Plasma processing device

Abstract

This invention generates uniform plasma by reducing the possibility of dielectric breakdown even when a dielectric plate is divided into a plurality of parts. This plasma processing device is provided with: an antenna (3) that generates plasma inside a vacuum container (1); and a plurality of dielectric plates (22) that are disposed so as to close an opening (11) of the vacuum container (1). At least a portion of the antenna (3) that overlaps a gap (22A) formed between the end surfaces of two adjacent dielectric plates (22) has insulating properties.

Description

Plasma processing equipment

[0001] The present disclosure relates to a plasma processing apparatus.

[0002] A plasma processing apparatus using an inductively coupled plasma is known, in which a high-frequency electric field generated by an antenna disposed outside a vacuum chamber is introduced through a dielectric window provided in the vacuum chamber. For example, Patent Document 1 describes a plasma processing apparatus that includes a slit plate that closes an opening formed in the vacuum chamber facing the antenna, and a dielectric plate that closes a slit formed in the slit plate from outside the vacuum chamber to form a dielectric window.

[0003] Japanese Patent Application Publication No. 2021-111595

[0004] However, in the plasma processing apparatus disclosed in Patent Document 1, when the dielectric plate is divided into multiple pieces to increase the length, the end faces of the dielectric plate and the metal surface of the slit plate disposed below the dielectric plate are exposed to the antenna, which may cause dielectric breakdown through the end faces of the dielectric plate.

[0005] An aspect of the present disclosure aims to reduce the possibility of dielectric breakdown and generate uniform plasma even when a dielectric plate is divided into multiple pieces.

[0006] In order to solve the above problems, a plasma processing apparatus according to one embodiment of the present disclosure comprises a vacuum container whose interior is evacuated to a vacuum, an antenna provided outside the vacuum container that generates plasma inside the vacuum container when a high-frequency current flows through it, and a plurality of dielectric plates arranged to cover openings formed in the vacuum container at positions facing the antenna, and when viewed from a direction perpendicular to a plane parallel to the dielectric plates, at least the portion of the antenna that overlaps with the gap formed between the end faces of two adjacent dielectric plates among the plurality of dielectric plates is insulating when viewed from the planar view.

[0007] According to one aspect of the present disclosure, even when the dielectric plate is divided into multiple pieces, the possibility of dielectric breakdown can be reduced and uniform plasma can be generated.

[0008] Fig. 3 is a cross-sectional view showing an example of the configuration of a plasma processing apparatus according to embodiment 1 of the present disclosure. Fig. 4 is a cross-sectional view showing an example of the peripheral structure of a radio frequency window provided in the plasma processing apparatus shown in Fig. 1. Fig. 5 is a cross-sectional view showing an enlarged view of a portion of dotted line A1 shown in Fig. 3.

[0009] [Embodiment 1] <Configuration of plasma processing apparatus 100> Figure 1 is a cross-sectional view showing an example of the configuration of a plasma processing apparatus 100 according to embodiment 1 of the present disclosure. In Figure 1, the direction in which multiple slits 24 are arranged is the X-axis direction, the direction from the vacuum vessel 1 toward the antenna 3 is the positive Z-axis direction, and the direction perpendicular to both the X-axis direction and the Z-axis direction is the Y-axis direction. The X-axis direction and the Z-axis direction are mutually perpendicular directions. The definitions of directions described here are also applicable to other figures.

[0010] The plasma processing apparatus 100 uses an inductively coupled plasma P1 to process a substrate W1 placed inside a vacuum chamber 1. The substrate W1 is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic EL display, or a flexible substrate for a flexible display.

[0011] The processing performed on the substrate W1 includes, for example, film formation by plasma CVD (Chemical Vapor Deposition) or sputtering, plasma etching, ashing, coating film removal, etc. As shown in Figure 1, the plasma processing apparatus 100 includes a vacuum chamber 1, a radio frequency window 2, an antenna 3, a vacuum exhaust device 4, and a radio frequency power supply 5.

[0012] <Configuration of Vacuum Vessel 1 and Vacuum Exhaust Device 4> The vacuum vessel 1 is, for example, a metal vessel, and has an opening 11 formed in an upper wall 1A on the positive side of the Z axis of the vacuum vessel 1. The opening 11 is formed in a position on the upper wall 1A facing the antenna 3. The vacuum vessel 1 is electrically grounded by being connected to the ground.

[0013] The interior of the vacuum vessel 1 is evacuated by a vacuum exhaust device 4. The vacuum exhaust device 4 has a pump that evacuates the interior of the vacuum vessel 1. A gas GS is introduced into the vacuum vessel 1 via, for example, a flow rate regulator (not shown) or at least one gas inlet 12 formed in the vacuum vessel 1.

[0014] The gas GS 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 GS may be a source gas or a dilution gas thereof (e.g., H ２ ) is diluted with the raw material gas SiH ４ In the case of ４ +NH ３ In the case of ４ +O ２ In the case of SiO ２ The film was then treated with SiF ４ +N ２ In the case of (1), a SiN:F film (fluorinated silicon nitride film) can be formed on the substrate W1.

[0015] <Configuration of Radio Frequency Window 2> Figure 2 is a cross-sectional view showing an example of the peripheral structure of the radio frequency window 2 included in the plasma processing apparatus 100 shown in Figure 1. The radio frequency window 2 introduces a radio frequency magnetic field generated by the antenna 3 into the vacuum vessel 1 in order to generate plasma P1 inside the vacuum vessel 1. As shown in Figures 1 and 2, the radio frequency window 2 includes a flange portion 21, a plurality of dielectric plates 22, and a plurality of beam portions 23. The radio frequency window 2 is provided on the upper wall 1A of the vacuum vessel 1.

[0016] When the high-frequency window 2 is viewed from the positive side of the Z-axis toward the negative side of the Z-axis, the flange portion 21 forms an outer frame portion of the high-frequency window 2. The multiple beam portions 23 are arranged side by side in the X-axis direction. Each of the multiple beam portions 23 extends along the Y-axis direction and is provided between the end of the flange portion 21 on the positive side of the Y-axis and the end of the flange portion 21 on the negative side of the Y-axis.

[0017] Each of the multiple beam portions 23 is connected to the flange portion 21. Slits 24 are formed between the multiple beam portions 23. In addition, a slit 24 is formed between the beam portion 23 and a portion of the flange portion 21 on the positive side of the X-axis, and a slit 24 is also formed between the beam portion 23 and a portion of the flange portion 21 on the negative side of the X-axis. The multiple slits 24 are formed side by side in the X-axis direction. Each of the multiple beam portions 23 supports both of two adjacent dielectric plates 22 out of the multiple dielectric plates 22.

[0018] The flange portion 21 and the beam portion 23 are made of metal and constitute a slit plate in which a plurality of slits 24 are formed. The mechanical strength of the flange portion 21 and the beam portion 23 is preferably higher than the mechanical strength of the dielectric plate 22 described below, and the thickness of the flange portion 21 and the beam portion 23 along the Z-axis direction is preferably greater than the thickness of the dielectric plate 22 along the Z-axis direction.

[0019] The flange portion 21 and the beam portion 23 are electrically grounded by being provided on the electrically grounded vacuum vessel 1. By being electrically grounded, the flange portion 21 and the beam portion 23 allow the magnetic field generated from the antenna 3 to pass into the inside of the vacuum vessel 1, and also block the electric field generated due to the potential of the antenna 3 when a high-frequency current I1 is introduced into the antenna 3. The magnetic field generated from the antenna 3 is introduced into the inside of the vacuum vessel 1 through the dielectric plate 22 and the plurality of slits 24.

[0020] The flange portion 21 and the beam portion 23 are made of a metal material such as one metal selected from the group including, for example, Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co, or an alloy thereof (for example, a stainless steel alloy or an aluminum alloy).

[0021] A seal S1 provided in the plasma processing apparatus 100 is interposed between the flange 21 and the upper wall 1A. The seal S1 provides a vacuum seal between the flange 21 and the upper wall 1A. The seal S1 is, for example, a gasket such as an O-ring or a rubber sheet. The seal S1 may also be, for example, an adhesive material. In this case, the seal S1 may be a lubricating oil such as a high-viscosity vacuum grease with a low vapor pressure.

[0022] <Configuration of Dielectric Plates 22> The plurality of dielectric plates 22 are provided on the flange portion 21 and the beam portion 23 so as to close the plurality of slits 24 from the outside of the vacuum vessel 1. Thus, the plurality of dielectric plates 22 are arranged so as to close the opening 11 formed in the vacuum vessel 1 at a position facing the antenna 3. The plurality of dielectric plates 22 block the movement of gas through the plurality of slits 24, that is, block the movement of gas through the opening 11. In this way, the plurality of dielectric plates 22 maintain the airtightness of the interior of the vacuum vessel 1.

[0023] Each of the plurality of dielectric plates 22 is a flat plate made entirely of a dielectric material. Each of the plurality of dielectric plates 22 is made of, for example, ceramics such as alumina, silicon carbide, or silicon nitride, inorganic materials such as quartz glass or alkali-free glass, or resin materials such as fluororesin. The plurality of dielectric plates 22 allow the magnetic field generated from the antenna 3 to pass into the interior of the vacuum vessel 1. As a result, a magnetic field is formed inside the vacuum vessel 1, generating an induced electric field, which ionizes the gas GS, generating plasma P1.

[0024] It is preferable that each of the plurality of dielectric plates 22 is made of a single plate. This makes it easy to reduce the thickness of each of the plurality of dielectric plates 22. Therefore, the distance between the antenna 3 and the vacuum vessel 1 can be easily shortened, making it easy to generate a high-frequency magnetic field inside the vacuum vessel 1 efficiently.

[0025] A gap 22A is formed between the end faces of each of the plurality of dielectric plates 22. That is, the gap 22A is formed between the end faces of two of the plurality of dielectric plates 22 that are adjacent to each other in the X-axis direction. As a result, each of the plurality of beam portions 23 is exposed to an insulator 31 (described later) through the gap 22A. Furthermore, the end of the flange portion 21 on the Y-axis positive side and the end on the Y-axis negative side are exposed to the insulator 31 through the gap 22A.

[0026] In the Z-axis direction, a seal portion S1 is interposed between the flange portion 21 and the dielectric plate 22 located furthest in the positive X-axis direction among the plurality of dielectric plates 22. In addition, in the Z-axis direction, a seal portion S1 is interposed between the flange portion 21 and the dielectric plate 22 located furthest in the negative X-axis direction among the plurality of dielectric plates 22. The seal portion S1 provides a vacuum seal between the flange portion 21 and the dielectric plate 22.

[0027] Furthermore, a seal portion S1 is also interposed between the plurality of dielectric plates 22 and the plurality of beam portions 23. The seal portion S1 provides a vacuum seal between the plurality of dielectric plates 22 and the plurality of beam portions 23. The seal portion S1 is used to fix the plurality of dielectric plates 22 to the flange portion 21 and the beam portions 23.

[0028] <Configuration of Antenna 3> The antenna 3 is provided outside the vacuum vessel 1 and is positioned facing the top wall 1A of the vacuum vessel 1. The antenna 3 generates a magnetic field when a high-frequency current I1 flows through it, thereby generating plasma P1 inside the vacuum vessel 1. The shape of the antenna 3 is rod-like or cylindrical. The number of antennas 3 is not limited to one, and may be multiple.

[0029] 1, both sides of the antenna 3 are curved in the positive direction of the Z axis. One end of the antenna 3, which is a power supply end, is connected to a high-frequency power supply 5 via a matching circuit (not shown). The other end of the antenna 3, which is a terminal end, is connected to ground G1 and is thereby electrically grounded. The terminal end may also be connected to ground G1 via a capacitor, a coil, or the like.

[0030] The central portion of the antenna 3 in the X-axis direction extends in parallel with the plurality of dielectric plates 22. In addition, the central portion of the antenna 3 extends in the X-axis direction along the plurality of dielectric plates 22, the plurality of beam portions 23, and the upper wall 1A of the vacuum vessel 1.

[0031] Here, a plan view refers to a view from a direction perpendicular to a plane parallel to the dielectric plate 22. The plane parallel to the dielectric plate 22 is the XY plane, and the direction perpendicular to the plane parallel to the dielectric plate 22 is the Z-axis direction. When the antenna 3 is viewed in a plan view, at least the portion of the antenna 3 that overlaps with the gap 22A is insulating.

[0032] 2, when viewed from the Z-axis direction, an insulator 31 is provided on the surface of at least a portion of the antenna 3 that overlaps with the gap 22A. Of the portions of the antenna 3 that overlap with the gap 22A, an insulator 31 is provided on each of the surface on the positive Z-axis side and the surface on the negative Z-axis side.

[0033] The insulator 31 is, for example, a flexible insulating sheet. The insulator 31 is provided along the curved surface of the antenna 3. The length of the insulator 31 along the X-axis direction is longer than the length of the gap 22A along the X-axis direction. This allows the portions of the antenna 3 other than the insulating portion to be separated from the gap 22A, thereby reliably preventing dielectric breakdown.

[0034] As described above, the portion where the antenna 3 and the gap 22A overlap in plan view can be made insulating by the simple configuration of providing the insulator 31 on the surface of the antenna 3, and dielectric breakdown can be prevented at low cost. In addition, the portion of the antenna 3 covered by the insulator 31 becomes an insulating portion.

[0035] The insulating portion of the antenna 3 is a portion opposite the beam portion 23 across the dielectric plate 22. Specifically, when viewed from the Z-axis direction, an insulator 31 is provided on the surface of the portion of the antenna 3 opposite the beam portion 23 across the dielectric plate 22. This prevents dielectric breakdown, which improves the durability of the beam portion 23 and enables the generation of uniform plasma P1 to continue for a long period of time.

[0036] <Configuration of High Frequency Power Supply 5> The high frequency power supply 5 can pass a high frequency current I1 through the antenna 3 via a matching circuit (not shown). The frequency of the high frequency is, for example, a common 13.56 MHz, but is not limited to this and may be changed as appropriate. The high frequency power supply 5 is connected to the ground. When the high frequency current I1 is introduced into the antenna 3 by the high frequency power supply 5, a magnetic field is generated around the antenna 3.

[0037] As a result, in the plasma processing apparatus 100, at least the portion of the antenna 3 that overlaps with the gap 22A formed between the end faces of two adjacent dielectric plates 22 among the plurality of dielectric plates 22 has insulating properties. Therefore, it is possible to prevent dielectric breakdown from occurring in the space between the antenna 3 and the vacuum chamber 1 via the gap 22A. Specifically, it is possible to prevent dielectric breakdown from occurring in the space between the antenna 3 and the beam portion 23.

[0038] Therefore, even when the antenna 3 is close to the gap 22A, that is, when the central portion of the antenna 3 in the X-axis direction extends parallel to the plurality of dielectric plates 22, it is possible to prevent dielectric breakdown from occurring. Since the central portion of the antenna 3 extends parallel to the plurality of dielectric plates 22, the center position of the high-frequency current I1 is constant within the central portion of the antenna 3.

[0039] The center position of the high-frequency current I1 is the center position of a cross section obtained by cutting the central portion of the antenna 3 with a plane perpendicular to the extension direction of the central portion of the antenna 3. The extension direction of the central portion of the antenna 3 is the X-axis direction, and the plane perpendicular to the extension direction of the central portion of the antenna 3 is the YZ plane. Since the center position of the high-frequency current I1 is constant within the central portion of the antenna 3, the continuity of the distribution of the high-frequency magnetic field generated by the antenna 3 can be improved.

[0040] By improving the continuity of the distribution of the high-frequency magnetic field, it is possible to generate a uniform plasma P1 inside the vacuum vessel 1. Therefore, even if the dielectric plate is divided into multiple pieces, it is possible to reduce the possibility of dielectric breakdown and generate a uniform plasma P1.

[0041] The case where the dielectric plate is divided into multiple pieces includes a case where the high-frequency window 2 includes multiple dielectric plates 22 in order to make the dielectric plate long, or a case where the dielectric plate is damaged. Even in such a case, discharge between the antenna 3 and the beam portion 23 through the gap 22A can be suppressed. Furthermore, since dielectric breakdown can be prevented from occurring in the space between the antenna 3 and the beam portion 23, damage to the seal portion S1 interposed between the multiple dielectric plates 22 and the multiple beam portions 23 can be prevented.

[0042] [Embodiment 2] Embodiment 2 of the present disclosure will be described below. For ease of explanation, members having the same functions as those described in embodiment 1 will be denoted by the same reference numerals, and their descriptions will not be repeated. Fig. 3 is a cross-sectional view showing an example of the peripheral structure of a radio frequency window 2 provided in a plasma processing apparatus according to embodiment 2 of the present disclosure. Fig. 4 is a cross-sectional view showing an enlarged view of the portion indicated by the dotted line A1 in Fig. 3.

[0043] 3, the plasma processing apparatus according to the second embodiment differs from the plasma processing apparatus 100 in that the antenna 3 is replaced with an antenna 3A. As shown in FIGS. 3 and 4, the antenna 3A includes at least two conductor elements 32, at least one insulating element 33, and a capacitive element 34.

[0044] The antenna 3A has a hollow structure, and a flow path through which the coolant CL flows is formed inside the antenna 3A. The conductor elements 32 are tubular metal pipes made of metal. The insulating elements 33 are provided between adjacent conductor elements 32 to insulate the conductor elements 32. The insulating elements 33 are tubular insulating pipes. The capacitive elements 34 are capacitors electrically connected in series with adjacent conductor elements 32.

[0045] In the following description, one of the adjacent conductor elements 32 may be referred to as the first conductor element 32A, and the other of the adjacent conductor elements 32 may be referred to as the second conductor element 32B. The number of insulating elements 33 and capacitive elements 34 is each one less than the number of conductor elements 32.

[0046] The coolant CL circulates through the antenna 3A through a circulation flow path (not shown) provided outside the vacuum vessel 1. The circulation flow path is provided with a temperature control mechanism (not shown), such as a heat exchanger, for adjusting the coolant CL to a constant temperature, and a circulation mechanism (not shown), such as a pump, for circulating the coolant CL through the circulation flow path. From the viewpoint of electrical insulation, high-resistivity water is preferred as the coolant CL, for example, pure water or water close to pure water. Alternatively, a liquid refrigerant other than water, such as a fluorine-based inert liquid, may be used as the coolant CL.

[0047] The conductor element 32 is a straight pipe having a linear flow path 32X formed therein through which the coolant CL flows. A male thread portion 32S is formed on the outer periphery of at least one longitudinal end of the conductor element 32. The end portion of the conductor element 32 having the male thread portion 32S and the remaining member are formed as separate parts and joined together, but the conductor element 32 may also be formed from a single member.

[0048] In order to standardize the components that connect the multiple conductor elements 32, it is preferable to provide interchangeability by forming male threads 32S at both longitudinal ends of the conductor elements 32. The conductor elements 32 are made of a material such as copper, aluminum, an alloy of these, or stainless steel.

[0049] The insulating element 33 has a straight pipe shape and a linear flow path 33X formed therein through which the coolant CL flows. Female threaded portions 33S are formed on the side walls of both axial end portions of the insulating element 33 to threadably engage with the male threaded portions 32S of the conductor element 32. Furthermore, recessed portions 33C are formed over the entire circumferential direction on the side walls of both axial end portions of the insulating element 33, closer to the axial center than the female threaded portions 33S, for fitting the first electrode 34A and the second electrode 34B of the capacitance element 34 therein.

[0050] The insulating element 33 is formed from a single member, but is not limited to this. The insulating element 33 may be made of a material such as alumina, fluororesin, polyethylene (PE), or engineering plastic. Examples of engineering plastic include polyphenylene sulfide (PPS) and polyether ether ketone (PEEK).

[0051] The capacitive element 34 is provided inside the insulating element 33. Specifically, the capacitive element 34 is provided in a flow path 33X formed inside the insulating element 33. The capacitive element 34 includes a first electrode 34A and a second electrode 34B. The first electrode 34A is electrically connected to the first conductor element 32A. The second electrode 34B is electrically connected to the second conductor element 32B and is disposed opposite the first electrode 34A. The space between the first electrode 34A and the second electrode 34B is filled with a coolant CL. In other words, the coolant CL flowing through the space between the first electrode 34A and the second electrode 34B serves as a dielectric that constitutes the capacitive element 34.

[0052] The first electrode 34A and the second electrode 34B are generally shaped like a solid of revolution, and a flow path 34X is formed in the center along the central axis. The first electrode 34A and the second electrode 34B each have a flange portion 341 and an extension portion 342. The flange portion 341 is in electrical contact with the end of the conductor element 32 on the insulating element 33 side. The extension portion 342 extends from the flange portion 341 toward the insulating element 33 side.

[0053] The first electrode 34A and the second electrode 34B may each have the flange portion 341 and the extension portion 342 formed from a single member, or may be formed from separate parts that are joined together. The material of the first electrode 34A and the second electrode 34B is, for example, aluminum, copper, or an alloy thereof.

[0054] The flange portion 341 is in contact with the end of the conductor element 32 on the insulating element 33 side over the entire circumferential direction. Specifically, the axial end face of the flange portion 341 is in contact with the tip face of the cylindrical contact portion 311 formed on the end of the conductor element 32 over the entire circumferential direction. In addition, the axial end face of the flange portion 341 is in electrical contact with the end face of the conductor element 32 via a ring-shaped multi-faceted contactor L1 provided on the outer periphery of the contact portion 311 of the conductor element 32.

[0055] Furthermore, a plurality of through holes 341H are formed in the thickness direction of the flange portion 341. By forming the through holes 341H in the flange portion 341, the flow resistance of the coolant CL due to the flange portion 341 can be reduced, and the coolant CL can be prevented from stagnating in the insulating element 33 and air bubbles can be prevented from accumulating in the insulating element 33.

[0056] The extension 342 has a cylindrical shape, and a flow path 34X is formed therein. The extension 342 of the first electrode 34A and the extension 342 of the second electrode 34B are arranged coaxially with each other. In other words, the extension 342 of the second electrode 34B is inserted into the extension 342 of the first electrode 34A. This forms a cylindrical space along the flow path direction between the extension 342 of the first electrode 34A and the extension 342 of the second electrode 34B.

[0057] The first electrode 34A and the second electrode 34B are fitted into recesses 33C formed in the side peripheral wall of the insulating element 33. Specifically, the first electrode 34A is fitted into the recess 33C formed on one axial end side of the insulating element 33, and the second electrode 34B is fitted into the recess 33C formed on the other axial end side of the insulating element 33.

[0058] By fitting the first electrode 34A and the second electrode 34B into each recess 33C in this manner, the extension 342 of the first electrode 34A and the extension 342 of the second electrode 34B are arranged coaxially with each other. Furthermore, by contacting the end faces of the flanges 341 of the first electrode 34A and the second electrode 34B with the surfaces of each recess 33C facing outward in the axial direction, the insertion dimension of the extension 342 of the second electrode 34B relative to the extension 342 of the first electrode 34A is determined.

[0059] Furthermore, the first electrode 34A and the second electrode 34B are fitted into the respective recesses 33C, and the male thread portion 32S of the conductor element 32 is screwed into the female thread portion 33S of the insulating element 33. As a result, the tip surface of the contact portion 311 of the conductor element 32 comes into contact with the flange portions 341 of the first electrode 34A and the second electrode 34B, and the first electrode 34A and the second electrode 34B are sandwiched and fixed between the conductor element 32 and the insulating element 33.

[0060] The connection between the conductor element 32 and the insulating element 33 has a sealing structure against vacuum and the coolant CL. The sealing structure is realized by a sealing portion S2 such as a packing provided at the base end of the male thread portion 32S. The sealing portion S2 may be the same as the sealing portion S1.

[0061] When the coolant CL flows from the first conductor element 32A, the coolant CL flows through the flow path 34X and through-hole 341H of the first electrode 34A to the second electrode 34B side. The coolant CL that has flowed to the second electrode 34B side flows through the flow path 34X and through-hole 341H of the second electrode 34B to the second conductor element 32B. At this time, the cylindrical space between the extension portion 342 of the first electrode 34A and the extension portion 342 of the second electrode 34B is filled with the coolant CL, the coolant CL acts as a dielectric, and the capacitance element 34 is formed.

[0062] Furthermore, the insulating element 33 is disposed in at least a portion of the antenna 3A that overlaps with the gap 22A. In addition, a capacitive element 34 is provided inside the insulating element 33. This prevents dielectric breakdown from occurring in the space between the antenna 3A and the beam portion 23, while reducing the reactance of the antenna 3A and the voltage of the antenna 3A.

[0063] Furthermore, the insulating element 33 is an insulating portion of the antenna 3A, and is located on the opposite side of the dielectric plate 22 from the beam portion 23. The length of the insulating element 33 along the X-axis direction is longer than the length of the gap 22A along the X-axis direction. This allows the conductor element 32 of the antenna 3A to be separated from the gap 22A, and dielectric breakdown can be reliably prevented.

[0064] [Summary] A plasma processing apparatus according to aspect 1 of the present disclosure comprises a vacuum container whose interior is evacuated to a vacuum, an antenna provided outside the vacuum container that generates plasma inside the vacuum container when a high-frequency current flows through it, and a plurality of dielectric plates arranged to cover openings formed in the vacuum container at positions facing the antenna, and when viewed from a direction perpendicular to a plane parallel to the dielectric plates, at least the portion of the antenna that overlaps with the gap formed between the end faces of two adjacent dielectric plates among the plurality of dielectric plates has insulating properties when viewed from a planar view.

[0065] The plasma processing apparatus according to aspect 2 of the present disclosure may further include, in the above-described aspect 1, a beam portion supporting both of two adjacent dielectric plates among the plurality of dielectric plates, and the insulating portion of the antenna may be a portion on the opposite side of the beam portion across the dielectric plates.

[0066] The plasma processing apparatus according to aspect 3 of the present disclosure may be the plasma processing apparatus according to aspect 1 or 2, wherein an insulator is provided on the surface of the overlapping portion of the antenna.

[0067] A plasma processing apparatus according to aspect 4 of the present disclosure is, in the above-mentioned aspect 1 or 2, such that the antenna comprises at least two conductor elements, an insulating element provided between adjacent conductor elements to insulate the conductor elements, and a capacitive element electrically connected to the conductor elements, and the insulating element may be arranged at the overlapping portion of the antenna.

[0068] [Additional Notes] 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.

[0069] REFERENCE SIGNS LIST 1 vacuum vessel 3, 3A antenna 11 opening 22 dielectric plate 22A gap 23 beam portion 31 insulator 32 conductor element 33 insulating element 34 capacitance element 100 plasma processing apparatus I1 high frequency current P1 plasma

Claims

1. A plasma processing apparatus comprising: a vacuum vessel whose interior is evacuated to a vacuum; an antenna provided outside the vacuum vessel that generates plasma inside the vacuum vessel when a high-frequency current flows through it; and a plurality of dielectric plates arranged to cover openings formed in the vacuum vessel at positions facing the antenna, wherein, when viewed from a direction perpendicular to a plane parallel to the dielectric plates, the antenna has insulating properties at least in a portion that overlaps with a gap formed between end faces of two adjacent dielectric plates among the plurality of dielectric plates when viewed from the plan view.

2. A plasma processing apparatus as described in claim 1, further comprising a beam portion supporting both of two adjacent dielectric plates among the plurality of dielectric plates, and the insulating portion of the antenna is a portion on the opposite side of the dielectric plate from the beam portion.

3. The plasma processing apparatus according to claim 1, wherein an insulator is provided on the surface of the overlapping portion of the antenna.

4. The plasma processing apparatus according to claim 1, wherein the antenna comprises at least two conductor elements, an insulating element provided between adjacent conductor elements to insulate the conductor elements, and a capacitive element electrically connected to the conductor elements, and the insulating element is arranged in the overlapping portion of the antenna.

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