Plasma processing equipment

Abstract

A technology is provided to suppress harmonics returning to a high frequency power supply of a plasma processing apparatus. [Solution] The disclosed plasma processing apparatus includes a chamber, an introduction section, a high-frequency power supply, a high-frequency supply line, and a resonator. The introduction section is positioned to introduce electromagnetic waves into a plasma generation region in the chamber. The high-frequency supply line is electrically connected to the high-frequency power supply. The resonator has a power feed section, a first end, a second end, and a waveguide. The power feed section is an inlet for the electromagnetic wave in the resonator and is connected to the high-frequency supply line. The waveguide extends between the first end and the second end for resonating the electromagnetic wave therebetween and is electromagnetically coupled to the introduction section. The distance between the power feed section and the first end along the propagation direction of the electromagnetic wave is shorter than the distance along the propagation direction between the first end and a point in the resonator where the impedance viewed from there toward the load during plasma excitation becomes equal to the characteristic impedance of the high-frequency supply line.

Description

[Technical Field]

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

[0002] Plasma processing apparatuses are used in plasma processing of substrates. One type of plasma processing apparatus includes a chamber, a high-frequency power supply, a resonator, an introduction section, and a matching box. The high-frequency power supply is coupled to the resonator. Electromagnetic waves from the resonator are supplied into the chamber from the introduction section. The matching box is connected between the high-frequency power supply and the resonator. Such a plasma processing apparatus is described in Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-92031 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for suppressing harmonics that are returned to a high frequency power supply of a plasma processing apparatus. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, an introduction portion, a radio frequency power source, a radio frequency supply line, and a resonator. The introduction portion is positioned to introduce an electromagnetic wave into a plasma generation region in the chamber. The radio frequency supply line is electrically connected to the radio frequency power source. The resonator has a feed portion, a first end, a second end, and a waveguide. The feed portion is an entrance for the electromagnetic wave in the resonator and is connected to the radio frequency supply line. The waveguide extends between the first end and the second end for resonating the electromagnetic wave therebetween and is electromagnetically coupled to the introduction portion. The distance between the feed portion and the first end along the propagation direction of the electromagnetic wave is shorter than the distance along the propagation direction between the first end and a point in the resonator where the impedance seen from there toward the load during plasma excitation is equal to the characteristic impedance of the radio frequency supply line. [Effects of the Invention]

[0006] According to one exemplary embodiment, it is possible to suppress harmonics that are returned to the high frequency power supply 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] 10A and 10B are diagrams illustrating an example of the relationship between the position in the propagation direction in the resonator and the voltage. [Figure 4] FIG. 2 illustrates an example of a capacitor that may be employed in a plasma processing apparatus according to an exemplary embodiment. [Figure 5] FIG. 10 is a diagram showing another example of a capacitor that can be employed in a plasma processing apparatus according to an exemplary embodiment. [Figure 6] FIG. 1 illustrates a plasma processing apparatus according to another exemplary embodiment. [Figure 7] FIG. 10 illustrates a plasma processing apparatus according to yet another exemplary embodiment. [Figure 8] FIG. 1 illustrates a coupler according to an exemplary embodiment. [Figure 9] FIG. 10 is a cross-sectional view illustrating a coupler according to another exemplary embodiment. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. 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, and a high-frequency power supply 24.

[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] 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) is 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 viewed from there toward the load during plasma excitation becomes equal to the characteristic impedance of the high-frequency supply line 40.

[0027] FIG. 3 is a diagram illustrating an example of the relationship between the position in the propagation direction within the resonator and the voltage. The horizontal axis of FIG. 3 indicates the position in the propagation direction of the electromagnetic wave within the resonator. In the resonator 20, the second end 202 is spaced a distance of λg / 2 from the first end 201 along the propagation direction of the electromagnetic wave. λg is the wavelength (i.e., the guide wavelength) of the electromagnetic wave (fundamental wave) within the resonator 20. The vertical axis of FIG. 3 indicates the voltages of the fundamental wave and harmonics of the electromagnetic wave within the resonator 20. As shown in FIG. 3, the voltage of the harmonic at a point that is closer to the first end 201 than the voltage of the harmonic at a point that is the distance L50 from the first end 201 is smaller than the voltage of the harmonic at a point that is the distance L50 from the first end 201. As described above, in the plasma processing apparatus 1, the distance between the power supply part 20p and the first end 201 is shorter than the distance L50, and therefore the voltage of the harmonic at the power supply part 20p is small. Therefore, the plasma processing apparatus 1 can suppress 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.

[0028] In one embodiment, the plasma processing apparatus 1 may include at least one capacitor 42 to suppress reflection of high-frequency power caused by the difference between the impedance seen from the power supply unit 20p toward the load and the characteristic impedance of the high-frequency supply line 40. The at least one capacitor 42 may form a capacitance between an inner conductor and an outer conductor of a coaxial line included in the high-frequency supply line 40.

[0029] Some examples of the at least one capacitor 42 will be described below with reference to Figures 4 and 5. Figure 4 is a diagram showing an example of a capacitor that can be employed in a plasma processing apparatus according to an exemplary embodiment. Figure 5 is a diagram showing another example of a capacitor that can be employed in a plasma processing apparatus according to an exemplary embodiment.

[0030] As shown in FIG. 4, the high-frequency supply line 40 may include a coaxial connector 40c, which is a coaxial line. The coaxial connector 40c includes an inner conductor 40i and an outer conductor 40o. The outer conductor 40o has a cylindrical shape and surrounds the inner conductor 40i. The inner conductor 40i and the outer conductor 40o extend coaxially. The lower end of the inner conductor 40i is electrically connected to the power supply unit 20p. In one embodiment, the lower end of the inner conductor 40i is electrically connected to a wall of the resonator 20 that defines the upper portion 20a from below. The lower end of the inner conductor 40i may be electrically connected to the power supply unit 20p via an elastic body 40s (e.g., a spring member) made of a conductor. The outer conductor 40o is also electrically connected to the wall of the resonator 20 that defines the upper portion 20a from above. A dielectric member 43 is disposed between the inner conductor 40i and the outer conductor 40o. The dielectric member 43 may have a cylindrical shape. The dielectric member 43 is made of, for example, polytetrafluoroethylene. In the example shown in FIG.

[0031] In the example shown in FIG. 5, the outer conductor 40o is electrically connected to a wall of the resonator 20 that defines the upper portion 20a from above via a cylindrical cover 44. The inner conductor 40i is rod-shaped and includes a distribution plate 45 between its upper and lower ends. The distribution plate 45 is disposed within the cover 44. In the example shown in FIG. 5, a plurality of capacitors 42 (e.g., ceramic capacitors) are connected in parallel between the distribution plate 45 and the wall of the resonator 20 that defines the upper portion 20a from above. As a result, the plurality of capacitors 42 are connected in parallel between the inner conductor 40i and the outer conductor 40o. The plurality of capacitors 42 are disposed within the cover 44. The plurality of capacitors 42 may be arranged along the circumferential direction around the rod-shaped portion of the inner conductor 40i. The plurality of capacitors 42 may be arranged at equal intervals around the rod-shaped portion of the inner conductor 40i.

[0032] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to Fig. 6. Fig. 6 is a diagram showing a plasma processing apparatus according to another exemplary embodiment. The plasma processing apparatus 1B shown in Fig. 6 will be described below from the viewpoint of differences from the plasma processing apparatus 1.

[0033] The plasma processing apparatus 1B does not include the capacitor 42, but further includes a circulator 25. The circulator 25 includes a first port 251, a second port 252, and a third port 253. The circulator 25 outputs the high-frequency power (traveling wave) received at the first port 251 from the second port 252, and outputs the high-frequency power (reflected wave) received at the second port 252 from the third port 253. The high-frequency power supply 24 is connected to the first port 251. The second port 252 is connected to the power supply unit 20p via the high-frequency supply line 40. The third port 253 is connected to the load 27. According to the plasma processing apparatus 1B, the reflected wave of the high-frequency power is returned to the load 27 by the circulator 25. Therefore, the reflected wave is prevented from being returned to the high-frequency power supply 24. In addition, instead of the circulator 25, the plasma processing apparatus 1B may include an isolator that outputs high-frequency power from the high-frequency power source 24 to the power supply section 20p via the high-frequency supply line 40 and outputs a reflected wave of the high-frequency power to the load 27.

[0034] A plasma processing apparatus according to another exemplary embodiment will be described below with reference to Fig. 7. Fig. 7 is a diagram showing a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 1C shown in Fig. 7 will be described below from the viewpoint of differences from the plasma processing apparatus 1.

[0035] The plasma processing apparatus 1C does not include a capacitor 42, but does include a coupler 30. The high-frequency power supply 24 is electrically connected to the power supply unit 20p via the coupler 30 and the high-frequency supply line 40. In the plasma processing apparatus 1C, the high-frequency supply line 40 may include a coaxial connector 40c and a coupling rod 40r. The coupling rod 40r is connected to the inner conductor of the coaxial connector 40c and is connected to the high-frequency power supply 24 via the coaxial connector 40c.

[0036] The coupler 30 includes a matching circuit 34. The matching circuit 34 is disposed in a grounded housing 30h (e.g., a metal housing). The matching circuit 34 has a variable impedance. The matching circuit 34 is connected between the coupling rod 40r and ground. The matching circuit 34 includes a variable capacitor 51 that provides the variable impedance.

[0037] The coupler 30 further includes a driver 34d and a controller 34c. The driver 34d is configured to drive the matching circuit 34 to adjust the variable impedance of the matching circuit 34. The controller 34c is configured to control the driver 34d to adjust the impedance of the matching circuit 34. The controller 34c includes a control circuit and a communication circuit. The control circuit of the controller 34c 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).

[0038] 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 an input unit of the high frequency power in the coupler 30. 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).

[0039] 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 circuit 34 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 unit 34c to adjust the variable impedance of the matching circuit 34 in order to reduce the power level of the reflected wave.

[0040] 8 will be referred to below in conjunction with FIG. 7. FIG. 8 is a diagram illustrating a coupler according to an exemplary embodiment. A coupler 30A shown in FIG. 8 can be used as the coupler 30 of the plasma processing apparatus 1C.

[0041] The coupler 30A includes a variable capacitor 51. The variable capacitor 51 is disposed in a housing 30h. The variable capacitor 51 is a variable capacitor. The variable capacitor 51 includes a fixed electrode 51s, a rotating electrode 51r, and a rotating shaft 51a. The rotating shaft 51a may include an insulating coupler 51i disposed between the electrode group including the fixed electrode 51s and the rotating electrode 51r and the driver 34d. The rotating shaft 51a extends, for example, vertically and is supported rotatably around its central axis. Note that the rotating shaft 51a may extend in other directions, such as horizontally.

[0042] The fixed electrode 51s is fixed so as not to move and is disposed substantially parallel to the rotating electrode 51r. The fixed electrode 51s is grounded. The rotating electrode 51r has a fan-like or semicircular shape and is connected to the rotating shaft 51a so as to be rotatable together with the rotating shaft 51a. The rotating electrode 51r is connected to the connecting rod 40r via a connecting plate 51cp made of a conductor. Note that the variable capacitor 51 may include a plurality of fixed electrodes 51s and a plurality of rotating electrodes 51r arranged alternately.

[0043] The coupler 30A further includes a driver 34d such as a motor (e.g., a stepping motor) and a controller 34c. The driver 34d and controller 34c may be disposed within the housing 30h. The driver 34d rotates the rotating shaft 51a and the rotating electrode 51r in response to an electrical signal from the controller 34c. The controller 34c is notified by the power supply controller 24c of the rotation angle position of the rotating electrode 51r for reducing the power level of the reflected wave. The controller 34c controls the driver 34d to adjust the rotation angle position of the rotating electrode 51r to the notified rotation angle position. This allows the variable capacitor 51 to adjust its capacitance (electrostatic capacity).

[0044] 9 and 10, a coupler according to another exemplary embodiment that can be employed as the coupler 30 of the plasma processing apparatus 1C will be described. Fig. 9 is a cross-sectional view showing the coupler according to the other exemplary embodiment. Fig. 10 is a cross-sectional view taken along line XX in Fig. 9.

[0045] 9 and 10, the high-frequency supply line 40 is configured as a coupling rod 40r extending upward from the feed portion 20p. In the coupler 30B, the matching circuit 34 includes a variable capacitor 54 instead of the variable capacitor 51. The variable capacitor 54 includes a plurality of capacitor elements 541. The plurality of capacitor elements 541 are arranged to form one or more columns. In the illustrated example, the plurality of capacitor elements 541 form two columns.

[0046] The matching circuit 34 of the coupler 30B includes a printed circuit board 541b, a capacitor plate 541p, and a plurality of dielectric members 541d. The printed circuit board 541b, the capacitor plate 541p, and the plurality of dielectric members 541d are provided in a housing 30h.

[0047] The printed circuit board 541b is provided inside the housing 30h and extends horizontally. The printed circuit board 541b may have a substantially rectangular shape. The printed circuit board 541b provides a plurality of capacitor patterns 541e and a ground pattern 541g on its bottom surface. The plurality of capacitor patterns 541e and the ground pattern 541g are formed from a metal such as copper. The plurality of capacitor patterns 541e have a substantially circular shape. The plurality of capacitor patterns 541e are arranged to form one or more rows (two rows in the illustrated example) as described above. The ground pattern 541g is connected to the bottom of the housing 30h, i.e., to ground, via a plurality of metal supports 54sp.

[0048] The capacitor plate 541p extends horizontally below the printed circuit board 541b so as to face the plurality of capacitor patterns 541e. The capacitor plate 541p may have a rectangular shape. The capacitor plate 541p extends between the RF power input portion 30i of the coupler 30 and the coupling rod 40r, and connects the RF power source 24 to the power feed portion 20p via the RF supply line 40 (i.e., the coupling rod 40r).

[0049] Each of the plurality of dielectric members 541d is held between a corresponding capacitor pattern among the plurality of capacitor patterns 541e and a capacitor plate 541p using a screw. The plurality of dielectric members 541d may be formed from polytetrafluoroethylene or the like and may have a ring shape. Each of the plurality of capacitor elements 541 described above is composed of one capacitor pattern among the plurality of capacitor patterns 541e, a capacitor plate 541p, and a dielectric member among the plurality of dielectric members 541d arranged therebetween.

[0050] The multiple capacitor patterns 541e may have the same area. In this case, the multiple capacitor elements 541 have the same capacitance (electrostatic capacity). Furthermore, the edge of each of the multiple capacitor patterns 541e may be slightly smaller than the size of the multiple dielectric members 541d so that the edge is positioned more inward than the edge of the corresponding one of the multiple dielectric members 541d. This can suppress creeping discharge.

[0051] The matching circuit 34 of the coupler 30B further includes a plurality of relays 71. Each of the plurality of 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 each of the plurality of relays 71 is connected to a corresponding one of the plurality of capacitor patterns 541e. Furthermore, the second contact 71t2 of each of the plurality of relays 71 is connected to the ground pattern 541g.

[0052] In the coupler 30B, the driver 34d is configured as a relay driver circuit for driving each of the plurality of relays 71, and is connected via a connector 54cn to the relay coils 71c of each of the plurality of relays 71. The driver 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.

[0053] Like the control unit 34c of the coupler 30A, the control unit 34c includes a control circuit 341 and a communication circuit 342. The control circuit 341 is capable of communicating with the power supply control unit 24c via the communication circuit 342. The control circuit 341 is notified of the set value of the capacitance of the variable capacitor 54 for reducing the power level of the reflected wave from the power supply control unit 24c via the communication circuit 342. The control circuit 341 controls the drive unit 34d (i.e., relay drive circuit) to set the state of the relay switch 71s of each of the multiple relays 71 in order to set the capacitance of the variable capacitor 54 to the notified set value.

[0054] 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.

[0055] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E12] below.

[0056] [E1] a chamber; an introduction section disposed to introduce electromagnetic waves into a plasma generation region within the chamber; A high frequency power source; a high frequency supply line electrically connected to the high frequency power supply; 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; Equipped with a distance between the power supply part and the first end along the propagation direction of the electromagnetic wave is shorter than a distance along the propagation direction between the first end and a point where impedance seen from the point toward the load when plasma is excited in the resonator becomes equal to a characteristic impedance of the high-frequency supply line; Plasma processing equipment.

[0057] [E2] The plasma processing apparatus according to E1, further comprising a capacitor arranged to suppress reflection of high frequency power at the power supply portion.

[0058] [E3] the high frequency supply line includes a coaxial line; the capacitor includes a dielectric member disposed between an inner conductor and an outer conductor of the coaxial line. The plasma processing apparatus according to E2.

[0059] [E4] the high frequency supply line includes a coaxial line; the capacitor includes a plurality of capacitors electrically connected between an inner conductor and an outer conductor of the coaxial line; the plurality of capacitors are arranged in a circumferential direction around the inner conductor; The plasma processing apparatus according to E2.

[0060] [E5] The plasma processing apparatus of E1, further comprising a circulator or isolator including a first port connected to the high frequency power supply, a second port connected to the high frequency supply line, and a third port connected to a load.

[0061] [E6] The plasma processing apparatus of E1, further comprising a coupler including an input for high frequency power generated by the high frequency power source, the coupler having a variable impedance and connected between the high frequency power source and the power feed.

[0062] [E7] The plasma processing apparatus of E6, wherein the coupler includes a variable capacitor that provides the variable impedance.

[0063] [E8] the high frequency supply line includes a coupling rod electrically connected between the high frequency power source and the power supply portion; the variable capacitor is electrically connected between the coupling rod and ground; The plasma processing apparatus according to E7.

[0064] [E9] The variable capacitor is a plurality of capacitor elements electrically connected to the high frequency supply line; a plurality of relays each including a relay switch and a relay coil, each having a first contact connected to a corresponding one of the plurality of capacitor elements and a second contact connected to ground; The plasma processing apparatus according to E7 or E8, comprising:

[0065] [E10] The variable capacitor is a capacitor plate connected to the high frequency supply line; a printed circuit board having a plurality of capacitor patterns and on which the plurality of relays are mounted; a plurality of dielectric members each disposed between a corresponding one of the plurality of capacitor patterns and the capacitor plate; Further comprising: each of the plurality of capacitor elements is composed of the capacitor plate, a corresponding capacitor pattern among the plurality of capacitor patterns, and a dielectric member among the plurality of dielectric members that is arranged between the capacitor plate and the corresponding capacitor pattern; The plasma processing apparatus according to E9.

[0066] [E11] The plasma processing apparatus of E10, wherein the plurality of capacitor elements have the same capacitance.

[0067] [E12] 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 according to any one of E1 to E11, comprising:

[0068] 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]

[0069] 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, 40...high frequency supply line.

Claims

1. a chamber; an introduction section disposed to introduce electromagnetic waves into a plasma generation region within the chamber; A high frequency power source; a high frequency supply line electrically connected to the high frequency power supply; 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; Equipped with a distance between the power supply part and the first end along the propagation direction of the electromagnetic wave is shorter than a distance along the propagation direction between the first end and a point where impedance seen from the point toward a load when plasma is excited in the resonator becomes equal to a characteristic impedance of the high-frequency supply line; Plasma processing equipment.

2. The plasma processing apparatus according to claim 1 , further comprising a capacitor arranged to suppress reflection of high frequency power at the power supply section.

3. the high frequency supply line includes a coaxial line; the capacitor includes a dielectric member disposed between an inner conductor and an outer conductor of the coaxial line. The plasma processing apparatus according to claim 2 .

4. the high frequency supply line includes a coaxial line; the capacitor includes a plurality of capacitors electrically connected between an inner conductor and an outer conductor of the coaxial line; the plurality of capacitors are arranged in a circumferential direction around the inner conductor; The plasma processing apparatus according to claim 2 .

5. 2. The plasma processing apparatus of claim 1, further comprising a circulator or isolator including a first port connected to the high frequency power supply, a second port connected to the high frequency supply line, and a third port connected to a load.

6. 2. The plasma processing apparatus of claim 1, further comprising a coupler having a variable impedance and including an input for the high frequency power generated by the high frequency power source, the coupler being connected between the high frequency power source and the power feed.

7. The plasma processing apparatus of claim 6 , wherein the coupler includes a variable capacitor that provides the variable impedance.

8. the high frequency supply line includes a coupling rod electrically connected between the high frequency power source and the power supply portion; the variable capacitor is electrically connected between the coupling rod and ground; The plasma processing apparatus according to claim 7 .

9. The variable capacitor is a plurality of capacitor elements electrically connected to the high frequency supply line; a plurality of relays each including a relay switch and a relay coil, each having a first contact connected to a corresponding one of the plurality of capacitor elements and a second contact connected to ground; The plasma processing apparatus of claim 7 , comprising:

10. The variable capacitor is a capacitor plate connected to the high frequency supply line; a printed circuit board having a plurality of capacitor patterns and on which the plurality of relays are mounted; a plurality of dielectric members each disposed between a corresponding one of the plurality of capacitor patterns and the capacitor plate; Further comprising: each of the plurality of capacitor elements is composed of the capacitor plate, a corresponding capacitor pattern among the plurality of capacitor patterns, and a dielectric member among the plurality of dielectric members that is arranged between the capacitor plate and the corresponding capacitor pattern; The plasma processing apparatus according to claim 9 .

11. The plasma processing apparatus according to claim 10 , wherein the plurality of capacitor elements have the same capacitance.

12. 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 according to any one of claims 1 to 11, comprising:

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