the plasma processing apparatus in step S103. [Figure 8] 10 is an example of a flowchart illustrating wear compensation for a first annular member. [Figure 9] 10 is an example of a graph showing a change in torque when the first annular member is driven. [Figure 10] FIG. 11 is a partially enlarged cross-sectional view showing an example of an operation of the ring assembly according to the third embodiment during substrate processing. [Figure 11] FIG. 11 is a partially enlarged cross-sectional view showing an example of an operation during a cleaning process of the ring assembly according to the third embodiment. [Figure 12] FIG. 11 is a partially enlarged cross-sectional view showing an example of an operation during a cleaning process of the ring assembly according to the fourth embodiment. [Figure 13] FIG. 11 is a partially enlarged cross-sectional view showing an example of an operation of the ring assembly according to the fifth embodiment during substrate processing. [Figure 14] FIG. 13 is a partially enlarged cross-sectional view showing an example of an operation during a cleaning process of the ring assembly according to the fifth embodiment. [Figure 15] FIG. 13 is a plan view illustrating an example of pin arrangement in a substrate support part having a ring assembly according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] [Plasma processing system] An example of the configuration of a plasma processing system will be described below: Fig. 1 is an example of a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus (substrate processing apparatus) 1.

[0010] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply system 30, an exhaust system 40, and a lifter 50 (see FIGS. 2 and 3, etc., described below). The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas into 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 insulated from the housing of the plasma processing chamber 10.

[0011] 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.

[0012] The ring assembly 112 includes a first annular member 112a that can be raised and lowered, and a second annular member 112b that supports the first annular member 112a (see FIGS. 2 and 3, which will be described later). The plasma processing apparatus 1 also includes a lifter 50 (see FIGS. 2 and 3, which will be described later) that raises and lowers the first annular member 112a. The ring assembly 112 and the lifter 50 will be described later with reference to FIGS. 2 and 3.

[0013] 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 chuck electrode 1111b disposed within the ceramic member 1111a. The electrostatic chuck electrode 1111b is also referred to as a clamping electrode. In one embodiment, the electrostatic chuck electrode 1111b is electrically connected or coupled to a chuck power supply. The chuck power supply may be a DC power supply or an AC power supply. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may be formed on another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. At least one bias electrode electrically connected to or coupled to a power supply 31 and / or a power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one bias electrode functions as a lower electrode. Alternatively, the conductive member of the base 1110 and the bias electrode within the ceramic member 1111a may function as multiple lower electrodes. In one embodiment, the first voltage generating unit 32a, which functions as a voltage pulse generating unit (described later), is electrically connected to or coupled to the bias electrode within the ceramic member 1111a, and the first RF generating unit 31a (described later) is electrically connected to or coupled to the conductive member of the base 1110. The electrostatic chuck electrode 1111b may function as a lower electrode. The substrate support 11 therefore comprises at least one bottom electrode.

[0014] 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.

[0015] 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 path 1110a, or a combination thereof. A heat transfer fluid such as brine or a 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 configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0016] 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.

[0017] 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.

[0018] The power supply system 30 includes a power supply 31 electrically connected or coupled to the plasma processing chamber 10. In one embodiment, the power supply 31 is electrically connected or coupled to the plasma processing chamber 10 via at least one impedance matcher. The impedance matcher may be a mechanically controlled matcher or an electronically controlled matcher. The power supply 31 is configured to supply at least one radio frequency (RF) signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing 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.

[0019] The power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode and configured to generate a source RF signal (source RF power) to generate plasma in the plasma processing space 10s. In one embodiment, the first RF generating unit 31a is electrically connected or coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching box. 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.

[0020] The second RF generating unit 31b is electrically connected or coupled to at least one lower electrode and configured to generate a bias RF signal (bias RF power). In one embodiment, the second RF generating unit 31b is electrically connected or coupled to at least one lower electrode via at least one impedance matcher. When the first RF generating unit 31a is electrically connected or coupled to a lower electrode, the second RF generating unit 31b may be electrically connected or coupled to the same lower electrode or to another lower electrode. 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 within a 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.

[0021] The power supply system 30 may also include a power supply 32 electrically connected or coupled to the plasma processing chamber 10. The power supply 32 includes a first voltage generating unit 32a and a second voltage generating unit 32b. In one embodiment, the first voltage generating unit 32a is electrically connected or coupled to at least one lower electrode and configured to generate a first voltage signal. The generated first voltage signal is applied to the at least one lower electrode. In one embodiment, the second voltage generating unit 32b is electrically connected or coupled to at least one upper electrode and configured to generate a second voltage signal. The generated second voltage signal is applied to the at least one upper electrode.

[0022] In various embodiments, the first and / or second voltage signals may be pulsed. In this case, the first voltage generator 32a and / or the second voltage generator 32b function as a voltage pulse generator configured to generate a sequence of voltage pulses. Thus, the sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. In one embodiment, the sequence of voltage pulses includes multiple cycles, each cycle including a burst of voltage pulses during a first period and a constant reference voltage during a second period. That is, the bursts of voltage pulses are repeated in the sequence of voltage pulses. The absolute value of the voltage level of the voltage pulses is greater than the absolute value of the voltage level of the reference voltage. The voltage pulses may have an arbitrary waveform, such as a rectangular, trapezoidal, triangular, or combination thereof, and the arbitrary waveform may change over time. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses within one cycle. The first and second voltage generating units 32a and 32b may be provided in addition to the power supply 31, or the first voltage generating unit 32a may be provided instead of the second RF generating unit 31b.

[0023] 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.

[0024] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various steps described herein. The controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various steps 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 be implemented, for example, by a computer 2a. The controller 2 may include a processing unit 2a1, a memory unit 2a2, and a communication interface 2a3. The functions performed by the processing unit 2a1 described in this disclosure may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, application-specific integrated circuits (ASICs), central processing units (CPUs), conventional circuitry, and / or combinations thereof, programmed to perform the described functions. A processor is considered to be a circuit or processing circuit that includes transistors and other circuitry. The processor may be a programmed processor that executes a program stored in the memory unit 2a2. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The 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).In this disclosure, a circuit, unit, or means is hardware that is programmed to implement or configured to implement a described function. The hardware may be any hardware described in this disclosure or any hardware that is programmed to implement or known to implement the described function. If the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0025] [Substrate Support Having Ring Assembly According to First Embodiment] Next, an example of the ring assembly 112 and the lifter 50 will be described with reference to Fig. 2. Fig. 2 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the first embodiment.

[0026] The ring assembly 112 shown in FIGS. 2(a) and 2(b) has a first annular member 112a, a second annular member 112b that supports the first annular member 112a, and a third annular member 112c.

[0027] The first annular member 112a and the second annular member 112b are also collectively referred to as an edge ring. The edge ring (first annular member 112a, second annular member 112b) is arranged to surround the periphery of the substrate W supported by the substrate support 11. The edge ring (first annular member 112a, second annular member 112b) may be made of, for example, SiC, Si, quartz, or the like. The edge ring is also referred to as a focus ring. The first annular member 112a is provided on the second annular member 112b. In other words, the first annular member 112a and the second annular member 112b at least partially overlap. In other words, the lower surface (supported surface) of the first annular member 112a is placed on the upper surface (supporting surface) of the second annular member 112b. The lower surface (supported surface) of the first annular member 112a and the upper surface (supporting surface) of the second annular member 112b are opposed to each other. In the example shown in FIGS. 2(a) and 2(b), the lower surface of the first annular member 112a becomes the supported surface that is supported by the upper surface (supporting surface) of the second annular member 112b when the first annular member 112a is placed on the second annular member 112b. The outer peripheral annular surface of the upper surface of the second annular member 112b becomes the supporting surface that abuts against the supported surface of the first annular member 112a when the first annular member 112a is placed on the second annular member 112b. Although the edge ring is described as being divided into the first annular member 112a and the second annular member 112b, this is not limiting and the edge ring may be configured as a single unit or may be divided into three or more members.

[0028] The third annular member 112c is also referred to as a cover ring. The cover ring (third annular member 112c) is disposed radially outside the edge rings (first annular member 112a and second annular member 112b). The cover ring (third annular member 112c) may be made of, for example, quartz.

[0029] The lifter 50 raises and lowers the first annular member 112a. The lifter 50 includes a plurality of (e.g., three or more) support pins 51 and an actuator 52. Each support pin 51 is inserted through a through-hole formed in the base 1110, a through-hole formed in the electrostatic chuck 1111, and a through-hole formed in the second annular member 112b, and is capable of protruding and retracting from the upper surface of the second annular member 112b (the mounting surface of the first annular member 112a).

[0030] The actuator 52 raises and lowers the plurality of support pins 51. The actuator 52 may be, for example, a motor such as a DC motor, a stepping motor, or a linear motor, an air drive mechanism such as an air cylinder, or a piezoelectric actuator.

[0031] The lifter 50 adjusts the height of the sheath (ion sheath) above the edge ring (first annular member 112a, second annular member 112b) by raising and lowering the first annular member 112a.

[0032] 2(a), by lowering the first annular member 112a, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) becomes lower than the height of the sheath above the substrate W (see the outline arrow). As a result, the angle of incidence of ions tilts inward in the outer peripheral region of the substrate W. Furthermore, even if the first annular member 112a is consumed by plasma and the height of the upper surface of the first annular member 112a decreases, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) also decreases (see the outline arrow), and the angle of incidence of ions tilts inward in the outer peripheral region of the substrate W.

[0033] Next, as shown in FIG. 2(b), the first annular member 112a is raised to raise the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) (see the outline arrow), so that the height of the sheath above the substrate W is equal to the height of the sheath above the edge ring (first annular member 112a, second annular member 112b). This allows the angle of incidence of ions to be perpendicular to the substrate W in the outer peripheral region of the substrate W. This allows the etching shape formed on the substrate W to be vertical.

[0034] Furthermore, although not shown, by further raising the first annular member 112a, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) is made higher than the height of the sheath above the substrate W. This causes the incident angle of ions to tilt outward in the outer edge region of the substrate W.

[0035] In this way, by adjusting the height of the first annular member 112a with the lifter 50, it is possible to control the angle of incidence of ions on the outer edge region of the substrate W. Furthermore, by raising the height of the first annular member 112a in accordance with wear of the first annular member 112a, it is possible to control the angle of incidence of ions on the outer edge region of the substrate W.

[0036] [Substrate Support Having Ring Assembly According to Second Embodiment] 2, the first annular member 112a is described as being insulated from the base 1110, which serves as a lower electrode and to which a source RF signal and / or a bias signal (bias RF signal, first voltage signal) is supplied, but this is not limiting. Another example of the ring assembly 112 and the lifter 50 will be described with reference to FIG. 3. FIG. 3 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the second embodiment.

[0037] The ring assembly 112 shown in FIGS. 3(a) and 3(b) has a first annular member 112a and a second annular member 112b that supports the first annular member 112a.

[0038] The first annular member 112a and the second annular member 112b are also collectively referred to as an edge ring. The edge ring (first annular member 112a, second annular member 112b) is arranged to surround the periphery of the substrate W supported by the substrate support 11. The edge ring (first annular member 112a, second annular member 112b) may be made of, for example, SiC, Si, quartz, or the like. The edge ring is also referred to as a focus ring. The first annular member 112a is provided on the second annular member 112b. In other words, the first annular member 112a and the second annular member 112b at least partially overlap. In other words, the lower surface (supported surface) of the first annular member 112a is placed on the upper surface (supporting surface) of the second annular member 112b. The lower surface (supported surface) of the first annular member 112a and the upper surface (supporting surface) of the second annular member 112b are opposed surfaces. In the example shown in FIGS. 3(a) and 3(b), the inner annular surface of the lower surface of the first annular member 112a becomes the supported surface that is supported by the upper surface (supporting surface) of the second annular member 112b when the first annular member 112a is placed on the second annular member 112b. The outer annular surface of the lower surface of the first annular member 112a is supported by the conductive ring 113. The outer annular surface of the upper surface of the second annular member 112b becomes the supporting surface that abuts against the supported surface of the first annular member 112a when the first annular member 112a is placed on the second annular member 112b. Furthermore, the edge ring is described as being divided into a first annular member 112a and a second annular member 112b, but this is not limited to this and it may be configured as a single unit or may be configured as being divided into three or more members.

[0039] The conductive ring 113 is an annular member made of a conductive material such as metal. The conductive ring 113 is disposed below the first annular member 112a. The conductive ring 113 is electrically connected to the base 1110 via conductive contacts 114. The upper surface of the conductive ring 113 abuts against the first annular member 112a, thereby establishing electrical continuity between the conductive ring 113 and the first annular member 112a. The conductive ring 113 is raised and lowered by a lifter 50.

[0040] The conductive contacts 114 are configured to ensure electrical continuity between the conductive ring 113 and the base 1110 even when the conductive ring 113 is raised and lowered by the lifter 50 .

[0041] The lifter 50 raises and lowers the first annular member 112a via the conductive ring 113. The lifter 50 includes a plurality of (for example, three or more) support pins 51 and an actuator 52. Each support pin 51 is inserted into a through-hole formed in the base 1110.

[0042] The actuator 52 raises and lowers the plurality of support pins 51. The actuator 52 may be, for example, a motor such as a DC motor, a stepping motor, or a linear motor, an air drive mechanism such as an air cylinder, or a piezoelectric actuator.

[0043] The lifter 50 raises and lowers the first annular member 112a via the conductive ring 113, thereby adjusting the height of the sheath above the edge ring (first annular member 112a, second annular member 112b).

[0044] 3(a), by lowering the first annular member 112a, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) becomes lower than the height of the sheath above the substrate W (see the outline arrow). As a result, the angle of incidence of ions is tilted inward in the outer peripheral region of the substrate W. Furthermore, even if the first annular member 112a is consumed by plasma and the height of the upper surface of the first annular member 112a is lowered, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) is lowered, and the angle of incidence of ions is tilted inward in the outer peripheral region of the substrate W.

[0045] Next, as shown in FIG. 3(b), the first annular member 112a is raised to raise the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) (see the outline arrow), so that the height of the sheath above the substrate W is equal to the height of the sheath above the edge ring (first annular member 112a, second annular member 112b). This allows the angle of incidence of ions to be perpendicular to the substrate W in the outer peripheral region of the substrate W. This allows the etching shape formed on the substrate W to be vertical.

[0046] Furthermore, although not shown, by further raising the first annular member 112a, the height of the sheath above the edge ring (first annular member 112a, second annular member 112b) is made higher than the height of the sheath above the substrate W. This causes the incident angle of ions to tilt outward in the outer edge region of the substrate W.

[0047] In this way, by adjusting the height of the first annular member 112a with the lifter 50, it is possible to control the angle of incidence of ions on the outer edge region of the substrate W. Furthermore, by raising the height of the first annular member 112a in accordance with wear of the first annular member 112a, it is possible to control the angle of incidence of ions on the outer edge region of the substrate W. Furthermore, the first annular member 112a is configured to be electrically connected to the base 1110 via the conductive ring 113 and the conductive contact 114. As a result, a voltage supplied to the base 1110 is applied to the first annular member 112a.

[0048] [Operation of plasma processing device] Fig. 4 is an example of a partially enlarged cross-sectional view showing the plasma processing apparatus 1 during substrate processing. In the following explanation, the plasma processing apparatus 1 will be described as having the configuration shown in Fig. 2. The same applies to the case where the plasma processing apparatus 1 has the configuration shown in Fig. 3, and redundant explanations will be omitted.

[0049] Here, an etching process will be described as an example of substrate processing. In the etching process, the control unit 2 controls the gas supply unit 20 to supply an etching gas to the plasma processing space 10s via the shower head 13, and controls the plasma generation unit (first RF generation unit 31a, etc.) to generate plasma of the etching gas in the plasma processing space 10s. Here, the control unit 2 controls the lifter 50 to lift the first annular member 112a in accordance with the amount of wear of the first annular member 112a. This controls the incident angle of ions on the outer peripheral region of the substrate W.

[0050] At this time, reaction by-products 300 of the substrate processing adhere to and accumulate not only on the upper surface of the first annular member 112a, but also on the lower surface of the first annular member 112a (the surface that abuts against the second annular member 112b when the first annular member 112a is placed on the second annular member 112b) and the upper surface of the second annular member 112b (the placement surface of the first annular member 112a).

[0051] The reaction by-products 300 deposited on the ring assembly 112 and the like may peel off from the wall surface, generating particles, which may adhere to the substrate W and reduce the yield of the semiconductor device formed on the substrate W. For this reason, the plasma processing apparatus 1 is subjected to a cleaning process.

[0052] The cleaning process of the plasma processing apparatus 1 will be described with reference to FIGS.

[0053] First, the cleaning process according to the reference example will be described with reference to Fig. 5. Fig. 5 is an example of a partially enlarged cross-sectional view of the plasma processing apparatus 1 for explaining the cleaning process according to the reference example.

[0054] Here, the control unit 2 controls the gas supply unit 20 to supply cleaning gas to the plasma processing space 10s via the shower head 13, and also controls the plasma generation unit (first RF generation unit 31a, etc.) to generate plasma of the etching gas in the plasma processing space 10s. As a result, ions of the cleaning gas generated by the plasma are attracted to the lower electrode (see the outline arrow), sputtering the first annular member 112a with the ions and cleaning the reaction by-products 300. The sputtered reaction by-products 300 are exhausted together with the gas to the outside of the plasma processing chamber 10. Here, ions do not collide with the lower surface of the first annular member 112a or the upper surface of the second annular member 112b, and there is a risk that the reaction by-products 300 adhering to the lower surface of the first annular member 112a or the upper surface of the second annular member 112b may remain.

[0055] Next, the cleaning process will be described with reference to Figures 6 and 7. Figure 6 is an example of a flowchart illustrating the cleaning process.

[0056] In step S101, the control unit 2 determines whether or not to start cleaning. The control unit 2 determines whether or not to perform cleaning processing based on predetermined conditions (for example, the number of substrates W to be processed, the processing time of the plasma processing apparatus, etc.). If cleaning processing is not to be performed (S101·NO), the control unit 2 returns to step S101 and repeats the processing of step S101. If cleaning is to be started (S101·YES), the control unit 2 proceeds to step S102. Note that the control unit 2 may control the substrate transport device (not shown) to place a dummy substrate W on the substrate support unit 11 and hold the substrate W by the electrostatic chuck 1111. Alternatively, the dummy substrate W may not be placed.

[0057] In step S102, the first annular member 112a is raised. Here, the control unit 2 controls the lifter 50 to raise the support pins 51, thereby bringing the first annular member 112a closer to the upper electrode (shower head 13).

[0058] Here, the first annular member 112a is raised so that its lower surface is positioned closer to the upper electrode than the midpoint between the gap between the upper and lower electrodes. The first annular member 112a is also raised so that its lower surface is positioned above and outside the sheath on the upper electrode side during cleaning gas plasma generation, which will be described later in step S103. The first annular member 112a may or may not abut against the upper electrode. If a holding mechanism (not shown) that holds the first annular member 112a by suction or clamping is provided on the ceiling of the plasma processing space 10s, after the first annular member 112a is held by the holding mechanism, the support pins 51 may be lowered and stored in the through-holes of the main body 111.

[0059] In step S103, plasma of the first cleaning gas is generated to perform cleaning processing. Here, the control unit 2 controls the gas supply unit 20 to supply the first cleaning gas to the plasma processing space 10s via the shower head 13, and controls the plasma generation unit (first RF generation unit 31a, etc.) to generate plasma of the etching gas in the plasma processing space 10s.

[0060] 7A and 7B are partial enlarged cross-sectional views of the plasma processing apparatus 1 in step S103. As shown in Fig. 7A, ions of the first cleaning gas generated by the plasma are drawn toward the lower electrode (base 1110) (see the outline arrow), sputtering the upper surface of the second annular member 112b and removing reaction by-products 300.

[0061] 7(b), the lower surface of the first annular member 112a is positioned above and outside (the side away from the plasma, the side closer to the upper electrode) the sheath (shown by the dashed line in FIG. 7(b)) formed around the upper electrode. As a result, ions of the first cleaning gas generated by the plasma are drawn toward the upper electrode (shower head 13) (see the open arrow), sputtering the lower surface of the first annular member 112a and removing reaction by-products 300.

[0062] In step S103, power (a second voltage signal) may be supplied from the second voltage generator 32b (a DC generator) to the upper electrode, thereby increasing the energy of ions colliding with the lower surface of the first annular member 112a and enabling favorable cleaning.

[0063] In step S103, the second RF generator 31b (bias power generator) may supply bias RF power (bias RF signal) to the lower electrode, or the first voltage generator 32a (bias power generator) may supply bias power (first voltage signal) to the lower electrode. This increases the energy of ions colliding with the upper surface of the second annular member 112b, enabling favorable cleaning.

[0064] In step S104, the first annular member 112a is lowered. Here, the control unit 2 controls the lifter 50 to lower the support pins 51, thereby bringing the first annular member 112a closer to the lower electrode (base 1110).

[0065] Here, the first annular member 112a is lowered so that the upper surface of the first annular member 112a is positioned closer to the upper electrode than the midpoint between the gap between the upper electrode and the lower electrode. The first annular member 112a is also lowered so that the upper surface of the first annular member 112a is positioned lower and outer than the sheath on the lower electrode side during cleaning gas plasma generation, which will be described later in step S105. The first annular member 112a may or may not abut against the second annular member 112b.

[0066] In step S105, plasma of the second cleaning gas is generated to perform cleaning processing. Here, the control unit 2 controls the gas supply unit 20 to supply the second cleaning gas to the plasma processing space 10s via the shower head 13, and controls the plasma generation unit (first RF generation unit 31a, etc.) to generate plasma of the etching gas in the plasma processing space 10s. The second cleaning gas may be the same gas as the first cleaning gas, or may be a gas different from the first cleaning gas.

[0067] Here, ions of the second cleaning gas generated by the plasma are drawn toward the lower electrode (base 1110) (see the white arrow), sputtering the upper surface of the first annular member 112a and removing reaction by-products 300 (see FIG. 5).

[0068] Here, the upper surface of the first annular member 112a is positioned below and outside the sheath formed around the lower electrode (the side away from the plasma, the side closer to the lower electrode), so that ions of the second cleaning gas generated by the plasma are drawn toward the lower electrode (base 1110) (see the open arrow), sputtering the upper surface of the first annular member 112a and removing reaction by-products 300.

[0069] In step S105, the second RF generator 31b (bias power generator) may supply bias RF power (bias RF signal) to the lower electrode, or the first voltage generator 32a (bias power generator) may supply bias power (first voltage signal) to the lower electrode. This increases the energy of ions colliding with the upper surface of the first annular member 112a, enabling favorable cleaning.

[0070] 6, the reaction by-products 300 can be removed from the first annular member 112a and the second annular member 112b, thereby cleaning the same. This can improve the yield of semiconductor devices formed on the substrates W. Furthermore, the cleaning process shown in FIG. 6 can shorten the cleaning time compared to cleaning the first annular member 112a and the second annular member 112b by opening the top of the plasma processing chamber 10, or cleaning the first annular member 112a and the second annular member 112b by transporting them outside the plasma processing chamber 10. In other words, the downtime of the plasma processing apparatus 1 can be reduced, and the productivity of the plasma processing apparatus 1 can be improved.

[0071] 6, the cleaning process is described using an example in which the process of cleaning the lower surface of the first annular member 112a and the upper surface of the second annular member 112b (S102, S103) is followed by the process of cleaning the upper surface of the first annular member 112a (S104, S105), but this is not limiting. Alternatively, the process of cleaning the lower surface of the first annular member 112a and the upper surface of the second annular member 112b (S102, S103) may be performed after the process of cleaning the upper surface of the first annular member 112a (see S104, S105).

[0072] Next, control of the amount of lift of the first annular member 112a based on the amount of wear of the first annular member 112a will be described with reference to Figures 8 and 9. Figure 8 is an example of a flowchart illustrating compensation for wear of the first annular member 112a. Here, a method will be described in which the amount of wear of the first annular member 112a is detected and the amount of lift of the first annular member 112a is controlled based on the amount of wear of the first annular member 112a, thereby controlling the angle of incidence of ions in the outer edge region of the substrate W.

[0073] In step S201, it is detected whether or not the cleaning process has been performed. In other words, the control unit 2 determines whether or not reaction by-products have accumulated on the first annular member 112a. If the control unit 2 determines that the cleaning process has been performed (YES in S201), the process by the control unit 2 proceeds to step S202.

[0074] In step S202, the support pin 51 is raised and lowered, and the torque of the actuator 52 is detected. It is preferable to detect the torque of the actuator 52 when the support pin 51 is raised. However, the torque of the actuator 52 may also be detected when the support pin 51 is lowered. Furthermore, the torque of the actuator 52 may be detected as the holding torque of the actuator 52.

[0075] The torque of the actuator 52 may be detected based on at least one of the power, current, voltage, etc. supplied to the actuator 52. Alternatively, the actuator 52 may be provided with a torque sensor (not shown) that detects torque, and the torque may be detected based on the detected value of the torque sensor.

[0076] 9 is an example of a graph showing changes in torque when driving the first annular member 112a. The horizontal axis represents the time the first annular member 112a is exposed to plasma (cumulative time of substrate processing). In other words, the horizontal axis corresponds to the amount of wear of the first annular member 112a due to plasma. The vertical axis represents the torque of the actuator 52 when driving the support pins 51 that support the first annular member 112a.

[0077] As shown in FIG. 9, the torque of the actuator 52 decreases as the first annular member 112a is consumed by the plasma.

[0078] In step S203, the control unit 2 calculates the amount of lift of the support pin 51 based on the detected torque of the actuator 52. Here, the control unit 2 pre-stores the torque value of the actuator 52 when the first annular member 112a is new (before wear) as an initial torque value. The control unit 2 calculates the amount of wear (weight reduction) of the first annular member 112a based on the difference between the initial torque value and the torque value detected in step S202. The control unit 2 then calculates the amount of reduction in the thickness of the first annular member 112a based on the calculated amount of wear (weight reduction) of the first annular member 112a. The control unit 2 pre-stores the amount of lift of the actuator 52 when the first annular member 112a is new (before wear) as an initial lift amount. The control unit 2 complements the amount of reduction in the thickness of the first annular member 112a to obtain the complemented lift amount.

[0079] In step S204, the support pins 51 are raised by the calculated amount of elevation (post-complementary elevation amount). This allows the height of the upper surface of the worn first annular member 112a to approach or match the height of the upper surface of the first annular member 112a before it is worn. This makes it possible to suppress fluctuations in the angle of incidence of ions at the outer edge region of the substrate W due to wear of the first annular member 112a. In other words, even if the first annular member 112a is worn, it is possible to form a desired etching shape on the substrate W.

[0080] The lifting amount of the support pin 51 may be compensated for every cleaning process. Also, when the amount of decrease in the thickness of the first annular member 112a calculated in step S203 exceeds a predetermined threshold, the lifting amount of the support pin 51 may be compensated for.

[0081] 8, the amount of wear of the first annular member 112a is calculated based on the torque when raising and lowering the support pin 51, and the first annular member 112a is raised based on the calculated amount of wear. This makes it possible to bring the height (position) of the upper surface of the first annular member 112a after wear closer to the height (position) of the upper surface of the first annular member 112a before wear.

[0082] However, measures against wear of the first annular member 112a are not limited to this. For example, the bias RF signal (bias RF power) supplied by the second RF generation unit 31b may be controlled based on the calculated amount of wear of the first annular member 112a. As a result, as shown in the configuration shown in FIG. 3, the bias power applied to the first annular member 112a via the conductive ring 113 and the conductive contact 114 is controlled to control the thickness of the sheath formed above the first annular member 112a. This makes it possible to suppress fluctuations in the angle of incidence of ions in the outer peripheral region of the substrate W.

[0083] The processes shown in Figures 5 and 8 have been described above using the plasma processing apparatus 1 as an example of a plasma processing apparatus that forms capacitively coupled plasma (CCP), but this is not limited to this and may also be applied to a plasma processing apparatus that forms inductively coupled plasma (ICP).

[0084] [Substrate Support Having Ring Assembly According to the Third Embodiment] Next, another example of the ring assembly 112 will be described with reference to Figures 10 and 11. Figure 10 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the third embodiment during substrate processing. Figure 11 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the third embodiment during cleaning processing.

[0085] The ring assembly 112 shown in FIGS. 10 and 11 includes a first annular member 112d, a second annular member 112e that supports the first annular member 112d, and a third annular member 112f.

[0086] The first annular member 112d and the second annular member 112e are also collectively referred to as an edge ring. The edge ring (first annular member 112d, second annular member 112e) is arranged to surround the periphery of the substrate W supported by the substrate support 11. The edge ring (first annular member 112d, second annular member 112e) may be made of, for example, SiC, Si, quartz, or the like. The edge ring is also referred to as a focus ring. The first annular member 112d is provided on the second annular member 112e. In other words, the first annular member 112d and the second annular member 112e at least partially overlap. In other words, the lower surface (supported surface) of the first annular member 112d is placed on the upper surface (supporting surface) of the second annular member 112e. The lower surface (supported surface) of the first annular member 112d and the upper surface (supporting surface) of the second annular member 112e are opposed surfaces. The inner annular surface of the lower surface of the first annular member 112d serves as the supported surface that is supported by the upper surface (supporting surface) of the second annular member 112e when the first annular member 112d is placed on the second annular member 112e. The outer annular surface of the lower surface of the first annular member 112d is supported by the conductive ring 113. The outer annular surface of the upper surface of the second annular member 112e serves as the supporting surface that abuts against the supported surface of the first annular member 112d when the first annular member 112d is placed on the second annular member 112e. Furthermore, the edge ring is described as being divided into a first annular member 112d and a second annular member 112e, but this is not limited to this and it may be configured as a single unit or may be configured as being divided into three or more members.

[0087] The third annular member 112f is also referred to as a cover ring. The cover ring (third annular member 112f) is disposed radially outside the edge rings (first annular member 112d and second annular member 112e). The cover ring (third annular member 112f) may be made of, for example, quartz.

[0088] The conductive ring 113 is an annular member made of a conductive material such as metal. The conductive ring 113 is disposed below the first annular member 112d. The conductive ring 113 is electrically connected to the base 1110 via conductive contacts 114. The upper surface of the conductive ring 113 abuts against the first annular member 112d, thereby establishing electrical continuity between the conductive ring 113 and the first annular member 112d. The conductive ring 113 is raised and lowered by a lifter 50.

[0089] The conductive contacts 114 are configured to ensure electrical continuity between the conductive ring 113 and the base 1110 even when the conductive ring 113 is raised and lowered by the lifter 50 .

[0090] The lifter 50 raises and lowers the first annular member 112d via the conductive ring 113. The lifter 50 includes a plurality of (for example, three or more) support pins 51 and an actuator (not shown). Each support pin 51 is inserted into a through-hole formed in the base 1110.

[0091] The lifter 50 raises and lowers the first annular member 112d via the conductive ring 113, thereby adjusting the height of the sheath above the edge ring (first annular member 112d, second annular member 112e).

[0092] 10, during substrate processing, the first annular member 112d is raised by the lifter 50, thereby raising the height of the sheath above the edge ring (first annular member 112d, second annular member 112e), and the height of the sheath above the substrate W is made equal to the height of the sheath above the edge ring (first annular member 112d, second annular member 112e). This allows the angle of incidence of ions to be perpendicular to the substrate W in the outer edge region of the substrate W. This allows the etching shape formed on the substrate W to be vertical.

[0093] At this time, reaction by-products 300 (see FIG. 4) of the substrate processing adhere to and accumulate not only on the upper surface of the first annular member 112d, but also on the lower surface of the first annular member 112d (the surface that abuts against the second annular member 112e when the first annular member 112d is placed on the second annular member 112e) and the upper surface of the second annular member 112e (the placement surface of the first annular member 112d).

[0094] The second annular member 112e is in contact with the base 1110 and is cooled by the temperature control module (flow path 1110a, etc.) of the base 1110. On the other hand, the first annular member 112d is supported by the support pins 51 during substrate processing. Therefore, the temperature of the first annular member 112d becomes higher than the temperature of the second annular member 112e during substrate processing. This makes it easier for reaction by-products 300 to adhere to the second annular member 112e.

[0095] The reaction by-products 300 deposited on the ring assembly 112 and the like may peel off from the wall surface, generating particles, which may adhere to the substrate W and reduce the yield of the semiconductor device formed on the substrate W. For this reason, the plasma processing apparatus 1 is subjected to a cleaning process.

[0096] As shown in FIG. 11 , during the cleaning process, the lifter 50 raises the first annular member 112d higher than the height during substrate processing. In other words, the distance between the first annular member 112d and the second annular member 112e during the cleaning process is made wider than the distance during substrate processing. This allows plasma P of the cleaning gas to enter between the first annular member 112d and the second annular member 112e. Then, ions of the cleaning gas generated by the plasma P are drawn into the base 1110, which serves as the lower electrode, and are then drawn into the second annular member 112e. Furthermore, ions of the cleaning gas are drawn into the first annular member 112d, which is electrically connected to the base 1110 via the conductive ring 113. As a result, the ions sputter on the upper surface of the first annular member 112d, the lower surface (supported surface) of the first annular member 112d, the upper surface (supporting surface) of the second annular member 112e, and the like, thereby cleaning off reaction by-products 300. The sputtered reaction by-products 300 are exhausted together with the gas outside the plasma processing chamber 10 .

[0097] Here, the first annular member 112d has an annular plate portion 112d1 and a bottom portion 112d2. The annular plate portion 112d1 is formed with a circular annular plate structure. The annular plate portion 112d1 has a supported surface on its lower surface that contacts the support surface of the second annular member 112e. The annular plate portion 112d1 is disposed above the second annular member 112e and faces the second annular member 112e. A bottom portion 112d2 is provided on the radially outer side of the annular plate portion 112d1. The bottom portion 112d2 has a circular annular shape and supports the annular plate portion 112d1. The bottom portion 112d2 protrudes downward from the bottom surface (supported surface) of the annular plate portion 112d1. The annular plate portion 112d1 and the bottom portion 112d2 may be formed integrally. The bottom portion 112d2 is disposed radially outward of the second annular member 112e. The bottom portion 112d2 is in contact with and supported by the conductive ring 113.

[0098] The height of the bottom portion 112d2 (the height from the lower surface of the annular plate portion 112d1 (the supported surface that comes into contact with the upper surface (support surface) of the second annular member 112e) to the lower surface of the bottom portion 112d2 (the surface that comes into contact with the conductive ring 113)) is formed to be higher than the height to which the first annular member 112d is lifted during the cleaning process. As a result, even when the first annular member 112d is lifted during the cleaning process, the lower surface of the bottom portion 112d2 is positioned lower than the support surface of the second annular member 112e. In other words, as shown in FIG. 11 , the conductive ring 113 is configured not to be exposed to the plasma P. This makes it possible to prevent contamination by metal atoms sputtered from the conductive ring 113 when the conductive ring 113 is exposed to the plasma P.

[0099] [Substrate Support Having Ring Assembly According to Fourth Embodiment] Next, another example of the ring assembly 112 will be described with reference to Fig. 12. Fig. 12 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the fourth embodiment during cleaning processing.

[0100] The ring assembly 112 shown in FIG. 12 includes a first annular member 112g, a second annular member 112h that supports the first annular member 112g, and a third annular member 112i. It has.

[0101] The first annular member 112g and the second annular member 112h are collectively referred to as an edge ring. The edge ring (first annular member 112g, second annular member 112h) is arranged to surround the periphery of the substrate W supported by the substrate support 11. The edge ring (first annular member 112g, second annular member 112h) may be made of, for example, SiC, Si, quartz, or the like. The edge ring is also referred to as a focus ring. The first annular member 112g is provided on the second annular member 112h. In other words, the first annular member 112g and the second annular member 112h at least partially overlap. In other words, the lower surface (supported surface) of the first annular member 112g is placed on the upper surface (supporting surface) of the second annular member 112h. The lower surface (supported surface) of the first annular member 112g and the upper surface (supporting surface) of the second annular member 112h are opposed surfaces. The inner annular surface of the lower surface of the first annular member 112g serves as the supported surface that is supported by the upper surface (supporting surface) of the second annular member 112h when the first annular member 112g is placed on the second annular member 112h. The outer annular surface of the lower surface of the first annular member 112g is supported by the conductive ring 113. The outer annular surface of the upper surface of the second annular member 112h serves as the supporting surface that abuts against the supported surface of the first annular member 112g when the first annular member 112g is placed on the second annular member 112h. Furthermore, the edge ring is described as being divided into a first annular member 112g and a second annular member 112h, but this is not limited to this and the edge ring may be configured as a single unit or may be configured as being divided into three or more members.

[0102] The third annular member 112i is also referred to as a cover ring. The cover ring (third annular member 112i) is disposed radially outside the edge rings (first annular member 112g, second annular member 112h). The cover ring (third annular member 112i) may be made of, for example, quartz.

[0103] The conductive ring 113 is an annular member made of a conductive material such as metal. The conductive ring 113 is disposed below the first annular member 112g. The conductive ring 113 is electrically connected to the base 1110 via conductive contacts 114. The upper surface of the conductive ring 113 abuts against the first annular member 112g, thereby establishing electrical continuity between the conductive ring 113 and the first annular member 112g. The conductive ring 113 is raised and lowered by a lifter 50.

[0104] The conductive contacts 114 are configured to ensure electrical continuity between the conductive ring 113 and the base 1110 even when the conductive ring 113 is raised and lowered by the lifter 50 .

[0105] The lifter 50 raises and lowers the first annular member 112g via the conductive ring 113. The lifter 50 includes a plurality of (for example, three or more) support pins 51 and an actuator (not shown). Each support pin 51 is inserted into a through-hole formed in the base 1110.

[0106] The lifter 50 raises and lowers the first annular member 112g via the conductive ring 113, thereby adjusting the height of the sheath above the edge ring (first annular member 112g, second annular member 112h).

[0107] During substrate processing, the height of the sheath is adjusted by raising the first annular member 112g with the lifter 50.

[0108] As shown in FIG. 12, during the cleaning process, the lifter 50 raises the first annular member 112g higher than the height during substrate processing. In other words, the distance between the first annular member 112g and the second annular member 112h during the cleaning process is made wider than the distance during substrate processing. This allows plasma P of the cleaning gas to enter between the first annular member 112g and the second annular member 112h. Then, ions of the cleaning gas generated by the plasma P are drawn into the base 1110, which serves as the lower electrode, and are then drawn into the second annular member 112h. Furthermore, ions of the cleaning gas are drawn into the first annular member 112g, which is electrically connected to the base 1110 via the conductive ring 113. As a result, the ions sputter on the upper surface of the first annular member 112g, the lower surface (supported surface) of the first annular member 112g, the upper surface (supporting surface) of the second annular member 112h, and the like, thereby cleaning off reaction by-products 300. The sputtered reaction by-products 300 are exhausted together with the gas outside the plasma processing chamber 10 .

[0109] Here, the conductive ring 113 is covered with a protective film 115. The protective film 115 is a film that is resistant to plasma. The protective film 115 may be, for example, a thermally sprayed film of Y2O3 or the like. The protective film 115 is formed on at least the inner peripheral side surface of the annular conductive ring 113. The protective film 115 may also be formed on the outer peripheral side surface and the upper surface of the conductive ring 113 (see FIG. 12). Although not shown, the protective film 115 may also be formed on the lower surface of the conductive ring 113. In other words, the surfaces of the conductive ring 113 that may be exposed to plasma are covered with the protective film 115.

[0110] As a result, even when the first annular member 112g is raised during the cleaning process, the conductive ring 113 is covered with the protective film 115. That is, as shown in Fig. 12, the conductive ring 113 is configured not to be directly exposed to the plasma P. This makes it possible to prevent contamination of the conductive ring 113 by metal atoms sputtered from the conductive ring 113 due to exposure of the conductive ring 113 to the plasma P.

[0111] Furthermore, the thickness and material of the protective film 115 formed on the upper surface of the conductive ring 113 (in other words, the protective film 115 between the first annular member 112g and the conductive ring 113) may be adjusted so that the conductive ring 113 and the first annular member 112g form a capacitive coupling. Specifically, the thickness and material are preferably adjusted so that the capacitance formed by the protective film 115 between the first annular member 112g and the conductive ring 113 is 10,000 pF or more.

[0112] [Substrate Support Having Ring Assembly According to Fifth Embodiment] Fig. 13 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the fifth embodiment during substrate processing. Fig. 14 is a partially enlarged cross-sectional view showing an example of the operation of the ring assembly 112 according to the fifth embodiment during cleaning processing. Fig. 15 is a plan view illustrating an example of the arrangement of pins in the substrate support part 11 having the ring assembly 112 according to the fifth embodiment. Note that Fig. 13 is a cross-sectional view taken along line AA in Fig. 15, and Fig. 14 is a cross-sectional view taken along line BB in Fig. 15.

[0113] The ring assembly 112 shown in FIG. 12 includes a first annular member 112j, a second annular member 112k that supports the first annular member 112j, a protective ring 112l, and a third annular member 112m. It has.

[0114] The first annular member 112j and the second annular member 112k are also collectively referred to as an edge ring. The edge ring (first annular member 112j, second annular member 112k) is arranged to surround the periphery of the substrate W supported by the substrate support 11. The edge ring (first annular member 112j, second annular member 112k) may be made of, for example, SiC, Si, quartz, or the like. The edge ring is also referred to as a focus ring. The first annular member 112j is provided on the second annular member 112k. In other words, the first annular member 112j and the second annular member 112k at least partially overlap. In other words, the lower surface (supported surface) of the first annular member 112j is placed on the upper surface (supporting surface) of the second annular member 112k. The lower surface (supported surface) of the first annular member 112j and the upper surface (supporting surface) of the second annular member 112k are opposed to each other. The inner annular surface of the lower surface of the first annular member 112j serves as the supported surface that is supported by the upper surface (supporting surface) of the second annular member 112k when the first annular member 112j is placed on the second annular member 112k. The outer annular surface of the lower surface of the first annular member 112j is supported by the conductive ring 113 via the protective ring 112l. The outer annular surface of the upper surface of the second annular member 112k serves as the supporting surface that abuts against the supported surface of the first annular member 112j when the first annular member 112j is placed on the second annular member 112k. Furthermore, the edge ring is described as being divided into a first annular member 112j and a second annular member 112k, but this is not limited to this and it may be configured as a single unit or may be configured as being divided into three or more members.

[0115] The third annular member 112m is also referred to as a cover ring. The cover ring (third annular member 112m) is disposed radially outside the edge rings (first annular member 112j and second annular member 112k). The cover ring (third annular member 112m) may be made of, for example, quartz.

[0116] The protective ring 112l, like the first annular member 112j and the second annular member 112k, may be made of, for example, any one of SiC, Si, quartz, etc. The protective ring 112l is disposed on the conductive ring 113 and covers the upper surface of the conductive ring 113.

[0117] The conductive ring 113 is an annular member made of a conductive material such as metal. The conductive ring 113 is disposed below the first annular member 112j. The conductive ring 113 is electrically connected to the base 1110 via conductive contacts 114. In addition, a protective ring 112l provided on the upper surface of the conductive ring 113 is configured to be able to abut against the first annular member 112j, thereby establishing electrical continuity among the conductive ring 113, the protective ring 112l, and the first annular member 112j. The conductive ring 113 is raised and lowered by a lifter 50.

[0118] The conductive contacts 114 are configured to ensure electrical continuity between the conductive ring 113 and the base 1110 even when the conductive ring 113 is raised and lowered by the lifter 50 .

[0119] The lifter 50 raises and lowers the first annular member 112j via the conductive ring 113 and the protective ring 112l. The lifter 50 includes a plurality of (e.g., three or more) support pins 51 and an actuator (not shown). Each support pin 51 is inserted into a through-hole formed in the base 1110. In FIG. 15, an example of the positions of the support pins 51 that raise and lower the conductive ring 113 is shown by dashed dotted lines. In the example of FIG. 15, three support pins 51 are arranged at equal intervals in the circumferential direction.

[0120] The lifter 55 raises and lowers the first annular member 112j. The lifter 55 includes a plurality of (e.g., three or more) support pins 56 and an actuator (not shown). Each support pin 56 is inserted into a through-hole formed in the base 1110, the conductive ring 113, and the protective ring 112l. In FIG. 15, dashed lines indicate an example of the positions at which the support pins 56 that raise and lower the first annular member 112j are arranged. In the example of FIG. 15, three support pins 56 are arranged at equal intervals in the circumferential direction.

[0121] As shown in FIG. 13, during substrate processing, the lifter 50 (support pins 51) raises the conductive ring 113, the protective ring 112l, and the first annular member 112j. Here, the base 1110, the conductive contacts 114, the conductive ring 113, the protective ring 112l, and the first annular member 112j are electrically connected. This raises the height of the sheath above the edge ring (the first annular member 112j and the second annular member 112k), making the height of the sheath above the substrate W equal to the height of the sheath above the edge ring (the first annular member 112j and the second annular member 112k). This allows the incident angle of ions to be perpendicular to the substrate W in the outer peripheral region of the substrate W. This allows the etching shape formed on the substrate W to be vertical.

[0122] As shown in FIG. 14, during the cleaning process, only the first annular member 112j is raised by the lifter 55 (support pins 56) to a height higher than that during substrate processing. In other words, the distance between the first annular member 112j and the second annular member 112k during the cleaning process is made wider than the distance during substrate processing. Furthermore, the first annular member 112j is supported by the support pins 56, and the first annular member 112j and the protective ring 112l are separated from each other, causing the first annular member 112j to be at a floating potential. This allows plasma P of the cleaning gas to enter between the first annular member 112j and the second annular member 112k. Then, ions of the cleaning gas generated by the plasma P are attracted to the base 1110, which serves as the lower electrode, and are then attracted to the second annular member 112k. Furthermore, ions of the cleaning gas are attracted to the first annular member 112g, which is at a floating potential. As a result, the upper surface of the first annular member 112j, the lower surface (supported surface) of the first annular member 112j, the upper surface (supporting surface) of the second annular member 112k, etc. are sputtered with ions to clean the reaction by-products 300. The sputtered reaction by-products 300 are exhausted to the outside of the plasma processing chamber 10 together with the gas.

[0123] During the cleaning process, the first annular member 112j is at a floating potential, which makes it possible to suppress wear of the first annular member 112j due to sputtering.

[0124] Furthermore, even when the first annular member 112g is raised during the cleaning process, the conductive ring 113 is covered by the protective ring 112l. That is, as shown in Fig. 14, the conductive ring 113 is configured not to be directly exposed to the plasma P. This makes it possible to prevent contamination of the conductive ring 113 by metal atoms sputtered from the conductive ring 113 due to exposure of the conductive ring 113 to the plasma P.

[0125] The above-disclosed embodiments include, for example, the following aspects. (Appendix 1) a plasma processing chamber; a substrate support disposed within the plasma processing chamber and configured to support a substrate; an annular member disposed to surround the substrate supported by the substrate support; a lifter capable of raising and lowering the annular member; a gas inlet for introducing a gas into the plasma processing chamber; a plasma generating unit that generates plasma in the plasma processing chamber; a control unit, the control unit controls the lifter to lift the annular member, the control unit is configured to control the plasma generating unit to generate plasma of a first cleaning gas while the annular member is raised, and to clean the lower surface of the annular member and a mounting surface of the annular member. Plasma processing equipment. (Appendix 2) the control unit controls the lifter to lower the annular member, the control unit is configured to control the plasma generating unit to generate plasma of the second cleaning gas while the annular member is in a lowered state, and clean the upper surface of the annular member. 2. The plasma processing apparatus according to claim 1. (Appendix 3) The annular member includes a first annular member and a second annular member, the first annular member is disposed on the second annular member, the lifter has a support pin that supports the first annular member and an actuator that raises and lowers the support pin, the control unit controls the lifter to lift the first annular member from the second annular member, the control unit controls the plasma generating unit to generate plasma of the first cleaning gas while the first annular member is raised from the second annular member, and cleans a lower surface of the first annular member and an upper surface of the second annular member; the control unit controls the lifter to lower the first annular member toward the second annular member, the control unit is configured to control the plasma generating unit to generate plasma of the second cleaning gas while the first annular member is lowered toward the second annular member, thereby cleaning the upper surface of the first annular member. 3. The plasma processing apparatus according to claim 2. (Appendix 4) When the first annular member is raised from the second annular member, a lower surface of the first annular member is positioned above and outside a sheath on a top plate side of the plasma processing chamber. 4. The plasma processing apparatus according to claim 3. (Appendix 5) a DC generator for supplying power to a top plate of the plasma processing chamber; supplying power from the DC generating unit to the top plate during cleaning of the lower surface of the first annular member and the upper surface of the second annular member; 5. The plasma processing apparatus according to claim 3 or 4. (Appendix 6) When the first annular member is lowered toward the second annular member, an upper surface of the first annular member is disposed below and outside the sheath on the substrate support portion side. 6. The plasma processing apparatus according to claim 3, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 7) a bias power generating unit for supplying bias power to the substrate support unit; supplying bias power from the bias power generation unit to the substrate support unit during cleaning of the lower surface of the first annular member and the upper surface of the second annular member and / or cleaning of the upper surface of the first annular member. 7. The plasma processing apparatus according to claim 6. (Appendix 8) The control unit The plasma generating unit is controlled to clean the upper surface of the first annular member after cleaning the lower surface of the first annular member and the upper surface of the second annular member. 8. The plasma processing apparatus according to claim 3, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 9) The control unit The plasma generating unit is controlled to clean the lower surface of the first annular member and the upper surface of the second annular member after cleaning the upper surface of the first annular member. 9. The plasma processing apparatus according to claim 3, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 10) The control unit The lifter is controlled after cleaning the annular member, and the amount of wear of the first annular member is detected based on the torque of the actuator. 10. The plasma processing apparatus according to claim 3, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 11) The control unit The lifter is controlled based on the amount of wear of the first annular member to control the amount of lift of the first annular member when processing the substrate. 11. The plasma processing apparatus according to claim 10. (Appendix 12) The control unit The bias power generating unit is configured to control the bias power generating unit based on the amount of wear of the first annular member to supply bias power to the first annular member. 8. The plasma processing apparatus according to claim 7. (Appendix 13) The first cleaning gas and the second cleaning gas are the same gas. 13. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 14) the first cleaning gas and the second cleaning gas are different gases; 13. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is a plasma processing apparatus. (Appendix 15) a conductive ring supporting the first annular member; the lifter raises and lowers the conductive ring and the first annular member; The first annular member is an annular plate portion disposed above and facing the second annular member; a bottom portion that is disposed radially outward of the second annular member, protrudes downward from the annular plate portion, and supports the annular plate portion, The height of the bottom portion is formed to be higher than the height at which the first annular member is lifted during a cleaning process. 4. The plasma processing apparatus according to claim 3. (Appendix 16) a conductive ring supporting the first annular member; the lifter raises and lowers the conductive ring and the first annular member; The conductive ring has a protective film on at least the inner peripheral side surface of the conductive ring. 4. The plasma processing apparatus according to claim 3. (Appendix 17) a conductive ring supporting the first annular member; a protective ring covering an upper surface of the conductive ring; The lifter is a first support pin that raises and lowers the conductive ring, the protective ring, and the first annular member; and a second support pin that raises and lowers the first annular member. 4. The plasma processing apparatus according to claim 3. (Appendix 18) A method for controlling a plasma processing apparatus including: a plasma processing chamber; a substrate support provided in the plasma processing chamber and configured to support a substrate; an annular member arranged to surround the substrate supported on the substrate support member; a lifter configured to raise and lower the annular member; a gas introduction unit configured to introduce gas into the plasma processing chamber; and a plasma generation unit configured to generate plasma in the plasma processing chamber, generating plasma of a first cleaning gas in a state in which the annular member is raised, and cleaning the lower surface of the annular member and the mounting surface of the annular member; A method for controlling a plasma processing apparatus. (Appendix 19) The method further includes generating plasma of a second cleaning gas while the annular member is lowered, thereby cleaning the upper surface of the annular member. 19. A method for controlling a plasma processing apparatus according to claim 18. (Appendix 20) After cleaning the annular member, detecting the amount of wear of the annular member based on the torque of the actuator of the lifter; controlling the amount of lift of the annular member based on the amount of wear mentioned above; 20. A method for controlling a plasma processing apparatus according to claim 19.

[0126] The present invention is not limited to the configurations described in the above embodiments, but may be combined with other elements, etc. These aspects can be changed without departing from the spirit of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0127] 1. Plasma processing equipment 2. Control section 10 Plasma Processing Chamber 10s Plasma treatment space 11 Substrate support 13 Shower head (gas inlet) 20 Gas supply unit 30 Power System 31a First RF generating unit (plasma generating unit) 31b Second RF generator (bias power generator) 32a First voltage generating unit (bias power generating unit) 32b Second voltage generating unit (DC generating unit) 40 Exhaust system 50,55 Lifter 51,56 Support pin 52 Actuator 112 Ring Assembly 112a, 112d, 112g, 112j First annular member 112b, 112e, 112h, 112k Second annular member 112c, 112f, 112i, 112m Third annular member 112l Protection Ring 113 Conductive Ring 114 Conductive Contact 115 Protective film W substrate

Claims

1. a plasma processing chamber; a substrate support disposed within the plasma processing chamber and configured to support a substrate; an annular member disposed to surround the substrate supported by the substrate support; a lifter capable of raising and lowering the annular member; a gas inlet for introducing a gas into the plasma processing chamber; a plasma generating unit that generates plasma in the plasma processing chamber; a control unit, the control unit controls the lifter to lift the annular member, the control unit is configured to control the plasma generating unit to generate plasma of a first cleaning gas while the annular member is raised, and to clean the lower surface of the annular member and a mounting surface of the annular member. Plasma processing equipment.

2. the control unit controls the lifter to lower the annular member, the control unit is configured to control the plasma generating unit to generate plasma of the second cleaning gas while the annular member is in a lowered state, and to clean the upper surface of the annular member. The plasma processing apparatus according to claim 1 .

3. The annular member includes a first annular member and a second annular member, the first annular member is disposed on the second annular member, the lifter includes a support pin that supports the first annular member and an actuator that raises and lowers the support pin, the control unit controls the lifter to lift the first annular member from the second annular member, the control unit controls the plasma generating unit to generate plasma of the first cleaning gas while the first annular member is raised from the second annular member, and cleans a lower surface of the first annular member and an upper surface of the second annular member; the control unit controls the lifter to lower the first annular member toward the second annular member, the control unit is configured to control the plasma generating unit to generate plasma of the second cleaning gas while the first annular member is lowered toward the second annular member, thereby cleaning the upper surface of the first annular member. The plasma processing apparatus according to claim 2 .

4. When the first annular member is raised from the second annular member, a lower surface of the first annular member is positioned above and outside a sheath on a top plate side of the plasma processing chamber. The plasma processing apparatus according to claim 3 .

5. a DC generator for supplying power to a top plate of the plasma processing chamber; supplying power from the DC generating unit to the top plate during cleaning of the lower surface of the first annular member and the upper surface of the second annular member; The plasma processing apparatus according to claim 4 .

6. When the first annular member is lowered toward the second annular member, an upper surface of the first annular member is disposed below and outside the sheath on the substrate support portion side.

6. The plasma processing apparatus according to claim 3, wherein the plasma processing apparatus is a plasma processing apparatus.

7. a bias power generating unit for supplying bias power to the substrate support unit; supplying bias power from the bias power generation unit to the substrate support unit during cleaning of the lower surface of the first annular member and the upper surface of the second annular member and / or cleaning of the upper surface of the first annular member. The plasma processing apparatus according to claim 6 .

8. The control unit The plasma generating unit is controlled to clean the upper surface of the first annular member after cleaning the lower surface of the first annular member and the upper surface of the second annular member. The plasma processing apparatus according to claim 3 .

9. The control unit The plasma generating unit is controlled to clean the lower surface of the first annular member and the upper surface of the second annular member after cleaning the upper surface of the first annular member. The plasma processing apparatus according to claim 3 .

10. The control unit The lifter is controlled after cleaning the annular member, and the amount of wear of the first annular member is detected based on the torque of the actuator. The plasma processing apparatus according to claim 3 .

11. The control unit The lifter is controlled based on the amount of wear of the first annular member to control the amount of lift of the first annular member when processing the substrate. The plasma processing apparatus according to claim 10.

12. The control unit The bias power generating unit is configured to control the bias power generating unit based on the amount of wear of the first annular member to supply bias power to the first annular member. The plasma processing apparatus according to claim 7 .

13. the first cleaning gas and the second cleaning gas are the same gas; The plasma processing apparatus according to claim 2 .

14. the first cleaning gas and the second cleaning gas are different gases; The plasma processing apparatus according to claim 2 .

15. a conductive ring supporting the first annular member; the lifter raises and lowers the conductive ring and the first annular member; The first annular member is an annular plate portion disposed above and facing the second annular member; a skirt portion disposed radially outward of the second annular member, protruding downward from the annular plate portion, and supporting the annular plate portion, The height of the bottom portion is formed to be higher than the height at which the first annular member is lifted during a cleaning process. The plasma processing apparatus according to claim 3 .

16. a conductive ring supporting the first annular member; the lifter raises and lowers the conductive ring and the first annular member; The conductive ring has a protective film on at least the inner peripheral side surface of the conductive ring. The plasma processing apparatus according to claim 3 .

17. a conductive ring supporting the first annular member; a protective ring covering an upper surface of the conductive ring; The lifter is a first support pin that raises and lowers the conductive ring, the protective ring, and the first annular member; and a second support pin that raises and lowers the first annular member. The plasma processing apparatus according to claim 3 .

18. 1. A method for controlling a plasma processing apparatus comprising: a plasma processing chamber; a substrate support section provided in the plasma processing chamber and configured to support a substrate; an annular member arranged to surround the substrate supported on the substrate support section; a lifter configured to raise and lower the annular member; a gas introduction section configured to introduce gas into the plasma processing chamber; and a plasma generation section configured to generate plasma in the plasma processing chamber, generating plasma of a first cleaning gas in a state in which the annular member is raised, and cleaning the lower surface of the annular member and the mounting surface of the annular member; A method for controlling a plasma processing apparatus.

19. The method further includes generating plasma of a second cleaning gas while the annular member is lowered, thereby cleaning the upper surface of the annular member. The method for controlling a plasma processing apparatus according to claim 18.

20. After cleaning the annular member, detecting the amount of wear of the annular member based on the torque of the actuator of the lifter; controlling the amount of lift of the annular member based on the amount of wear mentioned above; The method for controlling a plasma processing apparatus according to claim 19.

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