Film removing apparatus

Abstract

To widely secure a region where electrons are most strongly heated, and to reduce an adhesion amount of particles generated by removing a film of a workpiece to a dielectric plate.SOLUTION: A film removal device (101) includes a vacuum vessel (1) that houses a workpiece (20) therein to remove a film of the workpiece (20), an antenna (2) that generates plasma inside the vacuum vessel (1) when a high-frequency current flows, a dielectric (7) that separates the antenna (2) from a plasma space in the vacuum vessel (1), and a blocking structural body (9) that blocks at least a part of particles scattered by removal of the film from reaching a region (7a) in the dielectric (7). The blocking body (9) is arranged between the workpiece (20) and the dielectric body (7) at a spacing (D2) from the antenna (2) which is at least twice the spacing (D1) between the antenna (2) and the side of the dielectric body (7) facing the plasma space.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a film removal device that removes a film from an object to be treated. [Background technology]

[0002] There is known a plasma processing apparatus that uses an inductively coupled plasma, in which a high-frequency electric field generated by an antenna is introduced through a dielectric window provided in a vacuum chamber. For example, Patent Document 1 describes a plasma processing apparatus that includes a dielectric plate that covers a slit plate provided at an opening of the vacuum chamber from the outside, and a mask plate that covers the slit plate from the inside.

[0003] In a plasma processing apparatus using inductively coupled plasma, electrons are energized by being heated by a high-frequency electric field inside a vacuum chamber, and then collide with the gas to ionize the gas and generate plasma. The region where the electrons are most strongly heated (herein referred to as the "electron heating region") is limited to a very narrow area near the antenna inside the vacuum chamber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-104093 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the plasma processing apparatus disclosed in Patent Document 1, a mask plate is placed in the electron heating region. Therefore, the mask plate narrows the electron heating region and increases the surface area from which electrons and ions disappear. This reduces the amount of energy of the heated electrons and increases the amount of electron and ion disappearance. As a result, the density of the generated plasma decreases.

[0006] Another known example of the plasma processing apparatus is a film removal apparatus that removes a coating from a workpiece by irradiating the workpiece with ions in a plasma. In such a film removal apparatus, particles of the coating are knocked out of the workpiece by the ion irradiation and adhere to the inner wall of the vacuum chamber and the dielectric plate.

[0007] When the particles are conductive particles, the conductive layer formed by the conductive particles adhering to the dielectric plate shields the magnetic field generated by the antenna. This reduces the strength of the high-frequency induced electric field, resulting in a decrease in plasma density. Furthermore, the narrowing of the electron heating region by the conductive layer also reduces the plasma density.

[0008] One aspect of the present disclosure aims to ensure a wide area where electrons are most strongly heated, and to reduce the amount of particles that adhere to the dielectric plate when the workpiece is removed. [Means for solving the problem]

[0009] In order to solve the above problems, a film removal apparatus according to one embodiment of the present disclosure is a film removal apparatus for removing a coating from a workpiece, and includes a vacuum container that accommodates the workpiece, an antenna that generates plasma inside the vacuum container when a high-frequency current flows through it, a dielectric that separates the antenna from the plasma space in the vacuum container, and a blocking structure that prevents at least some of the particles that are scattered by the removal of the coating from reaching a predetermined area in the dielectric, and the blocking structure is positioned between the workpiece and the dielectric at a distance from the antenna that is at least twice the distance between the antenna and the surface of the dielectric facing the plasma space. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to ensure a wide area where electrons are most strongly heated, and also to reduce the amount of particles that adhere to the dielectric plate when the workpiece is removed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a vertical cross-sectional view showing the configuration of a film removal device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of the film removal device. [Figure 3] FIG. 10 is a vertical cross-sectional view showing the configuration of a film removal device according to a modified example of the first embodiment. [Figure 4] The structure of the film removal device shown in Figure 3 is such that the reattachment prevention part is placed at a certain distance from the dielectric plate. [Figure 5] FIG. 10 is a vertical cross-sectional view showing the configuration of a film removal device according to a second embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view showing the configuration of the film removal device shown in FIG. [Figure 7] 6 is a front view showing the configuration of a blocking structure in the film removal apparatus shown in FIG. 5. [Figure 8] 6 is a front view showing the configuration of another blocking structure in the film removal device shown in FIG. 5. FIG. [Figure 9] 7 is a front view showing the configuration of still another blocking structure in the film removal apparatus shown in FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment 1] Hereinafter, the first embodiment of the present disclosure will be described in detail.

[0013] <Configuration of film removal device> Fig. 1 is a vertical cross-sectional view showing the configuration of a film removal apparatus 101 according to this embodiment. Fig. 2 is a plan view showing the configuration of the film removal apparatus 101.

[0014] 1 and 2, the film removal apparatus 101 is an apparatus that removes a film formed on the surface of a workpiece 20 (object to be treated) using inductively coupled plasma. The film removal apparatus 101 includes a vacuum vessel 1, an antenna 2, a high-frequency power supply 3, a matching box 4, an impedance control unit 5, a bias power supply 6, a dielectric 7, an O-ring 8, and a blocking structure 9.

[0015] The vacuum vessel 1 is a vessel that houses the workpiece 20 and into which a gas serving as a plasma source is introduced. The vacuum vessel 1 has a main body 1a formed in the shape of a box that is long in the vertical direction. An opening 1b is provided on one side of the main body 1a. A dielectric 7, which will be described later, is disposed in the opening 1b.

[0016] The inside of the vacuum vessel 1 is evacuated by a vacuum exhaust device (not shown) and gas is introduced. An inert gas such as argon is used as the gas. The vacuum vessel 1 is made of, for example, metal and is electrically grounded.

[0017] The antenna 2 generates a high-frequency magnetic field when a high-frequency current flows due to high-frequency power supplied from the high-frequency power supply 3. The high-frequency magnetic field generates an induced electric field, which generates plasma inside the vacuum vessel 1. The antenna 2 is formed in a linear shape, specifically a straight line, and is arranged facing the vertical direction and facing the opening 1b of the vacuum vessel 1. The antenna 2 is arranged outside the vacuum vessel 1, close to the dielectric 7, so as to face the opening 1b.

[0018] One end of the antenna 2, which serves as a power supply end, is connected to a high-frequency power supply 3 via a matching box 4. The other end, which serves as a termination end of the antenna 2, is grounded via an impedance control unit 5. The antenna 2 is made of a material such as copper, aluminum, an alloy of these, or stainless steel, but may also be made of other materials.

[0019] The dielectric 7 is disposed in the main body 1a of the vacuum vessel 1 so as to close the opening 1b. The dielectric 7 is provided so as to separate the antenna 2 from the plasma space in the vacuum vessel 1. The dielectric 7 is a plate-shaped member made entirely of a dielectric material, such as ceramics, inorganic materials, or resin materials. An O-ring 8 seals the gap between the dielectric 7 and a step that forms the outer peripheral edge of the opening 1b in the main body 1a.

[0020] The workpiece 20 has a cylindrical shape. The workpiece 20 is an object to be processed, for example, a gear manufacturing tool or a machining tool such as a drill, on whose surface a coating is applied. The workpiece 20 is placed inside the vacuum chamber 1 so as to face in the vertical direction. The workpiece 20 is rotated so as to remove the coating uniformly. A bias voltage is applied to the workpiece 20 by a bias power supply 6.

[0021] The blocking structure 9 is a structure that prevents at least some of the particles that are scattered when the coating of the workpiece 20 is removed from reaching the dielectric 7. The blocking structure 9 is formed in a rod shape and is arranged inside the vacuum vessel 1 so as to face the antenna 2 in parallel or nearly parallel relation.

[0022] The blocking structure 9 is disposed between the workpiece 20 and the dielectric 7 at a distance D1 from the antenna 2. The distance D1 is at least twice the distance D2 between the antenna 2 and the surface of the dielectric 7 facing the plasma space. The blocking structure 9 is disposed closer to the workpiece 20 than a central position C between the antenna 2 and the workpiece 20. The central position C is a distance D3 from the antenna 2 and a distance D3 from the workpiece 20. The blocking structure 9 is disposed in a position where it cannot be reached by the magnetic field generated by the antenna 2 as described below.

[0023] <Film removal process using film removal equipment> In the film removal apparatus 101, when the vacuum chamber 1 is filled with argon gas and a high-frequency induction field is generated by a high-frequency current flowing through the antenna 2, electrons are agitated (heated) by the induction field. At this time, as shown in FIG. 2, the electrons are most strongly heated in the electron heating region A1. The electron heating region A1 is formed in the internal space of the vacuum chamber 1, centered around the antenna 2. The electron heating region A1 is limited to a very narrow range within the vacuum chamber 1 near the antenna 2, which is located outside the vacuum chamber 1. As the heated electrons diffuse widely, they collide with the argon gas. This ionizes the argon gas, continuously generating ions, electrons, etc., thereby maintaining plasma.

[0024] Positive ions I (argon ions) in the plasma collide with the workpiece 20, removing the coating on the surface of the workpiece 20. The removed coating becomes particles P and scatters through the internal space of the vacuum vessel 1. Some of the particles P scatter toward the dielectric 7, but some of these particles collide with the blocking structure 9 and change their course.

[0025] The particles P whose course has been changed in this way are prevented from reaching region 7a (predetermined region) of dielectric 7. Region 7a is a region of a certain range R1 centered on antenna 2 on the surface of dielectric 7 in electron heating region A1. Therefore, the amount of particles P adhering to region 7a on the surface of dielectric 7 within electron heating region A1 can be reduced.

[0026] Furthermore, in the electron heating region A1, no structures are arranged except for the dielectric 7. The dielectric 7 is necessary to maintain a vacuum inside the vacuum vessel 1 and to separate the internal space of the vacuum vessel 1 from the outside. Therefore, a wide area can be secured in which the electron heating region A1 effectively heats electrons.

[0027] As described above, by reducing the amount of particles P adhering to region 7a, it is possible to prevent the metal layer formed by particles P adhering to region 7a from shielding the magnetic field generated by antenna 2. Furthermore, it is possible to minimize the number of structures present in electron heating region A1. Therefore, it is possible to minimize the reduction in energy received by electrons in electron heating region A1 due to the structures in electron heating region A1. Therefore, it is possible to reduce the reduction in plasma density and generate high-density plasma.

[0028] 2, the blocking structure 9 is disposed closer to the workpiece 20 than the central position C. Furthermore, particles P ejected from the workpiece 20 by positive ions I fly out from the surface of the workpiece 20 within a certain degree of directional angular range. As a result, at a position close to the workpiece 20, the blocking structure 9 prevents particles P flying out within the above angular range from reaching the dielectric 7. Therefore, by appropriately setting the position of the blocking structure 9, it is possible to appropriately provide an area in the dielectric 7 where particles P do not adhere. Therefore, it is possible to reduce particle adhesion to the dielectric 7 in the electron heating region A1.

[0029] Furthermore, the blocking structure 9 can be formed small to fit within the above angle range, thereby reducing the disruption caused by the blocking structure 9 in the distribution of plasma toward the workpiece 20 inside the vacuum chamber 1.

[0030] Furthermore, by arranging the blocking structure 9 parallel to the antenna 2, the blocking structure 9 is arranged to face the electron heating region A1 formed along the longitudinal direction of the antenna 2. As a result, even a narrow, rod-shaped blocking structure 9 can effectively prevent particles P from adhering to the dielectric 7 in the electron heating region A1. Furthermore, because the blocking structure 9 is rod-shaped, the range in which the diffusion of electrons and plasma in the internal space of the vacuum vessel 1 is hindered can be made smaller.

[0031] Since the workpiece 20 has a cylindrical shape, the particles P knocked out from the workpiece 20 spread over a narrow range. In contrast, when a plate-shaped workpiece is removed instead of the workpiece 20, some of the particles P knocked out from the surface of the workpiece may reach the electron heating region A1 at an angle, even if they are knocked out from a position slightly off-center from the workpiece. For this reason, instead of the blocking structure 9, a blocking structure having a size that satisfies the condition for preventing such particles P from reaching the electron heating region A1 is used, and the blocking structure is disposed at a position that satisfies the condition.

[0032] <Variations> Modifications of this embodiment will be described below. For ease of explanation, components having the same functions as those described in this embodiment will be denoted by the same reference numerals, and their description will not be repeated.

[0033] 3 is a longitudinal sectional view showing the configuration of the film removal device 102 according to this modified example. FIG. 4 is a transverse sectional view showing the configuration of the film removal device 102.

[0034] As shown in Figures 3 and 4, the vacuum container 1 in the film removal apparatus 102 has a different structure from the vacuum container 1 in the film removal apparatus 101. Specifically, the vacuum container 1 has a main body 1c and a lid 1d. The main body 1c has an opening on one side. The end face on the opening side of the main body does not have a step like the main body 1a and is formed flat. The lid 1d is detachably attached to the main body 1a so as to close the opening of the main body 1c. An O-ring 8 seals the gap between the lid 1d and the end face on the opening side of the main body 1c.

[0035] The film removal apparatus 102 differs from the film removal apparatus 101 in that the antenna 2 is disposed inside the vacuum vessel 1. The antenna 2 is disposed in the internal space of the vacuum vessel 1 at a position close to the lid portion 1d.

[0036] The film removal apparatus 102 includes a dielectric 11 instead of the dielectric 7 of the film removal apparatus 101. The dielectric 11 has a cylindrical shape and is disposed between the inner wall surface of the upper end and the inner wall surface of the lower end of the main body 1c. The dielectric 11 is disposed at a certain distance from the antenna 2 so as to surround all of the portion of the antenna 2 exposed inside the vacuum vessel 1.

[0037] In the film removal apparatus 102, the blocking structure 9 is disposed at a position separated by a distance D1 from the antenna 2. The distance D1 is at least twice the distance D2 between the antenna 2 and the surface of the dielectric 11 on the plasma space side.

[0038] In the film removal apparatus 102 configured as described above, the film removed by collision of positive ions I in the plasma turns into particles P and scatters throughout the internal space of the vacuum vessel 1. Some of the particles P are prevented by the blocking structure 9 from reaching region 11a (predetermined region) of the dielectric 11. Region 11a is a region within a certain range R2 centered on the antenna 2 on the surface of the dielectric 11 in the electron heating region A2. The electron heating region A2 is formed around the antenna 2 and is the region where electrons are most strongly heated. Therefore, the amount of particles P adhering to region 11a on the surface of the dielectric 11 within the electron heating region A2 can be reduced.

[0039] Furthermore, in the electron heating region A2, no structures are arranged except for the dielectric 11. Therefore, a wide region in which the electron heating region A2 effectively heats electrons can be secured. Therefore, similar to the film removal device 101, a decrease in plasma density can be reduced and high-density plasma can be generated.

[0040] [Embodiment 2] A second embodiment of the present disclosure will be described below. For ease of explanation, components having the same functions as those described in the first embodiment will be denoted by the same reference numerals, and the description thereof will not be repeated.

[0041] <Configuration of film removal device> Fig. 5 is a longitudinal sectional view showing the configuration of a film removal apparatus 103 according to a second embodiment of the present disclosure. Fig. 6 is a transverse sectional view showing the configuration of the film removal apparatus 103. Fig. 7 is a front view showing the configuration of a blocking structure 10A in the film removal apparatus 103. Fig. 8 is a front view showing the configuration of another blocking structure 10B in the film removal apparatus 103. Fig. 9 is a front view showing the configuration of yet another blocking structure 10C in the film removal apparatus 103.

[0042] 5 and 6, like the above-described film removal apparatus 101, the film removal apparatus 103 includes a vacuum vessel 1, an antenna 2, a high-frequency power supply 3, a matching box 4, an impedance control unit 5, a bias power supply 6, a dielectric 7, and an O-ring 8. The film removal apparatus 103 includes a blocking structure 10 instead of the blocking structure 9 of the film removal apparatus 101.

[0043] In the film removal apparatus 103, the blocking structure 9 is disposed at a position separated by a distance D1 from the antenna 2. The distance D1 is at least twice the distance D2 between the antenna 2 and the surface of the dielectric 11 on the plasma space side.

[0044] The blocking structure 10 is a structure that prevents at least some of the particles scattered by the removal of the coating from the workpiece 20 from reaching the dielectric 7. The blocking structure 10 has a plurality of slits 10c, as will be described later.

[0045] The blocking structure 10 is disposed at a distance D1 from the antenna 2. The distance D1 is at least twice the distance D2 between the antenna 2 and the surface of the dielectric 7 facing the plasma space. The blocking structure 10 is disposed closer to the antenna 2 than the center position C between the antenna 2 and the workpiece 20. The blocking structure 10 is disposed at a position away from the electron heating region A1. The blocking structure 10 is disposed at a position where it cannot be reached by the magnetic field generated by the antenna 2.

[0046] The blocking structure 10 has a pair of end portions 10a and multiple intermediate portions 10b. The end portions 10a and the intermediate portions 10b are elongated rectangular members. The end portions 10a and the intermediate portions 10b are fixed to the main body 1c so that their longitudinal directions are oriented horizontally.

[0047] One end 10a is provided so as to hang down from the upper end of the main body 1c of the vacuum vessel 1. The other end 10a is provided so as to rise up from the lower end of the main body 1c. The multiple intermediate portions 10b are arranged at intervals between a pair of end portions 10a. Slits 10c are formed between the multiple intermediate portions 10b and between adjacent end portions 10a and intermediate portions 10b.

[0048] 7 to 9 show blocking structures 10A to 10C, respectively, as examples of the blocking structure 10. The blocking structure 10A shown in FIG. 7 has a pair of end portions 10a and both ends of the multiple intermediate portions 10b fixed to the inner wall surfaces of both sides of the main body 1a of the vacuum vessel 1, as shown in FIG. 6. The blocking structure 10B shown in FIG. 8 has a pair of fixing portions 10d that fix the pair of end portions 10a and both ends of the multiple intermediate portions 10b. Therefore, the opposite edge edges of the blocking structure 10B are not fixed to the inner wall surfaces of both sides of the main body 1a.

[0049] The blocking structure 10C shown in Figure 9 is configured such that the blocking structure 10B further includes a blocking portion 10e. The blocking portion 10e is provided so that the slit 10c is not formed in a predetermined area facing the antenna 2. Specifically, the blocking portion 10e is a long, thin plate-like portion in the blocking structure 10C that extends parallel to the antenna 2 so as to face the antenna 2 and is formed to have a width wider than that of the antenna 2. As a result, the slit 10c is blocked in the area where the blocking portion 10e is provided.

[0050] The blocking structure 10C has a width W2 that is narrower than the width W1 of the dielectric 7 in a direction perpendicular to the center line L facing the antenna 2. The width W1 is not the entire width of the dielectric 7, but the width of the portion of the dielectric 7 that is exposed to the internal space of the vacuum vessel 1.

[0051] <Film removal process using film removal equipment> In the film removal device 103 configured as described above, the film removed by collision of positive ions I in the plasma becomes particles P and scatters in the internal space of the vacuum vessel 1. Some of the particles P scatter toward the dielectric 7. Some of these particles adhere to the end portion 10a and the middle portion 10b of the blocking structure 10, while the remaining portion passes through the slits 10c of the blocking structure 10 and reaches the surface of the dielectric 7.

[0052] Since the blocking structure 10 is positioned closer to the dielectric 7 than the central position C, the conductive particles P passing through the slit 10c do not spread out widely but instead adhere to the surface of the dielectric 7 in a striped pattern. As a result, the conductive layer formed in a striped pattern shields the magnetic field generated by the antenna 2 and narrows the electron heating region A1.

[0053] However, there are also stripe-shaped regions on the dielectric 7 where particles do not adhere, corresponding to the end portion 10a and middle portion 10b of the blocking structure 10 where there are no slits 10c. This allows the magnetic field to pass through these regions, while also ensuring a region that strongly heats electrons. Therefore, the stripe-shaped conductor layer reduces the strength of the magnetic field passing through the dielectric 7 to some extent, but does not significantly reduce the strength of the magnetic field. Also, the electron heating region A1 is narrowed to some extent, but not significantly. Therefore, it does not result in a significant reduction in plasma density.

[0054] In contrast, if the blocking structure 10 is positioned further away from the dielectric 7 than the central position C, the conductor particles P passing through the slit 10c will spread out widely and adhere to the entire surface of the dielectric 7. As a result, the conductor layer formed on the entire surface of the dielectric 7 will shield the magnetic field generated by the antenna 2 and narrow the electron heating region A1. The electron heating region A1 will also be narrowed to almost the entire area. This will result in a significant reduction in plasma density.

[0055] The blocking structure 10C has the blocking portion 10e, so that the blocking portion 10e is provided to correspond to the electron heating region A1 formed in the vicinity of the antenna 2 inside the vacuum vessel 1. This makes it possible to reduce adhesion of particles onto the dielectric 7 in the electron heating region A1.

[0056] Furthermore, when the blocking structure 10C is used, the electron heating region A1 is formed near the center line L of the dielectric 7 facing the antenna 2. In the blocking structure 10C, the slits of the blocking structure 10C are not provided at positions farther away than the center line L of the dielectric 7. However, within the range where the slits 10c are not provided, even if particles P adhere to the dielectric 7, the electron heating region A1 does not narrow. Therefore, the blocking structure 10C can be formed compactly, which allows for reduction in material.

[0057] The above configuration can be applied to blocking structure 10B, which can be freely set in width. However, since both ends of paired end portions 10a and multiple intermediate portions 10b are fixed to the inner wall surfaces of both sides of main body 1a, the above configuration cannot be applied to blocking structure 10A, which cannot be freely set in width.

[0058] 〔summary〕 A film removal apparatus according to a first aspect of the present disclosure is a film removal apparatus for removing a coating from a workpiece, and includes a vacuum container that accommodates the workpiece, an antenna that generates plasma inside the vacuum container when a high-frequency current flows through it, a dielectric that separates the antenna from the plasma space in the vacuum container, and a blocking structure that prevents at least some of the particles that are scattered by the removal of the coating from reaching a predetermined area in the dielectric, and the blocking structure is positioned between the workpiece and the dielectric at a distance from the antenna that is at least twice the distance between the antenna and the surface of the dielectric facing the plasma space.

[0059] In the above configuration, the provision of the blocking structure prevents at least some of the particles scattered by the removal of the coating from reaching the dielectric. This reduces the amount of particles adhering to the dielectric in the region where electrons are most strongly heated. Furthermore, by locating the blocking structure at a position away from the antenna as described above, the only structure present in the region where electrons are most strongly heated is the dielectric, allowing the region to be kept large.

[0060] A film removal device according to a second aspect of the present disclosure may be configured in the first aspect such that the blocking structure is positioned closer to the workpiece than the central position between the antenna and the workpiece.

[0061] Particles ejected by ions fly off the surface of the workpiece within a certain angular range. Therefore, in the above configuration, by positioning the blocking structure near the workpiece, the blocking structure blocks particles from reaching the dielectric within the above angular range at a position close to the workpiece, allowing appropriate selection of areas of the dielectric where particle adhesion is desired to be avoided. Therefore, particle adhesion to the dielectric can be reduced in areas that heat electrons most strongly.

[0062] Furthermore, the blocking structure can be made small to fit within the above angle range, thereby reducing the disruption of plasma distribution toward the workpiece inside the vacuum chamber due to the blocking structure.

[0063] A film removal device according to a third aspect of the present disclosure may be configured in the first aspect such that the antenna is linear, and the blocking structure is formed in a rod shape and is arranged parallel to the antenna.

[0064] In the above configuration, the blocking structure is disposed so as to face the region formed along the longitudinal direction of the antenna where electrons are strongly heated, so that even a narrow, rod-shaped blocking structure can effectively prevent particles from adhering to the dielectric in the region where electrons are strongly heated.

[0065] In the film removal device according to a fourth aspect of the present disclosure, in any one of the first to third aspects, the antenna may be provided outside the vacuum vessel.

[0066] According to the above configuration, the antenna is not housed in the vacuum vessel, so that the vacuum vessel can be made smaller.

[0067] A film removal apparatus according to a fifth aspect of the present disclosure may be such that, in the first aspect, the blocking structure has a plurality of slits and is positioned closer to the antenna than the central position between the antenna and the workpiece.

[0068] In this configuration, since the blocking structure is located close to the dielectric, conductive particles passing through the slits in the blocking structure do not spread out significantly but instead deposit on the dielectric in stripes corresponding to the shape of the slits. As a result, the striped conductive layer shields the magnetic field generated by the antenna and narrows the area where electrons are strongly heated.

[0069] However, there are also stripe-like regions on the dielectric where particles do not adhere, corresponding to the portions of the blocking structure without slits. These regions allow the magnetic field to pass through, while also ensuring a region where electrons are strongly heated. Therefore, the strength of the magnetic field passing through the dielectric is reduced to some extent, but not significantly. Also, the region where electrons are strongly heated is narrowed to some extent, but not significantly. This makes it possible to avoid a significant reduction in plasma density.

[0070] A film removal device according to a sixth aspect of the present disclosure is the fifth aspect, wherein the blocking structure may have a blocking portion in which the slit is not formed in a predetermined range facing the antenna.

[0071] According to the above configuration, the blocking portion is provided in the vacuum vessel so as to correspond to the region formed near the antenna where electrons are strongly heated, thereby reducing particle adhesion onto the dielectric in the region where electrons are strongly heated.

[0072] A film removal apparatus according to a seventh aspect of the present disclosure may be such that, in the fifth or sixth aspect, the blocking structure has a width narrower than the width of the portion of the dielectric exposed to the internal space of the vacuum vessel in a direction perpendicular to the center line facing the antenna.

[0073] A region that strongly heats electrons is formed near the center line of the dielectric facing the antenna. In the above configuration, the slits in the blocking structure are not provided at a position farther away from the center line of the dielectric. However, even if particles adhere to the dielectric within the range where no slits are provided, the region that strongly heats electrons does not narrow. Therefore, the blocking structure can be made compact, allowing for reduction in material.

[0074] [Additional Notes] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. In addition, embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0075] 1 Vacuum container 1a,1e opening 2 antennas 7,11 Dielectrics 7a,11a area (predetermined area) 9,10 Blocking structure 10c slit 10e Blockade section 20 Workpiece (processing object) 101~103 Film removal equipment C center position D1,D2 distance L Chuo line W1, W2 width

Claims

1. A film removal device for removing a film from an object to be treated, a vacuum vessel that accommodates the object to be processed therein; an antenna that generates plasma inside the vacuum vessel when a high-frequency current flows through it; a dielectric separating the antenna from a plasma space in the vacuum vessel; a blocking structure that blocks at least some of the particles scattered by the removal of the coating from reaching a predetermined region in the dielectric; A film removal apparatus in which the blocking structure is positioned between the workpiece and the dielectric at a distance from the antenna that is at least twice the distance between the antenna and the surface of the dielectric facing the plasma space.

2. The film removal apparatus according to claim 1 , wherein the blocking structure is disposed closer to the object to be treated than a center position between the antenna and the object to be treated.

3. the antenna is linear; The film removal apparatus according to claim 2 , wherein the blocking structure is formed in a rod shape and is disposed parallel to the antenna.

4. The film removal apparatus according to claim 1 , wherein the antenna is provided outside the vacuum vessel.

5. The film removal apparatus according to claim 1 , wherein the blocking structure has a plurality of slits and is disposed closer to the antenna than a center position between the antenna and the object to be treated.

6. The film removal device according to claim 5 , wherein the blocking structure has a blocking portion in which the slit is not formed in a predetermined range facing the antenna.

7. The film removal apparatus according to claim 5 or 6, wherein the blocking structure has a width narrower than the width of the portion of the dielectric exposed to the internal space of the vacuum vessel in a direction perpendicular to a center line facing the antenna.

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