Antenna and plasma processing equipment

Abstract

This invention provides an antenna that enables film deposition at high temperatures for extended periods. [Solution] The antenna 3 comprises at least two cylindrical conductive elements 31, cylindrical insulating elements 32 provided between adjacent conductive elements 31 to insulate them, capacitive elements 33 electrically connected in series with adjacent conductive elements 31, and a brazing portion 35 that joins the conductive elements 31 and the insulating elements 32 by brazing with one axial end face of the conductive elements 31 and one axial end face of the insulating elements 32 facing each other.

Description

Technical Field

[0001] The present invention relates to an antenna and a plasma processing apparatus including the antenna.

Background Art

[0002] Plasma processing apparatuses that process a substrate using inductively coupled plasma (hereinafter also referred to as ICP) have been developed conventionally. In this plasma processing apparatus, an antenna for generating ICP by flowing a high-frequency current is used.

[0003] This type of antenna includes, for example, at least two cylindrical conductor elements as shown in Patent Document 1, an insulating element that is cylindrical and provided between adjacent conductor elements to insulate the conductor elements, and a capacitive element that is electrically connected in series to adjacent conductor elements.

[0004] In the above antenna, the conductor element is inserted into the insulating element, and the conductor element and the insulating element are connected. Specifically, a male screw portion is formed on the outer peripheral portion of the conductor element, and a female screw portion that engages with the male screw portion is formed on the inner side wall of the insulating element. By inserting the conductor element into the insulating element and screwing the male screw portion and the female screw portion, the conductor element and the insulating element are connected.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, as with the antenna described above, if a female thread is formed on the insulating element, the heat resistance of the insulating element decreases. As a result, if the antenna is used in a high-temperature environment, such as 1000°C, the insulating element may be damaged by the heat in a short time.

[0007] Therefore, the present invention was made to solve the above problems, and its main objective is to provide an antenna that enables film deposition at high temperatures for a long period of time. [Means for solving the problem]

[0008] In other words, the present invention is an antenna for generating plasma by passing a high-frequency current, and is characterized by comprising: at least two cylindrical conductive elements; cylindrical insulating elements provided between adjacent conductive elements to insulate them; capacitive elements electrically connected in series with adjacent conductive elements; and a brazing portion for joining the conductive elements and the insulating elements by brazing, with one axial end face of the conductive elements and one axial end face of the insulating elements facing each other.

[0009] With this configuration, the brazed joint joins the insulating element and the conductive element by brazing, which significantly increases the heat resistance of the insulating element compared to cases where, for example, a female screw portion is formed on the insulating element. As a result, even when using the antenna in a high-temperature environment such as 1000°C, damage to the insulating element can be prevented, and film deposition can be performed at high temperatures for extended periods. In addition, since the insulating element and the conductive element are joined by brazing, there is no need to form microstructures on the insulating element for joining with the conductive element. Therefore, compared to cases where microstructures such as female threads are formed on the insulating element, the strength of the insulating element can be increased, making it less likely to break even when the specified torque is reached.

[0010] The conductor element comprises a first conductor element and a second conductor element divided in the axial direction, wherein one axial end face of the first conductor element is joined to one axial end face of the insulating element by the brazing portion, and the second conductor element is connected to the other axial end of the first conductor element, and a screw mechanism is formed between the first conductor element and the second conductor element to connect them. In this configuration, the conductor element is stronger than the insulating element, and a screw mechanism is formed between the first and second conductor elements to connect them. Therefore, compared to the case where the screw mechanism is formed on the insulating element, the strength of the element with the screw mechanism can be increased, and even when the specified torque is reached, it is possible to prevent the element with the screw mechanism from being damaged.

[0011] One example is a configuration in which the first conductor element and the second conductor element are connected by the screw mechanism, thereby the first conductor element and the second conductor element sandwiching the electrodes of the capacitive element. With this configuration, the electrodes of the capacitive element can be fixed while in contact with the conductive element.

[0012] The insulating element may be made of a high-melting-point ceramic, a machinable ceramic, a transparent ceramic, quartz, Vesper, or an aromatic polyimide resin. With this configuration, the insulating elements are made of materials with high heat resistance, making them less likely to be damaged even in high-temperature environments.

[0013] Specific examples of the brazed portion include those made of silver, palladium, aluminum, or copper.

[0014] Examples include an insulating cover that covers the outer circumferential surface of the conductor element and the outer circumferential surface of the insulating element and is in the shape of a straight tube, and a protruding insulating portion made of insulating material that is provided on the outer circumferential surface of the conductor element and protrudes from the inner circumferential surface of the insulating cover beyond the outer circumferential surface of the conductor element. With this configuration, the electric field does not concentrate at the protruding insulating portion, so ions in the plasma do not collide with the insulating cover adjacent to the protruding insulating portion, thus preventing the insulating cover from being etched and damaged. Furthermore, even if the antenna or insulating cover bends, the protruding insulating portion can prevent contact between the antenna and the insulating cover.

[0015] The brazed portion mentioned above includes one that brazes the connection between the outer circumferential surface of the conductor element and the outer circumferential surface of the insulating element. In this configuration, if the dielectric of the capacitive element is cooling water, galvanic corrosion of the brazed joint can be prevented, and the strength of the brazed joint can be prevented, compared to the case where the brazed joint is brazed to the outer surface of the conductive element and the inner surface of the insulating element.

[0016] One example is a device that further includes a resin coating portion made of a resin material, which coats the connection portion between the inner circumferential surface of the conductor element and the inner circumferential surface of the insulating element. In this configuration, the resin coating is provided on the inside of the brazed joint via the connection between the conductive and insulating elements. As a result, when the dielectric of the capacitive element is cooling water, the resin coating prevents the cooling water from flowing towards the brazed joint, thereby further preventing galvanic corrosion of the brazed joint.

[0017] Furthermore, the plasma processing apparatus according to the present invention is characterized by comprising the antenna, a vacuum vessel in which the antenna is disposed either inside or outside, and a high-frequency power supply for applying a high-frequency current to the antenna. With a plasma processing apparatus configured in this way, the same effects as those of the antenna described above can be obtained. [Effects of the Invention]

[0018] According to the present invention configured in this manner, it is possible to provide an antenna that enables film deposition at high temperatures for extended periods. [Brief explanation of the drawing]

[0019] [Figure 1] It is a longitudinal sectional view schematically showing the configuration of the plasma processing apparatus of the present embodiment. [Figure 2] It is an enlarged sectional view schematically showing the peripheral configuration of the antenna of the embodiment. [Figure 3] It is an enlarged sectional view of the broken line portion in FIG. 2. [Figure 4] It is an enlarged sectional view schematically showing the peripheral configuration of the antenna of another embodiment. [Figure 5] It is an enlarged sectional view schematically showing the peripheral configuration of the antenna of another embodiment.

Mode for Carrying Out the Invention

[0020] Hereinafter, an embodiment of a plasma processing apparatus according to the present invention will be described with reference to the drawings. Note that, for the sake of clarity, all of the figures shown below may be schematically drawn with appropriate omissions or exaggerations. The same reference numerals are given to the same components, and the description thereof will be omitted as appropriate.

[0021] <Device Configuration> The plasma processing apparatus 100 of the present embodiment performs processing on a substrate W using 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 performed on the substrate W is, for example, film formation by plasma CVD method, etching, ashing, sputtering, or the like.

[0022] Note that this plasma processing apparatus 100 is also called a plasma CVD apparatus when performing film formation by 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.

[0023] Specifically, as shown in Figure 1, the plasma processing apparatus 100 comprises a vacuum vessel 2 that is evacuated and into which gas is introduced, a linear antenna 3 placed inside the vacuum vessel 2, and a high-frequency power supply 4 that applies high frequency to the antenna 3 to generate an inductively coupled plasma P inside the vacuum vessel 2. By applying high frequency from the high-frequency power supply 4 to the antenna 3, a high-frequency current IR flows through the antenna 3, generating an induced electric field inside the vacuum vessel 2 and creating an inductively coupled plasma P.

[0024] The vacuum container 2 is, for example, a metal container, and its interior is evacuated by a vacuum pump 7. In this example, the vacuum container 2 is electrically grounded.

[0025] Gas is introduced into the vacuum vessel 2, for example, via a flow regulator (not shown) and multiple gas inlets 21 formed on the side wall of the vacuum vessel 2. The gas should be appropriate to the processing to be performed on the substrate W. For example, when forming a film on the substrate W by plasma CVD, the gas is the raw material gas or a gas obtained by diluting it with a diluent gas (e.g., H2). To give a more specific example, if the raw material gas is SiH4, a Si film can be formed on the substrate W; if it is SiH4 + NH3, a SiN film can be formed; if it is SiH4 + O2, an SiO2 film can be formed; and if it is SiF4 + N2, a SiN:F film (fluorinated silicon nitride film) can be formed.

[0026] Furthermore, a substrate holder 8 for holding the substrate W is provided inside the vacuum chamber 2. As in this example, a bias voltage may be applied to the substrate holder 8 from a bias power supply 9. The bias voltage is, for example, a negative DC voltage or a negative pulse voltage, but is not limited to these. By using such a bias voltage, it is possible to control, for example, the energy of positive ions in the plasma P when they are incident on the substrate W, thereby controlling the degree of crystallinity of the film formed on the surface of the substrate W. A heater 81 for heating the substrate W may also be provided inside the substrate holder 8.

[0027] Antenna 3 is positioned above the substrate W inside the vacuum chamber 2, along the surface of the substrate W (for example, substantially parallel to the surface of the substrate W). There may be one or more antennas 3 placed inside the vacuum chamber 2.

[0028] The ends of the antenna 3 penetrate the opposing side walls of the vacuum container 2. Insulating members 11 are provided at the portions of the antenna 3 that penetrate to the outside of the vacuum container 2. The ends of the antenna 3 pass through each of these insulating members 11, and these penetrations are vacuum-sealed by, for example, a packing 12. The space between each insulating member 11 and the vacuum container 2 is also vacuum-sealed by, for example, a packing 13. The material of the insulating members 11 is, for example, ceramics such as alumina, quartz, or engineering plastics such as polyphenylene sulfide (PPS) or polyetheretherketone (PEEK).

[0029] A high-frequency power supply 4 is connected to the feed end 3a of the antenna 3 via a matching circuit 41, and the other end, the termination 3b, is directly grounded. The feed end 3a may also be connected to the high-frequency power supply 4 via a capacitor or coil, and the termination 3b may also be grounded via a capacitor or coil.

[0030] With the above configuration, a high-frequency current IR can be supplied from the high-frequency power supply 4 to the antenna 3 via the matching circuit 41. The frequency of the high-frequency current IR is, for example, a common 13.56 MHz, but is not limited to this.

[0031] Antenna 3 has a hollow structure with a passage through which coolant CL flows. The coolant CL flows through antenna 3 via a circulation passage 14 provided outside the vacuum container 2. The circulation passage 14 is equipped with a temperature control mechanism 141, such as a heat exchanger, for adjusting the coolant CL to a constant temperature, and a circulation mechanism 142, such as a pump, for circulating the coolant CL in the circulation passage 14. From the viewpoint of electrical insulation, water with high resistance is preferred as the coolant CL, for example, pure water or water close to pure water is preferred. In addition, liquid coolants other than water, such as fluorine-based inert liquids, may also be used.

[0032] Specifically, as shown in Figure 2, the antenna 3 comprises at least two cylindrical metal conductor elements 31 (hereinafter referred to as "metal pipes 31"), an insulating element 32 (hereinafter referred to as "insulating pipe 32") which is cylindrical and is provided between adjacent metal pipes 31 to insulate them, and a capacitor 33 which is a capacitive element electrically connected in series with adjacent metal pipes 31.

[0033] In this embodiment, there are two metal pipes 31, and one insulating pipe 32 and one capacitor 33. In the following description, one of the metal pipes 31 will also be referred to as the "first metal pipe 31A," and the other metal pipe as the "second metal pipe 31B." In order to make the antenna 3 longer, for example, 3m or more, the antenna 3 may have a configuration with three or more metal pipes 31. In this case, the number of insulating pipes 32 and capacitors 33 will each be one less than the number of metal pipes 31.

[0034] The metal pipe 31 is cylindrical in shape, with a straight channel 31x formed inside through which the coolant CL flows. The material of the metal pipe 31 may be, for example, copper, aluminum, gold, silver, alloys thereof, stainless steel, etc.

[0035] In this embodiment, the metal pipe 31 has a first conductor element 31a and a second conductor element 31b that are divided in the axial direction. The first conductor element 31a and the second conductor element 31b are cylindrical in shape. The first conductor element 31a has one axial end face facing the one axial end face of the insulating pipe 32. The second conductor element 31b is provided on the other axial end side of the first conductor element 31a.

[0036] Furthermore, a screw-fitting mechanism 34 is formed between the first conductor element 31a and the second conductor element 31b to connect them. In this embodiment, a female threaded portion 341 is formed on the inner circumferential surface of the first conductor element 31a, and a male threaded portion 342 that screws into the female threaded portion 341 is formed on the outer circumferential surface of the second conductor element 31b. As a result, when the second conductor element 31b is inserted into the first conductor element 31a from the opening on the other axial end of the first conductor element 31a, the female threaded portion 341 and the male threaded portion 342 are screwed together, and the first conductor element 31a and the second conductor element 31b are connected. Note that when the first conductor element 31a is inserted into the second conductor element 31b, the female threaded portion 341 may be formed on the second conductor element 31b and the male threaded portion 342 may be formed on the first conductor element 31a.

[0037] More specifically, the second conductor element 31b has a large-diameter portion 31b1 and a small-diameter portion 31b2 extending axially from one axial end face of the large-diameter portion 31b1 to the opposite side of the large-diameter portion 31b1. The first conductor element 31a has a surrounding portion 31a1 into which the small-diameter portion 31b2 is inserted. In this embodiment, the female thread portion 341 is formed circumferentially on the inner circumferential surface of the surrounding portion 31a1, and the male thread portion 342 is formed circumferentially on the outer circumferential surface of the small-diameter portion 31b2.

[0038] Furthermore, the connection between the first conductor element 31a and the second conductor element 31b has a sealing structure against vacuum and coolant CL. Specifically, as shown in Figures 2 and 3, a sealing member 16, such as a packing, is interposed between the first conductor element 31a and the second conductor element 31b, and this sealing member 16 realizes the sealing structure.

[0039] In this embodiment, as shown in Figures 2 and 3, a seal member receiving recess 17 for accommodating the seal member 16 is formed circumferentially on the outer circumferential surface of the small diameter portion 31b2, on the axial side of the male thread portion 342. With the seal member 16 accommodated in the seal member receiving recess 17, the female thread portion 341 and the male thread portion 342 are screwed together, so that the seal member 16 is joined to the portion on the inner circumferential surface of the surrounding portion 31a1 on the axial side of the female thread portion 341.

[0040] The insulating pipe 32 is cylindrical in shape, with a straight channel 32x formed inside through which the coolant CL flows. As shown in Figures 2 and 3, the axial end face of the insulating pipe 32 faces the axial end face of the conductor element 31. Specifically, the end face on one axial end of the insulating pipe 32 faces the axial end face of the first conductor element 31a of the first metal pipe 31A, and the end face on the other axial end of the insulating pipe 32 faces the axial end face of the second metal pipe 31B.

[0041] The insulating pipe 32 is made of a material with a high heat resistance temperature that can withstand high-temperature environments such as 1000°C. Specifically, the material of the insulating pipe 32 is, for example, a high-melting-point ceramic, a machinable ceramic, a transparent ceramic composed of, for example, yttrium oxide, quartz, Vesper, or an aromatic polyimide resin.

[0042] The capacitor 33 is located inside the insulating pipe 32, specifically inside the flow path 32x through which the cooling liquid CL of the insulating pipe 32 flows.

[0043] Specifically, the capacitor 33 comprises a first electrode 33A electrically connected to one of two adjacent metal pipes 31 (the first metal pipe 31A), and a second electrode 33B electrically connected to the other of the two adjacent metal pipes 31 (the second metal pipe 31B) and positioned opposite the first electrode 33A. The space between the first electrode 33A and the second electrode 33B is filled with coolant CL. In other words, the coolant CL flowing through the space between the first electrode 33A and the second electrode 33B becomes the dielectric material constituting the capacitor 33.

[0044] Each electrode 33A and 33B has a roughly rotating shape, and a main flow path 33x is formed in the center along its central axis. Specifically, each electrode 33A and 33B has a flange portion 331 that electrically contacts the metal pipe 31, and an extension portion 332 that extends from the flange portion 331 toward the insulating pipe 32. Each electrode 33A and 33B may be formed from a single material for the flange portion 331 and the extension portion 332, or they may be formed from separate parts and joined together. The material of electrodes 33A and 33B may be, for example, aluminum, copper, or alloys thereof.

[0045] The flange portion 331 is in contact with the ends of the first conductor element 31a and the second conductor element 31b over their entire circumference. Specifically, one axial end face of the flange portion 331 is in contact with the end of the first conductor element 31a, and the other axial end face of the flange portion 331 is in contact with one axial end face of the second conductor element 31b.

[0046] The extension portion 332 is cylindrical in shape, and the main flow path 33x is formed inside it. The extension portion 332 of the first electrode 33A and the extension portion 332 of the second electrode 33B are arranged coaxially with each other. In other words, the extension portion 332 of the second electrode 33B is inserted into the extension portion 332 of the first electrode 33A. As a result, a cylindrical space is formed between the extension portion 332 of the first electrode 33A and the extension portion 332 of the second electrode 33B, along the direction of the flow path.

[0047] Each electrode 33A and 33B configured in this way is sandwiched between the first conductor element 31a and the second conductor element 31b by the screw mechanism 34 connecting them. Specifically, an opposing surface 31a2 facing one axial end face of the small diameter portion 31b2 of the second conductor element 31b is formed on one axial end side of the first conductor element 31a. The female screw portion 341 and the male screw portion 342 are screwed together to connect the first conductor element 31a and the second conductor element 31b, so that the opposing surface 31a2 and one axial end face of the second conductor element 31b sandwich the flange portion 331. With this configuration, in the axial direction, the first conductor element 31a with the opposing surface 31a2 is interposed between one axial end face of the insulating pipe 32 and the flange portion 331, and the axial end face of the insulating pipe 32 does not come into contact with the flange portion 331.

[0048] In this embodiment, the opposing surface 31a2 formed on the first conductor element 31a of the first metal pipe 31A and the axial end face of the second conductor element 31b of the first metal pipe 31A sandwich the first electrode 33A. Similarly, the opposing surface 31a2 formed on the first conductor element 31a of the second metal pipe 31B and the axial end face of the second conductor element 31b of the second metal pipe 31B sandwich the second electrode 33B. By sandwiching each electrode 33A and 33B between the opposing surfaces 31a2 and the axial end face of the second conductor element 31b, the extension portion 332 of the first electrode 33A and the extension portion 332 of the second electrode 33B are arranged coaxially with each other, and each electrode 33A and 33B is sandwiched and fixed between the insulating pipe 32 and the metal pipe 31. Thus, the antenna 3 of this embodiment has a structure in which the metal pipe 31, the insulating pipe 32, the first electrode 33A, and the second electrode 33B are arranged coaxially. Furthermore, the insertion dimension of the extension portion 332 of the second electrode 33B relative to the extension portion 332 of the first electrode 33A is defined by the contact of the end faces of the flange portions 331 of each electrode 33A and 33B with each opposing surface 31a2.

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

[0050] With the above-described configuration, the sealing structure between the first conductor element 31a and the second conductor element 31b, and the electrical contact between the metal pipe 31 and each electrode 33A, 33B are performed together with the fastening of the female threaded portion 341 and the male threaded portion 342, making the assembly work extremely simple.

[0051] Furthermore, the antenna 3 includes a brazing section 35 that joins the metal pipe 31 and the insulating pipe 32 by brazing, with one axial end face of the metal pipe 31 and one axial end face of the insulating pipe 32 facing each other. The material constituting the brazing section 35 is, for example, silver, palladium, aluminum, or copper.

[0052] The brazed portion 35 brazes the connection between the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32. Specifically, one axial end face of the first conductor element 31a and one axial end face of the insulating pipe 32 are in contact in the axial direction, inside the flange portion 331, and the outer circumferential surface of this contact portion is brazed. As a result, one axial end face of the first conductor element 31a and one axial end face of the insulating pipe 32 are joined, and the brazed portion 35 is provided on the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32.

[0053] Furthermore, the antenna 3 of this embodiment further comprises an insulating cover 36 that covers the outer circumferential surface of the metal pipe 31 and the outer circumferential surface of the insulating pipe 32 and is in the shape of a straight tube, and a protruding insulating portion 37 made of insulating material that is provided on the outer circumferential surface of the metal pipe 31 and protrudes from the inner circumferential surface of the insulating cover 36 beyond the outer circumferential surface of the metal pipe 31.

[0054] The insulating cover 36 covers the portion of the antenna 3 located inside the vacuum container 2. Both ends of the insulating cover 36 are supported by insulating members 11. It is not necessary to seal the space between both ends of the insulating cover 36 and the insulating members 11. This is because even if gas enters the space inside the insulating cover 36, the space is small and the distance electrons travel is short, so plasma P is not usually generated in the space. The material of the insulating cover 36 may be, for example, quartz, alumina, fluororesin, silicon nitride, silicon carbide, or silicon.

[0055] By providing the insulating cover 36, it is possible to suppress the incidence of charged particles in the plasma P onto the metal pipe 31 that constitutes the antenna 3. This suppresses the rise in plasma potential caused by the incidence of charged particles (mainly electrons) onto the metal pipe 31, and also suppresses metal contamination of the plasma P and substrate W caused by sputtering of the metal pipe 31 by charged particles (mainly ions).

[0056] The protruding insulating portion 37 forms an annular shape surrounding the outer circumferential surface of the metal pipe 31. As shown in Figures 2 and 3, the outer circumferential surface of the protruding insulating portion 37 is located between the outer circumferential surface of the metal pipe 31 and the inner circumferential surface of the insulating cover 36. This prevents contact between the metal pipe 31 and insulating pipe 32 and the insulating cover 36 even if the antenna 3 bends. The insulating material is preferably a high-melting-point ceramic such as quartz or alumina, which is resistant to deformation even during prolonged plasma treatment.

[0057] In this embodiment, the protruding insulating portion 37 is housed in a receiving recess 38 formed on the outer circumferential surface of the metal pipe 31. Specifically, the receiving recess 38 is composed of one axial end face of the surrounding portion 31a1 of the first conductor element 31a, one axial end face of the large-diameter portion 31b1 of the second conductor element 31b, and the outer circumferential surface of the small-diameter portion 31b2 of the second conductor element 31b. With this configuration, when the female thread portion 341 and the male thread portion 342 are screwed together with the protruding insulating portion 37 surrounding the outer circumferential surface of the small-diameter portion 31b2, the protruding insulating portion 37 is sandwiched between the axial end face of the surrounding portion 31a1 and the axial end face of the large-diameter portion 31b1 and housed in the receiving recess 38.

[0058] <How to assemble the antenna> Next, a brief explanation will be given regarding the assembly method of the antenna 3 in this embodiment.

[0059] First, with the axial end face of the first conductor element 31a of the first metal pipe 31A and the axial end face of the insulating pipe 32 facing each other, the connection portion between the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32 is brazed. As a result, the axial end face of the first conductor element 31a is joined to the axial end face of the insulating pipe 32, and a brazed portion 35 is provided at the connection portion between the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32.

[0060] Similarly, the first conductor element 31a of the second metal pipe 31B and the insulating pipe 32 are also brazed. As a result, one axial end face of the first conductor element 31a of the second metal pipe 31B is joined to the other axial end face of the insulating pipe 32, and a brazed portion 35 is provided at the connection point between the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32. The order of brazing the metal pipes 31A and 31B is not particularly limited.

[0061] Next, the electrodes 33A and 33B are inserted into the first conductor element 31a and the insulating pipe 32.

[0062] Next, the protruding insulating portion 37 is attached to the outer circumferential surface of the small-diameter portion 31b2 of the second conductor element 31b.

[0063] With the first conductor element 31a and the insulating pipe 32 joined by the brazing joint 35, the second conductor element 31b is inserted toward the insulating pipe 32 from the opening on the other axial end of the first conductor element 31a. At this time, the female threaded portion 341 and the male threaded portion 342 are screwed together to connect the first conductor element 31a and the second conductor element 31b.

[0064] With the first conductor element 31a and the second conductor element 31b connected, the opposing surface 31a2 of the first conductor element 31a and the axial end surface of the small-diameter portion 31b2 of the second conductor element 31b sandwich the electrodes 33A and 33B. In this state, the sealing member 16 is joined to the portion on the inner circumferential surface of the surrounding portion 31a1 that is axially closer to the female screw portion 341. The protruding insulating portion 37 is housed in the receiving recess 38.

[0065] <Example of experiment> Antenna 3 of this embodiment was fabricated by brazing the connection between an insulating pipe made of ceramics and a metal pipe with copper. With a 1000°C heater placed 3 cm away from antenna 3, a high frequency was applied to antenna 3 to generate Ar plasma (15 Pa, 3 kW), and it was possible to generate Ar plasma for 1000 hours.

[0066] On the other hand, a conventional antenna was fabricated by connecting an insulating pipe made of PEEK with a metal pipe using screws. When a 1000°C heater was placed 3 cm away from this antenna and high-frequency current was applied to the antenna to generate Ar plasma (15 Pa, 3 kW), the antenna was damaged in 10 minutes.

[0067] <Effects of this embodiment> According to this embodiment, since the brazed portion 35 joins the conductor element 31 and the insulating element 32 by brazing, the heat resistance of the insulating element 32 can be greatly increased compared to the case where, for example, a female thread portion 341 is formed on the insulating element 32. As a result, even when the antenna 3 is used in a high-temperature environment such as 1000°C, damage to the insulating element 32 can be prevented, and film deposition can be performed at high temperatures for a long time. In addition, since the conductive element 31 and the insulating element 32 are joined by brazing, there is no need to form a microstructure on the insulating element 32 for joining with the conductive element 31. Therefore, compared to the case where a microstructure such as a female screw portion 341 is formed on the insulating element 32, the strength of the insulating element 32 can be increased, making it less likely to break even when the specified torque is reached.

[0068] <Other modified embodiments> However, the present invention is not limited to the embodiments described above.

[0069] For example, as shown in Figure 4, the antenna 3 may further include a resin coating portion 39 made of a resin material that coats the connection portion between the inner circumferential surface of the metal pipe 31 and the inner circumferential surface of the insulating pipe 32. The resin coating portion 39 is made of, for example, Teflon, polyimide, or the like.

[0070] Specifically, as shown in Figure 4, the resin coating portion 39 is provided on the inner circumferential surface of the first conductor element 31a and the inner circumferential surface of the insulating pipe 32. More specifically, the resin coating portion 39 is provided on the back surface of the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32, where the brazed portion 35 is provided. With this configuration, the connection portion of the first conductor element 31a and the insulating pipe 32 is sandwiched between the brazed portion 35 and the resin coating portion 39.

[0071] In the above embodiment, the first conductor element 31a and the second conductor element 31b were connected by a screw mechanism 34, but the invention is not limited to this. For example, as shown in Figure 5, the outer circumferential surface of the small-diameter portion 31b2 of the second conductor element 31b may be shaped to fit into the inner circumferential surface of the surrounding portion 31a1 of the first conductor element 31a. In this way, when the second conductor element 31b is inserted into the first conductor element 31a, the small-diameter portion 31b2 of the second conductor element 31b fits into the surrounding portion 31a1 of the first conductor element 31a, thereby connecting the first conductor element 31a and the second conductor element 31b. Note that when the first conductor element 31a is inserted into the second conductor element 31b, the inner circumferential surface of the second conductor element 31b may be configured to fit into the outer circumferential surface of the first conductor element 31a.

[0072] In the above embodiment, the brazed portion 35 was provided on the outer circumferential surface of the first conductor element 31a and the outer circumferential surface of the insulating pipe 32, but it may also be provided on the inner circumferential surface of the first conductor element 31a and the inner circumferential surface of the insulating pipe 32.

[0073] In the above embodiment, the metal pipe and the insulating pipe were tubular in shape with one internal flow path, but they may also have two or more internal flow paths, or branched internal flow paths.

[0074] In the electrodes 33A and 33B of the above embodiment, the extension portion 332 was cylindrical, but it may also be rectangular, flat, curved, or bent.

[0075] Furthermore, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from its spirit. [Explanation of Symbols]

[0076] 100... Plasma processing equipment W ··· circuit board P ···Inductively coupled plasma 2...Vacuum container 3... Antenna 31. Metal pipe (conducting element) 32 ···Insulating pipe (insulating element) 33... Capacitor 33A...First electrode 33B...Second electrode 34...Screwing mechanism 35 ···Brazing part 36...Insulating cover 37 ···Protruding insulating part 38 ···Receiving recess 39 ···Resin coating section CL ···Coolant (liquid dielectric)

Claims

1. It is an antenna that generates plasma by allowing high-frequency current to flow. At least two tubular conductive elements, An insulating element having a cylindrical shape and provided between adjacent conductive elements to insulate those conductive elements, A capacitive element electrically connected in series with the aforementioned conductor elements adjacent to each other, An antenna comprising a brazing portion for joining the conductor element and the insulating element by brazing, with the axial end face of the conductor element and the axial end face of the insulating element facing each other.

2. The aforementioned conductor element has a first conductor element and a second conductor element that are divided in the axial direction. The first conductor element is joined to the axial end face of the insulating element by the brazing portion, The second conductor element is connected to the other axial end of the first conductor element. The antenna according to claim 1, wherein a screw mechanism for connecting the first conductor element and the second conductor element is formed between the first conductor element and the second conductor element.

3. The antenna according to claim 2, wherein the first conductor element and the second conductor element are connected by the screw mechanism, so that the first conductor element and the second conductor element clamp the electrodes of the capacitive element.

4. The antenna according to claim 1, wherein the insulating element is made of a high-melting-point ceramic, a machinable ceramic, a transparent ceramic, quartz, Vesper, or an aromatic polyimide resin.

5. The antenna according to claim 1, wherein the brazed portion is made of silver, palladium, aluminum, or copper.

6. An insulating cover, which covers the outer circumferential surface of the conductor element and the outer circumferential surface of the insulating element, is provided, The antenna according to claim 1, further comprising a protruding insulating portion made of an insulating material, which is provided on the outer circumferential surface of the conductor element and protrudes from the outer circumferential surface of the conductor element toward the inner circumferential surface of the insulating cover.

7. The antenna according to claim 1, wherein the brazed portion brazes the connection portion between the outer circumferential surface of the conductor element and the outer circumferential surface of the insulating element.

8. The antenna according to claim 7, further comprising a resin coating portion made of a resin material, which coats the connection portion between the inner circumferential surface of the conductor element and the inner circumferential surface of the insulating element.

9. An antenna according to any one of claims 1 to 8, The aforementioned antenna is located inside or outside a vacuum vessel, A plasma processing apparatus comprising a high-frequency power supply for applying a high-frequency current to the antenna.

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