Plasma processing device

Abstract

The disclosed plasma processing apparatus includes a chamber, a substrate support part, an excitation electrode, an emission unit, and a resonator. The substrate support part is provided inside the chamber. The excitation electrode is provided above the substrate support part. The emission unit is provided so as to emit electromagnetic waves to the plasma generation space below the excitation electrode. The emission unit extends in a circumferential direction with respect to the central axis of the excitation electrode so as to surround the plasma generation space. The resonator is provided on the excitation electrode. The resonator includes a first end, a second end, and a plurality of slots. The plurality of slots are arranged along the second end and along the circumferential direction, and are provided so that electromagnetic waves in the resonator are supplied from the slots to the emission unit. Each of the plurality of slots is configured such that the longitudinal length thereof, which is in the circumferential direction, can be changed.

Description

Plasma processing equipment

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

[0002] Plasma processing apparatuses are used in substrate processing. One type of plasma processing apparatus is known, which excites gases using high-frequency waves, such as VHF waves or UHF waves. Patent Document 1 below 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 within the processing vessel. The upper electrode is provided above the stage via a space within 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 circumferentially around a 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 providing a waveguide. The waveguide of the resonator extends circumferentially around the central axis, extends in the direction of the central axis, and is connected to the introduction section.

[0003] Japanese Patent Application Laid-Open No. 2020-92031

[0004] The present disclosure provides a technique for adjusting the Q value of a resonator in a plasma processing apparatus.

[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 within the processing space. The excitation electrode has a central axis and is provided above the substrate support. The emitter is configured to emit electromagnetic waves into a plasma generation space below the excitation electrode. The emitter extends in a circumferential direction relative to the central axis to surround the plasma generation space. The resonator is provided on the excitation electrode. The resonator includes first and second ends configured to resonate electromagnetic waves therebetween, and a plurality of slots configured to supply the electromagnetic waves in the resonator to the emitter. The plurality of slots are arranged along the second end and in the circumferential direction. Each of the plurality of slots has the circumferential direction as its longitudinal direction, and is configured such that its length in the longitudinal direction is variable.

[0006] According to one exemplary embodiment, the Q value of a resonator in a plasma processing apparatus can be adjusted.

[0007] 1 is a diagram showing a plasma processing apparatus according to one exemplary embodiment; FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; FIG. 3 is a diagram showing a plasma processing apparatus according to another exemplary embodiment; FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3; FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3; FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3; FIG. 7 is a diagram showing an example of a positional relationship between a plurality of first slots and a plurality of second slots; FIG. 8 is a diagram showing another example of a positional relationship between a plurality of first slots and a plurality of second slots.

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

[0009] 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. The plasma processing apparatus 1 shown in Figs. 1 and 2 includes a chamber 10, a substrate support 12, an excitation electrode 14, an emission section 16, and a resonator 30.

[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 sidewall 10a and is open at its upper end. The chamber 10 and the sidewall 10a may have a substantially cylindrical shape. The processing space 10s is provided inside the sidewall 10a. The central axis of each of the chamber 10, the sidewall 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 yttrium oxide, yttrium oxide fluoride, yttrium fluoride, yttrium oxide, yttrium fluoride, or the like.

[0011] The bottom of the chamber 10 is provided with an exhaust port 10e, which is connected to an exhaust system that 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 a substantially horizontal position. The substrate support 12 has a substantially 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 metal (e.g., aluminum) and has a substantially disk shape. The central axis of the excitation electrode 14 is an axis AX.

[0014] The plasma processing apparatus 1 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 has 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. In the plasma processing apparatus 1, the plasma generation space 60p is provided above the processing space 10s, away from the processing space 10s.

[0015] The emitter 16 is provided to emit electromagnetic waves from there into the plasma generation space. In the plasma processing apparatus 1, the emitter 16 surrounds the plasma generation space 60p and is sandwiched between the excitation electrode 14 and the electrode 60. 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 from 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.

[0016] 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 60p. The shower plate 141 has 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.

[0017] 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 through the gas diffusion chamber 14d and a plurality of gas holes 14h into the plasma generation space 60p.

[0018] In the plasma processing apparatus 1, the gas in the plasma generation space 60p is excited by electromagnetic waves emitted into the plasma generation space 60p from the emission part 16. As a result, plasma is generated in the plasma generation space 60p. The activated species in the plasma generated in the plasma generation space 60p are supplied to the processing space 10s through the multiple holes 60h.

[0019] The resonator 30 is provided on the excitation electrode 14. The resonator 30 is electromagnetically coupled to the emission section 16. The resonator 30 provides a waveguide 32. The resonator 30 includes a conductor section 31 that defines the waveguide 32. The conductor section 31 is formed from a conductive material such as a metal. The conductive material that forms the conductor section 31 may include aluminum, stainless steel, copper, brass, or the like.

[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 electromagnetic waves propagating within the waveguide 32 at the first end 301 and the second end 302. The electromagnetic waves resonating within the resonator 30 are supplied to the emission portion 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 supply 34. The high-frequency power supply 34 is configured to generate high-frequency power. The electromagnetic waves introduced into the plasma generation space are generated based on the high-frequency power generated by the high-frequency power supply 34. The high-frequency power supply 34 may be directly connected to the resonator 30 using a coaxial line. That is, the high-frequency power supply 34 may be coupled to the waveguide of the resonator 30 without an impedance matching box. The coaxial line may include a connector 36 as a connection portion 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 uppermost layer of the multiple layers 320 of the waveguide 32 described below. In this case, the inner conductor of the connector 36 is connected to a conductor plate 31p (described below) that defines the uppermost layer from below, and the outer conductor of the connector 36 is connected to a conductor plate 31p (upper wall 31u) that defines the uppermost layer from above.

[0022] In one embodiment, the waveguide 32 may have a folded structure including a plurality of folded portions. In one embodiment, the waveguide 32 may be configured axially symmetric or rotationally symmetric with respect to the axis AX. Furthermore, 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.

[0023] The multiple conductor plates 31p extend radially from the axis AX and are arranged parallel to one another in the vertical direction, which is the direction in which the axis AX extends. The inner portion 31i and the outer portion 31o extend coaxially with 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. Each of the inner portion 31i and the outer portion 31o may be formed from a tubular (e.g., cylindrical) conductor wall extending between adjacent conductor plates 31p in the vertical direction.

[0024] The waveguide 32 may also include multiple layers 320. The multiple layers 320 extend in radial directions relative to the axis AX between the inner portion 31i and the outer portion 31o, and are arranged alternately with the multiple conductor plates 31p. Each of the multiple layers 320 is connected to the layer above it at one of multiple folded portions along the inner portion 31i or the outer portion 31o.

[0025] In one embodiment, the first end 301 is disposed above the second end 302. The first end 301 is provided by the outer portion 31o of the resonator 30. The first end 301 surrounds the top layer of the plurality of layers 320.

[0026] The second end 302 is formed by a wall 31wb of the outer portion 31o that surrounds the lowest layer of the multiple layers 320. The second end 302 extends circumferentially around the axis AX above the emission section 16. As shown in FIG. 2 , multiple slots 302s are formed in the lowest conductor plate 31b, which defines the lowest layer of the multiple conductor plates 31p from below. Note that in the plasma processing apparatus 1, the conductor plate 31b also serves as the upper electrode 142. The multiple slots 302s are arranged near or along the second end 302. The multiple slots 302s are coupled to the emission section 16 on the outer side of the excitation electrode 14. The multiple slots 302s extend circumferentially 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 conductor plate 31b. In one embodiment, the radial distance between the axis AX and the outer edge of each of the plurality of slots 302s may be approximately the same as the radius of the wall 31wb of the outer portion 31o. In this resonator 30, the electromagnetic wave is reflected at the second end 302 toward the first end 301. In addition, a portion of the electromagnetic wave propagating in the resonator 30 is coupled to the emission portion 16 through the plurality of slots 302s.

[0027] 2, each of the plurality of slots 302s has a longitudinal direction that is the circumferential direction, and the longitudinal length of each of the plurality of slots 302s can be changed.

[0028] 1 and 2, in the plasma processing apparatus 1, the resonator 30 further includes a plurality of short-circuiting members 70. Each of the plurality of short-circuiting members 70 shorts a pair of edges extending in the circumferential direction of a corresponding one of the plurality of slots 302s. As a result, each of the plurality of short-circuiting members 70 changes the longitudinal length of the corresponding slot.

[0029] In one embodiment, each of the multiple short-circuit members 70 may be a screw (e.g., a set screw) made of metal. In this case, multiple screw hole groups 142G are formed in the resonator 30, specifically, in the conductor plate 31b (or the upper electrode 142). Each of the multiple screw hole groups 142G includes multiple screw holes 142h. Each of the multiple screw holes 142h in each of the multiple screw hole groups 142G extends radially with respect to the axis AX. The multiple screw holes 142h in each of the multiple screw hole groups 142G penetrate one of a pair of edges of a corresponding slot among the multiple slots 302s and are arranged circumferentially along that edge. The multiple screw holes 142h in each of the multiple screw hole groups 142G may penetrate one edge of the corresponding slot between one end and the center in the longitudinal direction of the corresponding slot.

[0030] In one embodiment, the plurality of screw holes 142h in each of the plurality of screw hole groups 142G penetrate the conductive plate 31b from the outer edge of the conductive plate 31b to the corresponding slot. Each of the plurality of short-circuiting members 70, i.e., a screw, passes through a selected one of the plurality of screw holes 142h that penetrate one edge of the corresponding slot and the corresponding slot, thereby short-circuiting the pair of edges of the corresponding slot.

[0031] According to the plasma processing apparatus 1, the longitudinal lengths of the plurality of slots 302s are adjusted by the plurality of short-circuiting members 70. The shorter the lengths of the plurality of slots 302s, the higher the Q value of the resonator 30. Therefore, according to the plasma processing apparatus 1, the Q value of the resonator 30 can be adjusted.

[0032] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to FIGS. 3 to 6. FIG. 3 is a diagram showing a plasma processing apparatus according to another exemplary embodiment. FIG. 4 is a cross-sectional view taken along line VI-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3. A plasma processing apparatus 1B shown in FIGS. 3 to 6 will be described below from the perspective of differences from the plasma processing apparatus 1.

[0033] The plasma processing apparatus 1B does not include an electrode 60. In the plasma processing apparatus 1B, the discharge unit 16 extends to surround the shower plate 141. The shower plate 141 and the discharge unit 16 close the opening at the upper end of the chamber 10. In the plasma processing apparatus 1B, the plasma generation space is the space within the processing space 10s and directly below the shower plate 141.

[0034] The plasma processing apparatus 1B 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 is located on the axis AX. The gas pipe 64 is connected between the gas diffusion chamber 14d and the gas supply unit 20.

[0035] The plasma processing apparatus 1B includes a resonator 30B instead of the resonator 30. The resonator 30B will be described below from the perspective of differences from the resonator 30. In the resonator 30B, the conductor plate 31b is a conductor plate separate from the upper electrode 142 and extends above the upper electrode 142. Furthermore, a plurality of slots 302s are provided by the conductor plate 31b and the upper electrode 142.

[0036] Specifically, as shown in FIG. 5 , a plurality of slots 30bs (a plurality of first slots) are formed in the conductive plate 31b. The plurality of slots 30bs have their longitudinal direction aligned with the circumferential direction relative to the axis AX. The plurality of slots 30bs are arranged at equal intervals along the circumferential direction. Also, as shown in FIG. 6 , a plurality of slots 14s (a plurality of second slots) are formed in the upper electrode 142. The plurality of slots 14s have their longitudinal direction aligned with the circumferential direction relative to the axis AX. The plurality of slots 14s are arranged at equal intervals along the circumferential direction. The plurality of slots 14s are arranged below the plurality of slots 30bs.

[0037] The number of the slots 14s is the same as the number of the slots 30bs. The radius of curvature of the inner edges of the slots 14s about the axis AX is the same as or substantially the same as the radius of curvature of the inner edges of the slots 30bs about the axis AX. The radius of curvature of the outer edges of the slots 14s about the axis AX is the same as or substantially the same as the radius of curvature of the outer edges of the slots 30bs about the axis AX. Furthermore, the length in the longitudinal direction of the slots 14s is the same as or substantially the same as the length in the longitudinal direction of the slots 30bs.

[0038] In the resonator 30B, each of the multiple slots 302s is composed of one of the multiple slots 30bs and one of the multiple slots 14s, which overlap each other in the vertical direction. In the resonator 30B, the conductor plate 31b and the upper electrode 142 are configured so that the length of each of the multiple slots 302s can be changed by adjusting the circumferential positional relationship between the multiple slots 30bs and the multiple slots 14s. Therefore, one or both of the conductor plate 31b and the upper electrode 142 are configured to be rotatable around the axis AX. That is, the multiple slots 30bs and / or the multiple slots 14s can be rotated in the circumferential direction around the axis AX. One or both of the conductor plate 31b and the upper electrode 142 may be rotated manually. Alternatively, one or both of the conductor plate 31b and the upper electrode 142 may be rotated by an actuator such as a motor and a control unit that controls the actuator.

[0039] Now, reference will be made to FIGS. 7 and 8 . FIG. 7 is a diagram showing an example of the positional relationship between the multiple first slots and the multiple second slots. FIG. 8 is a diagram showing another example of the positional relationship between the multiple first slots and the multiple second slots. As shown in FIG. 7 , the circumferential length of each of the multiple slots 302s is maximum when the circumferential center positions of the multiple slots 30bs and the circumferential center positions of the multiple slots 14s coincide with each other. On the other hand, as shown in FIG. 8 , the circumferential length of each of the multiple slots 302s is shorter when the circumferential center positions of the multiple slots 30bs and the circumferential center positions of the multiple slots 14s are offset from each other.

[0040] As described above, the plasma processing apparatus 1B allows the circumferential, i.e., longitudinal, lengths of the plurality of slots 302s to be adjusted, thereby enabling the Q value of the resonator 30B to be adjusted.

[0041] 3 to 6 will be referred to again below, along with FIGS. 7 and 8. The number of slots 302s in the resonator 30B is nine in the state shown in FIG. 7. That is, the number of slots 302s is an odd number. When the number of slots 302s is an odd number, the generation of an electric field intensity distribution (or plasma density distribution) that is two-fold rotationally symmetric about the axis AX in the plasma generation space is suppressed compared to when the number of slots 302s is an even number. Note that the number of slots 302s may be any odd number other than nine, as long as it is five or more. The number of slots 302s in the resonator 30B may also be an even number.

[0042] In the plasma processing apparatus 1B, the outer portion 31o has a generally cylindrical shape and has the axis AX as its central axis. The outer portion 31o may include a plurality of walls 31w. Each of the plurality of walls 31w extends between corresponding adjacent conductor plates 31p in the vertical direction and has a generally cylindrical shape. Of the plurality of walls 31w, at least a wall 31wb surrounding the lowest layer extends along the sides of a polygon in a cross section perpendicular to the axis AX. Two or more or all of the plurality of walls 31w may extend along the sides of a polygon in a cross section perpendicular to the axis AX. In one embodiment, the wall 31wb may have a polygonal tube shape. Furthermore, two or more or all of the plurality of walls 31w may each have a polygonal tube shape. In the example shown in the figure, the polygon is a regular nonagon, but it may be another polygon.

[0043] In one embodiment, the wall 31wb may be formed from a plurality of plate-like bodies 311. Furthermore, each of two or more or all of the plurality of walls 31w may be formed from a plurality of plate-like bodies 311. Each of the plurality of plate-like bodies 311 is formed from the above-mentioned metal. Each of the plurality of plate-like bodies 311 may be a flat plate. Each of the plurality of plate-like bodies 311 extends along a corresponding side of the above-mentioned polygon in a cross section perpendicular to the axis AX.

[0044] In the resonator 30B, the magnitude of the current flowing in the radial direction relative to the axis AX in the conductor plate 31b has a circumferential distribution that is minimum in the direction from the axis AX toward the corners of the polygon and maximum at the centers of each side of the polygon. Therefore, in each of the multiple slots 302s, the electric field intensity distribution in the circumferential direction is adjusted.

[0045] In one embodiment, the number of slots 302s in the state shown in FIG. 7 may be the same as the number of corners of the polygon. Furthermore, when the slots 302s are in the state shown in FIG. 7, the positions of each corner of the polygon and the circumferential center positions of corresponding slots 302s may be aligned radially with respect to the axis AX. Typically, the magnitude of the current flowing radially toward the center of each slot 302s in the conductor plate 31b is maximized. However, in the resonator 30B, the magnitude of the current flowing radially in the conductor plate 31b is weakened at the center of each slot 302s and strengthened between adjacent slots 302s, resulting in a circumferential distribution of electric field strength that is highly uniform in each slot 302s.

[0046] 5, the plates 311 may be spaced apart from one another to provide gaps at the corners of the polygon. Alternatively, the vertically extending edge of each of the plates 311 may be connected to the vertically extending edge of a corresponding other plate of the plates 311 at the corresponding corner of the polygon. Note that when the plates 311 are spaced apart from one another to provide gaps at the corners of the polygon, the magnitude of the current flowing radially toward the corners of the polygon is further reduced.

[0047] The resonator 30B also has a plurality of inlets 31h in any one of the walls 31w of the outer portion 31o, which connect the waveguide 32 to the outside of the resonator 30B. The inlets 31h may be arranged along the circumferential direction. In one embodiment, the plurality of inlets 31h are provided in the wall 31wb, and connect the lowest layer of the plurality of layers 320 of the waveguide 32 to the outside of the resonator 30B.

[0048] In the plasma processing apparatus 1B, the excitation electrode 14 (e.g., the upper electrode 142) may include a built-in heating mechanism 143. The heating mechanism 143 may be a heater such as a resistance heating element. In this case, the heating mechanism 143 is connected to a heater power supply. The power of the heater power supply may be controlled by a controller in accordance with the difference between the temperature of the excitation electrode 14 measured by a temperature sensor and a target value.

[0049] The upper electrode 142 also provides a waveguide 14w between each of the plurality of slots 302s and the emission portion 16. The waveguide 14w extends in the circumferential direction centered on the axis AX and has a ring shape in plan view. In the plasma processing apparatus 1B, the electromagnetic waves emitted from the plurality of slots 302s are supplied to the emission portion 16 via the waveguide 14w.

[0050] The upper electrode 142 also provides a cavity 421 inside the waveguide 14w and between the upper electrode 142 and the resonator 30B. The cavity 421 is connected to the waveguide 14w via a plurality of communication holes 14c. The communication holes 14c are arranged in the circumferential direction. In the plasma processing apparatus 1B, the cavity 421 is connected to the space outside the resonator 30B via the inlet 31h, the waveguide 32, the plurality of slots 302s, the waveguide 14w, and the plurality of communication holes 14c.

[0051] The plasma processing apparatus 1B further includes a heat sink 51 and a fan 52. The heat sink 51 is disposed on a support 50 above the resonator 30B. The fan 52 is supported by the support 50 and connected to a flow path within the heat sink 51. In the plasma processing apparatus 1B, a cavity 422 is provided between the inner portion 31i of the resonator 30B and the gas pipe 64. The cavity 422 is connected between the cavity 421 and the flow path of the heat sink 51. The cavity 421 and the heat sink 51 are covered by a cover 53.

[0052] In the plasma processing apparatus 1B, gas (e.g., air) outside the resonator 30B is supplied to the cavity 421 through the inlet 31h, the waveguide 32, the slots 302s, the waveguide 14w, and the communication holes 14c. The gas supplied to the cavity 421 flows along the upper surface of the upper electrode 142 and exchanges heat with the upper electrode 142, i.e., the excitation electrode 14. The gas then passes through the cavity 422 and is supplied to a flow path in the heat sink 51, where it is cooled and then exhausted to the outside by the fan 52.

[0053] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0054] 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.

[0055] 1...plasma processing apparatus, 10...chamber, 12...substrate support portion, 14...excitation electrode, 16...emission portion, 30...resonator, 31...conductor portion, 31i...inner portion, 31o...outer portion, 31p...conductor plate, 301...first end, 302...second end, 302s...slot, 32...waveguide, 320...layer, 70...short-circuit member, 14s...slot, 30bs...slot.

Claims

1. A plasma processing apparatus comprising: a chamber providing a processing space therein; a substrate support section provided within the processing space; an excitation electrode having a central axis and provided above the substrate support section; an emitter section provided to emit electromagnetic waves into a plasma generation space below the excitation electrode, the emitter section extending in a circumferential direction about the central axis so as to surround the plasma generation space; and a resonator provided on the excitation electrode, wherein the resonator includes a first end and a second end provided to resonate electromagnetic waves therebetween, and a plurality of slots provided so that the electromagnetic waves in the resonator are supplied from them to the emitter section, the plurality of slots being arranged along the second end and along the circumferential direction, and each of the plurality of slots has the circumferential direction as its longitudinal direction, and is configured such that its length in the longitudinal direction is changeable.

2. The plasma processing apparatus according to claim 1, wherein the resonator further includes a plurality of short-circuiting members, each of which changes the length of a corresponding slot among the plurality of slots by short-circuiting a pair of edges extending in the circumferential direction in the corresponding slot.

3. The plasma processing apparatus of claim 2, wherein the resonator has a plurality of screw hole groups each including a plurality of screw holes, the plurality of screw holes of each of the plurality of screw hole groups penetrate one of the pair of edges of a corresponding slot among the plurality of slots and are arranged in a circumferential direction along the corresponding slot, and each of the plurality of short-circuiting members is a screw and short-circuits the pair of edges by passing through a selected screw hole among the plurality of screw holes penetrating the one edge of the corresponding slot and through the corresponding slot.

4. A plasma processing apparatus according to claim 3, wherein the plurality of screw holes in each of the plurality of screw hole groups penetrate the one edge between one end and a center in the longitudinal direction of the corresponding slot.

5. The plasma processing apparatus of claim 1, wherein the resonator includes: a first conductor plate having the circumferential direction as its longitudinal direction and having a plurality of first slots formed therein arranged along the circumferential direction; and a second conductor plate having the circumferential direction as its longitudinal direction and having a plurality of second slots formed therein arranged along the circumferential direction, the second conductor plate being disposed below the first conductor plate, each of the plurality of slots being composed of one of the plurality of first slots and one of the plurality of second slots, and the first conductor plate and the second conductor plate are configured to change the length of each of the plurality of slots by adjusting the positional relationship in the circumferential direction between the plurality of first slots and the plurality of second slots.

6. The plasma processing apparatus according to claim 5, wherein at least one of the first conductive plate and the second conductive plate is configured to be rotatable in the circumferential direction.

7. The plasma processing apparatus according to any one of claims 1 to 6, wherein the resonator includes an inner portion and an outer portion extending coaxially with respect to the central axis, and a plurality of conductor plates arranged parallel to each other along a vertical direction in which the central axis extends, and provides a waveguide extending between the outer portion and the inner portion and including a plurality of layers arranged alternately with the plurality of conductor plates, each of the plurality of layers being connected to a layer thereabove among the plurality of layers at one of a plurality of folded portions along the inner portion or the outer portion, the first end extending to surround a top layer of the plurality of layers, and the second end extending to surround a bottom layer of the plurality of layers.

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