Plasma processing device in liquid

Abstract

The in-liquid plasma processing apparatus includes a processing space and an active species supply unit capable of supplying in-liquid plasma to the processing space. The active species supply unit includes: a generation space into which a liquid can be introduced; a shower plate capable of introducing an active species contained in the plasma in the liquid generated in the generation space into the processing space, the shower plate having a plurality of shower holes arranged so as to be dispersed along the processing space; and a microwave supply unit including a radial line slot antenna having a plurality of slots arranged so as to be dispersed along the generation space. The microwave supply unit can supply microwaves to the liquid in the generation space via the radial line slot antenna.

Description

Technical Field

[0001] The exemplary embodiments of the present invention relate to a plasma processing apparatus in a liquid. Background Technology

[0002] In plasma etching, plasma generated by a radial line slot antenna (RLSA) is sometimes used to improve productivity in the miniaturization and scaling up of IC manufacturing. Patent Document 1 discloses a technique for inducing plasma in a liquid using a slot antenna. Active species generated by plasma in H2O liquid are expected to be applied to the modification of films used in semiconductor manufacturing (Patent Documents 2, 3), photoresist film stripping (Patent Document 4), etc.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-127705

[0006] Patent Document 2: Japanese Patent Publication No. 2013-515355

[0007] Patent Document 3: US Patent No. 7,521,378

[0008] Patent Document 4: Japanese Patent No. 7105649 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] The present invention provides a technique for increasing the number of active species and reducing the deviation in the concentration distribution of active species in the treatment of plasma contained in a liquid.

[0011] Means for solving technical problems

[0012] In one exemplary embodiment, a liquid plasma processing apparatus is provided. The liquid plasma processing apparatus includes a processing space, an active seed supply unit, a holding unit, and a discharge path. The processing space is configured to process a wafer using active seeds contained in liquid plasma within the processing space. The active seed supply unit is capable of supplying active seeds to the processing space. The holding unit is disposed opposite to the active seed supply unit across the processing space and is capable of holding the wafer. The discharge path is capable of discharging the active seeds supplied to the processing space from the processing space to the outside. The active seed supply unit includes a generation space, a microwave supply unit, and a spray plate. A liquid for generating liquid plasma is introduced into the generation space. The microwave supply unit is capable of supplying microwaves to the liquid introduced into the generation space to generate liquid plasma. The spray plate is capable of introducing active seeds and liquid together into the processing space and has a plurality of spray holes distributed along the processing space. The microwave supply unit includes a radial line slot antenna having a plurality of slots distributed along the generation space, and is capable of supplying microwaves to the liquid within the generation space via the radial line slot antenna.

[0013] Invention Effects

[0014] According to an exemplary embodiment, a technique can be provided to increase the number of active species and reduce the deviation in the concentration distribution of active species in a process using active species contained in plasma in a liquid. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating an exemplary embodiment of a plasma processing apparatus in a liquid.

[0016] Figure 2 It is a diagram illustrating the structure of the generative space of an example. Detailed Implementation

[0017] The following describes various exemplary implementation methods.

[0018] In one exemplary embodiment, a liquid plasma processing apparatus is provided. The liquid plasma processing apparatus includes a processing space, an active seed supply unit, a holding unit, and a discharge path. The processing space is configured to process a wafer using active seeds contained in liquid plasma within the processing space. The active seed supply unit is capable of supplying active seeds to the processing space. The holding unit is disposed opposite to the active seed supply unit across the processing space and is capable of holding the wafer. The discharge path is capable of discharging the active seeds supplied to the processing space from the processing space to the outside. The active seed supply unit includes a generation space, a microwave supply unit, and a spray plate. A liquid for generating liquid plasma is introduced into the generation space. The microwave supply unit is capable of supplying microwaves to the liquid introduced into the generation space to generate liquid plasma. The spray plate is capable of introducing active seeds and liquid together into the processing space and has a plurality of spray holes distributed along the processing space. The microwave supply unit includes a radial line slot antenna having a plurality of slots distributed along the generation space, and is capable of supplying microwaves to the liquid within the generation space via the radial line slot antenna.

[0019] According to the above-described liquid plasma processing apparatus, the number of active species in the liquid plasma can be increased by using liquid plasma. Furthermore, the above-described liquid plasma processing apparatus uses a radially linear slot antenna having multiple slots dispersed along the generation space, and a spray plate having multiple spray holes dispersed along the processing space. By using such a radially linear slot antenna and spray plate, the deviation in the concentration distribution of active species within the processing space can be reduced.

[0020] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in each drawing, the same or equivalent parts are labeled with the same reference numerals.

[0021] Reference Figure 1 and Figure 2 The structure of a liquid plasma processing apparatus 1 according to an exemplary embodiment will be described. Figure 1 This is a diagram showing the plasma processing device 1 in a liquid. Figure 2 This is a diagram illustrating the structure of a generation space 10, which is defined as an example of a plasma processing device 1 in a liquid.

[0022] The liquid plasma processing apparatus 1 is an apparatus capable of generating liquid plasma and processing a wafer W using the liquid plasma. The liquid plasma processing apparatus 1 includes a processing space PA, an active species supply unit PS, a holding unit WH, and a discharge path DP. The processing space PA is configured to process the wafer W using active species contained in the liquid plasma within the processing space PA. The discharge path DP is capable of discharging the liquid plasma supplied to the processing space PA to the outside.

[0023] The active species supply unit PS is capable of supplying active species contained in the plasma in the liquid to the processing space PA. The active species supply unit PS includes a generation space 10, a microwave supply unit MS, and a spray plate 13. The active species supply unit PS includes a storage chamber 11 and a wall 12. Furthermore, Figure 1 The plasma processing apparatus 1 in the liquid illustrated includes an active species supply unit PS, but is not limited thereto, and may include multiple active species supply units PS.

[0024] The storage chamber 11 is capable of storing the liquid to be introduced into the generation space 10. The wall 12 extends between the storage chamber 11 and the generation space 10 and divides the generation space 10. Figure 2 The planar shape of the generated space 10 shown is, for example, a circle, but it is not limited to this and can also be other shapes.

[0025] The outer surface 12a of the wall portion 12 is exposed in the storage chamber 11. The inner surface 12b of the wall portion 12 is exposed in the generation space 10. The wall portion 12 includes a connecting hole 12c that connects the storage chamber 11 and the generation space 10 and allows liquid to be introduced from the storage chamber 11 into the generation space 10.

[0026] A connecting hole 12c extends from the outer surface 12a to the inner surface 12b. The central axis AX2 of the connecting hole 12c extends at an angle θ relative to the tangent TG of the inner surface 12b at the intersection of the connecting hole 12c and the inner surface 12b when viewed from above. The angle θ satisfies 0 degrees < θ ≤ 90 degrees. That is, the connecting hole 12c can extend perpendicularly to the tangent TG or extend at an acute angle. The active seed supply unit PS may include multiple connecting holes 12c. Figure 2 The example shows eight connecting holes 12c, but there can be one connecting hole 12c, or there can be more than eight connecting holes.

[0027] The holding section WH is disposed opposite to the active seed supply section PS across the processing space PA, and is capable of holding the wafer W. The wafer W can be placed on the mounting surface HS of the holding section WH. The central axis AX1 of the holding section WH can be perpendicular to the mounting surface HS of the wafer W. The holding section WH can rotate about the central axis AX1. The holding section WH can be rotated about the central axis AX1 by a drive device (not shown). In addition, a protruding narrow portion (not shown) can be provided between the outer periphery of the holding section WH and the top of the processing space PA. In other words, the holding section WH can have a shape in which its outer periphery (edge) protrudes towards the top of the processing space PA. Thus, while the wafer W is held in the holding section WH, the processing space PA on the wafer W can be filled with liquid containing active seeds. The processing space PA is preferably filled with liquid containing active seeds, but it is sufficient as long as at least the wafer W held in the holding section WH can be immersed in the liquid containing active seeds.

[0028] The spray plate 13 is positioned above the mounting surface HS of the holding part WH and at a position opposite to the mounting surface HS. A processing space PA is provided between the spray plate 13 and the mounting surface HS.

[0029] Liquid for generating plasma can be introduced from the liquid supply device LS into the generation space 10 via the import path IP. The generation space 10 is located above the spray plate 13 and between the spray plate 13 and the antenna 20. The liquid supplied from the liquid supply device LS can be, for example, water, but other liquids can also be used.

[0030] The microwave supply unit MS is capable of supplying microwaves to the liquid introduced into the generation space 10 to generate plasma in the liquid. The microwave supply unit MS includes the generation space 10, a dielectric window 16, an antenna 20, a dielectric plate 25, a coaxial waveguide 30, a microwave generator 35, a rectangular waveguide 36, and a mode converter 37.

[0031] The coaxial waveguide 30 includes an inner conductor 31 and an outer conductor 32. The inner conductor 31 passes through the dielectric plate 25 and is connected to the antenna 20. The coaxial waveguide 30 is connected to the microwave generator 35 via a mode converter 37 and a rectangular waveguide 36.

[0032] The microwaves generated by the microwave generator 35 can propagate sequentially through the rectangular waveguide 36, the mode converter 37, the coaxial waveguide 30, and the dielectric plate 25. The rectangular waveguide 36, the mode converter 37, the coaxial waveguide 30, and the dielectric plate 25 can function as microwave guide paths.

[0033] The microwave supply unit MS includes an antenna 20 having a plurality of slits 21 distributed along the generation space 10, which can supply microwaves to the liquid within the generation space 10. The antenna 20 is disposed between a dielectric window 16 and a dielectric plate 25. Both the dielectric window 16 and the dielectric plate 25 are made of materials that are microwave-transparent, such as quartz, alumina, aluminum nitride, or other dielectric materials.

[0034] Antenna 20 can be a radial line slot antenna. Multiple slots 21 are distributed along the generation space 10. Therefore, microwaves can be supplied uniformly and without deviation to the liquid introduced into the generation space 10. Thus, for the plasma generated in the liquid within the generation space 10, the deviation in the concentration distribution of active species can be reduced.

[0035] Microwaves propagating in the dielectric plate 25 can be supplied into the generation space 10 through multiple slits 21 of the antenna 20 via the dielectric window 16. An electric field is formed by the microwaves below the dielectric window 16 in the generation space 10, thereby generating plasma in the liquid introduced into the generation space 10, thus enabling the generation of plasma in the liquid.

[0036] The spray plate 13 can introduce active species contained in the plasma generated in the liquid in the generation space 10 into the processing space PA. The spray plate 13 has a plurality of spray holes 13a. The plurality of spray holes 13a are distributed along the processing space PA. Therefore, active species can be uniformly supplied from the generation space 10 to the processing space PA with no deviation in the concentration of active species. Therefore, for the active species introduced into the processing space PA, the deviation in the concentration distribution of active species can be reduced. In particular, the deviation in the concentration distribution of active species on the wafer W placed on the mounting surface HS of the holding part WH can be further reduced.

[0037] The slit patterns of the multiple slits 21 in the antenna 20 and the spray hole patterns of the multiple spray holes 13a in the spray plate 13 can be set accordingly to adjust the concentration distribution of active species in the processing space PA.

[0038] According to the liquid plasma processing apparatus 1 described above, by using liquid plasma, the active species in the liquid plasma can be increased.

[0039] Furthermore, in the plasma processing apparatus 1 in the liquid, an antenna 20 having a plurality of slits 21 dispersedly arranged along the generation space 10 and a spray plate 13 having a plurality of spray holes 13a dispersedly arranged along the processing space PA are used. By using such an antenna 20 and a spray plate 13, the deviation in the concentration distribution of active species within the processing space PA can be reduced.

[0040] The above descriptions have illustrated various exemplary embodiments, but the embodiments are not limited to these exemplary embodiments. Various additions, omissions, substitutions, and changes can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0041] Various exemplary embodiments of the present invention are described below in [E1] to [E9].

[0042] [E1]

[0043] A plasma processing device in a liquid, characterized in that it comprises:

[0044] The processing space is configured to process the wafer using active species contained in plasma in a liquid.

[0045] An active seed supply unit is capable of supplying the active seed to the processing space;

[0046] A holding section, disposed opposite the active seed supply section across the processing space, is capable of holding the wafer; and

[0047] An exhaust path is provided that allows the active species supplied to the processing space to be discharged from the processing space to the outside.

[0048] The active seed supply unit includes:

[0049] A generation space into which a liquid for generating plasma in the liquid can be introduced;

[0050] A microwave supply unit capable of supplying microwaves to the liquid introduced into the generation space to generate plasma in the liquid; and

[0051] A spray plate, capable of introducing the active species and the liquid together into the processing space, has a plurality of spray holes dispersedly arranged along the processing space.

[0052] The microwave supply unit includes a radial slot antenna having a plurality of slots distributed along the generation space, which is capable of supplying microwaves to the liquid in the generation space via the radial slot antenna.

[0053] [E2]

[0054] The liquid plasma processing apparatus according to [E1] above is characterized in that:

[0055] The active seed supply unit includes:

[0056] Storage chamber, which is capable of storing the liquid to be introduced into the generation space; and

[0057] A wall portion that extends between the storage chamber and the generation space and divides the generation space.

[0058] The wall portion includes a connecting hole that connects the storage chamber to the generation space and allows the liquid to be introduced from the storage chamber to the generation space.

[0059] [E3]

[0060] The liquid plasma processing apparatus according to [E2] above is characterized in that:

[0061] The connecting hole extends from the outer side of the wall portion to the inner side of the wall portion.

[0062] The connecting hole extends perpendicularly to the tangent of the inner side at the intersection of the connecting hole and the inner side when viewed from above.

[0063] [E4]

[0064] The liquid plasma processing apparatus according to [E2] above is characterized in that:

[0065] The connecting hole extends from the outer side of the wall portion to the inner side of the wall portion.

[0066] The connecting hole extends at an acute angle to the tangent of the inner side at the intersection of the connecting hole and the inner side when viewed from above.

[0067] [E5]

[0068] The liquid plasma processing apparatus according to any one of [E2] to [E4] above is characterized in that:

[0069] The active seed supply section includes a plurality of the connecting holes.

[0070] [E6]

[0071] The liquid plasma processing apparatus according to any one of [E1] to [E5] above is characterized in that:

[0072] The liquid is water.

[0073] [E7]

[0074] The liquid plasma processing apparatus according to any one of [E1] to [E6] above is characterized in that:

[0075] It includes multiple active species supply units.

[0076] [E8]

[0077] The liquid plasma processing apparatus according to any one of [E1] to [E7] above is characterized in that:

[0078] The central axis of the holding portion is perpendicular to the mounting surface of the wafer.

[0079] The retaining part is capable of rotating about the central axis.

[0080] [E9]

[0081] The liquid plasma processing apparatus according to any one of [E1] to [E8] above is characterized in that:

[0082] The slit pattern of the radial slit antenna and the spray hole pattern of the spray plate can be set accordingly to adjust the concentration distribution of the active species in the processing space.

[0083] Based on the foregoing description, it should be understood that the various embodiments of the present invention have been described in this specification for illustrative purposes, and various changes may be made without departing from the scope and spirit of the invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

[0084] Explanation of reference numerals in the attached figures

[0085] 1…Plasma processing device in liquid, 10…Generation space, 11…Storage chamber, 12…Wall, 12a…Outer surface, 12b…Inner surface, 12c…Connecting hole, 13…Spray plate, 13a…Spray hole, 20…Antenna, 30…Coaxial waveguide, 31…Inner conductor, 32…Outer conductor, 35…Microwave generator, 36…Rectangular waveguide, 37…Mode converter, AX1…Central axis, AX2…Orifice central axis, DP…Drain path, HS…Placement surface, IP…Inlet path, LS…Liquid supply device, MS…Microwave supply section, PA…Processing space, PS…Active species supply section, TG…Tangent, W…Wafer, WH…Holding section.

Claims

1. A plasma processing device in a liquid, characterized in that, include: The processing space is configured to process the wafer using active species contained in plasma in a liquid. An active seed supply unit is capable of supplying the active seed to the processing space; A holding section, which is disposed opposite to the active seed supply section across the processing space, is capable of holding the wafer; and An exhaust path is provided that allows the active species supplied to the processing space to be discharged from the processing space to the outside. The active seed supply unit includes: A generation space into which a liquid for generating plasma in the liquid can be introduced; A microwave supply unit capable of supplying microwaves to the liquid introduced into the generation space to generate plasma in the liquid; and A spray plate, capable of introducing the active species and the liquid together into the processing space, has a plurality of spray holes dispersedly arranged along the processing space. The microwave supply unit includes a radial slot antenna having a plurality of slots distributed along the generation space, which is capable of supplying microwaves to the liquid in the generation space via the radial slot antenna.

2. The plasma treatment apparatus in a liquid according to claim 1, characterized in that: The active seed supply unit includes: Storage chamber, which is capable of storing the liquid to be introduced into the generation space; and A wall portion that extends between the storage chamber and the generation space and divides the generation space. The wall portion includes a connecting hole that connects the storage chamber to the generation space and allows the liquid to be introduced from the storage chamber to the generation space.

3. The plasma treatment apparatus in a liquid according to claim 2, characterized in that: The connecting hole extends from the outer side of the wall portion to the inner side of the wall portion. The connecting hole extends perpendicularly to the tangent of the inner side at the intersection of the connecting hole and the inner side when viewed from above.

4. The plasma treatment apparatus in a liquid according to claim 2, characterized in that: The connecting hole extends from the outer side of the wall portion to the inner side of the wall portion. The connecting hole extends at an acute angle to the tangent of the inner side at the intersection of the connecting hole and the inner side when viewed from above.

5. The plasma treatment apparatus in a liquid according to claim 2, characterized in that: The active seed supply section includes a plurality of the connecting holes.

6. The plasma treatment apparatus in a liquid according to any one of claims 1 to 5, characterized in that: The liquid is water.

7. The plasma treatment apparatus in a liquid according to any one of claims 1 to 5, characterized in that: It includes multiple active species supply units.

8. The plasma treatment apparatus in a liquid according to any one of claims 1 to 5, characterized in that: The central axis of the holding portion is perpendicular to the mounting surface of the wafer. The retaining part is capable of rotating about the central axis.

9. The plasma treatment apparatus in a liquid according to any one of claims 1 to 5, characterized in that: The slit pattern of the radial slit antenna and the spray hole pattern of the spray plate can be set accordingly to adjust the concentration distribution of the active species in the processing space.

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