Plasma processing equipment

Abstract

A plasma treatment device (1) comprises: a vacuum vessel (10) that comprises a peripheral wall (10a) formed from a dielectric and has accommodated therein a table on which to-be-treated objects (20) are disposed; an antenna (12) that is provided outside of the vacuum vessel so as to be rotatable around the peripheral wall and produces a high frequency magnetic field for generating plasma in the vacuum vessel; and a mask (30) that is provided between the table in the vacuum vessel and the peripheral wall and has a plurality of openings (30c) through which the high frequency magnetic field passes.

Description

Technical Field

[0006] , , ,

[0001] The present invention relates to a plasma processing apparatus for processing a workpiece using plasma.

Background Art

[0002] Conventionally, a technique for processing a workpiece using plasma has been known. In relation to this type of technique, for example, Patent Document 1 discloses a film removal apparatus that irradiates an ion flow onto a coating material (workpiece) set on a holder to remove a film from the coating material. The film removal apparatus described in Patent Document 1 places the coating material at an ion flow concentration portion where two or more ion flows overlap, and irradiates the ion flow while rotating the coating material to remove the film from the coating material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the film removal apparatus described in Patent Document 1, when performing film removal, a plurality of ion sources (high-frequency magnetic field generation sources) and a mechanism for rotating the coating material are required. Further, in order to concentrate the ion flow at the center of the vacuum chamber, there is a problem that the number of processes per unit time is reduced.

[0005] One aspect of the present invention aims to improve the processing efficiency of a plasma processing apparatus without using a plurality of high-frequency magnetic field generation sources.

Means for Solving the Problems

[0006] To solve the above problems, a plasma processing apparatus according to one aspect of the present invention comprises a vacuum vessel including a peripheral wall made of a dielectric material and housing a table on which an object to be processed is placed; an antenna provided outside the vacuum vessel so as to be rotatable around the peripheral wall and generating a high-frequency magnetic field for generating plasma inside the vacuum vessel; and a metal cylinder provided between the table and the peripheral wall inside the vacuum vessel and having a plurality of openings through which the high-frequency magnetic field passes. [Effects of the Invention]

[0007] According to one aspect of the present invention, the processing efficiency of a plasma processing apparatus can be improved without using multiple high-frequency magnetic field sources. [Brief explanation of the drawing]

[0008] [Figure 1] This is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus according to Embodiment 1. [Figure 2] Figure 1 is a plan view showing the configuration of the main parts of the plasma processing apparatus. [Figure 3] This is a schematic diagram showing the structure of the first capacitor on the power supply side. [Figure 4] This is a schematic diagram showing the structure of the second capacitor on the ground side. [Figure 5] This is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus according to Embodiment 2. [Figure 6] Figure 5 is a plan view showing the configuration of the main parts of the plasma processing apparatus. [Figure 7] This is a schematic diagram showing an example of the placement of the first and second masks. [Figure 8] This is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus according to Embodiment 3. [Figure 9] This is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus according to Embodiment 4. [Figure 10] This is a schematic diagram showing the structure of the third capacitor. [Figure 11]This is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus according to Embodiment 5. [Modes for carrying out the invention]

[0009] [Embodiment 1] Hereinafter, an embodiment according to one aspect of the present invention (hereinafter also referred to as "this embodiment") will be described based on the drawings. In this embodiment, an example in which the plasma processing apparatus according to the present invention is applied to a film removal apparatus will be described. Note that the following description is illustrative of the plasma processing apparatus according to the present invention, and the technical scope of the present invention is not limited to the illustrated example.

[0010] Figure 1 is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus 1 according to this embodiment. Figure 2 is a plan view showing the configuration of the main parts of the plasma processing apparatus 1 according to this embodiment.

[0011] [Configuration of Plasma Processing Unit 1] The plasma processing apparatus 1 comprises a vacuum vessel 10, an antenna 12, a table 21, and a mask 30 (metal cylinder).

[0012] (vacuum container 10) The vacuum container 10 is a container that houses a table 21 on which the workpiece 20 is placed. The inside of the vacuum container 10 is evacuated by a vacuum pump (not shown) and gas is introduced. The vacuum container 10 includes a cylindrical peripheral wall 10a made of a curved surface, a circular upper wall 10b that closes the upper side of the peripheral wall 10a, and a circular bottom wall 10c that closes the lower side of the peripheral wall 10a. The peripheral wall 10a is formed from the upper wall 10b to the bottom wall 10c. The peripheral wall 10a is made of a dielectric material. The upper wall 10b and the bottom wall 10c are made of metal and are electrically grounded.

[0013] (Table 21) Table 21 is a stage for placing a plurality of workpieces 20. Table 21 is housed inside the vacuum chamber 10. Table 21 has a disk shape with a circular shape in plan view. A plurality of holders 23 for holding the workpiece 20 are provided on Table 21. The plurality of holders 23 are arranged side by side at regular intervals in the circumferential direction at the outer edge of Table 21.

[0014] Table 21 is electrically connected to the pulse power supply 22. The workpiece 20 and Table 21 are electrically connected via the holder 23, and the bias voltage applied by the pulse power supply 22 is applied to the workpiece 20 via Table 21 and the holder 23.

[0015] Examples of the workpiece 20 include rotary tools such as drills, end mills, and reamers, as well as molds. The workpiece 20 is, for example, a member made of metal with a film made of inorganic substances formed on the surface in order to increase the surface hardness.

[0016] (Antenna 12) Antenna 12 is connected to the high-frequency power supply 11 and generates a high-frequency magnetic field for generating plasma inside the vacuum chamber 10. Antenna 12 is provided outside the vacuum chamber 10. One end of Antenna 12 is connected to the first capacitor 13, and the other end is connected to the second capacitor 14. The current output by the high-frequency power supply 11 is input to Antenna 12 via the first capacitor 13 and then flows into the grounded second capacitor 14.

[0017] Antenna 12 is a single bent hollow pipe, which turns back near the bottom wall 10c and bends from the outer periphery of the vacuum chamber 10 toward the center of the vacuum chamber 10 in the upper space of the upper wall 10b. Also, both ends of Antenna 12 are bent again at the center of the vacuum chamber 10, one end enters the first capacitor 13, and the other end enters the second capacitor 14. That is, Antenna 12 is provided so as to make a round trip from the upper part to the lower part of the vacuum chamber 10 along the circumferential wall 10a.

[0018] The high-frequency power supply 11 can supply high-frequency current to the antenna 12 via a matching circuit. When high-frequency current flows through the antenna 12, a high-frequency magnetic field is generated around the antenna 12, and a high-frequency magnetic field is generated at least inside the vacuum container 10 via the peripheral wall 10a.

[0019] The antenna 12 is rotatable around the cylindrical peripheral wall 10a, with respect to a rotation axis C that coincides with the central axis of the peripheral wall 10a. For example, a motor (not shown) is connected to the antenna 12, and by driving this motor, the antenna 12 rotates around the rotation axis C. Therefore, the first capacitor 13 and the second capacitor 14 are configured to allow a high-frequency current to flow through the rotating antenna 12.

[0020] Figure 3 is a schematic diagram showing the structure of the first capacitor 13 on the power supply side. Figure 4 is a schematic diagram showing the structure of the second capacitor 14 on the ground side. As shown in Figure 3, the first capacitor 13 has a cylindrical terminal 13a with one end closed, which is connected to the high-frequency power supply 11, and one end of the antenna 12 is located on the axis of rotation C. The space between the terminal 13a and one end of the antenna 12 is filled with a dielectric 13c and is rotatably sealed to prevent leakage of the dielectric 13c.

[0021] Similarly, as shown in Figure 4, the second capacitor 14 has the other end of the antenna 12 rotatably positioned around the rotation axis C, and the grounding terminal 14b is positioned in a ring shape at a distance from the other end of the antenna 12. The space between the other end of the antenna 12 and the terminal 14b is filled with dielectric 14c and is rotatably sealed to prevent leakage of the dielectric 14c.

[0022] Thus, the first capacitor 13 and the second capacitor 14 are filled with dielectric material at the electrical connection point with the antenna 12, and are structured to couple with a predetermined capacitance even when the antenna 12 rotates. Note that a coolant such as pure water may be used as the dielectric material 13c and 14c. As pure water, high-resistivity water with an electrical resistivity of, for example, 1 MΩ·cm or more can be used. The range of electrical resistivity of the pure water can be appropriately changed depending on the operating conditions of the plasma processing apparatus 1. By using pure water as the dielectric material, the pure water acts as a coolant, cooling the antenna 12, the first capacitor 13, and the second capacitor 14. Therefore, by using pure water as the dielectric material, the structure of the apparatus can be simplified.

[0023] Furthermore, using pure water as a dielectric offers the following advantages:

[0024] (1) Pure water has a very high dielectric constant and high voltage resistance, making it easy to achieve the performance of both mechanical components and electrical components such as capacitors.

[0025] (2) It can be applied to the rotating movable part of the antenna 12 without frictional resistance.

[0026] (3) Low environmental impact.

[0027] However, it is also possible to use materials other than pure water as the dielectric. Other examples of dielectrics include alumina and glass.

[0028] By rotating the antenna 12, a high-frequency magnetic field can be generated inside the vacuum vessel 10, moving along the peripheral wall 10a. Because a high-frequency magnetic field is applied inside the vacuum vessel 10, plasma P is generated in the areas corresponding to the high-frequency magnetic field inside the vacuum vessel 10. The density of plasma P depends on the magnetic field of the high-frequency magnetic field, and therefore changes depending on the distance from the antenna 12 (the distance from the peripheral wall of the part facing the antenna 12). In the example in Figure 2, plasma P is generated in the hatched area. As shown in Figure 2, plasma P is not generated throughout the entire inside of the vacuum vessel 10, but rather a plasma P of a density effective for plasma processing can be obtained only in a range within a certain distance from the antenna 12.

[0029] (Mask 30) The mask 30 is a metal cylinder placed inside the vacuum chamber 10, between the table 21 and the peripheral wall 10a, and positioned close to the peripheral wall 10a. Plasma P is generated inside the vacuum chamber 10, and the plasma P removes the coating from the surface of the workpiece 20, and the removed coating diffuses into the inside of the vacuum chamber 10. If the coating diffused inside the vacuum chamber 10 (hereinafter sometimes referred to as foreign matter) adheres to the inner surface 10d of the peripheral wall 10a, the plasma P generated by the inducing current flowing through the foreign matter weakens. Therefore, in order to prevent foreign matter from adhering to the inner surface 10d of the peripheral wall 10a, the mask 30 is placed between the table 21 and the peripheral wall 10a.

[0030] The mask 30 is grounded and includes multiple annular metal ring portions 30a arranged at intervals in the height direction (direction of the rotation axis C) of the vacuum vessel 10, and conductive portions 30b that connect adjacent metal ring portions 30a and provide electrical conductivity between the metal ring portions 30a. The mask 30 has a structure in which multiple metal ring portions 30a are connected by conductive portions 30b.

[0031] Each of the multiple metal ring portions 30a is arranged concentrically with the peripheral wall 10a in a plan view. Each of the multiple conductive portions 30b is provided between adjacent metal ring portions 30a and is arranged in a line along the height direction (direction of the rotation axis C) of the vacuum container 10. In other words, the multiple conductive portions 30b are arranged in positions that overlap each other in a plan view of the vacuum container 10.

[0032] In a side view of the vacuum vessel 10, an opening 30c is formed between adjacent metal ring portions 30a through which the high-frequency magnetic field generated by the antenna 12 passes. The high-frequency magnetic field generated by the antenna 12 is introduced into the inside of the mask 30 via the peripheral wall 10a and the opening 30c, generating plasma P around the workpiece 20 inside the vacuum vessel 10. The opening 30c may, for example, be a slit shape extending in the circumferential direction of the peripheral wall 10a.

[0033] Furthermore, the mask 30 is not limited to a structure in which a metal ring portion 30a is connected by a conductive portion 30b. For example, the mask 30 may be a cylindrical metal tube with numerous holes punched into its circumferential surface, similar to perforated metal.

[0034] [Operation of Plasma Processing Unit 1] In the plasma processing apparatus 1, as described above, the antenna 12 is rotatable around the peripheral wall 10a about the rotation axis C. As the antenna 12 rotates, the position of the plasma P also moves so as to rotate around the rotation axis C. Therefore, the workpieces 20 held by the holder 23 on the outer edge of the table 21 are sequentially plasma-treated, and the coating formed on the surface of the workpieces 20 is removed.

[0035] Since the workpiece 20 is connected to the pulse power supply 22 via the table 21 and holder 23, a bias voltage is applied by the pulse power supply 22. By adjusting the bias voltage, the energy of the ions in the plasma P when they are incident on the workpiece 20 can be controlled, enabling efficient film removal.

[0036] During this defilm removal process, electrons enter the workpiece 20 due to the action of plasma P, causing an electric current to flow and thus heating the workpiece 20. In the plasma processing apparatus 1, because the plasma P moves, the workpiece 20 is not heated when it is not being treated by plasma P, and is cooled by a cooling mechanism described later. In other words, plasma treatment and cooling are repeatedly performed on the workpiece 20. Therefore, the workpiece 20 can be defilmed by plasma treatment while preventing it from becoming too hot. The reason for cooling the workpiece 20 here is to prevent it from becoming brittle and easily damaged if it is heated too much.

[0037] Furthermore, a cooling mechanism (not shown) may be provided on the table 21 in order to forcibly cool the workpiece 20. This cooling mechanism may be, for example, a mechanism that cools the inside of the table 21 by passing a refrigerant through it. In the plasma processing apparatus 1, the table 21 does not have a rotation mechanism and is fixed to the vacuum chamber 10. Therefore, it is easier to provide a cooling mechanism on the table 21 compared to a configuration in which the table 21 has a rotation mechanism.

[0038] As described above, the plasma processing apparatus 1 according to Embodiment 1 includes a vacuum vessel 10 that includes a peripheral wall 10a made of a dielectric material and houses a table 21 on which an object to be processed 20 is placed inside; an antenna 12 that is provided outside the vacuum vessel 10 so as to be rotatable around the peripheral wall 10a and generates a high-frequency magnetic field that generates plasma P inside the vacuum vessel 10; and a mask 30 provided between the table 21 inside the vacuum vessel 10 and the peripheral wall 10a and having a plurality of openings 30c that allow the high-frequency magnetic field to pass through.

[0039] In the plasma processing apparatus 1, the antenna 12 is rotatable around the vacuum chamber 10, and the position of the plasma P moves as the antenna 12 rotates. Therefore, the plasma processing apparatus 1 can improve its processing efficiency without using multiple high-frequency magnetic field sources.

[0040] Furthermore, since the plasma processing apparatus 1 does not require a rotation mechanism for the table 21, it is easy to provide a cooling mechanism for the table 21. In addition, because the processing with plasma P is performed intermittently, the workpiece 20 is less likely to become hot, and damage due to weakening of the workpiece 20 can be prevented.

[0041] [Embodiment 2] Other embodiments of the present invention will be described below. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0042] Figure 5 is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus 2 according to Embodiment 2. Figure 6 is a plan view showing the configuration of the main parts of the plasma processing apparatus 2 according to Embodiment 2. Figure 7 is a schematic diagram showing an example of the arrangement of the first mask 31 (first metal cylinder) and the second mask 32 (second metal cylinder).

[0043] The plasma processing apparatus 2 differs from the plasma processing apparatus 1 of the above embodiment mainly in that it has two masks: a first mask 31 (first metal cylinder) and a second mask 32 (second metal cylinder).

[0044] As shown in Figures 5 to 7, the first mask 31 has a plurality of first openings 31c in a side view of the vacuum vessel 10. This first mask 31 has the same configuration as the mask 30 in the above embodiment. The second mask 32 has a plurality of second openings 32c in a side view of the vacuum vessel 10. The first mask 31 and the second mask 32 have different diameters, with the diameter of the second mask 32 being smaller than the diameter of the first mask 31. The first mask 31 is provided along the inner surface 10d of the peripheral wall 10a, and the second mask 32 is provided inside the first mask 31, that is, on the table 21 side of the first mask 31. Furthermore, the first mask 31 and the second mask 32 are spaced apart so that a radial gap G is formed between them. Both the first mask 31 and the second mask 32 are grounded.

[0045] The height positions of the first opening 31c and the second opening 32c of the first mask 31 and the second mask 32 are staggered. That is, in a side view of the vacuum vessel 10, the metal ring portion 32a of the second mask 32 is positioned at the location of the first opening 31c of the first mask 31, and the second opening 32c of the second mask 32 is covered by the metal ring portion 32a of the first mask 31.

[0046] In the plasma processing apparatus 2, the high-frequency magnetic field generated by the antenna 12 is introduced into the second mask 32 through the peripheral wall 10a, the first opening 31c, the gap G, and the second opening 32c, generating plasma P inside the vacuum vessel 10. Furthermore, because the plasma processing apparatus 2 is equipped with a second mask 32 in addition to the first mask 31, the adhesion of foreign matter to the inner surface 10d of the peripheral wall 10a can be more effectively reduced.

[0047] [Embodiment 3] Other embodiments of the present invention will be described below. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0048] Figure 8 is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus 3 according to this embodiment. The plasma processing apparatus 3 differs from the plasma processing apparatus 1 of the previous embodiment mainly in that it is equipped with a mask 33 instead of a mask 30.

[0049] The mask 33 has multiple metal ring sections 30a arranged in the height direction of the vacuum vessel 10, and adjacent metal ring sections 30a are connected by conductive sections 30b. In this case, each conductive section 30b is positioned offset in the circumferential direction of the metal ring section 30a so that they do not overlap each other in a plan view of the vacuum vessel 10. Each conductive section 30b is arranged at equal pitches with a constant interval D, for example. By setting the interval D to 15 mm or more, the reverse current flowing across the metal ring sections 30a via the conductive sections 30b in the direction along the antenna can be reduced, and the decrease in the high-frequency magnetic field for generating plasma can be suppressed.

[0050] Therefore, since the conductive parts 30b are not biased towards any particular location, a high-frequency magnetic field is generated uniformly inside the vacuum container 10, enabling uniform film removal with a uniform plasma P.

[0051] [Embodiment 4] Other embodiments of the present invention will be described below. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0052] Figure 9 is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus 4 according to Embodiment 4. In Embodiment 4, the upper wall 10b is a metal upper wall 15 and is connected to the ground potential. Also, the antenna 12 is connected to the third capacitor 16 instead of the second capacitor 14.

[0053] Figure 10 is a schematic diagram showing the structure of the third capacitor 16. The third capacitor 16 is provided circumferentially on the upper wall 15 and consists of the other end of the antenna 12 and a dielectric 16c. The dielectric 16c is located between the other end of the antenna 12 and the upper wall 15 and is in contact with them. In other words, the third capacitor 16 is a capacitor with the other end of the antenna 12 and the upper wall 15 as its electrodes.

[0054] In Embodiment 4, the other end of the antenna 12 can be grounded simply by connecting it to the upper wall 15 via the third capacitor 16, making wiring easier. Furthermore, by using pure water as the dielectric for the antenna 12, the first capacitor 13, and the third capacitor 16, the antenna 12, the first capacitor 13, and the third capacitor 16 can be cooled using the pure water as a coolant.

[0055] [Embodiment 5] Other embodiments of the present invention will be described below. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0056] Figure 11 is a partial cross-sectional perspective view showing the configuration of the main parts of the plasma processing apparatus 5 according to Embodiment 5. In the plasma processing apparatus 5, the holder 23 is provided in multiple stages, not just one, in the height direction of the vacuum vessel 10. In addition to the lower holder 23 that is in contact with the table 21, the upper holder 23 is provided via legs 24 that extend from the table 21 in the height direction of the vacuum vessel 10.

[0057] In this way, by providing multiple levels of holders 23 that hold the workpieces 20 on the table 21, the number of workpieces 20 that can be processed at once increases, making plasma processing more efficient.

[0058] 〔summary〕 A plasma processing apparatus according to embodiment 1 of the present invention comprises a vacuum vessel including a peripheral wall made of a dielectric material and housing a table on which an object to be processed is placed; an antenna provided outside the vacuum vessel so as to be rotatable around the peripheral wall and generating a high-frequency magnetic field for generating plasma inside the vacuum vessel; and a metal cylinder provided between the table and the peripheral wall inside the vacuum vessel and having a plurality of openings through which the high-frequency magnetic field passes.

[0059] With the above configuration, simply by rotating an antenna installed outside the vacuum vessel, a high-frequency magnetic field can be generated inside the vacuum vessel, thereby creating plasma within the vacuum vessel. This improves the efficiency of plasma processing on the workpiece. Furthermore, since the workpiece is not constantly subjected to plasma processing but is processed intermittently, it is possible to prevent the workpiece from becoming excessively hot.

[0060] In the plasma processing apparatus according to aspect 2 of the present invention, in aspect 1, the metal cylinder includes a plurality of annular metal ring portions arranged at intervals in the height direction of the vacuum vessel, and conductive portions that connect adjacent metal ring portions and provide electrical conductivity between them, and the opening may be formed between adjacent metal ring portions.

[0061] According to the above configuration, an opening can be provided between adjacent metal ring sections, allowing a metal cylinder to be constructed with a simple design.

[0062] In the plasma processing apparatus according to embodiment 3 of the present invention, in embodiment 2 above, the metal cylinder includes a first metal cylinder and a second metal cylinder provided inside the first metal cylinder, and in a side view of the vacuum vessel, the metal ring portion of the second metal cylinder may be positioned at the location of the opening of the first metal cylinder.

[0063] With the above configuration, the first and second metal cylinders fill the vacuum vessel without any gaps when viewed from the side. As a result, foreign matter removed by the plasma does not reattach to the peripheral wall but rather to the first or second metal cylinder, thus preventing deterioration of the dielectric material of the peripheral wall.

[0064] In the plasma processing apparatus according to embodiment 4 of the present invention, in embodiment 2 or 3, each of the conductive portions may be arranged offset in the circumferential direction of the metal ring portion such that they do not overlap each other in a plan view of the vacuum vessel.

[0065] According to the above configuration, the conductive parts in the metal cylinder are dispersed rather than concentrated in specific areas, resulting in a balanced and even distribution of the high-frequency magnetic field. Therefore, the plasma density is generated uniformly regardless of the antenna's rotation, enabling uniform film removal regardless of the position of the workpiece.

[0066] A plasma processing apparatus according to embodiment 5 of the present invention further comprises a plurality of holders for holding the object to be processed on the table, in any of embodiments 1 to 4, wherein the plurality of holders may be arranged in multiple stages in the height direction of the vacuum container.

[0067] With the above configuration, the number of objects that can be treated at once increases, making it possible to remove the film more efficiently.

[0068] In the plasma processing apparatus according to embodiment 6 of the present invention, in any of embodiments 1 to 5 above, the upper wall of the vacuum vessel is connected to ground potential, and one end of the antenna is connected to the upper wall via a dielectric.

[0069] With the above configuration, the antenna can be grounded via the upper wall, making it easy to wire the antenna.

[0070] In the plasma processing apparatus according to embodiment 7 of the present invention, the dielectric material may be pure water in embodiment 6.

[0071] With the above configuration, pure water can be used as the dielectric, allowing for efficient cooling of the antenna.

[0072] [Additional Notes] The present invention is not limited to the embodiments described above, 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 invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0073] For example, two or more of the configurations from Embodiments 1 to 5 may be adopted simultaneously. In this case, the effects of the multiple adopted configurations can be obtained simultaneously. [Explanation of Symbols]

[0074] 1, 2, 3, 4, 5 Plasma processing equipment 10 Vacuum container 10a Peripheral wall 10b, 15 Upper wall 10c bottom wall 10d Inner 11 High frequency power supply 12 antennas 13. First Capacitor 14. Second Capacitor 16. Third Capacitor 20. Items to be processed 21 Tables 22 pulse power supply 23 holders 30, 33 Mask (metal tube) 31. First mask (first metal cylinder) 32. Second mask (second metal cylinder) 30a, 32a Metal ring section 30b Continuity part 30c opening 31c 1st opening 32c 2nd opening

Claims

1. A vacuum vessel comprising a peripheral wall made of dielectric material and containing a table on which the object to be processed is placed, An antenna is provided outside the vacuum vessel so as to be rotatable around the peripheral wall, and generates a high-frequency magnetic field inside the vacuum vessel that generates plasma. A plasma processing apparatus comprising a metal cylinder provided between the table and the peripheral wall inside the vacuum vessel, having a plurality of openings through which the high-frequency magnetic field passes.

2. The metal cylinder includes a plurality of annular metal ring portions arranged at intervals in the height direction of the vacuum container, and conductive portions that connect adjacent metal ring portions and provide electrical conductivity between them. The plasma processing apparatus according to claim 1, wherein the opening is formed between adjacent metal ring portions.

3. The aforementioned metal cylinder includes a first metal cylinder and a second metal cylinder provided inside the first metal cylinder. The plasma processing apparatus according to claim 2, wherein, in a side view of the vacuum vessel, the metal ring portion of the second metal cylinder is positioned at the location of the opening of the first metal cylinder.

4. The plasma processing apparatus according to claim 2, wherein each of the conductive portions is arranged offset in the circumferential direction of the metal ring portion so that they do not overlap each other in a plan view of the vacuum vessel.

5. The table further comprises a plurality of holders for holding the object to be processed on the table, The plasma processing apparatus according to claim 1, wherein the plurality of holders are arranged in multiple stages in the height direction of the vacuum vessel.

6. The upper wall of the vacuum container is connected to the ground potential. The plasma processing apparatus according to claim 1, wherein one end of the antenna is connected to the upper wall via a dielectric.

7. The plasma processing apparatus according to claim 6, wherein the dielectric is pure water.

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