Film removal apparatus and film removal method

Abstract

This film removal device (100) comprises: a vacuum chamber (1) holding a workpiece (W1); an electrode (2) provided in the vacuum chamber (1) and having a first end (21) and a second end (22) that is disposed in a recess (W2) formed in the workpiece (W1); a gas feed mechanism (4) that feeds a gas from the first end (21) into the interior of the electrode (2); and a high-frequency power source (8) that applies a high-frequency voltage to the electrode.

Description

Technical Field

[0001] The present disclosure relates to a film removing device and a film removing method.

Background Art

[0002] Patent Document 1 discloses a plasma nitriding device for forming a nitride layer on the surface of a metal workpiece. The plasma nitriding device includes a sealed processing container, a positive electrode installed in the processing container, and a conductive screen installed so as to cover the workpiece and connected to the negative electrode. At least a part of the screen has a recess formed therein, and an auxiliary positive electrode connected to the positive electrode is disposed in a space formed outside the screen by the recess.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when applying the structure of the plasma nitriding device disclosed in Patent Document 1 to a film removing device for removing a coating film in a recess formed in a workpiece, there is a problem that the removed coating film adheres to the recess and the auxiliary positive electrode in the recess. One aspect of the present disclosure aims to sufficiently remove the coating film in the recess formed in the workpiece.

Means for Solving the Problems

[0005] To solve the above problems, a film removal apparatus according to one aspect of the present disclosure is a film removal apparatus for removing a coating film covering an object to be processed from the object to be processed by plasma, comprising: a vacuum vessel for housing the object to be processed inside; a pipe-shaped electrode provided in the vacuum vessel via an insulating member, having a first end located outside the vacuum vessel and a second end located in a recess formed in the object to be processed; a gas supply mechanism for supplying gas from the first end into the electrode and discharging gas from the second end; and a high-frequency power supply for generating plasma inside the vacuum vessel by applying a high-frequency voltage to the electrode.

[0006] Furthermore, in order to solve the above problems, a film removal method according to one aspect of the present disclosure is a film removal method for removing a coating film covering an object to be processed from the object to be processed by plasma, comprising: an arrangement step of arranging the object to be processed inside a vacuum container; an installation step of installing an electrode such that the first end of the pipe-shaped electrode provided in the vacuum container via an insulating member is arranged outside the vacuum container and the second end of the electrode is arranged in a recess formed in the object to be processed; a gas supply step of supplying gas from the first end to the inside of the electrode and discharging gas from the second end; and an application step of applying a high-frequency voltage to the electrode in order to generate plasma inside the vacuum container. [Effects of the Invention]

[0007] According to one aspect of this disclosure, the coating film formed in recesses on the workpiece can be sufficiently removed. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the configuration of the defilm removal device according to Embodiment 1 of this disclosure. [Figure 2] This figure shows the configuration of the defilm removal device according to Embodiment 2 of this disclosure. [Figure 3] Figure 2 is a cross-sectional view of the defilm removal apparatus along line AA. [Figure 4]This figure shows the configuration of the defilm removal device according to Embodiment 3 of this disclosure. [Figure 5] Figure 4 is a cross-sectional view of the defilm removal apparatus along line BB. [Modes for carrying out the invention]

[0009] [Embodiment 1] Figure 1 shows the configuration of a defilm removal device 100 according to Embodiment 1 of the present disclosure. In Figure 1, cross-sections of the vacuum vessel 1, electrode 2, insulating members 3 and 6, holder 5, and support part 51 are shown. Also in Figure 1, the direction from the support part 51 toward the vacuum evacuation device 10 is defined as the X-axis direction, the direction from the holder 5 toward the electrode 2 is defined as the Z-axis direction, and the direction perpendicular to both the X-axis direction and the Z-axis direction is defined as the Y-axis direction. The X-axis direction and the Z-axis direction are mutually orthogonal directions. The definitions of the X-axis direction, Y-axis direction, and Z-axis direction described herein shall also apply to other figures.

[0010] <Configuration of the film removal device 100> The film removal device 100 is a device that removes a coating film covering a workpiece W1 from the workpiece W1 using plasma. The workpiece W1 is, for example, a mold used for forming resin. As shown in Figure 1, the film removal device 100 comprises a vacuum chamber 1, electrodes 2, insulating members 3 and 6, a gas supply mechanism 4, a holder 5, a support part 51, a pulse power supply 7, a high-frequency power supply 8, a matching unit 81, a coil 9, and a vacuum evacuation device 10.

[0011] <Configuration of vacuum vessel 1 and electrode 2> The vacuum vessel 1 is constructed, for example, from a metal material, and houses the object to be processed W1 inside. The electrode 2 is formed in a pipe shape and has a first end 21 and a second end 22 opposite to the first end 21. The electrode 2 is provided on the upper wall 1A on the Z-axis positive side of the vacuum vessel 1 via an insulating member 3. The first end 21 is located outside the vacuum vessel 1, and the second end 22 is located in a recess W2 formed on the upper surface W3 on the Z-axis positive side of the object to be processed W1. The extension direction of the electrode 2 is in the Z-axis direction.

[0012] It is preferable that the second end 22 of the electrode 2 is positioned closer to the bottom of the recess W2 than to the center position in the Z-axis direction of the recess W2. This allows the coating film removed from the recess W2 to be discharged to the outside of the recess W2 without reattaching to the recess W2 when the gas supply mechanism 4 supplies gas into the inside of the electrode 2.

[0013] Furthermore, the electrode 2 may branch into multiple pipes along the path from the first end 21 toward the negative Z-axis, forming multiple second ends 22. This allows the gas supply mechanism 4 to supply gas into the electrode 2, discharging gas from the multiple second ends 22 over a wide area of ​​the recess W2.

[0014] <Configuration of insulating members 3 and 6> The insulating member 3 electrically insulates the vacuum container 1 from the electrode 2 and is provided between the opening formed in the upper wall 1A of the vacuum container 1 and the electrode 2. A portion of the electrode 2 is placed within the opening 31 formed in the insulating member 3, and a plurality of vacuum sealing members 32 are provided between the electrode 2 and the opening 31. The plurality of vacuum sealing members 32 create a vacuum seal between the electrode 2 and the opening 31.

[0015] The insulating member 6 electrically insulates the vacuum container 1 from the support portion 51 and is provided between the opening formed in the lower wall 1B on the negative Z-axis side of the vacuum container 1 and the support portion 51. A part of the support portion 51 is positioned within the opening 61 formed in the insulating member 6, and a plurality of vacuum sealing members 62 are provided between the support portion 51 and the opening 61. The plurality of vacuum sealing members 62 create a vacuum seal between the support portion 51 and the opening 61.

[0016] <Configuration of Gas Supply Mechanism 4> The gas supply mechanism 4 supplies gas into the electrode 2 from the first end 21 of the electrode 2, causing the gas to be discharged from the second end 22 of the electrode 2. The gas supply mechanism 4 is connected to the first end 21 of the electrode 2 via an insulating pipe (not shown) made of an insulating material such as resin, ceramics, or glass, for example, and controls the gas to a desired flow rate and supplies it into the electrode 2.

[0017] The pressure inside the vacuum chamber 1 is adjusted by a pressure regulating valve (not shown) provided between the vacuum chamber 1 and the vacuum evacuation device 10. It is preferable to increase the pressure inside the vacuum chamber 1 as the opening area on the upper surface W3 in the recess W2 of the workpiece W1 is smaller. Thereby, the coating film inside the recess W2 can be efficiently removed. The gas supply mechanism 4 preferably controls the gas pressure within a range of 0.5 Pa or more and 400 Pa or less.

[0018] The gas that the gas supply mechanism 4 supplies into the electrode 2 is an inert gas such as argon gas, for example. Since the flow of argon gas discharged from the second end 22 of the electrode 2 into the recess W2 becomes a viscous flow, it is convenient for removing the coating film inside the recess W2. However, when the coating film covering the workpiece W1 is a film made of carbon, the gas that the gas supply mechanism 4 supplies into the electrode 2 is preferably oxygen gas or a mixed gas of oxygen gas and argon gas. Also, depending on the type of the coating film, the gas that the gas supply mechanism 4 supplies into the electrode 2 may be a mixed gas of a halide containing fluorine or chlorine and a noble gas.

[0019] <Configuration of the Holder 5 and the Support Port 51> The holder 5 is made of a metal material and is provided inside the vacuum chamber 1 to support the workpiece W1. The holder 5 is supported by the support port 51. The support port 51 is provided on the lower wall 1B via an insulating member 6 and is made of a metal material. The end portion on the positive Z-axis direction side of the support port 51 is connected to the holder 5 inside the vacuum chamber 1, and the end portion on the negative Z-axis direction side of the support port 51 is electrically connected to the pulse power source 7 outside the vacuum chamber 1.

[0020] <Configuration of pulse power supply 7> The pulse power supply 7 is a DC pulse power supply that applies a pulse voltage that fluctuates mainly within the negative range to the workpiece W1. In other words, the pulse power supply 7 is a DC pulse power supply that periodically applies mainly negative pulse voltages to the workpiece W1. In pulse operation, the pulse power supply 7 applies a negative voltage when ON and zero or positive voltage when OFF. The frequency of the pulse voltage applied by the pulse power supply 7 to the workpiece W1 is preferably, for example, 75 kHz or more and 250 kHz or less.

[0021] The pulse power supply 7 applies a negative pulse voltage to the workpiece W1, and the high-frequency power supply 8 applies a high-frequency voltage to the electrode 2, thereby removing the coating film from the recess W2 by sputtering. The pulse voltage applied by the pulse power supply 7 to the workpiece W1 is preferably between -600V and -100V. The side of the pulse power supply 7 opposite to the side connected to the support 51 is connected to ground G1.

[0022] <Configuration of the high-frequency power supply 8 and matching circuit 81> The high-frequency power supply 8 is a power source for supplying high-frequency power to the electrode 2 by applying a high-frequency voltage to the electrode 2, thereby generating capacitive-coupled plasma (CCP) inside the vacuum chamber 1. With the second end 22 of the electrode 2 positioned within the recess W2 of the workpiece W1, the high-frequency power supply 8 can generate plasma within the recess W2 by applying a high-frequency voltage to the electrode 2. The high-frequency power supply 8 is electrically connected to the first end 21 of the electrode 2 via a matching unit 81.

[0023] The frequency of the high-frequency voltage applied to the electrode 2 by the high-frequency power supply 8 is preferably, for example, 13.56 MHz. The side of the high-frequency power supply 8 opposite to the side connected to the matching circuit 81 is connected to ground G2. The matching circuit 81 is an electrical circuit that matches the power from the high-frequency power supply 8 according to the load.

[0024] <Configuration of coil 9> Coil 9 is connected in parallel with electrode 2 and is electrically connected to matching unit 81. The side of coil 9 opposite to the side connected to matching unit 81 is connected to ground G3. By connecting coil 9 in parallel with electrode 2, plasma can be generated uniformly within the recess W2 of the workpiece W1, and the self-bias voltage of electrode 2 can be suppressed. Therefore, by suppressing the self-bias voltage of electrode 2 and applying a pulse voltage that mainly fluctuates in the negative range to the workpiece W1 using the pulse power supply 7, positive ions in the plasma can be attracted to the recess W2, and the coating film in the recess W2 can be removed more efficiently.

[0025] <Configuration of the vacuum exhaust system 10> The vacuum evacuation device 10 is a device that evacuates the inside of the vacuum container 1 through an outlet 1C formed in the vacuum container 1, and is, for example, a vacuum pump. After the inside of the vacuum container 1 is evacuated by the vacuum evacuation device 10, gas is introduced into the inside of the vacuum container 1 by the gas supply mechanism 4.

[0026] As described above, in the defilm removal apparatus 100, the electrode 2 is provided in the vacuum container 1 via an insulating member 3 such that the second end 22 of the electrode 2 is positioned in a recess W2 formed in the workpiece W1. This allows plasma to be generated in the recess W2 when a high-frequency voltage is applied to the electrode 2 by the high-frequency power supply 8, and by applying a pulse voltage to the workpiece W1 by the pulse power supply 7, the coating film in the recess W2 can be sufficiently removed. Furthermore, since the gas supply mechanism 4 discharges gas from the second end 22 of the electrode 2 positioned in the recess W2, the coating film in the recess W2 can be efficiently discharged to the outside of the recess W2.

[0027] <Membrane removal method> The following describes a method for removing a coating film covering an object W1 to be processed using plasma. First, the object W1 to be processed is placed on a holder 5 provided inside a vacuum container 1 (placement step). Next, the electrode 2 is installed such that the first end 21 of the pipe-shaped electrode 2, which is provided in the vacuum container 1 via an insulating member 3, is placed outside the vacuum container 1, and the second end 22 of the electrode 2 is placed inside a recess W2 formed in the object W1 to be processed (installation step).

[0028] After the electrodes 2 are placed in the vacuum vessel 1, the vacuum chamber 1 is evacuated using the vacuum evacuation device 10, and gas is supplied to the inside of the electrodes 2 from the first end 21 by the gas supply mechanism 4, causing the gas to be discharged from the second end 22 (gas supply process). After the gas supply by the gas supply mechanism 4 is started, the pressure inside the vacuum vessel 1 is adjusted to the desired pressure using a pressure adjustment valve (not shown). Then, in order to generate plasma inside the vacuum vessel 1, a high-frequency voltage is applied to the electrodes 2 by the high-frequency power supply 8 (application process). After starting the application of the high-frequency voltage by the high-frequency power supply 8 and confirming the illumination of the plasma, a pulse voltage is applied to the workpiece W1 by the pulse power supply 7.

[0029] [Embodiment 2] Embodiment 2 of this disclosure will be described below. For the sake of convenience, components having the same function as those described in Embodiment 1 will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 2 is a diagram showing the configuration of the defilm removal device 101 according to Embodiment 2 of this disclosure. Figure 3 is a cross-sectional view of the defilm removal device 101 shown in Figure 2, taken along line AA. In Figure 2, cross-sections of the multiple electrodes 2A, 2B, 2C and the multiple insulating members 3A, 3B, 3C are shown.

[0030] As shown in Figures 2 and 3, the defilm removal device 101 differs from the defilm removal device 100 in that it contains multiple materials to be processed WA, WB, WC, WD, and WE inside the vacuum container 1, and has multiple electrodes 2A to 2E. Furthermore, the defilm removal device 101 differs from the defilm removal device 100 in that it has multiple insulating members 3A to 3C, multiple coils 91, 92, and 93, and multiple variable capacitors C1, C2, and C3.

[0031] The vacuum container 1 is formed in a cylindrical shape and houses a plurality of objects to be processed WA to WE inside. The plurality of objects to be processed WA to WE are supported by a holder 5. The holder 5 is formed, for example, in a disc shape. It is preferable that the objects to be processed WA to WE have the same configuration as each other, for example, they may be the same configuration as the object to be processed W1 shown in Figure 1. A plurality of electrodes 2A to 2E are provided on the upper wall 1A of the vacuum container 1 via an insulating member.

[0032] Specifically, electrode 2A is provided on the upper wall 1A via an insulating member 3A, electrode 2B is provided on the upper wall 1A via an insulating member 3B, and electrode 2C is provided on the upper wall 1A via an insulating member 3C. In addition, electrode 2D is provided on the upper wall 1A via an insulating member (not shown), and electrode 2E is provided on the upper wall 1A via an insulating member (not shown).

[0033] The configuration of electrodes 2A to 2E is the same as the configuration of electrode 2 shown in Figure 1, and the configuration of insulating members 3A to 3C is the same as the configuration of insulating member 3 shown in Figure 1. The extension direction of electrodes 2A to 2E is the Z-axis direction. The defilm removal device 101 further comprises an insulating member provided between electrode 2D and upper wall 1A, and an insulating member provided between electrode 2E and upper wall 1A.

[0034] The second ends of electrodes 2A to 2E are positioned within recesses formed in each of the multiple workpieces WA to WE. Specifically, the second end 22A of electrode 2A is positioned within recess WA2 formed in workpiece WA, and the second end 22B of electrode 2B is positioned within recess WB2 formed in workpiece WB.

[0035] Furthermore, the second end 22C of electrode 2C is positioned within the recess WC2 formed in the workpiece WC. The second end of electrode 2D is positioned within the recess WD2 formed in the workpiece WD, and the second end of electrode 2E is positioned within the recess WE2 formed in the workpiece WE.

[0036] The gas supply mechanism 4 discharges gas from the second end of electrodes 2A to 2E by supplying gas from the first end of electrodes 2A to 2E into the interior of electrodes 2A to 2E. Specifically, the gas supply mechanism 4 is connected to the first end 21A of electrode 2A via an insulating pipe (not shown) made of an insulating material such as resin, ceramics, or glass. The gas supply mechanism 4 also discharges gas from the second end 22A by supplying gas from the first end 21A into the interior of electrode 2A.

[0037] Similarly, the gas supply mechanism 4 is connected to the first end 21B of electrode 2B, the first end 21C of electrode 2C, the first end of electrode 2D, and the first end of electrode 2E via an insulating pipe having the same configuration as the insulating pipe described above. The gas supply mechanism 4 also discharges gas from the second ends 22B, 22C, the second end of electrode 2D, and the second end of electrode 2E. The gas supply mechanism 4 supplies gas evenly to the interiors of the multiple electrodes 2A to 2E at the same pressure.

[0038] The pulse power supply 7 applies a pulse voltage to multiple workpieces WA to WE via the holder 5 and support 51. The high-frequency power supply 8 applies a high-frequency voltage to multiple electrodes 2A to 2C via the matching circuit 81 and variable capacitors C1 to C3, and applies a high-frequency voltage to electrodes 2D and 2E via the matching circuit 81 and two variable capacitors (not shown).

[0039] Electrodes 2A to 2E are connected in parallel to each other and in series with their corresponding variable capacitors. Variable capacitor C1 is connected in series with electrode 2A and is electrically connected between electrode 2A and the matching circuit 81. Variable capacitor C2 is connected in series with electrode 2B and is electrically connected between electrode 2B and the matching circuit 81. Variable capacitor C3 is connected in series with electrode 2C and is electrically connected between electrode 2C and the matching circuit 81.

[0040] The other two variable capacitors are also connected in series with electrodes 2D and 2E, respectively, and are electrically connected between electrodes 2D and 2E and the matching unit 81. The variable capacitors C1 to C3 and the other two variable capacitors are for adjusting or equalizing the high-frequency power supplied to the multiple electrodes 2A to 2E, and for adjusting or equalizing the high-frequency voltage applied to the multiple electrodes 2A to 2E. The defilm removal device 101 further comprises the other two variable capacitors.

[0041] Coil 91 is connected in parallel with electrode 2A and is electrically connected to variable capacitor C1. The side of coil 91 opposite to the side connected to variable capacitor C1 is connected to ground G31. Coil 92 is connected in parallel with electrode 2B and is electrically connected to variable capacitor C2. The side of coil 92 opposite to the side connected to variable capacitor C2 is connected to ground G32.

[0042] Similarly, coil 93 is connected in parallel with electrode 2C, and the side of coil 93 opposite to the side connected to the variable capacitor C3 is connected to ground G33. Electrodes 2D and 2E are also connected in parallel with the coil. The defilm removal device 101 further includes a coil connected in parallel with electrodes 2D and 2E.

[0043] The materials to be processed WA to WE may be of different types. In this case, the gas supply mechanism 4 may supply gas to the inside of the multiple electrodes 2A to 2E at different flow rates, and the variable capacitors C1 to C3 and the other two variable capacitors may be used to apply different high-frequency voltages to the multiple electrodes 2A to 2E.

[0044] As described above, in the decoupling apparatus 101, the second ends of electrodes 2A to 2E are positioned in recesses formed in each of the multiple workpieces WA to WE housed inside the vacuum container 1, and the high-frequency power supply 8 applies a high-frequency voltage to the multiple electrodes 2A to 2E. This allows the coating film to be removed from multiple workpieces WA to WE, thereby shortening the processing time. Furthermore, since the high-frequency power supply 8 applies a high-frequency voltage to multiple electrodes 2A to 2E, the cost associated with the high-frequency power supply 8 can be reduced. For example, if only one high-frequency power supply 8 is used, the cost associated with the high-frequency power supply 8 can be effectively reduced.

[0045] [Embodiment 3] Embodiment 3 of this disclosure will be described below. For the sake of convenience, components having the same function as those described in Embodiments 1 and 2 will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 4 is a diagram showing the configuration of the defilm removal device 102 according to Embodiment 3 of this disclosure. Figure 5 is a cross-sectional view of the defilm removal device 102 shown in Figure 4, taken along line BB. In Figure 4, cross-sections of the high-frequency windows 11A, 11C, antennas 12A, 12C, and shielding members 15A, 15C are shown. Also, in Figure 4, the vacuum exhaust device 10 and the outlet 1C are omitted.

[0046] As shown in Figures 4 and 5, the defilm removal device 102 differs from the defilm removal device 101 in that it is equipped with high-frequency windows 11A, 11C, 11D, and 11E, antennas 12A, 12C, 12D, and 12E, and a cooling mechanism 13.

[0047] Furthermore, the defilm removal device 102 differs from the defilm removal device 101 in that it is equipped with a high-frequency power supply 14 and a matching unit 141, shielding members 15A, 15C, 15D, and 15E, and a rotating mechanism 16. In addition, the defilm removal device 102 differs from the defilm removal device 101 in that the material to be processed WB is not placed inside the vacuum container 1, and it does not have electrodes 2B, coils 92, and variable capacitors C2.

[0048] <Configuration of high-frequency windows 11A, 11C~11E> The high-frequency windows 11A, 11C, and 11E are provided on the walls of the vacuum vessel 1 along the extension direction of electrodes 2A, 2C, 2D, and 2E, and introduce a high-frequency magnetic field that generates plasma inside the vacuum vessel 1. Specifically, the high-frequency window 11A is provided on the wall 1D along the Z-axis direction of the vacuum vessel 1, and introduces the high-frequency magnetic field generated by antenna 12A into the vacuum vessel 1.

[0049] Furthermore, the high-frequency window 11C is provided on the wall surface 1E of the vacuum vessel 1 along the Z-axis direction, and introduces the high-frequency magnetic field generated by the antenna 12C into the interior of the vacuum vessel 1. Similarly, the high-frequency windows 11D and 11E are provided on the wall surfaces of the vacuum vessel 1 along the Z-axis direction, and introduce the high-frequency magnetic fields generated by the antennas 12D and 12E into the interior of the vacuum vessel 1.

[0050] The high-frequency window 11A comprises a metal plate 111A and a dielectric plate 113A. Multiple slits 112A are formed in the metal plate 111A, and the metal plate 111A is provided in the vacuum vessel 1 so as to close the opening 1I formed in the wall surface 1D of the vacuum vessel 1. The dielectric plate 113A is provided on the metal plate 111A so as to cover at least the slits 112A.

[0051] Similarly, the high-frequency window 11C comprises a metal plate 111C and a dielectric plate 113C, the high-frequency window 11D comprises a metal plate 111D and a dielectric plate 113D, and the high-frequency window 11E comprises a metal plate 111E and a dielectric plate 113E. The configuration of the metal plates 111C, 111D, and 111E is the same as that of the metal plate 111A, and the configuration of the dielectric plates 113C, 113D, and 113E is the same as that of the dielectric plate 113A.

[0052] <Configuration of antennas 12A, 12C~12E> Antennas 12A, 12C-12E are each positioned outside the vacuum vessel 1, facing the high-frequency windows 11A, 11C-11E, and generate a high-frequency magnetic field that produces inductively coupled plasma (ICP). Specifically, antenna 12A is formed in a straight line and constructed from a metallic material such as copper. Antenna 12A is also positioned along the Z-axis direction outside the vacuum vessel 1, facing the high-frequency window 11A. The configuration of antennas 12C-12E is the same as that of antenna 12A.

[0053] <Configuration of cooling mechanism 13> The cooling mechanism 13 includes a heat exchanger and the like for adjusting the coolant circulating through the circulation channels 131 and 132 to a constant temperature, and a pump and the like for circulating the coolant through the circulation channels 131 and 132. The circulation channel 131 is located inside the antenna 12A, passing through the shield member 15A. The circulation channel 132 is located inside the antenna 12C, passing through the shield member 15C.

[0054] The circulation channels 131 and 132 guide the Joule heat generated in antennas 12A and 12C to the outside of antennas 12A and 12C. Therefore, antennas 12A and 12C, whose temperature has risen due to the generation of Joule heat, can be cooled by the cooling mechanism 13. Thus, the temperature of antennas 12A and 12C can be maintained at an appropriate temperature. Similarly, the cooling mechanism 13 adjusts the coolant circulating through the circulation channels provided inside antennas 12D and 12E to a constant temperature and circulates it.

[0055] <Configuration of the high-frequency power supply 14 and matching circuit 141> The high-frequency power supply 14 is a power source for generating plasma inside the vacuum vessel 1 by supplying high-frequency power to antennas 12A, 12C~12E by applying a high-frequency voltage to them. The high-frequency power supply 14 is electrically connected to antennas 12A, 12C~12E via a matching circuit 141.

[0056] The side of the high-frequency power supply 14 opposite to the side connected to the matching circuit 141 is connected to ground G4. The matching circuit 141 is an electrical circuit that matches the power from the high-frequency power supply 14 according to the load. The side of antenna 12A opposite to the side connected to the matching circuit 141 is connected to ground G51, and the side of antenna 12C opposite to the side connected to the matching circuit 141 is connected to ground G52. The sides of antennas 12D and 12E opposite to the side connected to the matching circuit 141 are also connected to ground.

[0057] <Configuration of shield members 15A, 15C~15E> The shielding members 15A, 15C to 15E are each provided on the wall surface of the vacuum vessel 1 along the Z-axis direction so as to surround the antennas 12A, 12C to 12E and the high-frequency windows 11A, 11C to 11E.

[0058] <Configuration of the rotating mechanism 16> The rotating mechanism 16 comprises rotary tables 161, 162, 163, and 164, and a rotating gear 165. Rotary tables 161 to 164 are rotatably mounted on the holder 5. Specifically, rotary table 161 is formed, for example, in the shape of a disc and is made of a metal material. The holder 5 is provided with a shaft (not shown) made of a metal material, and rotary table 161 is rotatably mounted on this shaft. Similarly, rotary tables 162 to 164 are also rotatably mounted on the holder 5.

[0059] Rotary table 161 is rotatably mounted on the holder 5 with axis A1, which coincides with electrode 2A, as its axis of rotation. Rotary table 162 is rotatably mounted on the holder 5 with axis A2, which coincides with electrode 2C, as its axis of rotation. Rotary table 163 is rotatably mounted on the holder 5 with axis A3, which coincides with electrode 2D, as its axis of rotation. Rotary table 164 is rotatably mounted on the holder 5 with axis A4, which coincides with electrode 2E, as its axis of rotation. Axes A1 to A4 are axes that extend along the Z-axis direction. Workpieces WA, WC to WE are placed on rotary tables 161 to 164, respectively.

[0060] The rotating gear 165 is movably positioned on the outer circumference of the holder 5. The rotating gear 165 rotates in the R1 direction shown in Figure 5 while contacting the outer circumference of the rotary tables 161-164. As a result, the rotary tables 161-164 rotate in the R2 direction shown in Figure 5. The rotating mechanism 16 rotates the rotary tables 161-164 by rotating the rotating gear 165 using a drive mechanism (not shown).

[0061] The rotating mechanism 16 rotates the workpiece WA around axis A1 by rotating the rotary table 161, and rotates the workpiece WC around axis A2 by rotating the rotary table 162. Furthermore, the rotating mechanism 16 rotates the workpiece WD around axis A3 by rotating the rotary table 163, and rotates the workpiece WE around axis A4 by rotating the rotary table 164.

[0062] As described above, the defilm removal device 102 introduces a high-frequency magnetic field that generates plasma into the vacuum vessel 1 from high-frequency windows 11A, 11C~11E provided on the wall surface of the vacuum vessel 1 along the Z-axis direction, and rotates the workpieces WA, WC~WE using the rotation mechanism 16. This allows the coating film to be removed from parts of the workpieces WA, WC~WE other than the recessed parts. In other words, the coating film on the outer parts of the workpieces WA, WC~WE can be uniformly removed, and the coating film on both the recessed and outer parts of the workpieces WA, WC~WE can be removed together.

[0063] 〔summary〕 A film removal apparatus according to a first aspect of the present disclosure is a film removal apparatus for removing a coating film covering an object to be processed from the object to be processed by plasma, comprising: a vacuum vessel for housing the object to be processed inside; a pipe-shaped electrode provided in the vacuum vessel via an insulating member, having a first end located outside the vacuum vessel and a second end located in a recess formed in the object to be processed; a gas supply mechanism for supplying gas from the first end into the electrode and discharging gas from the second end; and a high-frequency power supply for generating plasma inside the vacuum vessel by applying a high-frequency voltage to the electrode.

[0064] The defilm removal apparatus of a second aspect of this disclosure may further include, in the first aspect, a coil connected in parallel with the electrode and a pulse power supply capable of applying a pulse voltage that fluctuates within a negative range to the workpiece.

[0065] A defilm removal apparatus according to a third aspect of the present disclosure may be configured such that, in the first or second aspect described above, the vacuum vessel houses a plurality of objects to be processed, the vacuum vessel is provided with a plurality of electrodes via an insulating member, the second ends of the electrodes are placed in recesses formed in each of the plurality of objects to be processed, and the high-frequency power supply applies the high-frequency voltage to the plurality of electrodes.

[0066] The defilm removal apparatus of the fourth aspect of the present disclosure may further include, in any of the first to third aspects described above, a high-frequency window provided on the wall surface of the vacuum vessel along the extension direction of the electrode and for introducing a high-frequency magnetic field that generates plasma inside the vacuum vessel into the vacuum vessel; an antenna provided on the outside of the vacuum vessel so as to face the high-frequency window and for generating the high-frequency magnetic field; and a rotation mechanism for rotating the workpiece around a rotation axis along the extension direction of the electrode.

[0067] A fifth aspect of the present disclosure is a method for removing a coating film covering an object to be processed by plasma, comprising: a placement step of placing the object to be processed inside a vacuum container; a placement step of installing an electrode such that the first end of the pipe-shaped electrode provided in the vacuum container via an insulating member is placed outside the vacuum container and the second end of the electrode is placed in a recess formed in the object to be processed; a gas supply step of supplying gas from the first end to the inside of the electrode and discharging the gas from the second end; and an application step of applying a high-frequency voltage to the electrode in order to generate plasma inside the vacuum container.

[0068] This disclosure 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 this disclosure. [Explanation of Symbols]

[0069] 1 Vacuum container 1D, 1E wall 2, 2A~2E electrode 3, 3A~3C Insulating material 4. Gas supply mechanism 7. Pulse power supply 8 High frequency power supply 9, 91-93 coils 11A, 11C~11E High-frequency windows 12A, 12C~12E antenna 16 Rotation mechanism 21, 21A~21C 1st end 22, 22A~22C 2nd end 100~102 Film removal equipment A1~A4 axis W1, WA~WE - Items to be processed W2, WA2~WE2 recessed area

Claims

1. A coating removal apparatus for removing a coating film covering an object to be processed from the object to be processed by plasma, A vacuum container for housing the object to be processed, A pipe-shaped electrode provided in the vacuum container via an insulating member, the electrode having a first end located outside the vacuum container and a second end located within a recess formed in the object to be processed, A gas supply mechanism that supplies gas into the electrode from the first end and discharges gas from the second end, A defilm removal apparatus comprising a high-frequency power supply for generating plasma inside the vacuum container by applying a high-frequency voltage to the electrode.

2. A coil connected in parallel to the electrode, The defilm removal apparatus according to claim 1, further comprising a pulse power supply capable of applying a pulse voltage that fluctuates within a negative range to the workpiece.

3. The vacuum container houses a plurality of the objects to be processed inside, The vacuum vessel is provided with a plurality of electrodes via the insulating member, The second end of the electrode is positioned in the recess formed in each of the multiple objects to be processed. The defilm removal apparatus according to claim 1 or 2, characterized in that the high-frequency power supply applies the high-frequency voltage to the plurality of electrodes.

4. A high-frequency window is provided on the wall surface of the vacuum vessel along the extension direction of the electrode, and allows a high-frequency magnetic field that generates plasma inside the vacuum vessel to be introduced into the vacuum vessel. An antenna is provided on the outside of the vacuum vessel so as to face the high-frequency window and generates the high-frequency magnetic field, The defilm removal apparatus according to claim 1 or 2, further comprising a rotation mechanism for rotating the workpiece around a rotation axis along the extension direction of the electrode.

5. A method for removing a coating film from an object to be treated by using plasma, The arrangement step of placing the object to be processed inside the vacuum container, Installation step: Installing the electrode such that the first end of the pipe-shaped electrode, which is provided in the vacuum container via an insulating member, is positioned outside the vacuum container, and the second end of the electrode is positioned in a recess formed in the object to be processed. A gas supply step in which gas is supplied from the first end to the inside of the electrode, thereby causing the gas to be discharged from the second end, A film removal method characterized by including an application step of applying a high-frequency voltage to the electrode in order to generate plasma inside the vacuum container.

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