Matching box and plasma processing apparatus

Abstract

A technique is provided for reducing the difference in the influence of stray impedance among a plurality of relays in a matching box of a plasma processing apparatus. [Solution] The disclosed matching box includes a plurality of reactance elements and a plurality of relays. The plurality of reactance elements are connected to a high-frequency supply line of high-frequency power for plasma generation. Each of the plurality of relays includes a relay switch and a relay coil. The relay switch of each of the plurality of relays has a first contact connected to the conductor pattern of a corresponding one of the plurality of reactance elements and a second contact connected to a ground pattern. Each of the plurality of relays is arranged along the direction of the electric field between the conductor pattern of the corresponding one of the plurality of reactance elements and the ground pattern. The plurality of relays are arranged rotationally symmetrically with respect to the central axis of the high-frequency supply line or symmetrically with respect to a reference plane including the central axis.

Description

[Technical Field]

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

[0002] A plasma processing apparatus is used in plasma processing of a substrate. The plasma processing apparatus includes a high-frequency power supply that generates high-frequency power for generating plasma and a matching box. Patent Document 1 listed below discloses a matching box in which a plurality of series-connected circuits, each including a series connection of a capacitor and a switching element, are connected in parallel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-078495 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing the difference in the influence of stray impedance among a plurality of relays in a matching box of a plasma processing apparatus. [Means for solving the problem]

[0005] In one exemplary embodiment, a matcher is provided. The matcher includes a plurality of reactance elements and a plurality of relays. The plurality of reactance elements are connected to a high-frequency supply line for high-frequency power for plasma generation. Each of the plurality of relays includes a relay switch and a relay coil. The relay switch of each of the plurality of relays has a first contact connected to a conductor pattern of a corresponding one of the plurality of reactance elements and a second contact connected to a ground pattern. Each of the plurality of relays is arranged along the direction of an electric field between the conductor pattern of the corresponding one of the plurality of reactance elements and the ground pattern. The plurality of relays are arranged rotationally symmetrically with respect to a central axis of the high-frequency supply line or symmetrically with respect to a reference plane including the central axis. [Effects of the Invention]

[0006] According to one exemplary embodiment, it is possible to reduce the difference in the influence of stray impedance among a plurality of relays in a matching box of a plasma processing apparatus. [Brief explanation of the drawings]

[0007] [Figure 1] 1 illustrates a plasma processing apparatus according to an exemplary embodiment; [Figure 2] FIG. 2 illustrates a lower portion of a resonator of a plasma processing apparatus according to an exemplary embodiment. [Figure 3] FIG. 2 is a cross-sectional view illustrating a matcher according to an exemplary embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a cross-sectional view illustrating a matcher according to another exemplary embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 10 is a cross-sectional view illustrating a matcher according to yet another exemplary embodiment. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[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] 1 is a diagram showing a plasma processing apparatus according to an exemplary embodiment, which includes a chamber 10, a substrate support 12, an introduction section 16, a resonator 20, a high-frequency power supply 24, and a matching box 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 an axis line 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, which 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] In one embodiment, the plasma processing apparatus 1 may further include an upper electrode 14. The upper electrode 14 is provided above the substrate support 12 with a processing space 10s interposed therebetween. The upper electrode 14 is made of a conductor such as a metal (e.g., aluminum) and has a substantially disk shape. The central axis of the upper electrode 14 is an axis AX. The upper electrode 14, together with a shower plate 22 (described later), constitutes an excitation electrode.

[0014] The introduction part 16 is provided to emit electromagnetic waves from there into a plasma generation region. In the plasma processing apparatus 1, the plasma generation region is the space within the processing space 10s and directly below the excitation electrode, i.e., directly below the shower plate 22. In the plasma processing apparatus 1, the electromagnetic waves emitted from the introduction part 16 into the plasma generation region excite the gas in the plasma generation region to generate plasma. The electromagnetic waves emitted from the introduction part 16 into the plasma generation region may be high-frequency waves such as VHF waves or UHF waves. The introduction part 16 is formed from a dielectric material such as quartz, aluminum nitride, or aluminum oxide. In one embodiment, the introduction part 16 is provided at a lateral end of the processing space 10s and extends circumferentially around the axis AX. The introduction part 16 may have a ring shape.

[0015] The resonator 20 includes a power supply 20p and a waveguide 20w. The power supply 20p is an electromagnetic wave inlet for the waveguide 20w of the resonator 20. The electromagnetic wave is generated based on high-frequency power generated by a high-frequency power supply 24. The high-frequency power supply 24 may be configured to be able to change the frequency of the high-frequency power it outputs. The high-frequency power supply 24 and the power supply 20p are electrically connected via a high-frequency supply line 40. The electromagnetic wave is input to the power supply 20p of the resonator 20 via the high-frequency supply line 40. The resonator 20 resonates the electromagnetic wave input to the power supply 20p within the waveguide 20w and propagates it to the introduction portion 16. The electromagnetic wave is introduced from the introduction portion 16 into a plasma generation region. In one embodiment, the resonator 20 may be provided above the chamber 10 and on the upper electrode 14.

[0016] In one embodiment, the plasma processing apparatus 1 may further include a shower plate 22. The shower plate 22 may be made of a metal such as aluminum. The inlet portion 16 extends to surround the shower plate 22. The inlet portion 16 and the shower plate 22 are arranged to close an opening at the upper end of the chamber 10. The shower plate 22 provides a plurality of gas holes 22h. The plurality of gas holes 22h extend in the thickness direction (vertical direction) of the shower plate 22 and penetrate the shower plate 22.

[0017] The shower plate 22 is provided below the upper electrode 14. The shower plate 22 extends above the plasma generation region. The shower plate 22 and the upper electrode 14 define a gas diffusion space 14d therebetween. The central axis of the gas diffusion space 14d may be the axis AX. A plurality of gas holes 22h in the shower plate 22 are connected to the gas diffusion space 14d. The upper electrode 14 also provides an inlet 14h. The inlet 14h may extend on the axis AX. The inlet 14h is connected to the gas diffusion space 14d. A gas supply unit 26 is connected to the gas diffusion space 14d. Gas output from the gas supply unit 26 is supplied to the processing space 10s via the inlet 14h, the gas diffusion space 14d, and the plurality of gas holes 22h.

[0018] Hereinafter, reference will be made to FIG. 2 together with FIG. 1. FIG. 2 is a diagram illustrating the lower portion of a resonator of 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 waveguide 20w of the resonator 20 may provide a cavity surrounded by walls. The walls of the waveguide 20w are formed from a material such as metal. The walls of the waveguide 20w may be formed from an aluminum alloy, copper, nickel, stainless steel, or the like, and may be coated with a low-resistivity material such as silver, gold, or rhodium.

[0019] The resonator 20 includes a first end 201 and a second end 202. The first end 201 and the second end 202 constitute one end and the other end of a waveguide 20w of the resonator 20. The waveguide 20w extends between the first end 201 and the second end 202 and is electromagnetically coupled to the introduction portion 16.

[0020] In one embodiment, the wall of the resonator 20 may include an inner periphery 20i and an outer periphery 20o. The inner periphery 20i extends around a central axis AX and has a generally cylindrical shape. The outer periphery 20o extends coaxially with the inner periphery 20i around the axis AX. The outer periphery 20o may have a generally cylindrical shape.

[0021] The waveguide 20w may have a layer structure in which layers are alternately folded between the inner circumferential portion 20i and the outer circumferential portion 20o. The walls of the waveguide 20w may include multiple walls extending radially and circumferentially between adjacent layers of the layer structure and between the inner circumferential portion 20i and the outer circumferential portion 20o. The multiple walls may be annular plates.

[0022] The waveguide 20w may also include an upper portion 20a constituting the uppermost layer of the layer structure and a lower portion 20b constituting the lowermost layer of the layer structure. The layer structure may also include an intermediate portion 20c between the upper portion 20a and the lower portion 20b. In this embodiment, the upper portion 20a may provide a first end 201, i.e., an upper end, of the waveguide 20w at the outer periphery 20o. In this case, the first end 201 of the waveguide 20w extends along the circumferential direction around the axis AX. The lower portion 20b may also provide a second end 202, i.e., a lower end, of the waveguide 20w at the outer periphery 20o. In this case, the second end 202 of the waveguide 20w extends along the circumferential direction around the axis AX.

[0023] The resonator 20 provides a plurality of gaps 20g near or along the second end 202. The plurality of gaps 20g are arranged in the circumferential direction around the axis AX. Electromagnetic waves that resonate in the resonator 20 electromagnetically propagate to the introduction portion 16 through the plurality of gaps 20g.

[0024] In one embodiment, the upper electrode 14 provides a plurality of slots 14s as the plurality of gaps 20g and includes a plurality of beams 14b. The plurality of slots 14s are arranged above the introduction portion 16. The plurality of slots 14s electromagnetically couple the waveguide 20w and the introduction portion 16 to each other. The plurality of slots 14s penetrate the upper electrode 14 along its thickness direction (vertical direction) and extend long in the circumferential direction. The plurality of slots 14s are spaced apart from each other and arranged along the circumferential direction around the axis AX. The plurality of slots 14s may be arranged at equal intervals. The plurality of beams 14b are arranged alternately with the plurality of slots 14s along the circumferential direction around the axis AX. The plurality of beams 14b connect the inner and outer portions of the upper electrode 14 to each other.

[0025] In the plasma processing apparatus 1, electromagnetic waves resonate between the first end 201 and the second end 202 of the resonator 20. The electromagnetic waves resonating in the resonator 20 are supplied to the introduction portion 16 through the gaps 20g, i.e., the slots 14s. The electromagnetic waves supplied to the introduction portion 16 are emitted from the introduction portion 16 into a plasma generation region.

[0026] As shown in FIG. 1, in the plasma processing apparatus 1, the distance between the power supply part 20p and the first end 201 along the electromagnetic wave propagation direction (radial direction or the opposite direction) may be shorter than the distance L50. The distance L50 is the distance along the propagation direction between the first end 201 and a point in the resonator 20 where the impedance seen from the point toward the load during plasma excitation becomes equal to the characteristic impedance of the high-frequency supply line 40. In the plasma processing apparatus 1, since the distance between the power supply part 20p and the first end 201 is shorter than the distance L50, the voltage of the harmonics at the power supply part 20p is small. Therefore, the plasma processing apparatus 1 can suppress the harmonics returning to the high-frequency power supply 24. As a result, the plasma processing apparatus 1 can suppress the effects of high-frequency power loss and abnormal oscillation in the high-frequency power supply.

[0027] The matching box 30 is connected to a high-frequency supply line 40 between the high-frequency power supply 24 and the resonator 20. The matching box 30 includes an input section 30i. The input section 30i is part of the high-frequency supply line 40 and is configured as, for example, a coaxial connector. The high-frequency power supply 24 is connected to the input section 30i. The high-frequency power supply 24 and the power feeding section 20p are connected to each other by the high-frequency supply line 40.

[0028] The matching box 30 includes a matching circuit. The matching circuit includes a variable reactance unit 53. The variable reactance unit 53 includes a plurality of reactance elements and a plurality of relays 71. The variable reactance unit 53 is disposed in a grounded housing 30h (e.g., a metal housing). The variable reactance unit 53 is connected between the high-frequency supply line 40 and the ground. That is, the plurality of reactance elements of the variable reactance unit 53 are connected to the high-frequency supply line 40. The plurality of relays 71 are each connected between the plurality of reactance elements of the variable reactance unit 53 and the ground.

[0029] The matching circuit 30 further includes a drive circuit 34d and a control circuit 34c. The drive circuit 34d is configured with a circuit for changing the impedance of the variable reactance unit 53. The control circuit 34c is configured to control the drive circuit 34d. The control circuit 34c may be configured with a programmable processor such as a CPU or an MPU, a programmable logic device such as an FPGA (Field Programmable Gate Array), or a dedicated circuit such as an ASIC (Application Specific Integrated Circuit).

[0030] In one embodiment, the plasma processing apparatus 1 may further include a directional coupler and a power supply control unit 24c. The directional coupler may be provided within the high-frequency power supply 24 or between the high-frequency power supply 24 and the input unit 30i. The power supply control unit 24c may be configured from a programmable processor such as a CPU or an MPU, a programmable logic device such as an FPGA (Field Programmable Gate Array), or a dedicated circuit such as an ASIC (Application Specific Integrated Circuit).

[0031] The directional coupler outputs a signal reflecting the power level of the reflected wave of the high-frequency power to the power supply control unit 24c. The power supply control unit 24c controls the high-frequency power supply 24 or the matching box 30 in accordance with the signal from the directional coupler so as to reduce the power level of the reflected wave. The power supply control unit 24c may control the high-frequency power supply 24 to adjust the frequency of the high-frequency power in order to reduce the power level of the reflected wave. Alternatively, or in addition, the power supply control unit 24c may communicate with the control circuit 34c to cause the drive circuit 34d to adjust the reactance of the variable reactance unit 53 in order to reduce the power level of the reflected wave.

[0032] In the following, in addition to Figures 1 and 2, reference will be made to Figures 3 and 4. Figure 3 is a cross-sectional view showing a matching box according to one exemplary embodiment. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. Note that Figure 4 shows the structure of the matching box in vertical cross section.

[0033] 3 and 4 can be employed as the matching box 30 in the plasma processing apparatus 1. When the matching box 30A is used, the high-frequency supply line 40 may include a metal coupling rod 40r. The coupling rod 40r is connected between the input portion 30i (i.e., the inner conductor of the coaxial connector 40c) and the power supply portion 20p, and extends downward from the input portion 30i.

[0034] In matching device 30A, variable reactance unit 53 is disposed in housing 30h. In matching device 30A, housing 30h may have a cylindrical shape. Variable reactance unit 53 of the matching circuit of matching device 30A includes a plurality of capacitor elements 531 as a plurality of reactance elements, and also includes a plurality of relays 71.

[0035] Each of the plurality of capacitor elements 531 is connected to the high-frequency supply line 40 (for example, the coupling rod 40r). Specifically, one of a pair of electrodes of each of the plurality of capacitor elements 531 is connected to the high-frequency supply line 40 (for example, the coupling rod 40r). Each of the plurality of capacitor elements 531 includes a conductor pattern 531e (capacitor electrode pattern). The conductor pattern 531e is the other of the pair of electrodes of each of the plurality of capacitor elements 531.

[0036] Each of the multiple relays 71 includes a relay switch 71s and a relay coil 71c. The relay switch 71s includes a first contact 71t1 and a second contact 71t2, and can switch between disconnection and connection between the first contact 71t1 and the second contact 71t2 depending on the state (open or closed) of the relay switch 71s. The first contact 71t1 of the relay switch 71s of each of the multiple relays 71 is connected to the conductor pattern 531e of a corresponding capacitor element 531 among the multiple capacitor elements 531. In addition, the second contact 71t2 of the relay switch 71s of each of the multiple relays 71 is connected to the ground pattern 531g.

[0037] In the matching device 30A, the drive circuit 34d is configured to apply a DC voltage signal to the relay coils 71c of each of the plurality of relays 71 to set the state (open state or closed state) of the relay switch 71s of each of the plurality of relays 71. The control circuit 34c is capable of communicating with the power supply control unit 24c via a communication circuit. The control circuit 34c is notified via the communication circuit from the power supply control unit 24c of the capacitance setting value of the variable reactance unit 53 for reducing the power level of the reflected wave. The control circuit 34c controls the drive circuit 34d to set the state of the relay switch 71s of each of the plurality of relays 71 to the notified setting value.

[0038] In the matching device 30A, the conductor pattern 531e of each of the plurality of capacitor elements 531, i.e., the plurality of conductor patterns 531e, are arranged rotationally symmetrically with respect to the central axis MX of the high-frequency supply line 40 (e.g., the coupling rod 40r). Furthermore, each of the plurality of relays 71 is arranged along the direction of the electric field between the conductor pattern 531e of the corresponding capacitor element among the plurality of capacitor elements 531 and the ground pattern 531g. Furthermore, the plurality of relays 71 are arranged rotationally symmetrically with respect to the central axis MX of the high-frequency supply line 40. For example, the plurality of relays 71 are arranged such that the current path of the high-frequency current in each of the relays 71, including the relay switch 71s, is rotationally symmetric with respect to the central axis MX.

[0039] Within the housing 30h of the matching device 30A, TEM mode electromagnetic waves propagate along the direction of the central axis MX, generating a high-frequency electric field radially relative to the central axis MX and uniformly circumferentially relative to the axis AX. Therefore, a high-frequency electric field of approximately the same intensity is applied radially to each of the multiple relays 71. This reduces the difference in the influence of stray impedance among the multiple relays 71. This matching device 30A allows the total impedance to be regularly changed by driving the multiple relays 71.

[0040] 4, the plurality of relays 71 may be arranged at equal intervals in the circumferential direction with respect to the central axis MX. Furthermore, each of the plurality of capacitor elements 531 and a corresponding one of the plurality of relays 71 may be aligned along the radial direction with respect to the central axis MX between the high-frequency supply line 40 (e.g., the coupling rod 40r) and the ground pattern 531g.

[0041] In one embodiment, the matching box 30A may further include a printed circuit board 531b. The printed circuit board 531b is provided in the housing 30h and extends horizontally. The printed circuit board 531b has a substantially circular shape and is open at its center. The high-frequency supply line 40 extends through the opening of the printed circuit board 531b.

[0042] The printed circuit board 531b may have a plurality of relays 71 mounted on its upper surface. The printed circuit board 531b may have a plurality of conductor patterns 531e and a ground pattern 531g on its lower surface. The plurality of conductor patterns 531e and the ground pattern 531g are formed of a metal such as copper. The plurality of conductor patterns 531e have a substantially circular shape and are arranged circumferentially around the central axis MX. The plurality of conductor patterns 531e may be arranged at equal intervals. The ground pattern 531g extends radially outward from the plurality of conductor patterns 531e. The ground pattern 531g may have a ring shape and may extend around the central axis MX. The ground pattern 531g is connected to the bottom of the housing 30h, i.e., to ground, via a plurality of metal supports 53sp.

[0043] The matching box 30A further includes a capacitor plate 531p made of a metal such as copper. The capacitor plate 531p extends below the printed circuit board 531b so as to face the multiple conductor patterns 531e. The capacitor plate 531p may have a substantially ring shape. The inner edge of the capacitor plate 531p is connected to the high-frequency supply line 40 (e.g., the coupling rod 40r). The capacitor plate 531p forms a common electrode used as one of a pair of electrodes for each of the multiple capacitor elements 531.

[0044] The matching device 30A also includes a plurality of dielectric members 531d. The plurality of dielectric members 531d are formed of, for example, polytetrafluoroethylene. The plurality of dielectric members 531d may have a ring shape. Each of the plurality of dielectric members 531d is sandwiched between a corresponding one of the plurality of conductor patterns 531e and a capacitor plate 531p. Each of the plurality of capacitor elements 531 is composed of one of the plurality of conductor patterns 531e, a capacitor plate 531p, and a dielectric member of the plurality of dielectric members 531d arranged therebetween.

[0045] The multiple conductor patterns 531e may have the same area. In this case, the multiple capacitor elements 531 have the same capacitance (electrostatic capacity). Furthermore, the edge of each of the multiple conductor patterns 531e may be slightly smaller than the size of the multiple dielectric members 531d so that the edge is positioned more inward than the edge of the corresponding one of the multiple dielectric members 531d. This can suppress creeping discharge.

[0046] A matching box according to another exemplary embodiment will be described below with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view showing a matching box according to another exemplary embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. A matching box 30B shown in FIGS. 5 and 6 can be employed as the matching box 30 in the plasma processing apparatus 1. The matching box 30B will be described below from the perspective of differences from the matching box 30A.

[0047] In the matching box 30B, the plurality of capacitor elements 531 are arranged symmetrically with respect to a reference plane RP that includes the central axis MX. Also, in the matching box 30B, similar to the matching box 30A, each of the plurality of relays 71 is arranged along the direction of the electric field between the conductor pattern 531e and the ground pattern 531g of the corresponding capacitor element among the plurality of capacitor elements 531. Also, the plurality of relays 71 are arranged symmetrically with respect to the reference plane RP. For example, the plurality of relays 71 are arranged such that the current paths of the high-frequency currents in them, including the relay switches 71s, are positioned symmetrically with respect to the reference plane RP.

[0048] In the matching device 30B, a high-frequency electric field of approximately the same intensity is applied radially to each of the multiple relays 71. This reduces the difference in the influence of stray impedance among the multiple relays 71. With this matching device 30B, it is possible to regularly change the total impedance by driving the multiple relays 71.

[0049] In matching box 30B, housing 30h may have a substantially rectangular parallelepiped shape. In matching box 30B, printed circuit board 531b and capacitor plate 531p may each have a substantially rectangular shape.

[0050] In matching device 30B as well, printed circuit board 531b may have a plurality of relays 71 mounted on its upper surface. Printed circuit board 531b may also provide a plurality of conductor patterns 531e and a ground pattern 531g on its lower surface. In matching device 30B as well, each of a plurality of capacitor elements 531 may be composed of one of a plurality of conductor patterns 531e, a capacitor plate 531p, and a dielectric member of a plurality of dielectric members 531d arranged therebetween.

[0051] In the matching device 30B, the plurality of capacitor elements 531 are arranged along a first direction that is parallel to the reference plane RP and perpendicular to the central axis MX. The plurality of capacitor elements 531 may be arranged at equal intervals. The plurality of relays 71 are also arranged along the first direction. The plurality of relays 71 may also be arranged at equal intervals.

[0052] In matching device 30B, ground pattern 531g may include a first ground pattern 531g1 and a second ground pattern 531g2. First ground pattern 531g1 is disposed on one side of reference plane RP, and second ground pattern 531g2 is disposed on the other side of reference plane RP. First ground pattern 531g1 and second ground pattern 531g2 may have a substantially rectangular shape and may extend along a first direction.

[0053] In the matching switch 30B, each of the plurality of capacitor elements 531 and a corresponding one of the plurality of relays 71 are aligned on one side or the other of the reference plane RP, and between the reference plane RP and the first ground pattern 531g1 or the second ground pattern 531g2, along a second direction perpendicular to the reference plane RP. That is, each of the plurality of first capacitor elements arranged on one side of the reference plane RP among the plurality of capacitor elements 531 and a corresponding relay 71 are aligned along the second direction between the reference plane RP and the first ground pattern 531g1. Furthermore, each of the plurality of second capacitor elements arranged on one side of the reference plane RP among the plurality of capacitor elements 531 and a corresponding relay 71 are aligned along the second direction between the reference plane RP and the second ground pattern 531g2.

[0054] A matching device according to yet another exemplary embodiment will be described below with reference to FIGS. 7 and 8. FIG. 7 is a cross-sectional view showing a matching device according to yet another exemplary embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. A matching device 30C shown in FIGS. 7 and 8 can be employed as the matching device 30 in a plasma processing apparatus 1. In a plasma processing apparatus 1 including the matching device 30C, the distance between the power supply portion 20p and the first end 201 along the propagation direction of the electromagnetic wave may be longer than the distance L50. The matching device 30C will be described below from the perspective of differences from the matching device 30A.

[0055] The matching circuit of matching device 30C includes variable reactance unit 54 instead of variable reactance unit 53. Variable reactance unit 54 is disposed within housing 30h. In matching device 30C, housing 30h may have a cylindrical shape. Variable reactance unit 54 includes a plurality of inductor elements 541 as a plurality of reactance elements, and also includes a plurality of relays 71.

[0056] Each of the multiple inductor elements 541 may have the same inductance. Each of the multiple inductor elements 541 is connected to the high-frequency supply line 40 (e.g., the coupling rod 40r). Each of the multiple inductor elements 541 may be connected to the coupling rod 40r via a distribution plate 54p. The distribution plate 54p may be a substantially annular plate, and the inner edge of the distribution plate 54p may be connected to the coupling rod 40r.

[0057] Each of the multiple inductor elements 541 may include a conductor pattern 541e. The conductor pattern 541e may have a substantially circular shape. The conductor pattern 541e of each of the multiple inductor elements 541, i.e., the multiple conductor patterns 541e, may be disposed below the distribution board 54p. Each of the multiple inductor elements 541 may include a rod 541r. The rod 541r extends vertically between the distribution board 54p and a corresponding one of the multiple conductor patterns 541e.

[0058] The multiple conductor patterns 541e are arranged rotationally symmetrically with respect to the central axis MX of the high-frequency supply line 40 (e.g., the coupling rod 40r). Furthermore, in the matching switch 30C, each of the multiple relays 71 is arranged along the direction of the electric field between the conductor pattern 541e of the corresponding inductor element among the multiple inductor elements 541 and the ground pattern 531g. Furthermore, in the matching switch 30C, the multiple relays 71 are arranged rotationally symmetrically with respect to the central axis MX of the high-frequency supply line 40. For example, the multiple relays 71 are arranged such that the current path of the high-frequency current in them, including the relay switch 71s, is rotationally symmetric with respect to the central axis MX.

[0059] Within the housing 30h of the matching device 30C, TEM mode electromagnetic waves propagate along the direction of the central axis MX, generating a high-frequency electric field radially relative to the central axis MX and uniformly circumferentially relative to the axis AX. Therefore, a high-frequency electric field of approximately the same intensity is applied radially to each of the multiple relays 71. This reduces the difference in the influence of stray impedance among the multiple relays 71. With this matching device 30C, it is possible to regularly change the total impedance by driving the multiple relays 71.

[0060] 8, in the matching device 30C, the plurality of relays 71 may also be arranged at equal intervals in the circumferential direction with respect to the central axis MX. Furthermore, each of the plurality of inductor elements 541 and the corresponding relay among the plurality of relays 71 may be aligned along the radial direction with respect to the central axis MX between the high-frequency supply line 40 (e.g., the coupling rod 40r) and the ground pattern 541g.

[0061] In one embodiment, the matching box 30C may further include a printed circuit board 541b. The printed circuit board 541b is provided in the housing 30h and extends horizontally. The printed circuit board 541b has a substantially circular shape and is open at its center. The high-frequency supply line 40 extends through the opening of the printed circuit board 541b.

[0062] The printed circuit board 541b may have a plurality of relays 71 mounted on its upper surface. The printed circuit board 541b may also have a plurality of conductor patterns 541e on its upper surface and a ground pattern 541g on its lower surface. The conductor patterns 541e and the ground pattern 541g are formed of a metal such as copper. The conductor patterns 541e have a substantially circular shape and are arranged circumferentially around the central axis MX. The conductor patterns 541e may be arranged at equal intervals. The ground pattern 541g extends radially outward from the conductor patterns 541e. The ground pattern 541g may have a ring shape and extend around the central axis MX. The ground pattern 541g is connected to the bottom of the housing 30h, i.e., to ground, via a plurality of metal supports 53sp.

[0063] 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.

[0064] For example, in yet another exemplary embodiment, the multiple inductor elements 541 and the multiple relays 71 may be arranged symmetrically with respect to the reference plane RP, similar to the multiple capacitor elements 531 and the multiple relays 71 in the matching device 30B.

[0065] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E11] below.

[0066] [E1] a plurality of reactance elements connected to a high frequency supply line for high frequency power for plasma generation; a plurality of relays each including a relay switch and a relay coil, each having a first contact connected to a conductor pattern of a corresponding one of the plurality of reactance elements and a second contact connected to a ground pattern; Equipped with each of the plurality of relays is arranged along a direction of an electric field between the conductor pattern and the ground pattern of a corresponding one of the plurality of reactance elements; the plurality of relays are arranged rotationally symmetrically with respect to a central axis of the high-frequency supply line or symmetrically with respect to a reference plane including the central axis; Matching box.

[0067] [E2] The matching box according to E1, wherein each of the plurality of reactance elements is a capacitor element.

[0068] [E3] The matching box according to E1, wherein each of the plurality of reactance elements is an inductor element.

[0069] [E4] the plurality of reactance elements are arranged at equal intervals along a circumferential direction with respect to the central axis, the plurality of relays are arranged at equal intervals in the circumferential direction, the ground pattern has an annular shape and extends around the central axis; each of the plurality of reactance elements and a corresponding one of the plurality of relays are aligned along a radial direction with respect to the central axis between the high-frequency supply line and the ground pattern; The matching device according to any one of E1 to E3.

[0070] [E5] The matching box further includes a metal housing, the metal housing has a cylindrical shape and houses the plurality of reactance elements and the plurality of relays therein; A matching box as described in E4.

[0071] [E6] the plurality of reactance elements are arranged along a first direction that is parallel to the reference plane and perpendicular to the central axis, the plurality of relays are arranged along the first direction, the ground pattern includes a first ground pattern and a second ground pattern disposed on one side and the other side of the reference plane, respectively; the first ground pattern and the second ground pattern have a rectangular shape and extend along the first direction; The matching device according to any one of E1 to E3, wherein each of the plurality of reactance elements and a corresponding one of the plurality of relays are aligned on the one side or the other side, and between the reference plane and the first ground pattern or the second ground pattern, along a second direction perpendicular to the reference plane.

[0072] [E7] The matching box further includes a metal housing, the metal housing has a rectangular parallelepiped shape and houses the plurality of reactance elements and the plurality of relays therein; The matching box described in E6.

[0073] [E8] The matching box according to any one of E1 to E7, further including a drive circuit configured to apply a DC voltage signal to a relay coil of each of the plurality of relays to set the open / closed state of a relay switch of each of the plurality of relays.

[0074] [E9] The matching box according to any one of E1 to E8, further including a printed circuit board that provides the conductor pattern and the ground pattern for each of a plurality of reactance elements and that mounts the plurality of relays thereon.

[0075] [E10] a chamber; an introduction section disposed to introduce electromagnetic waves into a plasma generation region within the chamber; A high frequency power source; the high frequency supply line electrically connected to the high frequency power source; a resonator having a feed portion that is an inlet for an electromagnetic wave and is connected to the high-frequency supply line, a first end and a second end for resonating the electromagnetic wave therebetween, and a waveguide that extends between the first end and the second end and is electromagnetically coupled to the introduction portion; The matching box according to any one of E1 to E9, which is connected to the high-frequency supply line between the high-frequency power supply and the power supply unit; A plasma processing apparatus comprising:

[0076] [E11] The resonator comprises: an inner periphery extending around a central axis of the chamber and the resonator; a periphery extending about the central axis; the waveguide having a layer structure in which layers are alternately folded between the inner peripheral portion and the outer peripheral portion; an upper portion located on the uppermost layer of the layer structure and providing the first end at the outer periphery; a lower portion located in the lowest layer of the layer structure, the lower portion providing the second end at the outer periphery, and providing a plurality of slots along the second end that couple the waveguide and the lead-in portion to each other; The plasma processing apparatus of E10, comprising:

[0077] 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]

[0078] 1...plasma processing apparatus, 10...chamber, 12...substrate support portion, 16...introduction portion, 20...resonator, 20w...waveguide, 20p...power supply portion, 201...first end, 202...second end, 24...high frequency power supply, 30...matching box, 40...high frequency supply line, 531...capacitor element, 541...inductor element, 71...relay.

Claims

1. a plurality of reactance elements connected to a high frequency supply line for high frequency power for plasma generation; a plurality of relays each including a relay switch and a relay coil, each having a first contact connected to a conductor pattern of a corresponding one of the plurality of reactance elements and a second contact connected to a ground pattern; Equipped with each of the plurality of relays is arranged along a direction of an electric field between the conductor pattern and the ground pattern of a corresponding one of the plurality of reactance elements; the plurality of relays are arranged rotationally symmetrically with respect to a central axis of the high-frequency supply line or symmetrically with respect to a reference plane including the central axis; Matching box.

2. 2. The matching box according to claim 1, wherein each of the plurality of reactance elements is a capacitor element.

3. 2. The matching box according to claim 1, wherein each of the plurality of reactance elements is an inductor element.

4. the plurality of reactance elements are arranged at equal intervals along a circumferential direction with respect to the central axis, the plurality of relays are arranged at equal intervals in the circumferential direction, the ground pattern has an annular shape and extends around the central axis; each of the plurality of reactance elements and a corresponding one of the plurality of relays are aligned along a radial direction with respect to the central axis between the high-frequency supply line and the ground pattern; The matching device according to any one of claims 1 to 3.

5. The matching box further includes a metal housing, the metal housing has a cylindrical shape and houses the plurality of reactance elements and the plurality of relays therein; The matching device according to claim 4 .

6. the plurality of reactance elements are arranged along a first direction parallel to the reference plane and perpendicular to the central axis, the plurality of relays are arranged along the first direction, the ground pattern includes a first ground pattern and a second ground pattern disposed on one side and the other side of the reference plane, respectively; the first ground pattern and the second ground pattern have a rectangular shape and extend along the first direction, 4. The matching box according to claim 1, wherein each of the plurality of reactance elements and a corresponding one of the plurality of relays are aligned on the one side or the other side, and between the reference plane and the first ground pattern or the second ground pattern, along a second direction perpendicular to the reference plane.

7. The matching box further includes a metal housing, the metal housing has a rectangular parallelepiped shape and houses the plurality of reactance elements and the plurality of relays therein; The matching device according to claim 6.

8. 4. The matching box according to claim 1, further comprising a drive circuit configured to apply a DC voltage signal to a relay coil of each of the plurality of relays in order to set an open / closed state of a relay switch of each of the plurality of relays.

9. 4. The matching box according to claim 1, further comprising a printed circuit board that provides the conductor pattern and the ground pattern for each of a plurality of reactance elements and that mounts the plurality of relays thereon.

10. a chamber; an introduction section disposed to introduce electromagnetic waves into a plasma generation region within the chamber; A high frequency power source; the high frequency supply line electrically connected to the high frequency power source; a resonator having a feed portion that is an inlet for an electromagnetic wave and is connected to the high-frequency supply line, a first end and a second end for resonating the electromagnetic wave therebetween, and a waveguide that extends between the first end and the second end and is electromagnetically coupled to the introduction portion; the matching box according to any one of claims 1 to 3, connected to the high-frequency supply line between the high-frequency power supply and the power supply unit; A plasma processing apparatus comprising:

11. The resonator comprises: an inner periphery extending around a central axis of the chamber and the resonator; a periphery extending about the central axis; the waveguide having a layer structure in which layers are alternately folded between the inner peripheral portion and the outer peripheral portion; an upper portion located on the uppermost layer of the layer structure and providing the first end at the outer periphery; a lower portion located in the lowest layer of the layer structure, the lower portion providing the second end at the outer periphery and providing a plurality of slots along the second end that couple the waveguide and the lead-in portion to each other; The plasma processing apparatus of claim 10 , comprising:

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