Plasma processor

Abstract

To provide a technique for suppressing heat conduction from an excitation electrode of a plasma processor through a resonator and suppressing current loss.SOLUTION: The disclosed plasma processor includes a chamber, a substrate supporting unit, an excitation electrode, a discharge unit, and a resonator. The substrate supporting unit is provided in a processing space of the chamber. The excitation electrode is provided above the substrate supporting unit. The discharge unit discharges electromagnetic waves into a plasma generation space below the excitation electrode. The resonator is provided above the excitation electrode and is electromagnetically coupled to the discharge unit. A conductor part which defines the waveguide of the resonator is formed of a first conductor in a first part including a position located a quarter of the wavelength in the waveguide of an electromagnetic wave in the resonator distant from one end of the waveguide and is formed of a second conductor in a second part as the part other than the first part. The thermal conductivity of the first conductor is lower than the thermal conductivity of the second conductor.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A plasma processing apparatus is used in processing a substrate. One type of plasma processing apparatus is known that excites a gas using high frequency waves, such as VHF waves or UHF waves. The following Patent Document 1 discloses such a plasma processing apparatus. The plasma processing apparatus of Patent Document 1 includes a processing vessel, a stage, an upper electrode, an introduction section, and a waveguide section. The stage is provided in the processing vessel. The upper electrode is provided above the stage through a space in the processing vessel. The introduction section is an introduction section for high frequency waves. The introduction section is provided at a lateral end of the space and extends in a circumferential direction around the central axis of the processing vessel. The waveguide section is configured to supply high frequency waves to the introduction section. The waveguide section includes a resonator that provides a waveguide. The waveguide of the resonator extends in a circumferential direction around the central axis, extends in the direction in which the central axis extends, and is connected to the introduction section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-92031 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for suppressing heat conduction from an excitation electrode through a resonator in a plasma processing apparatus, and suppressing current loss. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, an excitation electrode, an emitter, and a resonator. The chamber provides a processing space therein. The substrate support is provided in the processing space. The excitation electrode is provided above the substrate support. The emitter is provided to emit electromagnetic waves into a plasma generation space below the excitation electrode. The resonator is provided on the excitation electrode and is electromagnetically coupled to the emitter. The resonator includes a conductor portion defining a waveguide thereof. The conductor portion is formed of a first conductor in a first portion including a position from one end of the waveguide to a position of ¼ of the guide wavelength of the electromagnetic wave in the resonator, and is formed of a second conductor in a second portion other than the first portion. The thermal conductivity of the first conductor is smaller than the thermal conductivity of the second conductor. Effect of the Invention

[0006] According to one exemplary embodiment, it is possible to suppress heat conduction from an excitation electrode of a plasma processing apparatus through a resonator, and to suppress current loss. [Brief description of the drawings]

[0007] [Figure 1] 1 illustrates a plasma processing apparatus according to an exemplary embodiment; [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 2 is a cross-sectional view taken along line VV in FIG. 1. [Figure 6] FIG. 1 illustrates a plasma processing apparatus according to another exemplary embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. [Figure 9]FIG. 7 is a cross-sectional view taken along line IX-IX in FIG. 6. [Figure 10] FIG. 7 is a cross-sectional view taken along line XX in FIG. 6. [Figure 11] FIG. 13 illustrates a plasma processing apparatus according to yet another exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0009] FIG. 1 is a diagram showing a plasma processing apparatus according to an exemplary embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. FIG. 5 is a cross-sectional view taken along line VV in FIG. 1. The plasma processing apparatus 1 shown in FIGS. 1 to 5 includes a chamber 10, a substrate support 12, an excitation electrode 14, an emission unit 16, and a resonator 30. The plasma processing apparatus 1 may further include a control unit 2.

[0010] The chamber 10 provides a processing space 10s therein. In the plasma processing apparatus 1, the substrate W is processed in the processing space 10s. The chamber 10 is made of a metal such as aluminum and is grounded. The chamber 10 has a side wall 10a and is open at its upper end. The chamber 10 and the side wall 10a may have a substantially cylindrical shape. The processing space 10s is provided inside the side wall 10a. The central axis of each of the chamber 10, the side wall 10a, and the processing space 10s is the axis AX. The chamber 10 may have a corrosion-resistant film on its surface. The corrosion-resistant film may be a ceramic film containing an yttrium oxide film, an yttrium oxide fluoride film, an yttrium fluoride film, an yttrium oxide, or an yttrium fluoride film.

[0011] The bottom of the chamber 10 provides an exhaust port 10e. An exhaust system is connected to the exhaust port 10e. The exhaust system may include a vacuum pump, such as a dry pump and / or a turbomolecular pump, and an automatic pressure control valve.

[0012] The substrate support 12 is provided in the processing space 10s. The substrate support 12 is configured to support the substrate W placed on its upper surface in an approximately horizontal manner. The substrate support 12 has an approximately disk shape. The central axis of the substrate support 12 is an axis AX.

[0013] The excitation electrode 14 is provided above the substrate support 12 via the processing space 10s. The excitation electrode 14 is made of a conductive material such as a metal (e.g., aluminum) and has a substantially disk shape. The central axis of the excitation electrode 14 is an axis AX.

[0014] The emitter 16 is provided to emit electromagnetic waves from there into the plasma generation space. In the plasma processing apparatus 1, the plasma generation space is the space in the processing space 10s and below the excitation electrode 14. The electromagnetic waves emitted from the emitter 16 into the plasma generation space may be high frequency waves such as VHF waves or UHF waves. The emitter 16 is formed of a dielectric material such as quartz, aluminum nitride, or aluminum oxide. The emitter 16 extends in the circumferential direction around the axis AX. The emitter 16 may have a ring shape. The emitter 16 may extend so as to surround the plasma generation space or a shower plate 141 described later. In the plasma processing apparatus 1, the gas in the chamber 10 is excited by the electromagnetic waves emitted from the emitter 16 into the plasma generation space. As a result, plasma is generated in the plasma generation space.

[0015] In one embodiment, the excitation electrode 14 may include a shower plate 141 and an upper electrode 142. The shower plate 141 is provided above the plasma generation space. The shower plate 141 closes the opening at the upper end of the chamber 10 together with the emission part 16. The shower plate 141 provides a plurality of gas holes 14h. The plurality of gas holes 14h extend in the thickness direction (vertical direction) of the shower plate 141 and penetrate the shower plate 141.

[0016] The upper electrode 142 is provided on the shower plate 141. The upper electrode 142 forms a gas diffusion chamber 14d between the shower plate 141 and the upper electrode 142. A gas supply unit 20 is connected to the gas diffusion chamber 14d. Gas from the gas supply unit 20 is discharged from a plurality of gas holes 14h through the gas diffusion chamber 14d into the plasma generation space (processing space 10s).

[0017] In one embodiment, the excitation electrode 14 may include a built-in heating mechanism 143. The heating mechanism 143 may be provided in the upper electrode 142. The heating mechanism 143 may be an electric heater, for example, a resistance heating element. In this case, the heating mechanism 143 is connected to the heater power supply 22. The heating mechanism 143 generates heat by power provided from the heater power supply 22. The plasma processing apparatus 1 may further include a temperature sensor 144. The temperature sensor 144 may be provided in the excitation electrode 14 or the upper electrode 142. The temperature sensor 144 includes, for example, a thermocouple. The temperature sensor 144 measures the temperature of the excitation electrode 14. In the plasma processing apparatus 1, the heater power supply 22 and a plurality of fans, which will be described later, are controlled by the control unit 2 so as to reduce the difference between the temperature measurement value measured by the temperature sensor 144 and the target temperature value of the excitation electrode 14.

[0018] The control unit 2 is a computer device including a processor, a storage unit such as a memory, and a communication interface. The control unit 2 is configured to execute a control program and control each unit of the plasma processing apparatus 1 according to recipe data.

[0019] The resonator 30 is disposed on the excitation electrode 14. The resonator 30 is electromagnetically coupled to the emitter 16. The resonator 30 provides a waveguide 32. The resonator 30 includes a conductor portion 31 that defines the waveguide 32. The conductor portion 31 is formed from a conductive material such as a metal.

[0020] The resonator 30 includes a first end 301 and a second end 302. The first end 301 is one end of the waveguide 32, and the second end 302 is the other end of the waveguide 32. The resonator 30 is configured to reflect and resonate an electromagnetic wave propagating in the waveguide 32 at the first end 301 and the second end 302. The electromagnetic wave resonated in the resonator 30 is supplied to the emission section 16 from a plurality of slots 302s (described later) and emitted into the plasma generation space.

[0021] The plasma processing apparatus 1 may further include a high-frequency power source 34. The high-frequency power source 34 is configured to generate high-frequency power. The electromagnetic waves introduced into the plasma generating space are generated based on the high-frequency power generated by the high-frequency power source 34. The high-frequency power source 34 may be directly connected to the resonator 30 using a coaxial line. That is, the high-frequency power source 34 may be coupled to the waveguide of the resonator 30 without an impedance matching device. The coaxial line may include a connector 36 as a connection part to the resonator 30. The connector 36 may be connected to the resonator 30 so as to introduce the electromagnetic waves into the resonator 30 from the top layer of the multiple layers 320 of the waveguide 32 described later. In this case, the inner conductor of the connector 36 is connected to a conductor plate 31p described later that defines the top layer from below, and the outer conductor of the connector 36 is connected to a conductor plate 31p (upper wall 31u) that defines the top layer from above.

[0022] The conductor section 31 of the resonator 30 includes a first section 311 and a second section 312. The first section 311 includes a position from the first end 301 of the waveguide 32 to a position ¼ of the guide wavelength of the electromagnetic wave in the resonator 30. The second section 312 is a section of the conductor section 31 other than the first section 311. The second section 312 may be all sections of the conductor section 31 other than the first section 311. The first section 311 is formed from a first conductor. The second section 312 is formed from a second conductor. The thermal conductivity of the first conductor is smaller than the thermal conductivity of the second conductor. Therefore, the electrical conductivity of the first conductor is smaller than the electrical conductivity of the second conductor. The first conductor includes, for example, stainless steel or brass. The second conductor includes, for example, aluminum or copper. The first section 311 may include a main body formed from the first conductor and a film covering the surface of the main body. This film may have an electrical conductivity greater than that of the first conductor and may be made of, for example, silver, copper, gold, or the like.

[0023] In the plasma processing apparatus 1, since the thermal conductivity of the first portion 311 of the resonator 30 is small, the thermal conduction from the excitation electrode 14 through the resonator 30 is suppressed. Therefore, the power consumption of the heater power supply 22 is suppressed. Furthermore, in the first portion 311, the voltage of the standing wave is maximized and the current of the standing wave is minimized. Therefore, according to the plasma processing apparatus 1, the current loss in the resonator 30 is suppressed.

[0024] In one embodiment, the waveguide 32 may have a folded structure including a plurality of folded portions. In this case, the first portion 311 may extend along one of the folded portions.

[0025] In one embodiment, the waveguide 32 may be configured axially or rotationally symmetrical with respect to the axis AX. In addition, in one embodiment, the conductor portion 31 may include an inner portion 31i (or an inner peripheral portion), an outer portion 31o (or an outer peripheral portion), and a plurality of conductor plates 31p. The inner portion 31i and the outer portion 31o extend coaxially with respect to the axis AX. Each of the inner portion 31i and the outer portion 31o may have a substantially cylindrical shape whose central axis is the axis AX. The plurality of conductor plates 31p extend in a radial direction with respect to the axis AX, and are arranged parallel to each other along the vertical direction in which the axis AX extends.

[0026] The waveguide 32 may also include a plurality of layers 320. The plurality of layers 320 extend in a radial direction with respect to the axis AX between the inner portion 31i and the outer portion 31o, and are arranged alternately with the plurality of conductive plates 31p. Each of the plurality of layers 320 is connected to the layer thereabove among the plurality of layers 320 at one of a plurality of folded portions along the inner portion 31i or the outer portion 31o.

[0027] In one embodiment, the first end 301 is provided above the second end 302. The first end 301 is provided by the outer portion 31o of the resonator 30. The first end 301 is an outer peripheral end of the top layer of the multiple layers 320 and surrounds the top layer. The second end 302 is provided by the outer portion 31o of the resonator 30. The second end 302 is an outer peripheral end of the bottom layer of the multiple layers 320 and surrounds the bottom layer. As shown in FIG. 4, a bottom conductor plate 31b that defines the bottom layer of the multiple conductor plates 31p from below has a plurality of slots 302s formed therein. The plurality of slots 302s are disposed near or along the second end 302. The plurality of slots 302s are coupled to the emitter 16 on the outside with respect to the excitation electrode 14. The plurality of slots 302s extend in a circumferential direction around the axis AX above the emitter 16. The multiple slots 302s extend in a circumferential direction with respect to the axis AX and are arranged along the circumferential direction. The multiple slots 302s are arranged alternately with the multiple portions 302r in the conductive plate 31b. In this resonator 30, the electromagnetic wave is reflected at the second end 302 toward the first end 301. Also, a portion of the electromagnetic wave propagating in the resonator 30 is coupled to the emission portion 16 through the multiple slots 302s. In this embodiment, the first portion 311 is a part of the outer portion 31o and surrounds one or more intermediate layers 320 among the multiple layers 320.

[0028] In one embodiment, the inner portion 31i may be formed of a cylindrical conductor wall extending between the conductor plates 31p adjacent to each other in the vertical direction. The outer portion 31o may be composed of a plurality of columns 33. The plurality of columns 33 are arranged in the circumferential direction with respect to the axis line AX between the conductor plates 31p adjacent to each other in the vertical direction in the outer portion 31o. Each of the plurality of columns 33 is aligned with the corresponding column 33 along the vertical direction. In this embodiment, the first portion 311 is composed of a plurality of columns 33 (a plurality of columns 331 in the figure) surrounding one or more intermediate layers 320 among the plurality of layers 320. In this embodiment, the thickness (radial thickness) of the conductor wall constituting the inner portion 31i may be thinner than the thickness (radial thickness) of the outer portion 31o. This suppresses heat conduction from the excitation electrode 14 through the inner portion 31i.

[0029] The plurality of columns 33 may be cylindrical. In this case, a bolt 70 may be passed through the inner holes of the plurality of columns 33 aligned along the vertical direction. The lower end of the bolt 70 may be screwed into the lowermost conductor plate 31b of the plurality of conductor plates 31p. A washer 71 and a nut 72 may be attached to the upper end of the bolt 70, and a coil spring 73 may be provided between the washer 71 and the upper wall 31u.

[0030] In an embodiment, the plasma processing apparatus 1 may further include a thin shield plate 30s. The thin shield plate 30s is made of a metal such as stainless steel. The thin shield plate 30s has a cylindrical shape and surrounds the outer portion 31o of the resonator 30. The thin shield plate 30s suppresses leakage of electromagnetic waves from the resonator 30.

[0031] In one embodiment, the plasma processing apparatus 1 may further include at least one conductive member 68. The conductive member 68 is provided between the resonator 30 and the excitation electrode 14 so as to form a gap between the resonator 30 and the excitation electrode 14. The conductive member 68 is made of a metal such as stainless steel. The conductive member 68 may have elasticity. The conductive member 68 is, for example, a shield spiral made of a metal. The conductive member 68 suppresses heat transfer between the resonator 30 and the excitation electrode 14.

[0032] The conductive member 68 is sandwiched between the conductor plate 31b and the excitation electrode 14. Thus, the conductive member 68 electrically connects the resonator 30 to the excitation electrode 14. The conductive member 68 may be arranged to form a ring around the axis line AX. In the illustrated example, as the at least one conductive member 68, two conductive members 68 are arranged in a ring shape around the axis line AX. The conductive member 68 may be arranged along a portion of the resonator 30 where a high-frequency current flows. In the illustrated example, the two conductive members 68 are arranged along a pair of edges of each of the multiple slots 302s.

[0033] In one embodiment, as shown in Fig. 3, at least one of the plurality of conductive plates 31p may have a plurality of slits SL formed therein. The plurality of slits SL penetrate the at least one conductive plate 31p in the thickness direction. The plurality of slits SL are arranged in the circumferential direction around the axis line AX and extend in the radial direction relative to the axis line AX. The plurality of slits SL suppresses the propagation of higher harmonics of the electromagnetic wave in the circumferential direction. In addition, the pressure loss of the heat medium in the waveguide 32, which will be described later, is suppressed.

[0034] The plasma processing apparatus 1 may further include a temperature regulator 18. The temperature regulator 18 is configured to supply a heat medium (for example, a gas such as air) along the upper surface of the excitation electrode 14.

[0035] The temperature regulator 18 includes a plurality of fans 40. The temperature regulator 18 provides a flow path 42. The plurality of fans 40 are arranged at approximately equal intervals around the axis line AX above the excitation electrode 14. The plurality of fans 40 are configured to form a flow of the heat medium in the flow path 42. In the plasma processing apparatus 1, each of the plurality of fans 40 can suck in and discharge the heat medium from the flow path 42.

[0036] The flow passage 42 extends from the opening 42a to the multiple openings 42b. The opening 42a is an inlet for the heat medium to the flow passage 42. The multiple openings 42b are outlets for the heat medium from the flow passage 42. Each of the multiple openings 42b opens directly below a corresponding one of the multiple fans 40.

[0037] The flow passage 42 is axially symmetric or rotationally symmetric with respect to the axis line AX. The flow passage 42 includes a partial flow passage 421 and a partial flow passage 422. The flow passage 42 may further include a partial flow passage 423.

[0038] The partial flow path 421 extends along the upper surface of the excitation electrode 14. The partial flow path 421 is provided between the conductor plate 31b of the resonator 30 and the excitation electrode 14. The partial flow path 421 extends in a radial direction from the axis line AX. The partial flow path 422 is connected to the partial flow path 421 via a plurality of communication holes 14c formed in the upper electrode 142. The partial flow paths 422 extend alternately in opposite directions between the plurality of fans 40 and the partial flow path 421. The opposite directions are a direction approaching the axis line AX and a radial direction with respect to the axis line AX. The opposite directions are perpendicular to the axis line AX. In one embodiment, the partial flow path 422 of the temperature regulator 18 is formed from the waveguide 32 of the resonator 30. Thus, the resonator 30 constitutes a heat exchanger for the excitation electrode 14.

[0039] The partial flow path 423 extends from the opening 42a to the partial flow path 421. The partial flow path 423 is provided inside the inner portion 31i of the resonator 30. The partial flow path 423 may have an axis line AX as its central axis line. That is, the partial flow path 423 may extend vertically along the axis line AX to the partial flow path 421.

[0040] In the plasma processing apparatus 1, the heat medium taken in through the opening 42a is supplied from the partial flow path 423 to the partial flow path 421, and flows along the upper surface of the excitation electrode 14 in the partial flow path 421. As a result, heat exchange occurs between the excitation electrode 14 and the heat medium. Then, the heat medium flows from the partial flow path 421 to the partial flow path 422, and is discharged to the outside of the plasma processing apparatus 1 through the multiple openings 42b by the multiple fans 40.

[0041] In one embodiment, a heater 66 may be provided inside the inner portion 31i of the resonator 30. In this embodiment, a heat medium preheated by the heater 66 is supplied to the partial flow passage 421. The heater 66 may, for example, preheat the heat medium to a temperature similar to the temperature of the excitation electrode 14 (for example, 180° C.). This improves the temperature controllability of the excitation electrode 14.

[0042] In one embodiment, the plasma processing apparatus 1 may further include a gas pipe 64. The gas pipe 64 extends vertically inside the inner portion 31i. The central axis of the gas pipe 64 may be located on the axis line AX. The gas pipe 64 is connected between the gas diffusion chamber 14d and the gas supply unit 20. The above-mentioned heater 66 may surround the gas pipe 64. Also, the heater 66 may be attached to the outer periphery of the gas pipe 64.

[0043] The temperature regulator 18 may further include a cooling unit 50. The cooling unit 50 may form a part of the partial flow path 422. Specifically, the cooling unit 50 includes a wall 50w, and a refrigerant is supplied from a chiller unit to the refrigerant flow path 50f that provides a refrigerant flow path 50f in the wall 50w. According to the temperature regulator 18, the heat medium cooled by the cooling unit 50 in the partial flow path 422 is discharged to the outside from the multiple fans 40. The wall 50w may be the upper wall 31u. The wall 50w may be any one of the multiple conductor plates 31p of the resonator 30 instead of the upper wall 31u.

[0044] In one embodiment, the length (height) of the waveguide 32 in the vertical direction of the top layer of the multiple layers 320 in the waveguide 32 may be longer than the lengths (heights) of the waveguide 32 in the vertical direction of other layers of the multiple layers 320. Since the top layer is provided near the multiple fans 40, the flow velocity of the heat medium in the top layer is high. According to this embodiment, it is possible to suppress pressure loss of the heat medium in the top layer where the flow velocity is high.

[0045] In one embodiment, the excitation electrode 14 may have a plurality of fins 14f. The plurality of fins 14f are provided by the upper electrode 142. The plurality of fins 14f protrude upward, extend in a radial direction relative to the axis line AX, and are arranged along the circumferential direction around the axis line AX. Each of the plurality of communication holes 14c is connected to a gap between two adjacent fins among the plurality of fins 14f. The plurality of fins 14f promotes heat exchange between the excitation electrode 14 and the heat medium.

[0046] Hereinafter, a plasma processing apparatus according to another exemplary embodiment will be described with reference to Figs. 6 to 10. Fig. 6 is a diagram showing a plasma processing apparatus according to another exemplary embodiment. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 6. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 6. Fig. 10 is a cross-sectional view taken along line XX in Fig. 6. Hereinafter, a plasma processing apparatus 1B shown in Figs. 6 to 10 will be described from the viewpoint of differences from the plasma processing apparatus 1.

[0047] The plasma processing apparatus 1B includes a resonator 30B instead of the resonator 30. The resonator 30B is provided above the excitation electrode 14. Like the resonator 30, the resonator 30B includes a waveguide 32 defined by a conductor portion 31. In the resonator 30B, the waveguide 32 also includes a plurality of layers 320. Like the conductor portion 31 of the resonator 30, the conductor portion 31 of the resonator 30B also includes a first portion 311 and a second portion 312.

[0048] In the temperature regulator 18 of the plasma processing apparatus 1B, the flow path 42 is formed in substantially the same manner as the flow path 42 of the plasma processing apparatus 1. Moreover, the partial flow path 422 of the temperature regulator 18 of the plasma processing apparatus 1B is formed from the waveguide 32 of the resonator 30. However, in the temperature regulator 18 of the plasma processing apparatus 1B, the partial flow path 422 is connected to the partial flow path 421 via a plurality of communication holes 42c formed in the conductive plate 31b. The plurality of communication holes 42c penetrate the conductive plate 31b and are arranged in the circumferential direction around the axis line AX.

[0049] In the plasma processing apparatus 1B, the heat medium is supplied from the multiple fans 40 to the partial flow passage 421 through the multiple openings 42b and the partial flow passages 422, and flows along the upper surface of the excitation electrode 14 in the partial flow passage 421. As a result, heat exchange occurs between the excitation electrode 14 and the heat medium. Then, the heat medium flows from the partial flow passage 421 to the partial flow passage 423. The heat medium is discharged from the partial flow passage 423 to the outside of the plasma processing apparatus 1B through the opening 42a.

[0050] In the plasma processing apparatus 1B, the upper wall 31u of the resonator 30 may have a plurality of fins 31f. The plurality of fins 31f protrude upward. The plurality of fins 31f extend in radial directions relative to the axis line AX and are arranged in the circumferential direction around the axis line AX. A heat insulating plate 80 may be disposed on the plurality of fins 31f. The heat insulating plate 80 is formed of, for example, polyimide.

[0051] The fins 31f provide a plurality of flow paths therebetween. The flow paths provided by the fins 31f extend in a radial direction relative to the axis AX and are arranged in a circumferential direction around the axis AX. The partial flow paths 423 and the openings 42a are connected to each other via the flow paths provided by the fins 31f. According to this embodiment, the heat medium is cooled by the fins 31f and then discharged from the openings 42a to the outside of the plasma processing apparatus 1B.

[0052] In the plasma processing apparatus 1B, the outer portion 31o has a substantially cylindrical shape and has the axis AX as its central axis. In the plasma processing apparatus 1B, the outer portion 31o may extend along each side of a polygon in a cross section perpendicular to the axis AX. That is, the outer portion 31o may have a polygonal tube shape. The outer portion 31o may be formed of a plurality of plate-like bodies 315 between adjacent conductor plates 31p in the vertical direction. Each of the plurality of plate-like bodies 315 is formed of a metal. Each of the plurality of plate-like bodies 315 may be a flat plate. Each of the plurality of plate-like bodies 315 extends along a corresponding side of the polygon in a cross section perpendicular to the axis AX.

[0053] In the plasma processing apparatus 1B as well, the plurality of plate-like bodies 315 constituting the first portion 311 are formed from the above-mentioned first conductor. Moreover, the second portion 312 is formed from the above-mentioned second conductor. The second portion 312 includes the plurality of plate-like bodies 315 constituting the second portion 312. In the plasma processing apparatus 1B as well, the second portion 312 may be all portions of the conductor portion 31 other than the first portion 311.

[0054] In the plasma processing apparatus 1B, the thermal conductivity of the first portion 311 is small, so that the thermal conduction from the excitation electrode 14 through the resonator 30 is suppressed. Therefore, the power consumption of the heater power supply 22 is suppressed. Furthermore, in the first portion 311, the voltage of the standing wave is maximized and the current of the standing wave is minimized. Therefore, according to the plasma processing apparatus 1B, the current loss in the resonator 30 is suppressed.

[0055] In the plasma processing apparatus 1B, each of the multiple plate-like bodies 315 is fixed to the conductive plate 31p above it and the conductive plate 31p below it by one or more screws 81. The one or more screws 81 may be formed from the above-mentioned first conductor. In this case, the difference in thermal expansion coefficient between each of the multiple plate-like bodies 315 constituting the first portion 311 and the one or more screws 81 is reduced. Therefore, damage to the one or more screws 81 is suppressed.

[0056] Hereinafter, a plasma processing apparatus according to still another exemplary embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram showing a plasma processing apparatus according to still another exemplary embodiment. Hereinafter, the plasma processing apparatus 1C shown in Fig. 11 will be described from the viewpoint of differences from the plasma processing apparatus 1.

[0057] The plasma processing apparatus 1C further includes an electrode 60. The electrode 60 is another excitation electrode. The electrode 60 has a substantially disk shape and is disposed so as to close the opening at the upper end of the chamber 10. The electrode 60 provides a plurality of holes 60h. The plurality of holes 60h penetrate the electrode 60 in the thickness direction. The excitation electrode 14 is disposed above the electrode 60. The excitation electrode 14 and the electrode 60 form a plasma generation space 60p therebetween. The emission section 16 surrounds the plasma generation space 60p and is sandwiched between the excitation electrode 14 and the electrode 60. In the plasma processing apparatus 1C, the plasma generation space 60p is provided above the processing space 10s, away from the processing space 10s.

[0058] In the plasma processing apparatus 1C, gas from the gas supply unit 20 is supplied to the plasma generating space 60p via the gas diffusion chamber 14d and the plurality of gas holes 14h. In the plasma generating space 60p, plasma is generated from the gas by the electromagnetic waves introduced into the plasma generating space 60p from the emission unit 16. The activated species in the plasma generated in the plasma generating space 60p are supplied to the processing space 10s through the plurality of holes 60h.

[0059] Moreover, the plasma processing apparatus 1C includes a resonator 30C instead of the resonator 30. The resonator 30C is provided above the excitation electrode 14. The resonator 30C includes a waveguide 32 defined by a conductor portion 31, similar to the resonator 30. The waveguide 32 also includes a plurality of layers 320 in the resonator 30C. Similarly to the conductor portion 31 of the resonator 30, the conductor portion 31 of the resonator 30 also includes a first portion 311 and a second portion 312. However, in the resonator 30C, the first end 301, i.e., the end opposite to one end of the waveguide 32, is the radial center of the plasma generation space 60p.

[0060] In the resonator 30C, the outer portion 31o may be formed in a substantially cylindrical shape. In the resonator 30C, the first portion 311 is a part of the inner portion 31i, and extends inside one or more intermediate layers 320 among the multiple layers 320. In the plasma processing apparatus 1C as well, the first portion 311 is formed from the above-mentioned first conductor. Moreover, the second portion 312 is formed from the above-mentioned second conductor. In the plasma processing apparatus 1C as well, the second portion 312 may be the entire portion of the conductor portion 31 other than the first portion 311.

[0061] In the plasma processing apparatus 1C, the thermal conductivity of the first portion 311 is small, so that the thermal conduction from the excitation electrode 14 through the resonator 30 is suppressed. Therefore, the power consumption of the heater power supply 22 is suppressed. Furthermore, in the first portion 311, the voltage of the standing wave is maximized and the current of the standing wave is minimized. Therefore, according to the plasma processing apparatus 1C, the current loss in the resonator 30 is suppressed.

[0062] In the temperature regulator 18 of the plasma processing apparatus 1C, the flow path 42 includes a partial flow path 421 and a partial flow path 422. The partial flow path 422 of the temperature regulator 18 of the plasma processing apparatus 1C is formed from the waveguide 32 of the resonator 30. In the temperature regulator 18 of the plasma processing apparatus 1C, the flow path 42 extends from the multiple openings 42b to the multiple openings 42a. The multiple openings 42b are inlets for the heat medium to the flow path 42 and are connected to the partial flow path 422. Each of the multiple openings 42b opens immediately below a corresponding fan among the multiple fans 40. The multiple openings 42a are outlets for the heat medium from the flow path 42 and are connected to the partial flow path 421. The multiple openings 42a are arranged along the circumferential direction around the axis line AX. In one embodiment, the multiple openings 42a are formed in the outer portion 31o of the resonator 30C.

[0063] In the plasma processing apparatus 1C, the heat medium is supplied from the multiple fans 40 to the partial flow passage 421 through the multiple openings 42b and the partial flow passage 422, and flows along the upper surface of the excitation electrode 14 in the partial flow passage 421. As a result, heat exchange occurs between the excitation electrode 14 and the heat medium. Then, the heat medium is discharged from the partial flow passage 421 to the outside of the plasma processing apparatus 1C through the multiple openings 42a.

[0064] 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. In addition, elements in different embodiments can be combined to form other embodiments.

[0065] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E12] below.

[0066] [E1] a chamber providing a processing volume therein; a substrate support disposed within the processing space; an excitation electrode provided above the substrate support; An emission section provided to emit electromagnetic waves into a plasma generation space below the excitation electrode; a resonator disposed on the excitation electrode and electromagnetically coupled to the emitter; Equipped with The resonator includes a conductor portion defining a waveguide thereof; the conductor portion is formed of a first conductor in a first portion including a position from one end of the waveguide to a position corresponding to ¼ of a guide wavelength of an electromagnetic wave in the resonator, and is formed of a second conductor in a second portion other than the first portion, The thermal conductivity of the first conductor is less than the thermal conductivity of the second conductor. Plasma processing equipment.

[0067] [E2] The waveguide has a structure including a plurality of folded portions, The first portion extends along one of the plurality of folded portions. The plasma processing apparatus according to E1.

[0068] [E3] the emission portion extends about a central axis of the chamber and the excitation electrode; The conductor portion is an inner portion and an outer portion extending coaxially with respect to the central axis; A plurality of conductor plates arranged parallel to each other along a vertical direction in which the central axis extends; Including, the waveguide extends between the outer portion and the inner portion and includes a plurality of layers interleaved with the plurality of conductive plates; each of the layers of the waveguide is connected to an upper layer of the layers at one of the turns along the inner portion or the outer portion; The plasma processing apparatus according to E2.

[0069] [E4] The plasma processing apparatus of E3, wherein the first portion is part of the outer portion.

[0070] [E5] the one end being an outer circumferential end of an uppermost layer of the plurality of layers; The waveguide further includes another end that is an outer circumferential end of a lowest layer of the plurality of layers, The plasma generation space is below the excitation electrode and within the processing space. 5. The plasma processing apparatus according to claim 3 or 4.

[0071] [E6] The plasma processing apparatus of E3, wherein the first portion is a part of the inner portion.

[0072] [E7] a second electrode interposed between the excitation electrode and the processing space and providing a plurality of holes connecting the plasma generation space and the processing space; The emission section is provided between the excitation electrode and the other electrode. The plasma processing apparatus according to E6.

[0073] [E8] The plasma processing apparatus of any one of E3 to E7, wherein a thickness of a wall constituting the inner portion is thinner than a thickness of a wall constituting the outer portion.

[0074] [E9] The plasma processing apparatus according to any one of E1 to E8, wherein the excitation electrode has a heating mechanism.

[0075] [E10] The plasma processing apparatus according to E9, wherein the heating mechanism is an electric heater.

[0076] [E11] The plasma processing apparatus of any one of E1 to E10, further comprising a fan configured to form a gas flow that passes through the waveguide between a surface of the excitation electrode and an outside of the resonator.

[0077] [E12] the first conductor comprises stainless steel or brass; The second conductor includes aluminum or copper. The plasma processing apparatus according to any one of E1 to E11.

[0078] 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. [Explanation of symbols]

[0079] 1...plasma processing apparatus, 10...chamber, 12...substrate support, 14...excitation electrode, 16...emission portion, 30...resonator, 31...conductor portion, 311...first portion, 312...second portion, 32...waveguide.

Claims

1. a chamber providing a processing volume therein; a substrate support disposed within the processing space; an excitation electrode provided above the substrate support; An emission section provided to emit electromagnetic waves into a plasma generation space below the excitation electrode; a resonator disposed on the excitation electrode and electromagnetically coupled to the emitter; Equipped with The resonator includes a conductor portion defining a waveguide thereof; the conductor portion is formed of a first conductor in a first portion including a position from one end of the waveguide to a position corresponding to ¼ of a guide wavelength of an electromagnetic wave in the resonator, and is formed of a second conductor in a second portion other than the first portion, The thermal conductivity of the first conductor is less than the thermal conductivity of the second conductor. Plasma processing equipment.

2. The waveguide has a structure including a plurality of folded portions, The first portion extends along one of the plurality of folded portions. The plasma processing apparatus according to claim 1 .

3. the emission portion extends about a central axis of the chamber and the excitation electrode; The conductor portion is an inner portion and an outer portion extending coaxially with respect to the central axis; A plurality of conductor plates arranged parallel to each other along a vertical direction in which the central axis extends; Including, the waveguide extends between the outer portion and the inner portion and includes a plurality of layers interleaved with the plurality of conductive plates; each of the layers of the waveguide is connected to an upper layer of the layers at one of the turns along the inner portion or the outer portion; The plasma processing apparatus according to claim 2 .

4. The plasma processing apparatus of claim 3 , wherein the first portion is a part of the outer portion.

5. the one end being an outer circumferential end of an uppermost layer of the plurality of layers; The waveguide further includes another end that is an outer circumferential end of a lowest layer of the plurality of layers, The plasma generation space is below the excitation electrode and within the processing space. The plasma processing apparatus according to claim 4 .

6. The plasma processing apparatus of claim 3 , wherein the first portion is a part of the inner portion.

7. a second electrode interposed between the excitation electrode and the processing space and providing a plurality of holes connecting the plasma generation space and the processing space; The emission section is provided between the excitation electrode and the other electrode. The plasma processing apparatus according to claim 6 .

8. 8. The plasma processing apparatus according to claim 3, wherein a thickness of a wall constituting the inner portion is thinner than a thickness of a wall constituting the outer portion.

9. 8. The plasma processing apparatus according to claim 1, wherein the excitation electrode has a heating mechanism.

10. The plasma processing apparatus according to claim 9 , wherein the heating mechanism is an electric heater.

11. The plasma processing apparatus according to claim 1 , further comprising a fan configured to generate a flow of gas through the waveguide between a surface of the excitation electrode and an exterior of the resonator.

12. the first conductor comprises stainless steel or brass; The second conductor includes aluminum or copper. The plasma processing apparatus according to any one of claims 1 to 7.

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