JP7022313B2 - Capacitive elements and plasma processing equipment - Google Patents

Description

The present invention relates to a capacitive element and a plasma processing apparatus including the capacitive element.

As shown in Patent Document 1, the capacitance element includes a pair of electrodes facing each other and a dielectric provided between these electrodes so as to be able to enter and exit, and the capacitance is increased by allowing the dielectric to enter and exit. There is a so-called variable capacitor that is variably configured.

In such a variable capacitor, if there is no gap between the pair of electrodes and the dielectric, there is a problem that the electrodes and the dielectric are damaged by moving the dielectric in and out between the pair of electrodes. Occurs.

On the other hand, when a gap is provided between the electrode and the dielectric, the relative permittivity of air is low (about 1.0), so that there arises a problem that the capacitance is significantly reduced.

Japanese Unexamined Patent Publication No. 8-69945

Therefore, the present invention has been made to solve the above-mentioned problems, and does not damage the pair of electrodes or the dielectric provided so as to be able to enter and exit between these electrodes, and further reduces the capacitance significantly. The main task is to make the capacitance variable while preventing it.

That is, the capacitive element according to the present invention includes a pair of fixed electrodes provided so as to face each other, a solid dielectric provided so as to be accessible between the pair of fixed electrodes, the pair of fixed electrodes, and the solid dielectric. It is characterized by comprising a storage container for accommodating a body and a liquid dielectric material introduced into the storage container and interposed between the pair of fixed electrodes.

In a capacitive element configured in this way, a liquid dielectric is interposed between a pair of fixed electrodes, so if a gap is provided between the fixed electrode and the solid dielectric, this gap will be filled with the liquid dielectric. Can be filled with the body. As a result, the solid dielectric can be moved in and out between the pair of fixed electrodes without damaging the fixed electrode or the solid dielectric, and the capacitance can be prevented from being significantly reduced.

It is preferable that the storage container has an introduction port for introducing the liquid dielectric and a take-out port for drawing out the liquid dielectric.
With such a configuration, the liquid dielectric flows inside the storage container, so that the liquid dielectric in the storage container is replaced. This makes it possible to suppress unexpected fluctuations in capacitance due to changes in the relative permittivity due to an increase in the temperature of the liquid dielectric.

One of the pair of fixed electrodes has a first flange member provided in the introduction port and a plurality of first fixed metal plates supported by the first flange member, and the pair of fixed electrodes is fixed. The other of the electrodes is a second flange member provided on the lead-out port and a plurality of second fixed metal plates supported by the second flange member so as to be located between the first fixed metal plates. It is preferable that the first flange member and the second flange member are formed with openings through which the liquid dielectric can flow.
In such a configuration, since the first fixed metal plate and the second fixed metal plate are inserted into the storage container via the introduction port and the outlet port, it is possible to insert these fixed metal plates. It is not necessary to form another port in the storage container, which facilitates manufacturing.

As a specific embodiment, the solid dielectric is supported by a rotary shaft body rotatably supported by the side wall of the storage container around a rotary shaft, and is supported by the rotary shaft body and rotates around the rotary shaft. , A configuration having a plurality of dielectric plates that move in and out between the first fixed metal plate and the second fixed metal plate.
With such a configuration, the space between the container and the rotating shaft can be sealed by a shaft seal, for example, the dielectric plate is moved in translation between the first fixed metal plate and the second fixed metal plate. Good sealing performance compared to.

In a state where the plurality of dielectric plates are extracted from between the first fixed metal plate and the second fixed metal plate, the plurality of dielectric plates can be attached to any of the first fixed metal plate and the second fixed metal plate. It is preferable not to face each other.
With such a configuration, the dielectric plate can be inserted and removed from the storage container without removing the first fixed metal plate and the second fixed metal plate from the storage container, and it is easy to assemble and maintain. Is good.

It is preferable that the liquid dielectric is water. In this case, electrical insulation can be ensured by using water having high resistance as the liquid dielectric.

It is preferable that the relative permittivity of the solid dielectric is smaller than the relative permittivity of water. In this case, when water is used as the liquid dielectric constant, the capacitance can be reduced in proportion to the facing area between the solid dielectric constant and the solid metal plate.

Further, a pair of fixed electrodes provided so as to face each other, a solid dielectric provided between the pair of fixed electrodes, a storage container for accommodating the pair of fixed electrodes and the solid dielectric, and the storage container. A capacitive element which is introduced into a container and includes a liquid dielectric interposed between the pair of fixed electrodes, and is configured so that the capacity of the liquid dielectric in the accommodating container can be changed. Is also one of the present inventions.
According to the capacitive element configured in this way, the capacitance can be changed by changing the capacitance of the liquid dielectric, so that it is possible to prevent the pair of fixed electrodes and the solid dielectric from being damaged. Moreover, since the liquid dielectric is interposed between the pair of fixed electrodes, it is possible to suppress a significant decrease in capacitance as compared with the case where the space between them is filled with air.

Further, the plasma processing apparatus according to the present invention includes the above-mentioned capacitive element, an antenna conductor electrically connected to the capacitive element, and an antenna conductor for causing a high-frequency current to flow to generate plasma. The liquid dielectric is a coolant for the antenna conductor.
With the plasma processing device configured in this way, the antenna conductor, which tends to become hot due to the heat generated during plasma generation, can be cooled by using a liquid dielectric, so that the antenna itself is damaged or the antenna conductor is damaged. It is possible to prevent damage to the peripheral structure and to stably generate plasma.

According to the present invention configured as described above, the capacitance is not damaged without damaging the pair of fixed electrodes or the dielectric provided between these electrodes so as to be able to enter and exit, and the capacitance is prevented from being significantly reduced. Can be made variable.

It is a vertical sectional view schematically showing the structure of the plasma processing apparatus of this embodiment. It is sectional drawing which shows typically the structure of the plasma processing apparatus of the same embodiment. It is sectional drawing which shows typically the variable capacitor of the same embodiment. It is a vertical sectional view schematically showing the variable capacitor of the same embodiment. It is a side view which looked at the variable capacitor of the same embodiment from the introduction port side. It is a schematic diagram which shows the state which the fixed metal plate and the movable dielectric of the same embodiment do not face each other. It is a schematic diagram which shows the structure of the 1st fixed electrode and the 2nd fixed electrode of the same embodiment. It is a schematic diagram which shows the state which the fixed metal plate and the movable metal plate of the same embodiment face each other.

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, or the like. The processing applied to the substrate W is, for example, film formation, etching, ashing, sputtering, or the like by a 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 FIGS. 1 and 2, the plasma processing apparatus 100 includes a vacuum vessel 2 that is evacuated and introduced with gas G, a linear antenna conductor 3 arranged in the vacuum vessel 2, and a linear antenna conductor 3. A high-frequency power source 4 for applying a high frequency for generating an induction-coupled plasma P to the antenna conductor 3 is provided in the vacuum vessel 2. By applying a high frequency from the high frequency power supply 4 to the antenna conductor 3, a high frequency current IR flows through the antenna conductor 3, an induced electric field is generated in the vacuum vessel 2, and an induced coupling type 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 5. The vacuum vessel 2 is electrically grounded in this example.

Gas G is introduced into the vacuum vessel 2 via, for example, a flow rate regulator (not shown) and a plurality of gas inlets 21 arranged in a direction along the antenna conductor 3. The gas G may be set according to the processing content applied to the substrate W.

Further, a substrate holder 6 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 6 from the bias power supply 7. 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 positive ions 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 61 for heating the substrate W may be provided in the substrate holder 6.

A plurality of antenna conductors 3 are 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 vicinity of both ends of the antenna conductor 3 penetrates the opposite side walls of the vacuum vessel 2, respectively. Insulating members 8 are provided at portions of the antenna conductor 3 that penetrate both ends of the antenna conductor 3 to the outside of the vacuum vessel 2. Both ends of the antenna conductor 3 penetrate each of the insulating members 8, and the penetrating portions are vacuum-sealed by, for example, packing 91. The space between each insulating member 8 and the vacuum container 2 is also vacuum-sealed by, for example, packing 92. The material of the insulating member 8 is, for example, ceramics such as alumina, quartz, engineering plastics such as polyphenylene sulfide (PPS) and polyetheretherketone (PEEK), and the like.

Further, in the antenna conductor 3, a portion 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 8. The material of the insulating cover 10 is, for example, quartz, alumina, fluororesin, silicon nitride, silicon carbide, silicon, or the like.

The plurality of antenna conductors 3 have a hollow structure having a flow path 3s through which the coolant CL flows. In the present embodiment, it is a metal pipe 31 having a straight tubular shape. The material of the metal pipe 31 is, for example, copper, aluminum, alloys thereof, stainless steel, or the like.

The coolant CL circulates through the antenna conductor 3 through a circulation flow path 11 provided outside the vacuum vessel 2, and the circulation flow path 11 is used to adjust the coolant CL to a constant temperature. A temperature control mechanism 111 such as a heat exchanger and a circulation mechanism 112 such as a pump for circulating the coolant CL in the circulation flow path 11 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 to it is preferable. In addition, a liquid refrigerant other than water, such as a fluorine-based inert liquid, may be used.

Further, as shown in FIG. 2, the plurality of antenna conductors 3 are connected by the connecting conductor 12 to form one antenna structure. That is, the ends of the antenna conductors 3 adjacent to each other extending to the outside of the vacuum vessel 2 are electrically connected by the connecting conductor 12. Specifically, in the antenna conductors 3 adjacent to each other, the end portion of one antenna conductor 3 and the end portion of the other antenna conductor 3 are electrically connected by the connecting conductor 12.

Here, the ends of the two antenna conductors 3 connected by the connecting conductor 12 are the ends located on the same side wall side. As a result, the plurality of antenna conductors 3 are configured so that high-frequency currents in opposite directions flow through the antenna conductors 3 adjacent to each other.

The connecting conductor 12 has a flow path inside, and the cooling liquid CL is configured to flow through the flow path. Specifically, one end of the connecting conductor 12 communicates with the flow path of one antenna conductor 3, and the other end of the connecting conductor 12 communicates with the flow path of the other antenna conductor 3. As a result, the coolant CL that has flowed through one of the antenna conductors 3 in the antenna conductors 3 adjacent to each other flows to the other antenna conductor 3 through the flow path of the connecting conductor 12. As a result, the plurality of antenna conductors 3 can be cooled by the common coolant CL. Further, since the plurality of antenna conductors 3 can be cooled by one flow path, the configuration of the circulation flow path 11 can be simplified.

One end of the plurality of antenna conductors 3 that is not connected by the connecting conductor 12 becomes the feeding end portion 3a, and the high frequency power supply 4 is connected to the feeding end portion 3a via the matching circuit 41. Further, the end portion 3b, which is the other end portion, 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 conductor 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.

<Structure of connecting conductor 12>
Next, the connecting conductor 12 will be described in detail with reference to FIGS. 3 to 7. In addition, in FIGS. 3 and 4, some sealing members and the like are omitted.

As shown in FIGS. 3 and 4, the connecting conductor 12 connects a variable capacitor 13 which is a capacitive element electrically connected to the antenna conductor 3 and the variable capacitor 13 and an end portion of one of the antenna conductors 3. It has a first connecting portion 14 and a second connecting portion 15 that connects the variable capacitor 13 and the end of the other antenna conductor 3.

The first connecting portion 14 and the second connecting portion 15 electrically contact the antenna conductor 3 by surrounding the end portion of the antenna conductor 3, and the opening portion 3H formed at the end portion of the antenna conductor 3 The coolant CL is led to the variable capacitor 13. The materials of the connecting portions 14 and 15 are, for example, copper, aluminum, alloys thereof, stainless steel and the like.

Each of the connecting portions 14 and 15 of the present embodiment is liquid-tightly mounted at the end of the antenna conductor 3 on the vacuum vessel 2 side of the opening 3H via a sealing member S1 such as an O-ring. The outside of the opening 3H is not constrained (see FIG. 3). As a result, the antenna conductor 3 is configured to allow a slight inclination with respect to the connecting portions 14 and 15.

The variable capacitor 13 is a capacitor between the first fixed electrode 16 electrically connected to one antenna conductor 3 and the first fixed electrode 16 electrically connected to the other antenna conductor 3. It has a second fixed electrode 17 forming the above, and a solid dielectric 18 provided so as to be accessible between the first fixed electrode 16 and the second fixed electrode 17.

The variable capacitor 13 of the present embodiment is configured so that the capacitance of the solid dielectric 18 can be changed by rotating it around a predetermined rotation axis C. The variable capacitor 13 includes an insulating container 19 for accommodating the first fixed electrode 16, the second fixed electrode 17, and the solid dielectric 18.

The storage container 19 has an introduction port P1 for introducing the coolant CL from one antenna conductor 3 and a take-out port P2 for leading the coolant CL to the other antenna conductor 3. The introduction port P1 is formed on one side wall of the storage container 19 (left side wall 19a in FIG. 3), and the outlet port P2 is formed on the other side wall of the storage container 19 (right side wall 19b in FIG. 3). The port P1 and the out-licensing port P2 are provided at positions facing each other. The storage container 19 of the present embodiment has a substantially rectangular parallelepiped shape having a hollow portion inside, but may have other shapes.

The first fixed electrode 16 and the second fixed electrode 17 are provided at different positions along the rotation axis C of the solid dielectric 18. In the present embodiment, the first fixed electrode 16 is provided by being inserted into the inside of the storage container 19 from the introduction port P1 of the storage container 19. Further, the second fixed electrode 17 is provided by being inserted into the storage container 19 from the lead-out port P2 of the storage container 19.

The first fixed electrode 16 has a plurality of first fixed metal plates 161 provided so as to face each other. Further, the second fixed electrode 17 has a plurality of second fixed metal plates 171 provided so as to be located between the first fixed metal plates 161. These fixed metal plates 161 and 171 are provided at substantially equal intervals along the rotation axis C, respectively, and the first fixed metal plate 161 is located in the middle of the second fixed metal plates 171 adjacent to each other. , The second fixed metal plate 171 is located in the middle of the first fixed metal plate 161 adjacent to each other. The gap between the first fixed metal plate 161 and the second fixed metal plate 171 is, for example, 1.5 mm to 3.0 mm.

The plurality of first fixed metal plates 161 have the same shape as each other, and are supported by the first flange member 162. The first flange member 162 is fixed to the left side wall 19a on which the introduction port P1 of the storage container 19 is formed, and here, a through hole 162H communicating with the introduction port P1 is formed. Further, the plurality of second fixed metal plates 171 have the same shape as each other, and are supported by the second flange member 172. The second flange member 172 is fixed to the right side wall 19b where the outlet port P2 of the storage container 19 is formed, and here, a through hole 172H communicating with the outlet port P2 is formed.

As shown in FIGS. 6 and 7, the first fixed metal plate 161 and the second fixed metal plate 171 have a flat plate shape, and have facing regions Z facing each other in a plan view. Note that FIG. 7 shows a state in which the first fixed electrode 16 and the second fixed electrode 17 are removed from the storage container 19 for convenience of explanation.

The facing region Z is set on the tip side of each of the fixed metal plates 161 and 171. By overlapping the facing regions Z of the fixed metal plates 161 and 171 in a plan view, the space between the facing regions Z is used as a capacitor. It is formed. The facing region Z here has, for example, a partial annular shape centered on the rotation axis C, and is a semicircular ring shape here, but may have a rectangular shape or various other shapes.

As shown in FIG. 3, the solid dielectric 18 has a rotary shaft body 181 rotatably supported around the rotary shaft C on the side wall of the storage container 19 (front side wall 19c in FIG. 3), and the rotary shaft body 181. It has a movable dielectric plate 182 that is supported by and moves in and out between the first fixed electrode 16 and the second fixed electrode 17.

The rotation axis 181 has a linear shape extending along the rotation axis C. The rotary shaft body 181 is configured such that one end thereof extends outward from the front side wall 19c of the storage container 19. Then, the front side wall 19c of the storage container 19 is rotatably supported by a sealing member S2 such as an O-ring. Here, the front side wall 19c is supported at two points by two O-rings. Further, the other end of the rotary shaft body 181 is rotatably in contact with the positioning recess 191 provided on the inner surface of the storage container 19.

Further, in the rotary shaft body 181, the portion 181x that supports the movable dielectric plate 182 is formed of a conductive material such as metal, and the portion 181y extending outward from the storage container 19 is formed of an insulating material such as resin. ing.

The movable dielectric plate 182 has a flat plate shape interposed between the first fixed metal plate 161 and the second fixed metal plate 171 and is arranged at substantially equal intervals along the rotation axis C. .. Here, the movable dielectric plate 182 and the first fixed metal plate 161 are separated from each other, and the movable dielectric plate 182 and the second fixed metal plate 171 are separated from each other. Specifically, the first A movable dielectric plate 182 is arranged between the fixed metal plate 161 and the second fixed metal plate 171. In FIG. 3, the number of the first fixed metal plate 161 is three, the number of the second fixed metal plate 171 is three, and the number of the movable dielectric plate 182 is five, but the present invention is not limited to this. The thickness dimension of the movable dielectric plate 182 is, for example, 1 mm.

These movable dielectric plates 182 are orthogonal to the rotation axis C and are provided in parallel with the first fixed metal plate 161 and the second fixed metal plate 171 and have the same shape as each other. Specifically, as shown in FIG. 6, the movable dielectric plate 182 has a shape including at least the facing region Z of the first fixed metal plate 161 and the second fixed metal plate 171. Here, in a plan view, the movable dielectric plate 182 is partially formed. It is an annular, more specifically a semicircular. The outer diameter of the movable dielectric plate 182 is substantially the same as the outer diameter of the facing region Z, but the outer diameter may be larger or smaller than the facing region Z. Further, the shape of the movable dielectric plate 182 is not limited to a partial annular shape such as a semicircular ring shape, but may be a rectangular shape or various other shapes.

By rotating the solid dielectric 18 in the variable capacitor 13 configured in this way, as shown in FIG. 8, it faces the first fixed metal plate 161 and the second fixed metal plate 171 in the movable dielectric plate 182. The facing area A, that is, the facing area A of the portion of the movable dielectric plate 182 that is interposed between the first fixed metal plate 161 and the second fixed metal plate 171 changes. In the present embodiment, the tip sides 161a and 171a of the fixed metal plates 161 and 171 on the rotation axis C side are arcuate, and by rotating the solid dielectric 18, the facing area A is the rotation angle of the solid dielectric 18. It changes in proportion to θ.

Further, the movable dielectric plate 182 has an intervening position in which the entire movable dielectric plate 182 is interposed between the first fixed metal plate 161 and the second fixed metal plate 171 and the movable dielectric plate 182 is the first fixed metal plate 161 and the first fixed metal plate 161. It rotates and moves to and from a non-intervening position that does not face any of the second fixed metal plates 171. When the movable dielectric plate 182 is in the non-intervening position, as shown in FIG. 6, in a plan view, the end sides 182a facing the fixed metal plates 161 and 171 of the movable dielectric plate 182 and the fixed metal plate 161 , 171 is provided with a gap X between the end sides 161b and 171b facing the movable dielectric plate 182. This makes the solid dielectric 18 removable in the axial direction. In the present embodiment, the solid dielectric 18 is removed by removing the front side wall 19c supporting the solid dielectric 18 along the axial direction.

In the above configuration, when the coolant CL flows in from the introduction port P1 of the storage container 19, the inside of the storage container 19 is filled with the coolant CL. As a result, the space between the first fixed metal plate 161 and the second fixed metal plate 171 is filled with the coolant CL, and the coolant CL becomes the dielectric of the variable capacitor 13. That is, the variable capacitor 13 of the present embodiment includes two types of dielectrics, a liquid dielectric and the above-mentioned solid dielectric 18. More specifically, the coolant CL, which is a liquid dielectric, is water here and has a relative permittivity of about 80 at 20 ° C. On the other hand, the solid dielectric 18 has a smaller relative permittivity than the liquid dielectric, that is, has a smaller relative permittivity than water. More specifically, the solid dielectric 18 has a relative permittivity of 10 or less, such as quartz having a relative permittivity of 3.8 and alumina having a relative permittivity of 8.5. As described above, since the relative permittivity of the solid dielectric 18 is smaller than the relative permittivity of the liquid dielectric, the movable dielectric plate 182 is rotationally moved from the non-intervening position to the intervening position according to the rotation angle θ. And the capacitance is reduced.

Here, in the present embodiment, the facing directions of the fixed metal plates 161 and 171 and the movable dielectric plate 182 are configured to be orthogonal to the facing directions of the introduction port P1 and the extraction port P2. That is, the fixed metal plates 161 and 171 and the movable dielectric plate 182 are provided along the opposite directions of the introduction port P1 and the take-out port P2. With this configuration, the coolant CL easily flows inside the storage container 19. As a result, the coolant CL in the storage container 19 can be easily replaced, and the variable capacitor 13 can be efficiently cooled. Further, the coolant CL flowing in from the introduction port P1 easily flows in between the fixed metal plates 161 and 171 and the movable dielectric plate 182, and easily flows out between the fixed metal plates 161 and 171 and the movable dielectric plate 182. As a result, the replacement of the coolant between the fixed metal plates 161 and 171 and the movable dielectric plate 182 becomes easy, and the temperature change of the coolant CL, which is the liquid dielectric, is suppressed. This makes it easier to keep the capacitance of the variable capacitor 13 constant. Further, air bubbles are less likely to stay between the fixed metal plates 161 and 171 and the movable dielectric plate 182.

<Effect of this embodiment>
According to the plasma processing apparatus 100 of the present embodiment configured as described above, between the first fixed metal plate 161 and the movable dielectric plate 182, and between the second fixed metal plate 171 and the movable dielectric plate 182. Since the coolant CL, which is a liquid dielectric, is interposed between them, the movable dielectric plate 182 can be rotated without damaging the fixed metal plates 161 and 171 and the movable dielectric plate 182.
Moreover, the capacitance is higher than, for example, when air is present between the first fixed metal plate 161 and the movable dielectric plate 182 or between the second fixed metal plate 171 and the movable dielectric plate 182. Can be prevented from dropping significantly.

Further, since the solid dielectric 18 is configured so that the movable dielectric plate 182 moves in and out between the first fixed metal plate 161 and the second fixed metal plate 171 by rotating the rotating shaft body 181. For example, the sealing property is better than the configuration in which the movable dielectric plate 182 is translated and moved between the first fixed metal plate 161 and the second fixed metal plate 171.

Further, since the movable dielectric plate 182 does not face any of the first fixed metal plate 161 and the second fixed metal plate 171 in the state where the movable dielectric plate 182 is in the non-intervening position, the first fixed metal The solid dielectric 18 can be inserted and removed from the storage container 19 without removing the plate 161 and the second fixed metal plate 171 from the storage container 19, and the assembleability and maintainability are good.

In addition, since the solid dielectric 18 has a smaller relative permittivity than the liquid dielectric CL, the capacitance of the variable capacitor is roughly determined by the coolant CL, and the capacitance is determined. Can be finely adjusted by rotating the solid dielectric 18.

Moreover, since the antenna conductor 3 can be cooled by the coolant CL, the plasma P can be stably generated. Further, since the dielectric of the variable capacitor 13 is composed of the coolant CL flowing through the antenna conductor 3, it is possible to suppress unexpected fluctuations in the capacitance while cooling the variable capacitor 13.

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

For example, as the liquid dielectric, water as the coolant CL was used in the above embodiment, but various liquids such as oil and ion exchange liquid may be used as the liquid dielectric, not limited to water. In the above embodiment, it was stated that the relative permittivity of water is about 80 at 20 ° C., but when a liquid dielectric whose relative permittivity changes depending on the temperature such as water is used, the operating temperature is Not limited to 20 ° C., various temperatures may be selected. As the solid dielectric, one having a small relative permittivity at the operating temperature of the liquid dielectric can be used. Further, even when a liquid dielectric whose relative permittivity changes with frequency is used, the frequency used is not particularly limited.
Further, as the solid dielectric 18, although a dielectric permit smaller than the relative permittivity of the liquid dielectric is used in the above embodiment, a dielectric permit larger than the relative permittivity of the liquid dielectric 18 may be used. In this case, by rotationally moving the movable dielectric plate 182 from the non-intervening position to the intervening position, the capacitance increases according to the rotation angle θ.

In the above embodiment, the movable dielectric plate 182 rotates around the rotation axis C, but the movable dielectric plate 182 may slide and move (translate) in one direction. Here, as a configuration in which the movable dielectric plate 182 slides and moves, even if the movable dielectric plate 182 slides in a direction orthogonal to the fixed metal plates 161 and 171 and the facing area changes. Alternatively, the movable dielectric plate 182 may slide and move along the facing direction with the fixed metal plates 161 and 171 to change the facing distance.

Further, in the above embodiment, the variable capacitor 13 is configured so that the capacitance is changed by rotating the solid dielectric 18, but the variable capacitor 13 accommodates the solid dielectric 18 without moving it. The capacitance may be changed by increasing or decreasing the capacity of the liquid dielectric in the container 19.
In this case, it is preferable to store a liquid different from the cooling liquid circulating in the circulation flow path 11 as a liquid dielectric in the storage container 19, and the capacity of the liquid dielectric may be adjusted automatically or manually.

Further, in the above embodiment, the variable capacitor 13 is provided between the antenna conductors 3 adjacent to each other, but it may be provided between the antenna conductor 3 and the ground. In this case, the first fixed electrode 16 is electrically connected to the antenna conductor 3, and the second fixed electrode 17 is grounded. Furthermore, the variable capacitor 13 may be provided between the matching circuit 41 and the antenna conductor 3. In this case, the first fixed electrode 16 is electrically connected to the matching circuit 41, and the second fixed electrode 17 is electrically connected to the antenna conductor 3.

Moreover, in the above-described embodiment, the antenna conductor 3 has a linear shape, but 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.

Further, the variable capacitor of the present invention does not necessarily have to be used in a plasma processing device, and may be applied to various devices.

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 conductor 3S ... Flow path CL ... Coolant 13 ... Variable capacitor 16 First fixed electrode 161 ... Fixed metal plate 17 ... Second fixed electrode 171 ... Fixed metal plate 18 ... Solid dielectric C ... Rotating shaft 182 ... Movable dielectric Body plate 161a, 171a ... Tip side 161b, 171b ... End side 182a ... End side 19 ... Containment container P1 ... Introduction port P2 ... Derivation port

Claims (9)

A pair of fixed electrodes provided facing each other and
A solid dielectric provided between the pair of fixed electrodes so that they can be moved in and out,
A container for accommodating the pair of fixed electrodes and the solid dielectric,
A capacitive element that is introduced into the container and comprises a liquid dielectric that is interposed between the pair of fixed electrodes. The capacitive element according to claim 1, wherein the storage container has an introduction port for introducing the liquid dielectric and a take-out port for eliciting the liquid dielectric. One of the pair of fixed electrodes has a first flange member provided on the introduction port and a plurality of first fixed metal plates supported by the first flange member.
A plurality of second flange members supported by the second flange member so that the other of the pair of fixed electrodes is located between the second flange member provided in the lead-out port and the first fixed metal plate. Has a fixed metal plate and
The capacitive element according to claim 2, wherein an opening through which the liquid dielectric can flow is formed in the first flange member and the second flange member. The solid dielectric is
A rotation shaft body rotatably supported around the rotation axis on the side wall of the storage container,
3. The third aspect of the invention, which has a plurality of dielectric plates that are supported by the rotating shaft body and rotate around the rotating shaft, and have a plurality of dielectric plates that move in and out between the first fixed metal plate and the second fixed metal plate. Capacitive element. In a state where the plurality of dielectric plates are extracted from between the first fixed metal plate and the second fixed metal plate, the plurality of dielectric plates can be attached to any of the first fixed metal plate and the second fixed metal plate. The capacitive element according to claim 4, which does not face each other. The capacitive element according to any one of claims 1 to 5, wherein the liquid dielectric is water. The capacitive element according to any one of claims 1 to 6, wherein the relative permittivity of the solid dielectric is smaller than the relative permittivity of water. A pair of fixed electrodes provided facing each other and
A solid dielectric provided between the pair of fixed electrodes and
A container for accommodating the pair of fixed electrodes and the solid dielectric,
A liquid dielectric introduced into the container and interposed between the pair of fixed electrodes is provided.
A capacitive element configured so that the capacitance of the liquid dielectric in the containing container can be changed. The capacitive element according to any one of claims 1 to 8.
It is electrically connected to the capacitive element and is provided with an antenna conductor for generating plasma by passing a high frequency current.
A plasma processing device in which the liquid dielectric is a coolant for the antenna conductor.

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