Antenna and plasma processing apparatus

Abstract

To realize an antenna capable of operating even under high-temperature conditions.SOLUTION: An antenna (3) includes at least two conductor elements (31) and an insulating element (32). The conductor elements and the insulating element are connected to each other by an adhesive member (34).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an antenna and a plasma processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a plasma processing apparatus including two adjacent conductor elements, an insulating element that insulates the two conductor elements from each other, and a heater that heats a substrate holder. In this plasma processing apparatus, the insulating element is made of a material such as resin or alumina, and the conductor elements and the insulating element are connected by screwing together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-133326 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology described above, when the substrate is heated to a high temperature of around 1000°C to improve lamination efficiency, the LC antenna is also heated by the radiant heat received from the substrate. If quartz glass, ceramic, or the like is used for the insulating element to increase the heat resistance of the LC antenna, there is a risk of breakage at the connection with the conductor element because quartz glass and ceramic have low mechanical strength.

[0005] An object of the present disclosure is to provide an antenna that can operate even in a high-temperature environment and a plasma processing apparatus that includes the antenna. [Means for solving the problem]

[0006] In order to solve the above problems, an antenna according to one embodiment of the present disclosure is an antenna for generating plasma, comprising at least two conductor elements and an insulating element positioned between the conductor elements, and the conductor elements and the insulating element are connected by an adhesive member.

[0007] A plasma processing apparatus according to an aspect of the present disclosure includes the antenna. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, the antenna can be operated even in a high-temperature environment. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a cross-sectional configuration of a plasma processing apparatus according to the present disclosure. [Figure 2] 2 is a cross-sectional view showing the internal structure of an antenna provided in the plasma processing apparatus shown in FIG. [Figure 3] FIG. 1 illustrates an example of an antenna according to the present disclosure. [Figure 4] FIG. 10 is a cross-sectional view showing the internal structure of an antenna according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Embodiment 1] An embodiment of the present disclosure will be described in detail below with reference to the drawings. Fig. 1 is a cross-sectional view showing a cross-sectional configuration of a plasma processing apparatus 1 according to a first embodiment of the present disclosure. In Fig. 1, the direction in which the antenna 3 extends is defined as the X-axis direction, the direction from the vacuum vessel 2 toward the antenna 3 is defined as the Z-axis direction, and the direction perpendicular to both the X-axis direction and the Z-axis direction is defined as the Y-axis direction.

[0011] 1, the plasma processing apparatus 1 performs plasma processing on a substrate W1 using an inductively coupled plasma P1. The substrate W1 may be, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic electroluminescence (EL) display, or a flexible substrate for a flexible display. The processing performed on the substrate W1 may include, for example, film formation by a plasma CVD method or a sputtering method, plasma etching, ashing, or coating film removal.

[0012] The plasma processing apparatus 1 includes a vacuum vessel 2, an antenna 3, a high-frequency power supply 4, a vacuum exhaust device 5, a holder 6, an insulating cover 7, and an insulating member 8. The vacuum vessel 2 is, for example, a metal vessel, and the interior of the vacuum vessel 2 is evacuated to a vacuum by the vacuum exhaust device 5. The vacuum vessel 2 is electrically grounded. A gas inlet 21 is formed in the vacuum vessel 2, and a gas G1 is introduced into the vacuum vessel 2 from the gas inlet 21.

[0013] The gas G1 may be selected depending on the processing to be performed on the substrate W1. For example, when a film is formed on the substrate W1 by plasma CVD, the gas G1 is a source gas or a gas obtained by diluting the source gas with a diluent gas such as H2. More specifically, when the source gas is SiH4, a Si film can be formed on the substrate W1; when SiH4+NH3, a SiN film can be formed; when SiH4+O2, a SiO2 film can be formed; and when SiF4+N2, a SiN:F film (fluorinated silicon nitride film) can be formed.

[0014] The antenna 3 emits electromagnetic waves for generating plasma P1 when a high-frequency current IR is passed through it, and is disposed inside the vacuum vessel 2. The antenna 3 is disposed inside the vacuum vessel 2 on the positive Z-axis direction side relative to the substrate W1 so as to be along the surface of the substrate W1. The number of antennas 3 disposed inside the vacuum vessel 2 may be one or more.

[0015] The high frequency power supply 4 applies high frequency to the antenna 3 to generate plasma P1 inside the vacuum vessel 2. When the high frequency power supply 4 applies high frequency to the antenna 3, a high frequency current IR flows through the antenna 3, an induced electric field is generated inside the vacuum vessel 2, and plasma P1 is generated.

[0016] The holder 6 is provided inside the vacuum chamber 2 and holds the substrate W1. A bias voltage is applied to the holder 6 from a bias power supply 9. The bias voltage is, for example, a negative DC voltage or a negative bias voltage. This bias voltage can, for example, control the energy of positive ions in the plasma P1 when they are incident on the substrate W1, thereby controlling the crystallinity of the film formed on the surface of the substrate W1. A heater 81 for heating the substrate W1 is provided inside the holder 6. The heater 81 can heat the substrate W1 to at least 1000°C.

[0017] Both ends of the antenna 3 airtightly penetrate the opposing side walls of the vacuum vessel 2. Insulating members 8 are provided at the portions of the vacuum vessel 2 through which both ends of the antenna 3 penetrate. Both ends of the antenna 3 airtightly penetrate the respective insulating members 8.

[0018] The insulating member 8 is made of a material such as ceramics such as alumina, quartz, or engineering plastics such as polyphenylene sulfide (PPS) or polyether ether ketone (PEEK). The portion of the antenna 3 located inside the vacuum vessel 2 is covered with a tubular insulating cover 7. Both ends of the insulating cover 7 are supported by the insulating member 8. Most of the insulating cover 7 does not come into contact with the antenna 3.

[0019] It is not necessary to seal the gap between both ends of the insulating cover 7 and the insulating member 8. This is because the space inside the insulating cover 7 is small, and even if gas G1 enters the space inside the insulating cover 7, the travel distance of charged particles is short, so plasma P1 is not usually generated in the space inside the insulating cover 7. The material of the insulating cover 7 is an inorganic, high-resistance material such as quartz, alumina, silicon nitride, or silicon carbide.

[0020] A high-frequency power supply 4 is connected to a power feeding end 3a, which is one end of the antenna 3, via a matching circuit 41, and a termination end 3b, which is the other end of the antenna 3, is directly grounded. Note that the termination end 3b may be grounded via a capacitor, a coil, or the like. The high-frequency power supply 4 can pass a high-frequency current IR through the antenna 3 via the matching circuit 41. The frequency of the high-frequency current is, for example, a common 13.56 MHz, but is not limited to this.

[0021] The coolant CL circulates inside the antenna 3 through a circulation flow path 11 provided outside the vacuum vessel 2. The circulation flow path 11 is provided with a temperature adjustment mechanism 12 and a circulation mechanism 13. The temperature adjustment mechanism 12 is a heat exchanger or the like for adjusting the coolant CL to a constant temperature. The circulation mechanism 13 is a pump or the like for circulating the coolant CL through the circulation flow path 11. From the viewpoint of electrical insulation, the coolant CL is preferably water with high resistance, for example, pure water or water close to pure water. Furthermore, a liquid refrigerant other than water, such as a fluorine-based inert liquid, may also be used as the coolant CL.

[0022] [Antenna 3] Fig. 2 is a cross-sectional view showing the internal structure of the antenna 3 included in the plasma processing apparatus 1 shown in Fig. 1. As shown in Fig. 2, the antenna 3 includes at least two conductor elements 31, at least one capacitive element 33, at least one insulating element 32, and an adhesive member 34. The antenna 3 extends in the axial direction and has a hollow structure in which a flow path is formed through which the coolant CL flows. The axial direction refers to the longitudinal direction of the antenna 3 and is shown as the X-axis direction in Fig. 2.

[0023] The conductor element 31 is a tubular conductive pipe, such as a metal pipe. A linear flow path through which the coolant CL flows is formed inside the conductor element 31. The conductor element 31 is made of a material such as copper, aluminum, an alloy thereof, or stainless steel.

[0024] At least two conductor elements 31 are provided along the longitudinal direction of the antenna 3, and the multiple conductor elements 31 are connected with an insulating element 32 sandwiched between them. The conductor elements 31 have a first protrusion 35 that protrudes in the longitudinal direction of the antenna 3. The outer diameter of the first protrusion 35 is smaller than the outer diameter of the main body of the conductor element 31.

[0025] The insulating element 32 is a tubular insulating pipe made of an insulating material. A linear flow path through which the coolant CL flows is formed inside the insulating element 32. The insulating element 32 is made of a material such as ceramics such as alumina, fluororesin, polyethylene (PE), or engineering plastics such as polyphenylene sulfide (PPS) or polyether ether ketone (PEEK).

[0026] The insulating element 32 is provided between two conductor elements 31 and is connected to each conductor element 31. This allows the insulating element 32 to insulate adjacent conductor elements 31 from each other. The insulating element 32 has a protrusion 37 that protrudes in the longitudinal direction of the antenna. The inner diameter of the protrusion 37 is larger than the outer diameter of the first protrusion 35 of the conductor element 31, and the opening formed by the protrusion 37 can receive the first protrusion 35. In other words, the first protrusion 35 is located inside the protrusion 37.

[0027] The capacitance element 33 is a tubular metal capacitor. A linear flow path through which the coolant CL flows is formed inside the capacitance element 33. The capacitance element 33 is made of a material such as aluminum, copper, or an alloy thereof.

[0028] The capacitive element 33 is disposed between two adjacent conductor elements 31 and inside the insulating element 32. The capacitive element 33 has a first electrode 33A and a second electrode 33B. The first electrode 33A is connected to one of the conductor elements 31, and the second electrode 33B is connected to the other conductor element 31. The first electrode 33A and the second electrode 33B are not directly connected to each other.

[0029] The first electrode 33A and the second electrode 33B have flange-shaped ends on the side in contact with the conductor element 31, and the flange-shaped portions are provided with through-holes 331 for passing the coolant CL. The first electrode 33A and the second electrode 33B also have end faces 36 on the flange-shaped portions that face in the longitudinal direction of the antenna 3.

[0030] An end face 36 of the first electrode 33A abuts against one of the first protrusions 35, and an end face 36 of the second electrode 33B abuts against the other of the first protrusions 35. In this case, the protrusion length of the protrusion 37 when the end face 36 is used as the reference is shorter than the protrusion length of the first protrusion 35. Therefore, a gap is formed between the tip 37A of the protrusion 37 and a step surface 31A located at the base of the first protrusion 35. The step surface 31A is a surface of the conductor element 31 facing the direction in which the insulating element 32 is located, and is located farther from the insulating element 32 than the end face 35A of the first protrusion 35, forming a step with the end face 35A in the X-axis direction.

[0031] Generally, the generated plasma P1 can be made uniform by reducing the impedance of the antenna 3. For this reason, the conductor elements 31 are not directly connected to each other, but are electrically connected via the capacitance element 33, thereby reducing the impedance. With the above configuration, the conductor elements 31 and the capacitance element 33 are reliably electrically connected, thereby reliably reducing the impedance of the antenna 3 and contributing to the uniformity of the plasma P1.

[0032] Furthermore, since the protrusion length of the first protrusion 35 is longer than that of the protrusion 37, a part of the outer surface of the first protrusion 35 is exposed between the tip 37A of the protrusion 37 and the step surface 31A of the first protrusion 35. The antenna 3 is provided with a spacer 38 on this exposed outer surface.

[0033] The spacer 38 is a protruding insulating body that protrudes in a direction perpendicular to the longitudinal direction of the antenna 3 beyond the outer surfaces of the conductor element 31 and the insulating element 32. The spacer 38 is made of an insulating material, for example, quartz glass, a high-melting-point ceramic such as alumina, or the like.

[0034] If the insulating cover 7 and the conductor element 31 come into contact during operation of the plasma processing apparatus 1, an electric field will concentrate at the contact point, which may result in damage to the insulating cover 7. By having the spacer 38 protrude beyond the outer surfaces of the conductor element 31 and the insulating element 32, contact between the insulating cover 7 and the conductor element 31 can be prevented.

[0035] The spacer 38 is annular and is formed by butting two semi-annular members together. An adhesive may be used to connect the spacer 38. Therefore, the spacer 38 can be provided even after the conductor element 31 and the insulating element 32 are connected. This allows the spacer 38 to be provided after the conductor element 31, the capacitive element 33, and the insulating element 32 are connected, thereby improving the assembly efficiency of the antenna 3.

[0036] (Method of connecting the conductor element 31 and the insulating element 32) The conductor element 31 and the insulating element 32 are connected by an adhesive member 34. For example, if the insulating element 32 and the conductor element 31 are connected by a screw structure, the strength of the insulating element 32 at the connection portion is required. In contrast, according to the above configuration, by connecting the insulating element 32 and the conductor element 31 by the adhesive member 34, the insulating element 32 and the conductor element 31 can be connected without relying on the strength of the insulating element 32. This reduces the risk of damage to the insulating element 32. This allows the use of a highly heat-resistant insulating element 32, allowing the antenna 3 that generates the plasma P1 to operate for a long period of time in a high-temperature environment.

[0037] Furthermore, the adhesive member 34 does not necessarily have to be made of a heat-resistant material. For example, in the plasma processing apparatus 1, when the substrate W1 is heated using the heater 81, the substrate W1 reaches a high temperature of nearly 1000°C. At this time, if the antenna 3 and the substrate W1 are close to each other, for example, about 30 mm apart, the antenna 3 is also heated by radiant heat from the substrate W1. However, because the coolant CL flows inside the antenna 3, the adhesiveness and durability of the adhesive member 34 are unlikely to be impaired depending on the application position and amount of the adhesive member 34.

[0038] The adhesive member 34 may contain an ultraviolet curing resin. By using an ultraviolet curing resin as the adhesive member 34, it is possible to increase the airtightness between the insulating element 32 and the conductor element 31, and also to improve the efficiency of the work of joining the insulating element 32 and the conductor element 31.

[0039] Furthermore, the adhesive member 34 is located between the outer surface of the first convex portion 35 and the inner surface of the protruding portion 37, and the insulating element 32 has a material that is transparent to ultraviolet light. According to the above configuration, the adhesive member 34 is located on the outer surface of the first convex portion 35 of the conductor element 31, and is covered by the protruding portion 37 of the insulating element 32. Even with this configuration, the insulating element 32 has a material that is transparent to ultraviolet light, so that the ultraviolet curable resin can be cured by applying ultraviolet light to the adhesive member 34 containing the ultraviolet curable resin from outside the insulating element 32.

[0040] Materials that are transparent to ultraviolet light include, for example, quartz glass and transparent ceramics (transparent yttrium oxides such as Y2O3).

[0041] The adhesive member 34 may also contain water glass. Using water glass as the adhesive member 34 can improve the airtightness between the insulating element 32 and the conductor element 31. Furthermore, compared to ultraviolet curing resin, no special treatment such as irradiation with ultraviolet light is required to harden the water glass, and the efficiency of the work of joining the insulating element 32 and the conductor element 31 can be improved.

[0042] Fig. 3 is a diagram showing an example of an antenna 3 according to the present disclosure. As shown in Fig. 3, the conductor elements 31 and the insulating elements 32 may be connected in a long length. Although Fig. 3 shows an antenna 3 including three insulating elements 32, the number of insulating elements 32 and conductor elements 31 included in the antenna 3 is not particularly limited. By lengthening the antenna 3, the generation area of ​​the plasma P1 can be widened, thereby improving the processing efficiency for the substrate W1.

[0043] [Embodiment 2] Other embodiments of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0044] 4 is a cross-sectional view showing the internal structure of an antenna 3B according to another embodiment. The antenna 3B includes a conductor element 31B and an insulating element 32B instead of the conductor element 31 and the insulating element 32 of the antenna 3 described above.

[0045] The insulating element 32B has a protrusion 37B. The conductor element 31B has a first protrusion 35B located inside the protrusion 37B. The first protrusion 35B has at least one second protrusion 40. The second protrusion 40 protrudes in a direction perpendicular to the longitudinal direction of the antenna 3B and is located inside the protrusion 37B. The second protrusion 40 protrudes in a substantially cross direction, as shown in the VV cross-sectional view of FIG. 4, for example. The number and shape of the second protrusions 40, and the arrangement when multiple second protrusions 40 are provided, are not particularly limited. Furthermore, the protrusion 37B has a recess on its inner surface that fits with the convex shape of the second protrusion 40.

[0046] Furthermore, the adhesive member 34 is located between the outer surfaces of the first convex portion 35B and the second convex portion 40 and the inner surface of the protrusion 37B.

[0047] According to the above configuration, by providing the second convex portion 40, the application area of ​​the adhesive member 34 can be increased compared to when only the first convex portion 35 is provided as in embodiment 1, thereby improving adhesion and preventing the insulating element 32 and the conductor element 31 from rotating circumferentially around the axis, thereby reducing loosening and damage due to rotation, etc.

[0048] 〔summary〕 A first aspect of the antenna according to the present disclosure is an antenna for generating plasma, comprising at least two conductor elements and an insulating element positioned between the conductor elements, the conductor elements and the insulating element being connected by an adhesive member.

[0049] A second aspect of the antenna according to the present disclosure is the same as the first aspect, wherein the adhesive member includes an ultraviolet curable resin.

[0050] Aspect 3 of the antenna according to the present disclosure is any of aspects 1 and 2, wherein the insulating element has a protruding portion protruding in the longitudinal direction of the antenna, the conductor element has a first protruding portion protruding in the longitudinal direction of the antenna, the first protruding portion being located inside the protruding portion, the adhesive member being located between the outer surface of the first protruding portion and the inner surface of the protruding portion, and the insulating element is made of a material that is transparent to ultraviolet rays.

[0051] A fourth aspect of the antenna according to the present disclosure is the first aspect, wherein the adhesive member includes water glass.

[0052] A fifth aspect of the antenna according to the present disclosure is any one of aspects 1 to 4, further comprising a capacitive element disposed inside the insulating element and having an end face facing the longitudinal direction of the antenna, wherein the insulating element has a protruding portion protruding in the longitudinal direction of the antenna, the conductor element has a first protruding portion protruding in the longitudinal direction of the antenna, the first protruding portion abutting the end face, and the protruding length of the protruding portion based on the end face is shorter than the length of the first protruding portion.

[0053] A sixth aspect of the antenna according to the present disclosure is any one of the first to fifth aspects, further comprising a protruding insulating body on the exposed outer surface of the first convex portion, which protrudes in a direction perpendicular to the longitudinal direction of the antenna beyond the outer surfaces of the conductor element and the insulating element.

[0054] A seventh aspect of the antenna according to the present disclosure is any one of the first to sixth aspects, wherein the conductor element and the insulating element are connected in a long length.

[0055] An eighth aspect of the antenna according to the present disclosure is any one of the first to seventh aspects, wherein the insulating element has a protruding portion protruding in the longitudinal direction of the antenna, the conductor element has a first protruding portion protruding in the longitudinal direction of the antenna, the first protruding portion being located inside the protruding portion and having at least one second protruding portion, the second protruding portion protruding in a direction perpendicular to the longitudinal direction of the antenna, and the adhesive member being located between the outer surfaces of the first protruding portion and the second protruding portion and the inner surface of the protruding portion.

[0056] A plasma generation device according to the present disclosure includes the antenna according to any one of the first to eighth aspects.

[0057] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0058] 1. Plasma processing equipment 2 Vacuum container 3, 3B Antenna 31, 31B Conductor elements 32, 32B insulating elements 33 Capacitor element 34 Adhesive material 35, 35B First convex part 36 End face 37 Protrusion 38 Spacer 40 Second convex part 7 Insulation cover W1 board P1 Plasma CL coolant

Claims

1. An antenna for generating plasma, at least two conductor elements; an insulating element located between the conductor elements; The antenna, wherein the conductor element and the insulating element are connected by an adhesive member.

2. The antenna according to claim 1 , wherein the adhesive member includes an ultraviolet curable resin.

3. the insulating element has a protrusion that protrudes in the longitudinal direction of the antenna, the conductor element has a first protrusion protruding in the longitudinal direction of the antenna, the first convex portion is located inside the protruding portion, the adhesive member is located between an outer surface of the first convex portion and an inner surface of the protruding portion, 3. The antenna of claim 2, wherein the insulating element comprises a material that is transparent to ultraviolet light.

4. The antenna of claim 1 , wherein the adhesive member comprises water glass.

5. a capacitance element disposed inside the insulating element and having an end surface facing a longitudinal direction of the antenna; the insulating element has a protrusion that protrudes in the longitudinal direction of the antenna, the conductor element has a first protrusion protruding in the longitudinal direction of the antenna, the first protrusion abuts against the end surface, The antenna according to claim 1 , wherein a protruding length of the protruding portion from the end face is shorter than a length of the first convex portion.

6. 6. The antenna according to claim 5, further comprising a protruding insulating body on the exposed outer surface of the first protrusion, the protruding body protruding in a direction perpendicular to the longitudinal direction of the antenna beyond the outer surfaces of the conductor element and the insulating element.

7. The antenna of claim 1 , wherein the conductive element and the insulating element are joined together in an elongated manner.

8. the insulating element has a protrusion that protrudes in the longitudinal direction of the antenna, the conductor element has a first protrusion protruding in the longitudinal direction of the antenna, the first protrusion is located inside the protruding portion and has at least one second protrusion, the second protrusion protrudes in a direction perpendicular to the longitudinal direction of the antenna, The antenna according to claim 1 , wherein the adhesive member is located between outer surfaces of the first and second protrusions and an inner surface of the protrusion.

9. A plasma processing apparatus comprising the antenna according to claim 1 .

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