Plasma processing apparatus and plasma processing method

Abstract

Provided is plasma treatment device, said plasma treatment device comprising: a plasma treatment chamber; a substrate support part that is disposed inside the plasma treatment chamber; an annular baffle plate that is disposed so as to surround the substrate support part and that has a plurality of openings; a first annular plate that, below the annular baffle plate, is disposed such that an inner end thereof is fixed to a side wall of the substrate support part; a movable structure that is disposed below the first annular plate, and that has a cylindrical wall body which is disposed in the vertical direction along the side wall of the plasma treatment chamber, and which forms a gap between the cylindrical wall body and the side wall of the plasma treatment chamber, and a second annular plate which is disposed on an inner wall upper end of the cylindrical wall body, and which overlaps a part of the first annular plate in the vertical direction to form an annular overlap portion; and an actuator that moves the movable structure in the vertical direction.

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a substrate processing apparatus including a processing chamber for performing plasma processing on a substrate, an exhaust chamber communicating with the processing chamber, an exhaust plate having a plurality of first ventilation holes and separating the processing chamber from the exhaust chamber, and an exhaust adjustment plate disposed in the exhaust chamber. According to the substrate processing apparatus described in Patent Document 1, the exhaust adjustment plate has a plurality of second ventilation holes and is configured to be able to come into contact with the exhaust plate in parallel with each other and to be able to be separated from the exhaust plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-15451 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure provides a plasma processing apparatus capable of controlling the internal pressure of a processing chamber in a short time. [Means for solving the problem]

[0005] One aspect of the present disclosure is a plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate disposed to surround the substrate support and having a plurality of openings; a first annular plate disposed below the annular baffle plate with its inner end fixed to a side wall of the substrate support; a movable structure disposed below the first annular plate, the movable structure having a cylindrical wall disposed vertically along the side wall of the plasma processing chamber and forming a gap between itself and the side wall of the plasma processing chamber; and a second annular plate disposed at the upper end of the inner wall of the cylindrical wall and vertically overlapping a portion of the first annular plate to form an annular overlapping portion; and an actuator that moves the movable structure vertically. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide a plasma processing apparatus capable of controlling the internal pressure of a processing chamber in a short time. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating a configuration of a plasma processing system. [Figure 2] 1 is a vertical cross-sectional view schematically showing an example of the configuration of a plasma processing apparatus. [Figure 3] FIG. 2 is an enlarged view of a main part of an exhaust system; [Figure 4] FIG. 4 is a perspective cross-sectional view showing an outline of a configuration example of a second pressure adjustment mechanism. [Figure 5] FIG. 10 is a plan view showing an example of the arrangement of a second pressure adjustment mechanism. [Figure 6] 10 is an explanatory diagram showing an example of the relationship between the separation in the second pressure adjustment mechanism and the internal pressure of the plasma processing chamber. FIG. [Figure 7] FIG. 10 is an enlarged view of a main part showing a modified example of the second pressure adjustment mechanism. [Figure 8] FIG. 10 is a perspective cross-sectional view showing a modified example of the second pressure adjustment mechanism. [Figure 9]FIG. 10 is an enlarged view of a main part showing a modified example of the second pressure adjustment mechanism. [Figure 10] FIG. 10 is an enlarged view of a main part showing a modified example of the second pressure adjustment mechanism. [Figure 11] FIG. 10 is an explanatory diagram showing the results of an example of the technology disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, a processing gas is supplied to a semiconductor substrate (hereinafter simply referred to as "substrate"), and the substrate is subjected to various plasma processes such as etching, film formation, and diffusion. These plasma processes are performed in a plasma processing apparatus having a processing chamber whose interior can be controlled to a reduced pressure atmosphere. In such a plasma processing apparatus, it is important to precisely control the internal pressure of the processing chamber in order to properly perform plasma processing on the substrate.

[0009] The above-mentioned Patent Document 1 discloses a substrate processing apparatus (plasma processing apparatus) that includes an exhaust plate that separates a processing chamber (processing chamber) from an exhaust chamber, and an exhaust adjustment plate that is configured to be able to come into contact with the exhaust plate and be separable from the exhaust plate in order to precisely control the internal pressure of the processing chamber. The exhaust plate and the exhaust adjustment plate each have a plurality of ventilation holes that penetrate through them in the thickness direction. The substrate processing apparatus described in Patent Document 1 is configured to enable precise pressure adjustment at relatively low pressures and relatively high pressures by adjusting the position of the exhaust adjustment plate relative to the exhaust plate.

[0010] In recent semiconductor device manufacturing processes, the demand for finer patterns formed on substrate surfaces has led to a demand for adjusting the internal pressure of a processing chamber in a short period of time. However, the processing chamber in which plasma processing is performed requires, for example, plasma gas and a large-capacity power source, which increases the capacity, making it difficult to adjust the pressure in a short period of time. In particular, when a plasma processing apparatus has an inductively coupled plasma (ICP) plasma generation unit, the processing chamber generally has a large capacity, making it an important challenge to adjust the internal pressure of the processing chamber in a short period of time.

[0011] The technology disclosed herein has been made in consideration of the above circumstances, and provides a plasma processing apparatus capable of controlling the internal pressure of a processing chamber in a short time. Hereinafter, a plasma processing system including a plasma processing apparatus according to this embodiment and a plasma processing method according to one embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] <Configuration of plasma processing system> First, a plasma processing system according to one embodiment will be described below. Fig. 1 is an explanatory diagram showing an outline of the configuration of the plasma processing system.

[0013] 1, the plasma processing system includes a plasma processing apparatus 1 and a controller 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12.

[0014] 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.

[0015] 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 generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0016] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN). The storage medium may be temporary or non-temporary.

[0017] <Configuration of plasma processing apparatus> The following describes an example of the configuration of an inductively coupled plasma processing apparatus (ICP) as an example of the plasma processing apparatus 1. FIG.

[0018] The inductively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, an exhaust system 40, and a pressure detector 50. 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 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas exhaust port for exhausting gas from the plasma processing space 10s. The volume of the plasma processing chamber 10 is, for example, 50 L or more.

[0019] 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, and the ring assembly 112 is disposed on the annular region 111b so as to surround the substrate W on the central region 111a. 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.

[0020] In one embodiment, the main body 111 includes a base (not shown) and an electrostatic chuck (not shown). The base includes a conductive member. The conductive member of the base can function as a bias electrode. The electrostatic chuck is disposed on the base. The electrostatic chuck includes an electrostatic electrode (not shown). The electrostatic chuck has a central region 111a. In one embodiment, the electrostatic chuck also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck, such as the 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 and the annular insulating member. At least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32 (described later) may be disposed within the electrostatic chuck. In this case, the at least one RF / DC electrode functions as a bias electrode. Note that the conductive member of the base and the at least one RF / DC electrode may function as multiple bias electrodes. Alternatively, the electrostatic electrode may function as the bias electrode. The substrate support 11 therefore comprises at least one bias electrode.

[0021] 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.

[0022] Although not shown, the substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. In one embodiment, the flow path is formed in the base, and one or more heaters are disposed in the electrostatic chuck. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The second RF generating unit 31b is coupled to at least one bias electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one bias electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0028] 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.

[0029] 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 either positive or negative polarity. The sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one cycle. 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.

[0030] 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.

[0031] The exhaust system 40 exhausts and reduces the pressure inside the plasma processing chamber 10 (plasma processing space 10s) through an exhaust path 10e formed around the substrate support 11 in a plan view and a gas exhaust port 10f formed on the bottom surface of the plasma processing chamber 10. The exhaust system 40 includes an annular baffle plate 41 that separates the plasma processing space 10s from the exhaust path 10e, a first pressure adjustment mechanism 42 that opens and closes the gas exhaust port 10f by operating a drive mechanism 42a, and an exhaust mechanism 43 that exhausts the inside of the plasma processing space 10s via the first pressure adjustment mechanism 42. In this embodiment, a second pressure adjustment mechanism 60 is disposed downstream of the annular baffle plate 41 in the exhaust path 10e to quickly adjust the internal pressure of the plasma processing space 10s. The second pressure adjustment mechanism 60 includes an upper plate 61, a movable structure 62, and an actuator 63. The detailed configuration of the exhaust system 40, including the second pressure adjustment mechanism 60, will be described later.

[0032] The pressure detector 50 measures the internal pressure of the plasma processing chamber 10 (plasma processing space 10s) during plasma processing. The type of pressure detector 50 is not particularly limited, and can be any type that can measure the internal pressure of the plasma processing chamber 10.

[0033] <Exhaust system configuration> Next, a detailed configuration example of the above-mentioned exhaust system 40 will be described. Fig. 3 is an enlarged view showing a main part of the exhaust system 40. Fig. 4 is a perspective cross-sectional view schematically showing a second pressure adjustment mechanism 60 provided in the exhaust system 40.

[0034] As described above, the exhaust system 40 includes the annular baffle plate 41 , the first pressure adjustment mechanism 42 , the exhaust mechanism 43 and the second pressure adjustment mechanism 60 .

[0035] The annular baffle plate 41 is disposed around the substrate support 11 in a plan view to separate the plasma processing space 10s from the exhaust path 10e. The annular baffle plate 41 is an annular plate-shaped member having a number of openings 41a. The openings 41a connect the plasma processing space 10s to the exhaust path 10e and capture or reflect plasma generated in the plasma processing space 10s to prevent leakage into the exhaust path 10e. The annular baffle plate 41 is disposed parallel to the substrate W placed on the substrate support 11 and is positioned above the substrate W, more specifically, below the substrate support surface in the drawing. The annular baffle plate 41 is disposed horizontally to surround the sidewall of the substrate support 11 and has a number of openings 41a formed to penetrate the annular baffle plate 41 vertically.

[0036] The first pressure adjustment mechanism 42 adjusts the depressurization operation of the plasma processing space 10s performed by the exhaust mechanism 43, i.e., adjusts the internal pressure (depressurization degree) of the plasma processing chamber 10. As the first pressure adjustment mechanism 42, a pressure control valve such as an APC (Adaptive Pressure Control) valve or a poppet valve can be selected. Therefore, the pressure control valve is configured to control the pressure inside the plasma processing chamber and is selected from at least either an APC valve or a poppet valve.

[0037] The exhaust mechanism 43 reduces the pressure inside the plasma processing space 10s. The exhaust mechanism 43 may include a vacuum pump such as a turbo molecular pump or a dry pump, or a combination thereof.

[0038] The second pressure adjustment mechanism 60 includes an upper plate 61, a movable structure 62, and an actuator 63 as described above.

[0039] The upper plate (first annular plate) 61 is fixedly arranged with respect to the side wall 11a of the substrate support portion 11, for example, on the downstream side of the annular baffle plate 41 in the exhaust path 10e. Therefore, the first annular plate 61 is arranged below the annular baffle plate 41. In one embodiment, the fixed upper annular plate 61 is fixed to the side wall 11a of the substrate support portion 11 and extends horizontally outward from the side wall 11a of the substrate support portion 11. And a first gap G1 is formed between the fixed upper annular plate 61 and the side wall 102 of the plasma processing chamber 10. In one embodiment, the distance H1 between the annular baffle plate 41 and the fixed upper annular plate 61 is 40 mm or more. In one embodiment, the first annular plate 61 completely overlaps the annular baffle plate 41 in the vertical direction. The upper plate 61 is an annular non-porous plate member having no openings, and the width L1 of the annular portion (see FIG. 3) is formed smaller than the width L3 of the annular baffle plate 41 (see FIG. 3). In other words, an exhaust flow path G1 with a width of [L3 - L1] is formed between the outer end portion of the upper plate 61 and the side wall 102 of the plasma processing chamber 10. The width L1 of the upper plate 61 can be arbitrarily designed. At this time, it is desirable that the width [L3 - L1] of the exhaust flow path G1 is at least smaller than the width L1 of the upper plate 61 (L3 - L1 < L1). In other words, the width L1 of the upper plate 61 is larger than half the width (L3 / 2) of the annular baffle plate 4i. Also, the width [L3 - L1] of the exhaust flow path G1 is larger than the width of the gap C described later.

[0040] Note that the distance H1 (see FIG. 3) between the annular baffle plate 41 and the upper plate 61 can also be arbitrarily designed, but from the viewpoint of appropriately adjusting the exhaust conductance, for example, it is preferable that the distance H1 is at least 40 mm or more.

[0041] The movable structure 62 is disposed on the sidewall 102 side of the plasma processing chamber 10, for example, downstream of the upper plate 61 in the exhaust path 10e. Therefore, the movable structure 62 is disposed below the fixed upper annular plate 61. In one embodiment, the movable structure 62 includes a cylindrical wall 62a and a lower plate 62b. The cylindrical wall 62a and the lower plate 62b may be separate members or may be integrated. The movable structure 62 has a substantially L-shaped cross section formed by the cylindrical wall 62a and the lower plate 62b. Therefore, in the following description, the movable structure 62 may also be referred to as an L-shaped structure.

[0042] The cylindrical wall 62a is disposed vertically along the sidewall 102 of the plasma processing chamber 10 and is spaced slightly from the sidewall 102 to form a gap C between the cylindrical wall 62a and the sidewall 102 as a bypass flow path. That is, the cylindrical wall 62a and the sidewall 102 of the plasma processing chamber 10 are concentrically disposed, and the cylindrical wall 62a has an outer diameter slightly smaller than the inner diameter of the sidewall 102. As a result, an annular gap C is formed between the sidewall 102, which constitutes the inner wall surface of the plasma processing chamber 10, and the cylindrical wall 62a of the movable structure 62. In one embodiment, the cylindrical wall 62a is formed of a non-porous member having no openings and extends vertically along the sidewall 102 of the plasma processing chamber 10. A second gap G2 is formed between the cylindrical wall 62a and the sidewall 102 of the plasma processing chamber 10. In one embodiment, the cylindrical wall has a vertical dimension H2 of 10 mm to 60 mm.

[0043] The width L4 (see FIG. 3) of the gap C (second gap G2) is determined so that an exhaust flow can be constantly generated from the plasma processing space 10s by the exhaust mechanism 43 and so that the internal pressure of the plasma processing space 10s is not affected during plasma processing, and is preferably 2.0 mm or less. In one embodiment, the annular gap C has the same width L4 around its entire circumference. The length of the gap C, in other words, the vertical length H2 of the cylindrical wall 62a (see FIG. 3), is determined in consideration of the width L4 of the gap C, and is preferably 10 mm to 60 mm. Specifically, the vertical length H2 of the cylindrical wall 62a is determined so that the conductance of exhaust performed by the exhaust mechanism 43 through the gap C (hereinafter simply referred to as "exhaust conductance") becomes a predetermined desired value. More specifically, the length H2 of the gap C is determined to be long when the width L4 of the gap C is large, and is determined to be short when the width L4 of the gap C is small, so that the exhaust conductance becomes a desired value.

[0044] The lower plate (second annular plate) 62b is connected to the cylindrical wall 62a so as to protrude from the upper end of the inner wall (radially inner side surface) of the cylindrical wall 62a toward the inner periphery (i.e., radially inward) of the plasma processing chamber 10. The lower plate 62b is disposed substantially parallel to the upper plate 61, for example, downstream of the upper plate 61 in the exhaust path 10e. Therefore, the second annular plate 62b is disposed below the first annular plate 61. In one embodiment, the lower annular plate 62b extends horizontally inward from the upper end of the cylindrical wall 62a. The lower annular plate 62b has an annular overlapping portion 62c that vertically overlaps with the fixed upper annular plate 61. A third gap G3 is formed between the lower annular plate 62b and the side wall 11a of the substrate support 11. In one embodiment, the first gap G1 is smaller than the width L1 of the fixed upper annular plate 61 and larger than the second gap G2. In one embodiment, the second annular plate 62b completely overlaps the annular baffle plate 41 in the vertical direction. The lower plate 62b is an annular, imperforate plate-like member having no openings, and the width L2 of the movable structure 62 (see FIG. 3: the sum of the width of the annular portion of the lower plate 62b and the thickness of the cylindrical wall 62a) is smaller than the width L3 of the annular baffle plate 41. In other words, an exhaust flow path G3 having a width [L3-L2] is formed between the outer end of the lower plate 62b and the sidewall 102 of the plasma processing chamber 10. The width L2 of the lower plate 62b can be designed arbitrarily.

[0045] Furthermore, the first annular plate 61 and the second annular plate 62b do not have multiple openings that penetrate in the vertical direction, as in the annular baffle plate 41. Therefore, each of the multiple openings 41a of the annular baffle plate 41 is blocked by at least one of the first annular plate 61 and the second annular plate 62b (more specifically, the movable structure 62 including the cylindrical wall body 62a) in a plan view. That is, each opening 41a of the annular baffle plate 41 may be selectively blocked by either the first annular plate 61 or the second annular plate 62b in a plan view, or may be blocked by both the first annular plate 61 and the second annular plate 62b in a plan view. Therefore, when looking vertically downward from above the multiple openings 41a, the space below the second annular plate 62b is not visible.

[0046] In this embodiment, the movable structure 62 is configured to be movable toward or away from the upper plate 61 (in the illustrated example, the vertical direction) by, for example, the operation of the actuator 63. In other words, the movable structure 62 is configured to arbitrarily adjust the distance H3 (see FIG. 3 ) between the lower plate 62b and the upper plate 61 by the operation of the actuator 63. The operation of the actuator 63 is controlled, for example, by the control unit 2. The adjustment range of the distance H3 can be arbitrarily designed, but from the viewpoint of appropriately controlling the pressure in the plasma processing space 10s, it is desirable that the distance H3 be adjustable between at least 5 and 50 mm. Therefore, at least one actuator 63 is configured to move only the movable structure 62 in the vertical direction based on the pressure detected by the pressure detector 50. That is, at least one actuator 63 is configured to move the movable structure 62 in the vertical direction without moving the first annular plate 61. That is, the first annular plate 61 functions as a fixed annular plate, and the second annular plate 62b of the movable structure 62 functions as a movable annular plate. This changes the distance H3 between the first annular plate 61 and the second annular plate 62b.

[0047] Here, as shown in FIGS. 3 and 5, the upper plate 61 and the lower plate 62b according to the present embodiment are arranged so as to form an annular overlapping portion OV in which at least a part in the radial direction overlaps with respect to the exhaust direction (vertical direction in the illustrated example) in the exhaust path 10e. In other words, the upper plate 61 and the lower plate 62b determine their respective widths L1 and L2 so as to form the annular overlapping portion OV shown in FIGS. 3 and 5 (L3 < L1 + L2). The width of the annular overlapping portion OV can be arbitrarily designed, but for example, it may be designed to be 5 to 10 mm. In one embodiment, the second annular plate 62b is disposed below the first annular plate 61 and has a second annular overlapping portion 62c. The second annular overlapping portion 62c overlaps vertically with a part of the first annular plate 61 (that is, the first annular overlapping portion 61c). Therefore, the annular overlapping portion OV of the upper plate 61 and the lower plate 62b is a portion where a part of the second annular plate 62b (that is, the second annular overlapping portion 62c) and a part of the first annular plate 61 (that is, the first annular overlapping portion 61c) overlap vertically.

[0048] Also, at this time, the magnitude relationship between the width L1 of the upper plate 61 and the width L�2 of the lower plate 62b is not particularly limited. For example, either one of the width L1 and the width L2 may be larger, or the width L1 and the width L2 may be the same. However, from the viewpoint of appropriately adjusting the exhaust conductance, it is preferable that the width L1 is larger than the width L2 (L1 > L2).

[0049] The exhaust system 40 included in the plasma processing apparatus 1 according to the present embodiment is configured as described above.

[0050] Here, in the plasma processing performed using a conventional plasma processing apparatus, it is necessary to supply a processing gas to the entire inside of the plasma processing chamber including the plasma processing space and the exhaust path, or to perform exhaust by the exhaust system. As a result, it has taken a long time to control the pressure of the plasma processing chamber (plasma processing space).

[0051] In this regard, in this embodiment, as described above, the upper plate 61 and the movable structure 62 (second pressure adjustment mechanism 60) that form the annular overlapping portion OV in at least a portion of the radial direction are arranged in the exhaust path 10e, and the lower plate 62b of the movable structure 62 is configured to be movable toward and away from the upper plate 61. Furthermore, no openings are formed in the upper plate 61 and the lower plate 62b. Therefore, by reducing the distance H3 shown in FIG. 3, the upper plate 61 and the lower plate 62b function as a second pressure adjustment valve.

[0052] In other words, by reducing the distance H3 between the upper plate 61 and the lower plate 62b, the exhaust path 10e downstream of the lower plate 62b can be separated from the plasma processing space 10s, thereby artificially reducing the volume of the plasma processing chamber 10. Since the volume of the plasma processing chamber 10 is reduced in this manner, the time required to control the pressure in the plasma processing space 10s can be shortened.

[0053] Furthermore, in the second pressure adjustment mechanism 60 according to this embodiment, the lower plate 62b is configured to be movable toward and away from the upper plate 61 as described above, which allows the amount of air exhausted from the plasma processing space 10s by the exhaust mechanism 43 to be adjusted as desired, thereby enabling precise control of the internal pressure of the plasma processing space 10s. That is, since the amount of air exhausted from the plasma processing space 10s changes depending on the distance H3 between the upper plate 61 and the lower plate 62b, the internal pressure of the plasma processing space 10s can be appropriately controlled by adjusting the distance H3 based on the measurement results of the pressure detector 50, for example.

[0054] Specifically, for example, when the internal pressure of the plasma processing space 10s is lower than the set pressure, the lower plate 62b is raised to reduce the distance H3, thereby reducing the amount of exhaust, and therefore the internal pressure of the plasma processing space 10s can be increased.Also, for example, when the internal pressure of the plasma processing space 10s is higher than the set pressure, the lower plate 62b is lowered to increase the distance H3, thereby increasing the amount of exhaust, and therefore the internal pressure of the plasma processing space 10s can be decreased.

[0055] In addition, at this time, by using the first pressure adjustment mechanism 42 arranged at the bottom of the plasma processing chamber 10 in addition to the second pressure adjustment mechanism 60 to adjust the exhaust from the plasma processing space 10s in two stages, the internal pressure of the plasma processing space 10s can be controlled even more precisely.

[0056] Furthermore, according to the plasma processing apparatus 1 of this embodiment, in addition to exhaust from the distance H3 between the upper plate 61 and the lower plate 62b, minute constant exhaust of the plasma processing space 10s is performed from the gap C formed between the cylindrical wall 62a of the movable structure 62 and the side wall 102 of the plasma processing chamber 10.

[0057] As a result of intensive research, the present inventors have found that if the gap C is not formed between the cylindrical wall 62a of the movable structure 62 and the sidewall 102 of the plasma processing chamber 10 and the plasma processing space 10s is evacuated only through the distance H3 between the upper plate 61 and the lower plate 62b, it may be impossible to properly perform plasma processing on the substrate W. Specifically, as shown in Fig. 6, when the distance H3 between the upper plate 61 and the lower plate 62b is small, the change in the internal pressure of the plasma processing space 10s (the value of the exhaust conductance in the example of Fig. 6) becomes large (sharp), and it has been found that this pressure change makes it impossible to properly perform plasma processing on the substrate W.

[0058] In this regard, in the exhaust system 40 of the plasma processing apparatus 1 according to this embodiment, minute constant exhaust of the plasma processing space 10s is performed through the gap C, so that even if the distance H3 between the upper plate 61 and the lower plate 62b is reduced as shown in FIG. 6, the change in internal pressure is prevented from becoming large (steep), and plasma processing of the substrate W can be performed appropriately.

[0059] Particularly, according to this embodiment, the width L4 and length H2 of the gap C are each specified so as not to affect the internal pressure of the plasma processing space 10s during plasma processing. Specifically, the preferred width L4 of the gap C is 2.0 mm or less, as described above, and the preferred length H2 is 10 mm to 60 mm, as described above. This prevents the internal pressure of the plasma processing space 10s from suddenly changing due to constant exhaust from the gap C, thereby achieving appropriate plasma processing results for the substrate W.

[0060] <Modification>

[0061] In the second pressure adjustment mechanism 60 in the above embodiment, the upper plate 61 is disposed on the sidewall 11a side of the substrate support 11, and the movable structure 62 is disposed on the sidewall 102 side of the plasma processing chamber 10, but these arrangements are not limited to the above embodiment. That is, for example, as in a second pressure adjustment mechanism 200 shown in Figures 7 and 8, the upper plate 201 may be fixedly disposed on the sidewall 102 side of the plasma processing chamber 10, and the movable structure 202 may be disposed on the sidewall 11a side of the substrate support 11. In this case, a gap C for constantly ventilating the plasma processing space 10s is formed between the cylindrical wall 202a of the movable structure 202 and the sidewall 11a of the substrate support 11. In other words, the lower plate 202b of the movable structure 202 is provided integrally with the cylindrical wall 202a so as to protrude from the upper end of the outer wall side (radially outer side surface) of the cylindrical wall 202a toward the outer periphery (i.e., radially outward) of the plasma processing chamber 10. That is, in the example shown in FIGS. 7 and 8, the fixed upper annular plate 201 is fixed to the sidewall 102 of the plasma processing chamber 10 and extends horizontally inward from the sidewall 102 of the plasma processing chamber 10. A first gap G1' is formed between the fixed upper annular plate 201 and the sidewall 11a of the substrate support 11. The movable structure 202 is disposed below the fixed upper annular plate 201. The movable structure 202 has the cylindrical wall 202a and the lower annular plate 202b, which may be separate members or may be integrated. The cylindrical wall 202a extends vertically along the sidewall 11a of the substrate support 11. A second gap G2' is formed between the cylindrical wall 202a and the sidewall 11a of the substrate support 11. The lower annular plate 202b extends horizontally outward from the upper end of the cylindrical wall 202a. The lower annular plate 202b has an annular overlapping portion OV that overlaps the fixed upper annular plate 201 in the vertical direction. A third gap G3' is formed between the lower annular plate 202b and the sidewall 102 of the plasma processing chamber 10. The actuator is configured to move the movable structure 202 vertically. The fixed upper annular plate 201 and the lower annular plate 202b are annular, imperforate plate-like members without any openings. Even in such a case, the internal pressure of the plasma processing space 10s can be precisely controlled and the time required for the pressure control can be appropriately shortened by adjusting the distance H3 between the upper plate 201 and the lower plate 202b based on the measurement results of the pressure detector 50. Therefore, the first annular plate 201 may be fixed to the sidewall 102 of the plasma processing chamber 10, and in this case, the movable structure 202 is disposed on or near the sidewall 11a of the substrate support 11.

[0062] Furthermore, in the second pressure adjustment mechanism 60 in the above embodiment, the upper plate 61 is disposed below the annular baffle plate 41, and the movable structure 62 is disposed below the upper plate 61. However, these arrangements are not limited to those in the above embodiment. That is, for example, as in a second pressure adjustment mechanism 300 shown in FIG. 9 , a substantially L-shaped L-shaped structure 302 may be fixedly disposed below the annular baffle plate 41, and the movable lower plate 301 may be disposed below an upper plate 302b of the L-shaped structure 302. In this case, the L-shaped structure 302 includes a cylindrical wall body 302a disposed along the sidewall 102 of the plasma processing chamber 10, and an upper plate 302b integrally formed with the cylindrical wall body 302a so as to protrude from an upper end of the inner wall side of the cylindrical wall body 302a toward the inner periphery of the plasma processing chamber 10. In this case, a gap C for constantly ventilating the plasma processing space 10s is formed between the cylindrical wall 302a of the L-shaped structure 302 and the sidewall 102 of the plasma processing chamber 10. Furthermore, in this case, the L-shaped structure 302 is fixedly disposed near the sidewall 102 of the plasma processing chamber 10, and the movable lower plate 301 is fixedly disposed on the sidewall 11a of the substrate support 11. The movable lower plate 301 is configured to be movable toward and away from the upper plate 302b by an actuator 303. Even in such a case, the internal pressure of the plasma processing space 10s can be precisely controlled and the time required for the pressure control can be appropriately shortened by adjusting the distance H3 between the upper plate 302b and the movable lower plate 301 based on the measurement results of the pressure detector 50. Therefore, the L-shaped structure 302 may be fixed near the sidewall 102 of the plasma processing chamber 10, and in this case, the first annular plate 301 is disposed below the L-shaped structure 302 and on or near the sidewall 11a of the substrate support 11 so as to be vertically movable.

[0063] 9, the L-shaped structure 302 is disposed on the sidewall 102 side of the plasma processing chamber 10, and the movable lower plate 301 is disposed on the sidewall 11a side of the substrate support 11. However, this arrangement is not limited to the above embodiment. That is, for example, as in the second pressure adjustment mechanism 400 shown in FIG. 10, an L-shaped structure 402 having a substantially L-shape may be disposed on the sidewall 11a side of the substrate support 11, and the movable lower plate 401 may be disposed on the sidewall 102 side of the plasma processing chamber 10. In this case, a gap C for constantly ventilating the plasma processing space 10s is formed between the cylindrical wall 402a of the L-shaped structure 402 and the sidewall 11a of the substrate support 11. Even in such a case, the internal pressure of the plasma processing space 10s can be precisely controlled and the time required for the pressure control can be appropriately shortened by adjusting the distance H3 between the upper plate 402b and the movable lower plate 401 based on the measurement results of the pressure detector 50. Therefore, the L-shaped structure 402 may be fixed near the sidewall 11a of the substrate support 11, and in this case, the first annular plate 401 is disposed movably in the vertical direction on or near the sidewall 102 of the plasma processing chamber 10.

[0064] In the above embodiment, the position of the upper plate 61 is fixed relative to the position of the annular baffle plate 41, and the lower plate 62b is configured to be movable toward or away from the upper plate 61 (vertically). However, the configuration of the exhaust system is not limited to this. That is, although not shown, the lower plate 62b may be fixed relative to the position of the annular baffle plate 41, and the upper plate 61 (movable structure 62) may be configured to be movable between the annular baffle plate 41 and the lower plate 62b. In other words, the upper plate 61 (movable structure 62) may be configured to be movable toward or away from the lower plate 62b. Therefore, at least one actuator 63 is configured to move only the first annular plate 61 in the vertical direction based on the pressure detected by the pressure detector 50. That is, at least one actuator 63 is configured to move the first annular plate 61 in the vertical direction without moving the L-shaped structure. This changes the distance H3 between the first annular plate 61 and the second annular plate 62b. Even in such a case, by adjusting the distance H3 between the upper plate 61 and the lower plate 62b based on the measurement results from the pressure detector 50, the internal pressure of the plasma processing space 10s can be precisely controlled and the time required for the pressure control can be appropriately shortened.

[0065] Furthermore, both the upper plate 61 and the lower plate 62b (movable structure 62) may be configured to be movable toward and away from each other (vertical direction). Therefore, at least one actuator 63 is configured to move the first annular plate 61 and the second annular plate in the vertical direction based on the pressure detected by the pressure detector 50. This changes the distance H3 between the first annular plate 61 and the second annular plate 62b. Even in this case, by adjusting the distance H3 between the upper plate 61 and the lower plate 62b based on the measurement results from the pressure detector 50, the internal pressure of the plasma processing space 10s can be precisely controlled and the time required for the pressure control can be appropriately shortened.

[0066] Note that this structure for vertically moving the upper plate 61 instead of or in addition to the substantially L-shaped movable structure 62 is not limited to the second pressure adjustment mechanism 60 described above, but can also be similarly applied to the second pressure adjustment mechanisms 200, 300, and 400 shown in Figures 7 to 10. Therefore, in any of the second pressure adjustment mechanisms 60, 200, 300, and 400, the distance H3 between the first and second annular plates is configured to be freely adjustable by the operation of at least one actuator. Therefore, the plasma processing apparatus of the embodiment comprises a first annular plate arranged below the annular baffle plate, a second annular plate arranged to overlap a portion of the first annular plate in the vertical direction, a cylindrical wall arranged vertically from the radial end of either the first annular plate or the second annular plate along the side wall of the plasma processing chamber or the side wall of the substrate support part, forming a gap between the side wall of the plasma processing chamber or the side wall of the substrate support part, and at least one actuator that moves at least one of the first annular plate and the second annular plate vertically relative to one another.

[0067] <Plasma treatment method> Next, a plasma processing method using the plasma processing system configured as above will be described. In the following description, an example will be given in which the plasma processing apparatus 1 is equipped with the second pressure adjustment mechanism 60 shown in Figures 3 and 4. In the plasma processing apparatus 1, any plasma processing such as etching, film formation, diffusion, etc. is performed on the substrate W.

[0068] In plasma processing, first, the substrate W is transferred into the plasma processing chamber 10 and placed on the substrate support 11. Then, a DC voltage is applied to the electrodes in the electrostatic chuck, so that the substrate W is attracted and held by the electrostatic chuck by Coulomb force. After the substrate W is transferred into the plasma processing chamber 10, the inside of the plasma processing chamber 10 is depressurized to a desired vacuum level by the exhaust system 40.

[0069] Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the central gas inlet 13. Furthermore, the first RF generator 31a supplies high-frequency power HF for plasma generation to the antenna 14, generating plasma from the processing gas in the plasma processing space 10s. The generated plasma then acts to subject the substrate W on the substrate support 11 to the desired plasma processing. That is, the substrate W is subjected to plasma processing by being exposed to the generated plasma. The internal pressure of the plasma processing chamber 10 during plasma processing is measured (detected) over time by the pressure detector 50.

[0070] The internal pressure of the plasma processing chamber 10 is adjusted to a desired set pressure by supplying processing gas to the plasma processing space 10s. By reducing the distance H3 between the upper plate 61 and the lower plate 62b as described above, the upper plate 61 and the lower plate 62b function as a second pressure regulating valve, thereby virtually reducing the volume of the plasma processing chamber 10. This allows the internal pressure of the plasma processing chamber 10 to be controlled in a short time. Furthermore, at this time, as described above, the plasma processing space 10s is constantly evacuated through the gap C formed between the cylindrical wall 62a of the movable structure 62 and the sidewall 102 of the plasma processing chamber 10. This prevents the internal pressure of the plasma processing chamber 10 from changing sharply even when the distance H3 between the upper plate 61 and the lower plate 62b is reduced.

[0071] As described above, in a plasma processing apparatus, it is important to precisely control the internal pressure of the plasma processing chamber 10 to properly perform plasma processing on a substrate W. Therefore, in this embodiment, the distance H3 between the upper plate 61 and the lower plate 62b in the exhaust system 40 is controlled based on the internal pressure of the plasma processing chamber 10 measured by the pressure detector 50. Specifically, if the measurement result by the pressure detector 50 is lower than the set pressure for the plasma processing, the lower plate 62b is raised to decrease the distance H3, thereby increasing the internal pressure of the plasma processing chamber 10. On the other hand, if the measurement result by the pressure detector 50 is higher than the set pressure for the plasma processing, the lower plate 62b is lowered to increase the distance H3, thereby decreasing the internal pressure of the plasma processing chamber 10. Therefore, the control unit 2 compares the pressure detected by the pressure detector 50 with a predetermined set pressure and determines whether the detected pressure is higher and / or lower than the set pressure. Then, the control unit 2 controls at least one actuator 63 so that the distance H3 becomes longer when the detected pressure is higher than the set pressure, and so that the distance H3 becomes shorter when the detected pressure is lower than the set pressure. For example, in the example of Fig. 3, the control unit 2 lowers the movable structure 62 when the detected pressure is higher than the set pressure, and raises the movable structure 62 when the detected pressure is lower than the set pressure.

[0072] When the plasma processing of the substrate W is completed, the supply of high frequency power HF and high frequency power LF from the RF power supply 31 and the supply of processing gas by the gas supply unit 20 are stopped. If high frequency power LF was supplied during the plasma processing, the supply of the high frequency power LF is also stopped. Next, the processing gas is exhausted from the inside of the plasma processing chamber 10 by the exhaust system 40. Next, the supply of heat transfer gas to the backside of the substrate W is stopped, and the electrostatic chuck stops attracting and holding the substrate W.

[0073] The substrate W that has been subjected to the plasma processing is then transferred by a substrate transfer mechanism (not shown) from the plasma processing chamber 10 to an external device such as a transfer chamber, and the series of plasma processing steps for the substrate W is completed.

[0074] In the plasma processing according to the embodiment described above, the lower plate 62b is moved appropriately based on the internal pressure of the plasma processing chamber 10 measured by the pressure detector 50 during the plasma processing, but the method of controlling the lower plate 62b is not limited to this. For example, instead of feedback-controlling the movement of the lower plate 62b based on the internal pressure measured by the pressure detector 50 during the plasma processing, the distance H3 may be changed for each process based on the preset pressure for each process before the start of the plasma processing.

[0075] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0076] For example, in the above embodiment, the plasma processing apparatus 1 is described as including an inductively coupled plasma generating unit, but the configuration of the plasma generating unit is not limited to this. In other words, by applying the technology of the present disclosure to various plasma processing apparatuses that require a reduction in the time required for pressure control, the time required for the pressure control can be appropriately reduced. [Example]

[0077] Hereinafter, examples of the technology according to the present disclosure will be described, but the technology is not limited to the following examples.

[0078] The inventors measured the time required to control the internal pressure of the plasma processing chamber in two cases: when the volume of the plasma processing chamber was artificially reduced by shortening the distance H3 using the above-mentioned second pressure adjustment mechanism 60 (Example); and when the second pressure adjustment mechanism 60 was not included and the volume of the plasma processing chamber included the volume of the exhaust path 10e (Comparative Example). Specifically, in each of the example and comparative example, a processing gas was supplied to the plasma processing space, and the time until the internal pressure of the plasma processing chamber was increased to a desired set pressure was measured.

[0079] 11 is a graph showing the relationship between the flow rate of the processing gas supplied to the plasma processing chamber (horizontal axis) and the time required to reach the set pressure (vertical axis). In this example, the set pressure was 100 mT, and the processing gas supply flow rates were 100 sccm, 500 sccm, and 1000 sccm. In the figure, the solid line indicates the example, and the dashed line indicates the comparative example.

[0080] 11, it can be seen that the time required for the internal pressure to reach the set pressure can be shortened by controlling the internal pressure of the plasma processing chamber 10 while reducing the distance H3 between the upper plate 61 and the lower plate 62b. Specifically, the inventors have conducted studies and found that the time required for the internal pressure to reach the set pressure in the example can be shortened by approximately 30 to 40% compared to when the second pressure adjustment mechanism 60 is not included. It was also confirmed that the change in the internal pressure of the plasma processing chamber can be made gentler by constantly exhausting air from the gap C formed between the cylindrical wall 62a and the side wall 102 of the plasma processing chamber 10.

[0081] As can be seen from the above results, by providing the upper plate 61 and the movable structure 62, which function as a second pressure regulating valve, in the plasma processing apparatus 1, it is possible to appropriately shorten the time required for pressure control of the plasma processing chamber 10. At the same time, it is possible to moderate the change in the internal pressure of the plasma processing chamber 10 (prevent the internal pressure from changing too rapidly), thereby obtaining an appropriate plasma processing result for the substrate W. [Explanation of symbols]

[0082] 1. Plasma processing equipment 10 Plasma Processing Chamber 11 Substrate support 11a (substrate support) side wall 41 Annular baffle plate 41a aperture 61 Upper plate 62 Movable structure 62a Cylindrical wall 62b Lower plate 63 Actuator 102 (plasma processing chamber) sidewall C gap OV circular overlap W substrate

Claims

1. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate having a plurality of openings and disposed to surround the substrate support; a stationary upper annular plate disposed below the annular baffle plate and extending outward from a sidewall of the substrate support, wherein a first gap is formed between the stationary upper annular plate and a sidewall of the plasma processing chamber; a movable structure disposed below the fixed upper annular plate, the movable structure comprising: a cylindrical wall extending longitudinally along a sidewall of the plasma processing chamber, wherein a second gap is formed between the cylindrical wall and the sidewall of the plasma processing chamber; a movable structure including a lower annular plate extending inwardly from an upper end of the cylindrical wall, the lower annular plate having an annular overlap portion that longitudinally overlaps the fixed upper annular plate, forming a third gap between the lower annular plate and a sidewall of the substrate support; an actuator configured to move the movable structure in a vertical direction.

2. a pressure detector for detecting a pressure within the plasma processing chamber; The plasma processing apparatus of claim 1 , further comprising: a controller configured to control the actuator to vary the relative distance between the fixed upper annular plate and the movable structure based on the detected pressure.

3. The control unit When the detected pressure is higher than a set pressure, the actuator is controlled to increase the distance. The plasma processing apparatus according to claim 2 , wherein the actuator is controlled to reduce the distance when the detected pressure is lower than the set pressure.

4. 4. The plasma processing apparatus according to claim 1, wherein the second gap is 2.0 mm or less.

5. 5. The plasma processing apparatus of claim 4, wherein the annular overlap portion has a width of 5 mm to 10 mm.

6. The plasma processing apparatus of claim 5 , wherein the first gap is smaller than a width of the fixed upper annular plate and larger than the second gap.

7. 7. The plasma processing apparatus of claim 6, wherein the distance between the annular baffle plate and the fixed upper annular plate is 40 mm or more.

8. 5. The plasma processing apparatus according to claim 4, wherein the cylindrical wall has a vertical dimension of 10 mm to 60 mm.

9. The plasma processing apparatus of claim 4 , wherein the width of the fixed upper annular plate is greater than the width of the lower annular plate.

10. The plasma processing apparatus of claim 4 , wherein the plasma processing chamber has a volume of 50 L or more.

11. a pressure control valve configured to control a pressure within the plasma processing chamber; The pressure control valve is an APC (Adaptive Pressure Control) The plasma processing apparatus according to claim 10, wherein the pressure control valve is selected from at least one of a pressure control valve and a poppet valve.

12. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate having a plurality of openings and disposed to surround the substrate support; a stationary upper annular plate disposed below the annular baffle plate and extending inwardly from a sidewall of the plasma processing chamber, wherein a first gap is formed between the stationary upper annular plate and the sidewall of the substrate support; and a movable structure disposed below the fixed upper annular plate, the movable structure comprising: a cylindrical wall extending longitudinally along a sidewall of the substrate support, wherein a second gap is formed between the cylindrical wall and the sidewall of the substrate support; a movable structure including a lower annular plate extending outwardly from an upper end of the cylindrical wall, the lower annular plate having an annular overlap portion that longitudinally overlaps the fixed upper annular plate, forming a third gap between the lower annular plate and a sidewall of the plasma processing chamber; an actuator configured to move the movable structure in a vertical direction.

13. a pressure detector for detecting a pressure within the plasma processing chamber; The plasma processing apparatus of claim 12 , further comprising: a controller configured to control the actuator to vary the relative distance between the fixed upper annular plate and the movable structure based on the detected pressure.

14. The control unit When the detected pressure is higher than a set pressure, the actuator is controlled to increase the distance. The plasma processing apparatus of claim 13 , wherein the actuator is controlled to decrease the distance when the detected pressure is lower than the set pressure.

15. The plasma processing apparatus according to any one of claims 12 to 14, wherein the second gap is 2.0 mm or less.

16. The plasma processing apparatus of claim 15, wherein the annular overlap portion has a width of 5 mm to 10 mm.

17. 16. The plasma processing apparatus of claim 15, wherein the cylindrical wall has a vertical dimension of 10 mm to 60 mm.

18. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate having a plurality of openings and disposed to surround the substrate support; a first annular plate disposed below the annular baffle plate and extending outward from a sidewall of the substrate support, wherein a first gap is formed between the first annular plate and a sidewall of the plasma processing chamber; and a structure disposed below the first annular plate, the structure comprising: a cylindrical wall extending longitudinally along a sidewall of the plasma processing chamber, wherein a second gap is formed between the cylindrical wall and the sidewall of the plasma processing chamber; a second annular plate extending inwardly from an upper end of the cylindrical wall, the second annular plate having an annular overlap portion that longitudinally overlaps the first annular plate, and a third gap being formed between the second annular plate and a sidewall of the substrate support; at least one actuator configured to move at least one of the first annular plate and the structure in a longitudinal direction.

19. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate having a plurality of openings and disposed to surround the substrate support; a first annular plate disposed below the annular baffle plate; a second annular plate disposed so as to overlap a portion of the first annular plate in a longitudinal direction; a cylindrical wall body that is disposed in a vertical direction from a radial end of either the first annular plate or the second annular plate along a side wall of the plasma processing chamber or a side wall of the substrate support, and that forms a gap of 2.0 mm or less between the cylindrical wall body and the side wall of the plasma processing chamber or the side wall of the substrate support; at least one actuator that moves at least one of the first annular plate and the second annular plate relatively in a vertical direction.

20. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; an annular baffle plate having a plurality of openings and disposed to surround the substrate support; a first annular plate disposed below the annular baffle plate and having an inner end fixed to a side wall of the substrate support; a movable structure disposed below the first annular plate, a cylindrical wall disposed longitudinally along a sidewall of the plasma processing chamber, forming a gap between the sidewall and the cylindrical wall; a movable structure including a second annular plate disposed on an upper end of an inner wall of the cylindrical wall body and overlapping a portion of the first annular plate in a longitudinal direction to form an annular overlapping portion; an actuator that moves the movable structure in a vertical direction; a pressure detector for detecting a pressure in the plasma processing chamber, (a) performing a plasma processing on a substrate supported by the substrate support; (b) sensing the pressure within the plasma processing chamber; (c) moving the movable structure longitudinally relative to the first annular plate based on the detected pressure.

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