JP6931461B2 - Antenna for plasma generation, plasma processing device and antenna structure equipped with it - Google Patents

Description

The present invention relates to an antenna for generating inductively coupled plasma by passing a high frequency current, a plasma processing device provided with the antenna, and an antenna structure.

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

In this type of plasma processing apparatus, if the antenna is lengthened to accommodate a large substrate or the like, the impedance of the antenna becomes large, which causes a large potential difference between both ends of the antenna. As a result, there is a problem that the uniformity of the plasma such as the density distribution, the potential distribution, and the electron temperature distribution of the plasma is deteriorated due to the influence of this large potential difference, and the uniformity of the substrate processing is deteriorated. Further, when the impedance of the antenna becomes large, there is a problem that it becomes difficult for a high frequency current to flow through the antenna.

In order to solve such a problem, as shown in Patent Document 1, a plurality of metal pipes are connected with a hollow insulator interposed between adjacent metal pipes, and are connected to the outer peripheral portion of the hollow insulator. It is conceivable that a capacitor, which is a capacitive element, is arranged. This capacitor is electrically connected in series to the metal pipes on both sides of the hollow insulator, and has a first electrode electrically connected to the metal pipe on one side of the hollow insulator and the other side of the hollow insulator. It has a second electrode that is electrically connected to the metal pipe of the above and is arranged so as to face the first electrode, and a dielectric sheet that is arranged between the first electrode and the second electrode. There is.

Japanese Unexamined Patent Publication No. 2016-721168

However, since the above-mentioned capacitor has a laminated structure of a first electrode, a dielectric sheet and a second electrode, a gap may occur between the electrodes and the dielectric sheet. Then, an arc discharge may occur in this gap, which may lead to deterioration of the capacitor, so there is room for improvement in the structure of the capacitor.

Here, in order to prevent a gap from being formed between the electrode and the dielectric sheet, it is conceivable to apply an adhesive to both sides of the dielectric sheet to bond the electrodes. However, the electrical performance of this adhesive changes the performance of the dielectric sheet, making it difficult to manufacture the required capacitance value and the like.

In addition, in order to fill the gap generated between the electrode and the dielectric sheet, it is conceivable to provide a structure for pressing them from the surroundings. However, by providing the pressing structure, the structure around the antenna becomes complicated, and the uniformity of the plasma generated in the surroundings may be deteriorated.

Therefore, the present invention has been made to solve the above problems, and incorporates a capacitive element into the antenna to reduce the impedance of the antenna and eliminate the gap generated between the electrodes and the dielectric constituting the capacitive element. Is the main issue.

That is, the antenna for generating plasma according to the present invention is an antenna for generating plasma by passing a high frequency current, and has at least two conductor elements and a first conductor element and a second conductor adjacent to each other. The capacitance element includes an insulating element provided between the elements and insulating them, and a capacitance element electrically connected in series with the first conductor element and the second conductor element, and the capacitance element is the first conductor element. An electrode composed of a part of the conductor element of the above, or an electrode electrically connected to the first conductor element, the first electrode arranged on the first conductor element side of the insulating element, and the said. It is electrically connected to the second conductor element, extends from the second conductor element side through the inside of the insulating element to the first conductor element side, and is arranged so as to face the first electrode. The conductor is composed of a second electrode formed therein and a dielectric material that fills the space between the first electrode and the second electrode, and the dielectric material is a liquid.

In the case of such an antenna for generating plasma, a capacitive element is electrically connected in series to conductor elements adjacent to each other provided via an insulating element, so that the combined reactance of the antenna is simply described. Since the form is obtained by subtracting the capacitive reactance from the inductive reactance, the impedance of the antenna can be reduced. As a result, even when the antenna is lengthened, the increase in impedance can be suppressed, high-frequency current can easily flow through the antenna, and plasma can be efficiently generated.
In particular, according to the present invention, since the space between the first electrode and the second electrode is filled with a liquid dielectric, it is possible to eliminate the gap generated between the electrodes and the dielectric constituting the capacitive element. .. As a result, it is possible to eliminate the arc discharge that may occur in the gap between the electrode and the dielectric, and to eliminate the damage to the capacitive element due to the arc discharge. Further, the capacitance value can be set accurately from the distance between the first electrode and the second electrode, the facing area, and the relative permittivity of the liquid dielectric without considering the gap. Further, it is possible to eliminate the need for a structure for pressing the electrodes and the dielectric for filling the gap, and it is possible to prevent the structure around the antenna from becoming complicated due to the pressing structure and the resulting deterioration of plasma uniformity. In addition, since the second electrode is made to face the first electrode by extending from the second conductor element side through the inside of the insulating element to the first conductor element side, the extension dimension can be changed. The capacitance value required for the capacitive element can be easily obtained.

In an embodiment for simplifying the structure of the capacitive element, the first electrode has a tubular shape, and the second electrode is an extension portion inserted into the internal space of the first electrode. A configuration having the above can be mentioned.

It is desirable that the distance between the inner peripheral surface of the first electrode and the outer peripheral surface of the extending portion is constant along the circumferential direction.
With this configuration, the distribution of the high-frequency current flowing through the conductor element can be made uniform in the circumferential direction, and plasma with good uniformity can be generated.

In order to cool the antenna and stably generate plasma, it is conceivable that each of the conductor elements has a tubular shape and a coolant is circulated inside each of the conductor elements. In this configuration, the coolant flowing inside the first conductor element flows between the first electrode and the second electrode, functions as the dielectric, and is formed on the second electrode. It is desirable that the conductor is guided into the second electrode through the one or more through holes and flows out into the inside of the second conductor element.
With such a configuration, by using the coolant as a dielectric, it is not necessary to prepare a dielectric separately from the coolant, and the first electrode and the second electrode can be cooled. Normally, the coolant is adjusted to a constant temperature by a temperature control mechanism, and by using this coolant as a dielectric, it is possible to suppress the change in the relative permittivity due to the temperature change and suppress the change in the capacitance value. Further, when water is used as the coolant, the relative permittivity of water is about 80 (20 ° C.), which is larger than that of the resin dielectric sheet, so that a capacitive element capable of withstanding a high voltage can be configured. can.

In the above-described configuration, that is, in the configuration in which the second electrode is provided with a through hole and the coolant is guided into the second electrode through the through hole, in order to reduce the resistance to the flow of the coolant, the second electrode is described. It is desirable that one or a plurality of grooves are formed so as to communicate with the through hole and extend along the flow direction of the coolant.

Further, the plasma processing apparatus according to the present invention includes a vacuum container that is evacuated and introduced with gas, an antenna arranged inside or outside the vacuum container, and a high-frequency power source that allows a high-frequency current to flow through the antenna. The substrate is configured to be processed by using the plasma generated by the antenna, and the antenna is characterized by having the above-described configuration.
According to this plasma processing apparatus, the above-mentioned antenna can efficiently generate plasma having good uniformity, so that the uniformity and efficiency of substrate processing can be improved.

In order to perform processing on a large-area substrate in this plasma processing apparatus, it is conceivable to include a plurality of the antennas. In this case, both ends of the antenna extend out of the vacuum vessel, and in the antennas adjacent to each other, the end of one antenna and the end of the other antenna are electrically connected by a connecting conductor. Therefore, it is desirable to configure the antennas so that high-frequency currents in opposite directions flow through the antennas adjacent to each other.

It is desirable that the connecting conductor has a flow path inside, and a coolant flows through the flow path.

A cooling liquid flows inside the conductor element and the insulating element, and the cooling liquid flowing through one of the antennas in the antennas adjacent to each other flows to the other antenna through the flow path of the connecting conductor. Is desirable.
With this configuration, both the antenna and the connecting conductor can be cooled by a common coolant. Further, since a plurality of antennas can be cooled by one flow path, the configuration of the circulation flow path for circulating the coolant can be simplified. If the flow path of the antenna and the flow path of the connecting conductor become long, the dielectric constant may decrease on the downstream side due to the rise of the coolant. Therefore, the number of antennas connected by the connecting conductor is set in consideration of the temperature rise of the coolant, and for example, the number of antennas is about four.

When the feeding side end and the grounding side end of the two antennas are connected by a connecting conductor, the impedance due to the connecting conductor increases. As a result, the potential of the end on the feeding side may rise with respect to the end on the grounding side due to the energization of high-frequency current, or the voltage may rise or fall depending on the impedance of the connecting conductor. be. This causes non-uniformity of the generated plasma.
In order to preferably solve this problem, the connecting conductors include one conductor portion connected to one of the antennas in the antennas adjacent to each other, and the other conductor portion connected to the other antenna. It is desirable to have a capacitive element electrically connected in series to the one conductor portion and the other conductor portion. By providing the capacitive element in the connecting conductor in this way, the impedance of the connecting conductor can be made equivalent to zero, and the increase in impedance due to the connecting conductor can be eliminated.

In the plasma processing apparatus, it is conceivable to provide an insulating cover for covering the antenna for the purpose of suppressing the charged particles in the plasma from being incident on the conductor elements constituting the antenna. At this time, if the antenna is lengthened due to the above-mentioned antenna configuration, the antenna bends and the insulating element comes into contact with the insulating cover which has become hot due to plasma. When the insulating element is made of resin, the problem of thermal damage becomes particularly remarkable.
In order to preferably solve this problem, a convex portion protruding toward the insulating cover is formed on the outer peripheral surface of at least one of the first conductor element or the second conductor element. desirable.
With this configuration, even if the antenna is bent, the convex portion comes into contact with the insulating cover so that the insulating element does not come into contact with the insulating cover. This makes it possible to prevent thermal damage to the insulating element. Further, by preventing the insulating element from coming into contact with the insulating cover, it is possible to prevent the temperature of the coolant, which is the dielectric of the capacitive element, from rising due to the contact of the insulating element with the insulating cover. As a result, the change in the dielectric constant of the coolant can be suppressed.

In order to reliably prevent contact between the insulating element and the insulating cover, it is desirable that the convex portion is formed continuously or intermittently over the entire circumferential direction of the outer peripheral surface. Further, with this configuration, the contact area between the convex portion and the insulating cover can be increased, and the load on the insulating cover can be dispersed.

In order to reliably prevent contact between the insulating element and the insulating cover, the convex portion is formed at a position adjacent to the insulating element on the outer peripheral surfaces of the first conductor element and the second conductor element. It is desirable to be there.

Further, the antenna structure according to the present invention includes the above-mentioned antenna and an insulating cover covering the antenna, and the insulating cover is provided on at least one outer peripheral surface of the first conductor element or the second conductor element. It is characterized in that a convex portion protruding toward is formed.

Further, the antenna structure according to the present invention includes an antenna for generating plasma through which a high-frequency current is passed, and an insulating cover covering the antenna, and the antenna is adjacent to at least two conductor elements. An insulating element provided between the first conductor element and the second conductor element to insulate them, and a capacitive element electrically connected in series with the first conductor element and the second conductor element. The capacitive element is electrically connected to a first electrode electrically connected to one of the conductor elements adjacent to each other, and is electrically connected to the other of the conductor elements adjacent to each other, and the first electrode is provided. The first conductor element is composed of a second electrode arranged so as to face each other and a dielectric material that fills the space between the first electrode and the second electrode, and the dielectric material is a liquid. Alternatively, it is characterized in that a convex portion projecting toward the insulating cover is formed on at least one outer peripheral surface of the second conductor element.

According to the present invention configured in this way, the impedance of the antenna can be reduced by incorporating the capacitive element into the antenna, and the gap generated between the electrodes and the dielectric constituting the capacitive element can be eliminated, so that the uniformity is achieved. It is possible to efficiently generate a good plasma.

It is a vertical sectional view which shows typically the structure of the plasma processing apparatus of this embodiment. It is an enlarged cross-sectional view which shows typically the peripheral structure of the capacitive element in the antenna of the same embodiment. It is an enlarged cross-sectional view which shows typically the capacitive element of the modification embodiment. It is an enlarged cross-sectional view which shows typically the capacitive element of the modification embodiment. It is an enlarged cross-sectional view which shows typically the capacitive element of the modification embodiment. It is an enlarged cross-sectional view which shows typically the capacitive element of the modification embodiment. It is sectional drawing which shows typically the structure of the plasma processing apparatus of a modification embodiment. It is sectional drawing which shows typically the structure of the plasma processing apparatus of a modification embodiment. It is an enlarged cross-sectional view which shows typically the peripheral structure of the capacitive element in the antenna of the modified embodiment. It is an enlarged cross-sectional view which shows the state which the convex part is in contact with an insulating cover. It is an enlarged cross-sectional view which shows the deformation example of a convex part.

Hereinafter, an embodiment of the plasma processing apparatus according to the present invention will be described with reference to the drawings.

<Device configuration>
The plasma processing apparatus 100 of the present embodiment processes the 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, and the like. The treatment applied to the substrate W is, for example, film formation, etching, ashing, sputtering, etc. by the plasma CVD method.

The plasma processing apparatus 100 includes a plasma CVD apparatus when forming a film by a plasma CVD method, a plasma etching apparatus when performing etching, a plasma ashing apparatus when performing ashing, and a plasma sputtering apparatus when performing sputtering. Called.

Specifically, as shown in FIG. 1, the plasma processing apparatus 100 includes a vacuum vessel 2 that is evacuated and into which a gas 7 is introduced, a linear antenna 3 arranged in the vacuum vessel 2, and the inside of the vacuum vessel 2. It is provided with a high frequency power source 4 that applies a high frequency for generating an induction coupling type plasma P to the antenna 3. By applying a high frequency from the high frequency power supply 4 to the antenna 3, a high frequency current IR flows through the antenna 3, an inductive electric field is generated in the vacuum vessel 2, and an inductively coupled plasma P is generated.

The vacuum container 2 is, for example, a metal container, and the inside thereof is evacuated by the vacuum exhaust device 6. The vacuum vessel 2 is electrically grounded in this example.

The gas 7 is introduced into the vacuum vessel 2 via, for example, a flow rate regulator (not shown) and a plurality of gas introduction ports 21 arranged in a direction along the antenna 3. The gas 7 may be a gas 7 according to the processing content to be applied to the substrate W. For example, when performing film formation on the substrate W by the plasma CVD method, a gas 7 is a gas diluted with the raw material gas or a dilution gas (e.g., H _2). More specifically, when the raw material gas is SiH _4, a Si film is used, when SiH ₄ + NH ₃ is used, a SiN film is used, when SiH ₄ + O ₂ is used, a SiO ₂ film is used, and when SiF ₄ + N ₂ is used, a SiN film is used. : The F film (fluoride silicon nitride film) can be formed on the substrate W, respectively.

Further, a substrate holder 8 for holding the substrate W is provided in the vacuum container 2. As in this example, a bias voltage may be applied to the substrate holder 8 from the bias power supply 9. The bias voltage is, for example, a negative DC voltage, a negative bias voltage, or the like, but is not limited thereto. With such a bias voltage, for example, the energy when the cations in the plasma P are incident on the substrate W can be controlled to control the crystallinity of the film formed on the surface of the substrate W. .. A heater 81 for heating the substrate W may be provided in the substrate holder 8.

The antenna 3 is arranged above the substrate W in the vacuum vessel 2 along the surface of the substrate W (for example, substantially parallel to the surface of the substrate W). The number of antennas 3 arranged in the vacuum container 2 may be one or a plurality.

The vicinity of both ends of the antenna 3 penetrates the side walls facing each other of the vacuum vessel 2. Insulating members 11 are provided at portions that allow both ends of the antenna 3 to penetrate the outside of the vacuum vessel 2. Both ends of the antenna 3 penetrate each of the insulating members 11, and the penetrating portions are vacuum-sealed by, for example, packing 12. The insulating member 11 and the vacuum container 2 are also vacuum-sealed by, for example, 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 polyetheretherketone (PEEK).

Further, in the antenna 3, a portion of the antenna 3 located inside the vacuum container 2 is covered with a straight tubular insulating cover 10. Both ends of the insulating cover 10 are supported by the insulating member 11. It is not necessary to seal between both ends of the insulating cover 10 and the insulating member 11. This is because even if the gas 7 enters the space inside the insulating cover 10, the plasma P is not normally generated in the space because the space is small and the moving distance of electrons is short. The material of the insulating cover 10 is, for example, quartz, alumina, fluororesin, silicon nitride, silicon carbide, silicon, or the like.

By providing the insulating cover 10, it is possible to prevent the charged particles in the plasma P from being incident on the metal pipe 31 constituting the antenna 3, so that the charged particles (mainly electrons) are incident on the metal pipe 31. The increase in plasma potential can be suppressed, and the metal pipe 31 can be suppressed from being sputtered by charged particles (mainly ions) to cause metal contamination (metal contamination) on the plasma P and the substrate W. ..

A high-frequency power supply 4 is connected to the feeding end 3a, which is one end of the antenna 3, via a matching circuit 41, and the ending 3b, which is the other end, is directly grounded. The terminal portion 3b may be grounded via a capacitor, a coil, or the like.

With the above configuration, a high frequency current IR can be passed from the high frequency power supply 4 to the antenna 3 via the matching circuit 41. The high frequency frequency is, for example, 13.56 MHz, which is common, but is not limited to this.

The antenna 3 has a hollow structure having a flow path through which the coolant CL flows. Specifically, as shown in FIG. 2, the antenna 3 is provided between at least two tubular metal conductor elements 31 (hereinafter, referred to as “metal pipe 31”) and metal pipes 31 adjacent to each other. A tubular insulating element 32 (hereinafter, referred to as “insulated pipe 32”) that insulates the metal pipes 31 and a capacitor 33 that is a capacitive element electrically connected in series with the metal pipes 31 adjacent to each other are provided. ing.

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 a "first metal pipe 31A", and the other metal pipe 31 is also referred to as a "second metal pipe 31B". Here, the first metal pipe 31A is a metal pipe 31 arranged on the upstream side in the flow direction of the coolant CL, and the second metal pipe 31B is a metal arranged on the downstream side in the flow direction of the coolant CL. It is a pipe 31. Further, the first metal pipe 31A and the second metal pipe 31B have the same outer diameter and inner diameter, and are arranged coaxially. However, the outer diameter and inner diameter of the metal pipe 31 may be changed as appropriate, and the arrangement does not necessarily have to be coaxial. Further, the antenna 3 may have a configuration having three or more metal pipes 31, and in this case, the number of the insulating pipes 32 and the capacitors 33 are both one less than the number of the metal pipes 31.

As shown in FIG. 1, the coolant CL circulates the antenna 3 through a circulation flow path 14 provided outside the vacuum vessel 2, and the coolant CL is constant in the circulation flow path 14. A temperature control mechanism 141 such as a heat exchanger for adjusting the temperature and a circulation mechanism 142 such as a pump for circulating the coolant CL in the circulation flow path 14 are provided. As the coolant CL, water having high resistance is preferable from the viewpoint of electrical insulation, and for example, pure water or water close thereto is preferable. In addition, a liquid refrigerant other than water, such as a fluorine-based inert liquid, may be used.

The metal pipe 31 has a straight tubular shape in which a linear flow path 31x through which the coolant CL flows is formed. The material of the metal pipe 31 is, for example, copper, aluminum, alloys thereof, stainless steel, and the like.

The insulating pipe 32 has a straight tubular shape in which a linear flow path 32x through which the coolant CL flows is formed. The insulating pipe 32 of the present embodiment has the same outer diameter as the metal pipe 31, and is arranged coaxially with the metal pipe 31. Further, the insulating pipe 32 is formed of a single member, and the material thereof is, for example, alumina, fluororesin, polyethylene (PE), engineering plastic (for example, polyphenylene sulfide (PPS), polyetheretherketone (PEEK)). ) Etc.) etc. The dimensions, arrangement, and members of the insulating pipe 32 are not limited to the above.

The capacitor 33 is interposed between the first metal pipe 31A and the second metal pipe 32B, and the flow path 31x of the first metal pipe 31A and the flow path 31x of the second metal pipe 31B are inside the capacitor 33. The main flow path 33x that communicates with is formed.

Specifically, the capacitor 33 is electrically connected to the first metal pipe 31A and is arranged on the first metal pipe 31A side of the insulating pipe 32 with the first electrode 33A and the second metal pipe 31B. A second electrode that is electrically connected and extends from the second metal pipe 31B side through the inside of the insulating pipe 32 to the first metal pipe 31A side and is arranged so as to face the first electrode 33A. 33B is provided, and the coolant CL is configured to fill the space S between the first electrode 33A and the second electrode 33B. That is, the coolant CL flowing through the space S between the first electrode 33A and the second electrode 33B becomes the dielectric material constituting the capacitor 33.

Here, the first electrode 33A and the first metal pipe 31A are screwed into a male screw portion formed at one axial end portion and a female screw portion formed at the other axial end portion. It is configured to be connected to each other by.
In the present embodiment, the male screw portion 31a is formed on the inner peripheral portion at the axial end portion of the first metal pipe 31A, and the female screw portion 33a is formed on the outer peripheral portion at the axial end portion of the first electrode 33A. By screwing these together, the axial end portion of the first electrode 33A is connected in a state of being inserted into the first metal pipe 31A.

Further, the second electrode 33B and the second metal pipe 31B are formed by screwing a male screw portion formed at one axial end portion and a female screw portion formed at the other axial end portion. It is configured to be connected to each other.
In the present embodiment, the male screw portion 31a is formed on the outer peripheral portion at the axial end portion of the second metal pipe 31B, and the female screw portion 33a is formed on the inner peripheral portion at the axial end portion of the second electrode 33B. By screwing these together, the axial end portion of the second metal pipe 31B is connected in a state of being inserted into the second electrode 33B.

Hereinafter, the electrodes 33A and 33B will be described in detail.

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 the central axis thereof. Each of the electrodes 33A and 33B here has a tubular shape, and is provided so as not to project outward from the metal pipe 31 when viewed from the axial direction. The materials of the electrodes 33A and 33B are, for example, aluminum, copper, alloys thereof, and the like.

Specifically, the electrodes 33A and 33B come into contact with the end of the metal pipe 31 on the insulating pipe 32 side by being screwed into the metal pipe 31, and are electrically connected to each other from the contact portion 331 and the contact portion 331. It has an extension portion 332 extending to the insulation pipe 32 side. The contact portion 331 and the extension portion 332 may be formed of a single member, or may be formed of a separate member and joined to each other.

The contact portion 331 is in contact with the end portion of the metal pipe 31 on the insulating pipe 32 side over the entire circumferential direction. Specifically, the contact portion 331 has a cylindrical shape, and its axial end surface contacts the tip surface of the cylindrical contacted portion 311 formed at the end portion of the metal pipe 31 over the entire circumferential direction. .. The outer diameter of the contact portion 331 is equal to or less than the outer diameter of the metal pipe 31, and is the same as the outer diameter of the metal pipe 31 here.
Further, the contact portion 331 is in electrical contact with the end face of the metal pipe 31 via a ring-shaped multi-faceted contactor 15 provided between the contact portion 331 and the contacted portion 311. However, it is not always necessary to provide both the contacted portion 311 and the ring-shaped multi-faceted contactor 15, and the contact portion 331 and the metal pipe 31 may be electrically contacted by either one of them.
Further, a sealing structure for vacuum and coolant CL is interposed between the contact portion 331 and the contacted portion 311. The seal structure of the present embodiment is realized by a seal member 16 such as an O-ring provided between the contact portion 331 and the contacted portion 311.

The extending portion 332 has a cylindrical shape, and a main flow path 33x is formed inside the extending portion 332. The extension portion 332 of the first electrode 33A (hereinafter referred to as "first extension portion 332A") and the extension portion 332 of the second electrode 33B (hereinafter referred to as "second extension portion 332B") are , They are arranged coaxially with each other, and as shown in FIG. 2, a double cylinder structure is formed in which the first extension portion 332A is arranged on the outside and the second extension portion 332B is arranged on the inside. ..

The first extending portion 332A is provided between the contact portion 331 of the first electrode 33A and the insulating pipe 32, and the base end portion thereof is joined to the contact portion 331 and the tip end thereof. The portion is fixed to the insulating pipe 32. More specifically, the axial end of the contact portion 331 on the insulating pipe 32 side has a notch 331a having a notch in the circumferential direction formed on the outer peripheral portion, and has a smaller outer diameter than the other portions. The base end portion of the first extending portion 332A is configured to fit into the notch portion 331a. Further, the axial end portion of the insulating pipe 32 on the first metal pipe 31A side has an outer peripheral cutout portion 32a formed by notching the outer peripheral portion in the circumferential direction, and the outer diameter is smaller than that of the other portions. The tip of the first extending portion 332A is configured to fit into the outer peripheral cutout portion 32a.
That is, the inner diameter of the first extending portion 332A is the same as or slightly larger than the outer diameter of the axial end portion of the contact portion 331 on the insulating pipe 32 side, and the shaft of the insulating pipe 32 on the first metal pipe 31A side. Same as or slightly larger than the outer diameter of the directional end. On the other hand, the outer diameter of the first extending portion 332A is designed to be equal to or less than the outer diameter of the metal pipe 31, and is the same as the outer diameter of the metal pipe 31 here.
The base end portion and the contact portion 331 of the first extension portion 332A are joined by, for example, welding M, and the tip portion and the insulating pipe 32 of the first extension portion 332A are fixed by, for example, brazing B or the like. However, the joining method and the fixing method are not limited to this.

As described above, the second extension portion 332B extends from the second metal pipe 31B side through the inside of the insulating pipe 32 to the first metal pipe 31A side, and is doubled together with the first extension portion 332A. It constitutes a tubular structure.
Therefore, the second extending portion 332B is provided between the contact portion 331 of the second electrode 33B and the insulating pipe 32 so that the outer diameter of the tip portion is smaller than the outer diameter of the base end portion. It has a reduced diameter element 333 configured in the above, and a straight pipe element 334 extending from the tip end portion of the reduced diameter element 333 to the first metal pipe 31A side through the inside of the insulating pipe 32. The diameter reduction element 333 and the straight pipe element 334 may be formed of a single member, or may be formed of different parts and joined by welding or the like.

The diameter reduction element 333 is configured such that at least the outer diameter is gradually reduced or gradually reduced from the base end portion to the tip end portion, and here, the outer diameter and the inner diameter are gradually reduced. The diameter reduction element 333 has a base end portion joined to the contact portion 331 and a tip end portion fixed to the insulating pipe 32. More specifically, as described above, the axial end portion of the contact portion 331 on the insulating pipe 32 side has a notch portion 331a having a notch in the circumferential direction formed on the outer peripheral portion and has an outer diameter larger than that of the other portions. It is made smaller, and is configured so that the base end portion of the diameter reduction element 333 fits into the notch portion 331a. Further, the axial end portion of the insulating pipe 32 on the second metal pipe 31B side has an inner peripheral notch portion 32b formed by notching the inner peripheral portion in the circumferential direction, and the inner diameter is smaller than that of the other portions. , The tip of the diameter reduction element 333 is fitted to the inner peripheral notch 32b.
That is, the inner diameter of the base end of the reduced diameter element 333 is the same as or slightly larger than the outer diameter of the axial end of the contact portion 331 on the insulating pipe 32 side, and the outer diameter of the tip of the reduced diameter element 333 is the insulating pipe. It is the same as or slightly smaller than the inner diameter of the axial end of 32 on the first metal pipe side. Further, the outer diameter of the base end portion of the reduced diameter element 333 is designed to be equal to or less than the outer diameter of the metal pipe 31, which is the same as the outer diameter of the metal pipe 31 here.
The base end portion and the contact portion 331 of the diameter reduction element 333 are joined by welding M or the like, and the tip portion and the insulating pipe 32 of the diameter reduction element 333 are fixed by brazing B or the like, but they are joined. The method and fixing method are not limited to this.

The straight pipe element 334 is provided in a state of extending from the tip end portion of the diameter reduction element 333 toward the first metal pipe 31A, passing through the inside of the insulating pipe 32, and being inserted into the inside of the first extending portion 332A. There is. As a result, a cylindrical space S along the flow path direction is formed between the straight pipe element 334 and the first extending portion 332A. Specifically, the straight pipe element 334 has an outer diameter smaller than the inner diameter of the insulating pipe 32 and the inner diameter of the first extending portion 332A, and is arranged coaxially with the first extending portion 332A. As a result, the distance between the inner peripheral surface of the first extending portion 332A and the outer peripheral surface of the straight pipe element 334 becomes constant along the circumferential direction. The inner diameter of the straight pipe element 334 is the same as the inner diameter of the tip of the reduced diameter element 333, but is not limited to this.

Further, the straight pipe element 334 is formed with a plurality of through holes 332h that penetrate the peripheral wall in the thickness direction. Specifically, these through holes 332h are formed along the flow direction of the coolant CL so as to face at least a part of the inner peripheral surface of the insulating pipe 32, and are formed between the straight pipe element 334 and the insulating pipe 32. The space communicates with the main flow path 33x of the second electrode 33B. These through holes 332h are provided at equal intervals in the circumferential direction and are provided along the axial direction from the base end of the straight pipe element 334 to the tip end of the first extending portion 332A. By providing such a through hole 332h, the flow path resistance of the coolant CL by the second electrode 33B is reduced, the coolant CL stays in the insulating pipe 32, and air bubbles are generated in the insulating pipe 32. It can be prevented from accumulating.

According to the electrodes 33A and 33B configured in this way, the tip surface of the contacted portion 311 of the metal pipe 31 is screwed into the female threaded portion 33a of the electrodes 33A and 33B by screwing the male threaded portion 31a of the metal pipe 31. Is in contact with the contact portion 331 of the electrodes 33A and 33B, and the space between them is sealed by the sealing member 16, and the electrodes 33A and 33B are arranged coaxially with each other, and the first electrode 33A is extended. The insertion dimension of the extension portion 332B of the second electrode 33B with respect to the protrusion 332A is defined.
In this way, the seal between the metal pipe 31 and the insulating pipe 32, the electrical contact between the metal pipe 31 and the electrodes 33A and 33B, and the arrangement of the electrodes 33A and 33B are such that the male threaded portion 31a and the female threaded portion 33a are arranged. Since it is performed at the same time as fastening, the assembly work becomes very simple.

In this configuration, when the coolant CL flows from the first metal pipe 31A, a part of the coolant CL flows from the main flow path 33x of the first electrode 33A to the main flow path 33x of the second electrode 33B. It is guided to the inside of the second metal pipe 31B, and the others branch from the main flow path 33x and flow into the space S between the first extension portion 332A and the second extension portion 332B. The coolant CL that has flowed into the space S joins the main flow path 33x of the second electrode 33B through the through hole 332h and is guided to the inside of the second metal pipe 31B. At this time, the cylindrical space S between the extending portion 332A of the first electrode 33A and the extending portion 332B of the second electrode 33B is filled with the coolant CL, and the coolant CL becomes a dielectric material. It functions and the capacitor 33 is configured.

<Effect of this embodiment>
According to the plasma processing apparatus 100 of the present embodiment configured in this way, since the capacitors 33 are electrically connected in series to the metal pipes 31 adjacent to each other via the insulating pipe 32, the combined reactance of the antenna 3 is determined. Simply put, the impedance of the antenna 3 can be reduced because the inductive reactance is subtracted from the capacitive reactance. As a result, even when the antenna 3 is lengthened, the increase in the impedance can be suppressed, the high-frequency current easily flows through the antenna 3, and the inductively coupled plasma P can be efficiently generated.

In particular, according to the present embodiment, since the space S between the first electrode 33A and the second electrode 33B is filled with the liquid dielectric (cooling liquid CL), the electrodes 33A and 33B constituting the capacitor 33 and the electrodes 33B and 33B It is possible to eliminate the gap generated between the dielectrics. As a result, it is possible to eliminate the arc discharge that may occur in the gap between the electrodes 33A and 33B and the dielectric, and to eliminate the damage to the capacitor 33 due to the arc discharge. Further, the distance between the extending portion 332A of the first electrode 33A and the extending portion 332B of the second electrode 33B, the facing area, and the relative permittivity of the liquid dielectric (coolant CL) are not taken into consideration. The capacitance value can be set accurately from the rate. Further, the structure for pressing the electrodes 33A and 33B and the dielectric for filling the gap can be eliminated, and the complicated structure around the antenna due to the pressing structure and the resulting deterioration of the uniformity of the plasma P can be prevented. be able to. In addition, the second electrode 33B is extended from the second metal pipe 31B side through the inside of the insulating pipe 32 to the first metal pipe 31A side so as to face the first electrode 33A. By changing the dimensions, the capacitance value required for the capacitor 33 can be easily obtained.

Since the coolant CL that cools the antenna 3 is a dielectric, it is not necessary to prepare a dielectric separately from the coolant CL, and the electrodes 33A and 33B can be cooled. Further, normally, the coolant CL is adjusted to a constant temperature by the temperature control mechanism 141, and by using this coolant CL as a dielectric material, the change in the relative permittivity due to the temperature change is suppressed and the change in the capacitance value is suppressed. It can be suppressed. Further, when water is used as the coolant CL, the relative permittivity of water is about 80 (20 ° C.), which is larger than that of the resin dielectric sheet. Therefore, a capacitor 33 capable of withstanding a high voltage is configured. Can be done. As described above, if the dielectric has a large relative permittivity, a sufficient capacitance value can be obtained even if the capacitor 33 has a double-cylinder structure including two extending portions 332A and 332B. Further, by manufacturing the electrodes 33A and 33B while making the verticality of the extending portion 332 with respect to the contact portion 331 of the electrodes 33A and 33B accurate, the capacitance value can be set accurately. In addition, impurities may be mixed due to electrolysis of water, but they can be removed by providing a filter such as an ion exchange membrane filter on the circulation flow path 14, and the capacitance value of the capacitor 33 changes. It can be suppressed.

Further, the distance between the inner peripheral surface of the first extending portion 332A and the outer peripheral surface of the second extending portion 332B (more specifically, the outer peripheral surface of the straight pipe element 334) is made constant along the circumferential direction. Therefore, the distribution of the high-frequency current flowing through the metal pipe 31 can be made uniform in the circumferential direction to generate plasma having good uniformity.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

For example, in the above embodiment, the second electrode 33B has a tubular shape, and the main flow path 33x is formed from the first metal pipe 31A side to the entire second metal pipe 31B side. As shown in FIG. 3, the second electrode 33B may have a main flow path 33x formed on the second metal pipe 31B side and a solid first metal pipe 31A side.
In this case, in order to reduce the flow path resistance of the coolant CL by the second electrode 33B, the second electrode 33B communicates with the through hole 332h and extends along the flow direction of the coolant CL. It is preferable that the groove 332 g is formed. Specifically, the groove 332g is a bottomed groove extending in the axial direction provided for each through hole 332h, and the opening thereof is formed so as to face the inner peripheral surface of the insulating pipe 32.
Further, as shown in FIG. 3, the tip corner portion 332c of the second extension portion 332B may be tapered (conical shape) in order to alleviate the electric field concentration at the tip corner portion 332c of the second electrode 33B. good.

Further, as described above, when a part of the second electrode 33B is solid, the flow path resistance of the coolant CL becomes larger than when the second electrode 33B is tubular. As a mode for reducing the flow path resistance, it is conceivable to make the second electrode 33B thinner, but then the distance between the inner peripheral surface of the first electrode 33A and the outer peripheral surface of the second electrode 33B becomes longer. , The capacitance value of the capacitor 33 becomes small, and there is a possibility that it cannot withstand a high voltage.
Therefore, in order to secure the capacitance value required for the capacitor 33 while reducing the flow path resistance of the coolant CL by the second electrode 33B, as shown in FIG. 4, the first electrode 33A is the second electrode 33A. It is preferable to have a throttle portion 335 formed at a position facing the electrode 33B of the above and having a small inner diameter.
In such a configuration, the second electrode 33B is thinned to reduce the flow path resistance of the coolant CL, and the throttle portion 335 is formed on the first electrode 33A. The distance between the outer peripheral surface of the first electrode 33A and the inner peripheral surface of the second electrode 33B can be shortened, and the capacitance value required for the capacitor 33 can be secured.

Further, in the above-described embodiment, the communication hole 332h is provided along the axial direction from the base end of the straight pipe element 334 to the tip end of the first extension portion 332A, but as shown in FIG. The through hole 332h may be provided along the axial direction beyond the tip of the first extending portion 332A, or, although not shown, does not extend to the base end of the straight pipe element 334, but in front of the through hole 332h. You may let it stay.

Further, in the above embodiment, the case where the first electrode 33A is a separate member from the metal pipe 31 has been described, but as shown in FIG. 6, the first electrode 33A is composed of a part of the metal pipe 31. It may be.
As a specific embodiment, the axial end of the first metal pipe 31A is extended toward the insulating pipe 32, and the second electrode 33B is passed through the inside of the insulating pipe 32 from the second metal pipe 31B side. A configuration extending inside the metal pipe 31A of the above can be mentioned. In this case, the axial end portion of the first metal pipe 32 is fixed to the insulating pipe 32, and the specific fixing method is the same as in the above embodiment, on the side of the first metal pipe 31A of the insulating pipe 32. An outer peripheral notch 32a having an outer peripheral portion cut out in the circumferential direction is formed at the axial end, and the axial end of the first metal pipe 31A is fitted into the outer peripheral notch 32a, for example, brazing B. For example, a method of fixing by means of.
With such a configuration, the portion of the first metal pipe 31A facing the second electrode can function as the first electrode 33A, and the same effect as that of the embodiment can be achieved while reducing the number of parts. Can be obtained.

In addition, in the above-described embodiment, the metal pipe 31 arranged on the upstream side in the flow direction of the coolant CL is the first metal pipe 31A, and the metal pipe 31 arranged on the downstream side in the flow direction of the coolant CL is the second metal pipe 31A. However, on the contrary, the metal pipe 31 arranged on the downstream side in the flow direction of the coolant CL was used as the first metal pipe 31A and was arranged on the upstream side in the flow direction of the coolant CL. The metal pipe 31 may be used as the second metal pipe 31B. In other words, in a state where each member is arranged as shown in FIG. 2, the flow direction of the coolant CL may be opposite to that of the embodiment. However, considering the ease with which air can escape when the coolant CL is started to flow, it is advantageous to flow the coolant CL in the direction of the embodiment.

Further, as shown in FIG. 7, in the plasma processing apparatus 100 having a plurality of antennas 3, both ends of each antenna 3 are extended to the outside of the vacuum container 2, and one of the antennas 3 is attached to the antennas 3 adjacent to each other. The end portion and the other end portion of the antenna 3 may be electrically connected by the connecting conductor 17. Here, the ends of the two antennas connected by the connecting conductor 17 are the ends located on the same side wall side. As a result, the plurality of antennas 3 are configured so that high-frequency currents in opposite directions flow through the antennas 4 adjacent to each other. By forming a plurality of antennas into a single antenna structure by the connecting conductor 17 in this way, it is possible to easily expand the size of the substrate to be processed.

The connecting conductor 17 has a flow path inside, and the cooling liquid is configured to flow through the flow path. Specifically, one end of the connecting conductor 17 communicates with the flow path of one antenna 3, and the other end of the connecting conductor 17 communicates with the flow path of the other antenna 3. As a result, the cooling liquid that has flowed through one of the antennas 3 in the antennas 3 adjacent to each other flows to the other antenna 3 through the flow path of the connecting conductor 17. As a result, both the antenna 3 and the connecting conductor 17 can be cooled by the common cooling liquid. Further, since the plurality of antennas 3 can be cooled by one flow path, the configuration of the circulation flow path 14 can be simplified.

Further, the connecting conductor 17 includes one conductor portion 17a connected to one antenna 3 in the antennas 3 adjacent to each other, the other conductor portion 17c connected to the other antenna 3, one conductor portion 17a and the other. It has a capacitor 17c which is a capacitive element electrically connected in series to the conductor portion 17b of the above. The configurations of the conductor portions 17a and 17b may be the same as those of the conductor element 31 of the embodiment, and the configuration of the capacitor 17c may be the same as that of the capacitor 33 of the embodiment, for example. By providing the capacitor 17c on the connecting conductor 17 in this way, the impedance of the connecting conductor 17 can be made equivalent to zero, and the increase in impedance due to the connecting conductor 17 can be eliminated. Further, the capacitor 17c may be used as a variable capacitor to adjust the capacitance.

The configuration of the connecting conductor 17 is not limited to FIG. 7, and for example, as shown in FIG. 8, the connecting conductor 17 may have no capacitive element. In the case of this configuration, in the antennas 3 adjacent to each other, the inductance of the feeding side end 3a of one antenna 3 and the ground side end 3b of the other antenna 3 and the connecting conductor 17 are combined with the other conductor element 31. The same inductive reactance and capacitive reactance are continuously repeated over the entire plurality of antennas 3 in the same manner as the inductance of the above. As a result, it is possible to eliminate the apparent increase in impedance due to the connecting conductors of the plurality of antennas 3 as a whole. As a result, uniform plasma P can be generated along the antenna 3 in the length direction and the arrangement direction.

Further, as shown in FIG. 9, in the antenna 3, a convex portion 3T protruding toward the insulating cover 10 is provided on the outer peripheral surface of the metal pipe 32 or the electrode located on at least one of both sides of the insulating pipe 32 in the axial direction. You may. Note that FIG. 10 shows a state in which the antenna 3 is in a bent state, and a state in which the lower portion of the convex portion 3T is in contact with the inner surface of the insulating cover 10.

The capacitor 33 shown in FIG. 9 has a first electrode 33A electrically connected to the first metal pipe 31A on one side of the insulating pipe 32 and a second metal pipe 31B on the other side of the insulating pipe 32. It is provided with a second electrode 33B which is electrically connected to the first electrode 33A and is arranged so as to face the first electrode 33A, and the space between the first electrode 33A and the second electrode 33B is cooled. The CL is configured to meet. That is, the coolant CL flowing in the space between the first electrode 33A and the second electrode 33B becomes a dielectric of the liquid constituting the capacitor 33. Each of the electrodes 33A and 33B has a substantially rotating body shape, and a flow path 33x is formed in the central portion along the central axis thereof. 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 a cylindrical extension extending from the flange portion 331 to the insulating pipe 32 side, for example. It has a protrusion 332 and a protrusion 332. The flange portion 331 is sandwiched between the metal pipe 31 and the insulating pipe 32. Further, a through hole 331h through which cooling water flows is also formed in the flange portion.

It is desirable that the convex portions 3T provided on the antenna 3 are provided adjacent to both sides of the insulating pipe 32 in the axial direction. The convex portions 3T are continuously or intermittently provided over the entire circumferential direction of the members (metal pipes 31A and 31B in FIG. 9) located on both sides of the insulating pipe 32 in the axial direction. Considering the bending due to the weight of the antenna 3, it may be formed only on the lower portions of the metal pipes 31A and 31B. Here, the protruding dimension of the convex portion from the outer peripheral surface of the metal pipe is such that the insulating pipe 32 does not come into contact with the insulating cover 10 due to the bending of the antenna 3. The cross-sectional shape of the convex portion 3T may be rectangular as shown in FIG. 9, at least the tip may be arcuate, or at least the tip may be triangular. good.

When a plurality of insulating pipes 32 are provided in the antenna 3, it is desirable that these convex portions 3T are provided adjacent to both sides of each insulating pipe 32 in the axial direction. Further, each insulating pipe 32 may be provided adjacent to one side in the axial direction. With this configuration, when the amount of deflection of the antenna 3 becomes large, the plurality of convex portions 3T arranged in the axial direction come into contact with the insulating cover 10, and the load applied to the insulating cover 10 is dispersed. Can be done.

The position where the convex portion 3T is provided with respect to the insulating pipe 32 is not limited to the position adjacent to the insulating cover 32, and may be a position where the insulating pipe 32 does not come into contact with the insulating cover 10 due to the bending of the antenna 3. Further, in addition to the configuration in which the convex portion 3T is integrally formed with the metal pipes 31A and 31B, as shown in FIG. 11, a concave portion 3M is formed on the outer peripheral surface of the metal pipes 31A and 31B to form the concave portion 3M. It may be configured by fitting the ring-shaped member 3R which becomes the convex portion 3T.

By providing the convex portion 3T on the antenna 3 in this way, even if the antenna 3 is bent, the convex portion 3T comes into contact with the insulating cover 10 so that the insulating pipe 32 does not come into contact with the insulating cover 10. .. This makes it possible to prevent thermal damage to the insulating pipe 32 made of resin or the like. Further, by preventing the insulating pipe 32 and the insulating cover 10 from coming into contact with each other, it is possible to prevent the temperature of the coolant serving as the dielectric of the capacitor 33 from rising due to the contact of the insulating pipe 32 with the insulating cover 10. As a result, the change in the dielectric constant of the coolant can be suppressed.

The convex portion 3T can also be provided in the antenna 3 illustrated in the above embodiment. In this case, the members located on at least one of both sides of the insulating pipe 32 in the axial direction of the embodiment (for example, the first metal pipe 31A, the first electrode 33A, the second metal pipe 31B, the second electrode 33B). A convex portion 3T is provided on the contact portion 331 or the diameter reduction element 333) of the above.

Moreover, in the above-described embodiment, the antenna has a linear shape, 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.

In addition, the conductor element and the insulating element were tubular with one internal flow path, but may have two or more internal flow paths or a branched internal flow path. good. Further, the conductor element and / or the insulating element may be solid.

In the electrode of the above embodiment, the extending portion has a cylindrical shape, but may have another square tubular shape, a flat plate shape, or a curved or bent plate shape.

In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ・ ・ ・ Plasma processing device W ・ ・ ・ Substrate P ・ ・ ・ Inductively coupled plasma 2 ・ ・ ・ Vacuum container 3 ・ ・ ・ Antenna 31 ・ ・ ・ Metal pipe (conductor element)
32 ... Insulation pipe (insulation element)
33 ・ ・ ・ Capacitor 33A ・ ・ ・ First electrode 33B ・ ・ ・ Second electrode 331 ・ ・ ・ Contact part 332 ・ ・ ・ Extension part CL ・ ・ ・ Coolant (liquid dielectric)
4 ・ ・ ・ High frequency power supply

Claims (15)

It is an antenna for generating plasma by passing a high frequency current.
At least two conductor elements, an insulating element provided between the first conductor element and the second conductor element adjacent to each other to insulate them, the first conductor element, the second conductor element, and electricity. Equipped with capacitive elements connected in series
The capacitive element is
An electrode composed of a part of the first conductor element or an electrode electrically connected to the first conductor element, the first electrode arranged on the first conductor element side of the insulating element. When,
It is electrically connected to the second conductor element, extends from the second conductor element side through the inside of the insulating element to the first conductor element side, and faces the first electrode. With the placed second electrode,
It consists of a dielectric that fills the space between the first electrode and the second electrode.
An antenna in which the dielectric is a liquid. The first electrode has a tubular shape and has a tubular shape.
The antenna according to claim 1, wherein the second electrode has an extending portion inserted into the internal space of the first electrode. The antenna according to claim 2, wherein the distance between the inner peripheral surface of the first electrode and the outer peripheral surface of the extending portion is constant along the circumferential direction. Each of the conductor elements is tubular and has a tubular shape.
The cooling liquid flowing inside the first conductor element flows between the first electrode and the second electrode and functions as the dielectric, and the 1 or 1 formed on the second electrode The antenna according to any one of claims 1 to 3, which is configured to be guided into the second electrode from a plurality of through holes and flow out into the inside of the second conductor element. The antenna according to claim 4, wherein the second electrode communicates with the through hole and has one or a plurality of grooves extending along the flow direction of the coolant. A vacuum container that is evacuated and introduced with gas,
The antenna according to any one of claims 1 to 5, which is arranged inside the vacuum container or outside the vacuum container.
It is equipped with a high-frequency power supply that allows a high-frequency current to flow through the antenna.
A plasma processing apparatus configured to process a substrate using the plasma generated by the antenna. Equipped with multiple antennas
Both ends of the antenna extend out of the vacuum vessel.
In the antennas adjacent to each other, the end of one of the antennas and the end of the other antenna are electrically connected by a connecting conductor so that high-frequency currents in opposite directions flow through the antennas adjacent to each other. The plasma processing apparatus according to claim 6, which is configured. The plasma processing apparatus according to claim 7, wherein the connecting conductor has a flow path inside, and a coolant flows through the flow path. The coolant flows inside the conductor element and the insulating element.
The plasma processing apparatus according to claim 8, wherein in the antennas adjacent to each other, the cooling liquid flowing through one of the antennas flows to the other antenna through the flow path of the connecting conductor. The connecting conductors include one conductor portion connected to one of the antennas in the antennas adjacent to each other, the other conductor portion connected to the other antenna, the one conductor portion and the other conductor portion. The plasma processing apparatus according to any one of claims 7 to 9, further comprising a capacitive element electrically connected in series to the above. Further provided with an insulating cover covering the antenna
The invention according to any one of claims 6 to 10, wherein a convex portion projecting toward the insulating cover is formed on the outer peripheral surface of at least one of the first conductor element or the second conductor element. Plasma processing equipment. The plasma processing apparatus according to claim 11, wherein the convex portion is continuously or intermittently formed over the entire circumferential direction of the outer peripheral surface. The plasma processing apparatus according to claim 11 or 12, wherein the convex portion is formed at a position adjacent to the insulating element on the outer peripheral surface of the first conductor element and the second conductor element. The antenna according to any one of claims 1 to 5.
It is provided with an insulating cover that covers the antenna.
An antenna structure in which a convex portion projecting toward the insulating cover is formed on the outer peripheral surface of at least one of the first conductor element or the second conductor element. An antenna for generating plasma by passing a high-frequency current,
It is provided with an insulating cover that covers the antenna.
The antenna includes at least two conductor elements, an insulating element provided between the first conductor element and the second conductor element adjacent to each other and insulating them, and the first conductor element and the second conductor element. It is equipped with a conductor element and a capacitive element electrically connected in series.
The capacitive element is electrically connected to a first electrode electrically connected to one of the conductor elements adjacent to each other and to the other of the conductor elements adjacent to each other, and faces the first electrode. The dielectric is a liquid, and is composed of a second electrode arranged therein and a dielectric that fills the space between the first electrode and the second electrode.
An antenna structure in which a convex portion projecting toward the insulating cover is formed on the outer peripheral surface of at least one of the first conductor element or the second conductor element.

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