Static elimination device and static elimination method

Abstract

The present application relates to an electrostatic elimination device and an electrostatic elimination method. The electrostatic elimination device comprises: a vacuum chamber in which a charged body can be arranged; a high vacuum processing unit arranged inside the vacuum chamber to perform high vacuum processing on the charged body; and an electrostatic elimination processing unit comprising a plasma generating device for supplying plasma generated by electron cyclotron resonance to the inside of the vacuum chamber, and performing electrostatic elimination on the charged body by the plasma. The plasma generating device comprises a plasma source, which is arranged inside the vacuum chamber and generates the plasma for performing electrostatic elimination on the charged body.

Description

[0001] This application is a divisional application of the following application:

[0002] Invention Title: Static Elimination Device and Plasma Generator

[0003] International filing date: November 28, 2018

[0004] International Application Number: PCT / JP2018 / 043779

[0005] National application number: 201880024348.0 Technical Field

[0006] The present invention relates to a static electricity eliminating device and a static electricity eliminating method.

[0007] This application claims priority based on Japanese Patent Application No. 2018-170898 filed in Japan on September 12, 2018, and the contents are incorporated herein by reference. Background Art

[0008] In the past, static eliminators with vacuum chambers have been used to perform vacuum deposition and other treatments and static elimination on charged bodies in the vacuum chamber. The vacuum chamber of such static eliminators needs to have two spaces: a space for vacuum deposition and other treatments with a high degree of vacuum, i.e., a high vacuum region; and a space for static elimination with a low degree of vacuum, i.e., a low vacuum region. Such static eliminators eject gas toward the charged body, which is the object of static elimination, in the evacuated vacuum chamber, thereby performing static elimination on the charged body (see Patent Document 1). More specifically, such static eliminators perform static elimination on the charged body by causing the charged body to discharge passively. For example, such static eliminators cause a gas such as argon to flow through a gas inlet pipe to the low vacuum region where static elimination is performed, generate plasma using a DC power supply, and bring the object of static elimination into contact with the plasma, thereby performing static elimination on the charged body (see Patent Document 2).

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Publication No. 2009-181938

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 10-298758 Summary of the invention

[0013] Problems to be solved by the invention

[0014] However, such a static eliminator needs to have a high vacuum region and a low vacuum region, and thus there is a problem of increasing the size of the device.

[0015] In view of the above circumstances, an object of the present invention is to provide a static eliminator that does not require a high vacuum region and a low vacuum region.

[0016] Solutions for solving problems

[0017] One embodiment of the present invention is an electrostatic elimination device, comprising: a vacuum chamber in which a charged body can be arranged and which has a high vacuum processing portion; and a plasma generating device that supplies plasma generated by electron cyclotron resonance to the interior of the vacuum chamber, the plasma generating device comprising: a plasma source that generates the plasma; and a flange that sets the plasma source inside the vacuum chamber.

[0018] Effects of the Invention

[0019] According to the present invention, it is possible to provide a static elimination device which does not need to have a high vacuum region and a low vacuum region. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing an example of the configuration of the static eliminator 100 according to the embodiment.

[0021] Figure 2 It is a diagram showing an example of the configuration of a plasma generator 500 according to the embodiment.

[0022] Figure 3 : is a schematic cross-sectional view of the plasma source 501 in the embodiment.

[0023] Figure 4 is a schematic top view of a plasma source 501 in an embodiment.

[0024] Figure 5 This is a schematic cross-sectional view for explaining the operation of the plasma source 501 in the embodiment.

[0025] Figure 6 1 is a diagram showing an example of the arrangement of the openings 610 when the nozzle unit 60 in the embodiment has a plurality of openings 610 .

[0026] Figure 7 1 is a diagram showing experimental results showing the effect of extracting plasma from the plasma source 501 by the extraction electrode 507 in the embodiment.

[0027] Figure 8 FIG. 1 is a diagram showing an example of the inhibitor 101 in a modified example.

[0028] Fig. 9This is an explanatory diagram for explaining an experimental environment of an experiment showing the effect of the inhibitor 101 in a modified example.

[0029] Fig.10 1 is a diagram showing an example of experimental results showing the effect of the inhibitor 101 in the modified example. DETAILED DESCRIPTION

[0030] Figure 1 It is a diagram showing an example of the configuration of the static eliminator 100 according to the embodiment.

[0031] The static eliminator 100 performs static elimination on the charged body 9. Furthermore, the static eliminator 100 performs a process requiring high vacuum, such as vapor deposition, on the charged body 9. Hereinafter, for the sake of convenience, the process requiring high vacuum will be referred to as high vacuum process. The charged body 9 may be any object that can be charged, for example, it may be a thin film sheet that is the object of the vapor deposition process. In the static eliminator 100, static elimination is performed on the thin film sheet, for example, in order to suppress the reduction in processing accuracy caused by the charging of the thin film sheet during the processing of the thin film sheet. The charging of the thin film sheet is generated by the movement and friction of the polymer material constituting the thin film sheet. The static eliminator 100 performs static elimination in a process requiring static elimination, for example, in the process of conveying an insulator such as a polymer material. The static eliminator 100 performs static elimination in a process requiring static elimination, for example, in the process performed by the high vacuum processing unit 3 described later.

[0032] The static eliminator 100 includes, for example, a vacuum chamber 1 , a vacuum pump 2 , a high vacuum processing unit 3 , a delivery unit 4 - 1 , guide units 4 - 2 to 4 - 5 , a take-up unit 4 - 6 , a conveyor 4 - 7 , and a static eliminator 5 .

[0033] The vacuum chamber 1 is a shell having a hollow interior. If the difference between the external pressure and the internal pressure is less than a predetermined pressure, the vacuum chamber 1 will not deform. The vacuum chamber 1 can be provided with a charged body 9 inside.

[0034] The vacuum pump 2 draws out the air in the vacuum chamber 1 to make the pressure in the vacuum chamber 1 reach a predetermined pressure. The predetermined pressure is, for example, 10 -5 Above Pa and below 1Pa.

[0035] The high vacuum treatment section 3 performs high vacuum treatment on the charged body 9. High vacuum treatment is a treatment performed in a high vacuum. -5 The vacuum is not less than Pa and not more than 1 Pa. The high vacuum processing unit 3 may be any unit that performs high vacuum processing, and may be, for example, a vapor deposition unit.

[0036] The high vacuum processing section 3, for example, performs, in a vacuum chamber maintained at a high vacuum, a conveying process of an insulator such as a polymer material, a vapor deposition process of metals such as aluminum, nickel, titanium, and chromium, a ceramic vapor deposition process of SiO, SiO2, Al2O3, CaF2, SnO2, etc., a micro-machining process of semiconductor materials such as chips in VLSI (very large scale integration) manufacturing, a thin film forming process, a thin film generating process of organic materials in an organic EL (electro-luminescence) production process, an aluminum vapor deposition process used as a cathode, and the like.

[0037] The charged body 9 is conveyed by the delivery unit 4-1, guide units 4-2 to 4-5, take-up unit 4-6, and conveyor belt 4-7. More specifically, the charged body 9 is delivered by the delivery unit 4-1, and is conveyed by the conveyor belt 4-7 through the guide units 4-2 to 4-5 to the take-up unit 4-6.

[0038] The static elimination processing unit 5 performs static elimination on the charged body 9, and includes a plasma generator 500. The plasma generator 500 generates plasma, and is connected to the vacuum chamber 1 via a flange.

[0039] The plasma generated by the plasma generator 500 fills the interior of the vacuum chamber 1 .

[0040] Figure 2 It is a diagram showing an example of the configuration of a plasma generator 500 according to the embodiment.

[0041] The plasma generating device 500 includes, for example, a plasma source 501 , a connecting portion 502 , a heat conducting portion 503 , a flange 504 , a gas nozzle 505 , a microwave feedthrough 506 , an extraction electrode 507 , a microwave tuner 508 , a filament 509 , a gas source 510 , a flow meter 511 , an RF oscillator 512 , and a power meter 513 .

[0042] The plasma source 501 generates plasma using electron cyclotron resonance. The plasma source 501 generates plasma using electron cyclotron resonance, and therefore is electrodeless. The detailed structure of the plasma source 501 will be described later.

[0043] The connection part 502 connects the flange 504 and the plasma source 501, and conducts the heat generated in the plasma source 501 to the flange 504 via the heat conducting part 503. The connection part 502 suppresses the plasma source 501 from reaching a predetermined temperature or above. As long as the connection part 502 has a thermal conductivity that suppresses the plasma source 501 from reaching a predetermined temperature or above, it can be any component. The connection part 502 can be, for example, an aluminum block, a copper block, or a carbon block.

[0044] The heat conducting part 503 conducts the heat conducted by the connection part 502 to the flange 504. The heat conducting part 503 suppresses the plasma source 501 from reaching a predetermined temperature or higher. The heat conducting part 503 has a thermal conductivity that suppresses the plasma source 501 from reaching a predetermined temperature or higher, and may be any component as long as it has a thermal conductivity higher than that of the connection part 502. The heat conducting part 503 may be, for example, a copper mesh or a carbon sheet.

[0045] Flange 504 connects plasma source 501 to vacuum chamber 1, and plasma source 501 is arranged inside vacuum chamber 1. Flange 504 is connected to connection part 502, and releases the heat conducted through connection part 502 and heat conducting part 503 to the outside of vacuum chamber 1. Flange can be any flange, for example, can be a flange based on ICF standard.

[0046] The gas nozzle 505 supplies gas to the plasma source 501. For example, the gas nozzle 505 supplies gas to the space 21 described later. As long as the gas supplied by the gas nozzle 505 is a gas that helps to generate plasma, it can be any gas. The gas supplied by the gas nozzle 505 can be, for example, an inert gas such as xenon, argon, and nitrogen, or an active gas such as air and oxygen. Hereinafter, the gas supplied by the gas nozzle 505 is referred to as a discharge gas.

[0047] The microwave feedthrough 506 transmits microwaves from the outside of the vacuum chamber 1 to the plasma source 501. As long as the microwave feedthrough 506 can transmit microwaves from the outside of the vacuum chamber 1 to the plasma source 501, it can be any component. The microwave feedthrough 506 can be, for example, a microwave coaxial cable connected to an SMA terminal. It should be noted that as long as the frequency of the microwave transmitted by the microwave feedthrough 506 is a frequency that satisfies the electron cyclotron resonance condition, it can be any frequency, for example, it can be 4.25 GHz.

[0048] The extraction electrode 507 attracts plasma generated by the plasma source 501. For example, by applying a predetermined voltage, the extraction electrode 507 has a predetermined potential, and attracts plasma by the potential difference between the extraction electrode 507 and the plasma source 501. The extraction electrode 507 may be in any shape as long as it does not confine the plasma, for example, it may be a circle with a diameter of 2 cm.

[0049] The microwave tuner 508 suppresses the reduction in the transmission efficiency of the microwave to the plasma source 501. For example, the microwave tuner 508 reflects the microwave that is reflected without being absorbed by the plasma source 501 toward the plasma source 501, thereby suppressing the reduction in the transmission efficiency. This means that the microwave tuner 508 matches the impedance between the microwave feedthrough 506 and the plasma generated in the plasma source 501.

[0050] The filament 509 ignites the gas supplied to the plasma source 501. The filament 509 is a filament for plasma ignition, and can ignite a gas with a small flow rate and a gas with a large ionization energy. It should be noted that the plasma generator 500 does not necessarily need to include the filament 509.

[0051] The gas source 510 supplies the discharge gas to the gas nozzle 505. The gas source 510 may be any member as long as it can supply the discharge gas to the gas nozzle 505, for example, it may be a container in which the discharge gas is placed.

[0052] The flow meter 511 measures the flow rate of the gas flowing into the gas injection port 505 .

[0053] The RF oscillator 512 generates microwaves. The microwaves generated by the RF oscillator 512 are transmitted to the plasma source 501 via the microwave feedthrough 506 .

[0054] The power meter 513 measures the power of microwaves transmitted through the microwave feedthrough 506 and reflected by the plasma source 501. The user reads the measured value of the power meter 513 and can determine whether the plasma has been ignited based on the read measured value.

[0055] As described above, since the plasma generator 500 includes the flange 504 , the user can install the plasma source 501 at any location in the vacuum chamber 1 .

[0056] <Detailed description of plasma source 501>

[0057] Here, refer to Figure 3 and Figure 4 The plasma source 501 will be described in detail. In the following, for the convenience of description, an orthogonal coordinate system having an X-axis, a Y-axis, and a Z-axis is introduced.

[0058] The plasma source 501 generates plasma in a high vacuum. More specifically, the plasma source 501 generates plasma in a vacuum degree substantially the same as that of the high vacuum processing unit 3. The plasma source 501 will be described in detail below.

[0059] Figure 3 : is a schematic cross-sectional view of the plasma source 501 in the embodiment.

[0060] Figure 4 is a schematic top view of a plasma source 501 in an embodiment. Figure 3 Shown in Figure 4 The cross section at the position of the A1-A2 line.

[0061] The plasma source 501 includes a cylindrical magnet portion 10 , a cylindrical body 20 , a first magnetic path portion 30 , a second magnetic path portion 40 , an antenna 50 , a nozzle portion 60 , a gas nozzle 505 , and an insulating member 70 .

[0062] The cylindrical magnet part 10 is a cylindrical magnetic body, and its interior is hollow. The cylindrical magnet part 10 has an open end 10a (first open end) and an open end 10b (second open end) located on the opposite side of the open end 10a. In the cylindrical magnet part 10, for example, the open end 10a has an S polarity (first polarity), and the open end 10b has an N polarity (second polarity) opposite to the S polarity.

[0063] like Figure 4 As shown, in the cylindrical magnet part 10, for example, a plurality of block magnets 10M made of samarium cobalt are arranged annularly on the XY axis plane. The polarity of the cylindrical magnet part 10 is not limited to the above example, and the open end 10a can represent N polarity and the open end 10b can represent S polarity.

[0064] The outer shape of the cylindrical magnet part 10 is, for example, circular. The outer diameter of the cylindrical magnet part 10 is, for example, 50 mm or less, thereby miniaturizing the plasma source 501. The outer shape of the cylindrical magnet part 10 is not limited to a circle, but may be a polygon such as a triangle, a quadrilateral, a pentagon, a hexagon, etc.

[0065] The cylindrical body 20 is surrounded by the cylindrical magnet portion 10. The interior of the cylindrical body 20 is hollow. The cylindrical body 20 has an open end 20a and an open end 20b located on the side opposite to the open end 20a. The open end 20a is configured to be coplanar with the open end 10a. The open end 20b is configured to be coplanar with the open end 10b. On the XY axis plane, the cylindrical body 20 and the cylindrical magnet portion 10 are arranged in concentric circles. The cylindrical body 20 and the cylindrical magnet portion 10 do not necessarily need to be located in concentric circles, and their respective central axes may also be slightly offset from each other.

[0066] The outer shape of the cylindrical body 20 is appropriately changed according to the outer shape of the cylindrical magnet portion 10. Figure 4 In the example of the present invention, the outer shape of the cylindrical body 20 is circular. The cylindrical body 20 contains molybdenum (Mo), for example.

[0067] The magnetic circuit portion 30 (first magnetic circuit portion) is connected to the open end 10a of the cylindrical magnet portion 10 and the open end 20a of the cylindrical body 20. The magnetic circuit portion 30 closes the open ends 10a, 20a. Here, "closing" is not limited to the magnetic circuit portion 30 closing the open ends 10a, 20a without a gap, but also includes the case where there is a small gap or the magnetic circuit portion 30 is closed with a small diameter hole for other components to pass through. The magnetic circuit portion 30 is plate-shaped. The magnetic circuit portion 30 is a ferromagnetic body, for example, made of soft iron. The outer shape of the magnetic circuit portion 30 is appropriately changed according to the outer shape of the cylindrical magnet portion 10. Figure 4 In the example, the outer shape of the magnetic circuit portion 30 is circular.

[0068] The magnetic circuit portion 30 has a protrusion 90 provided in the space 21. The protrusion 90 protrudes from the magnetic circuit portion 30 toward the corner 410 described later. The protrusion 90 is cylindrical and surrounds a portion of the antenna 50. The wall thickness of the top end 91 of the protrusion 90 becomes thinner as it approaches the corner 410 of the magnetic circuit portion 40 (the second magnetic circuit portion). The angle of the top end 91 is, for example, an acute angle. The magnetic mirror ratio of the magnetic field formed between the top end 91 and the corner 410 is greater than 1.5. As long as the cross-section of the protrusion 90 observed from the Z-axis direction is a shape with a genus of 1 in topology, it can be any shape, for example, a ring.

[0069] In addition, in order to perform magnetic mirror confinement on the electrons heated by the electron cyclotron resonance, the magnetic field strength of the top portion 91 and the corner portion 410 must be higher than the magnetic field that satisfies the electron cyclotron resonance condition. The relationship between the microwave frequency f and the magnetic field B that satisfies the electron cyclotron resonance condition is 2πf=eB / m. Here, e is the basic charge, and m is the electron mass. When the microwave frequency is 2.45 GHz, the magnetic field that satisfies the electron cyclotron resonance condition is 875 Gauss.

[0070] The magnetic circuit portion 40 is connected to the open end 10b of the cylindrical magnet portion 10 and the open end 20b of the cylindrical body 20. The magnetic circuit portion 40 is arranged opposite to the magnetic circuit portion 30 via the cylindrical magnet portion 10. The magnetic circuit portion 40 is plate-shaped. The magnetic circuit portion 40 is a ferromagnetic body, for example, made of soft iron. The outer shape of the magnetic circuit portion 40 is appropriately changed according to the outer shape of the cylindrical magnet portion 10.

[0071] exist Figure 4 In the example, the outer shape of the magnetic circuit portion 40 is circular.

[0072] The magnetic circuit portion 40 has an opening portion 420 (first opening portion), and the opening portion 420 opens the space 21 surrounded by the cylindrical body 20. The opening portion 420 is arranged in a concentric circle shape relative to the magnetic circuit portions 30 and 40. The opening portion 420 does not necessarily need to be arranged in a concentric circle shape relative to the magnetic circuit portions 30 and 40, and the respective center axes may be slightly offset from each other. The inner diameter of the opening portion 420 is larger than the outer diameter of the protrusion 90. The outer diameter of the protrusion 90 refers to the maximum value of the outer peripheral diagonal length passing through the center of the cross section perpendicular to the Z axis. It should be noted that the outer peripheral diagonal length refers to the diameter of the circle formed by the outer edge line of the protrusion 90 formed in a circular ring shape. In addition, from another point of view, the outer diameter of the protrusion 90 is the inner side of the area surrounded by the inner circumference of the opening portion 420.

[0073] Here, the corner portion 410 is explained. The corner portion 410 is a position where the main surface 40a of the second magnetic circuit portion 40 on the side of the first magnetic circuit portion 30 in the second magnetic circuit portion 40 intersects with the inner wall 420w of the first opening portion 420. Hereinafter, the angle formed by the main surface 40a and the inner wall 420w is referred to as the angle of the corner portion 410. The opening portion 420 is provided in the magnetic circuit portion 40, thereby forming a corner portion 410 in the magnetic circuit portion 40 where the main surface 40a on the side of the magnetic circuit portion 30 of the magnetic circuit portion 40 intersects with the inner wall 420w of the opening portion 420. Figure 3 In the example, the angle of the corner 410 is approximately 90°. The angle of the corner 410 may also be an acute angle. For example, when the angle of the corner 410 is an acute angle, the cross-sectional shape of the opening 420 becomes a cone whose inner diameter gradually widens as it moves away from the magnetic circuit portion 30. It should be noted that the main surface of the magnetic circuit portion 40 located on the side opposite to the main surface 40a is set as the main surface 40b.

[0074] The antenna 50 is introduced from the outside of the plasma source 501 into the plasma source 501. For example, the antenna 50 passes through the magnetic circuit portion 30 and is introduced into the space 21. The antenna 50 is a so-called microwave transmitter. The antenna 50 contains, for example, molybdenum.

[0075] The antenna 50 is connected to the microwave feedthrough 506. The antenna 50 is connected to the RF oscillator 512 via the microwave feedthrough 506, and receives the supply of microwave power based on the RF oscillator 512. Thus, the antenna 50 radiates microwaves to the space 21. As long as the wavelength of the microwave is a wavelength that satisfies the electron cyclotron resonance condition, it can be any wavelength. The wavelength of the microwave can be, for example, 122 mm (2.45 GHz).

[0076] The antenna 50 is, for example, in the shape of a rod and is bent in the middle. For example, the antenna 50 includes a first antenna portion 51 and a second antenna portion 52 connected to the first antenna portion 51 .

[0077] The shape of the antenna 50 is not necessarily a rod, and does not necessarily need to be bent in the middle. The shape of the antenna 50 can be any shape as long as it is connected to the microwave feedthrough 506 and can radiate microwaves to the space 21. The shape of the antenna 50 can be, for example, a straight line.

[0078] The first antenna portion 51 is, for example, perpendicular to the magnetic circuit portion 30 and extends in a direction from the magnetic circuit portion 30 toward a nozzle portion 60 described later. The first antenna portion 51 is, for example, located on the central axis of the magnetic circuit portion 30 .

[0079] The second antenna portion 52 intersects with the first antenna portion 51. Figure 3In the example, the first antenna portion 51 is orthogonal to the second antenna portion 52, and the antenna 50 is L-shaped. The second antenna portion 52 is also located between the top portion 91 and the corner portion 410. That is, the second antenna portion 52 is inserted into the magnetic field B1. It should be noted that the details of the magnetic field B1 will be described later, but the magnetic field B1 is a magnetic field formed in the space 21 by the magnetic circuit portion 30, the magnetic circuit portion 40 and the cylindrical magnet portion 10. In this way, by changing the structure of the antenna 50 to be bent, microwaves are efficiently absorbed into the plasma. The angle formed by the first antenna portion 51 and the second antenna portion 52 is not limited to being orthogonal, and can also be an obtuse angle or an acute angle.

[0080] The nozzle portion 60 is connected to the magnetic circuit portion 40 on the side opposite to the magnetic circuit portion 30. For example, the nozzle portion 60 is connected to the main surface 40b of the magnetic circuit portion 40. The nozzle portion 60 has an opening portion 610 (second opening portion). The opening portion 610 is connected to the opening portion 420. The opening area of ​​the opening portion 610 is smaller than the opening area of ​​the opening portion 420. As long as the nozzle portion 60 has an opening portion, it can be any component. The nozzle portion 60 can be, for example, a punched metal plate.

[0081] The opening 610 is arranged concentrically with respect to the opening 420. The opening 610 does not necessarily need to be arranged concentrically with respect to the opening 420, and the central axes of each may be slightly offset from each other. The inner diameter of the opening 610 is, for example, 5 mm. The space 21 is connected to the outside of the device through the opening 610, so that the plasma generated in the space 21 can be taken out from the opening 610. The nozzle portion 60 includes, for example, molybdenum. The thickness of the opening is, for example, 5 mm, 2.5 mm, or 1 mm.

[0082] A gas nozzle 505 is introduced from the outside of the plasma source 501 into the space 21. The gas nozzle 505 penetrates the magnetic circuit portion 30, for example, and is introduced into the space 21. The gas nozzle 505 penetrates the cylindrical magnet portion 10 and the cylindrical body 20, for example, and is introduced into the space 21. The gas nozzle 505 penetrates the magnetic circuit portion 40 and the nozzle portion 60, for example, and is introduced into the space 21.

[0083] The supply port 505p is a supply port for supplying discharge gas in the gas nozzle 505, and the supply port 505p is arranged so that the distance between the supply port 505p and the top 50p of the antenna 50 is the shortest. For example, when the gas nozzle 505 and the antenna 50 are viewed from the Z-axis direction, the supply port 505p and the top 50p are opposite to each other.

[0084] The insulating member 70 is provided between the antenna 50 and the magnetic circuit portion 30. The insulating member 70 includes fluorocarbon resin, quartz, etc. Thus, the antenna 50 and the magnetic circuit portion 30 are kept insulated.

[0085] In the plasma source 501, when the inner diameter of the cylindrical body 20 is set to a (mm) and the microwave cutoff wavelength of the microwave power supplied to the space 21 is set to λ (mm), the plasma source 501 is configured to satisfy the relationship of λ>3.41×(a / 2). When the cylindrical body 20 is a polygon, the inner diameter a is set to the maximum inner diameter of the inner diameter passing through the central axis of the cylindrical body 20.

[0086] Figure 5 This is a schematic cross-sectional view for explaining the operation of the plasma source 501 in the embodiment.

[0087] In the plasma source 501, the magnetic circuit portion 30 connected to the cylindrical magnet portion 10 and the magnetic circuit portion 40 connected to the cylindrical magnet portion 10 respectively function as a yoke. In addition, the magnetic circuit portion 30 has a protrusion 90, and the magnetic circuit portion 40 has a corner 410. Thus, a magnetic field B1 (magnetic mirror magnetic field) with a high magnetic mirror ratio is formed between the protrusions of both sides (between the protrusion 90 and the corner 410). In addition, the protrusion 90 is cylindrical, and the opening 420 of the magnetic circuit portion 40 is circular, so the magnetic field B1 is formed in a circular ring shape.

[0088] In this state, when the discharge gas is supplied from the supply port 505p to the space 21 and the microwave is supplied from the antenna 50 to the space 21, the discharge gas is discharged, and due to the interaction between the microwave and the magnetic field B1, electron cyclotron resonance occurs in the space 21. As a result, energy is selectively and directly supplied to electrons in the plasma, and the electrons with high energy collide with the discharge gas to generate high-density plasma in the space 21.

[0089] Here, the plasma source 501 is configured to satisfy the relationship of λ>3.41×(a / 2). As a result, microwaves are less likely to resonate in the space 21, and the travel of microwaves in the space 21 is suppressed. As a result, microwaves are less likely to leak from the plasma source 501. In addition, if resonance does not occur, the microwave electric field will not increase, and the microwave loss on the container wall surface, which is proportional to the microwave electric field, can be suppressed.

[0090] Furthermore, in the plasma source 501, a magnetic mirror magnetic field (magnetic field B1) is formed between the protrusion 90 and the corner 410, and the electrons confined in the magnetic field B1 are continuously heated by electron cyclotron resonance. Thus, even if the electric field of the microwave is weak, high-energy electrons capable of ionizing the discharge gas can be generated.

[0091] In addition, in the plasma source 501, the inner diameter of the opening 420 is configured to be larger than the outer diameter of the protrusion 90. Therefore, in the magnetic field B1, the magnetic flux lines become sparser as they move from the protrusion 90 toward the corner 410. As a result, the magnetic flux density on the nozzle portion 60 side becomes smaller than the magnetic flux density on the protrusion 90 side.

[0092] Thus, a low magnetic field region is formed near the opening 610 of the nozzle 60 in the space 21, and it is difficult to capture plasma by the magnetic field near the opening 610. Therefore, the mobility of the plasma near the opening 610 is improved, and electrons or ions in the plasma are efficiently ejected from the opening 610.

[0093] For example, when xenon gas at a flow rate of about 0.3 sccm is introduced from the supply port 505 p into the space 21 and 8 W microwaves are input into the antenna 50 , an electron current of about 200 mA and an ion current of about 5 mA are obtained from the opening 610 .

[0094] It should be noted that the ions in the plasma remaining in the space 21 pass through the magnetic field B1 and reach the inner wall of the cylindrical body 20 or the main surface of the magnetic circuit parts 30 and 40. The ions that hit the cylindrical body 20 or the magnetic circuit parts 30 and 40 lose their charge and return to neutral gas, and are reused as discharge gas.

[0095] Therefore, in the plasma source 501 , plasma can be maintained with an extremely small gas flow rate.

[0096] On the other hand, on the side of the protrusion 90, the magnetic flux lines become denser as they move from the corner 410 toward the protrusion 90. As a result, a high magnetic field region is formed near the insulating member 70, and among the plasma generated in the space 21, the density of the plasma exposed to the insulating member 70 is higher than the density of the plasma generated in the opening 420.

[0097] Thus, during discharge, even if foreign matter such as contaminants and coatings are deposited on the insulating member 70, the foreign matter will be immediately removed by the sputtering effect based on the plasma. Assuming that the foreign matter includes metal, if the foreign matter is deposited on the insulating member 70, the antenna 50 and the magnetic circuit portion 30 are connected, and microwaves cannot be fully supplied from the antenna 50 to the space 21.

[0098] In contrast, in the plasma source 501, foreign matter on the insulating member 70 is removed by self-cleaning as long as plasma is generated in the space 21. That is, the plasma source 501 can be operated for a long period of time without maintenance.

[0099] In addition, in the plasma source 501, the supply port 505p is configured to be closest to the top end 50p of the antenna 50, so that the discharge gas is supplied to the vicinity of the second antenna portion 52. Therefore, the discharge gas introduced from the supply port 505p into the space 21 is efficiently ionized by the microwave emitted from the antenna 50. As a result, high-density plasma is generated in the space 21.

[0100] Furthermore, when the distance between the magnetic circuit portion 30 and the nozzle portion 60 is L (mm), the plasma source 501 may be configured to satisfy the relationship λ>3.41×(L / 2). This more reliably prevents microwaves from leaking from the opening 610 of the nozzle portion 60.

[0101] Thus, the plasma source 501 includes the cylindrical magnet portion 10 , the cylindrical body 20 , the first magnetic path portion 30 , the second magnetic path portion 40 , the antenna 50 , the nozzle portion 60 , the gas nozzle 505 , and the insulating member 70 .

[0102] The cylindrical magnet portion 10 has a first opening end 10a and a second opening end 10b located on the opposite side to the first opening end 10a. The first opening end 10a has a first polarity, and the second opening end 10b has a second polarity opposite to the first polarity.

[0103] The cylindrical body 20 is surrounded by the cylindrical magnet portion 10 .

[0104] The first magnetic path portion 30 is in contact with the first opening end 10 a and closes the first opening end 10 a.

[0105] The second magnetic circuit portion 40 is connected to the second opening end 10 b and is arranged to face the first magnetic circuit portion 30 . The second magnetic circuit portion 40 has a first opening 420 that opens to the space 21 surrounded by the cylindrical body 20 .

[0106] The antenna 50 passes through the first magnetic circuit portion 30 and is introduced into the space 21 , and can supply microwave power to the space 21 .

[0107] The nozzle portion 60 is in contact with the second magnetic circuit portion 40 on the side opposite to the first magnetic circuit portion 30 , and has a second opening portion 610 having an opening area smaller than that of the first opening portion 420 and communicating with the first opening portion 420 .

[0108] The gas nozzle 505 penetrates the cylindrical magnet portion 10 and the cylindrical body 20 , and can also supply the discharge gas to the space 21 .

[0109] An insulating member 70 is provided between the antenna 50 and the first magnetic circuit portion 30 .

[0110] In the plasma source 501 , when the inner diameter of the cylindrical body 20 is a (mm) and the microwave cutoff wavelength of the microwave power supplied to the space 21 is λ (mm), the relationship of λ>3.41×(a / 2) is satisfied.

[0111] For such a plasma source 501 , microwaves are unlikely to leak from the plasma source 501 , and high-density plasma is generated by the plasma source 501 , which can eject electrons or ions to the outside of the plasma source 501 .

[0112] More specifically, since microwaves are not easily leaked from the plasma source 501, the plasma generator 500 can generate plasma at a low flow rate. Therefore, the plasma generator 500 can suppress the decrease in the vacuum degree inside the vacuum chamber 1 as the plasma is generated. It should be noted that the low flow rate means a flow rate that can maintain plasma, such as 0.05 SCM to 50 SCM.

[0113] As described above, the nozzle portion 60 suppresses the leakage of microwaves and the leakage of discharge gas. The degree to which the nozzle portion 60 suppresses the leakage of microwaves and discharge gas depends on the thickness of the nozzle portion 60 and the size or number of the openings 610. In addition, the amount of plasma released from the space 21 to the inside of the vacuum chamber 1 through the openings 610 also depends on the thickness of the nozzle portion 60 and the size or number of the openings 610.

[0114] Specifically, the thinner the nozzle portion 60 is, the easier it is for microwaves, discharge gas, and plasma to leak into the vacuum chamber 1. In addition, the larger the size or number of the openings 610 is, the easier it is for microwaves, discharge gas, and plasma to leak into the vacuum chamber 1. The more microwaves and discharge gas leak, the lower the efficiency of plasma generation. The lower the amount of plasma released, the lower the efficiency of static elimination.

[0115] In this way, the nozzle part 60 controls the leakage of microwaves, the leakage of discharge gas, and the amount of plasma released, so the designer of the static eliminator 100 needs to appropriately design the thickness of the nozzle part 60 and the size or number of the openings 610 according to the purpose.

[0116] Figure 6 1 is a diagram showing an example of the arrangement of the openings 610 when the nozzle unit 60 in the embodiment has a plurality of openings 610 .

[0117] exist Figure 6 In the figure, the nozzle portion 60 includes a plurality of circular openings 610 having the same diameter and length in a lattice pattern.

[0118] Figure 7 1 is a diagram showing experimental results showing the effect of extracting plasma from the plasma source 501 by the extraction electrode 507 in the embodiment.

[0119] exist Figure 7 The horizontal axis represents the reach distance of the ion current generated from the plasma source 501. Figure 7 The middle vertical axis represents the current value of the ion current. Figure 7 This indicates that the current value of the ion current increases as the ion current passes through the extraction electrode 507. This indicates that the extraction electrode 507 has an effect of extracting plasma.

[0120] Summary

[0121] The static eliminator 100 configured in this way includes a plasma generator 500 including a plasma source 501 capable of generating plasma by a low-flow discharge gas and a connection portion 502 for conducting heat generated by the plasma source 501 to the outside of the device, thereby generating plasma while suppressing a decrease in the vacuum degree inside the vacuum chamber 1. Therefore, it is not necessary to have a high vacuum region and a low vacuum region, and the size of the device can be suppressed.

[0122] In the static eliminator 100 thus configured, the plasma generator 500 includes the flange 504. Therefore, by attaching the flange to the housing of the vacuum chamber 1, the static eliminator 100 thus configured can be equipped with the plasma generator 500 at any position on the housing of the vacuum chamber 1 where the flange is located.

[0123] Furthermore, since the static eliminator 100 configured in this manner includes the heat transfer unit 503 , it is possible to dissipate the heat generated in the plasma source 501 , thereby suppressing the occurrence of unstable operation due to high heat.

[0124] Furthermore, since the static eliminator 100 configured as above includes the plasma generator 500 , it is not necessary to have a high vacuum region and a low vacuum region as described above. Therefore, the static eliminator 100 configured as above can reduce the load on the vacuum pump 2 .

[0125] In addition, since the static eliminator 100 configured in this way includes the electrodeless plasma generator 500, it is not necessary to generate plasma by direct current discharge. Therefore, the static eliminator 100 configured in this way can suppress the reduction in plasma generation efficiency and the degradation of the static eliminator 100 due to the consumption of the electrodes used for discharge.

[0126] Furthermore, the static eliminator 100 configured in this manner can generate plasma as long as the flow rate of the discharge gas is within the range of 0.05 SCM to 50 SCM. Furthermore, the static eliminator 100 configured in this manner can generate plasma using a variety of discharge gases.

[0127] Therefore, the charged body 9 can be subjected to static elimination by using a discharge gas of a type and flow rate suitable for static elimination of the charged body 9. Static elimination suitable for the charged body 9 means that the intrusion into the charged body 9 due to static elimination is lower than a predetermined level.

[0128] (Variation Example)

[0129] It should be noted that the plasma generator 500 does not necessarily need to have only one opening 610 as the opening 610 for ejecting plasma. The plasma generator 500 may also have multiple openings 610 as the openings for ejecting plasma. The plasma generator 500 having multiple openings 610 can release the plasma generated in the space 21 of the plasma source 501 into the static elimination device 100 more than the case where the opening 610 is one.

[0130] The plasma generating device 500 may include, as an opening portion for ejecting plasma, a plurality of opening portions 610 arranged in a honeycomb shape, a plurality of opening portions 610 arranged in a grid shape, a plurality of opening portions 610 each having a different size, or a plurality of opening portions 610 each having a non-fixed distance from the nearest opening portion.

[0131] It should be noted that the extraction electrode 507 may be in any shape as long as it can extract plasma.

[0132] The extraction electrode 507 may be, for example, a hollow shape in which a line connecting the center of the plasma source 501 and the center of the charged body 9 passes substantially through the center, and may be, for example, cylindrical or annular.

[0133] It should be noted that the static eliminator 100 may include a blocking plate that blocks a portion of the charged body 9 from contacting the plasma.

[0134] Figure 8 FIG. 1 is a diagram showing an example of the inhibitor 101 in a modified example.

[0135] exist Figure 8 In, with Figure 2 Components with the same functions are denoted by the same reference numerals and their description is omitted. Figure 8 In the embodiment, the barrier 101 covers a portion of the charged body 9, and blocks the contact between the plasma and the charged body 9. In this way, the portion blocked from contact with the plasma by the barrier 101 is still charged and is not statically eliminated. The barrier 101 may be, for example, a conductive member that blocks the plasma at a portion where static elimination is not required. The barrier 101 may be, for example, a punched metal plate.

[0136] Since the static elimination device 100 of the modified example configured in this way includes the inhibitor 101 , static elimination can be performed on only a part of the charged body 9 .

[0137] Fig. 9 This is an explanatory diagram for explaining an experimental environment of an experiment showing the effect of the inhibitor 101 in a modified example.

[0138] The neutralizer 900 radiates plasma. The obstruction member 101 is located 600 mm downward from the neutralizer 900. The charged electrode 901 is located 20 mm downward from the obstruction member 101. The charged electrode 901 is the object of static elimination of the neutralizer 900. 100 V is applied to the charged electrode 901. In the experiment, the distance between one end of the obstruction member 101 and one end of the charged electrode 901 is set to L, and the static elimination current flowing when the distance L is changed is measured. The static elimination current is the current flowing through the charged electrode 901 when the charged electrode 901 is in contact with the plasma. In the experiment, the attenuation rate of the plasma emitted from the neutralizer 900 due to the obstruction member 101 is calculated based on the magnitude of the measured static elimination current.

[0139] Fig.10 1 is a diagram showing an example of experimental results showing the effect of the inhibitor 101 in the modified example.

[0140] Fig.10 The vertical axis of represents the transmittance of plasma. The transmittance is the ratio of the static elimination current flowing to the charged electrode 901 when the obstruction member 101 is present to the static elimination current flowing to the charged electrode 901 when the obstruction member 101 is not present. Fig.10 The horizontal axis represents the distance L. Fig.10 This indicates that the longer the distance L is, the lower the transmittance of plasma is.

[0141] It should be noted that the plasma generator 500 may include a heat conducting portion 503a between the plasma source 501 and the connecting portion 502, wherein the heat conducting portion 503a has a higher thermal conductivity than the connecting portion 502. The heat conducting portion 503a may be any component as long as it has a higher thermal conductivity than the connecting portion 502.

[0142] The heat conducting portion 503 a may be, for example, a copper mesh or a carbon sheet.

[0143] It should be noted that the vacuum chamber 1 is an example of a connection target.

[0144] As mentioned above, although the embodiment of this invention is described in detail with reference to drawings, the specific structure is not limited to this embodiment, and also includes the design etc. which do not deviate from the scope of the summary of this invention.

[0145] Industrial Applicability

[0146] According to the static eliminator and plasma generator described above, it is possible to provide a static eliminator that does not require a high vacuum region and a low vacuum region.

[0147] Description of Reference Numerals

[0148] 1 Vacuum chamber;

[0149] 2 Vacuum pump;

[0150] 3. High vacuum treatment department;

[0151] 4-1 Sending Department;

[0152] 4-2 Guidance section;

[0153] 4-3 Guidance;

[0154] 4-4 Guidance;

[0155] 4-5 guide part;

[0156] 4-6 Coiling section;

[0157] 4-7 conveyor belts;

[0158] 5. Static electricity elimination treatment unit;

[0159] 100 static elimination device;

[0160] 500 Plasma generating device;

[0161] 501 plasma source;

[0162] 502 connection part;

[0163] 503 heat transfer part;

[0164] 503a heat transfer part;

[0165] 504 flange;

[0166] 505 gas nozzle;

[0167] 506 Microwave Feedthrough;

[0168] 507 extraction electrode;

[0169] 508 Microwave Tuner;

[0170] 509 filament;

[0171] 510 Gas source;

[0172] 511 flow meter;

[0173] 512 RF oscillator 512;

[0174] 513 Power meter;

[0175] 10: cylindrical magnet portion;

[0176] 20 cylinder;

[0177] 30 first magnetic circuit portion;

[0178] 40 second magnetic circuit portion;

[0179] 50 antenna;

[0180] 60 nozzle portion;

[0181] 70 Insulating components;

[0182] 101 Obstruction.

Claims

1. A static eliminator, comprising: A vacuum chamber, in which a charged body can be placed; a high vacuum processing unit, disposed inside the vacuum chamber, for performing high vacuum processing on the charged body; and The static electricity elimination processing unit includes a plasma generating device for supplying plasma generated by electron cyclotron resonance into the vacuum chamber, and static electricity is eliminated from the charged body by the plasma. The plasma generating device comprises: an electrodeless plasma source, the plasma source being arranged inside the vacuum chamber and generating the plasma for eliminating static electricity from the charged body; a connecting portion for conducting heat generated by the plasma source to the outside of the static eliminating device; and a heat conducting portion being located between the plasma source and the connecting portion and having a higher thermal conductivity than that of the connecting portion. The invention further comprises an extraction electrode which is located between the plasma source and the charged body and attracts the plasma generated by the plasma source.

2. The static eliminator according to claim 1, wherein: The extraction electrode has a hollow shape in which a line connecting the center of the plasma source and the center of the charged body passes substantially through the center.

3. The static eliminator according to claim 1 or 2, wherein: The plasma source includes a space for generating the plasma and a plurality of openings for ejecting the plasma generated in the space to the outside.

4. The static eliminator according to claim 1 or 2, wherein: The pressure in the vacuum chamber is 10 -5 Above Pa and below 1Pa.

5. The static eliminator according to claim 1 or 2, wherein: An obstruction member for obstructing contact between a part of the charged body and the plasma is further provided.

6. The static eliminator according to claim 1 or 2, wherein: The high vacuum processing section performs at least one of a metal vapor deposition process, a ceramic vapor deposition process, a semiconductor material micro-machining process, a semiconductor thin film forming process, an organic material thin film forming process, and a vapor deposition process of aluminum used as a cathode.

7. The static eliminator according to claim 1 or 2, wherein: Also available: an RF oscillator disposed outside the vacuum chamber and generating microwaves; as well as The microwave feedthrough transmits the microwave generated by the RF oscillator to the inside of the vacuum chamber.

8. The static eliminator according to claim 1 or 2, wherein: A flange is further provided for installing the plasma source inside the vacuum chamber.

9. The static eliminator according to claim 1 or 2, wherein: A gas source is further provided. The gas source is provided outside the vacuum chamber and supplies a gas that contributes to the generation of the plasma into the vacuum chamber.

10. A method for eliminating static electricity, A high vacuum treatment is performed on a charged body placed inside a vacuum chamber. Plasma generated by electron cyclotron resonance is supplied into the vacuum chamber through an electrodeless plasma source disposed inside the vacuum chamber, and the plasma generated by the plasma source is attracted by an extraction electrode disposed between the plasma source and the charged body. The charged body is subjected to static elimination by the plasma, The static elimination method is implemented by the static elimination device as claimed in claim 1.

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