TWI723353B - Antenna and plasma processing device - Google Patents

Abstract

The present invention provides an antenna and a plasma processing device, which can ensure the sealing performance between a conductor element and a hollow insulator even when the antenna is lengthened. The antenna 3 is used to flow a high-frequency current IR to generate plasma P, and includes: at least a pair of cylindrical conductor elements 31; a hollow insulator 32, which is provided between the conductor elements 31 adjacent to each other, and the conductor elements 31 The inner space is connected; and the metal sealing member S is respectively provided between a pair of conductor elements 31 and the hollow insulator 32.

Description

Antenna and plasma processing device

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

Previously, a plasma processing device has been proposed. The plasma processing device flows a high-frequency current in an antenna and generates an inductively coupled plasma (ICP (Inductively Coupled Plasma)) by using the induced electric field generated therefrom. The coupled plasma processes the substrate.

In this type of plasma processing apparatus, if the antenna is lengthened in order to cope with a large-scale substrate or the like, the impedance of the antenna increases, thereby generating a large potential difference between the two ends of the antenna. As a result, due to the influence of the large potential difference, the uniformity of the plasma such as the density distribution, potential distribution, and electron temperature distribution of the plasma deteriorates, and even the uniformity of substrate processing deteriorates. In addition, if the impedance of the antenna increases, there is also a problem that it is difficult to flow a high-frequency current through the antenna.

In order to solve such problems and the like, as shown in Patent Document 1, it is conceived that a hollow insulator is interposed between adjacent metal tubes, a plurality of metal tubes are connected, and a capacitor as a capacitive element is arranged on the outer periphery of the hollow insulator. Specifically, the metal pipe and the hollow insulator are screw-fastened, and in order to ensure the sealing performance between these members, a rubber O-ring is interposed between the outer peripheral surface of the metal pipe and the inner peripheral surface of the hollow insulator between. Furthermore, the metal pipes screwed on both sides of the hollow insulator are electrically connected in series with the capacitive element. In short, the combined reactance of the antenna becomes the reactance obtained by subtracting the capacitive reactance from the inductive reactance. As a result, the impedance of the antenna can be reduced, the increase in the impedance can be suppressed even when the antenna is lengthened, high-frequency current can easily flow through the antenna, and plasma with good uniformity can be efficiently generated.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2016-138598

However, with such a configuration, the elastic force of the O-ring decreases due to aging deterioration or thermal influence, and it is difficult to ensure the sealing performance for a long period of time.

Therefore, the present invention is made to solve the above-mentioned problems, and its main problem is to ensure the airtightness between the conductor element and the hollow insulator even when the antenna is lengthened.

That is, the antenna of the present invention is used to flow high-frequency current to generate plasma, and is characterized by including: at least a pair of cylindrical conductor elements; a hollow insulator provided between the conductor elements adjacent to each other, and these The internal spaces of the conductor elements are in communication; and a metal seal is respectively provided between the pair of conductor elements and the hollow insulator.

If it is an antenna constructed in this way, a pair of conductor elements and a hollow insulator There are metal seals between the rubber O-rings that are more resistant to years of deterioration or thermal influence, so even when the antenna is lengthened, the airtightness between the conductor element and the hollow insulator can be ensured.

If the hollow insulator contains, for example, a material weaker than a metal seal such as a resin, the hollow insulator will deform even if the metal seal is to be crushed, resulting in poor sealing performance.

Therefore, it is preferable to further include a receiving member provided at both ends of the hollow insulator and contacted by the metal seal, and the receiving member includes a stronger material than the hollow insulator.

With this configuration, the receiving member containing a stronger material than the hollow insulator receives the metal seal, so that deformation of the hollow insulator can be suppressed and the metal seal can be crushed reliably.

Preferably, it further includes a capacitor element electrically connected in series with the pair of conductor elements, and the capacitor element has: a first electrode electrically connected to one of the pair of conductor elements and passing through the The inside of the hollow insulator extends to the other side of the pair of conductor elements; and the second electrode is electrically connected to the other of the pair of conductor elements and extends through the inside of the hollow insulator To one side of the pair of conductor elements facing the first electrode, the first electrode is provided on one of the receiving members, and the second electrode is provided on the other of the receiving members.

With this configuration, the capacitive element and the pair of conductor elements are electrically connected in series. Therefore, as described above, the combined reactance of the antenna can be reduced by the inductive reactance minus the electrical reactance. The form of capacitive reactance. As a result, the impedance of the antenna can be reduced, the increase in the impedance can be suppressed even when the antenna is lengthened, high-frequency current can easily flow through the antenna, and plasma with good uniformity can be efficiently generated.

Furthermore, the first electrode and the second electrode are respectively provided on the receiving member. Therefore, if the receiving member is mounted on the hollow insulator, the first electrode and the second electrode can be opposed to each other, and the capacitor element can be easily formed.

When the receiving member is detachably provided on the hollow insulator, the relative positional relationship between the first electrode and the second electrode may change every time the receiving member is mounted on the hollow insulator, so the reproducibility of the capacitance of the capacitor element is poor.

Therefore, it is preferable that the receiving member is welded to the hollow insulator.

If so, the receiving member and the hollow insulator are integrated, so that the reproducibility of the electrostatic capacitance is not reduced. Moreover, the receiving member and the hollow insulator are welded, so there is no need to provide a seal between these members, so that the number of parts can be reduced.

As a specific structure of the metal seal, it is preferable to have: a first ferrule (ferrule), which contacts the receiving member; and a second ferrule, which is arranged closer to the conductor element side than the first ferrule And a press-fitting member, which presses the second ferrule toward the first ferrule side in the axial direction, and is screwed to the receiving member.

With such a configuration, it is possible to perform a surface seal between the receiving member and the first ferrule. Therefore, compared with a shaft seal that uses a metal gasket or a metal O-ring as a metal seal, for example, The tightness is better.

The dielectric of the capacitor element is preferably a liquid that fills the space between the first electrode and the second electrode.

With this configuration, the space between the first electrode and the second electrode is filled with the dielectric substance of the liquid, so the gap between the electrode and the dielectric substance constituting the capacitor element can be eliminated. As a result, the arc discharge that may be generated in the gap between the electrode and the dielectric substance can be eliminated, and the damage of the capacitor element caused by the arc discharge can be eliminated. In addition, regardless of the gap, the capacitance value can be set with high accuracy based on the distance between the first electrode and the second electrode, the facing area, and the relative permittivity of the dielectric substance of the liquid. Furthermore, the structure of the pressing electrode and the dielectric substance for filling the gap may not be required, so that the complication of the antenna peripheral structure caused by the pressing structure and the resulting degradation of plasma uniformity can be prevented.

The dielectric substance is preferably a cooling liquid flowing inside the pair of conductor elements.

With such a configuration, the cooling liquid can be used to cool the antenna, which tends to become high temperature due to the heat generated during plasma generation, so that damage to the antenna itself or damage to the surrounding structure can be prevented, and the plasma can be stably generated .

Furthermore, since the coolant is used as the dielectric of the capacitor element, it is possible to cool the capacitor element and suppress unexpected changes in electrostatic capacitance.

Furthermore, by using the cooling liquid as a dielectric substance while adjusting the coolant to a constant temperature by the temperature adjustment mechanism, the change in the relative permittivity caused by the temperature change can be suppressed, and the change in the electrostatic capacitance caused by this can be suppressed.

In addition, the plasma processing apparatus of the present invention is characterized by including the antenna, a vacuum container in which the antenna is arranged inside or outside, and a high-frequency power supply that applies a high-frequency current to the antenna.

If it is the plasma processing apparatus comprised in this way, the same effect as the said antenna can be acquired.

According to the invention thus constituted, even when the antenna is lengthened, the sealing property between the conductor element and the hollow insulator can be ensured.

2: Vacuum container

3: antenna

3a: Power supply end

3b: Terminal

4: high frequency power supply

6: Vacuum exhaust device

7: Gas

8: substrate holder

9: Bias power supply

10: Insulating cover

11: Insulating member

12, 13: liner

14: Circulating flow path

18: Processing room

19: Dielectric window

20: Antenna Room

21: Gas inlet

31: Metal tube (conductor element)

31A: The first metal tube

31B: second metal tube

31t: end

31x, 32x: flow path

32: Insulating tube (hollow insulator)

33: Capacitor

33A: first electrode

33B: second electrode

33x: Mainstream road

41: matching circuit

81: heater

100: Plasma processing device

141: Thermostat

142: Circulation Mechanism

321: Countersink

CL: Coolant (liquid dielectric)

F: flange

IR: high frequency current

N1: External thread

N2: Internal thread

P: Inductively coupled plasma

S: Metal seal

S1: The first ring

S1a, S2a: Front end

S1b, S2b: rear end

S2: Second ring

S21, S31: front inner peripheral surface

S22, S32: Rear inner peripheral surface

S23: Ring protrusion

S3: Press-in components

S4: Metal washers

S5: Metal O-ring

W: substrate

X1: The first pressed surface

X2: The second pressed surface

X3: The third pressed surface

X4: back

Y1: The first pressing surface

Y2: The second pressing surface

Y3: The third pressing surface

Y4: pressing surface

Z: receiving component

Z1: one end

Z2: the other end

Z3: Large diameter part

Za: abutting surface

Zh: Through hole

Fig. 1 is a longitudinal cross-sectional view schematically showing the configuration of the plasma processing apparatus of the present embodiment.

Fig. 2 is an enlarged cross-sectional view schematically showing the peripheral structure of the antenna of the embodiment.

Fig. 3 is a schematic diagram showing the structure of the metal seal of the embodiment.

Fig. 4 is a schematic diagram showing the structure of a metal seal according to a modified embodiment.

Fig. 5 is a schematic diagram showing the structure of a metal seal according to a modified embodiment.

Fig. 6 is a longitudinal sectional view schematically showing the configuration of a plasma processing apparatus according to a modified embodiment.

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

<Device configuration>

The plasma processing apparatus 100 of the present embodiment uses inductively coupled plasma P to process the substrate W. The substrate W is, for example, a liquid crystal display or organic electroluminescence (Electroluminescence, EL) Displays and other flat panel displays (Flat Panel Display, FPD) substrates, flexible substrates for flexible displays, etc. In addition, the processing performed on the substrate W is, for example, film formation by a plasma chemical vapor deposition (Chemical Vapor Deposition, CVD) method, etching, ashing, sputtering, and the like.

Furthermore, the plasma processing device 100 is also called a plasma CVD device when the film is formed by a plasma CVD method, and is also called a plasma etching device when etching is performed, and when ashing is performed It is also called a plasma ashing device, and it is also called a plasma sputtering device in the case of sputtering.

Specifically, as shown in FIG. 1, the plasma processing apparatus 100 has a vacuum container 2 evacuated and introduced with a gas 7, a linear antenna 3 arranged in the vacuum container 2, and a vacuum container 2 to be used. The high frequency in which inductively coupled plasma P is generated is applied to the high frequency power source 4 of the antenna 3. Furthermore, by applying a high frequency to the antenna 3 from the high frequency power supply 4, and a high frequency current IR flows in the antenna 3, an induced electric field is generated in the vacuum container 2 to generate an inductive coupling type plasma P.

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

In the vacuum container 2, the gas 7 is introduced through, for example, a flow regulator (not shown) and a plurality of gas introduction ports 21 formed on the side wall of the vacuum container 2. The gas 7 only needs to correspond to the content of the processing performed on the substrate W. For example, in the case of film formation on the substrate W by the plasma CVD method, the gas 7 is a source gas or a gas obtained _{by diluting the source gas with a dilution gas (for example, H 2 ).} If a further specific example, the raw material gas is available at the Si film is formed on the substrate W when SiH case _4, the raw material gas is SiH ₄ + when the case of NH ₃ can be in the SiN film was formed on the substrate W, the raw material gas is In the case of SiH ₄ +O _{2 , a SiO 2} film can be formed on the substrate W _{, and in the case of SiF 4} +N ₂ as the source gas, a SiN:F film (fluorinated silicon nitride film) can be formed on the substrate W.

In addition, a substrate holder 8 that holds the substrate W is provided in the vacuum container 2. As in this example, a bias voltage can also be applied to the substrate holder 8 from a bias power source 9. The bias voltage is, for example, a negative direct current voltage, a negative pulse voltage, etc., but is not limited to this. Such a bias voltage can control, for example, the energy of the positive ions in the plasma P when incident on the substrate W, and control the crystallinity of the film formed on the surface of the substrate W, and the like. 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). There may be one antenna 3 arranged in the vacuum container 2 or multiple antennas.

The vicinity of both ends of the antenna 3 penetrates the opposing side walls of the vacuum container 2 respectively. Insulating members 11 are respectively provided in the portions where both ends of the antenna 3 penetrate outside the vacuum container 2. Both ends of the antenna 3 penetrate through each insulating member 11, and the penetration portion thereof is vacuum-sealed by a packing 12, for example. The insulating member 11 and the vacuum container 2 are also vacuum sealed by a gasket 13, for example. Furthermore, the material of the insulating member 11 is, for example, ceramics such as alumina, quartz, or engineering plastics such as polyphenylene sulfide (PPS), polyether-ether-ketone (PEEK), etc.

Furthermore, the portion of the antenna 3 located in the vacuum container 2 is covered by a straight tube-shaped insulating cover 10. Both ends of the insulating cover 10 are supported by insulating members 11. Furthermore, the two ends of the insulating cover 10 and the insulating member 11 may not be sealed. The reason is that even if the gas 7 enters the space in the insulating cover 10, the space is small and the moving distance of the electrons is short, so plasma P is usually not generated in the space. Furthermore, the material of the insulating cover 10 is, for example, quartz, alumina, fluororesin, silicon nitride, silicon carbide, silicon, etc.

By providing the insulating cover 10, it is possible to suppress the charged particles in the plasma P from entering the metal tube 31 constituting the antenna 3, and therefore it is possible to suppress the increase in the plasma potential caused by the charged particles (mainly electrons) entering the metal tube 31. In addition, the metal tube 31 can be prevented from being sputtered by charged particles (mainly ions) to cause metal contamination to the plasma P and the substrate W.

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

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

The antenna 3 has a hollow structure having a flow path through which the cooling liquid CL flows inside. Furthermore, the cooling liquid CL circulates through the antenna 3 through a circulation flow path 14 provided outside the vacuum vessel 2. The circulation flow path 14 is provided with a channel for adjusting the cooling liquid CL. A temperature adjustment mechanism 141 such as a heat exchanger to a constant temperature, and a circulation mechanism 142 such as a pump for circulating the coolant CL in the circulation flow path 14. As the coolant CL, from the viewpoint of electrical insulation, high-resistance water is preferable, for example, pure water or water close to pure water is preferable. In addition, for example, a liquid refrigerant other than water such as a fluorine-based inert liquid may also be used.

Specifically, as shown in FIG. 2, the antenna 3 has: at least a pair of tubular metal conductor elements 31 (hereinafter referred to as "metal tube 31"); and a tubular hollow insulator 32 (hereinafter referred to as "insulating tube 32"), which are arranged between the metal pipes 31 adjacent to each other to insulate the metal pipes 31.

In this embodiment, the number of metal pipes 31 is two, and the number of insulating pipes 32 is one. In the following description, one of the metal pipes 31 is also referred to as the "first metal pipe 31A", and the other metal pipe is also referred to as the "second metal pipe 31B". Furthermore, the antenna 3 may also have a configuration with three or more metal tubes 31. In this case, the number of insulating tubes 32 is one less than the number of metal tubes 31.

The metal tube 31 has a straight tube shape in which a linear flow path 31x in which the cooling liquid CL flows is formed, and the material is, for example, copper, aluminum, alloys of these metals, stainless steel, or the like.

The insulating tube 32 has a straight tube shape, and a linear flow path 32x in which the cooling liquid CL flows is formed. The insulating tube 32 of this embodiment is formed of a single member, but it may be formed by joining a plurality of members. Furthermore, the material of the insulating tube 32 is, for example, alumina, fluororesin, polyethylene (PE), engineering plastics (for example, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc.).

Furthermore, as shown in Figs. 2 and 3, the antenna 3 of this embodiment A metal seal (metal seal) S separately provided between the first metal pipe 31A and the insulating pipe 32, and between the second metal pipe 31B and the insulating pipe 32

More specifically, the metal seal S is used to ensure the sealability between the metal pipes 31A, 31B, and the insulating pipe 32. Here, the metal seal S is configured as follows: it is pressed to contact the insulating pipe 32 At least a part of the receiving members Z at both ends of the tube 32 is deformed by pressing by this.

First, the receiving member Z will be described.

The receiving member Z is used to prevent deformation of the insulating tube 32 when the metal seal S is pressed and deformed, and includes a stronger material than the insulating tube 32, such as aluminum, copper, alloys of these metals, and other metals.

As shown in FIG. 2, the receiving member Z communicates with the insulating tube 32, one end Z1 is fitted into the counterbore 321 in which the inner wall of the insulating tube 32 is embedded, and the end 31t of the metal tube 31 extends from the other end Z2. insert. Furthermore, the outer diameter of the end 31t of the metal pipe 31 is smaller than the outer diameter of the center of the metal pipe 31, and the inner diameter of the receiving member Z is approximately the same as or slightly larger than the outer diameter of the end 31t of the metal pipe 31.

The one end part Z1 of the receiving member Z is formed with the contact surface Za which the end part 31t of the metal pipe 31 inserted from the other end part Z2 abuts.

The abutting surface Za is a surface on which the end surface of the metal pipe 31 abuts, and when the end surface of the metal pipe 31 abuts on the abutting surface Za, the receiving member Z and the metal pipe 31 are electrically connected.

At the other end Z2 of the receiving member Z, a first pressed surface X1 to which the metal seal S is pressed and in contact is formed.

The first pressed surface X1 is formed on the inner circumference of the other end Z2 of the receiving member Z The surface is a truncated cone-shaped inclined surface gradually expanding in diameter from the one end Z1 side to the other end Z2 side, and is inclined with respect to the axial direction of the antenna 3. In addition, a male thread part N1 is formed on the outer peripheral surface of the other end part Z2, and the male thread part N1 is configured to screw a press-fitting member S3 of a constituent element of the metal seal S described later.

In this receiving member Z, a large-diameter portion Z3 having a larger outer diameter than the insulating tube 32 is provided between one end portion Z1 and the other end portion Z2. Furthermore, by making the large diameter portion Z3 abut on the end surface of the insulating tube 32 and welding the abutting part, the receiving member Z and the insulating tube 32 are integrally provided inseparably.

Next, the metal seal S will be described.

As shown in FIG. 3, the metal seal S is interposed between the receiving member Z and the metal pipe 31, and is called a so-called double ferrule. Specifically, the metal seal S has a first ferrule S1 that is pressed to contact the receiving member Z, a second ferrule S2 located closer to the metal tube 31 than the first ferrule S1, and a second ferrule S2 is a press-fitting member S3 press-fitted from the metal pipe 31 side to the first ferrule S1 side. The first ferrule S1, the second ferrule S2, and the press-fitting member S3 are ring-shaped externally embedded in the end 31t of the metal pipe 31, where they are made of the same material as the metal pipe 31, namely copper, aluminum, and these metals. It is formed of alloy, stainless steel, etc., but it may also be formed of a material different from that of the metal pipe 31.

The first ferrule S1 has an inner diameter that is approximately the same as or slightly larger than the outer diameter of the end 31t of the metal pipe 31, the rear end S1b is pressed by the second ferrule S2, and the front end S1a is pressed into the receiving member Z . The outer peripheral surface of the first ferrule S1 is a frusto-conical inclined surface whose diameter gradually expands from the front end S1a to the rear end S1b. Furthermore, the front end portion S1a side of the outer peripheral surface is formed as a first press that is pressed and contacts the first pressed surface X1. The pressing surface Y1 is inclined with respect to the axial direction of the antenna 3. In addition, in the rear end S1b of the first ferrule S1, a second pressed surface X2 to which the front end S2a of the second ferrule S2 is pressed and contacted is formed. The second pressed surface X2 is formed by cutting the rear end S1b of the first ferrule S1, for example, and is set here on the inner peripheral surface of the rear end S1b. The second pressed surface X2 here is an inclined surface gradually expanding in diameter toward the rear, and is inclined with respect to the axial direction of the antenna 3.

The second ferrule S2 has a front inner peripheral surface S21 whose inner diameter is approximately the same as or slightly larger than the outer diameter of the end 31t of the metal pipe 31, and a rear inner peripheral surface S22 whose diameter gradually expands toward the rear from the front inner peripheral surface S21 , The rear end S2b is pressed by the pressing member S3, and the front end S2a is pressed into the rear end S1b of the first ferrule S1. A second pressing surface Y2 that is pressed to contact the second pressed surface X2 is formed at the front end portion S2a of the second ferrule S2. The second pressing surface Y2 is, for example, an inclined surface gradually expanding in diameter from the front end portion S2 a to the rear, and is inclined with respect to the axial direction of the antenna 3. In addition, at the rear end portion S2b of the second ferrule S2, there are formed a third pressed surface X3 pressed by the press-fitting member S3, and an annular protrusion S23 projecting radially inward from the rear inner peripheral surface S22 . The third pressed surface X3 is an inclined surface whose diameter gradually decreases toward the rear, and is inclined with respect to the axial direction of the antenna 3. By inclining the third pressed surface X3 in this way, when the pressing member S3 presses the second ferrule S2 into the first ferrule S1, a force for pressing the second ferrule S2 inward in the radial direction is generated. As a result, the annular protrusion S23 is pressed and deformed so as to shrink toward the outer peripheral surface of the metal pipe 31, and the second ferrule S2 is fixed to the metal pipe 31.

The press-fitting member S3 has: a front inner peripheral surface S31 formed with a female screw portion N2 screwed to a male screw portion N1 formed on the outer peripheral surface of the receiving member Z; and The inner diameter of the rear inner peripheral surface S32 is approximately the same as or slightly larger than the outer diameter of the end 31t of the metal pipe 31. On the inner peripheral surface of the press-fitting member S3, between the front inner peripheral surface S31 and the rear inner peripheral surface S32, a third pressing surface Y3 that presses the third pressed surface X3 is provided. The third pressing surface Y3 here is an inclined surface whose diameter gradually decreases toward the rear, and is inclined with respect to the axial direction of the antenna 3.

According to the above configuration, by screwing the female thread portion N2 of the press-fitting member S3 to the male thread portion N1 of the receiving member Z, the third pressing surface Y3 of the press-fitting member S3 presses the third ring of the second ferrule S2. The pressing surface X3 presses the second ferrule S2 into the first ferrule S1 in the axial direction. Thereby, the second pressing surface Y2 of the second ferrule S2 presses the second pressed surface X2 of the first ferrule S1, and presses the first ferrule S1 into the receiving member Z in the axial direction. Furthermore, the first pressing surface Y1 of the first ferrule S1 is pressed to contact the first pressed surface X1 of the receiving member Z, and the tip portion S1a of the first ferrule S1 is pressed and deformed, and the first pressing surface Y1 is connected to the first pressed surface X1. The space between the pressed surfaces X1 is kept air-tight or liquid-tight.

In addition, in the process of screwing the press-fitting member S3 to the receiving member Z to seal between the first pressing surface Y1 and the first pressed surface X1 as described above, the first ferrule S1 and the second ferrule S2 And one end Z1 of the receiving member Z is pressed and deformed in the radial direction, whereby the receiving member Z, the first ferrule S1, and the second ferrule S2 are integrally fastened and clamped to the metal pipe 31.

As shown in FIG. 2, the antenna 3 thus constructed further has a capacitor 33, which is a capacitive element electrically connected in series with the metal tubes 31 adjacent to each other. The capacitor 33 is provided inside the insulating tube 32, and here, is provided inside the flow path 32x through which the cooling liquid CL of the insulating tube 32 flows.

Specifically, the capacitor 33 includes a first electrode 33A electrically connected to one of the metal tubes 31 adjacent to each other (first metal tube 31A), and another one (first metal tube 31A) connected to the other metal tube 31 adjacent to each other. The two metal pipes 31B) are electrically connected to the second electrode 33B arranged opposite to the first electrode 33A, and are configured to fill the space between the first electrode 33A and the second electrode 33B with the coolant CL. That is, the cooling liquid CL flowing in the space between the first electrode 33A and the second electrode 33B becomes the dielectric substance constituting the capacitor 33.

Each of the electrodes 33A and 33B has a substantially rotating body shape, and a main flow path 33x is formed at the center along the center axis. Specifically, the electrodes 33A and 33B have a cylindrical shape and are arranged coaxially with each other. Here, the inner diameter of the first electrode 33A is larger than the outer diameter of the second electrode 33B, and the second electrode 33B is inserted inside the first electrode 33A. Thereby, a cylindrical space along the flow path direction is formed between the first electrode 33A and the second electrode 33B.

The electrodes 33A and 33B configured in this way are integrally provided on the receiving member Z. Here, the electrodes 33A, the electrodes 33B, and the receiving member Z are formed integrally by a single member, but these parts may be formed and joined by different parts. In addition, the materials of the electrodes 33A and 33B are, for example, aluminum, copper, alloys of these metals, or the like.

In this way, the electrodes 33A and 33B are integrally provided on the receiving member Z. Therefore, by welding the receiving member Z to both ends of the insulating tube 32 as described above, the first electrode 33A and the second electrode 33B are connected to each other. It is arranged on the same axis and defines the insertion size of the second electrode 33B into the first electrode 33A. Moreover, by connecting the metal pipe 31A, The metal pipe 31B is inserted from the other end Z2 of the receiving member Z as described above, and abuts against the contact surface Za formed at the one end Z1 of the receiving member Z, thereby connecting the first metal pipe 31A and the first electrode 33A It is electrically connected, and electrically connects the second metal tube 31B and the second electrode 33B.

In this configuration, when the cooling liquid CL gradually flows from the first metal pipe 31A, the cooling liquid CL flows to the second electrode 33B side through the main flow path 33x of the first electrode 33A. The coolant CL flowing to the second electrode 33B side passes through the main flow path 33x of the second electrode 33B and flows to the second metal pipe 31B. At this time, the cylindrical space between the first electrode 33A and the second electrode 33B is filled with the cooling liquid CL, and the cooling liquid CL becomes a dielectric substance to constitute the capacitor 33. Furthermore, at one end Z1 of the receiving member Z, a plurality of through holes Zh are formed in the thickness direction. By providing such a through hole Zh, the flow path resistance of the cooling liquid CL caused by the receiving member Z can be reduced, and the stagnation of the cooling liquid CL in the insulating tube 32 and the accumulation of air bubbles in the insulating tube 32 can be prevented.

<Effects of this embodiment>

According to the antenna 3 of the present embodiment configured in this way, a metal seal S that is more resistant to aging deterioration or thermal influence than a rubber O-ring is provided between the pair of metal pipes 31 and the insulating pipe 32, and therefore Even when the antenna 3 is lengthened, the sealing property between the metal tube 31 and the insulating tube 32 can be ensured.

Furthermore, the receiving member Z is welded to the insulating tube 32, and the receiving member Z, the first ferrule S1, and the second ferrule S2 are integrally fastened and clamped to the metal tube 31, so that the metal tube 31 or the insulating tube 32 can be restrained from being damaged. Looseness can also ensure sealing in this respect.

In addition, it is made of a stronger material than the insulating tube 32. The receiving members Z at both ends of the tube 32 can prevent the insulating tube 32 from being deformed when the metal seal S is pressed and deformed, so that the metal seal S can be reliably pressed and deformed.

Furthermore, since the capacitor 33 is electrically connected in series with the pair of metal tubes 31, the combined reactance of the antenna 3 can be made into a form in which the capacitive reactance is subtracted from the inductive reactance. As a result, the impedance of the antenna 3 can be reduced, and the increase in the impedance of the antenna 3 can be suppressed even when the antenna 3 is lengthened, a high-frequency current can easily flow through the antenna 3, and a plasma P with good uniformity can be generated efficiently.

Furthermore, the electrodes 33A and 33B are respectively provided on the receiving member Z. Therefore, when the receiving member Z is welded to the insulating tube 32, the relative positional relationship between the first electrode 33A and the second electrode is defined, and the electrodes 33A, 33A and 33B are maintained after welding. The positional relationship of the electrode 33B does not cause a decrease in the reproducibility of the capacitance of the capacitor. Furthermore, since the receiving member Z and the insulating tube 32 are welded, there is no need to provide a seal between these members, so that the number of parts can be reduced.

In addition, the first pressing surface Y1 of the first ferrule S1 or the first pressed surface X1 of the receiving member Z is an inclined surface and has a component along the axial direction of the antenna 3. Therefore, the first pressing surface Y1 and the first pressed surface X1 A surface seal is performed between the pressed surface X1. By this, for example, the first pressing surface Y1 or the first pressed surface X1 is a surface perpendicular to the axial direction of the antenna 3, and the sealing performance is better than a configuration in which the surfaces are sealed by the shaft.

The dielectric of the capacitor 33 is a liquid that fills the space between the first electrode 33A and the second electrode 33B, so the gap between the electrodes 33A, the electrode 33B and the dielectric constituting the capacitor 33 can be eliminated. As a result, it can be eliminated The arc discharge that may occur in the gap between the electrode 33A, the electrode 33B, and the dielectric substance eliminates the damage of the capacitor 33 caused by the arc discharge. In addition, regardless of the gap, the capacitance value can be set with high accuracy based on the distance between the first electrode 33A and the second electrode 33B, the facing area, and the relative permittivity of the dielectric substance of the liquid. Furthermore, a structure for pressing the electrodes 33A, 33B, and the dielectric substance to fill the gap may not be required, so that the complication of the antenna peripheral structure caused by the pressing structure and the resulting plasma P can be prevented. Deterioration of uniformity.

The dielectric substance is a cooling liquid flowing inside the metal tube 31, so the cooling liquid CL can be used to cool the metal tube 31, which tends to become high temperature due to the heat generated during plasma generation, so that the antenna 3 itself can be prevented from being damaged or The damage of the peripheral structure, etc., can cause the plasma P to be stably generated.

Furthermore, since the coolant CL is used as the dielectric of the capacitor 33, it is possible to cool the capacitor 33 and suppress unexpected changes in its electrostatic capacitance.

Furthermore, by adjusting the coolant CL to a constant temperature by the temperature adjustment mechanism 141 as a dielectric material, the change in the relative dielectric constant caused by the temperature change can be suppressed, thereby suppressing the change in the electrostatic capacitance generated therewith. .

<Other Modified Embodiments>

In addition, the present invention is not limited to the above-mentioned embodiment.

For example, as the metal seal S, the double ferrule type is used in the above-mentioned embodiment, but the metal gasket S4 may be used as shown in FIG. 4.

More specifically, a flange F is provided here at the end of the metal pipe 31, and the metal seal S includes, for example, an annular ring arranged between the flange F and the receiving member Z. A metal washer S4 having a circular shape, and a press-fitting member S3 for press-fitting the metal washer S4 to the receiving member Z.

In addition, the press-fitting member S3 is configured to be screwed to the receiving member Z in the same manner as in the above-mentioned embodiment, and has a pressing surface Y4 that presses the back surface X4 of the flange F.

According to the above configuration, by screwing the pressing member S3 to the receiving member Z, the pressing surface Y4 of the pressing member S3 presses the back surface X4 of the flange F, and the metal pipe 31 is pressed into the receiving member Z in the axial direction. Thereby, the metal gasket S4 is crushed between the flange F of the metal pipe 31 and the receiving member Z, and these members are kept airtight or liquid-tight.

In addition, as the metal seal S, a metal O-ring S5 may be used as shown in FIG. 5, and although not shown, a single ferrule may be used.

Furthermore, in the aforementioned embodiment, the first pressed surface X1, the first pressing surface Y1, the second pressed surface X2, the second pressing surface Y2, the third pressed surface X3, and the third pressing surface Y3 are all opposite to The inclined surface of the antenna 3 inclined in the axial direction, but may be a surface in which a part of the surfaces X1 to X3 and Y1 to Y3 are perpendicular to the axial direction of the antenna 3.

In the above-mentioned embodiment, the insulating tube and the receiving member are inseparably integrated by welding, but they may be integrated by a joining method different from welding. Furthermore, the insulating tube and the receiving member do not necessarily need to be integrated. As long as the sealing between these members can be ensured, the receiving member may be detachably installed with respect to the insulating tube by, for example, screw fastening.

In the plasma processing apparatus 100 of the above-mentioned embodiment, the antenna 3 is arranged in the processing chamber of the substrate W. However, as shown in FIG. 6, the antenna 3 may be arranged outside the processing chamber 18. In this case, the multiple antennas 3 are arranged in the vacuum container 2 by the dielectric The antenna room 20 is separated from the processing room 18 by the window 19. Furthermore, the antenna chamber 20 is evacuated by the vacuum exhaust device 6. With this plasma processing apparatus 100, the conditions such as the pressure of the processing chamber 18 and the conditions such as the pressure of the antenna chamber 20 can be separately controlled, the plasma P can be efficiently generated, and the substrate W can be efficiently processed.

In addition, the metal pipe and the insulating pipe have a tubular shape with one internal flow path, but they may also have two or more internal flow paths or branched internal flow paths. In addition, the metal tube or insulating tube may also be solid.

In the electrode of the above-mentioned embodiment, the projecting portion is cylindrical, but it may be other square cylindrical shapes, flat plates, or curved or bent plates.

In addition, the present invention is not limited to the above-mentioned embodiment, and of course various modifications can be made within a range that does not deviate from the gist.

3‧‧‧Antenna

31A‧‧‧The first metal tube

31B‧‧‧Second metal tube

31t‧‧‧End

31x、32x‧‧‧Flow path

32‧‧‧Insulation tube (hollow insulator)

33‧‧‧Capacitor

33A‧‧‧First electrode

33B‧‧‧Second electrode

33x‧‧‧Main Road

321‧‧‧Counterbore

CL‧‧‧Cooling fluid (liquid dielectric)

N1‧‧‧External thread

N2‧‧‧Internal thread

S‧‧‧Metal seal

S1‧‧‧First loop

S2‧‧‧Second ring

S3‧‧‧Press-in component

X1‧‧‧The first pressed surface

Z‧‧‧Receiving component

Z1‧‧‧One end

Z2‧‧‧The other end

Z3‧‧‧Large diameter department

Za‧‧‧Abutting surface

Zh‧‧‧Through hole

Claims (7)

An antenna for generating plasma by flowing high-frequency current, comprising: at least a pair of cylindrical conductor elements; a hollow insulator, which is arranged between the conductor elements adjacent to each other and communicates with the inner space of the conductor element And metal seals, respectively provided between the pair of conductor elements and the hollow insulator, and the antenna further includes: a receiving member provided at both ends of the hollow insulator, and for the metal seal The receiving member includes a material with stronger strength than the hollow insulator. The antenna described in item 1 of the scope of patent application further includes: a capacitor element electrically connected in series with the pair of conductor elements, the capacitor element having: a first electrode, and one of the pair of conductor elements Is electrically connected to the hollow insulator and extends to the other side of the pair of conductor elements; and a second electrode is electrically connected to the other of the pair of conductor elements, and Passing through the inside of the hollow insulator and extending to one side of the pair of conductor elements, facing the first electrode, the first electrode is provided on one of the receiving members, and the second electrode Set on the other said receiving member. The antenna described in item 2 of the scope of patent application, wherein the receiving member is welded to the hollow insulator. The antenna according to any one of items 1 to 3 in the scope of the patent application, wherein the metal seal has: a first ferrule that contacts the receiving member; and a second ferrule that is disposed in comparison with the first ferrule. The ferrule is closer to the conductor element side; and a press-fitting member for press-fitting the second ferrule toward the first ferrule in the axial direction, and is screwed to the receiving member. According to the antenna described in item 2 or item 3 of the scope of patent application, the dielectric substance of the capacitor element is a liquid that fills the space between the first electrode and the second electrode. The antenna according to claim 5, wherein the dielectric substance is a cooling liquid flowing inside the pair of conductor elements. A plasma processing device, comprising: the antenna according to any one of items 1 to 6 of the scope of the patent application; a vacuum container in which the antenna is arranged inside or outside; and a high-frequency power supply for the antenna Apply high frequency current.

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