Plasma processing device and upper assembly

Abstract

The disclosed plasma processing device comprises a chamber, a plasma generation unit, a substrate support unit in the chamber, an upper assembly, and a gas supply unit. The plasma generation unit is configured so as to generate plasma in the chamber. The upper assembly includes an upper electrode, an insulating ring, and a conductive ring. The upper electrode includes a plurality of first gas holes that open toward a plasma processing space in the chamber and is disposed above the substrate support unit. The insulating ring surrounds the upper electrode. The conductive ring includes a plurality of second gas holes that open toward the plasma processing space, surround the insulation ring, and are disposed above the space between the substrate support unit and a side wall of the chamber. The gas supply unit is configured so as to supply gas to the plurality of first gas holes and the plurality of second gas holes.

Description

Plasma processing apparatus and upper assembly

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and an upper assembly.

[0002] The capacitively coupled plasma processing apparatus includes a chamber, a substrate support, and an upper electrode. The substrate support includes a lower electrode and is disposed within the chamber. The upper electrode is disposed above the substrate support. Patent Document 1 listed below discloses a plasma processing apparatus in which the upper electrode is divided into an inner upper electrode and an outer upper electrode, and a variable DC power supply for applying voltage is connected to each of the inner upper electrode and the outer upper electrode.

[0003] JP 2013-141024 A

[0004] The present disclosure provides techniques for increasing control over the rate of plasma processing at the edge of a substrate.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a plasma generating unit, a substrate support, an upper assembly, and a gas supply unit. The chamber has a plasma processing space. The plasma generating unit is configured to generate plasma in the chamber. The substrate support is located within the chamber. The upper assembly is disposed above the plasma processing space. The upper assembly includes an upper electrode, an insulating ring, and a conductive ring. The upper electrode has a plurality of first gas holes opening into the plasma processing space and is disposed above the substrate support. The insulating ring surrounds the upper electrode. The conductive ring has a plurality of second gas holes opening into the plasma processing space, surrounds the insulating ring, and is disposed above a space between the substrate support and a sidewall of the chamber. The gas supply unit is configured to supply gas to be discharged into the plasma processing space to the plurality of first gas holes and the plurality of second gas holes.

[0006] According to one exemplary embodiment, increased control over the rate of plasma processing at the edge of the substrate is achieved.

[0007] FIG. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus; FIG. 2 is a diagram illustrating a plasma processing apparatus according to an exemplary embodiment; FIG. 3 is a diagram illustrating a plasma processing apparatus according to an exemplary embodiment; FIG. 4 is a plan view illustrating an example of an arrangement of a plurality of second gas holes; FIG. 5 is a block diagram of a processing circuit that performs the operations described herein on a computer; FIG. 6 is a diagram illustrating simulation results; and FIG. 7 is a graph illustrating experimental results. FIG. 8 is a diagram illustrating a plasma processing apparatus according to another exemplary embodiment; FIG. 9 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment; and FIG. 10 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment.

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

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

[0010] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 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 has at least one gas inlet for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0011] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a 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.

[0012] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. 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 (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (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 (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. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0013] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0014] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate 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.

[0015] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0016] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

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

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

[0019] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0020] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0021] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0022] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

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

[0024] 2 and 3, each of which illustrates a plasma processing apparatus according to an exemplary embodiment. As shown in FIGS. 2 and 3, the plasma processing apparatus 1 includes a chamber 10 and a substrate support 11.

[0025] The sidewall 10a of the chamber 10 may have a passage 10p. The passage 10p can be opened and closed by a gate valve 10g. The substrate W passes through the passage 10p when being transferred between the inside and outside of the chamber 10. The bottom of the chamber 10 has a gas exhaust port 10e. The exhaust system 40 is connected to the space inside the chamber 10 via the gas exhaust port 10e.

[0026] The substrate support 11 is disposed within the chamber 10. The substrate support 11 may include a base 1110 and an electrostatic chuck 1111. The electrostatic chuck 1111 is configured to support a substrate W and an edge ring ER. The edge ring ER is part of a ring assembly 112. The substrate W is disposed on the substrate support 11 within a region surrounded by the edge ring ER.

[0027] In one embodiment, the substrate support 11 may further include a support member 114, an insulating region 116, and a conductive region 118. The support member 114 extends upward from the bottom of the chamber 10 and supports a base 1110 and an electrostatic chuck 1111, i.e., the main body 111 (see FIG. 1), disposed thereon. The support member 114 is formed from an insulating material such as aluminum oxide or quartz. The support member 114 may have a generally cylindrical shape.

[0028] The insulating region 116 is made of an insulating material such as quartz and extends to surround the outer peripheries of the support member 114 and the main body 111. The insulating region 116 may have a substantially cylindrical shape. The outer edge portion of the edge ring ER may be disposed on the insulating region 116.

[0029] The conductive region 118 is formed of a conductive material such as aluminum. The surface of the conductive region 118 may be formed of a film of a plasma-resistant material. This film may be formed of aluminum oxide, yttrium oxide, or yttrium fluoride. The conductive region 118 extends to surround the outer periphery of the insulating region 116. The conductive region 118 may have a substantially cylindrical shape. The conductive region 118 is electrically grounded.

[0030] In one embodiment, the plasma processing apparatus 1 may further include a baffle member 10b. The baffle member 10b is disposed in the space between the substrate support 11 and the sidewall 10a of the chamber 10, dividing the space into an upper space and a lower space of the baffle member 10b. The lower space is located between the baffle member 10b and the bottom of the chamber 10 and is connected to the gas exhaust port 10e. The baffle member 10b has a plurality of through holes that connect the upper space and the lower space of the baffle member 10b to each other.

[0031] The baffle member 10b is made of a conductive material such as aluminum. The surface of the baffle member 10b may be made of a film of a plasma-resistant material. This film may be made of aluminum oxide, yttrium oxide, or yttrium fluoride. The baffle member 10b is electrically grounded.

[0032] In one embodiment, the inner edge of the baffle member 10b is sandwiched between the conductive region 118 and the bottom of the chamber 10. The outer edge of the baffle member 10b is fixed to a liner 10L that extends along the inner circumferential surface of the sidewall 10a of the chamber 10. The liner 10L may have a generally cylindrical shape.

[0033] 2 and 3, the plasma processing apparatus 1 further includes an upper assembly 13A. The upper assembly 13A is disposed above the plasma processing space 10s and above the substrate support 11.

[0034] The upper assembly 13A includes the shower head 13 described above. The upper assembly 13A has a plurality of first gas holes 131 and a plurality of second gas holes 132. The plurality of first gas holes 131 and the plurality of second gas holes 132 constitute the plurality of gas inlets 13c (see FIG. 1 ). The plurality of first gas holes 131 open toward the plasma processing space 10s above the substrate support 11. The plurality of second gas holes 132 open toward the plasma processing space 10s outside the plurality of first gas holes 131 in the radial direction relative to the central axis of the substrate support 11, i.e., the axis AX. Note that the axis AX may be the central axis of the chamber 10 and the plasma processing space 10s.

[0035] In the plasma processing apparatus 1, the gas supply unit 20 is configured to supply gas to be discharged into the plasma processing space 10s to a plurality of first gas holes 131 and a plurality of second gas holes 132. In the plasma processing apparatus 1, plasma is generated in the plasma processing space 10s from the gas supplied from each of the plurality of first gas holes 131 and the plurality of second gas holes 132. The substrate W is processed by chemical species from the plasma. For example, the substrate W is etched by the chemical species from the plasma.

[0036] In one embodiment, the radial distance from the axis AX to the center point of each of the plurality of second gas holes 132 is 200 mm or more and 250 mm or less. The center point of each of the plurality of second gas holes 132 is the center point of the open end of each of the plurality of second gas holes 132 facing the plasma processing space 10s. A plasma processing apparatus 1 having such an upper assembly 13A can process a substrate W having a diameter of 300 mm. With such a plasma processing apparatus 1, the gas supplied from the plurality of second gas holes 132 improves controllability of the plasma processing rate at the edge of the substrate W.

[0037] In one embodiment, the upper assembly 13A includes the above-described upper electrode 13E, and further includes an insulating ring 14 and a conductive ring 15. The upper electrode 13E, the insulating ring 14, and the conductive ring 15 share an axis AX as their central axis.

[0038] The upper electrode 13E has a substantially disk shape and is disposed above the substrate support 11. The second DC generating unit 32b may be connected to the upper electrode 13E via a filter 32f. The filter 32f is an electric filter configured to block or attenuate the RF signal.

[0039] The upper electrode 13E has a plurality of first gas holes 131. The plurality of first gas holes 131 are distributed across the upper electrode 13E so that gas can be discharged from the plurality of first gas holes 131 toward the entire upper surface of the substrate W. The upper electrode 13E has a gas diffusion chamber 321. The plurality of first gas holes 131 are connected to the gas diffusion chamber 321 and extend downward from the gas diffusion chamber 321.

[0040] The insulating ring 14 is formed in a substantially ring shape and surrounds the upper electrode 13E. The insulating ring 14 is formed of one or more insulating materials. In one embodiment, the insulating ring 14 may include a first insulating ring 141 and a second insulating ring 142. The first insulating ring 141 defines the plasma processing space 10s from above. That is, the lower surface of the first insulating ring 141 is in contact with the plasma processing space 10s. The second insulating ring 142 is disposed on the first insulating ring 141. The first insulating ring 141 may be made of quartz, and the second insulating ring 142 may be made of aluminum oxide.

[0041] The conductive ring 15 is formed in a substantially ring shape and surrounds the insulating ring 14. In the illustrated example, the conductive ring 15 surrounds the first insulating ring 141. The conductive ring 15 is formed of a conductive material. The conductive ring 15 may be formed of a material containing silicon, or may be formed of silicon or silicon carbide. The conductive ring 15 may be electrically grounded. Note that the upper electrode 13E is electrically isolated from the conductive ring 15, and the potential of the upper electrode 13E may be set to a potential different from the ground potential of the conductive ring 15. In another example, the upper assembly 13A may be electrically grounded. For example, in the upper assembly 13A, the upper electrode 13E and the conductive ring 15 may be electrically grounded. When the upper assembly 13A is electrically grounded, the conductive ring 15 and the top plate 133 may be integrated, and the cooling members 341 and 342 may be integrated. Furthermore, if the upper assembly 13A is electrically grounded, the upper assembly 13A does not need to include the first insulating ring 141 and the second insulating ring 142.

[0042] The conductive ring 15 is disposed above the space between the substrate support 11 and the sidewall 10a of the chamber 10. The conductive ring 15 has a plurality of second gas holes 132. The second gas holes 132 are open toward the plasma processing space 10s above the space between the outer periphery of the substrate support 11 and the sidewall 10a of the chamber 10. The second gas holes 132 are connected to the gas diffusion chamber 322 and extend downward from the gas diffusion chamber 322. The gas diffusion chamber 322 may be provided within a cooling member 342, which will be described later.

[0043] The conductive ring 15 may be supported by a ring member 16. In this case, the ring member 16 extends between the side wall 10a of the chamber 10 and the conductive ring 15.

[0044] As described above, the gas supply unit 20 is configured to supply gas discharged into the plasma processing space 10s to the plurality of first gas holes 131 and the plurality of second gas holes 132. The gas supply unit 20 supplies gas to the plurality of first gas holes 131 via the gas diffusion chamber 321. The gas supply unit 20 supplies gas to the plurality of second gas holes 132 via the gas diffusion chamber 322. According to this plasma processing apparatus 1, the gas supplied from the plurality of second gas holes 132 improves the controllability of the plasma processing rate at the edge of the substrate W. In the following description, the gas discharged from the plurality of second gas holes 132 may be referred to as a side gas.

[0045] In one embodiment, the gas supply unit 20 may include a first gas supply unit 201 and a second gas supply unit 202. The first gas supply unit 201 is configured to supply gas to the plurality of first gas holes 131. The second gas supply unit 202 is configured to supply gas to the plurality of second gas holes 132. In this embodiment, the side gas discharged from the plurality of second gas holes 132 into the plasma processing space 10s is controlled independently of the gas discharged from the plurality of first gas holes 131 into the plasma processing space 10s. Therefore, the independent controllability of the plasma processing rate at the edge of the substrate W is enhanced.

[0046] In addition, instead of the first gas supply unit 201 and the second gas supply unit 202, i.e., two gas supply units, a single gas supply unit may be configured to distribute gas to a plurality of first gas holes 131 and a plurality of second gas holes 132.

[0047] In one embodiment, the first gas supply unit 201 may include a main gas supply unit 201 m and an additive gas supply unit 201 a. The additive gas supplied from the additive gas supply unit 201 a is mixed with the main gas supplied from the main gas supply unit 201 m. The mixed gas containing the main gas and the additive gas is discharged into the plasma processing space 10 s through the plurality of first gas holes 131.

[0048] In one embodiment, the main gas may include one or more of a halogen-containing gas, a phosphorus-containing gas, a fluorocarbon gas, a hydrofluorocarbon gas, a hydrogen-containing gas, an oxygen-containing gas, and a noble gas. The halogen-containing gas may include HBr, Cl, or the like. ２ , N.F. ３ , hydrogen fluoride (HF), and tungsten fluoride (WF ６ The phosphorus-containing gas may include one or more phosphorus-containing substances. The one or more phosphorus-containing substances may include PF ３ The one or more phosphorus-containing materials may include one or more other phosphorus-containing materials. The fluorocarbon gas may include CF ４ , C ４ F ８ , and C ４ F ６ The hydrofluorocarbon gas may contain one or more of the following: ４ H ２ F ６ and CH ２ F ２ The hydrogen-containing gas may contain one or more of: ２ The oxygen-containing gas may include O ２ The noble gas may include argon. The additive gas may include a fluorocarbon gas. The fluorocarbon gas in the additive gas may include C ４ F ８ and C ４ F６ It may include one or more of the following:

[0049] The side gas discharged from the second gas supply unit 202 through the second gas holes 132 may contain one or more of a halogen-containing gas, a fluorocarbon gas, and a hydrofluorocarbon gas. The halogen-containing gas in the side gas may be HBr, Cl, or the like. ２ , hydrogen fluoride (HF), and tungsten fluoride (WF ６ The fluorocarbon gas in the side gas may include one or more of C ４ F ８ and C ４ F ６ The hydrofluorocarbon gas in the side gas may include one or more of: ４ H ２ F ６ and CH ２ F ２ It may include one or more of the following:

[0050] As shown in FIGS. 2 and 3 , the conductive ring 15 has a gas hole formation region 15r. A plurality of second gas holes 132 are formed in the gas hole formation region 15r. The gas hole formation region 15r is an annular region. The radius of the inner edge of the gas hole formation region 15r relative to the axis AX is equal to or greater than the radius of the inner edge of the conductive ring 15. The radius of the outer edge of the gas hole formation region 15r relative to the axis AX may be equal to or less than half the sum of the radii of the inner and outer edges of the conductive ring 15. A plasma processing apparatus 1 including such an upper assembly 13A can process a substrate W having a diameter of 300 mm. With such a plasma processing apparatus 1, the side gas supplied from the plurality of second gas holes 132 enhances controllability of the plasma processing rate at the edge of the substrate W.

[0051] In one embodiment, the conductive ring 15 may not have gas holes outside the gas hole forming region 15r, in which case a relatively high concentration of side gas can be obtained at the edge of the substrate W.

[0052] Further reference will be made to FIG. 4 below. FIG. 4 is a plan view showing an example of the arrangement of the multiple second gas holes. The multiple second gas holes 132 may be arranged along at least one circle centered on the axis AX. That is, the multiple second gas holes 132 may be arranged such that their center points are located on at least one circle centered on the axis AX. The center points of the multiple second gas holes 132 may be arranged at equal intervals on at least one circle. Also, as shown in FIG. 4 , the multiple second gas holes 132 may be arranged along multiple concentric circles 132c. That is, the multiple second gas holes 132 may be arranged such that their center points are located on multiple concentric circles 132c centered on the axis AX. In each of the multiple concentric circles 132c, the center points of the multiple second gas holes 132 may be arranged at equal intervals. In the example shown in FIG. 4, the number of the concentric circles 132c is three, but the number of the concentric circles 132c is not limited to three.

[0053] The radius of an inscribed circle 132i of one or more second gas holes 132 provided at the innermost position and centered on the axis AX is the radius r of the outer periphery of the substrate support 11. １１ (see FIG. 2) The periphery of the substrate support 11 may be defined by an insulating region 116 and / or a conductive region 118.

[0054] In one embodiment, the plurality of first gas holes 131 may include a plurality of gas holes 311, a plurality of gas holes 312, and a plurality of gas holes 313. The plurality of gas holes 311 are formed in a central region of the upper electrode 13E. The central region of the upper electrode 13E is located above a central region of the substrate W. The plurality of gas holes 311 are distributed throughout the central region of the upper electrode 13E. The plurality of gas holes 313 are formed in an edge region of the upper electrode 13E. The edge region of the upper electrode 13E is located above an edge region of the substrate W. The plurality of gas holes 313 are distributed throughout the edge region of the upper electrode 13E. The plurality of gas holes 312 are formed in an intermediate region between the central region and edge region of the upper electrode 13E. The intermediate region of the upper electrode 13E is located above an intermediate region between the central region and edge region of the substrate W. The plurality of gas holes 312 are distributed throughout the intermediate region of the upper electrode 13E.

[0055] In one embodiment, the gas diffusion chamber 321 may include a gas diffusion chamber 3211, a gas diffusion chamber 3212, and a gas diffusion chamber 3213. The gas diffusion chambers 3211, 3212, and 3213 are separated from one another. The gas diffusion chamber 3211 is formed in a central region of the upper electrode 13E. The plurality of gas holes 311 are connected to the gas diffusion chamber 3211 and extend downward from the gas diffusion chamber 3211. The gas diffusion chamber 3212 is formed in an intermediate region of the upper electrode 13E. The plurality of gas holes 312 are connected to the gas diffusion chamber 3212 and extend downward from the gas diffusion chamber 3212. The gas diffusion chamber 3213 is formed in an edge region of the upper electrode 13E. The plurality of gas holes 313 are connected to the gas diffusion chamber 3213 and extend downward from the gas diffusion chamber 3213.

[0056] In one embodiment, the main gas supply unit 201m may be connected to the gas diffusion chamber 3211, the gas diffusion chamber 3212, and the gas diffusion chamber 3213 via the flow splitter 201s. That is, the main gas from the main gas supply unit 201m may be distributed by the flow splitter 201s to the gas diffusion chamber 3211, the gas diffusion chamber 3212, and the gas diffusion chamber 3213. In this case, the additive gas supply unit 201a may be connected to three gas lines that connect the flow splitter 201s to the gas diffusion chamber 3211, the gas diffusion chamber 3212, and the gas diffusion chamber 3213, respectively.

[0057] In one embodiment, the upper electrode 13E may include a top plate 133 and a cooling member 341 (first cooling member). The top plate 133 has a substantially disk shape. The central axis of the top plate 133 is the axis AX. The top plate 133 defines the plasma processing space 10s from above. That is, the top plate 133 is in contact with the plasma processing space 10s. The top plate 133 is made of a conductive material. The top plate 133 may be made of a material containing silicon, or may be made of silicon or silicon carbide.

[0058] The cooling member 341 is disposed on the top plate 133. The cooling member 341 may have a substantially disk shape. The cooling member 341 may support the top plate 133. The cooling member 341 is formed of a metal such as aluminum. The cooling member 341 is electrically connected to the top plate 133. The cooling member 341 may have the above-described gas diffusion chamber 321 therein.

[0059] The cooling member 341 has a flow path 341f therein. The flow path 341f receives a refrigerant supplied from the chiller unit 18. The refrigerant flows through the flow path 341f and is returned to the chiller unit 18. The top plate 133 is cooled by heat exchange with the cooling member 341. In one embodiment, a heat transfer sheet 351 (first heat transfer sheet) may be sandwiched between the top plate 133 and the cooling member 341. The heat transfer sheet 351 further promotes heat exchange between the top plate 133 and the cooling member 341.

[0060] In one embodiment, the upper assembly 13A may further include a cooling member 342 (second cooling member). The cooling member 342 is disposed on the conductive ring 15. The cooling member 342 is generally ring-shaped and surrounds the insulating ring 14. The cooling member 342 is formed from a metal such as aluminum. The cooling member 342 may be electrically connected to the conductive ring 15. The cooling member 342 may have the above-described gas diffusion chamber 322 therein.

[0061] The cooling member 342 has a flow path 342f therein. The flow path 342f receives a refrigerant supplied from the chiller unit 18. The refrigerant flows through the flow path 342f and is returned to the chiller unit 18. The conductive ring 15 is cooled by heat exchange with the cooling member 342. In one embodiment, a heat transfer sheet 352 (second heat transfer sheet) may be sandwiched between the conductive ring 15 and the cooling member 342. The heat transfer sheet 352 further promotes heat exchange between the conductive ring 15 and the cooling member 342.

[0062] In one embodiment, the outlet of flow path 341f may be connected to the inlet of flow path 342f via a pipe. In this case, the refrigerant from the chiller unit 18 flows through flow path 341f from the inlet to the outlet of flow path 341f, then flows through flow path 342f from the inlet to the outlet of flow path 342f, and is returned to the chiller unit 18 from the outlet of flow path 342f. Alternatively, two chiller units 18 may be connected to flow path 341f and flow path 342f, respectively.

[0063] The following describes examples of processing circuits that can be used as one or more processing circuits in the plasma processing apparatus 1, such as the controller 2 and / or the power supply controller. FIG. 5 is a block diagram of a processing circuit for implementing the operations described herein on a computer. FIG. 5 illustrates a processing circuit 130 that can be used to control a control process on any computer. The descriptions or blocks in the flowcharts represent modules, segments, or portions of code that include one or more executable instructions for implementing specific logical functions or steps of the process. As will be understood by those skilled in the art, other examples having functions that can be performed in a different order than that shown or described, such as substantially simultaneously or in reverse order, depending on the functionality involved, are within the scope of the exemplary embodiments of the present disclosure. The various elements, features, and processes described herein may be used independently of each other or combined in various ways. All conceivable combinations and subcombinations are within the scope of the present disclosure.

[0064] In Figure 5, processing circuitry 130 includes a CPU 1200 that performs one or more of the control processes described above and / or below. Process data and instructions may be stored in memory 1202. These process data and instructions may be stored on a storage medium disk 1204, such as a hard disk drive (HDD) or a portable storage medium, or may be stored remotely. Furthermore, the present disclosure as claimed is not limited by the form of computer-readable medium on which instructions for processes according to the present invention are stored. For example, these instructions may be stored on a CD, DVD, flash memory, RAM, ROM, PROM, EPROM, EEPROM, hard disk, or any other information processing device, such as a server and / or computer, with which processing circuitry 130 communicates.

[0065] Furthermore, the claimed disclosure may be provided as a utility application, a background daemon, a component of an operating system, or a combination thereof, and may execute in conjunction with CPU 1200 and an operating system known to those skilled in the art, such as Microsoft Windows®, UNIX®, Solaris®, LINUX®, Apple MAC-OS, etc.

[0066] The hardware elements making up the processing circuit 130 can be realized by various circuit elements. Furthermore, each function of the above-described embodiments can be implemented by a circuit including one or more processing circuits. As shown in FIG. 5, the processing circuit includes a specifically programmed processing unit, such as a processing unit (CPU) 1200. The processing circuit also includes devices such as application specific integrated circuits (ASICs) or conventional circuit components configured to perform the described functions.

[0067] 5, processing circuitry 130 includes a CPU 1200 that performs the above-described processing. Processing circuitry 130 may be a general-purpose computer or a specific dedicated machine. In one embodiment, processing circuitry 130 functions as a specific dedicated machine when processing device 1200 is programmed to control each part of plasma processing device 1, such as power supply 30, gas supply unit 20, and chiller unit 18.

[0068] Alternatively or additionally, CPU 1200 may be implemented on an FPGA, ASIC, PLD, or using discrete logic circuitry, as will be appreciated by those skilled in the art. Furthermore, CPU 1200 may be implemented as multiple processing units cooperating to perform in parallel the instructions of the processes of the present invention described above.

[0069] 5 also includes a network controller 1206, such as an Intel Ethernet PRO network interface card from Intel Corporation of America, for interfacing with a network 1228. As can be appreciated, the network 1228 may be a public network, such as the Internet, a private network, such as a LAN or WAN, or any combination thereof, and may include sub-networks, such as a PSTN or ISDN. The network 1228 may also be wired, such as an Ethernet network, or wireless, such as a cellular network, including EDGE, 3G, and 4G wireless cellular systems. The wireless network may also be Wi-Fi, Bluetooth, or any other known form of wireless communication.

[0070] The processing circuitry 130 further includes a display device controller 1208, such as a graphics card or graphics adapter, for interfacing with a display device 1210, such as a monitor. A general-purpose I / O interface 1212 interfaces with a keyboard and / or mouse 1214 and a touch panel 1216, which may be integral with or separate from the display device 1210. The general-purpose I / O interface also connects to various peripheral devices 1218, such as printers and scanners.

[0071] The storage controller 1224 is connected to the storage media disk 1204 via a communication bus 1226, such as ISA, EISA, VESA, PCI, etc., and all components of the processing circuit 130 are connected to each other. The display device 1210, keyboard and / or mouse 1214, and the general features and functions of the display device controller 1208, storage controller 1224, network controller 1206, audio controller 1220, and general purpose I / O interface 1212 are not described herein for the sake of brevity, as they are well known.

[0072] The exemplary circuit elements described in this disclosure may be substituted with other elements and may have different structures than the examples described herein. Furthermore, circuits configured to implement the features described herein may be implemented in multiple circuit units (e.g., chips), or these features may be combined into the circuitry of a single chipset.

[0073] The functions and features described herein may also be performed by various distributed components on a system. For example, one or more processing devices may perform the functions of these systems, where the processing devices are distributed across multiple components communicating within a network. Distributed components may include various human interface and communication devices (e.g., display monitors, smartphones, tablets, personal digital assistants (PDAs)), as well as one or more client and server machines that can share processing. The network may be a private network, such as a LAN or WAN, or a public network, such as the Internet. Input to the system may be received directly by a user or remotely in real time or as a batch process. Furthermore, portions of the embodiments may be implemented on modules or hardware other than those described above. Accordingly, other embodiments are within the scope of the claims.

[0074] Simulations performed to evaluate the plasma processing apparatus 1 are described below. In the simulations, the controllability of the side gas flow rate and the side gas concentration at the edge of a substrate on the substrate support 11 of the plasma processing apparatus 1 were determined. As described above, the side gas was a gas discharged from the second gas holes 132. The substrate had a diameter of 300 mm. In the simulations, the controllability of the side gas flow rate and the side gas concentration were determined while changing the distance r from the axis AX to the center point of each of the second gas holes 132, i.e., the radius of the circle along which the center points of the second gas holes 132 were arranged. The controllability of the side gas flow rate was determined as the ratio of the side gas flow rate at the edge of the substrate to the side gas flow rate at the center of the substrate. The side gas concentration was determined as the percentage of the side gas flow rate at the edge of the substrate relative to the flow rates at the edge of all gases discharged from the first gas holes 131 and the second gas holes 132.

[0075] The results of the simulation are shown in FIG. 6 . In the graph of FIG. 6 , the horizontal axis represents the distance r from the axis AX to the center point of each of the multiple second gas holes 132, the left vertical axis represents the controllability of the side gas flow rate, and the right vertical axis represents the side gas concentration. As shown in FIG. 6 , it was confirmed that high controllability of the side gas flow rate at the edge of the substrate was achieved when the distance r was 200 mm or more. It was also confirmed that high concentration of the side gas was achieved at the edge of the substrate when the distance r was 250 mm or less. Therefore, it was confirmed that high controllability of the side gas flow rate and high concentration of the side gas were achieved at the edge of the substrate when the radial distance from the axis AX to the center point of each of the multiple second gas holes 132 was 200 mm or more and 250 mm or less.

[0076] The following describes first to fourth experiments conducted to evaluate the plasma processing apparatus 1. In the first to fourth experiments, plasma etching was performed on a resist film of a sample substrate using the plasma processing apparatus 1. In the first to fourth experiments, H ２ A process gas containing a gas, a halogen-containing gas, and a hydrofluorocarbon gas was supplied into the chamber 10 as a gas for plasma etching. In the first experiment, C ４ F ８ In the second experiment, C gas was further supplied as a deposition gas from the plurality of second gas holes 132. ４ F ８ In the third experiment, C gas was supplied from the plurality of gas holes 313 as a deposition gas. ４ F ６ In the fourth experiment, C gas was supplied from the plurality of second gas holes 132 as a deposition gas. ４ F ６ In the first to fourth experiments, the flow rate of the deposition gas was adjusted so that the etching rates of the resist film at the center of the sample substrate were the same.

[0077] In the first to fourth experiments, the etching rate of the resist film was determined at each of multiple positions radially relative to the center of the sample substrate. The results are shown in FIG. 7 . In FIG. 7 , the horizontal axis represents the radial distance from the center of the sample substrate for each of the multiple positions, and the vertical axis represents the normalized etching rate. The normalized etching rate is a value obtained by normalizing the etching rate at each of the multiple positions with the etching rate at the same position in the first experiment. Comparisons between the first and second experiments and between the third and fourth experiments demonstrate that supplying deposition gas from multiple second gas holes 132 significantly improves the etching rate at the edge of the sample substrate compared to supplying deposition gas from multiple gas holes 313. Therefore, it was confirmed that the plasma processing apparatus 1 can improve the controllability of the plasma processing rate at the edge of the substrate.

[0078] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to Fig. 8. Fig. 8 is a diagram showing a plasma processing apparatus according to another exemplary embodiment. The plasma processing apparatus 1B shown in Fig. 8 will be described below from the viewpoint of differences from the plasma processing apparatus 1 shown in Figs. 2 and 3.

[0079] The plasma processing apparatus 1B differs from the plasma processing apparatus 1 in that it includes an upper assembly 13B instead of the upper assembly 13A. Other configurations of the plasma processing apparatus 1B may be similar to other configurations of the plasma processing apparatus 1.

[0080] In the upper assembly 13B, the upper electrode 13E and the conductive ring 15 are both electrically grounded. In one embodiment, the upper assembly 13B may further include a conductor 350. The conductor 350 may be made of a conductive material, for example, a metal such as aluminum. The conductor 350 electrically connects the upper electrode 13E and the conductive ring 15 to each other. The upper electrode 13E and the conductive ring 15 may be electrically connected to each other via the cooling member 341, the conductor 350, and the cooling member 342. In this case, the conductor 350 is interposed between the cooling members 341 and 342 and electrically connects the cooling members 341 and 342 to each other. The conductor 350 may extend circumferentially around the axis line AX in the space between the cooling members 341 and 342. The conductor 350 may have a ring shape. The upper assembly 13B may be electrically grounded. For example, in the upper assembly 13B, the upper electrode 13E and the conductive ring 15 may be electrically grounded. When the upper assembly 13B is electrically grounded, the conductive ring 15 and the top plate 133 may be integrated, and the cooling members 341 and 342 may be integrated. Furthermore, when the upper assembly 13B is electrically grounded, the upper assembly 13B does not need to include the first insulating ring 141.

[0081] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to Fig. 9. Fig. 9 is a diagram showing a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 1C shown in Fig. 9 will be described below from the viewpoint of differences from the plasma processing apparatus 1 shown in Figs. 2 and 3.

[0082] The plasma processing apparatus 1C differs from the plasma processing apparatus 1 in that it includes an upper assembly 13C instead of the upper assembly 13A. Other configurations of the plasma processing apparatus 1C may be similar to other configurations of the plasma processing apparatus 1.

[0083] In the upper assembly 13C, the second gas holes 132 may extend obliquely downward so as to approach the axis AX from their upper end to their lower end. In the upper assembly 13C, the second gas holes 132 may extend toward the edge of the central region 111a (substrate support surface) or the edge of the substrate W placed on the central region 111a, and open toward the edge of the central region 111a or the edge of the substrate W. The upper assembly 13C allows gas from the second gas holes 132 to be supplied almost directly to the edge of the substrate. This improves controllability of the plasma processing rate at the edge of the substrate W. In the upper assembly 13C, the lower surface of the conductive ring 15 extends at approximately the same height as the lower surface of the upper electrode 13E (e.g., the lower surface of the top plate 133). The upper assembly 13C may be electrically grounded. In the upper assembly 13C, similarly to the upper assembly 13B, the upper electrode 13E may be electrically grounded together with the conductive ring 15. When the upper assembly 13C is electrically grounded, the conductive ring 15 and the top plate 133 may be integrated, and the cooling members 341 and 342 may be integrated. Furthermore, when the upper assembly 13C is electrically grounded, the upper assembly 13C does not need to include the first insulating ring 141 and the second insulating ring 142.

[0084] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to Fig. 10. Fig. 10 is a diagram showing a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 1D shown in Fig. 10 will be described below from the viewpoint of differences from the plasma processing apparatus 1 shown in Figs. 2 and 3.

[0085] The plasma processing apparatus 1D differs from the plasma processing apparatus 1 in that it includes an upper assembly 13D instead of the upper assembly 13A. Other configurations of the plasma processing apparatus 1D may be similar to those of the plasma processing apparatus 1. The upper assembly 13D may be electrically grounded, similar to the upper assembly 13B. For example, in the upper assembly 13D, the upper electrode 13E and the conductive ring 15 may be electrically grounded. When the upper assembly 13D is electrically grounded, the conductive ring 15 and the top plate 133 may be integrated, and the cooling members 341 and 342 may be integrated. When the upper assembly 13D is electrically grounded, the upper assembly 13D may not include the first insulating ring 141 and the second insulating ring 142.

[0086] In the upper assembly 13D, the conductive ring 15 provides open ends of the plurality of second gas holes 132 on its lower surface, which extends substantially horizontally below the lower surface of the upper electrode 13E (e.g., the lower surface of the top plate 133). Outside the lower surface of the conductive ring 15, the lower surface of the upper assembly 13D may be flush with the lower surface of the conductive ring 15. Between the lower surface of the conductive ring 15 and the lower surface of the upper electrode 13E, the surface of the conductive ring 15 facing the plasma processing space 10s forms a slope that approaches the axis AX as it approaches the upper end from the lower end. With the upper assembly 13D, the open ends of the plurality of second gas holes 132 are closer to the edge of the substrate W. This improves controllability of the plasma processing rate at the edge of the substrate W.

[0087] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0088] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E25] below.

[0089] a plasma generating unit configured to generate plasma in the chamber; a substrate supporting unit in the chamber; an upper assembly disposed above the plasma processing space, the upper assembly including: an upper electrode disposed above the substrate supporting unit, the upper electrode having a plurality of first gas holes opening toward the plasma processing space; an insulating ring surrounding the upper electrode; and a conductive ring disposed above a space between the substrate supporting unit and a sidewall of the chamber, the conductive ring having a plurality of second gas holes opening toward the plasma processing space, the conductive ring surrounding the insulating ring; and a gas supply unit configured to supply gas to be discharged into the plasma processing space to the plurality of first gas holes and the plurality of second gas holes.

[0090] [E2] The plasma processing apparatus according to E1, wherein a radial distance from a central axis of the conductive ring and the substrate support part to a center point of each of the plurality of second gas holes is 200 mm or more and 250 mm or less.

[0091] [E3] The plasma processing apparatus described in E2, wherein the conductive ring includes a gas hole formation region in which the plurality of second gas holes are formed, the radius of an inner edge of the gas hole formation region relative to the central axis is equal to or greater than the radius of the inner edge of the conductive ring, and the radius of an outer edge of the gas hole formation region relative to the central axis is equal to or less than half the sum of the radius of the inner edge and the radius of the outer edge of the conductive ring.

[0092] [E4] The plasma processing apparatus according to E3, wherein the conductive ring does not have gas holes outside the gas hole formation region.

[0093] [E5] The plasma processing apparatus according to any one of E2 to E4, wherein the second gas holes are arranged along a plurality of concentric circles around the central axis.

[0094] [E6] The plasma processing apparatus according to any one of E2 to E5, wherein the radius of an inscribed circle centered on the central axis of one or more second gas holes provided at the innermost position among the plurality of second gas holes is larger than the radius of the outer periphery of the substrate support part.

[0095] [E7] The plasma processing apparatus according to any one of E1 to E6, wherein the gas supply unit includes: a first gas supply unit that supplies the gas to be discharged into the plasma processing space to the plurality of first gas holes; and a second gas supply unit that is independent of the first gas supply unit and supplies the gas to be discharged into the plasma processing space to the plurality of second gas holes.

[0096] [E8] The plasma processing apparatus according to any one of E1 to E7, wherein the conductive ring is grounded.

[0097] [E9] The plasma processing apparatus according to E8, wherein the upper electrode is grounded.

[0098] [E10] The plasma processing apparatus according to any one of E1 to E9, wherein the substrate support portion includes a substrate support surface that supports a substrate, and the plurality of second gas holes extend obliquely downward toward an edge of the substrate support surface or an edge of a substrate placed on the substrate support surface.

[0099] [E11] The plasma processing apparatus according to any one of E1 to E9, wherein the conductive ring includes a lower surface extending below a lower surface of the upper electrode, and the lower surface of the conductive ring provides open ends of the plurality of second gas holes.

[0100] [E12] The plasma processing apparatus according to any one of E1 to E11, wherein the upper electrode includes: a top plate having the plurality of first gas holes; a first cooling member having a refrigerant flow path and arranged on the top plate; and a first heat transfer sheet sandwiched between the first cooling member and the top plate; and the upper assembly further includes: a second cooling member having a refrigerant flow path and arranged on the conductive ring; and a second heat transfer sheet sandwiched between the second cooling member and the conductive ring.

[0101] [E13] The plasma processing apparatus according to any one of E1 to E12, wherein the plasma generating unit includes an RF power supply electrically coupled to the substrate support unit.

[0102] [E14] An upper assembly arranged above a plasma processing space in a chamber in a capacitively coupled plasma processing apparatus, comprising: an upper electrode having a plurality of first gas holes opening toward the plasma processing space and arranged above a substrate support part in the chamber; an insulating ring surrounding the upper electrode; and a conductive ring having a plurality of second gas holes opening toward the plasma processing space, surrounding the insulating ring, and arranged above a space between the substrate support part and a side wall of the chamber.

[0103] [E15] The upper assembly according to E14, wherein a radial distance from a central axis of the conductive ring to a center point of each of the plurality of second gas holes is equal to or greater than 200 mm and equal to or less than 250 mm.

[0104] [E16] The upper assembly described in E15, wherein the conductive ring includes a gas hole formation region in which the plurality of second gas holes are formed, the radius of the inner edge of the gas hole formation region relative to the central axis is equal to or greater than the radius of the inner edge of the conductive ring, and the radius of the outer edge of the gas hole formation region relative to the central axis is equal to or less than 1 / 2 of the sum of the radius of the inner edge and the radius of the outer edge of the conductive ring.

[0105] [E17] The upper assembly according to E16, wherein the conductive ring does not have gas holes outside the gas hole formation region.

[0106] [E18] The upper assembly according to any one of E15 to E17, wherein the second gas holes are arranged along a plurality of concentric circles around the central axis.

[0107] [E19] The upper assembly of any one of E14 to E18, wherein the conductive ring is grounded.

[0108] [E20] The upper assembly of E19, wherein the upper electrode is grounded.

[0109] [E21] The upper assembly described in any one of E14 to E20, wherein the substrate support portion includes a substrate support surface that supports a substrate, and the plurality of second gas holes extend obliquely downward toward an edge of the substrate support surface or an edge of a substrate placed on the substrate support surface.

[0110] [E22] The upper assembly described in any one of E14 to E20, wherein the conductive ring includes a lower surface that extends below a lower surface of the upper electrode, and the lower surface of the conductive ring provides open ends of the plurality of second gas holes.

[0111] [E23] An upper assembly described in any one of E14 to E22, wherein the upper electrode includes: a top plate having the plurality of first gas holes; a first cooling member having a refrigerant flow path and arranged on the top plate; and a first heat transfer sheet sandwiched between the first cooling member and the top plate; and the upper assembly further includes: a second cooling member having a refrigerant flow path and arranged on the conductive ring; and a second heat transfer sheet sandwiched between the second cooling member and the conductive ring.

[0112] [E24] A plasma processing apparatus comprising: a chamber having a plasma processing space; a plasma generation unit configured to generate plasma in the chamber; a substrate support unit in the chamber; and an upper assembly arranged above the plasma processing space, the upper assembly having: a plurality of first gas holes above the substrate support unit opening toward the plasma processing space; and a plurality of second gas holes opening toward the plasma processing space outside the plurality of first gas holes in a radial direction with respect to a central axis of the substrate support unit; and a gas supply unit configured to supply gas discharged into the plasma processing space to the plurality of first gas holes and the plurality of second gas holes, wherein a radial distance from the central axis of the substrate support unit to a center point of each of the plurality of second gas holes is 200 mm or more and 250 mm or less.

[0113] [E25] The plasma processing apparatus of E24, wherein the upper assembly is grounded.

[0114] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0115] 1... plasma processing apparatus, 10... chamber, 11... substrate support, 13A... upper assembly, 13E... upper electrode, 14... insulating ring, 15... conductive ring, 131... first gas hole, 132... second gas hole.

Claims

a plasma generating unit configured to generate plasma in the chamber; a substrate support within the chamber; an upper assembly disposed above the plasma processing space, the upper assembly including: an upper electrode disposed above the substrate support, the upper electrode having a plurality of first gas holes opening into the plasma processing space; an insulating ring surrounding the upper electrode; and a conductive ring disposed above a space between the substrate support and a sidewall of the chamber, the conductive ring having a plurality of second gas holes opening into the plasma processing space, the conductive ring surrounding the insulating ring; and a gas supply unit configured to supply gas to be discharged into the plasma processing space to the plurality of first gas holes and the plurality of second gas holes.

2. The plasma processing apparatus according to claim 1, wherein the radial distance from the central axis of said conductive ring and said substrate support part to the center point of each of said plurality of second gas holes is 200 mm or more and 250 mm or less.

3. The plasma processing apparatus of claim 2, wherein the conductive ring includes a gas hole formation region in which the plurality of second gas holes are formed, the radius of the inner edge of the gas hole formation region relative to the central axis is equal to or greater than the radius of the inner edge of the conductive ring, and the radius of the outer edge of the gas hole formation region relative to the central axis is equal to or less than half the sum of the radius of the inner edge and the radius of the outer edge of the conductive ring.

4. The plasma processing apparatus according to claim 3, wherein said conductive ring has no gas holes outside said gas hole forming region.

5. A plasma processing apparatus according to any one of claims 2 to 4, wherein the plurality of second gas holes are arranged along a plurality of concentric circles around the central axis.

6. A plasma processing apparatus according to any one of claims 2 to 4, wherein the radius of an inscribed circle centered on the central axis of one or more second gas holes located innermost among the plurality of second gas holes is larger than the radius of the outer periphery of the substrate support part.

7. A plasma processing apparatus according to any one of claims 1 to 4, wherein the gas supply unit includes: a first gas supply unit that supplies the gas to be discharged into the plasma processing space to the plurality of first gas holes; and a second gas supply unit that is independent of the first gas supply unit and that supplies the gas to be discharged into the plasma processing space to the plurality of second gas holes.

8. The plasma processing apparatus according to any one of claims 1 to 4, wherein the conductive ring is grounded.

9. The plasma processing apparatus according to claim 8, wherein the upper electrode is grounded.

10. The plasma processing apparatus according to any one of claims 1 to 4, wherein the substrate support portion includes a substrate support surface that supports a substrate, and the plurality of second gas holes extend obliquely downward toward an edge of the substrate support surface or an edge of a substrate placed on the substrate support surface.

11. The plasma processing apparatus according to any one of claims 1 to 4, wherein the conductive ring includes a lower surface that extends below a lower surface of the upper electrode, and the lower surface of the conductive ring provides open ends of the plurality of second gas holes.

12. A plasma processing apparatus as described in any one of claims 1 to 4, wherein the upper electrode includes: a top plate having the plurality of first gas holes; a first cooling member having a refrigerant flow path and arranged on the top plate; and a first heat transfer sheet sandwiched between the first cooling member and the top plate; and the upper assembly further includes: a second cooling member having a refrigerant flow path and arranged on the conductive ring; and a second heat transfer sheet sandwiched between the second cooling member and the conductive ring.

13. The plasma processing apparatus according to any one of claims 1 to 4, wherein the plasma generating section includes an RF power supply electrically coupled to the substrate support section.

14. An upper assembly disposed above a plasma processing space in a chamber of a capacitively coupled plasma processing apparatus, comprising: an upper electrode having a plurality of first gas holes opening into the plasma processing space and disposed above a substrate support in the chamber; an insulating ring surrounding the upper electrode; and a conductive ring having a plurality of second gas holes opening into the plasma processing space, surrounding the insulating ring, and disposed above a space between the substrate support and a sidewall of the chamber.

15. The upper assembly according to claim 14, wherein the radial distance from the central axis of said conductive ring to the center point of each of said plurality of second gas holes is not less than 200 mm and not more than 250 mm.

16. The upper assembly described in claim 15, wherein the conductive ring includes a gas hole forming region in which the plurality of second gas holes are formed, the radius of the inner edge of the gas hole forming region relative to the central axis is equal to or greater than the radius of the inner edge of the conductive ring, and the radius of the outer edge of the gas hole forming region relative to the central axis is equal to or less than half the sum of the radius of the inner edge and the radius of the outer edge of the conductive ring.

17. The upper assembly according to claim 16, wherein the conductive ring has no gas holes outside the gas hole forming region.

18. An upper assembly according to any one of claims 15 to 17, wherein the plurality of second gas holes are arranged along a plurality of concentric circles around the central axis.

19. An upper assembly as claimed in any one of claims 14 to 17, wherein the conductive ring is grounded.

20. The upper assembly of claim 19, wherein the upper electrode is grounded.

21. An upper assembly according to any one of claims 14 to 17, wherein the substrate support portion includes a substrate support surface that supports a substrate, and the plurality of second gas holes extend obliquely downward toward an edge of the substrate support surface or an edge of a substrate placed on the substrate support surface.

22. An upper assembly as described in any one of claims 14 to 17, wherein the conductive ring includes a lower surface that extends below a lower surface of the upper electrode, and the lower surface of the conductive ring provides open ends of the plurality of second gas holes.

23. An upper assembly as described in any one of claims 14 to 17, wherein the upper electrode includes: a top plate having the plurality of first gas holes; a first cooling member having a refrigerant flow path and disposed on the top plate; and a first heat transfer sheet sandwiched between the first cooling member and the top plate; and the upper assembly further includes: a second cooling member having a refrigerant flow path and disposed on the conductive ring; and a second heat transfer sheet sandwiched between the second cooling member and the conductive ring.

24. A plasma processing apparatus comprising: a chamber having a plasma processing space; a plasma generation unit configured to generate plasma in the chamber; a substrate support unit within the chamber; and an upper assembly disposed above the plasma processing space, the upper assembly having: a plurality of first gas holes above the substrate support unit opening toward the plasma processing space; and a plurality of second gas holes opening toward the plasma processing space radially outside the plurality of first gas holes relative to a central axis of the substrate support unit; and a gas supply unit configured to supply gas discharged into the plasma processing space to the plurality of first gas holes and the plurality of second gas holes, wherein the radial distance from the central axis of the substrate support unit to the center point of each of the plurality of second gas holes is 200 mm or more and 250 mm or less.

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