In-liquid plasma treatment apparatus

Abstract

To provide a technique for reducing a deviation in concentration distribution of active species while increasing the active species in a treatment using the active species contained in in-liquid plasma.SOLUTION: An in-liquid plasma treatment apparatus is provided. A treatment space is constructed so that a treatment using active species contained in an in-liquid plasma is performed on a wafer. An active species supply part is constructed so as to supply the in-liquid plasma into the treatment space. A generation space is constructed so that liquid to be used for the generation of the in-liquid plasma is introduced. A shower plate is constructed so as to introduce the active species contained in the in-liquid plasma generated in the generation space into a processing space, and has a plurality of shower holes arranged so as to be expanded along the processing space. A microwave supply part includes a radial line slot antenna having a plurality of slots arranged so as to be expanded along the generation space, and is constructed so to supply a microwave into the liquid in the generation space via the radial line slot antenna.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An exemplary embodiment of the present disclosure relates to a submerged plasma processing apparatus. [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 large diameter of IC manufacturing. Patent Document 1 discloses a technique for inducing in-liquid plasma using a slot antenna. Active species generated by in-liquid HO plasma are expected to be applied to the modification of films used in semiconductor manufacturing (Patent Documents 2 and 3), photoresist film stripping (Patent Document 4), and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-127705 A [Patent Document 2] Special table 2013-515355 publication [Patent Document 3] U.S. Patent No. 7,521,378 [Patent Document 4] Patent No. 7105649 specification Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing bias in the concentration distribution of active species while increasing the amount of active species in a process using active species contained in in-liquid plasma. [Means for solving the problem]

[0005] In one exemplary embodiment, a submerged plasma processing apparatus is provided. The submerged plasma processing apparatus includes a processing space, an active species supply unit, a holding unit, and an exhaust path. The processing space is configured to perform processing on a wafer using active species contained in the submerged plasma. The active species supply unit is configured to supply active species to the processing space. The holding unit is arranged opposite to the active species supply unit across the processing space and configured to hold the wafer. The exhaust path is configured to exhaust the active species supplied to the processing space from the processing space to the outside. The active species supply unit includes a generation space, a microwave supply unit, and a shower plate. The generation space is configured to introduce a liquid used for generating the submerged plasma. The microwave supply unit is configured to generate the submerged plasma by supplying microwaves to the liquid introduced into the generation space. The shower plate is configured to introduce the active species into the processing space together with the liquid, and has a plurality of shower holes arranged to extend along the processing space. The microwave supply unit includes a radial line slot antenna having a plurality of slots arranged extending along the generation space, and is configured to supply microwaves to the liquid in the generation space via the radial line slot antenna. Effect of the Invention

[0006] According to one exemplary embodiment, there is provided a technique for reducing bias in concentration distribution of active species while increasing the amount of active species in a process using active species contained in in-liquid plasma. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 illustrates a submerged plasma processing apparatus according to an exemplary embodiment. [Diagram 2] FIG. 1 illustrates an arrangement defining an example generation space. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a submerged plasma processing apparatus is provided. The submerged plasma processing apparatus includes a processing space, an active species supply unit, a holding unit, and an exhaust path. The processing space is configured to perform processing on a wafer using active species contained in the submerged plasma. The active species supply unit is configured to supply active species to the processing space. The holding unit is arranged opposite to the active species supply unit across the processing space and configured to hold the wafer. The exhaust path is configured to exhaust the active species supplied to the processing space from the processing space to the outside. The active species supply unit includes a generation space, a microwave supply unit, and a shower plate. The generation space is configured to introduce a liquid used for generating the submerged plasma. The microwave supply unit is configured to generate the submerged plasma by supplying microwaves to the liquid introduced into the generation space. The shower plate is configured to introduce the active species into the processing space together with the liquid, and has a plurality of shower holes arranged to extend along the processing space. The microwave supply unit includes a radial line slot antenna having a plurality of slots arranged extending along the generation space, and is configured to supply microwaves to the liquid in the generation space via the radial line slot antenna.

[0010] According to the above-mentioned in-liquid plasma processing apparatus, the active species in the in-liquid plasma can be increased by using the in-liquid plasma. Also, the above-mentioned in-liquid plasma processing apparatus uses a radial line slot antenna having a plurality of slots arranged in a spreading manner along the generation space, and a shower plate having a plurality of shower holes arranged in a spreading manner along the processing space. By using such a radial line slot antenna and shower plate, the bias of the concentration distribution of the active species in the processing space can be reduced.

[0011] Various exemplary embodiments will now be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0012] The configuration of a submerged plasma processing apparatus 1 according to an exemplary embodiment will be described with reference to Figures 1 and 2. Figure 1 is a diagram showing the submerged plasma processing apparatus 1. Figure 2 is a diagram showing an example of the configuration defining a generation space 10 included in the submerged plasma processing apparatus 1.

[0013] The in-liquid plasma processing apparatus 1 is an apparatus capable of generating in-liquid plasma and processing a wafer W by the in-liquid plasma. The in-liquid plasma processing apparatus 1 includes a processing space PA, an active species supply unit PS, a holder WH, and a drainage path DP. The processing space PA is configured so that processing is performed on the wafer W using active species contained in the in-liquid plasma. The drainage path DP is configured to discharge the in-liquid plasma supplied to the processing space PA to the outside.

[0014] The active species supply part PS is configured to supply active species contained in the in-liquid plasma to the processing space PA. The active species supply part PS includes a generation space 10, a microwave supply part MS, and a shower plate 13. The active species supply part PS includes a storage chamber 11 and a wall part 12. Note that the in-liquid plasma processing apparatus 1 illustrated in Fig. 1 includes one active species supply part PS, but is not limited thereto, and may include a plurality of active species supply parts PS.

[0015] The storage chamber 11 is configured to store the liquid to be introduced into the generation space 10. The wall portion 12 extends between the storage chamber 11 and the generation space 10 to define the generation space 10. The planar shape of the generation space 10 shown in FIG. 2 is circular as an example, but is not limited thereto and may be other shapes.

[0016] An outer surface 12a of the wall portion 12 is exposed to the storage chamber 11. An inner surface 12b of the wall portion 12 is exposed to the generation space 10. The wall portion 12 includes a communication hole 12c that communicates between the storage chamber 11 and the generation space 10 and is configured to introduce liquid from the storage chamber 11 to the generation space 10.

[0017] The communication hole 12c extends from the outer surface 12a to the inner surface 12b. In a plan view, the hole center axis AX2 of the communication hole 12c extends at an angle θ with respect to a tangent TG of the inner surface 12b at the intersection of the communication hole 12c and the inner surface 12b. The angle θ satisfies 0 degrees < θ ≦ 90 degrees. The active species supply section PS may include multiple communication holes 12c. Although eight communication holes 12c are illustrated in FIG. 2, the number of communication holes 12c may be one or a number other than eight.

[0018] The holding part WH is disposed opposite to the active species supply part PS across the processing space PA and is configured to hold the wafer W. The wafer W can be placed on a placement surface HS of the holding part WH. The central axis AX1 of the holding part WH can be perpendicular to the placement surface HS of the wafer W. The holding part WH is configured to be rotatable about the central axis AX1 as a rotation axis. The holding part WH can be rotated about the central axis AX1 by a driving device (not shown). A protruding narrowed part (not shown) can be provided on the outer periphery of the holding part WH between the outer periphery of the holding part WH and the ceiling of the processing space PA. In other words, the holding part WH can have a shape in which its outer periphery (edge) is raised toward the ceiling of the processing space PA. Thereby, when the wafer W is held by the holding part WH, the processing space PA above the wafer W can be filled with a liquid containing active species. It is preferable that the processing space PA is filled with a liquid containing active species, but it is sufficient that at least the wafer W held by the holding part WH can be immersed in the liquid containing active species.

[0019] The shower plate 13 is disposed above the mounting surface HS of the holder WH at a position facing the mounting surface HS. A processing space PA is provided between the shower plate 13 and the mounting surface HS.

[0020] The generation space 10 is configured so that a liquid used to generate in-liquid plasma is introduced from a liquid supply device LS via an introduction path IP. The generation space 10 is provided above the shower plate 13 and between the shower plate 13 and the antenna 20. The liquid supplied from the liquid supply device LS may be, for example, water, but liquids other than water may also be used.

[0021] The microwave supply unit MS is configured to generate in-liquid plasma by supplying microwaves to the liquid introduced into the generation space 10. 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.

[0022] 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. A microwave generator 35 is connected to the coaxial waveguide 30 via a mode converter 37 and a rectangular waveguide 36.

[0023] Microwaves generated by the microwave generator 35 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 function as a microwave introduction path.

[0024] The microwave supply unit MS includes an antenna 20 having a plurality of slots 21 arranged along the generation space 10, and is configured to supply microwaves to the liquid in the generation space 10 via the antenna 20. The antenna 20 is provided between the dielectric window 16 and the dielectric plate 25. The materials of the dielectric window 16 and the dielectric plate 25 are both transparent to microwaves and may be dielectric materials such as quartz, aluminum oxide, aluminum nitride, etc.

[0025] The antenna 20 may be a radial line slot antenna. The multiple slots 21 are arranged to extend along the generation space 10. For this reason, microwaves can be uniformly supplied to the liquid introduced into the generation space 10 without being biased. Therefore, for the in-liquid plasma generated in the generation space 10, bias in the concentration distribution of active species can be reduced.

[0026] The microwaves propagating through the dielectric plate 25 are supplied from the multiple slots 21 of the antenna 20 into the generation space 10 via the dielectric window 16. An electric field is formed below the dielectric window 16 in the generation space 10 by the microwaves, and plasma is generated in the liquid introduced into the generation space 10, whereby in-liquid plasma can be generated.

[0027] The shower plate 13 is configured to introduce active species contained in the in-liquid plasma generated in the generation space 10 into the processing space PA. The shower plate 13 has a plurality of shower holes 13a. The plurality of shower holes 13a are arranged spreading along the processing space PA. Therefore, the active species can be uniformly supplied from the generation space 10 to the processing space PA without the concentration of the active species being biased. Therefore, the bias of the concentration distribution of the active species introduced into the processing space PA can be reduced. In particular, the bias of the concentration distribution of the active species on the wafer W placed on the placement surface HS of the holder WH can be further reduced.

[0028] The slot pattern of the plurality of slots 21 in the antenna 20 and the shower hole pattern of the plurality of shower holes 13a in the shower plate 13 can be set in accordance with the adjustment of the concentration distribution of the active species in the processing space PA.

[0029] According to the above-described in-liquid plasma processing apparatus 1, the active species in the in-liquid plasma can be increased by using the in-liquid plasma.

[0030] The liquid plasma processing apparatus 1 uses an antenna 20 having a plurality of slots 21 arranged along the generation space 10, and a shower plate 13 having a plurality of shower holes 13a arranged along the processing space PA. By using such an antenna 20 and shower plate 13, it is possible to reduce the bias in the concentration distribution of active species in the processing space PA.

[0031] 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. In addition, elements in different embodiments can be combined to form other embodiments.

[0032] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E9] below.

[0033] [E1] a processing space configured to perform processing on a wafer using active species contained in the in-liquid plasma; an active species supply unit configured to supply the active species to the processing space; a holder that is disposed opposite the active species supply unit across the processing space and is configured to hold the wafer; a discharge path configured to discharge the active species supplied to the processing space from the processing space to the outside; Equipped with The active species supply unit is A generation space configured to introduce a liquid used for generating the in-liquid plasma; A microwave supply unit configured to supply microwaves to the liquid introduced into the generation space to generate the in-liquid plasma; a shower plate configured to introduce the active species together with the liquid into the processing space, the shower plate having a plurality of shower holes arranged along the processing space; Including, The microwave supply unit includes a radial line slot antenna having a plurality of slots arranged along the generation space, and is configured to supply the microwaves to the liquid in the generation space via the radial line slot antenna. Submerged plasma processing equipment.

[0034] [E2] The active species supply unit is A reservoir configured to store the liquid to be introduced into the generation space; A wall portion extending between the storage chamber and the generation space and defining the generation space; Including, The wall portion includes a communication hole configured to communicate the storage chamber and the generation space and introduce the liquid from the storage chamber to the generation space. The liquid plasma processing apparatus according to the above [E1].

[0035] [E3] The communication hole extends from an outer surface of the wall portion to an inner surface of the wall portion, The communication hole extends perpendicularly to a tangent to the inner surface at an intersection of the communication hole and the inner surface in a plan view. The liquid plasma processing apparatus according to the above [E2].

[0036] [E4] The communication hole extends from an outer surface of the wall portion to an inner surface of the wall portion, the communication hole extends at an acute angle with respect to a tangent to the inner surface at an intersection of the communication hole and the inner surface in a plan view; The liquid plasma processing apparatus according to the above [E2].

[0037] [E5] The active species supply unit includes a plurality of the communication holes. The liquid plasma processing apparatus according to any one of the above items [E2] to [E4].

[0038] [E6] The liquid is water. The liquid plasma processing apparatus according to any one of the above items [E1] to [E5].

[0039] [E7] A plurality of the active species supply units are provided. The liquid plasma processing apparatus according to any one of the above items [E1] to [E6].

[0040] [E8] the central axis of the holding portion is perpendicular to the wafer placement surface, The holding portion is configured to be rotatable about the central axis as a rotation axis. The liquid plasma processing apparatus according to any one of the above items [E1] to [E7].

[0041] [E9] a slot pattern of the radial line slot antenna and a shower hole pattern of the shower plate are set in accordance with an adjustment of a concentration distribution of the active species in the processing space. The liquid plasma processing apparatus according to any one of the above items [E1] to [E8].

[0042] 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]

[0043] DESCRIPTION OF THE SYMBOLS 1...submerged plasma processing apparatus, 10...generation space, 11...storage chamber, 12...wall, 12a...outer surface, 12b...inner surface, 12c...communicating hole, 13...shower plate, 13a...shower 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...central axis of hole, DP...drainage path, HS...mounting surface, IP...introduction path, LS...liquid supply apparatus, MS...microwave supply unit, PA...processing space, PS...active species supply unit, TG...tangent, W...wafer, WH...holding unit.

Claims

1. a processing space configured to perform processing on a wafer using active species contained in the in-liquid plasma; an active species supply unit configured to supply the active species to the processing space; a holder that is disposed opposite the active species supply unit across the processing space and is configured to hold the wafer; a discharge path configured to discharge the active species supplied to the processing space from the processing space to the outside; Equipped with The active species supply unit is A generation space configured to introduce a liquid used for generating the in-liquid plasma; A microwave supply unit configured to supply microwaves to the liquid introduced into the generation space to generate the in-liquid plasma; a shower plate configured to introduce the active species together with the liquid into the processing space, the shower plate having a plurality of shower holes arranged along the processing space; Including, The microwave supply unit includes a radial line slot antenna having a plurality of slots arranged along the generation space, and is configured to supply the microwaves to the liquid in the generation space via the radial line slot antenna. Submerged plasma processing equipment.

2. The active species supply unit is A reservoir configured to store the liquid to be introduced into the generation space; A wall portion extending between the storage chamber and the generation space and defining the generation space; Including, The wall portion includes a communication hole configured to communicate the storage chamber and the generation space and introduce the liquid from the storage chamber to the generation space. The submerged plasma processing apparatus according to claim 1 .

3. The communication hole extends from an outer surface of the wall portion to an inner surface of the wall portion, The communication hole extends perpendicularly to a tangent to the inner surface at an intersection of the communication hole and the inner surface in a plan view. The submerged plasma processing apparatus according to claim 2 .

4. The communication hole extends from an outer surface of the wall portion to an inner surface of the wall portion, the communication hole extends at an acute angle with respect to a tangent to the inner surface at an intersection of the communication hole and the inner surface in a plan view; The submerged plasma processing apparatus according to claim 2 .

5. The active species supply unit includes a plurality of the communication holes. The submerged plasma processing apparatus according to claim 2 .

6. The liquid is water. The submerged plasma processing apparatus according to any one of claims 1 to 5.

7. A plurality of the active species supply units are provided. The submerged plasma processing apparatus according to any one of claims 1 to 5.

8. the central axis of the holding portion is perpendicular to the wafer placement surface, The holding portion is configured to be rotatable about the central axis as a rotation axis. The submerged plasma processing apparatus according to any one of claims 1 to 5.

9. a slot pattern of the radial line slot antenna and a shower hole pattern of the shower plate are set in accordance with an adjustment of a concentration distribution of the active species in the processing space. The submerged plasma processing apparatus according to any one of claims 1 to 5.

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