Mounting table and plasma treatment apparatus

Abstract

This mounting table comprises: an electrostatic chuck on which a substrate is placed; an insulating member provided so as to circle around the outside of the electrostatic chuck; and one or more rings disposed on an upper portion of the insulating member and extending along the circumferential direction of the insulating member. The mounting table also includes a closing member that extends along the circumferential direction of the insulating member and that closes a boundary between the insulating member and the ring. As a result of the boundary being closed by the closing member, the mounting table can suppress deposits adhering to the mounting table.

Description

Mounting table and plasma processing apparatus

[0001] The present disclosure relates to a mounting table and a plasma processing apparatus.

[0002] Patent Document 1 discloses a plasma processing apparatus (processing apparatus) that performs plasma processing on a substrate placed on a stage. This plasma processing apparatus 1 has a ring, such as a cover ring or an edge ring, placed around the periphery of the substrate placed on the electrostatic chuck of the stage. The plasma processing apparatus also includes an annular insulating member (insulator) on the outside of the layered structure of the base and the electrostatic chuck.

[0003] JP 2023-113850 A

[0004] The present disclosure provides a technique that can prevent deposits from adhering to a mounting table on which a substrate is placed.

[0005] According to one aspect of the present disclosure, there is provided a mounting table comprising: an electrostatic chuck for mounting a substrate; an insulating member arranged to surround the outside of the electrostatic chuck; one or more rings arranged on top of the insulating member and extending circumferentially around the insulating member; and a blocking member extending circumferentially around the insulating member and blocking a boundary between the insulating member and the ring.

[0006] According to one aspect, it is possible to prevent deposits from adhering to a stage on which a substrate is placed.

[0007] 3A is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus; FIG. 3B is a diagram showing a state of the mounting table according to the embodiment during plasma processing; FIG. 3C is a diagram showing a state of the mounting table according to the reference example during plasma processing; and FIG. 3D is a flowchart showing a method of assembling a ring assembly. FIG. 5A is a cross-sectional view showing an enlarged view of the outer periphery of the mounting table according to a first modified example; and FIG. 5B is a cross-sectional view showing an enlarged view of the outer periphery of the mounting table according to a second modified example.

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

[0009] First, an example of the configuration of a plasma processing system will be described. Fig. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus.

[0010] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a mounting table 11 and a gas inlet unit. The gas inlet unit is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet unit includes a showerhead 13. The mounting table 11 is disposed inside the plasma processing chamber 10. The showerhead 13 is disposed above the mounting table 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 mounting table 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas into the plasma processing space 10s and at least one gas exhaust port 10e for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the mounting table 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0011] The mounting table 11 includes a main body 50 and a ring assembly 60. The main body 50 has a central region 50a for supporting a substrate W and an annular region 50b for supporting the ring assembly 60. A wafer is an example of a substrate W. The annular region 50b of the main body 50 surrounds the central region 50a of the main body 50 in a plan view. The substrate W is disposed on the central region 50a of the main body 50, and the ring assembly 60 is disposed on the annular region 50b of the main body 50 so as to surround the substrate W on the central region 50a of the main body 50. Therefore, the central region 50a is also called a substrate support surface for supporting the substrate W, and the annular region 50b is also called a ring support surface for supporting the ring assembly 60.

[0012] In one embodiment, the main body 50 includes a base 51 and an electrostatic chuck 52. The base 51 includes a conductive member. The conductive member of the base 51 may function as a lower electrode. The electrostatic chuck 52 is disposed on the base 51. The electrostatic chuck 52 includes a ceramic member 52a and an electrostatic electrode 52b disposed within the ceramic member 52a. The ceramic member 52a has a central region 50a. In one embodiment, the ceramic member 52a also has an annular region 50b. Note that the annular region 50b may also be provided on another member surrounding the electrostatic chuck 52, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 60 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 52 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 52a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 51 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 52b may function as the lower electrode. Therefore, the mounting table 11 includes at least one lower electrode.

[0013] Ring assembly 60 includes one or more rings. In one embodiment, the one or more rings include, for example, one focus ring 61 and one or more cover rings 62 (see FIG. 2 ). Focus ring 61 is made of a conductive material, and cover ring 62 is made of an insulating or conductive material.

[0014] The mounting table 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 52, the ring assembly 60, and the substrate W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 51a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 51a. In one embodiment, the flow path 51a is formed in the base 51, and one or more heaters are disposed in the ceramic member 52a of the electrostatic chuck 52. The mounting table 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas to a gap between the back surface of the substrate W and the central region 50a.

[0015] The showerhead 13 is configured to introduce at least one process 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 process 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 inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0016] 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.

[0017] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0018] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0019] The second RF generator 31b is coupled to at least one lower 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 lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0020] 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 the at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the 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.

[0021] 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 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.

[0022] 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.

[0023] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described in this disclosure. The controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include a processor 2a1, a storage unit 2a2, and a communication interface 2a3. The controller 2 may be implemented, for example, by a computer 2a. The processor 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processor 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processor 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0024] Next, the configuration of the mounting table 11 installed in the plasma processing apparatus 1 will be specifically described with reference to Fig. 2. Fig. 2 is an enlarged cross-sectional view showing the outer periphery of the mounting table 11.

[0025] The mounting table 11 includes a main body 50 including a base 51 and an electrostatic chuck 52 stacked together, and a ring assembly 60 mounted on the upper surface of the main body 50 together with the substrate W. The ring assembly 60 according to the embodiment includes a focus ring 61 and multiple cover rings 62. For example, the cover ring 62 can be separated into two members, a first cover ring 621 and a second cover ring 622. In other words, the ring assembly 60 is mounted on the upper surface of the main body 50 in a state where the focus ring 61, the first cover ring 621, and the second cover ring 622 are assembled. The number of rings in the ring assembly 60 is not particularly limited. For example, the focus ring 61 may be composed of multiple rings. Furthermore, for example, the cover ring 62 may be composed of three or more rings, or may be a single ring (see also FIG. 5B , described below).

[0026] The main body 50 of the mounting table 11 includes an insulating member 53 on the outer periphery of the laminated structure of the base 51 and the electrostatic chuck 52. The insulating member 53 is made of a hard, heat-resistant insulating material such as ceramics or quartz. The insulating member 53 is an insulator ring that is formed in a circular shape in a plan view and surrounds the radially outer side of the base 51 and the electrostatic chuck 52 to define the outer shape of the main body 50. The insulating member 53 prevents radicals, ions, etc. that move from the plasma processing space 10s to the gas exhaust port 10e from reacting with the base 51, etc., to generate by-products (deposits).

[0027] The insulating member 53 has a protrusion 531 that protrudes vertically upward on the radially inner side of the upper end surface. The protrusion 531 is formed in a circular ring shape in a plan view and extends along the circumferential direction of the insulating member 53. When the ring assembly 60 is placed, the upper surface of the protrusion 531 faces the lower surface of a portion of the first cover ring 621.

[0028] Furthermore, main body 50 includes a conductive unit 55 that electrically connects base 51 and focus ring 61. Conductive unit 55 supplies a signal (power, such as a bias RF signal, a bias DC signal, or a source RF signal) supplied from power supply 30 to base 51 to focus ring 61. For example, focus ring 61 to which a bias voltage is applied forms a sheath electric field in plasma processing space 10s above it. For example, plasma processing apparatus 1 controls the sheath electric field above substrate W and the sheath electric field above focus ring 61 to be at the same height, thereby vertically attracting ions in the plasma and improving the in-plane uniformity of plasma processing.

[0029] The conductive portion 55 includes a first conductive ring 551, a connecting member 552, and a second conductive ring 553 to form a power supply path that bypasses the electrostatic chuck 52. The first conductive ring 551 and the second conductive ring 553 are formed of an electrically connectable and elastically deformable conductive material. The first conductive ring 551 and the second conductive ring 553 may be, for example, a spiral tube. Note that one or both of the first conductive ring 551 and the second conductive ring 553 may not be annular and circumferentially surround the base 51, but may be a plurality of arc-shaped members divided in the circumferential direction.

[0030] The first conductive ring 551 is disposed in a groove 511 formed in the outer peripheral surface of the base 51, and the portion protruding from the groove 511 contacts the inner peripheral surface of the connecting member 552. The groove 511 forms an annular shape around the outer peripheral surface of the base 51 near the upper side. The first conductive ring 551 is sandwiched between the groove 511 and the connecting member 552 in an elastically deformed state, thereby enabling a stable electrical connection between the base 51 and the connecting member 552 to be maintained.

[0031] The connecting member 552 is formed in a circular ring shape that surrounds the radially outer side of the base 51 and the electrostatic chuck 52 in a plan view. The connecting member 552 is installed so as to bridge a range extending vertically from the upper part of the base 51 to a height exceeding the height position of the annular region 50b of the electrostatic chuck 52. The connecting member 552 is formed of a conductive material that is harder than the first conductive ring 551 and the second conductive ring 553. Examples of materials for the connecting member 552 include metal materials such as aluminum, copper, iron, and alloys thereof.

[0032] The connecting member 552 has a circular recess 552c cut out from the inside on the vertically upper side, and this recess 552c accommodates the second conductive ring 553. The connecting member 552 may be assembled to have a slight clearance to absorb differences in thermal expansion coefficients with the base 51, the insulating member 53, etc. Alternatively, the connecting member 552 may be assembled in a form in which it contacts some or all of the base 51, the insulating member 53, etc.

[0033] Second conductive ring 553 is disposed so as to surround and contact the inner circumferential surface of recessed portion 552c of connecting member 552. Second conductive ring 553 is sandwiched in an elastically deformed state between connecting member 552 and focus ring 61, thereby stably maintaining the electrical connection between connecting member 552 and focus ring 61. Note that recessed portion 552c of connecting member 552 may have a restricting structure, such as a recessed groove, that restricts removal of second conductive ring 553.

[0034] Meanwhile, focus ring 61 of ring assembly 60 is disposed between the stepped surfaces of central region 50a and annular region 50b of electrostatic chuck 52 and the inside of second conductive ring 553. Focus ring 61 is made of a hard conductive material (including a semiconductor) and has a circular ring shape in a plan view. Examples of materials for focus ring 61 include silicon, silicon carbide, and other metals. A signal (power) from power supply 30 is supplied to focus ring 61 via base 51 and conductive portion 55. For example, a bias voltage (bias RF signal, bias DC signal) is applied to focus ring 61 during plasma processing, thereby forming a sheath electric field in plasma processing space 10s above focus ring 61.

[0035] The focus ring 61 may have a protrusion 611 (see dotted line in FIG. 2 ) at a side of the substrate W placed in the central region 50 a of the electrostatic chuck 52, the protrusion 611 being at approximately the same height as the upper surface of the substrate W. Alternatively, the focus ring 61 may contact the rear surface of the substrate W placed in the central region 50 a of the electrostatic chuck 52. This allows a bias voltage to be applied to the substrate W as well via the base 51, the conductive part 55, and the focus ring 61. Alternatively, the focus ring 61 may be placed such that the upper surface is spaced apart from (not in contact with) the rear surface of the substrate W.

[0036] The first cover ring 621, which is one of the cover rings 62, is formed in an annular shape extending circumferentially radially outward from the outer edge of the substrate W (in other words, above the insulating member 53). The first cover ring 621 is placed so as to cover the insulating member 53, the connecting member 552, the second conductive ring 553, and the outer peripheries of the focus ring 61. By covering the connecting member 552 and the second conductive ring 553, the first cover ring 621 prevents these components from being directly exposed to plasma in the plasma processing space 10s.

[0037] The first cover ring 621 is made of an insulating material such as aluminum oxide or quartz. Alternatively, the first cover ring 621 according to the embodiment may be made of a conductive material similar to that of the focus ring 61. This allows the plasma processing apparatus 1 to form a sheath electric field above the first cover ring 621.

[0038] For example, the height position of the first cover ring 621 may be set to the same height as the upper surface of the substrate W placed in the central region 50 a. In addition, a step portion 621 b is provided on the upper surface of the first cover ring 621 on the radially outer side, on which the second cover ring 622 can be caught.

[0039] The second cover ring 622 is a member having an annular shape in a plan view and is disposed radially outward of the first cover ring 621. The second cover ring 622 covers the blocking member 70 (described later) to accommodate the blocking member 70 without exposing it to the plasma processing space 10s. The second cover ring 622 has a flange 622f on its vertically upper side and radially inner side that can be assembled to the stepped portion 621b of the first cover ring 621. The upper surface of the second cover ring 622, including the flange 622f, is assembled so as to be substantially flush with the upper surface of the first cover ring 621.

[0040] The second covering ring 622 is preferably formed using the insulating material listed for the first covering ring 621. It is also preferable that the first covering ring 621 and the second covering ring 622 are made of the same material. This makes it possible to suppress the difference in thermal expansion between the components of the divided covering ring 62. When the covering ring 62 is in an assembled state, a space 63 in which the blocking member 70 can be placed is formed between the upper surface of the insulating member 53, the outer peripheral surface 621o of the first covering ring 621, and the inner peripheral surface of the second covering ring 622.

[0041] When the ring assembly 60 is mounted on the mounting table 11 configured as described above, a gap C may occur between the main body 50 and the ring assembly 60 mounted on top of the main body 50. This type of gap C occurs due to assembly errors of the main body 50 or the ring assembly 60 or dimensional errors of each component. For this reason, it is difficult to predict the position and size of the gap C. For example, examples of the gap C include a gap C1 between the insulating member 53 and the second cover ring 622, a gap C2 between the insulating member 53 (protrusion 531) and the first cover ring 621, a vertical gap C3 between the insulating member 53 and the connecting member 552, a horizontal gap C4 between the insulating member 53 and the connecting member 552, and a gap C5 between the connecting member 552 and the first cover ring 621.

[0042] If a gap C is formed between the main body 50 and the ring assembly 60, radicals R (or ions) may enter through the gap C during plasma processing. The behavior of radicals R that have entered the gap C will be described below with reference to FIGS. 3A and 3B. FIG. 3A is a diagram showing the state of the mounting table 11 according to the embodiment during plasma processing. FIG. 3B is a diagram showing the state of the mounting table 11' according to the reference example during plasma processing.

[0043] As shown in FIG. 3B , the mounting table 11′ according to the reference example includes a ring assembly 60 that includes a focus ring 61 and a cover ring 62 that is not divided into two pieces. The mounting table 11′ does not include a blocking member 70 between the main body 50 and the ring assembly 60. In this case, radicals R may enter each gap C and reach the base 51, the connecting member 552, the focus ring 61, and the like. Specifically, the radicals R enter through the gap C1 between the insulating member 53 and the cover ring 62 and reach the connecting member 552. Some of the radicals R react with the connecting member 552, which is made of a conductive material, to form by-products (deposits) and adhere to the connecting member 552. Other radicals R may travel through the vertical gap C3 between the insulating member 53 and the connecting member 552 and then through the horizontal gap C4 between the insulating member 53 and the connecting member 552, thereby reaching the base 51. The other part of the radicals R reacts with the base 51 made of a conductive material, forming deposits and adhering to the base 51. Alternatively, the other part of the radicals R may reach the focus ring 61 by moving through the gap C5 between the connecting member 552 and the cover ring 62.

[0044] That is, in the plasma processing apparatus 1 having the mounting table 11′, by repeating plasma processing multiple times, deposits accumulate on all or part of the base 51, the connecting member 552, and the focus ring 61. For example, when this type of deposit is scattered in the plasma processing space 10s, it adheres to the substrate W and becomes particles.

[0045] 2 , the mounting table 11 according to the embodiment includes a blocking member 70 that blocks the gap C. The blocking member 70 integrally covers the outer peripheral surface 531o of the protrusion 531 of the insulating member 53 and the outer peripheral surface 621o of the first cover ring 621, thereby blocking the boundary between the protrusion 531 and the second cover ring 622.

[0046] The blocking member 70 has an annular shape in a plan view and is formed in a band shape having a certain length spanning the outer peripheral surface 531o of the convex portion 531 and the outer peripheral surface 621o of the first cover ring 621. In other words, the blocking member 70 wraps around the entire outer peripheral surfaces 531o, 621o in the circumferential direction while covering the gap C2 between the upper surface of the convex portion 531 of the insulating member 53 and the lower surface of the first cover ring 621. This allows the blocking member 70 to reliably block the entire gap C2.

[0047] The blocking member 70 may be made of, for example, a resin material (rubber material) that has high heat resistance and elasticity. When the blocking member 70 is made of a rubber material, the blocking member 70 can be easily attached to the outer peripheral surfaces 531o, 621o by placing the first covering ring 621 on the protrusion 531, expanding the blocking member 70 to face the outer peripheral surfaces 531o, 621o, and then contracting the blocking member 70. The material of the blocking member 70 is not particularly limited as long as it can block the boundary between the protrusion 531 and the second covering ring 622. For example, a non-elastic material may be used. The blocking member 70 may be made of an insulating material (organic or inorganic), a conductive material, or a semiconductor material. For example, the blocking member 70 may be made of glass fiber plastic, carbon fiber plastic, or the like.

[0048] The mounting table 11 preferably also includes a restricting portion 71 that restricts the detachment of the blocking member 70. For example, the restricting portion 71 may be a tapered surface 71t in which the outer peripheral surface 531o of the protrusion 531 and the outer peripheral surface 621o of the first cover ring 621 are flush with each other and continuously connected to each other, and the diameter of the tapered surface 71t decreases toward the mounting direction of the blocking member 70 (vertically downward). The inclination angle of the tapered surface 71t relative to the vertical direction is not particularly limited, but may be set to, for example, a range of approximately 1° to 5°. In this embodiment, the inclination angle of the tapered surface 71t is 3°. By including this tapered surface 71t, the mounting table 11 improves the contact between the insulating member 53 and the first cover ring 621 and the blocking member 70. In other words, the mounting table 11 can more reliably prevent the blocking member 70, which is mounted on the tapered surface 71t, from detaching upward in the vertical direction.

[0049] The second cover ring 622 placed radially outward of the first cover ring 621 covers the upper part of the insulating member 53 and also functions as a member for protecting the blocking member 70. This prevents the blocking member 70 from being directly exposed to the plasma in the plasma processing space 10s.

[0050] 3A , even if radicals R enter through the gap C1 between the insulating member 53 and the second cover ring 622, the mounting table 11 according to the above embodiment can prevent further intrusion by the blocking member 70. In other words, the blocking member 70 blocks the intrusion of radicals R into the gap C2 between the convex portion 531 of the insulating member 53 and the first cover ring 621. This prevents the radicals R from reaching the base 51 or the connecting member 552. By preventing the adhesion of deposits, the mounting table 11 can stably perform plasma processing on the substrate W.

[0051] 4 is a flowchart showing a method for assembling the ring assembly 60. When placing the ring assembly 60 on the main body 50, the worker assembles the ring assembly 60 onto the upper part of the main body 50, for example, by the assembly method shown in FIG.

[0052] In this assembly method, an operator first places focus ring 61 in annular region 50b of electrostatic chuck 52 (step S101). At this time, the operator inserts focus ring 61 into the recess in annular region 50b so that the outer circumferential surface of focus ring 61 contacts second conductive ring 553 of conductive portion 55, which has been installed in advance. Alternatively, mounting table 11 may be configured such that focus ring 61 is inserted first, and then second conductive ring 553 is installed between connecting member 552 and focus ring 61.

[0053] After placing focus ring 61, the worker places first cover ring 621 so as to overlap the outer periphery of focus ring 61 (step S102). For example, the worker places first cover ring 621 on focus ring 61 while accommodating connecting member 552 inside first cover ring 621. As a result, the outer periphery of first cover ring 621 overlaps the upper surface of convex portion 531 of insulating member 53, and a tapered surface 71t is formed in which outer periphery surface 621o of first cover ring 621 and outer periphery surface 531o of convex portion 531 are flush with each other.

[0054] In this state, the worker attaches the blocking member 70 to the tapered surface 71t and closes the boundary between the insulating member 53 and the first cover ring 621 with the blocking member 70 (step S103). As described above, the worker expands the blocking member 70 to face the tapered surface 71t, and then contracts the blocking member 70, thereby easily attaching the blocking member 70 to the tapered surface 71t. In addition, the blocking member 70 attached to the tapered surface 71t is prevented from coming off vertically upward (in the direction opposite to the attachment direction).

[0055] Finally, the worker places the second covering ring 622 radially outward of the first covering ring 621 (step S104). The worker places the second covering ring 622 so that the flange 622f fits into the stepped portion 621b of the first covering ring 621. This places the blocking member 70 in the space 63 surrounded by the insulating member 53, the first covering ring 621, and the second covering ring 622.

[0056] By using the above assembly method, the worker can smoothly form a configuration in which the gap C2 between the connecting member 552 and the first cover ring 621 is covered by the blocking member 70 and the blocking member 70 is protected by the second cover ring 622. The mounting table 11 to which the ring assembly 60 is assembled in this manner can prevent the intrusion of radicals R by the blocking member 70 and suppress the adhesion of deposits.

[0057] Furthermore, the ring assembly 60 of the mounting table 11 includes the first cover ring 621 and the second cover ring 622, which allows for greater layout flexibility, such as by attaching the blocking member 70 to the first cover ring 621 side. In particular, the blocking member 70 integrally covers the outer peripheral surface 531o of the insulating member 53 (the protrusion 531) and the outer peripheral surface 621o of the first cover ring 621, thereby more reliably blocking the gap C that occurs at the boundary. Furthermore, the second cover ring 622 prevents the blocking member 70 from being exposed to the outside, thereby suppressing deterioration of the blocking member 70.

[0058] The ring assembly 60 has the focus ring 61 inside the first cover ring 621, which allows for the formation of a good sheath electric field radially outward from the substrate W. Furthermore, if power is supplied to the focus ring 61 via the conductive part 55, the thickness of the sheath electric field can be easily controlled. Furthermore, the mounting table 11 includes the restricting part 71 (tapered surface 72t), which prevents the attached blocking member 70 from coming off. Furthermore, since the blocking member 70 is made of a rubber material, the blocking member 70 can be easily attached in response to an operator's operation to expand and contract the blocking member 70 when placing the cover ring 62.

[0059] The mounting table 11 and the plasma processing apparatus 1 according to the embodiment are not limited to the above embodiment and may take various modifications. For example, the mounting table 11 may be installed in a substrate processing apparatus other than the plasma processing apparatus 1. Even in this case, the provision of the blocking member 70 can prevent deposits and the like from adhering to components within the mounting table 11. The mounting table 11 may be configured without the conductive member 55 for supplying power to the focus ring 61. Furthermore, the mounting table 11 may be configured without the focus ring 61 as a ring. Conversely, the mounting table 11 may not include the cover ring 62, and the blocking member 70 may be disposed at the boundary between the insulating member 53 and the focus ring 61. The restricting portion 71 is not limited to the tapered surface 72t, and may be a structure, such as a protrusion, on which the blocking member 70 can be hooked.

[0060] 5A shows a mounting table 11A according to a first modified example, which differs from the mounting table 11 according to the embodiment in that an O-ring 75, which is an elastically deformable blocking member having a circular cross section, is used instead of the strip-shaped blocking member 70. Note that, in the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0061] For example, the O-ring 75 is housed in a recess 622a formed on the inner circumferential surface of the second cover ring 622, and airtightly closes the gap (space 63) between the opposing protrusion 531 of the insulating member 53. Even in this case, the O-ring 75 can prevent the intrusion of radicals R. The recess 622a also functions as a restricting portion 71 that restricts the movement of the O-ring 75. In short, the blocking member 70 is not limited to a strip shape, and various shapes may be employed as long as it can close the gap between the insulating member 53 and the ring assembly 60.

[0062] A mounting table 11B according to a second modification shown in FIG. 5B differs from the mounting tables 11 and 11A in that it uses a single cover ring 62 that is not divided into multiple pieces and that a strip-shaped blocking member 76 is installed at the boundary between the cover ring 62 and the insulating member 53. In the example shown in FIG. 5B, the blocking member 76 is exposed to the space connecting the plasma processing space 10s and the gas exhaust port 10e. By using a material with high plasma resistance for the blocking member 76, it is possible to continuously block the gap C while suppressing deterioration due to the plasma. For example, a flexible ceramic sheet or the like can be used as the material for the blocking member 76.

[0063] The above-disclosed embodiments include, for example, the following aspects.

[0064] [Supplementary Note 1] A mounting table comprising: an electrostatic chuck for mounting a substrate thereon; an insulating member provided so as to surround the outside of the electrostatic chuck; one or more rings disposed on top of the insulating member and extending along the circumferential direction of the insulating member; and a blocking member extending along the circumferential direction of the insulating member and blocking a boundary between the insulating member and the ring.

[0065] [Supplementary Note 2] The mounting table described in Supplementary Note 1, wherein the ring includes a first cover ring arranged radially outward from the substrate and a second cover ring arranged radially outward from the first cover ring, and the blocking member blocks at least one of the boundary between the insulating member and the first cover ring or the boundary between the insulating member and the first cover ring.

[0066] [Supplementary Note 3] The mounting table according to Supplementary Note 2, wherein the second cover ring covers the closing member to prevent the closing member from being exposed to an outside of the mounting table.

[0067] [Supplementary Note 4] The mounting table according to Supplementary Note 2 or 3, wherein the blocking member integrally covers an outer peripheral surface of the insulating member and an outer peripheral surface of the first cover ring.

[0068] [Supplementary Note 5] The mounting table according to any one of Supplementary Notes 2 to 4, wherein the ring includes a focus ring made of a conductive material and disposed inside the first cover ring.

[0069] [Supplementary Note 6] The mounting table according to Supplementary Note 5, further comprising: a base disposed below the electrostatic chuck and connected to a power supply; and a conductive part providing electrical continuity between the base and the focus ring, wherein the first cover ring covers a portion of the focus ring and the conductive part.

[0070] [Supplementary Note 7] The mounting table according to any one of Supplementary Notes 1 to 6, further comprising a restricting portion that restricts the closure member from being removed.

[0071] [Supplementary Note 8] The mounting table according to Supplementary Note 7, wherein the restricting portion is a tapered surface that is continuous with a surface of the insulating member on which the blocking member is provided and a surface of the ring, and that decreases in diameter in the mounting direction of the blocking member.

[0072] [Supplementary Note 9] The mounting table according to any one of Supplementary Notes 1 to 8, wherein the blocking member is made of a rubber material having elasticity.

[0073] [Supplementary Note 10] A plasma processing apparatus comprising: the mounting table according to any one of Supplementary Notes 1 to 9; and a plasma processing chamber having the mounting table therein and capable of performing plasma processing on the substrate mounted on the mounting table.

[0074] The mounting tables 11, 11A, 11B and the plasma processing apparatus 1 according to the embodiments disclosed herein are illustrative in all respects and are not limiting. The embodiments can be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above embodiments can be configured in other ways and can be combined together without any inconsistency.

[0075] The plasma processing apparatus 1 of the present disclosure can be applied to any type of apparatus, including atomic layer deposition (ALD) apparatus, capacitively coupled plasma (CCP), inductively coupled plasma (ICP), radial line slot antenna (RLSA), electron cyclotron resonance plasma (ECR), and helicon wave plasma (HWP).

[0076] This application claims priority from Japanese Patent Application No. 2024-085636, filed on May 27, 2024, with the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0077] 11, 11A, 11B Mounting table 52 Electrostatic chuck 53 Insulating member 60 Ring assembly 70 Closing member W Substrate

Claims

1. A mounting table comprising: an electrostatic chuck for placing a substrate thereon; an insulating member arranged to surround the outside of the electrostatic chuck; one or more rings arranged on top of the insulating member and extending circumferentially around the insulating member; and a blocking member extending circumferentially around the insulating member and blocking the boundary between the insulating member and the ring.

2. The mounting table according to claim 1, wherein the ring includes a first cover ring positioned radially outward from the substrate and a second cover ring positioned radially outward from the first cover ring, and the blocking member blocks at least one of the boundary between the insulating member and the first cover ring or the boundary between the insulating member and the first cover ring.

3. The mounting table according to claim 2, wherein the second cover ring covers the closing member to prevent the closing member from being exposed to the outside of the mounting table.

4. The mounting table according to claim 2, wherein the blocking member integrally covers the outer peripheral surface of the insulating member and the outer peripheral surface of the first cover ring.

5. The mounting table according to claim 2, wherein the ring has a focus ring made of a conductive material inside the first cover ring.

6. The mounting table according to claim 5, further comprising: a base disposed below the electrostatic chuck and connected to a power source; and a conductive portion providing electrical continuity between the base and the focus ring, wherein the first cover ring covers a portion of the focus ring and the conductive portion.

7. The mounting table according to claim 1, further comprising a restricting portion that restricts the closure member from being removed.

8. The mounting table according to claim 7, wherein the restricting portion is a tapered surface that connects the surface of the insulating member on which the blocking member is provided and the surface of the ring, and that decreases in diameter in the direction in which the blocking member is attached.

9. The mounting table according to claim 1, wherein the blocking member is made of a resilient rubber material.

10. A plasma processing apparatus comprising: a mounting table according to any one of claims 1 to 9; and a plasma processing chamber having the mounting table therein and capable of performing plasma processing on the substrate placed on the mounting table.

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