Plasma processing equipment

Abstract

To provide a technology that reduces the size of an electromagnetic wave resonator in a plasma processing device.SOLUTION: A plasma processing device disclosed herein includes a chamber and a waveguide. The waveguide is configured to propagate electromagnetic waves to generate a plasma within the chamber. The waveguide includes a resonator configured to resonate electromagnetic waves therein. The resonator includes a microstrip and a dielectric member. A portion of the dielectric member constitutes a dielectric layer of the microstrip.SELECTED DRAWING: Figure 1

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 device manufacturing. Patent Document 1 listed below discloses a plasma processing apparatus that uses VHF waves. The VHF waves are introduced into a chamber via a power supply unit. The power supply unit includes a resonator unit. The resonator unit includes a pair of metal reflectors. The pair of metal reflectors are arranged at an interval of 1 / 4 of the wavelength of the VHF waves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-106290 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing the size of a resonating portion of an electromagnetic wave in 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 and a waveguide. The waveguide is configured to propagate an electromagnetic wave to generate plasma within the chamber. The waveguide includes a resonator configured to resonate the electromagnetic wave therein. The resonator includes a microstrip and a dielectric member. A portion of the dielectric member constitutes a dielectric layer of the microstrip. [Effects of the Invention]

[0006] According to one exemplary embodiment, a technique is provided for reducing the size of an electromagnetic wave resonant portion in a plasma processing apparatus. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view schematically illustrating a plasma processing apparatus according to an exemplary embodiment. [Figure 2] 2 is a partial enlarged cross-sectional view of a waveguide of a plasma processing apparatus according to an exemplary embodiment. FIG. 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] FIG. 1 is a cross-sectional view schematically illustrating a plasma processing apparatus according to an exemplary embodiment. FIG. 2 is a partially enlarged cross-sectional view of a waveguide of the plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 shown in FIGS. 1 and 2 is configured to generate plasma using electromagnetic waves. The electromagnetic waves are VHF waves or UHF waves. The VHF wave band is 30 MHz to 300 MHz, and the UHF wave band is 300 MHz to 3 GHz.

[0010] The plasma processing apparatus 1 includes a chamber 10. The chamber 10 defines an internal space. The substrate W is processed within the internal space of the chamber 10. The chamber 10 has an axis AX as its central axis. The axis AX extends in the vertical direction.

[0011] In one embodiment, the chamber 10 may include a chamber body 12. The chamber body 12 has a generally cylindrical shape and is open at the top. The chamber body 12 provides the sidewalls and bottom of the chamber 10. The chamber body 12 is formed from a metal such as aluminum. The chamber body 12 is grounded.

[0012] The sidewall of the chamber body 12 provides a passage 12p. The substrate W passes through the passage 12p when being transferred between the inside and outside of the chamber 10. The passage 12p can be opened and closed by a gate valve 12v. The gate valve 12v is provided along the sidewall of the chamber body 12.

[0013] The chamber 10 may further include an upper wall 14. The upper wall 14 is formed from a metal such as aluminum. The upper wall 14, together with a coaxial waveguide 42 (described later), closes an opening at the top of the chamber body 12. The upper wall 14, together with the chamber body 12, is grounded.

[0014] The bottom of the chamber 10 provides an exhaust port, which is connected to an exhaust system 16. The exhaust system 16 includes a pressure controller, such as an automatic pressure control valve, and a vacuum pump, such as a turbomolecular pump.

[0015] The plasma processing apparatus 1 may further include a substrate support 18. The substrate support 18 is provided in the chamber 10. The substrate support 18 is configured to support a substrate W placed thereon. The substrate W is placed on the substrate support 18 in a substantially horizontal state. The substrate support 18 may be supported by a support member 19. The support member 19 extends upward from the bottom of the chamber 10. The substrate support 18 and the support member 19 may be made of a dielectric material such as aluminum nitride.

[0016] The plasma processing apparatus 1 may further include a showerhead 20. The showerhead 20 is made of a metal such as aluminum. The showerhead 20 has a generally disk-like shape and may have a hollow structure. The showerhead 20 shares an axis AX as its central axis. The showerhead 20 is provided above the substrate support 18 and below the upper wall 14. The showerhead 20 constitutes a ceiling portion that defines the internal space of the chamber 10.

[0017] The showerhead 20 provides a plurality of gas holes 20h. The plurality of gas holes 20h open toward the interior space of the chamber 10. The showerhead 20 further provides a gas diffusion chamber 20c therein. The plurality of gas holes 20h are connected to the gas diffusion chamber 20c and extend downward from the gas diffusion chamber 20c.

[0018] The plasma processing apparatus 1 may include an inner conductor 421 (described later) of the coaxial waveguide 42 as a gas supply pipe. The inner conductor 421 is configured as a cylindrical tube. The inner conductor 421 is made of a metal such as aluminum. The inner conductor 421 extends vertically above the showerhead 20. The inner conductor 421 shares an axis AX as its central axis. The lower end of the inner conductor 421 is connected to the upper center of the showerhead 20. The upper center of the showerhead 20 provides a gas inlet. The inlet is connected to the gas diffusion chamber 20c. The inner conductor 421 supplies gas to the showerhead 20. The gas from the inner conductor 421 is introduced into the chamber 10 from multiple gas holes 20h via the inlet of the showerhead 20 and the gas diffusion chamber 20c.

[0019] In one embodiment, the plasma processing apparatus 1 may further include a first gas source 24, a second gas source 26, and a remote plasma source 28. The first gas source 24 is connected to the inner conductor 421 (i.e., a gas supply pipe). The first gas source 24 may be a gas source for a deposition gas. The deposition gas may include a silicon-containing gas. The silicon-containing gas may include, for example, SiH4. The deposition gas may further include other gases. For example, the deposition gas may further include NH3 gas, N2 gas, a rare gas such as Ar, etc. The gas (e.g., deposition gas) from the first gas source 24 is introduced into the chamber 10 from the showerhead 20 via the inner conductor 421 (i.e., a gas supply pipe).

[0020] The second gas source 26 is connected to the inner conductor 421 (i.e., the gas supply pipe) via the remote plasma source 28. The second gas source 26 can be a gas source of a cleaning gas. The cleaning gas may include a halogen-containing gas. The halogen-containing gas may include, for example, NF3 and / or Cl2. The cleaning gas may further include other gases. The cleaning gas may further include a noble gas such as Ar.

[0021] The remote plasma source 28 excites gas from the second gas source 26 to generate plasma at a location remote from the chamber 10. In one embodiment, the remote plasma source 28 generates plasma from a cleaning gas. The remote plasma source 28 may be any type of plasma source. Examples of the remote plasma source 28 include a capacitively coupled plasma source, an inductively coupled plasma source, or a plasma source that generates plasma using microwaves. Radicals in the plasma generated in the remote plasma source 28 are introduced into the chamber 10 from the showerhead 20 via the inner conductor 421.

[0022] In order to suppress deactivation of radicals, the inner conductor 421 (i.e., the gas supply pipe) may have a relatively large diameter. The outer diameter (diameter) of the inner conductor 421 is, for example, 40 mm or more. In one example, the outer diameter (diameter) of the inner conductor 421 is 80 mm. The inner conductor 421 has a cylindrical shape, and the outer diameter (diameter) of the inner conductor 421 is the outer diameter of the inner conductor 421 at the other portion 421a of the flange portion 421f described later. The flange portion 421f forms a part of the longitudinal direction of the inner conductor 421. The flange portion 421f has an annular shape and extends centered on the axis AX. The flange portion 421f protrudes radially from the other portion 421a of the inner conductor 421. The inner conductor 421 may form a part of the waveguide 40 described later.

[0023] The showerhead 20 is spaced downward from the top wall 14. The space between the showerhead 20 and the top wall 14 forms part of the waveguide 30. The waveguide 30 also includes the space provided by the inner conductor 421 between the inner conductor 421 and the top wall 14.

[0024] The plasma processing apparatus 1 may further include an introduction section 32. The introduction section 32 is made of a dielectric material such as aluminum oxide. The introduction section 32 is provided along the outer periphery of the shower head 20 so as to introduce electromagnetic waves into the chamber 10 from there. The introduction section 32 has a ring shape. The introduction section 32 closes the gap between the shower head 20 and the chamber body 12 and is connected to the waveguide 30. The introduction section 32 may also be provided along the sidewall of the chamber 10.

[0025] The plasma processing apparatus 1 further includes a waveguide 40. The waveguide 40 is configured to propagate electromagnetic waves to generate plasma within the chamber 10. The waveguide 40 may be provided above the chamber 10.

[0026] The plasma processing apparatus 1 may further include a supply path 36 for the electromagnetic wave. The supply path 36 is connected to the waveguide 40. In one embodiment, the supply path 36 has a coaxial structure. That is, the supply path 36 includes a center conductor 361 and an outer conductor 362. The outer conductor 362 has a substantially cylindrical shape. The outer conductor 362 is connected to the outer conductor 422 of the coaxial waveguide 42. The center conductor 361 is rod-shaped and is disposed coaxially with the outer conductor 362 within the outer conductor 362. The supply path 36 may further include a dielectric member 363. The dielectric member 363 fills the gap between the center conductor 361 and the outer conductor 362. The dielectric member 363 is formed of, for example, polytetrafluoroethylene (PTFE).

[0027] The central conductor 361 is connected to the inner conductor 421. Specifically, one end of the central conductor 361 is connected to the flange 421f. The flange 421f may be a part of the central conductor 361. Alternatively, the flange 421f may be formed by the inner conductor 421 and the central conductor 361.

[0028] The plasma processing apparatus 1 may further include a matching box 50 and a power supply 60. The other end of the central conductor 361 is connected to the power supply 60 via the matching box 50. The power supply 60 is an electromagnetic wave generator. The matching box 50 has an impedance matching circuit. The impedance matching circuit is configured to match the impedance of the load of the power supply 60 to the output impedance of the power supply 60. The impedance matching circuit has a variable impedance. The impedance matching circuit may be, for example, a π-type circuit.

[0029] In the plasma processing apparatus 1, electromagnetic waves from the power supply 60 are introduced into the chamber 10 from the inlet 32 ​​via the matching box 50, the supply path 36 (central conductor 361), the waveguide 40, and the waveguide 30 around the shower head 20. The electromagnetic waves excite the gas (e.g., film formation gas) from the first gas source 24 in the chamber 10, generating plasma.

[0030] The waveguide 40 includes a resonator 44. The waveguide 40 may further include a coaxial waveguide 42 and a lid 43 (lid conductor). In one embodiment, the coaxial waveguide 42 extends vertically above the chamber 10, and its central axis is the axis AX. The coaxial waveguide 42 includes the inner conductor 421 and outer conductor 422 described above. The outer conductor 422 is made of a metal such as aluminum and has a substantially cylindrical shape. The inner conductor 421 is disposed within the outer conductor 422 and is coaxial with the outer conductor 422.

[0031] The lid 43 is made of a metal such as aluminum and closes the opening between the inner conductor 421 and the outer conductor 422 at one end (e.g., the upper end) of the coaxial waveguide 42. The lid 43 is electrically connected to the outer conductor 422. The other end (e.g., the lower end) of the outer conductor 422 is connected to the upper wall 14.

[0032] The resonator 44 is configured to resonate an electromagnetic wave therein. The resonator 44 includes a microstrip 45 and a dielectric member 46. The resonator 44 may be provided between one end (e.g., the upper end) and the other end (e.g., the lower end) of the coaxial waveguide 42. That is, the microstrip 45 and the dielectric member 46 may be provided between one end (e.g., the upper end) and the other end (e.g., the lower end) of the coaxial waveguide 42. In one embodiment, the resonator 44 is provided above the lower surface of the flange 421f.

[0033] The dielectric member 46 is made of, for example, polytetrafluoroethylene (PTFE). The dielectric member 46 includes a dielectric layer 463 as a part thereof. The dielectric layer 463 forms the microstrip 45. In this way, in the plasma processing apparatus 1, a part of the dielectric member 46 forms the dielectric layer 463 of the microstrip. Other parts of the dielectric member 46 also form the resonator unit 44. Therefore, the resonator unit 44 includes multiple parts having different impedances. In the plasma processing apparatus 1, the microstrip 45 and the dielectric member 46 enable the resonator unit 44 to resonate electromagnetic waves even though it is small in size.

[0034] In one embodiment, the resonator unit 44 may further include a ground conductor 48 in addition to the dielectric member 46. The ground conductor 48 may be provided on the dielectric member 46. The ground conductor 48 is electrically connected to the lid 43.

[0035] The microstrip 45 of the resonator unit 44 may include a microstrip conductor, a dielectric layer 463, and an annular ground portion 481. The microstrip conductor of the microstrip 45 is the flange portion 421f described above. The dielectric layer 463 has a ring shape and extends about the axis AX. The dielectric layer 463 is provided on the microstrip conductor, i.e., the flange portion 421f. The annular ground portion 481 is a part of the ground conductor 48. The annular ground portion 481 has a ring shape and extends about the axis AX. The annular ground portion 481 is provided on the dielectric layer 463.

[0036] In one embodiment, the dielectric member 46 may further include a first cylindrical portion 461 and a second cylindrical portion 462. The first cylindrical portion 461 has a substantially cylindrical shape. The first cylindrical portion 461 is interposed between the outer edge of the flange portion 421f and the outer conductor 422, and extends toward one end (e.g., the upper end) of the coaxial waveguide 42. The central axis of the first cylindrical portion 461 may be an axis AX.

[0037] The second cylindrical portion 462 has a substantially cylindrical shape. The second cylindrical portion 462 is provided inside the first cylindrical portion 461 and extends from the flange portion 421f along the inner conductor 421 toward one end (e.g., the upper end) of the coaxial waveguide 42. The central axis of the second cylindrical portion 462 may be the axis AX.

[0038] The dielectric layer 463 extends between the first cylindrical portion 461 and the second cylindrical portion 462. The dielectric layer 463 may extend between the middle position in the longitudinal direction (height direction) of the first cylindrical portion 461 and the lower end of the second cylindrical portion 462.

[0039] In one embodiment, the dielectric member 46 may have a recess 44r. The recess 44r is a hollow and extends on the dielectric layer 463 and between the first cylindrical portion 461 and the second cylindrical portion 462. The recess 44r has an annular shape and extends about the axis AX.

[0040] The above-described ground conductor 48 may further include a cylindrical ground portion 482. The cylindrical ground portion 482 has a substantially cylindrical shape and extends about the axis AX. The cylindrical ground portion 482 extends along the first cylindrical portion 461 from the outer edge of the annular ground portion 481 toward one end (e.g., the upper end) of the coaxial waveguide 42.

[0041] The ground conductor 48 may further include another annular ground portion 483. The annular ground portion 483 has a ring shape and extends about the axis AX. The annular ground portion 483 extends radially outward from one end (e.g., the upper end) of the cylindrical ground portion 482. The ground conductor 48 may be electrically connected to the cover 43 by sandwiching the annular ground portion 483 between the cover 43 and the first cylindrical portion 461 of the dielectric member 46.

[0042] In one embodiment, the dielectric member 46 can provide different impedances in the first cylindrical portion 461, the microstrip 45, the second cylindrical portion 462, and the recess 44r, respectively. Therefore, the dielectric member 46 allows electromagnetic waves to resonate in the resonator 44 even if its size is considerably small.

[0043] In addition, the electric field strength of the electromagnetic waves propagating from the microstrip 45 toward the recess 44r is high in the region along the inner conductor 421, but since the second cylindrical portion 462 is provided in that region, abnormal discharge in that region is suppressed.

[0044] Furthermore, in the plasma processing apparatus 1, the inner conductor 421 is connected to the upper center of the shower head 20, and the central conductor 361 of the electromagnetic wave supply path 36 is connected to the flange 421f of this inner conductor 421. Therefore, the electromagnetic wave propagates uniformly around the inner conductor 421. The electromagnetic wave is introduced into the chamber 10 from the introduction part 32 provided along the outer periphery of the shower head 20 via the inner conductor 421 and the shower head 20. Therefore, the plasma processing apparatus 1 can improve the uniformity of the plasma density distribution in the chamber 10.

[0045] Furthermore, according to the plasma processing apparatus 1, deposits formed in the chamber 10 during the film formation process can be removed by radicals from the plasma of the cleaning gas. The radicals from the plasma of the cleaning gas are supplied via the inner conductor 421, which is a gas supply pipe, and the shower head 20, so that deactivation of the radicals is suppressed and they are supplied uniformly into the chamber 10. Therefore, according to the plasma processing apparatus 1, the chamber 10 can be cleaned uniformly and efficiently.

[0046] 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.

[0047] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E12] below.

[0048] [E1] a chamber; a waveguide configured to propagate electromagnetic waves to generate a plasma within the chamber, the waveguide including a resonator configured to resonate the electromagnetic waves therein; Equipped with the resonator unit includes a microstrip and a dielectric member; a portion of the dielectric member constitutes a dielectric layer of the microstrip; Plasma processing equipment.

[0049] In the embodiment of [E1], a part of the dielectric member constitutes the dielectric layer of the microstrip. In addition, another part of the dielectric member also constitutes the resonator. Therefore, in the embodiment of [E1], the resonator includes multiple parts having different impedances. According to the embodiment of [E1], the microstrip and the dielectric member enable the resonator to resonate electromagnetic waves even if it is small in size.

[0050] [E2] The waveguide portion is a coaxial waveguide including an outer conductor and an inner conductor having an annular flange and disposed within the outer conductor; a cover conductor that closes an opening between the inner conductor and the outer conductor at one end of the coaxial waveguide; Further comprising: The resonator unit is the dielectric member provided between the one end and the other end of the coaxial waveguide; a ground conductor provided on the dielectric member; Further comprising: The microstrip a microstrip conductor that is the flange; the dielectric layer having an annular shape and provided on the microstrip conductor; a ring-shaped ground portion that is a part of the ground conductor and is provided on the dielectric layer; Including, [E1] The plasma processing apparatus according to the present invention.

[0051] [E3] The dielectric member is a first cylindrical portion interposed between an outer edge of the flange portion and the outer conductor and extending toward one end of the coaxial waveguide; a second cylindrical portion extending from the flange portion toward one end of the coaxial waveguide along the inner conductor; the dielectric layer extending between the first cylindrical portion and the second cylindrical portion; The plasma processing apparatus according to [E2], comprising:

[0052] [E4] The plasma processing apparatus according to [E3], wherein the dielectric member provides a recess that is a cavity on the dielectric layer and between the first cylindrical portion and the second cylindrical portion.

[0053] [E5] The plasma processing apparatus according to [E4], wherein the ground conductor further includes a cylindrical ground portion extending along the first cylindrical portion within the recess.

[0054] [E6] a supply path for electromagnetic waves having a coaxial structure and connected between a power source and the coaxial waveguide; The supply path includes a central conductor connected to the flange portion. The plasma processing apparatus according to any one of [E2] to [E5].

[0055] [E7] the coaxial waveguide extends vertically above the chamber, The resonating portion is provided above the lower surface of the flange portion. The plasma processing apparatus according to any one of [E2] to [E6].

[0056] [E8] The plasma processing apparatus according to [E7], wherein the inner conductor of the coaxial waveguide constitutes a gas supply pipe.

[0057] [E9] a substrate support disposed within the chamber; a showerhead formed of metal, providing a plurality of gas holes opening into a space within the chamber, and disposed above the substrate support; an introduction portion formed from a dielectric material and provided along the outer periphery of the showerhead or a sidewall of the chamber so as to introduce electromagnetic waves into the chamber; Further provided with The plasma processing apparatus according to [E8], wherein the gas supply pipe extends vertically above the chamber and is connected to the center of an upper portion of the showerhead, and a waveguide connected to the resonator unit is provided between the resonator unit and the introduction unit.

[0058] [E10] a first gas source of a film forming gas connected to the gas supply pipe; a second source of cleaning gas; a remote plasma source connected between the second gas source and the gas supply line; The plasma processing apparatus according to [E8] or [E9], further comprising:

[0059] [E11] The plasma processing apparatus according to [E10], wherein the film forming gas contains a silicon-containing gas.

[0060] [E12] The plasma processing apparatus according to [E10] or [E11], wherein the cleaning gas contains a halogen-containing gas.

[0061] 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]

[0062] 1...plasma processing apparatus, 10...chamber, 40...waveguide portion, 44...resonator portion, 45...microstrip, 46...dielectric member, 463...dielectric layer

Claims

1. a chamber; a waveguide configured to propagate electromagnetic waves to generate a plasma within the chamber, the waveguide including a resonator configured to resonate the electromagnetic waves therein; Equipped with The waveguide portion is a coaxial waveguide including an outer conductor and an inner conductor having an annular flange and disposed within the outer conductor; a cover conductor that closes an opening between the inner conductor and the outer conductor at one end of the coaxial waveguide; Further comprising: The resonator unit is Microstrip and a dielectric member provided between the one end and the other end of the coaxial waveguide; a ground conductor provided on the dielectric member; Including, a portion of the dielectric member constitutes a dielectric layer of the microstrip; The microstrip a microstrip conductor that is the flange; the dielectric layer having an annular shape and provided on the microstrip conductor; a ring-shaped ground portion that is a part of the ground conductor and is provided on the dielectric layer; Including, The dielectric member is a first cylindrical portion interposed between an outer edge of the flange portion and the outer conductor and extending toward one end of the coaxial waveguide; a second cylindrical portion extending from the flange portion toward one end of the coaxial waveguide along the inner conductor; the dielectric layer extending between the first cylindrical portion and the second cylindrical portion; Including, the dielectric member provides a recess that is a cavity on the dielectric layer and between the first cylindrical portion and the second cylindrical portion; Plasma processing equipment.

2. The plasma processing apparatus according to claim 1 , wherein the ground conductor further includes a cylindrical ground portion extending along the first cylindrical portion within the recess.

3. a supply path of electromagnetic waves having a coaxial structure and connected between a power source and the coaxial waveguide; The supply path includes a central conductor connected to the flange portion.

3. The plasma processing apparatus according to claim 1 or 2.

4. the coaxial waveguide extends vertically above the chamber, The resonating portion is provided above the lower surface of the flange portion.

3. The plasma processing apparatus according to claim 1 or 2.

5. 5. The plasma processing apparatus of claim 4, wherein the inner conductor of the coaxial waveguide constitutes a gas supply pipe.

6. a substrate support disposed within the chamber; a showerhead formed of metal, providing a plurality of gas holes opening into a space within the chamber, and disposed above the substrate support; an introduction portion formed from a dielectric material and provided along the outer periphery of the showerhead or a sidewall of the chamber so as to introduce electromagnetic waves into the chamber from the introduction portion; Further provided with 6. The plasma processing apparatus of claim 5, wherein the gas supply pipe extends vertically above the chamber and is connected to an upper center of the showerhead, and provides a waveguide connected to the resonator between the resonator and the introduction part.

7. a first gas source of a film forming gas connected to the gas supply pipe; a second source of cleaning gas; a remote plasma source connected between the second gas source and the gas supply line; The plasma processing apparatus according to claim 5 , further comprising:

8. The plasma processing apparatus according to claim 7 , wherein the film forming gas includes a silicon-containing gas.

9. The plasma processing apparatus of claim 7 , wherein the cleaning gas includes a halogen-containing gas.

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