Plasma processing apparatus

Abstract

To provide a technology that can improve uniformity of plasma density on a substrate in a plasma processing apparatus and suppress adhesion of particles to the substrate.SOLUTION: A plasma processing apparatus comprises: a plasma generation unit that is configured to generate plasma above a substrate supporting part within a plasma processing chamber; an exhaust plate that is arranged between a sidewall of the plasma processing chamber and the substrate supporting part; an electrode plate that is arranged between the sidewall and the substrate supporting part and above the exhaust plate; a power supply that is configured to apply a positive voltage and a negative voltage to the electrode plate; and a control unit that is configured to control the power supply. The control unit controls the power supply to apply a negative voltage to the electrode plate from the power supply when plasma is being generated by the plasma generation unit, and to apply a positive voltage to the electrode plate from the power supply when plasma is not being generated by the plasma generation unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An exemplary embodiment of the present disclosure relates to a plasma processing apparatus. [Background technology]

[0002] 2. Description of the Related Art In a plasma processing apparatus, Patent Document 1 describes a technique in which two baffle plates are arranged between a plasma processing space and an exhaust space, and a voltage is applied to the two baffle plates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-137352 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for improving the uniformity of plasma density on a substrate in a plasma processing apparatus and suppressing particle adhesion to the substrate. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, a plasma processing apparatus includes a plasma processing chamber having a sidewall, a substrate support disposed within the plasma processing chamber, a plasma generation unit configured to generate plasma above the substrate support within the plasma processing chamber, an exhaust plate disposed between the sidewall and the substrate support, an electrode plate disposed between the sidewall and the substrate support and above the exhaust plate, at least one power supply configured to apply a positive voltage and a negative voltage to the electrode plate, and a controller configured to control the at least one power supply, wherein the controller is configured to control the at least one power supply so that when plasma is generated by the plasma generation unit, the at least one power supply applies a negative voltage to the electrode plate, and when plasma is not generated by the plasma generation unit, the at least one power supply applies a positive voltage to the electrode plate. [Effects of the Invention]

[0006] According to one exemplary embodiment of the present disclosure, it is possible to provide a technology that can improve the uniformity of plasma density on a substrate in a plasma processing apparatus and also suppress adhesion of particles to the substrate. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing apparatus. [Figure 3] FIG. 4 is a plan view illustrating an example of the configuration of an exhaust plate. [Figure 4] FIG. 2 is a plan view illustrating an example of the configuration of an electrode plate. [Figure 5] 10A and 10B are diagrams illustrating an example of the configuration of an exhaust plate and an electrode plate arranged between a side wall of a chamber and a substrate support part. [Figure 6] 3A to 3C are diagrams for explaining an example of a source RF signal waveform, a bias signal waveform, and a voltage waveform applied to an electrode plate. [Figure 7]3A to 3C are diagrams for explaining an example of a source RF signal waveform, a bias signal waveform, and a voltage waveform applied to an electrode plate. [Figure 8] 3A to 3C are diagrams for explaining examples of two types of source RF signal waveforms, a bias signal waveform, and a voltage waveform applied to an electrode plate. [Figure 9] 10A and 10B are diagrams for explaining an example of particle movement when a positive voltage is applied to an electrode plate. [Figure 10] 10 is a diagram for explaining an example of a voltage waveform applied to an electrode plate when plasma is not generated. FIG. [Figure 11] FIG. 10 is a diagram illustrating another example of the configuration of the plasma processing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, a plasma processing chamber having a sidewall is provided, the plasma processing chamber comprising: a substrate support disposed within the plasma processing chamber; a plasma generating unit configured to generate plasma above the substrate support within the plasma processing chamber; an exhaust plate disposed between the sidewall and the substrate support; an electrode plate disposed between the sidewall and the substrate support and above the exhaust plate; at least one power supply configured to apply a positive voltage and a negative voltage to the electrode plate; and a controller configured to control the at least one power supply, wherein the controller controls the power supplies such that when plasma is generated by the plasma generating unit, the at least one power supply applies a negative voltage to the electrode plate, and when plasma is not generated by the plasma generating unit, the at least one power supply applies a positive voltage to the electrode plate. a plasma processing apparatus including a plasma processing chamber, a substrate support disposed within the plasma processing chamber, a plasma generation unit configured to generate plasma above the substrate support within the plasma processing chamber, an exhaust plate disposed between a sidewall and the substrate support, an electrode plate disposed between the sidewall and the substrate support and above the exhaust plate, at least one power supply configured to apply a positive voltage and a negative voltage to the electrode plate, and a controller configured to control the at least one power supply, wherein the controller is configured to control the at least one power supply so that when plasma is being generated by the plasma generation unit, the at least one power supply applies a negative voltage to the electrode plate, and when plasma is not being generated by the plasma generation unit, the at least one power supply applies a positive voltage to the electrode plate.

[0010] In one exemplary embodiment, the controller controls the at least one power supply to have a first period during which a positive voltage is applied to the electrode plate by the at least one power supply and a second period during which no voltage is applied to the electrode plate by the at least one power supply when plasma is not being generated.

[0011] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0012] <An example of a plasma processing system> FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0013] 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.

[0014] 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).

[0015] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0016] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10 (also simply referred to as the "chamber"), a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0017] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0018] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be 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 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0019] 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.

[0020] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0021] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0022] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0023] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma 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 generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0024] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. 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.

[0025] The second RF generating unit 31b is coupled to at least one lower 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 lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

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

[0027] In various embodiments, 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. In one embodiment, a waveform generator for generating a 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.

[0028] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0029] In one embodiment, as shown in FIG. 2, the plasma processing apparatus 1 further includes an exhaust plate 200, an electrode plate 201, and a power supply 202.

[0030] In one embodiment, the exhaust plate 200 is disposed between the substrate support 11 and the sidewall 10a of the chamber 10. The exhaust plate 200 has an annular plate shape. The exhaust plate 200 is disposed horizontally with the plate surface facing up and down. The exhaust plate 200 may be formed of a conductive material. The conductive material may include a metal such as aluminum. The exhaust plate 200 may be formed of an insulating material. The surface of the exhaust plate 200 may be coated with a plasma-resistant material.

[0031] FIG. 3 is a plan view illustrating an example of the configuration of the exhaust plate 200. The exhaust plate 200 has a plurality of openings 210 formed therein, penetrating the plate in the vertical direction. The plurality of openings 210 may have a dot shape. Each opening 210 may be a circular hole. The plurality of openings 210 may be arranged in a line along the radial direction of the exhaust plate 200, and the plurality of openings 210 in the line may be arranged over the entire circumferential direction of the exhaust plate 200. The plurality of openings 210 may be arranged over the entire region of the exhaust plate 200. Each opening 210 may have a slit shape.

[0032] In one embodiment, as shown in FIG. 2 , the electrode plate 201 is disposed between the substrate support 11 and the side wall 10a of the chamber 10. The electrode plate 201 has an annular plate shape. The electrode plate 201 is disposed above the exhaust plate 200. The electrode plate 201 is disposed horizontally with the plate surface facing up and down. The electrode plate 201 may be disposed parallel to the exhaust plate 200. The electrode plate 201 is disposed so as to have a gap between it and the exhaust plate 200. The electrode plate 201 may also be disposed so as to be in contact with the exhaust plate 200.

[0033] The electrode plate 201 is made of a conductive material. The conductive material may be silicon or a silicon-containing material. The surface of the electrode plate 201 may be coated with a plasma-resistant material.

[0034] FIG. 4 is a plan view illustrating an example of the configuration of the electrode plate 201. The electrode plate 201 has a plurality of openings 220 formed therein, penetrating the electrode plate 201 in the vertical direction. The plurality of openings 220 may have a dot shape. Each opening 220 may be a circular hole. The plurality of openings 220 may be arranged in a line along the radial direction of the electrode plate 201, and the plurality of openings 220 in the line may be arranged over the entire circumferential direction of the electrode plate 201. The plurality of openings 220 may be arranged over the entire area of ​​the electrode plate 201. Each opening 220 may have a slit shape. The electrode plate 201 may have the same shape and size as the exhaust plate 200. The openings 220 may have the same shape and size as the openings 210.

[0035] 5, the openings 220 in the electrode plate 201 overlap the openings 210 in the exhaust plate 200 in the vertical direction. The plasma processing space 10s and the exhaust space including the gas exhaust port 10e are in communication with each other via the openings 220 in the electrode plate 201 and the openings 210 in the exhaust plate 200.

[0036] In one embodiment, as shown in FIG. 2 , the power supply 202 includes a positive DC power supply 250 and a negative DC power supply 251. The positive DC power supply 250 is electrically connected to the electrode plate 201 via a first switch 260 and a filter 270. The negative DC power supply 251 is electrically connected to the electrode plate 201 via a second switch 280 and a filter 270. The positive DC power supply 250 can apply a positive voltage to the electrode plate 201 by turning on the first switch 260. The negative DC power supply 251 can apply a negative voltage to the electrode plate 201 by turning on the second switch 280. The filter 270 is configured to remove RF signals and can prevent RF signals from the chamber 10 from reaching the positive DC power supply 250 and the negative DC power supply 251. The positive DC power supply 250 and the negative DC power supply 251 are electrically connected to ground potential. The power supply 202 may have other configurations as long as it can selectively apply a positive voltage or a negative voltage to the electrode plate 201 .

[0037] 2 and 5, the substrate support 11 includes an annular insulating member 300 and an annular conductive member 301. The annular insulating member 300 is configured to cover the outer peripheral surfaces of the electrostatic chuck 1111, the ring assembly 112, and the base 1110. The annular insulating member 300 may have a substantially cylindrical shape. The annular insulating member 300 may include an insulating material such as quartz.

[0038] The annular conductive member 301 is configured to cover the outer peripheral surface of the annular insulating member 300. The annular conductive member 301 is electrically insulated from the electrostatic chuck 1111, the ring assembly 112, and the base 1110 by the annular insulating member 300. The annular conductive member 301 may have a substantially cylindrical shape. The annular conductive member 301 may include a metal such as aluminum. The annular conductive member 301 is electrically connected to the bottom 10c of the chamber 10. The bottom 10c of the chamber 10 is electrically connected to ground potential. The side wall 10a of the chamber 10 is electrically connected to ground potential.

[0039] 5 , the exhaust plate 200 may be fixed to or supported by the annular conductive member 301 and the sidewall 10a of the chamber 10. The exhaust plate 200 may be electrically connected to the annular conductive member 301 and the sidewall 10a of the chamber 10. The electrode plate 201 may be fixed to or supported by the annular insulating member 300 and the sidewall 10a of the chamber 10. In one embodiment, the electrode plate 201 is insulated from surrounding parts such as the annular conductive member 301, the exhaust plate 200, the electrostatic chuck 1111, the ring assembly 112, and the base 1110.

[0040] <An example of a plasma processing method> The plasma processing method includes an etching process in which plasma is used to etch a film on a substrate W. In one embodiment, the plasma processing method is performed by a control unit 2 in a plasma processing apparatus 1.

[0041] In the plasma processing apparatus 1 shown in FIG. 2, first, the substrate W is carried into the chamber 10 by a transfer arm, placed on the substrate support portion 11 by a lifter, and held on the substrate support portion 11 by suction.

[0042] Next, a processing gas is supplied to the plasma processing space 10s by the gas supply unit 20 through the shower head 13. The processing gas supplied at this time includes a gas that generates active species necessary for etching the substrate W.

[0043] A source RF signal for generating plasma is supplied to the upper electrode and / or lower electrode by the RF power supply 31 of the plasma generating unit 12. A bias signal for attracting ion components in the plasma to the substrate is supplied to the lower electrode by the RF power supply 31 or DC power supply 32. The atmosphere in the plasma processing space 10s is exhausted from the gas exhaust port 10e, and the pressure inside the plasma processing space 10s is reduced. In this way, plasma is generated from the processing gas on the substrate support 11 in the plasma processing space 10s, and the substrate W is etched.

[0044] When plasma is generated by the plasma generating unit 12, a negative voltage is applied to the electrode plate 201 by the negative DC power supply 251. In the example shown in FIG. 6, a source RF signal is supplied to the upper electrode and a bias RF signal is supplied to the lower electrode (while the supply of the source RF signal and the bias RF signal is ON), and a negative voltage is applied to the electrode plate 201. In the example shown in FIG. 7, a source RF signal is supplied to the upper electrode and a pulsed bias DC signal is supplied to the lower electrode (while the supply of the source RF signal and the bias DC signal is ON), and a negative voltage is applied to the electrode plate 201. In the example shown in FIG. 8, a first source RF signal is supplied to the upper electrode, a second source RF signal is supplied to the lower electrode, and a bias RF signal is supplied to the lower electrode (while the supply of two types of source RF signals with different frequencies and the bias RF signal is ON), and a negative voltage is applied to the electrode plate 201. In the above example, the voltage level (absolute value) of the negative voltage applied to the electrode plate 201 may be smaller than the voltage level (absolute value) of the potential of the substrate on the substrate support portion 11.

[0045] 5, when plasma is generated by the plasma generating unit 12, a negative voltage is applied to the electrode plate 201 by the negative DC power supply 251, and negatively charged electron components in the plasma in the plasma processing space 10s are moved away from the electrode plate 201. This increases the density of the electron components above the electrode plate 201, which in turn inhibits the electron components of the plasma from diffusing outward from above the substrate W on the substrate support unit 11, making the plasma density above the substrate W uniform across the substrate surface. Furthermore, the plasma density above the substrate W also increases. During plasma generation, a plasma sheath PS is generated above the substrate W, and negatively charged particles float above the plasma sheath PS and do not adhere to the substrate W.

[0046] When plasma is not generated by the plasma generation unit 12, a positive voltage is applied to the electrode plate 201 by the positive DC power supply 250. In the example shown in FIG. 6, a positive voltage is applied to the electrode plate 201 while a source RF signal is not supplied to the upper electrode and a bias RF signal is not supplied to the lower electrode (while the supply of the source RF signal and the bias RF signal is OFF). In the example shown in FIG. 7, a positive voltage is applied to the electrode plate 201 while a source RF signal is not supplied to the upper electrode and a pulsed bias DC signal is not supplied to the lower electrode (while the supply of the source RF signal and the bias DC signal is OFF). In the example shown in FIG. 8, a positive voltage is applied to the electrode plate 201 while a first source RF signal is not supplied to the upper electrode, a second source RF signal is not supplied to the lower electrode, and a bias RF signal is not supplied to the lower electrode (while the supply of the two types of source RF signals and the bias RF signal is OFF). In the above example, the voltage level (absolute value) of the positive voltage applied to the electrode plate 201 may be smaller than the voltage level (absolute value) of the potential of the substrate on the substrate support 11. The voltage level (absolute value) of the positive voltage applied to the electrode plate 201 may be larger than the voltage level (absolute value) of the negative voltage applied to the electrode plate 201.

[0047] 9, when plasma is not being generated by the plasma generating unit 12, a positive voltage is applied to the electrode plate 201 by the positive DC power supply 250, and negatively charged particles floating above the substrate W on the substrate support unit 11 are attracted to the electrode plate 201. The particles attracted to the electrode plate 201 are exhausted from the gas exhaust port 10e through the openings 220 in the electrode plate 201 and the openings 210 in the exhaust plate 200. As a result, the particles are removed from above the substrate W, and the particles are prevented from falling onto and adhering to the substrate W. Furthermore, the particles are removed from the plasma processing space 10s, and the next substrate processing can be carried out appropriately without being affected by the particles.

[0048] Furthermore, when plasma is not being generated by the plasma generating unit 12 (during idling), there may be a first period (ON) in which a positive voltage is applied to the electrode plate 201 by the positive DC power supply 250, and a second period (OFF) in which a positive voltage is not applied to the electrode plate 201 by the positive DC power supply 250. In the example shown in FIG. 10 , while a source RF signal is not being supplied to the upper electrode and a bias RF signal is not being supplied to the lower electrode (while the supply of the source RF signal and the bias RF signal is OFF), the application of a positive voltage to the electrode plate 201 is turned ON and OFF. By doing so, for example, before the substrate W is supported by the substrate support 11 or after the substrate W has moved from the substrate support 11, particles on the surface of or above the substrate support 11 can be removed. That is, by turning ON the application of a positive voltage to the electrode plate 201, particles on the substrate support 11 can be attracted to the electrode plate 201. Furthermore, by turning off the application of the positive voltage to the electrode plate 201, for example, particles adhering to the electrode plate 201 can be discharged by the exhaust system 40 from the gas discharge port 10e.

[0049] According to this exemplary embodiment, the plasma processing apparatus 1 includes an exhaust plate 200 disposed between the sidewall 10a of the plasma processing chamber 10 and the substrate support 11, an electrode plate 201 disposed between the sidewall 10a and the substrate support 11 and above the exhaust plate 200, a power supply 202 configured to apply a positive voltage and a negative voltage to the electrode plate 201, and a controller 2 configured to control the power supply 202, wherein the controller 2 controls the power supply 202 so that when plasma is generated by the plasma generation unit 12, a negative voltage is applied to the electrode plate 201 by the negative DC power supply 251, and when plasma is not generated by the plasma generation unit 12, a positive voltage is applied to the electrode plate 201 by the positive DC power supply 250. This prevents electron components of the plasma from diffusing outward from above the substrate W on the substrate support 11 during plasma generation, thereby making the plasma density above the substrate W uniform across the substrate surface. Furthermore, when plasma is not being generated, negatively charged particles are removed from above the substrate W, preventing the particles from falling onto and adhering to the substrate W. As a result, the plasma processing apparatus 1 can improve the uniformity of the plasma density above the substrate and also prevent particles from adhering to the substrate.

[0050] In the above embodiment, the electrode plate 201 covers the entire surface of the exhaust plate 200, but as shown in FIG. 11 , the electrode plate 201 may cover only a portion of the exhaust plate 200. That is, the electrode plate 201 may be disposed on a portion of the upper surface of the exhaust plate 200. The electrode plate 201 may be disposed on an inner region of the exhaust plate 200.

[0051] The shape of the electrode plate 201 can be selected arbitrarily, and may be other shapes such as an arc shape, etc. The electrode plate 201 may also be divided into a plurality of parts and configured from a plurality of sections.

[0052] The exhaust plate 200 may also serve as the electrode plate 201. In this case, the exhaust plate 200 is made of a conductive material. The exhaust plate 200 is connected to a positive DC power supply 250 and a negative DC power supply 251 of the power supply 202. The exhaust plate 200 is insulated from surrounding parts such as the annular conductive member 301, the exhaust plate 200, the electrostatic chuck 1111, the ring assembly 112, and the base 1110.

[0053] Although the above exemplary embodiment has been applied to a capacitively coupled plasma processing apparatus, the present invention is not limited to this and may be applied to other plasma processing apparatuses. For example, the present invention may be applied to an inductively coupled plasma processing apparatus instead of a capacitively coupled plasma processing apparatus.

[0054] Embodiments of the present disclosure further include the following aspects.

[0055] (Appendix 1) a plasma processing chamber having a sidewall; a substrate support disposed within the plasma processing chamber; a plasma generating unit configured to generate a plasma above the substrate support within the plasma processing chamber; an exhaust plate disposed between the sidewall and the substrate support; an electrode plate disposed between the sidewall and the substrate support and above the exhaust plate; at least one power supply configured to apply a positive voltage and a negative voltage to the electrode plates; a controller configured to control the at least one power source; The control unit The at least one power source is controlled so that, when the plasma is generated by the plasma generating unit, a negative voltage is applied to the electrode plate by the at least one power source, and, when the plasma is not generated by the plasma generating unit, a positive voltage is applied to the electrode plate by the at least one power source. Plasma processing equipment.

[0056] (Appendix 2) 2. The plasma processing apparatus according to claim 1, wherein the control unit controls the at least one power source to have a first period in which the at least one power source applies a positive voltage to the electrode plate when the plasma is not generated, and a second period in which the at least one power source does not apply a voltage to the electrode plate.

[0057] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments. [Explanation of symbols]

[0058] 1: Plasma processing apparatus, 2: Control unit, 10: Chamber, 11: Substrate support unit, 12: Plasma generation unit, 200: Exhaust plate, 201: Electrode plate, 202: Power supply, 250: Positive DC power supply, 251: Negative DC power supply, W: Substrate

Claims

1. a plasma processing chamber having a sidewall; a substrate support disposed within the plasma processing chamber; a plasma generating unit configured to generate a plasma above the substrate support within the plasma processing chamber; an exhaust plate disposed between the sidewall and the substrate support; an electrode plate disposed between the sidewall and the substrate support and above the exhaust plate; at least one power supply configured to apply a positive voltage and a negative voltage to the electrode plates; a controller configured to control the at least one power source; The control unit The at least one power source is controlled so that, when the plasma is generated by the plasma generating unit, a negative voltage is applied to the electrode plate by the at least one power source, and, when the plasma is not generated by the plasma generating unit, a positive voltage is applied to the electrode plate by the at least one power source. Plasma processing equipment.

2. 2. The plasma processing apparatus according to claim 1, wherein the control unit controls the at least one power source so as to have a first period during which the at least one power source applies a positive voltage to the electrode plate when the plasma is not being generated, and a second period during which the at least one power source does not apply a voltage to the electrode plate.

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