Plasma processing apparatus and substrate support

Abstract

The plasma processing apparatus suppresses fluctuations in base potential even when a pulsed DC signal is supplied. The plasma processing apparatus includes a chamber, a bias power supply that supplies a pulsed bias DC signal, a substrate support that supports a substrate and an edge ring within the chamber, and an electrical path. The substrate support includes an electrostatic chuck formed of a dielectric material and including a first region that holds the substrate and a second region that is disposed around the first region and holds the edge ring, a first bias electrode disposed within the first region, a second bias electrode disposed within the second region, a base that supports the electrostatic chuck, and a first impedance adjustment mechanism having a first variable capacitor connected between the second bias electrode and the base. The electrical path includes a first electrical path that connects the bias power supply, the base, and the first bias electrode, and a second electrical path that connects the bias power supply, the base, the first impedance adjustment mechanism, and the second bias electrode.

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus and a substrate support. [Background technology]

[0002] Patent Document 1 discloses a plasma processing apparatus comprising: a chamber; a bias power supply configured to generate an electric bias; a substrate support configured to support a substrate and an edge ring in the chamber, the substrate support having a first region configured to hold the substrate, a second region surrounding the first region and configured to hold the edge ring, a first bias electrode provided in the first region to receive the electric bias, a first impedance adjustment electrode provided in the first region and grounded, a second bias electrode provided in the second region to receive the electric bias, and a second impedance adjustment electrode provided in the second region and grounded; an impedance adjustment mechanism connected to at least one of the first impedance adjustment electrode and the second impedance adjustment electrode; and an electrical path connecting the bias power supply, the first bias electrode, and the second bias electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-87396 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a plasma processing apparatus and a substrate support that can suppress fluctuations in base potential even when a pulsed DC signal is supplied. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a plasma processing apparatus includes a chamber, a bias power supply configured to supply a pulsed bias DC signal, a substrate support configured to support a substrate and an edge ring within the chamber, and an electrical path. The substrate support includes an electrostatic chuck formed of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region surrounding the first region for holding the edge ring, a first bias electrode provided within the first region, a second bias electrode provided within the second region, a base supporting the electrostatic chuck, and a first impedance adjustment mechanism configured to have a first variable capacitor connected between the second bias electrode and the base. The electrical path includes a first electrical path connecting the bias power supply, the base, and the first bias electrode, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the second bias electrode. [Effects of the Invention]

[0006] According to the present disclosure, fluctuations in the base potential can be suppressed even when a pulsed DC signal is supplied. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing apparatus according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing an example of electrical connections between the substrate support and plasma in this embodiment. [Figure 3] FIG. 3 is a diagram showing an example of an equivalent circuit of the substrate support and plasma in this embodiment. [Figure 4] FIG. 4 is a diagram showing an example of electrical connection between a substrate support and plasma in a reference example. [Figure 5] FIG. 5 is a diagram showing an example of an equivalent circuit of the substrate support part and plasma in the reference example. [Figure 6] FIG. 6 is a graph showing an example of the relationship between the impedance of the plasma processing chamber and the capacitance of the variable capacitor in this embodiment. [Figure 7] FIG. 7 is a graph showing an example of the relationship between the impedance on the ring assembly side and the capacitance of the variable capacitor in this embodiment. [Figure 8] FIG. 8 is a graph showing an example of the relationship between the impedance of the plasma processing chamber and the capacitance of the variable capacitor in the reference example. [Figure 9] FIG. 9 is a graph showing an example of the relationship between the impedance on the ring assembly side and the capacitance of the variable capacitor in the reference example. [Figure 10] FIG. 10 is a graph showing an example of the relationship between the potential and the capacitance of the variable capacitor in this embodiment. [Figure 11] FIG. 11 is a graph showing an example of the change in etching rate in this embodiment. [Figure 12] FIG. 12 is a graph showing an example of the relationship between the potential and the capacitance of the variable capacitor in the reference example. [Figure 13] FIG. 13 is a graph showing an example of changes in etching rate in a reference example. [Figure 14] FIG. 14 is a diagram showing an example of tilt control of the substrate edge in this embodiment. [Figure 15] FIG. 15 is a diagram showing an example of tilt control of the substrate edge in this embodiment. [Figure 16] FIG. 16 is a diagram illustrating an example of an impedance adjusting mechanism in the first modification. [Figure 17] FIG. 17 is a diagram illustrating an example of an impedance adjusting mechanism in the second modification. [Figure 18] FIG. 18 is a diagram illustrating an example of an electrostatic chuck and a base in the third modification. [Figure 19] FIG. 19 is a diagram showing an example of an electrostatic chuck and a base in the fourth modification. [Figure 20] FIG. 20 is a diagram illustrating a configuration example of a plasma processing apparatus in which a ring-shaped conductor is arranged. [Figure 21]FIG. 21 is a diagram illustrating an example of the configuration of a second conductor having a ring-shaped conductor. [Figure 22] FIG. 22 is a plan view of the annular conductor for illustrating the connection positions of a plurality of second connection conductors. [Figure 23] FIG. 23 is a diagram for explaining a configuration example of a plasma processing apparatus when a connector is arranged. [Figure 24] FIG. 24 is a diagram for explaining a configuration example of a plasma processing apparatus in which the connector has a fitting structure. [Figure 25] FIG. 25 is a diagram for explaining a configuration example of a plasma processing apparatus when the connector has a touch structure. [Figure 26] FIG. 26 is a plan view of an annular conductor for explaining an example of a plurality of conductor regions included in the annular conductor. [Figure 27] FIG. 27 is a side view of an annular conductor for explaining an example of a plurality of conductor regions included in the annular conductor. [Figure 28] FIG. 28 is a side view showing an example of an annular conductor having a plurality of conductor regions with different cross-sectional areas. [Figure 29] FIG. 29 is a side view showing an example of an annular conductor having a plurality of conductor regions with different cross-sectional areas. [Figure 30] FIG. 30 is a diagram illustrating a configuration example of a plasma processing apparatus in which a variable capacitor is disposed on each of a plurality of second connecting conductors. [Figure 31] FIG. 31 is a diagram illustrating an example of the configuration of a plasma processing apparatus in which a variable capacitor is disposed on each of a plurality of connecting conductors. [Figure 32] FIG. 32 is a diagram for explaining a configuration example of a plasma processing apparatus in which a sensor is arranged. [Figure 33] FIG. 33 is a diagram illustrating another example of the configuration of the plasma processing apparatus when a sensor is disposed. [Figure 34] FIG. 34 is a diagram illustrating another example of the configuration of the substrate support part of the plasma processing apparatus. [Figure 35]FIG. 35 is a diagram illustrating an example of the configuration of the substrate support part when the impedance adjustment mechanism has an additional capacitor. [Figure 36] FIG. 36 is a plan view of the substrate support part for explaining an example of the arrangement of the first variable capacitor and the additional capacitor. [Figure 37] FIG. 37 is a diagram for explaining an electrical circuit formed in the plasma sheath of the edge ring and the substrate support portion. [Figure 38] FIG. 38 is a diagram illustrating an example of the configuration of the substrate support part when an additional coil is connected to a conductor to which an additional capacitor is connected. [Figure 39] FIG. 39 is a diagram illustrating an example of the configuration of the substrate support part when an additional coil is connected to the conductor to which the first variable capacitor is connected. [Figure 40] FIG. 40 is a diagram illustrating a configuration example of a substrate support part when an LC series circuit is connected to a node of a conductor to which a first variable capacitor is connected. [Figure 41] FIG. 41 is a diagram illustrating an example of the configuration of a substrate support part having a grounding case that surrounds a conductor to which a first variable capacitor is connected. [Figure 42] Figure 42 is a diagram illustrating an example configuration of a substrate support part that includes multiple connection conductors that electrically connect the first variable capacitor and the second bias electrode in parallel, and the path lengths of the multiple connection conductors are uniform. [Figure 43] FIG. 43 is a plan view of the second bias electrode for explaining an example of the arrangement of connection points between a plurality of connection conductors and the second bias electrode. [Figure 44] FIG. 44 is a diagram illustrating a configuration example of a substrate support part in which an impedance element is connected to at least one of a plurality of connection conductors. [Figure 45] FIG. 45 is a diagram illustrating another example of the configuration of a plasma processing apparatus having a first impedance adjustment mechanism. [Figure 46] FIG. 46 is a diagram illustrating another example of the configuration of a plasma processing apparatus having a first impedance adjustment mechanism. [Figure 47] FIG. 47 is a diagram for explaining a configuration example of a plasma processing apparatus in which the bias power supply has an RF power supply and a DC power supply. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a plasma processing apparatus and a substrate support will be described in detail below with reference to the accompanying drawings. However, the disclosed technology is not limited to the following embodiments.

[0009] In plasma processing systems, the potential of an edge ring may be controlled to control the tilt of the edge of a substrate being processed. For example, it has been proposed to provide an electrode in the electrostatic chuck of a substrate support at a position corresponding to the edge ring and to control the capacitance of a variable capacitor connected between the electrode and ground. In addition, in plasma processing systems, it has been proposed to use a direct current (DC) pulsed power supply connected to the substrate support, supplying a pulsed DC (Direct Current) signal, to achieve monochromatic ion energy and vertical ion angle. However, when using a DC pulsed power supply, changing the capacitance of the variable capacitor connected between the electrode in the electrostatic chuck and ground fluctuates the impedance of the chamber as seen from the DC pulsed power supply. The fluctuation in chamber impedance also fluctuates the output current of the DC pulsed power supply. This fluctuation also fluctuates the base potential of the substrate support connected to the DC pulsed power supply, potentially resulting in a process shift. In other words, the potential of the substrate, which is approximately equal to the base potential, fluctuates. Therefore, it is expected that fluctuations in the base potential can be suppressed even when a pulsed DC signal is supplied.

[0010] [Configuration of plasma processing apparatus 1] An exemplary configuration of a plasma processing system will be described below. FIG. 1 illustrates an exemplary configuration of a plasma processing apparatus according to an embodiment of the present disclosure. 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 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed 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 planar 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 referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112. The substrate support 11 is an example of a substrate support, the central region 111a is an example of a first region, and the annular region 111b is an example of a second region. In the following description, the central region 111a may be referred to as a substrate support surface 111a, and the annular region 111b may be referred to as a ring support surface 111b.

[0012] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. That is, the conductive member of the base 1110 can function as part of an electrical path 38 connected to a first bias electrode 34 and a second bias electrode 35, which will be described later. A power supply line 33a is connected to the bottom of the base 1110. Note that the power supply line 33a is also included in the electrical path 38. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to a radio frequency (RF) power supply 31 and / or a direct current (DC) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, at least one RF / DC electrode functions as a lower electrode. That is, a first bias electrode 34 and a second bias electrode 35 (described later), which are examples of RF / DC electrodes, are electrically connected to the RF power supply 31 and / or the DC power supply 32 via an electrical path 38. When a bias RF signal and / or a DC signal (described later) is supplied to at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Note that a conductive member of the base 1110 and at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as the lower electrode, or the first bias electrode 34 may function as the electrostatic electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0013] 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.

[0014] 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.

[0015] The electrostatic chuck 1111 is formed of a dielectric ceramic member 1111a and includes, in order from the substrate support surface 111a side, an electrostatic electrode 1111b and a first bias electrode 34 therein below the substrate support surface 111a. The electrostatic chuck 1111 also includes a second bias electrode 35 therein below the ring support surface 111b. The first bias electrode 34 is connected to, for example, the bottom of the base 1110 via a conductor 36b passing through a through hole 36a in the base 1110. An insulating sleeve (not shown) is provided inside the through hole 36a, electrically insulating the base 1110 and the conductor 36b within the through hole 36a. The second bias electrode 35 is connected to, for example, the bottom of the base 1110 via a conductor 37b passing through a through hole 37a in the base 1110 and an impedance adjustment mechanism 50. An insulating sleeve (not shown) is provided inside the through-hole 37a, and the base 1110 and the conductor 37b are electrically insulated from each other inside the through-hole 37a.

[0016] That is, the first bias electrode 34 is connected to the matching circuit 33 (described later) via the conductor 36b, the base 1110, and the power supply line 33a, thereby forming an electrical path 38 (first electrical path). Also, the second bias electrode 35 is connected to the matching circuit 33 (described later) via the conductor 37b, the impedance adjustment mechanism 50, the base 1110, and the power supply line 33a, thereby forming an electrical path 38 (second electrical path). Note that the connection between the first bias electrode 34 and the second bias electrode 35 and the base 1110 is not limited to a conductive member, and any method capable of supplying a bias RF / DC signal, such as magnetic resonance, capacitive coupling, or inductive coupling, may be used. That is, the electrical path 38 is configured to connect a bias power supply (for example, a second RF generating unit 31b and / or a first DC generating unit 32a (described later)), the first bias electrode 34, and the second bias electrode 35. Furthermore, the electrical path 38 may be configured so that the second RF generating unit 31b and / or the first DC generating unit 32a, which will be described later, are not connected to the base 1110, but so that the second RF generating unit 31b and / or the first DC generating unit 32a are directly connected to the first bias electrode 34. Similarly, the electrical path 38 may be configured so that the second RF generating unit 31b and / or the first DC generating unit 32a are directly connected to the second bias electrode 35 via the impedance adjustment mechanism 50.

[0017] The impedance adjustment mechanism 50 adjusts the amount of RF / DC signal (electrical bias) supplied from the second bias electrode 35 to the plasma side. That is, the impedance adjustment mechanism 50 adjusts the power supplied to the plasma via the ring assembly 112 out of the substrate W and the ring assembly 112. That is, by adjusting the amount of RF / DC signal flowing to the ring assembly 112 side by the impedance adjustment mechanism 50, the potential of the ring assembly 112 is adjusted and used to control the tilt angle and / or adjust the etching rate. Note that the elements constituting the electrical path 38, including the impedance adjustment mechanism 50, distribute the bias RF / DC signal to the substrate W and the ring assembly 112, and therefore may be referred to as a bias split mechanism in the following description.

[0018] By locating the first bias electrode 34 and the second bias electrode 35 as close as possible to the substrate W and the ring assembly 112, the impedance of the capacitor formed by the substrate W and the ring assembly 112, the ceramic member 1111a, and these electrodes is reduced. This reduces the potential difference between the first bias electrode 34 and the second bias electrode 35 and the substrate W and the ring assembly 112. Similarly, the impedance of the capacitor formed by the first bias electrode 34 and the electrostatic electrode 1111b can also be reduced. Furthermore, the impedance of the capacitor formed by the electrostatic electrode 1111b and the substrate W, the second bias electrode 35, and the ring assembly 112 can also be reduced.

[0019] For the electrical path 38 (first electrical path) on the substrate support surface 111a side, an impedance adjustment mechanism may be provided on the conductor 36b. In this case, the first bias electrode 34 is connected to a matching circuit 33 (described later) via the conductor 36b, the impedance adjustment mechanism, the base 1110, and the power supply line 33a, thereby forming the electrical path 38.

[0020] As described above, the substrate support 11 is configured to include an electrostatic chuck 1111, a first bias electrode 34, a second bias electrode 35, a base 1110, and an impedance adjustment mechanism (first impedance adjustment mechanism) 50. The electrostatic chuck 1111 includes a first region for holding a substrate W and a second region surrounding the first region for holding an edge ring, and is formed of a dielectric material. The first bias electrode 34 is provided within the first region. The second bias electrode 35 is provided within the second region. The base 1110 supports the electrostatic chuck 1111. The impedance adjustment mechanism 50 is configured to include a variable capacitor 51 (first variable capacitor) described below connected between the second bias electrode 35 and the base 1110. The ring assembly 112 (edge ​​ring), the second region, and the second bias electrode 35 are formed in an annular shape. The substrate support 11 is formed so that the first region and the second region of the electrostatic chuck 1111 are integrated.

[0021] 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.

[0022] 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.

[0023] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode (first bias electrode 34, second bias electrode 35) and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF / DC 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.

[0024] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. When the first RF generating unit 31a is coupled to the lower electrode, for example, the first RF generating unit 31a is coupled to the first bias electrode 34 via the matching circuit 33, the feed line 33a, the base 1110, the conductor 37b, and the impedance adjusting mechanism 50. 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 provided to at least one lower electrode and / or at least one upper electrode within the plasma processing chamber 10 to generate a capacitively coupled plasma.

[0025] The second RF generating unit 31b is coupled to the first bias electrode 34 via the matching circuit 33, the feed line 33a, the base 1110, and the conductor 36b. The second RF generating unit 31b is coupled to the second bias electrode 35 via the matching circuit 33, the feed line 33a, the base 1110, the conductor 37b, and the impedance adjusting mechanism 50. The second RF generating unit 31b is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency 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.

[0026] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal (bias DC signal) is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0027] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating a sequence of voltage pulses from a DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. That is, the first DC generator 32a and the waveform generator are an example of a bias power supply (DC pulse power supply) configured to supply a pulsed bias DC signal. In this case, the first DC signal (bias DC signal) may be expressed as including the generated sequence of voltage pulses. That is, the first DC signal is an example of a pulsed bias DC signal. Also, in one embodiment, the first DC generator 32a may include a waveform generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulse may have a positive polarity or a negative polarity. Furthermore, the voltage pulse sequence may include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. The first and second DC generators 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generator 32a may be provided instead of the second RF generator 31b.

[0028] The matching circuit 33 is provided between the first RF generating unit 31a, the second RF generating unit 31b, and the first DC generating unit 32a and the substrate support 11 (base 1110) and is connected thereto. The matching circuit 33 enables a source RF signal and / or a bias RF signal to be supplied from the first RF generating unit 31a and / or the second RF generating unit 31b to the substrate support 11 via the matching circuit 33. The matching circuit 33 also enables a first DC signal (bias DC signal) to be supplied from the first DC generating unit 32a to the substrate support 11 via the matching circuit 33.

[0029] 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.

[0030] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0031] [Bias split mechanism] Next, a bias split mechanism that distributes a bias RF / DC signal will be described with reference to Figures 2 and 3. Figure 2 is a diagram showing an example of an electrical connection between a substrate support and plasma in this embodiment. Figure 3 is a diagram showing an example of an equivalent circuit of a substrate support and plasma in this embodiment.

[0032] As shown in FIG. 2 , in this embodiment, a bias RF / DC signal is supplied from a power supply 30 to a base 1110 via a matching circuit 33. The power supply 30 includes a first RF generator 31a, a second RF generator 31b, and a first DC generator 32a that supply the bias RF / DC signal. A first bias electrode 34 is connected to the base 1110 via a conductor 36b as part of an electrical path 38. The first bias electrode 34 is electrically connected to the substrate W via a capacitor C4 formed between the substrate W and the ceramic member 1111a of the electrostatic chuck 1111. The substrate W is also electrically connected to the plasma P generated in the plasma processing chamber 10 via a capacitor C5 formed between the substrate W and the first bias electrode 34, and is electrically grounded via the plasma processing chamber 10.

[0033] The second bias electrode 35 is connected to the base 1110 as part of the electrical path 38 via the conductor 37b and the variable capacitor 51. The variable capacitor 51 is an example of the impedance adjustment mechanism 50. The variable range of the capacitance of the variable capacitor 51 may be, for example, 10 pF to 2000 pF. The variable range of the capacitance of the variable capacitor 51 may be further expanded to include at least one of a range less than 10 pF and a range greater than 2000 pF. The impedance adjustment mechanism 50 may include other elements such as a coil, a capacitor, and a resistor. The second bias electrode 35 is electrically connected to the base 1110 via a capacitor C1 formed between the second bias electrode 35 and the base 1110 by the ceramic member 1111a of the electrostatic chuck 1111. In other words, the variable capacitor 51 and the capacitor C1 are connected in parallel between the second bias electrode 35 and the base 1110. The second bias electrode 35 is electrically connected to the ring assembly 112 (edge ​​ring) via a capacitor C2 formed between the second bias electrode 35 and the ring assembly 112 (edge ​​ring) by the ceramic member 1111a of the electrostatic chuck 1111. The ring assembly 112 is further electrically connected to the plasma P via a capacitor C3 formed between the second bias electrode 35 and the plasma P, and is electrically grounded via the plasma processing chamber 10.

[0034] The electrical connection between the substrate support 11 and the plasma P shown in FIG. 2 is represented by an equivalent circuit 10b in FIG. 3. As shown in FIG. 3, in the equivalent circuit 10b, starting from the power supply 30, a coil L1 is connected in series, and the circuit on the ring assembly 112 side and the circuit on the substrate W side are connected in parallel. In other words, the bias RF / DC signal is distributed to the ring assembly 112 side and the substrate W side. Note that the matching circuit 33 is omitted in FIG. 3, and the coil L1 represents a parasitic inductance. The circuit on the ring assembly 112 side includes a parallel connection of a variable capacitor 51 and a capacitor C1, and a series connection of capacitors C2 and C3, which are electrically grounded. Note that the combined capacitance of the variable capacitor 51 and the capacitor C1 is represented as capacitance C11. Meanwhile, the circuit on the substrate W side (the substrate support surface 111a side) includes a series connection of capacitors C4 and C5, which are electrically grounded. Note that the plasma P is omitted from the equivalent circuit 10b.

[0035] As described above, the electrical path 38 includes a first electrical path and a second electrical path. The first electrical path connects the power supply 30 (bias power supply), the base 1110, and the first bias electrode 34. The second electrical path connects the power supply 30 (bias power supply), the base 1110, the impedance adjustment mechanism 50 (first impedance adjustment mechanism), and the second bias electrode 35. The plasma processing apparatus 1 may further include a second impedance adjustment mechanism having a second variable capacitor connected between the first bias electrode 34 and the base 1110 for the electrical path 38 (first electrical path) on the substrate support surface 111a side. In this case, the first electrical path connects the power supply 30 (bias power supply), the base 1110, the second impedance adjustment mechanism, and the first bias electrode 34.

[0036] 2 and 3, the impedance of the plasma processing chamber 10 remains constant even when the capacitance of the variable capacitor 51 is changed. Therefore, when a pulsed bias DC signal is supplied from the first DC generator 32a, the capacitance of the variable capacitor 51 can be changed to control the potential of the ring assembly 112 while keeping the potential of the base 1110 (the potential of the substrate W) constant.

[0037] Furthermore, in this embodiment, when a first DC signal (bias DC signal) is supplied from the first DC generating unit 32a to the base 1110, the voltage or potential of each part of the electrical path 38 may be measured, and feedback control may be performed on the first DC generating unit 32a. Note that the output voltage of the first DC generating unit 32a can be set and controlled by the control unit 2. In this case, the plasma processing apparatus 1 includes, for example, a voltage sensor 45, a potential sensor 46, and a potential sensor 47 (see FIG. 2). The voltage sensor 45 measures the output voltage of the first DC generating unit 32a. The potential sensor 46 measures the potential of the base 1110. The potential sensor 47 measures the potential between the variable capacitor 51 and the second bias electrode 35. The voltage sensor 45, the potential sensor 46, and the potential sensor 47 output their respective measured values ​​to the control unit 2.

[0038] The control unit 2 controls the first DC generating unit 32a so that the measurement value of the voltage sensor 45 or the potential sensor 46 becomes constant when the capacitance of the variable capacitor 51 is changed. That is, the control unit 2 performs feedback control to adjust the output voltage of the first DC generating unit 32a based on the measurement value of the voltage sensor 45 or the potential sensor 46 so that the measurement value of the voltage sensor 45 or the potential sensor 46 becomes constant. The control unit 2 may also calculate a potential ratio based on the measurement values ​​of the potential sensors 46 and 47, and adjust the output voltage of the first DC generating unit 32a so that the calculated potential ratio becomes a target value.

[0039] The control parameters of the first DC generating unit 32a include, for example, at least one of the frequency and duty ratio of the voltage pulse (DC pulse) included in the first DC signal (bias DC signal). For example, the frequency of the voltage pulse can be 400 kHz. The frequency of the voltage pulse may be any frequency in the range of 200 Hz to 3 MHz. For example, the duty ratio of the voltage pulse can be 20%. The duty ratio of the voltage pulse may be any duty ratio equal to or greater than 20%. The first DC generating unit 32a can change the duty ratio of the voltage pulse, and therefore, by changing the capacitance of the variable capacitor 51, the time required for electron charging can be changed in addition to controlling the potentials of the substrate W and the ring assembly 112. That is, in the plasma processing apparatus 1, the process can be tuned by changing the time required for electron charging based on the duty ratio of the voltage pulse of the first DC generating unit 32a and the capacitance of the variable capacitor 51.

[0040] Next, a bias split mechanism of a reference example will be described with reference to Figures 4 and 5. Figure 4 is a diagram showing an example of electrical connection between a substrate support and plasma in the reference example. Figure 5 is a diagram showing an example of an equivalent circuit of the substrate support and plasma in the reference example.

[0041] As shown in FIG. 4 , in the reference example, a bias RF / DC signal is supplied from a power supply 30 to a base 1110 via a matching circuit 33. The power supply 30 includes a first RF generator 31a, a second RF generator 31b, and a first DC generator 32a that supply the bias RF / DC signal. A first bias electrode 34 is connected to the base 1110 via a conductor 36b as part of an electrical path 38. The first bias electrode 34 is electrically connected to the substrate W via a capacitor C4 formed between the substrate W and the ceramic member 1111a of the electrostatic chuck 1111. The substrate W is also electrically connected to the plasma P via a capacitor C5 formed between the substrate W and the plasma P, and is electrically grounded via the plasma processing chamber 10.

[0042] The second bias electrode 35a is connected to the base 1110 via the conductor 37b as part of the electrical path 38. That is, in the reference example, the variable capacitor 51 is not included in the electrical path 38. In the reference example, an impedance adjustment electrode 60 is provided in the electrostatic chuck 1111, closer to the ring assembly 112 than the second bias electrode 35a. The impedance adjustment electrode 60 is grounded via a conductor 61b passing through a through hole 61a and a variable capacitor 62. The variable capacitor 62 is provided to adjust the impedance on the ring assembly 112 side. Note that, like the through hole 36a, an insulating sleeve (not shown) is provided inside the through hole 61a, and the base 1110 and the conductor 61b are electrically insulated from each other within the through hole 61a.

[0043] The second bias electrode 35a is electrically connected to the impedance adjusting electrode 60 via a capacitor C6 formed between the second bias electrode 35a and the impedance adjusting electrode 60 by the ceramic member 1111a of the electrostatic chuck 1111. The impedance adjusting electrode 60 is also electrically connected to the ring assembly 112 via a capacitor C7 formed between the second bias electrode 35a and the ring assembly 112 by the ceramic member 1111a of the electrostatic chuck 1111. The ring assembly 112 is also electrically connected to the plasma P via a capacitor C8 formed between the second bias electrode 35a and the plasma P, and is electrically grounded via the plasma processing chamber 10. In other words, the series-connected capacitors C7 and C8 and the variable capacitor 62 are connected in parallel between the impedance adjusting electrode 60 and ground.

[0044] The electrical connection between the substrate support 11 and the plasma P shown in FIG. 4 is represented by an equivalent circuit 10c in FIG. 5. As shown in FIG. 5, in the equivalent circuit 10c, starting from the power supply 30, a coil L1 is connected in series, and the circuit on the ring assembly 112 side and the circuit on the substrate W side are connected in parallel. In other words, the bias RF / DC signal is distributed to the ring assembly 112 side and the substrate W side. Note that the matching circuit 33 is omitted in FIG. 5, and the coil L1 represents a parasitic inductance. In the circuit on the ring assembly 112 side, a parallel connection of capacitors C7 and C8 connected in series with capacitor C6 and a variable capacitor 62 is connected in series, and capacitor C8 and variable capacitor 62 are electrically grounded. Note that the combined capacitance of the parallel connection of capacitors C7 and C8 connected in series with variable capacitor 62 is represented as capacitance C81. On the other hand, in the circuit on the substrate W side (substrate supporting surface 111a side), capacitors C4 and C5 are connected in series and electrically grounded. In the equivalent circuit 10c, the plasma P is omitted.

[0045] 4 and 5, when the capacitance of the variable capacitor 62 is changed, the bias DC signal that flows from the variable capacitor 62 to ground without passing through the plasma P changes, causing a change in the impedance of the plasma processing chamber 10. Therefore, when a pulsed bias DC signal (first DC signal) is supplied from the first DC generator 32a of the power supply 30, the output current of the first DC generator 32a changes, causing a change in the potential of the base 1110 (which is approximately equal to the potential of the substrate W). The potential of the base 1110 is expressed by the following equation (1):

[0046] Vpp = Vout + (XL × Iout) (1)

[0047] Here, Vpp indicates the potential of the base 1110 (substantially equal to the potential of the substrate W), and Vout indicates the output voltage of the first DC generating unit 32a before changing the capacitance of the variable capacitor 62. XL indicates the reactance in the circuit including the matching circuit 33, and Iout indicates the output current that fluctuates when the capacitance of the variable capacitor 62 is changed. Note that (XL × Iout) in equation (1) indicates the amount of fluctuation in the output voltage of the first DC generating unit 32a that occurs when the capacitance of the variable capacitor 62 is changed. That is, in the reference example, the voltage applied to the base 1110 is boosted.

[0048] Next, the impedance of the plasma processing chamber 10 in this embodiment and a reference example will be compared with the impedance on the ring assembly 112 side using Figures 6 to 9. Figure 6 is a graph showing an example of the relationship between the impedance of the plasma processing chamber and the capacitance of the variable capacitor in this embodiment. Figure 7 is a graph showing an example of the relationship between the impedance on the ring assembly side and the capacitance of the variable capacitor in this embodiment. Note that in each of the graphs in Figures 6 to 9, the impedance and capacitance are normalized within a predetermined range, as it is sufficient to show the change in impedance relative to the change in capacitance.

[0049] In this embodiment, when the capacitance C of the variable capacitor 51 is changed, the impedance Z1 of the entire plasma processing chamber 10 (the entire equivalent circuit 10b) remains substantially constant, as shown in graph 70 of Fig. 6. Furthermore, as shown in graph 71 of Fig. 7, the impedance Z2 on the ring assembly 112 side (the capacitance C11 side of the equivalent circuit 10b) changes depending on the capacitance C of the variable capacitor 51. That is, in this embodiment, when the first DC signal (pulsed DC signal) is supplied, even if the capacitance C of the variable capacitor 51 is changed, it is possible to control the impedance Z2 on the ring assembly 112 side while suppressing fluctuations in the impedance Z1.

[0050] FIG. 8 is a graph showing an example of the relationship between the impedance of the plasma processing chamber and the capacitance of the variable capacitor in a reference example. FIG. 9 is a graph showing an example of the relationship between the impedance on the ring assembly side and the capacitance of the variable capacitor in a reference example. In the reference example, when the capacitance C' of the variable capacitor 62 is changed, as shown in graph 72 of FIG. 8, the impedance Z3 of the entire plasma processing chamber 10 (the entire equivalent circuit 10c) changes depending on the capacitance C' of the variable capacitor 62. Furthermore, as shown in graph 73 of FIG. 9, the impedance Z4 on the ring assembly 112 side (the capacitance C81 side of the equivalent circuit 10c) changes depending on the capacitance C' of the variable capacitor 62. That is, in the reference example, when a first DC signal (pulsed DC signal) is supplied, changing the capacitance C' of the variable capacitor 62 changes not only the impedance Z4 but also the impedance Z3.

[0051] Next, the potential of the base 1110 and the ring assembly 112 and the variation in the etching rate in this embodiment and the reference example will be described with reference to Figures 10 to 13. Figure 10 is a graph showing an example of the relationship between the potential and the capacitance of the variable capacitor in this embodiment. Figure 11 is a graph showing an example of the change in the etching rate in this embodiment. Note that in each of the graphs in Figures 10 to 13, it is sufficient to show the relative changes in the potential, capacitance, and etching rate, so they are normalized within a predetermined range.

[0052] Graph 74 in FIG. 10 shows the potential of the base 1110 when the capacitance C of the variable capacitor 51 is changed. Graph 75 shows the potential of the ring assembly 112 when the capacitance C of the variable capacitor 51 is changed. As shown in graphs 74 and 75, in this embodiment, even if the capacitance C of the variable capacitor 51 is changed, the potential of the base 1110 (substantially equal to the potential of the substrate W) remains substantially constant. In contrast, the potential of the ring assembly 112 changes so as to increase as the capacitance C of the variable capacitor 51 increases. In other words, the potential of the ring assembly 112 changes in accordance with the change in the capacitance C of the variable capacitor 51. As described above, in this embodiment, when the first DC signal (pulsed DC signal) is supplied, even if the capacitance C of the variable capacitor 51 is changed, it is possible to control the potential of the ring assembly 112 while suppressing fluctuations in the potential of the base 1110.

[0053] Graphs 76 to 78 in Fig. 11 show an example of the etching rate of the oxide film in the radial direction of the substrate W when the capacitance C of the variable capacitor 51 is set to the minimum, intermediate, and maximum values ​​of graphs 74 and 75 in Fig. 10. As shown in graphs 76 to 78, in this embodiment, even if the capacitance C of the variable capacitor 51 is changed, the variation in the etching rate can be kept to, for example, less than 2%.

[0054] FIG. 12 is a graph showing an example of the relationship between the potential and the capacitance of the variable capacitor in the reference example. Graph 80 in FIG. 12 shows the potential of the base 1110 when the capacitance C' of the variable capacitor 62 is changed. Graph 81 shows the potential of the ring assembly 112 when the capacitance C' of the variable capacitor 62 is changed. As shown in graphs 80 and 81, in the reference example, when the capacitance C' of the variable capacitor 62 is changed, the potential of the base 1110 (which is approximately equal to the potential of the substrate W) increases as the capacitance C' increases. In contrast, the potential of the ring assembly 112 remains approximately constant even when the capacitance C' of the variable capacitor 62 is changed. In other words, the potential of the base 1110 changes in accordance with the capacitance C' of the variable capacitor 62.

[0055] Fig. 13 is a graph showing an example of changes in etching rate in a reference example. Graphs 82 and 83 in Fig. 13 show an example of the etching rate of an oxide film in the radial direction of the substrate W when the capacitance C' of the variable capacitor 62 is set to the minimum and maximum values ​​of graphs 80 and 81 in Fig. 12. As shown in graphs 82 and 83, in the reference example, when the capacitance C' of the variable capacitor 62 is changed, the variation in the etching rate is, for example, about 13%. Graphs 76 to 78 in Fig. 11 and graphs 82 and 83 in Fig. 13 show that the variation in the etching rate is suppressed in this embodiment.

[0056] [Tilt control of board edge] Next, tilt control of the substrate edge using this embodiment will be described with reference to FIGS. 14 and 15. FIGS. 14 and 15 are diagrams showing an example of tilt control of the substrate edge in this embodiment. In the example of FIGS. 14 and 15, the impedance adjustment mechanism 50 includes a variable capacitor 51, a capacitor 52, and a coil 53. The capacitor 52 is connected in parallel with the variable capacitor 51 and shifts the variable range of the capacitance of the impedance adjustment mechanism 50. For example, if the variable range of the capacitance of the variable capacitor 51 is 10 pF to 2000 pF, connecting a 500 pF capacitor 52 in parallel can change the variable range of the capacitance of the variable capacitor 51 to 510 pF to 2500 pF. The coil 53 represents a parasitic inductance. A first DC signal is supplied to the base 1110 from the first DC generator 32a via the matching circuit 33.

[0057] The example in FIG. 14 shows a case where the capacitance of the variable capacitor 51 is reduced, that is, where the reactance of the variable capacitor 51 is increased. In this case, when comparing the power 90 of the first DC signal on the first bias electrode 34 side with the power 91 of the first DC signal on the second bias electrode 35 side, for example, it is assumed that the power 90 flows more than the power 91. Note that in the examples in FIGS. 14 and 15, two second bias electrodes 35 are provided, one on the inner periphery side and one on the outer periphery side, and conductors 37b are connected to each. Furthermore, the height of the plasma sheath 92 at the top of the ring assembly 112 is lower than the top of the substrate W. Note that the plasma sheath 92 is a line that represents a predetermined potential. At this time, ions 93 generated by the plasma P are drawn inward of the substrate W at an angle as indicated by the electric field direction 94. That is, at the edge of the substrate W, the electric field direction 94 is inclined toward the inside of the substrate W, and, for example, an inner tilt occurs in which the bottom of a hole formed by etching is inclined toward the inside of the substrate W.

[0058] The example of FIG. 15 shows a case where the capacitance of the variable capacitor 51 is increased, that is, the reactance of the variable capacitor 51 is decreased. In this case, when comparing the power 90 of the first DC signal on the first bias electrode 34 side with the power 91a of the first DC signal on the second bias electrode 35 side, for example, it is assumed that the power 90 and the power 91a flow at approximately the same level. At this time, it is assumed that the plasma sheath 92a is at approximately the same height above the substrate W and above the ring assembly 112. Ions 93 generated in the plasma P are drawn perpendicular to the substrate W, as indicated by the electric field direction 94a, and tilting does not occur. Note that the example of FIG. 15 shows that tilt control is possible by changing the power 91a on the ring assembly 112 side. The capacitance of the variable capacitor 51 may be increased, for example, when the ring assembly 112 is worn out. In this case, the height of the ring assembly 112 itself is lowered, and the plasma sheath above the ring assembly 112 is lower than above the substrate W. Therefore, by increasing the capacitance of the variable capacitor 51, the height of the plasma sheath above the substrate W and the height above the ring assembly 112 can be made approximately the same. Note that tilt control is not limited to cases where the ring assembly 112 is worn out, and therefore changes in the height of the ring assembly 112 itself are not shown in Fig. 14. In this way, in this embodiment, tilt control at the edge of the substrate W can be performed by changing the capacitance of the impedance adjustment mechanism 50.

[0059] (Variation 1) Next, Modification 1 will be described with reference to FIG. 16. FIG. 16 is a diagram illustrating an example of an impedance adjustment mechanism in Modification 1. As shown in FIG. 16, in Modification 1, a switch 54 is provided in the impedance adjustment mechanism 50. The switch 54 switches whether or not to bypass the variable capacitor 51. When the switch 54 is switched to bypass the variable capacitor 51, the base 1110 and the second bias electrode 35 are connected. That is, the first DC generation unit 32a, the matching circuit 33, the base 1110, the switch 54, and the second bias electrode 35 are connected as a circuit on the ring assembly 112 side (a second electrical path of the electrical path 38). In other words, the impedance adjustment mechanism 50 (first impedance adjustment mechanism) has the switch 54 that bypasses the variable capacitor 51 (first variable capacitor) and connects the base 1110 and the second bias electrode 35. This makes it possible to increase the variable range of the capacitance in the circuit on the ring assembly 112 side.

[0060] (Variation 2) Next, Modification 2 will be described with reference to FIG. 17 . FIG. 17 is a diagram illustrating an example of an impedance adjustment mechanism in Modification 2. As shown in FIG. 17 , Modification 2 includes a capacitor 55 in the impedance adjustment mechanism 50. The capacitor 55 is connected in parallel with the plasma load to increase the amount of potential control on the ring assembly 112 side. The capacitor 55 may be a fixed-value capacitor or a variable capacitor. The capacitance of the capacitor 55 is set to a value within a range that does not significantly affect the potential on the ring assembly 112 side, that is, a value within a range that does not cause potential fluctuations as large as those in the reference example. In Modification 2, the first DC generator 32 a, the matching circuit 33, the base 1110, and the variable capacitor 51 are connected in series as a circuit on the ring assembly 112 side (the second electrical path of the electrical path 38), and are further connected to the second bias electrode 35 and the capacitor 55, which are connected in parallel. In other words, the impedance adjustment mechanism 50 (first impedance adjustment mechanism) has a capacitor 55 connected in parallel to the plasma load generated in the plasma processing chamber 10, on the second bias electrode 35 side of the variable capacitor 51 (first variable capacitor). This makes it possible to adjust the capacitance of the load (plasma load and capacitor 55) on the ring assembly 112 side in Modification 2. That is, in Modification 2, the amount of potential control on the ring assembly 112 side can be increased according to the capacitance of the capacitor 55.

[0061] (Variation 3) Next, Modification 3 will be described with reference to FIG. 18 . FIG. 18 is a diagram illustrating an example of an electrostatic chuck and a base in Modification 3. As shown in FIG. 18 , in Modification 3, the main body 111 of the substrate support unit 11 includes electrostatic chucks 1111c and 1111d instead of the electrostatic chuck 1111. The electrostatic chucks 1111c and 1111d are configured such that the central region 111a and the annular region 111b of the electrostatic chuck 1111 are separate members. That is, the substrate support unit 11 of Modification 3 is formed such that the central region 111a (first region) and the annular region 111b (second region) of the electrostatic chucks (electrostatic chucks 1111c and 1111d) are separate members. That is, the electrostatic chuck 1111c has the central region 111a and includes a first bias electrode 34 and an electrostatic electrode 1111b (not shown) therein. The boundary between the electrostatic chuck 1111c and the electrostatic chuck 1111d may be a gap or may be in contact with each other. The electrostatic chuck 1111d has an annular region 111b and a second bias electrode 35 therein. The electrostatic chuck 1111d may have an electrostatic electrode therein. Furthermore, the base 1110 may be a base 1110d divided into a lower member 1110b and an upper member 1110c. The lower member 1110b and the upper member 1110c are, for example, both formed of a conductor and electrically connected to each other.

[0062] 1 and 2, the first bias electrode 34 is connected to, for example, the first DC generator 32a via the conductor 36b, the base 1110 (lower member 1110b), and the matching circuit 33. The second bias electrode 35 is connected to, for example, the first DC generator 32a via the conductor 37b, the variable capacitor 51, the base 1110 (lower member 1110b), and the matching circuit 33. In the third modification, the electrostatic chucks 1111c and 1111d are formed as separate members, which makes it possible to absorb deformation due to thermal expansion and facilitates the manufacture of the electrostatic chucks 1111c and 1111d.

[0063] (Variation 4) Next, Modification 4 will be described with reference to FIG. 19. FIG. 19 is a diagram illustrating an example of an electrostatic chuck and a base in Modification 4. As shown in FIG. 19, in Modification 4, similar to Modification 3, the main body 111 of the substrate support 11 includes electrostatic chucks 1111c and 1111d instead of the electrostatic chuck 1111. Furthermore, in Modification 4, instead of the base 1110, a base 1110g is provided which is divided into a lower member 1110b, a first upper member 1110e, and a second upper member 1110f. A gap may be provided at the boundary between the first upper member 1110e and the second upper member 1110f, or they may be in contact with each other. The first upper member 1110e and the second upper member 1110f are, for example, both made of a conductor and are electrically connected to the lower member 1110b. That is, the base 1110g of Modification 4 includes a first upper member 1110e that supports a first region of the electrostatic chuck, a second upper member 1110f that supports a second region of the electrostatic chuck, and a lower member 1110b that supports the first upper member 1110e and the second upper member 1110f. That is, the first upper member 1110e supports the electrostatic chuck 1111c, and the second upper member 1110f supports the electrostatic chuck 1111d. The base 1110g is formed so that the first upper member 1110e, the second upper member 1110f, and the lower member 1110b are each separate. Note that, in the embodiment and Modifications 1 to 3, the base 1110 can also be said to be formed so that the first upper member 1110e, the second upper member 1110f, and the lower member 1110b are integrated.

[0064] In the fourth modification, similar to the present embodiment shown in FIGS. 1 and 2, the first bias electrode 34 is connected to, for example, the first DC generator 32a via the conductor 36b, the base 1110g (lower member 1110b), and the matching circuit 33. The second bias electrode 35 is connected to, for example, the first DC generator 32a via the conductor 37b, the variable capacitor 51, the base 1110g (lower member 1110b), and the matching circuit 33. The first upper member 1110e and the second upper member 1110f may each be temperature-controlled. In the fourth modification, the electrostatic chucks 1111c and 1111d and the first and second upper members 1110e and 1110f are configured as separate members, so that the temperatures of the central region 111a and the annular region 111b can be controlled. Furthermore, the electrostatic chucks 1111c and 1111d and the base 1110g can be easily manufactured.

[0065] In the above-described embodiment, the plasma processing apparatus 1 is described as an example in which a process such as etching is performed on a substrate W using capacitively coupled plasma as a plasma source, but the disclosed technology is not limited to this. As long as the apparatus performs a process on a substrate W using plasma, the plasma source is not limited to capacitively coupled plasma, and any plasma source such as inductively coupled plasma, microwave plasma, or magnetron plasma can be used. For example, when inductively coupled plasma is used, a source RF signal output from an RF power supply is supplied to an antenna disposed on or above the plasma processing chamber to generate inductively coupled plasma.

[0066] As described above, according to this embodiment, the plasma processing apparatus 1 includes a chamber (plasma processing chamber 10), a bias power supply (first DC generator 32a) configured to supply a pulsed bias DC signal, a substrate support (substrate support 11) configured to support a substrate W and an edge ring (ring assembly 112) in the chamber, and an electrical path 38. The substrate support includes a first region (central region 111a) for holding the substrate W and a second region (annular region 111b) provided around the first region for holding the edge ring, an electrostatic chuck 1111 formed of a dielectric, a first bias electrode 34 provided inside the first region, a second bias electrode 35 provided inside the second region, a base 1110 supporting the electrostatic chuck 1111, and a first impedance adjustment mechanism (impedance adjustment mechanism 50) configured to have a first variable capacitor (variable capacitor 51) connected between the second bias electrode 35 and the base 1110. The electrical path 38 has a first electrical path connecting the bias power supply, the base 1110, and the first bias electrode 34, and a second electrical path connecting the bias power supply, the base 1110, the first impedance adjustment mechanism, and the second bias electrode 35. As a result, fluctuations in the base potential can be suppressed even when a pulsed DC signal is supplied.

[0067] Furthermore, according to this embodiment, the edge ring, the second region, and the second bias electrode 35 are formed in an annular shape, which makes it possible to suppress fluctuations in the base potential over the entire circumference of the base 1110.

[0068] Furthermore, according to the first modification, the first impedance adjustment mechanism is configured to include a switch 54 that bypasses the first variable capacitor and connects the base 1110 to the second bias electrode 35. As a result, the variable range of the capacitance in the circuit on the ring assembly 112 side can be increased.

[0069] Furthermore, according to the second modification, the first impedance adjustment mechanism is configured to have a capacitor 55 connected in parallel with the plasma load generated in the chamber on the second bias electrode 35 side of the first variable capacitor. As a result, the amount of potential control on the ring assembly 112 side can be increased according to the capacitance of the capacitor 55.

[0070] Moreover, according to this embodiment, the plasma processing apparatus 1 further includes a second impedance adjustment mechanism configured to have a second variable capacitor connected between the first bias electrode 34 and the base 1110. Furthermore, the first electrical path connects the bias power supply, the base 1110, the second impedance adjustment mechanism, and the first bias electrode 34. As a result, the potential on the substrate W side can be controlled.

[0071] Furthermore, according to this embodiment and modified examples 1 and 2, the substrate support is formed so that the first region and the second region of the electrostatic chuck 1111 are integrated. As a result, electrodes and wiring that span the first region and the second region can be formed inside the electrostatic chuck 1111.

[0072] Furthermore, according to Modifications 3 and 4, the substrate support is formed so that the first and second regions of the electrostatic chuck are separate bodies (electrostatic chucks 1111c and 1111d), which makes it possible to absorb deformation due to thermal expansion and facilitate the manufacture of the electrostatic chucks 1111c and 1111d.

[0073] Furthermore, according to Modification 4, the base 1110g includes a first upper member 1110e that supports a first region of the electrostatic chuck, a second upper member 1110f that supports a second region of the electrostatic chuck, and a lower member 1110b that supports the first upper member 1110e and the second upper member 1110f. As a result, the temperatures of the central region 111a and the annular region 111b can be controlled.

[0074] Furthermore, according to this embodiment and modifications 1 to 3, the base 1110 is formed so that the first upper member 1110e, the second upper member 1110f, and the lower member 1110b are integrated together, thereby improving the degree of freedom in arranging the wiring and piping inside the base 1110.

[0075] Furthermore, according to Modification 4, base 1110g is formed so that first upper member 1110e, second upper member 1110f, and lower member 1110b are separate members, which makes it possible to control the temperatures of central region 111a and annular region 111b, and also simplifies the manufacture of base 1110.

[0076] According to the present embodiment, the plasma processing apparatus 1 further includes an RF power supply (first RF generator 31a) configured to supply a source RF signal, thereby generating plasma in the plasma processing chamber 10.

[0077] Furthermore, according to this embodiment, a source RF signal is supplied to at least one lower electrode (base 1110, first bias electrode 34) and / or at least one upper electrode (shower head 13) in the chamber to generate capacitively coupled plasma. As a result, capacitively coupled plasma can be generated in the plasma processing chamber 10. Furthermore, when a source RF signal is supplied to the upper electrode, the ratio of radicals to ions in the plasma processing space 10s can be adjusted by supplying a source RF signal to the lower electrode having a lower frequency than the source RF signal on the upper electrode side.

[0078] Also, according to this embodiment, a source RF signal is supplied to an antenna disposed on or above the chamber to generate an inductively coupled plasma, thereby generating an inductively coupled plasma within the chamber.

[0079] <Other aspects of the above embodiment> <Example of placing a ring conductor> In the above embodiments, as shown in Figures 20 and 21, the second electrical path 590 of the electrical path 38 may include a ring-shaped conductor 600 arranged below the base 1110, a first connecting conductor 601 that electrically connects the ring-shaped conductor 600 and the base 1110 via a first variable capacitor 51 (impedance adjustment mechanism 50), and a plurality of second connecting conductors 602 that electrically connect the ring-shaped conductor 600 and the second bias electrode 35 in parallel.

[0080] The annular conductor 600 is disposed horizontally below the base 1110. The annular conductor 600 is disposed so that its center coincides with the center of the base 1110 in a plan view. The annular conductor 600 is disposed parallel to the second bias electrode 35.

[0081] The multiple second connecting conductors 602 are connected in parallel to the annular conductor 600 at equal intervals along the circumferential direction of the annular conductor 600. In one embodiment, as shown in Fig. 22 , the multiple second connecting conductors 602 are arranged in plan view so as to be symmetrical with respect to an imaginary line L1 that passes through a connection position P1 between the first connecting conductor 601 and the annular conductor 600 and a center P2 of the annular conductor 600.

[0082] 21 , the multiple second connecting conductors 602 are connected in parallel to the second bias electrode 35 at equal intervals along the circumferential direction of the second bias electrode 35. Each of the multiple second connecting conductors 602 may extend in the vertical direction from the annular conductor 600 toward the second bias electrode 35. Each of the multiple second connecting conductors 602 may be connected to the second bias electrode 35 through a through-hole 1110h in the base 1110.

[0083] 23 , the plasma processing apparatus 1 may further include a connector 650 for connecting each of the second connecting conductors 602 to the annular conductor 600. In one embodiment, the connector 650 is configured to absorb misalignment between each of the second connecting conductors 602 and the annular conductor 600. The connector 650 is configured to detachably connect each of the second connecting conductors 602 to the annular conductor 600.

[0084] As shown in Fig. 24, the connector 650 may have a fitting structure. In one embodiment, the connector 650 has a socket 660 erected on the annular conductor 600, and a plug 661 placed on the second connection conductor 602. The plug 661 extends in the vertical direction, and a lower end of the plug 661 protrudes below the base 1110. The socket 660 has an insulating main body 670 and a conductor portion 671 placed inside the main body 670. The conductor portion 671 has an insertion hole 672 into which the plug 661 is inserted. The insertion hole 672 extends in the vertical direction. The conductor portion 671 fits with and is electrically connected to the plug 661 when the plug 661 is inserted into the insertion hole 672.

[0085] A main body 670 of the socket 660 is arranged so as to be movable horizontally relative to the annular conductor 600. A conductor portion 671 of the socket 660 is electrically connected to the annular conductor 600 by a conductor 673. This allows the electrical and physical connection between the socket 660 and the plug 661 to be maintained even if the socket 660 is displaced horizontally relative to the annular conductor 600.

[0086] As shown in FIG. 25 , the connector 650 may have a touch structure. In one embodiment, the connector 650 has a pressing portion 680 and a receiving portion 681 against which the pressing portion 680 is pressed. The pressing portion 680 is provided upright on the annular conductor 600. At least the upper end of the pressing portion 680 is a conductor and is electrically connected to the annular conductor 600. The upper end of the pressing portion 680 may have elasticity that allows it to expand and contract in the vertical direction. The receiving portion 681 is fixed to the lower surface of the base 1110. At least the lower end of the receiving portion 681 is a conductor and is electrically connected to the second connecting conductor 602. By pressing the upper end of the pressing portion 680 against the lower end of the receiving portion 681, the annular conductor 600 and the second connecting conductor 602 can be electrically and physically connected to each other. The lower end of the receiving portion 681 has a larger area than the upper end of the pressing portion 680. As a result, even if the pressing portion 680 is displaced in the horizontal direction, the electrical and physical connection between the pressing portion 680 and the receiving portion 681 is maintained.

[0087] 26 and 27 , a first connecting conductor 601 is connected to a first connection position P1 of an annular conductor 600. The annular conductor 600 has multiple, for example, four, conductor regions 600a, 600b, 600c, and 600d that are located at different distances from the first connection position P1. That is, the annular conductor 600 has a first conductor region 600a that is closest to the first connection position P1, a second conductor region 600b that is second closest to the first connection position P1, a third conductor region 600c that is third closest to the first connection position P1, and a fourth conductor region 600d that is farthest from the first connection position P1. The four conductor regions 600a, 600b, 600c, and 600d may be divided at a connection position P3 where multiple second connecting conductors 602 are connected to the annular conductor 600.

[0088] The four conductor regions 600a, 600b, 600c, and 600d are configured so that their electrical resistance decreases with increasing distance from the first connection position P1. That is, the electrical resistance of the second conductor region 600b is smaller than that of the first conductor region 600a, the electrical resistance of the third conductor region 600c is smaller than that of the second conductor region 600b, and the electrical resistance of the fourth conductor region 600d is smaller than that of the third conductor region 600c. The electrical resistance of the four conductor regions 600a, 600b, 600c, and 600d may be changed by changing the materials of the four conductor regions 600a, 600b, 600c, and 600d. As shown in FIG. 28, the electrical resistance of the four conductor regions 600a, 600b, 600c, and 600d may be changed by changing the cross-sectional area (thickness of the annular conductor) of the four conductor regions 600a, 600b, 600c, and 600d. The cross-sectional areas of the four conductor regions 600a, 600b, 600c, and 600d may be changed in stages (discontinuously). As shown in FIG. 29, the cross-sectional areas of the four conductor regions 600a, 600b, 600c, and 600d may be changed continuously. Furthermore, the electrical resistance of each of the four conductor regions 600a, 600b, 600c, and 600d may vary within the same conductor region and gradually decrease with increasing distance from the first connection position P1. According to this exemplary embodiment, the lengths of the multiple electrical paths from the first connecting conductor 601 through the annular conductor 600 and the multiple second connecting conductors 602 to the second bias electrode 35 are different, which can prevent voltage bias from occurring in the circumferential direction of the second bias electrode 35.

[0089] <Example in which a variable capacitor is arranged on each of a plurality of second connecting conductors> 30 , a plurality of first connecting conductors 601 may be arranged, and a first variable capacitor 51 (impedance adjustment mechanism 50) may be arranged in each of the plurality of first connecting conductors 601. That is, the second conductor 221 may include an annular conductor 600 arranged below the base 1110, a plurality of first connecting conductors 601 that electrically connect the annular conductor 600 and the base 1110 in parallel, and a plurality of second connecting conductors 602 that electrically connect the annular conductor 600 and the second bias electrode 35 in parallel, and the first variable capacitor 51 may be arranged in each of the plurality of first connecting conductors 601. The plurality of first connecting conductors 601 may be connected in parallel to the annular conductor 600 at equal intervals along the circumferential direction of the annular conductor 600. The plurality of first connecting conductors 601 may be connected in parallel to the base 1110 at equal intervals along the circumferential direction of the outer periphery of the base 1110. Other configurations of the second electrical path 590, including the annular conductor 600 and the second connecting conductor 602, may be similar to those of the above-described embodiment shown in Figures 20 to 29. According to this exemplary embodiment, the potential of each portion in the circumferential direction of the ring assembly 112 can be adjusted individually, and the bias in the potential in the circumferential direction of the ring assembly 112 can be reduced.

[0090] <Example of placing a variable capacitor on each of multiple connecting conductors> 31 , the second conductor 221 may include a plurality of connection conductors 700 that electrically connect the base 1110 and the second bias electrode 35 in parallel, and a first variable capacitor 51 (impedance adjustment mechanism 50) may be disposed in each of the plurality of connection conductors 700. The plurality of connection conductors 700 may be connected in parallel to the base 1110 at equal intervals along the circumferential direction of the outer periphery of the base 1110. The plurality of connection conductors 700 may be connected in parallel to the second bias electrode 35 at equal intervals along the circumferential direction of the second bias electrode 35. According to this exemplary embodiment, the potential of each portion in the circumferential direction of the ring assembly 112 can be adjusted individually, thereby reducing bias in the potential in the circumferential direction of the ring assembly 112.

[0091] <Configuration example of plasma processing apparatus when sensors are arranged> 32 , the electrical path 38 may include a bias transmission line 222 that electrically connects the power supply 30 to the base 1110, and the plasma processing apparatus 1 may include a sensor 280 configured to detect a voltage at a given position on the bias transmission line 222. The control unit 2 may be configured to control the supply of a bias signal by the power supply 30 so that the voltage detected by the sensor 280 is constant.

[0092] The matching circuit 33 may include a sensor 280. The sensor 280 may be configured to detect a voltage at the position of the matching circuit 33 on the bias transmission line 222.

[0093] In one embodiment, the voltage signal detected by the sensor 280 is output to the control unit 2 and stored in a storage unit. The control unit 2 executes a program and, based on the voltage data in the storage unit, feedback-controls the supply of the bias signal by the power supply 30 so that the voltage detected by the sensor 280 (Vpp (Voltage peak to peak)) remains constant. According to this exemplary embodiment, the voltage of the bias signal supplied to the base 1110 is controlled to be constant, so that the voltage of the first bias electrode 34 is stabilized and fluctuations in the potential of the substrate W are suppressed. As a result, process fluctuations of the substrate W are suppressed, and plasma processing is performed appropriately.

[0094] 33, the plasma processing apparatus 1 may include a sensor 300 configured to detect the voltage and current at a given position on the bias transmission line 222. The control unit 2 may be configured to determine the potential of the substrate W on the substrate support 11 based on the voltage and current detected by the sensor 300, and to control the supply of a bias signal by the power supply 30 so that the potential of the substrate W is constant.

[0095] The sensor 300 may be electrically connected to a node on the bias transmission line 222 between the matching circuit 33 and the base 1110. The sensor 300 may be configured to detect the current and voltage at the node on the bias transmission line 222 between the matching circuit 33 and the base 1110.

[0096] In one embodiment, the voltage signal and current signal detected by the sensor 300 are output to the control unit 2 and stored in a storage unit. The control unit 2 executes a program to estimate and determine the potential of the substrate W on the substrate support 11 based on the voltage and current of the bias signal detected by the sensor 300 and a conversion coefficient. The control unit 2 then executes the program to feedback-control the supply of the bias signal by the power supply 30 so that the determined potential of the substrate W (Vpp (Voltage peak to peak) voltage) becomes constant. The conversion coefficient may be a pre-determined coefficient stored in a storage unit of the control unit 2. According to this exemplary embodiment, the supply of the bias signal by the power supply 30 is controlled so that the potential of the substrate W becomes constant, thereby suppressing process fluctuations of the substrate W and performing appropriate plasma processing.

[0097] <Example of cleaning method for plasma processing apparatus> In the above embodiment, the control unit 2 may be configured to (a) plasma process the substrate on the substrate support member 11 in the chamber 10, and (b) adjust the impedance of the variable impedance element (first variable capacitor 51) to an impedance greater than the impedance in (a) to plasma clean the inside of the chamber 10. (b) may include at least one of a first plasma cleaning performed with the substrate supported on the substrate support member 11, and a second plasma cleaning performed with the substrate not supported on the substrate support member 11. The impedance adjustment mechanism 50 may include a capacitor and a switch as the variable impedance element, or may include only a switch.

[0098] According to this exemplary embodiment, in (a), for example, the potential of the ring assembly 112 can be adjusted by the first variable capacitor 51, thereby making the plasma sheath 92 on the ring assembly 112 side and the substrate W side closer to horizontal. As a result, ions in the plasma enter the outer periphery of the substrate W approximately perpendicularly, improving the etching rate and etching profile. Also, in (b), the impedance of the first variable capacitor 51 can be adjusted to be larger than the impedance in (a), thereby lowering the potential of the ring assembly 112 below the potential of the substrate W and the substrate support surface 210, and making the plasma sheath 92 on the ring assembly 112 lower than the substrate W side. As a result, ions in the plasma above the ring assembly 112 can be made to obliquely enter the outer periphery of the substrate W, suppressing ion collisions with the ring assembly 112 and suppressing wear of the ring assembly 112. Also, ions in the plasma above the ring assembly 112 can be made to collide with the vicinity of the outer periphery of the central region 111a of the substrate support 11, thereby removing deposits that have accumulated near the outer periphery of the central region 111a.

[0099] In the above-described embodiments, the impedance adjustment mechanism 50 may include other elements such as a coil, a resistor, a switch, etc. The impedance adjustment mechanism 50 may include multiple variable impedance elements, not just one. The variable impedance element of the impedance adjustment mechanism 50 may include at least one element selected from a variable capacitor, a variable resistor, and a variable inductor.

[0100] <Other examples of conductive base configurations> 34, in the above-described fourth modification, the height position of the upper surface 900b of the second upper member 1110f may be the same as or higher than the height position of the upper surface 900a of the first upper member 1110e. The height position of the lower surface of the annular region 111b may be higher than the height position of the upper surface of the first upper member 1110e. The height position of the lower surface of the annular region 111b may be higher than the height position of the lower surface of the central region 111a. Each of the first upper member 1110e and the second upper member 1110f may be provided with a flow path 1110a through which a heat transfer fluid (refrigerant) flows.

[0101] <Configuration example of a circuit having a capacitor 55> 35 , as in the above-described second modification, when the impedance adjustment mechanism 50 has a capacitor 55 electrically connected to a node on the conductor 37b (second electrical path 590) via a conductor 1500, the conductor section 1501 connecting the first variable capacitor 51 and the capacitor 55 may be shortened. In one embodiment, as shown in FIG. 36 , the first variable capacitor 51 and the capacitor 55 may be arranged so that, in a plan view of the substrate support part 11, the interior angle α1 formed by an imaginary line L20 passing through the first variable capacitor 51 and the center O1 of the substrate support part 11 and an imaginary line L21 passing through the capacitor 55 and the center O1 is 90° or less.

[0102] 37 is a diagram illustrating an electrical circuit formed between the plasma sheath PS of the ring assembly 112 and the substrate support 11 during plasma generation. In the circuit of the substrate support 11, the capacitance component C10 and resistance component R10 of the electrostatic chuck 1111 and the first variable capacitor 51 (capacitance V C ) are connected in parallel to the power supply 30. In the plasma sheath PS of the ring assembly 112, the capacitance component C12 of the plasma sheath PS and the capacitor 55 (capacitance C13) are connected in parallel to the circuit of the substrate support 11. Here, by bringing the first variable capacitor 51 and the capacitor 55 closer to each other, the conductor section 1501 connecting the first variable capacitor 51 and the capacitor 55 becomes shorter, and the reactance component L10 in the conductor section 1501 becomes smaller. As a result, the reactance component L11 of the conductor section 1502 extending from the first variable capacitor 51 toward the capacitance component C12 of the plasma sheath becomes larger, forming a so-called bridge circuit. As a result, parallel resonance is suppressed between the capacitance component C10 of the electrostatic chuck 1111, the first variable capacitor 51, and the reactance component L10 of the conductor section 1501. As a result, power loss and overcurrent caused by the occurrence of parallel resonance are suppressed.

[0103] <Another Configuration Example of a Circuit Having a Capacitor 55> 38, a coil 1600 may be connected to a conductor 1500 that connects the node of the conductor 37b (second electrical path 590) and the capacitor 55. This prevents the source RF signal from entering the ring assembly 112 and the second bias electrode 35 and flowing to the capacitor 55 via the conductor 37b and the conductor 1500 of the impedance adjustment mechanism 50 when the source RF signal for plasma generation is supplied to the upper electrode. This prevents the source RF signal from flowing locally to the portion of the ring assembly 112 where the capacitor 55 is located (the portion above the capacitor 55) in the circumferential direction of the ring assembly 112, thereby preventing the plasma distribution in the substrate surface from becoming uneven. In this example, the source RF signal may be in the range of 1 MHz to 400 MHz.

[0104] <Configuration example of a circuit including the first variable capacitor 51> 39, a coil 1650 may be connected between the first variable capacitor 51 and the second bias electrode 35 in the conductor 37b (second electrical path 590). This prevents the source RF signal from entering the ring assembly 112 and the second bias electrode 35 and flowing to the first variable capacitor 51 through the conductor 37b of the impedance adjustment mechanism 50 when the source RF signal for plasma generation is supplied to the upper electrode. This prevents the source RF signal from flowing locally in the portion of the ring assembly 112 in the circumferential direction where the first variable capacitor 51 is located (the portion above the first variable capacitor 51), thereby preventing the plasma distribution in the substrate surface from becoming uneven.

[0105] <Another Configuration Example of the Circuit Including the First Variable Capacitor 51> As shown in FIG. 40 , a coil 1750 may be disposed, electrically connected to a node on the conductor 37b via the conductor 1700. The conductor 1700 is connected to a node on the conductor 37b between the first variable capacitor 51 and the second bias electrode 35. The coil 1750 is connected to ground potential. This forms a parallel resonant circuit with the stray capacitance of the first variable capacitor 51 and the coil 1750, preventing the source RF signal from entering the ring assembly 112 and the second bias electrode 35 and flowing to the first variable capacitor 51 through the conductor 37b of the impedance adjustment mechanism 50. Furthermore, in addition to the coil 1750, a capacitor 1751 is connected in series to the conductor 1700. The capacitor 1751 is connected to ground potential. This forms an LC series circuit in the conductor 1700, preventing the bias signal supplied to the lower electrode from flowing to ground potential through the conductor 1700.

[0106] 41 , the stray capacitance between the conductor 37b and the grounding case 1800 surrounding the conductor 37b may be reduced. That is, the distance between the conductor 37b and the grounding case 1800 may be increased as much as possible. In one embodiment, the distance between the conductor 37b and the grounding case 1800 may be increased by 2 cm or more. This prevents the source RF signal from entering the ring assembly 112 and the second bias electrode 35 and flowing to the first variable capacitor 51 via the conductor 37b of the impedance adjustment mechanism 50.

[0107] <Configuration example of the circuit between the first variable capacitor 51 and the second bias electrode 35> As shown in FIG. 42, the conductor 37b (second electrical path 590) includes a plurality of connection conductors 1900 that electrically connect the first variable capacitor 51 and the second bias electrode 35 in parallel. As shown in FIG. 43, connection points 1950 to which the plurality of connection conductors 1900 are connected in the second bias electrode 35 are arranged at equal intervals along the circumferential direction of the second bias electrode 35. The plurality of connection conductors 1900 are adjusted to have substantially equal impedance. In one embodiment, as shown in FIG. 42, the impedance of the plurality of connection conductors 1900 may be adjusted by making the path lengths from the first variable capacitor 51 to the second bias electrode 35 equal. In this case, the plurality of connection conductors 1900 may be formed on a printed circuit board 1960, and the path lengths may be made uniform. The printed circuit board 1960 may be disposed below the base 1110. 44, the impedance of the plurality of connecting conductors 1900 may be adjusted by adding an impedance element 1970 to at least one of the plurality of connecting conductors 1900. The impedance element 1970 may be a coil, a capacitor, a resistor, or a combination thereof. The impedance of the plurality of connecting conductors 1900 may be adjusted by changing the material of at least one of the plurality of connecting conductors 1900. The impedance of the plurality of connecting conductors 1900 may be matched by other methods.

[0108] This makes it possible to uniform the currents flowing through the plurality of connecting conductors 1900 when a source RF signal for generating plasma is supplied to the upper electrode and the source RF signal enters the plurality of connecting conductors 1900 via the connection point 1950 between the ring assembly 112 and the second bias electrode 35. As a result, it is possible to prevent a relatively large current from flowing through a specific connecting conductor 1900, thereby preventing the plasma distribution in the substrate surface from becoming uneven.

[0109] <Other examples of electrical path configurations> 45 , the substrate support 11 may include an electrostatic chuck 1111 formed of a dielectric material, a first bias electrode 34 provided within the first region, a second bias electrode 35 provided within the second region, a base 1110 supporting the electrostatic chuck 1111, and a first impedance adjustment mechanism (impedance adjustment mechanism 50) configured to have a first variable capacitor (variable capacitor 51) connected between the second bias electrode 35 and the first bias electrode 34. The electrical path 38 may include a first electrical path 580 connecting the bias power supply and the first bias electrode 34, and a second electrical path 590 connecting the bias power supply, the first bias electrode 34, the first impedance adjustment mechanism, and the second bias electrode 35. That is, the bias power supply is connected directly to the first bias electrode 34 instead of the base 1110, and the second bias electrode 35 is connected to the first bias electrode 34 instead of the base 1110. The first impedance adjustment mechanism is connected to the electrical path between the second bias electrode 35 and the first bias electrode 34. Other configurations of this embodiment may be similar to those of the above embodiments. According to this embodiment, fluctuations in the base potential can be suppressed even when a pulsed DC signal is supplied. Note that all aspects described in the above embodiments may be applied to this embodiment.

[0110] <Other examples of electrical path configurations> In one embodiment, as shown in FIG. 46 , the substrate support 11 includes a first region (central region 111a) for holding the substrate W and a second region (annular region 111b) surrounding the first region for holding an edge ring. The substrate support 11 may include an electrostatic chuck 1111 made of a dielectric material, a base 1110 for supporting the electrostatic chuck 1111, and a first impedance adjustment mechanism (impedance adjustment mechanism 50) having a first variable capacitor (variable capacitor 51) connected between the base 1110 and the ring assembly 112. The electrical path 38 may include a first electrical path connecting the bias power supply and the base 1110, and a second electrical path connecting the bias power supply, the base 1110, the first impedance adjustment mechanism, and the ring assembly 112. That is, the first bias electrode 34 is not provided, and the bias power supply is connected to the base 1110. The first impedance adjustment mechanism is connected to the edge ring, not to the second bias electrode 35. Other configurations of this embodiment may be similar to those of the above-described embodiments. According to this embodiment, fluctuations in the base potential can be suppressed even when a pulsed DC signal is supplied. Note that all of the aspects described in the above embodiments may be applied to this embodiment.

[0111] In the above embodiments, the power supply 30 may be configured to supply both an RF signal and a pulsed voltage signal to the base 1110 as a bias signal. That is, in the above embodiments, as shown in FIG. 47, the power supply 30 may have an RF power supply 31 configured to supply a bias RF signal and a DC power supply 32 configured to supply a bias DC signal. The frequency of the RF signal supplied by the power supply 30 may be in the range of 100 kHz to 60 MHz. The pulsed voltage signal supplied by the power supply 30 may have a sequence of multiple voltage pulses. The frequency of the voltage pulses may be 400 kHz. The frequency of the voltage pulses may be any frequency in the range of 200 kHz to 3 MHz. Furthermore, the duty ratio of the voltage pulses may be 20% or more.

[0112] In the above embodiments, the source power supply of the plasma generating unit may supply a source RF signal to either the upper electrode (for example, a shower head) or the lower electrode (for example, a conductive base).

[0113] The present disclosure can also be configured as follows. (1) a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the second bias electrode and the base; configured to have the electrical path includes a first electrical path connecting the bias power supply, the base, and the first bias electrode, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the second bias electrode; Plasma processing equipment. (2) The plasma processing apparatus according to (1), wherein the edge ring, the second region, and the second bias electrode are formed in an annular shape. (3) the first impedance adjustment mechanism is configured to have a switch that bypasses the first variable capacitor and connects the base and the second bias electrode. The plasma processing apparatus according to (1) or (2) above. (4) the first impedance adjustment mechanism is configured to have a capacitor connected in parallel with a plasma load generated in the chamber, on the second bias electrode side of the first variable capacitor. The plasma processing apparatus according to (1) or (2) above. (5) a second impedance adjustment mechanism configured to have a second variable capacitor connected between the first bias electrode and the base; the first electrical path connects the bias power supply, the base, the second impedance adjustment mechanism, and the first bias electrode; The plasma processing apparatus according to any one of (1) to (4) above. (6) the substrate support is formed such that the first region and the second region of the electrostatic chuck are integrated together; The plasma processing apparatus according to any one of (1) to (5) above. (7) the substrate support is formed such that the first region and the second region of the electrostatic chuck are separate. The plasma processing apparatus according to any one of (1) to (5) above. (8) the base includes a first upper member that supports the first region of the electrostatic chuck, a second upper member that supports the second region of the electrostatic chuck, and a lower member that supports the first upper member and the second upper member. The plasma processing apparatus according to (7) above. (9) The base is formed so that the first upper member, the second upper member, and the lower member are integrated together. The plasma processing apparatus according to (8) above. (10) The base is formed so that the first upper member, the second upper member, and the lower member are separate members. The plasma processing apparatus according to (9) above. (11) The plasma processing apparatus according to any one of (1) to (10), further comprising an RF power supply configured to supply a source RF signal. (12) the source RF signal is supplied to at least one lower electrode and / or at least one upper electrode in the chamber to generate a capacitively coupled plasma; The plasma processing apparatus according to (11) above. (13) the source RF signal is provided to an antenna located on or above the chamber to generate an inductively coupled plasma; The plasma processing apparatus according to (11) above. (14) The second electrical path is an annular conductor disposed below the base; a first connecting conductor that electrically connects the annular conductor and the base via the first variable capacitor; a plurality of second connection conductors that electrically connect the annular conductor and the second bias electrode in parallel, The plasma processing apparatus according to any one of (1) to (13). (15) the plurality of second connecting conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor. (14) The plasma processing apparatus according to (14). (16) the plurality of second connection conductors are connected in parallel to the second bias electrode at equal intervals along the circumferential direction of the second bias electrode; (14) The plasma processing apparatus according to (15). (17) further comprising a connector for connecting each of the second connection conductors to the annular conductor; The plasma processing apparatus according to any one of (14) to (16). (18) the connector is configured to be able to absorb misalignment between each of the second connection conductors and the annular conductor. (17) The plasma processing apparatus according to (17). (19) the first connecting conductor is connected to a first connecting position of the annular conductor; the annular conductor includes a plurality of conductor regions that are different in distance from the first connection position, The plurality of conductor regions are configured so that the electrical resistance decreases as the distance from the first connection position increases. The plasma processing apparatus according to any one of (14) to (18). (20) The second electrical path is an annular conductor disposed below the base; a plurality of first connection conductors that electrically connect the annular conductor and the base in parallel; a plurality of second connection conductors that electrically connect the annular conductor and the second bias electrode in parallel, the first impedance adjustment mechanism is disposed on each of the plurality of first connection conductors; The plasma processing apparatus according to any one of (1) to (13). (twenty one) the plurality of first connection conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor; (20) The plasma processing apparatus according to (20). (twenty two) the second electrical path includes a plurality of connection conductors that electrically connect the base and the second bias electrode in parallel, the first impedance adjustment mechanism is disposed on each of the plurality of connecting conductors; The plasma processing apparatus according to any one of (1) to (13). (twenty three) the plurality of connection conductors are connected in parallel to the second bias electrode at equal intervals along the circumferential direction of the second bias electrode. (22) The plasma processing apparatus according to (22). (twenty four) further comprising an RF power supply configured to provide an RF bias signal to the base. The plasma processing apparatus according to any one of (1) to (23). (twenty five) a substrate support for supporting a substrate and an edge ring in a chamber of a plasma processing apparatus, the substrate support including a first region for holding the substrate and a second region for holding the edge ring, the second region being provided around the first region and being made of a dielectric material; and an electrostatic chuck. a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; an impedance adjustment mechanism configured to have a variable capacitor connected between the second bias electrode and the base; configured to include a first electrical path connecting the base connected to a bias power supply that supplies a pulsed bias DC signal and the first bias electrode, and a second electrical path connecting the base connected to the bias power supply, the impedance adjustment mechanism, and the second bias electrode; Board support. (26) a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the second bias electrode and the base; configured to have the electrical path includes a first electrical path connecting the bias power supply, the base, and the first bias electrode, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the second bias electrode; Plasma processing equipment. (27) The plasma processing apparatus according to (26), wherein the edge ring, the second region, and the second bias electrode are formed in an annular shape. (28) the first impedance adjustment mechanism is configured to have a switch that bypasses the first variable capacitor and connects the first bias electrode and the second bias electrode. The plasma processing apparatus according to (26) or (27) above. (29) the first impedance adjustment mechanism is configured to have a capacitor connected in parallel with a plasma load generated in the chamber, on the second bias electrode side of the first variable capacitor. The plasma processing apparatus according to (26) or (27) above. (30) a second impedance adjustment mechanism configured to have a second variable capacitor connected between the bias power supply and the first bias electrode; the first electrical path connects the bias power supply, the second impedance adjustment mechanism, and the first bias electrode; The plasma processing apparatus according to any one of (26) to (29) above. (31) the substrate support is formed such that the first region and the second region of the electrostatic chuck are integrated together; The plasma processing apparatus according to any one of (26) to (30) above. (32) the substrate support is formed such that the first region and the second region of the electrostatic chuck are separate. The plasma processing apparatus according to any one of (26) to (30) above. (33) the base includes a first upper member that supports the first region of the electrostatic chuck, a second upper member that supports the second region of the electrostatic chuck, and a lower member that supports the first upper member and the second upper member. The plasma processing apparatus according to (32) above. (34) The base is formed so that the first upper member, the second upper member, and the lower member are integrated together. The plasma processing apparatus according to (33) above. (35) The base is formed so that the first upper member, the second upper member, and the lower member are separate members. The plasma processing apparatus according to (34) above. (36) The plasma processing apparatus according to any one of (26) to (35), further comprising an RF power supply configured to supply a source RF signal. (37) the source RF signal is supplied to at least one lower electrode and / or at least one upper electrode in the chamber to generate a capacitively coupled plasma; The plasma processing apparatus according to (36) above. (38) the source RF signal is provided to an antenna located on or above the chamber to generate an inductively coupled plasma; The plasma processing apparatus according to (36) above. (39) The second electrical path is an annular conductor disposed below the base; a first connecting conductor that electrically connects the annular conductor and the first bias electrode via the first variable capacitor; a plurality of second connection conductors that electrically connect the annular conductor and the second bias electrode in parallel, The plasma processing apparatus according to any one of (26) to (38). (40) the plurality of second connecting conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor. (39) A plasma processing apparatus according to (39). (41) the plurality of second connection conductors are connected in parallel to the second bias electrode at equal intervals along the circumferential direction of the second bias electrode; (39) or (40) according to the plasma processing apparatus. (42) further comprising a connector for connecting each of the second connection conductors to the annular conductor; The plasma processing apparatus according to any one of (39) to (41). (43) the connector is configured to be able to absorb misalignment between each of the second connection conductors and the annular conductor. (42) A plasma processing apparatus according to (42). (44) the first connecting conductor is connected to a first connecting position of the annular conductor; the annular conductor includes a plurality of conductor regions that are different in distance from the first connection position, The plurality of conductor regions are configured so that the electrical resistance decreases as the distance from the first connection position increases. The plasma processing apparatus according to any one of (39) to (43). (45) The second electrical path is an annular conductor disposed below the base; a plurality of first connection conductors that electrically connect the annular conductor and the first bias electrode in parallel; a plurality of second connection conductors that electrically connect the annular conductor and the second bias electrode in parallel, the first impedance adjustment mechanism is disposed on each of the plurality of first connection conductors; The plasma processing apparatus according to any one of (26) to (38). (46) the plurality of first connection conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor; (45) A plasma processing apparatus according to (45). (47) the second electrical path includes a plurality of connection conductors that electrically connect the first bias electrode and the second bias electrode in parallel, the first impedance adjustment mechanism is disposed on each of the plurality of connecting conductors; The plasma processing apparatus according to any one of (26) to (38). (48) the plurality of connection conductors are connected in parallel to the second bias electrode at equal intervals along the circumferential direction of the second bias electrode. (47) A plasma processing apparatus according to (47). (49) further comprising an RF power supply configured to supply an RF bias signal to the first bias electrode. The plasma processing apparatus according to any one of (26) to (48). (50) a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the base and the edge ring; The electrical path includes a first electrical path connecting the bias power supply and the base, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the edge ring. (51) The plasma processing apparatus according to (50), wherein the edge ring and the second region are formed in an annular shape. (52) the first impedance adjustment mechanism is configured to have a switch that bypasses the first variable capacitor and connects the base and the edge ring. The plasma processing apparatus according to (50) or (51) above. (53) the first impedance adjustment mechanism is configured to have a capacitor connected in parallel with a plasma load generated in the chamber, on the edge ring side of the first variable capacitor. The plasma processing apparatus according to (50) or (51) above. (54) a second impedance adjustment mechanism configured to have a second variable capacitor connected between the bias power supply and the base; the first electrical path connects the bias power supply, the second impedance adjustment mechanism, and the base; The plasma processing apparatus according to any one of (50) to (53) above. (55) the substrate support is formed such that the first region and the second region of the electrostatic chuck are integrated together; The plasma processing apparatus according to any one of (50) to (54) above. (56) the substrate support is formed such that the first region and the second region of the electrostatic chuck are separate. The plasma processing apparatus according to any one of (50) to (54) above. (57) the base includes a first upper member that supports the first region of the electrostatic chuck, a second upper member that supports the second region of the electrostatic chuck, and a lower member that supports the first upper member and the second upper member. The plasma processing apparatus according to (56) above. (58) The base is formed so that the first upper member, the second upper member, and the lower member are integrated together. The plasma processing apparatus according to (57) above. (59) The base is formed so that the first upper member, the second upper member, and the lower member are separate members. The plasma processing apparatus according to (58) above. (60) The plasma processing apparatus according to any one of (50) to (59), further comprising an RF power supply configured to supply a source RF signal. (61) the source RF signal is supplied to at least one lower electrode and / or at least one upper electrode in the chamber to generate a capacitively coupled plasma; The plasma processing apparatus according to (60) above. (62) the source RF signal is provided to an antenna located on or above the chamber to generate an inductively coupled plasma; The plasma processing apparatus according to (60) above. (63) The second electrical path is an annular conductor disposed below the base; a first connecting conductor that electrically connects the annular conductor and the base via the first variable capacitor; a plurality of second connection conductors electrically connecting the annular conductor and the edge ring in parallel; The plasma processing apparatus according to any one of (50) to (52). (64) the plurality of second connecting conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor. (63) The plasma processing apparatus according to (63). (65) the plurality of second connecting conductors are connected in parallel to the edge ring at equal intervals along the circumferential direction of the edge ring. (63) or (64) according to the plasma processing apparatus. (66) further comprising a connector for connecting each of the second connection conductors to the annular conductor; The plasma processing apparatus according to any one of (63) to (65). (67) the connector is configured to be able to absorb misalignment between each of the second connection conductors and the annular conductor. (66) A plasma processing apparatus according to (66). (68) the first connecting conductor is connected to a first connecting position of the annular conductor; the annular conductor includes a plurality of conductor regions that are different in distance from the first connection position, The plurality of conductor regions are configured so that the electrical resistance decreases as the distance from the first connection position increases. The plasma processing apparatus according to any one of (63) to (67). (69) The second electrical path is an annular conductor disposed below the base; a plurality of first connection conductors that electrically connect the annular conductor and the base in parallel; a plurality of second connection conductors that electrically connect the annular conductor and the edge ring in parallel, the first impedance adjustment mechanism is disposed on each of the plurality of first connection conductors; The plasma processing apparatus according to any one of (50) to (62). (70) the plurality of first connection conductors are connected in parallel to the annular conductor at equal intervals along the circumferential direction of the annular conductor; (69) A plasma processing apparatus according to (69). (71) the second electrical path includes a plurality of connection conductors that electrically connect the base and the edge ring in parallel; the first impedance adjustment mechanism is disposed on each of the plurality of connecting conductors; The plasma processing apparatus according to any one of (50) to (62). (72) the plurality of connection conductors are connected in parallel to the edge ring at equal intervals along the circumferential direction of the edge ring; (71) A plasma processing apparatus according to (71). (73) further comprising an RF power supply configured to provide an RF bias signal to the base. The plasma processing apparatus according to any one of (50) to (72).

[0114] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments. [Explanation of symbols]

[0115] 1. Plasma processing equipment 10 Plasma Processing Chamber 11 Substrate support 13. Shower head 31 RF power supply 31a First RF generation unit 31b Second RF generation unit 32 DC power supply 32a First DC generation unit 32b Second DC generation unit 33 Matching circuit 34 First bias electrode 35 Second bias electrode 38 Electrical Path 50 Impedance adjustment mechanism 51 Variable Capacitor 52,55 capacitor 54 Switch 112 Ring Assembly 111a Central area 111b Annular Region 1110,1110g base 1110b Lower member 1110e First upper member 1110f Second upper member 1111, 1111c, 1111d Electrostatic chuck W substrate

Claims

1. a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the second bias electrode and the base; The electrical path includes a first electrical path connecting the bias power supply, the base, and the first bias electrode, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the second bias electrode.

2. The plasma processing apparatus of claim 1 , wherein the edge ring, the second region, and the second bias electrode are formed in an annular shape.

3. 3. The plasma processing apparatus according to claim 1, wherein the first impedance adjustment mechanism includes a switch that bypasses the first variable capacitor and connects the base and the second bias electrode.

4. 3. The plasma processing apparatus according to claim 1, wherein the first impedance adjustment mechanism is configured to have a capacitor connected in parallel to a plasma load generated in the chamber on the second bias electrode side of the first variable capacitor.

5. a second impedance adjustment mechanism configured to have a second variable capacitor connected between the first bias electrode and the base; 3. The plasma processing apparatus according to claim 1, wherein the first electrical path connects the bias power supply, the base, the second impedance adjustment mechanism, and the first bias electrode.

6. 3. The plasma processing apparatus according to claim 1, wherein the substrate support is formed so that the first region and the second region of the electrostatic chuck are integrated together.

7. 3. The plasma processing apparatus according to claim 1, wherein the substrate support is formed such that the first region and the second region of the electrostatic chuck are separate bodies.

8. 8. The plasma processing apparatus of claim 7, wherein the base comprises a first upper member supporting the first region of the electrostatic chuck, a second upper member supporting the second region of the electrostatic chuck, and a lower member supporting the first upper member and the second upper member.

9. The plasma processing apparatus of claim 8 , wherein the base is formed such that the first upper member, the second upper member, and the lower member are integrated together.

10. The plasma processing apparatus according to claim 9 , wherein the base is formed so that the first upper member, the second upper member, and the lower member are separate bodies.

11. The plasma processing apparatus of claim 1 or 2, further comprising an RF power supply configured to provide a source RF signal.

12. The plasma processing apparatus of claim 11 , wherein the source RF signal is supplied to at least one lower electrode and / or at least one upper electrode in the chamber to generate a capacitively coupled plasma.

13. The plasma processing apparatus of claim 11 , wherein the source RF signal is supplied to an antenna located on or above the chamber to generate an inductively coupled plasma.

14. The second electrical path is an annular conductor disposed below the base; a first connecting conductor that electrically connects the annular conductor and the base via the first variable capacitor; The plasma processing apparatus according to claim 1 , further comprising: a plurality of second connection conductors electrically connecting the annular conductor and the second bias electrode in parallel.

15. The plasma processing apparatus according to claim 14 , wherein the plurality of second connection conductors are connected in parallel to the annular conductor at equal intervals along a circumferential direction of the annular conductor.

16. 15. The plasma processing apparatus according to claim 14, wherein the plurality of second connection conductors are connected in parallel to the second bias electrode at equal intervals along a circumferential direction of the second bias electrode.

17. The plasma processing apparatus of claim 14 , further comprising a connector for connecting each of the second connection conductors to the annular conductor.

18. The plasma processing apparatus according to claim 17 , wherein the connector is configured to be able to absorb misalignment between each of the second connection conductors and the annular conductor.

19. the first connecting conductor is connected to a first connecting position of the annular conductor; the annular conductor includes a plurality of conductor regions that are different in distance from the first connection position, The plasma processing apparatus according to claim 14 , wherein the plurality of conductive regions are configured so that the electrical resistance thereof decreases as the distance from the first connection position increases.

20. The second electrical path is an annular conductor disposed below the base; a plurality of first connection conductors that electrically connect the annular conductor and the base in parallel; a plurality of second connection conductors electrically connecting the annular conductor and the second bias electrode in parallel, The plasma processing apparatus according to claim 1 , wherein the first impedance adjustment mechanism is disposed on each of the plurality of first connection conductors.

21. 21. The plasma processing apparatus according to claim 20, wherein the plurality of first connection conductors are connected in parallel to the annular conductor at equal intervals along a circumferential direction of the annular conductor.

22. the second electrical path includes a plurality of connection conductors that electrically connect the base and the second bias electrode in parallel, The plasma processing apparatus according to claim 1 , wherein the first impedance adjustment mechanism is disposed on each of the plurality of connection conductors.

23. 23. The plasma processing apparatus according to claim 22, wherein the plurality of connection conductors are connected in parallel to the second bias electrode at equal intervals along a circumferential direction of the second bias electrode.

24. The plasma processing apparatus of claim 1 , further comprising an RF power supply configured to provide an RF bias signal to the pedestal.

25. 1. A substrate support for supporting a substrate and an edge ring in a chamber of a plasma processing apparatus, comprising: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; an impedance adjustment mechanism configured to have a variable capacitor connected between the second bias electrode and the base, a first electrical path connecting the base connected to a bias power supply that supplies a pulsed bias DC signal and the first bias electrode, and a second electrical path connecting the base connected to the bias power supply, the impedance adjustment mechanism, and the second bias electrode.

26. a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a first bias electrode provided within the first region, a second bias electrode provided within the second region, and a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the second bias electrode and the first bias electrode; The electrical path includes a first electrical path connecting the bias power supply and the first bias electrode, and a second electrical path connecting the bias power supply, the first bias electrode, the first impedance adjustment mechanism, and the second bias electrode.

27. a chamber; a bias power supply configured to provide a pulsed bias DC signal; a substrate support configured to support a substrate and an edge ring within the chamber; An electrical path; Equipped with The substrate support includes: an electrostatic chuck made of a dielectric material, the electrostatic chuck including a first region for holding the substrate and a second region provided around the first region for holding the edge ring; a base supporting the electrostatic chuck; a first impedance adjustment mechanism configured to have a first variable capacitor connected between the base and the edge ring; The electrical path includes a first electrical path connecting the bias power supply and the base, and a second electrical path connecting the bias power supply, the base, the first impedance adjustment mechanism, and the edge ring.

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