Plasma processing device and substrate processing system

Abstract

Disclosed is a plasma processing device including a chamber, a substrate support unit, an edge ring, a lift mechanism, a plasma generation unit, and a bias power supply. The substrate support unit is disposed in the chamber. The lift mechanism is configured to vertically move the edge ring with respect to the substrate support unit. The substrate support unit includes: a base electrically coupled to the bias power supply and / or a high-frequency power supply of the plasma generation unit; and an electrostatic chuck on the base. The lift mechanism includes a conductive ring and a connection member. The conductive ring electrically couples to the edge ring while supporting the edge ring mounted thereon. The connection member is configured to maintain electrical connection between the conductive ring and the base in response to movement of the edge ring and the conductive ring by the lift mechanism.

Description

Plasma processing apparatus and substrate processing system

[0001] SUMMARY Exemplary embodiments of the present disclosure relate to plasma processing apparatuses and substrate processing systems.

[0002] A plasma processing apparatus is used for plasma processing of a substrate. The plasma processing apparatus includes a chamber and a substrate support. The substrate support is disposed in the chamber. The substrate support includes a base and an electrostatic chuck. A bias power supply is connected to the base, which generates an electric bias for attracting ions from the plasma to the substrate. The electrostatic chuck is configured to support the substrate and an edge ring surrounding the substrate. Patent Document 1 listed below discloses a plasma processing apparatus configured to move the edge ring up and down.

[0003] Japanese Patent Application Laid-Open No. 2020-113753

[0004] The present disclosure provides techniques for reducing the difference between the top position of the plasma sheath on the edge ring and the top position of the plasma sheath on the substrate.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, an edge ring, a lift mechanism, a plasma generating unit, and a bias power supply. The substrate support is disposed within the chamber. The edge ring is electrically conductive and is disposed to surround a substrate on the substrate support. The lift mechanism is configured to move the edge ring up and down. The plasma generating unit includes a radio frequency power supply and is configured to generate plasma within the chamber. The bias power supply is configured to generate an electrical bias to attract ions from the plasma to the substrate on the substrate support. The substrate support includes a base electrically coupled to the bias power supply and / or the radio frequency power supply, and an electrostatic chuck on the base. The lift mechanism includes a conductive ring, a rod, an actuator, and a connecting member. The conductive ring supports the edge ring mounted thereon and is electrically coupled to the edge ring. The rod extends vertically below the conductive ring. The actuator is configured to move the edge ring up and down via the rod and the conductive ring. The connecting member provides an electrical connection between the conductive ring and the base. The connection member is configured to maintain the electrical connection in response to movement of the conductive ring.

[0006] According to one exemplary embodiment, the difference between the top position of the plasma sheath on the edge ring and the top position of the plasma sheath on the substrate can be reduced.

[0007] 15A is a diagram for explaining an example configuration of a plasma processing system. FIG. 15B is a diagram for explaining an example configuration of an inductively coupled plasma processing apparatus. FIG. 15C is a diagram for explaining a substrate support and lift mechanism according to one exemplary embodiment. FIG. 15D is a diagram for explaining a substrate support and lift mechanism according to another exemplary embodiment. FIG. 15E is a diagram for explaining a substrate processing system according to one exemplary embodiment. FIG. 15F is a diagram for explaining a substrate support and lift mechanism according to yet another exemplary embodiment. FIG. 15F is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus. FIG. 15C is a diagram for explaining a substrate support and lift mechanism according to yet another exemplary embodiment. FIG. 15D is a diagram for explaining a substrate support and lift mechanism according to yet another exemplary embodiment. FIG. 15F is a diagram for explaining a plasma processing method according to one exemplary embodiment. FIG. 15A is a diagram for explaining an example configuration of an imaging device used with plasma processing apparatuses according to various exemplary embodiments, and FIG. 15B is a diagram for explaining an example configuration of a measuring device used with plasma processing apparatuses according to various exemplary embodiments. FIG. 15C is a diagram for explaining a plasma processing method according to another exemplary embodiment. 1A-1C are diagrams illustrating an example of a measurement instrument for use with a plasma processing apparatus according to various exemplary embodiments; FIG. 1B are diagrams illustrating an edge ring and a conductive ring according to yet another exemplary embodiment; FIG. 1C are diagrams illustrating an edge ring and a conductive ring according to yet another exemplary embodiment; FIG. 1D are diagrams illustrating a substrate support and lift mechanism according to yet another exemplary embodiment; FIG. 1F are graphs illustrating experimental results; and FIG. 1G are diagrams illustrating a substrate support and lift mechanism according to one exemplary embodiment.

[0008] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0009] FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0010] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0011] 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. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The 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).

[0012] The following describes a configuration example of an inductively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of an inductively coupled plasma processing apparatus.

[0013] The inductively 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 chamber 10 includes a dielectric window 101. The plasma processing apparatus 1 also includes a substrate support 11, a gas inlet, and an antenna 14. The substrate support 11 is disposed within the plasma processing chamber 10. The antenna 14 is disposed on or above the plasma processing chamber 10 (i.e., on or above the dielectric window 101). The plasma processing chamber 10 has a plasma processing space 10s defined by the dielectric window 101, a sidewall 102 of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded.

[0014] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0015] 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 bias electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple bias electrodes. Alternatively, the electrostatic electrode 1111b may function as a bias electrode. Therefore, the substrate support 11 includes at least one bias electrode.

[0016] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0017] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0018] The gas inlet is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. In one embodiment, the gas inlet includes a center gas injector (CGI) 13. The center gas injector 13 is disposed above the substrate support 11 and attached to a central opening formed in the dielectric window 101. The center gas injector 13 has at least one gas supply port 13a, at least one gas flow path 13b, and at least one gas inlet port 13c. The process gas supplied to the gas supply port 13a passes through the gas flow path 13b and is introduced into the plasma processing space 10s from the gas inlet port 13c. Note that the gas inlet may include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 102 in addition to or instead of the center gas injector 13.

[0019] 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 gas inlet through a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0020] 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 bias electrode and the antenna 14. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generating unit 12. Furthermore, by supplying a bias RF signal to the at least one bias electrode, a bias potential is generated on the substrate W, thereby attracting ions in the formed plasma to the substrate W.

[0021] 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 the antenna 14 via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to the antenna 14.

[0022] The second RF generator 31b is coupled to at least one bias electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one bias electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] 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 bias DC generator 32a. In one embodiment, the bias DC generator 32a is connected to at least one bias electrode and configured to generate a bias DC signal. The generated bias DC signal is applied to the at least one bias electrode.

[0024] In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one bias electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the bias DC generator 32a and at least one bias electrode. Thus, the bias DC generator 32a and the waveform generator constitute a voltage pulse generator. The voltage pulses may have positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. Note that the bias DC generator 32a may be provided in addition to the RF power supply 31 or may be provided instead of the second RF generator 31b.

[0025] The antenna 14 includes one or more coils. In one embodiment, the antenna 14 may include an outer coil and an inner coil arranged coaxially. In this case, the RF power supply 31 may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generator may be connected to both the outer coil and the inner coil, or separate RF generators may be connected to the outer coil and the inner coil separately.

[0026] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0027]

[0033] Reference is now made to Figure 3, which illustrates a substrate support and lift mechanism according to one exemplary embodiment. The substrate support 11 and lift mechanism 50 shown in Figure 3 can be employed in the plasma processing apparatus 1.

[0028] As described above, the substrate support 11 is configured to support an edge ring UR (upper edge ring). The edge ring UR is part of the ring assembly 112. The edge ring UR is disposed to surround the substrate W on the substrate support 11. The edge ring UR is made of an electrically conductive material such as silicon, silicon carbide, tungsten, etc.

[0029] The substrate support 11 includes the base 1110 and the electrostatic chuck 1111, as described above. The base 1110 is an electrically conductive member or includes an electrically conductive member therein. At least one bias power supply, such as the second RF generator 31b and / or the bias DC generator 32a, is electrically coupled to the base 1110 (or its conductive member). The at least one bias power supply is configured to generate an electrical bias to attract ions from the plasma to the substrate W on the substrate support 11. The electrical bias includes a sequence of bias RF signals and / or voltage pulses as described above.

[0030] The electrostatic chuck 1111 is disposed on a base 1110. The electrostatic chuck 1111 includes a first portion P1 and a second portion P2. The first portion P1 has a substrate support surface (i.e., a central region 111a) as its upper surface. The first portion P1 and the substrate support surface have a substantially circular planar shape. The central axis of the first portion P1 and the substrate support surface is the central axis of the substrate support part 11. The first portion P1 includes the above-mentioned electrostatic electrode 1111b. When a DC voltage is applied to the electrostatic electrode 1111b from a DC power supply, an electrostatic attractive force is generated between the first portion P1 and the substrate W. The first portion P1 holds the substrate W by the generated electrostatic attractive force.

[0031] The second portion P2 extends circumferentially around the central axis of the substrate support 11 to surround the first portion P1. The second portion P2 has a ring support surface (i.e., an annular region 111b) as its upper surface. The second portion P2 and the ring support surface have a substantially annular planar shape. The second portion P2 may include at least one electrostatic electrode. The second portion P2 may include electrodes BEa and BEb as the at least one electrostatic electrode. The electrodes BEa and BEb constitute bipolar electrodes. A voltage is applied to the electrodes BEa and BEb from at least one power supply so as to generate a potential difference between them. This generates an electrostatic attraction between the edge ring UR and the second portion P2. The second portion P2 holds the edge ring UR by the generated electrostatic attraction.

[0032] In one embodiment, the ring support surface extends at a position lower than the substrate support surface. In this case, the first portion P1 includes a sidewall surface 111s extending between the substrate support surface and the ring support surface. In this case, an edge ring LR (lower edge ring) may be disposed along the sidewall surface 111s and on the ring support surface. The edge ring LR constitutes part of the ring assembly 112. The edge ring LR may be formed from a conductive material such as silicon, silicon carbide, tungsten, or the like. Alternatively, the edge ring LR may be formed from an insulating material such as quartz. In this case, the edge ring UR is disposed on the edge ring LR. The ring support surface and the sidewall surface 111s are protected by the edge ring LR.

[0033] 3, the substrate support 11 may further include a cover ring CR and an insulating member IM. The insulating member IM is made of an insulating material such as quartz and has a generally cylindrical shape. The insulating member IM extends in the circumferential direction around the central axis of the substrate support 11 so as to surround the base 1110 and the electrostatic chuck 1111. The cover ring CR has a generally disk shape and is disposed on the insulating member IM so as to surround the edge ring UR.

[0034] The plasma processing apparatus 1 further includes a lift mechanism 50. The lift mechanism 50 includes a conductive ring 51, at least one rod 52, an actuator 53, and at least one connecting member .

[0035] The conductive ring 51 is formed of a metal or conductive material such as aluminum and has a generally ring shape. The conductive ring 51 extends circumferentially around the central axis of the substrate support 11, inside the insulating member IM, to surround the base 1110 and the electrostatic chuck 1111. The conductive ring 51 is configured to support the edge ring UR placed thereon and to be electrically coupled to the edge ring UR. That is, the conductive ring 51 is configured to be conductively or capacitively coupled to the edge ring UR while supporting the edge ring UR. In the example of FIG. 3 , the conductive ring 51 is electrically connected to the edge ring UR while supporting the edge ring UR. Note that the exposed surface of the conductive ring 51 may be covered with a plasma-resistant film. This film may be made of a material such as aluminum oxide or yttrium fluoride, and may be formed by a method such as anodizing or thermal spraying.

[0036] The at least one rod 52 extends in the vertical direction below the conductive ring 51. The at least one rod 52 may be insulating. In this case, it is possible to suppress the electrical bias from flowing into the actuator 53 via the at least one rod 52. In one embodiment, the lift mechanism 50 may include a plurality of rods 52 as the at least one rod 52. The plurality of rods 52 are arranged along the circumferential direction around the central axis of the substrate support 11. The plurality of rods 52 may be arranged at equal intervals along the circumferential direction.

[0037] The actuator 53 is disposed below the at least one rod 52 and is connected to the at least one rod 52. The actuator 53 is configured to move the edge ring up and down via the at least one rod 52 and the conductive ring 51. The actuator 53 may be, for example, a pneumatic or hydraulic cylinder, or a motor.

[0038] The at least one connecting member 54 provides an electrical connection between the conductive ring 51 and the base 1110 (or a conductive member thereof). The at least one connecting member 54 is configured to maintain the electrical connection in response to movement of the conductive ring 51. The at least one connecting member 54 may be configured to be deformable in response to movement of the conductive ring 51. Note that when the lift mechanism 50 includes a plurality of rods 52, the at least one connecting member 54 may include a plurality of connecting members 54.

[0039] 3 , at least one connecting member 54 includes an upper portion 54a, a deformed portion 54b, and a lower portion 54c. The upper portion 54a, the deformed portion 54b, and the lower portion 54c are formed from a conductive material. The upper portion 54a is disposed directly below the conductive ring 51 and is fixed to the conductive ring 51. The upper portion 54a is electrically connected to the conductive ring 51. The lower portion 54c is disposed below the upper portion 54a and is fixed to the base 1110. The lower portion 54c is electrically connected to the base 1110.

[0040] The deformed portion 54b extends between the upper portion 54a and the lower portion 54c. The upper end of the deformed portion 54b is fixed to the upper portion 54a, and the lower end of the deformed portion 54b is fixed to the lower portion 54c. The deformed portion 54b is electrically connected to the upper portion 54a and the lower portion 54c. The deformed portion 54b may be a bellows as shown in FIG. 3.

[0041] At least one rod 52 penetrates the lower portion 54c, passes through the deformed portion 54b, and extends to a region directly below the upper portion 54a. When the at least one rod 52 is moved upward by the actuator 53, the edge ring UR is moved upward via the upper portion 54a and the conductive ring 51 (see FIG. 23 ). The edge ring UR is moved upward in accordance with a decrease in its thickness to reduce the difference between the upper end position of the plasma sheath on the substrate W and the upper end position of the plasma sheath on the edge ring UR. In the plasma processing apparatus 1, even when the edge ring UR is moved upward from the electrostatic chuck 1111, the connecting member 54 maintains electrical connection between the base 1110 and the edge ring UR. In the plasma processing apparatus 1, the edge ring UR is not electrically floating, so the edge ring UR can function to reduce the difference between the upper end position of the plasma sheath on the substrate W and the upper end position of the plasma sheath on the edge ring UR.

[0042] The connecting member 54 may be a cylindrical member having a plurality of slits formed in its sidewall surface so as to be elastically deformable in the longitudinal direction. For example, the connecting member 54 may be a flexure.

[0043] Reference will now be made to Fig. 4, which illustrates a substrate support and lift mechanism according to another exemplary embodiment. The substrate support 11 and lift mechanism 50 shown in Fig. 4 may be employed in the plasma processing apparatus 1. The embodiment of Fig. 4 will be described below in terms of differences from the embodiment of Fig. 3.

[0044] As shown in FIG. 4 , the lift mechanism 50 may have a deformed portion 54b that is a contact band instead of a bellows. The upper end of the deformed portion 54b may be fixed to the conductive ring 51. The lower end of the deformed portion 54b may be fixed to the base 1110. The deformed portion 54b shown in FIG. 4 is flexible in the vertical direction. As shown in FIG. 4 , the deformed portion 54b may have a generally arc-shaped configuration that bulges outward. In this case, the insulating member IM may provide a recess into which a portion of the deformed portion 54b is disposed.

[0045] Reference will now be made to FIG. 5 . FIG. 5 is a diagram illustrating a substrate processing system according to an exemplary embodiment. The substrate processing system PS illustrated in FIG. 5 includes a transfer module TM, multiple process modules PM1 to PM7 (multiple substrate processing modules), and a controller MC. The substrate processing system PS may further include pedestals LPa to LPd, containers FUa to FUd, a loader module LM, an aligner AN, a load lock module LL1, a load lock module LL2, and a stocker module RSM (ring stocker). Note that the number of pedestals, containers, and load lock modules in the substrate processing system PS may be any number greater than or equal to one. The number of process modules in the substrate processing system PS may be any number greater than or equal to two.

[0046] The pedestals LPa to LPd are arranged along one edge of the loader module LM. The containers FUa to FUd are mounted on the pedestals LPa to LPd, respectively. Each of the containers FUa to FUd is, for example, a container called a FOUP (Front Opening Unified Pod). Each of the containers FUa to FUd is configured to accommodate substrates W therein.

[0047] The loader module LM has a transfer chamber. The pressure in the transfer chamber of the loader module LM is set to atmospheric pressure. The loader module LM has a transfer robot LMR. The transfer robot LMR is controlled by a controller MC. The transfer robot LMR is configured to transfer substrates W through the transfer chamber of the loader module LM. The transfer robot LMR can transfer substrates W between each of the containers FUa to FUd and an aligner AN, between the aligner AN and each of the load lock modules LL1, LL2, and between each of the load lock modules LL1, LL2 and each of the containers FUa to FUd. The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (align) the position of the substrate W.

[0048] Each of the load lock modules LL1 and LL2 is connected between the transfer chamber of the loader module LM and the transfer chamber TC of the transfer module TM. Each of the load lock modules LL1 and LL2 provides a preliminary decompression chamber. A gate valve is provided between each of the preliminary decompression chambers of the load lock modules LL1 and LL2 and the transfer chamber of the loader module LM. Furthermore, a gate valve is provided between each of the preliminary decompression chambers of the load lock modules LL1 and LL2 and the transfer chamber TC of the transfer module TM.

[0049] The transfer module TM has a transfer chamber TC (vacuum transfer chamber) and a transfer robot TR. The transfer chamber TC is configured so that the internal space thereof can be depressurized. The transfer robot TR includes a pick TP (end effector). The transfer robot TR may include at least two picks TP. In the illustrated example, the transfer robot TR includes two picks TP. One of the two picks TP is provided above the other. The transfer robot TR is configured to transfer a substrate W placed on any one of the two picks TP through the transfer chamber TC. The transfer robot TR is controlled by a controller MC.

[0050] The transfer module TM may be provided with position detection sensors S11 and S12. The position detection sensors S11 and S12 are provided on the transfer path of the substrate W and edge ring from the transfer module TM to the process module PM1. The position detection sensors S11 and S12 are used to correct the positions of the substrate W and edge ring being transferred from the transfer module TM to the process module PM1. The position detection sensors S11 and S12 are provided, for example, near a gate valve separating the transfer module TM and the process module PM1. The position detection sensors S11 and S12 are arranged, for example, so that the distance between them is smaller than the outer diameter of the substrate W and smaller than the inner diameter of the edge ring. The transfer module TM may be provided with position detection sensors S21, S22, S31, S32, S41, S42, S51, S52, S61, S62, S71, and S72, in addition to the position detection sensors S11 and S12. Position detection sensors S21 and S22 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM2. Position detection sensors S31 and S32 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM3. Position detection sensors S41 and S42 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM4. Position detection sensors S51 and S52 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM5. Position detection sensors S61 and S62 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM6. Position detection sensors S71 and S72 are provided on the transport path of the substrate W and edge ring from the transport module TM to the process module PM7.

[0051] In one embodiment, the transport robot TR is configured to transport an edge ring for a substrate support of any one of the process modules PM1 to PM7. The edge ring is an edge ring UR or a ring set including an edge ring UR and an edge ring LR. The edge ring is placed on any one of two picks TP and transported. Each pick TP has a sensor TS. The sensor TS is an optical sensor configured to measure the position of a ring member such as an edge ring on the substrate support.

[0052] Each of the process modules PM1 to PM7 is an apparatus configured to perform dedicated substrate processing and includes a processing chamber (substrate processing chamber). A gate valve is provided between the processing chamber and the transfer chamber TC. At least one of the process modules PM1 to PM7 is a plasma processing apparatus 1.

[0053] The stocker module RSM (ring stocker) is connected to the transfer chamber TC via a gate valve. The stocker module RSM has a chamber and can accommodate multiple edge rings therein.

[0054] The controller MC is configured to control each part of the substrate processing system PS. The controller MC may be a computer including a processor, a storage device, an input device, a display device, etc. The controller MC executes a control program stored in the storage device and controls each part of the substrate processing system PS based on the recipe data stored in the storage device.

[0055] A plasma processing apparatus 1 used as a process module of a substrate processing system PS may include a substrate support 11 shown in any one of FIGS. 6 to 9. Each of FIGS. 6 to 9 illustrates a substrate support and a lift mechanism according to yet another exemplary embodiment. In each of the embodiments shown in FIGS. 6 to 9, the edge ring of the plasma processing apparatus 1 can be transferred by a transfer robot TR and replaced with a corresponding edge ring in a stocker module RSM.

[0056] 6, the substrate support 11 has a plurality of through holes extending vertically therethrough. The through holes of the substrate support 11 are arranged circumferentially around the central axis of the substrate support 11. The through holes of the substrate support 11 may be arranged at equal intervals. The edge ring LR also has a plurality of through holes formed therein that are aligned with the through holes of the substrate support 11.

[0057] 6, the edge ring UR can be lifted upward from the substrate support 11 by a lift mechanism 60. The lift mechanism 60 includes a plurality of lift pins 61 and an actuator 62. The plurality of lift pins 61 are inserted into a plurality of through-holes in the substrate support 11, respectively. The actuator 62 is connected to the plurality of lift pins 61 and is configured to move the plurality of lift pins 61 up and down.

[0058] When the lift pins 61 are moved upward by the actuators 62 with their upper ends in contact with the edge ring UR, the edge ring UR is lifted upward from the substrate support part 11. In this state, the transport robot TR moves the pick TP below the edge ring UR. Then, as the lift pins 61 move downward, the edge ring UR is handed over to the pick TP. Thereafter, the edge ring UR is transported to the stocker module RSM by the transport robot TR.

[0059] Then, the replacement edge ring UR is transferred from the stocker module RSM into the chamber 10 by the transfer robot TR. Then, the plurality of lift pins 61 are moved upward by the actuator 62, and the edge ring UR is handed over to the plurality of lift pins 61. Then, the pick TP moves to the outside of the chamber 10, and the plurality of lift pins 61 move downward. As a result, the replacement edge ring UR is placed on the substrate support part 11.

[0060] 7, the substrate support 11 has a plurality of through holes extending vertically therethrough. The through holes of the substrate support 11 are arranged in a circumferential direction around the central axis of the substrate support 11. The through holes of the substrate support 11 may be arranged at equal intervals in the circumferential direction. The edge ring LR does not have a plurality of through holes aligned with the through holes of the substrate support 11.

[0061] 7, a ring set including the edge ring UR and the edge ring LR can be lifted upward from the substrate support 11 by a lift mechanism 70. The lift mechanism 70 includes a plurality of lift pins 71 and an actuator 72. The plurality of lift pins 71 are inserted into a plurality of through-holes in the substrate support 11, respectively. The actuator 72 is connected to the plurality of lift pins 71 and is configured to move the plurality of lift pins 71 up and down.

[0062] When the lift pins 71 are moved upward by the actuator 72 with their upper ends in contact with the edge ring LR, the ring set is lifted upward from the substrate support 11. In this state, the transport robot TR moves the pick TP below the ring set. Then, as the lift pins 71 move downward, the ring set is handed over to the pick TP. Thereafter, the ring set is transported to the stocker module RSM by the transport robot TR.

[0063] Then, the replacement ring set is transferred from the stocker module RSM into the chamber 10 by the transfer robot TR. Then, the plurality of lift pins 71 are moved upward by the actuator 72, and the ring set is handed over to the plurality of lift pins 71. Then, the pick TP moves to the outside of the chamber 10, and the plurality of lift pins 71 move downward. As a result, the replacement ring set is placed on the substrate support part 11.

[0064] In the embodiment of FIG. 8 , the conductive ring 51 extends to a region above the edge ring LR so as to support the edge ring UR by its upper inner edge. In the embodiment of FIG. 8 , an outer ring OR is disposed on the conductive ring 51 to surround the edge ring UR. The outer ring OR may be formed of an insulating material such as quartz. In the embodiment of FIG. 8 , as in the embodiment of FIG. 6 , the substrate support 11 also has a plurality of through holes extending therethrough. The through holes in the substrate support 11 are arranged along the circumferential direction around the central axis of the substrate support 11. The through holes in the substrate support 11 may be arranged at equal intervals along the circumferential direction. Furthermore, the edge ring LR has a plurality of through holes formed therein that are aligned with the through holes in the substrate support 11.

[0065] The operations of the lift mechanism 60 and the transport robot TR for replacing the edge ring UR in the embodiment of FIG. 8 are similar to the operations of the lift mechanism 60 and the transport robot TR for replacing the edge ring UR in the embodiment of FIG.

[0066] In the embodiment of FIG. 9 , the edge ring LR has an outer diameter smaller than the outer diameter of the edge ring UR. The edge ring UR is disposed on the edge ring LR such that its outer edge protrudes radially outward relative to the edge ring LR. The conductive ring 51 supports the outer edge of the edge ring UR by its upper inner edge. In the embodiment of FIG. 9 , an outer ring OR is disposed on the conductive ring 51 to surround the edge ring UR. The outer ring OR may be formed from an insulating material such as quartz. Also, in the embodiment of FIG. 9 , another outer ring BOR is disposed below the upper end of the conductive ring 51 to surround the edge ring LR. The outer ring BOR may be formed from an insulating material such as quartz.

[0067] In the embodiment of Fig. 9, the substrate support 11 also has a plurality of through holes extending therethrough, similar to the embodiment of Fig. 7. The plurality of through holes in the substrate support 11 are arranged along the circumferential direction around the central axis of the substrate support 11. The plurality of through holes in the substrate support 11 may be arranged at equal intervals along the circumferential direction. The edge ring LR does not have a plurality of through holes aligned with the plurality of through holes in the substrate support 11.

[0068] The operations of the lift mechanism 70 and the transport robot TR for replacing the edge ring in the embodiment of FIG. 9 are similar to the operations of the lift mechanism 70 and the transport robot TR for replacing the edge ring in the embodiment of FIG.

[0069] In yet another exemplary embodiment, the plasma processing apparatus 1 may be configured to selectively replace only the edge ring UR or the above-described ring set. For example, the plasma processing apparatus 1 may have both the lift mechanism 60 and the lift mechanism 70. In this case, the plurality of lift pins 61 and the plurality of lift pins 71 are arranged alternately along the circumferential direction. No through-holes are formed in the edge ring LR above each of the plurality of lift pins 71. In this case, it is possible to selectively replace only the edge ring UR shown in FIG. 6 using the lift mechanism 60 or to replace the ring set including the edge ring UR and edge ring LR shown in FIG. 6 using the lift mechanism 70. Alternatively, it is possible to selectively replace only the edge ring UR shown in FIG. 9 using the lift mechanism 60 or to replace the ring set including the edge ring UR and edge ring LR shown in FIG. 9 using the lift mechanism 70.

[0070] An example of the configuration of a capacitively coupled plasma processing apparatus will be described below as another example of the plasma processing apparatus 1. FIG. 10 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 shown in FIG. 10 includes a substrate support 11 and a lift mechanism 50 of the plasma processing apparatus according to any of the various exemplary embodiments described above. The plasma processing apparatus 1 shown in FIG. 10 may also include the lift mechanism 60 and / or the lift mechanism 70 described above. The plasma processing apparatus 1 shown in FIG. 10 may also be employed as a process module in a substrate processing system PS. The capacitively coupled plasma processing apparatus 1 shown in FIG. 10 will be described below from the perspective of differences from the inductively coupled plasma processing apparatus 1 shown in FIG. 2.

[0071] In the plasma processing apparatus 1 shown in Figure 10, the gas inlet unit includes a showerhead 13A. The showerhead 13A is disposed above a substrate support 11. In one embodiment, the showerhead 13A constitutes at least a portion of the ceiling of a plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13A, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13A and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0072] The showerhead 13A is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13A has at least one gas supply port 13Aa, at least one gas diffusion chamber 13Ab, and multiple gas inlets 13Ac. The process gas supplied to the gas supply port 13Aa passes through the gas diffusion chamber 13Ab and is introduced into the plasma processing space 10s from the multiple gas inlets 13Ac. The showerhead 13A also includes at least one upper electrode. In addition to the showerhead 13A, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0073] In the plasma processing apparatus 1 shown in Figure 10, a radio frequency power supply and / or at least one bias power supply are electrically coupled to the base 1110 (or its conductive member), i.e., the lower electrode. The radio frequency power supply is a first RF generator 31a, which constitutes the plasma generator 12. The at least one bias power supply includes a second RF generator 31b and / or a bias DC generator 32a (i.e., a first DC generator). The at least one bias power supply is configured to generate an electrical bias to attract ions from the plasma to the substrate W on the substrate support 11. The electrical bias includes the above-mentioned bias RF signal and / or a sequence of voltage pulses.

[0074] 10 , the DC power supply 32 may further include a second DC generator 32b in addition to the bias DC generator 32a, i.e., the first DC generator 32a. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to 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 at least one upper electrode.

[0075] In various embodiments, in addition to the first DC signal, a second DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0076] Reference will now be made to FIG. 11 , which illustrates a substrate support and a lift mechanism according to yet another exemplary embodiment. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 11 can be employed in the inductively coupled plasma processing apparatus 1 or the capacitively coupled plasma processing apparatus 1 described above. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 11 will be described below in terms of differences from the substrate support 11 and the lift mechanism 50 illustrated in FIG. 3 .

[0077] Similar to the lift mechanism 50 shown in FIG. 3 , the lift mechanism 50 shown in FIG. 11 can electrically couple (e.g., establish electrical continuity) the conductive ring 51 to the edge ring UR while supporting the edge ring UR on the conductive ring 51. That is, the lift mechanism 50 shown in FIG. 11 can also create a first state in which the edge ring UR and the base 1110 are electrically coupled to each other (e.g., a state of continuity between the edge ring UR and the base 1110). The lift mechanism 50 shown in FIG. 11 can also separate the conductive ring 51 from the edge ring UR by lowering the conductive ring 51 downward via the rod 52 using the actuator 53. That is, the lift mechanism 50 shown in FIG. 11 can separate the conductive ring 51 from the edge ring UR to create a second state in which the edge ring UR and the base 1110 are electrically isolated from each other (e.g., a state of non-conduction between the edge ring UR and the base 1110). Therefore, the lift mechanism 50 shown in FIG. 11 constitutes a switch that is configured to be able to switch between a first state and a second state.

[0078] Reference will now be made to FIG. 12 , which illustrates a substrate support and a lift mechanism according to yet another exemplary embodiment. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 12 can be employed in the inductively coupled plasma processing apparatus 1 or the capacitively coupled plasma processing apparatus 1 described above. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 12 will be described below in terms of differences from the substrate support 11 and the lift mechanism 50 illustrated in FIG. 4 .

[0079] The plasma processing apparatus 1 including the lift mechanism 50 shown in FIG. 12 further includes a switch 56. The switch 56 may be part of the lift mechanism 50. The switch 56 includes a switching element and is connected between the connection member 54 and the conductive ring 51 or between the connection member 54 and the base 1110. When the switching element of the switch 56 is in an ON state (closed state), a first state is formed in which the edge ring UR and the base 1110 are electrically coupled to each other (e.g., a conductive state between the edge ring UR and the base 1110). When the switching element of the switch 56 is in an OFF state (open state), a second state is formed in which the edge ring UR and the base 1110 are electrically isolated from each other (e.g., a non-conductive state between the edge ring UR and the base 1110).

[0080] Reference will now be made to FIG. 13 , which illustrates a substrate support and a lift mechanism according to yet another exemplary embodiment. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 13 can be employed in the inductively coupled plasma processing apparatus 1 or the capacitively coupled plasma processing apparatus 1 described above. The substrate support 11 and the lift mechanism 50 illustrated in FIG. 13 will be described below in terms of differences from the substrate support 11 and the lift mechanism 50 illustrated in FIG. 6 .

[0081] The plasma processing apparatus 1 including the lift mechanism 50 shown in FIG. 13 includes a lift mechanism 60 as a switch configured to be switchable between the first state and the second state described above. In the lift mechanism 60, all of the lift pins 61 are formed of an insulating material. When the lift mechanism 60 positions all of the lift pins 61 so that the edge ring UR is supported on the conductive ring 51 and electrically connected to the conductive ring 51, the first state (e.g., a conductive state between the edge ring UR and the base 1110) is established. When the lift mechanism 60 lifts the edge ring UR upward from the conductive ring 51 and separates it from the conductive ring 51, the second state (e.g., a non-conductive state between the edge ring UR and the base 1110) is established.

[0082] 11 to 13, it is possible to switch between the first state and the second state as necessary. The switch can be controlled by the control unit 2. Hereinafter, with reference to FIGS. 14 to 18, a plasma processing method performed in the plasma processing apparatus 1 including the switch shown in FIGS. 11 to 13 will be described.

[0083] Please refer to Figures 14 and 15(a). Figure 14 is a flow chart showing a plasma processing method according to one exemplary embodiment. Figure 15(a) is a diagram showing an example of an imaging device used with plasma processing apparatuses according to various exemplary embodiments. In the plasma processing method shown in Figure 14 (hereinafter referred to as "method MT"), an imaging device 80 shown in Figure 15(a) can be used. The imaging device 80 can be arranged in the aligner AN. The imaging device 80 may be arranged in any location as long as it can acquire an image of the substrate W.

[0084] The method MT is performed with the substrate W placed on the substrate support 11. The method MT starts with a step STa, in which the control unit 2 reads a recipe.

[0085] In the subsequent process STJ, the control unit 2 determines whether electrical coupling (e.g., conduction) between the edge ring UR and the base 1110 is necessary. In the process STJ, if the control unit 2 determines that the plasma density on the edge ring UR should be increased, the control unit 2 may determine that electrical coupling between the edge ring UR and the base 1110 is necessary. On the other hand, in the process STJ, if the control unit 2 determines that the plasma density on the edge ring UR should not be increased, the control unit 2 may determine that electrical coupling between the edge ring UR and the base 1110 is not necessary.

[0086] When the control unit 2 determines that the plasma density on the edge ring UR should be increased, it controls the switch to form a first state (e.g., a conductive state between the edge ring UR and the base 1110) in step STb. On the other hand, when the control unit 2 determines that the plasma density on the edge ring UR should not be increased, it controls the switch to form a second state (e.g., a non-conductive state between the edge ring UR and the base 1110) in step STc.

[0087] Next, step STd is performed. In step STd, the control unit 2 controls each part of the plasma processing apparatus 1 so as to perform plasma processing according to the above-described recipe. When step STd is performed, if the edge ring UR and the base 1110 are electrically coupled to each other (e.g., they are electrically connected to each other), the plasma density on the edge ring UR increases due to the source RF signal and / or the electrical bias supplied from the base 1110 to the edge ring UR via the conductive ring 51.

[0088] For the purpose of making a determination in step STJ, the control unit 2 may acquire, from the imaging device 80, an image of the upper surface of the substrate W that was processed using the same recipe in the plasma processing apparatus 1 before the substrate W placed on the substrate support 11. The control unit 2 may determine, based on this image, whether or not to increase the plasma density on the edge ring UR. In one embodiment, in step STd, multiple holes may be formed in the substrate W by the plasma processing based on the recipe. In this case, if the control unit 2 determines in step STJ from the image acquired from the imaging device 80 that the circularity of the holes in the edge region and on the upper surface of the substrate W is equal to or less than a threshold value, the control unit 2 performs step STb. On the other hand, if the control unit 2 determines in step STJ from the image acquired from the imaging device 80 that the circularity is greater than the threshold value, the control unit 2 performs step STc. The circularity may be the ratio of the minimum width to the maximum width of the holes in the edge region and on the upper surface of the substrate W.

[0089] Reference will now be made to FIG. 15B in conjunction with FIG. 14 . FIG. 15B illustrates an example of a measuring device that can be used with a plasma processing apparatus according to various exemplary embodiments. In the method MT, a measuring device 82 shown in FIG. 15B may be used. The measuring device 82 is attached to a pick TP. The measuring device 82 is configured to measure the thickness of a deposit on the edge ring UR. The measuring device 82 may include an image sensor that acquires an image of the edge ring UR, or may include another optical sensor configured to measure the thickness of a deposit on the edge ring UR.

[0090] The control unit 2 may determine whether or not to increase the density of plasma on the edge ring UR, depending on the thickness of deposits on the edge ring UR measured by the measuring device 82. In one embodiment, in process STd, cleaning inside the chamber 10 is performed by plasma processing based on a recipe. In this case, if the control unit 2 determines in process STJ that the thickness of deposits on the edge ring UR measured by the measuring device 82 is equal to or greater than the threshold value, it performs process STb. On the other hand, if the control unit 2 determines in process STJ that the thickness of deposits on the edge ring UR measured by the measuring device 82 is smaller than the threshold value, it performs process STc. If process STd is performed after process STb, the density of plasma on the edge ring UR increases, and removal of deposits on the edge ring UR is promoted. Note that, in the cleaning in process STd, O ２ In the cleaning step STd, a cleaning gas containing an oxygen-containing gas or other gas is used, and cleaning can be performed by plasma generated from the cleaning gas. Furthermore, during the cleaning step STd, no object may be placed on the central region 111 a of the substrate support 11, and a dummy wafer may be placed on the central region 111 a.

[0091] Reference will now be made to Fig. 16, which is a flow chart showing a plasma processing method according to another exemplary embodiment. The plasma processing method shown in Fig. 16 (hereinafter referred to as "method MTA") starts with step STa, which is the same as step STa of method MT. Method MTA is performed with a substrate W placed on a substrate support 11.

[0092] In the subsequent process STAd, the control unit 2 selects the first process specified in the recipe. The recipe includes multiple processes, and the recipe specifies setting information regarding the electrical coupling (e.g., conduction) between the edge ring UR and the base 1110 for each process. The setting information is information that specifies the above-mentioned first state (e.g., conductive state) or second state (e.g., non-conductive state).

[0093] In the subsequent process STAJ, the control unit 2 determines whether electrical coupling between the edge ring UR and the base 1110 is necessary based on the setting information specified in the recipe for the selected process. If the control unit 2 determines that electrical coupling between the edge ring UR and the base 1110 is necessary in the process STAJ, the control unit 2 performs process STb in the same manner as in the method MT. On the other hand, if the control unit 2 determines that electrical coupling between the edge ring UR and the base 1110 is not necessary in the process STAJ, the control unit 2 performs process STc in the same manner as in the method MT. Then, the control unit 2 controls each component of the plasma processing apparatus 1 to perform the process selected in process STAe.

[0094] In the subsequent process STAJb, the control unit 2 determines whether all processes included in the recipe have been completed. If the control unit 2 determines that all processes have not been completed, it selects the next process included in the recipe in process STAf and continues processing from process STAJ. On the other hand, if the control unit 2 determines that all processes have been completed in process STAJb, it ends the method MTA.

[0095] Reference will now be made to Figures 17 and 18. Figure 17 is a flow chart illustrating a plasma processing method according to yet another exemplary embodiment. Figure 18 is a diagram illustrating an example of a measuring instrument that can be used with plasma processing apparatuses according to various exemplary embodiments. In the plasma processing method shown in Figure 17 (hereinafter referred to as "method MTB"), a measuring instrument 200 shown in Figure 18 can be used.

[0096] The measuring device 200 includes a condenser lens 202, an optical fiber 204, a light source 206, a photodetector 208, and a calculation unit 210. The condenser lens 202 is provided above the ceiling 10U of the chamber 10, and is optically coupled to the substrate W on the substrate support 11 via an optical window in the ceiling 10U. The ceiling 10U is the dielectric window 101 or the shower head 13A.

[0097] The condensing lens 202 is optically connected to a light source 206 and a photodetector 208 (polychromator) via an optical fiber 204. The light source 206 emits light Ls. The light Ls emitted from the light source 206 is irradiated onto the substrate W via the optical fiber 204 and the condensing lens 202. The light Ls is reflected at multiple locations within the substrate W at different heights, generating interference light Li. The interference light Li is input to the photodetector 208 via the condensing lens 202 and the optical fiber 204. The photodetector 208 is configured to detect the light intensity of the interference light Li. The calculation unit 210 is configured to measure the etching depth of the substrate W based on changes in the light intensity of the interference light Li detected by the photodetector 208. The light intensity of the interference light Li changes periodically depending on the etching depth of the substrate W. Therefore, the calculation unit 210 can identify the etching depth of the substrate W from changes in the light intensity of the interference light Li.

[0098] 17 , method MTB begins with step STa, which is the same as step STa of method MT. Method MTB is performed with the substrate W placed on the substrate support 11. In the subsequent step SBd, the control unit 2 starts plasma processing according to a recipe, specifically, plasma etching on the substrate W. In the plasma etching, the control unit 2 controls each part of the plasma processing apparatus 1 according to the recipe. Note that at the start of plasma etching in step STBd, a second state (e.g., a non-conductive state between the edge ring UR and the base 1110) is formed.

[0099] Steps STBJ to STBJb are performed during the period in which plasma etching started in step STBd is being performed. In step STBJ, the control unit 2 determines whether electrical connection (e.g., conduction) between the edge ring UR and the base 1110 is necessary. Specifically, the control unit 2 determines whether the etching depth measured by the measuring device 200 has reached a threshold value. If the control unit 2 determines that the etching depth has reached the threshold value, it performs step STb. On the other hand, if the control unit 2 determines that the etching depth has not reached the threshold value, it performs step STc and maintains the second state (e.g., non-conductive state).

[0100] In the subsequent step STBJb, it is determined whether or not to terminate the process started in step STd, i.e., plasma etching. If the plasma etching is not to be terminated, the process is repeated from step STBJ. On the other hand, if the plasma etching is to be terminated, the control unit 2 terminates the method MTB.

[0101] Reference is now made to FIG. 19 , which illustrates an edge ring and a conductive ring according to yet another exemplary embodiment. As described above, in various exemplary embodiments, the conductive ring 51 may contact the edge ring UR and be electrically connected to the edge ring UR, thereby establishing a conductive state between the edge ring UR and the base 1110 as the first state. Alternatively, as shown in FIG. 19 , the conductive ring 51 may be electrically connected to the edge ring UR via a member 51 c, thereby establishing a conductive state between the edge ring UR and the base 1110 as the first state. The member 51 c is made of a conductive material such as metal. When the first state is established, the member 51 c is sandwiched between the edge ring UR and the conductive ring 51. The member 51 c may have elasticity. The member 51 c may be a canted coil spring.

[0102] Reference is now made to FIG. 20 , which illustrates an edge ring and a conductive ring according to yet another exemplary embodiment. The conductive ring 51 may form the first state by capacitively coupling to the edge ring UR. As illustrated in FIG. 20 , the conductive ring 51 may include a dielectric region 51f on its upper surface. In this case, the conductive ring 51 capacitively couples to the edge ring UR while supporting the edge ring UR, which is placed on the dielectric region 51f. The dielectric region 51f may be a film formed from a dielectric material. The dielectric region 51f may cover the surface of the conductive ring 51. The dielectric region 51f may be formed by thermal spraying of a material such as yttrium oxide.

[0103] Reference will now be made to FIG. 21 , which illustrates a substrate support and lift mechanism according to yet another exemplary embodiment. In the various exemplary embodiments described above, the edge ring UR and the edge ring LR may have the structure illustrated in FIG. 21 . As illustrated in FIG. 21 , the edge ring LR includes an inner periphery LRi, a middle portion LRm, and an outer periphery LRo. The inner periphery LRi is ring-shaped and is disposed on the ring support surface along the side wall surface 111s. The edge region of the substrate W is located above the inner periphery LRi. The outer periphery LRo is ring-shaped and extends radially outward from the inner periphery LRi. The edge ring UR is disposed on the outer periphery LRo. The middle portion LRm is ring-shaped and extends between the inner periphery LRi and the outer periphery LRo. The middle portion LRm is interposed between the edge of the substrate W on the substrate support surface and the inner periphery of the edge ring UR. The height direction position of the upper surface of the intermediate portion LRm is higher than the height direction positions of the upper surfaces of the inner peripheral portion LRi and the outer peripheral portion LRo. The intermediate portion LRm may have a thickness greater than the thickness of the inner peripheral portion LRi and the thickness of the outer peripheral portion LRo.

[0104] When the edge ring UR is disposed on the edge ring LR in contact with the edge ring LR, the edge ring UR exchanges heat with the base 1110 via the edge ring LR and the electrostatic chuck 1111. On the other hand, when the edge ring UR is elevated relative to the edge ring LR, the temperature of the edge ring UR may rise. With the intermediate portion LRm, as shown in FIG. 21 , the inner circumferential surface of the edge ring UR is radially spaced a distance D from the edge of the substrate W. Therefore, even if the temperature of the edge ring UR rises, the temperature of the edge region of the substrate W is suppressed from rising. Furthermore, even when the edge ring UR shown in FIG. 21 is used, the difference between the upper end position of the plasma sheath on the substrate W and the upper end position of the plasma sheath on the edge ring UR can be reduced. As a result, ions can be supplied perpendicularly to the edge region of the substrate W, thereby vertically forming a recess such as a hole in the edge region of the substrate W. The distance D may be 10 mm or less, 6 mm or less, or approximately 6 mm.

[0105] The results of an experiment conducted to evaluate the embodiments shown in Figures 3 and 21 will be described below. In the experiment, plasma etching was performed on a silicon-containing film of a sample substrate using the plasma processing apparatus 1 shown in Figure 10, and the angle of a hole formed in the silicon-containing film was determined. The hole angle was 90° when the hole extended in the thickness direction of the sample substrate, i.e., the vertical direction, was smaller than 90° when the hole was inclined toward the outside of the sample substrate, and larger than 90° when the hole was inclined toward the center of the sample substrate.

[0106] FIG. 22 is a graph showing the results of the experiment. In FIG. 22, the horizontal axis represents the driving amount of the conductive ring 51. When the edge ring UR is in contact with and positioned on the edge ring LR, the driving amount is 0. As the edge ring UR is raised above the edge ring LR and the vertical distance between the edge ring UR and the edge ring LR increases, the driving amount increases. In FIG. 22, the vertical axis represents the hole angle. The rectangular plots in FIG. 22 represent the hole angle obtained when an unworn edge ring UR is used in the plasma processing apparatus 1 having the configuration shown in FIG. 3 and the driving amount is 0. The circular plots in FIG. 22 represent the hole angle obtained when an edge ring UR having a thickness 1 mm smaller than the unworn edge ring UR in the plasma processing apparatus 1 having the configuration shown in FIG. 3 is used. The triangular plots in FIG. 22 represent the hole angle obtained when an edge ring UR having a thickness 1 mm smaller than the unworn edge ring UR and a distance D of 6 mm is used in the plasma processing apparatus 1 having the configuration shown in FIG. 21. As shown in Fig. 22, it was confirmed that the hole angle can be adjusted according to the drive amount when the configuration shown in Fig. 21 is used, as in the case of using the configuration shown in Fig. 3. Furthermore, with the configuration shown in Fig. 21, the increase in the hole angle with respect to the increase in the drive amount was smaller than when using the configuration shown in Fig. 3. This confirmed that the configuration shown in Fig. 21 can provide high control resolution for the hole angle.

[0107] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0108] For example, any one of the above-mentioned containers FUa to FUd may be used as the stocker module RSM.

[0109] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E19] below.

[0110] a substrate support disposed within the chamber; an edge ring having electrical conductivity and disposed to surround a substrate on the substrate support; a lift mechanism configured to move the edge ring up and down; a plasma generation unit including a radio frequency power supply and configured to generate plasma within the chamber; and a bias power supply configured to generate an electrical bias to attract ions from the plasma to the substrate on the substrate support, wherein the substrate support includes: a base electrically coupled to the bias power supply and / or the radio frequency power supply; and an electrostatic chuck on the base; wherein the lift mechanism includes: a conductive ring electrically coupled to the edge ring while supporting the edge ring placed thereon; a rod extending vertically below the conductive ring; an actuator configured to move the edge ring up and down via the rod and the conductive ring; and a connecting member providing an electrical connection between the conductive ring and the base, the connecting member being configured to maintain the electrical connection in accordance with the movement of the conductive ring.

[0111] [E2] The plasma processing apparatus according to E1, wherein the connection member is deformable in response to movement of the conductive ring.

[0112] [E3] The plasma processing apparatus according to E2, wherein the connection member includes a bellows, a contact band, or a cylindrical member having a plurality of slits formed in its side wall surface so as to be elastically deformable in the longitudinal direction.

[0113] [E4] The plasma processing apparatus according to any one of E1 to E3, wherein the rod has insulating properties.

[0114] [E5] The plasma processing apparatus according to any one of E1 to E4, wherein an exposed area on the surface of the conductive ring is covered with a film that is resistant to the plasma.

[0115] [E6] The plasma processing apparatus described in any one of E1 to E5, wherein the edge ring is an upper edge ring, and the plasma processing apparatus further includes a lower edge ring on which the upper edge ring is disposed, and the electrostatic chuck includes: a first portion having a substrate support surface; and a second portion having a ring support surface extending at a position lower than the substrate support surface and extending outside the first portion, and the first portion includes a sidewall surface extending between the substrate support surface and the ring support surface, and the lower edge ring is disposed along the sidewall surface and on the ring support surface.

[0116] [E7] The plasma processing apparatus described in E6, wherein the lower edge ring includes: an inner peripheral portion arranged along the side wall surface; an outer peripheral portion extending radially outward from the inner peripheral portion and on which the upper edge ring is arranged; and an intermediate portion extending between the inner peripheral portion and the outer peripheral portion and interposed between an edge of a substrate on the substrate support surface and the inner peripheral surface of the upper edge ring.

[0117] [E8] The plasma processing apparatus according to E6 or E7, wherein the lower edge ring is conductive.

[0118] [E9] The plasma processing apparatus according to E6 or E7, wherein the lower edge ring has insulating properties.

[0119] [E10] The plasma processing apparatus according to any one of E6 to E9, further comprising: another lift mechanism configured to lift the upper edge ring or a ring set including the upper edge ring and the lower edge ring from the electrostatic chuck.

[0120] [E11] The plasma processing apparatus according to any one of E1 to E10, further comprising a switch configured to be able to switch between a first state in which the edge ring and the base are electrically coupled to each other and a second state in which the edge ring and the base are electrically isolated from each other.

[0121] [E12] The plasma processing apparatus according to E11, wherein the lift mechanism is the switch and is configured to create the second state by lowering the conductive ring with the actuator so as to separate the conductive ring from the edge ring.

[0122] [E13] The plasma processing apparatus according to E11, wherein the switch includes a switching element connected between the connection member and the conductive ring or between the connection member and the base.

[0123] [E14] The plasma processing apparatus of E11, wherein the switch includes another lift mechanism configured to create the second state by lifting the edge ring from the conductive ring.

[0124] [E15] The plasma processing apparatus according to E11, further comprising a control unit configured to control the switch to form the first state or the second state according to a loaded recipe.

[0125] [E16] The plasma processing apparatus according to E11, further comprising: a measuring device configured to measure an etching depth of the substrate on the substrate support; and a control unit configured to control the switch to switch from the second state to the first state when the etching depth measured by the measuring device reaches a threshold value.

[0126] [E17] A substrate processing system comprising: a plasma processing apparatus according to E10; a transfer module including a transfer chamber and a transfer robot connected to the plasma processing apparatus; a ring stocker configured to accommodate the upper edge ring or the upper edge ring and the ring set therein; and a control unit, wherein the control unit is configured to control the separate lift mechanism and the transfer robot to exchange the upper edge ring or the ring set in the chamber of the plasma processing apparatus with the upper edge ring or the ring set in the chamber via the transfer chamber.

[0127] [E18] A substrate processing system comprising: the plasma processing apparatus according to E11; an imaging device configured to acquire an image of a substrate etched by the plasma processing apparatus; and a control unit, wherein the control unit is configured to control the switch to form the first state when etching the substrate later in the plasma processing apparatus if the circularity of a hole in an edge region of a previously processed substrate is equal to or less than a threshold value from the image of the substrate.

[0128] [E19] A substrate processing system comprising: the plasma processing apparatus according to E11; a measuring device configured to measure a thickness of a deposit on the edge ring; and a control unit, wherein the control unit is configured to control the switch to form the second state when the thickness of the deposit is smaller than a threshold value during a cleaning process in the chamber, and to form the first state when the thickness of the deposit is equal to or greater than the threshold value.

[0129] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0130] 1...plasma processing apparatus, 10...chamber, 11...substrate support part, 12...plasma generation part, 1110...base, 1111...electrostatic chuck, 50...lift mechanism, 51...conductive ring, 52...rod, 53...actuator, 54...connecting member, PS...substrate processing system, TM...transfer module, RSM...storage module, MC...control part.

Claims

1. A plasma processing apparatus comprising: a chamber; a substrate support disposed within the chamber; an edge ring, the edge ring being conductive and disposed to surround a substrate on the substrate support; a lift mechanism configured to move the edge ring up and down; a plasma generating unit configured to generate plasma within the chamber, the edge ring being electrically connected to the bias power supply and / or the radio frequency power supply; and a bias power supply configured to generate an electrical bias to attract ions from the plasma to the substrate on the substrate support, wherein the substrate support comprises: a base electrically connected to the bias power supply and / or the radio frequency power supply; and an electrostatic chuck on the base, wherein the lift mechanism comprises: a conductive ring electrically connected to the edge ring while supporting the edge ring placed thereon; a rod extending vertically below the conductive ring; 2. The plasma processing apparatus according to claim 1, wherein said connecting member is deformable in response to movement of said conductive ring.

3. The plasma processing apparatus according to claim 2, wherein the connection member includes a bellows, a contact band, or a cylindrical member having a plurality of slits formed in its side wall surface so as to be elastically deformable in the longitudinal direction.

4. The plasma processing apparatus according to any one of claims 1 to 3, wherein the rod has insulating properties.

5. The plasma processing apparatus according to claim 1, wherein an exposed area on the surface of said conductive ring is covered with a film resistant to said plasma.

6. A plasma processing apparatus as described in any one of claims 1 to 3, wherein the edge ring is an upper edge ring, the plasma processing apparatus further comprises a lower edge ring on which the upper edge ring is disposed, the electrostatic chuck comprises: a first portion having a substrate support surface; and a second portion having a ring support surface extending at a position lower than the substrate support surface and extending outside the first portion, the first portion including a sidewall surface extending between the substrate support surface and the ring support surface, and the lower edge ring is disposed along the sidewall surface and on the ring support surface.

7. The plasma processing apparatus of claim 6, wherein the lower edge ring includes: an inner circumferential portion arranged along the side wall surface; an outer circumferential portion extending radially outward from the inner circumferential portion and on which the upper edge ring is arranged; and an intermediate portion extending between the inner circumferential portion and the outer circumferential portion and interposed between an edge of a substrate on the substrate support surface and the inner circumferential surface of the upper edge ring.

8. The plasma processing apparatus of claim 6, wherein the lower edge ring is electrically conductive.

9. The plasma processing apparatus of claim 6, wherein the lower edge ring is insulating.

10. The plasma processing apparatus of claim 6, further comprising a separate lift mechanism configured to lift the upper edge ring or a ring set including the upper edge ring and the lower edge ring from the electrostatic chuck.

11. A plasma processing apparatus according to any one of claims 1 to 3, further comprising a switch configured to be able to switch between a first state in which the edge ring and the base are electrically coupled to each other and a second state in which the edge ring and the base are electrically isolated from each other.

12. The plasma processing apparatus of claim 11, wherein the lift mechanism is the switch and is configured to create the second state by lowering the conductive ring with the actuator so as to separate the conductive ring from the edge ring.

13. The plasma processing apparatus according to claim 11, wherein the switch includes a switching element connected between the connection member and the conductive ring or between the connection member and the base.

14. The plasma processing apparatus of claim 11, wherein the switch includes another lift mechanism configured to create the second state by lifting the edge ring off the conductive ring.

15. The plasma processing apparatus according to claim 11, further comprising a control unit configured to control the switch to form the first state or the second state according to a loaded recipe.

16. The plasma processing apparatus of claim 11, further comprising: a measuring device configured to measure an etching depth of the substrate on the substrate support; and a control unit configured to control the switch to switch from the second state to the first state when the etching depth measured by the measuring device reaches a threshold value.

17. A substrate processing system comprising: a plasma processing apparatus as described in claim 10; a transfer module including a transfer chamber and a transfer robot connected to the plasma processing apparatus; a ring stocker configured to accommodate the upper edge ring or the upper edge ring and the ring set therein; and a control unit, wherein the control unit is configured to control the separate lift mechanism and the transfer robot to exchange the upper edge ring or the ring set in the chamber of the plasma processing apparatus with the upper edge ring or the ring set in the chamber via the transfer chamber.

18. A substrate processing system comprising: a plasma processing apparatus as described in claim 11; an imaging device configured to acquire an image of a substrate etched by the plasma processing apparatus; and a control unit, wherein the control unit is configured to control the switch to form the first state when etching the substrate later in the plasma processing apparatus when the circularity of a hole in an edge region of a previously processed substrate is equal to or less than a threshold value from the image of the substrate.

19. A substrate processing system comprising: a plasma processing apparatus as described in claim 11; a measuring device configured to measure a thickness of a deposit on the edge ring; and a control unit, wherein the control unit is configured to control the switch to form the second state when the thickness of the deposit is smaller than a threshold value during a cleaning process in the chamber, and to form the first state when the thickness of the deposit is equal to or greater than the threshold value.

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