Plasma processing equipment

Abstract

The present invention provides a plasma processing apparatus that can suppress electromagnetic waves propagating along the inner wall of a processing vessel. [Solution] The plasma processing apparatus comprises a processing container that houses a substrate and defines a processing space with a top wall, side walls, and a bottom wall; a microwave generating unit configured to generate microwaves for generating plasma; a microwave radiating unit provided above the top wall and configured to radiate microwaves toward the processing container; a microwave transmission window made of dielectric material provided at a position corresponding to the microwave radiating unit on the top wall; and a resonator array structure arranged in at least one of the walls of the top wall and side walls, formed by arranging a plurality of resonators that are capable of resonating with the magnetic field component of microwaves and whose size is smaller than the wavelength of microwaves.

Description

[Technical Field]

[0001] This disclosure relates to a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a plasma processing apparatus having multiple microwave radiation mechanisms on the top wall of the processing vessel. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-031706 [Overview of the project] [Problems that the invention aims to solve]

[0004] This disclosure provides a plasma processing apparatus that can suppress electromagnetic waves propagating along the inner wall of a processing vessel. [Means for solving the problem]

[0005] A plasma processing apparatus according to one aspect of the present disclosure includes a processing vessel for housing a substrate and defining a processing space by a top wall, side walls, and a bottom wall; a microwave generating unit configured to generate microwaves for generating plasma; a microwave radiating unit provided above the top wall and configured to radiate microwaves toward the processing vessel; a microwave transmission window made of dielectric material provided at a position corresponding to the microwave radiating unit on the top wall; and a resonator array structure arranged in at least one of the walls of the top wall and side walls, formed by arranging a plurality of resonators that are capable of resonating with the magnetic field component of microwaves and whose size is smaller than the wavelength of microwaves. [Effects of the Invention]

[0006] According to this disclosure, electromagnetic waves propagating along the inner wall of the processing container can be suppressed.

Brief Description of the Drawings

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus according to this embodiment. [Figure 2] FIG. 2 is a view showing an example of the configuration of a microwave introduction apparatus according to this embodiment. [Figure 3] FIG. 3 is a view schematically showing an example of a microwave radiation mechanism according to this embodiment. [Figure 4] FIG. 4 is a plan view schematically showing an example of the top wall portion of a processing container according to this embodiment. [Figure 5] FIG. 5 is a perspective view schematically showing an example of the top wall portion of a processing container according to this embodiment. [Figure 6] FIG. 6 is a view showing an example of the relationship between the traveling direction of an electromagnetic wave and the direction of a ring member according to this embodiment. [Figure 7] FIG. 7 is a view showing an example of the configuration of a resonator according to this embodiment. [Figure 8] FIG. 8 is a view showing an example of the configuration of a resonator according to this embodiment. [Figure 9] FIG. 9 is a view showing another example of the configuration of a resonator according to this embodiment. [Figure 10] FIG. 10 is a view showing an example of a cross-section of a resonator according to this embodiment. [Figure 11] FIG. 11 is a view showing an example of the arrangement of resonators in a resonator array structure according to this embodiment. [Figure 12] FIG. 12 is a view showing an example of the arrangement of resonators in a resonator array structure according to this embodiment. [Figure 13] FIG. 13 is a view showing an example of the relationship between the S21 value of a resonator and the frequency of a microwave. [Figure 14] FIG. 14 is a view showing an example of a simulation model. [Figure 15] FIG. 15 is an enlarged view showing an example near the sheath of a simulation model. [Figure 16]FIG. 16 is a graph showing an example of the relationship between the relative permeability of the resonator array structure and the power absorbed by the plasma. [Figure 17] FIG. 17 is a diagram showing an example of the simulation results when the relative permeability of the resonator array structure is a positive value. [Figure 18] FIG. 18 is a diagram showing an example of the simulation results when the relative permeability of the resonator array structure is a negative value. [Figure 19] FIG. 19 is an enlarged view showing an example of the vicinity of the sheath of the simulation model when there is a conductive film. [Figure 20] FIG. 20 is a graph showing an example of the relationship between the conductivity of the conductive film and the power absorbed by the plasma and the conductive film. [Figure 21] FIG. 21 is a graph showing an example of the relationship between the relative permeability of the resonator array structure and the power absorbed by the plasma and the conductive film. [Figure 22] FIG. 22 is a diagram showing an example of the simulation results when there is a conductive film and the relative permeability of the resonator array structure is a positive value. [Figure 23] FIG. 23 is a diagram showing an example of the simulation results when there is a conductive film and the relative permeability of the resonator array structure is a negative value. [Figure 24] FIG. 24 is a perspective view schematically showing an example of the side wall portion of the processing vessel according to the first modification. [Figure 25] FIG. 25 is a diagram showing an example of the relationship between the traveling direction of the electromagnetic wave, the resonator array structure, and the gas introduction nozzle according to the first modification. [Figure 26] FIG. 26 is a plan view showing an example of the configuration of the dielectric window and the resonator array structure according to the second modification as viewed from below. MODE FOR CARRYING OUT THE INVENTION

[0008] Hereinafter, embodiments of the disclosed plasma processing apparatus will be described in detail based on the drawings. Note that the disclosed technology is not limited by the following embodiments.

[0009] Incidentally, in plasma processing equipment that uses microwaves for plasma excitation, the power of the microwaves supplied into the processing vessel is sometimes increased to increase the electron density of the plasma. The higher the power of the microwaves supplied into the processing vessel, the higher the electron density of the plasma can be.

[0010] Here, it is known that when the electron density of the plasma reaches a certain upper limit by increasing the power of the microwaves supplied into the processing vessel, the dielectric constant of the space inside the processing vessel becomes negative. This upper limit of electron density is appropriately called the "cutoff density." In addition, the refractive index is known as an indicator of whether microwaves propagate through space or not. The refractive index N is expressed by the following equation (1). N = √ε√μ ···(1) However, ε is the permittivity and μ is the permeability.

[0011] Since magnetic permeability is generally positive, if the dielectric constant of the space inside the processing container is negative, then according to equation (1) above, the refractive index of the space inside the processing container becomes a purely imaginary number. As a result, microwaves are attenuated and cannot propagate through the space inside the processing container. Thus, when the electron density of the plasma reaches the cutoff density, microwaves cannot propagate through the space inside the processing container, and the power of the microwaves is not sufficiently absorbed by the plasma. Consequently, there is a problem in that the densification of the plasma generated over a wide area inside the processing container is hindered.

[0012] Furthermore, in plasma processing equipment having a microwave radiation section on the top wall of the processing vessel, plasma is generated directly beneath the top wall. In such plasma processing equipment, surface waves propagating along the plasma interface can spread widely along the top wall. As a result, discharges may occur or particle sources may develop in gaps near the connection between the top wall and the side walls, or in gas introduction nozzles. Therefore, it is expected that electromagnetic waves propagating along the inner wall of the processing vessel can be suppressed by eliminating the propagation mode of surface waves on the inner wall of the processing vessel.

[0013] [Configuration of Plasma Processing System] Figure 1 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus according to this embodiment. The plasma processing apparatus 100 shown in Figure 1 includes a processing vessel 101, a mounting table 102, a gas supply mechanism 103, an exhaust device 104, a microwave introduction device 105, and a control unit 106. The processing vessel 101 houses the substrate W. The mounting table 102 places the substrate W on it. The gas supply mechanism 103 supplies gas into the processing vessel 101. The exhaust device 104 exhausts the inside of the processing vessel 101. The microwave introduction device 105 generates microwaves to generate plasma inside the processing vessel 101 and introduces microwaves into the processing vessel 101. The control unit 106 controls the operation of each part of the plasma processing apparatus 100.

[0014] The processing container 101 is made of a metallic material such as aluminum or its alloys, and provides a substantially cylindrical processing space S inside. The processing container 101 has a plate-shaped top wall portion 111 and a bottom wall portion 113, and side walls 112 connecting them. The microwave introduction device 105 is provided on top of the processing container 101 and functions as a plasma generation means that generates plasma by introducing electromagnetic waves (microwaves) into the processing container 101. The microwave introduction device 105 will be described in detail later.

[0015] The top wall 111 has multiple openings into which the microwave radiation mechanism, resonator array structure, and gas introduction section of the microwave introduction device 105, described later, are fitted. The side wall 112 has an inlet / outlet 114 for loading and unloading the substrate W, which is the object to be processed, between the processing container 101 and a transport chamber (not shown) adjacent to it. The inlet / outlet 114 is opened and closed by a gate valve 115. An exhaust device 104 is provided in the bottom wall 113. The exhaust device 104 is provided in an exhaust pipe 116 connected to the bottom wall 113 and is equipped with a vacuum pump and a pressure control valve. The vacuum pump of the exhaust device 104 exhausts the inside of the processing container 101 via the exhaust pipe 116. The pressure inside the processing container 101 is controlled by the pressure control valve.

[0016] The mounting base 102 is disc-shaped and made of ceramics such as AlN. The mounting base 102 is supported by a cylindrical support member 120 made of ceramics such as AlN that extends upward from the center of the bottom of the processing container 101. A guide ring 181 for guiding the substrate W is provided on the outer edge of the mounting base 102. Inside the mounting base 102, a lifting pin (not shown) for raising and lowering the substrate W is provided so as to be able to protrude from and retract relative to the upper surface of the mounting base 102. Furthermore, a resistance heating type heater 182 is embedded inside the mounting base 102, and this heater 182 is powered by a heater power supply 183 to heat the substrate W on the mounting base 102. In addition, a thermocouple (not shown) is inserted into the mounting base 102, and based on the signal from the thermocouple, the heating temperature of the substrate W can be controlled to a predetermined temperature in the range of, for example, 300 to 1000°C. Furthermore, an electrode 184, approximately the same size as the substrate W, is embedded above the heater 182 within the mounting base 102, and a high-frequency bias power supply 122 is electrically connected to this electrode 184. A high-frequency bias is applied to the electrode 184 from this high-frequency bias power supply 122 to draw ions into the mounting base 102. Note that the high-frequency bias power supply 122 may not be provided depending on the characteristics of the plasma processing.

[0017] The gas supply mechanism 103 is for introducing plasma generation gas and raw material gas for forming films to be deposited, such as carbon films, into the processing container 101, and has a plurality of gas introduction nozzles 123. The gas introduction nozzles 123 are fitted into openings formed in the top wall portion 111 of the processing container 101. Gas supply piping 191 is connected to the gas introduction nozzles 123. This gas supply piping 191 branches into five branch pipes 191a, 191b, 191c, 191d, and 191e. Ar gas supply source 192, O2 gas supply source 193, N2 gas supply source 194, H2 gas supply source 195, and C2H2 gas supply source 196 are connected to these branch pipes 191a, 191b, 191c, 191d, and 191e. The Ar gas supply source 192 supplies Ar gas as a noble gas (precious gas) which is the plasma generation gas. O2 gas source 193 supplies O2 gas as an oxidizing gas, which is a cleaning gas. N2 gas source 194 supplies N2 gas, which is used as a purging gas, etc. H2 gas source 195 supplies H2 gas as a reducing gas. C2H2 gas source 196 supplies acetylene (C2H2) gas as a carbon-containing gas, which is a film-forming raw material gas. Note that C2H2 gas source 196 may also supply other carbon-containing gases such as ethylene (C2H4).

[0018] Although not shown in the diagram, branch pipes 191a, 191b, 191c, 191d, and 191e are equipped with mass flow controllers and valves before and after them for flow rate control. Furthermore, by providing a shower plate to supply C2H2 gas and H2 gas to a position closer to the substrate W, gas dissociation can be adjusted. A similar effect can also be achieved by extending the nozzles supplying these gases downwards.

[0019] As described above, the microwave introduction device 105 is installed above the processing vessel 101 and functions as a plasma generation means that introduces electromagnetic waves (microwaves) into the processing vessel 101 to generate plasma.

[0020] Figure 2 shows an example of the configuration of a microwave introduction device according to this embodiment. As shown in Figures 1 and 2, the microwave introduction device 105 has a top wall portion 111 of the processing container 101, a microwave output unit 130, and an antenna unit 140. The top wall portion 111 functions as a top plate. The microwave output unit 130 generates microwaves and distributes and outputs the microwaves to multiple paths. The antenna unit 140 introduces the microwaves output from the microwave output unit 130 into the processing container 101.

[0021] The microwave output unit 130 includes a microwave power supply 131, a microwave oscillator 132, an amplifier 133, and a distributor 134. The microwave oscillator 132 is solid-state and, for example, oscillates microwaves at 2.45 GHz (e.g., PLL oscillation). Note that the microwave frequency is not limited to 2.45 GHz, but can be any frequency in the range of 700 MHz to 10 GHz, such as 915 MHz, 8.35 GHz, 5.8 GHz, or 1.98 GHz. The amplifier 133 amplifies the microwaves oscillated by the microwave oscillator 132. The distributor 134 distributes the microwaves amplified by the amplifier 133 to multiple paths. The distributor 134 distributes the microwaves while matching the impedance of the input and output sides.

[0022] Furthermore, the microwave output unit 130 allows for adjustment of the microwave frequency, power, and bandwidth. For example, the microwave output unit 130 can generate a single-frequency microwave by setting the microwave bandwidth to approximately 0. The microwave output unit 130 can also generate a microwave containing multiple frequency components belonging to a predetermined frequency bandwidth (hereinafter referred to as "broadband microwave" as appropriate). The power of these multiple frequency components may be the same, or only the central frequency component within the bandwidth may have a higher power than the other frequency components. The microwave output unit 130 can adjust the microwave power within a range of, for example, 0W to 5000W. The microwave output unit 130 can adjust the microwave frequency or the central frequency of the broadband microwave within a range of, for example, 2.3GHz to 2.5GHz, and can adjust the bandwidth of the broadband microwave within a range of, for example, 0MHz to 100MHz. Furthermore, the microwave output unit 130 can adjust the frequency pitch (carrier pitch) of multiple frequency components of the broadband microwave, for example, within a range of 0 to 25 kHz. Note that the microwave output unit 130 is an example of a microwave generator.

[0023] The antenna unit 140 includes a plurality of antenna modules 141. Each of the plurality of antenna modules 141 introduces microwaves distributed by the distributor 134 into the processing container 101. The configuration of all of the plurality of antenna modules 141 is identical. Each antenna module 141 has an amplifier section 142 that mainly amplifies and outputs the distributed microwaves, and a microwave radiation mechanism 143 that radiates the microwaves output from the amplifier section 142 into the processing container 101.

[0024] The amplifier section 142 includes a phase shifter 145, a variable gain amplifier 146, a main amplifier 147, and an isolator 148. The phase shifter 145 changes the phase of the microwave. The variable gain amplifier 146 adjusts the power level of the microwave input to the main amplifier 147. The main amplifier 147 is configured as a solid-state amplifier. The isolator 148 separates the reflected microwave that is reflected by the antenna section of the microwave radiation mechanism 143 (described later) and heads towards the main amplifier 147.

[0025] Here, the microwave radiation mechanism 143 will be described using Figure 3. Figure 3 is a schematic diagram showing an example of the microwave radiation mechanism according to this embodiment. Multiple microwave radiation mechanisms 143 are provided on the top wall portion 111, as shown in Figure 1. Also, as shown in Figure 3, the microwave radiation mechanism 143 has a cylindrical outer conductor 152 and an inner conductor 153 provided coaxially with the outer conductor 152. The microwave radiation mechanism 143 has a coaxial tube 151 having a microwave transmission path between the outer conductor 152 and the inner conductor 153, a tuner 154, a power supply unit 155, and an antenna unit 156. The tuner 154 matches the impedance of the load to the characteristic impedance of the microwave power supply 131. The power supply unit 155 supplies amplified microwaves from the amplifier unit 142 to the microwave transmission path. The antenna unit 156 radiates microwaves from the coaxial tube 151 into the processing container 101. Note that the microwave radiation mechanism 143 is an example of a microwave radiation section.

[0026] The power supply unit 155 receives microwaves amplified by the amplifier unit 142 via a coaxial cable from the side of the upper end of the outer conductor 152, and radiates microwaves, for example, through a power supply antenna. This microwave radiation supplies microwave power to the microwave transmission path between the outer conductor 152 and the inner conductor 153, and the microwave power propagates toward the antenna unit 156.

[0027] The antenna section 156 is provided at the lower end of the coaxial tube 151. The antenna section 156 includes a disc-shaped planar antenna 161 connected to the lower end of the inner conductor 153, a slow-wave material 162 positioned on the upper side of the planar antenna 161, and a microwave-transmitting plate 163 positioned on the lower side of the planar antenna 161. The microwave-transmitting plate 163 is an example of a microwave-transmitting window. The microwave-transmitting plate 163 is fitted into the top wall section 111, and its lower surface is exposed to the internal space of the processing container 101. The planar antenna 161 has a slot 161a formed to penetrate through it. The shape of the slot 161a is appropriately set so that microwaves are radiated efficiently. A dielectric material may be inserted into the slot 161a.

[0028] The slow-wave material 162 is made of a material having a dielectric constant greater than that of a vacuum, and its thickness can be used to adjust the phase of the microwaves, thereby maximizing the microwave radiation energy. The microwave transmission plate 163 is also made of a dielectric material and has a shape that allows microwaves to be efficiently radiated in TE mode. The microwaves that pass through the microwave transmission plate 163 generate plasma in the space inside the processing container 101. Examples of materials that can be used to make up the slow-wave material 162 and the microwave transmission plate 163 include quartz, ceramics, fluororesins such as polytetrafluoroethylene resin, and polyimide resin.

[0029] Tuner 154 constitutes a slug tuner. As shown in Figure 3, tuner 154 has slugs 171a and 171b, an actuator 172, and a tuner controller 173. Slugs 171a and 171b are two slugs located on the base end (upper end) side of the antenna section 156 of the coaxial tube 151. The actuator 172 drives these two slugs independently. The tuner controller 173 controls the actuator 172.

[0030] The slags 171a and 171b are plate-shaped and annular, made of a dielectric material such as ceramics, and are positioned between the outer conductor 152 and the inner conductor 153 of the coaxial tube 151. The actuator 172 drives the slags 171a and 171b individually by rotating two screws, for example, located inside the inner conductor 153, into which the slags 171a and 171b are screwed. Based on a command from the tuner controller 173, the actuator 172 moves the slags 171a and 171b vertically. The tuner controller 173 adjusts the positions of the slags 171a and 171b so that the impedance of the termination is 50Ω.

[0031] The main amplifier 147, tuner 154, and planar antenna 161 are located in close proximity. The tuner 154 and planar antenna 161 form a lumped-element circuit and function as a resonator. An impedance mismatch exists at the mounting point of the planar antenna 161. However, since the tuner 154 directly tunes to the plasma load, high-precision tuning including the plasma can be achieved, eliminating the effects of reflections on the planar antenna 161.

[0032] Figure 4 is a schematic plan view showing an example of the top wall portion of the processing container according to this embodiment. Figure 4 corresponds to the portion of the processing space S inside the side wall portion 112 in the cross-section AA of Figure 1. As shown in Figure 4, in this embodiment, seven microwave radiation mechanisms 143 are provided, and the microwave transmission plates 163 corresponding to them are arranged in an evenly spaced, hexagonal close-packed arrangement. That is, one of the seven microwave transmission plates 163 is located in the center of the top wall portion 111, and the other six microwave transmission plates 163 are arranged around it. These seven microwave transmission plates 163 are arranged so that adjacent microwave transmission plates 163 are equally spaced. In addition, the multiple gas introduction nozzles 123 of the gas supply mechanism 103 are arranged to surround the central microwave transmission plate 163. Note that the number of microwave radiation mechanisms 143 is not limited to seven.

[0033] A resonator array structure 200 is provided around the microwave-transmitting plate 163. In other words, the resonator array structure 200 is positioned on the top wall portion 111 so as to be located between the microwave-transmitting plate 163 (microwave-transmitting window) and the connection between the top wall portion 111 and the side wall portion 112. That is, the resonator array structure 200 is positioned on the top wall portion 111 so as to surround the multiple microwave radiation mechanisms 143 (microwave radiation sections) and the microwave-transmitting plate 163 (microwave-transmitting window). The resonator array structure 200 is formed by arranging multiple resonators that are capable of resonating with the magnetic field component of microwaves and whose size is smaller than the wavelength of microwaves, and is located, for example, inside the top wall portion 111. In other words, the resonator array structure 200 is fitted into a recess provided in the top wall portion 111, for example, and the lower surface of the top wall portion 111 and the lower surface of the resonator array structure 200 form the same plane.

[0034] The resonator array structure 200 is positioned on the top wall 111 so as to surround the microwave transmission plate 163, thereby suppressing the propagation of surface waves that propagate along the plasma interface among the microwaves supplied to the processing space S by the microwave radiation mechanism 143. The propagation path of electromagnetic waves is mainly within the sheath, and its propagation mode is influenced by both the adjacent plasma and the top wall 111. By appropriately setting the permeability of the resonator array structure 200, a state can be created in which there are no propagation modes of electromagnetic waves propagating within this sheath. In other words, in this embodiment, the propagation of electromagnetic waves can be suppressed without directly installing a metal body in the propagation path of the electromagnetic waves.

[0035] Here, with reference to Figures 4 to 6, the detailed configuration of the resonator array structure 200 will be described. Figure 5 is a schematic perspective view showing an example of the top wall portion of the processing vessel according to this embodiment. As shown in Figures 4 and 5, the resonator array structure 200 is annular in shape surrounding the microwave transmission plate 163, and a plurality of resonators 201 are arranged in the circumferential and radial directions. Each resonator 201 consists of a C-shaped ring member 211 made of a conductor and a dielectric 212 surrounding the ring member 211. In other words, each resonator 201 may include a dielectric 212 surrounding the ring member 211. For example, the dielectric forming the resonator array structure 200 also serves as the dielectric 212. Figures 4 and 5 show the arrangement of each ring member 211 among the plurality of resonators 201. The ring members 211 are arranged in the direction in which the C shape is visible in the cross-sectional direction of the resonator array structure 200 in Figure 1. Each resonator 201 may include two or more C-shaped ring members 211 made of conductors. In this case, even if the dimensions of the ring members 211 are small, it is possible to handle low frequencies.

[0036] The multiple resonators 201 of the resonator array structure 200 are arranged radially from the center of the top wall portion 111 of the processing container 101. Furthermore, the multiple resonators 201 are arranged on multiple concentric circles 202-204. In other words, the multiple resonators 201 are arranged in a direction where the holes in the ring member 211 intersect with the circles 202-204. Alternatively, multiple resonator array structures 200 may be arranged on the top wall portion 111 so as to surround the multiple microwave radiation mechanisms 143 (microwave radiation sections) and microwave transmission plates 163 (microwave transmission windows). In this case, in each resonator array structure 200, the multiple resonators 201 are arranged radially from the center of the microwave transmission plate 163. That is, multiple resonator array structures 200 are arranged so as to surround each of the seven microwave transmission plates 163. In other words, multiple resonator array structures 200 are arranged on the top wall portion 111 so as to surround each of the multiple microwave transmission plates 163 (microwave transmission windows).

[0037] Figure 6 is a diagram illustrating an example of the relationship between the direction of electromagnetic wave propagation and the direction of the ring member according to this embodiment. In Figure 6, the direction of electromagnetic wave propagation and the direction of the ring member 211 are shown in a part of the resonator array structure 200. The ring member 211 is surrounded by a dielectric 212. In this embodiment, of the microwaves supplied from the microwave radiation mechanism 143, the surface waves propagating at the plasma interface propagate radially from the center of the top wall portion 111, as shown by the arrow 205 indicating the direction of electromagnetic wave propagation in Figure 4. That is, since the electromagnetic waves in the sheath propagate in TM mode, the magnetic field is oriented horizontally with respect to the direction of electromagnetic wave propagation. The resonator array structure 200 is arranged such that the magnetic field penetrates the ring member 211.

[0038] Here, we will describe some configuration examples for each of the multiple resonators 201. The multiple resonators 201 may be configured, for example, by embedding multiple ring members 211 in a dielectric 212 that constitutes a resonator array structure 200, as shown in Figures 4 and 5. Each of the multiple resonators 201 constitutes a series resonant circuit consisting of a capacitor equivalent element and a coil equivalent element. Furthermore, each of the multiple resonators 201 has a size of less than 1 / 10 of the microwave wavelength.

[0039] Furthermore, the resonator 201 may be configured such that a ring member 211 is formed on the surface of the dielectric plate, as shown in Figures 7 to 10. In this case, the series resonant circuit is realized by patterning a conductor on a plane. Figure 7 is a diagram showing an example of the configuration of a resonator according to this embodiment. The resonator 201A shown in Figure 7 has a structure in which two C-shaped ring members 211A made of conductors, which are opposite to each other and concentric, are stacked on one surface of the dielectric plate 212A. Capacitor equivalent elements are formed on the opposing surfaces of the inner ring member 211A and the outer ring member 211A, and at both ends of each ring member 211A, and coil equivalent elements are formed along each ring member 211A. As a result, the resonator 201A can constitute a series resonant circuit.

[0040] Figure 8 shows an example of the configuration of a resonator according to this embodiment. The resonator 201B shown in Figure 8 has a structure in which a dielectric plate 212B is placed between two C-shaped ring members 211B made of conductors, which are adjacent to each other and facing opposite directions. That is, in the resonator 201B, the dielectric plate 212B is sandwiched between two C-shaped ring members 211B that are facing opposite directions. Capacitor equivalent elements are formed on the opposing surfaces of the two C-shaped ring members 211B and at both ends of each ring member 211B, and coil equivalent elements are formed along each ring member 211B. As a result, the resonator 201B can constitute a series resonant circuit. It can also be said that the resonator 201B is formed for each pair of two C-shaped ring members 211B.

[0041] In the resonator 201B shown in Figure 8, the number of ring members 211B arranged (hereinafter also referred to as "number of layers") is 2, but the number of layers of ring members 211B may be greater than 2. Figure 9 shows another example of the configuration of the resonator according to this embodiment. The resonator 201B shown in Figure 9 has a structure in which N (N≧2) C-shaped ring members 211B made of conductors are arranged, and dielectric plates 212B are arranged between ring members 211B that are adjacent to each other and facing opposite directions. Even with such a structure, the resonator 201B can constitute a series resonant circuit.

[0042] Furthermore, an insulating coating may be formed on each of the multiple resonators 201. Figure 10 is a diagram showing an example of a cross-section of a resonator according to this embodiment. Figure 10 shows a side cross-section of the resonator 201B shown in Figure 8. An insulating coating (an example of a dielectric film) 213 is formed on the surface of the resonator 201B. The material of the coating 213 is, for example, ceramic. The thickness of the coating 213 is, for example, in the range of 0.001 mm to 2 mm. By forming an insulating coating 213 on each of the multiple resonators 201, abnormal discharge in each of the multiple resonators 201 can be suppressed. In addition, by forming an insulating coating 213 on each of the multiple resonators 201, exposure of the ring member 211B to plasma can be suppressed.

[0043] Furthermore, the multiple resonators 201 may be configured such that, for example, multiple ring members 211 can be inserted from the atmospheric side of the resonator array structure 200. Figure 11 is a diagram showing an example of the arrangement of resonators in the resonator array structure according to this embodiment. In the resonator array structure 200 shown in Figure 11, the ring members 211 can be fitted into grooves provided in the dielectric 212 from the atmospheric side, and the ring members 211 are not exposed to the plasma P generated in the processing space S. In addition, the ring members 211 can be replaced without opening the processing container 101 to the atmosphere. The replacement of the ring members 211 may include, for example, replacement with ring members 211 with different resonant frequencies.

[0044] Furthermore, the multiple resonators 201 may be arranged, for example, so as to be exposed to the processing space S side of the resonator array structure 200. Figure 12 is a diagram showing an example of the arrangement of resonators in the resonator array structure according to this embodiment. In the resonator array structure 200 shown in Figure 12, the ring member 211 is exposed to the processing space S side from the dielectric 212, and the ring member 211 is exposed to the plasma P generated in the processing space S. In this case, the ring member 211 may be coated with an insulator, such as the insulating film 213 described above, or the conductor of the ring member 211 may be exposed. When suppressing the generation of particles, it is preferable for the ring member 211 to be coated with an insulator.

[0045] The control unit 106 includes a processor, memory, and an input / output interface. The memory stores programs and process recipes, etc. The processor reads and executes programs from the memory, and based on the process recipes stored in the memory, it comprehensively controls each part of the plasma processing apparatus 100 via the input / output interface.

[0046] When plasma is generated in the processing space S, for example, the control unit 106 controls the microwave supplied to the processing space S by the microwave radiation mechanism 143 and the plurality of resonators 201 to resonate in a target frequency band higher than the resonance frequencies of the plurality of resonators 201. Here, the resonance frequency is, for example, the frequency at which the transmission characteristic value (e.g., S 21 value) of the plurality of resonators 201 becomes a minimum value.

[0047] FIG. 13 is a diagram showing an example of the relationship between the S 21 value of the resonator and the frequency of the microwave. When the frequency of the microwave supplied to the processing space S by the microwave radiation mechanism 143 coincides with the resonance frequency f r (= about 2.35 GHz) of the plurality of resonators 201, the S 21 value of the plurality of resonators 201 becomes a minimum value, and resonance between the microwave and the plurality of resonators 201 occurs. The resonance between the microwave and the plurality of resonators 201 is maintained even in a predetermined frequency band (e.g., about 0.1 GHz) higher than the resonance frequency f r of the plurality of resonators 201. In a predetermined frequency band higher than the resonance frequency f r of the plurality of resonators 201, the propagation mode of the surface wave in the sheath of the processing space S can be eliminated by the resonance between the microwave and the plurality of resonators 201. The target frequency band of the present embodiment is set to a predetermined frequency band (e.g., about 0.1 GHz) higher than the resonance frequency f r of the plurality of resonators 201. The target frequency band is preferably, for example, within 0.05 times the resonance frequency f r of the plurality of resonators 201. The resonance frequencies f r of the plurality of resonators 201 arranged on the plurality of circumferences 202 to 204 are, for example, the same frequency.

[0048] Regarding the propagation of electromagnetic waves through multiple resonators, the relationship between resonant frequency, refractive index, dielectric constant, and permeability has been reported, for example, by DRSmith, DCVier, Th. Koschny, and CMSoukoulis et al. in "Electromagnetic parameter retrieval from inhomogeneous metamaterials" in "PHYSICAL REVIEW E 71, 036617 (2005)".

[0049] [Simulation Model] Next, a simulation model will be described for the case where the resonator array structure 200 is placed on the top wall section 111. Figure 14 is a diagram showing an example of the simulation model. Figure 15 is an enlarged view showing an example of the vicinity of the sheath of the simulation model. The simulation model 220 shown in Figure 14 is an axisymmetric model in which one antenna module 141 is placed in the center of the top wall section 111 and UHF (Ultra High Frequency) electromagnetic waves are supplied. The resonator array structure 200 is applicable to both cases where the antenna unit 140 is a multi-antenna including multiple antenna modules 141 and a single antenna including one antenna module 141. For this reason, the simulation model 220 uses a single antenna. In the case of a single antenna, one antenna module 141 corresponds to a microwave source that radiates microwaves using one planar slot antenna. Plasma P is generated by the electromagnetic waves supplied from the microwave-transmitting plate 163 of the antenna module 141. The dielectric constant of plasma P is ε r For example, ε r It is set to =-100-5i.

[0050] As shown in Figure 15, when the region 221 near the boundary between the resonator array structure 200 and the plasma P is enlarged, a sheath 222 is set at the boundary between the resonator array structure 200 and the plasma P. The sheath 222 is a vacuum and is set up so that electromagnetic waves can propagate when each resonator 201 of the resonator array structure 200 is not resonating.

[0051] [Simulation Results] Next, the simulation results will be explained using Figures 16 to 18. Figure 16 is a graph showing an example of the relationship between the relative permeability of the resonator array structure and the power absorbed by the plasma. Graph 223 in Figure 16 shows the power absorbed by the plasma P per 1W of incident wave when the relative permeability of the resonator array structure 200 (metamaterial) is set from "1" to "-10". The relative permittivity of the resonator array structure 200 is assumed to be "9.6". When the relative permeability of the resonator array structure 200 is "1" (point 225 in Figure 16), approximately 0.3W is absorbed by the plasma P per 1W of incident wave, and approximately 0.7W of energy is dissipated as a surface wave.

[0052] Next, let's look at the metamaterial region 224 where the relative permittivity of the resonator array structure 200 is negative. When the relative permeability of the resonator array structure 200 is "-1", approximately 0.3 W is absorbed by the plasma P for every 1 W of incident wave, and approximately 0.7 W is dissipated as a surface wave. When the relative permeability of the resonator array structure 200 is "-1.5", approximately 0.875 W is absorbed by the plasma P for every 1 W of incident wave, and approximately 0.125 W is dissipated as a surface wave. When the relative permeability of the resonator array structure 200 is "-2", approximately 0.98 W is absorbed by the plasma P for every 1 W of incident wave, and approximately 0.02 W is dissipated as a surface wave. In the region where the relative permeability of the resonator array structure 200 is between "-2.5" and "-10" (point 226 in Figure 16), it can be seen that for every 1W of incident wave, 1W is absorbed by the plasma P, and almost no energy is dissipated as a surface wave. In other words, in the metamaterial region 224, when the relative permeability of the resonator array structure 200 is "-2" or less, surface wave propagation can be suppressed.

[0053] Figure 17 shows an example of a simulation result when the relative permeability of the resonator array structure is a positive value. The simulation result 227 shown in Figure 17 represents the electric field strength when the relative permeability of the resonator array structure 200 is "1" (point 225 in Figure 16). In simulation result 227, electromagnetic waves (surface waves) supplied from the microwave permeable plate 163 propagate along the surface of the resonator array structure 200 toward the side wall portion 112. In other words, in simulation result 227, electromagnetic waves (surface waves) supplied from the microwave permeable plate 163 propagate through the sheath 222 and reach the side wall portion 112.

[0054] Figure 18 shows an example of a simulation result when the relative permeability of the resonator array structure is a negative value. Simulation result 228 shown in Figure 18 represents the electric field strength when the relative permeability of the resonator array structure 200 is "-10" (point 226 in Figure 16). In simulation result 228, the propagation of electromagnetic waves (surface waves) supplied from the microwave transmission plate 163 is suppressed in the resonator array structure 200. In other words, in simulation result 228, surface wave propagation is suppressed by the resonator array structure 200, and the propagation of electromagnetic waves into gaps such as the connection between the top wall portion 111 and the side wall portion 112 can be suppressed.

[0055] Next, using Figures 19 to 23, we will explain the simulation results when a conductive film is formed on the inner wall of the processing vessel 101, that is, when a conductive film is present on the surface of the top wall portion 111, including the resonator array structure 200, on the processing space S side. Figure 19 is an enlarged view showing an example of the vicinity of the sheath in the simulation model when a conductive film is present. In Figure 19, the region 221 near the boundary between the resonator array structure 200 and the plasma P is shown in an enlarged view when a conductive film is present. In Figure 19, a conductive film 229 is set on the lower surface of the resonator array structure 200, and a sheath 222 is set at the boundary between the conductive film 229 and the plasma P. The sheath 222 is a vacuum and is set so that electromagnetic waves can propagate when each resonator 201 of the resonator array structure 200 is not resonating. The conductive film 229 can be, for example, aluminum fluoride (AlF3). The conductive film 229 may also be a by-product generated during the process.

[0056] Figure 20 is a graph showing an example of the relationship between the conductivity of a conductive film and the power absorbed by the plasma and the conductive film. In Figure 20, the conductivity σ [S / m] of the conductive film 229 and the power absorbed by the plasma P and the conductive film 229 are shown. Also in Figure 20, the relative permeability of the resonator array structure 200 (metamaterial) is set to "1" and the relative permittivity is set to "9.6". Graph 230 shows the power absorbed by the plasma P per 1W of incident wave. Graph 231 shows the power absorbed by the conductive film 229 per 1W of incident wave.

[0057] From Graph 231, when the conductive film 229 has a specific conductivity σ as shown in region 232, the heat loss in the conductive film 229 becomes very large. For example, if the conductivity σ is 10 3 At [S / m], approximately 0.98 W of incident wave power is absorbed by the conductive film 229, and approximately 0.02 W is absorbed by the plasma P. In other words, a large portion of the incident wave power is absorbed by the conductive film 229, resulting in heat loss. On the other hand, if the conductivity σ of the conductive film 229 is 10 5 It can be seen that, in the case of [S / m] and when it is 10 [S / m] or less, the incident wave is not absorbed by the conductive film 229 to the extent of region 232.

[0058] Figure 21 is a graph showing an example of the relationship between the relative permeability of a resonator array structure and the power absorbed by the plasma and conductive film. In Figure 21, the conductivity σ of the conductive film 229 is set to σ = 10 3 The graphs show the power absorbed by the plasma P and the conductive film 229 when the relative permeability of the resonator array structure 200 (metamaterial) is varied from "1" to "-200" in [S / m]. Graph 233 shows the power absorbed by the plasma P per 1W of incident wave. Graph 234 shows the power absorbed by the conductive film 229 per 1W of incident wave. The relative permittivity of the resonator array structure 200 is assumed to be "9.6". When the relative permeability of the resonator array structure 200 is "1", approximately 0.02W is absorbed by the plasma P and approximately 0.98W is absorbed by the conductive film 229 per 1W of incident wave. In this case, the heat loss in the conductive film 229 becomes very large. In other words, energy is lost and heat is generated in the conductive film 229, so the energy efficiency decreases and particles are more likely to be generated.

[0059] When the relative permeability of the resonator array structure 200 is changed to be significantly negative, if the relative permittivity is "-50", approximately 0.91 W per 1 W of incident wave is absorbed by the plasma P and approximately 0.09 W is absorbed by the conductive film 229. If the relative permeability of the resonator array structure 200 is "-100", approximately 0.97 W per 1 W of incident wave is absorbed by the plasma P and approximately 0.03 W is absorbed by the conductive film 229. The case where the relative permeability of the resonator array structure 200 is "-200" is almost the same as the case where it is "-100", with approximately 0.97 W per 1 W of incident wave being absorbed by the plasma P and approximately 0.03 W being absorbed by the conductive film 229. In other words, it can be seen that in the region where the relative permeability of the resonator array structure 200 is "-100" or less, heat loss in the conductive film 229 can be almost suppressed.

[0060] Figure 22 shows an example of a simulation result when there is a conductive film and the relative permeability of the resonator array structure is positive. The simulation result 235 shown in Figure 22 represents the electric field strength when there is a conductive film 229 as shown in Figure 19 and the relative permeability of the resonator array structure 200 is "1". In simulation result 235, electromagnetic waves (surface waves) supplied from the microwave transmission plate 163 propagate along the surface of the resonator array structure 200 towards the side wall 112 while being absorbed by the conductive film 229. That is, in simulation result 235, electromagnetic waves (surface waves) supplied from the microwave transmission plate 163 propagate through the sheath 222 and reach the side wall 112 while being absorbed by the conductive film 229.

[0061] Figure 23 shows an example of a simulation result when there is a conductive film and the relative permeability of the resonator array structure is negative. The simulation result 236 shown in Figure 23 represents the electric field strength when there is a conductive film 229 as shown in Figure 19 and the relative permeability of the resonator array structure 200 is "-100". In simulation result 236, the electromagnetic waves (surface waves) supplied from the microwave transmission plate 163 are not absorbed by the conductive film 229, but are almost entirely absorbed by the plasma P. In other words, in simulation result 228, surface wave propagation and absorption by the conductive film 229 are suppressed by the resonator array structure 200. That is, the energy loss of the conductive film 229 can be suppressed by the resonator array structure 200.

[0062] [Example 1] In the above embodiment, the resonator array structure 200 is placed on the top wall portion 111, but the resonator array structure may also be placed on the side wall portion 112. That is, the resonator array structure may be placed on at least one of the walls, either the top wall portion 111 or the side wall portion 112. Modification 1 describes an example in which the resonator array structure is placed on the side wall portion 112, using Figures 24 and 25.

[0063] Figure 24 is a schematic perspective view showing an example of the side wall portion of a processing container according to Modification 1. As shown in Figure 24, the resonator array structure 300 is arranged in an annular manner on the side wall portion 112. That is, at least a portion of the side wall portion 112 is formed by the resonator array structure 300, and the wall surface of the side wall portion 112 on the processing space S side is formed of a dielectric. The resonator array structure 300 has a plurality of resonators 201 arranged in the circumferential and radial directions. Each resonator 201 consists of a C-shaped ring member 211 and a dielectric 312 surrounding the ring member 211. For example, the dielectric forming the resonator array structure 300 also serves as the dielectric 312. Figure 24 shows the arrangement of each ring member 211 among the plurality of resonators 201. The ring members 211 are arranged in the direction in which the C shape is visible in the longitudinal cross-sectional direction of the processing container 101.

[0064] The multiple resonators 201 of the resonator array structure 300 are arranged radially with respect to the center of the processing container 101. Furthermore, the multiple resonators 201 are arranged, for example, on multiple concentric circles 302, 303. That is, the multiple resonators 201 are arranged in a direction such that the holes in the ring member 211 intersect with the circles 302, 303. Additionally, the circles 302, 303 are arranged in two tiers vertically on the processing container 101.

[0065] Figure 25 shows an example of the relationship between the direction of electromagnetic wave propagation, the resonator array structure, and the gas introduction nozzle according to Modification 1. As shown in Figure 25, the resonator array structure 300 is positioned above the gas introduction nozzle 123a, that is, towards the top wall 111, in the cross-section of the side wall portion 112.

[0066] The gas introduction nozzle 123a supplies processing gas to the processing space S from the side wall portion 112 in the direction of arrow 123b. In other words, the gas introduction nozzle 123a is an example of one or more side gas injectors (SGI) attached to one or more openings formed in the side wall portion 112. Note that the gas introduction nozzle 123a may be provided in addition to the gas introduction nozzle 123 provided on the top wall portion 111, or it may be provided in place of the gas introduction nozzle 123.

[0067] In other words, the plasma processing apparatus 100 further has a gas introduction nozzle 123a in the side wall portion 112 for introducing a gas for generating plasma into the processing container 101. The resonator array structure 300 is positioned on the side wall portion 112 so as to be located between the microwave transmission plate 163 (microwave transmission window) and the gas introduction nozzle 123a. That is, the resonator array structure 300 is positioned on the side wall portion 112 so as to be located between the connection portion between the top wall portion 111 and the side wall portion 112 and the gas introduction nozzle 123a.

[0068] As shown in Figure 25, of the microwaves supplied from the microwave radiation mechanism 143, surface waves propagating along the plasma interface propagate from the top wall portion 111 to the side wall portion 112, as indicated by the arrow 320 which shows the direction of electromagnetic wave propagation. In the resonator array structure 300, the ring member 211 is arranged in the direction in which a C shape is visible in the cross-section of Figure 25 (not shown), and the magnetic field of the propagating electromagnetic wave penetrates the ring member 211 as indicated by the arrow 320. In other words, the resonator array structure 300, like the resonator array structure 200, can suppress the propagation of surface waves, and thus can suppress the arrival of electromagnetic waves at the gas introduction nozzle 123a. For this reason, in the modified example 1, discharge and particle generation near the gas introduction nozzle 123a can be further suppressed.

[0069] Furthermore, the resonator array structure 300 may be combined with the resonator array structure 200 which is placed on the top wall portion 111. For example, if there are restrictions on the placement of the resonator array structure 200 on the top wall portion 111, the restriction on the placement of the resonator array structure 200 can be compensated for by placing the resonator array structure 300 on the side wall portion 112 corresponding to the location where the placement of the resonator array structure 200 is restricted. In other words, the resonator array structures 200 and 300 may be placed separately. Also, the resonator array structures 200 and 300 may be provided inside at least one of the walls of the top wall portion 111 and the side wall portion 112. In other words, there may be a top wall portion 111 or a side wall portion 112 made of dielectric material between the resonator array structures 200 and 300 and the processing space S.

[0070] [Differentiation 2] In the above embodiment, microwaves supplied from the microwave radiation mechanism 143 were supplied to the processing space S via the microwave transmission plate 163. However, a resonator array structure may be further arranged on the lower surface of the microwave transmission plate 163. Modification 2 describes an example in which a resonator array structure is further arranged on the lower surface of the microwave transmission plate 163, using Figure 26.

[0071] Figure 26 is a plan view showing an example of the configuration of the dielectric window and resonator array structure according to Modification 2, viewed from below. In Figure 26, the lower surface of one of the multiple microwave transmitting plates 163, which are dielectric windows, is shown in a disc shape. In Modification 2, as shown in Figure 26, a resonator array structure 400 is provided at the lower surface of the microwave transmitting plate 163, that is, at positions corresponding to the multiple microwave radiation mechanisms 143 of the top wall portion 111. The resonator array structure 400 is formed by arranging multiple resonators 201B that can resonate with the magnetic field component of microwaves and whose size is smaller than the wavelength of microwaves, and is located inside the processing container 101. The lower surface of the microwave transmitting plate 163 may be in contact with or separated from the resonator array structure 400.

[0072] The position of the resonator array structure 400 within the processing vessel 101 allows the microwaves supplied to the processing space S by the microwave radiation mechanism 143 to resonate with the multiple resonators of the resonator array structure 400. This resonance between the microwaves and the multiple resonators allows for efficient supply of microwaves to the processing space S in the processing vessel 101 and enables the permeability of the processing space S to be made negative. When the permeability of the processing space S is negative, even if the electron density of the plasma generated within the processing space S reaches the cutoff density and the dielectric constant of the processing space S is negative, the refractive index becomes a real number according to equation (1) above, allowing microwaves to propagate within the processing space S. As a result, even when the electron density of the plasma generated within the processing space S reaches the cutoff density, microwaves can propagate beyond the plasma skin depth, and the microwave power is efficiently absorbed by the plasma. Consequently, a high-density plasma can be generated over a wide area beyond the plasma skin depth. In other words, according to the plasma processing apparatus 100 of the modified example 2, the resonator array structure 400 is located inside the processing vessel 101, thereby enabling high-density plasma distribution over a wide area.

[0073] The resonator array structure 400 is formed by arranging multiple resonators 201B in a grid pattern, each capable of resonating with the magnetic field component of microwaves and having a size smaller than the wavelength of microwaves. Note that the multiple resonators 201B may also be resonators 201A as shown in Figure 7. In the example in Figure 26, the resonators 201B are arranged such that cells 420 surrounded by the resonators 201B are formed in 5 columns in the X-axis direction and 5 rows in the Y-axis direction. In other words, the cells 420 form a 5x5 square array 430. In the array 430, the diameter of the microwave transmission plate 163 and the length of one side of the resonator array structure 400 are approximately the same length. Therefore, the peripheral cells 420, with the exception of some cells 420 (1st row 3 columns, 3rd row 1 column, 3rd row 5 columns, 5th row 3 columns), are arranged across the microwave transmission plate 163 and the top wall 111. Thus, when some cells 420 of the resonator array structure 400 are arranged across the microwave transmission plate 163 and the top wall portion 111, it is preferable that the top wall portion 111 be a dielectric in order to propagate microwaves. Furthermore, the resonant frequency f of the resonator 201B of the resonator array structure 400 r The resonant frequency f of resonator 201 of the resonator array structure 200,300 r It may be the same frequency.

[0074] Thus, in the modified example 2, by further arranging the resonator array structure 400 on the lower surface of the microwave transmitting plate 163, the horizontal spread of plasma from the microwave transmitting plate 163 can be further suppressed. In other words, since the plasma is confined to the cells 420 of the resonator array structure 400, interference between adjacent microwave radiation mechanisms 143 can also be suppressed. Furthermore, the spread of plasma toward the side wall 112 and the gas introduction nozzle 123 can also be further suppressed. As a result, contamination of aluminum, yttrium, etc. due to damage to the side wall 112 and abnormal discharge near the gas introduction nozzle 123 can be further suppressed. In addition, the process processing speed can be stabilized by stabilizing the plasma discharge. Although not shown in the figures, the multiple resonators 201B may be arranged on a base plate made of dielectric material, and the base plate may also be included in the resonator array structure 400. In this case, the resonator array structure 400 can be easily attached to the top wall 111. Furthermore, in Modification 2, the surface waves are reflected by the resonator array structures 200 and 300, absorbed by the plasma, and then returned to the resonator array structure 400, thereby improving the power efficiency of the resonator array structure 400. In other words, in Modification 2, electromagnetic waves (surface waves) in areas far from the resonator array structure 400 can be controlled by the resonator array structures 200 and 300.

[0075] [Difference 3] In the above embodiment, the resonant frequency f of the multiple resonators 201 in the resonator array structure 200 r Although the same frequency was assumed for circumferences 202 to 204, different frequencies may be used for each circumference from 202 to 204. For example, the resonant frequency f of multiple resonators 201 with circumferences of 202 r The resonant frequency f of multiple resonators 201 with a circumference of 203 and a frequency of 2.45 GHz r The resonant frequency f of multiple resonators 201 with a circumference of 204 and a frequency of 1.98 GHz r This can also be set to 915 MHz. This increases the frequency at which surface wave propagation can be suppressed.

[0076] Also, for example, the resonant frequency f of multiple resonators 201 with a circumference of 202 r The resonant frequency f of multiple resonators 201 with a circumference of 203 and a frequency of 910MHz. r The resonant frequency f of multiple resonators 201 with a circumference of 204 and a frequency of 915MHz r The frequency may be set to 920 MHz. This allows control over the radial distribution (spread) of the plasma in the processing vessel 101.

[0077] As described above, according to this embodiment, the plasma processing apparatus 100 includes a processing vessel 101, a microwave generation unit (microwave output unit 130), a microwave radiation unit (microwave radiation mechanism 143), a microwave transmission window (microwave transmission plate 163), and a resonator array structure (resonator array structure 200, 300). The processing vessel 101 houses the substrate W and defines the processing space S with a top wall 111, side walls 112, and a bottom wall 113. The microwave generation unit is configured to generate microwaves for generating plasma. The microwave radiation unit is provided above the top wall 111 and is configured to radiate microwaves toward the processing vessel 101. The microwave transmission window is provided at a position corresponding to the microwave radiation unit on the top wall 111 and is a microwave transmission window made of a dielectric material. The resonator array structure is formed by arranging multiple resonators 201, which are arranged in at least one of the walls of the top wall 111 and the side wall 112, and are capable of resonating with the magnetic field component of microwaves and have a size smaller than the wavelength of microwaves. As a result, electromagnetic waves propagating along the inner wall of the processing container 101 can be suppressed.

[0078] Furthermore, according to this embodiment, the resonator array structure is provided inside the wall. As a result, the propagation modes of the electromagnetic wave propagation path are eliminated, so the propagation of electromagnetic waves can be suppressed without directly installing a metal body in the electromagnetic wave propagation path.

[0079] Furthermore, according to this embodiment, the resonator 201 includes two or more C-shaped ring members 211 made of conductors. As a result, the resonator 201 can resonate with microwaves.

[0080] Furthermore, according to this embodiment, the resonator 201 includes a dielectric 212 surrounding the ring member 211. As a result, particle generation can be suppressed.

[0081] Furthermore, according to this embodiment, the ring member 211 can be inserted into the resonator 201 from the atmospheric side of the resonator array structure. As a result, the ring member 211 can be replaced without opening the processing container 101 to the atmosphere.

[0082] Furthermore, according to this embodiment, the resonator array structure 200 is positioned on the top wall portion 111 so as to be located between the microwave transmission window and the connection portion between the top wall portion 111 and the side wall portion 112. As a result, electromagnetic waves propagating along the inner wall of the processing container 101 can be suppressed.

[0083] Furthermore, according to this embodiment, multiple microwave radiation sections and microwave transmission windows are provided. The resonator array structure 200 is also arranged on the top wall section 111 so as to surround the multiple microwave transmission windows. As a result, electromagnetic waves propagating from the multiple microwave transmission windows along the inner wall of the processing container 101 can be suppressed.

[0084] Furthermore, according to this embodiment, multiple microwave radiation sections and microwave transmission windows are provided. In addition, multiple resonator array structures 200 are arranged on the top wall section 111 so as to surround each of the multiple microwave transmission windows. As a result, electromagnetic waves propagating along the inner wall of the processing container 101 can be suppressed for each of the multiple microwave transmission windows.

[0085] Furthermore, according to Modification 1, the side wall portion 112 further includes a gas introduction nozzle 123a for introducing a gas for generating plasma into the processing container 101. The resonator array structure 300 is also positioned on the side wall portion 112 between the microwave transmission window and the gas introduction nozzle 123a. As a result, the propagation of surface waves can be suppressed, thereby suppressing the arrival of electromagnetic waves at the gas introduction nozzle 123a. In addition, discharge and particle generation near the gas introduction nozzle 123a can be further suppressed.

[0086] Furthermore, according to Modification 1, the resonator array structure 300 is positioned on the side wall portion 112 so as to be located between the connection between the top wall portion 111 and the side wall portion 112 and the gas introduction nozzle 123a. As a result, the propagation of surface waves can be suppressed, and thus the arrival of electromagnetic waves to the gas introduction nozzle 123a can be suppressed. In addition, discharge and particle generation near the gas introduction nozzle 123a can be further suppressed.

[0087] Furthermore, according to this embodiment, the multiple resonators 201 are arranged radially from the center of the processing container 101. As a result, the propagation modes of electromagnetic waves (surface waves) that propagate along the inner wall of the processing container 101 can be eliminated.

[0088] Furthermore, according to Modification 3, the resonator array structure is arranged on multiple concentric circles (circumferences 202-204, 302, 303) where multiple resonators 201 are arranged. In addition, the resonant frequencies of the multiple resonators 201 differ for each circumference. As a result, the frequency at which surface wave propagation can be suppressed can be increased. Furthermore, the radial distribution (spread) of the plasma processing vessel 101 can be controlled.

[0089] Furthermore, according to this embodiment, the resonator array structure has a relative permeability of -100 or less. As a result, when the conductive film 229 is present, heat loss in the conductive film 229 can be suppressed.

[0090] Furthermore, according to this embodiment, a conductive film (conductive film 229) is formed on the inner wall of the processing container 101. As a result, when the relative permeability of the resonator array structure is -100 or less, heat loss in the conductive film 229 can be suppressed.

[0091] Furthermore, according to Modification 2, the resonator array structure (resonator array structure 400) is further positioned on the lower surface of the microwave transmission window. As a result, the power efficiency of the resonator array structure 400 can be improved.

[0092] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0093] Furthermore, this disclosure can also be structured as follows: (1) A processing container that houses a substrate and defines the processing space with its top wall, side walls, and bottom wall, A microwave generator configured to generate microwaves for generating plasma, A microwave radiation unit is provided above the top wall portion and configured to radiate microwaves toward the processing container, A microwave-transmitting window made of a dielectric material is provided at a position corresponding to the microwave radiation section of the top wall, A resonator array structure is formed by arranging a plurality of resonators, each arranged in at least one of the wall portions of the top wall portion and the side wall portion, which are capable of resonating with the magnetic field component of the microwave and whose size is smaller than the wavelength of the microwave; A plasma processing apparatus having (2) The aforementioned resonator array structure is provided inside the wall portion, The plasma processing apparatus described in (1) above. (3) The resonator includes two or more C-shaped ring members made of conductors. The plasma processing apparatus described in (1) or (2) above. (4) The resonator includes a dielectric material surrounding the ring member, The plasma processing apparatus described in (3) above. (5) The resonator is such that the ring member can be inserted from the atmospheric side of the resonator array structure. The plasma processing apparatus described in (3) or (4) above. (6) The resonator array structure is positioned on the top wall so as to be located between the microwave transmission window and the connection between the top wall and the side wall. A plasma processing apparatus according to any one of (1) to (5) above. (7) Multiple microwave radiation units and microwave transmission windows are provided, The resonator array structure is arranged on the top wall so as to surround the plurality of microwave transmission windows. The plasma processing apparatus described in (6) above. (8) Multiple microwave radiation units and microwave transmission windows are provided, The resonator array structure is arranged in multiple locations on the top wall so as to surround each of the multiple microwave transmission windows. The plasma processing apparatus described in (6) above. (9) The side wall portion further includes a gas introduction nozzle for introducing the gas for generating the plasma into the processing container, The resonator array structure is positioned on the side wall so as to be located between the microwave transmission window and the gas introduction nozzle. A plasma processing apparatus according to any one of (1) to (8) above. (10) The resonator array structure is positioned on the side wall so as to be located between the connection between the top wall and the side wall and the gas introduction nozzle. The plasma processing apparatus described in (9) above. (11) The plurality of resonators are arranged radially from the center of the processing vessel. A plasma processing apparatus according to any one of (1) to (10) above. (12) The aforementioned resonator array structure is such that the plurality of resonators are arranged on the circumferences of a plurality of concentric circles. The plurality of resonators have resonant frequencies that differ for each part of the circumference. The plasma processing apparatus described in (11) above. (13) The aforementioned resonator array structure has a relative permeability of -100 or less. A plasma processing apparatus according to any one of (1) to (12) above. (14) A conductive film is formed on the inner wall of the processing container. The plasma processing apparatus described in (13) above. (15) The aforementioned resonator array structure is further positioned on the lower surface of the microwave transmission window, A plasma processing apparatus according to any one of (1) to (14) above. [Explanation of Symbols]

[0094] 100 Plasma Processing Equipment 101 Processing container 111 Top wall section 112 Side wall section 113 Bottom wall section 123,123a Gas introduction nozzle 130 Microwave output section 143 Microwave Emission Mechanism 163 Microwave-transmitting plate 200, 300, 400 resonator array structures (metamaterials) 201, 201A, 201B resonators (metaatoms) Circumferences of 202-204, 302, 303 211 Ring member 212,312 dielectrics 222 Sheath 229 Conductive film S processing space W board

Claims

1. A processing container that houses a substrate and defines the processing space with its top wall, side walls, and bottom wall, A microwave generator configured to generate microwaves for generating plasma, A microwave radiation unit is provided above the top wall portion and configured to radiate microwaves toward the processing container, A microwave-transmitting window made of a dielectric material is provided at a position corresponding to the microwave radiation section of the top wall, A resonator array structure is formed by arranging a plurality of resonators, each arranged in at least one of the top wall portion and the side wall portion, which are capable of resonating with the magnetic field component of the microwave and whose size is smaller than the wavelength of the microwave; A plasma processing apparatus having

2. The aforementioned resonator array structure is provided inside the wall portion, The plasma processing apparatus according to claim 1.

3. The resonator includes two or more C-shaped ring members made of conductors. The plasma processing apparatus according to claim 1 or 2.

4. The resonator includes a dielectric material surrounding the ring member, The plasma processing apparatus according to claim 3.

5. The resonator is such that the ring member can be inserted from the atmospheric side of the resonator array structure. The plasma processing apparatus according to claim 3.

6. The resonator array structure is positioned on the top wall so as to be located between the microwave transmission window and the connection between the top wall and the side wall. The plasma processing apparatus according to claim 1 or 2.

7. Multiple microwave radiation units and microwave transmission windows are provided, The resonator array structure is arranged on the top wall so as to surround the plurality of microwave transmission windows. The plasma processing apparatus according to claim 6.

8. Multiple microwave radiation units and microwave transmission windows are provided, The resonator array structure is arranged in multiple locations on the top wall so as to surround each of the multiple microwave transmission windows. The plasma processing apparatus according to claim 6.

9. The side wall portion further includes a gas introduction nozzle for introducing the gas for generating the plasma into the processing container, The resonator array structure is positioned on the side wall so as to be located between the microwave transmission window and the gas introduction nozzle. The plasma processing apparatus according to claim 1 or 2.

10. The resonator array structure is positioned on the side wall so as to be located between the connection between the top wall and the side wall and the gas introduction nozzle. The plasma processing apparatus according to claim 9.

11. The plurality of resonators are arranged radially from the center of the processing vessel. The plasma processing apparatus according to claim 1 or 2.

12. The aforementioned resonator array structure is such that the plurality of resonators are arranged on the circumferences of a plurality of concentric circles. The plurality of resonators have resonant frequencies that differ for each part of the circumference. The plasma processing apparatus according to claim 11.

13. The aforementioned resonator array structure has a relative permeability of -100 or less. The plasma processing apparatus according to claim 1 or 2.

14. A conductive film is formed on the inner wall of the processing container. The plasma processing apparatus according to claim 13.

15. The aforementioned resonator array structure is further positioned on the lower surface of the microwave transmission window, The plasma processing apparatus according to claim 1 or 2.

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