Antenna for plasma generation, and plasma processing device including the same

Abstract

To provide a plasma generation antenna for preventing electric corrosion due to electric conduction.SOLUTION: An antenna includes two conductor elements 31, an insulator element 32 that insulates between the adjacent conductor elements 31, a capacitor element 33 electrically connected in series to the conductor element 31 and including a first electrode 33A connected to one of the conductor elements 31, a second electrode 33B connected to the other conductor element 31 and facing the first electrode 33A, and a liquid dielectric in a space between the first electrode 33A and the second electrode 33B, and a spacer member 34 between the first electrode 31A and the one conductor element 31 and between the second electrode 33B and the other conductor element 31. The conductor element 31 and the spacer member 34 are formed of different metals and an oxide film or a metal film formed of the same metal as the conductor element is formed on a surface of the spacer member 34.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an antenna for generating an inductively coupled plasma by flowing a high-frequency current therethrough, and a plasma processing apparatus including the antenna.

Background Art

[0002] Conventionally, a plasma processing apparatus has been proposed in which a high-frequency current is passed through an antenna to generate an inductively coupled plasma (abbreviated as ICP) by the induced electric field generated thereby, and the substrate is processed using this inductively coupled plasma.

[0003] As an antenna for generating such an inductively coupled plasma, as shown in Patent Document 1, an LC antenna in which an inductive element (L) and a capacitive element (C) are connected in series is considered. Specifically, this LC antenna includes at least two conductor elements, an insulating element provided between the two conductor elements to insulate them, and a capacitive element electrically connected in series between the two conductor elements. The capacitive element is composed of a first electrode electrically connected to one conductor element, a second electrode electrically connected to the other conductor element and arranged to face the first electrode, and a dielectric that is a liquid filling the space between the first electrode and the second electrode. As the liquid serving as the dielectric, a coolant for cooling the antenna is used.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the LC antenna as described above, a spacer may be interposed between the metal pipe constituting the conductor element and each electrode constituting the capacitive element. In this case, each electrode constituting the capacitive element and the spacer are made of the same kind of metal (for example, aluminum), and the metal pipe constituting the conductor element is often made of a metal different from the spacer and each electrode (for example, copper). In such a mode, when the antenna is energized for a long time, electrolytic corrosion (dissimilar metal contact corrosion) occurs due to the contact between the spacer and the conductor element made of different metals in the presence of the coolant flowing through the antenna, and the surface of the spacer made of aluminum, which is a relatively base metal, is locally corroded. Then, a high-resistance region and a low-resistance region are generated in the spacer, and when an electric current flows through the low-resistance region, the region is locally heated and there is a risk of breakage.

[0006] The present invention has been made to solve the above problems, and its main object is to prevent electrolytic corrosion due to long-term energization and extend the life of the antenna.

Means for Solving the Problems

[0007] That is, the antenna according to one aspect of the present invention is for generating a plasma by flowing a high-frequency current, and includes at least two conductor elements, an insulating element provided between the adjacent conductor elements to insulate them, and a capacitive element electrically connected in series with the adjacent conductor elements. The capacitive element includes a first electrode electrically connected to one of the adjacent conductor elements, a second electrode electrically connected to the other of the adjacent conductor elements and disposed opposite to the first electrode, and a dielectric which is a liquid filling the space between the first electrode and the second electrode. The antenna further includes spacer members interposed between the first electrode and the one conductor element, and between the second electrode and the other conductor element, respectively. The conductor element and the spacer member are made of different metals from each other, and an oxide film or a metal film made of the same metal as the conductor element is formed on the surface of the spacer member.

[0008] With such a configuration, since a metal film made of the same metal as the oxide film or the conductor element is formed on the surface of the spacer member, it is possible to prevent dissimilar metal contact in a liquid such as a coolant that constitutes the dielectric. Thereby, it is possible to prevent electrolytic corrosion (dissimilar metal contact corrosion) due to long-term energization, extend the life of the antenna, and improve the reliability of the plasma processing apparatus.

[0009] As a specific embodiment of the antenna, the conductor element, the insulating element, and the spacer member are tubular, the capacitive element is provided inside the insulating element, and the dielectric is a coolant flowing inside the conductor element, the insulating element, and the spacer member.

[0010] In the antenna of the above aspect, it is preferable that the conductor element and the spacer member are arranged coaxially with each other, and the flow path formed by the inner peripheral surface of the metal pipe and the flow path formed by the inner peripheral surface of the spacer member have the same flow path length. In this way, since the inner peripheral surface of the conductor element and the inner peripheral surface of the spacer member constituting the flow path can be flush, the flow path resistance can be reduced and the locations where dissimilar metal contact corrosion may occur can be reduced.

[0011] In the antenna of the above aspect, it is preferable that the oxide film or the metal film is formed at least in the adjacent region to the conductor element on the inner peripheral surface of the spacer member. In this way, by forming an oxide film or a metal film in the adjacent region to the conductor element where dissimilar metal contact corrosion is likely to occur on the inner peripheral surface of the spacer member, it is possible to efficiently prevent dissimilar metal contact corrosion with a small amount of film. In this case, if it is formed on the entire inner peripheral surface of the spacer member, dissimilar metal contact corrosion can be more reliably prevented.

[0012] Also, the antenna in another aspect of the present invention is for generating plasma by flowing a high-frequency current therethrough, and includes at least two conductor elements, an insulating element provided between the adjacent conductor elements for insulating them, a capacitive element electrically connected in series with the adjacent conductor elements, a first electrode electrically connected to one of the adjacent conductor elements, a second electrode electrically connected to the other of the adjacent conductor elements and disposed opposite to the first electrode, a dielectric which is a liquid filling the space between the first electrode and the second electrode, and spacer members interposed between the first electrode and the one conductor element and between the second electrode and the other conductor element, respectively, wherein the conductor elements and the spacer members are made of different metals, and an insulating sheet is interposed between the spacer members and the conductor elements.

[0013] With such a configuration, by interposing an insulating sheet between the spacer member and the conductor element, the spacer member and the conductor element can be separated so as not to physically contact each other, preventing electrolytic corrosion due to contact between different metals of the spacer member and the conductor element in the liquid, and the antenna can have a longer lifespan. Moreover, if the thickness of the insulating sheet is made sufficiently small, the spacer member, the conductor element, and the insulating sheet function as a capacitor, and the spacer member and the metal pipe can be electrically connected.

[0014] In yet another embodiment of the present invention, an antenna is provided for generating plasma by passing a high-frequency current through it, and comprises at least two conductor elements, an insulating element provided between adjacent conductor elements to insulate the conductor elements, a capacitive element electrically connected in series with the adjacent conductor elements, the capacitive element comprising a first electrode electrically connected to one of the adjacent conductor elements, a second electrode electrically connected to the other of the adjacent conductor elements and arranged opposite the first electrode, and a dielectric that is a liquid filling the space between the first electrode and the second electrode, and spacer members respectively interposed between the first electrode and the one of the conductor elements, and between the second electrode and the other conductor element, and the conductor elements and the spacer members are each made of the same metal.

[0015] With this configuration, since the conductor element and the spacer member are made of the same metal, dissimilar metal corrosion does not occur between these members even when electricity is passed through them for a long period of time, thereby extending the life of the antenna and improving the reliability of the plasma processing apparatus.

[0016] Furthermore, a plasma processing apparatus according to one aspect of the present invention comprises a vacuum vessel which is evacuated to a vacuum and into which a gas is introduced, an antenna according to any of the aspects of the present invention described above which is disposed within the vacuum vessel, and a high-frequency power source which supplies a high-frequency current to the antenna, and is configured to process a substrate using plasma generated by the antenna.

[0017] In addition, a plasma processing apparatus according to another aspect of the present invention comprises a processing chamber which is evacuated to a vacuum and into which a gas is introduced, an antenna according to any of the aspects of the present invention described above which is arranged outside the processing chamber, and a high-frequency power source which supplies a high-frequency current to the antenna, and is configured to process a substrate in the processing chamber using plasma generated by the antenna.

[0018] With such a plasma processing apparatus, the same operational effects as those of the antenna of the present invention described above can be achieved.

Advantages of the Invention

[0019] According to the present invention configured as described above, it is possible to prevent electrolytic corrosion due to long-term energization and extend the life of the antenna.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0021] Hereinafter, a film forming apparatus and a film forming method according to an embodiment of the invention will be described with reference to the drawings.

[0022] <Apparatus Configuration> The plasma processing apparatus 100 of the present embodiment performs processing on a substrate W using an inductively coupled plasma P. Here, the substrate W is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic EL display, a flexible substrate for a flexible display, or the like. Further, the processing performed on the substrate W is, for example, film formation by plasma CVD method, etching, ashing, sputtering, or the like.

[0023] Note that when the plasma processing apparatus 100 performs film formation by the plasma CVD method, it is also called a plasma CVD apparatus; when performing etching, it is called a plasma etching apparatus; when performing ashing, it is called a plasma ashing apparatus; and when performing sputtering, it is called a plasma sputtering apparatus.

[0024] Specifically, as shown in FIG. 1, the plasma processing apparatus 100 includes a vacuum chamber 2 that is evacuated and into which a gas 7 is introduced, a linear antenna 3 disposed in the vacuum chamber 2, and a high-frequency power supply 4 that applies a high-frequency wave for generating an inductively coupled plasma P into the vacuum chamber 2 to the antenna 3. When a high-frequency wave is applied from the high-frequency power supply 4 to the antenna 3, a high-frequency current IR flows through the antenna 3, an induced electric field is generated in the vacuum chamber 2, and an inductively coupled plasma P is generated.

[0025] The vacuum chamber 2 is, for example, a container made of metal, and its interior is evacuated by a vacuum evacuation device 6. The vacuum chamber 2 is electrically grounded in this example.

[0026] The gas 7 is introduced into the vacuum chamber 2 via, for example, a flow regulator (not shown) and a plurality of gas inlets 21 arranged along the direction of the antenna 3. The gas 7 may be selected according to the processing content to be applied to the substrate W. For example, when forming a film on the substrate W by the plasma CVD method, the gas 7 is a source gas or a gas diluted with a dilution gas (e.g., H2). More specifically, when the source gas is SiH4, an Si film can be formed on the substrate W; when it is SiH4 + NH3, an SiN film can be formed; when it is SiH4 + O2, an SiO2 film can be formed; and when it is SiF4 + N2, an SiN:F film (fluorinated silicon nitride film) can be formed on the substrate W, respectively.

[0027] In addition, a substrate holder 8 for holding the substrate W is provided in the vacuum chamber 2. As in this example, a bias voltage may be applied from a bias power supply 9 to the substrate holder 8. The bias voltage is, for example, a negative DC voltage, a negative bias voltage, etc., but is not limited thereto. By such a bias voltage, for example, the energy when positive ions in the plasma P enter the substrate W can be controlled, and the crystallinity of the film formed on the surface of the substrate W can be controlled. A heater 81 for heating the substrate W may be provided in the substrate holder 8.

[0028] The antenna 3 is disposed above the substrate W in the vacuum chamber 2 along the surface of the substrate W (for example, substantially parallel to the surface of the substrate W). The antenna 3 disposed in the vacuum chamber 2 may be one or a plurality.

[0029] Near both ends of the antenna 3, the opposite side walls of the vacuum chamber 2 are respectively penetrated. Insulating members 11 are respectively provided at the portions where both ends of the antenna 3 penetrate outside the vacuum chamber 2. Each of these insulating members 11 has both ends of the antenna 3 penetrating therethrough, and the penetration portion is vacuum-sealed by, for example, a packing 12. Between each insulating member 11 and the vacuum chamber 2 is also vacuum-sealed by, for example, a packing 13. The material of the insulating member 11 is, for example, ceramics such as alumina, quartz, or engineering plastics such as polyphenylene sulfide (PPS) and polyether ether ketone (PEEK).

[0030] Furthermore, in the antenna 3, the portion located in the vacuum chamber 2 is covered by a straight tubular insulating cover 10. Both ends of the insulating cover 10 are supported by the insulating members 11. It should be noted that it is not necessary to seal between both ends of the insulating cover 10 and the insulating members 11. Even if the gas 7 enters the space inside the insulating cover 10, since the space is small and the electron movement distance is short, plasma P usually does not generate in the space. The material of the insulating cover 10 is, for example, quartz, alumina, fluororesin, silicon nitride, silicon carbide, silicon, etc.

[0031] By providing the insulating cover 10, it is possible to suppress charged particles in the plasma P from entering the metal pipe 31 that constitutes the antenna 3. Therefore, it is possible to suppress an increase in the plasma potential due to the incidence of charged particles (mainly electrons) on the metal pipe 31, and it is also possible to suppress metal contamination (metal contamination) of the plasma P and the substrate W caused by the metal pipe 31 being sputtered by charged particles (mainly ions).

[0032] A high-frequency power source 4 is connected to the power supply end 3a, which is one end of the antenna 3, via a matching circuit 41, and the other end, the termination end 3b, is directly grounded. Note that the termination end 3b may be grounded via a capacitor, a coil, or the like.

[0033] With the above configuration, a high-frequency current IR can be passed through the antenna 3 from the high-frequency power source 4 via the matching circuit 41. The frequency of the high frequency is, for example, a general 13.56 MHz, but it is not limited to this.

[0034] The antenna 3 has a hollow structure with a flow path through which a coolant CL flows inside. Specifically, as shown in FIGS. 2 to 4, the antenna 3 includes at least two tubular metal conductor elements 31 (hereinafter referred to as "metal pipes 31"), a tubular insulating element 32 (hereinafter referred to as "insulating pipe 32") provided between adjacent metal pipes 31 to insulate those metal pipes 31, and a capacitor 33 that is a capacitive element electrically connected in series with adjacent metal pipes 31.

[0035] In this embodiment, the number of metal pipes 31 is two, and the number of insulating pipes 32 and capacitors 33 is one each. In the following description, one metal pipe 31 is also referred to as the "first metal pipe 31A" and the other metal pipe as the "second metal pipe 31B". Note that the antenna 3 may have a configuration having three or more metal pipes 31. In this case, the number of insulating pipes 32 and capacitors 33 is one less than the number of metal pipes 31.

[0036] The coolant CL flows through the antenna 3 via a circulation channel 14 provided outside the vacuum container 2. In the circulation channel 14, a temperature control mechanism 141 such as a heat exchanger for adjusting the coolant CL to a constant temperature and a circulation mechanism 142 such as a pump for circulating the coolant CL in the circulation channel 14 are provided. As the coolant CL, from the viewpoint of electrical insulation, highly resistive water is preferable, for example, pure water or water close thereto is preferable. In addition, for example, a liquid refrigerant other than water such as a fluorine-based inert liquid may be used.

[0037] The metal pipe 31 is a straight pipe having a straight flow path 31x inside which the coolant CL flows. And, a male screw portion 31a is formed on the outer peripheral portion of at least one end portion in the longitudinal direction of the metal pipe 31. In the metal pipe 31 of the present embodiment, the end portion where the male screw portion 31a is formed and other members are formed by separate parts and joined together, but it may be formed from a single member. In order to achieve commonality of parts with a configuration for connecting a plurality of metal pipes 31, it is desirable to form male screw portions 31a at both ends in the longitudinal direction of the metal pipe 31 to provide compatibility. The material of the metal pipe 31 is, for example, copper, aluminum, alloys thereof, stainless steel, etc.

[0038] The insulating pipe 32 is a straight pipe having a straight flow path 32x inside which the coolant CL flows. And, female screw portions 32a that are screwed and connected to the male screw portions 31a of the metal pipe 31 are formed on the side peripheral walls at both ends in the axial direction of the insulating pipe 32. Further, on the side peripheral walls at both ends in the axial direction of the insulating pipe 32, recesses 32b for fitting the respective electrodes 33A, 33B of the capacitor 33 are formed over the entire circumferential direction on the axially central side of the female screw portions 32a. The insulating pipe 32 of the present embodiment is formed from a single member, but is not limited thereto. The material of the insulating pipe 32 is, for example, alumina, fluororesin, polyethylene (PE), engineering plastics (such as polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc.).

[0039] The capacitor 33 is provided inside the insulating pipe 32, specifically, in the flow path 32x through which the coolant CL of the insulating pipe 32 flows.

[0040] Specifically, the capacitor 33 includes a first electrode 33A electrically connected to one of the adjacent metal pipes 31 (the first metal pipe 31A), and is electrically connected to the other of the adjacent metal pipes 31 (the second metal pipe 31B), and a second electrode 33B disposed opposite to the first electrode 33A. The space between the first electrode 33A and the second electrode 33B is configured to be filled with the coolant CL. That is, the coolant CL flowing through the space between the first electrode 33A and the second electrode 33B becomes the dielectric constituting the capacitor 33.

[0041] Each of the electrodes 33A and 33B has a substantially rotating body shape, and a main flow path 33x is formed in the central portion along its central axis. Specifically, each of the electrodes 33A and 33B has a flange portion 331 that electrically contacts the end portion of the metal pipe 31 on the insulating pipe 32 side, and an extending portion 332 that extends from the flange portion 331 toward the insulating pipe 32 side. Each of the electrodes 33A and 33B in the present embodiment may be formed from a single member for the flange portion 331 and the extending portion 332, or may be formed from separate components and joined together. The material of the electrodes 33A and 33B is, for example, aluminum, copper, alloys thereof, and the like.

[0042] Further, a plurality of through holes 331h are formed in the flange portion 331 in the thickness direction. By providing the through holes 331h in the flange portion 331, the flow path resistance of the coolant CL by the flange portion 331 can be reduced, and the retention of the coolant CL in the insulating pipe 32 and the accumulation of air bubbles in the insulating pipe 32 can be prevented.

[0043] The extending portion 332 has a cylindrical shape, and a main flow path 33x is formed inside thereof. The extending portion 332 of the first electrode 33A and the extending portion 332 of the second electrode 33B are arranged coaxially with each other. That is, the extending portion 332 of the first electrode 33A is inserted into the extending portion 332 of the second electrode 33B. Thereby, a cylindrical space along the flow path direction is formed between the extending portion 332 of the first electrode 33A and the extending portion 332 of the second electrode 33B.

[0044] Each electrode 33A and 33B configured as described above is fitted into a recess 32b formed in the side peripheral wall of the insulating pipe 32. Specifically, the first electrode 33A is fitted into the recess 32b formed at one end side in the axial direction of the insulating pipe 32, and the second electrode 33B is fitted into the recess 32b formed at the other end side in the axial direction of the insulating pipe 32. By fitting each electrode 33A and 33B into each recess 32b in this way, the extending portion 332 of the first electrode 33A and the extending portion 332 of the second electrode 33B are arranged coaxially with each other. Further, the insertion dimension of the extending portion 332 of the second electrode 33B with respect to the extending portion 332 of the first electrode 33A is defined by the end surfaces of the flange portions 331 of each electrode 33A and 33B coming into contact with the surfaces facing the outside in the axial direction of each recess 32b.

[0045] In the present embodiment, a spacer member 34 is provided between the first metal pipe 31A and the first electrode 33A, and between the second metal pipe 31B and the second electrode 33B, respectively. The spacer member 34 has a substantially rotary body shape (specifically, a substantially short pipe shape), and a flow path 34x is formed in the central portion along its central axis. The material of the spacer member 34 is, for example, aluminum, copper, and alloys thereof.

[0046] The end of the spacer member 34 on the side of the insulating pipe 32 is in contact with the flange portions 331 of the respective electrodes 33A and 33B over the entire circumferential direction. Specifically, one axial end face of the spacer member 34 is in contact with the axial end face of the flange portion 331 over the entire circumferential direction. Also, the end of the spacer member 34 on the side of the metal pipe 31 is in contact with the ends of the respective metal pipes 31A and 31B over the circumferential direction. Specifically, the other axial end face of the spacer member 34 is in contact with the axial end face (tip face) of the metal pipe 31 over the entire circumferential direction. In this way, the metal pipe 31, the spacer member 34, and the respective electrodes 33A and 33B are electrically connected.

[0047] The flow path diameter of the flow path 34x formed by the spacer member 34 and the flow path diameter of the flow path 31x formed by the metal pipe are the same as each other. And by arranging these members coaxially, the inner circumferential surfaces forming the flow paths 34x and 31x are flush.

[0048] Also, by fitting the respective electrodes 33A and 33B and the spacer member 34 into the respective recesses 32b of the insulating pipe 32 and screwing the male screw portion 31a of the metal pipe 31 into the female screw portion 32a of the insulating pipe 32, the tip face of the metal pipe 31 comes into contact with the spacer member 34, and the respective electrodes 33A and 33B and the spacer member 34 are sandwiched and fixed between the insulating pipe 32 and the metal pipe 31. Thus, the antenna 3 of the present embodiment has a structure in which the metal pipe 31, the insulating pipe 32, the spacer member, the first electrode 33A, and the second electrode 33B are arranged coaxially. Note that the connection portion between the metal pipe 31 and the insulating pipe 32 has a sealing structure against vacuum and the coolant CL. The sealing structure of the present embodiment is realized by a sealing member such as a packing provided at the base end portion of the male screw portion 31a. Note that a tapered screw structure for pipes may also be used.

[0049] In this configuration, when the coolant CL flows from the first metal pipe 31A, the coolant CL flows toward the second electrode 33B through the main flow path 33x and the through hole 331h of the first electrode 33A. The coolant CL that has flowed toward the second electrode 33B flows into the second metal pipe 31B through the main flow path 33x and the through hole 331h of the second electrode 33B. At this time, the cylindrical space between the extension 332 of the first electrode 33A and the extension 332 of the second electrode 33B is filled with the coolant CL, and the coolant CL becomes a dielectric to form the capacitor 33.

[0050] In the antenna 3 of the present embodiment, each of the electrodes 33A and 33B and the spacer member 34 are made of the same kind of metal, and the metal pipe 31, each of the electrodes 33A and 33B, and the spacer member 34 are made of different kinds of metal. Specifically, in the present embodiment, each of the electrodes 33A and 33B and the spacer member 34 are made of aluminum, and the metal pipe 31 is made of copper. In the present embodiment, in order to avoid dissimilar metal contact corrosion (galvanic corrosion) between the metal pipe 31 and the spacer member 34 in the cooling water CL, the surface of the spacer member 34 is subjected to anodizing treatment to form an oxide film (aluminum oxide film). This oxide film is formed in a region adjacent to the metal pipe 31 on at least the inner surface 34a that forms the flow path 34x of the surface of the spacer member 34, and preferably is formed on the entire inner surface 34a. More preferably, an oxide film is formed on the entire surface of the spacer member 34. Also, in the present embodiment, an oxide film is formed on the surfaces of each of the electrodes 33A and 33B. The thickness of the oxide film is, for example, about 5 μm to about 20 μm, but is not limited thereto.

[0051] <Effects of the Present Embodiment> According to the antenna 3 of the present embodiment configured as described above, since the surface of the spacer member 34 is covered with an oxide film formed by performing anodizing treatment, it is possible to prevent dissimilar metal contact with the metal pipe 31 in the coolant CL. Thereby, it is possible to prevent electrolytic corrosion (dissimilar metal contact corrosion) due to long-term energization, extend the life of the antenna 3, and improve the reliability of the plasma processing apparatus 100.

[0052] Note that the antenna for plasma generation of the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, by performing anodizing treatment on the surface of the spacer member 34, dissimilar metal contact corrosion with the metal pipe 31 was prevented, but it is not limited to this. In other embodiments, as shown in FIG. 5, an insulating sheet 35 may be interposed between the opposing surfaces of the spacer member 34 and the metal pipe 31 to physically separate the spacer member 34 and the metal pipe 31. In this aspect, the spacer member 34, the metal pipe 31, and the insulating sheet 35 function as a capacitor, and the spacer member 34 and the metal pipe 31 are electrically connected. The insulating sheet 35 is, for example, a resin material such as a fluororesin and has a thickness of several μm. In this case, anodizing treatment may or may not be performed on the surface of the spacer member 34.

[0053] Furthermore, in still other embodiments, when the metal pipe 31 and the spacer member 34 are made of dissimilar metals, the surface of the spacer member 34 may be covered with a metal film of the same kind as the metal constituting the metal pipe 31. For example, when the metal pipe 31 is made of copper and the spacer member 34 is made of aluminum, the surface of the spacer member 34 may be covered with copper plating.

[0054] In the above embodiment, the metal pipe 31, each of the electrodes 33A and 33B, and the spacer member 34 were made of dissimilar metals, but the present invention is not limited to this. In other embodiments, the metal pipe 31, each of the electrodes 33A and 33B, and the spacer member 34 may be made of the same kind of metal (for example, copper). Even in this case, it is possible to prevent the contact corrosion between dissimilar metals between the spacer member 34 and the metal pipe 31.

[0055] In the plasma processing apparatus 100 of the above embodiment, the antenna 3 was disposed in the processing chamber for the substrate W. However, as shown in FIG. 6, the antenna 3 may be disposed outside the processing chamber 18. In this case, the plurality of antennas 3 are disposed in an antenna chamber 20 partitioned from the processing chamber 18 by a dielectric window 19 in the vacuum vessel 2. The antenna chamber 20 is evacuated by a vacuum exhaust device 21. With this plasma processing apparatus 100, it is possible to individually control conditions such as the pressure in the processing chamber 18 and conditions such as the pressure in the antenna chamber 20, efficiently generate the plasma P, and efficiently process the substrate W.

[0056] Furthermore, in the above embodiment, the antenna was linear, but it may have a curved or bent shape. In this case, the metal pipe may have a curved or bent shape, or the insulating pipe may have a curved or bent shape.

[0057] In addition, the conductor element and the insulating element were tubular having one internal flow path, but they may have two or more internal flow paths, or may have branched internal flow paths. Also, the conductor element and / or the insulating element may be solid.

[0058] In the electrode of the above embodiment, the extending portion was cylindrical, but it may have other rectangular tubular shapes, or may be flat, curved, or bent plate-shaped.

[0059] Needless to say, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit thereof.

Description of Symbols

[0060] 3 ··· Antenna 31 ··· Conductor Element 32 ··· Insulating Element 33 ··· Capacitor Element 33A ··· First Electrode 33B ··· Second Electrode 34 ··· Spacer Member

Claims

1. An antenna for generating plasma by flowing a high-frequency current, comprising: at least two conductor elements; an insulating element provided between the adjacent conductor elements to insulate them; a capacitive element electrically connected in series with the adjacent conductor elements, the capacitive element comprising a first electrode electrically connected to one of the adjacent conductor elements, a second electrode electrically connected to the other of the adjacent conductor elements and arranged opposite to the first electrode, and a dielectric which is a liquid filling the space between the first electrode and the second electrode; spacer members interposed between the first electrode and the one conductor element and between the second electrode and the other conductor element respectively; wherein the conductor element and the spacer member are made of different metals; an antenna in which an oxide film or a metal film made of the same metal as the conductor element is formed on the surface of the spacer member.

2. The conductor element, the insulating element and the spacer member are tubular, the capacitive element is provided inside the insulating element, The antenna according to claim 1, wherein the dielectric is a coolant flowing inside the conductor element, the insulating element and the spacer member.

3. the conductor element and the spacer member are arranged coaxially with each other, and the flow path formed by the inner circumferential surface of the metal pipe and the flow path formed by the inner circumferential surface of the spacer member have the same flow path length. The antenna according to claim 2.

4. The antenna according to claim 3, wherein the oxide film or the metal film is formed at least in the adjacent region of the surface of the spacer member with the conductor element.

5. The antenna according to claim 4, wherein the oxide film or the metal film is formed on the entire surface of the spacer member.

6. An antenna for generating plasma by flowing a high-frequency current, comprising: at least two conductor elements; an insulating element provided between the adjacent conductor elements to insulate them; A capacitive element electrically connected in series with the conductor elements adjacent to each other, comprising: a first electrode electrically connected to one of the conductor elements adjacent to each other; a second electrode electrically connected to the other of the conductor elements adjacent to each other and disposed opposite to the first electrode; and a dielectric which is a liquid filling the space between the first electrode and the second electrode. A spacer member interposed between the first electrode and the one conductor element and between the second electrode and the other conductor element respectively. The conductor element and the spacer member are made of different metals from each other. An antenna in which an insulating sheet is interposed between the spacer member and the conductor element.

7. An antenna for flowing a high-frequency current to generate plasma, comprising: At least two conductor elements; An insulating element provided between the conductor elements adjacent to each other to insulate those conductor elements; A capacitive element electrically connected in series with the conductor elements adjacent to each other, comprising: a first electrode electrically connected to one of the conductor elements adjacent to each other; a second electrode electrically connected to the other of the conductor elements adjacent to each other and disposed opposite to the first electrode; and a dielectric which is a liquid filling the space between the first electrode and the second electrode. A spacer member interposed between the first electrode and the one conductor element and between the second electrode and the other conductor element respectively. An antenna in which the conductor element and the spacer member are made of the same metal from each other.

8. A vacuum chamber evacuated and into which gas is introduced; The antenna according to any one of claims 1 to 7 disposed in the vacuum chamber; A high-frequency power source for flowing a high-frequency current through the antenna; and A plasma processing apparatus configured to perform processing on a substrate using the plasma generated by the antenna.

9. A processing chamber evacuated and into which gas is introduced; The antenna according to any one of claims 1 to 7 disposed outside the processing chamber; A high-frequency power source for flowing a high-frequency current through the antenna; and A plasma processing apparatus configured to perform processing on a substrate in the processing chamber using the plasma generated by the antenna.

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